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M271 Redbridge Roundabout Improvement PCF Stages 3 and 5 Environmental Assessment Report
ENVIR ONMEN TAL ASSESSM ENT R EPORT
Sept 2018
Registered office Bridge House, 1 Walnut Tree Close, Guildford GU1 4LZ Highways England Company Limited registered in England and Wales number 09346363
Contents Executive Summary ...... 4 1. Introduction ...... 5 1.1 Overview of the Project ...... 5 1.2 Purpose of the Environmental Assessment Report ...... 5 1.3 Legislation and Policy Framework ...... 5 1.4 Consenting Route ...... 12 1.5 The Developer and Designer ...... 12 2. The Project...... 14 2.1 Need for the Project ...... 14 2.2 Project Objectives ...... 14 2.3 Project Location ...... 15 2.4 Project Description ...... 15 2.5 Construction, Operation and Long Term Management ...... 16 2.6 Design Considerations ...... 17 3. Alternatives Considered ...... 21 3.1 Options Considered in PCF Stage 0 ...... 21 3.2 Options Considered in PCF Stage 1 ...... 21 3.3 Options Considered in PCF Stage 2 ...... 21 4. Environmental Assessment Methodology ...... 23 4.1 Scoping ...... 23 4.2 Surveys and Predictive Techniques, and Methods...... 24 4.3 General Assessment Assumptions and Limitations ...... 24 4.4 Significance Criteria ...... 25 4.5 Mitigation and Enhancement ...... 26 5. Air Quality ...... 28 5.1 Introduction ...... 28 5.2 Legislative and Policy Framework ...... 28 5.3 Study Area ...... 30 5.4 Baseline Environment ...... 31 5.5 Methodology and Assessment Criteria ...... 36 5.6 Assessment Assumptions and Limitations ...... 45 5.7 Potential Effects ...... 46 5.8 Design, Mitigation and Enhancement Measures ...... 51 5.9 Residual Effects ...... 51 6. Cultural Heritage ...... 52 7. Landscape and Visual ...... 53 7.1 Introduction ...... 53 7.2 Legislative and Policy Framework ...... 53 7.3 Study Area ...... 55 7.4 Baseline Environment ...... 56 7.5 Methodology and Assessment Criteria ...... 60 7.6 Assessment Assumptions and Limitations ...... 61
Registered office Bridge House, 1 Walnut Tree Close, Guildford GU1 4LZ Highways England Company Limited registered in England and Wales number 09346363 M271 Redbridge Roundabout Improvement PCF Stages 3 and 5 Environmental Assessment Report
7.7 Potential Effects ...... 62 7.8 Design, Mitigation and Enhancement Measures ...... 62 7.9 Residual Effects ...... 63 8. Biodiversity...... 70 8.1 Introduction ...... 70 8.2 Legislative and Policy Framework ...... 71 8.3 Study Area ...... 71 8.4 Baseline Environment ...... 71 8.5 Methodology and Assessment Criteria ...... 75 8.6 Assessment Assumptions and Limitations ...... 76 8.7 Potential Effects ...... 77 8.8 Design, Mitigation and Enhancement Measures ...... 80 8.9 Residual Effects ...... 80 9. Geology and Soils ...... 81 9.1 Introduction ...... 81 9.2 Legislative and Policy Framework ...... 81 9.3 Study Area ...... 82 9.4 Baseline Environment ...... 82 9.5 Methodology and Assessment Criteria ...... 88 9.6 Assessment Assumptions and Limitations ...... 89 9.7 Potential Effects ...... 89 9.8 Design, Mitigation and Enhancement Measures ...... 91 9.9 Residual Effects ...... 95 10. Materials ...... 96 10.1 Introduction ...... 96 10.2 Legislative and Policy Framework ...... 97 10.3 Study Area ...... 99 10.4 Baseline Environment ...... 99 10.5 Methodology and Assessment Criteria ...... 102 10.6 Assessment Assumptions and Limitations ...... 103 10.7 Potential Effects ...... 104 10.8 Design, Mitigation and Enhancement Measures ...... 108 10.9 Residual Effects ...... 113 11. Noise and Vibration ...... 117 11.1 Introduction ...... 117 11.2 Legislative and Policy Framework ...... 118 11.3 Study Area ...... 125 11.4 Baseline Environment ...... 126 11.5 Methodology and Assessment Criteria ...... 128 11.6 Assessment Assumptions and Limitations ...... 132 11.7 Potential Effects ...... 133 11.8 Design, Mitigation and Enhancement Measures ...... 148 11.9 Residual Effects ...... 149 12. People and Communities ...... 150
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12.1 Introduction ...... 150 12.2 Legislative and Policy Framework ...... 150 12.3 Study Area ...... 152 12.4 Baseline Environment ...... 152 12.5 Methodology and Assessment Criteria ...... 155 12.6 Potential Effects ...... 157 12.7 Design, Mitigation and Enhancement Measures ...... 162 12.8 Residual Effects ...... 164 13. Road Drainage and Water Environment ...... 166 13.1 Introduction ...... 166 13.2 Legislative and Policy Framework ...... 166 13.3 Study Area ...... 168 13.4 Baseline Environment ...... 169 13.5 Methodology and Assessment Criteria ...... 173 13.6 Assessment Assumptions and Limitations ...... 174 13.7 Potential Effects ...... 174 13.8 Design, Mitigation and Enhancement Measures ...... 176 13.9 Residual Effects ...... 178 14. Climate Change ...... 180 14.1 Introduction ...... 180 14.2 Legislative and Policy Framework ...... 180 14.3 Study Area ...... 180 14.4 Baseline Environment ...... 181 14.5 Methodology and Assessment Criteria ...... 183 14.6 Assessment Assumptions and Limitations ...... 183 14.7 Potential Effects ...... 184 14.8 Design, Mitigation and Enhancement Measures ...... 186 14.9 Residual Effects ...... 187 15. Assessment of Cumulative Effects ...... 188 15.1 Introduction ...... 188 15.2 Legislative and Policy Framework ...... 188 15.3 Study Area ...... 188 15.4 Baseline Environment ...... 188 15.5 Methodology and Assessment Criteria ...... 190 15.6 Potential Effects ...... 191 15.7 Residual Effects ...... 193 16. Summary and Conclusion ...... 195 References ...... 201
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Executive Summary
Highways England is charged with operating, maintaining and improving England’s motorways and major A roads (the Strategic Road Network (SRN)). This includes modernising and maintaining highways, as well as running the network and keeping traffic moving. The Roads Investment Strategy (RIS) sets out the funding for major road schemes across England and includes proposals to improve the M271/A35 Redbridge Roundabout, three miles west of Southampton City Centre during the current road period (2015 to 2020).
This document is the Project Control Framework (PCF) Stages 3 and 5 Environmental Assessment Report (EAR) for the M271 Redbridge Roundabout Improvement Scheme (hereafter referred to as the Proposed Scheme). Its main purpose is to demonstrate that an adequate environmental assessment has been undertaken. This report specifically describes the environmental baseline and potential effects associated with the Proposed Scheme as well as mitigation required to minimise these effects. The report also determines any likely significant effects to the environment.
The scheme proposals include widening of the M271/A35 Redbridge Roundabout utilising the inner central island and area to the north-east of the roundabout to accommodate four circularity lanes to the south and a segregated free-flow left lane merging to the A33 eastbound on-slip road. The Proposed Scheme also involves the relocation of two toucan crossings, creation of an additional toucan crossing and the upgrade of subway and an existing footbridge for greater access for cyclists and pedestrians.
The Proposed Scheme falls entirely within the existing highways corridor on land owned/controlled by Highways England or Southampton City Council, both of whom are Highways Authorities. No additional land acquisition is therefore required. The Proposed Scheme is located within an Air Quality Management Area (AQMA) and a Noise Important Area (NIA). In addition, the Proposed Scheme is within 1km of the Solent and Southampton Water Ramsar (north-west of the Proposed Scheme), also designated as a Special Protection Area (SPA), Special Area for Conservation (SAC) and Site of Special Scientific Interest (SSSI).
It has been considered that there would be significant adverse effects to some sensitive visual receptors (i.e. residents at Redbridge Tower), cyclists using short section (400m) of NCN Route 236 and noise receptors (e.g. residents at 197 - 227 Cuckmere Lane, 4 Coniston Road etc.) during construction of the Proposed Scheme. However, all of these effects would be temporary and localised, and have therefore not been considered to be a ‘key factor or material in the decision- making process’ (Highways Agency et al., 2008a) of Environmental Impact Assessment (EIA) for this particular scheme. In accordance to DMRB HA 205/08 (Highways Agency et al., 2008a), “temporary effects are considered to be less significant than permanent effects”.
Furthermore, the overall landscape and visual effects during the construction phase of the Proposed Scheme have been assessed as not significant. Construction activities would be controlled as far as reasonably practicable through the application of suitable control measures, described further in Appendix B and the outline Environmental Management Plan (EMP) (Jacobs, 2018b).
With implementation of the proposed mitigations, it can be concluded that there would be no likely significant residual effects on any of the environmental topics due to the Proposed Scheme. A Notification of Determination would be published by Highways England to demonstrate that Proposed Scheme is not subject to EIA in accordance with Part VA of the Highways Act 1980 implementing Directive 2011/92/EU as amended.
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1. Introduction 1.1 Overview of the Project
1.1.1 Highways England is the government company charged with driving forward our motorways and Major A roads (The Strategic Road Network (SRN)). This includes modernisation and maintenance of the highways, as well as running the network and keeping traffic moving.
1.1.2 The Proposed Scheme is part of the SRN and comprises the development and delivery of a scheme for reducing congestion journey time reliability and safety on the M271/A35 Redbridge Roundabout, three miles west of Southampton City Centre. The roundabout is situated where the motorway network connects via the M271 with the remainder of Southampton’s road network.
1.1.3 The proposals include widening of the roundabout utilising the inner central island and area to the north-east of the M271/A35 Redbridge Roundabout to accommodate four circularity lanes to the south and a segregated free-flow left lane merging to the A33 eastbound on-slip road. The Proposed Scheme also involves relocation of two toucan crossings, creation of an additional toucan crossing and the upgrade of a subway and an existing footbridge for greater access for cyclists and pedestrians.
1.2 Purpose of the Environmental Assessment Report
1.2.1 This Environmental Assessment Report (EAR) has been prepared as part of a suite of documents to support the Highways England approvals process (gateway) at the end of Stages 3 and 5 under Highways England’s Project Control Framework (PCF) for a Single Option Project, prior to construction. It is not a statutory Environmental Impact Assessment (EIA) document. It is produced to demonstrate that an assessment of potential effects has been completed for the M271 Redbridge Roundabout Improvement scheme (hereafter referred to as the ‘Proposed Scheme’), with the intention to satisfy the statutory requirements.
1.2.2 This report describes the environmental baseline and potential effects associated with the Proposed Scheme, as well as mitigation required to minimise any effects. The report is intended to demonstrate that the Proposed Scheme is not subject to EIA in accordance with Part VA of the Highways Act 1980 implementing Directive 2011/92/EU as amended.
1.3 Legislation and Policy Framework
1.3.1 The Proposed Scheme could help meet wider Highways England Key Performance Indicators (KPIs) and specially there are two KPIs relevant to the environmental assessment. These are:
Delivering better environmental outcomes:
- number of Noise Important Areas (NIA) mitigated; and
- delivery of improve biodiversity, as set out in the Company’s Biodiversity Plan (Highways England, 2015a).
Helping cyclists, walkers and other vulnerable users:
- the number of new or upgraded crossings.
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1.3.2 The Proposed Scheme also requires assessment under the Habitats Directive (92/43/EEC). The aim of this assessment is to identify whether the Proposed Scheme would have Likely Significant Effects (LSE) on qualifying interest features of European sites.
1.3.3 An initial screening assessment carried out in PCF Stage 2 has concluded that there was insufficient information to determine that LSE would not occur on the following six European sites:
Solent and Southampton Water Ramsar site;
Solent Maritime Special Area of Conservation (SAC);
Solent and Southampton Water Special Protection Area (SPA);
Proposed Solent and Dorset coast SPA;
Mottisfont Bats SAC; and
Briddlesford Copses SAC.
1.3.4 Further assessment has been carried out as part of the current PCF Stages 3 and 5 works and concluded that there would be no significant effects to any of the six European Sites as a result of the Proposed Scheme. For further information, please refer to PCF Stages 3 and 5 Habitat Regulations Assessment (HRA) Stage 1: Screening document (Jacobs, 2018a). Natural England has been consulted and provided comments to the first draft of the HRA: Screening report in May 2018. The report was revised and reissued to Natural England in June 2018. They concurred with the conclusion of the HRA: Screening report.
1.3.5 The following tables provide a high-level summary of the national and local planning policy documents relevant to the Proposed Scheme. An overview of the relevant policy objectives regarding environmental improvements to existing transport infrastructure is provided.
National Policy
Table 1.1: National policy relevant to the Proposed Scheme
Planning policy Relevance to Proposed Scheme document National The NPPF sets out the Government’s economic, environmental and Planning Policy social planning policies and is a material consideration in planning Framework decisions. The NPPF is underpinned by a presumption in favour of (NPPF) (DCLG, sustainable development. 2012) The NPPF places a focus on planning for prosperity, people and places, promoting increased levels of development and supporting infrastructure, whilst also protecting and enhancing the natural and historic environment. One of the core principles of the NPPF is the need to “proactively drive and support sustainable economic development to deliver the homes, business and industrial units, infrastructure and thriving local places that the country needs. Every effort should be made objectively to identify and then meet the housing, business and other development needs of an area, and respond positively to wider opportunities for growth” (Page 5). National Policy The Proposed Scheme is considered to be an ‘improvement’ of the
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Planning policy Relevance to Proposed Scheme document Statement for highway with no significant residual environmental impacts and National therefore is unlikely to be a National Significant Infrastructure Project. Networks (NPS However, the NPS can still provide a sound framework for the NN) (DfT, 2014) development of any highway improvement scheme. Should significant environmental effects materialise as the project progresses, compliance with the NPS is an essential requirement for a successful DCO application. The NPS NN acknowledges that “on the road network, it is estimated that around 16% of all travel time in 2010 was spent in traffic” (Paragraph 2.3) and “the pressure on our networks is expected to increase even further as the long term drivers for demand to travel – GDP and population – are forecast to increase substantially over coming years” (Paragraph 2.4). The NPS NN asserts that “a well-functioning Strategic Road Network is critical in enabling safe and reliable journeys and the movement of goods in support of the national and regional economies” (Paragraph 2.13). It acknowledges that “without improving the road network, including its performance, it would be difficult to support further economic development, employment and housing and this would impede economic growth and reduce people's quality of life. The Government has therefore concluded that at a strategic level there is a compelling need for development of the national road network” (Paragraph 2.22). The NPS NN advocates that the “Government’s wider policy is to bring forward improvements and enhancements to the existing Strategic Road Network to address the needs” identified in the NPS NN (Paragraph 2.23). This includes junction improvements and improvements to trunk roads, in particular dualing of the single carriageway strategic trunk roads and additional lanes on existing dual carriageways to increase capacity and to improve performance and resilience.
Local Policy
1.3.6 The Proposed Scheme is located wholly within the administrative boundary of the Unitary Authority (UA) of Southampton City Council.
1.3.7 For the preparation of any further EIA works, Design Manual for Roads and Bridges (DMRB) guidance provides the methodology for screening of environmental impacts and further assessment and mitigation. This requires an assessment of the Proposed Scheme objectives in the light of national and local planning policy and legislation. As such, local policy from Southampton City Council is considered below.
1.3.8 Table 1.2 details the local policy documents relevant to the Proposed Scheme.
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Table 1.2: Local policy relevant to the Proposed Scheme
Planning Relevance to Proposed Scheme policy document Southampton The LTP3 outlines the long term plans for transport in the Solent Local area until 2031. Transport Plan The first part of the LTP sets out the shared approach to transport in (LTP3) and South Hampshire in 2031 and has been developed jointly by the Implementation three local Transport Authorities of Hampshire County Council, Plan (SCC, Portsmouth City Council and Southampton City Council. The second 2011) part sets out a four-year implementation plan setting out the transport schemes proposed for delivery within Southampton between 2011 and 2015. The LTP3 acknowledges that the key transport challenges facing the Solent are congestion, pollution, road safety and public health (Page 6). To overcome these challenges, the authorities will manage and maintain the road network, will improve public transport and will encourage people to change their travel habits. Policy A - is to develop transport improvements that support sustainable economic growth and development within South Hampshire. Policy B - is to work with the Highways Agency, Network Rail, Ports and Airports to ensure reliable access to and from South Hampshire’s three international gateways for people and freight. Policy C - is to optimise the capacity of the highway network and improve journey time reliability for all modes. Policy D - is to achieve and sustain a high-quality, resilient and well- maintained highway network for all. Policy E - is to deliver improvements in air quality. Policy G - is to improve road safety across the sub-region. Policy H - is to promote active travel modes and development supporting infrastructure. The M271/A33 Redbridge Roundabout capacity improvement project is recognised in the Implementation Plan as a major project for delivery by Highways England before 2021. The main purpose of the upgrade is to increase the capacity of the junction but it is also intended to support employment, housing and access to the Port (Page 35). Southampton The Southampton City Council Strategy 2016 advocates that City Council Southampton will be “a city of opportunity where everyone thrives” Strategy 2016 (Page 1). – 2020 (SCC, Of relevance to the Proposed Scheme are the following objectives 2016a) which the Council want to achieve for the area: Southampton is a city with strong and sustainable economic growth People in Southampton live safe, healthy, independent lives Southampton is a modern, attractive city where people are proud to live and work A Clean Air The Clean Air Strategy for Southampton 2016-2025 asserts that
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Planning Relevance to Proposed Scheme policy document Strategy for Southampton City Council is committed to improving the city’s air Southampton quality. 2016 – 2025 Road transport is recognised as the biggest contributor to pollution (SCC, 2016b) across the city followed by industry. The national Air Quality Plan for Nitrogen Dioxide in UK (2015) includes the implementation of a Clean Air Zone in Southampton. By 2020, the most polluting vehicles including older buses, coaches, taxi’s and lorries will be discouraged in Southampton through the levying of a penalty charge. The Council intends to deliver a package of measures as part of the city’s Air Quality Action Plan and Clean Air Zone Plan to encourage behaviours supporting improvements in air quality. The Council intend to establish the Southampton Clean Air Zone (CAZ) on a voluntary basis, with no charging, by 2017. They will also improve transport and freight delivery systems through efficient infrastructure, uptake of new and innovative technologies and increased uptake of public transport, cycling and walking. Local The Core Strategy is one of the plans that make up the adopted Development Local Plan. It was originally adopted in 2010 and replaced some of Framework the policies in the Local Plan Review. The Core Strategy was Core Strategy amended in 2015 to incorporate changes in the adopted Core Development Strategy Partial Review. Plan Document On the Core Strategy Key Diagram, the M271/A33 junction is - Amended identified as a key gateway into Southampton. Core Strategy Policy CS 9 - ‘Port of Southampton’ asserts support for appropriate (SCC, 2015a) road improvements leading to the port. Policy CS 13 - ‘Fundamentals of Design’ advocates that development should follow a robust design process and be assessed against the twelve principles identified in the policy. Principle 8 - is to “promote a highly accessible, well connected city including an accessible waterfront” and principle 9 is to “improve accessibility throughout the city by ensuring that developments, including buildings, streets and public spaces, are accessible to all users including senior citizens and disabled people”. Policy CS 18 - ‘Transport: Reduce – Manage – Invest’ recognises that “to support the regional economy, enhance air quality and achieve a modal shift to more environmentally sustainable transport, a ‘reduce-manage-invest’ approach will be taken”. In relation to strategic transport the policy asserts that the Council will work with the appropriate authorities to maintain “appropriate access to the strategic road network incorporating the A33, M271…”. They will also secure strategic developer contributions “to address the increased travel demands of new development”, to seek to deliver “mitigation measures for the M271, M27 and M3 Motorways, including Active Traffic Management, junction improvements and improved access to the Port of Southampton”. In relation to citywide transport, the Council will continue to “support infrastructure and
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Planning Relevance to Proposed Scheme policy document secure developer contributions which promote public transport and active travel (walking and cycling) particularly in relation to the city, town, district and local centres”. The policy will also require new developments to “consider impact on air quality, particularly in Air Quality Management Areas (AQMAs) through the promotion of access by sustainable modes of travel”. Policy CS 20 - ‘Tackling and Adapting to Climate Change’ asserts that the Council will continue to implement the measures identified in the Council’s Climate Change and Air Quality Strategy 2004 and any subsequent revisions. Developments must also assist with managing surface water run-off through the implementation of Sustainable Drainage Systems (SuDS) and measures to reduce or avoid water contamination and safeguard groundwater supply. Policy CS 22 - ‘Promoting Biodiversity and Protecting Habitats’ asserts that the Council will ensure “development does not adversely affect the integrity of international designations and the necessary mitigation measures are provided; or the development otherwise meets the Habitats Directive” and “is unlikely to have an unacceptable impact on a national or local designation; and that any such impact…is avoided, mitigation or as a last resort compensated for”. Policy CS 25 - ‘The Delivery of Infrastructure and Developer Contributions’ asserts that the Council “will continue to work with infrastructure providers to further review the needs for infrastructure within the city for the next 20 years. Proposals for physical infrastructure that help meet the needs generated by new development and by existing communities within Southampton will be permitted, subject to meeting other relevant LDF policies”. City of The Local Plan Review was first adopted in March 2006 and was Southampton subsequently amended in 2010 and again in 2015. local plan Policy SDP 1 - ‘Quality of Development’ asserts that planning review - permission for development will only be granted where it “does not Amended in unacceptably affect the health, safety and amenity of the city and its 2015 (SCC, citizens”. 2015b) Policy SDP 4 - ‘Development Access’ advocates that development will only be permitted where access into the development provides in priority order for pedestrians and disables people, cyclists, public transport and private transport. Policy SDP 7 - ‘Context’ asserts that “development which would cause material harm to the character and/or appearance of an area will not be permitted”. Policy SDP 10 - ‘Safety and Security’ advocates that development will only be permitted where it provides: (i) natural surveillance of any public space; (ii) safe and secure locations for any associated car and cycle parking; (iii) safe and secure public routes which seek to minimise both
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Planning Relevance to Proposed Scheme policy document actual and perceived opportunities for criminal activity; and (iv) satisfactory lighting. Policy SDP 11 - ‘Accessibility and Movement’ states that planning permission will only be granted for development which: (i) contributes to an attractive network of public routes and spaces for pedestrians, cyclists and vehicles; (ii) secures adequate access for all pedestrians including people with mobility and sensory difficulties such as elderly people, disabled people, the very young and those using prams and wheelchairs. Policy SDP 12 - ‘Landscape and Biodiversity’ asserts that “development proposals will not be permitted without a landscape/habitat creation and management scheme appropriate to its setting”. Policy SDP 12 - ‘Resource Conservation’ asserts that “developments should be designed in a way which minimises their overall demand for resources”. Policy SDP 15 - ‘Air Quality’ advocates that planning permission will be refused: (i) where the effect of the proposal would contribute significantly to the exceedance of the National Air Quality Strategy Standards; or (ii) where the proposal would be materially affected by existing and continuous poor air quality. Policy SDP 16 - ‘Noise’ asserts that “i) noise-generating development will not be permitted if it would cause an unacceptable level of noise impact”. A noise impact report may need to be submitted with the planning application to assess noise effects. Policy SDP 17 - ‘Lighting’ sets out specific requirements for external lighting, namely that “the lighting scheme proposed is the minimum required for the security and working purposes to achieve its purpose” and that light spill and potential glare and impacts on streetscape is minimised. Policy SDP 22 - ‘Contaminated Land’ asserts that “planning permission for development on or adjacent to land that is known to be, or may be contaminated, will only be granted where…it has been demonstrated that the potential for contamination has been properly assessed”. Policy NE 1 ‘International Sites’ acknowledges the following sites are located in the area: a) Part of the Solent Maritime Special Area for Conservation (SAC); b) Part of the Solent and Southampton Water Special Protection Area (SPA); and c) Part of the Solent and Southampton Water Ramsar site. Policy NE 4 - ‘Protected Species’ asserts that “development will not
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Planning Relevance to Proposed Scheme policy document be permitted which would adversely affect species… identified as a priority species in the UK Biodiversity Action Plan or any local Biodiversity Action Plan… unless there is a need for the development which outweighs the ecological importance of the site”. Policy HE 6 - ‘Archaeological Remains’ advocates that “where important archaeological remains may exist the impact of development upon the archaeological resource has been examined and evaluated”. Adopted Local The Proposed Scheme does not fall within any local plan Plan map allocations. Immediately to the south of the site is the Redbridge (SCC, 2015c) Local Area of Archaeological Potential (Policy HE 6). The Redbridge Community School (approximately 20m north-east) and Studland Road playing fields (approximately 25m north) are both allocated as Open Space (Policy CLT 3). Further afield, approximately 270m to the west is the Solent and Southampton Water Ramsar site, SPA, SAC and Site of Special Scientific Interest (SSSI). Whilst not shown on the Local Plan map, the site also lies within the Redbridge Road AQMA for Nitrogen Dioxide NO2.
1.3.9 The Hampshire Minerals and Waste Plan (2013) also forms part of the Southampton Local Development Framework and is described in Chapter 10 ‘Materials’.
1.4 Consenting Route
1.4.1 The proposed improvements to the M217 Redbridge Roundabout are considered to fall within the permitted development rights granted to Highways England under the Town and Country Planning (General Permitted Development) Order 2015 (as amended). Schedule 2 Part 9 Class B which states: “Class B – development by the Secretary of State or a strategic highways company under the Highways Act 1980 Permitted development B. The carrying out by the Secretary of State or a strategic highways company of works in exercise of the functions of the Secretary of State or the company under the Highways Act 1980(a), or works in connection with, or incidental to, the exercise of those functions.”
1.4.2 Part V of the Highways Act 1980 details the powers of improvement available to Highways England provided there are no significant residual environmental impacts from the development. The EAR demonstrates that there are only moderate/significant impacts during construction and these are temporary and would not impact on the successful screening of the development. Therefore, permitted development rights cover the proposed works and no express consent is required for the proposed works.
1.5 The Developer and Designer
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1.5.1 Highways England is the developer for the Proposed Scheme, acting on behalf of the Department for Transport, implementing the works in accordance with the Government commitments outlined within the Road Investment Strategy (RIS) (DfT, 2015).
1.5.2 Jacobs has been appointed as the designer and is also leading the environmental assessment for PCF Stages 3 and 5 and is a registered consultant holding the Institute of Environmental Management and Assessment (IEMA) Quality Mark.
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2. The Project 2.1 Need for the Project
2.1.1 The M271/A35 Redbridge Roundabout is a vital route connecting the M271 motorway with the remainder of Southampton’s road network. The site is the gateway to Southampton from the west, and provides the main access to Southampton’s Western Docks. The roundabout experiences congestion particularly during peak times, resulting in queues along the M271 affecting the Highways England strategic network. The congestion also results in safety implications associated with the existing infrastructure at the roundabout and its use.
2.1.2 The Proposed Scheme is required to mitigate existing issues with congestion and safety. There are also economic justifications for the Proposed Scheme, as the M271/A35 Redbridge Roundabout is the entryway to Southampton and its Western Docks. Any increased traffic flow into and out of these areas is likely to contribute to the economic development of the area, through increased accessibility, improved journey time reliability and reduced travel times.
2.1.3 In December 2014, the Department of Transport published the RIS for 2015 - 2020 (DfT, 2015). The RIS sets out a list of schemes to be developed by Highways England over a five-year period. The current Proposed Scheme is one of the schemes within the RIS portfolio. The Proposed Scheme is now being progressed through the Highways England Single Option Projects PCF and this EAR has been prepared for a combined PCF Stages 3 (preliminary design) and PCF Stage 5 (construction preparation) following PCF Stage 2 (options selection).
2.2 Project Objectives
2.2.1 The Proposed Scheme helps to achieve the following key strategic outcomes, as outlined in the Highways England Delivery Plan 2015 - 2020 (DfT, 2015):
Supporting economic growth – through a modern and reliable network that reduces delays, creates jobs, helps business and opens up new areas for development.
A safe serviceable network – where no one should be harmed when travelling or working.
A more free-flowing network – where routine delays are more infrequent and journeys are safer and more reliable.
An improved environment – where our activities ensure a long-term and sustainable benefit to the environment.
A more accessible and integrated network – giving people the freedom to choose their mode of transport and enable safe movement across and alongside it.
2.2.2 The Proposed Scheme also contributes to the achievement of KPIs associated with each of the strategic outcomes above. Relevant KPIs to the environmental assessment are provided in Section 1.3
2.2.3 Specific scheme objectives are listed below:
Improvement to average peak hour speed from the M271 southbound to the Redbridge Roundabout and reduction of peak hour queue lengths on all approaches to the junction.
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Reduction in average journey times through the Redbridge Roundabout for buses and general traffic.
Reduction in total number of accidents and accidents involving Walkers, Cyclists and Horse Riders (WCHRs).
Reduction in number of surface water flooding incidents and Nitrogen dioxide (NO2) and noise levels.
Increase in the number of pedestrians and cyclists using the WCHRs facilities.
2.3 Project Location
2.3.1 The M271/A35 Redbridge Roundabout is located at the southern end of the M271, approximately three miles to the west of Southampton City Centre at its intersection with the A33 (Redbridge Road) and the A35 (Totton Bypass). The M271 is generally a dual two lane motorway widening to three lanes on the approach to the roundabout. The M271 currently exits the roundabout in two lanes but an additional third lane beyond the roundabout provides a dedicated traffic lane towards the local Redbridge area. Both the A33 and the A35 generally run as a dual two lanes carriageway on their approach to the roundabout and join along an elevated flyover. Additional ground level two-lanes on/off slip roads connect these roads to the M271 through the roundabout whilst local widening to a third lane maintains access to the local areas in the vicinity.
2.3.2 The Proposed Scheme falls entirely within the existing highways corridor on land owned/controlled by Highways England or Southampton City Council, both of whom are Highways Authorities. No additional land acquisition is therefore required. The footprint of the Proposed Scheme including temporary construction area is approximately 2.9 hectares. The M271/A35 Redbridge Roundabout is located within a suburban landscape on the outskirts of Southampton. The immediate surrounding area of Redbridge is predominately residential mixed with light industrial. The site is located within an Air Quality Management Area (AQMA) (Southampton City Council’s AQMA No. 5), and a NIA (2192) as identified by the Department of Environment, Food and Rural Affairs (Defra) (Figure 2.1). In addition, the Proposed Scheme is within 1km of the Solent and Southampton Water Ramsar (200m west of the Proposed Scheme), also designated as a SPA, SAC and Site of Special Scientific Interest (SSSI) (Figure 2.1).
2.3.3 All figures for this EAR are provided in Appendix A.
2.4 Project Description
2.4.1 It is recommended that the description of the Proposed Scheme below is read in conjunction with Figure 2.2.
2.4.2 The Proposed Scheme involves widening to the south and north-east of the M271/A35 Redbridge Roundabout to accommodate an additional lane, and to create a segregated free-flow left lane merging to the A33 eastbound on-slip road, respectively. The widening would utilise the inner central island and land to the north-east of the roundabout, slightly encroaching onto the Redbridge Tower car park.
2.4.3 Two existing toucan crossings would be relocated and an additional toucan crossing would be created. The existing subway to the north of the Proposed Scheme would be upgraded with new lighting and covered with anti-graffiti paint. However, the subway to the south of the roundabout would be infilled, to create space for the new widened shared footway of 4m width. The existing footbridge would also be upgraded for combined
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pedestrians’ and cyclists’ use. In addition, two noise barriers of 5m and 4m height would be erected to the north east and south of the Proposed Scheme with the intention of reducing noise levels within the surrounding area, respectively.
2.4.4 The existing speed limit of 70mph on the M271 southbound carriageway would be gradually reduced to 40mph in advance of the proposed segregated left turn lane. A speed limit of 40mph would also be implemented over a length of the segregated left lane and continued over the eastbound A33 merge slip road, as well as over the circulatory carriageway of the roundabout.
2.5 Construction, Operation and Long Term Management
Construction
2.5.1 Construction of the Proposed Scheme would be undertaken by a Principal Contractor who would make proposals as to the bespoke methodology of construction. To carry out an assessment of the impacts arising from construction, assumptions have therefore been made as to how the Proposed Scheme could be built. A possible construction methodology has been produced and detailed in the Buildability Report (Jacobs, 2017a).
2.5.2 Whilst the methodology in the Buildability Report (Jacobs, 2017a) is based on best practice and within the constraints of the site and the design, it is indicative and therefore can be amended. For the purpose of this report, the assessment has been based on this methodology. If the contractor used a different methodology, a review of the impacts would need to be carried out, with an explanation of why the alternatives were preferred to the one proposed.
2.5.3 It is currently assumed that the Proposed Scheme would be constructed in seven consecutive phases, starting off with site clearance and ending with resurfacing of roads and road markings. The Proposed Scheme would be likely to take approximately seven months to construct and to be operational (open to traffic) in 2019.
2.5.4 The following construction works are planned to be carried out as part of the Proposed Scheme:
site clearance (vegetation and trees on the verges and within the central roundabout island);
footway widening and realignment;
carriageway widening;
demolition of existing pedestrian overbridge;
earthworks;
construction of retaining wall;
construction of pedestrian overbridge;
infill to pedestrian subway;
maintenance of existing subway;
relocation of pedestrian crossings;
relocation of traffic signals; and
other small civils works.
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2.5.5 It is assumed that all permanent construction works would be carried out within the existing highways boundary; however, some temporary land take would be required north of the A33 eastbound and south of the A33 westbound on land owned/controlled by Southampton City Council. The location of a construction compound south of Redbridge Towers and Cuckmere Lane has been assumed. Whilst the construction of the Proposed Scheme was on-going, compound sites would remain lit (with lighting directed appropriately to minimise light pollution to nearby residents), fenced and secured at all times.
2.5.6 Due to the nature of the Proposed Scheme, it is assumed that no haul roads would need to be constructed – construction plant and vehicles would access the works area from public roads via relevant site access/egress points in the temporary traffic management.
2.5.7 Temporary traffic management would be required to provide safe access and working areas for construction and ensure safe flow of vehicles and WCHRs through the Proposed Scheme. Access to Public Right of Ways (PRoWs) and private properties would be kept open where possible. Where they could not be kept open, suitable temporary diversions would be put in place and agreed with the relevant Southampton authority.
Operation and Maintenance
2.5.8 The M271/A35 Redbridge Roundabout would remain lit during the operation phase. Maintenance activities would be likely to include cyclic activities such as routine footbridge inspections, noise barriers, landscape mitigation, drainage maintenance and litter picking.
Decommissioning
2.5.9 Decommissioning has not been considered within this report, as it is assumed that the road would remain in place in the future. The subject of routine maintenance is included within the operation and maintenance section above.
2.6 Design Considerations
Embedded Mitigation
2.6.1 Environmental assessment in Stages 1 and 2 has influenced the overall concept of the designs. This has included embedded (or primary) mitigation, and forms a critical component of the overall scheme. This includes the upgrade of subway, footbridge and footways to better accommodate WCHRs. Environmental constraints including length/duration of WCHRs journeys and trees and biodiversity (potentially impacted) have also been taken into account in the consideration of footbridge structure options early in PCF Stage 3. For example, a steel truss structure was chosen for the footbridge on its aesthetic appeal as well as buildability point of view. A steel truss structure offers a light and more open aspect than the half-through options which present a solid elevation.
2.6.2 Drainage design of the Proposed Scheme has been designed for a climate change allowance of 20%. Flow attenuation is checked for 1 in 1 year, 1 in 5 years, 1 in 30 years and 1 in 100 years return period with uplift of 20% for climate change, to ensure that the proposed drainage design does not cause an increase over existing peak discharge rates and detriment flood risk over the existing scenario. The 20% climate change has been applied by increasing the additional catchment area in proposed scenario.
2.6.3 Noise barriers have been designed into the Proposed Scheme in the area around Redbridge Towers to the north-east of the scheme, and around the closest properties on
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Old Redbridge Road to the south of the scheme. They are at 5m and 4m height respectively. These barriers are embedded into the design of the Proposed Scheme to attempt to reduce noise levels arising from the operation phase of the Proposed Scheme to NIA 2192.
2.6.4 Other embedded mitigations are outlined in the individual topic chapters under ‘Design, Mitigation and Enhancement Measures’.
Resilience to Environmental Risks, Accidents and Disasters
2.6.5 Environmental risks, accidents and disasters (referred to in this report as events) are defined as a sudden, catastrophic occurrence that could result in serious damage to human welfare or the environment. An event can be caused by natural processes or human actions and result in major disruption to society and communities, causing economic and environmental losses.
2.6.6 The EIA Regulations 2017, now require that risks due to accidents and disasters are considered within the EIA process. The Proposed Scheme will be at risk from events, potentially leading to problems with operation or the need for additional maintenance. An accidents and disasters assessment has been completed, with the purpose of identifying ways to adapt the Proposed Scheme to make it more resilient to these events. Types of events of relevance to the Proposed Scheme have been taken from the International Federation of Red Cross and Red Crescent Societies website (2017), and the National Risk Register of Civil Emergencies (2017). Events have been selected based on the nature and location of the Proposed Scheme.
2.6.7 Table 2.1 provides a risk assessment of major events having the potential to affect the Proposed Scheme, as well as indicating where these are reported and mitigated within the environmental assessment.
Table 2.1: Major events risk assessment and adaptation summary
Event Likelihood Consequences Proposed mitigation measure Widespread The National Risk Widespread electricity Back up procedures are electricity Register failure could disrupt the included within the failure probability of a technology and telecommunications widespread signalling on the system to maintain electricity failure transport network. This communications as far as occurring in the could result in confusion possible in the event of a next five years is 3 for vehicle travellers, as failure. As such (out of 5), with an well as increasing widespread electricity impact severity of the risk of accidents. failure are not considered 4 (out of 5). further. Major The National Risk Major accidents could Although accidents are transport Register result in fatalities, likely to take place on the accidents probability of a casualties, and damage Redbridge Roundabout, major transport to infrastructure, these are not likely to accident occurring causing disruption to the occur at a scale that in the next five network. There can also would be considered a years is 2 (out of be impacts on local national or regional 5), with an impact communities if not disaster. The objective of severity of 3 (out of equipped to deal with a the Proposed Scheme is
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Event Likelihood Consequences Proposed mitigation measure 5). large scale event in the to reduce congestion and area. Environmental improve safety, which damage could occur if a should reduce the crash resulted in probability of an incident spillage of contaminants occurring. As such traffic (e.g. in the event of an accidents is not oil tanker crash). considered further. Severe The National Risk Heavy snowfall could The UK Met office has a weather – Register result in serious system in place providing low (sub- probability of disruption to a transport warnings of extreme zero) severe weather network, resulting in weather. Highways temperature occurring in the road closures and England and local and heavy next five years is 4 increasing the hazard of authorities operate gritting snow (out of 5), with an vehicle accidents. This lorries and manage impact severity of has the potential to operations for removing 4 (out of 5). result in casualties and snow. These existing fatalities. Environmental mitigation measures damage could occur if a reduce the risk of crash resulted in accidents occurring. As spillage of contaminants such snow storms are not (e.g. if an oil tanker considered further. crasher). Severe The National Risk Heatwaves with high Road pavements have weather – Register temperature could result been designed in heatwaves probability of in disruption to a accordance with DMRB severe weather transport network, guidance on pavement occurring in the resulting in road design and maintenance next five years is 4 closures and increasing HD 26/06 (Highways (out of 5), with an the hazard of vehicle Agency et.al., 2006) and impact severity of accidents due to tarmac IAN 73/06 (Highways 4 (out of 5). melting and technology England (2009a), and overheating. This could would be able to increase maintenance withstand the predicted costs due to additional increase in summer mean repairs. temperature of 2.8ºC in the South East England region. River The National Risk River flooding could The UK Met office and Flooding Register result in disruption to Environment Agency probability of River essential services, have a system in place flooding occurring particularly transport. providing warnings of in the next five Flooding could close extreme weather. A Flood years is 3 (out of roads and/or lead to Risk Assessment (FRA) 5), with an impact major delays. In was undertaken for this severity of 4 (out of addition, heavy flooding scheme in accordance 5). could contribute to with the requirements of difficult driving the National Planning conditions, potentially Policy Framework and accompanying National
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Event Likelihood Consequences Proposed mitigation measure leading to accidents. Planning Practice Guidance. Please refer to Chapter 13 ‘Road Drainage and Water Environment’ for further details.
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3. Alternatives Considered
3.1 Options Considered in PCF Stage 0
3.1.1 At PCF Stage 0, three options were considered. The traffic modelling indicated that Options 1 and 2 could provide possible journey time benefits to road users, whilst Option 3 (PCF Stage 0) would worsen existing traffic conditions.
3.1.2 The PCF Stage 0 Option 3 was identified as being unlikely to meet the objectives of the scheme, and was therefore not considered beyond PCF Stage 0.
3.2 Options Considered in PCF Stage 1
3.2.1 Options considered in PCF Stage 1 (options identification) were developed from options considered in PCF Stage 0, taking into account Southampton City Council comments. A further alternative option was developed for consideration; this further option replaced Option 3 at PCF Stage 0. Options 1, 2 and the new Option 3 described below, were then considered in the Stage 1 Environmental Study Report (ESR) (WSP, 2016a):
Option 1: Provision of a new at-grade through-about link with two lanes joining A33 westbound off-slip to M271 northbound;
Option 2: Provision of enhanced circulatory capacity to the south and east sides of Redbridge Roundabout; and
Option 3: Provision of enhanced circulatory capacity to the south, west and east sides of Redbridge Roundabout. Lane widths were also wider than those proposed for Option 2.
3.2.2 All three options proposed included provision of a segregated free-flow left turning link between the southbound M271 and the A33 eastbound on-slip. In addition, the bus gate on the A33 westbound off-slip leading to the roundabout was also proposed to be removed. The potential for the addition of a new footbridge spanning the M271, across the north side of the existing roundabout junction was also identified. This additional facility could be provided in any of the above three options and was further considered during PCF Stage 2 - Option Selection.
3.2.3 Environmental findings of the three options can be found in the PCF Stage 1 ESR (WSP, 2016a). At the end of PCF Stage 1, Option 1 was disregarded due to safety issues associated with the at-grade crossings and the proposed free-flow lane. It was considered incompatible with the Client Scheme Requirements and not deemed acceptable by Southampton City Council due to safety concerns.
3.3 Options Considered in PCF Stage 2
3.3.1 Options 2 and 3 from PCF Stage 1 were taken forward for further development within PCF Stage 2 (option selection). Options 2 and 3 were considered effectively as being variants of the same improvement strategy, with Option 3 providing a greater increase in capacity compared with Option 2, through more extensive widening of the existing roundabout circulatory carriageway.
3.3.2 General to both options:
A segregated free-flow left turn link between the M271 (southbound) and the A33 (eastbound) on-slip road towards Southampton.
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Removal of both toucan crossings across the A33 (east and west bound) off-slip road.
Removal of the bus gate on A33 westbound off-slip whilst maintaining the existing bus lane on the approach to the roundabout.
3.3.3 Option 2: an additional circulatory lane to the south side of the roundabout to increase capacity. In this option the proposal is to maintain and upgrade the subway on the north side of the roundabout, and construction of a modified footbridge. The additional southern carriageway lane could require closure of the southern subway.
3.3.4 Option 3: This option incorporates an extra traffic lane on the west and southern sides of the roundabout necessitating carriageway widening and the possible removal of the subway on the southern side. Similar to Option 2, it is proposed to maintain and upgrade the subway on the north side of the roundabout with a modified footbridge. The northern circulatory lane would also be modified to reflect a lower traffic demand at this location.
3.3.5 Environmental findings of the two options can be found in Stage 2 ESR (WSP, 2017).
3.3.6 As a result of the Public Consultation towards the end of PCF Stage 2 (9th November 2016 to 16th December 2016), Option 2 was revised to take into account the public comments and Option 3 disregarded on the grounds that a greater amount of construction is required. Environmental impact is not a key decision making factor as the Proposed Scheme is confined by its nature (widening of existing roundabout) and space.
3.3.7 The revision to Option 2 included additional elements, such as the removal of the southern subway and adaption of wider 4m lanes from 3.65m on the roundabout to improve capacity and free flow movement. This revised Option 2 is therefore subject to further environmental assessment, particularly with design refinement along the A33 eastbound slip road in PCF Stages 3 and 5.
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4. Environmental Assessment Methodology 4.1 Scoping
4.1.1 This section provides an overview approach to the PCF Stages 3 and 5 environmental assessment. The environmental appraisal has been carried out by a team of specialists working in close iterative collaboration with engineers responsible for the design of the Proposed Scheme. This approach provides an opportunity to avoid or reduce environmental effects at source, and allows the most effective mitigation of unavoidable effects.
4.1.2 The EAR includes the topics covered within the DMRB guidance and IAN 125/15 (Highways Agency et al., 1993a and Highways England 2015b). Additional topics, as set out in the EIA Directive 2014/52/EU (amending Directive 2011/92/EU), have also been considered. Table 4.1 documents the topics from the EIA Directive 2014 and where these are generally covered within this report. There may be some topics that cross over more than one section.
Table 4.1: Topics from the EIA Directive 2014/52/EU covered within this report
EIA Directive topic Main location in the report Human health Various chapters including Chapters 5, 9, 11, 12 and 15. Nature Conservation (flora and fauna) Chapter 8 ‘Biodiversity’. Land (e.g. land take) Chapter 12 ‘People and Communities’. Soil (e.g. organic matter, erosion, Chapter 9 ‘Geology and Soils’. compaction, sealing) Water (hydromorphological changes, Chapter 13 ‘Road Drainage and Water quality and quantity) Environment’. Air Chapter 5 ‘Air Quality’. Climate (e.g. carbon footprint, impacts Chapter 10 ‘Materials’ and Chapter 14 relevant to adaptation) ‘Climate Change’. Material assets Chapter 12 ‘People and Communities’. Cultural heritage including architectural Scoped out from this EAR. and archaeological aspects Landscape Chapter 7 ‘Landscape and Visual’. Emission of pollutants Chapter 5 ‘Air Quality’ and Chapter 13 ‘Road Drainage and Water Environment’. Noise and vibration Chapter 11 ‘Noise and Vibration’. Light Chapter 7 ‘Landscape and Visual’. Heat and radiation Not applicable on a road scheme. Creation of nuisances All chapters (Chapters 5-15). Disposal and recovery of waste Chapter 10 ‘Materials’. Risks due to accidents and disaster Section 2.6 ‘Design Considerations’ and Chapter 14 ‘Climate Change’. Cumulative effects Chapter 15 ‘Cumulative Effects’.
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4.1.3 There is no potential for a residual significant effect to cultural heritage assets during construction and operation phases of the Proposed Scheme. No further assessment is required and therefore the cultural heritage topic has been scoped out and is not included in this EAR. The heat and radiation topic required under the EIA Regulations 2017 is not relevant to a road scheme and has therefore also been scoped out of this report. The Proposed Scheme would not introduce any sources of radiation, and would generate limited amounts of heat from minor elements such as lighting.
4.2 Surveys and Predictive Techniques, and Methods
4.2.1 A 1km wide corridor study area was used in general around the Proposed Scheme for the baseline review. For biodiversity, study areas were increased to 2km to assess potential impacts on non-statutory designated sites, and 5km to assess potential impacts on statutory designated. Additionally, a 30 km study area was also used to check for SACs, designated for bats, as recommended by current guidance set out in the DMRB HD 44/09 (Highways Agency et al., 2009a). Specific study areas are outlined in the individual topic chapters.
4.2.2 Guidance on environmental assessment for highways projects is given in Volume 11 of DMRB (Highways Agency et al., 1993a), with guidance on environmental design and mitigation in Volume 10 (Highways Agency et al., 2001a). Environmental assessment methodology and mitigation developed for this Proposed Scheme are therefore based on DMRB Volume 11 and 10 (Highways Agency et.al., 1993a and Highways England, 2001a), respectively.
4.2.3 Where relevant, the environmental assessment draws on updated guidance since DMRB Volume 11 (Highways Agency et al., 1993a) was published, such as the Interim Advice Notes (IANs). Interim Advice Notes are issued by Highways England when new guidance emerges yet to be incorporated into the DMRB. More details of the method proposed to be used are provided in each of the environmental topic chapters (Chapters 5-15).
4.2.4 Technical drawings ‘Fit for Tender’ have been used to informed the environmental assessment in this EAR.
4.3 General Assessment Assumptions and Limitations
4.3.1 It is assumed that all permanent construction works and mitigation measures can be accommodated within the existing highways corridor on land owned/controlled by Highways England or Southampton City Council, both of whom are Highways Authorities. If land take is required, the Proposed Scheme may result in the need for a statutory consenting process. Specific assumptions and limitations for each environmental topic are highlighted within its relevant chapter.
4.3.2 The traffic flow and speed figures provided for air quality and noise and vibration assessments were produced from the Sub-Regional Transport Model (SRTM). The SRTM is a regional multi-model, variable demand model developed by Systra on behalf of Solent Transport. The SRTM represented the Proposed Scheme and has a base year of 2015 and forecast years of 2019 and 2036.
4.3.3 For the purpose of the PCF Stages 3 and 5 environmental assessments, it is assumed that the existing M271/A35 Redbridge Roundabout would remain open during construction. It assumed that the Proposed Scheme has a baseline year of 2017 (excluding traffic data with baseline year of 2015), an opening year of 2019 and a design year of 2036 (17 years after opening).
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4.3.4 The baseline conditions are based on conditions that would exist in the absence of the Proposed Scheme either (a) at the time that construction is expected to start, for impacts arising from construction; or (b) at the time that the Proposed Scheme is expected to open to traffic, for impacts arising from its operation. Some disciplines also considered the Proposed Scheme design, 15 years post opening. Therefore, identification of the baseline conditions involves predicting changes likely to happen in the intervening period, for reasons unrelated to the Proposed Scheme. The baseline conditions set out in this report are based on the best information currently available. For the future years, the effects of the Proposed Scheme have been compared with the Do-Minimum (DM) conditions; ‘Do- Minimum’ conditions are the conditions predicted to exist in that year in the absence of the Proposed Scheme.
4.3.5 The main limitation of this report is that it is written at a given point in time and can only be based on information available up to this point. This includes the assumption that the information provided at Stage 1 and Stage 2 and the third party sources are accurate and current at the time of preparing this report. References are included to provide details of relevant sources.
4.4 Significance Criteria
4.4.1 The environment assessment will identify all potential impacts that could arise due to the construction and operation of the Proposed Scheme. Impacts can affect the environment in a variety of ways. Impacts could be: beneficial/positive or adverse/negative; direct or indirect; secondary or cumulative; temporary or permanent; or short, medium or long term. The differing features of the environment affected by the Proposed Scheme are known as receptors, they can range from specific plants, animals or human beings living near the Proposed Scheme or passing through the area, through to landscape as a whole and the physical (including health), ecological and cultural elements within it. Cumulative effects and impact interactions are also identified. The approach to the assessment of cumulative effects is set out in Chapter 15 – Cumulative Effects.
4.4.2 Effects, whether beneficial or adverse, would be expressed in terms of their significance. Significance is derived through consideration of the sensitivity of a receptor (sometimes referred to as its value or importance) and the magnitude of the effect, as defined by the degree of change from the baseline. Therefore, the significance of an effect is influenced by both of these variables.
4.4.3 The significance of any particular effect can be assessed through the use of a matrix, with the values of sensitivity of the receptor along one axis and the magnitude of the effect on the other. A typical matrix is provided in Table 2.4 of the DMRB Volume 11, Section 2, Part 5, and is reproduced in Table 4.2.
Table 4.2: Typical matrix for assessment of significant effects
Sensitivity or Magnitude of impact value No change Negligible Minor Moderate Major Very high Neutral Slight Moderate Large or Large or or Large Very Large Very Large High Neutral Slight Slight or Moderate Large or Moderate or Large Very Large Medium Neutral Neutral or Slight Slight or Moderate
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Sensitivity or Magnitude of impact value No change Negligible Minor Moderate Major Slight Moderate or Large Low Neutral Neutral or Neutral or Slight Slight or Slight Slight Moderate Negligible Neutral Neutral Neutral or Neutral or Slight Slight Slight
4.4.4 The majority of environmental topics within this EAR draw upon a matrix to carry out the assessment. However, some topics use calculations to assess effects in numerical terms instead of the matrix-based approach (i.e. air quality and noise and vibration). In all cases, informed professional judgement is applied to the assessment to underpin the outcomes identified through the matrix or calculation assessments.
4.4.5 Significance categories are described in Table 2.3 in Volume 11, Section 2, Part 5 of the DMRB guidance (Highways Agency et al., 2008a). This describes effects with very large or a large significance as being ‘key factors in the decision making process’ and ‘likely to be material in the decision making process’ respectively. Therefore, large and very large effects are considered ‘significant’ for the purposes of the EIA regulations. In addition to large and very large significant effects, moderate effects are also considered as ‘significant’ in this report.
4.5 Mitigation and Enhancement
4.5.1 Mitigation measures aim to avoid effects at their source, perhaps through amendments to the Proposed Scheme design or by regulating the timing and location of activities. It is defined within DMRB Volume 11, Section 1, Part 7 (HA 218/08) (Highways Agency et.al., 2008b) as “measures intended to avoid, reduce and, where possible, remedy significant adverse environmental effects”. Mitigation measures for the Proposed Scheme have been developed in accordance to the mitigation hierarchy of avoidance, minimisation, restoration and compensation.
4.5.2 Mitigation could take several forms either primary (embedded), secondary (foreseeable), or tertiary. The IEMA (2016) definition for each type of mitigation is described below:
Primary mitigation: intrinsic part of design evolution (i.e. reducing height of a building to reduce visual impact).
Secondary mitigation: requires further activity to achieve the anticipated outcome. It is described in the topic chapters and secured through planning conditions and management plans.
Tertiary mitigation: this is required regardless of the EIA because it is generally imposed through legislative requirements or standard sector practices (i.e. implementing considerate contractor practices to reduce nuisance from site work). These measures would be captured in a Construction Environmental Management Plan (CEMP).
4.5.3 Tertiary mitigation for each topic within this EAR is provided in Appendix B: Good Practice (Tertiary Mitigation). It is assumed that this mitigation is required regardless of the EIA because it is generally imposed through legislative requirements or standard sector
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practices (e.g. implementing considerate contractor practices to reduce nuisance from site work).
4.5.4 Where the Proposed Scheme would cause significant adverse effects, secondary mitigation measures have been proposed. If effects cannot be mitigated, it could be appropriate for compensatory measures to be taken, for example to provide replacement habitat. The purpose of any mitigation measure is to eliminate the effect, or if not possible, to reduce its significance.
4.5.5 Enhancement refers to deliberate attempts taken in the design of the Proposed Scheme and programme to ensure the success of a wider range of direct and indirect positive outcomes to environment. It is defined within DMRB Volume 11, Section 1, Part 7 (HA 218/08) (Highways Agency et.al., 2008b) as “measure that is over and above what is required to mitigate the adverse effects of a project”.
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5. Air Quality 5.1 Introduction
5.1.1 Air quality is a consideration for any development proposal involving significant changes in the nature and location of emissions to air. The Proposed Scheme for the M271 Redbridge Roundabout, Southampton would attract more traffic than the existing road infrastructure, and would change traffic flows on other roads in a wider surrounding area. This would have the potential to increase emissions from vehicle traffic and change ambient air quality at nearby sensitive receptors.
5.1.2 A detailed assessment has been undertaken to establish the potential effects of the Proposed Scheme on local and regional air quality.
5.2 Legislative and Policy Framework
European Legislation
5.2.1 The EU Directive on ambient air quality (2008/50/EC) sets out a range of mandatory Limit Values for different pollutants including nitrogen dioxide (NO2) and particulate matter less than 10 microns (PM10), the key traffic related pollutants.
5.2.2 Defra assesses and reports annually on compliance with the Limit Values (Table 5.1) to the European Commission. For the purposes of Limit Value assessment and reporting, the UK is divided into 43 zones. The main pollutants of concern with respect to compliance are NO2 and PM10. The Air Quality (Standards) Regulations 2010 transpose into English law the requirements of Directives 2008/50/EC on ambient air quality.
National Legislation
5.2.3 Part IV of the Environment Act (1995) requires the UK Government to produce a national Air Quality Strategy (AQS) which contains standards, objectives and measures for improving ambient air quality.
5.2.4 The ambient air quality standards and objectives are given statutory backing in England through the Air Quality (England) Regulations 2000, the Air Quality (England) (Amendment) Regulations 2002. The AQS objectives for the protection of human health and applicable to this assessment are presented in Table 5.1.
Table 5.1: Air Quality Objectives and EU Limit Values for NO2 and PM10 for the protection of human health
Air Quality Objectives EU Limit Values
Pollutant Concentration Averaging Compliance Concentration Compliance Period Date Date
3 3 NO2 200µg/m 1 Hour mean 31 Dec 2005 200µg/m (18 1 Jan 2010 (not to be exceedances) exceeded more than 18 times per year)
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Air Quality Objectives EU Limit Values
Pollutant Concentration Averaging Compliance Concentration Compliance Period Date Date
40µg/m3 Annual mean 31 Dec 2005 40µg/m3 1 Jan 2010 3 3 PM10 50µg/m 24 Hour 31 Dec 2010 50µg/m (35 1 Jan 2005 mean (not to exceedances) be exceeded more than 35 times per year) 40µg/m3 Annual mean 31 Dec 2004 40µg/m3 1 Jan 2005
5.2.5 The Air Quality Objectives only apply where members of the public are likely to be regularly present for the averaging time of the objective (i.e. where people will be exposed to pollutants).
5.2.6 The AQS objectives and EU Limit Values for the protection of vegetation and ecosystems applicable to this assessment are presented in Table 5.2.
Table 5.2: Air Quality Objectives and EU Limit Values for the protection of vegetation
Air Quality Objectives EU Limit Values
Pollutant Concentration Averaging Compliance Concentration Compliance Period Date Date NOx 30µg/m3 Annual 31 Dec 2000 30µg/m3 19 July 2001 mean
5.2.7 Local authorities have no legal requirement to comply with AQS objectives. They are however required to demonstrate best efforts to work towards achieving AQS objectives.
5.2.8 Under the Local Air Quality Management (LAQM) regime local authorities have a duty to make periodic reviews of local air quality against the AQS objectives. Where a local authority’s review and assessment of local air quality indicates that AQS objectives are not expected to be achieved, local authorities are required to designate an Air Quality Management Area (AQMA). An Air Quality Action Plan (AQAP) must then be formulated, outlining a plan of action to meet AQS objectives in the AQMA.
AQS objectives/EU limit values
5.2.9 Whilst AQS Objectives and EU Limit Values are identical in relation to the concentrations that are applied, they are different and it is important to understand how they are interpreted and therefore assessed. Local authorities are required to demonstrate best efforts to achieve the AQS Objectives whereas the UK government has a mandatory requirement to achieve EU Limit Values.
5.2.10 The air quality assessment considers the impacts on both AQS Objectives (- does the scheme lead to a significant impact on air quality at individual properties) and EU Limit Values (would the scheme impact on Defra’s plans to achieve compliance with the Limit Values).
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Environmental Protection Act 1990
5.2.11 Generally, dust is only a cause of annoyance but when of sufficient scale and frequency it could become a statutory nuisance. The relevant legislation dealing with statutory nuisance is given in Part III of the Environmental Protection Act 1990 (EPA 1990).
National planning policy framework
5.2.12 The NPPF published in 2012 sets out the Government’s planning policies for England and how these are expected to be applied. The NPPF revokes forty-four planning documents including: Planning Policy Statement 23: Planning and Pollution Control. Paragraph124 considers impacts of developments on air quality:
“Planning policies should sustain compliance with and contribute towards EU limit values or national objectives for pollutants, taking into account the presence of Air Quality Management Areas and the cumulative impacts on air quality from individual sites in local areas. Planning decisions should ensure that any new development in Air Quality Management Areas is consistent with the local air quality action plan.”
5.2.13 The NPPF therefore requires:
Consideration of the scheme air quality impacts on the UK’s ability to comply with the Air Quality Directive; and
Consideration of scheme air quality impacts on national objectives for pollutants.
5.2.14 However, the NPPF does not provide guidance on how to come to a judgement on sustaining compliance with the Air Quality Directive.
National Policy Statement for National Networks (NN NPS)
5.2.15 The NPS NN (DfT, 2014) sets out the Government’s policies to deliver the development of Nationally Significant Infrastructure Projects on the national road and rail networks in England. The Secretary of State uses the NPS NN as the primary basis for making decisions on development consent applications for national networks Nationally Significant Infrastructure Projects in England.
5.2.16 Paragraphs 5.11 – 5.13 provide context of where the decision maker should consider substantive weight judgements or whether they should recommend refusal.
5.2.17 Further details with regards to the European and National legislations as outlined above can be found in Appendix C.1 at the end of this chapter.
5.3 Study Area
Local air quality, which relates to pollutants with potential to affect human health and ecosystems at a local level.
Regional emissions, which relates to pollutants dispersing over a larger area, with potential to affect human health, ecosystems or climate change.
5.3.1 The study area for the assessment of local air quality has been defined in line with the guidance contained in DMRB Volume 11, Section 3, Part 1 (HA 207/07) (Highways Agency et al., 2007). The study area comprised of all roads that impact on:
all land within 200m of the centre line of the existing road;
land within 200m of the centre line of the Proposed Scheme; and
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land within 200m of any other ‘affected roads’.
5.3.2 Affected roads were identified by qualifying criteria published in HA207/07 (Highways Agency et al., 2007), based on changes between Do-Minimum (DM) and Do-Something (DS) scenarios, as follows:
Local air quality: - road alignment will change by 5m or more - daily traffic flows will change by 1,000 Annual Average Daily Traffic (AADT) or more - Heavy Duty Vehicle (HDV) flows will change by 200 AADT or more - daily average speed will change by 10kph or more - peak hour speed will change by 20kph or more
Regional emissions: - daily traffic flows will change by 10% AADT or more - Heavy Duty Vehicle flows will change by 10% AADT or more - daily average speed will change by 20kph or more.
5.3.3 Data from the traffic model has been used to define the study area using the above criteria. Figure 5.1 defines the local air quality study area and constraints. The study area covers the Proposed Scheme and also sections of the local road network serving these areas. Details of the traffic data are provided in Appendix C.2.
5.3.4 There were 19 links that met the screening criteria for change of more than 1000 AADT flows for all vehicles and/or 200 AADT flows for HDV for the scheme. These links include the M271 southbound and northbound, sections of the Redbridge roundabout, slip roads onto/off the A33 and the A35. The majority of the affected links trigger due to increase of traffic flow with the Proposed Scheme.
5.4 Baseline Environment
5.4.1 To provide an assessment of the significance of any new development proposal (in terms of air quality), it is necessary to identify and understand the baseline air quality conditions in and around the study area. This provides a reference level against which any potential changes in air quality can be assessed. Since the baseline air quality is predicted to change in the future (mainly because vehicle emissions are changing), the baseline situation is extrapolated forward to the opening year. The DM scenario is the predicted baseline for the opening year. The DS scenario is the same as the DM, but also includes the Proposed Scheme. The baseline year used for the Proposed Scheme is 2015.
5.4.2 To identify the existing air quality conditions, a review of information has been undertaken, including the latest local authority air quality reports, monitoring data and background concentration maps. This section presents the results of the review. The affected roads and air quality constraints including AQMAs are shown in Figure 5.1.
5.4.3 The National Risk Register (2017) probability of a major poor air quality incident occurring in the next five years is 4 (out of 5), with an impact severity of 3 (out of 5).
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Local air quality management
5.4.4 The Proposed Scheme, and the study area, is located within the jurisdiction of Southampton City Council. The baseline assessment includes a brief review and summary of the LAQM reports. Monitoring data has been obtained directly from the local authority where necessary.
5.4.5 The 2016 Southampton Annual Status Report concluded that road transport emissions are the major source of air pollution in Southampton. Southampton City Council has designated 10 AQMAs across the city where the annual mean NO2 concentration exceeds the Air Quality Objective (AQO) of 40µg/m3.
5.4.6 One AQMA (No. 5 Redbridge Road) is located within the scheme boundary. It encompasses Redbridge Road flyover and roundabout, sections of the approaching roads, properties and land along Millbrook Road West. The location of the AQMA is shown in Figure 5.1. It was declared for annual mean NO2 concentrations being at risk of or currently exceeding the AQO.
5.4.7 There is no AQMA declared for PM10 exceedances in Southampton.
Local air quality monitoring
5.4.8 Southampton City Council currently operates diffusion tube monitoring at 68 locations (SCC, 2017a), and 12 sites are within the AQMA No.5 and/or close to the Proposed Scheme. In 2016, seven sites (N101, N104, N116, N124, N130, N134 and N152) exceeded the annual mean NO2 objective. It should be noted that the monitoring locations tend to be in worst-case locations, and may not be representative of locations actually representing public exposure.
5.4.9 Table 5.3 contains the position and bias adjusted concentrations at the 12 sites between 2012 and 2016.
Table 5.3: Local bias adjusted diffusion tube monitoring data
Annual mean NO2 concentration (µg/m3) Site ID Site location Type 2012 2013 2014 2015 2016 N101* Redbridge School AMS Roadside 44.6 42.7 41.7 - - N101* Redbridge School AMS Roadside - - - 44.7 54.3 (fence) N103 485 Millbrook Road Roadside 34.7 32.3 34.9 31.7 33.7 N104 Regent Park Junction Roadside 41.6 41.2 42.3 38.4 40.3 N115 54 Redbridge Road Roadside 43.3 37.5 37.9 36.4 38.4 N116 57 Redbridge Road Roadside 43.2 42.1 41.9 38.1 40.5 N122 151 Paynes Road Roadside 36.3 30.4 32.6 31.5 32.8 N124 305 Millbrook Road Roadside 43.1 39.9 41.1 37.3 40.2 N130 367A Millbrook Road Roadside 47.9 42.2 46.6 44.8 44.9 N133 539 Millbrook Road Roadside 34.5 31.5 32.4 30.7 31.4
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Annual mean NO2 concentration (µg/m3) Site ID Site location Type 2012 2013 2014 2015 2016 N134 Ladbrokes Millbrook road Roadside 39.2 41.2 39.6 37.6 41.2 N152 M271 Roadside 59.7 58.4 56.9 49.1 52.2 N153 Coniston road Roadside 35.5 31.7 37.7 31.2 33.7 * Site relocated in 2015.
5.4.10 Southampton City Council operated two continuous monitors in the AQMA No.5 but both sites were decommissioned in 2013 and 2014. Defra has carried out continuous monitoring at one location on the A33, within their Automatic Urban and Rural Network (AURN), since 2016. The locations of these continuous monitors are shown in Figure 5.1 and the measured data are shown in Table 5.4.
Table 5.4: Local continuous monitoring data
Site ID Site location Annual mean NO2 concentration (µg/m3)
2012 2013 2014 2015 2016 2017
CM2 Redbridge School - 45 Ceased operation (Jan 2014) CM5 Millbrook road 43 41 42 Ceased operation (end of 2014) AURN Southampton A33 - - - - 43 40* Data is provisional
5.4.11 The annual mean NO2 concentrations measured at these continuous monitors exceeded the objective between 2012 – 2016 (although no data was available from 2015). The 3 measured annual mean NO2 at the A33 AURN site is 40µg/m in 2017. The 2017 concentration at the objective limit, it suggests likely exceedance of the AQO especially taken into account the inherent inaccuracy and year to year variation in air quality monitoring.
3 5.4.12 The measured annual mean PM10 at A33 AURN site is 19µg/m in 2017, just under half the objective limit.
Scheme specific diffusion tube monitoring
5.4.13 Highways England undertook a scheme specific diffusion tube monitoring survey at 27 locations for NO2 concentrations over two periods: January – June 2016; and
November 2016 – May 2017.
The details and monitoring results are summarised in Table 5.5.
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Table 5.5: Scheme specific diffusion tube monitoring data
Jan – Jun 2016 Nov 2016 – May 2017 Survey Survey
Bias Bias Site ID X Y Site Type Adjusted Adjusted Short to 2015 Data 2015 Long term Annual Capture Annual adjustment Mean Mean (µg/m3)* (µg/m3) HE_01 437502 113686 Roadside 33.6 67% 0.731 35.4 HE_02 437395 113816 Roadside 30.9 83% 0.792 29.6 HE_03 437917 113481 Roadside 64.5 50% 0.930 57.9 HE_04 439019 112659 Urban 30.6 100% 0.835 33.2 Backgrou nd HE_05 438335 113309 Roadside 45.1 100% 0.835 55.7 HE_06 438437 113331 Roadside 32.5 100% 0.835 37.1 HE_07 438467 113329 Roadside 35.7 100% 0.835 36.5 HE_08 438435 113293 Roadside 37.2 100% 0.835 45.8 HE_09 438622 112993 Roadside 39.1 50% 0.759 38.8 HE_10 438273 113505 Roadside 35.9 33% 0.778 37.3 HE_11 438435 113434 Roadside 33.7 100% 0.835 32.6 HE_12 437323 113859 Roadside 34.1 100% 0.835 32.2 HE_13 437880 113862 Roadside <75% DC 17% 1.077 35.2 HE_17 437968 113410 Roadside 58.5 100% 0.835 53.7 HE_18 438117 113380 Roadside <75% DC 100% 0.835 38.5 HE_19 438893 112876 Roadside 41.5 100% 0.835 40.6 HE_20 438924 112997 Roadside 31.6 100% 0.835 34.2 HE_21 439309 112816 Roadside 65.1 67% 0.723 52.2 HE_22 439741 112748 Roadside <75% DC 17% 0.725 51.1 HE_23 439235 112850 Roadside 39.0 83% 0.861 40.8 HE_24 437818 113549 Roadside 49.7 83% 0.792 49.3 -26 HE_27 437024 113731 Roadside 27.5 83% 0.882 28.7 HE_28 437018 113761 Roadside 26.2 100% 0.835 27.7 HE_29 437018 113836 Roadside 26.2 100% 0.835 27.7 HE_30 436435 113073 Roadside N/A 33% 0.649 38.5 HE_31 436472 113363 Roadside N/A 67% 0.731 31.4
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Jan – Jun 2016 Nov 2016 – May 2017 Survey Survey
Bias Bias Site ID X Y Site Type Adjusted Adjusted Short to 2015 Data 2015 Long term Annual Capture Annual adjustment Mean Mean (µg/m3)* (µg/m3) HE_32 436925 113648 Roadside N/A 67% 0.975 45.3 *DC = Data capture, details are not provided in the M271 Stage 2 report
5.4.14 In the January to June 2016 survey there were 21 sites with good data capture (>75%), 3 with the annual mean NO2 concentration objective of 40µg/m exceeded at seven sites. The highest concentration was measured at Millbrook Road West (Site HE_21) at 65.1µg/m3.
5.4.15 In the November 2016 to May 2017 survey, there were 17 sites with good data capture 3 (>75%), with the annual mean NO2 concentration objective of 40µg/m exceeded at six sites. The highest concentration was measured at A35 Millbrook roundabout (Site HE_03) at 57.9µg/m3.
Defra’s background concentration mapping
5.4.16 Defra maps indicate that background concentrations around the Proposed Scheme are below the respective annual mean AQOs for NO2 and PM10. However, the background concentration for the annual mean NOx is above the objective of NOx for vegetation (30µg/m3). Details of background concentrations are shown in Table 5.6.
Table 5.6: Defra’s background mapping concentrations for assessment years
Averaged Total Background Concentration (Grid square 2015 Base Year (µg/m3) 2019 Opening Year (µg/m3) 436500, 113500 and 437500, 113500)
NOx 37.2 32.3
NO2 24.1 21.6
PM10 16.9 16.1
5.4.17 Background concentrations of NO2 and PM10 are currently well within the AQOs and it is predicted that they should improve over time due to the expected reduction in emissions from all emission sources.
Defra’s air quality plan and pollution climate modelling
5.4.18 Defra produced a Southampton Air Quality Plan (SAQP) (July 2017) (SCC, 2017b) for tackling roadside NO2 concentrations in Southampton Urban Area agglomeration zone (UK0019). The SAQP concluded that local road traffic was the dominant source of the exceedances with the largest contribution from diesel cars, diesel light good vehicles and heavy good vehicles on the motorways.
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5.4.19 Defra undertook air quality modelling for the 2015 reference year for the whole of the UK. Concentration projections across the UK in the years 2017 to 2030 are available from Defra’s UK-AIR Background Maps website (https://uk-air.defra.gov.uk/data/laqm- background-home, accessed 2018)
5.4.20 The 2015 predictions and future projections indicate the roadside annual mean NO2 concentrations along the M271, A33 and A35 within the scheme boundary were in the range of 38.7µg/m3 – 62.5µg/m3 in 2015 and in the range of 33.0µg/m3 – 51.8µg/m3 in 2019, which in both cases exceeds the limit value. Defra’s model results suggest that compliance with the annual mean limit value is unlikely to be achieved by 2019. The Pollution Climate Modelling (PCM) concentrations at links within the scheme boundary are shown in Table 5.7.
5.4.21 One of the actions for Southampton City Council is to introduce a mandated Clean Air Zone in 2019 with enforced emission standards for buses, coaches, heavy good vehicles and taxis in line with the National Clean Air Zone Framework.
Table 5.7: Defra’s PCM annual mean NO2 concentrations
Road Name PCM Link ID 2015 (PCM Model base year) 2019 Projected (µg/m3) (µg/m3) A33 Redbridge 6368 57.7 46.3 Road M271 26062 38.7 33.0 A35 Redbridge 73615 62.5 51.8 Causeway
5.4.22 There are a number of significant planning proposals along the M271 corridor. All of them have the potential to affect the traffic flows along the A33 and thus air quality. According to the SAQP (2017) the proposed scheme is considered to be one of the measures expected to help address pollution sources associated with traffic related to Southampton docks.
Modelled estimates of baseline concentrations at monitoring locations – model verification
5.4.23 The air quality study area is defined by the traffic changes predicted to result from the Proposed Scheme. At the monitoring locations (outlined above), estimates have been made by dispersion modelling of the base year; this is taken to represent the current air quality situation at these locations. Dispersion models use meteorological data to represent the way that emissions from vehicles are transported through the atmosphere.
5.4.24 The base year dispersion modelling indicated a good overall agreement between predicted concentrations and measured concentrations at the monitoring locations. Details of the model verification exercise are provided in Appendix C.3.
5.5 Methodology and Assessment Criteria
Methodology
Construction phase
5.5.1 One of the main concerns regarding air quality impact during construction is the potential impact from fugitive dust. There are no nationally recognised criteria defining levels of dust causing an annoyance. Fugitive dust effects can be controlled under the Statutory
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Nuisance provisions of Part III of the Environmental Protection Act, 1990. Where required, best practice fugitive dust control measures outlined in the Institute of Air Quality Management (IAQM) guidance on the assessment of dust (Holman et al., 2014) have been identified.
5.5.2 Major construction projects can give rise to increased long-term and short-term PM10 concentrations. Potential air quality impacts from the construction phase of the Proposed Scheme are summarised below:
There is the potential for dust nuisance upon human and ecological receptors within 200m of construction sites and haulage routes associated with the Proposed Scheme.
The construction phase could potentially result in an increase in HDV vehicle flows within the study area, and therefore increased pollutant concentrations at receptors, although these would be temporary in nature.
5.5.3 Detailed information on construction works has not been available for this stage. As such, a construction dust assessment has not been undertaken. Construction dust would be assessed at a later stage. Best practice construction dust mitigation measures would be implemented with the Proposed Scheme, reducing any potential impacts to an acceptable level once the construction dust assessment had been completed.
5.5.4 Effects of emissions from construction traffic have been scoped out of this assessment, due to the relatively small number of trips generated by construction traffic (below 200 HDVs) and the anticipated duration of the works.
Operation phase
5.5.5 The assessment identifies potential air quality effects by predicting changes in air quality pollutant concentrations resulting from the combination of background concentrations with the contributions from roads in the study area, including the Proposed Scheme.
5.5.6 This assessment conforms to the standard practice of EIA, whereby a baseline is established, and then the situation with the development in place (DS) is compared with the situation without it (DM). The effect of the Proposed Scheme has been assessed using the DMRB Guidance HA207/07 (Highways Agency et al., 2007) and relevant supplementary IANs (Highways Agency, 2013a, b and c), and LAQM TG (16) (Defra, 2016).
5.5.7 Relevant IANs include:
Interim Advice Note 174/13 (Highway Agency, 2013a), Updated advice for evaluating significant local air quality effects for users of DMRB Volume 11, Section 3, Part 1 ‘Air Quality’.
Interim Advice Note 170/12v3 (Highway Agency, 2013b), Updated air quality advice for the assessment of future NOx and NO2 projections for users of DMRB Volume 11, Section 3, Part 1 ‘Air Quality’.
Interim Advice Note 175/13 (Highway Agency, 2013c), Updated advice on risk assessment related to compliance with the EU Directive on ambient air quality and the production of Scheme Air Quality Action Plans for users of DMRB Volume 11, Section 3, Part 1 ‘Air Quality’.
Interim Advice Note 185/15 (Highway Agency, 2015), Updated traffic, air quality and noise advice on the assessment of link speeds and generation of traffic data into
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‘speed-bands’ for users of DMRB Volume 11, Section 3, Part 1 ‘Air Quality’ and Volume 11, Section 3, Part 7 ‘Noise’.
5.5.8 The DMRB allows for either a ‘detailed’ or ‘simple’ assessment covering local air quality impacts on human health and ecosystem receptors, and regional emissions. For the Proposed Scheme, a detailed assessment has been completed for local air quality, taking into account diurnal changes of traffic flows using the dispersion modelling software, ADMS-Roads (V4.1); and a simple assessment has been completed for regional emissions.
Assessment scenarios
5.5.9 The assessment method is to quantify the ambient pollution concentrations for a number of road traffic scenarios. The following scenarios were assessed:
baseline year 2015;
opening year 2019 without the Proposed Scheme or DM;
opening year 2019 with Proposed Scheme or DS.
5.5.10 In addition to these, future scenarios 15 years after opening are considered for regional emissions:
design year 2036 DM;
design year 2036 DS.
5.5.11 The assessment covers different geographic scales, as follows:
Local air quality, focusing only on the headline pollutants NOx/NO2 and PM10 for sensitive human receptors and NOx for designated habitats.
Regional air quality, focusing on NOx, PM10 and carbon dioxide (CO2) emissions because of their effect on climate.
Traffic data
5.5.12 Traffic data for the modelling scenarios were derived from the traffic models produced by Systra on behalf of Highways England. The base year air quality modelling uses traffic data, pollution measurements and meteorological measurements from 2015.
5.5.13 Traffic data that represent the average conditions occurring in specific time periods were provided. These specific periods are described in Table 5.8 below.
Table 5.8: Annual Average Weekday time periods used in the assessment
Traffic Period Time Period
AADT 00:00 – 23:00 Annual Average Weekday Traffic (AAWT) 00:00 – 23:00 AAWT AM peak (AM) 07:00 – 10:00 AAWT inter-peak (IP) 10:00 – 16:00 AAWT PM peak (PM) 16:00 – 19:00 AAWT off peak (OP) 19:00 – 07:00
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5.5.14 For each time period, the following traffic data parameters were provided:
total traffic flow, defined as vehicles/hour;
percentage HDV;
vehicle speed, in kph;
vehicle speed band, in kph; and
vehicle speed band category.
Local air quality modelling methodology
5.5.15 An assessment of potential air quality effects from the Proposed Scheme has been undertaken using the ADMS-Roads Air Dispersion Modelling Software, developed by Cambridge Environmental Research Consultants Ltd (CERC). This software is an atmospheric modelling system focusing on road traffic as a source of pollutant emissions. It is a recognised tool for carrying out air quality impact assessments and has been comprehensively validated both by the manufacturer and independently.
5.5.16 This software is used both by regulatory authorities and commercial organisations to assist in decision making related to air quality and traffic management, urban planning and public health in many countries around the world. Version 4.1 was used for this assessment.
5.5.17 It should be noted that dispersion models provide an estimate of concentrations arising from input emissions and historical meteorological data. The estimates produced, whilst appropriately representing the complex factors involved in atmospheric dispersion, are subject to uncertainty. Whilst the predictions provided by the models should not be regarded as definitive statements of concentrations arising in the future, they are the most reasonable, robust and representative estimates available. The estimates are composed of calculations made at a single point on each residential property.
Meteorological data
5.5.18 The effect of meteorological conditions on dispersion is given a complex treatment within the model. The most significant factors in the dispersion of emitted pollutants are wind speed and direction. The meteorological data site considered to be most representative of conditions across the study area was Southampton Airport, which was the most reliable meteorological site close to the study area.
Vehicle emissions
5.5.19 The modelling system takes into account the emissions produced by Light Duty Vehicles (LDV), less than 3.5 tonnes; and HDV, greater than 3.5 tonnes, travelling at a certain speed along a section of road over an average hour. A speed pivot adjustment factor is calculated by dividing the observed speed in the base year by the modelled speed in the base year. From this a speed category is assigned to each modelled road link with the emission rate for each speed category predefined (Highway England, 2017). Speed banded emission rates for LDVs and HDVs were taken from Highways England speed band emission factors IAN 185/13 Version 3 (Nov, 2017). The traffic data for each time period is then used to calculate the emissions for each road link. The use of the time period data ensures that the diurnal emissions profile is consistent with that predicted by the traffic model. Emission for the road links from the HDV and LDV components were then entered into the dispersion model.
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Sensitive receptors
5.5.20 Section 3.13 of HA 207/07 Air Quality (Highways Agency, 2007) identifies two types of receptors which should be considered. These are as follows:
residential properties and other sensitive receptors (such as schools, nursing homes, hospitals etc.); and
ecological sites designated at international, European or national level that may be sensitive to nitrogen (N) deposition (i.e. SSSI, SPAs, SACs and Ramsar sites).
5.5.21 Building usage has been determined using the Ordnance Survey Address Base Plus dataset, and receptor calculations have been made at the worst case building façade.
5.5.22 A total of 766 receptors have been identified within the study area, of which 110 have been included in the dispersion modelling for the detailed assessment using professional judgement for being:
close to the affected roads;
representative of the maximum impacts of the Proposed Scheme in that region; and
at risk of exceeding the annual mean NO2 AQO (shown as dots on Figure 5.2).
Designated habitat sites
5.5.23 There are five designated sites within 200m of the scheme boundary. Lower Test Valley SSSI, the Solent Maritime SAC, the Solent Maritime Ramsar lies to the north west, the Eling and Bury Marshes SSSI to the south west and the Solent and Southampton Water SPA are also included in the study area. These areas are sensitive to nitrogen deposition and to ambient concentrations of oxides of nitrogen (NOx), both of which could be affected by changes in road traffic emissions as a consequence of the Proposed Scheme. The details of the identified designated sites are shown in Table 5.9.
Table 5.9: Designated sites within the study area
Site Name Designation Key habitats within 200m of Critical scheme* Load* (kg N/ha/yr) Solent and Ramsar Same as Solent Maritime SAC and Southampton Southampton Water Water SPA combined Eling and Bury SSSI Pioneer, low-mid, mid-upper 20-30 Marshes saltmarshes Shifting coastal dunes 10-20 Coastal stable dune grasslands - 8-10 acid type Coastal stable dune grasslands - 10-15 calcareous type Meso- and eutrophic Quercus 15-20 woodland Acid grassland N/A Unmanaged Broadleaf/Coniferous N/A
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Site Name Designation Key habitats within 200m of Critical scheme* Load* (kg N/ha/yr) Woodland Calcareous grassland (using base N/A cation) Solent Maritime SAC Coastal stable dune grasslands 8-15 Shifting coastal dunes 10-20 Pioneer, low-mid, mid-upper 20-30 saltmarshes Acid grassland N/A Solent and SPA Pioneer, low-mid, mid-upper 20-30 Southampton Water saltmarshes Shifting coastal dunes 10-20 Coastal stable dune grasslands - 8-10 acid type Coastal stable dune grasslands - 10-15 calcareous type Low and medium altitude hay 20-30 meadows Acid grassland N/A Calcareous grassland (using base N/A cation) Lower Test Valley SSSI Rich fens 15-30 Low and medium altitude hay 20-30 meadows Acid grassland N/A Calcareous grassland (using base N/A cation) * Key habitats and critical loads are provided by APIS (2017) and had been confirmed with the scheme ecologist.
Background concentrations
5.5.24 ‘Background’ air quality is a concept used in assessments of the effects of particular emissions sources (i.e. the modelled road sources). The background accounts for the non- modelled ambient concentrations, which can be from both background and other local emission sources. The road derived pollution is added to the background pollution concentration to derive the total ambient concentration.
5.5.25 Defra provides empirically-derived national background maps, providing estimates of background pollutant concentrations on a 1km x 1km grid square resolution; the data being obtained from Defra (2015). The data for NOx, NO2 and PM10 have recently been updated, with a base year of 2015 from which future years can be projected.
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5.5.26 The ‘in-grid square’ contribution from motorway, trunk ‘A’ road and primary ‘A’ road sectors have been removed from the background annual mean NOx and PM10 concentration estimates. Background annual mean NO2 estimates have been corrected using the Defra’s Background NO2 Calculator (Version 6.0). This process has been undertaken to avoid double counting of road traffic emissions included in the dispersion model. Where predicted concentrations for specific receptors are presented, the sector- removed background concentrations used are also presented.
5.5.27 The model is used to predict the road traffic contributions to NOx and PM10 concentrations at specified receptors. Adjustments are applied to the model predictions based on a comparison against measured air quality concentrations, in a process known as model verification and adjustment. The modelled road contributions of NOx, NO2 and PM10 were adjusted to correct them against measured road components derived from monitoring data, following an adjustment method set out in LAQM TG (16) (Defra, 2016). NOx and NO2 concentrations were calculated using the NOx from NO2 calculator (Version 6.1) available on the Defra website. The calculator was issued in conjunction with the LAQM TG (16) (Defra, 2016) guidance. A total environmental concentration is then produced by addition of the adjusted road contribution to the background concentration. Further detail on the verification process is provided in Appendix C.3.
5.5.28 For the opening year predictions, a further adjustment step is undertaken to account for the observed trends in the under-prediction of ambient roadside NOx and NO2 using Highways England’s LTTE6 NOx and NO2 projections. The latest factors have been used, which have been reviewed by Highways England who concluded that no update is required. The application of these factors is likely to result in an over estimation of concentrations and is conservative. Further explanation and justification for this approach can be found in Appendix C.3
5.5.29 This method is not applied to PM10 predictions, and the results based on the LAQM TG (16) (Defra, 2016) method are the final predicted concentrations throughout the assessment.
Regional emissions methodology
5.5.30 For the regional emissions assessment, traffic data have been screened using the regional criteria to identify an appropriate affected road network.
5.5.31 Emissions for LDVs and HDVs have been taken from Highways England speed band emission factors for use with IAN185/13 Calculators (Version 3) (November 2017). Annual average daily flow traffic data has been used to calculate the emission rate for each road link. These emissions are vehicle-weighted averaged emissions for the national vehicle fleet. Emissions factors have been defined by year to represent the predicted vehicle fleet, and the range of vehicle types and EURO emissions standards present across the fleet.
Assessment of Magnitude and Significance
5.5.32 The model results have been used to assess whether there are any significant effects as a consequence of the Proposed Scheme.
5.5.33 Highways England’s approach to evaluating significant air quality effects is set out in two IANs (IAN 174/13 Highways Agency (2013a) and IAN 175/13 (Highways Agency (2013c)). These IANs are intended to reflect the change in national planning policy associated with the NPPF.
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5.5.34 Highways England’s approach to air quality assessment identifies and assesses sensitive receptors near roads where air quality might be affected. Consequently, areas where exceedance to national AQOs might be expected are considered, including AQMAs. The model results have been used to identify those receptors in exceedance of AQOs in either the DM or DS scenario. These are the only receptors that have been considered in the judgement of significance. The change in predicted concentration has then been calculated as the difference between DS and DM model results at these receptors.
5.5.35 Where the difference in concentrations has been calculated as less than 1% of the AQO (e.g. less than 0.4μg/m³ for annual average NO2) then imperceptible change at these receptors has been judged. These can be scoped out of the judgement on significance.
5.5.36 Highways England has developed a framework to provide guidance on the number of receptors for each of the magnitude of change categories that might result in a significant effect. These are guideline values only, and are to be used to inform professional judgement on significant effects of a scheme. These guideline bands are based on Highways England’s considered opinion and are intended to help provide consistency across all Highways England schemes. The significance categories and guideline property numbers are summarised in Table 5.10.
Table 5.10: Guideline to number of properties constituting a significant effect
Magnitude of Number of receptors with:
Change in NO2 (μg/m³) Worsening of AQO already above Improvement of an AQO already objective or creation of a new above objective or the removal exceedance of an existing exceedance Large (>4) 1 to 10 1 to 10 Medium (>2) 10 to 30 10 to 30 Small (>0.4) 30 to 60 30 to 60
5.5.37 Where values are equal to or less than the lower limit of a given category it is considered that a scheme is likely to not have a ‘significant’ effect. Where values are equal to or greater than the upper limit of the range for a given category it is considered that the potential impact of a route option would be likely to cause a ‘significant’ effect. Where values lie between the guideline ranges for a given category, further consideration based on a balanced judgement of the overall impacts across the whole of a study area should be undertaken, including consideration of both worsening and improvement.
5.5.38 Greater significance is attributed to magnitudes of change (the higher above the air quality thresholds the prediction is) and to the predicted exceedances of short-term air quality rather than long-term exceedances. To assist this judgement, consideration should be given (but not limited) to the following:
5.5.39 Scheme effects are more likely to be significant where:
there are no/few receptors with any improvements;
PM10 annual averages are affected by small, medium or large deteriorations
short-term exceedances may be caused or worsened by a scheme for either NO2 or PM10.
5.5.40 Scheme effects are more likely to be ‘significant ‘where:
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there are receptors with small, medium or large improvements
PM10 annual averages are not affected by small, medium or large deteriorations
short-term exceedances are not caused or worsened by the scheme for either NO2 or PM10.
5.5.41 The establishment of overall air quality significance for a scheme should also consider:
whether it detracts or supports measures set out in relevant local authority air quality action plans;
if a scheme represents a low or high compliance risk with the EU directive on air quality;
if any designated site(s) are affected; and
if there is any available potential effective mitigation.
5.5.42 The EU Directive on Ambient Air Quality and Clean Air for Europe (2008/50/EC) sets limit values for a range of pollutants. The purpose of the Directive is to protect human health, and the environment as a whole. Defra reports annually (on behalf of the UK government) on the status of air quality to the European Commission. Highways England’s compliance risk assessment test (IAN 175/13 (Highways Agency (2013a)) has been developed to enable decision makers to judge a scheme’s likelihood of non-compliance with the EU Directive. The compliance risk assessment test also informs the air quality significance test. The compliance risk flow chart illustrating how the assessment has been undertaken is provided in Figure 5.3.
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Figure 5.3: Compliance risk flow chart
5.6 Assessment Assumptions and Limitations
5.6.1 Traffic data assumptions provided by Jacobs’ traffic team include the following:
Speed pivoting – The traffic model coverage is small, and also as the traffic model data was taken from data held by a third party, the traffic team were unable to access the count data use in calibration. Therefore, a cross model calibration exercise was undertaken for the same junction between Paramics (a previously calibrated and WebTAG compliant model) and Saturn. The speeds within both models were broadly comparable, indicating that the speeds used to underpin the air quality modelling are appropriate.
Annual Average Daily Traffic conversion factors – these have been supplied by an HE Transport Consultant, Systra. However, no factor was provided for a 4-hour period overnight. Therefore, the traffic team derived a factor based on the trends of the provided AADT factors.
5.6.2 Traffic flow data was obtained from the SRTM from Systra. When requesting expansion factors to calculate 18 and 24 hours AAWT figures, Systra advised that separate factors for HDV’s were not readily available and that the global (all vehicles all routes) factors are
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generally used. As no further supporting data was available, the expansion factors for HDV’s are assumed to be equal to the global factors.
5.6.3 The following factors that could affect concentrations have not been taken into account in the assessment, as none of them are present within the study area:
The effect of cuttings/embankments/barriers/vegetation.
Changes in local terrain/topography as LAQM TG (16) (Defra, 2016) only recommends inclusion of terrain data for road schemes if the gradient change for any road is greater 10% (Defra, 2016, Paragraph 7.436).
5.7 Potential Effects
Construction Effects
5.7.1 Construction activities associated with the Proposed Scheme could have an impact on local air quality. These could be broadly classified into exhaust emissions from site equipment and vehicles, and fugitive dust emissions from site activities. Exposure to poor air quality could cause several health effects, both physical and mental. These include respiratory health issues (such as asthma) and cardiovascular health problems (e.g. health disease).
5.7.2 The operation of site equipment, vehicles and machinery would result in the emissions of exhaust gases into the atmosphere. However, such emissions would be unlikely to be significant, particularly in comparison to levels of similar emissions from vehicle movements along the local road network. Furthermore, impacts could be mitigated by standard measures including the use of equipment meeting recent emission control standards and operation of well-maintained equipment. These measures will be included in the Dust Management Plan as outlined in the outline Environmental Management Plan (EMP) (Jacobs, 2018b). As such the air quality impacts of site equipment during construction, including carbon emissions and health impacts that stem from air quality, have been scoped out of the EIA.
5.7.3 Construction traffic information is currently unavailable. However, it is anticipated that the level of traffic associated with the construction would be unlikely to meet the ‘affected road’ screening criteria and therefore construction impacts relating to exhaust emissions have been scoped out of the assessment.
5.7.4 There is a potential for some construction activities, if not properly controlled to generate dust. This could lead to deterioration in air quality due to dust and PM10 emissions (potentially affecting human health) around the construction site and access routes.
5.7.5 Fugitive dust emissions would be expected to be variable in nature and would depend upon the type and extent of activity, soil type and moisture, road surface conditions and weather conditions. Periods of dry weather combined with higher wind speeds would have the potential to generate more dust.
5.7.6 Fugitive dust arising from construction activities generally has a particle size greater than the PM10 fraction. However, construction activities could contribute to local PM10 concentrations. Consequently, unmitigated dust impacts could harm human and ecological health and cause nuisance. Appropriate dust control measures can be highly effective for controlling emissions from potential dust generating activities and adverse effects can be greatly reduced or eliminated.
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5.7.7 Overall, with the proper implementation of appropriate mitigation measures, it is considered that potential air quality, dust and health impacts during construction would be likely to be not significant.
Operational Effects
Human receptors
5.7.8 This section presents the effects of the operation of the Proposed Scheme on local air quality along affected roads in the study area. The results presented are based on the values predicted using the Gap Analysis methodology, taking into account long term trends (LTTE6) for NOx and NO2. This approach is considered to be more conservative and representative of opening year impacts than the LAQM TG (16) (Defra, 2016) methodology.
5.7.9 Overall, based on the 110 receptors modelled, it is predicted that there would be a small reduction in annual mean NO2 concentration at two receptors (i.e. a reduction in concentration of between 0.4µg/m3 and 2µg/m3) and an imperceptible reduction in annual 3 mean NO2 concentration at 12 receptors (i.e. less than 0.4µg/m reduction in concentration). These receptors are located along Old Redbridge Road, where there is a predicted reduction in vehicle flow with the scheme.
5.7.10 There is one exceedance of the NO2 annual mean AQO and no exceedances of the PM10 annual mean AQO predicted in the 2019 DM and DS scenarios. It is not predicted that the 24-hour PM10 mean objective would be exceeded at any of the receptors modelled. Annual mean PM10 predictions are not discussed further.
5.7.11 Overall, based on the 110 receptors modelled, it is predicted that there would be a small increase in annual mean NO2 concentration at two receptors (i.e. an increase in concentration of between 0.4µg/m3 and 2µg/m3) and an imperceptible reduction in annual 3 mean NO2 concentration at 90 receptors (i.e. less than 0.4µg/m reduction in concentration). The maximum increase in annual mean NO2 concentration would be observed at Receptor_37, which is located closest to the entry slip road onto the M271, with a predicted increase of 0.5µg/m3. This location is within the AQMA and the annual mean NO2 concentration is predicted to exceed the relevant AQO with and without scheme.
5.7.12 It is worth noting that in 2015 (i.e. the base year) the diffusion tubes closest to Receptor_37 and N153, which is located a similar distance from the kerbside measured 3 an annual mean NO2 concentration of 31.2 µg/m . Therefore, the diffusion tube location N153 is considered to be representative of the concentrations predicted at Receptor_37. This indicates that the predicted concentration at Receptor_37 is likely to be an overestimate, and the actual concentration is likely to be closer to the concentrations measured at N153, i.e. less than 40 µg/m3 and compliant with the AQO.
5.7.13 The annual mean NO2 concentrations at the receptors along the northbound M271, at Coniston Road, are predicted to increase with the scheme by 0.3 – 0. 5µg/m3. The increase in concentrations are due to the emissions from the increased vehicle flows on M271 with the scheme.
5.7.14 The annual mean NO2 concentrations at the receptors to the north east of the Redbridge roundabout, apartment blocks at Cuckmere Lane, were predicted to increase by 0.1 – 0.2µg/m3 with the scheme. These increases in concentrations are due to the emissions
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from the increased vehicle flows and the new slip road being brought closer to these receptors.
5.7.15 The annual mean NO2 concentrations at the receptors along Old Redbridge Road, to the south of the A33 on slip are predicted to increase with the scheme, by a maximum of 0.1µg/m3. The increases in concentrations would be due to the emissions from increased vehicle flows on the slip road.
5.7.16 The annual mean NO2 concentrations are predicted to remain unchanged in 2019 at four receptors with the scheme, increase at 92 receptors and decrease at 14 receptors. On balance the Proposed Scheme leads to an increase in concentrations in the study area. Concentrations in future years (i.e. 2019) are typically expected to be lower than in the base year (i.e. 2015), due to improving vehicle emissions of the road vehicle fleet in general. However, this could be eroded by increases in road traffic in future years.
5.7.17 The maximum modelled annual mean NO2 concentration is at Receptor_37 (Coniston Road) at 42.2µg/m3 in the DS scenario (see Table 5.11). The maximum modelled annual 3 mean PM10 concentration is at Receptor_5 (Cuckmere Lane) at 22.7µg/m in the DM scenario. Table 5.11 below depicts the concentrations for all receptors that are within 10% 3 of the AQO for NO2 (i.e. 36µg/m or higher) in either the DM or DS, only Receptor_37 exceeds the AQO. However, as discussed previously, the concentrations at Receptor_37 are likely to be overestimated with the actual concentrations, similar to those measured at N153, and compliant with the AQO. These sites have the highest concentrations within the study area and all have a small magnitude of change increase in NO2 concentrations. The highest increase in concentration for NO2 is predicted at Receptor_37, followed by Receptor_1 and Receptor_35, these are also shown in Table 5.11. All receptors for NO2 are predicted to have an imperceptible or small change in concentrations.
Table 5.11: Highest 2019 annual mean NO2 for DM and DS scenarios
3 Modelled X Y Annual mean NO2 concentration (µg/m ) receptor (to 1 decimal place) name 2015 Base 2019 DM 2019 DS Change Magnitude of Change Receptor_1 437428 113785 37.3 37.9 38.2 0.4 Imperceptible Receptor_5 437488 113759 37.2 37.5 37.7 0.2 Imperceptible Receptor_15 437405 113826 37.2 38.0 38.1 0.1 Imperceptible Receptor_19 437405 113847 36.9 37.7 37.7 0.1 Imperceptible Receptor_35 437340 113882 37.1 37.9 38.4 0.4 Small adverse Receptor_36 437309 113857 35.7 36.3 36.6 0.3 Imperceptible Receptor_37 437344 113870 40.5 41.7 42.2 0.5 Small adverse Receptor_42 437128 113689 35.9 37.5 37.7 0.1 Imperceptible Receptor_45 437474 113690 36.8 37.2 36.6 -0.6 Small beneficial
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3 5.7.18 Concentrations for all receptors for PM10 are all predicted to be less than 23 µg/m in both the DM and DS, which is significantly lower than the PM10 annual average AQO of 40µg/m3.
5.7.19 Annual mean NO2 and PM10 predictions for all representative receptors included in the assessment are presented in Appendix C.4
5.7.20 Exceedances of the NO2 1-hour mean would be unlikely to occur where the annual mean prediction is expected to be below 60µg/m3.
5.7.21 Using the formula provided by LAQM TG (16) Paragraph 7.92, the maximum number of 24-hour mean exceedances of the PM10 is 8 times a year for both DM and DS scenarios, below the objective of 35 times a year.
5.7.22 Based on Highways England advice on the guidelines for the consideration of significant effects (IAN 174/13 Highways Agency (2013a)), the Proposed Scheme would be unlikely to have a significant effect (based on the guideline of 30) on local air quality or health impacts that stem from poor air quality, as there would be only one exceedance of the annual mean NO2 AQO. As discussed this one exceedance is likely to be an overestimate with the actual concentration likely to be less that the AQO based on the measured concentration at a nearby representative diffusion tube, N153. This judgement of significance is based on the Gap Analysis using LTTE6 for NOx and NO2. The Gap Analysis method is not relevant to PM10 concentrations.
Compliance risk assessment
5.7.23 The Proposed Scheme study area contains three roads forming part of Defra’s assessment for the European Commission on the status of air quality in the UK. The Compliance Risk Road Network comprises the affected road network study area and is presented in Figure 5.4.
5.7.24 The modelling used for the local air quality assessment has been combined with Defra’s PCM model dataset to determine the risk of whether the Proposed Scheme would affect the UK's ability to comply with the European Air Quality Directive.
5.7.25 The values reported by Defra based on the PCM model have all been found to be above the EU limit values, except for the M271. Table 5.12 defines considerations for compliance risk. The compliance risk assessment has identified that the Proposed Scheme would have a low risk to neutral of being non-compliant with the EU directive on ambient air quality. Details of Compliance risk assessment results are presented in Appendix C.5.
Table 5.12: Compliance risk assessment summary
IAN 175/13 Compliance Risk Link ID Link ID IAN 175/13 Compliance Link ID Flow Chart 73615 6368 Risk Flow Chart 26062 For each road in the Yes Yes For each road in the No Compliance Risk Road Compliance Risk Road Network, is the PCM model Network, is the PCM concentration > 40µg/m3 in model concentration > the opening year? 40µg/m3 in the opening year?
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IAN 175/13 Compliance Risk Link ID Link ID IAN 175/13 Compliance Link ID Flow Chart 73615 6368 Risk Flow Chart 26062 Does the Scheme increase No Yes Does the Scheme Yes concentrations on any of increase concentrations these roads? on any of these roads? For each road is the level of No No Based on changes in No change > 1% of the AQ AQ at the nearest threshold for the receptor does the corresponding nearest Scheme cause EU LV to receptors? be exceeded? Compliance Risk Low Neutral Compliance Risk Low Risk Risk
Designated sites (ecosystems)
5.7.26 The results of the ecosystems modelling are presented Table 5.13. The results show that there are no exceedances of the annual mean NOx AQO predicted at the modelled locations with and without Proposed Scheme in the opening year. This exceedance is due to the background concentration of 32.3µg/m3, which alone exceeds the AQO of 30µg/m3. However, the changes would be less than 0.4 µg/m3 magnitude in terms of change. Therefore, the effects would be imperceptible and unlikely to be significant in according to the IAN 174/13 (Highways Agency, 2013a). Details of ecological results are presented in Appendix C.6.
Table 5.13: 2019 annual mean NOx results for DM and DS scenarios
3 Receptor Annual mean NOx concentration (µg/m )
2019 DM 2019 DS Absolute change Magnitude of Change (DS-DM) Eco_0m 46.5 46.6 0.13 Imperceptible Eco_10m 46.7 46.8 0.12 Imperceptible Eco_20m 46.1 46.2 0.11 Imperceptible Eco_30m 45.0 45.1 0.10 Imperceptible
Regional emissions
5.7.27 Regional emissions of NOx, PM10 and CO2 have been calculated for opening year 2019 and 2036, and the results are shown in Table 5.14 and Table 5.15.
Table 5.14: 2019 Annual NOx, PM10 and CO2 emissions for DM and DS scenarios
Pollutant Annual regional emission in tonnes (tonne per year)
2019 DM 2019 DS Absolute change % Change (DS-DM) (DS-DM)
NOx 1.8 1.5 -0.3 -19%
PM10 0.5 0.5 0.004 1%
CO2 831.8 620.0 -211.8 -25%
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5.7.28 The results for the opening year 2019 indicate a decrease in NOx emissions of 0.3 tonnes/year; a reduction of 19% with the Proposed Scheme in place (compared to the DM scenario). PM10 emissions have been predicted to increase by just 1% compared with the DM scenario. CO2 emissions are predicted to decrease by 211.8 tonnes/year, which is a decrease of 25% compared to the DM scenario.
Table 5.15: 2036 Annual NOx, PM10 and CO2 emissions for DM and DS scenarios
Pollutant Annual regional emission in tonnes (tonne per year)
2036 DM 2036 DS Absolute change % Change (DS-DM) (DS-DM)
NOx 1.2 1.0 -0.2 -18%
PM10 0.5 0.4 -0.09 -17%
CO2 1247.7 1021.8 -225.9 -18%
5.7.29 The results for the design year 2036 indicate a reduction in NOx emissions of 0.2 tonnes/year; a reduction of 18% with the Proposed Scheme in place (compared to the DM scenario). PM10 emissions are predicted to reduce by 0.09 tonnes/year; a reduction of 17% compared with the DM scenario. CO2 emissions are predicted to reduce by 226 tonnes/year, which is a reduction of 18% when compared to the DM scenario.
5.8 Design, Mitigation and Enhancement Measures
5.8.1 The results of the air quality assessment have indicated that no further mitigation measures are required in addition to tertiary mitigation (i.e. implementation of Dust Management Plan) mentioned in Section 5.7.2.
5.9 Residual Effects
5.9.1 Overall there would be no significant residual effects on air quality or health effects in relation to air quality. See Chapter 12 ‘People and Communities’ for further health impacts. Risk of major poor air quality incident would also not be exacerbated by Proposed Scheme.
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6. Cultural Heritage
6.1.1 Despite the presence of Medium to High value heritage assets (e.g. Redbridge Bridge and The Chestnuts listed buildings and former Southampton and Salisbury Canal) within the study area, no expansion beyond the current highway boundary has been proposed. The proposed works would also have limited effect on the current setting of the heritage assets. The potential for an adverse impact of the Proposed Scheme on the cultural heritage assets and their setting has been identified as Negligible to Slight overall. This would have a combined potential for a Neutral to Slight Adverse impact to the setting of the heritage owing to the damage and disruption to the setting of historic buildings and landscapes through visual and noise intrusion. Implementation of considerate contractor practices (e.g. screening of intrusive elements) to reduce the impact of site work are recommended to further reduce impacts to cultural heritage assets.
6.1.2 There is the further potential for a negligible to slight beneficial effect during operation to the setting of the heritage assets through the potential decrease in congestion and improved pedestrian infrastructure. This environmental topic has therefore been ‘Scoped Out’ of this report.
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7. Landscape and Visual 7.1 Introduction
7.1.1 The purpose of this chapter is to identify the potential impacts on landscape and visual amenity associated with the Proposed Scheme at M271/A35 Redbridge Roundabout.
7.1.2 It is unlikely that the Proposed Scheme would cause any significant landscape and visual effects, due to the existing presence of the M271, Redbridge Roundabout, the A33 and the A35, with their signs and associated traffic. Impacts on road users and people at places of work have been scoped out from further assessment. This is because these receptors are considered to be of low sensitivity, and visual effects are likely to be insignificant during construction and operation given the surrounding visual context of highway infrastructure.
7.1.3 This section provides an assessment of the effects on the following key landscape and visual receptors:
townscape, including existing vegetation and landform;
users of public footpath, footways and cycle route;
residents of residential properties;
people using public facilities and open spaces; and
people using amenity space.
7.1.4 The scope of this assessment is based on professional judgement.
7.2 Legislative and Policy Framework
Relevant Planning Policy
7.2.1 Planning policies and landscape designations of relevance to the Proposed Scheme are set out below. These have been taken into consideration, for example in terms of assessing the value of receptors and identifying mitigation measures.
7.2.2 The European Landscape Convention (Council of Europe, Florence, 2000) defines ‘Landscape’ as “an area, as perceived by people, whose character is the result of the action and interaction of natural and/or human factors”. It also recognises that all landscapes are potentially important, irrespective of location or condition and should be considered in any assessment of effects. It states that “the landscape is an important part of the quality of life for people everywhere: in urban areas and in the countryside, in degraded areas as well as areas of high quality, in areas recognised as being of outstanding beauty as well as every day areas”.
7.2.3 ‘Townscape’ is presented in Guidelines for Landscape and Visual Impact Assessment (GLVIA) 3rd Edition (Landscape Institute and Institute of Environmental Management and Assessment, 2013) as “areas where buildings and related infrastructure are the dominant components”.
7.2.4 The National Policy Statement for National Networks (NPS NN) (DfT, 2014) provides landscape guidance for development of the strategic road network. Paragraph 5.160 states that “Adverse landscape and visual effects may be minimised through the appropriate siting of infrastructure, design (including choice of materials) and landscaping
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schemes, depending on the size and type of proposed project. Materials and designs for infrastructure should always be given careful consideration”.
7.2.5 The National Planning Policy Framework (NPPF) (DCLG, 2012) recognises the landscape as an important part of sustainable development and in particular its environmental role as a contributing factor in understanding the natural, built and historic environment. The Policies of relevance to this topic within the NPPF) are listed below:
Chapter 7: Requiring Good Design – addresses the connections between people and places and the integration of new development into the natural, built and historic environment. New developments should “establish a strong sense of place, using streetscapes and buildings to create attractive and comfortable places to live, work and visit”. The potential of the site should be optimised and green and other public space incorporated as part of developments, that are required to be “visually attractive as a result of good architecture and appropriate landscaping”.
Chapter 8: Promoting Healthy Communities – concerns high quality open spaces, local green space and land of recreational usage. New development should contain a “clear and legible pedestrian routes, and high quality public space, which encourage the active and continual use of public areas”.
Chapter 11: Conserving and Enhancing the Natural Environment – covers the intention to prevent “both new and existing development from contributing to or being put at unacceptable risk from, or being adversely affected by unacceptable levels of soil, air, water or noise pollution or land instability”.
7.2.6 The Local Plan Review, first adopted in March 2006, provides the main policy context for the city of Southampton. Parts of the Local Plan Review were replaced or changed by policies in the adopted Core Strategy. A revised version of the Local Plan Review was produced in 2015 (SCC, 2015b) to show the updated policies including the following relevant ‘saved’ policies that remain in operation:
SDP 6 – Urban Design Principles. This requires all new developments to be accompanied by a design statement which includes commentary on seven key design principles, including: urban form and public space; massing, scale and appearance; and landscape and biodiversity.
SDP 7 – Context. This document states that any development which would cause material harm to character and/or appearance of an area will not be permitted. It notes that “context is about understanding the uses, visual characteristics and the patterns of local life of an area”.
SDP 12 - Landscape and biodiversity. This policy requires new development proposals to include a landscape/habitat creation and management plan with suitable protection for all retained trees and habitats. Particular attention needs to be paid to enhancing the environment along road corridors and at the gateways to the city centre.
7.2.7 Southampton City Council’s Adopted Core Strategy (Amended March 2015) describes at Section 3.2 its spatial vision for what the city will look and feel like in 2026 as “an environmentally sustainable city which protects and enhances the natural environment. The green grid will be extended and enhanced to promote greater biodiversity, to improve the physical connections into and between open spaces for wildlife and residents. Improved open spaces and pedestrian and cycle links will encourage increased physical activity, improved health and an improved quality of life”.
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7.2.8 The vision will be delivered in the following Strategic Objectives which are intended to create strong and distinctive neighbourhoods making Southampton a good place to live:
S7: Create excellence in design quality through well designed and contemporary public spaces that are safe, accessible and create a sense of place.
S12: Create accessible high quality parks and open spaces that contribute towards the city’s network of open spaces and promote participation in sport and active recreation.
S15: Create a high quality physical environment and public realm for a better city for people to live, work and play.
7.2.9 The following Core Strategy policies are of relevance:
Policy CS 13 – Fundamentals of Design. This policy seeks to encourage robust, analysis-based and context-driven innovative design solutions that pay due regard to Southampton’s architecture, landscape, heritage and archaeology, public realm and open space, accessibility, and urban form and scale. With respect to landscape, developments should contribute to the ‘greening of the city’ incorporating landscape qualities, Green Infrastructure and Biodiversity. Development should impact positively on health, safety and amenity of the city and its citizens, including incorporating appropriate mitigation measures.
Policy CS 21 – Protecting and Enhancing Open Space. This policy seeks to configure open spaces in order to achieve wider community benefits such as improving the quality of open space.
7.2.10 Redbridge Roundabout forms part of the city’s network of open spaces and is classed as Amenity Green Space in Southampton’s Green Space Strategy. The Strategy recognises the contribution that well managed parks and open spaces make to the sense of place and quality of life. It notes, “Busy green spaces are safer spaces”.
7.2.11 Consultation was undertaken on landscape matters with Southampton City Council in October 2017. It has been requested that ‘any trees to be lost shall be replaced on a favourable basis (a two for one basis unless circumstances dictate otherwise and agreed in advance)’.
7.3 Study Area
7.3.1 The study area for this Landscape and Visual Impact Assessment (LVIA) is based on the extent of the visual envelope (area from where there would be views towards the Proposed Scheme), which is contained within a distance of up to 300m from the Proposed Scheme. The visual envelope has been defined by desk study supported by field observation and is based on professional judgement.
7.3.2 The visual envelope, as shown in Figure 7.1, is constrained by surrounding built development and should be regarded as the maximum ‘worst case’ extent of visibility from the surrounding landscape.
7.3.3 The proposed study area defined for the LVIA has therefore been based on a distance of up to 300m from the Proposed Scheme.
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7.4 Baseline Environment
Baseline Sources
7.4.1 The landscape and visual baseline conditions within the study area have been established by desk study supplemented by a site walkover survey on the 20th June 2017. The following data sources have been used to inform the baseline conditions:
1:25,000 scale OS Explorer Map;
aerial photography (Google Earth and Google Maps);
GIS data sets for landscape planning constraints;
published sources of national landscape character assessment (Natural England, 2014a);
Governments Multi-Agency Geographic Information for the Countryside (MAGIC) website (Natural England, 2017);
Southampton City Council’s Adopted Core Strategy (SCC, 2015a); and nd City of Southampton Local Plan Review – Adopted version 2 revision (SCC, 2015b).
Baseline Conditions
Landscape designations and constraints
7.4.2 Landscape planning constraints are illustrated in Figure 7.1.
7.4.3 An off-road cycle path runs along the southern side of Redbridge Road, south of Redbridge Roundabout.
7.4.4 Footpath Southampton 07 (PRoW) lies within the study area, located to the north of Redbridge Roundabout and runs on the bridge crossing the M271.
7.4.5 One yew tree (T2-067 T1 Yew TPO 1976) protected by a Tree Preservation Order (TPO) is located west of Clover Nooke, to the south-west of Redbridge Roundabout, several TPO trees are located to the south of Old Redbridge Road, a group of TPO trees are situated west of Redbridge Community School and a small group north of Redbridge Towers. Location of these TPOs are in the Arboriculture Impact Assessment Report in Appendix D.
7.4.6 Hazeldene Mee’s House, The Cottage and The Nooke Listed Buildings are located to the south-west of Redbridge Roundabout, north of Old Redbridge Road.
7.4.7 The central area of Redbridge Roundabout and adjoining open space between Clover Nooke and the A33 westbound carriageway are categorised as Amenity Green Space within Southampton’s Green Space Strategy (GSS) Technical Document, Southampton City Council (SCC, 2008). This open space forms part of the city’s publicly accessible green spaces by providing an amenity space for the local area, which is valued by the local community. As a minimum, the GSS recommends the Amenity Green Space should include grass, shrubs and trees and should link with other green spaces, such as those at Clover Nooke and Redbridge Tower, and exceed over 0.1ha in size. The GSS recommends open space of this nature is reconfigured to improve its quality for recreational purposes and ease management.
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Landscape character
7.4.8 The study area lies within Natural England’s National Character Area (NCA) 128 South Hampshire Lowlands. It is described as a “low-lying plain between the chalk hills of the Hampshire and South Downs and Southampton Water. The NCA is dominated by the city and port of Southampton and its adjoining towns and suburbs – 29 per cent of the area is urban. In the more rural areas, it is a mixture of farmland, particularly pasture, and woodland”.
7.4.9 Southampton Water Landscape Character Area (refer to Integrated Character Assessment, Hampshire Country, 2010), which lies close to the western edge of the study area, is internationally recognised for its importance for waterfowl and waders and for its wetland habitats such as mud flats and salt marshes. Despite the close proximity of the M271/A35 Redbridge Roundabout to the Lower Test Valley and saltmarshes, there is no intervisibility between the Proposed Scheme and the rural landscape from this urban location, therefore this County Character Area is scoped out.
Townscape
7.4.10 Southampton City Council’s City Centre Urban Design Guide, ‘6. Southampton Character Area Guidelines’ (2000) provides a description of the urban character areas in Southampton. It does not extend as far as the study area, therefore the townscape character was determined through a site walkover appraisal.
7.4.11 The M271/A35 Redbridge Roundabout is a key interchange within the wider transport network for the south-east. In landscape terms, it is a complex grade separated junction between the M271/A35/A33/Gover Road comprising major roads at ground level and the A35 Redbridge Flyover, The Causeway, which crosses over the central roundabout. The roundabout itself marks the gateway to the city for the M271/M3 traffic approaching from the east. It is surrounded by high and low-rise residential development and commercial/industrial units.
7.4.12 With the exception of commercial and industrial units to the west of the roundabout, the study area comprises various types of residential development constructed between the mid and late 20th century. Major roads have created clear separation between residential, commercial/industrial and transport land uses within the study area. The network of major roads has disrupted the former small scale pattern of streets and junctions, and the resulting fragmented local road pattern. Heavy vehicle flows and high noise levels impedes pedestrian circulation and human interaction.
7.4.13 To the north, between Gover Road and the M271/A35 – The Causeway, low density residential development constructed in the mid to late 20th century predominantly two storey semi-detached houses and detached bungalows. Residential development to the east and south of the Proposed Scheme site comprises Redbridge Towers, which is approximately 20 storeys high and a local landmark, and several three to four storey high residential blocks set within amenity tree and shrub planting. The existing motorway junction and traffic dominate the study area and therefore this is not considered a tranquil area.
7.4.14 The commercial/industrial units are also low-rise and set back from the A35 between Redbridge Roundabout and The Causeway to the west. Within the study area they comprise car dealerships, and light industrial workshops.
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7.4.15 The large scale Redbridge Flyover and adjoining major roads are dominant features in the landscape and are prominent in views from surrounding residential properties. The flyover rises above the roofs of nearby low-rise residential/commercial/industrial premises where the bridge, traffic and street lighting are prominent on the skyline.
7.4.16 The network of large-scale major roads dominates the townscape of the study area. Generally, buildings within the study area lack local distinctiveness. Major roads and the M271/A35 Redbridge Roundabout have fragmented the arrangement of buildings, open space and pedestrian routes. The road network and heavy traffic dominates the quality of the environment for pedestrians and nearby residential receptors.
Site context
7.4.17 The Proposed Scheme site is located in an urban and well-lit context in the Millbrook area of Southampton on the western edge of the city close to the Lower Test Valley and the Solent and Southampton Water sites of international and ecological significance.
7.4.18 Although the underlying topography of the Proposed Scheme site and study area is flat and low lying due to its close proximity to the Test Valley, the landform is dominated by large scale elements within the highway boundary, including the Redbridge Flyover and engineered slopes.
7.4.19 Open space within the roundabout comprises well-maintained grass and ornamental trees with paving beneath the route of the Redbridge Flyover. The undulating landform within the roundabout is an attractive element. Footways cross through the roundabout. They include a high-level footbridge that links with Redbridge Towers and subways beneath the roads that link with Gover Road to the north and the A33/A35 on the southern edge of the roundabout. Pedestrians and cyclists frequently use these routes, which link adjacent residential areas with local shops, public transport facilities etc.
Vegetation
7.4.20 Highway planting within the Proposed Scheme site comprises:
Small groups of semi-mature trees on the northern, eastern and southern edge of the open space within Redbridge Roundabout, including pine and birch trees, contribute to visual amenity. These trees are located within Amenity Green Space.
Several specimen trees and a well maintained beech hedge (approximately 1.5m high) south of Redbridge Roundabout/A33 westbound carriageway and Clover Nooke (three to four storey residential properties). These trees and the hedge contribute to visual amenity and are located within Amenity Green Space.
Mature broadleaf and coniferous vegetation on the cutting slope on the north-eastern edge of Redbridge Roundabout. These plants screen/filter views of the M271/A35 junction from the lower storeys of Redbridge Towers (20 storeys residential building) and adjoining four storey buildings. The highway vegetation contributes to visual amenity.
Mature broadleaf and coniferous vegetation on the northern edge of Redbridge Roundabout next to two storey residential properties off Gover Road, filters views from adjoining houses and contributes to visual amenity.
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Views and visual amenity
7.4.21 Built development surrounding Redbridge Roundabout generally restricts views of the Proposed Scheme site from the areas in close proximity to it. Increased viewing distances are available along Gover Road, the A33, the A35 and the M271.
7.4.22 Visual receptors have been identified from desk-based study and the visual envelope mapping. They have been verified on site and are shown in Figure 7.1 and Table 7.5 below.
7.4.23 Figures 7.2a, 7.2b and 7.2c illustrates the character of views from publicly accessible areas.
7.4.24 North of Redbridge Roundabout, the Proposed Scheme site is visible, especially in winter, from the first floor of the residential properties at the southern end of Coniston Road. A wooden fence to the south curtails views to the site from the first floor. In summer, existing trees screen some views to the south. The existing footbridge crossing the A33 (eastbound) and flyover are visible from the first floor of the properties all along Coniston Road. From the north, the northern part of the site is also visible from a restricted section of the M271, up to the overbridge where footpath Southampton 07 runs. View Point (VP) 1 in Figure 7.2a illustrates the view from the north-west of the junction, to the south of Coniston Road at the junction with the A33. VP2 in Figure 7.2a illustrates the view from the Redbridge Roundabout looking to the north-west towards the properties at Coniston Road.
7.4.25 East of Redbridge Roundabout, the Proposed Scheme site is visible from Redbridge Tower that has elevated views from it, adjacent four-storey blocks north-east and south- east of it and Cuckmere Lane. Redbridge Flyover is in the foreground as it is approximately at the same level as these residential buildings. In summer, trees north-east and east of Redbridge Roundabout soften some views of roads, Redbridge Roundabout and the flyover from the four-storey blocks, the first floors of Redbridge Tower and Cuckmere Lane. There are lateral views of the site from the southern edge of the football field at Redbridge Community School. The site is visible from a restricted section of the A33; refer to VP3 and VP4 in Figure 2b.
7.4.26 From the south, the Proposed Scheme site and flyover are visible from visual receptors south of the A33. These include three-storey blocks at Clover Nooke, several terraced houses, car dealers, the cycle route running along the road south of Redbridge Flyover and Old Redbridge Road. VP5 in Figure 7.2c illustrates the view from the A33 eastbound carriageway looking to the south at the junction between the A33 and Old Redbridge Road. VP6 shows the view from the footway south of the flyover, at the pedestrian crossing looking to the west towards Redbridge Roundabout.
7.4.27 From the west, the western side of the Proposed Scheme site is visible from a lorry dealership and Gover Road. Few residential properties along the western side of Gover Road and the residential properties along the eastern side of the road have lateral views of the site.
7.4.28 Redbridge Flyover is a dominant feature in all views.
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7.5 Methodology and Assessment Criteria
Methodology
7.5.1 A qualitative assessment has been carried out based on the level of preliminary design information available at this stage, in accordance with a Simple Assessment, as set out within IAN 135/10 Landscape and Visual Effects Assessment (Highways Agency, 2010a). The assessment also takes account of Guidelines for Landscape and Visual Impact Assessment (GLVIA) 3rd Edition (Landscape Institute and Institute of Environmental Management and Assessment, 2013).
7.5.2 The assessment of significance of effect for the landscape and visual receptors takes into account mitigation measures.
7.5.3 Effects on landscape and visual receptors are described for a winter’s day during construction, a winter’s day at the start of operation and a summer’s day fifteen years after the proposed improvement works become operational (future year). The assessments in winter for construction and start of operation provide a worst case scenario, when intervening vegetation is not in leaf and when any mitigation planting is unestablished and ineffective in reducing the significance of visual effects. The assessment for the future year is undertaken in summer to show the full effectiveness of any mitigation planting.
7.5.4 A site visit was undertaken in June 2017 to determine the extent of the visual envelope and the nature of views from sensitive receptors from publicly accessible areas.
Assessment of Magnitude and Significance
7.5.5 The criteria used to determine the sensitivity of landscape and visual receptors, the magnitude and significance of landscape and visual effects are those provided in IAN 135/10, Landscape and Visual Effects Assessment (Highways Agency, 2010a) and are presented in Appendix E.
7.5.6 The magnitude of landscape impact relates to the degree of change the Proposed Scheme would cause. Factors that have been taken into consideration include the scale, geographical extent, duration and nature of potential changes. Mitigation that could reduce adverse impacts has been taken into consideration (refer to Section 7.7 ‘Potential Effects’ and Section 7.8 ‘Design, Mitigation and Enhancement Measures’). Definitions relating to the magnitude of landscape and visual impact are presented in Table E.1 in Appendix E.
7.5.7 Table E.2 in Appendix E informs consideration of the sensitivity of the key landscape and visual receptors identified and mapped in Figure 7.1.
7.5.8 The significance of landscape and visual effect has been determined through combining the sensitivity of the landscape and visual receptors with the magnitude of landscape and visual impact.
7.5.9 In accordance with Simple Assessment, and to make the assessment proportionate to the Proposed Scheme, visual effects have been considered in broad terms. The view from sensitive receptors surrounding the Proposed Scheme have been assessed to illustrate the visual effects during construction and operation phases. The assessment is supported by schedules, included in Appendix F and photographs in Figure 7.2 illustrating the nature of the townscape.
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7.5.10 Table 4.2 has been used as a guide to assist the professional judgement in deciding the significance of landscape and visual effects. Effects of moderate or greater significance are considered to be significant effects in this chapter.
Value of Receptors
7.5.11 The key landscape receptor is the local townscape, which includes existing vegetation and landform that contributes to the sense of place. Highways infrastructure dominates the townscape of the study area, which is not designated and lacks features of value. However, Redbridge Roundabout is classed as Amenity Green Space and therefore, the local townscape has been assessed as being of medium value overall.
7.5.12 Visual receptors are shown on Figure 7.1. The sensitivity of visual receptors is presented in Table 7.1 below.
Table 7.1: Sensitivity of key visual receptors within the study area
Visual Receptor Sensitivity Footpath, footways and cycle route F1 – Users of Southampton 07 (PROW) High F2 – Users of footways along Gover Road Moderate F3 – Users of footway north of the A33 F4 – Users of shared footway and cycleway south of Redbridge flyover F5 – Users of footways within roundabout and footbridge Residential properties R1 R2 – Residents at properties at Gover Road High R3 – Residents at properties at Coniston Road R5 – Residents at Redbridge Towers and properties south-east of it R6 – Residents at properties at Oakridge Road R7 – Residents at properties south of Old Redbridge Road R8 – Residents at properties north of Old Redbridge Road R9 – Residents at Hazeldene Mee’s House, The Cottage, The Nooke Listed Buildings Amenity space A1 - Users of Redbridge Roundabout Moderate Public facilities and open space P1 – People at Redbridge Community School Moderate
7.6 Assessment Assumptions and Limitations
7.6.1 Landscape and Visual Impact Assessment has been based on construction assumptions provided in Section 2.5 ‘Construction’. Minimal disruption during construction is assumed.
7.6.2 Professional judgement has been used in the LVIA to assess visual impacts where no access is possible, for example, from high rise buildings. The site survey was undertaken in summer when deciduous vegetation was in leaf. Professional judgement and use of winter street view material where available has been used to inform the winter visual impact assessment. This constitutes an appropriate and proportionate approach given the
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restricted number of visual receptors, and the limited extent of existing screening vegetation within this urban context.
7.7 Potential Effects
Construction Effects
7.7.1 During the construction period, potential adverse landscape and visual effects would be caused by the presence of construction activity, including movement of construction plant, the presence of a contractor’s compound, demolition of the existing footbridge and loss of existing vegetation.
Operational Effects
7.7.2 During operation, potential landscape and visual effects would be caused by the increased prominence of highway infrastructure within the townscape, which would be exacerbated by loss of existing vegetation.
7.8 Design, Mitigation and Enhancement Measures
7.8.1 The following measures are embedded (primary) mitigation into the design of the Proposed Scheme:
vegetation would be removed only where essential to construct the Proposed Scheme and allow for sight lines and safety requirements. For vegetation to be retained, please refer to Figure 7.3.
tree protection fencing would be installed in accordance with BS5837:2012 Trees in relation to design, demolition and construction (BSI, 2012); and
where noise barriers are required to the north-east and south of the Redbridge Roundabout, timber adsorptive noise barriers are proposed to allow integration within the existing townscape and height would be kept to a minimum of 5m and 4m, respectively.
7.8.2 The following Secondary mitigation measures to reduce any adverse effects have been applied to preliminary detailed design and are shown in Figure 7.3 Drawing No. HE551515-JAC-ELS-00-DR-LE-0002 and Figure 7.4 Drawing No. HE551515-JAC-ELS- 00-DR-LE-0003:
7.8.3 Construction
The use of no-dig construction methods and materials are proposed for the shared footway/cycleway north of Clover Nooke to avoid the removal of encroaching trees.
7.8.4 Operation
Planting new ornamental shrub species, mainly evergreen, a mix of native evergreen and deciduous tree species and bulbs to the north of the proposed shared footway/cycleway north of Clover Nooke to improve the Amenity Green Space.
Planting new ornamental shrub, bulbs and groundcover species and a mix of native evergreen and deciduous tree species suitable to the context on the existing island west of Redbridge Roundabout to improve the relationship of the existing junction with the surrounding townscape character.
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Reinforcement of existing vegetation north-west of Redbridge Roundabout with new native planting to improve landscape integration.
New landscape design of Redbridge Roundabout to enhance this Amenity Green Space and create an attractive and safe area for the local community.
New lighting to be in accordance with best practice, directed appropriately to minimise light pollution to nearby residents.
Where fencing is proposed to the south of the proposed shared footway/cycleway, a visually appealing fence type should be considered to contribute to the amenity of the area.
Planting a mix of native evergreen and deciduous tree species to the south of the proposed noise barrier and fencing north of Clover Nooke to promote landscape integration.
7.8.5 Engineered retaining structures are required. Such retaining structures limit opportunities for planting mitigation within the road boundary as existing slopes would be cut, reducing the space for planting with consequent adverse effects on townscape, character and views. Landscape mitigation measures include a 3m wide strip outside the proposed retaining wall east of Redbridge Roundabout for new shrubs and tree planting to replace the trees lost during construction.
7.8.6 Due to limited space available and utilities and visibility splay constraints, it is not possible to comply with Southampton City Council’s ‘Two for One’ tree planting condition. For the location of proposed trees, please refer to Landscape Plan (Figure 7.3), for number of trees proposed refer to Planting Schedules (Figure 7.4).
7.9 Residual Effects
Construction Effects
Landscape receptors
7.9.1 Temporary construction activity and the construction compound to the south of Redbridge Towers and along the A33 westbound carriageway would slightly exacerbate the prominence of the road corridor and junction as a discordant feature within the townscape setting. However, adverse effects on townscape character would be limited to a restricted area. Construction activity would be in an urban, well-lit context and consequently there would be a negligible impact on night-time views. As there is an existing low level of tranquillity associated with the existing road corridor and junction, there would be no significant effect on the tranquillity of the townscape.
7.9.2 The widening of the road north of Redbridge Roundabout would lead to permanent loss of existing mature trees to the north-east of the roundabout. Cutting of the existing slope and the construction of a retaining wall would limit opportunities for new planting. Elsewhere, there would be a temporary loss of trees during construction until replaced by new tree planting. This would cause a moderate adverse effect because vegetation contributes towards the surrounding townscape pattern, provides amenity value and partial screening in summer for the first floors of Redbridge Towers and the residential buildings south-east of it.
7.9.3 Construction earthworks supporting new footways within Redbridge Roundabout would slightly change the landform. There would also be a minor magnitude change to the
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landform north-east of the roundabout due to the cutting of slope and construction of retaining wall that would slightly change the profile of the existing embankment.
Visual receptors
7.9.4 The most significant visual effect during construction would be for residents at Redbridge Towers, in particular properties to the south-east and north of Old Redbridge Road that have existing available views on the junction and traffic. Construction compounds would lead to minor adverse impacts and moderate adverse effects on views. Construction activity would be visible and would be added to the baseline view of the traffic. Removal of vegetation south-west of Redbridge Towers would exacerbate existing views of the road corridors, junction and traffic from the first floors of Redbridge Towers and the buildings to the south-east.
7.9.5 The shared footway and cycleway south of Redbridge Flyover, the footways within the roundabout, Redbridge Roundabout Amenity Space and the footbridge would be directly affected by construction activity. The magnitude of impact for these receptors would therefore be minor adverse and the significance of effect slight adverse.
7.9.6 Views of the construction activity would also be available from the first floor of properties at the southern end of Coniston Road, especially in winter, and from properties south of Old Redbridge Road. There would be temporary minor adverse impacts and slight adverse effects.
7.9.7 Residents at properties along Coniston Road, at Oakridge Road, Hazeldene Mee’s House, The Cottage and The Nooke Listed Buildings, properties at Gover Road and users of footways along it, would have partial or glimpsed views of the construction activity, generally due to existing settlements and vegetation curtailing views. The magnitude of impact would be negligible adverse and the significance of effect slight adverse.
7.9.8 Negligible adverse and slight adverse effects would also be experienced by users of the footway north of the A33 and on Footpath Southampton 07 at the overbridge on the M271. The users of the footway north of the A33 would have close views of the construction activity but the current view from this footway is on the traffic along the A33 and the Redbridge Flyover.
7.9.9 People at Redbridge Community School would have oblique views of the construction activity only from the southern edge of the football field, therefore the magnitude of impact would be negligible adverse and the significance of effect neutral.
Operational Effects
7.9.10 Whilst IAN 135/10 (Highways Agency, 2010a) does not recommend assessment before and after mitigation, the potential impacts as assessed on a winter’s day in Year 1 would be similar to assessment without mitigation because planting mitigation would be immature and ineffective. Residual effects following the application of mitigation are assessed on a summer’s day in Year 15, when vegetation would be established. No significant effects have been identified during operation.
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Year 1
Landscape receptors
7.9.11 With the end of construction activity, changes in the character of the townscape would be slight due to the restricted area affected by changes. The main adverse impact would be due to the permanent loss of vegetation north-east of Redbridge Roundabout and the limited opportunities for mitigation planting in this limited location.
7.9.12 At Year 1 impact on vegetation and landform would be less as grassland on new earthworks within Redbridge Roundabout and upgraded verges would establish quickly, making changes on landform negligible. New trees and shrubs would be planted, but these would have no appreciable beneficial effect at this stage, until planting had become more established. The overall magnitude of impact on vegetation would therefore remain adverse; however, the level of significance effects would reduce to slight adverse by new planting.
Visual receptors
7.9.13 After completion of the Proposed Scheme, the permanent loss of vegetation to the north- east of Redbridge Roundabout would be the main cause of visual impacts. Existing views of road corridors, junction and traffic from Redbridge Towers would be increased due to vegetation loss, especially for residents on the first floor. However, views from the upper floors would remain approximately the same because views are elevated and the planted vegetation does not currently perform any screening function. Permanent changes in vegetation would also be perceived from the first floor of properties at Coniston Road, roundabout and footpaths.
7.9.14 Residents within properties south-east of Redbridge Towers would experience a change in view, from a line of trees to a noise barrier 5m high screening views to the road. The magnitude of impact would be negligible adverse and the significance of effect slight adverse. The construction of a noise barrier south of Redbridge Roundabout would partially screen views of the road and flyover from three buildings north of Old Redbridge Road. Establishment of vegetation would also help to integrate the noise barrier resulting in a negligible beneficial impact and slight beneficial effect. New lighting would cause no significant effect because its extent would be similar to the existing.
Year 15
7.9.15 After 15 years the planting would be established and effective in contributing to the landscape fabric and as visual screening.
Landscape receptors
7.9.16 Establishment of mitigation planting would improve the relationship between the road corridor and junction with the surrounding townscape. The new design of Redbridge Roundabout aims to create an attractive western gateway to the city of Southampton, and the new pavement, footways and planting within the roundabout would create a sense of place and enhance the amenity space. After 15 years, no change would be perceived on townscape and the significance of effect would be neutral, but there would be a minor beneficial impact on Redbridge Roundabout amenity space and a slight beneficial effect due to new proposed ornamental vegetation.
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Visual receptors
7.9.17 After 15 years, a negligible change in views would be experienced by residents at properties: southern end of Coniston Road; Redbridge Towers and properties south-east of it; and properties north of Old Redbridge Road (and few properties and users of footways at the junction between Gover Road and the A33). Even though trees to the north-east of Redbridge Roundabout would be permanently lost, new tree and shrub planting at Redbridge Roundabout and along the A33 carriageway would compensate for the loss. The new design of the roundabout with ornamental shrub species, trees and bulbs would enhance views from residential properties surrounding it, and the roundabout would be a new and attractive focal point within the junction. Loss of vegetation and change in view are unlikely to be perceived.
7.9.18 Redbridge Roundabout would be enhanced and become a small attractive and safe green space for the local community. There would be negligible impact for users of Redbridge Roundabout Amenity Green Space and the significance of effects would be slight beneficial.
Summary
7.9.19 The Proposed Scheme aims to meet the objectives set out within landscape planning policy set out within Section 7.2 ‘Legislative and Policy Framework’ where feasible. The landscape strategy proposes new planting (see Section 7.8 ‘Design, Mitigation and Enhancements Measures) that would offer potential opportunities for improving the relationship of the existing road corridor and junction with the adjacent townscape. This would create a sense of place, reinforcing the character of the local townscape and enhancing the road users’ experience through improved views of the townscape.
7.9.20 It is considered that there would be moderate adverse effects to some sensitive visual receptors i.e. residents at Redbridge Towers but only during construction of the Proposed Scheme. The effects would last approximately seven months (temporary) and are not considered to be the ‘key factor or material in the decision making process’ (Highways Agency et al., 2008a) of EIA for this particular scheme. Overall landscape and visual effects during the construction phase of the Proposed Scheme are not considered to be significant.
7.9.21 With the application of mitigation measures detailed in Section 7.8, it is predicted that the potential landscape and visual effects would be reduced with no significant residual effects during the operational phase. Table 7.6 below summarises the potential landscape and visual impacts predicted during construction and operation of the Proposed Scheme. The table also outlines proposed landscape mitigation and enhancement measures, as detailed in Section 7.8 ‘Design, Mitigation and Enhancement Measures’, and potential residual effects following their implementation. A complete and detailed assessment of landscape and visual effects can be found in Appendix F ‘Landscape and Visual Effects Schedule’.
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Table 7.6: Landscape mitigation and enhancement opportunities
Receptor Potential effects Mitigation opportunities/enhancement (P = Residual effects primary mitigation, S = secondary mitigation, T = tertiary mitigation)
Landscape receptors Townscape including Construction activity and loss Vegetation to be removed only where essential Enhancement of the vegetation of vegetation would slightly (P). Amenity Green Space and exacerbate the prominence of Tree protection fencing would be installed in improvement of the the road corridor and junction accordance with BS5837:2012 Trees in relation to relationship of the existing as a discordant feature within design, demolition and construction (P). road corridor and junction the townscape setting. Building styles, structures and material to be with the surrounding appropriate to the townscape context (P). townscape, reinforcing local Use of no-dig construction methods and materials townscape character. for the shared footway/cycleway north of Clover Nooke (S). New ornamental trees, shrub and bulb species and amenity grassland seeding to improve the Amenity Green Space and promote landscape integration (S). Landform Negligible change on Protect/maintain the attractive undulating No perceptible changes. landform due to construction landform on the roundabout. Grassland seeding within Redbridge (S). Roundabout. Minor change of New ornamental trees, shrub and bulb species landform north-east of the and amenity grassland seeding to improve the roundabout due to cutting of Amenity Green Space and promote landscape slope and construction of the integration (S). retaining wall, during operation would be negligible. Visual receptors Residents at properties Construction activity Vegetation to be removed only where essential Enhancement of Redbridge at Coniston Road and noticeable due to
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Receptor Potential effects Mitigation opportunities/enhancement (P = Residual effects primary mitigation, S = secondary mitigation, T
= tertiary mitigation) Redbridge Towers and construction compound (P). Roundabout. buildings south-east of it location. Permanent loss of Attractive structure considered for the proposed New tree and shrub planting (R3 R4 R5) vegetation would be footbridge (P). would mitigate the view of Users of Footpath noticeable. Existing views of New ornamental trees, shrub and bulb species the noise barrier from the Southampton 07 (F1) road corridors, Redbridge and amenity grassland seeding to improve the buildings south-east of Flyover, traffic and Redbridge Amenity Green Space and promote landscape Redbridge Towers. Roundabout would be integration (S). exacerbated. Direct views of 3m wide strip outside the proposed retaining wall footbridge. east of Redbridge Roundabout for new shrubs and tree planting to replace trees lost during construction (S). Residents at properties Construction activity (and Vegetation to be removed only where essential Establishment of new tree, north and south of Old construction compound) and (P). shrub and bulbs planting Redbridge Road, removal of vegetation would Building styles, structures and material to be would enhance the Amenity Hazeldene Mee’s be noticeable. Removal of a appropriate to the townscape context (P). Green Space. House, The Cottage, hedge along the shared Use of no-dig construction methods and materials The Nooke Listed footway/cycleway would open for the shared footway/cycleway north of Clover Buildings (R8 R9) up new views on road from Nooke. (S). Users of shared footway road level. Construction of a New ornamental trees, shrub and bulb species and cycleway south of noise barrier south-west of and bulbs and amenity grassland seeding to Redbridge Flyover (F4) roundabout would also be improve the Amenity Green Space and promote slightly visible. landscape integration (S). Residents at Gover Lateral views of the New ornamental trees, shrub and bulb species New tree and shrub planting Road (R1 R2) construction activity. No and amenity grassland seeding to improve the within Redbridge Footways along Gover perceptible change in view Amenity Green Space and promote landscape Roundabout and the island Road (F2) during operation. integration (S). west of it would be an opportunity to enhance the Amenity Green Space and soften the flyover.
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Receptor Potential effects Mitigation opportunities/enhancement (P = Residual effects primary mitigation, S = secondary mitigation, T
= tertiary mitigation) Users of Footways The footways, footbridge and Vegetation to be removed only where essential New design of Redbridge within roundabout and Redbridge Roundabout would (P). Roundabout, new tree, footbridge (F5) be directly impacted by New ornamental trees, shrub and bulb species shrub and bulbs planting Users of Redbridge construction activity. and amenity grassland seeding to improve the would enhance the Amenity Roundabout Amenity Amenity Green Space and promote landscape Green Space, and create an Space (A1) integration (S). attractive and safe area for Building styles, structures and material to be the local community. appropriate to the townscape context (P).
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8. Biodiversity 8.1 Introduction
8.1.1 Phase 1 habitat survey completed in October 2017 identified several statutory and non- statutory sites for biodiversity with the potential to be affected by the Proposed Scheme. The survey found that the habitats within the boundary of the Proposed Scheme, and those adjacent to areas affected by construction and operation of the scheme comprised of, amenity grassland (<0.3ha), scattered trees and scrub (<0.1ha), and hard-standing (comprising metalled footpaths of negligible value). The habitats were all found to be anthropogenic in nature; they did not support any legally protected plant species; they did not support any notable plants of conservation concern; they were assessed as not rare; and can be easily recreated.
8.1.2 It was also considered that habitats would not be functionally linked to those within statutory or non-statutory designated sites for biodiversity and would not provide resources for mobile species from such sites. Habitats affected by the Proposed Scheme have therefore been assigned a negligible value and are not considered further in this assessment. Whilst the habitats affected by the Proposed Scheme are of negligible value, they do have the potential to support nesting birds and bats. With a high degree of confidence, it is considered that there would be no significant impacts on any other protected or notable species or species group.
8.1.3 The trees and scrub do have potential to support nesting birds. This potential is limited by the highly disturbed nature of the habitats due to the existing roads and due to the size of area likely to be affected. Taken together, it is considered with a high degree of certainty that some birds would use trees and scrub areas that could be affected, but these species would be common and garden species and would be in low numbers. The valuation of the bird population affected would therefore be negligible.
8.1.4 Despite the negligible valuation of the bird population affected, all active birds nest are legally protected, and measures would need to be placed during construction to protect active bird nests if habitats are removed during the breading season (March to August inclusive). These measures most commonly include pre-works surveys and/or supervision of clearance works by Ecological Clerk of Works (ECoW).
8.1.5 The survey also found habitats with the potential to support foraging bats. However, this was considered to be extremely limited due to the amount of habitats with the potential to be affected; the level of disturbance from noise and lighting caused by local traffic; and poor habitat connectivity with better quality greenspace habitats in the wider landscape. Three trees with low bat roosting potential1 may require removal. In line with best practice guidance (Collins, 2016), soft-felling of these trees (if required) is recommended and it would be at this point that roosts would be confirmed. In the extremely unlikely event that all three trees support roosts, they would be low status roosts supporting small numbers of bats only. These could be easily recreated, via the installation of bat boxes as compensation, and no residual effects would be likely. All activities involving disturbance or destruction of roosts must still be completed in accordance with the legislation protecting bats, but in the context of impact assessment, effects would not be significant, based on bats also being given a negligible value.
1 No potential roosting features seen but potential identified in one due to a tree having a double leader and two having with ivy coverings that may hide potential roosting features.
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8.1.6 The potential for effects on statutory and non-statutory sites for biodiversity have not been scoped out, and therefore these alone are taken forward and discussed further in this chapter.
8.2 Legislative and Policy Framework
8.2.1 The primary legislation relevant to this assessment are:
The Conservation of Habitats and Species Regulations 2017;
The Countryside and Rights of Way Act 2000;
The Natural Environment and Rural Communities Act 2006;
The Water Environment (Water Framework Directive (WFD)) (England and Wales) (Amendment) Regulations 2015; and
The Wildlife and Countryside Act 1981 (as amended).
8.2.2 Guidance used in this assessment includes:
Chartered Institute of Ecology and Environmental Management (CIEEM) (2016), Guidelines for Ecological Impact Assessment in the UK and Ireland.
Highways Agency et al. (2001b), DMRB, Volume 10: Environmental Design, Section 4, Nature Conservation.
Highways Agency et al. (2009a), DMRB, Volume 11: Environmental Assessment, Section 4, Assessment of Implications on European Sites.
Highways Agency (2010b), IAN 130/10, Ecology and Nature Conservation: Criteria for Impact Assessment.
8.2.3 The policy framework relevant to biodiversity are provided in Table 1.1 (e.g. NPPF and NPS).
8.3 Study Area
8.3.1 The collection of desk-based information included a search area of 2km for statutory and non-statutory sites for biodiversity, 2km from the Proposed Scheme for European designated sites for biodiversity and 30km for European sites designated for bats (in accordance with DMRB guidance (Highways Agency et al., 2009a)).
8.3.2 The study area for gathering information from surveys included searching all accessible habitats within and adjacent to the boundary of the Proposed Scheme. The study area has been determined based on the low quality of habitats present and therefore the lack of potential for those habitats to contribute to the conservation value of other habitats within a wider study area. Appropriate buffer zones for survey has been determined using professional judgement based on the scale and extent of the project works. This is in accordance with DMRB (Highways Agency et. al., 2001b)
8.4 Baseline Environment
Baseline Sources
8.4.1 The following sources of data have been used in this assessment:
Collins, J. (2016), Bat Surveys for Professional Ecologists: Good Practice Guidelines, (3rd Edition), London: Bat Conservation Trust.
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Eaton, M.A. et al. (2015), Birds of Conservation Concern 4: the population status of birds in the United Kingdom, Channel Islands and Isle of Man, British Birds, 108, 708– 746.
Environment Alliance (2012), Pollution Prevention Guidelines – Working at construction and demolition sites: PPG62.
Holman et al., (2014), Institute of Air Quality Management (IAQM): Guidance on the assessment of dust from demolition and construction.
International Union for Conservation of Nature (2015), The IUCN Red List of Threatened Species, Version 2015.1.
Joint Nature Conservation Committee (JNCC) (2008), Information on Ramsar Wetlands (RIS): Solent and Southampton Water Ramsar. Version 3.0.
Joint Nature Conservation Committee (2015a), Natura 2000 – Standard Data Form: Solent and Southampton Water SPA UK9011061.
Joint Nature Conservation Committee (2015b). Natura 2000 – Standard Data Form: Solent Maritime SAC UK0030059.
Natural England and Defra (2016). Solent and Dorset Coast potential Special Protection Area: comment on proposals.
Natural England (2014b), European Site Conservation Objectives for Solent Maritime SAC (UK0030059).
Natural England (2014c), European Site Conservation Objectives for Solent and Southampton Water SPA (UK9011061).
Natural England (2014d), European Site Conservation Objectives for Mottisfont Bats Special Area of Conservation Site code: UK0030334.
Natural England (2014e), European Site Conservation Objectives for Briddlesford Copses Special Area of Conservation Site Code: UK0030328.
Governments Multi-Agency Geographic Information for the Countryside (MAGIC) website (Natural England, 2017);
Natural England (2018a), Lower Test Valley SSSI citation.
Natural England (2018b), Eling and Bury Marshes SSSI citation.
Natural England (2018c), River Test SSSI citation.
Woods Ballard, B. et al. (2015), The Sustainable Drainage Systems (SuDS) Manual (C753), London: CIRIA.
Baseline Conditions
Statutory and non-statutory sites for biodiversity
8.4.2 Within 5km of the Proposed Scheme, there are four European statutory sites for biodiversity, and two within 30km designated for bats, as summarised in Table 8.1.
2 This document has been withdrawn as best practice guidance, but still provides useful examples of possible mitigation approaches.
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Table 8.1: European statutory designated sites within 5km of the Proposed Scheme and within 30km where they are designated for bats
Site Designating feature Distance from scheme Solent and Criteria 1 – Many wetland habitats characteristic of 200m west Southampton Water the biogeographic region: saline lagoons, Ramsar saltmarshes, estuaries, intertidal flats, shallow coastal waters, grazing marshes, reedbeds, coastal woodland and rocky boulder reefs. Criteria 2 – Important assemblage of rare plants (eight Red Data Book Species) and invertebrates (33 Red Data Book Species). Criteria 5 – Assemblages of waterfowl of international importance. Criteria 6 – Species/populations occurring at levels of international importance (ringed plover (Charadrius hiaticula), dark-bellied brent goose (Branta bernicla), Eurasian teal (Anas crecca) and black-tailed godwit (Limosa limosa islandica)). Solent Maritime 1130 Estuaries 200m west Special Area of 1320 Spartina swards (Spartinion maritimae) Conservation (SAC) 1330 Atlantic salt meadows (Glauco-Puccinellietalia maritimae) 1110 Sandbanks slightly covered by sea water all of the time. 1140 Mudflats and sandflats not covered by seawater at low tide. 1150 Coastal lagoons (priority feature). 1210 Annual vegetation of drift lines. 1220 Perennial vegetation of stony banks. 1310 Salicornia and other annuals colonizing mud and sand. 2120 "Shifting dunes along the shoreline with Ammophila arenaria ("white dunes")". 1016 Desmoulin’s whorl snail (Vertigo moulinsiana). Solent and Supporting population of European importance of 200m west Southampton Water the following species listed on Annex 1 of the Special Protection Directive (79/409/EEC) during the breeding season: Area (SPA) (common tern (Sterna hirundo), little tern (Sternula albifrons), Mediterranean gull (Larus melanocephalus), roseate tern (Sterna dougallii), Sandwich tern (Sterna sandvicensis)). Overwinter (black-tailed godwit, dark-bellied Brent goose, ringed plover), Eurasian teal). Assemblage qualification – wetland of international importance supporting at least 20,000 waterfowl. Potential Solent and The proposal for the Solent and Dorset Coast SPA 265m west
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Site Designating feature Distance from scheme Dorset Coast SPA is to create a new marine SPA for internationally important populations of common tern, little tern and Sandwich tern. Mottisfont Bats SAC Barbastelle bats (Barbastella barbastellus). 13.9km north Briddlesford Copses Bechstein’s bat (Myotis bechsteinii). 28.3km SAC south west
8.4.3 Within 2km of the Proposed Scheme there are three statutory designated sites for biodiversity, as summarised in Table 8.2. There are no non-statutory sites for biodiversity within 2km of the Proposed Scheme.
Table 8.2: Statutory designated sites for biodiversity within 2km of the Proposed Scheme, excluding European sites
Site Designating feature Distance from scheme Lower Test The site comprises the upper estuary of the River Test 240m west Valley Site of and exhibits a gradation from salt through brackish to Special Scientific freshwater conditions. It consists of one of the most Interest (SSSI) extensive reed beds on the south coast with flanking unimproved meadowland intersected by numerous tidal creeks: and flooded on high water spring tides. Eling and Bury The SSSI embraces two dissimilar saltmarshes and 345m Marshes SSSI their intervening intertidal mudflats at the head of south west Southampton Water. Eling Great Marsh is a 13ha grazed saltmarsh with a close sward of saltmarsh-grass (Puccinellia maritima) with creeping bent (Agrostis stolonifera) and red fescue (Festuca rubra) sub- dominant. The Southampton Water estuary, of which Eling Great Marsh is part, is nationally important for its wader populations. River Test SSSI The River Test is a classic chalk stream. It is one of the 1.3km most species-rich lowland rivers in England. north west
8.4.4 The area of land covered by the Proposed Scheme is characterised by roads, hard standing, buildings, amenity grassland and planted trees on the Redbridge Roundabout, as well as shrub and tree plantings consistent with an urban environment on the road verges. A total of 26 trees and one group of young saplings have the potential to be affected by the Proposed Scheme and therefore have been assessed for their potential to contain bat roosts. There were three trees with a low potential to support roosting bats (according to the Bat Conservation Trust (Collins, 2016) classification system). The trees and shrubs were also found to have some potential to support small numbers of nesting birds.
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8.5 Methodology and Assessment Criteria
Methodology
8.5.1 The impact assessment for terrestrial and freshwater ecology was carried out based on the methodology described in Chapter 4 ‘Environmental Assessment Methodology’. This follows a stepwise process in which:
receptors are identified and valued;
pathways for effects on receptors are identified;
the magnitude of change of the effect is determined (with embedded mitigation i.e. plainly understood and uncontroversial); and finally
the significance of the effect is calculated.
8.5.2 Following this process, secondary and tertiary mitigation measures could be required, in the event that significant effects are identified or where there is at potential for significance reduction. It should be noted that the process by which significant effects are identified is separate from the determination of whether activities during construction or operation are likely to be in compliance with wildlife legislation. This is due to breaches in wildlife legislation not necessarily equating to significant effects.
Assessment of Magnitude and Significance
8.5.3 In accordance with Section 4.4, the assessment of effects was made based on establishing the value/sensitivity of the receptor and determining the magnitude of the environmental change predicted to occur. In Section 4.4 the magnitude of effect is split into five categories: no change; negligible; minor; moderate; and major. In this section each magnitude has been determined by taking into account CIEEM (2016) guidance. The use of other sources of reference is in accordance with IAN 130/10 (Highways Agency, 2010b).
Value of Receptors
8.5.4 For the determination of value of ecological receptors, DMRB (2001b) guidance has been used in combination with Chapter 4, where there are five valuation categories described. These are shown in Table E.2 in Appendix E, with brief descriptions of the criteria used in each case for this section. These are flexible to allow for localised conditions and contexts to be used in the final determination.
8.5.5 The valuations for all receptors discussed in Section 8.4 are provided in Table 8.3 as well as the justification why they have not been taken forward in the assessment.
8.5.6 Potential effects of the Proposed Scheme during construction and operation phases to biodiversity are provided in Table 8.4 and Table 8.5, respectively. Table 8.3 also includes justification as to whether or not the receptors ned to be further assessed.
Table 8.3: Value of receptors
Receptor Value Justification Receptor taken forward Solent and Southampton Very high There is the potential for air quality Yes
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Receptor Value Justification Receptor taken forward Water Ramsar and hydrological changes to affect Solent Maritime Special Very high the receptor. Yes Area of Conservation (SAC) Solent and Southampton Very high Yes Water Special Protection Area (SPA) Proposed Solent and Very high Yes Dorset Coast SPA Lower Test Valley Site of High Yes Special Scientific Interest (SSSI) Eling and Bury Marshes High Yes SSSI River Test SSSI High There is the potential for Yes hydrological changes to affect fish species migrating through aquatic habitats affected by the Proposed Scheme before they reach the SSSI. Mottisfont Bats SAC Very high The Proposed Scheme does not No Briddlesford Copses SAC Very high support habitats likely to be used No by bats from the SAC, and the SAC is considered to be outside of the zone of influence of effects arising from construction or operation phases of the Proposed Scheme. Habitats Negligible See Section 8.1 No Breeding birds Negligible See Section 8.1 No Bats Negligible See Section 8.1 No
8.6 Assessment Assumptions and Limitations
8.6.1 The assessment has been made on the assumption that the likelihood of Annex 1 bird species associated with SPAs or Annex 1 bat species associated with SACs using the habitats affected by the Proposed Scheme is negligible. This is based on the small size, poor quality, high levels of existing disturbance and poor connectivity with areas of higher quality habitats, as described in Sections 8.1.2 to 8.1.6. It is therefore considered with a high degree of confidence that further surveys would not improve the understanding of the potential effects of the Proposed Scheme on these species groups, and they are not required.
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8.7 Potential Effects
Construction Effects
8.7.1 Hydrological changes via de-watering of excavation, run-off from stored excavated materials or pollution events during refuelling could affect water entering storm drains that reach the River Test and Southampton Water and therefore statutory sites for biodiversity. The assessment of this potential effect is presented in Table 8.4. The assessment has been made in terms of comparing the value of features to the magnitude of change using the method outlined in Chapter 4. Magnitude of change includes taking into account duration and reversibility, and is only determined once mitigation has been applied.
8.7.2 There is potential for deposition of nitrogen and acid (from sulphur dioxide) to cause air quality to decrease sufficiently and affect ecological receptors during construction of the Proposed Scheme. The potential impacts of acid and nitrogen deposition from combustion engine powered plant could affect soil chemistry and growth of plant species in habitats within statutory designated sites for biodiversity in the study area. This could either inhibit species that contribute to the value to habitats within designated sites, or promote the growth of species that are deleterious within habitats. Typically, these would be fast growing nitrophilic species that overrun low growing diverse areas e.g. common nettles (Urtica dioica). There is also the potential for releases of fugitive dust from the use of mechanised plant, inhibiting photosynthesis by smothering plants in sensitive habitats.
8.7.3 Potentially significant effects in the form of disturbance, mortality or injury of species during vegetation clearance that could affect active bird nests or bats would be unlikely (see Sections 8.1), albeit works would still need to comply with the legislation protecting species against these effects.
Operational Effects
8.7.4 The identification and assessment of potential effects during operation is presented in Table 8.5. This shows that hydrological change is the only pathway for a significant effect to occur. This is via the potential pollution and increased amount of surface water leading into storm drains that eventually flow into the River Test and Southampton Water.
8.7.5 As described in Chapter 5, air quality changes with a high enough magnitude to affect ecological receptors are not predicted to occur.
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Table 8.4: Receptor value, mitigation and likelihood of significant effects during construction
Effect Receptor Mitigation opportunities/enhancement (P = primary Likely Significant pathways mitigation, S = secondary mitigation, T = tertiary magnitude of effect mitigation) impact possible Hydrological Solent and Southampton Water Ramsar Best practice measures for preventing run-off from No change. No changes and Solent Maritime SAC construction areas such as fencing, silt-trapping and pollution. Solent and Southampton Water SPA bunding of fuelling areas (Environmental Alliance, Proposed Solent and Dorset Coast SPA 2007). These would be included in a Construction Environmental Management Plan (CEMP) or similar Lower Test Valley SSSI that the principal contractor would be contractually Eling and Bury Marshes SSSI obliged to comply with (T). River Test SSSI Air quality Solent and Southampton Water Ramsar Standard measures to avoid reductions in air quality No change. No changes Solent Maritime SAC covered in the CEMP or Dust Management Plan. Solent and Southampton Water SPA Measures include: wetting/damping of haul routes; Proposed Solent and Dorset Coast SPA covering of stored loose materials; and ensuring selection of plant machinery for exhaust emission Lower Test Valley SSSI efficiency where possible and that it is well maintained Eling and Bury Marshes SSSI (T). River Test SSSI
Table 8.5: Receptor value, mitigation and likelihood of significant effects during operation
Effect Receptor Mitigation opportunities/enhancement (P = primary Likely Significant pathways mitigation, S = secondary mitigation, T = tertiary magnitude of effect mitigation) impact possible Hydrological Solent and Southampton Water Ramsar Best practice measures for managing drainage from No change. No changes and Solent Maritime SAC the scheme via a suitable drainage strategy (Woods pollution. Solent and Southampton Water SPA et al., 2015) (P). Refer to Chapter 13 ‘Road Drainage Proposed Solent and Dorset Coast SPA and Water Environment’ and Drainage Condition Grade Report (Jacobs, 2017b) for details on the Lower Test Valley SSSI Proposed Scheme’s drainage strategy. Eling and Bury Marshes SSSI
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Effect Receptor Mitigation opportunities/enhancement (P = primary Likely Significant pathways mitigation, S = secondary mitigation, T = tertiary magnitude of effect mitigation) impact possible River Test SSSI
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8.8 Design, Mitigation and Enhancement Measures
8.8.1 Outwith the primary and tertiary mitigation measures described in Table 8.4 and Table 8.5, it is not considered that there would be any requirements for additional design or mitigation measures. It is also considered that due to the heavily urbanised and disturbed location of the Proposed Scheme, enhancement in terms of betterment for ecological receptors is unlikely to be worthwhile.
8.8.2 There would be no impacts on European protected species and therefore a European Protected Species licence is not required.
8.9 Residual Effects
8.9.1 It is not considered that there would be any significant residual effects on any ecological receptors during construction or operation phase of the Proposed Scheme. This follow the findings of Chapter 13 ‘Road Drainage and Water Environment’, and air quality modelling which shows that the predicted changes in air quality would not have the potential to affect habitats within designated sites during operation phase of the Proposed Scheme (see Chapter 5).
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9. Geology and Soils 9.1 Introduction
9.1.1 Based on initial potential baseline receptors review, the following geology and soils potential receptors have been scoped in for this PCF Stages 3 and 5 EAR:
human health - construction workers, maintenance workers, current and future site users and nearby site users;
groundwater - Secondary A Aquifer within the superficial deposits and bedrock;
surface water (River Test);
ecologically important sites (Solent Maritime and Solent and Southampton Water sites (Habitats Directive Site, Birds Directive Site, SAC, SPA and Ramsar site) and Lower Test Valley SSSI); and
buildings and services (onsite).
9.1.2 Justification for scoping out agricultural soils, mineral resources and geological sites are provided below:
Agricultural soils – majority of the Proposed Scheme area is urban land with minimal natural soil likely to be present and no agricultural possibility. The small amount of poor quality soil to the north of the site is unlikely to be impacted by the Proposed Scheme.
Mineral resources - There is no mineral safe guarding area within the study area and therefore no further assessment is required.
Geological Sites - There are no designated geological sites within the study area and therefore no further assessment is required.
9.2 Legislative and Policy Framework
9.2.1 The relevant legislation, policy and guidance used in the production of the geology and soils chapter of the EAR are presented below:
Design Manual for Roads and Bridges, Volume 11, Section 3, Part 11, Geology and Soils (Highways Agency et al.,1993b) overall standard used for highways schemes EIAs;
Part 2A of the Environmental Protection Act 1990, Statutory Guidance - legislation on land contamination and Defra (2012) – supporting document on how legislation should be implemented;
Contaminated Land Report 11: Model Procedures for the Management of Land Contamination, Environment Agency (2004) – primary guidance used for contaminated land assessment;
The Water Framework Directive (WFD) (2015) - framework for the protection of inland surface waters (rivers and lakes transitional waters (estuaries)), coastal waters and groundwater, which includes risks from contamination guidance - to be used for assessment of impacts to controlled waters;
Construction Industry Research and Information Association (CIRIA) C665 (2007) – guidance used for assessment of impacts from ground gas;
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National Planning Policy Framework (DCLG, 2012), National Planning Practice Guidance (NPPG) and the local planning policies of Southampton City Council; and
Building Research Establishment (2005) Concrete in Aggressive Ground (3rd ed.) – to be used for assessment of impacts to buildings and services.
9.3 Study Area
9.3.1 For the purposes of assessing geology and soils potentially affected by the Proposed Scheme, the study area is the working area (i.e. the land that would be given over to the temporary possession of the construction contractor) plus an additional 250m buffer zone added around this working area. The 250m buffer is based on ‘Guidance for the Safe Development of Housing on Land Affected by Contamination R&D66: 2008 Volume 1’. The guidance, whilst written to be relevant to housing development, is also generally considered applicable to other forms of development, to existing developments and to undeveloped land, where such sites are on land affected by contamination.
9.3.2 The guidance states that features at greater distances should only be described if they have the potential to affect the land quality at the site (e.g. landfills) or the wider environmental quality of the site. For this assessment the buffer zone has been extended to approximately 500m for landfills and geological faults. For groundwater abstractions, the buffer zone has been extended to approximately 1km. The study area is shown on the potential sources of contamination plan (Figure 9.1).
9.4 Baseline Environment
Baseline Sources
9.4.1 The following data sources have been used to inform a description of the existing geology and soils baseline conditions:
Groundsure reports, references: GS-2724341 (Enviroinsight) (2016a) and GS- 2724342 (Geoinsight) (2016b), dated 5 February 2016;
WSP (2016b) Preliminary Sources Study Report (PSSR), M271 Redbridge Roundabout PCF Stage 2, Report Number: 70019110-003;
WSP (2017) M271/A35 Redbridge Roundabout, PCF Stage 2 ESR, Report Number: HE551515-WSP-GEN-M271PCF-RE-PM-ESR003;
Historical borehole records (BGS, 2017a);
‘What’s in Your Backyard’ (EA, 2017a) – for key background information including groundwater zones and landfill sites;
Governments Multi-Agency Geographic Information for the Countryside (MAGIC) website (Natural England, 2017); and
M271 Redbridge Roundabout Unexploded Ordnance (UXO) Desk Study and Risk Assessment; and Reference: P7020-17-R1 Rev A (Zetica, 2017).
Nicholls Colton Group (2017), Factual Report on a Ground Investigation (GI) for the M271 Redbridge Roundabout. Report No. G17167-FR.
Ground Investigation Report, M271 Stage 3 EAR, Jacobs, 2017
Highways Agency Geotechnical Data Management System (HA GDMS), Accessed 2017
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9.4.2 It should be noted that at the time of writing, historical maps referred to in the PSSR (WSP, 2016b) have not been viewed by Jacobs as the MapInsight element of the 3-part Groundsure report has not been provided.
Baseline Conditions
Made ground
9.4.3 The Groundsure reports (2016a and b) and British Geological Society (BGS) (2017b) mapping indicate the presence of artificial/made ground deposits beneath the majority of the study area. There are several BGS borehole records that indicate the made ground comprises tarmacadam, topsoil, gravel and concrete, hoggin (a buff coloured compactable groundcover comprising clay, gravel and sand or granite dust) and mixed fill, up to depths of 0.6-1.2m below ground level (bgl).
9.4.4 The Preliminary Sources Study Report (WSP, 2016b) mentioned that there is a former canal running through the study area which is considered to have been infilled. The available borehole records do not indicate the nature of the infill materials in this area and it is also unclear when the canal was infilled.
9.4.5 Made ground was encountered during the GI (NCG, 2017) in all exploratory holes and generally comprised tarmacadam, topsoil, gravel (with brick, glass, metal, ceramics, plastic and clinker) and reworked natural fill. These deposits were present up to a depth of 3.5m bgl.
Superficial geology
9.4.6 The entire study area is underlain by River Terrace Deposits (RTD) comprising sand and gravel with local lenses of silt, clay or peat. The BGS borehole records describe the RTD as gravel intermixed with varying proportions of clay, silt, and sand up to depths of 3.7- 5.7m bgl. Superficial deposits were encountered during the GI (NCG, 2017) and were generally described as sandy/cobbly gravel up to a depth of 8.5m bgl.
Solid geology
9.4.7 The study area is predominantly underlain by the Wittering Formation (sand, silt, and clay). The BGS indicates that The Earnley Sands Formation (sand, silt, and clay) is likely to be present in the south and south-east of the study area. Published stratigraphy indicates that the Wittering Formation underlies the Earnley Sand Formation. The solid geology encountered during the GI (NCG, 2017) was found to comprise predominantly clay and silt, with firmness increasing with depth. This is considered to be deposits of the Wittering Formation.
9.4.8 There are no recorded geological faults on or within 500m of the study area.
Ground workings/hazards
9.4.9 The Groundsure Geoinsight report (2016b) indicates historical surface ground working features (derived from historical mapping) including the former canal running through the south and west of the study area. The location of this canal is shown on the potential sources of contamination plan (Figure 9.1). There are also unspecified heaps which appear beneath the location of the existing Redbridge road and these are therefore considered to have been removed during construction of the existing roundabout.
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9.4.10 The Geoinsight report has identified a very low risk of compressible deposits, collapsible deposits, running sands and landslides being present along the Proposed Scheme. However, the report does indicate a moderate subsidence risk associated with shrink- swell clays within the study area.
9.4.11 There are no records of mining, extraction and natural cavities within the study area.
Hydrogeology
9.4.12 The RTD beneath the study area are classified by the Environment Agency as Secondary A Aquifer. They contain permeable horizons capable of supporting local water supplies and/or provide an important source of base flow to rivers. The Earnley Sand and Wittering formations are also classified by the Environment Agency as Secondary (A) Aquifers.
9.4.13 The study area does not lie within a groundwater Source Protection Zone (SPZ) and no licensed groundwater abstractions (including potable water abstraction licenses) are recorded within 1km of the study area. The PSSR (WSP, 2016b) report indicates that groundwater is considered to flow to the west towards the River Test and Southampton Water. However, no previous investigation has been reviewed confirming this to be the case.
9.4.14 Further details of these features (including groundwater flood risk information) are presented in Chapter 13 ‘Road Drainage and Water Environment’.
Hydrology
9.4.15 The major surface water feature is the River Test (Primary River), located approximately 180m west of the study area, and flowing southwards through multiple channels towards Southampton Water (approximately 150m west of the study area). There is no publically available data indicating the chemical and biological quality of the River Test, within 1km of the Proposed Scheme.
9.4.16 There are two discharge consents located approximately 180m west of the study area. These are for the discharge of sewage for a pumping station. Given the distance of the consents from the scheme these have not been considered as potential sources of contamination risk and have therefore been excluded from further assessment. Furthermore, there are no licensed surface water abstractions indicated within 1km of the Proposed Scheme.
9.4.17 Further details of these features (including flood risk information) are presented in Chapter 13 ‘Road Drainage and Water Environment’.
Ecologically important sites
9.4.18 Ecologically important sites are provided and discussed in Chapter 8 ‘Biodiversity’ and the Stage 3 Habitat Regulation Assessment (HRA) document (Jacobs, 2018a).
Other designations
9.4.19 The study area is also within a nitrate vulnerable zone. Nitrate vulnerable zones are areas designated as being at risk from agricultural nitrate pollution. Occupiers of sites within these zones must follow government guidance if they use any manufactured fertilisers, manures or other materials containing nitrogen on agricultural land in a nitrate vulnerable zone.
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Unexploded ordnance risk
9.4.20 An UXO Desk Study and Risk Assessment was produced by Zetica in August 2017. The assessment found no indication that the Proposed Scheme area was bombed, and no other significant sources of UXO hazard have been identified in the study area. The report concluded that the study area has a low UXO hazard level.
Potential contaminative land uses
Historical land use
9.4.21 Historical land use within the study area is summarised below. Historical maps included in the Groundsure Report provided in the PSSR Report. The below summarises the site history presented in the PSSR (WSP, 2016b) report:
The first map (1869) shows a small village and a canal within the study area. The surrounding area is mostly open land with a gravel pit approximately 80m to the east of the study area and a train station and associated tracks approximately 100m south.
Between 1869 – 1933 new roads are constructed over the River Test heading west and alongside the old canal heading north. A gravel pit is labelled 100m to the north- east of the study area alongside some tanks. Terraced housing has been constructed to the south-east of the study area.
Between 1933 – 1942 some farmland is redeveloped into residential housing and commercial buildings.
Between 1942 – 1947 a government training centre is constructed in open land to the south of the study area.
Between 1947 – 1962 there is further development of residential and commercial buildings on remaining open land within the study area and the land adjacent to the study area. Land that is still open is at this time now labelled as “sports ground” or “playing field”. A government training centre has been redeveloped to a depot.
Between 1962 – 1967 Redbridge roundabout has been constructed linking Redbridge causeway to Redbridge road.
Between 1967 – 1979 the M271 road has been completed to the north of the study area with associated flyover.
No other significant developments have occurred since 1979.
9.4.22 The PSSR historic maps also notes that Redbridge railway station continues to operate 200m south of the Proposed Scheme, serving the Wessex Main Line and South Western Main Line. In the late nineteenth and early twentieth centuries (approximately 1870-1914), Redbridge railway station is known to have been used for gunpowder transportation. However, due its distance from the study area and the age of any land contamination, it has been excluded from further assessment.
9.4.23 Due to the distance of the gravel pits from the study area and the fact that the locations of the pits appear to have been developed upon they are not considered to be a significant risk to the Proposed Scheme, so have been excluded from further assessment.
Contemporary land use
9.4.24 There are several active contemporary trade directory entries identified within the Groundsure report both on and within 250m of the study area but no current petrol or fuel
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stations within 250m of the study area. There are five electricity sub-stations within the study area (the locations of these are shown on the potential sources of contamination plan, Figure 9.1). Two of the sub-stations are adjacent to the Proposed Scheme.
9.4.25 Furthermore, there are four garages, an unspecified works site/factory, a vehicle hire business and a construction hire business located within the study area. The garages all appear to be minor repair facilities and therefore not considered significant as a land contamination risk (the locations of these are shown on the potential sources of contamination plan, Figure 9.1).
Landfill and waste management sites
9.4.26 Two historical landfills have been identified within 500m of the study area:
Redbridge Lane landfill site approximately 120m north-west of the Proposed Scheme accepts household waste. Operation dates are not given; and
Saltings Landfill (registered as three landfill sites) approximately 200m south of the Proposed Scheme accepting a mixture of commercial, household, inert and industrial waste. Only one of the sites has operational dates; 1969 – 1971.
9.4.27 No other waste management sites have been identified within 250m of the study area. For capacity of waste management within Hampshire and the region, please refer to Chapter 10 ‘Materials’.
Contaminated land designations
9.4.28 The Groundsure report confirms that there are no sites on or within the Proposed Scheme area that have been determined as Contaminated Land under Part 2A of the Environmental Protection Act 1990 (Defra, 2012).
Ground investigation 2017
9.4.29 A GI was undertaken by Nicholls Colton Group for the Proposed Scheme in September 2017. The GI provided information on ground and groundwater conditions and comprised:
five cable percussion boreholes (BH01 to BH05) to a maximum depth of 17.5m bgl;
seven hand dug pits (HP01 to HP07) to a maximum depth of 1.5m bgl; and
eight trial pits (TP01 to TP08) to a maximum depth of 4m bgl.
Soil chemical analysis
9.4.30 From the GI, selected soil samples were scheduled for chemical testing. The soils chemical analysis data have been screened against Generic Acceptance Criteria (GAC), for public open space end use (residential). This is considered appropriate for this development. An explanation of these screening criteria is provided in Appendix G. Samples were analysed for metals, Total Petroleum Hydrocarbons (TPH), Poly Aromatic Hydrocarbons (PAH), Semi-Volatile Organic Compounds (SVOCs), Phenol and pH.
9.4.31 Samples were also assessed in-situ using the headspace testing methodology to assess the presence of potentially vaporous material within the soil. The results of the soil chemical analysis are discussed in the summary below.
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Waste soil assessment
9.4.32 Should excavated materials be required to be disposed off-site, a provisional waste assessment has been undertaken. An explanation of the waste soil assessment methodology is provided in Appendix G. Waste Acceptance Criteria (WAC) testing data has also been used to assess landfill suitability for possible disposal of waste soil. An explanation of the WAC assessment methodology is provided in Appendix G.
Groundwater sampling and chemical analysis
9.4.33 Three rounds of groundwater sampling have been undertaken with samples obtained from each of the five borehole installations. The results of the water chemical analyse are discussed within the summary below.
Ground gas monitoring
9.4.34 Three rounds of ground gas monitoring have been undertaken by Nicholls Colton Group during the recent GI in the five boreholes. Data obtained during this monitoring is discussed within the summary below.
Summary of ground investigation findings:
All soils data assessed is below the assessment criteria for human health exposure.
Loose asbestos fibres were detected in one hand pit sample (HP01, 0.15m). The fibres were determined to be chrysotile asbestos fibres (white asbestos). Subsequent quantification analysis confirmed this to be below the laboratory quantification detection limit (<0.0001%).
Analysis of samples using the headspace methodology detected low level (<5ppm) Volatile Organic Compounds (VOCs) within HP03 and TP02. However, slightly elevated levels of VOCs were detected in TP01 at 1m, 2m and 3m bgl respectively. Two of these samples (1m and 3m bgl) were also scheduled for VOC analysis in the laboratory but neither identified any VOCs above the limit of detection.
The waste assessment undertaken for all soil samples indicated that majority would be classed as “non-hazardous” for waste disposal purposes, with the exception of HP01 (0.15m) which would be classed as “hazardous” for waste disposal purposes.
Waste Acceptance Criteria testing was undertaken on 15 soil samples. Of these samples, 10 are likely to be suitable for disposal in an inert landfill, with four likely to be suitable for disposal in a non-hazardous landfill. Based on the WAC testing, the sample identified as hazardous (HP01, 0.15m), is likely to be suitable for disposal in stable, non-reactive hazardous waste cells of a non-hazardous waste landfill.
During the gas and vapour monitoring, negligible concentrations of methane (0.1% v/v) were detected in all borehole installations. Carbon dioxide has been detected at a maximum concentration of 5% in BH03. Flow readings do not indicate a significant driving force behind the gas present as they are negligible. These readings were all taken during rising pressure conditions. A gas risk assessment has been undertaken in accordance with CIRIA (2007) guidance using the data and has established that all boreholes are classified as Characteristic Situation (CS) 1.
A groundwater risk assessment has been undertaken on the analysis of the samples taken during the three monitoring rounds. The assessment indicates slightly elevated
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levels of PAHs in the third round of monitoring at borehole BH01, and slightly elevated TPH in all boreholes. All other determinants were below assessment criteria.
Conceptual site model
9.4.35 A risk assessment and Conceptual Site Model (CSM) has been developed for the Proposed Scheme to identify the main potential land contamination impacts based upon baseline conditions and the GI data. The CSM is presented as a table in Appendix H and illustrated pictorially in Figure 9.2.
9.4.36 The methodology applied is based on guidance by CIRIA (2001) ‘C552: Contaminated Land Risk Assessment - A Guide to Good Practice’. Further details are presented in Appendix H.
9.4.37 The main risks identified from the CSM are as follows:
moderate to low risk to construction workers, groundwater, buildings and services and ecologically important sites;
moderate to low risk to future maintenance workers and surface water; and
low risk to current and future sites users and nearby site users.
9.5 Methodology and Assessment Criteria
Methodology
9.5.1 Assessment of potential impacts on or from geology and soils has been undertaken in general accordance with the guidance provided in DMRB, Volume 11, Section 3, Part 11 (Highways Agency et al., 1993b). However, DMRB provides limited detailed guidance on the assessment of potential impacts related to geology and soils and some of the guidance has been superseded since the document was produced. Therefore, an element of professional judgement has been applied when assessing impacts and the DMRB guidance has been adapted to take account of current legislation and guidance.
9.5.2 For the baseline assessment, a desk-based review has initially been undertaken for the Proposed Scheme to gather relevant information on baseline conditions of geology and soils along the route. The topics researched, and the sources of information consulted are given in the Baseline Environment section of this chapter.
9.5.3 The GI data has been assessed using methodologies outlined in Appendix G and a contamination source – pathway - receptor risk assessment has followed the methodology presented in Appendix H
Assessment of Magnitude and Significance
9.5.4 The potential magnitude of impact with respect to, or from, geology and soils within the study area are defined according to the criteria set out in Table E.1 in Appendix E. The sensitivity of features of interest with respect to potential impacts to, or from, geology and soils within the study area are defined according to the criteria set out in Table E.2 in Appendix E.
9.5.5 The assessment of significance of effect on geology and soils has been derived through consideration of the value/sensitivity of the receptor and the magnitude of change as shown in Table 4.2.
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Value of Receptors
9.5.6 From the baseline information presented in this chapter, a number of key receptors have been identified which could be impacted by the Proposed Scheme. These are presented in Table 9.1 below and the value/sensitivity of these receptors has been assessed using Table E.2 in Appendix E.
Table 9.1: Key receptor sensitivities
Receptor Description of Receptor Sensitivity Human health Construction workers, maintenance workers, Very High current and future site users and nearby site users.
Groundwater - River Terrace Deposits and Wittering Formation. High Secondary A Aquifer Surface water River Test. Medium Ecologically important Solent Maritime and Solent and Southampton Very High sites Water sites (Habitats Directive Site, Birds Directive Site, SAC, SPA and Ramsar site) and Lower Test Valley SSSI. Buildings and services Buried structures. Medium
9.6 Assessment Assumptions and Limitations
9.6.1 This assessment is based on a previous desk study review of a number of sources of information (identified in Section 9.4) that has been assumed to be reliable. The assessment has also been based upon the GI undertaken in 2017, which included chemical analysis of soil and groundwater and gas data obtained during subsequent monitoring.
9.6.2 The National Risk Register probability of a major urban accidents such as fires and explosions and oil spills occurring in the next five years is 2 (out of 5), with an impact severity of 3 (out of 5). The Proposed Scheme is a small road improvement scheme unlikely to cause fires and explosion or oil spills that would be classified as a major accident. Risk of major urban accidents from the Proposed Scheme are therefore scoped out of this chapter.
9.7 Potential Effects
9.7.1 Table 9.2 presents the potential effects to geology and soils during construction and operation phases of the Proposed Scheme.
Table 9.2: Geology and soils construction and operational phase effects
Receptor Potential effects Construction phase Human Health – construction Adverse health effects to construction workers during workers construction work involving ground disturbance from direct contact with potentially contaminated soil and groundwater through dermal absorption, inhalation and
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Receptor Potential effects ingestion of dust and inhalation of hazardous gases or vapours. Human health - general Adverse health effects to the general public from public, inhalation and ingestion of dust or exposure to mud or current and nearby site users runoff generated during the construction phase which could contain elevated concentrations of contaminants. Groundwater - Secondary A Reduced groundwater quality resulting from: Aquifer within the superficial accidental spills and leaks (from construction plant, deposits and bedrock site compounds, fuel storage areas, materials storage and stockpiling areas) or from the release of concrete and cement products during construction; reduced groundwater quality (from potential contamination migration of existing contamination and from potential contamination released or introduced during the works); and mobilisation and vertical migration of shallow contamination into underlying aquifer during installation of piled foundations. Surface water (River Test) Reduction in quality of surface water (River Test) as a result of release of contaminants via surface run-off from construction activities: release of concrete and cement products during construction; direct runoff from contaminated arisings and stockpiles; and release of suspended sediments from excavation/exposed ground. Ecologically important sites Damage to the ecological sites resulting from potential (Solent Maritime and Solent mobilisation or release of contamination to the and Southampton Water sites ecological sites. (Habitats Directive Site, Birds Directive Site, SAC, SPA and Ramsar site) and Lower Test Valley SSSI) Buildings and services Damage to building or services from explosion as a (onsite) result of the accumulation and migration of harmful gas and/or vapours, caused by ground disturbance or/and as a consequence of contact with aggressive ground conditions Operation phase Human health – maintenance Adverse health effects to maintenance workers from workers the potential inhalation of hazardous gases or vapours within enclosed spaces during routine maintenance work. Human health - general Adverse health effects to the general public from public exposure to contamination from spills from vehicles future and nearby site users and run-off, and other potential releases during
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Receptor Potential effects operation. No significant difference in risk is anticipated from current use. Groundwater - Secondary A Reduction in groundwater or surface water quality as a Aquifer within the superficial consequence of contamination from road operation. deposits and bedrock and Same level of risk as present situation. surface water Ecologically important sites Damage to the ecological sites resulting from release (Solent Maritime and Solent of contamination to the ecological sites from potential and Southampton Water sites spills during operation. (Habitats Directive Site, Birds No significant difference in risk is anticipated from the Directive Site, SAC, SPA and current use. Ramsar site) and Lower Test Valley SSSI) Buildings and services Damage to buildings and services as a consequence (onsite) of contact with aggressive ground conditions. No significant difference in risk is anticipated from the current use.
9.8 Design, Mitigation and Enhancement Measures
Construction Phase
9.8.1 Further works are required to assess potential effects to human health, ground water, surface water, buildings and services (on-site) and the ecologically important sites. A GI has been undertaken and the data used to assess the risks to identified receptors.
9.8.2 Based on the information and design, proposed mitigation is outlined in Table 9.3 to address the potential effects to geology and soils identified above. The proposed mitigations are discussed in further detail below Table 9.3. Primary, secondary and tertiary mitigation measures are outlined below. The assessment of likely significant residual effects from the Proposed Scheme with primary, secondary and tertiary mitigation are also summarised in Table 9.3. The likely significant residual effects have been assessed using Table 2.4 of DMRB Volume 11 Section 2 Part 5 HA 205/08 (Highways Agency et al., 2008a), with professional judgment applied.
Table 9.3: Proposed mitigation measures and summary of likely significant residual effects with the Proposed Scheme
Receptors Mitigation opportunities/enhancement (P = Residual primary mitigation, S = secondary mitigation, Effects T = tertiary mitigation) Construction phase Human health – A Construction Environmental Management Slight construction workers Plan (CEMP) should be prepared and adverse implemented to identify measures to control contamination risk (T). An asbestos response procedure should be developed in the event that suspected asbestos-containing materials were to be
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Receptors Mitigation opportunities/enhancement (P = Residual primary mitigation, S = secondary mitigation, Effects T = tertiary mitigation) identified during the works (T). A Scheme Asbestos Management Plan (SAMP) has been developed (Jacobs, 2018c). Recommendations for surveys and management should be adopted where intrusive works are proposed (T). Human health - A CEMP should be prepared and implemented Slight general public, to identify measures to control contamination adverse current and nearby site risk (T). users An asbestos response procedure should be developed in the event that suspected asbestos-containing materials are identified during the works (T). A SAMP has been developed (T). Groundwater - A CEMP should be prepared and implemented Slight Secondary A Aquifer to identify measures to control contamination adverse within the superficial risk (T). deposits and bedrock; A Piling risk assessment should be developed and and should include mitigation measures Surface water (River appropriate to the identified risks (S). Test) Ecologically important A CEMP should be prepared and implemented Slight sites (Solent Maritime to identify measures to control contamination adverse and Solent and risk (T). Southampton Water sites (Habitats Directive Site, Birds Directive Site, SAC, SPA and Ramsar site) and Lower Test Valley SSSI) Buildings and services Design foundations in accordance with BRE Slight (onsite) Special Digest 1 (2005) based on assessment adverse of aggressive ground conditions (P).
9.8.3 The majority of potential construction impacts from the Proposed Scheme can be controlled and mitigated by implementing a CEMP. Based on the GI (NCG, 2017) it is considered unlikely that substantial amounts of contaminated ground exist at the site. However, since the GI cannot fully investigate all ground within the Proposed Scheme area, it cannot be discounted that contaminants (including asbestos) could be present locally in areas not previously investigated (or assessed). It is therefore, recommended that measures to deal with any existing or unexpected contamination are included within the CEMP.
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Construction Environmental Management Plan
9.8.4 The CEMP is a principal mitigation measure for the Proposed Scheme and would be developed by the Principal Contractor based on the outline EMP (Jacobs, 2018b), produced as part of this PCF Stages 3 and 5. The outline EMP would form the base for the development of the CEMP by Principal Contractor prior to construction.
9.8.5 Mitigation measures which should be incorporated into the CEMP to include the following:
Control measures to deal with any contamination which could arise during the construction works. This should in turn include: - a watching brief method of working in place during future excavation works so that any suspected contaminated material not previously identified is properly identified and segregated to avoid worker exposure, cross contamination or production of preferential pathways. - if any significant areas of suspect contamination are identified through visual or olfactory evidence during the construction works or contamination is caused inadvertently during the works, representative samples should be taken of the suspect material by a suitably qualified person and sent for laboratory analysis to assess the risk to potential receptors. As a worst case, if significant contamination were found where ground works could not be avoided, then the material could need removal for treatment or disposal and replaced with clean material prior to groundwork re-commencing.
Control measures to ensure that discharges of potentially contaminated water to ground does not occur. Such measures could include using cut-off ditches or installing silt traps around excavation works or exposed ground and stockpiles to prevent the uncontrolled release of sediments or contaminants from accidental spillages to soil or groundwater or treating water prior to discharge.
Control measures to limit the potential impacts from concrete preparation. Measures should be put in place to ensure pre-mixing of the required concrete is undertaken off- site or in controlled areas of site compounds if feasible. Where this was not feasible the risks could be reduced by limiting the mixing and handling of wet concrete on site to designated areas where the release of runoff could be controlled and contained;
Control measures to mitigate any risks during dewatering (if required), to prevent the potential release of contaminated waters (in areas of shallow groundwater). Any contaminated water generated during dewatering should be collected and potentially treated prior to discharge.
Control measures to ensure that generation of dust is minimised and managed in accordance with best practice (e.g. suppression, damping down, wheel washing etc.). Dust Management Plan to be produced and included in Annex B of the CEMP prior to construction. If contamination is identified in soils during the works which could become airborne, monitoring of dust for both quantity and chemical and asbestos composition could be required to identify the level of risk and allow assessment of the effectiveness of mitigation measures. Areas of higher risk include open excavations, earth embankments and/or haulage routes.
Control measures to prevent the importation of contaminated or unsuitable fill materials to the site. Representative sampling of imported materials and materials excavated for re-use within the scheme could require chemical contamination testing for a range of soil and soil leachate analytical suites and assessment against appropriate limit values for protection of controlled waters and human health.
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Control measures to limit the spread of potential contamination and for the protection of any soil stockpiles.
Measures should be included to manage the boreholes installed during the GI. Boreholes should be decommissioned prior to the construction works unless required for monitoring purposes, as they could become potential pathways for surface derived contamination into groundwater if they were damaged or allowed to deteriorate. Any boreholes retained for monitoring should be protected so potential contaminants do not impact the underlying strata.
The monitoring of any mitigation measures should be undertaken during the construction works to ensure that protective measures are adequate and that the need for any corrective action is identified in a timely manner.
Gas risk mitigation measures
9.8.6 The gas data obtained during the GI does not indicate significant quantities of gas present nor significant driving force behind it which could force any gas present towards neighbouring residential properties. However, carbon dioxide has been recorded to be present up to 5% in the boreholes which exceeds the 1.5% workplace exposure limit set out in the HSE Guidance.
9.8.7 The gas data has been assessed using the guidance set out in CIRIA C665 (2007). All boreholes were identified as being of “Characteristic Situation 1”.
9.8.8 The risks from ground gas are considered to be very low. However, the potential to encounter gas could remain and should be considered within method statements and risk assessments, particularly for work in confined spaces.
Asbestos
9.8.9 An appropriate response procedure should be developed in the event that suspected asbestos-containing materials are identified during the works. The response procedure should meet the requirements of the Car-SoilTM Control of Asbestos Regulations 2012: Interpretation for Managing and Working with Asbestos in Soil and Construction & Demolition materials: Industry Guidance (CL:AIRE, 2016).
9.8.10 Although, no quantifiable asbestos has been identified from the GI, as stated in the CEMP section, a watching brief method of working should be in place during future excavation works.
9.8.11 With respect to the risks to off-site users from loose asbestos fibres present in the made ground, construction works have been assessed to present a low risk of exposure through the inhalation of airborne dust/fibres. This should be controlled and managed through adequate suppression and damping down of the soil during ground works.
9.8.12 An asbestos survey has been undertaken of structures within the Proposed Scheme area. Assessment of buildings, highway structures and general highway areas should be undertaken where intrusive works are planned during refurbishment, modification, demolition, reconstruction or extension.
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Other construction mitigation
9.8.13 A piling risk assessment should be undertaken for any areas where piling would potentially impact aquifers, to include appropriate mitigation measures once the risk assessment has been carried out.
9.8.14 Based on results of the GI, the nature of potentially aggressive ground conditions for buried structures has been established, and should inform the design of structures in contact with the ground, in accordance with British Research Establishment Special Digest 1 (2005).
Operation Phase
9.8.15 The operational impacts can be mitigated by Highways England or Southampton City Council incorporating standard highway design measures. On completion of works, most of the exposed ground surface would be covered with hardstanding or landscaping thereby preventing the exposure of future road users or users of surrounding land to possible contamination remaining beneath the site.
9.8.16 Following construction and during the road operation, regular monitoring and maintenance should be undertaken (managed by Highways England/Southampton City Council), to make sure that any protective measures put in place were adequate and that the need for any corrective action was identified in a timely manner.
9.8.17 Maintenance works are anticipated to be carried out periodically during operation and could require occasional excavation beneath the hardstanding or within verges and landscaped areas. If contaminated materials were identified during the construction works and remained beneath the road during operation, details of the locations and types of contaminants present would need to be included in the health and safety file for the Proposed Scheme. This would inform future maintenance workers and ensure appropriate precautions are taken during any works likely to disturb the material.
Mitigation of risk to surface waters
9.8.18 Mitigation measures for protection of surface waters are provided within Chapter 13 ‘Road Drainage and the Water Environment’ under ‘Design, Mitigation and Enhancement Measures’ section.
9.9 Residual Effects
9.9.1 Further details of the mitigation measures discussed above would be presented in the CEMP, pilling risk assessment, asbestos response procedure and SAMP. It is considered that with the above primary, secondary and tertiary mitigation measures employed during construction and operation phases of the Proposed Scheme, the significance of residual effects would be likely to be slight adverse for all receptors.
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10. Materials 10.1 Introduction
10.1.1 It is unlikely that the Proposed Scheme would cause any significant materials resources and waste generation effects during the operation phase due to similar maintenance requirements to the existing/current baseline condition. Effects to materials and waste during the operation phase of the Proposed Scheme have therefore been ‘scoped out’ and are not included in this EAR.
10.1.2 This chapter only assesses likely significant effects associated with the use of materials and the generation of waste associated with the construction of the Proposed Scheme. The assessment is based on IAN 153/11 Guidance on the Environmental Assessment of Material Resources (Highways Agency, 2011).
10.1.3 The consumption of material resources and generation of wastes could give rise to environmental impacts that would need to be managed and mitigated. Two main areas are assessed:
provision and use of materials resources; and
generation and management of wastes and the effect on waste management infrastructure.
10.1.4 Whilst the use of materials and the production of waste could potentially affect the full range of environmental media and assessment topics, their effect on the wider environment has been assessed as part of each of the technical chapters in this EAR.
Material Resources
10.1.5 Material resources include both primary materials, such as aggregates and minerals, and secondary manufactured products, such as recycled aggregates and plastics. Some material resources for construction of the Proposed Scheme would originate off-site and some would arise on-site, such as excavated soils, redundant street furniture or recovered material from demolished carriageways. The production, sourcing, transport, handling, storage and use of these materials, as well as the disposal of any surplus, all have the potential to affect the environment.
Waste
10.1.6 In considering material resource use and waste management, it is important to define when, under current legislation, a material is considered to be a waste. The Waste Framework Directive (European Directive 2006/12/EC, as amended by Directive 2008/98/EC) defines waste as any substance, or object, that the holder discards or is required to discharge. Some types of waste are harmful to human health, or to the environment, either immediately or over an extended period of time. These are defined as hazardous wastes.
10.1.7 Once a material has become waste, it remains a waste until it has been fully recovered and no longer poses a potential threat to the environment or to human health, at which point it is no longer subject to the controls required by the Directive. These principles are applied by the Environment Agency to waste used as aggregate/construction material in civil engineering applications. Construction wastes account for approximately three times as much waste as domestic waste from all UK households combined.
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10.2 Legislative and Policy Framework
10.2.1 There is a wide range of UK legislative instruments relevant to the management of waste and materials. A review of the legislation and planning guidance has identified key relevant statutory and policy requirements applicable to materials resource use and waste management for the Proposed Scheme. These are presented in Table 10.1.
Table 10.1: Applicable statutory and policy requirements
Reference Legal/policy requirements Council Directive By 2020, the recovery of non-hazardous construction (2008/98/EC) of the European and demolition waste shall be increased to a minimum Parliament and of the Council of 70% by weight. on Waste: Waste Framework Directive. Waste Management Plan for England (Defra, 2013). Highways Agency Procurement Strategy 2009 (Highways Agency, 2009b). Waste (England and Wales) ‘Take reasonable steps when transferring waste to Regulations 2011 apply the following waste management hierarchy; (a) prevention; (b) preparing for reuse; (c) recycling; (d) other recovery; and (e) disposal.’ Hazardous Waste (England These Regulations set out how wastes are defined as and Wales) Regulations 2005. hazardous due to the physical or chemical hazards they pose and the additional duty of care requirements this imposes. The Regulations require waste movements to be accompanied by a specific waste transfer note called a ‘consignment note’, which includes additional information such as the main chemical constituents, details of specific hazardous properties and how the waste is packaged. National Planning Policy for ‘Helping to secure the re-use, recovery or disposal of Waste (DCLG, 2014). waste without endangering human health and without harming the environment’ ‘The handling of waste arising from the construction and operation of development, maximises reuse/recovery opportunities, and minimises off-site disposal’. National Policy Statement for Advocates the ‘waste hierarchy’ principle. ‘Applicants National Networks (NPS NN) are required to minimise the amount of waste (DfT, 2014). produced and the volume of waste sent for disposal unless it can be demonstrated that an alternative approach results in the best overall environmental outcome. Waste must be managed properly both on and off-site, and must be dealt with appropriately by
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Reference Legal/policy requirements the waste infrastructure available’.
Hampshire Minerals and Sets out the long term spatial vision and strategy for Waste Plan 2013-2030 (HCC, sustainable minerals and waste development in 2013). Hampshire until 2030. Policy 25 outlines the goals of 60% recycling and 95% diversion from landfill by 2020. The objective within Hampshire is to reuse, recycle and recover as much construction, demolition and excavation waste generated within the county as possible.
10.2.2 The UK Government removed the statutory requirement for Site Waste Management Plans (SWMP) in October 2013. SWMPs were previously required for construction and demolition projects in England. However, as their use is considered good practice, any requirements to ensure that demolition and construction wastes are dealt with in an appropriate manner and in accordance with the waste hierarchy, would be met and secured by using a SWMP. This approach is consistent with the guidance in the NPS NN (DfT, 2014) to implement sustainable waste management through the application of the waste hierarchy.
10.2.3 Waste management is structured around a ‘waste hierarchy’, defining the order of preference of the various options. Figure 10.1 illustrates the waste hierarchy in diagrammatic form.
Figure 10.1: The waste hierarchy
10.2.4 Generally, all legislation and policy drivers aim to increase the efficiency of resource use, minimise waste, maximise the re-use/recycling/recovery of waste, and reduce carbon emissions.
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10.3 Study Area
10.3.1 The study area for materials and waste assessment is split into two parts:
All land contained within the Proposed Scheme boundary, within which materials would be contained and waste generated and managed including any areas identified for temporary uses. Such temporary land could include temporary storage areas for soils and other materials, construction compounds, haul-roads and land for temporary construction site drainage.
The study area for the baseline has been extended to include the locations of raw materials production (such as quarries) and waste management facilities and associated transportation network within Southampton City Council and Hampshire County Council.
10.4 Baseline Environment
Baseline Sources
10.4.1 Baseline information has been obtained from a number of sources including the Hampshire Minerals & Waste Plan (HMWP) (HCC, 2013), HMWP Local Aggregate Assessment (HCC, 2016) and the Environment Agency (EA, 2017b).
Baseline Conditions
Materials
10.4.2 The principal materials used in road construction are aggregates, including sand and gravel. Primary aggregate’ “is the term used for aggregate produced from naturally occurring mineral deposits and used for the first time” (BGS, 2013). The Proposed Scheme would require materials to create the new carriageway, footpaths/cycleway, resurfacing and associated infrastructure. This could include the use of primary materials or secondary recycled materials e.g. recycled concrete sources on site, or recycled materials brought in from off site, possibly from another nearby construction project.
10.4.3 The HMWP was jointly adopted by Hampshire County Council, Southampton City Council, Portsmouth City Council, the New Forest National Park Authority and the South Downs National Park Authority in 2013. The HMWP includes a local aggregates assessment with the latest update published in December 2016 (HCC, 2016). This assessment concludes that ‘Hampshire has a full range of supply options available to meet aggregate needs within the HMWP area, including recycled and secondary aggregate, imported materials, marine-won and land-won aggregates’. Table 10.2 shows the average sales and extraction rate of materials within Hampshire.
Table 10.2: Aggregate sales and extraction rate in Hampshire 2016
Average 3 year Local aggregates assessment sales (Mt) extraction rate (Mt) All sand and gravel 0.9 1.6 Recycled/ secondary aggregates 1.0 0.8 Marine sand & gravel 1.5 1.4 Rail depot sales (crushed rock) 0.4 0.5
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10.4.4 The HMWP indicates the combined landbank for sand and gravel would be sufficient for Hampshire’s needs, and therefore it is expected that majority of aggregates used for the completion of construction of the Proposed Scheme would be locally sourced.
10.4.5 The other materials needed for the Proposed Scheme, for example, steel, plastic and pre- cast concrete would be likely to be transported from areas further afield due to the availability of the required materials.
10.4.6 Due to EU competition regulations, it is not possible to prescribe material sources. Based on current data and the information detailed above, it is inferred that there would be likely to be primary aggregates available locally during the lifetime of the Proposed Scheme. Potential sources of alternative aggregates would be investigated at the construction stage, including opportunities to reuse materials from other major development sites in the area at the time.
Waste
10.4.7 The Proposed Scheme would potentially produce a range of waste types including inert, non-hazardous and small volumes of hazardous wastes. The majority of wastes assumed to be produced are construction and demolition wastes. There would also be a small amount of non-construction and demolition waste associated with construction workers including packaging, food waste and sewerage.
10.4.8 The HMWP local aggregate assessment (HCC, 2016), estimates the current capacity for the production of recycled aggregate in Hampshire to be just less than 2.6 million tonnes. This capacity is based on assessment of facilities able to recycle materials according to the standards set out in the Waste and Resources Action Programme (WRAP) Protocol for the Production of Aggregates from Inert Waste (WRAP and EA, 2012). This figure is reported to be significantly greater than sales of this type of recycled aggregate over the last 10 years (0.8 million tonnes per annum) indicating significant spare headroom capacity for treatment of materials arising from the Proposed Scheme.
10.4.9 In September 2017, the Environment Agency released the 2016 waste management data tables (EA, 2017b). This data shows a total of 7,022,000 tonnes of permitted waste transfer capacity and 11,624,000 tonnes of permitted treatment capacity (including the metal recycling sector) in the south-east of England in 2016. In addition to the transfer and treatment capacity, the Environment Agency data tables show a total of 3,203,000 tonnes of incinerator capacity in 2016 in the south-east of England, including 567,000 tonnes of capacity within Hampshire.
10.4.10 Table 10.3 provides details of some of the waste transfer and waste treatment management facilities and their distance from the Proposed Scheme. This information has been taken from the Environment Agency’s Waste Data Interrogator 2015 (EA, 2015). This is not an exhaustive list of waste management facilities but provides an overview of the different facilities that are located near to the Proposed Scheme.
Table 10.3: Transfer and treatment facilities and distance from the Proposed Scheme
Name of transfer and treatment Type of facility Distance facilities (km) Lee Lane Quarry Physical Treatment 4 R F S F Recycling Physical Treatment 14
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Name of transfer and treatment Type of facility Distance facilities (km) Rookery Farm Aggregate Recycling Physical Treatment 17 Facility Wessex Demolition and Salvage Material Recycling Facility 19 R & R Contractors Non-Haz Waste Transfer 25 Down End Wood Transfer Facility Composting 28 Courtwood Farm Non-Haz Waste Transfer/Treatment 31 Chilbolton Down Composting Composting 31 Facility A303 Recycling Facility Physical Treatment 32 Transfer Station At Quay Lane Non-Haz Waste Transfer/Treatment 34 Taurus Waste Recycling Ltd Non-Haz Waste Transfer 34 Solent Waste Services Ltd, Toronto Non-Haz Waste Transfer 35 Place, Gosport Home Farm Transfer Station Non-Haz Waste Transfer 38 Windmill Down Farm Waste Inert Waste Transfer/Treatment 41 Transfer Station Havant Waste Transfer Station Non-Haz Waste Transfer 45 Alton Waste Transfer & Recycling Non-Haz Waste Transfer 53 Centre Wade Road Non-Haz Waste Transfer 54 37 Hollybrook Pk, Bordon Inert Waste Transfer 59 Whitehouse Farm Transfer Station Haz Waste Transfer 66 Eversley Haulage Park Material Recycling Facility 66 Warren Heath Recycling Facility Physical Treatment 67 Aldershot Recycling Facility Physical Treatment 74 Hollybush Lane Waste Transfer Physical Treatment 74 Station & Recycling Facility 1a Hollybush Industrial Park Haz Waste Transfer/Treatment 83
10.4.11 In accordance with the waste hierarchy the disposal of waste would only be considered if recycling or recovery was not possible. The Environment Agency data tables show a total of 76,979,000 cubic metres of landfill capacity within the south-east of England, including 560,000 cubic metres of hazardous landfill capacity. An indication of the availability of landfill in close proximity to the Proposed Scheme is provided in Table 10.4 including the type, and locations of the landfills, based on data available within the Environment Agency Waste Data Interrogator 2016 (EA, 2016). Due to the distance of the hazardous landfill within south-east England to the Proposed Scheme the sites within the south-west are also presented below, the capacity of these landfills in the south-west in 2016 was 1,748,000 cubic metres.
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Table 10.4: Landfill category and distance from the Proposed Scheme
Landfill Landfill Distance category (km) Bleakhill Landfill Inert 40 Squab Wood Landfill Non hazardous 15 Blue Haze Landfill Non hazardous 35 Apsley Farm Landfill Non hazardous 52 Parkgate Farm Hazardous Landfill (south-west England) Hazardous 124 Wingmoor Farm (south-west England) Hazardous 164 Pinden Quarry Landfill (south-east of England) Hazardous 177
10.5 Methodology and Assessment Criteria
Methodology
10.5.1 The Proposed Scheme encompasses modification and upgrading of an existing road junction and roundabout. Materials and waste impacts of the Proposed Scheme would be small scale (compared to construction of new roads, or major works on extensive lengths of existing roads). However, IAN 153/11 indicates that projects with an estimated cost greater than £300,000 (such as this scheme) have the potential for impacts and effects resulting from the use of materials and the generation of waste. As such, schemes >£300,000 should be subject to assessment.
10.5.2 It is therefore appropriate to complete the assessment of the default design broadly in accordance with the ‘Detailed Assessment’ approach for the default scheme design. However, although the project is currently at PCF Stages 3 and 5, there remain some limitations regarding estimations of quantities of wastes and materials.
Assessment of Magnitude and Significance
Materials
10.5.3 This section considers the potential environmental impacts and effects associated with the use of materials and the production and management of waste during the construction of the Proposed Scheme in accordance with Highways England IAN 153/11 (Highways Agency, 2011a) and professional judgement. In terms of materials resource depletion there is no guidance given in either DMRB HA 205/08 (Highways Agency et.al., 2008a) or IAN 153/11 (Highways Agency, 2011) for assessment of significance of impact in relation to this topic. Therefore, the assessment for materials is based on the quantification of the carbon footprint of the materials used as a proxy for other environmental effects.
10.5.4 This methodology does not include sensitivity/value criteria for the carbon footprint assessment, which would need to be accounted for to derive the significance of any effect, and only magnitude is used to describe the impact. Levels of magnitude are defined in Table E.1 in Appendix E. The magnitude of effects associated with material use for the default design has been derived from a calculation of embodied carbon associated with those materials known to be required for the construction of the Proposed Scheme using Highways England’s Carbon Tool (2016).
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Waste
10.5.5 The published guidance does not provide definitions for receptor sensitivity/value or significance of impact in relation to waste. Therefore, professional judgement has therefore been used to determine sensitivity, magnitude and significance criteria for this topic.. Magnitude and sensitivity criteria for waste are provided in Table E.1 and Table E.2 in Appendix E, respectively.
10.5.6 Determination of the sensitivity of waste management facilities is based on the available waste management capacity. For example, a high sensitivity waste management operation (or even the whole waste management infrastructure in the area) could be considered to have very limited capacity for the waste type requiring treatment/disposal. This could be particularly true of hazardous or difficult wastes where local capacity is limited. Low sensitivity operations/local infrastructure could be considered to be large, or numerous waste management sites with plenty of capacity to deal with the waste arisings.
10.5.7 Assessment of significance of effect on waste has been derived through consideration of the value/sensitivity of the receptor and the magnitude of change as shown in Table 4.2.
Value of Receptors
10.5.8 Receptor types likely to be at risk of impacts under this topic include:
resource depletion from quarries, other sources of minerals and other finite raw material resources;
the capacity of waste management infrastructure, such as landfills, materials recovery facilities, composting sites and energy from waste plant etc.; and
policy and targets relevant to materials and waste.
10.6 Assessment Assumptions and Limitations
10.6.1 Detailed information on materials requirements and waste generated, such as the exact sources/origins of materials, is not available at this time. Information on the permitted capacity of waste treatment and disposal facilities are provided in the baseline Section 10.4; however, it should be noted that changes to this permitted capacity both before and during the construction of the Proposed Scheme cannot be identified at this stage.
10.6.2 Baseline information, potential impacts and mitigation are described based on published information (e.g. environmental permits) regarding mineral quarries and waste management facilities, etc. The level of detail with regards to materials required for, and wastes to be generated by, the Proposed Scheme is limited by the design information available to estimate material use and waste management requirements. Estimated quantities in this assessment can only be taken as approximate and indicative based on the design and available information.
10.6.3 Further details on contaminated soils are available in Chapter 9 ‘Soils and Geology’.
10.6.4 The operation effects of the Proposed Scheme, associated with ongoing maintenance works, would be relatively unchanged compared to the existing situation, as the Proposed Scheme involves improvement of an existing road junction. Existing maintenance activities include inspection and repair of barriers and signage, drain inspection and clearance, road repairs and road verge/vegetation maintenance (amongst other activities). For Highways England and parties acting on their behalf, future maintenance activities would include broadly the same tasks. In terms of materials resources and waste generation, operational
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effects are therefore considered likely to be insignificant and have, therefore, been scoped out of the assessment.
10.6.5 In addition, some environmental impacts associated with the extraction and transport of primary raw materials and manufactured products would occur off-site. The source and processing/manufacture of materials cannot be determined, and the production of these materials would be likely to have been the subject of separate consent procedures (such as applications for planning permission and environmental permits) which could have included environmental assessment. Therefore, it is outside the scope of this assessment to consider environmental impacts associated with the extraction of raw materials, the manufacture of products and the transport of materials and wastes.
10.7 Potential Effects
10.7.1 Potential environmental impacts associated with material resources and the generation of waste would occur at each stage of the Proposed Scheme’s material flow cycle. Figure 10.2 below is a simplified diagrammatic representation of materials resource flows identifying material resource use and the management of waste.
Figure 10.2: Project material flow diagram (Highways Agency, 2011)
Materials
10.7.2 The types of materials likely to be required for construction are common to all road schemes. Indicative estimated quantities of the major materials required are provided in Table 10.5.
Table 10.5: Summary of estimated main materials types and quantitates
Proposed Material resource required for the Quantities of material Scheme activity Proposed Scheme resource required Site preparation No anticipated material requirements N/A and clearance during demolition Demolition No anticipated material requirements N/A during demolition Site construction Imported fill materials 2,826m3 Pavement (including base) 1,323m3
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Proposed Material resource required for the Quantities of material Scheme activity Proposed Scheme resource required Civils - Concrete (including pavement 1,851t concrete slab) Concrete (in-situ) 514m3 Soils – Top soil 1,067m3 Steel (including footbridge structure) 35t Steel (including length of safety barriers) 406m Drainage Plastic pipework: 150 mm 213m 225 mm 51m Pre-cast concrete pipework: 225 mm 24no. 900 mm 30no. Pre-cast concrete manholes: 900mm up to 3m 5no. 1200mm up to 3m 1no. 1500mm up to 3m 2no. 1800mm up to 3m 1no. Cable (power cable) 255m Cable ducting 255m Road signs 32no. Operation and N/A N/A maintenance
Earthworks
10.7.3 Existing soils, infrastructure and demolition materials are considered to be potential material resources. The following outlines the anticipated cut and fill volumes for the Proposed Scheme:
Approximate cut volume 1,070m3
Approximate fill volume 3,896m3
Volume difference 2,826m3
10.7.4 It is estimated that a minimum of 2,826m3 of additional fill would be needed to be imported onto site for the default design of the Proposed Scheme.
10.7.5 Potential environmental impacts of materials include those associated with the extraction and transport of primary materials, the processing and manufacture of secondary materials, and the transportation of both primary and secondary materials to use on construction sites are excluded from this assessment as detailed in 10.6.5.
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Carbon
10.7.6 The total embodied carbon of the materials to be used has been calculated using the Highways England’s Carbon Tool v1.03. Table 10.6 provides estimates of the embodied carbon contained within the main materials as detailed Table 10.5 that would be used to construct the Proposed Scheme. Accordingly, using the assessment methodology set out below, the magnitude of the impact has been assessed to be 1,171 tonnes CO2e, representing a negligible impact for materials use.
Table 10.6: Estimated embodies and transport carbon for the Proposed Scheme
Carbon source Total carbon dioxide equivalent
emissions CO2e (tonnes) Imported fill materials (including topsoil) 79 Road pavement (new asphalt) 638 Concrete (non-structural – subway fill and 75 foundations) Civil Structure (concrete and steel for 315 footbridge) Steel (including safety barriers, pedestrian 22 gantry/parapet) Street furniture (Signs and lighting (including 10 cables and ducting) Drainage 26 Total 1,171
10.7.7 It should be noted that the carbon emissions associated with the transport of materials to the site have not been assessed as the source of the materials is not known at this time. However, wherever possible materials would be sourced locally, thereby minimising the associated transport distances and carbon emissions.
Waste
10.7.8 Most of the waste generated by the Proposed Scheme would be Construction and Demolition (C&D) type waste. The C&D wastes most relevant to this Proposed Scheme are inert wastes including aggregate. In addition, off-cuts and waste timber, plastics, packaging and mixed waste could be included.
10.7.9 For wastes and surplus or defective materials, impacts are primarily associated with the production, movement, transport and processing (including recycling/recovery) of the wastes on and off-site and, if required, their disposal at licenced off-site facilities.
10.7.10 The potential quantities of wastes are largely unknown at this stage, but wastage rates from WRAP’s The Designing Out Waste Tool for Civil Engineering Projects (WRAP, 2010) of between 2.5% and 5% are considered to be ‘good wastage rates’ have been applied to the construction materials to estimate the waste arisings generated during the construction stage of the Proposed Scheme.
10.7.11 The following table summarises the expected types of waste to be generated by the Proposed Scheme.
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Table 10.7: Key waste types and estimated quantities generated by the Proposed Scheme
Project Potential wastes sources Quantities of Additional information on activity and possible waste forecast waste arising classifications to be produced Site Site clearance, site Vegetation Vegetation waste would preparation preparation works and clearance - be used on-site wherever and groundworks 19,929m2 possible or taken off-site clearance for composting. Unknown Existing earthworks from quantities of excavations to be reused inert waste from on-site wherever possible. excavation Demolition Break up and removal of 2,590m2 It is expected that up to redundant pavement 95% of the road planings would be reprocessed and incorporated into the new subsurface. The remaining 5% would need an alternative outlet. Taking down and reuse of 27no. Plan to segregate and street furniture on-site reuse material on-site. Taking down and removal 61no. Plan to segregate and of street furniture for recycle materials off-site recycling/ disposal off-site wherever possible. Taking down and removal 636m Plan to segregate and of safety barrier and guard recycle materials off-site rail wherever possible. Taking down and removal 226m Plan to segregate and of fencing recycle materials off-site wherever possible Taking down and removal 1,045m Plan to segregate and of kerbing recycle materials off-site wherever possible Demolition of existing Unknown Plan to segregate and footbridge quantities recycle materials off-site wherever possible Partial demolition of Unknown Plan to segregate and existing south subway quantities recycle materials off-site wherever possible Site Reject imported fill 71m3 Quantities are estimates Construction materials only. Reject pavement 33m3 Plan to segregate and (including new asphalt) recycle materials off-site wherever possible Reject concrete 46t Reject drainage pipework: 6m Plastic 2no. Pre-cast concrete
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Project Potential wastes sources Quantities of Additional information on activity and possible waste forecast waste arising classifications to be produced Reject Steel (including 1tonne footbridge structure) Reject Steel (including 10m safety barriers, pedestrian gantry/parapet) Reject Signs and lighting N/A (including LED lights) Operation Small amounts of waste Unknown Types and quantities and likely to be produced on quantity similar to current wastes maintenance an ongoing basis. Unlikely from maintenance to be significant. activities.
10.7.12 A potential impact is the risk of utilising the capacity of waste management treatment or disposal facilities, either through permanent or temporary severance of access to existing waste management sites, or by filling a local waste management facility up to capacity with wastes. This could force locally-produced wastes to be transported greater distances for disposal elsewhere. However, considering the volumes of waste generated by the Proposed Scheme, this is considered to be unlikely.
10.8 Design, Mitigation and Enhancement Measures
10.8.1 There is significant synergy between materials re-use and the avoidance of the generation of waste and a substantial overlap between the mitigation measures for materials and waste. Structures, drainage, road restraint systems, street lighting and signage products would be procured with consideration of the environmental impacts associated with their manufacture, as well as other considerations such as structural design, carbon footprint, energy consumption, long-life performance, visual impacts, durability and cost. Both reinforced concrete and steel structures include a measurable recycled content in their manufacture. Where possible, the availability of responsibly sourced local and recycled materials would be considered to reduce potential environmental effects, such as from transport emissions.
10.8.2 The choice of whether to use primary or secondary aggregates (or a combination of both) would be made considering a combination of factors such as performance requirements, value for money, materials source, specification, production and transport. Secondary (recycled) aggregates may not always have the lowest impact on the environment and materials would be selected based on a consideration of all relevant factors (including transport impacts, carbon benefits and reduction of impacts associated with extraction of virgin aggregates).
10.8.3 Within design and during construction the principles of the waste hierarchy (see Figure 10.1) would be applied to minimise waste generation and maximise re-use of materials on- site as tertiary mitigation, where possible. Where re-use is not possible, alternative options would be sought off-site such as reprocessing into aggregate or the use of inert materials on local farms.
10.8.4 For all potential waste arisings, the contractor would be required to comply with The Environmental Permitting (England and Wales) Regulations 2015. Consideration would
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also be given to The Definition of Waste: Development Industry Code of Practice (Contaminated Land; Applications in Real Environments (CL:AIRE, 2011), and appropriate Environment Agency Pollution Prevention Guidelines (PPGs)3. In addition, WRAP’s ‘Designing out Waste: A Design Team Guide for Civil Engineering’ (WRAP and EA, 2012) would be utilised by the contractor and referenced in the SWMP.
10.8.5 If necessary, the contractor would consult the Environment Agency for advice. If wastes could not be legitimately re-used on site, they would be removed using a licenced carrier to a permitted recycling or disposal facility in line with regulatory requirements.
10.8.6 The above would provide a framework to support HMWP (2013 – 2030); Policy 30: Construction, demolition and excavation waste development (HCC, 2013), which states:
10.8.7 “Where there is a beneficial outcome from the use of inert CDE waste in developments, such as the restoration of mineral workings, landfill engineering, civil engineering and other infrastructure projects, the use would be supported provided that as far as reasonably practicable all materials capable of producing high quality recycled aggregates have been removed for recycling.
10.8.8 Development to maximise the recovery of (CDE) waste to produce at least 1 million tonnes per annum of high quality recycled/secondary aggregates will be supported”
10.8.9 The above also aligns with the New Forest District Council Local Development Framework, Core Strategy, New Forest District outside the National Park (NFDC, 2009), which provides the following within the Core Strategies (CS):
Policy CS1 Sustainable development principles: (d) ensuring building construction and other forms of development adheres to high environmental standards with particular regard to energy efficiency, water efficiency, use of sustainable materials and the minimisation of waste (as further developed in Policy CS4).
Policy CS4 Energy and resource use: (d) use recycled materials in construction where possible.
10.8.10 The local plan is currently under review and any materials or waste policies included within the reviewed local plan would need to be complied with to be in line with local policy. This would be assessed during development of the CEMP and SWMP as described below.
Construction Environmental Management Plan
10.8.11 A principal mitigation measure would be the development and implementation of a CEMP. The CEMP would be developed by the Principal Contractor prior to construction works and implemented during PCF Stage 6 – Construction, Commissioning and Handover. The Outline EMP (Jacobs, 2018b), produced as part of PCF Stages 3 and 5 forms the base for the development of the CEMP by the Principal Contractor. The CEMP would include the following:
Details of the approach to environmental management throughout the construction phase, with the primary aim of mitigating any adverse impacts from construction activity on identified sensitive receptors.
Procurement and waste management protocols/KPIs and targets designed to minimise impacts on the environment and maximise local procurement of materials and waste management options.
3 Note: all PPGs were withdrawn in December 2015 but are still available through the National Archives, and are still considered to contain useful ‘good practice guidance’ applicable to the Proposed Scheme
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Good materials management methods, such as recovery and re-use of temporary works materials, as well as use of ‘just-in-time’ delivery to minimise double handling etc.
To minimise effects on amenity, materials for import and waste disposal would be transported appropriately along prescribed routes. Prescribed routes would be included in the main construction contract documents. The Contractor would be required to seek approval from the relevant authority should they wish to use any other routes.
Risk/impact-specific method statements and strategic details of how relevant environmental impacts would be addressed throughout the Proposed Scheme.
Implementation of a Site Waste Management Plan
10.8.12 Though not now mandatory in the UK, a SWMP would be developed, either as part of the CEMP or as a separate document, and would be regularly updated during construction of either option. The plan would identify, prior to the start of construction works, the types and likely quantities of wastes that could be generated. It would set out, in an auditable manner, how waste would be reduced, re-used, managed and disposed of in accordance with WRAP Guidance. The SWMP would be developed by the Principal Contractor using the Outline SWMP provided in the outline EMP (Jacobs, 2018b) in PCF Stages 3 and 5 as a guide, before commencement of the construction phase and any advanced works contract and would include waste minimisation targets and associated KPIs.
10.8.13 The SWMP would set out how all construction phase materials would be managed. This could include specific soils management plans developed under the following voluntary and industry regulated Codes of Practice such as:
Construction Code of Practice for the Sustainable Use of Soils on Construction Sites (Defra, 2009) provides guidance for the excavation, handling, storage and final placement of soils; and
Definition of Waste: Development Industry Code of Practice (CL:AIRE, 2011).
10.8.14 These provide a process whereby contaminated soils can be re-used on the site of origin (i.e. they do not become a waste) if they are proven, through appropriate risk assessments, to be suitable for use. They also provide for soils with elevated contamination levels to be used directly on another site provided that they are suitable for use at that site.
10.8.15 Implementation of the SWMP would minimise waste at source, specified during detailed design and construction, by facilitating measures to maximise re-use of materials on-site and reduce the need for new construction materials. Regular reviews of, and updates to, the SWMP would enable the monitoring of the effectiveness of mitigation measures in minimising waste generation, especially disposal to landfill.
10.8.16 Where materials generated during construction cannot be used for the Proposed Scheme, opportunities would be sought to re-use the materials on other local schemes.
10.8.17 It could be possible to recycle all, or most, of the road surface (planings) for incorporation in other schemes or for sale to other local construction projects. The Environment Agency Regulatory Position Statement 075 (EA, 2014) applies to the movement and reuse of the road planings produced during the demolition phase. It is currently expected that 95% of the road planings arising would be recycled into the base course, with the remaining 5%
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requiring an alternative outlet. The contractor would need to ensure compliance with relevant legislation when considering the reuse of this material.
10.8.18 Where suitable, green waste would be recycled, such as through on-site landscaping or ecological improvement works; for example, for habitat creation, or spread as chippings or mulch, with appropriate consideration and control of any pollution risk. Green waste could also be taken off-site for composting at a suitably permitted waste management facility.
Hazardous wastes
10.8.19 If contaminated soils are encountered during the construction works, further investigation, testing and risk assessment would be undertaken to determine whether the soils could either stay on-site, require treatment to make them suitable to remain on-site, or would need to be disposed of off-site. Details for dealing with unexpected contaminated soils would be included in the CEMP. Due to the nature of the works it is not anticipated that there would be significant quantities of other hazardous wastes generated.
10.8.20 Please refer to Section 9.8 under Chapter 9 ‘Geology and Soils’, for mitigation on encountering asbestos during construction works.
Summary of mitigation
10.8.21 Table 10.8 below summarises, the general mitigation tools and processes that would be adopted for the Proposed Scheme in relation to managing materials resource and waste. The assessment significant residual effects following mitigation is provided in Section 10.9.
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Table 10.8: Summary of mitigations measures
Scheme activity Potential effects Description of mitigation measures How the measures would be implemented, associated with material (P = primary mitigation, S = secondary measured and monitored resource use/waste mitigation, T = tertiary mitigation) management Site remediation/ Disposal of demolition Site waste Management Plan (SWMP) Implemented by contractor. Use of Preparation/ wastes and soils including use of targets as Key Performance weighbridge records and waste transfer Demolition unsuitable for use on-site Indicators (KPIs) (T). Market testing for the notes. Audited regularly by Environmental use of wastes off-site via the materials Clerk of Works (ECoW). Set aside areas for exchange (S). Pre-demolition audit to storage of waste for appraisal/treatment as identify wastes (S). appropriate. On-site use of demolition Materials Management Strategy with Incorporation of on-site recovered materials in wastes, soils and green Construction Environmental Management detailed design. Implemented by contractor. waste Plan (CEMP) (T), SWMP and KPIs (T). Audited regularly by ECoW. Production of hazardous Contaminated land risk assessment and Use of weighbridge records and special wastes SWMP (T). On or off-site treatment of waste transfer notes. Audited regularly by contaminated soils for any other hazardous ECoW. wastes identified on-site, as appropriate (S). Construction Material use and Materials management Strategy within Procurement policies to be implemented by depletion (e.g. virgin CEMP (T). Use of procurement policies, the contractor. Measured via weighbridge aggregates) targets and KPIs to maximise local sourcing records and receipts and analysis of of materials and the inclusion of as much procurement criteria used for specific recycled content as practicable in materials. Audited regularly by ECoW. Set accordance with the required specifications aside areas for storage of materials for re- of the construction material (S). use. Carbon footprint of As above. As above. Procurement policies to include materials use whole life CO2 emissions data as a KPI for all materials. Transport of materials As above and use of ‘just-in-time’ delivery to Procurement and waste management policies and wastes (carbon minimise double handling (S). Traffic and sensitive routing arrangements to be footprint impact) management to minimise effects on amenity implemented by the contractor. Measured via
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Scheme activity Potential effects Description of mitigation measures How the measures would be implemented, associated with material measured and monitored (P = primary mitigation, S = secondary resource use/waste mitigation, T = tertiary mitigation) management (S). weighbridge records and receipts and analysis of procurement criteria used for specific materials. Audited regularly by ECoW. Wastes from materials SWMP and KPIs (T). Provision of Implemented by contractor. Use of use and municipal solid segregation facilities (S). weighbridge records and waste transfer waste production notes. Audited regularly by ECoW.
10.9 Residual Effects
10.9.1 Assessment of significant residual effects of the Proposed Scheme to materials and waste with mitigations during the construction phase is provided in Table 10.9. It is considered that with the above mitigations, the Proposed Scheme would not likely cause significant residual effects to materials and wastes during the construction and operation phases.
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Table 10.9: Assessment reporting matrix (adapted from IAN 153/11 (Highways England, 2011)
Potential effects Description of the effects Likely sensitivity and Brief description of mitigation Residual magnitude of effect measures effects During site clearance preparation and demolition On-site use of Suitable soils would be stored and Low sensitivity. Implementation of waste management Neutral demolition reused on the Proposed Scheme in arrangements would be in accordance wastes, inert landscape areas. Inert materials Negligible - short- with the management strategy set out in materials, soils generated could be reused on-site term, permanent and the Construction Environmental and green waste where possible for subbase or direct adverse Management Plan (CEMP), including drainage works. impact. Site Waste Management Plan (SWMP) and Key Performance Indicators (KPIs). Treatment of Some of the demolition waste, inert Low sensitivity. Implementation of waste management Neutral or demolition materials and soils would be unsuitable arrangements would be in accordance slight wastes, inert for reuse on-site. Thus, this would Minor - short-term, with the management strategy set out in adverse materials and need to be taken off-site for recycling. permanent and direct the CEMP, including SWMP and KPIs. soils unsuitable If waste required treatment off-site, adverse impact. Market testing for the potential for for use on-site there is recycling treatment available in wastes to be used off-site. the Hampshire Waste Management Plan (HWMP) area. If waste could be reused at other construction sites, the magnitude of effect would be further reduced. Disposal of Some of the demolition waste, inert Low sensitivity. Implementation of waste management Slight demolition materials and soils would be unsuitable arrangements would be in accordance adverse wastes, inert for reuse on-site. Thus, this would Major - long-term, with the management strategy set out in materials and need to be taken off-site for disposal. If permanent and direct the CEMP, including SWMP and KPIs. soils unsuitable waste required disposal off-site, there adverse impact. Market testing for the potential for for use on-site is landfill capacity available in HWMP wastes to be used off-site. area. Due to the quantity of waste produced by the Proposed Scheme the significance has been assessed as
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Potential effects Description of the effects Likely sensitivity and Brief description of mitigation Residual magnitude of effect measures effects slight. Production of Low volumes of hazardous waste Low sensitivity. Implementation of waste management Slight hazardous would be expected to be generated, arrangements would be in accordance adverse wastes and facilities for hazardous waste are Major - long-term, with the management strategy set out in present in south-east and south-west permanent and direct the CEMP, including SWMP and KPIs. of England. It has been assumed that adverse impact. 95% of the road planings would be recycled and reused. Due to the quantity of waste produced by the Proposed Scheme the significance has been assessed as slight. During construction Material use and Materials predominantly available N/A Implementation of waste management Neutral depletion (e.g. locally and additional methods to arrangements would be in accordance virgin reduce the use and impacts of external with the management strategy set out in aggregates) primary materials would be considered the CEMP, including SWMP and KPIs. throughout the development of the Maximise local sourcing of materials Proposed Scheme. This could include and the inclusion of as much recycled reuse of on-site materials and use of content as practicable. Maximise the secondary/recycled materials locally use of on-site material, wherever and responsibly sourced. practicable. Due to the quantity of material required by the Proposed Scheme the significance has been assessed as neutral.
Carbon footprint It is estimated that 1,171 tonnes CO2e Negligible. As above. N/A of materials use would be produced as a result of the material use on the Proposed Scheme. Reuse of surplus Suitable materials from cut and fill Low sensitivity. Implementation of waste management Neutral
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Potential effects Description of the effects Likely sensitivity and Brief description of mitigation Residual magnitude of effect measures effects construction would be stored and reused on-site. arrangements would be in accordance materials and Inert materials generated could be Negligible – short- with the management strategy set out in waste on-site reused on-site where possible for term, permanent and the CEMP, including SWMP and KPIs. subbase or drainage works. direct adverse.
Recycling of Some of the surplus construction Low sensitivity. Implementation of waste management Neutral or surplus materials and waste would be arrangements would be in accordance slight construction unsuitable for reuse on-site. It is Minor magnitude, with the management strategy set out in adverse materials and assumed that any surplus materials or short-term, the CEMP, including SWMP and KPIs. waste waste would be segregated at the site permanent and direct prior to being taken off-site for adverse impact. recycling. If waste required recycling off-site, then there is recycling capacity available in HWMP area.
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11. Noise and Vibration 11.1 Introduction
11.1.1 This assessment examines the effects of the Proposed Scheme on traffic noise and vibration levels at DMRB, Volume 11, Section 3, Part 7 – Noise and Vibration (HD 213/11) (Highways Agency et al., 2011). It addresses both the direct effects of traffic likely to use the Proposed Scheme and the effects of redistributed traffic on the existing road network. Health effects associated to noise are also included in this chapter. The assessment takes account of traffic noise mitigation measures incorporated into the Scheme design.
11.1.2 The assessment also considers short-term temporary construction effects and describes how noise and vibration from these activities would be controlled. The results of the assessment are described below with further detail provided in tables of results and noise maps (Figures 11.1 to 11.6).
11.1.3 The assessment of operational noise and vibration effects is based upon comparisons between the levels with the Proposed Scheme (DS) and without the Proposed Scheme (DM). These comparisons are undertaken for the opening year and for the design year, 15 years after opening. The calculated noise level changes have been used to assess, via established methods for determining subjective responses to changes in traffic noise, the potential effects of the Proposed Scheme.
11.1.4 Noise impacts could result from changes in:
road alignment (vertical and horizontal);
sound generation (traffic flow, speed, gradient and road surface type); and
sound propagation (ground absorption, screening, reflection and scattering).
11.1.5 Traffic flows and the level of noise they generate, fluctuate in intensity hourly, daily and seasonally, therefore the impact of traffic noise is assessed in terms of a time-averaged indicator.
Noise and human hearing
11.1.6 The human ear responds to a wide range of sound pressures, from 0dB (the threshold of hearing) up to about 130dB (approximating to the threshold of pain). Table 11.1 shows indicative noise levels associated with different noise sources. They are intended to provide an appreciation of noise levels commonly experienced in various situations.
Table 11.1: Typical dB(A) noise levels
Noise Source Typical dB(A) Level Rural night-time background 20 - 40 Quiet country bedroom at night 30 - 35 Quiet library 40 Quiet office, air conditioner 50 Car at 40mph at 100m 55 General office or supermarket 60 Conversational speech at 1m 60 - 65
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Noise Source Typical dB(A) Level Car at 25 mph at 7.5m 70 Pavement of busy street 85 Hand held hydraulic breaker (20kg) at 7m 95 Jet aircraft at 250m 105
11.1.7 The frequency response of the human hearing system is less sensitive to low and high frequency sounds than it is in the mid frequency region. For this reason, noise levels are usually expressed in dB(A) units, resulting from an electrical “A-weighting” filter having similar frequency characteristics to those of the ear.
11.1.8 The noise level response of the human hearing system is logarithmic rather than linear in nature, and able to detect a noise level difference of about 1dB(A) between two steady sounds, when they are presented in rapid succession under controlled laboratory conditions. The smallest change in environmental noise that is generally noticed by an individual is about 3dB(A). A 10dB(A) change approximates to a subjective doubling or halving of loudness.
11.1.9 Noise levels close to a road fluctuate with time and may be characterised by various statistical descriptors of the noise. For example, the LA10,1h level is the “A” weighted noise level exceeded for 10% of a 1-hour period. Research has shown that the arithmetic average of the 18, 1-hour LA10 levels (depicted as LA10,18h) between 06:00 and 24:00 hours shows a reasonably good correlation with community responses to traffic noise. This unit is used in the UK for the assessment of road traffic noise.
11.1.10 As noise levels are logarithmic quantities, when two or more noise levels are added together, their total is the logarithmic, not arithmetic, sum of the individual levels. For example, adding together two noise levels each of 60dB gives a total of 63dB, not 120dB. If the difference between two noise levels is 10dB or more, the logarithmic sum of the two values equates to the higher of the two levels.
11.1.11 Further context and definitions of technical terms used in this assessment are presented in Appendix I.
11.2 Legislative and Policy Framework
Legislation and Guidance
11.2.1 The assessment has taken into account relevant guidance, legislation and regulations, including those provide in Table 11.2.
Table 11.2: Guidance, legislation and regulations relevant to noise and vibration
Reference Legal/policy requirements Land Part 1 of the Land Compensation Act provides a means by which Compensation compensation can be paid to owners of land or property which has Act, 1973 experienced a loss in value caused by the use of public works, such as new or improved roads. Noise and vibration are two factors that would be considered in any claims for compensation, but the claim should consider all changes and effects, including betterment.
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Reference Legal/policy requirements Claims can be made under Part 1 of the Act from one to seven years after the opening of a road project. However, consideration of the likely extent of claims may be made during the design phase of a road project following the completion of the statutory process. Noise Insulation The Regulations provide the framework to determine the Regulations entitlement to noise insulation treatment at eligible buildings (i.e. 1975, as dwellings and other building used for residential purposes within amended 1988 300m from the nearest point on the new or altered highway). Should a Proposed Scheme alter the existing noise environment, so that properties now experience noise conditions above the levels described below, there may be a requirement to provide noise insulation to mitigate the effects of a Proposed Scheme. For properties to be entitled to noise insulation the following three conditions should be met: the combined expected maximum noise traffic level, i.e. the relevant noise level from the new or altered highway together with any other traffic in the vicinity must not be less than the specified noise level, 68dB LA10,18h (with levels of 67.5dB being rounded up); the relevant noise level is at least 1dB(A) more than the prevailing noise level, i.e. the total traffic existing before the works to construct or improve the highway were begun; and the contribution to the increase in the relevant noise level from the new or altered highway must be at least 1dB(A). The noise should be assessed at a reception point located 1m in front of the most exposed window or door in the façade of an eligible room. Traffic flows used in the calculations should be the maximum expected in a period of 15 years after opening to traffic. The predictions are normally undertaken using the Annual Average Weekday Traffic (AAWT). Control of Section 61 of the CoPA 1974 sets out procedures for those Pollution Act undertaking works to obtain “Prior Consent” for construction works (CoPA), 1974 within agreed limits. Applications for such consent are made to the local authority and contain a method statement of the works and the steps to be taken to minimise noise. Under Section 60 of the Act, the local authority has powers to attach conditions to, limit or qualify any consent to allow for changes and limit the duration of any consents. It is noted that although it is generally for those undertaking the works to decide whether or not to seek such consent, this is also dependent on the custom and practice of the local authority. Some local authorities request demonstration of best practicable means rather than formal “Prior Consent” applications. For control of noise and vibration at construction sites, BS 5228: 2009 - Code of Practice for noise and vibration control on construction and open sites, Part 1: Noise and Part 2: Vibration (BSI, 2014a and b), provides guidance for predicting construction
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Reference Legal/policy requirements noise and also provides advice on noise and vibration control techniques.
World Health A Night Noise Guideline of 40 dB Lnight,outside is recommended Organization within the document. This free-field noise level incident at the (WHO), Night property façade is considered by WHO to protect the public, Noise Guidelines including most of the vulnerable groups (such as children, the for Europe chronically ill and elderly), from the adverse health effects of night (WHO, 2009) noise.
WHO also recommends an Interim Target (IT) of 55 dB Lnight,outside for situations where the achievement of NNG is not feasible in the short term. The guidance considers that this IT can be temporarily considered by policy-makers for exceptional local situations. No timescale is recommended to achieve these noise levels. Member States are encouraged to gradually reduce the proportion of the population exposed to levels over the IT within the context of meeting wider sustainable development objectives. Environmental Directive 2002/49/EC of the European Parliament and of the Noise Directive, Council of the European Union relates to the assessment and 2002 management of environmental noise, and it is normally referred as the Environmental Noise Directive. Environmental Noise Directive promotes the implementation of three steps: undertake strategic noise mapping to determine exposure to environmental noise; ensure information on environmental noise is made available to the public; and establish Action Plans based on the strategic noise mapping results, aiming to prevent and reduce the environmental noise where necessary, and to preserve environmental noise quality where it is considered good. Environmental Noise Directive has been transposed as the Environmental Noise (England) Regulations 2006 (as amended) into English law. As part of this process, noise mapping has been undertaken. Locations subject to the highest noise levels (top 1% of the population) have been identified as Noise Important Areas (NIAs). The main objective of this process is to identify the areas which require potential action. BS5228:2009+A1 BS5228 ‘Code of practice for noise and vibration control on Part 1 and Part 2 construction and open sites’, gives recommendations on noise (BSI, 2014a and control relating to construction activities. The standard also b) provides methods for the prediction and assessment of noise and vibration due to construction. Design Manual Part 7, Noise and Vibration (HD 213/11) advises on the for Roads and appropriate level of noise and vibration assessment for road Bridges (DMRB), schemes, and provides the methodology for the assessment of Volume 11, operational noise within this assessment. Section 3, 2011 The procedure to assess impact uses three levels: a) scoping, b) (Highways simple and c) detailed. Selecting the appropriate level of Agency et al.,
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Reference Legal/policy requirements 2011) assessment depends on the following threshold criteria: permanent change in magnitude of 1dB(A) in the short term (i.e. on opening); permanent change in magnitude of 3dB(A) in the long term (i.e. between opening and future assessment years);
the predicted noise level during night-time Lnight,outside is greater than 55dB in any scenario. The night-time noise level will be calculated in line with the methodology presented in the Transport Research Laboratory report ‘Converting the UK traffic noise index LA10,18h to EU noise indices for noise mapping’. The assessment would be based on the criteria for short-term and long-term noise impacts as outlined in the Table E.1 in Appendix E Calculation of This memorandum describes the procedures for calculating noise Road Traffic from road traffic. It is divided into three sections: Noise (CRTN), Section I: A general method of calculation is set out, step by (DfT,1988) step, for predicting noise levels at a distance from a highway. This takes into account different traffic parameters, intervening ground cover, road configuration and site layout. Section II: Provides additional procedures that may need to be considered when applying the method given in Section I to specific situations. The aim has been to permit prediction in as many cases as possible. Section III: The procedure and requirements to be met during such measurements are detailed, together with details of a simplified measurement procedure, which is acceptable in certain circumstances. Guidelines for The Guidelines for Environmental Noise Impact Assessment Environmental produced by the Institute of Environmental Management and Noise Impact Assessment (IEMA) in 2014 provides criterion for defining Assessment, significance. The guidelines address the key principles of noise (IEMA, 2014) impact assessment, and provide specific support on now noise assessment fits within the EIA process. Where necessary, the significance of the effect can be determined by considering the generic scale for describing a range of noise effects on a receptor as set out in Table 7-7 of the guidance. The potential effects described in the table and their consequential impacts primarily refer to individuals in and around their homes. The principles described can also be applied to people at other noise-sensitive receptors, although the detailed changes in attitude and behaviour may be different.
Policy Framework
The National Planning Policy Framework
11.2.2 Section 11 “Conserving and enhancing the natural environment” (DCLG, 2012) advises that the planning system should contribute to and enhance the natural and local environment by:
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Preventing both new and existing development from contributing to or being put at an unacceptable risk from, or being adversely affected by, unacceptable levels of soil, air, water or noise pollution or land instability.
11.2.3 With regard to planning policies and decisions, these should aim to:
avoid noise giving rise to significant adverse impacts on health and quality of life as a result of new development;
mitigate and reduce to a minimum other adverse impacts on health and quality of life arising from noise from new development, including through the use of conditions;
recognise that development would often create some noise and existing businesses wanting to develop in continuance of their business should not have unreasonable restrictions put on them because of nearby land uses since they were established; and
identify and protect areas of tranquillity that have remained relatively undisturbed by noise and are prized for their recreational and amenity value for this reason.
Noise Policy Statement for England
11.2.4 The vision of the Noise Policy Statement for England (Defra, 2010) is to promote good health and good quality of life through the effective management of noise within the context of government policy on sustainable development.
11.2.5 This vision is supported by three aims:
avoid significant adverse impacts on health and quality of life;
mitigate and minimise adverse impacts on health and quality of life; and
where possible, contribute to the improvement of health and quality of life.
11.2.6 The Noise Policy Statement for England (Defra, 2010) establishes the concept of effect levels, and whether the overall noise effect will be below the significant and lowest observed adverse effect levels with regard to health and quality of life. Significant Observed Adverse Effect Level (SOAEL) is the level of noise exposure above which adverse effects on health and quality of life can be detected. Lowest Observed Adverse Effect Level (LOAEL) is the level of noise exposure above which adverse effects on health and quality of life can be detected. There is also a No Observed Effect Level (NOEL).
11.2.7 The Proposed Scheme should therefore aim to positively improve the health and quality of life of sensitive receptors in the surrounding area by reducing environmental noise levels generated by the road network through the design of the Proposed Scheme.
National Policy Statement for National Networks
11.2.8 The NPS NN (DfT, 2014) provides details on the required content of an EIA with regards to how environmental noise should be assessed. These requirements have been considered within this assessment at an appropriate level. The NPS NN (DfT, 2014) states that the following will needed to be considered when undertaking an EIA for a development in which significant noise impacts are likely to arise:
a description of noise sources including likely usage (i.e. movements, fleet mix and diurnal pattern);
identification of noise sensitive premises and noise sensitive areas that may be affected;
characteristics of the existing noise environment;
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a prediction of how the noise environment would change with the proposed development;
an assessment of the effect of predicted changes in the noise environment on any noise sensitive areas;
mitigation measures, using best available techniques to reduce the noise impact; and
the nature and extent of the noise assessment should be proportionate to the likely noise impact.
11.2.9 Operational noise with respect to humans should be assessed using the principles of the relevant British Standards and other guidance. The prediction of road traffic noise should be undertaken using the Calculation of Road Traffic Noise (CRTN) (DfT, 1988).
Planning Practice Guidance
11.2.10 National Planning Practice Guidance – Noise sets out how planning can manage potential noise impacts in new development. It advises that planning authorities should take account of the acoustic environment and in doing so consider:
whether or not a significant adverse effect is occurring or likely to occur;
whether or not an adverse effect is occurring or likely to occur; and
whether or not a good standard of amenity can be achieved.
11.2.11 The Planning Practice Guidance states that these potential effects should be evaluated by comparison with the SOAEL and the LOAEL for the given situation. To illustrate these thresholds and help identify where noise could be a concern, Planning Practice Guidance provides an example table of noise exposure hierarchy which is provided below.
Table 11.3: Noise exposure hierarchy based on the likely average response
Perception Examples of Outcomes Increasing Action effect level Not No Effect No Observed No specific noticeable Effect measures required Noticeable Noise can be heard, but does not cause No Observed No specific and not any change in behaviour or attitude. Adverse measures intrusive Can slightly affect the acoustic character Effect Level required of the area but not such that there is a perceived change in the quality of life. Lowest Observed Adverse Effect Level Noticeable Noise can be heard and causes small Observed Mitigate and and changes in behaviour and/or attitude, Adverse reduce to a intrusive e.g. turning up volume of television; Effect minimum speaking more loudly; where there is no alternative ventilation, having to close windows for some of the time because of the noise. Potential for some reported sleep disturbance. Affects the acoustic character of the area such that there is a perceived change in the quality of life.
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Perception Examples of Outcomes Increasing Action effect level Significant Observed Adverse Effect Level (SOAEL) Noticeable The noise causes a material change in Significant Avoid and behaviour and/or attitude, e.g. avoiding Observed disruptive certain activities during periods of Adverse intrusion; where there is no alternative Effect ventilation, having to keep windows closed most of the time because of the noise. Potential for sleep disturbance resulting in difficulty in getting to sleep, premature awakening and difficulty in getting back to sleep. Quality of life diminished due to change in acoustic character of the area.
11.2.12 Table 11.4 shows the values this assessment has adopted for the daytime and night-time SOAEL and LOAEL which follows the approach adopted by Highways England on other previous highways schemes to define the significant effects in terms of noise from road traffic.
Table 11.4: SOAEL and LOAEL for long-term road traffic noise during daytime and night-time
Night-time threshold Daytime threshold noise level noise level Effect Level Free-field Façade Free-field L [dB] Aeq,16h LA10,18h [dB] Lnight, outside [dB] Significant effects ≥ 63 ≥ 68 ≥ 55 (SOAEL) Adverse effects ≥ 50 ≥ 55 ≥ 40 (LOAEL) Source: Night-noise guidelines for Europe, (WHO, 2009) for night-time values. Noise Insulation Regulations Relevant Noise Level for the daytime SOAEL. Guidelines for community noise, WHO, 1999 for daytime LOAEL from the 50 dB LAeq,16h (7-23), outdoors for the onset of moderate community annoyance.
11.2.13 Guidance on the relationship between long term exposure to noise and the onset of certain health effects is given in the Guidelines for Community Noise (WHO, 1999). A level of 50dB LAeq,16h is considered to relate to moderate annoyance in outdoor living areas, increasing to 55dB LAeq,16h for serious annoyance, in the majority of the population. Based on this guidance, 50dB LAeq,16h has been adopted to represent the LOAEL for daytime noise.
11.2.14 The Noise Insulation Regulations 1975 (as amended 1988) specify that a dwelling may be entitled to noise insulation when a new or improved road transport noise source causes increases in noise at a dwelling by at least 1dB to above 68dB LA10,18h. Using a façade correction of 2.5dB and advice in the TRL report ‘Converting the UK traffic noise index LA10,18h to EU noise indices for noise mapping’ results in a levels of 63dB LAeq,16h under
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free-field conditions. Based on this, 63dB LAeq,16h has been adopted to represent the SOAEL for daytime noise.
11.2.15 There is no clear evidence upon which to conclusively derive a LOAEL and SOAEL for daytime effects at all types of receptors. Therefore, for the purposes of this assessment the threshold for dwellings has been applied to all receptors.
11.2.16 Both the LA10,18h façade noise level and LAeq,16h free-field noise levels are shown due to the different parameters used in different sources. Conversion from LA10,18h to LAeq,16h uses the relationship as set out in TAG Unit A3 (LAeq,16h = LA10,18h – 2 dB) with a further subtraction of 2.5 dB for conversion from façade to free-field.
11.2.17 For night‐time, the Night Noise Guidelines for Europe (WHO, 2009) refers to a Night Noise Guideline of 40 dB Lnight,outside and an interim target of 55 dB Lnight,outside which have been adopted as the LOAEL and SOAEL for night-time respectively.
11.2.18 Any residential dwelling with an increase in noise of 1dB or more due to the Proposed Scheme in either the short term or long term where the absolute level is above the SOAEL, is considered to have a significant effect in terms of Policy4.
11.2.19 A 1dB change has been used as this is the smallest change perceptible by humans under laboratory conditions.
EIA Significance
11.2.20 A moderate impact in the short term (3dB or greater) has been taken as an indicator of a potential significant effect. The level of 3dB has been chosen as this is a level at which a receptor would perceive the change in noise as intrusive, could cause a change in behaviour, and lead to a perception of change in quality of life5. When determining the final significance for a receptor or group of receptors, other factors (e.g. absolute levels) are also considered.
11.3 Study Area
11.3.1 The delimitation of the study area for the assessment of noise during operation has been undertaken considering the guidance contained in DMRB HD 213/11 (Highways Agency et al., 2011).
11.3.2 The study area is defined as being within 600m of both the Proposed Scheme boundary and any other roads in the network predicted to experience noise level changes of at least 1dB LA10,18h in the opening year or 3dB LA10,18h in the future year, out to a maximum distance of around 1km from the actual Proposed Scheme boundary. Due to the extents of the traffic model, the northern extent of the study area has been curtailed at the M271 J1. There are no sensitive receptors in the area that has been omitted from the assessment.
11.3.3 Noise predictions have been conducted at all floors and facades at each receptor, and the floor/façade with the least beneficial change in noise level used for the assessment. The predicted noise levels relate to the façades of buildings so include the 2.5dB ‘façade correction’ described in CRTN. These façade LA10,18h levels have been used in the quantitative assessment of the Proposed Scheme. The noise contour maps shown in Figures 11.3 – 11.6) show ‘free-field’ LA10,18h noise levels (i.e. without the reflective effect
4 Planning Practice Guidance – Noise (PPG-N) states that: “In cases where existing noise sensitive locations already experience high noise levels, a development that is expected to cause even a small increase in the overall noise level may result in a significant adverse effect occurring even though little to no change in behaviour would be likely to occur”. 5 Guidelines for Environmental Noise Impact Assessment – Institute of Environmental Management and Assessment, October 2014
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of a façade) and serve to illustrate the geographic extent of noise level bands and changes within the study area, which consists of open countryside and residential areas.
11.3.4 Noise levels have been calculated at residential and non-residential noise sensitive receptors, including schools and colleges, churches, hotels, hospitals and public open spaces within the study area. The non-residential receptors included in the study area are:
Learning Land Day Nursery
Millbrook Christian Centre
Church of All Saints
Redbridge Community School
Redbridge Pre School
Redbridge Primary School
Redbridge Youth Centre
Southampton Gymnastic Centre
Southampton Rugby Club
Southampton Sports Club
Test Playing Fields
11.3.5 The Proposed Scheme is located within Noise Important Area (NIA) 2192 (owned by Highways England and Southampton). This NIA covers residential properties in Redbridge Tower, Coniston Road and Clover Nooke. Other NIAs within the study area are 2240 (Southampton), 3362 (Hants) and 2250 (Southampton).
11.4 Baseline Environment
11.4.1 A baseline sound level monitoring survey has been undertaken to characterise the existing sound environment (during the day, evening and night periods) at sensitive receptors in the vicinity of the Proposed Scheme. The locations of each of the monitoring sites are displayed in Figure 11.1. The monitoring locations were selected to best represent the affected groups of receptors around the Proposed Scheme.
11.4.2 The baseline sound levels have been used in the subsequent assessment of effects that could arise during construction of the Proposed Scheme. The noise baseline survey was undertaken over three weeks between November 2017 and February 2018, during which occasional periods of adverse weather conditions were experienced in addition to the failure of some monitoring equipment. Periods affected by adverse weather were excluded from the periodic averages calculated. Due to the data loss suffered in 2017, a further survey was undertaken in February 2018.
General noise climate
11.4.3 Baseline sound level monitoring was undertaken between 24th November and 6th December 2017, with further monitoring undertaken between 1st and 2nd February 2018. The measured baseline data gathered during the sound level survey are presented in Table 11.5. Details regarding the sound level monitoring survey, including observations made during the survey, are presented in Appendix I.
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11.4.4 Locations LT1 and LT2 are long-term noise monitoring locations where noise monitoring kits were deployed and left unattended. A surveyor was present on deployment and collection to record the audible noise sources.
11.4.5 Locations ST1 and ST2 are short-term noise monitoring locations where noise monitoring kits were deployed for 3 consecutive hours between 10:00 and 17:00 on a weekday following the shortened procedure method described in CRTN (DfT,1988). Additionally, night noise survey was conducted at these locations to measure the noise levels between 23:00 and 02:00.
Table 11.5: Measured noise levels
Ref Measurement Period Measured Sound Level Location and Date
LAeq,T LAmax,T LA1,T LA10,T LA90,T LT1** 8 Old Redbridge Weekday daytime 58 73 62 59 56 Road Weekday evening 55 71 59 56 53 24 – 28 November Weekday night- 52 63 55 52 46 2017 time 1 – 2 February 2018 Saturday daytime 55 74 59 56 52 Weekend evening 53 70 57 54 50
Weekday LA10,18h - - - 57 - LT2** 4 Coniston Road Weekday daytime - - - - - 28 – 29 November Weekday evening 56 75 61 58 53 20173 Weekday night- 52 67 58 54 46 time Saturday daytime - - - - - Weekend evening - - - - - ST1* Clover Nooke Weekday daytime 69 88 74 70 66 1) 24 November 2017 6 December 2017 Weekday night- 61 76 64 62 53 1 – 2 February 2018 time 2) 1) Weekday LA10,18h - - - 69 - ST2* Redbridge Tower Weekday daytime 63 87 68 64 61 24 November 2017 1) 1 – 2 February 2018 Weekday night- 60 71 63 61 56 time 2) 1) Weekday LA10,18h - - - 63 - Note 1: Weekday daytime sound level derived using the shortened measurement procedure defined in CRTN (DfT, 1988). Note 2: Weekday night-time sound level based on a series of sample measurements between 23:00 – 02:00 and considered to be a conservative indication of night-time weekday sound level at the locations.
Note 3: LA10,18hr noise level not presented as it is derived from limited data set due to data loss during survey. * Façade incident monitoring location
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Ref Measurement Period Measured Sound Level Location and Date
LAeq,T LAmax,T LA1,T LA10,T LA90,T ** Free-field monitoring location Weekday daytime: Monday to Friday 07:00 to 19:00 Weekday evening: Monday to Friday 19:00 to 23:00 Weekday night-time: Monday to Friday 23:00 to 07:00 Saturday daytime: Saturday 07:00 to 13:00 Weekend evening: Saturday 13:00 to 23:00 and Sunday 07:00 to 23:00
11.4.6 Redbridge rail station is around 250m to south of the Proposed Scheme on the junction of both Wessex Main Line and South Western Main Line. Rail traffic noise levels were found not to contribute to the existing noise environment in the vicinity of the Proposed Scheme.
11.5 Methodology and Assessment Criteria
11.5.1 A construction contractor has not been appointed at this time. However, once appointed it is anticipated that the construction contractor shall confirm the plant/equipment to be used, the programme for construction and the construction strategy to be adopted. All of this would be included within the construction method statements for the works. It has not been possible to quantify the benefits of the full suite of control measures that shall be adopted during construction (examples of which are presented within Appendix B.6 and outline EMP (Jacobs, 2018b)), and the assessment approach adopted for construction noise and vibration effects has been undertaken on a reasonably precautionary basis and is considered to represent worst-case assessment of construction impacts.
Methodology
Construction noise
11.5.2 Construction noise levels have been calculated at seven sensitive sample receptors in the vicinity of the Proposed Scheme, selected as worst-case prediction locations and as being representative of local receptor groups. These sample receptors are shown on Figure 11.2. Noise predictions have been undertaken using the noise model, incorporating the calculation algorithms described in BS 5228-1 (BSI, 2014a).
11.5.3 The effects of construction noise are temporary and defined by the intrusion that construction noise causes in the existing noise environment (or soundscape) of the area. Table 11.6 shows the LOAELs and SOAELs for construction noise that have been used within this assessment. Table 11.6 is adapted from BS 5228-1 (BSI, 2014a) Annex E, which describes methods for evaluating the potential significant effect of construction noise.
11.5.4 The construction noise limit thresholds presented in Annex E of BS 5228-1 (BSI, 2014a) have been developed over several decades. Fixed noise limits were originally promoted by the Wilson Committee in their report on noise, as presented to Parliament in 1963. The fixed noise limits have been expanded over time to include a suite of noise levels covering different periods of the day and taking into account the varying sensitivities through these periods. Section E.3 of BS 5228-1 (BSI, 2014a) provides two example methods for assessing the potential for significant noise effects during construction. Section E.3.3 describes ‘Example method 2 – 5 dB(A) change’, which is the assessment approach adopted for this scheme.
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Table 11.6: Threshold of potential significant adverse effects at dwellings in dB LAeq,T, adapted from BS 5228-1 Annex E
Time Period Threshold Categories
LOAEL SOAEL Day (0700-1900 Exceeds pre-construction Threshold level determined as per weekday and 0700- ambient sound level BS 5228:2009 + A2014 Section 1200 Saturdays) (LAeq,T) E3.3.3 Exceeds pre-construction Threshold level determined as per Night (2300-0700) ambient sound level BS 5228:2009 + A2014 Section (LAeq,T) E3.3.3 Evening and Exceeds pre-construction Threshold level determined as per weekends (time ambient sound level BS 5228:2009 + A2014 Section periods not covered (LAeq,T) E3.3.3 above)
11.5.5 As described within Annex E.3.3 of BS 5228-1 (BSI, 2014a), noise levels generated by construction activities are considered to be potentially significant if the total noise (pre- construction baseline noise plus construction noise) exceeds the pre-construction baseline noise by 5dB or more, subject to lower cut off values presented in Annex E.3.3 from construction noise alone (e.g. minimum of 65dB LAeq,T for the weekday daytime period). Other factors have been considered in determining if there would be the potential for a significant adverse effect, such as the number of receptors affected and the duration of the impact.
Construction vibration
11.5.6 Vibration is a low frequency disturbance producing physical movement in buildings or to their occupants. Ground-borne vibration is usually measured in terms of Peak Particle Velocity (PPV), measured in terms of movement in mm/s.
11.5.7 Assessment of the likelihood of significant effects, as a result of ground-borne vibrations arising from construction activities, has been carried out using the guidance contained within BS 5228-2 (BSI, 2014b).
11.5.8 Table 11.7 presents the guideline PPV vibration levels, from BS 5228-2, for human response to construction vibration used within this assessment.
Table 11.7: Guidance on the human response to vibration from BS5228-2
Vibration level Effect (ppv) 0.14 mm/s Vibration might just be perceptible in the most sensitive situations for most vibration frequencies associated with construction. At lower frequencies, people are less sensitive to vibration 0.3 mm/s Vibration might just be perceptible in residential environments (LOAEL) 1.0 mm/s It is likely that vibration of this level in residential environments (SOAEL) would cause complaint, but can be tolerated if prior warning and
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Vibration level Effect (ppv) explanation has been given to residents 10.0 mm/s Vibration is likely to be intolerable for any more than very brief exposure to this level
11.5.9 This assessment shall consider vibration levels at sensitive residential properties of ≥1.0 mm/s PPV as potentially significant, and as is consistent with the approach outlined above for construction noise, this would equate to the SOAEL value for vibration during construction. Other factors have been considered in determining if there would be potential for a significant adverse effect, such as the number of receptors affected and the duration of the impact. For building structure response, BS 5228-2: (BSI, 2014b) reproduces advice given in BS 7385-2:1993 concerning vibration levels which could potentially result in building damage. The response of a building to ground-borne vibration is affected by the type of foundation, underlying ground conditions, the building construction and the state of repair of the building.
11.5.10 Table 11.8 reproduces the guidance detailed in BS 5228-2 (BSI, 2014b) on building classification and guide values for cosmetic building damage. Minor damage is possible at vibration magnitudes greater than twice those given in Table 11.8 with major damage at values greater than four times the values in the table. BS 7385-2:1993 also notes that the probability of cosmetic damage tends towards zero at 12.5 mm/s peak component particle velocity.
Table 11.8: Effects of vibration levels on building structures from BS5228-2
PPV in frequency range of predominant pulse Type of Building 4 Hz to 15 Hz 15 Hz and above
Reinforced or framed structures 50 mm/s 50 mm/s Industrial and heavy commercial buildings
Un-reinforced or light framed structures 15 mm/s at 4 Hz 20 mm/s at 15 Hz increasing to 20 increasing to 50 mm/s Residential or light commercial buildings mm/s at 15 Hz at 40 Hz and above
Operational noise
11.5.11 Section 3 and Annex 1 of DMRB HD 213/11 (Highways Agency et al., 2011) describes three levels of study as follows:
scoping to determine the need for a noise and vibration impact assessment;
simple assessment to identify the noise and vibration impacts associated with the project; and
detailed assessment of noise and vibration impact at dwellings and other sensitive receptors when threshold values are exceeded.
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11.5.12 This study follows the ‘detailed assessment’ method described in Paragraphs A1.25 to A1.38 of DMRB HD 213/11 (Highways Agency et al., 2011). The methodology includes the assessment of effects due to the following:
permanent traffic noise;
permanent traffic nuisance;
permanent traffic induced vibration; and
temporary impacts.
11.5.13 In accordance with Paragraph A4.14 in DMRB HD 213/11 (Highways Agency et al., 2011), the noise predictions have been based upon the forecast ‘most likely’ AAWT flows, speeds and percentage of heavy vehicles for the DM and DS situations in both the opening and design years. Only roads with flows of at least 1000 vehicles per 18 hour AAWT have been considered, in accordance with the advice in CRTN (DfT, 1988).
11.5.14 Noise changes associated with the Proposed Scheme are assessed using the following comparisons:
short-term traffic noise comparison, DM (2019) against DS (2019);
long-term traffic noise comparison with Scheme, DM (2019) against DS (2036); and
long-term traffic noise comparison without Scheme, DM (2019) against DM (2036).
11.5.15 DMRB HD 213/11 (Highways Agency et al., 2011) requires an assessment of the impact of night-time noise whereby receptors would be exposed to a freefield Lnight, outside of 55dB or greater in any scenario. Night time noise levels have been calculated using the advice in the TRL report (2002) ‘Converting the UK traffic noise index LA10,18h to EU noise indices for noise mapping’.
11.5.16 Road traffic noise levels have been calculated at representative receptors using the method detailed in CRTN (DfT, 1988). This is the Government’s prescribed method and has been developed from extensive measurement data and validated out to distances of about 300m from trafficked roads for the purposes of the Noise Insulation Regulations. Studies undertaken by TRL (2002) in connection with the current version of DMRB HD 213/11 (Highways Agency et al., 2011) have shown that the CRTN (DfT, 1988) algorithms can be reliably used up to 600m.
11.5.17 The CRTN (DfT, 1988) method for predicting noise from a road consists of five main stages:
Division of the road into a number of segments.
Calculation of the Basic Noise Level for each road segment, at a reference distance of 10m away from the nearside carriageway edge.
Calculation of the noise level from each road segment at the reception point by modifying the Basic Noise Level to take account of distance, ground attenuation and screening.
Correction of the noise level at the reception point to take account of site layout features including reflections from buildings and façades, and the size of the source segments.
Combination of the contributions from all road segments to give the total noise level at each reception point.
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11.5.18 Traffic noise predictions have been conducted using the CadnaA computer program. This program implements the algorithms contained within CRTN (DfT, 1988) and the additional calculation advice described in Annex 4 of DMRB HD 213/11 (Highways Agency et al., 2011). It has been used to build three-dimensional models of the existing road layout, the Proposed Scheme and adjacent areas including features such as buildings, landforms and barriers. Other inputs to the model include traffic flows and speeds, the nature of the road surface and the type of intervening ground between each road segment and each receiver.
11.5.19 DMRB HD 213/11 (Highways Agency et al., 2011) (Tables 3.1 and 3.2 in that document) gives the following classification for the magnitude of noise impacts, recognising that it may not be applicable in all circumstances. This is duplicated in Table E.1 in Appendix E.
Operational vibration
11.5.20 Traffic-induced airborne vibration may manifest itself as the rattling of badly fitted windows or light objects, which typically occurs if the frequency of exhaust noise happens to coincide with a resonant frequency of an element of the building. Airborne vibration nuisance has been assessed on the basis that ‘for a given level of noise exposure, the percentage of people bothered by vibration is 10% lower than the corresponding figure for noise nuisance’ ((Highways Agency et al., 2011, Annex 3, Paragraph A3.22).
11.5.21 Traffic-induced ground borne vibration may result from the passage of vehicles over discontinuities, such as badly reinstated trenches, in the road surface. TRL Research Report 102 concludes that with a surface irregularity of about 20mm within about 5m of a building, there was the possibility of perceptible ground borne vibrations being generated during the passage of heavy vehicles. The threshold of vibration perception is significantly lower than the threshold for building damage. As newly constructed and well maintained roads would not have surface irregularities of this magnitude, it may reasonably be concluded that ground borne vibration would not be an issue, and has not been considered further.
11.6 Assessment Assumptions and Limitations
11.6.1 Due to the extents of the traffic model made available, the northern extent of the study area has been curtailed at the J1 of the M271. However, no effects at sensitive receptors would occur in this area, and therefore this does not affect the assessment outcomes.
11.6.2 Speed pivoting – The traffic model coverage is small, and also as the traffic model data was taken from data held by a third party, the traffic team were unable to access the count data for use in calibration. Therefore, a cross model calibration exercise was undertaken for the same junction between Paramics (a previously calibrated and WebTAG compliant model) and Saturn. The speeds within both models were broadly comparable therefore indicating that the speeds used to underpin the noise modelling are appropriate.
11.6.3 Speed banding as per IAN 185/15 (Highways Agency, 2015) has been used. The speed band “Light Congestion” has been applied to all roads approaching the junctions, or if within 100m of a roundabout, in according to the IAN 185/15 (Highways Agency, 2015).
11.6.4 Traffic flow data was obtained from the SRTM from Systra. When requesting expansion factors to calculate 18 hour AAWT figures, Systra advised that separate factors for HDV’s were not readily available and that the global (all vehicles all routes) factors are generally used. As no further supporting data was available, the expansion factors for HDV’s are assumed to be equal to the global factors.
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11.6.5 The AddressBase data used to define sensitive receptors does not contain details on the precise location of each property within an overall residential block (i.e. Redbridge Tower). Therefore, each individual receptor has been modelled at each floor level and on each façade. This leads to a higher number of properties being identified as experiencing effects than would be expected in practice.
11.6.6 A construction contractor had not been appointed at the time of the construction noise and vibration assessment being made. As such, a series of generally conservative technical assumptions have been made in the assessment of potential noise and vibration impacts during construction.
11.7 Potential Effects
Construction Effects
Noise
11.7.1 There are a number of receptors in the vicinity of the Proposed Scheme and associated construction works. Several number of activities associated with the construction phase of the Proposed Scheme have the potential to result in adverse noise and vibration impacts at nearby sensitive receptors. Exposure to noise can also link to several health effects, both physical and mental. These include cardiovascular health problems (e.g. heart disease), anxiety, depression and sleep disturbance.
11.7.2 The construction works identified as having the greatest likelihood of causing a significant effect have been identified. Predicted noise levels during these works are shown in Table 11.9 at seven sensitive sample receptors close to the Proposed Scheme. The table also presents the highest noise contribution for each of these construction activities, and the associated noise change for each sample receptor. Where possible all works shall be undertaken during the core working hours of 08:00 to 18:00 (weekdays) excluding bank holidays (see Appendix B.6).
11.7.3 The noise change at each sample receptor during the worst case construction activity has been determined subject to the lower thresholds for daytime, evening and night-time assessment of noise taken from Annex E of BS 5228-1 (BSI, 2014a).
11.7.4 The baseline noise levels shown in Table 11.10 have been derived from a combination of the measured noise levels and those predicted for the DM 2019 scenario. These levels have been converted to LAeq,12h daytime levels, LAeq,4h evening time levels and LAeq,8h night time levels using Method 3 contained within the TRL (2002) document Converting the UK traffic noise index LA10,18h to EU noise indices for noise mapping. All noise levels in Table 11.9 are façade incident noise levels for ease of comparison
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Table 11.9: Construction noise levels at sample receptors
Predicted Noise Level from Representative Baseline Baseline Noise Total Noise Change in Noise 2 Construction Works LAeq,T dB Monitoring Location Level Level
Lday Levening Lnight Lday Levening Lnight Lday Levening Lnight
1
Receptor
1 Day Evening Night
(B) (C=A+B) (C-B)
Topsoil strip and removal trees of Service diversion Piling and excavation Footbridge demolishing Footbridge construction Existing road surface break up and removal, Maximum (Average) Road surfacing, planning and pavement, Maximum (Average) Highest Noise Level (A) 8 Old 64 63 64 70 58 70 70 70 LT1 Day LT1 LT1 61 58 55 71 70 70 10 12 15 Redbridge (66) (66) Evening Night Road 4 72 71 66 73 62 75 75 75 Predicted LT2 LT2 65 59 55 75 75 75 10 16 20 Coniston (70) (70) Evening Night Road Clover 71 70 69 75 64 88 87 88 ST1 Day ST1 ST1 69 61 61 88 88 88 19 27 27 Nooke (78) (78) Night Night Redbridge 78 76 74 82 70 78 77 82 ST2 Day ST2 ST2 63 60 60 82 82 82 19 22 22 Tower (74) (73) Night Night 1 71 70 69 76 64 78 77 78 Predicted Predicted Predicted 68 67 64 78 78 78 10 11 14 Coniston (75) (75)
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Predicted Noise Level from Representative Baseline Baseline Noise Total Noise Change in Noise 2 Construction Works LAeq,T dB Monitoring Location Level Level
Lday Levening Lnight Lday Levening Lnight Lday Levening Lnight
1
Receptor
1 Day Evening Night
(B) (C=A+B) (C-B)
Topsoil strip and removal trees of Service diversion Piling and excavation Footbridge demolishing Footbridge construction Existing road surface break up and removal, Maximum (Average) Road surfacing, planning and pavement, Maximum (Average) Highest Noise Level (A) Road 2 Gover 69 68 68 74 63 78 78 78 Predicted Predicted Predicted 67 65 61 78 78 78 11 13 17 Road (76) (75) 197 - 227 82 81 73 80 68 80 80 82 Predicted Predicted Predicted 68 66 61 82 82 82 14 16 21 Cuckmere (77) (76) Lane Note 1: Maximum noise level is the maximum construction noise level to be experienced by the sample receptor from the activity, when the work is undertaken in the closest proximity to it. Average noise level is the average construction noise level experienced by the sample receptor during the entirety of the activity. Note 2: Baseline noise levels are façade incidence noise levels by applying a +2.5dB correction factor to the free-field measured and predicted values.
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Topsoil stripping and removal of trees
11.7.5 It is anticipated that this activity would be undertaken within typical hours of construction (08:00 to 18:00) and would be of a duration of less than one month. This activity would take place between the north and east of Redbridge roundabout, in front of Redbridge Tower. Noise resulting from this activity has been predicted to be as high as 82dB LAeq,T, predicted at the southern façade of 197 - 227 Cuckmere Lane, the worst affected receptor. Construction noise levels in excess of 65dB LAeq,T have been predicted at the facades of all sample receptors, with the exception of 8 Old Redbridge Road.
11.7.6 The resulting ambient noise level has been predicted to increase by 5dB or more above the existing daytime ambient noise level at the façades of 8 Old Redbridge Road (+5dB), 4 Coniston Road (+8dB), 1 Coniston Road (+5dB), 197 - 227 Cuckmere Lane (+14dB) and Redbridge Tower (+15dB).
11.7.7 The predicted construction noise levels have been found to be above the daytime guideline noise limit (65dB LAeq,T) and ambient noise levels predicted to increase by 5dB or more. Despite the relatively short-duration of this activity, significant adverse effects have been predicted at the sample receptors in the above paragraph, with the greatest impacts predicted to be experienced at 197 – 227 Cuckmere Lane and Redbridge Tower.
11.7.8 These noise effects would be controlled as far as reasonably practicable through the application of suitable control measures, described further within Appendix B.6 and outline EMP (Jacobs, 2018b).
Service diversion
11.7.9 It is anticipated that this activity would be undertaken within typical hours of construction (08:00 to 18:00), however some night-time works would be required. Night-time working would not involve any breaking of ground and noise emissions during the night-time period are anticipated to be lower than those presented below. In addition, it is anticipated that this activity would occur for a duration of less than one month.
11.7.10 This activity would take place between the north and east of Redbridge Roundabout, in front of Redbridge Tower. Noise resulting from this activity has been predicted to be as high as 81dB LAeq,T, predicted at the southern façade of 197 - 227 Cuckmere Lane. Construction noise levels in excess of 65dB LAeq,T are predicted at the facades of all sample receptors with the exception of 8 Old Redbridge Road.
11.7.11 The resulting ambient noise level has been predicted to increase by 5dB or more above the existing daytime ambient noise level at the façades of 197 - 227 Cuckmere Lane (+13dB), 4 Coniston Road (+7dB) and Redbridge Tower (+13dB).
11.7.12 The predicted construction noise levels are above the daytime guideline noise limit (65dB LAeq,T) and ambient noise levels are predicted to increase by 5dB or more. Despite the relatively short-duration of this activity, significant adverse effects have been predicted at the sample receptors in the above paragraph, with the greatest impacts predicted to be experienced at 197 – 227 Cuckmere Lane and Redbridge Tower.
11.7.13 Construction noise levels from service diversion activities that could occur during the night-time period are likely to be lower than the predicted noise levels presented above (there will be no ground breaking activities at night). However, significant construction
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noise effects during the night time period cannot be discounted and noise mitigation, such as limiting noisy activities during these sensitive periods, should be adopted.
11.7.14 These noise effects would be controlled as far as reasonably practicable through the application of suitable control measures, described further within Appendix B.6 and outline EMP (Jacobs, 2018b).
Bored piling and excavation
11.7.15 It is anticipated that this activity would be undertaken within typical hours of construction (08:00 to 18:00) and would be of a duration of less than one month. This activity would take place inside the eastern quadrant of Redbridge roundabout, to construct a retaining wall. Noise resulting from this activity has been predicted to be as high as 74dB LAeq,T, at the southern façade of Redbridge tower, the worst affected receptor. Construction noise levels in excess of 65dB LAeq,T have been predicted at the facades of all sample receptors with the exception of 8 Old Redbridge Road.
11.7.16 The resulting ambient noise level has been predicted to increase by 5dB or more above the existing daytime ambient noise level at the façades of 8 Old Redbridge Road (+5dB), 197 - 227 Cuckmere Lane (+11dB) and Redbridge Tower (+6dB).
11.7.17 The predicted construction noise levels are above the daytime guideline noise limit (65dB LAeq,T) and ambient noise levels have been predicted to increase by 5dB or more. Despite the relatively short-duration of this activity, significant adverse effects have been predicted at the sample receptors in the above paragraph, with the greatest impacts predicted to be experienced at 197 – 227 Cuckmere Lane.
11.7.18 These noise effects would be controlled as far as reasonably practicable through the application of suitable control measures, described further within Appendix B.6 and outline EMP (Jacobs, 2018b).
Footbridge demolition
11.7.19 It is anticipated that this activity would be undertaken during full road closures during a weekend period. Noise resulting from this activity has been predicted to be as high as 82dB LAeq, predicted at the western façade of Redbridge Tower, the worst affected receptor. Construction noise levels in excess of 55dB LAeq,T have been predicted at the facades of all sample receptors.
11.7.20 The resulting ambient noise level has been predicted to increase by 5dB or more above the existing daytime ambient noise level at the façades of all sample receptors, by between +7dB (at Clover Nooke) and +19dB (at Redbridge Tower).
11.7.21 The predicted construction noise levels would be above the lower weekend daytime guideline noise limit (55dB LAeq,T) and ambient noise levels would be predicted to increase by 5dB or more. As such, and despite the relatively short-duration of this activity, significant adverse effects have been predicted at all sample receptors.
11.7.22 These noise effects would be controlled as far as reasonably practicable through the application of suitable control measures, described further within Appendix B.6 and outline EMP (Jacobs, 2018b).
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Footbridge Construction
11.7.23 It is anticipated that this activity would be undertaken within typical hours of construction (08:00 to 18:00), however some weekend, and possibly night-time working would be required. Night-time working would involve the use of a bridge lift only and noise emissions during the night-time period are anticipated to be lower than those presented below. It is anticipated that this activity would occur for a duration of less than one month.
11.7.24 Noise resulting from this activity has been predicted to be as high as 70dB LAeq,T, at the southern façade of Redbridge tower, the worst affected receptor. Construction noise levels in excess of 65dB LAeq,T are predicted at the facades of Redbridge Tower and 197 - 227 Cuckmere Lane.
11.7.25 The resulting ambient noise level has been predicted to increase by 5dB or more above the existing daytime ambient noise level at the façade of Redbridge Tower (+8dB).
11.7.26 The predicted construction noise levels would be above the daytime guideline noise limit (65dBLAeq,T) and ambient noise levels would be predicted to increase by 5dB or more at Redbridge Tower. Despite the relatively short-duration of this activity, significant adverse effects have been predicted at Redbridge Tower.
11.7.27 Noise levels from footbridge construction activities that could occur during the weekend and night-time period are likely to be lower than the predicted construction noise levels presented above. However, significant construction noise effects during the night-time period cannot be discounted and noise mitigation, such as limiting noisy activities during these sensitive periods, shall be adopted.
11.7.28 These noise effects would be controlled as far as reasonably practicable through the application of suitable control measures, described further within Appendix B.6 and outline EMP (Jacobs, 2018b).
Break up and remove existing road surface
11.7.29 It is anticipated that this activity would be undertaken at night during road closures and would be of a duration of less than one month. This activity would take place over the area of the Proposed Scheme. The average construction noise levels range between 66dB and 78dB LAeq,T. Noise resulting from this activity has been predicted to be as high as 88dB LAeq,T, at the façade of Clover Nooke, the worst affected receptor, while construction activities were taking place in close proximity to this receptor. Construction noise levels in excess of 45dB LAeq,T have been predicted at the facades of all sample receptors.
11.7.30 The resulting ambient noise level has been predicted to increase by 5dB or more above the existing night-time ambient noise level at the façades of all sample receptors, by between +14dB (at 1 Coniston Road) and +27dB (at Clover Nooke), when considering maximum (rather than average) predicted noise levels.
11.7.31 The predicted construction noise levels would be above the night-time guideline noise limit (45dB LAeq,T) and ambient noise levels would be predicted to increase by 5dB or more. As such, and despite the relatively short-duration of this activity, significant adverse effects have been predicted at all sample receptors, the largest of which are predicted at Clover Nooke.
11.7.32 These noise effects would be controlled as far as reasonably practicable through the application of suitable control measures, described further within Appendix B.6.
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Road surfacing, planning and pavement
11.7.33 It is anticipated that this activity would be undertaken at night during road closures and would be of a duration of less than one month. This activity would take place over the area of the Proposed Scheme, the average construction noise level ranging between 66 and 78dB LAeq,T. Noise resulting from this activity has been predicted to be as high as 87dB LAeq,T, at the façade of Clover Nooke, the worst affected receptor. Construction noise levels in excess of 45dB LAeq,T have been predicted at the facades of all sample receptors.
11.7.34 The resulting ambient noise level has been predicted to increase by 5dB or more above the existing night-time ambient noise level at the façades of all sample receptors, by between +13dB (at 1 Coniston Road) and +26dB (at Clover Nooke), when considering maximum (rather than average) predicted noise levels.
11.7.35 The predicted construction noise levels are above the night-time guideline noise limit (45dB LAeq,T) and ambient noise levels have been predicted to increase by 5dB or more. As such, and despite the relatively short-duration of this activity, significant adverse effects have been predicted at all sample receptors, the largest of which are predicted at Clover Nooke.
11.7.36 These noise effects would be controlled as far as reasonably practicable through the application of suitable control measures, described further within Appendix B.6 and outline EMP (Jacobs, 2018b).
Vibration
11.7.37 Proposed construction activities having the potential to give rise to largest levels of vibration at receptors would be associated with vibratory earthwork compacting works and bored piling activities. Such works would be associated with the construction activities of piling and road surfacing, planning and pavement.
11.7.38 Within the indicative information that the construction contractor has provided, the Bomag Tandem BW190 vibratory roller has been identified for use in the embankment construction team.
11.7.39 Table 11.10 details predicted vibration levels for earth compaction associated with the construction works. The predictions have been derived using the techniques contained with BS 5228-2 (BSI, 2014b), predicted at the nearest sensitive receptors to the proposed embankment construction areas. Both the 5% and 50% scaling factors have been used for the probability of the predicted value being exceeded, for both the ‘steady state’ and ‘start up and run down’ operation.
11.7.40 The differences in prediction between a 5% probability and 50% probability of the predicted value being exceeded gives an indication of the uncertainty of the predicted levels. It should be noted that the 5% probability is considered a worst-case assumption.
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Table 11.10: Predicted ground-borne vibration from vibratory soil compaction plant
Receptor Nearest Predicted ground-borne vibration level (PPV, distance to mm/s) vibratory soil Steady state Start up and run down compaction 50% 5% 50% 5% (m) probability probability probability probability 8 Old Redbridge 70 0.1 0.5 0.3 0.8 Road 4 Coniston Road 13 1.5 5.4 2.2 5.9 Clover Nooke 9 2.3 8.5 3.3 8.8 Redbridge Tower 32 0.4 1.6 0.8 2.0 1 Coniston Road 19 0.9 3.2 1.4 3.8 2 Gover Road 11 1.8 6.6 2.6 7.1 197 - 227 Cuckmere 11 1.8 6.6 2.6 7.1 Lane
11.7.41 As vibration passes through the foundations of a building the level alters as an effect of the transfer function. Such transfer functions differ between properties; however, a general reduction in vibration from free-field to foundations of 60% is often applied. However, for the purpose of this assessment no reduction has been assumed representing a conservative assessment approach.
11.7.42 Within residential buildings a vibration level of 1.0 mm/s ppv would be likely to be perceptible to residents, and according to the guidance within BS 5228-2, could lead to complaint. When assuming a less conservative probability of exceedance (50%), a vibration level of 2.3 mm/s has been predicted for the worst affected receptor. This level would have potential to be perceptible to occupants of residential buildings and would be likely to cause complaints if not advanced warning was given.
11.7.43 In all cases, the predicted vibration levels shown in Table 11.10 fall well below the vibration levels defined in BS 7385-2:1993 which could give rise to cosmetic damage to buildings. In addition, given the transient nature of the soil compaction works, this level of vibration would only be experienced for short duration, e.g. two to three days, when the compaction works occurred at the nearest position to the properties.
11.7.44 Vibration emissions from other general construction plant and equipment likely to be used at the site (e.g. excavators and dumper trucks) should be no greater than those of a vibratory roller. As such, no significant ground borne vibration effects have been anticipated from them.
11.7.45 Consideration has been given to the potential for adverse ground borne vibration effects resulting from bored piling in eastern side of the Redbridge roundabout. Ground borne vibration predictions have been undertaken using the indicative prediction algorithms contained within BS 5228-2 for vibratory piling used in lieu of unavailable alternatives. The predicted vibration levels at sample distances are presented within Table 11.11.
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Table 11.11: Predicted ground-borne vibration from bored piling plant
Receptor Nearest Predicted ground-borne vibration level (PPV, mm/s) distance to bored Steady state Start up and run down piling (m) 50% 5% 50% 5% probability probability probability probability 8 Old Redbridge 141* 0.1 0.3 0.2 0.7 Road 4 Coniston Road 63 0.2 0.8 0.4 1.8 Clover Nooke 76 0.1 0.6 0.3 1.5 Redbridge Tower 46 0.3 1.3 0.6 2.7 1 Coniston Road 69 0.2 0.7 0.4 1.7 2 Gover Road 90 0.1 0.5 0.3 1.2 197 - 227 50 0.3 1.1 0.6 2.4 Cuckmere Lane *Extrapolated value, distance between receptor and construction site >100m and outside the parameter range given within BS 5228-2.
11.7.46 The nearest residential receptor to the piling works, Redbridge, is located approximately 46m away. At this distance, vibration due to bored piling would be anticipated to be 1.3 mm/s PPV (with a 5% probability of predicted value being exceeded), increasing to 2.7 mm/s PPV (with a 5% probability of predicted value being exceeded) during start-up and rundown transient conditions. This level of vibration is above the threshold for potential significant adverse effect (1.0 mm/s PPV), meaning complaints from resident are likely, if no advance warning is provided. Sample receptors 4 Coniston Road, Clover Nooke, 1 Coniston Road and 2 Gover Road are also predicted to experience vibration levels in excess of 1.0 mm/s PPV. As such, significant adverse effects have been predicted at these sample receptors.
Construction traffic
11.7.47 A Traffic Management Plan has been developed in consultation with BBPL and Southampton City Council, which identifies the measures that shall be adopted to mitigate disruption caused by temporary construction traffic. Construction traffic is anticipated to access the scheme via the M271, and given the already substantially high traffic flows on this road, it is considered that the subsequent increase in noise and vibration during construction would be negligible.
11.7.48 Temporary traffic diversions would be implemented whilst the existing carriageway is resurfaced for a period of two weekend days. The proposed diversion routes are along Redbridge Road, Tebourba Way, the A3057, Brownhill Way and along Totton Bypass (A35). These diversion routes are regularly used when closures are put in place for the network operators to carry out routine and capital maintenance works at this location. It is anticipated that potential noise and vibration disturbance as a result of the traffic diversion will be minimised through implementation of controls outlined within the Traffic Management Plan. In addition to this, the diversions would occur for a relatively short period (two weekend days). Therefore, no significant adverse noise and vibration effects are anticipated.
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Operational Effects
DMRB noise assessment
11.7.49 A total of 1951 residential and 12 non-residential Noise Sensitive Receptors (NSRs) within the study area have been assessed and their noise impacts classified using the advice in DMRB HD 213/11 (Highways Agency et al., 2011).
11.7.50 The results at all 1951 residential receptors are included in Appendix J and noise contours showing the geographical extent to changes in free field noise level are included in Figures 11.3 to 11.6.
11.7.51 All DS scenario calculations undertaken have accounted for two barriers included in the Proposed Scheme design. These are in the following locations:
Northeast of the Scheme, close to Redbridge Tower (5m high).
South of the Scheme, close the Clover Nooke (4m high).
The noise barrier locations are also shown in Figure 7.3.
Short-term traffic noise comparison, DM (2019) against DS (2019)
11.7.52 This compares the DM and DS scenarios in the opening year. The results of this assessment classify each NSR according to the magnitude of the short term noise impact at its façade.
Table 11.12: Short-term Traffic Noise Comparison, DM (2019) against DS (2019)
Daytime Night time
Change in noise level Number of other Number of Number of sensitive dwellings dwellings receptors 0.1 – 0.9 1367 8 244 Increase in noise 1.0 – 2.9 0 0 0 level LA10,18h 3.0 – 4.9 0 0 0 5+ 0 0 0 No Change 196 0 22 0.1 – 0.9 371 3 61 Decrease in noise 1.0 – 2.9 17 0 0 level LA10,18h 3.0 – 4.9 0 0 0 5+ 0 0 0
11.7.53 The majority of decreases in noise have been found to be along Old Redbridge Road, Westover Road, Gover Road and Pat Bear Close. According to Table 11.12, 17 dwellings situated on the aforementioned roads would experience a perceptible decrease in LA10,18h noise level of 1dB(A) or more in the short term.
11.7.54 No dwellings would experience a perceptible noise level increase in the short term. A noise contour plot showing the extents of the changes in free-field LA10,18h noise level is shown in Figure 11.3.
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11.7.55 The only road with a perceptible change in noise outside the study area is Test Lane that runs parallel to the M271. The change in Basic Noise Level on this road is predicted to be a decrease of 3.1dB. There are no sensitive receptors within 50m of this road outside of the study area.
Long-term traffic noise comparison without Proposed Scheme, DM (2019) against DM (2036)
11.7.56 Assessing the change in noise over the design period without the Proposed Scheme shows how many properties would be affected by noise due to natural changes in traffic levels by the design year. The magnitude of the noise impact over the design period has been assessed using the ‘long term’ magnitude classification given in DMRB HD 213/11 (Highways Agency et al., 2011). A summary of the changes in noise level are shown in Table 11.13.
Table 11.13: Long-term traffic noise comparison without Proposed Scheme, DM (2019) against DM (2036)
Daytime Night-time Change in noise level Number of Number of other Number of dwellings sensitive receptors dwellings 0.1 – 2.9 1837 9 327 Increase in noise level 3.0 – 4.9 40 0 0 LA10,18h 5.0 – 9.9 53 0 0 10+ 0 0 0 No Change 0 11 0 0 0.1 – 2.9 10 3 0 Decrease in noise level 3.0 – 4.9 0 0 0 LA10,18h 5.0 – 9.9 0 0 0 10+ 0 0 0
11.7.57 If the Proposed Scheme were not to be built there would be no perceptible decreases of 3dB or more in LA10,18h noise level for any NSRs. A total of 40 dwellings would experience a minor increase in LA10,18h noise level, and a further 53 a moderate increase. Moderate increases would be considered significant but are not due to the Proposed Scheme. All moderate increases are located on Old Redbridge Road.
11.7.58 A noise contour plot showing the extents of the changes in free-field LA10,18h noise level is shown in Figure 11.4.
Long-term traffic noise comparison with Proposed Scheme, DM (2019) against DS (2036)
11.7.59 Table 11.14 compares the opening year DM and design year DS scenarios. Analysis of these changes allows for the identification of the number of NSRs affected by long term changes in noise due to the Proposed Scheme and growth in traffic.
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Table 11.14: Long-term traffic noise comparison with Proposed Scheme, DM (2019) against DS (2036)
Daytime Night-time Change in noise level Number of Number of other Number of dwellings sensitive receptors dwellings 0.1 – 2.9 1951 12 327 Increase in noise level 3.0 – 4.9 0 0 0 LA10,18h 5.0 – 9.9 0 0 0 10+ 0 0 0 No Change 0 0 0 0 0.1 – 2.9 0 0 0 Decrease in noise level 3.0 – 4.9 0 0 0 LA10,18h 5.0 – 9.9 0 0 0 10+ 0 0 0
11.7.60 No roads have been predicted to have a perceptible change of 3dB or more in LA10,18h noise level as a result of the Proposed Scheme by the design year. A noise contour plot showing the extents of the changes in free-field LA10,18h noise level is shown in Figure 11.5.
11.7.61 With the Proposed Scheme in place there would be no significant EIA effects as there are no Moderate or Major impacts. This represents an improvement over the long term Do- minimum comparison where Moderate increases were predicted, and suggests that the Scheme would be beneficial in terms of long-term significant effects.
Noise insulation regulations assessment
11.7.62 No formal offers of noise insulation can be made until after the completion of the statutory processes and the finalisation of the detailed engineering design of a Proposed Scheme.
11.7.63 The results of the noise calculations indicate that there are no properties that would potentially qualify for noise insulation under The Noise Insulation Regulations 1975 (as amended 1988).
Noise nuisance assessment
11.7.64 DMRB HD 213/11 (Highways Agency et al., 2011) states that noise nuisance assessments should be undertaken in the following scenarios:
Opening Year DM to Design Year DM
Opening Year DM to Design Year DS
11.7.65 The noise nuisance assessment determines the change in the proportion of the population that would be bothered by noise, reported in Table 11.15. The assessment has been limited to properties within the study area due to the reliability of the noise prediction method beyond this distance.
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Table 11.15: Change in noise nuisance at residential properties within the study area
Change in nuisance level Do-minimum Proposed Scheme Number of Number of dwellings dwellings Increase in nuisance <0 - <10% 1911 856 level 10 – <20% 19 1083 20 - <30% 0 12 30 - <40% 0 0 ≥40% 0 0 No Change =0% 11 0 Decrease in nuisance <0 - <10% 10 0 level 10 – <20% 0 0 20 - <30% 0 0 30 - <40% 0 0 ≥40% 0 0
11.7.66 The table above shows that if the Proposed Scheme were not built there would be an increase in noise nuisance at the majority of properties due to natural traffic growth by the design year. There would be 1055 fewer properties experiencing an increase in nuisance level of between 0% and 10%, however 1064 additional properties would experience an increase in nuisance level of between 10% and 20% and a further 12 properties where nuisance would increase to between 20% and 30%.
11.7.67 The reasons for this increase in nuisance are discussed in the noise impact assessments above. The method in DMRB HD 213/11 (Highways Agency et al., 2011) for nuisance assessment takes a worst case approach. A change in noise in the short term is shown to give a greater change in nuisance than a gradual change in noise over a period of years. The table reports the highest levels of nuisance, which for increases in noise occurs on Scheme opening.
DMRB airborne vibration assessment
11.7.68 DMRB HD 213/11 (Highways Agency et al., 2011) states that traffic induced airborne vibration would be likely to affect a very small proportion of the population at noise exposure levels below 58dB LA10,18h. The method for assessing vibration has also been based on data up to 40m from the Proposed Scheme and the DMRB advises that caution should be exercised when assessing properties beyond this distance.
11.7.69 This assessment has considered all properties within the study area that experience noise levels of at least 58dB LA10,18h. It assesses the change in the proportion of the population that would be bothered by traffic induced airborne vibration. The vibration assessment has been undertaken for the following scenarios:
Opening Year Do Minimum to Design Year Do Minimum
Opening Year Do Minimum to Design Year Do Something
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Table 11.16: Airborne vibration assessment
Change in nuisance level Do-minimum Proposed Scheme Number of Number of dwellings dwellings Increase in nuisance <0 - <10% 851 882 level 10 – <20% 1 0 20 - <30% 0 0 30 - <40% 0 0 ≥40% 0 0 No Change =0% 1081 1069 Decrease in nuisance <0 - <10% 0 0 level 10 – <20% 0 0 20 - <30% 0 0 30 - <40% 0 0 ≥40% 0 0
11.7.70 The table above (Table 11.6) shows that if the Proposed Scheme were not built 851 dwellings would experience an increase in nuisance level of between 0% and 10% and 19 dwellings would experience an increase in nuisance level of between 10% and 20%.
11.7.71 The table above shows that if the Proposed Scheme were built the number of properties experiencing no change in nuisance level would reduce to 1069. 31 additional properties would experience an increase in nuisance level of between 0% and 10%. As a result of the Proposed Scheme there would be no properties experiencing a nuisance level larger than 10%.
Noise Policy Statement for England
Policy aim to avoid significant adverse impacts
11.7.72 Table 11.17 shows the number of residential receptors below the LOAEL, between LOAEL and SOAEL, and above SOAEL for the daytime.
Table 11.17: Number of residential receptors experiencing each l effect level (day time)
Impact Effect Level Opening Year
Do Minimum Do Something Below LOAEL 972 957 Between LOAEL and SOAEL 897 912 Above SOAEL 82 82
11.7.73 Table 11.18 shows the number of residential receptors below the LOAEL, between LOAEL and SOAEL, and above SOAEL for the night time.
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Table 11.18: Number of residential receptors experiencing each effect level (night time)
Impact Effect Level Opening Year
Do Minimum Do Something Below LOAEL 116 112 Between LOAEL and SOAEL 1568 1566 Above SOAEL 267 273
11.7.74 Table 11.19 shows the number of comparison of residential receptors below the LOAEL, between LOAEL and SOAEL and above SOAEL in the short term and long term scenarios.
Table 11.19: Effects of Proposed Scheme on number of properties with each effect level
Impact Effect Level Change in no. Change in no. properties properties (day) (night)
Short term Short term Below LOAEL -15 -4 Between LOAEL and SOAEL 15 -2 Above SOAEL 0 6
11.7.75 There are no properties above SOAEL that are predicted to experience an increase of 1dB due to the Proposed Scheme.
11.7.76 In the short term, the Proposed Scheme would not increase the number of properties above the SOAEL due to daytime or night-time noise. It is concluded that Proposed Scheme meets the first aim of the NPSE.
Policy aim to mitigate and minimise adverse impacts
11.7.77 The second aim of the NPSE is to minimise adverse impacts on health and quality of life from environmental, noise within the context of Government policy on sustainable development. There are no adverse policy impacts predicted to arise from the Proposed Scheme.
Policy aim to contribute to the improvement of health and quality of life where possible
11.7.78 The Proposed Scheme design includes two noise barriers (shown on Figure 7.3). The noise contour plots shown in Figures 11.3 to 11.6 demonstrate that these barriers are effective at achieving an overall reduction in noise at receptors to the south and east of Redbridge roundabout.
11.7.79 The use of low noise surfacing has not been included in the Scheme design, as it is only effective at speeds above 75kph. All of the Proposed Scheme roads have speeds lower than 75kph in all scenarios.
11.7.80 Although, due to the design constraints discussed earlier, the barriers are not able to mitigate noise for very elevated receptors, it is considered that the inclusion of these barriers in the design meets the policy aim to contribute to the improvement of health and
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quality of life through the control of environmental noise within the context of Government policy on sustainable development, where possible.
Summary of compliance with aims of NPSE
11.7.81 It is considered that the Proposed Scheme would meet the aims of the NPSE for the following reasons.
There are no significant impacts during the day or night.
There are no significant policy impacts.
The best available mitigation is included in the design, and reduces noise levels at all properties where achievable, given design constraints.
Summary of EIA effects
11.7.82 As there are no long term changes in noise of at least 3dB, it can be concluded that the Proposed Scheme causes no significant EIA effects.
11.7.83 The effects of long term natural traffic growth without the Scheme would be perceptible at sensitive receptors.
11.7.84 Therefore, the Proposed Scheme is beneficial in mitigating the long term effects that would be caused by natural traffic growth.
Noise Important Areas
11.7.85 Noise Important Areas are considered to be where the top 1% of the population experience the highest noise levels (Defra, 2014) and where the competent authority should look, where feasible, to reduce noise levels.
11.7.86 Proposed noise barriers are effective at reducing noise levels, such that there are no adverse noise impacts expected at properties within NIA 2192.
11.8 Design, Mitigation and Enhancement Measures
11.8.1 The properties on Coniston Road are protected by an existing noise barrier. The Proposed Scheme design includes two noise barriers near Redbridge Towers (5m high) and Clover Nooke (4m high). The barrier locations are shown in Figure 7.3, and the effects of these barriers have been included in the operational results presented in this chapter. The barrier heights have been defined as the maximum possible without causing impacts on other environmental topic such as Landscape and Visual.
11.8.2 The use of low noise surfacing has been discounted as it is only effective at speeds above 75kph. All of the scheme roads have speeds lower than 75kph in all scenarios.
11.8.3 Typically noise insulation could provide noise reductions of 20-30dB within properties depending on the existing glazing and ventilation at these properties. It should be noted that the Noise Insulation Regulations require that ventilation would need to be provided in any room where noise insulation is to be installed. As the treatment is for the building façade this measure would not affect noise levels outside the properties, but internal noise levels would be likely to be acceptable with noise levels being below the significant effect level.
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11.8.4 Noise and vibration effects during construction would be controlled as far as reasonably practicable through the application of suitable control measures, described further within Appendix B.6 and outline EMP (Jacobs, 2018b).
11.9 Residual Effects
Construction Effects
11.9.1 Significant adverse effects due to construction noise are predicted at sensitive receptors in the vicinity of the Proposed Scheme. Adverse noise effects during construction shall be most significant where works are undertaken during the night-time period.
11.9.2 It is predicted that soil compaction and bored piling construction activities may result in vibration levels at the nearest residential properties that would cause complaint, but can be tolerated if prior warning and explanation has been given to residents. Local residents should be informed when specific noisy activities with vibration impacts, would be likely to occur (Jacobs, 2018b). Cosmetic or structural damage of buildings is not anticipated during construction. The examples of good practice for noise and vibration control during construction, as outlined in Appendix B.6 and outline EMP (Jacobs, 2018b), should be adopted during construction.
11.9.3 Noise and vibration emissions should be controlled as far as reasonably practicable through the application of suitable control measures, which are described further within Appendix B.6 and outline EMP (Jacobs, 2018b). At this time, it is not possible to discount the potential for significant temporary residual construction effects at the closest sensitive receptors to the Proposed Scheme.
Operational Effects
11.9.4 The operational noise and vibration assessment has identified the following:
The Proposed Scheme has a noise benefit in the opening year when the largest numbers of NSRs would experience perceptible decreases in noise. On opening, there would be no NSRs with perceptible increases in noise and 17 receptors with perceptible decreases in noise.
If the Proposed Scheme were not to be built, 40 NSRs would experience a minor increase in noise level, and a further 53 would experience a moderate increase. These increases are due to natural traffic growth.
By the design year, the Scheme would not result in perceptible changes in noise level at any NSRs.
It is considered that the Proposed Scheme would meet the aims of the NPSE. The community health in the region would likely improve with the Proposed Scheme. See Chapter 12 ‘People and Communities’ for further health assessment.
The Proposed Scheme meets the objective of reducing noise levels for majority of properties within NIA 2192.
11.9.5 There would be no residual significant effects. it has been considered that there would be a slight beneficial effect on noise and vibration during operation phase.
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12. People and Communities 12.1 Introduction
12.1.1 This topic chapter reports the potential effects of the Proposed Scheme on the following sub-topics as identified in the DMRB and IAN 125/15:
pedestrian, cyclists, equestrians and community effects;
vehicle travellers (specifically the issue of driver stress); and
land use.
12.1.2 Although the DMRB does not currently provide much specific guidance, the potential effects on bus travellers are also being included in this topic since there is potential for the Proposed Scheme to affect access to bus stops and disrupt services.
12.1.3 The recently amended EIA Directive includes ‘population’ and ‘human health’ among the aspects to be considered in EIA, and there is potential for the Proposed Scheme to affect some of the main determinants of health (access to services, local amenity, local environment). The topics of ‘population’ and ‘health’ are being considered for this chapter, in relation to the guidance set out in the DMRB Volume 11, Section 3, Part 8 Pedestrian, cyclists, equestrians and community effects (Highways Agency et al., 1993c).
12.2 Legislative and Policy Framework
National Policy
12.2.1 National policy of relevance to the People and Communities topic area is set out in Table 12.1.
Table 12.1: National policy and guidance
Document Considerations National Planning Policy Section 4 (Promoting sustainable travel) states that Framework (NPPF) ‘Encouragement should be given to solutions which support (DCLG, 2012) reductions in greenhouse gas emissions and reduce congestion’ (paragraph 30) and that planning authorities should consider whether ‘opportunities for sustainable transport modes have been taken up, depending on the nature and location of the site, to reduce the need for major transport infrastructure’. New development should ‘give priority to pedestrian and cycle movements, and have access to high quality public transport facilities’ (paragraph 32) and ‘create safe and secure layouts which minimise conflicts between traffic and cyclists or pedestrians’. Section 8 (Promoting healthy communities) provides that planning decisions should aim to achieve places which promote ‘safe and accessible environments’ and that contain ‘clear and legible pedestrian routes’ (paragraph 69). It also states that ‘Local authorities should seek opportunities to provide better facilities for users, for example by adding links to existing rights of way networks including National Trails’ (para 75).
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Document Considerations National Policy Statement The NPS NN states that the needs of cyclists and for National Networks pedestrians should be considered in the design of new road (NPS NN) (DfT, 2014) schemes. Opportunities to invest in infrastructure in locations where the national road network severs communities and acts as a barrier to cycling and walking should be considered, which may include correcting historic problems to ensure that it is easy and safe for cyclists to use junctions. National network schemes should also take account of the accessibility requirements of all that use them (including disabled users), and that all reasonable opportunities to deliver improvements in accessibility on and to the existing road network should be taken. With respect to land use, NPS NN provides that existing open space, sports and recreational buildings and land should not be developed unless the land is surplus to requirements or the loss would be replaced by equivalent or better provision in terms of quantity and quality in a suitable location.
Regional and Local Policy
12.2.2 Regional and local policy of relevance to the people and communities topic area is set out in Table 12.2.
Table 12.2: Local policy and guidance
Document Considerations Hampshire Local Relevant policies within the Hampshire Local Transport Plan Transport Plan 2011-2031 and Southampton City Council Local Transport Plan 3 2011-2031 (HCC, include: 2011) Policy H: To promote active travel modes and develop Local Transport supporting infrastructure - this policy aims to encourage and Plan 3, (SCC, 2011) make it easier for people to walk or cycle for everyday journeys through the delivery of comprehensive walking and cycling networks within the region and improvements to existing pedestrian and cyclist crossings. Policy M: To develop and deliver high-quality public realm improvements - this policy aims to improve accessibility within the region and develop a higher quality of life through improvements through a reduction in street clutter and streetscape enhancements. Amended Local SDP 22 Accessibility and Movement states that ‘new Plan Review (2nd development should have regard to the retention/ provision of Revision) (SCC, important routes and linkages which contribute to the ease of 2015b) movement within an area. Connections of roads, streets and open spaces, footpaths and public transport routes should give people the maximum choice in how they make their journeys but the presumption will be that the needs of the pedestrian and cyclist should come before the needs of the motor car.’ Local Development Policy CS 19 Transport: Reduce – Manage -Invest includes a
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Document Considerations Framework Core commitment to promote patterns and forms of development that Strategy reduce the need to travel by car and which seek to promote active Development Plan lifestyles. It states that where appropriate new development Document: should promote access to the Rights of Way network. Policy Amended Version CS21 – Protecting and Enhancing Open Space contains a Incorporating the commitment to protect and enhance key open spaces including Core Strategy Southampton Common, central, district and local parks. (SCC, 2015a)
12.3 Study Area
12.3.1 The proposed study areas for each of the relevant subtopics and aspects are:
pedestrian, cyclists, equestrians and community severance: the extent of the Proposed Scheme, including temporary land take required during construction (see Figure 12.1);
vehicle travellers (driver stress and bus travellers): all roads that fall within or adjoin the Proposed Scheme (see Figure 12.1);
community health: the spatial extent of the Redbridge ward as set out in Public Health England health profiles; and
land use and material assets: the footprint of the Proposed Scheme as shown on Figure 12.1 including temporary land take required during construction.
12.3.2 In the absence of published guidance, these study areas have been developed based on professional judgment. The study areas are considered to provide sufficient distance to identify the people and communities receptors likely to be most affected by the construction and operation of the Proposed Scheme.
12.4 Baseline Environment
Baseline sources
12.4.1 The following sources of information have been used during a desktop study of baseline information:
Ordnance Survey mapping;
aerial photography;
Sustrans National Cycle Network (NCN) online mapping application (Sustrans, 2017);
Southampton City Council Public Rights of Way (PRoW) online mapping application (SCC, 2017c);
M271/A35 Redbridge Roundabout Non-Motorised Users Context Report (WSP, 2016c); and
Public Health England Health Profiles data (Public Health England, 2017).
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Baseline Conditions
Pedestrians, cyclists and community effects
Footways and shared use paths
Footways and shared use paths within the study area likely to be directly affected by the Proposed Scheme are shown on Figure 12.1 and include:
shared use path (a path designated for use by both pedestrians and cyclists) on the north-western side of Redbridge roundabout between Gover Road and the stub end of Coniston Road;
footway to the north of Redbridge roundabout between the A35 on-slip and Gover Road;
shared use path which runs adjacent to the eastbound carriageway of the A33 between Redbridge Towers and Park Side Avenue;
shared use foot/cycleway to the south of Redbridge roundabout which runs adjacent to the eastbound carriageway of the A35 and westbound carriageway of the A33;
footway adjacent to the westbound carriageway of the A33 Old Redbridge Road and the toucan crossing;
un-named footbridge on the north-eastern side of Redbridge roundabout that connects the roundabout to residential properties within the Redbridge Towers area;
shared use path which connects the shared use path adjacent to the A33 eastbound carriageway with Redbridge Towers; and
two un-named subways:
- subway on the southern side of the roundabout that provides access to the roundabout from areas such as the Nissan Garage and properties within Clover Nooke; and
- subway on the north-western side of the roundabout that provides access to the roundabout from Gover Road.
12.4.2 There are further footways within the study area along residential roads and between residential properties in housing estates to the north, south and east of Redbridge roundabout. These would not be likely to be affected by the Proposed Scheme, and are therefore not described in further detail.
Designated cycle routes
12.4.3 The NCN Route 236 runs from Lyndhurst, New Forest north along the A35 towards Redbridge via Redbridge roundabout and along the A33 between Redbridge roundabout east towards Southampton city centre where it joins NCN Routes 2 and 23 (see Figure 12.1). National Cycle Network Route 36 has both traffic free and on road sections. Within the study area the route is traffic free as it runs along the A35 between Totton and Redbridge via Redbridge roundabout, but becomes an on-road route east of Oakridge Road on the A33.
12.4.4 There is a local cycle route which runs between Redbridge roundabout and Millbrook roundabout to the north of the A3 (see Figure 12.1). The route is traffic free between Redbridge roundabout and Parkside Avenue, as it crosses Wimpson Lane and along
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Tebourba Way. The route is on road where it runs along Green Park Road and Cleasby Close.
Community facilities
12.4.5 There are several community facilities within the study area likely to be accessed by active travel modes (i.e. on foot or by bicycle) by residents living or working within the residential areas immediately to the north, north-east, north-west, south, south-east and south-west of the Proposed Scheme (see Figure 12.1). These include:
Redbridge Community and Redbridge Primary Schools - these are two schools located approximately 125m east and 200m north of the Proposed Scheme respectively; and
Redbridge Railway Station - Redbridge Railway Station is located approximately 200m south of the Proposed Scheme.
12.4.6 There are also employment areas to the north-west, north-east and south of Redbridge roundabout (see Figure 12.1), such as Adams Morey, West Way Nissan Southampton, Southampton Gym Club and Southampton Gymnastics Centre. These are likely to be accessed by active travel modes from surrounding residential areas via the footways and shared use paths which form part of Redbridge roundabout.
Vehicle travellers
Driver stress
12.4.7 Road safety within Southampton has been steadily increasing since the 2000, however casualties are still seen at hot spots/bottlenecks. Although not identified as a road safety ‘hot spot’ by the Southampton’s Local Transport Plan, it is likely that Redbridge roundabout contributes to increased driver fear levels through the combination of the presence of pedestrian routes, and high speeds associated with the A35. Although it is not possible to assess route uncertainty, it is thought due to the level of fear and frustration experienced by vehicle travellers, the level of driver stress experienced is likely to be high.
Bus travellers
12.4.8 There are three bus stops within close proximity to Redbridge roundabout: Redbridge roundabout (east bound), Redbridge roundabout (northwest bound) and Redbridge School (see Figure 12.1). These three bus stops between them serve a total of five bus routes.
Land use and material assets
12.4.9 Redbridge Towers (residential apartments block) is located immediately north-east of the Redbridge roundabout, within the area of temporary land take to the north-east of the Proposed Scheme (see Figure 12.1). A small proportion of this temporary land take falls within an area of open space designated as amenity land at the eastern boundary of Redbridge Towers.
12.4.10 Clover Nooke residential apartment blocks are located immediately south-east of Redbridge roundabout, adjacent to the A33. There would be some temporary land take during construction from the lands associated with Clover Nooke residential apartment blocks.
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12.4.11 The northern half of the land within Redbridge roundabout is described as open space (amenity land) by Southampton City Council (as shown on Southampton City Council INSPIRE WMS web application (SCC, 2014a)).
Community health
12.4.12 The 2011 census showed that the proportion of people in Redbridge with bad or very bad health is higher than the Southampton UA and England average.
12.4.13 Public health information provided by Public Health England (2017) (Table 12.3) shows that the proportion of obese children and adults is slightly higher in the Redbridge Ward relative to the Southampton UA and England averages. The proportion of premature deaths related to cardiovascular disease is also higher than the England average. However, the percentage of physically active adults in Redbridge is aligned with the England average.
Table 12.3: Health trends in the Redbridge area
Measure Redbridge Ward Southampton UA England General health bad 6.7% 5.1% 5.5% or very bad Under 75 mortality 83.4 (per 100,000 86.9 (per 100,000 74.6 (per 100,000 rate: cardiovascular population) population) population) Obese adults 29.9% 22.7% 24.1% Obese children 24.4% 20.9% 19% (year 6) Percentage of 57.5% 54.2% 57.0% physically active adults
12.4.14 Redbridge roundabout is located within both an AQMA and a Defra recognised NIA, indicating that there are recognised traffic-related air quality and noise issues in the immediate area that may have impacts on human health and well-being. More details on the specific air quality and noise baselines within the study area can be found in the relevant chapters of this report (Chapter 5 ‘Air Quality’ and Chapter 11 ‘Noise and Vibration’).
12.4.15 Accident data provided by Southampton City Council shows that there was an average of 7.2 collisions per year for the area covering Redbridge roundabout to Millbrook Roundabout during the 5-year period between August 2010 and July 2015. Of the 36 collisions that occurred during this period, two resulted in serious injury. There were seven collisions involving pedestrians or cyclists (giving an average of 1.44 per year), all resulting in slight injury.
12.5 Methodology and Assessment Criteria
Methodology
Pedestrians, cyclists and community severance
12.5.1 The assessment of effects on pedestrians, cyclists and community severance is based on guidance provided in DMRB Pedestrians, Cyclists, Equestrians and Community Effects
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(Volume 11, Section 3, Part 9) (Highways Agency et al., 1993d) and considers effects during both construction and operation.
Vehicle travellers
Driver stress
12.5.2 This chapter includes an assessment of driver stress during construction of the Proposed Scheme. The quantitative method for the assessment of driver stress provided in DMRB Vehicle Travellers (Volume 11, Section 3, Part 9) (Highways Agency et al., 1993d) is based on the premise that driver stress increases at high flow rates and low speeds, and requires continuous lengths of carriageway over 1km. For this reason, it is not suitable for the assessment of driver stress for vehicle travellers using the Redbridge roundabout as the Proposed Scheme comprises a roundabout rather than a section of single or dual carriageway. Therefore, a qualitative assessment of driver frustration, fear of potential accidents and route uncertainty has been undertaken based on professional judgement and informed by DMRB Vehicle Travellers.
Bus travellers
12.5.3 There is no published guidance on the assessment of effects on bus travellers, and therefore a qualitative assessment of the effects on bus stops and bus journey times during construction has been undertaken based on professional judgement.
Land use and material assets
12.5.4 The assessment of effects on land use follows guidance provided in DMRB Land Use (Volume 11, Section 3, Part 6) (Highways Agency et al., 1993e) and considers effects on private assets and open space within the footprint of the Proposed Scheme during construction.
Community health
12.5.5 In the absence of published guidance, a qualitative assessment of effects on community health during operation has been undertaken based on professional judgement and informed by the air quality (Chapter 5) and noise (Chapter 11) assessment outcomes.
Assessment of Magnitude and Significance
Pedestrians, cyclists and community severance
12.5.6 The criteria for magnitude of change on pedestrian and cyclist routes is given in Table E.1 in Appendix E. These criteria were developed based on guidance provided in DMRB Pedestrians, Cyclists, Equestrians and Community Effects (Volume 11, Section 3, Part 9) (Highways Agency et al., 1993d).
12.5.7 The assessment of significance of effect on pedestrian and cyclist routes has been derived through consideration of the value/sensitivity of the receptor and the magnitude of change as shown in Table 4.2.
Vehicle travellers
12.5.8 The assessment of effects on driver stress and bus travellers is descriptive in nature and does not require the assignment of magnitude of change or significance of effect.
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Land use and material assets
12.5.9 The criteria for magnitude of change on land use and material assets is given in Table E.1 in Appendix E.
12.5.10 The assessment of significance of effect on pedestrian and cyclist routes has been derived through consideration of the value/sensitivity of the receptor and the magnitude of change as shown in Table 4.2.
Community health
12.5.11 The assessment of effects on community health involves a qualitative interpretation of the likely beneficial and/or adverse effects of the Proposed Scheme based on professional judgement. No assignment of magnitude of change or significance of effect has been applied due to the variability of an individual’s susceptibility and experience and the lack of quantitative evidence to support the assessment.
Value of Receptors
Pedestrian and cyclist routes
12.5.12 All pedestrian and cyclist infrastructure within the footprint of the Proposed Scheme has been assigned high value on the basis that they form part of active travel routes between local residential areas and key community facilities located within close proximity to Redbridge roundabout, including Redbridge Primary School, Redbridge Community School and Redbridge Railway Station. In addition, the shared use path to the south of Redbridge roundabout forms part of a NCN 236 and is likely also to be used by cyclists making longer distance active travel journeys between Southampton City Centre and smaller outlying communities such as Totton.
Vehicle travellers
12.5.13 In accordance with DMRB Vehicle Travellers (Volume 11, Section 3, Part 9) (Highways Agency et al., 1993d), the roads within the study area for assessment of effects on vehicle travellers have not been assigned a value. The methodology for assessment of effects on driver stress and bus travellers is described in Paragraphs 12.5.2 and 12.5.3, respectively.
Land use and material assets
12.5.14 Private assets and open space within the study area have been assigned medium value on the basis that each affected area of land is limited in extent but likely to be of value to local residents for amenity and informal recreational use.
Community health
12.5.15 The methodology for assessment of effects on community health (see Paragraph 12.5.5) does not involve the assignment of value to receptors.
12.6 Potential Effects
12.6.1 This section sets out the potential effects that are predicted to arise in the absence of the proposed mitigation as set out in Section 12.7.
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Construction Effects
Pedestrians, cyclists and community severance
12.6.2 As described in Paragraph 12.5.12 all pedestrian and cyclist routes within the study area have been assigned high value.
12.6.3 There would be temporary disruptions or loss of access to pedestrian and cyclist facilities within the study area as described in Table 12.4, and a reduction in amenity of these routes as a result of the noise and dust generated by nearby construction activities. However, the construction works would be phased to minimise the inconvenience experienced by pedestrians and cyclists using these routes, and full access between community facilities located to the north and south of Redbridge roundabout would be maintained throughout construction. Further information with regards to proposed pedestrian and cyclist routing during construction is provided in the Buildability Report (Jacobs, 2017a).
Table 12.4: Effects on pedestrians and cyclist routes
Receptor Potential effects Magnitude (clockwise, starting at Redbridge Towers) Redbridge Towers Temporary loss of access during demolition of the Negligible footbridge existing footway bridge for a total period of approximately 36 days. An alternative link to Gover Road subway and Clover Nooke subway would be available via existing shared use paths to the east and grade controlled crossings along the A33 eastbound and westbound carriageways. Shared use path link This shared use path would be permanently Minor to Redbridge Towers removed during construction. Access to Redbridge Towers from the shared use path adjacent to the eastbound carriageway of the A33 would be maintained via the existing pedestrian entrance to the east. Shared use path There would be no access between Redbridge No adjacent to the Towers and Redbridge Community School for a change eastbound period of approximately several weeks due to carriageway of the construction works. Redbridge Towers footbridge A33 would also be closed during this period. An alternative route would be available via the grade controlled crossings on the A33, and therefore there would be no effect. Pedestrian access to Redbridge Towers via Cuckmere Lane would be maintained throughout construction. Toucan crossings The existing toucan crossings would be No immediately east of demolished; however, an alternative route of change Redbridge comparable length would be available via newly roundabout constructed controlled at grade crossings of on A33 eastbound carriageway and Redbridge Towers shared use path.
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Receptor Potential effects Magnitude (clockwise, starting at Redbridge Towers) Shared use path to There would be a temporary loss of access along Moderate the south of sections of the route between Redbridge Redbridge roundabout and Old Redbridge road over a total roundabout (route of period of approximately 3 months. During the NCN 236) majority of this time users would have the option to divert north over Redbridge roundabout via Clover Nooke subway and Redbridge Towers footbridge, and then south back across A33 shared use path via the at-grade crossings to the east of Redbridge roundabout to re-join the shared use path. Cyclists would have to dismount to use this diversion, and it is likely to discourage use of the route during the period of construction. Alternatively, a diversion south along Old Redbridge Road could be taken. This would be a similar distance (approximately 410m) but is a trafficked route which would be less favourable for some cyclists, particularly children. For a period of approximately 30 days cyclists would have little alternative but to take the Old Redbridge Road, although pedestrians could also cross to, and use the footway which runs adjacent to the A33 eastbound carriageway. Footway between Temporary disruption to access for a period of Negligible Old Redbridge Road approximately 5 months. An alternative east-west and the A33 route is available via the shared use path to the eastbound toucan south of Redbridge roundabout. crossing. Clover Nooke Temporary loss of access during demolition of Negligible subway existing footway. An alternative link to Gover Road subway and Redbridge Towers footbridge would be available via existing shared use paths to the east and grade controlled crossings on A33 eastbound and westbound carriageways. The temporary diversion would increase the length of the route by approximately 110m. Gover Road subway Temporary loss of access for a period of 1 month. Minor and shared use An alternative link to Clover Nooke subway and footway/subway to Redbridge Towers footway would be provided via the northeast of a temporary route. Cyclists would be required to Redbridge dismount in order to use the temporary link. roundabout Footway to the north Temporary loss of access for a period of 35 days. Negligible of Redbridge An alternative route would be available via the roundabout existing footways either side of Gover Road.
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Vehicle travellers
Driver stress
12.6.4 There would be a temporary increase in driver stress due to the traffic management measures required during construction. Increased congestion and journey times, combined with route uncertainty, would all contribute to this effect. However, the baseline level of driver stress for roads within the footprint of the Proposed Scheme is high and the duration of this effect would be temporary. Once construction was complete, driver stress would be reduced from baseline levels.
12.6.5 Temporary traffic management measures would be required to safely manage vehicle movements through Redbridge roundabout during construction of the Proposed Scheme. During the bulk of the construction period (approximately seven months) these would include lane closures (limited to off-peak times on weekdays) and the use of temporary road markings (see Buildability Report (Jacobs, 2017a)). Temporary diversions would be implemented whilst the existing carriageway was resurfaced for a period of two weekend days. Vehicles travelling between Junction 1 of the M271 and the A35 at Redbridge roundabout would be diverted east via Brownhill Way, Romsey Road, Tebourba Road and Redbridge Road (see Buildability Report (Jacobs, 2017a)). Access for local traffic would be maintained along Test Lane. Vehicles travelling north between the A33 and M271 would be diverted via Totton Roundabout whilst works to the southern portion of the roundabout were underway.
Bus travellers
12.6.6 Access to Redbridge roundabout (eastbound) bus stop from the east would be temporarily disrupted during resurfacing of the existing A35 carriageway and widening of the shared use path running between the A35 and the stub end of Coniston Road. Access to the Redbridge roundabout (westbound) bus stop would be disrupted during widening of the shared use path to the south of the Proposed Scheme.
12.6.7 Journey times of the bus routes which make use of Redbridge roundabout and adjoining roads with the footprint of the Proposed Scheme would increase as a result of the traffic management measures required during construction (as described in Paragraphs 12.6.4 and 12.6.5) which include closure of the bus lane on the westbound carriageway of the A33 for a period of approximately five months.
Land use and material assets
12.6.8 As described in Paragraph 12.5.14 private assets and community space within the study area have been assigned medium value.
Residential properties
12.6.9 The main construction compound for the Proposed Scheme would be located within Southampton City Council land associated with Redbridge Towers residential accommodation blocks. This loss of land would reduce the availability of parking within this residential area and also result in loss of pedestrian access from the shared use path running adjacent to the westbound carriageway of the A33. Therefore, the magnitude of change would be small, and the significance of effect would be minor adverse.
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12.6.10 There would also be temporary land take from Southampton City Council land associated with Clover Nooke residential accommodation blocks during construction. The area of land affected would be very small (approximately 0.06ha) (see Figure 12.1), however pedestrian access to Clover Nooke residential apartments from the shared use path which runs adjacent to the westbound carriageway of the A33 would be lost. It is not considered that this temporary land take would affect the usage or enjoyment of Clover Nooke residential accommodation blocks, representing a negligible magnitude of change. The significance of the effect would be neutral.
Open space
12.6.11 There would be a small area of temporary land take from open space (amenity land) located to the south of Redbridge Towers residential accommodation blocks. The total area of land affected would be less than 0.02ha (see Figure 12.1), the majority of which falls a verge to the shared use path which runs adjacent to the eastbound carriageway of the A33. The significance of this effect would be neutral.
12.6.12 Access to the open space (amenity land) within the northern half of Redbridge roundabout would be restricted during construction. There would also be an adverse effect on the recreation amenity of this land due to noise, disruption and potential dust generated by the construction works that would be sufficient to discourage use. However, existing recreational use is limited due to its small area and location within the centre of a busy roundabout. On this basis, the magnitude of change would be small, and the significance of effect would be minor adverse.
Operational Effects
Pedestrians, cyclists and community severance
12.6.13 Effects on pedestrian and cyclist routes within the footprint of the Proposed Scheme are set out in Table 12.5.
12.6.14 As described in Paragraph 12.4.18 all pedestrian and cyclist routes within the study area have been assigned high value.
Table 12.5: Effects on pedestrians, cyclists and community severance
Receptor Potential effects Magnitude (clockwise, starting at Redbridge Towers) Redbridge Towers The footbridge would be replaced with a shared Minor footbridge use path of greater width than the existing provision, improving the amenity of this route for cyclists. Shared use path Improved accessibility and amenity due to Minor adjacent to the widening and resurfacing of shared use path. eastbound carriageway of the A33 Toucan crossings The toucan crossing on the on eastbound Negligible immediately east of carriageway of the A33 would be relocated to the
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Receptor Potential effects Magnitude (clockwise, starting at Redbridge Towers) Redbridge east to give greater visibility for oncoming traffic roundabout and improved road traffic safety. Shared use footway/ Improved amenity due to widening and Minor cycleway to the resurfacing of shared use path. south of Redbridge roundabout/NCN 236 Clover Nooke Clover Nooke subway would be demolished, with Medium subway pedestrians and cyclists travelling towards Redbridge Towers footbridge rerouted along the widened shared use path via the two new toucan crossings to the east. This permanent diversion would increase the length of the route between Clover Nooke subway and Redbridge Towers by approximately 150m, but would improve the accessibility and amenity of the route (particularly for cyclists). Footway to the Improved accessibility and amenity due to Minor north-east of widening and resurfacing of shared use path. Redbridge roundabout Gover Road subway Increase in amenity due to improved lighting and Negligible and adjoining shared CCTV and redecoration. use path
Community health
12.6.15 The improvement to pedestrian and cyclist infrastructure on and around Redbridge roundabout would support active lifestyles within the local community by further encouraging residents to walk or cycle between their homes and places or work or study. For this reason, health related to active lifestyles would be likely to be maintained or slightly improved from the baseline.
12.6.16 Exposure to air pollution and noise is linked to several health effects, both physical and mental. These include respiratory health issues (such as asthma) and cardiovascular health problems (e.g. heart disease), anxiety, depression and sleep disturbance. Reference should be made to the air quality and noise assessments to find out how the Proposed Scheme would affect these aspects of human health.
12.7 Design, Mitigation and Enhancement Measures
12.7.1 Mitigation opportunities for the potential adverse effects identified in Section 12.6 are set out in Table 12.6.
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Table 12.6: Design, mitigation and enhancement measures
Receptor Mitigation opportunities/enhancement (P = Residual Effects primary mitigation, S = secondary mitigation, T = tertiary mitigation) Construction phase Pedestrians, cyclists and community severance All identified Liaise with stakeholders prior to Localised effects on routes within commencement of construction works (T). convenience and the footprint of Provide appropriate signage for temporary amenity would be likely the Proposed diversions (T). to remain even after Scheme Use of construction management measures secondary mitigation. to reduce noise and dust generated by Negligible to moderate construction works (T). adverse effect Construction works to be minimised during dependant on location time periods where children are travelling to (as described in Table and from school, and ensure robust 12.4). construction management practices in place in routes used by school children (T). Vehicle travellers Vehicle Schedule construction works to avoid busy Increased driver stress travellers using times of day where possible (T). still likely, especially at the highway Provide appropriate signage for lane peak traffic times. within the closures or temporary diversions (T). footprint of the Provide advance notice of traffic Proposed management measures and any diversion Scheme routes on easily accessible public forum (T). Bus travellers Maintain safe access to bus Temporary disruption in stops/temporarily relocate bus stops if access to bus stops. required (T). With mitigation in place, Liaise with bus companies to identify the effects of service suitable alternative temporary bus stop disruption would be locations if required (S). better tolerated by bus Liaise with bus companies in advance of users. works so that they plan their services and advise their passengers accordingly (S).
Land use and material assets Redbridge Liaise with stakeholders prior to Slight adverse. With Towers commencement of construction works (T). mitigation in place the residential Land would be reinstated to its previous use effects of the temporary accommodation (T). loss of land and blocks Provide appropriate signage for temporary disruption in access (Southampton diversions (T). would be better tolerated City Council) by residents.
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Receptor Mitigation opportunities/enhancement (P = Residual Effects primary mitigation, S = secondary mitigation, T = tertiary mitigation) Clover Nooke Liaise with stakeholders prior to Slight adverse. With residential commencement of construction works (T). mitigation in place the accommodation Land would be reinstated to its previous use temporary loss of land blocks (T). and disruption in access (Southampton Maintain safe access for pedestrians would be better tolerated City Council) throughout construction period, utilising by stakeholders. diversions where required (T). Provide appropriate signage for temporary diversions (T). Open space Liaise with stakeholders prior to Slight adverse. With (amenity land) commencement of construction works (T). mitigation in place the at Redbridge Implement noise and dust management temporary loss of access roundabout measures as described in Chapter 5 ‘Air would be better tolerated quality’ and Chapter 11 ‘Noise and by stakeholders. Vibration’ (T). Restore land made available by demolition of existing structures to grassland in line with adjacent land use (P). Open space Liaise with stakeholders prior to Slight adverse. With (amenity land) commencement of construction works (T). mitigation in place the at Redbridge Implement noise and dust management temporary loss of access Towers measures as described in Chapter 5 ‘Air would be better tolerated accommodation quality’ and Chapter 11 ‘Noise and by stakeholders. blocks Vibration’ (T). Restore land made available by demolition of existing structures to grassland in line with surrounding land use (P).
12.8 Residual Effects
12.8.1 During construction of the Proposed Scheme there would be a temporary increase in driver stress for vehicle traffic due to the traffic management measures required to maintain safe movement of vehicles around Redbridge roundabout. These would likely increase journey times and bus travellers would likely also be affected by increased journey times and disruptions in access to the bus stops in very close proximity to Redbridge roundabout (Redbridge roundabout (east bound) and Redbridge roundabout (north-west bound)).
12.8.2 There would be temporary disruptions in access along pedestrian and cyclist routes within the footprint of the Proposed Scheme during construction, and a reduction in amenity of these routes due to the noise and potential dust generated by the construction activities. However, the construction works would be sequenced to ensure that full circulatory access around Redbridge roundabout is maintained throughout the construction period using diversions. Further mitigation opportunities include either the provision of an appropriate east-west diversion route for the shared use path which runs south of Redbridge roundabout and forms part of NCN Route 236 during construction, or identification of appropriate construction management measures such that the route can
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safely remain open throughout construction for pedestrians and cyclists. It is likely that cyclists would need to be diverted along Old Redbridge Road for the period that the NCN Route 236 is temporarily closed. Although this would be temporary and affect only about 400m of route, it would mean cyclists would have to negotiate a route with vehicular traffic, instead of the shared-use path. On this basis, it is considered that this would be moderate adverse during construction. Although the effect of this 400m length of the route is considered significant, no cumulative effects on NCN Route 236 have been identified. The Propose Scheme impact to the cycle route as a whole is not considered significant. Careful liaison with the local highways authority would be undertaken in advance of the works, to agree suitable measures for the temporary closure.
12.8.3 Once complete, the Proposed Scheme would improve the amenity of pedestrian and cyclist routes within the area through the widening of existing footways, replacement of Clover Nooke subway with controlled at-grade crossing points on the westbound carriageway of the A33, and relocation of the toucan crossing on the eastbound carriageway of the A33 at a position of greater visibility to oncoming traffic. These improvements would particularly benefit cyclists navigating around Redbridge roundabout as part of longer journeys. More generally, improved pedestrian and cyclist infrastructure would also help improve community health through supporting active lifestyles within the local community and encouraging residents to undertake active travel journeys.
12.8.4 No effects of material consideration (large or very large) have been predicted for construction or operation of the Proposed Scheme.
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13. Road Drainage and Water Environment 13.1 Introduction
13.1.1 Reviews of OS mapping and aerial photography as well as Environment Agency mapping, did not identify any watercourses within the study area other than the River Test which becomes Southampton Water further down the estuary (beyond the study area) at its confluence with the River Itchen. This is part of the Southampton Water, Water Framework Directive (WFD) transitional water body catchment (currently achieving Moderate Status) and is directly connected to the Proposed Scheme by the Millbrook piped watercourse via an outfall at Redbridge Roundabout.
13.1.2 This EAR provides an overview of the existing waterbody characteristics within the study area. An assessment of the potential impacts of the additional discharge from the Proposed Scheme at Redbridge Roundabout is then made against each quality element parameter with supporting information provided in Appendix K.
13.1.3 A Flood Risk Assessment (FRA) has also been completed (Appendix L).
13.2 Legislative and Policy Framework
EU and UK Legislation and Policy
13.2.1 The Department of the Environment, Food and Rural Affairs is responsible for all aspects of water policy in England. Management and enforcement of this water policy is the responsibility of the Environment Agency. Some of the key current legislations relating to the water environment are given below:
European Union Water Framework Directive (Directive 2000/60/EC);
Water Environment (WFD) (England and Wales) Regulations 2003 (SI 3242/2003);
Flood Risk (England and Wales) Regulations 2009;
Flood and Water Management Act 2010;
Sustainable Drainage (Procedure) (England) Regulations 2012;
Sustainable Drainage (Approval and Adoption) (England) Order 2012;
Sustainable Drainage (Enforcement) (England) Order 2012;
Sustainable Drainage (Appeals) (England) Regulations 2012;
Water Resources Act 1991;
Environment Act 1995;
Groundwater (England and Wales) Regulations 2009;
Control of Pollution (Applications, Appeals and Registers) Regulations 1996 (SI1996/2971);
Environmental Protection Act 1990;
Land Drainage Act 1991 and 1994;
Water Act 2003;
Control of Pollution (Consents for Discharge) (Secretary of State Functions) Regulations 1989; and
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Design Manual for Roads and Bridges, Volume 11, Section 3, Part 10, Road Drainage and the Water Environment (Highways Agency et al., 1993f).
National Policy
13.2.2 The NPPF (DCLG, 2012) and accompanying NPPG was published in March 2012 and supersedes the former topic based PPG and Planning Policy Statements (PPS). The NPPF (DCLG, 2012) provides guidance and direction to local planning authorities and outlines the process by which they must take into account flood risk as an integral part of the planning process.
13.2.3 The NPPF sets strict tests to protect people and property from flooding which all local planning authorities are expected to follow. Where these tests are not met, national policy is clear that new development should not be allowed. The main steps are designed to ensure that if there are better sites in terms of flood risk, or a proposed development cannot be made safe, it should not be permitted.
13.2.4 In March 2014, the Technical Guidance of the NPPF was replaced with the NPPG – flood risk and coastal change. This provides further guidance to local planning authorities to ensure the effective implementation of planning policy set out in the NPPF on development in areas at risk of flooding. While superseding PPS23 and 25, the content in the NPPF incorporates the aims and objectives of those documents.
Site-specific flood risk assessment
13.2.5 Footnote 20 in the NPPF states that a site-specific FRA is required for proposals of 1 hectare or greater in Flood Zone 1; all proposals for new development (including minor development and change of use) in Flood Zones 2 and 3, or in an area within Flood Zone 1 with critical drainage problems (as notified to the local planning authority by the Environment Agency); and where proposed development or a change of use to a more vulnerable class may be subject to other sources of flooding.
13.2.6 Additionally, the FRA should demonstrate to the decision-maker how flood risk would be managed now and over the development’s lifetime, taking climate change into account, and with regard to the vulnerability of its users. The FRA should establish:
whether a proposed development is likely to be affected by current or future flooding from any source;
whether it will increase flood risk elsewhere;
whether the measures proposed to deal with these effects and risks are appropriate;
the evidence for the local planning authority to apply (if necessary) the Sequential Test; and
whether the development will be safe and pass the Exception Test, if applicable.
Local flood risk policy
The City of Southampton Local Plan
13.2.7 The Local Plan provides the framework for all development in the city up until 2026. It consists of a collection of the adopted plans, which help guide appropriate development in Southampton. The Core Strategy (SCC, 2015a) is one of the Plans that makes up the adopted Local Plan. It aims to promote the economic growth of the city and deliver the
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sustainable community strategy’s vision for Southampton. The Strategy includes various policies and strategies relevant to flood risk for future development. These are:
‘Core Strategy Policy CS 23: ‘The Council will work with the Environment Agency and other key stakeholders to manage flood risk in the city, particularly in relation to new development in the flood risk zones within the city centre and Northam… Development will achieve an appropriate degree of safety taking into account standards of defence and sea level rise over the life of the development’.
Core Strategy Policy CS 25: ‘development will only be permitted if the necessary infrastructure services, facilities and amenities to meet the needs of the development are available or to be provided at the appropriate time. Southampton City Council will seek developer contributions towards measures required in association with the development, which may include flood defence infrastructure, to deliver sustainable development and be safe’.
Southampton level 2 strategic flood risk assessment
13.2.8 The Strategic Flood Risk Assessment (SFRA) (SCC, 2017d) provides an overview of all sources of flood risk in Southampton, predominantly focusing within the Southampton City Council. The key objectives of the Level 2 SFRA is to:
‘inform policies and plans to ensure future developments, where appropriate, have been subjected to the Sequential Test and Exception Test;
form part of the evidence base supporting the development allocations within the Local Plan to ensure they are in accordance with the NPPF;
identify strategies to limit flood risks and adapt to climate change; and
ensure the safety of new development.’
13.2.9 As required by NPPG, the SFRA (SCC, 2017d) assesses flood risk from the various flood sources, as if each are likely to present a range of different risks. The sources identified are; tidal, fluvial, surface water, groundwater, sewers and artificial sources.
Southampton local flood risk management strategy
13.2.10 The purpose of the strategy (SCC, 2014b) is to guide the community and risk management authorities to better understand and manage flood risk within Southampton. It sets out a statutory framework, guiding principles and objectives that will help communities, the public sector and other organisations to work together to manage flood risk.
Overview of Relevant Guidance
13.2.11 Other relevant guidance includes DMRB, the Environment Agency’s PPGs, the Memorandum of Understanding between the Environment Agency and the Highways Agency on Highways Issues (dated November 2009) and the NPS NN (DfT, 2014). The NPS NN sets out the need for development (including roads and rail projects) and provides the policy against which decisions on major projects is made. Guidance is also provided by the CIRIA Association covering design and operation guidance of structures such as culverts and outfalls.
13.3 Study Area
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13.3.1 The study area for the flood risk and groundwater assessment in this chapter is taken to be a 1km corridor around the Proposed Scheme. The study area for the WFD compliance differed as described in Appendix K.
13.4 Baseline Environment
Baseline Sources
13.4.1 The following key data sources have been used to inform a description of the existing water environment baseline conditions:
Aerial imagery;
British Geological Survey online mapping (BGS, 2017b);
Environment Agency ‘Areas Susceptible to Groundwater Flooding (AfA190)’ (EA, 2010);
Environment Agency ‘What’s in Your Backyard’ (EA, 2017a);
Environment Agency ‘Risk of Flooding from Surface Water’ (EA, 2017a), available from Government open data website;
Environment Agency published flood zones (EA, 2017a), available from Government open data website;
Environment Agency ‘Flood Map for Planning’ (EA, 2017c), available from Government open data website;
Environment Agency Risk of Reservoir Flooding mapping (EA, 2017c), available from Government open data website;
Environment Agency Areas Benefitting from Flood Defences mapping (EA, 2017c);
Environment Agency Historic Flood Extents (EA, 2017d), available from Government open data website;
Environment Agency Catchment Data Explorer (EA, 2017e) www.environment.data.gov.uk/catchment-planning
Existing WFD status and objectives for the 2015 South East River Basin Management Plan (EA, 2016) and updated 2016 dataset.
Governments Multi-Agency Geographic Information for the Countryside (MAGIC) website (Natural England, 2017);
Historical borehole records (BGS, 2017a).
Local Lead Flood Risk Authority Section 19 Flood Investigation Reports;
National Receptor Database (EA, 2017f);
Ordnance survey maps, contemporary OS Maps;
Southampton Coastal Strategy (SCC, 2012);
Southampton Level 2 Strategic Flood Risk Assessment (SCC, 2017d);
Southampton Local Flood Risk Management Strategy (SCC, 2014b);
Water and Sewerage Companies Flood Report;
WSP (2016b) PSSR, M271 Redbridge Roundabout PCF Stage 2. Report Number: 70019110-003; and
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WSP (2017) M271/A35 Redbridge Roundabout, PCF Stage 2 ESR. Report Number: HE551515-WSP-GEN-M271PCF-RE-PM-ESR003.
Baseline Conditions
Existing site characteristics
Topography
13.4.2 The LIDAR mapping within this SFRA documents (SCC, 2017d) indicates that digital terrain model for this area is 0m above ordnance datum. The high and low points of the road network are to be confirmed.
Existing site drainage
13.4.3 Existing drainage in the Proposed Scheme area comprises public sewers (operated by Southern Water) and the highways drainage network, which extends from north east to west of Redbridge roundabout, joining south of the pedestrian subway. The Drainage Condition Grade Report (Ref: HE551515-JAC-EGN-00-RP-LE-0015, Rev00; Dated 18 October 2017) (Jacobs, 2017b) provides a detailed review of the existing surface water drainage network. Overall the drainage system is considered to be in a satisfactory condition with only minor, hairline fractures. The road gullies and their respective connections are Southampton City Council’s highways assets and have minor defects within the study area. Pipe defects have been reported to Southern Water for incorporation into their maintenance programme.
Hydromorphology
13.4.4 The River Test drains a predominantly rural catchment in Hampshire flowing for 64km from its source near Ashe to Southampton where it joins the River Itchen. However as typical of all chalk streams the channel morphology has been significantly modified throughout its length for functions such as milling, land drainage etc. The bedrock geology of the catchment is dominated to the north by chalk which feeds the groundwater base flows to the rivers. In its fluvial reaches the river is classified as a chalk stream and SSSIs supporting a diversity of associated mammal, fish, invertebrate and plant habitats. Major urban areas, such as Southampton, are concentrated along the coast where the underlying geology is predominantly clay.
Water Framework Directive status
13.4.5 For the purposes of the WFD, a study area has been defined which includes the northern tidal extent of the River Test to Testwood and the southwestern tidal channel at Eling as part of the Environment Agency Southampton Water Operational Catchment. Please note, this study area differs from the areas analysed for flood risk and groundwater assessments. The surface water drainage from Redbridge roundabout has not been shown to have hydrological connections to any other waterbodies so the WFD assessment does not include additional adjacent catchments.
13.4.6 The study area lies within the Southampton Water transitional (estuarine) WFD water body, which is currently achieving Moderate Status. The South East River Basin Management Plan aims to achieve Good Status by 2027.
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13.4.7 WFD compliance of the Proposed Scheme is assessed by identifying the baseline conditions of the biological, physico-chemical and hydromorphological quality elements; identifying the potential impacts from the Proposed Scheme on quality elements; and, assessing the Proposed Scheme against WFD status objectives, other EU legislation and overall compliance.
Flood risk
Fluvial flooding
13.4.8 The Environment Agency’s ‘Flood Map for Planning’ indicates that the Proposed Scheme area lies within Flood Zone 1, with less than a 0.1% Annual Exceedance Probability (AEP) of flooding.
13.4.9 The Proposed Scheme is approximately 230m north-east of the Main River, River Test and lies within 120m distance of Flood Zone 3 area, that is associated with this river.
Surface water flooding
13.4.10 The Environment Agency’s Surface Water Flood Risk mapping was reviewed online in December 2017 (see Annex A of Appendix J ‘FRA’); sections of the study area are at risk of surface water flooding from a range of risk classifications, as described below:
There is a high (greater than 3.3% (1 in 30) AEP) risk of surface water flooding to a very small area of the southbound ring of the roundabout with a flood depth of between 300mm - 900mm. There are also areas on the Redbridge Flyover, A33 Redbridge Road (both arms), that have a flood depth of less than 300mm.
There is a medium (3.3% to 1% (1 in 30 to 1 in 100) AEP) risk of surface water flooding to a very small area of the southbound ring of the roundabout with a flood depth >900mm. The direction of flow is towards the centre of the roundabout. There are also areas on the Redbridge Flyover, A33 Redbridge Road (both arms) designated to have a flood depth of between 300mm - >900mm. In addition, eastbound ring of the roundabout is detailed to have a flood depth <900mm, with a flow velocity of 0.25m/s heading in the direction of towards the centre of the roundabout.
There is a low (1% to 0.1% (1 in 100 to 1 in 1,000) AEP) risk of surface water flooding to most of the roads and roundabout within the study area of the Proposed Scheme, in particular on the westbound arm, A33 Redbridge Road. The majority of the surface water has velocities over 0.25m/s and depths of below 900mm.
13.4.11 The Level 2 SFRA (SCC, 2017d) details that there have been a number of recorded surface water flood incidents on the western section of the roundabout and on the western arm.
Groundwater flooding
13.4.12 The areas susceptible to groundwater flooding map identified in the Level 2 SFRA (SCC, 2017d) details that the susceptibility of groundwater flooding throughout the study area is high (over 75%). The Geological overview – Bedrock Permeability map (Map 5) within this SFRA (SCC, 2017d), detail that the bedrock in this area has moderate permeability. Furthermore, it details that there is one recorded groundwater flooding incident potentially at this site area or within a close proximity; however, it is unclear.
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13.4.13 The LIDAR mapping within this SFRA document indicates that the height in the digital terrain model for this area is 0m. It can therefore be assumed that the recorded groundwater flooding susceptibility is due to the high groundwater table associated with the River Test.
Coastal/tidal flooding
13.4.14 The Level 2 SFRA (SCC, 2017d) details that the proposed area is not within an area presently at risk of tidal flooding. The SFRA provides the modelled output of the projected impacts of climate change and sea level rise on tidal flood risk in this area up until the year 2115. The map produced highlights that this scheme falls outside the area at risk, however the area immediately south of the outbound west arm is designated to be in an area of low to medium future tidal flood hazard.
Reservoir failure
13.4.15 The Environment Agency’s mapping details that the Proposed Scheme is not within an area designated at risk of flooding from reservoir failure.
Sewer flooding
13.4.16 According to the Level 2 SFRA there are no recorded sewer flooding within the near vicinity.
Factors influencing the baseline
13.4.17 Baseline conditions for flood risk could change over the anticipated lifetime of the Proposed Scheme as a consequence of climate change, land use changes and measures to improve watercourses in line with WFD objectives. It is likely that flood events including major flooding incident would increase in frequency and magnitude in the study area over the lifetime of the development.
Groundwater
13.4.18 As outlined in Chapter 9 ‘Geology and Soils’, the River Terrace Deposits (RTD) beneath the study area are classified by the Environment Agency as Secondary A aquifer. The Earnley Sand and Wittering formations are also classified by the Environment Agency as Secondary A aquifers. The permeability of the bedrock is likely to be variable (low to high, intergranular flow).
13.4.19 The study area does not lie within a groundwater SPZ and no licensed groundwater abstractions (including potable water abstraction licences) are recorded within 1km of the study area. The groundwater vulnerability map covering the study area describes the soils and superficial deposits (RTD) as having a high leaching potential.
13.4.20 Information on unlicensed groundwater abstractions, i.e. those of less than 20m3/day that do not need an abstraction licence from the Environment Agency (sometimes referred to as Private Water Supplies), was sought from Southampton City Council. Southampton City Council informed that they had no records. Therefore, no information was available to either confirm or rule out the presence of such supplies within the study area. While there is a low likelihood of the use of small groundwater abstractions in this area (e.g. from an undocumented well), their presence cannot be entirely ruled out.
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13.4.21 Groundwater level information in the study area is available from eight historical borehole records held by the BGS and boreholes excavated during a GI carried out during September 2017. Details of both data sets are provided in the GI report (NCG, 2017).
13.4.22 The available information suggests that groundwater levels within the study area are generally likely to be in the range of 1m to 4m bgl. However, historical data records are sparse and the limited period of monitoring available from the recent GI would not be expected to have recorded the highest groundwater levels that would develop in the study area and there is insufficient information available to confirm likely seasonal variation of the groundwater levels recorded.
13.4.23 The historical borehole logs record groundwater levels between ground level and 4.5m bgl. These were recorded across all seasons but in different years between 1962 and 1989. The recent GI logs recorded water strikes between 3.0m and 6.3m bgl and standing groundwater levels between 2.4m and 7.0m bgl.
13.4.24 Subsequent monitoring in installations in five of the recent GI boreholes recorded groundwater levels between 2.1m and 4.25m bgl. The installations were in the RTD and upper bedrock and this monitoring was carried out on three occasions over a 15-day period in September 2017. The relatively low elevation of the study area and proximity to the tidal River Test suggests that groundwater levels may be influenced by tidal levels. However, this monitoring recorded very consistent groundwater levels in each borehole (timing of monitoring with respect to tides was not available).
13.5 Methodology and Assessment Criteria
Methodology
13.5.1 An assessment of the potential impacts of the Proposed Scheme has been undertaken following guidance derived from the DMRB guidance including HD 45/09 (Highways Agency et al., 2009b). Informed professional judgement has been relied upon. The criteria for assessing the magnitude and sensitivity of potential impacts are set out in Table E.1 and E.2 in Appendix E, respectively.
13.5.2 Flood risk effects are assessed in accordance with the requirements of the NPPF and accompanying NPPG.
Assessment of Magnitude and Significance
13.5.3 Table E.1 in Appendix E provides an outline of the assessment criteria for the magnitude of effect that could occur on flooding, geomorphology and water quality receptors. Table C.2 provides an overview of the criteria used to define the receptor sensitivities based on DMRB guidance (HD45/09) (Highways Agency et al., 2009b).
13.5.4 The significance of a potential effect on the water environment is determined by combining the sensitivity of a receptor and the magnitude of an effect. Table 13.1 provides a matrix used in this chapter showing this combination. The most significant potential effects are shown in red, followed by those in orange. For the purposes of the environmental assessment in this chapter, neutral/slight effects (shown as yellow) are assessed as not being significant.
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Table 13.1: Matrix for assigning the overall significance of effect of the Proposed Scheme on water environment
Sensitivity of Magnitude of Effect Receptor Negligible Minor Moderate Major Very High Neutral Moderate/Large Large/Very Very Large Large High Neutral Slight/Moderate Moderate/Large Large/Very Large Medium Neutral Slight Moderate Large Low Neutral Neutral Slight Slight/Moderate
Value of Receptors
13.5.5 Table 13.2 provides an outline of the sensitivities of the receptors from the baseline assessment for flood risk and groundwater. The criteria used to define these sensitivities are outlined in Table E.2 in Appendix E.
Table 13.2: Sensitivities of receptors
Sensitivity Criteria Description Very High Flood risk and drainage: None. Groundwater: None. High Flood risk and drainage: Surface water flood risk along southbound ring of the roundabout, Redbridge flyover and A33 Redbridge Road; groundwater flooding. Groundwater: Secondary A River Terrace Deposits and Wittering Formation; groundwater abstractions. Medium Flood risk and drainage: Surface water flood risk along local roads. Groundwater: None. Low Flood risk and drainage: None. Groundwater: None.
13.6 Assessment Assumptions and Limitations
13.6.1 The assessment for the road drainage and water environment is based on the following assumptions/limitations:
assumes that there would be no new drainage outfalls required to surface waters and that drainage would be through the existing system or to ground. The design adopts the former approach which has been accepted in principle by Southern Water; and
EAR assessment is based on available information and data at the time of writing assumed to be reliable.
13.7 Potential Effects
13.7.1 The following section of the report outlines potential effects that have been identified during both the construction and operation phases of the Proposed Scheme. The potential effects of the Proposed Scheme on the WFD status of the Southampton Water transitional
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water body are described in more detail in Appendix K. The overall WFD compliance of the Proposed Scheme during operation and following mitigation measures is discussed in Section 13.9.
Construction Effects
Flood risk
13.7.2 Potential changes to flood risk can occur during the construction phase. Table 13.3 includes this potential effect.
Groundwater
13.7.3 Small areas of cut are proposed in three areas and these could create groundwater drainage and drawdown of groundwater levels in the vicinity if they intercept the water table. Assuming an existing groundwater level 1m below current ground level, only one of these cut areas is likely to intercept groundwater. There is a small cut adjacent to the southbound side of the M271, north of Redbridge roundabout and approximately 20m west of Redbridge Towers, which will extend to approximately 1.83m below current ground level.
13.7.4 A conservative estimation of the potential radius of influence of groundwater drawdown effects associated with groundwater drainage at this cutting (using Sichardt’s method, (Preene et al., 2016)) produced of a range of 2m to 55m, depending on variability of the hydraulic properties of the RTD. A small area of the M271 and Redbridge Towers would fall within the upper end of this range.
13.7.5 Table 13.3 summarises the potential construction effects associated with the Proposed Scheme.
Table 13.3: Potential construction effects
Topic Potential effects Flood Risk Loss of floodplain storage due to construction activities taking place within the floodplain, as well as increase in risk of flooding (including drainage). The site is located within Flood Zone 1 therefore; the proposed development would not result in any loss of active floodplain. The drainage strategy would mean no increase in risk of flooding. Change in flow paths due to construction activities either blocking existing or creating new flow paths, resulting in increased flood risk. The drainage strategy for the Proposed Scheme means that there would be no blockage of existing flow paths or creation of new flow paths. Alterations to culverts and other structures conveying water could result in a temporary loss of capacity resulting in increased flood risk. The drainage strategy for the Proposed Scheme means that there would be no temporary loss of capacity. Cuttings may provide a route of egress for groundwater, potentially placing the new road at risk. The temporary increase in impermeable surface due to haul routes could lead to increased volumes of runoff that would otherwise
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Topic Potential effects infiltrate in to the soils, and, an increase in the speed of flows being conveyed to watercourse. This would lead to an increase in flood water height and an increase in the risk of flooding. Groundwater Reduced groundwater quality (as outlined in Chapter 9 ‘Geology and Soils’) resulting from: accidental spills and leaks (from construction plant, site compounds, fuel storage areas, materials storage and stockpiling areas) or from the release of concrete and cement products during construction; and potential contamination migration of existing contamination and from potential contamination released or introduced during the works). Reduced groundwater quantity resulting from drainage effects at cuttings intercepting the water table. Damage to buildings or services due to subsidence caused by falling water table due to groundwater drainage at excavations.
Operational Effects
Flood Risk
13.7.6 Potential effects on flood risk could arise during the operational phase. Table 13.4 includes this potential effect.
Groundwater
13.7.7 Potential operational effects to groundwater are similar to those outlined in the construction section above. Table 13.4 provides a summary of these potential effects.
Table 13.4: Potential Operational Impacts on the Proposed Scheme
Topic Potential effects Flood Risk Increase in permanent impermeable areas resulting in increased surface water runoff volume and rate, subsequently resulting in increased risk of flooding. Groundwater Reduction in groundwater quality as a result of contamination from road operation (hydrocarbons from vehicles, salt from de-icing measures etc.). Reduction in groundwater quantity as a result of drainage effects at cuttings intercepting the water table and obstruction of groundwater flows by sub-surface structures (e.g. foundations/piles and drains).
13.8 Design, Mitigation and Enhancement Measures
13.8.1 Mitigation to prevent potential effects associated with an increase in flood risk and impacts on groundwater quantity and quality would need to be in place during construction and operation phases of the Proposed Scheme. In general, a CEMP would be in place to limit/eliminate potential effects during construction. The drainage strategy (Jacobs, 2017b) would also mitigate effects during construction and operation phases. Table 13.5 provides
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an overview of the potential mitigation measures that could be implemented to mitigate potential effects on flood risk and groundwater.
Table 13.5: Design, mitigation and enhancement measures
Topic Mitigation opportunities/enhancement (P = primary mitigation, S = secondary mitigation, T = tertiary mitigation) During Construction Flood Risk Locating work areas outside the floodplain where possible (P). Where this were not possible, temporary floodplain compensation could be required to offset storage losses (T). Designing site areas to avoid changing fluvial and surface water flow routes where possible (P). A Construction Environment Management Plan (CEMP) would be in place, including measures to prevent increased speed of flow conveyance (T). Providing attenuation storage within site drainage to restrict runoff to lowest rates (T). Groundwater If unidentified Private Water Supplies were found during construction to be affected by the Proposed Scheme, then a mitigation would be to provide a local domestic mains supply to the affected property (S). A CEMP would be in place, including measures to prevent polluted surface water from reaching the groundwater (T). If cuttings are confirmed to intercept the water table a subsidence assessment would be undertaken to quantify potential effects on nearby structures. If effects were confirmed mitigation measures would be implemented: e.g. installation of groundwater cut-off walls to prevent groundwater drawdown or strengthening of foundations (P). During Operation Flood Risk The site is located within Flood Zone 1; therefore, the proposed development would not result in any loss of active floodplain. Structures located outside the floodplain where possible (P). Runoff from the road would be attenuated then discharged in accordance with the drainage strategy (P). Drainage strategy provides sufficiently culvert capacity to maintain existing surface water overland flow paths (P). Groundwater During the road operation, regular monitoring and maintenance should be undertaken (managed by Highways England/Southampton City Council), to ensure that drainage systems and any protective measures that are put in place (e.g. groundwater cut-off walls or measures to protect foundations) are adequate and that the need for any corrective action is identified in a timely manner (T).
13.8.2 As the site is located in Flood Zone 1 the development would not however result in the loss of floodplain. A FRA has been completed (Appendix J).
13.8.3 In accordance with NPPF guidance (and based on available information and flood risk data), the FRA demonstrates that the development would satisfy the following requirements.
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remain operational and safe for users in times of flood (alternative access point to the rear of the site);
result in no net loss of active floodplain storage; and
not impede water flows (based on flood mapping available) and not increase flood risk elsewhere.
13.8.4 If un-licenced groundwater abstractions were identified within the study area, they would need to be individually assessed and any at potential risk should be monitored and protected or replaced if necessary. This would be the responsibility of the Principal Contractor.
13.9 Residual Effects
Water Framework Directive status
13.9.1 An analysis of the impact of the Proposed Scheme on Southampton Water quality elements (Appendix K) shows that there is no significant overall impact at a local or WFD water body scale. In fact, the proposed roundabout improvements and mitigation efforts will improve flood attenuation, thereby reducing peak discharges and flood risk and reducing the piped discharged supplied to the River Test and Southampton Water WFD water body.
13.9.2 The existing catchment area for surface water drainage at Redbridge roundabout is estimated to be 1.73ha, of which 1.44ha are impermeable surfaces. Following the modifications in the Proposed Scheme, the surface water drainage area is predicted to increase to 1.77ha, of which 1.53ha are impermeable surfaces. As a result, the negligible increase in road runoff from the very small addition of paved impermeable surfaces is unlikely to affect dissolved organic nitrogen levels in the River Test, or include tributyltin; thereby not preventing the Southampton Water water body from achieving Good status. The headwall controlling discharge into the River Test will remain and therefore be unchanged in size/ design.
13.9.3 An assessment of potential pollution impacts from spillages has been undertaken for the Proposed Scheme taking account of annual average daily traffic use (AADT), road length and the percentage of heavy good vehicles transporting harmful loads (Appendix N). The results of the spillage assessment confirm that the annual probability of a serious pollution event occurring is 0.07%. According to DMRB guidelines (Volume 11, Section 3, Part 10, 45/09 Annex I), the acceptable risk of a serious pollution event occurring is when the annual probability is predicted to be less than 1%.
13.9.4 The WFD water body is protected by the Shellfish Water Directive and Nitrates Directive, however, it is considered that the proposed improvements to the Redbridge roundabout are compliant with EU legislation.
13.9.5 The WFD Compliance Note provided in Appendix K has provided an overview of the potential impacts of the Proposed Scheme on the WFD water bodies within the study area. Highways England Water Risk Assessment Tool (HEWRAT) is not directly applicable to estuaries. Table 13.6 provides an overview of the compliance of the Proposed Scheme against the WFD objectives. The proposals are considered to be complaint with the legislation and would not cause a deterioration or prevent the WFD water body from achieving Good in the future.
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Table 13.6: Overall WFD compliance WFD objective Scheme compliance Deterioration in the status/potential of The assessment has concluded that the the water body proposed works would not lead to a deterioration in the specific quality elements or the overall WFD water body status. Ability of the water body to achieve The scheme would be unlikely to affect the Good Status/Potential ability of the WFD water body to achieve Good Status. Impact on the WFD objectives of other Additional WFD water bodies have not been water bodies within the same River considered in the assessment as there is no Basin District apparent hydrological link with the Proposed Scheme; other waterbodies would be unlikely to be negatively impacted by the proposals. Impact on implementation of the WFD The scheme would be unlikely to affect the mitigation measures and other EU implementation of the catchment WFD legislation mitigation measures and would not affect any other EU legislation.
Flood risk
13.9.6 The Proposed Scheme would result in an increase in impermeable area of approximately 960m2 and consequently runoff. However, the Scheme would include embedded mitigation to ensure this does not increase existing levels of flood risk and major flood risk. It is considered that there would be no significant effects on flooding.
13.9.7 The Proposed Scheme is located within Flood Zone 1 and therefore the development would not remove existing floodplain and consequently compensatory storage would not be required.
13.9.8 Based on information contained within the Environment Agency mapping (reviewed January 2017), the Proposed Scheme is located in an area designated with high groundwater vulnerability. It has therefore been assumed that infiltration of surface water runoff would not be a viable drainage proposal.
Groundwater
13.9.9 It is considered that with the mitigation measures in place for operation of the Proposed Scheme, the significance of residual effects would be likely to be neutral for groundwater receptors, due to potential disruption of groundwater flows of negligible magnitude. However, monitoring of any mitigation measures need to be in place during construction, particularly to evaluate groundwater levels during cutting works. At present there is a potential slight adverse effect arising from cutting works.
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14. Climate Change 14.1 Introduction
14.1.1 This chapter outlines the methodology used to identify and assess likely effects of the Proposed Scheme on climate change and the vulnerability of the Scheme to climate change, during construction and operation.
14.1.2 This chapter has been divided into the following subtopics to address the climate change requirements outlined in the EIA Regulations 2017:
vulnerability of the Proposed Scheme to climate change and how climate change would potentially manifest itself in the future; and
effects of the Proposed Scheme on climate especially Greenhouse Gases (GHG) and carbon. This includes a quantification of the carbon footprint of the Proposed Scheme as part of the consideration of GHG emissions and effects on climate change.
14.1.3 The Proposed Scheme would be unlikely to have any other significant effects on climate. Therefore, this chapter focusses on the GHG and carbon effects. The likely effect of climate change on different receptors such as ecology and water environment are considered in the Habitat Regulations Assessment report (Jacobs, 2018a) and Chapter 13 ‘Road Drainage and Water Environment’ respectively, and not duplicated here.
14.2 Legislative and Policy Framework
14.2.1 The UK government set a target to significantly reduce UK greenhouse gases emissions (reduction of at least 80% of 1990 levels by 2050) through the Climate Change Act 2008. The Act also require Government to assess risks and opportunities of climate change to the UK.
14.2.2 The NPS NN (2014, para 5.17) requires consideration of the carbon impact as part of the appraisal of scheme options and to describe any likely significant climate factors within the Environmental Statement. It also notes that it is very unlikely that the impact of a road project will, in isolation, affect the ability of Government to meet its carbon reduction plan targets. However, for road projects applicants should provide evidence of the carbon impact of the project and an assessment against the Government’s carbon budgets.
14.2.3 In addition, the Southampton Low Carbon City Strategy and Delivery Plan (2011) sets out Southampton City Council’s vision for a low carbon city and carbon reduction.
14.3 Study Area
14.3.1 Assessment of the vulnerability of the Proposed Scheme to climate change study area has been the south-east England region, where Southampton is situated. This region is considered to be the most appropriate as the Proposed Scheme falls within the south east England administration area of the UK Climate Projection (2009) (UKCP09). Historical climate and climate prediction of this region are used as baseline condition.
14.3.2 There is no readily defined study area for effects of a Scheme on climate regarding GHG, as the effects of GHG from all projects contribute towards global climate change. Assessment of the Proposed Scheme to climate change are assessed in life cycles in accordance to Section 7 of PAS 2080:2016 (BSI, 2016). The study area and specific lifecycle assessed for this Proposed Scheme are quantified below:
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products and materials (i.e. embedded carbon, use of materials for temporary and permanent construction activities) – footprint of the Proposed Scheme (see Paragraph 2.3.2)
construction/installation processes (i.e. construction plant use) – footprint of the Proposed Scheme (see Paragraph 2.3.2).
user utilisation of infrastructure, i.e. movement of vehicles during the operation phase – air quality study area of affected roads. See Figure 5.1 for this study area.
14.3.3 There are carbon emissions associated with other lifecycle stages such as operational energy use (i.e. electricity and direct fossil fuel consumption for operation of signage and lighting) and maintenance, repair, replacement and refurbishment over the planned operational life-time of the project. However, as the Proposed Scheme is an improvement to an existing roundabout, scope for additional lighting and signage and maintenance works required are minimal (see Table 14.1). Carbon emissions from these objects would be negligible and relatively unchanged compared to the existing condition. These two lifecycle stages are therefore scoped out of this chapter.
Table 14.1: Comparison of existing and future operational energy use and maintenance requirement
Existing condition Future condition with the Proposed Scheme Lighting Mixture of fluorescent and LED All LED (more energy efficient) Replacement required every 3 years Replacement required every 30 years Signage 34 road signs 32 road signs (16 being re-used) Majority adjacent to road Majority behind safety barrier
14.4 Baseline Environment
Baseline Sources
14.4.1 The following key data sources have been used to inform a description of the existing climate baseline conditions:
Met Office Southampton W.C. Climate (Met Office, 2017);
Guidance: Flood risk assessments: climate change allowances, flooding and coastal change (EA, 2017g);
UK greenhouse gas emissions national statistics: 1990-2016 (DBEIS, 2018);
Summary of climate change risks for south east England: to coincide with the publication of the UK Climate Change Risk Assessment (CCRA) (CCRA, 2012);
UK Climate Change Risk Assessment 2017 (CCRA, 2017); and
UK Climate Projection for 2050s under medium emissions scenarios (2014).
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Baseline Conditions
Vulnerability of the scheme to climate change
14.4.2 The area around the Proposed Scheme experiences average daily temperatures of around 3°C to 10°C in winter and around 12°C to 21°C in the summer (Met Office, 2017). The region has a milder climate than most areas of the UK due to its southern location and the climate stabilising effect of the sea protecting against the more extreme weather of the Atlantic coast. The South East region of England experiences a total annual rainfall of approximately 788mm, with October being the wettest month with a total of 93mm (Met Office, 2017).
14.4.3 The Proposed Scheme is also located in the South East river basin district. Rivers in the South East river basin district are estimated to see a total potential change of peak river flow within the central allowance category of 10% (2015 to 2039), 20% (2040 to 2069) and 35% (2070 to 2115) (EA, 2017g).
14.4.4 Across England as a whole, average land temperatures have risen by approximately 1ºC over the last century (CCRA, 2017). England is seeing a trend towards warmer winters and hotter summers with sea levels rising by approximate 3mm a year (CCRA, 2017). Current trends and forecasts predict that the south-east of England will experience the following potential effects due to climate change (CCRA, 2012):
increase frequency of flooding;
hotter summers (with an increased number of heat wave events); and
water scarcity, particularly during the summer.
14.4.5 Table 2.1 under Section 2.1 ‘Design Considerations’ provide aspect of road infrastructure that could be impacted by potential effects of climate change mentioned above.
14.4.6 The UKCP09 summarises the projected changes in climate for the South East of England by the 2080s for the medium emissions scenario as describes below:
the central estimate of increase in winter mean temperature is 2.2ºC; it is very unlikely to be less than 1.1ºC and is very unlikely to be more than 3.4ºC. A wider range of uncertainty is from 0.9ºC to 3.8ºC.
the central estimate of increase in summer mean temperature is 2.8ºC; it is very unlikely to be less than 1.3ºC and is very unlikely to be more than 4.6ºC. A wider range of uncertainty is from 1.1ºC to 5.2ºC.
the central estimate of increase in summer mean daily maximum temperature is 3.7ºC; it is very unlikely to be less than 1.4ºC and is very unlikely to be more than 6.6ºC. A wider range of uncertainty is from 1.2ºC to 7.4ºC.
the central estimate of increase in summer mean daily minimum temperature is 3ºC; it is very unlikely to be less than 1.3ºC and is very unlikely to be more than 5.1ºC. A wider range of uncertainty is from 1.2ºC to 5.7ºC.
the central estimate of change in annual mean precipitation is 0%; it is very unlikely to be less than -5% and is very unlikely to be more than 6%. A wider range of uncertainty is from -6% to 6%.
the central estimate of change in winter mean precipitation is 16%; it is very unlikely to be less than 2% and is very unlikely to be more than 36%. A wider range of uncertainty is from 1% to 40%.
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the central estimate of change in summer mean precipitation is -19%; it is very unlikely to be less than -41% and is very unlikely to be more than 7%. A wider range of uncertainty is from -43% to 16%.
Effects of the scheme on climate change
14.4.7 The Government has a legally binding framework to cut GHG emissions by at least 80% by 2050 (DfT, 2014, p.49). The total background of UK emissions for 20166 is 468 million tonnes of CO2e; with transport being the largest emitting sector (DBEIS, 2018). To meet the fifth carbon budget, transport emission would need to be reduced by an average of 4% per year to 2030 (Committee on Climate Change, 2017). However, the emissions from any UK infrastructure scheme compared against the UK total will always be negligible.
14.4.8 The baseline emissions of the Proposed Scheme during the operation phase is based on the DM scenario of the traffic data. The traffic emissions for the DM scenarios are estimated to be 502.5 tCO2e/year during opening year (2019) and 2620.5 tCO2e/year during design year (2036) (see Table 5.14 and Table 5.15, respectively under Chapter 5 ‘Air Quality’). The carbon baseline conditions associated with construction are set at zero, as there is no current construction at the site.
14.5 Methodology and Assessment Criteria
14.5.1 A high level proportionate climate change assessment has been undertaken based on IEMA’s ‘Assessing Greenhouse Gas Emissions and Evaluating their Significance (IEMA, 2017) guidance. Professional judgement has been used to determine the significance of effect of climate change to the Proposed Scheme. At the beginning of PCF Stage 3 the vulnerability of the Proposed Scheme to climate change has been assessed to identifying ways during design to adapt the Scheme to make it more resilient to climate change and extreme weather events.
14.5.2 Construction carbon has been calculated using a carbon calculator to record how much carbon would be likely to be generated during construction of the Proposed Scheme. The methodology for this assessment is the same as the methodology for materials assessment outlined in Paragraphs 10.5.3 and 1.05.4 under Chapter 10 ‘Materials’. Operation carbon has been quantified as part of air quality assessment using DS traffic data obtained from Systra regional model. Levels of magnitude for carbon from construction carbon calculations are defined in Table E.1 in Appendix E and would be used along with professional judgement to determine significance. As there is no guidance for significance level of regional carbon emission, professional judgement would be used.
14.6 Assessment Assumptions and Limitations
14.6.1 Similar to Chapter 10 ‘Materials’, climate impacts associated with carbon emission from the extraction and transport of primary raw materials and manufactured products would occur off-site. The source and processing/manufacture of materials cannot be determined at this time, and the production of these materials would be likely to have been the subject of separate consent procedures (such as applications for planning permission and environmental permits) including environmental assessment.
14.6.2 Structures, drainage, road restraint systems, street lighting and signage products would be procured with consideration of the environmental impacts associated with their
6 Last reported year at the time of preparing this chapter.
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manufacture such as carbon footprint, energy consumption and long-life performance. Both reinforced concrete and steel structures include a measurable recycled content in their manufacture. Where possible, the availability of responsibly sourced local and recycled materials would also be considered to reduce carbon footprint, such as from transport emissions. With professional judgement, climate impacts associate with extraction of raw materials, the manufacture of products and the transport of materials would not be significant and has therefore been scoped out of this chapter.
14.7 Potential Effects
Vulnerability of the Scheme to Climate Change
14.7.1 Changes in climate variables (and impacts associated with extreme weather) could potentially impact on the road itself and supporting infrastructure including the footbridge, earthworks and drainage. However, not all climate related impacts are threats, there are likely to be opportunities brought about by climate change. Table 14.2 outlines the key potential impacts (and opportunities) of climate change and its effects on different aspect of the Proposed Scheme. Some aspect of infrastructure elements can be more or less vulnerable that the others. For example, roadside furniture such as road signs are more vulnerable to high wind damage than bigger structure such as the footbridge.
14.7.2 Majority of effects of climate change on road infrastructure, such as warmer temperatures increased thermal loading on the footbridge and pavements causing expansion, bleeding and rutting or flooding causing drainage blockages increasing maintenance frequency and costs. Flooding and surface water impacts are further covered in Chapter 13 ‘Road Drainage and Water Environment.
Table 14.2: Potential climate change impacts and its effects on different aspect of the Proposed Scheme
Aspect Impact: lower Impact: higher Impact: higher Impact: precipitation precipitation temperature Wind Roads More rapid Increased risk of Overheating of Loading of binder traffic accidents technology. structures. deterioration. and disruption Softening, from flooding. deformation and Loss of strength damage to of layer materials. bitumen Damage to in asphalt. structure and Expansion and surfaces. Erosion of unpaved buckling of shoulders. concrete roads and structures. Footbridge Expansion and Loading of buckling of structures concrete roads and structures. Earthworks Damage to Increased slope Damage to Erosion vegetation and vegetation and
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Aspect Impact: lower Impact: higher Impact: higher Impact: precipitation precipitation temperature Wind more instability and more difficult to erosion of difficult to establish erosion surface. Soil establish erosion protection saturation leading protection measure of to undercutting. measure of grassland. grassland. Landscape Damage to Damage to plantings vegetation and vegetation and reduction in the reduction in the effectiveness and effectiveness and aesthetic appeal aesthetic appeal of landscape of landscape plans. plans. Drainage Erosion, silting Blockages and Expansion and and waste cracking of the sedimentation accumulation. system.
14.7.3 The risk of major accidents and disasters is greater during precipitation events, cold extremes and warmer temperatures. This is due to reduced visibility, increase breaking distance and an influence on the mode, frequency, and types of trip that individuals take. Increasing temperatures and changes in precipitation patterns has the potential to exacerbate road safety issues further as seen in Table 14.2.
Effects of the Scheme on Climate Change
14.7.4 The Proposed Scheme has the potential to generate carbon during construction through the use of materials and construction vehicle movements and has the potential to change traffic movements and therefore the operational carbon associated with this.
14.7.5 Total estimated carbon emissions from use of materials for temporary and permanent construction activities have been estimated to be 1,171 tCO2e (see Table 10.5 under Chapter 10 ‘Materials’), while for the ‘user utilisation of infrastructure’ stage or emissions from traffic during operation of the Proposed Scheme under DS scenario at the opening year (2019) has been estimated to be 483.3 tCO2e/year (see Table 5.14 under Chapter 5 ‘Air Quality’). A decrease of 4% compared to the DM scenario.
14.7.6 For CO2 emissions from traffic during operation under DS at the design year (2036), it has been estimated that 2736.5 tCO2e would be produced per year, an increase of 4% compared to the DM scenario (see Table 5.15 under Chapter 5 ‘Air Quality). Decrease of carbon emissions during the opening year would be due to the reduction of traffic congestion and better flow movement of traffic in the regional network with the addition of the Proposed Scheme. Increase in carbon emissions during the operation year of 2036 would be due to the increased traffic flow. This would be likely to be from more vehicles being on the road or the scheme attracting more traffic onto the network. Year 2036 emissions could potentially be lower than the modelled figure as electric cars become more common and vehicle engines efficiency of burning fuels increases.
14.7.7 It should be noted that the carbon emissions associated with use of construction plants and the transport of materials to the site have not been assessed as the exact type of plant and source of the materials is not known at this time and would be chosen by the
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appointed principal contractor. However, such emissions would be unlikely to be significant particularly with construction compound adjacent to the scheme and materials available locally, minimising the associated transport distances and carbon emissions. Wherever possible, on-site materials would also be reused secondary/recycled materials responsibly sourced. Further mitigations to reduce impacts would also include standard measures such as use of equipment meeting recent emission control standards and operation of well-maintained equipment included in the CEMP.
14.8 Design, Mitigation and Enhancement Measures
Vulnerability of the Scheme to climate change
14.8.1 Potential mitigation measures for reducing vulnerability of road infrastructure receptors to climate impacts have been discussed with the project teams, including engineers during the design stage to identify the provision of appropriate mitigation measures. Please refer to Section 2.6 ‘Design Considerations’ for these mitigations measures
14.8.2 Drainage design of the Proposed Scheme has been designed for climate change allowance of 20% (Jacobs, 2017b) and FRA has also been carried out for the Proposed Scheme (see Appendix J). A wide range of species including 16% of evergreen which delivers better ecosystem services has been incorporated into the landscape design. Diversity in species choices are the core of adaptation and would ensure resilience of the Proposed Scheme with future climate change scenarios. Choice of planting species also takes into account native species that do not require large quantity of water to maintain. Proposed plantings would be unlikely to be impacted by changes in future climate; once established they would provide effective visual screening.
Effects of the Scheme on Climate Change
14.8.3 Mitigation measures for effects on carbon footprint would be similar to the materials and waste hierarchy and consist of strategic approaches that drive reduction across all lifecycle stages of the Proposed Scheme. Strategically, emissions are mitigated by applying the carbon reduction hierarchy PAS 2080:2016 (BSI, 2016) which cover:
build nothing - challenge the root cause of the need; explore alternative approaches to achieve the desired outcome;
build less - maximise the use of existing assets; optimise asset operation and management to reduce the extent of new construction required;
build clever - design in the use of low carbon materials, streamline delivery processes, minimise resource consumption; and
build efficiently - embrace new construction technologies; eliminate waste.
It should be acknowledged that application of the hierarchy is part of the inherent outcome of good design practice and therefore embedded within the design of this Proposed Scheme. At a Scheme level and at a structures/equipment level within the Scheme.
14.8.4 Mitigation measures for the specific lifecycle stage are provided in Table 14.3.
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Table 14.3: Carbon emissions mitigation measures
Scheme lifecycle stage Mitigation measures Temporary and permanent Reduction of materials consumption would be carried construction materials. out in accordance with mitigation measures outlined in Chapter 10 ‘Materials’. Construction/installation Construction plant emissions would be managed via process. the Construction Environmental Management Plan (CEMP), which should specify plant operator efficiency requirements. In-use traffic on the scheme. N/A
14.9 Residual Effects
Vulnerability of the Scheme to climate change
14.9.1 With mitigation measures outlined in Section 14.7.1 and 14.7.2 in place, and a milder climate than most areas of the UK, vulnerability of the Proposed Scheme to climate change effects would not be considered significant.
Effects of the scheme on climate change
14.9.2 Effects of the Proposed Scheme to climate change has been considered not to be significant. The magnitude of carbon emission as a result of the material used for temporary and permanent construction activities would be negligible with no potential for significant effect.
14.9.3 CO2 emissions from traffic during operation (both at opening year and design year) have also been considered not to be significant. The Proposed Scheme would provide short term benefit of reducing carbon emission from traffic by 4%, future increase of 4% in the year 2036 could further be reduced with advancement in vehicle technology.
14.9.4 This result ties in with NPS NN (DfT, 2014, p.49) statement that ‘the impact of road development on aggregate levels of emission is likely to be very small’. Mitigation measures would be implemented aimed at reducing carbon emission wherever possible and striving to meet Government’s carbon budgets for the transport sector.
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15. Assessment of Cumulative Effects 15.1 Introduction
15.1.1 Cumulative effects occur when incremental environmental, social and economic impacts caused by past, present and reasonably foreseeable activities combine to create an additive or synergistic level of effect. They can occur during both construction and operation of a Proposed Scheme. This chapter provides an assessment of the potential cumulative effects of the Proposed Scheme, and those of the Proposed Scheme in combination with other major proposed developments.
15.1.2 In accordance to DMRB HA 205/08 (Highways Agency et al., 2008a), cumulative effects normally fall within two categories, as follows:
Type 1 - Cumulative effects from a single project (or intra-development effects) The effect arises from the combined action of a number of different environmental topic specific impacts upon a single receptor/resource.
Type 2 - Cumulative effects from different, nearby projects, in combination with the project being assessed (or inter-development effects) The effects could arise from the combined action of a number of different projects, in combination with the project being assessed, on a single receptor/resource. This could include multiple impacts of the same or a similar type from a number of projects upon the same receptor/resource.
15.1.3 This chapter assesses both intra-development effects and inter-development effects.
15.2 Legislative and Policy Framework
15.2.1 The assessment of cumulative effects is required in EIA, in line with Town and Country Planning (EIA) Regulations 2017 and guidance within DMRB Volume 11, Section 2, Part 5 (Highways Agency et al., 2008a). The need to consider cumulative effects in planning and decision making also is set out in planning policy in particular to NPS NN (DfT, 2014, para 4.16).
15.3 Study Area
15.3.1 The study area, also termed the spatial Zones of Influence (ZOI) for the assessment of intra-development effects is identified within the relevant environmental topic chapters of this EAR (Chapter 5 -14). The study area for the identification of potential inter- development effects covers an area extending approximately 3km from the Proposed Scheme boundary. Due to the size of the Proposed Scheme, this is considered adequate.
15.4 Baseline Environment
Baseline Sources
15.4.1 The following key data sources have been used to inform a description of the existing inter-development cumulative baseline conditions:
Southampton City Council planning portal (SCC, 2017e);
Test Valley Borough Council planning portal (TVBC, 2017); and
New Forest District Council Planning Portal (NFDC, 2017).
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Baseline Conditions
15.4.2 The baseline conditions of receptors that could potential be impacted by intra- development effects are covered within the relevant environmental topic chapters of this EAR (Chapter 5 -14).
15.4.3 Review of developments within 3km of the Proposed Scheme for inter-development effects baseline conditions has been undertaken and outlined in Table 15.1 below.
Table 15.1: Schemes and developments within 3km of the Proposed Scheme
Development Description Planning Distance (scheme) status from Proposed Scheme (approx.) (km) Southampton City Environmental improvement Planning 0km Council (SCC) works including new parking approval; (adjacent landscape areas, changes to landscaping, conditions to the environment creation of recreation spaces, are currently Proposed improvements to the new bin stores and entrance being Scheme) estates at Cuckmere canopies. discharged Lane and Studland through SCC. Close.
(SCC Ref: 16/00294/R3CFL) Erection of up to Outline application for the Planning 0.5km 12,941 square erection of up to 12,941 square approval; metres of Class B21 metres of business floorspace conditions business and/or (Class B1) and/or general are currently general industry floor industry (Class B2), with being space with access associated works including discharged from Adanac Drive. drainage, vehicular access from through Test Adanac Drive, car parking and Valley (SCC Ref: landscaping. Borough 14/00128/OUT/ Council TVBC Ref: (TVBC) 14/00138/FULLS). (Frogmore Lane). Land at Test Lane, Land at Test Lane, Southampton. Planning 0.75km Southampton. Redevelopment of the site to approval; Redevelopment of provide 19,132 square metres of conditions the site to provide employment floorspace in three are currently 19,132 square buildings (Units 1 and 3 to be being metres of storage and distribution use discharged employment (Class B8), Unit 2 to be Business through SCC. floorspace in three use (Class B1c) and/or storage buildings and distribution use (Class B8)) with an area of open space, associated landscaping,
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Development Description Planning Distance (scheme) status from Proposed Scheme (approx.) (km) (SCC Ref: servicing areas and car parking 14/01911/FUL) with vehicular access from Test Lane. Mixed development Scoping Opinion sought in June Planning 1.25km for Land of Eling 2014 for mixed development application Wharf, Eling, Totton including two hectares of not yet SO40 9GD employment use and up to 200 submitted. residential units. (NFDC Ref: 14/10643) Land Adjacent Screening opinion sought in July Planning 1.5km Bargain Farm 2017 relation to erection of a approved on Frogmore Lane care scheme comprising 80 bed the 21st Aug Nursling care home and 61 bed 2017; EIA not Southampton rehabilitation centre, access and required. Hampshire SO16 parking. 0XS
(TVDC Ref: 17/01773/SCRS) Testwood to A Scoping Opinion was Planning 2km Otterbourne pipeline requested from New Forest and application Test Valley District Councils not yet (NFDC Ref: under the EIA Regulations 2011 submitted. 16/11336 / TVDC in September 2016 for the Ref: proposed development of 16/02433/SCOS) pipeline scheme between Testwood and Otterbourne. Southampton Erection of a new multi-storey car Planning 2.75km General Hospital park within Car Park 4 (off approval; Coxford Road), additional car Conditions (SCDC Ref: parking and realignment of Car were being 15/00841/FUL) Park 1 (off Tremona Road) with discharged in associated infrastructure at 2017. Southampton General Hospital.
15.5 Methodology and Assessment Criteria
15.5.1 Intra-development cumulative effects would be presented for receptors which could be affected by more one EIA topic. Where a receptor has been identified as only experiencing one effect or where only one topic has identified effects on the receptor there is no potential for intra-development effects to occur. A checklist matrix approach has been used to demonstrate links/receptors and where it would be covered within this EAR.
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15.5.2 For inter-development cumulative effects, a desk study has been completed to identify committed developments (projects) within 3km of the Proposed Scheme. The DMRB states that the significance should be determined by the extent to which the impacts can be accommodated by the resource. The assessment should take into account the following factors when determining significance:
Which receptors/resources are affected?
How will the activity or activities affect the condition of the receptors/resource?
What are the probabilities of such effects occurring?
What ability does the receptor/resource have to absorb further effects before change becomes irreversible?
15.5.3 Effects are identified as direct, indirect, permanent or temporary. Their magnitude is identified, standard mitigation measures have been taken into account and the residual significance of the effects assessed using the guidance in DMRB Volume 11, Section 2, Part 5 HA 205/08 (Highways Agency et al., 2008a).
Assessment Assumptions and Limitations
15.5.4 The traffic model used to inform the air quality and noise and vibration assessments takes into account projected traffic growth from planned development in the surrounding area of the Proposed Scheme. Therefore, the cumulative effects of development in terms of traffic has already been included as part of the environmental assessment and are therefore not assessed in this section.
15.5.5 An assessment of the inter-cumulative impacts has been carried out with other local developments identified (where information and data is available). It should be noted that the certainty associated with the assessment of cumulative impacts is by necessity lower than with non-cumulative assessments due to the variable quantity and quality of data available for other projects and the difficulties of considering cumulative impacts on receptors. The inter-project cumulative effects assessment presented in this report may also rely upon environmental information and assessments reported by third-parties.
15.6 Potential Effects
Intra-development Effects
15.6.1 Table 15.2 demonstrated links/relations between some of the existing topic chapters and existing receptors and where it is covered within this report or other environmental related products. The ones that link generally fall into the category of health and social economics.
15.6.2 Combined effects of air quality, noise and vibration and road drainage and water environment to protected species/ecology during construction and operation phases are covered in the HRA (Jacobs 2018a) and Chapter 8 ‘Biodiversity’ of this report. Links have been identified between people and the topics for noise, vibration, dust, traffic, visual and changes to amenity and visual. These could have direct combined effects on human health, for example respiratory problems or indirectly through stress caused by changes to job due to access and visual. Assessment of these combined effects are covered in Chapter 12 ‘People and Communities’ under ‘community health’ subheading.
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Table 15.2: Potential intra-development cumulative effects
Sensitive Construction Phase Operational Phase
receptors
15.6.3 T
a ngestion
b vibration
l amenities
e amenities environment
environment
Visual changes Visual changes
Noise Noise and
Dust and air quality Dust and air quality
1 Noise and Vibration
Traffic and congestion Traffic and co Access services to and
5 Access services to and
Road drainage and water Road drainage and water Local. residents 2
Recreational users s h Businesses/o Widerw community
Protected species/ l ecology i nks between businesses and the local/region economy that may be impacted by changes in traffic flow such as potentially increased congestion during construction and reduced congestion during operation.
15.6.4 The impacts of the construction of the Proposed Scheme could affect local businesses and schools in terms of the congestion, putting people off from using certain routes and the loss of passing trade. The congestion could also impact the region economy as the Redbridge Roundabout provide the main access to the Southampton’s Western Docks. The impacts are however temporary (approximately seven months) and may be offsetted by businesses that benefit from a construction workforce being located within the area. Standard good practice (tertiary) mitigation would include engaging with the local communities and businesses to explain construction programmes and potential diversion routes in advance, to plan and prepare for changes. It is assumed that the benefits and dis-benefits relating to socio-economics during the construction phase would create a slight overall effect in the area. Therefore, there would be no significant effects to socio- economics during construction.
15.6.5 The operational benefits have been assessed as part of the business case. It identifies that the Proposed Scheme will generate benefits to business users especially the docks through addressing issues with congestion and safety on the existing network. This would likely lead to a significant benefit to the local and regional economy during the operational phase.
Inter-development Effects
Landscape and visual
15.6.6 If the construction programme of Southampton City Council landscape environment improvements scheme (adjacent to the Proposed Scheme) coincide with the Proposed Scheme construction programme or overlap, there would be an increase in visual impacts
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from prolong construction period, additional construction machinery, vehicle movement and loss of vegetation. However, it is anticipated that construction of Southampton City Council landscape environment improvements scheme would be completed this year prior to the construction of the Proposed Scheme and therefore the combined effects are considered not to be significant.
15.6.7 Landscape mitigation of the landscape environment improvements scheme was taken into account during landscape design for the Proposed Scheme. During operation phase, proposed plantings of both the landscape environment improvements scheme and the Proposed Scheme, would further enhance the Amenity Green Space and townscape of the Redbridge Roundabout area. The combined effects during operation would be slight beneficial.
Biodiversity
15.6.8 With mitigation measures, the level of significance effect of the Proposed scheme during construction and operation phases to biodiversity are assessed as neutral. In combination with other developments in the study area, it is unlikely that the combined effects would be significant. Geology and soils
15.6.9 With mitigation measures, the level of significance effect of the Proposed scheme during construction and operation phases to geology and soils are assessed as slight adverse. In combination with other developments in the study area, it is unlikely that the combined effects would be significant.
Materials
15.6.10 With mitigation measures, the level of significance effect of the Proposed scheme during construction and operation phases to materials are assessed as neutral to slight adverse. In combination with other developments in the study area, it is unlikely that the combined effects would be significant.
People and community
15.6.11 Construction effects to people and community are very localised (i.e. shared use path to the south of Redbridge roundabout); in combination with other developments in the study area, it is unlikely that the combined effects would be significant. It is also anticipated that the closest development (Southampton City Council landscape environment improvements scheme) construction phase would not overlap with the Proposed Scheme.
Road drainage and water environment
15.6.12 The Proposed Scheme is located within Flood Zone 1 and in an area designated with high groundwater vulnerability. Effects to flood risk is therefore assessed as low and with mitigation measures, effects to groundwater would be slight adverse. In combination with other developments and mitigation for groundwater, it is unlikely that the combined effects would be significant.
15.7 Residual Effects
15.7.1 It is anticipated that there would be no likely significant intra-cumulative effects resulting from the construction and operation of the Proposed Scheme across environmental topics,
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and no likely significant intra-cumulative effects from the construction and operation of the Proposed Scheme with other developments within the area.
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16. Summary and Conclusion
16.1.1 This section summarises the findings of the PCF Stage 3 and 5 environmental assessment reported in this Environmental Assessment Report (EAR). These are summarised in Table 16.1 for each environmental topic. The potential impact is described in the first column, whilst the final column shows the overall potential residual effects following proposed mitigation described in the middle column of the table. For further explanation and detail, the reader should refer to the individual topic chapters.
16.1.2 It has been considered that there would be significant adverse effects to some sensitive visual receptors (i.e. residents at Redbridge Tower), cyclists using short section (400m) of NCN Route 236 and noise receptors (e.g. residents at 197 - 227 Cuckmere Lane, 4 Coniston Road etc.) during construction of the Proposed Scheme. However, all of these effects would be temporary and localised, and have therefore not been considered to be a ‘key factor or material in the decision making process’ (Highways Agency et al., 2008a) of EIA for this particular scheme. In accordance to DMRB HA 205/08 (Highways Agency et al., 2008a), “temporary effects are considered to be less significant than permanent effects”.
16.1.3 Furthermore, the overall landscape and visual effects during the construction phase of the Proposed Scheme have been assessed as not significant. Construction activities would be controlled as far as reasonably practicable through the application of suitable control measures, described further in Appendix B and the outline Environmental Management Plan (EMP) (Jacobs, 2018b).
16.1.4 With implementation of the proposed mitigations, it can be concluded that there would be no likely significant residual effects on any of the environmental topics due to the Proposed Scheme.
Table 16.1: Summary of residual environmental effects after mitigation
Description of impacts Proposed mitigation Likely residual effects (after mitigation) Air Quality (Chapter 5) Changes in local air Implementation of Dust Management Plan No quality during and Construction Environmental construction. Management Plan (CEMP). Changes in local and N/A No regional air quality during operation. Cultural Heritage – scoped out of the EAR Landscape and Visual (Chapter 7) Tranquillity of townscape Design of structures and material appropriate No due to loss of vegetation. to townscape context. Vegetation to be removed only where essential. Tree protection fencing installed in
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Description of impacts Proposed mitigation Likely residual effects (after mitigation) accordance with BS5837:2012 (BSI, 2012). Use of no-dig construction methods and materials for the shared footway/cycleway north of Clover Nooke. New ornamental trees, shrub and bulb species and amenity grassland seeding to improve the Amenity Green Space and promote landscape integration. Effects of Proposed Protect/maintain the attractive undulating No Scheme earthworks on landform on the roundabout. landform. Grassland seeding. New ornamental trees, shrub and bulb species and amenity grassland seeding to improve the Amenity Green Space and promote landscape integration. Visual effects to users of Vegetation to be removed only where No Footpath Southampton essential. 07, and residents at Attractive structure considered for the properties on Coniston proposed footbridge. Road; and at Redbridge New ornamental trees, shrub and bulb Towers and buildings species and amenity grassland seeding to south-east of it. improve the Amenity Green Space and promote landscape integration. 3m wide strip outside the proposed retaining wall east of Redbridge Roundabout for new shrubs and tree planting to replace trees lost during construction. Visual effects to users of Vegetation to be removed only where No shared footway and essential. cycleway south of Building styles, structures and material used Redbridge Flyover, and appropriate to the townscape context. residents at properties Use of no-dig construction methods and north and south of Old materials for the shared footway/cycleway Redbridge Road; north of Clover Nooke. Hazeldene Mee’s House; New ornamental trees, shrub and bulb The Cottage; and The species and amenity grassland seeding to Nooke Listed Buildings. improve the Amenity Green Space and promote landscape integration. Visual effects to users of New ornamental trees, shrub and bulb No footways along Gover species and amenity grassland seeding to Road and residents on improve the Amenity Green Space and Gover Road. promote landscape integration (S). Visual effects to users of Vegetation to be removed only where No footways within essential.
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Description of impacts Proposed mitigation Likely residual effects (after mitigation) roundabout and New ornamental trees, shrub and bulb footbridge, and users of species and amenity grassland seeding to Redbridge Roundabout improve the Amenity Green Space and Amenity Space. promote landscape integration. Building styles, structures and material used appropriate to the townscape context. Biodiversity (Chapter 8) Air quality changes, and No hydrological changes and pollution to European statutory designated sites (including Solent and Southampton Water Ramsar; Solent Maritime Implementation of CEMP and Dust SAC; Solent and Management Plan to reduce generation of Southampton Water SPA; dust, plant machinery exhaust emission and and proposed Solent and run-off from construction areas. Dorset Coast SPA). Managing drainage from the Proposed Air quality changes, and Scheme. No hydrological changes and pollution to statutory designated sites (including Lower Test Valley SSSI; Eling and Bury Marshes SSSI; and River Test SSSI). Geology and Soils (Chapter 9) Health effects to Implementation of a CEMP to identify No construction workers, measures to control contamination risk. general public and Implantation of Scheme Asbestos current and nearby site Management Plan (SAMP) (Jacobs, 2018c) users. (including an asbestos response procedure in the event that suspected asbestos-containing materials are identified during the construction works). Surveys and management adopted where intrusive works are proposed. Reduction in quality of No groundwater - Secondary A Aquifer within the Implementation of CEMP to control superficial deposits and contamination risk. bedrock; and Piling risk assessment. surface water (River Test).
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Description of impacts Proposed mitigation Likely residual effects (after mitigation) Damage to buildings and Foundation designed in accordance with BRE No services (onsite) from Special Digest 1 (2005) based on ground disturbance. assessment of aggressive ground conditions. Materials (Chapter 10) Material use and Implementation of CEMP (including Site No depletion (i.e. virgin Waste Management Plan (SWMP) and Key aggregates). Performance Indicators (KPIs)). Carbon footprint of Maximise local sourcing of materials and the No materials transport and inclusion of as much recycled content as use. practicable. Maximisation of the use of on-site material, wherever practicable. Production of hazardous No wastes. Reuse of surplus No construction materials Implementation of CEMP (including SWMP and waste on-site. and KPIs). Recycling of surplus No construction materials and waste. Noise and Vibration (Chapter 11) Construction noise and Implementation of CEMP including suitable Yes (but vibration impacts to control measures to reduce noise and temporary nearby sensitive vibration, such as informing local residents and receptors. when specific noisy activities with vibration localised) impacts would be likely to occur. Traffic noise impacts to Two noise barriers near Redbridge Towers No nearby sensitive (5m high) and Clover Nooke (4m high) receptors during embedded into design. operation. People and Communities (Chapter 12) Access to all identified Implementation of CEMP which include: No routes with the footprint of Liaise with stakeholders prior to the Proposed Scheme commencement of construction works. (i.e. Redbridge Towers Provide appropriate signage for temporary footbridge or path diversions. adjacent to the eastbound Use of construction management measures carriageway of the A33). to reduce noise and dust generated by construction works. Construction works to be minimised during time periods where children are travelling to and from school, and ensure robust
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Description of impacts Proposed mitigation Likely residual effects (after mitigation) construction management practices in place in routes used by school children. Driver stress to vehicle Schedule construction works to avoid busy No travellers. times of day where possible. Provide appropriate signage for lane closures or temporary diversions. Provide advance notice of traffic management measures and any diversion routes on easily accessible public forum. Access to bus stops. Maintain safe access to bus stops/temporarily No relocate bus stops if required. Liaise with bus companies to identify suitable alternative temporary bus stop locations if required. Liaise with bus companies in advance of works so that they can plan their services and advise their passengers accordingly. Temporary loss of land Liaise with stakeholders prior to No and disruption in access commencement of construction works. to Redbridge Towers and Land would be reinstated to its previous use. Clover Nook blocks Provide appropriate signage for temporary diversions. Maintain safe access for pedestrians throughout construction period, utilising diversions where required. Temporary loss of access Liaise with stakeholders prior to No to Open space (amenity commencement of construction works. land) at Redbridge Implement noise and dust management roundabout and measures as described in Chapter 5 ‘Air Redbridge Towers. quality’ and Chapter 11 ‘Noise and Vibration’. Restore land made available by demolition of existing structures to grassland in line with surrounding land use. Road Drainage and Water Environment (Chapter 13) Flood risk from loss of Locating work areas outside the floodplain No floodplain storage and where possible and designing site areas to change in flow paths. avoid changing fluvial and surface water flow routes where possible. Implementation of CEMP including measures to prevent increased speed of flow conveyance. Providing attenuation storage within site drainage to restrict runoff to lowest rates.
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Description of impacts Proposed mitigation Likely residual effects (after mitigation) Drainage strategy provides sufficiently culvert capacity to maintain existing surface water overland flow paths. Reduce groundwater If unidentified Private Water Supplies were No quality and quantity. found during construction to be affected by the Proposed Scheme, then a mitigation would be to provide a local domestic mains supply to the affected property Implementation of CEMP including measures to prevent polluted surface water from reaching the groundwater. During the road operation, regular monitoring and maintenance should be undertaken to ensure that any protective measures that are put in place are adequate and that the need for any corrective action is identified in a timely manner. Climate Change (Chapter 14) Changes in climate Flood Risk Assessment (FRA) and No variables impacting the embedded design for climate change (i.e. Proposed Scheme. allowance of 20% for climate change in the drainage design) Impacts to national Implementation of CEMP (including SWMP No carbon footprint. and KPIs).
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Appendix A. Figures
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Appendix B. Good practice (tertiary mitigation)
This appendix covers good practice (tertiary) mitigation. These are the standard design and construction considerations which are assumed to apply, either because they are seen as industry/good practice, or are a legislative requirement. Certain environmental effects can be screened out based on the assumption that these measures would be implemented. These actions would underpin the Construction Environmental Management Plan (CEMP) produced prior to construction by the Principal Contractor. Where the standard good practice cannot apply, due to site constraints for example, then this would be documented in the environmental reporting and in any associated contract documents.
This document is intended to be a summary of the key tertiary mitigation that would be carried out for the Proposed Scheme. It is not intended to be comprehensive, and should be read alongside CIRIA’s Environmental Good Practice Site Guide (CIRIA, 2015), where a full description of standard good practice measures for each topic, as well as site checklists, can be found. Further guidance is referenced in each specific environmental topic where relevant (Chapters 5 - 15).
B.1 Air quality
B.1.1 Emissions
The works must be carried out in accordance with “Best Practicable Means” (BPM) as defined in Section 72 of the Control of Pollution Act 1974. To achieve this, the following mitigation measures would be undertaken, as necessary during the implementation/construction phase of the works:
All machinery used on site must be maintained according to manufacturers’ instructions and there must be no excessive exhaust smoke. Engines must be switched off during periods of prolonged inactivity.
Any works likely to result in odorous emissions would be planned appropriately to minimise any effect.
Equip vehicles and plant with exhaust filtration systems. Any plant emitting black smoke would be removed from service immediately.
Locate plant away from sensitive human and ecological receptors where possible.
Use battery powered equipment over diesel powered, where possible.
B.1.2 Dust
Appropriate dust control measures would be implemented, including:
Programmes for clearing or damping down of roadways and other areas on-site, especially during dry and windy periods and undertaking a programme of off-site road sweeping/washing, where required.
Provisions for the screening, enclosing, spraying (or other dust controls) of spoil stockpiles, rubble or construction materials. Sheeting of lorries carrying soil and other dust sources and covering/enclosing other dust producing machinery such as crushers and conveyors. Take into account prevailing winds when siting stockpiled materials to minimise impacts on local receptors wherever possible.
Prohibition of any on-site burning of materials.
B.2 Cultural heritage
During construction, the following procedures would be integrated into working practices:
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Weekly progress talks and toolbox talks as required would be delivered to site staff, alerting them to the scope of any changes to site conditions.
Locations of known archaeological interest/value, or areas where archaeological work is planned to be undertaken, would be signposted/fenced off to avoid unintentional damage.
B.2.1 Unexpected discoveries during work
Where a previously unknown heritage asset is discovered or a known heritage asset proves to be more significant than foreseen at the time of application, the local planning authority is advised to work with the developer to seek a proportionate solution that protects the significance of the new discovery, so far as is practical, within the existing scheme. Developers are advised to incorporate the potential for unexpected discoveries into their risk-management strategies.
B.3 Landscape
A baseline must be established prior to the works which the site must be reinstated to following completion of the works. A photographic survey must be carried out for evidence of the site condition prior to the works. During works an acceptable site appearance must be maintained during construction and the site must be tidy and orderly throughout construction. The site must be left in a clean and tidy state on completion, all temporary works must be removed and the ground must be restored to its previous condition, or better, before completion of the contract, using the photographic record taken prior to the works as a baseline.
No works to any trees within the scheme shall take place without consultation with the tree officer. The local tree officer would be contacted where the tree has a Tree Preservation Order, lies within a Conservation Area and/or the tree is felt to be significant (e.g. is a veteran, ancient, or notable tree). All tree works would be undertaken or supervised by a suitably qualified arboriculturist.
Construction works (including vehicle access and material storage) must not take place within the outer edge of the canopy of the tree or within the root zone in accordance with BS5837 (BSI, 2012). Fencing should be erected prior to works and all fenced off areas shall be considered to be outside the working area and not used in any way; machinery or materials shall not be stored beneath or tied to trees. For works taking place below the canopy, the team should consider hand digging within the root zone.
Nuisance from light pollution would be controlled through measures such as positioning lighting away from sensitive receptors, use of directional lighting, use of hoods or shields on lighting to minimise light spill, only using lighting only in areas where lighting is required (e.g. for health and safety or security reasons), and using the minimum level of lighting necessary for its intended function. Motion sensitive or infrared methods should be used where possible to minimise excessive light pollution.
B.4 Nature conservation
Existing vegetation would be retained in situ where possible. Any proposed vegetation clearance would be shown on appropriate plans and would be agreed with the Environmental Co-ordinator prior to works. This includes clearance associated with site surveys prior to construction. Vegetation removal undertaken as part of site surveys or construction must be replaced after completion of the works to a similar of better standard.
Vegetation shall only be removed outside the bird nesting season (1st March to 31st August). Where clearance work is unavoidable outside these dates, the area for clearance must be inspected by an Environmental Clerk of Works (ECoW) or an ecologist to check for bird nests and
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possible bat roosts. Before site work commences, areas of sensitive habitat would be fenced off, and movements of site workers within these areas restricted.
To control the spread of invasive weeds in accordance with the Wildlife and Countryside Act 1981 any plant or machinery must be thoroughly cleaned that has been used in areas infested with the following invasive weeds: Japanese Knotweed (Fallopia japonica), Giant Hogweed (Heracleum mantegazzianum) and Himalayan (or Indian) Balsam (Impatiens glandulifera royle). Water used to clean vehicles must be controlled to prevent the spread of the plant (through seeds, rhizomes, fragments etc.). The area should be cordoned off the area to prevent any inadvertent spreading.
All trees identified for removal shall be inspected for bats. Trees which are not to be removed would be protected from light and noise disturbance.
B.5 Geology and soils
B.5.1 Geology and soils
Soil management during site work should be undertaken in accordance with the Construction Code of Practice for the Sustainable Use of Soils on Construction Sites (Defra, 2009). Topsoil moved during construction works (e.g. during excavation) must be replaced in its original location to enable regeneration of flora from the seed source in the topsoil. Topsoil must be stored in separate stockpiles to subsoil to retain the soil structure. Topsoil stockpiles should be designed taking into consideration site conditions and the nature/composition of the soil.
Protective surfacing would be used in areas of machinery tracking where soil stripping has not been employed. This would need to include suitable surfacing for protecting exposed tree roots. Appropriate de-compaction techniques should be agreed with the Environmental Coordinator in advance of construction.
B.5.2 Land contamination
A geotechnical report would be prepared to identify risks from contaminated land. This would identify actions required to minimise risks to human health and the environment based on a source pathway receptor model. The actions and recommendations would be included within the relevant contract documentation.
A contingency plan would be prepared detailing the actions to be taken in the event of an accidental release of contaminants to the environment, or if unexpected contamination is encountered. In general, when contamination is unexpectedly found, site work would cease and the emergency procedures adopted. This would include isolating the affected area and informing the regulator to agree further action.
B.6 Noise and vibration
The works must be carried out in accordance with BPM as defined in Section 72 of the Control of Pollution Act 1974 and in accordance with the Recommendations of BS5228 Part 1 and 2 (BSI, 2014a and b). To achieve this, the following mitigation measures would be undertaken, as necessary during the implementation/construction phase of the works:
The appropriate selection of plant, construction methods and programming. Only plant conforming with or better than relevant national or international standards, directives or recommendations on noise or vibration emissions would be used. Construction plant would be maintained in good condition with regards to minimising noise output and workers exposed to harmful noise and vibration.
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Construction plant would be operated and maintained appropriately, having regard to the manufacturer's written recommendations or using other appropriate operation and maintenance programmes which reduce noise and vibration emissions. All vehicles and plant would be switched off when not in use.
Design and use of site hoardings and screens, where necessary, to provide acoustic screening at the earliest opportunity. Where practicable, gates would not be located opposite buildings containing noise sensitive receptors.
Choice of routes and programming for the transport of construction materials, spoil and personnel to reduce the risk of increased noise and vibration impacts due to the construction.
Vehicle and mechanical plant used for the purpose of the works should be fitted with effective exhaust silencers, to be maintained in good working order and operated in such a manner as to minimise noise emissions. Plant items that comply with the relevant EU/UK noise limits applicable to that equipment would be used.
Works would be confined to the hours between 8am and 6pm where reasonably practicable to do so. Where night-time construction activities are required, contractor shall endeavour to minimise noise and vibration emissions during this sensitive period. Excessive noise operations and works outside of the core construction hours would need to be agreed in advance with the Environmental Health Officer of the local authority and outlined within the Contract Documents.
Community engagement to give notice of when noisy/vibration generating activities would take place and the duration, as well as the reason and measures in place to reduce nuisance. The is likely to include letter correspondence.
The positioning of construction plant and activities to minimise noise at sensitive locations. Positioning plant to face away from receptors.
Equipment that breaks concrete by munching or similar, rather than by percussion, would be used as far as is practicable.
The use of mufflers on pneumatic tools.
Where practicable, rotary drills actuated by hydraulic or electrical power should be used for excavating hard materials.
The use of non-reciprocating construction plant wherever practicable.
The use, where necessary, of effective sound reducing enclosures.
The construction contractor, once appointed and only after BPM have been implemented, would consider whether the provision of noise insulation or temporary rehousing shall be offered. The criteria that shall be used in identifying eligible properties shall be agreed with the Environmental Health Officer of the local authority, but are likely to be broadly consistent with the guideline levels presented within BS 5228-1.
The contractor should consult with the Environmental Health Officer of the local authority, when detailed construction methods and programme are available, to determine whether any construction activities/ phases will be required to be undertaken under a consent from the local authority under Section 61 of the Control of Pollution Act 1974.
B.7 People and communities
B.7.1 Landowners and community
Members of the community are to be kept regularly informed of the works through active community liaison. This would include notification of noisy activities, heavy traffic periods and start and end dates of key phasing. Members of the public should be provided with access to a contact
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number where to address any concerns or complaints about the scheme. Complaints should be responded to within 48 hours of receipt, with the responses recorded. Site staff should carry contact cards to give to the public if approached to ensure complaints/queries are dealt with effectively.
All private accesses would be maintained or agreed with the landowner in advance of works where alternative arrangements are required. Photographic evidence should be taken of the condition of access routes to allow reinstatement to be as good, or better, than before works.
B.7.2 Traffic and transport
A traffic management plan would be developed to outline traffic management actions required during construction. This would need to be agreed with the Environmental Coordinator and the Relevant Highways Authorities. This should outline measures to minimise route and journey mileage to and from and around site, prevent nuisance to the community caused by parking, vehicle movements and access restrictions. It should also ensure suitable control for the means of access and egress to the public highway. Traffic management measures would include:
designating an area of the site for site based staff vehicles;
putting procedures in place to avoid the queuing of site vehicles outside of the site boundary;
identify sensitive receptors (e.g. schools and residences) and put measures in place to reduce impacts to these receptors;
establishing and communicating traffic restrictions around the site;
designated haul routes and walkways, with adequate traffic management (such as speed limits) within the site;
inspect, service, and maintain site vehicles regularly to ensure efficient running;
turning off vehicle engines when stationary/being unloaded/not in use;
vehicles to be loaded/unloaded of off the highway were possible; and
wheel washing facilities to be provided to reduce the spread of mud on the public highways.
B.7.3 Rights of way and areas of open space
All rights of way and public open space would be kept open where possible. Access should not be obstructed by machinery or storage of materials. Inspections should be made to ensure rights of way are maintained during construction to be safe and accessible for users.
Where rights of way cannot be kept open, suitable temporary diversions would need to be put in place and agreed with the relevant Public Rights of Way Officer. The diversions should be clearly marked at both ends with signage explaining the diversion, the duration of the diversion and a contact number for any concerns.
Any permanent closures or diversions would need specific mitigation which would be outlined within the environmental reports and contract documents. All temporary and permanent closures would require consent from the relevant Council. Permanent closures and diversions should be designed in accordance with the Equality Act, providing access for all.
B.8 Road drainage and the water environment
Contractors shall ensure that procedures and provisions to ensure protection from discharge to land, air or water are made in proportion to the risks to the environment. Environment Agency Pollution Prevention Guidelines (PPGs) would be followed at all times. These document good
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practice measures required to minimise pollution risks including the use and design of drip trays or bunded areas, minimising silt and pollution from entering watercourses and developing an emergency plan prior to works.
Store all potentially polluting substances away from surface and foul water drains, watercourses and sensitive areas. Oils storage must be in accordance with legislation. Chemicals would only be transferred between containers in a suitable bunded area. Maintain plant regularly and inspect condition of drip trays prior to use. Drip trays and plant nappies should be used under static and portable plant to prevent leaks and drips contaminating the ground and/or water. Drip trays or similar should always be used during refuelling operations.
An emergency procedure would be in place for intrusive site activities. Spill kits would be made available on site and site staff would be trained as to how to use them. Spill kits should be stored in a marked bag in a well-signposted location and protected to prevent damage from the weather. These should be stored near to where they may be needed. Ensure that if materials from the spill kit are used that they are replaced immediately.
B.9 Energy, materials and waste
B.9.1 Energy
Carbon generated during construction works would be minimised through reducing energy consumption and increasing energy efficiency. This would include measures such as planning a projects energy usage; maintaining machinery and keeping plant in good working condition to minimise energy consumption, and switching off when not in used to avoid unnecessary fuel consumption; choosing the right plant for the job required (e.g. using oversized or undersized equipment not suitable for the task required); and managing site office and accommodation energy usage.
B.9.2 Material procurement and management
Structures, drainage, road restraint systems, street lighting and signage products would be procured for the Proposed Scheme with consideration of the environmental impacts associated with their manufacture, as well as other considerations such as structural design, carbon footprint, energy consumption, long-life performance, visual impacts, durability and cost. Both reinforced concrete and steel structures should include a measurable recycled content in their manufacture. Where possible, the availability of responsibly sourced local and recycled materials would be considered in order to reduce potential environmental effects, such as from transport emissions.
All timber purchased should be from labelled sources (Forestry Stewardship Council). The Contractor would maintain data to demonstrate a chain of custody for all timber used in construction.
A procurement strategy should be developed to source sustainable aggregates and other materials where possible. Targets for secondary materials should be set at the start of construction.
Materials would be managed appropriately based on their likely environmental impacts and legislative requirements. Materials considered to be hazardous, regulated under the COSHH, would be stored, used, and disposed of in accordance with the materials relevant COSHH datasheet.
Material stockpiles would be managed to prevent silty run-off to the waterbodies through measures such as bunding, vegetation, cut-off trenches, silt fencing, and berms. Consideration
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would be given to the profiling and vegetation planting on stockpiles to increase stability and minimise nuisance from dust emissions.
B.9.3 Waste production and disposal
Construction sites would allow the separation of waste materials to maximise recycling to minimise impacts on landfill sites. This should follow the waste hierarchy of avoid, reduce, reuse, recycle before exploring disposal. On site reuse and recycling should be given greater weight than offsite, to minimise traffic movements. Guidance on when material should not be classed as waste can be found in CL:AIRE Code of Practice (CL:AIRE, 2011). The Contractor should prepare a Site Waste Management Plan (SWMP) to outline how they would address waste and this should include targets that minimise offsite disposal during construction.
Waste must be classified in line with the European Waste Catalogue, as inert, non-hazardous, or hazardous, and disposed of accordingly. Contractors shall ensure that all aspects relating to their Duty of Care and Waste Management Regulations are met and maintained at all times. Verification of procedures in place for waste management shall be required. Responsible waste management shall include waste being transferred by appropriately registered carriers and only removed to sites licensed to accept to type of waste in question. Unauthorised waste shall be prevented from entering or leaving the site. Hazardous wastes shall be kept separately and securely in labelled containers suitable for the task and disposed of in accordance with the Hazardous Waste Regulations.
Wastes requiring specialist removal (such as asbestos and sharps) shall be removed from site accordance with a specific method statement, reviewed and approved by the contractor.
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Appendix C. Air Quality Supporting Information
C.1 European and National Air Quality Legislations
C.1.1 European Legislation
The EU Directive on ambient air quality (2008/50/EC) consolidated previous air quality directives (apart from the Fourth Daughter Directive), setting Limit Values or Target Values for the concentrations of specific air pollutants and providing a new regulatory framework for particulate matter smaller than 2.5µm in diameter (PM2.5). It also allows Member States to apply to postpone attainment deadlines.
Defra assess and reports annually on compliance with the Limit Values to the European Commission. For the purposes of their assessment and reporting, the UK is divided in to 43 zones. The status of each zone in relation to a Limit Value is determined within the compliance assessment by the maximum measured or maximum modelled concentrations in the zone.
EU Limit Values apply throughout the zones and agglomerations, the zone/agglomerations achieve compliance when everywhere within the zone/agglomeration is below the EU Limit Value (although there are exceptions to where the EU Limit Value applies in Annex III of the Air Quality Directive, locations where members of the public can’t access or there is no fixed habitation, industrial premises etc.).
C.1.2 National Legislation
The Air Quality Objectives only apply where members of the public are likely to be regularly present for the averaging time of the objective (i.e. where people will be exposed to pollutants). The annual mean objectives apply to all locations where members of the public might be regularly exposed; these include building façades of residential properties, schools, hospitals, care homes, etc. The 24-hour mean objective applies to all locations where the annual mean objective would apply, together with hotels and gardens of residential properties. The 1-hour mean objective also applies at these locations as well as at any outdoor location where a member of the public might reasonably be expected to stay for 1 hour or more, such as shopping streets, parks and sports grounds, as well as bus stations and railway stations that are not fully enclosed.
C.1.3 AQs Objectives/EU Limit Values
Reporting against compliance with EU Limit Values is undertaken by Defra and reported at a zonal/agglomeration level. Zones/agglomerations only comply when everywhere in the zone is below the EU Limit Value and this is the basis of Defra’s reporting, which is designed to determine what the maximum concentration is within the zone and hence determine the date the zone will comply with the Limit Value. AQS Objectives are assessed at a much more local level where an AQMA can be designated as a result of exceedance at individual properties.
C.1.4 Environmental Protection Act 1990
A statutory nuisance in relation to dust and deposits is defined under Section 79 of the act as follows:
(d) Any dust, steam, smell or other effluvia arising on industrial, trade or business premises and being prejudicial to health or a nuisance.
(e) any accumulation or deposit which is prejudicial to heath or a nuisance.
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Under the provisions of the Act where a local authority is satisfied that a Statutory Nuisance exists, it is under a mandatory duty to serve an Abatement Notice requiring abatement or cessation of one or more activities deemed to be causing the nuisance. In the absence of any kind of standard, identification of a nuisance is dependent on the professional judgment of the local authority as to whether Best Practical Means (BPM) are being employed to control emissions. Where BPM is evident or can be clearly demonstrated then a particular activity cannot be deemed to be causing a Statutory Nuisance.
C.1.5 National Policy Statement for National Networks (NPS NN)
The NPS NN sets out the Government’s policies to deliver the development of nationally significant infrastructure projects on the national road and rail networks in England.
Paragraph 5.11 states that Air quality considerations are likely to be particularly relevant where schemes are proposed:
Within or adjacent to Air Quality Management Areas (AQMA); roads identified as being above Limit Values or nature conservation sites (including Natura 2000 sites and SSSIs, including those outside England); and
Where changes are sufficient to bring about the need for a new AQMAs or change the size of an existing AQMA; or bring about changes to exceedances of the Limit Values, or where they may have the potential to impact on nature conservation sites.
Paragraph 5.12 and 5.13 provides the advice to the decision maker which should be used when determining whether a scheme should receive consent.
Paragraph 5.12 “The Secretary of State must give air quality considerations substantial weight where, after taking into account mitigation, a project would lead to a significant air quality impact in relation to EIA and/or where they lead to a deterioration in air quality in a zone/agglomeration”.
Paragraph 5.13 “The Secretary of State should refuse consent where, after taking into account mitigation, the air quality impacts of the scheme will:
- result in a zone/agglomeration which is currently reported as being compliant with the Air Quality Directive becoming non-compliant; or
- affect the ability of a non-compliant area to achieve compliance within the most recent timescales reported to the European Commission at the time of the decision”.
Although the NPS NN relates to nationally significant infrastructure projects the policy in relation to advice to the decision maker should be applied to the assessment of all Highway England’s road schemes.
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C.2 Air Quality Traffic Data Screening
Spee Spee DMRB Screening Two way AADT Two-way HGV d d Criteria Directio Unique ID limit limit n DM DS Chang AADT HGV Overal DM DS Change DM DS (kph) (kph) e AFF AFF l AFF Two 14132_14101 48 48 24150 24164 14 1963 1962 -1 No No No Way 14235_14102 One way 48 48 3704 3671 -33 74 70 -3 No No No 14137_14103 One way 48 48 5102 5079 -23 467 464 -3 No No No 14134_14104 One way 48 48 4008 3864 -143 107 102 -5 No No No 14131_14111 One way 64 64 12228 12316 89 581 583 3 No No No 14134_14111 One way 48 48 5633 5558 -75 502 507 4 No No No 14104_14111 One way 48 48 4008 3864 -143 107 102 -5 No No No 14134_14131 One way 64 64 10994 11097 103 461 458 -2 No No No Two 14544_14131 64 64 66288 67167 879 2483 2514 31 No No No Way Two 14136_14131 64 64 43066 43753 687 1442 1472 31 No No No Way 14235_14132 One way 48 48 12126 12126 0 1045 1045 -1 No No No Two 14101_14132 48 48 24150 24164 14 1963 1962 -1 No No No Way 14132_14134 One way 48 48 12024 12038 14 917 917 0 No No No 14235_14134 One way 48 48 4907 4810 -98 79 79 1 No No No 14102_14134 One way 48 48 3704 3671 -33 74 70 -3 No No No
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Spee Spee DMRB Screening Two way AADT Two-way HGV d d Criteria Directio Unique ID limit limit n DM DS Chang AADT HGV Overal DM DS Change DM DS (kph) (kph) e AFF AFF l AFF Two 14131_14136 64 64 43066 43753 687 1442 1472 31 No No No Way Two 14138_14136 64 64 43066 43753 687 1442 1472 31 No No No Way 14233_14137 One way 80 80 8393 8414 21 423 425 1 No No No 14203_14137 One way 48 48 8682 8644 -38 568 560 -8 No No No 14205_14137 One way 48 48 4563 4575 11 200 203 3 No No No 14137_14138 One way 64 64 7391 7340 -52 317 316 -1 No No No Two 14139_14138 64 64 56949 57408 459 2082 2111 29 No No No Way Two 14136_14138 64 64 43066 43753 687 1442 1472 31 No No No Way Two 14138_14139 64 64 56949 57408 459 2082 2111 29 No No No Way 14232_14203 One way 48 48 4995 4936 -59 97 92 -5 No No No 14111_14203 One way 48 48 13117 13042 -75 977 982 5 No No No 14204_14203 One way 48 48 735 806 71 40 38 -2 No No No 14111_14204 One way 48 48 735 806 71 40 38 -2 No No No 14203_14205 One way 48 48 4563 4575 11 200 203 3 No No No Two 14233_14212 80 80 13997 13981 -16 771 775 4 No No No Way
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Spee Spee DMRB Screening Two way AADT Two-way HGV d d Criteria Directio Unique ID limit limit n DM DS Chang AADT HGV Overal DM DS Change DM DS (kph) (kph) e AFF AFF l AFF Two 14232_14221 48 48 13011 12825 -186 270 263 -6 No No No Way Two 14221_14232 48 48 13011 12825 -186 270 263 -6 No No No Way 14111_14232 One way 48 48 8015 7889 -126 173 171 -1 No No No Two 14212_14233 80 80 13997 13981 -16 771 775 4 No No No Way 14203_14233 One way 80 80 5604 5567 -37 347 350 3 No No No 14138_14235 One way 64 64 6492 6315 -177 324 323 -1 No No No 14137_14235 One way 48 48 9144 9214 70 407 408 1 No No No 14103_14235 One way 48 48 5102 5079 -23 467 464 -3 No No No Two 14533_14501 48 48 5513 5420 -92 144 144 -1 No No No Way Two 14539_14502 48 48 2234 2349 115 110 111 1 No No No Way 14513_14511 One way 64 64 17343 18667 1324 1283 1296 13 Yes No Yes Two 17834_14511 80 80 71219 72128 908 3869 3879 10 No No No Way Two 14537_14511 64 64 36825 36432 -393 1609 1623 14 No No No Way 14543_14512 One way 64 64 12857 14509 1652 483 493 10 Yes No Yes
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Spee Spee DMRB Screening Two way AADT Two-way HGV d d Criteria Directio Unique ID limit limit n DM DS Chang AADT HGV Overal DM DS Change DM DS (kph) (kph) e AFF AFF l AFF 14541_14512 One way 48 48 11700 11955 255 756 744 -12 No No No 14562_14512 One way 48 48 5550 6622 1073 320 345 25 Yes No Yes 14512_14513 One way 48 48 30091 33087 2995 1559 1582 23 Yes No Yes Two 14531_14521 48 48 318 5 -313 0 0 0 No No No Way Two 27621_14521 80 80 937 461 -476 3 2 -1 No No No Way Two 14533_14521 48 48 656 491 -165 4 3 0 No No No Way Two 14539_14531 48 48 318 5 -313 0 0 0 No No No Way Two 14521_14531 48 48 318 5 -313 0 0 0 No No No Way Two 14535_14533 48 48 5207 5006 -201 144 144 -1 No No No Way Two 14501_14533 48 48 5513 5420 -92 144 144 -1 No No No Way Two 14521_14533 48 48 656 491 -165 4 3 0 No No No Way 14511_14534 One way 64 64 16581 16584 3 955 939 -16 No No No 14513_14534 One way 48 48 1278 7245 5967 29 157 129 Yes No Yes 14563_14534 One way 48 48 11470 7175 -4295 247 129 -118 Yes No Yes
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Spee Spee DMRB Screening Two way AADT Two-way HGV d d Criteria Directio Unique ID limit limit n DM DS Chang AADT HGV Overal DM DS Change DM DS (kph) (kph) e AFF AFF l AFF Two 14533_14535 48 48 5207 5006 -201 144 144 -1 No No No Way 14534_14535 One way 48 48 1722 1787 64 12 12 1 No No No Two 14511_14537 64 64 36825 36432 -393 1609 1623 14 No No No Way Two 14544_14537 64 64 36825 36432 -393 1609 1623 14 No No No Way 14534_14538 One way 48 48 9040 13650 4610 571 621 50 Yes No Yes 14564_14538 One way 48 48 18059 15088 -2971 632 579 -53 Yes No Yes 14535_14538 One way 48 48 3485 3220 -265 133 131 -1 No No No Two 14502_14539 48 48 2234 2349 115 110 111 1 No No No Way Two 14531_14539 48 48 318 5 -313 0 0 0 No No No Way Two 14543_14539 48 48 2545 2346 -199 110 111 0 No No No Way 14538_14540 One way 112 112 28718 30260 1542 1088 1078 -10 Yes No Yes 14538_14541 One way 48 48 962 379 -583 137 114 -23 No No No 14561_14541 One way 48 48 888 1316 428 111 139 28 No No No 14551_14541 One way 112 112 31865 18213 -13652 1300 974 -325 Yes Yes Yes 14541_14542 One way 64 64 16392 1313 -15079 469 138 -331 Yes Yes Yes
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Spee Spee DMRB Screening Two way AADT Two-way HGV d d Criteria Directio Unique ID limit limit n DM DS Chang AADT HGV Overal DM DS Change DM DS (kph) (kph) e AFF AFF l AFF Two 14539_14543 48 48 2545 2346 -199 110 111 0 No No No Way 14544_14543 One way 64 64 13069 14264 1196 403 413 9 Yes No Yes Two 14537_14544 64 64 36825 36432 -393 1609 1623 14 No No No Way 14542_14544 One way 64 64 16392 16469 76 469 476 8 No No No Two 14131_14544 64 64 66288 67167 879 2483 2514 31 No No No Way 14547_14545 One way 112 112 28718 30260 1542 1088 1078 -10 Yes No Yes 14540_14547 One way 112 112 28718 30260 1542 1088 1078 -10 Yes No Yes 14655_14551 One way 112 112 31865 33369 1504 1300 1313 13 Yes No Yes 14538_14561 One way 48 48 888 1316 428 111 139 28 No No No 14541_14562 One way 48 48 5550 6622 1073 320 345 25 Yes No Yes 14513_14563 One way 48 48 11470 7175 -4295 247 129 -118 Yes No Yes 14534_14564 One way 48 48 18059 15088 -2971 632 579 -53 Yes No Yes 17834_17231 One way 64 64 12816 13160 344 454 453 -1 No No No Two 17833_17735 48 48 24407 24792 385 1125 1128 3 No No No Way Two 17834_17738 80 80 46812 47336 523 2744 2750 6 No No No Way 17231_17833 One way 64 64 12816 13160 344 454 453 -1 No No No
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Spee Spee DMRB Screening Two way AADT Two-way HGV d d Criteria Directio Unique ID limit limit n DM DS Chang AADT HGV Overal DM DS Change DM DS (kph) (kph) e AFF AFF l AFF Two 17735_17833 48 48 24407 24792 385 1125 1128 3 No No No Way 17833_17834 One way 64 64 11590 11632 41 672 676 4 No No No Two 14511_17834 80 80 71219 72128 908 3869 3879 10 No No No Way Two 17738_17834 80 80 46812 47336 523 2744 2750 6 No No No Way Two 14521_27621 80 80 937 461 -476 3 2 -1 No No No Way 14551_14542 One way - 64 - 15156 15156 - 338 338 Yes Yes Yes
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C.3 Air Quality Verification
The comparison of modelled concentrations with local monitored concentrations is a process termed ‘verification’. Model verification investigates the discrepancies between modelled and measured concentrations, which can arise due to the presence of inaccuracies and/or uncertainties in model input data, modelling and monitoring data assumptions. The following are examples of potential causes of such discrepancy:
estimates of background pollutant concentrations;
meteorological data uncertainties;
traffic data uncertainties;
model input parameters, such as ‘roughness length’; and
overall limitations of the dispersion model.
C.3.1 Model Precision
Residual uncertainty may remain after systematic error or ‘model accuracy’ has been accounted for in the final predictions. Residual uncertainty may be considered synonymous with the ‘precision’ of the model predictions (i.e. how wide the scatter or residual variability of the predicted values compare with the monitored true value; once systematic error has been allowed for). The quantification of model precision provides an estimate of how the final predictions may deviate from true (monitored) values at the same location over the same period.
Suitable local monitoring data for the purpose of verification is available for concentrations of NO2 at the locations shown in the Figure 5.1A. This monitoring data have been used to validate the dispersion model prediction and obtain adjustment factors, which can be applied to predictions of pollutant concentrations in the base and future years.
C.3.2 Model Performance
An evaluation of model performance has been undertaken to establish confidence in model results. LAQM TG (16) identifies a number of statistical procedures that are appropriate to evaluate model performance and assess the uncertainty. The statistical parameters used in this assessment are:
root mean square error (RMSE);
fractional bias (FB); and
correlation coefficient (CC).
A brief for explanation of each statistic is provided in Table C.1, and further details can be found in LAQM TG (16) Box 7.13.
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Table C.1: Model performance statistics
Statistical Ideal Comments parameter value RMSE is used to define the average error or uncertainty of the model. The units of RMSE are the same as the quantities compared. If the RMSE values are higher than 25% of the objective being assessed, it is recommended that the model inputs and verification should be revisited in order to make improvements.
RMSE For example, if the model predictions are for the annual mean NO2 0.01 objective of 40μg/m3, if an RMSE of 10μg/m3 or above is determined for a model it is advised to revisit the model parameters and model verification. Ideally an RMSE within 10% of the air quality objective would be 3 derived, which equates to 4μg/m for the annual mean NO2 objective. It is used to identify if the model shows a systematic tendency to over or under predict. FB FB values vary between +2 and -2 and has an ideal value of zero. 0.00 Negative values suggest a model over-prediction and positive values suggest a model under-prediction. It is used to measure the linear relationship between predicted and observed data. A value of zero means no relationship and a value of 1 CC means absolute relationship. 1.00 This statistic can be particularly useful when comparing a large number of model and observed data points.
These parameters estimate how the model results agree or diverge from the observations.
These calculations have been carried out prior to, and after, adjustment and provide information on the improvement of the model predictions as a result of the application of the verification adjustment factors.
C.3.3 Assessment Verification
The verification process involves a review of the modelled pollutant concentrations against corresponding monitoring data to determine how well the air quality model has performed. Depending on the outcome it may be considered that the model has performed adequately and that there is no need to adjust any of the modelled results (LAQM TG (16)).
Alternatively, the model could perform poorly7 against the monitoring data. There is then a need to check all the input data to ensure that it is reasonable and accurately represented in the air quality modelling process.
Where all input data, such as traffic data, emissions rates and background concentrations, have been checked and considered as reasonable, then the modelled results require adjustment to best align with the monitoring data. This may either be a single verification adjustment factor to be applied to the modelled concentrations across the study area, or a range of different adjustment factors to account for different zones in the study area (e.g. motorways, local roads).
7 The acceptable limits of model verification performance are set out in Defra’s Local Air Quality Management Technical Guidance (2009)
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The model verification review identified a range of adjustment factors to be applied to the modelled concentrations to achieve a realistic representation of the monitored NO2 concentrations.
The non-adjusted modelled versus monitored NO2 concentrations are presented in Table C.2.
Table C.2: Non-adjusted modelled vs monitored NO2
Monitor ID X(m) Y(m) Monitored Non-adjusted Monitored annual mean modelled versus
NO2 (µg/m³) annual mean modelled (%
NO2 (µg/m³) difference) N101 437543 113726 44.7 34.3 -23.3% N115 437939 113473 36.4 34.6 -5.0% N116 437951 113407 38.1 30.4 -20.3% N153 437325 113860 31.2 33.3 6.6% HE_002 437395 113816 29.6 35.5 19.9% HE_012 437323 113859 32.2 32.2 -0.2% HE_017 437968 113410 53.7 38.7 -28.1% HE_024-026 437818 113549 49.3 42.9 -12.9% HE_027 437024 113731 28.7 27.6 -3.8% HE_028 437018 113761 27.7 26.7 -3.6% HE_029 437018 113836 27.7 25.7 -7.3%
The initial comparison between the predicted concentrations and monitoring data illustrates that the model tends to under-predict NO2 concentrations over the modelled area.
Model adjustment has, therefore, undertaken in accordance with LAQM TG (16). Data were collected from a number of suitable diffusion tube monitoring sites in the vicinity of the Proposed Scheme.
The results suggested that the model was under-predicting road NOx concentrations. The ratio between monitored and modelled road NOx was 1.429. Adjusted modelled versus monitored total NO2 concentrations are presented in Table C.3. Modelled Road NOx concentrations predicted at sensitive receptors in the base and opening year scenarios were multiplied by the adjustment factor (1.429) to account for the under-prediction of road NOx by the model.
Table C.3: Adjusted modelled vs monitored NO2
Monitor ID X(m) Y(m) Monitored Adjusted Monitored annual mean modelled versus
NO2 (µg/m³) annual mean modelled (%
NO2 (µg/m³) difference) N101 437543 4E+06 44.7 38.3 -14.30% N115 437939 113473 36.4 38.8 6.50% N116 437951 113407 38.1 32.9 -13.60% N153 437325 113860 31.2 36.9 18.40% HE_002 437395 113816 29.6 40 35.10%
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HE_012 437323 113859 32.2 35.4 9.90% HE_017 437968 113410 53.7 44.3 -17.70% HE_024-026 437818 113549 49.3 50 1.40% HE_027 437024 113731 28.7 29 1.20% HE_028 437018 113761 27.7 27.7 0.20% HE_029 437018 113836 27.7 26.3 -4.90%
The summary results and model performance statistics defined in LAQM TG (16) are provided in Table C.4.
Table C.4: Model performance statistics
Summary table No adjustment NOx roads adjustment Within +10% 1 7 Within -10% 5 1 Within +-10% 6 8 Within +10 to 25% 1 1 Within -10 to 25% 5 3 Within +-10 to 25% 6 4 Over +25% 0 1 Under -25% 1 0 Greater +-25% 1 1 Within +-25% 12 12 Total 13 13 Adjustment factors
NOx roads adjustment - 1.429 Uncertainties assessment Correlation 0.848 0.847 RMSE (µg/m3) 6.595 4.941 Fractional bias 0.106 -0.003
Figure C.1 provides a comparison of the modelled total NO2 versus monitored total NO2 for no adjustment of the dataset. Figure C.2 provides a comparison of the adjusted modelled total NO2 versus monitored total NO2.
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Figure C.1: Modelled total NO2 versus monitored total NO2 for no adjustment of the dataset
Figure C.2: Adjusted modelled total NO2 versus monitored total NO2.
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A comparison of the performance of the modelled concentrations from the air quality model against the monitoring data has been undertaken. The results show that one verification result deviates by greater than +/-25% between the modelled and monitored concentrations. The model performance statistics show that the uncertainty in the predictions of adjusted total NO2 was acceptable as the RMSE is less than 10µg/m3 and close to 4µg/m3 for the study area.
C.4 Air Quality Modelling Results – Human Receptors
3 Modelled X Y Annual mean NO2 concentration (µg/m ) receptor (to 1 decimal place) name 2015 2019 2019 Change Magnitude Base DM DS of Change R_1 437428 113785 37.3 37.9 38.2 0.4 Imperceptibl e R_2 437428 113785 34.1 34.4 34.5 0.1 Imperceptibl e R_3 437428 113785 31.8 31.8 31.9 0.1 Imperceptibl e R_4 437428 113785 29.8 29.7 29.7 0.0 Imperceptibl e R_5 437488 113759 37.2 37.5 37.7 0.2 Imperceptibl e R_6 437488 113759 33.7 33.8 33.9 0.0 Imperceptibl e R_7 437488 113759 30.8 30.7 30.7 0.0 Imperceptibl e R_8 437488 113759 28.9 28.7 28.7 0.0 Imperceptibl e R_9 437470 113799 32.6 32.7 32.9 0.1 Imperceptibl e R_10 437470 113799 31.7 31.7 31.8 0.1 Imperceptibl e R_11 437417.31 113821.05 35.4 36.0 36.2 0.2 Imperceptibl e R_12 437417.31 113821.05 33.3 33.6 33.7 0.1 Imperceptibl e R_13 437417.31 113821.05 31.1 31.1 31.2 0.1 Imperceptibl e R_14 437417.31 113821.05 29.4 29.2 29.3 0.1 Imperceptibl e R_15 437405.34 113826.05 37.2 38.0 38.1 0.1 Imperceptibl e R_16 437405.34 113826.05 34.0 34.4 34.5 0.1 Imperceptibl e
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R_17 437405.34 113826.05 31.3 31.4 31.5 0.1 Imperceptibl e R_18 437405.34 113826.05 29.4 29.2 29.3 0.1 Imperceptibl e R_19 437405.19 113847.05 36.9 37.7 37.7 0.1 Imperceptibl e R_20 437405.19 113847.05 33.8 34.1 34.3 0.1 Imperceptibl e R_21 437405.19 113847.05 31.1 31.2 31.3 0.1 Imperceptibl e R_22 437405.19 113847.05 29.2 29.1 29.1 0.1 Imperceptibl e R_23 437451.31 113882.15 31.3 31.5 31.6 0.2 Imperceptibl e R_24 437451.31 113882.15 30.9 31.0 31.1 0.2 Imperceptibl e R_25 437451.31 113882.15 30.1 30.1 30.3 0.1 Imperceptibl e R_26 437398.81 113711.45 33.8 34.2 34.3 0.1 Imperceptibl e R_27 437398.81 113711.45 32.6 32.8 32.9 0.1 Imperceptibl e R_28 437398.81 113711.45 31.0 31.0 31.1 0.0 Imperceptibl e R_29 437319.34 113710.77 34.4 34.9 34.7 -0.2 Imperceptibl e R_30 437319.34 113710.77 32.7 33.0 33.0 0.0 Imperceptibl e R_31 437319.34 113710.77 30.8 30.9 30.9 0.1 Imperceptibl e R_32 437354.81 113711.2 35.3 36.0 35.6 -0.4 Small beneficial R_33 437354.81 113711.2 33.4 33.8 33.6 -0.2 Imperceptibl e R_34 437354.81 113711.2 31.2 31.3 31.3 0.0 Imperceptibl e R_35 437340.06 113881.7 37.1 37.9 38.4 0.4 Small adverse R_36 437309.44 113856.5 35.7 36.3 36.6 0.3 Imperceptibl e R_37 437344 113870 40.5 41.7 42.2 0.5 Small adverse
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R_38 437273.34 113839.95 34.1 34.6 34.7 0.1 Imperceptibl e R_39 437257.84 113852.35 31.9 32.1 32.2 0.1 Imperceptibl e R_40 437210.44 113833.05 30.5 30.6 30.7 0.1 Imperceptibl e R_41 437053.16 113705.65 30.9 31.0 31.1 0.1 Imperceptibl e R_42 437127.69 113689.39 35.9 37.5 37.7 0.1 Imperceptibl e R_43 437195.59 113678 30.6 31.1 31.1 0.0 Imperceptibl e R_44 437028 113808 26.9 26.5 26.5 0.0 Imperceptibl e R_45 437474 113689.8 36.8 37.2 36.6 -0.6 Small beneficial R_46 437441.75 113700.6 34.5 34.7 34.9 0.1 Imperceptibl e R_47 437547.28 113756.68 32.2 32.2 32.1 0.0 Imperceptibl e R_48 437497.41 113596.9 27.6 27.2 27.2 0.0 Imperceptibl e R_49 437203.53 113843.8 29.8 29.9 29.9 0.0 Imperceptibl e R_50 437199.56 113854.06 29.5 29.5 29.5 0.0 Imperceptibl e R_51 437249.25 113857.35 31.4 31.6 31.6 0.0 Imperceptibl e R_52 437146.75 113685.3 33.4 34.6 34.7 0.1 Imperceptibl e R_53 437154.31 113683.65 32.7 33.7 33.8 0.1 Imperceptibl e R_54 437161.59 113682.1 32.2 33.0 33.1 0.1 Imperceptibl e R_55 437173 113681.95 31.7 32.4 32.5 0.1 Imperceptibl e R_56 437180.31 113680.65 31.3 31.9 32.0 0.1 Imperceptibl e R_57 437188.16 113679.3 30.9 31.4 31.5 0.0 Imperceptibl e R_58 437206.19 113673.55 30.1 30.3 30.4 0.0 Imperceptibl e
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R_59 437213 113645.35 28.4 28.4 28.4 -0.1 Imperceptibl e R_60 437220.91 113640.25 28.2 28.1 28.1 0.0 Imperceptibl e R_61 437288.19 113649.3 28.4 28.3 28.2 -0.1 Imperceptibl e R_62 437278.91 113649.3 28.4 28.3 28.2 -0.1 Imperceptibl e R_63 437258.16 113649.75 28.4 28.4 28.3 -0.1 Imperceptibl e R_64 437336.19 113682.4 30.5 30.5 30.5 -0.1 Imperceptibl e R_65 437364 113642.45 28.8 28.7 28.7 0.0 Imperceptibl e R_66 437374.25 113671.05 29.9 29.8 29.8 0.0 Imperceptibl e R_67 437463.56 113689.65 34.8 35.0 34.8 -0.3 Imperceptibl e R_68 437464 113876.65 30.6 30.6 30.8 0.1 Imperceptibl e R_69 437332 113886.95 35.0 35.5 35.9 0.3 Imperceptibl e R_70 437325.56 113902.55 33.4 33.8 34.1 0.3 Imperceptibl e R_71 437318.59 113918.15 32.5 32.8 33.1 0.3 Imperceptibl e R_72 437311.75 113931.65 31.8 32.0 32.3 0.3 Imperceptibl e R_73 437308.56 113941.05 31.6 31.8 32.1 0.3 Imperceptibl e R_74 437304.09 113947.2 31.3 31.4 31.7 0.3 Imperceptibl e R_75 437231.41 113879.8 30.0 30.0 30.0 0.0 Imperceptibl e R_76 437228.38 113885.04 29.8 29.7 29.7 0.0 Imperceptibl e R_77 437220.56 113893.3 29.5 29.4 29.4 0.0 Imperceptibl e R_78 437217.69 113898.25 29.3 29.2 29.2 0.0 Imperceptibl e R_79 437211.59 113907.7 29.0 28.8 28.8 0.0 Imperceptibl e
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R_80 437517.91 113589.7 27.5 27.1 27.1 0.0 Imperceptibl e R_81 437554.56 113577.3 27.5 27.0 27.1 0.0 Imperceptibl e R_82 437584.91 113566.95 27.5 27.1 27.1 0.0 Imperceptibl e R_83 437616.75 113556.35 27.6 27.2 27.2 0.0 Imperceptibl e R_84 437595.25 113532.45 26.8 26.3 26.3 0.0 Imperceptibl e R_85 437576.5 113538.9 26.8 26.3 26.3 0.0 Imperceptibl e R_86 437547.06 113548.95 26.8 26.3 26.3 0.0 Imperceptibl e R_87 437524.06 113556.95 26.8 26.3 26.4 0.0 Imperceptibl e R_88 437403 113644.25 29.0 28.8 28.9 0.1 Imperceptibl e R_89 437436.75 113605 27.4 27.1 27.1 0.0 Imperceptibl e R_90 437469.34 113603.45 27.6 27.2 27.2 0.0 Imperceptibl e R_91 437046.16 113715.25 30.6 30.6 30.7 0.1 Imperceptibl e R_92 437030.81 113790.7 27.2 26.9 26.9 0.0 Imperceptibl e R_93 437039.06 113722.2 30.0 29.9 30.0 0.0 Imperceptibl e R_94 437155.19 113847.85 28.6 28.5 28.5 0.0 Imperceptibl e R_95 437146.19 113844.15 28.4 28.3 28.3 0.0 Imperceptibl e R_96 437140 113841.6 28.3 28.2 28.2 0.0 Imperceptibl e R_97 437130.81 113836.35 28.2 28.0 28.0 0.0 Imperceptibl e R_98 437118.91 113830.1 28.0 27.9 27.9 0.0 Imperceptibl e R_99 437107.25 113823.15 28.0 27.8 27.8 0.0 Imperceptibl e R_100 437103.34 113826.45 27.8 27.6 27.6 0.0 Imperceptibl e
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R_101 437090.56 113830.55 27.4 27.2 27.2 0.0 Imperceptibl e R_102 437299.69 113859 33.9 34.4 34.6 0.2 Imperceptibl e R_103 437285.34 113844.3 34.6 35.1 35.3 0.2 Imperceptibl e R_104 437282.5 113852.85 33.0 33.4 33.5 0.1 Imperceptibl e R_105 437270 113857.05 31.8 32.0 32.1 0.1 Imperceptibl e R_106 437291.75 113684.2 30.2 30.3 30.3 0.0 Imperceptibl e R_107 437286.66 113683.77 30.1 30.2 30.2 0.0 Imperceptibl e R_108 437278 113680 29.8 29.9 29.9 0.0 Imperceptibl e R_109 437271.91 113679.38 29.8 29.9 29.9 0.0 Imperceptibl e R_110 437256.34 113681 30.0 30.1 30.1 0.0 Imperceptibl e
3 Modelled X Y Annual mean PM10 concentration (µg/m ) receptor (to 1 decimal place) name 2015 2019 2019 Change Magnitude Base DM DS of Change R_1 437428 113785 22.7 21.9 22.2 0.3 Imperceptibl e R_2 437428 113785 21.1 20.4 20.6 0.2 Imperceptibl e R_3 437428 113785 20 19.4 19.5 0.1 Imperceptibl e R_4 437428 113785 19.1 18.6 18.7 0.1 Imperceptibl e R_5 437488 113759 23.5 22.7 22.9 0.2 Imperceptibl e R_6 437488 113759 21.5 20.8 20.9 0.1 Imperceptibl e R_7 437488 113759 19.9 19.3 19.4 0.1 Imperceptibl e R_8 437488 113759 18.9 18.4 18.5 0.1 Imperceptibl e
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R_9 437470 113799 20.5 19.8 20 0.2 Imperceptibl e R_10 437470 113799 20 19.4 19.6 0.2 Imperceptibl e R_11 437417.31 113821.05 20.6 19.9 20.4 0.5 Small adverse R_12 437417.31 113821.05 19.9 19.4 19.7 0.3 Imperceptibl e R_13 437417.31 113821.05 19.3 18.8 19 0.2 Imperceptibl e R_14 437417.31 113821.05 18.8 18.3 18.4 0.1 Imperceptibl e R_15 437405.34 113826.05 20.7 20 20.8 0.8 Small adverse R_16 437405.34 113826.05 20 19.4 19.8 0.4 Small adverse R_17 437405.34 113826.05 19.3 18.8 19 0.2 Imperceptibl e R_18 437405.34 113826.05 18.7 18.3 18.4 0.1 Imperceptibl e R_19 437405.19 113847.05 19.9 19.3 20.2 0.9 Small adverse R_20 437405.19 113847.05 19.5 18.9 19.4 0.5 Small adverse R_21 437405.19 113847.05 19 18.5 18.7 0.2 Imperceptibl e R_22 437405.19 113847.05 18.6 18.1 18.2 0.1 Imperceptibl e R_23 437451.31 113882.15 18.8 18.3 18.6 0.3 Imperceptibl e R_24 437451.31 113882.15 18.7 18.2 18.5 0.3 Imperceptibl e R_25 437451.31 113882.15 18.6 18.1 18.3 0.2 Imperceptibl e R_26 437398.81 113711.45 21.2 20.5 20.7 0.2 Imperceptibl e R_27 437398.81 113711.45 20.6 20 20.1 0.1 Imperceptibl e R_28 437398.81 113711.45 19.9 19.3 19.4 0.1 Imperceptibl e R_29 437319.34 113710.77 21.4 20.8 20.8 0 Imperceptibl e
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R_30 437319.34 113710.77 20.6 20 20.1 0.1 Imperceptibl e R_31 437319.34 113710.77 19.7 19.2 19.3 0.1 Imperceptibl e R_32 437354.81 113711.2 21.8 21 21.1 0.1 Imperceptibl e R_33 437354.81 113711.2 20.9 20.2 20.3 0.1 Imperceptibl e R_34 437354.81 113711.2 19.9 19.3 19.4 0.1 Imperceptibl e R_35 437340.06 113881.7 19.6 19.1 19.4 0.3 Imperceptibl e R_36 437309.44 113856.5 20.7 20.1 20.3 0.2 Imperceptibl e R_37 437344 113870 20.2 19.6 20 0.4 Imperceptibl e R_38 437273.34 113839.95 21 20.3 20.4 0.1 Imperceptibl e R_39 437257.84 113852.35 20 19.4 19.5 0.1 Imperceptibl e R_40 437210.44 113833.05 19.6 19.1 19.1 0 Imperceptibl e R_41 437053.16 113705.65 20 19.5 19.6 0.1 Imperceptibl e R_42 437127.69 113689.39 22.7 22.3 22.4 0.1 Imperceptibl e R_43 437195.59 113678 19.9 19.4 19.5 0.1 Imperceptibl e R_44 437028 113808 18 17.6 17.6 0 Imperceptibl e R_45 437474 113689.8 22.8 21.9 22 0.1 Imperceptibl e R_46 437441.75 113700.6 21.8 21.1 21.3 0.2 Imperceptibl e R_47 437547.28 113756.68 20.8 20.2 20.3 0.1 Imperceptibl e R_48 437497.41 113596.9 18.4 18 18 0 Imperceptibl e R_49 437203.53 113843.8 19.2 18.8 18.8 0 Imperceptibl e R_50 437199.56 113854.06 19.1 18.6 18.6 0 Imperceptibl e
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R_51 437249.25 113857.35 19.8 19.3 19.3 0 Imperceptibl e R_52 437146.75 113685.3 21.4 21 21 0 Imperceptibl e R_53 437154.31 113683.65 21 20.6 20.6 0 Imperceptibl e R_54 437161.59 113682.1 20.7 20.3 20.3 0 Imperceptibl e R_55 437173 113681.95 20.4 20 20.1 0.1 Imperceptibl e R_56 437180.31 113680.65 20.2 19.8 19.8 0 Imperceptibl e R_57 437188.16 113679.3 20 19.6 19.6 0 Imperceptibl e R_58 437206.19 113673.55 19.5 19.1 19.2 0.1 Imperceptibl e R_59 437213 113645.35 18.8 18.4 18.4 0 Imperceptibl e R_60 437220.91 113640.25 18.6 18.3 18.3 0 Imperceptibl e R_61 437288.19 113649.3 18.7 18.3 18.3 0 Imperceptibl e R_62 437278.91 113649.3 18.7 18.3 18.3 0 Imperceptibl e R_63 437258.16 113649.75 18.7 18.4 18.3 -0.1 Imperceptibl e R_64 437336.19 113682.4 19.6 19.1 19.1 0 Imperceptibl e R_65 437364 113642.45 18.9 18.5 18.5 0 Imperceptibl e R_66 437374.25 113671.05 19.3 18.8 18.9 0.1 Imperceptibl e R_67 437463.56 113689.65 21.9 21.1 21.2 0.1 Imperceptibl e R_68 437464 113876.65 18.8 18.3 18.5 0.2 Imperceptibl e R_69 437332 113886.95 19.4 18.9 19.1 0.2 Imperceptibl e R_70 437325.56 113902.55 19 18.5 18.7 0.2 Imperceptibl e R_71 437318.59 113918.15 18.7 18.2 18.4 0.2 Imperceptibl e
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R_72 437311.75 113931.65 18.5 18.1 18.1 0 Imperceptibl e R_73 437308.56 113941.05 18.4 18 18 0 Imperceptibl e R_74 437304.09 113947.2 18.3 17.9 18 0.1 Imperceptibl e R_75 437231.41 113879.8 19.2 18.7 18.7 0 Imperceptibl e R_76 437228.38 113885.04 19 18.6 18.6 0 Imperceptibl e R_77 437220.56 113893.3 18.9 18.5 18.5 0 Imperceptibl e R_78 437217.69 113898.25 18.8 18.4 18.4 0 Imperceptibl e R_79 437211.59 113907.7 18.7 18.2 18.2 0 Imperceptibl e R_80 437517.91 113589.7 18.4 18 18 0 Imperceptibl e R_81 437554.56 113577.3 18.5 18 18.1 0.1 Imperceptibl e R_82 437584.91 113566.95 18.5 18.1 18.1 0 Imperceptibl e R_83 437616.75 113556.35 18.6 18.2 18.2 0 Imperceptibl e R_84 437595.25 113532.45 18.2 17.7 17.8 0.1 Imperceptibl e R_85 437576.5 113538.9 18.1 17.7 17.8 0.1 Imperceptibl e R_86 437547.06 113548.95 18.1 17.7 17.7 0 Imperceptibl e R_87 437524.06 113556.95 18.1 17.7 17.7 0 Imperceptibl e R_88 437403 113644.25 18.9 18.5 18.5 0 Imperceptibl e R_89 437436.75 113605 18.3 17.9 17.9 0 Imperceptibl e R_90 437469.34 113603.45 18.4 18 18 0 Imperceptibl e R_91 437046.16 113715.25 19.8 19.4 19.4 0 Imperceptibl e R_92 437030.81 113790.7 18.2 17.8 17.8 0 Imperceptibl e
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R_93 437039.06 113722.2 19.6 19.1 19.1 0 Imperceptibl e R_94 437155.19 113847.85 18.7 18.3 18.3 0 Imperceptibl e R_95 437146.19 113844.15 18.7 18.2 18.3 0.1 Imperceptibl e R_96 437140 113841.6 18.6 18.2 18.2 0 Imperceptibl e R_97 437130.81 113836.35 18.6 18.1 18.2 0.1 Imperceptibl e R_98 437118.91 113830.1 18.5 18.1 18.1 0 Imperceptibl e R_99 437107.25 113823.15 18.5 18.1 18.1 0 Imperceptibl e R_100 437103.34 113826.45 18.4 18 18 0 Imperceptibl e R_101 437090.56 113830.55 18.3 17.8 17.9 0.1 Imperceptibl e R_102 437299.69 113859 20.3 19.7 19.8 0.1 Imperceptibl e R_103 437285.34 113844.3 21 20.3 20.5 0.2 Imperceptibl e R_104 437282.5 113852.85 20.2 19.6 19.8 0.2 Imperceptibl e R_105 437270 113857.05 19.8 19.3 19.3 0 Imperceptibl e R_106 437291.75 113684.2 19.5 19 19 0 Imperceptibl e R_107 437286.66 113683.77 19.5 19 19 0 Imperceptibl e R_108 437278 113680 19.3 18.9 18.9 0 Imperceptibl e R_109 437271.91 113679.38 19.3 18.9 18.9 0 Imperceptibl e R_110 437256.34 113681 19.4 19 19 0 Imperceptibl e
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C.5 EU Compliance Risk Assessment
PCM Model base year)
HA link ID Defra Link Census ID Zone / Agglomeration NoRef Is it Complianta Zone? Equivalent2019 Opening Year NO2 (T) Projected2019 with CAZs 2019 Projected with measures CAZs and other 2015 ( Receptor ID DM DS Change Equivalent PCM DS Compliance Risk A33 Redbridge Road 6368 UK0019 No 46.3 46.3 46.3 57.7 6368_1 46.2 46.4 0.2 46.5 Neutral M271 26062 UK0019 No 33.0 33.0 33.0 38.7 26062_1 53. 0 54.3 1.2 34.3 Low Risk M271 26062 UK0031 Yes 33.0 33.0 33.0 38.7 26062_1 53. 0 54.3 1.2 34.3 Low Risk A35 Redbridge Causeway 73615 UK0019 No 51.8 51.8 51.8 62.5 73615_1 30.3 30.4 0.1 51.8 Low Risk
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C.6 Air Quality Modelling Results – Ecological Receptors
3 Receptor name / distance Annual mean NOx concentration (µg/m )
DM DS Change Magnitude of Change Eco_0m 46.5 46.6 0.1 Imperceptible Eco_10m 46.7 46.8 0.1 Imperceptible Eco_20m 46.1 46.2 0.1 Imperceptible Eco_30m 45.0 45.1 0.1 Imperceptible Eco_40m 43.9 44.0 0.1 Imperceptible Eco_50m 27.1 27.2 0.1 Imperceptible Eco_60m 26.2 26.3 0.1 Imperceptible Eco_70m 25.5 25.5 0.1 Imperceptible Eco_80m 24.8 24.9 0.1 Imperceptible Eco_90m 24.2 24.3 0.1 Imperceptible Eco_100m 23.8 23.8 0.1 Imperceptible Eco_110m 23.4 23.4 0.1 Imperceptible Eco_120m 23.0 23.0 0.1 Imperceptible Eco_130m 22.7 22.7 0.1 Imperceptible Eco_140m 22.4 22.4 0.1 Imperceptible Eco_150m 22.2 22.2 0.0 Imperceptible Eco_160m 21.9 22.0 0.0 Imperceptible Eco_170m 21.7 21.8 0.0 Imperceptible Eco_180m 21.6 21.6 0.0 Imperceptible Eco_190m 21.4 21.5 0.0 Imperceptible Eco_200m 21.3 21.3 0.0 Imperceptible
C.7 Long Term Trends of NOx and NO2
In July 2011 Defra published a report (Defra, 2011) examining the long term air quality trends in NOx and NO2 concentrations. It identified that there has been a clear decrease in NO2 concentrations between 1996 and 2002. Thereafter NO2 concentrations have stabilised with little to no reduction between 2004 and 2012. The consequence of the conclusions of Defra’s advice on long term trends is that there is now a gap between current projected vehicle emission reductions and projections on the annual rate of improvements in ambient air quality, which are built into the vehicle emission factors, the projected background maps and the NOx to NO2 calculator.
Highways England has developed the Gap Analysis methodology to adjust model predictions based on the method in LAQM TG (16) to account for the long term NOx and NO2 profiles. This uses the relationship between the base year vehicle emission rates and the opening year vehicle emission rates, and the measured trends in roadside air quality concentrations to uplift opening year predicted concentrations to align them better with the long term trends of NOx and NO2.
The current trends in air quality are based on measurements of emissions from the existing vehicle fleet. New vehicles will need to comply with the more stringent Euro 6/VI emissions
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standards from September 2014 onwards. Vehicles complying with the Euro 6/VI emissions standard are not yet on the road network, and therefore their performance is not present in the long term air quality monitoring trends. If the Euro 6/VI fleet emissions perform as predicted, then this should lead to substantial reductions in predicted future roadside air quality concentrations.
However, because the likely effects of Euro 6/VI vehicles on air quality are yet to be fully understood, Highways England’s advice is that a long term trend based on the existing fleet is assumed to be linear and to continue at this projected rate of decrease into the future.
The gap analysis methodology (IAN 170/12v3) (Highways Agency, 2013b) incorporates the Euro 6/VI improvements. These projection factors are referred to as ‘LTTE6’. The LTTE6 factors assume that there is no reduction in emissions from pre-Euro 6/VI fleet and the only reductions can be from the new Euro 6/VI vehicles entering the fleet. They also take a precautionary approach to account for uncertainty associated with Euro 6/VI performance and fleet mix in the future, rather than assuming full reductions in emissions occur as predicted by Euro 6/VI, which has not been observed by air quality monitoring trends associated with recent Euro standards. This is implemented into LTTE6 by taking the mid-point between the measured trend predictions (which assume no improvement in emissions associated with Euro 6/VI) and predicted Euro 6/VI uptake and emission improvements.
A judgement has been made as to which set of NOx and NO2 projections (Defra’s LAQM TG (16), HE’s LTTE6 or any interim alternative long term trend projections) should be relied upon to form a concluding view of significance. The projections used to derive assessment results have been used to determine the overall significance of the scheme's impacts.
For this assessment, HE’s LTTE6 NOx and NO2 projections have been used as they are considered to be the most reasonable prediction of likely actual future NOx and NO2 concentrations, and have been used in the calculations for this updated local air quality assessment. The table below provides the results before the LTTE6 were applied to NO2 concentrations.
3 Modelled X Y Annual mean NO2 concentration (µg/m ) receptor (to 1 decimal place) name 2015 2019 2019 Change Magnitude Base DM DS of Change R_1 437428 113785 37.3 33.6 33.9 0.3 Imperceptibl e R_2 437428 113785 34.1 30.6 30.7 0.1 Imperceptibl e R_3 437428 113785 31.8 28.5 28.5 0.0 Imperceptibl e R_4 437428 113785 29.8 26.7 26.7 0.0 Imperceptibl e R_5 437488 113759 37.2 33.2 33.4 0.2 Imperceptibl e R_6 437488 113759 33.7 30.1 30.2 0.0 Imperceptibl e R_7 437488 113759 30.8 27.5 27.5 0.0 Imperceptibl e
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R_8 437488 113759 28.9 25.8 25.9 0.0 Imperceptibl e R_9 437470 113799 32.6 29.2 29.3 0.1 Imperceptibl e R_10 437470 113799 31.7 28.4 28.5 0.1 Imperceptibl e R_11 437417.3 113821.05 35.4 32.0 32.2 0.2 Imperceptibl 1 e R_12 437417.3 113821.05 33.3 30.0 30.1 0.1 Imperceptibl 1 e R_13 437417.3 113821.05 31.1 27.9 28.0 0.1 Imperceptibl 1 e R_14 437417.3 113821.05 29.4 26.3 26.4 0.1 Imperceptibl 1 e R_15 437405.3 113826.05 37.2 33.7 33.8 0.1 Imperceptibl 4 e R_16 437405.3 113826.05 34.0 30.7 30.8 0.1 Imperceptibl 4 e R_17 437405.3 113826.05 31.3 28.2 28.2 0.1 Imperceptibl 4 e R_18 437405.3 113826.05 29.4 26.4 26.4 0.1 Imperceptibl 4 e R_19 437405.1 113847.05 36.9 33.6 33.6 0.1 Imperceptibl 9 e R_20 437405.1 113847.05 33.8 30.6 30.6 0.1 Imperceptibl 9 e R_21 437405.1 113847.05 31.1 28.0 28.1 0.1 Imperceptibl 9 e R_22 437405.1 113847.05 29.2 26.2 26.3 0.1 Imperceptibl 9 e R_23 437451.3 113882.15 31.3 28.3 28.4 0.2 Imperceptibl 1 e R_24 437451.3 113882.15 30.9 27.9 28.0 0.1 Imperceptibl 1 e R_25 437451.3 113882.15 30.1 27.1 27.3 0.1 Imperceptibl 1 e R_26 437398.8 113711.45 33.8 30.4 30.5 0.1 Imperceptibl 1 e R_27 437398.8 113711.45 32.6 29.3 29.3 0.1 Imperceptibl 1 e R_28 437398.8 113711.45 31.0 27.8 27.8 0.0 Imperceptibl 1 e R_29 437319.3 113710.77 34.4 31.0 30.8 -0.2 Imperceptibl
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4 e R_30 437319.3 113710.77 32.7 29.4 29.4 0.0 Imperceptibl 4 e R_31 437319.3 113710.77 30.8 27.6 27.7 0.1 Imperceptibl 4 e R_32 437354.8 113711.2 35.3 31.9 31.5 -0.4 Imperceptibl 1 e R_33 437354.8 113711.2 33.4 30.1 29.9 -0.2 Imperceptibl 1 e R_34 437354.8 113711.2 31.2 28.0 28.0 0.0 Imperceptibl 1 e R_35 437340.0 113881.7 37.1 33.9 34.3 0.4 Imperceptibl 6 e R_36 437309.4 113856.5 35.7 32.3 32.6 0.3 Imperceptibl 4 e R_37 437344 113870 40.5 37.3 37.7 0.4 Small adverse R_38 437273.3 113839.95 34.1 30.8 30.8 0.1 Imperceptibl 4 e R_39 437257.8 113852.35 31.9 28.7 28.8 0.0 Imperceptibl 4 e R_40 437210.4 113833.05 30.5 27.4 27.5 0.1 Imperceptibl 4 e R_41 437053.1 113705.65 30.9 27.7 27.8 0.1 Imperceptibl 6 e R_42 437127.6 113689.39 35.9 33.1 33.2 0.1 Imperceptibl 9 e R_43 437195.5 113678 30.6 27.8 27.8 0.0 Imperceptibl 9 e R_44 437028 113808 26.9 24.0 24.1 0.0 Imperceptibl e R_45 437474 113689.8 36.8 32.9 32.4 -0.5 Imperceptibl e R_46 437441.7 113700.6 34.5 30.9 31.0 0.1 Imperceptibl 5 e R_47 437547.2 113756.68 32.2 28.7 28.7 0.0 Imperceptibl 8 e R_48 437497.4 113596.9 27.6 24.6 24.6 0.0 Imperceptibl 1 e R_49 437203.5 113843.8 29.8 26.8 26.9 0.0 Imperceptibl 3 e R_50 437199.5 113854.06 29.5 26.5 26.5 0.0 Imperceptibl 6 e
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R_51 437249.2 113857.35 31.4 28.3 28.3 0.0 Imperceptibl 5 e R_52 437146.7 113685.3 33.4 30.6 30.7 0.1 Imperceptibl 5 e R_53 437154.3 113683.65 32.7 29.9 30.0 0.1 Imperceptibl 1 e R_54 437161.5 113682.1 32.2 29.3 29.4 0.1 Imperceptibl 9 e R_55 437173 113681.95 31.7 28.9 28.9 0.1 Imperceptibl e R_56 437180.3 113680.65 31.3 28.5 28.5 0.0 Imperceptibl 1 e R_57 437188.1 113679.3 30.9 28.1 28.1 0.0 Imperceptibl 6 e R_58 437206.1 113673.55 30.1 27.2 27.2 0.0 Imperceptibl 9 e R_59 437213 113645.35 28.4 25.6 25.6 -0.1 Imperceptibl e R_60 437220.9 113640.25 28.2 25.4 25.3 0.0 Imperceptibl 1 e R_61 437288.1 113649.3 28.4 25.6 25.5 -0.1 Imperceptibl 9 e R_62 437278.9 113649.3 28.4 25.6 25.5 -0.1 Imperceptibl 1 e R_63 437258.1 113649.75 28.4 25.6 25.5 -0.1 Imperceptibl 6 e R_64 437336.1 113682.4 30.5 27.4 27.3 -0.1 Imperceptibl 9 e R_65 437364 113642.45 28.8 25.8 25.8 0.0 Imperceptibl e R_66 437374.2 113671.05 29.9 26.8 26.8 0.0 Imperceptibl 5 e R_67 437463.5 113689.65 34.8 31.1 30.9 -0.2 Imperceptibl 6 e R_68 437464 113876.65 30.6 27.6 27.7 0.1 Imperceptibl e R_69 437332 113886.95 35.0 31.8 32.1 0.3 Imperceptibl e R_70 437325.5 113902.55 33.4 30.4 30.6 0.3 Imperceptibl 6 e R_71 437318.5 113918.15 32.5 29.5 29.7 0.3 Imperceptibl 9 e R_72 437311.7 113931.65 31.8 28.9 29.1 0.3 Imperceptibl
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5 e R_73 437308.5 113941.05 31.6 28.7 29.0 0.3 Imperceptibl 6 e R_74 437304.0 113947.2 31.3 28.4 28.6 0.3 Imperceptibl 9 e R_75 437231.4 113879.8 30.0 27.0 27.0 0.0 Imperceptibl 1 e R_76 437228.3 113885.04 29.8 26.7 26.8 0.0 Imperceptibl 8 e R_77 437220.5 113893.3 29.5 26.5 26.5 0.0 Imperceptibl 6 e R_78 437217.6 113898.25 29.3 26.3 26.3 0.0 Imperceptibl 9 e R_79 437211.5 113907.7 29.0 26.0 26.0 0.0 Imperceptibl 9 e R_80 437517.9 113589.7 27.5 24.5 24.6 0.0 Imperceptibl 1 e R_81 437554.5 113577.3 27.5 24.5 24.5 0.0 Imperceptibl 6 e R_82 437584.9 113566.95 27.5 24.5 24.6 0.0 Imperceptibl 1 e R_83 437616.7 113556.35 27.6 24.6 24.6 0.0 Imperceptibl 5 e R_84 437595.2 113532.45 26.8 23.9 23.9 0.0 Imperceptibl 5 e R_85 437576.5 113538.9 26.8 23.9 23.9 0.0 Imperceptibl e R_86 437547.0 113548.95 26.8 23.9 23.9 0.0 Imperceptibl 6 e R_87 437524.0 113556.95 26.8 23.9 23.9 0.0 Imperceptibl 6 e R_88 437403 113644.25 29.0 25.9 25.9 0.1 Imperceptibl e R_89 437436.7 113605 27.4 24.5 24.5 0.0 Imperceptibl 5 e R_90 437469.3 113603.45 27.6 24.6 24.6 0.0 Imperceptibl 4 e R_91 437046.1 113715.25 30.6 27.4 27.4 0.1 Imperceptibl 6 e R_92 437030.8 113790.7 27.2 24.4 24.4 0.0 Imperceptibl 1 e R_93 437039.0 113722.2 30.0 26.9 26.9 0.0 Imperceptibl 6 e
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R_94 437155.1 113847.85 28.6 25.7 25.7 0.0 Imperceptibl 9 e R_95 437146.1 113844.15 28.4 25.5 25.6 0.0 Imperceptibl 9 e R_96 437140 113841.6 28.3 25.4 25.4 0.0 Imperceptibl e R_97 437130.8 113836.35 28.2 25.3 25.3 0.0 Imperceptibl 1 e R_98 437118.9 113830.1 28.0 25.2 25.2 0.0 Imperceptibl 1 e R_99 437107.2 113823.15 28.0 25.1 25.1 0.0 Imperceptibl 5 e R_100 437103.3 113826.45 27.8 24.9 25.0 0.0 Imperceptibl 4 e R_101 437090.5 113830.55 27.4 24.6 24.6 0.0 Imperceptibl 6 e R_102 437299.6 113859 33.9 30.6 30.8 0.2 Imperceptibl 9 e R_103 437285.3 113844.3 34.6 31.2 31.4 0.2 Imperceptibl 4 e R_104 437282.5 113852.85 33.0 29.8 29.9 0.1 Imperceptibl e R_105 437270 113857.05 31.8 28.7 28.8 0.1 Imperceptibl e R_106 437291.7 113684.2 30.2 27.1 27.1 0.0 Imperceptibl 5 e R_107 437286.6 113683.77 30.1 27.1 27.1 0.0 Imperceptibl 6 e R_108 437278 113680 29.8 26.8 26.8 0.0 Imperceptibl e R_109 437271.9 113679.38 29.8 26.8 26.8 0.0 Imperceptibl 1 e R_110 437256.3 113681 30.0 27.0 27.0 0.0 Imperceptibl 4 e
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Appendix D. Arboricultural Impact Assessment Report
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Appendix E. Criteria used per environmental topic to assess the magnitude levels (amount of change) and sensitivity (value or importance)
Table E.1: Topic specific interpretation of the DMRB guidance for magnitude criteria for the Proposed Scheme
Magnitude Topic specific criteria Landscape (using the criteria set out in Interim Advice Note 135/10 Landscape and visual effects assessment, Highways England, 2010a) Major Landscape Adverse: Total loss or large scale damage to existing character or distinctive features and elements, and/or the addition of new but uncharacteristic conspicuous features and elements. Beneficial: Large scale improvement of character by the restoration of features and elements, and/or the removal of uncharacteristic and conspicuous features and elements, or by the addition of new distinctive features. Visual The Proposed Scheme, or a part of it, would become the dominant feature or focal point of the view. Moderate Landscape Adverse: Partial loss or noticeable damage to existing character or distinctive features and elements, and/or the addition of new but uncharacteristic noticeable features and elements. Beneficial: Partial or noticeable improvement of character by the restoration of existing features and elements, and/or the removal of uncharacteristic and noticeable features and elements, or by the addition of new characteristic features. Visual The Proposed Scheme, or a part of it, would form a noticeable feature or element of the view which is readily apparent to the receptor. Minor Landscape Adverse: Slight loss or damage to existing character or features and elements, and/or the addition of new but uncharacteristic features and elements. Beneficial: Slight improvement of character by the restoration of existing features and elements, and/or the removal of uncharacteristic features and elements, or by the addition of new characteristic elements. Visual The Proposed Scheme, or a part of it, would be perceptible but not alter the overall balance of features and elements that comprise the existing view. Negligible Landscape Adverse: Barely noticeable loss or damage to existing character or features and elements, and/or the addition of new but uncharacteristic features and elements. Beneficial: Barely noticeable improvement of character by the
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Magnitude Topic specific criteria restoration of existing features and elements, and/or the removal of uncharacteristic features and elements, or by the addition of new characteristic elements. Visual Only a very small part of Proposed Scheme would be discernible, or it is at such a distance that it would form a barely noticeable feature or element of the view. No change Landscape No noticeable loss, damage or alteration to character or features or elements. Visual No part of the Proposed Scheme, or work or activity associated with it, is discernible. Biodiversity (using the criteria set out in CIEEM (2016) guidance) Major Each magnitude was determined using the following factors: Moderate positive or adverse; Minor extent (the product of the proportion of the receptor affected by the effect on a geographic scale and therefore the integrity of the Negligible receptor); No change magnitude (i.e. size); duration; timing; frequency; and reversibility. Geology and soils (bespoke criteria using DMRB guidance) Major adverse Soil quality Permanent loss or sterilisation of identified Best and Most Versatile (BMV) soil resources. Contamination Chronic damage to human health likely to result in “significant harm” as defined by Environmental Protection Act (EPA) 1990 Part 2A. Long term risk to sensitive water resource. Catastrophic damage to buildings/properties. Significant or irreversible long term damage to a particular ecosystem or organism forming part of that system. Site of geological importance Severe damage to the site so that it is unrecognisable compared to baseline conditions. Mineral resources Total loss/sterilisation of the identified reserve/resource. Groundwater, surface water and ecologically important sites Major permanent or long-term damage to groundwater or surface water quality. Existing resource use irreparably impacted. Changes to quality or water table level would have a significant damaging impact upon local ecology. Moderate adverse Soil quality
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Magnitude Topic specific criteria Reduction in quality of the BMV soil resources. Loss or sterilisation of other soil resources. Contamination Acute damage to human health. Pollution of sensitive water resource. Significant change to an ecosystem or organism forming part of that ecosystem. Sites of geological importance Partial loss of the key characteristics of the site. Mineral resources Sterilisation of a significant part (>50%) of the identified reserve/resource. Loss of access to the whole of the identified resource (although the reserve/resource remains intact). Groundwater, surface water and ecologically important sites Medium damage to the local groundwater regime or surface water quality, predicted to have negative impact on resource use. Medium impacts on local ecology could result. Minor adverse Soil quality Measurable reduction in quality of other soil resources. Contamination Harm which may not be significant and may result in financial loss, or expenditure to resolve. No permanent effects to human health (preventable by PPE) or to local ecology. Easily repairable effects of damage to buildings, structures and services. Sites of geological importance Minor loss of the key characteristics of the site. Mineral resources Partial (less than 50%) sterilisation of the identified reserve/resource. Groundwater, surface water and ecologically important sites Changes to groundwater or surface water quality, groundwater levels or yields, not representing a risk to existing resource use or ecology. Negligible adverse Very slight or no change from baseline conditions. No Change No loss or alteration of characteristics, receptors or elements; no observable positive or negative impact. Negligible beneficial Very slight or no change from baseline conditions. Minor beneficial Soil quality Measurable improvement in quality of other soil resources. Contamination Removal of some identified pollutant linkages so that risks to receptors are reduced slightly. Sites of geological importance Minor improvements to the key characteristics of the site. Mineral resources Extraction and beneficial reuse of a part (<50%) of the identified
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Magnitude Topic specific criteria reserve/resource. Groundwater, surface water and ecologically important sites Changes to groundwater or surface water quality, groundwater levels or yields, representing a minor improvement to existing resource use or ecology. Moderate beneficial Soil quality Measurable improvement in quality of BMV soil resources. Contamination: Removal of the majority of identified pollutant linkages so that risks to receptors are reduced. Sites of geological importance Improvements to the key characteristics of the site. Mineral resources Extraction and beneficial reuse of a significant part (>50%) of the identified reserve/resource. Groundwater, surface water and ecologically important sites Changes to the local groundwater regime or surface water quality predicted to result in a medium improvement to resources, water quality or to local ecology. Major beneficial Soil quality Permanent gain or creation of new BMV soil resources. Contamination Removal of all identified pollutant linkages that pose a risk to identified receptors. Site of geological importance Improvements of the site so that key characteristics/receptors are significantly enhanced or new receptors of interest are exposed. Mineral resources Extraction and beneficial reuse of the identified reserve/resource. Groundwater, surface water and ecologically important sites Major permanent or long-term improvement of groundwater or surface water quality, local ecology or available groundwater yield.
Materials – Carbon (using criteria from Highways England’s Carbon Tool (2016) - Total CO2 equivalent (CO2e) of materials (tonnes)) Major >40,000 Moderate 20,000 – 40,000 Minor 5,000 – 20,000 Negligible 1,000 – 5,000 No change <1,000 Materials – Waste Major Waste is predominantly disposed of to landfill or to incineration without energy recovery with little or no prior segregation. Moderate Wastes are predominantly disposed of by incineration with energy recovery.
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Magnitude Topic specific criteria Negligible Wastes are predominantly segregated and sent for composting, recycling or for further segregation and sorting at a materials recovery facility. Minor Wastes are predominantly re-used on-site or at an appropriately licensed or registered exempt site elsewhere. Noise and vibration (based upon the criteria for short-term and long-term noise impacts outlined in Tables 3.1 and 3.2 of DMRB Section 3 Part 7 for noise (Highways Agency, 2015)) Short term noise impact (Noise Long term noise impact (Noise Change, db LA10, 18h) Change, db LA10, 18h) Major 5+ 10+ Moderate 3 - 4.9 5 – 9.9 Minor 1 - 2.9 3 - 4.9 Negligible 0.1 - 0.9 0.1 - 2.9 No Change 0.0 0.0 People and communities – pedestrian, cyclist and community severance (Criteria developed based on guidance provided in DMRB Pedestrians, Cyclists, Equestrians and Community Effects (Volume 11, Section 3, Part 9) (Highways Agency et al., 1993d)) Large Permanent severance of active travel pedestrian/cyclist route. Permanent increase in either journey length or duration of greater than 500m (for pedestrians) and/or 6 minutes (pedestrians and cyclists). New uncontrolled at-grade crossing of road carrying more than 16,000 vehicles per day (AADT). Permanent increase or reduction in amenity of route that would affect usage. Medium Permanent increase in either journey length or duration of between 250m and 500m (pedestrians) and/or or between three and six minutes (pedestrians and cyclists). New uncontrolled at-grade crossing of road carrying 8,000-16,000 vehicles per day (AADT). Temporary increase or reduction in amenity of route that would affect usage. Small Permanent increase or reduction in amenity of route that would not affect usage. New uncontrolled at-grade crossing of road carrying fewer than 8,000 vehicles per day (AADT). New controlled at-grade crossing or grade separated crossing. Negligible Temporary increase or reduction in amenity of route that would not affect usage. People and communities – land use and material assets (bespoke criteria using DMRB guidance) Large Property or asset completely demolished and/or all land taken on permanent basis. Medium Property or asset partially demolished. Permanent land-take sufficient to affect usage or enjoyment of property
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Magnitude Topic specific criteria or asset.
Small Permanent land take that would not substantively affect enjoyment or usage of property or asset. Temporary land-take sufficient to affect usage or enjoyment of property or asset. Negligible Temporary land-take that would not substantively affect enjoyment or usage of the property or asset. Road drainage and the water environment (criteria based on DMRB guidance) Major adverse Flood Risk and Drainage: Results in an increase in peak flood level (1% annual probability) >100 mm. Groundwater: Major permanent or long-term change to groundwater quality or available yield. Existing resource use irreparably effected. Changes to quality or water table level would have an impact upon local ecology. Moderate adverse Flood Risk and Drainage: Results in an increase in peak flood level (1% annual probability) >50 mm. Groundwater: Changes to the local groundwater regime predicted to have a slight impact on resource use. Minor adverse Flood Risk and Drainage: Results in increase in peak flood level (1% annual probability) >10mm. Groundwater: Changes to groundwater quality, levels or yields not representing a risk to existing resource use or ecology. Negligible Flood Risk and Drainage: Negligible change in peak flood level (1% annual probability) <+/- 10 mm. Groundwater: Very slight change from groundwater baseline conditions approximating to a ‘no change’ situation. Minor beneficial Flood Risk and Drainage: Results in a reduction in peak flood level (1% annual probability) >10 mm. Groundwater: Changes to groundwater quality, levels or yields representing a minor improvement to existing resource use or ecology. Moderate beneficial Flood Risk and Drainage: Results in a reduction in peak flood level (1% annual probability) >50 mm. Groundwater: Changes to the local groundwater regime predicted to result in a moderate improvement to resources or groundwater quality or to local ecology. Major beneficial Flood Risk and Drainage: Results in a reduction in peak flood level (1% annual probability) >100 mm. Groundwater: Major permanent or long-term improvement of groundwater quality or available yield, or to local ecology.
Table E.2: Topic specific interpretation of the DMRB guidance for sensitivity criteria for the Proposed Scheme
Sensitivity/value Topic specific criteria Landscape (using the sensitivity criteria set out in Interim Advice Note 135/10 (Highways
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Sensitivity/value Topic specific criteria Agency, 2010a)) High Landscapes Landscapes which by nature of their character would be unable to accommodate change of the type proposed. Typically, these would be: of high quality with distinctive elements and features making a positive contribution to character and sense of place; likely to be designated, but the aspects which underpin such value may also be present outside designated areas, especially at the local scale; areas of special recognised value through use, perception or historic and cultural associations; and likely to contain features and elements that are rare and could not be replaced. Views residential properties; users of Public Rights of Way (PRoW) or other recreational trails (e.g. National Trails, footpaths, bridleways etc.); users of recreational facilities where the purpose of that recreation is enjoyment of the countryside (e.g. Country Parks, National Trust or other access land etc.); and highly valued views (e.g. from heritage assets, views featured in art and literature). Moderate Landscapes Landscapes which by nature of their character would be able to partly accommodate change of the type proposed. Typically, these would be: comprised of commonplace elements and features creating generally unremarkable character but with some sense of place; locally designated, or their value may be expressed through non- statutory local publications; containing some features of value through use, perception or historic and cultural associations; and likely to contain some features and elements that could not be replaced. Views outdoor workers; users of scenic roads, railways or waterways or users of designated tourist routes; and schools and other institutional buildings, and their outdoor areas. Low Landscapes Landscapes which by nature of their character would be able to accommodate change of the type proposed. Typically, these would be: comprised of some features and elements that are discordant, derelict or in decline, resulting in indistinct character with little or no sense of place; not designated; containing few, if any, features of value through use, perception or
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Sensitivity/value Topic specific criteria historic and cultural associations; and likely to contain few, if any, features and elements that could not be replaced. Views indoor workers; users of main roads (e.g. trunk roads) or passengers in public transport on main arterial routes; and users of recreational facilities where the purpose of the recreation is not related to the view (e.g. sports facilities). Biodiversity (bespoke criteria using Guidelines for Ecological Impact Assessment (CIEEM, 2016) in combination with DMRB HA 205/08 (Highways Agency et al., 2008b) to provide consistency across chapters) Very high The receptor8 could be an international statutory designated site for (international) nature conservation e.g. an SAC or SPA. The receptor could be a legally protected habitat or species that is important on an international scale. High The receptor could be a national statutory designated site for nature (national) conservation e.g. an SSSI. The receptor could be a legally protected habitat or species that is important on a national scale. Medium The receptor could be a non-statutory designated site for nature (county to regional) conservation e.g. a Site of Importance for Nature Conservation. The receptor may fulfil the criteria of being low value, but additionally would be legally protected and/or is listed in accordance with the requirements of Section 41 of the Natural Environmental and Rural Communities Act 2006. Low The receptor is relatively common and widespread but has elevated (local) conservation status, e.g. is listed as a Local Biodiversity Action Plan habitat or species, is a bird listed as red or amber by the Birds of Conservation Concern (Eaton et al., 2015) or is Red Data Book listed (International Union for Conservation of Nature, 2015). Negligible The receptor is abundant and widespread. The receptor receives no (site only) legal protection and is not of elevated conservation concern status. Geology and soils (bespoke criteria using DMRB guidance) Very high Soil quality Agricultural Land Classification (ALC) Grade 1 land – excellent quality soil, Best Most Versatile (BMV). Human receptors Human Receptors i.e. construction workers, future site users, maintenance workers, adjacent land users and future construction workers. Controlled waters - groundwater Principal aquifer providing a valuable resource because of its high quality and yield, or extensive exploitation for public and/or agricultural and/or industrial supply. Source Protection Zone (SPZ) 1 (Inner
8 Note that CIEEM guidance (2016) uses the term ‘feature’ instead of ‘receptor’.
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Sensitivity/value Topic specific criteria Protection Zone). Designated sites of biodiversity dependent on groundwater. Controlled waters - surface water Internationally important watercourses. Public water supplies. Listed sites of geological importance Geology has an international designation (i.e. Geopark status) and/or has a very low capacity to accommodate change. Mineral resources Geological resource safeguarding area (international importance). Ecologically important sites The feature could be an international statutory designated site for Biodiversity e.g. SAC or SPA. The feature could be a legally protected habitat or species that is important on an international scale. High Soil quality ALC Grade 2 – very good quality (BMV) soil; and ALC Subgrade 3a – good quality (BMV) soil. Controlled waters - groundwater Secondary A aquifer capable of supporting water supplies at a local scale and forming an important source of base flow to significant surface waters. SPZ 2 (Outer Protection Zone). Local areas of biodiversity known to be sensitive to groundwater impacts. Controlled waters - surface water Nationally and regionally important watercourses. Public water supplies. Listed sites of geological importance Geology has a national designation (i.e. SSSI) and/or has a very low capacity to accommodate change. Mineral resources Category 1 Aggregates Safeguarding Area (National Importance). Ecologically important sites The feature could be a national statutory designated site for biodiversity e.g. SSSI, ancient woodland or local nature reserve. The feature could be a legally protected habitat or species that is important on a national scale. Medium Soil quality ALC Subgrade 3b – moderate quality soil. Controlled waters - groundwater Secondary B aquifer and/or poor groundwater quality and/or low permeability make exploitation of groundwater unlikely. SPZ3 (Source Catchment Protection Zone). Changes to groundwater not expected to have an impact on local ecology. Controlled waters - surface water Main rivers within a catchment. Locally important water courses. Private water supplies serving three or more properties. Listed sites of geological importance Geology has a local or regional designation (i.e. LoGS) and/or has a low
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Sensitivity/value Topic specific criteria capacity to accommodate any change. Mineral resources Category 2 Aggregates Safeguarding Area (local and regional importance). Ecologically important sites The feature could be a non-statutory designated site for biodiversity e.g. a Site of Importance for Nature Conservation. The feature may fulfil the criteria of being low value, but additionally would be legally protected and / or is listed in accordance with the requirements of Section 41 of the Natural Environmental and Rural Communities Act 2006. Low Soil quality ALC Grade 4 – poor quality soil; and ALC Grade 5 – very poor quality soil. Controlled waters - groundwater Very poor groundwater quality and/or very low permeability making exploitation of groundwater unfeasible. No known past or existing exploitation of this water body. Changes to groundwater are irrelevant to local ecology. Controlled waters - surface water Minor watercourses or water bodies. Listed sites of geological importance Geology not listed but possesses key characteristics which could be locally important and/or has a high capacity to accommodate change. Mineral resources Limited mineral resources identified or unfeasible to extract (e.g. urban area). Ecologically important sites Feature is relatively common and widespread but has elevated conservation status, e.g. is listed as a Local Biodiversity Action Plan habitat or species, is a bird listed as red or amber by the Birds of Conservation Concern (Eaton et al., 2015) or is Red Data Book listed (International Union for Conservation of Nature, 2015). Negligible Soil quality Urban land - No agricultural grade soil present. Controlled waters - groundwater Strata not classified as an aquifer under the WFD. Controlled waters - surface water Very minor watercourses or water bodies. Listed sites of geological importance Geology is non-distinctive and/or is likely to tolerate the proposed change or there are no listed sites. Mineral resources No mineral resources identified. Ecologically important sites Feature is abundant and widespread. Feature receives no legal
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Sensitivity/value Topic specific criteria protection and is not of elevated conservation concern status.
Materials – Waste
Very High There is no available waste management capacity for any waste arising from the Proposed Scheme. High There is limited waste management capacity in relation to the forecast waste arising from the Proposed Scheme. Medium There is adequate waste management capacity for the majority of wastes arising from the Proposed Scheme. Low There is adequate available waste management capacity for all wastes arising from the Proposed Scheme. People and communities – pedestrian, cyclist and community severance (bespoke criteria using DMRB guidance) Very high Routes to key facilities such as schools, public transport access points, centres of employment or shopping areas that are regularly used by vulnerable users such as elderly, school children, people with disabilities, or for which there are limited alternative routes available. High Busy routes to key community facilities such as shopping areas, doctors, leisure centres, and employment sites for which comparable alternative routes exist. Medium Routes used to access community facilities occasionally. Low Informal paths and short-cuts used regularly by the community but with no regulatory or agreed access permissions. Negligible Informal paths and short-cuts occasionally used by the community but with no regulatory or agreed access permissions. Road drainage and water environment (criteria based on DMRB guidance Table A4.3 of HD45/09 (Highways Agency et.al., 2009b)) Very High Flood risk and drainage: More than 100 residential properties or critical infrastructure at risk from flooding. Groundwater: Principal aquifer providing a valuable resource because of its high quality and yield, or extensive exploitation for public and/or agricultural and/or industrial supply. Source Protection Zone (SPZ) 1 (Inner Protection Zone). Designated sites of nature conservation dependant on groundwater. High Flood risk and drainage: Between 10 and 100 residential properties or industrial premises or regional main roads at risk from flooding. Groundwater: Secondary A aquifer capable of supporting water supplies at a local scale and forming an important source of base flow to significant surface waters. SPZ 2 (Outer Protection Zone). Local areas of nature conservation known to be sensitive to groundwater effects. Medium Flood risk and drainage: 10 or fewer residential/industrial properties, local roads at risk from flooding. Critical social infrastructure and residential properties not affected. Groundwater: Secondary B aquifer and/or poor groundwater quality
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Sensitivity/value Topic specific criteria and/or low permeability make exploitation of groundwater unlikely. SPZ3 (Source Catchment Protection Zone). Changes to groundwater not expected to have an impact on local ecology. Low Flood risk and drainage: Limited constraints and a low probability of flooding of residential and industrial properties. Local minor roads and agricultural land. Groundwater: Very poor groundwater quality and/or very low permeability make exploitation of groundwater unfeasible. No known past or existing exploitation of this water body. Changes to groundwater are irrelevant to local ecology.
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Appendix F. Landscape and Visual Effects Schedule
Table F.1: Landscape Assessment – effects on townscape character and physical landscape receptors
Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) Townscape The townscape is not Construction activity and With the removal of Establishment of new designated and lacks features of construction compounds at construction activity changes vegetation and the new value. Redbridge Roundabout the south of Redbridge in the character of the landscape design of marks the gateway to the city Towers and along the A33 townscape would only be just Redbridge Roundabout would from the west. It is surrounded westbound carriageway noticeable. Removal of enhance the Amenity Green by high and low-rise residential would be noticeable and vegetation north-east of Space. It would improve the development and lorry and car would slightly exacerbate Redbridge Roundabout would relationship of the existing dealership/commercial units the prominence of the road be permanent. New road corridor and junction separated by road corridor. The corridor and junction as a additional light streets would with the surrounding network of major roads has discordant feature within the slightly increase the lighting townscape, creating a sense disrupted the former small scale townscape setting. There of the area with negligible of place and reinforcing the pattern of streets and junctions, would be negligible impact impact on night-time views. local townscape character. resulting in a fragmented local on night-time views because Impact: Negligible adverse Impact: No change road pattern. Heavy vehicle construction activity would Effect: Neutral Effect: Neutral flows and high noise levels be in an urban, well-lit impedes pedestrian circulation context. and human interaction. Mitigation: Landscape Redbridge Towers mitigation would limit the (approximately 20 storeys high) impact on townscape is a local landmark. Redbridge through minimal loss of Flyover and major roads are existing vegetation. dominant features in the Impact: Minor adverse townscape and are prominent in Effect: Slight adverse views from surrounding residential properties, and traffic and street lighting are prominent
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Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) on the skyline. Generally, buildings within the study area lack local distinctiveness. Sensitivity: Moderate Vegetation Screening vegetation including Proposed back of verge Loss of vegetation north-east Once established, new mature broadleaf and coniferous visibility splay to provide a of Redbridge Roundabout ornamental tree and shrub trees to the north-west and minimum 50m stopping would be permanent. species would enhance the north-east of Redbridge sight distance along the However, proposed tree Amenity Green Space. Roundabout. Small groups of segregated left turn lane planting would replace trees Impact: Minor beneficial semi-mature trees within the would lead to permanent lost east of the roundabout Effect: Slight beneficial roundabout and several loss of tree planting in a and on the roundabout itself. specimen trees and shrubs limited location north-east of Newly planted trees (up 4.0 along the westbound the roundabout. East of the to 4.5m high) would have carriageway of the A33. One roundabout and on the limited beneficial visual effect yew tree south-west of roundabout, there would be at this stage and overall Redbridge Roundabout and two a temporary loss of tree effects would remain groups of trees protected by a planting and a minor loss of adverse. Tree Preservation Order (TPO) vegetation along the Impact: Minor adverse are close to the redline westbound carriageway of Effect: Slight adverse boundary. Several TPO trees the A33 for the proposed are located on the southern part shared footway/cycleway. of the study area. No impact to TPO Sensitivity: Moderate vegetation. Mitigation: Vegetation would be removed only where essential to construct the Proposed Scheme and allow for sight lines and safety requirements.
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Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) Impact: Moderate adverse Effect: Moderate adverse Landform Generally flat landform within Negligible change on Grassland would quickly After 15 years, change would the study area. Landform within landform due to construction establish on the re-gradated be negligible. Redbridge Roundabout is of new footpaths within slopes within Redbridge Impact: Negligible adverse undulated. Redbridge Roundabout. Roundabout and changes Effect: Neutral Sensitivity: Low Minor change of landform would be negligible. north-east of the roundabout Impact: Minor adverse due to cutting of slope and Effect: Slight adverse construction of retaining wall. Impact: Minor adverse Effect: Slight adverse Residents at Close views of Redbridge Construction activity would With the removal of the After establishment of properties at Roundabout, footbridge crossing be visible in winter from the construction activity and vegetation, there would be an the southern the A33 (eastbound) and the first floor of the properties, compound, visual impact enhancement of Redbridge end of Flyover from the first floor of the especially at Redbridge would be reduced. Roundabout and views of Coniston properties, especially in winter. Roundabout, the footbridge Grassland within Redbridge flyover structure slightly Road (R4) A wooden fence to the south of and north-east of the Roundabout would establish softened. the properties curtail views to roundabout where loss of quickly. Newly planted trees Impact: Negligible the site from the first floor. In vegetation would be and shrubs would have no beneficial summer existing trees screen noticeable. South of appreciable beneficial visual Effect: Slight beneficial some views to the south. Redbridge Towers the effect at this stage. Sensitivity: High construction would be Impact: Negligible adverse visible. Effect: Slight adverse Impact: Minor adverse Effect: Slight adverse Residents at The existing footbridge crossing The demolition of the With the construction of a After establishment of
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Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) properties the A33 (eastbound) and flyover footbridge and the new footbridge the changes vegetation, the view would be along are visible from the first floor of construction of a new in view would be less approximately the same. Coniston the properties along Coniston footbridge would be visible perceptible. Impact: No change Road (R3) Road, especially in winter. from the first floor of the Newly planted trees would Effect: Neutral Sensitivity: High properties. Loss of have no appreciable vegetation south-east of beneficial visual effect at this Redbridge Roundabout stage. would also be perceived in Impact: Negligible adverse summer. Effect: Slight adverse Impact: Negligible adverse Effect: Slight adverse Residents at Close views of Redbridge A construction compound After the removal of After establishment of new Redbridge Roundabout, footbridge crossing would be located to the construction compound and tree and shrub planting, and Towers and the A33 (eastbound) and the south of Redbridge Towers construction activity, impacts the construction of a noise properties Flyover. In summer tree planting and the buildings south-east would be less. Loss of trees barrier, the road, junction and south-east of partially screen views of the of it. Removal of vegetation would be permanent. The flyover would be no more it (R5) flyover from the first floors of would exacerbate views of proposed noise barrier would visible from the first floor of Redbridge Towers and the four the flyover. Construction of be higher than the current Redbridge Towers and the storey buildings to the south- the footbridge would be fence south of these building directly south-east of east of it. noticeable. properties and would screen it. View from the buildings Sensitivity: High Impact: Minor adverse the flyover and the south-east of Redbridge Effect: Moderate adverse roundabout from the first Towers would be floors of Redbridge Tower approximately the same. New and the building directly to tree and shrub vegetation the south-east of it. From the within Redbridge Roundabout upper floors, the change in would enhance the Amenity view would be negligible. Green Space and create a Newly planted trees would sense of place. The Amenity have no appreciable Green Space within
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Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) beneficial visual effect at this Redbridge Roundabout would stage. be a new focal point for Impact: Negligible adverse residents at Redbridge Effect: Slight adverse Towers and loss of vegetation south of it would be less perceived. Impact: No change Effect: Neutral Residents at Close views of Redbridge A construction compound After the removal of After establishment of properties Roundabout and the Flyover. In would be located to the construction compound and vegetation views from the north of Old summer, trees often views of the north of the properties. construction activity, impacts eastern buildings would be Redbridge flyover. Construction activity and would be reduced. A fence approximately the same. The Road (R8) Sensitivity: High removal of vegetation would would replace an existing view of the road and flyover be noticeable along the new hedge along the shared from the western properties shared footpath/cycleway, footpath/cycleway but the would be partially screened along the westbound overall view from the by the noise barrier and the carriageway of the A33, properties would barely proposed vegetation, once Redbridge Roundabout and change. A new noise barrier established, would help to the junction between Old 4m high, located along the integrate the noise barrier. Redbridge Road and the shared footway/cycleway, Impact: Negligible beneficial A33. south of the Roundabout, Effect: Slight beneficial Impact: Minor adverse would partially screen views Effect: Moderate adverse of the road and flyover from the western buildings north of Old Redbridge Road. Newly planted trees and shrubs would have no appreciable beneficial visual effect at this stage.
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Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) Impact: Negligible adverse Effect: Slight adverse Residents at The A33 is visible from the first Construction activity along After removal of the No change in view. properties at floor of the properties. the A33 would be just visible construction compound and Impact: No change Oakridge Sensitivity: High from the first floor of the construction activity there Effect: Neutral Road (R6) properties. would be no change in view. Impact: Negligible adverse Impact: No change Effect: Slight adverse Effect: Neutral Residential Redbridge Flyover is visible to The removal of a hedge After the removal of No change in view. properties the north. along the shared construction compound and Impact: No change south of Old Sensitivity: High footpath/cycleway would construction activity, and the Effect: Neutral Redbridge open up views of a construction of a fence at the Road (R7) construction compound and place of the removed hedge, construction activity located the view would approximately along the footpath/cycleway. be the same. Lateral views of construction Impact: No change activity at the junction Effect: Neutral between Old Redbridge Road and the A33 would also be available from the eastern building. Impact: Minor adverse Effect: Slight adverse Residents at Redbridge Flyover is visible Construction activity at the After removal of construction No change in view. Hazeldene from the eastern part of the western side of Redbridge activity, the view would be the Impact: No change Mee’s House, building. Roundabout would be just same. Effect: Neutral The Cottage, Sensitivity: High visible especially in winter Impact: No change The Nooke from the eastern side of the Effect: Neutral
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Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) Listed building. Construction of a Buildings noise barrier would also be (Grade II) just visible. (R9) Impact: Negligible adverse Effect: Slight adverse Residents at Few residential properties along Lateral views of the After removal of construction New tree and shrub planting properties at the western side of Gover Road, construction activity at the activity, the view would be the within Redbridge Roundabout Gover Road the residential properties along roundabout and at the island same. and the island west of it (R1; R2) and the eastern side of the road and west of it would be visible Impact: No change would enhance the Amenity users of the footways along the road from the residential Effect: Neutral Green Space and soften the footways have lateral views of Redbridge properties, direct views from flyover. along Gover Roundabout, Redbridge Flyover the footways. Impact: Negligible beneficial Road (F2) and the island west of it. Impact: Negligible adverse Effect: Slight beneficial Sensitivity: High Effect: Slight adverse
Users of The northern part of Redbridge Construction activity north of After removal of construction No change in view. Southampton Roundabout is visible. Redbridge Roundabout activity, the view would be the Impact: No change 07 (PRoW) Sensitivity: High would be visible. same. Effect: Neutral (F1) Impact: Negligible adverse Impact: No change Effect: Slight adverse Effect: Neutral Users of The footway runs along the A33, Construction activity would After removal of construction No change in view. footways therefore the road, Redbridge be noticeable but would activity, the overall view Impact: No change north of the Flyover and Redbridge barely alter the current view would be the same. Loss of Effect: Neutral A33 (F3) Roundabout are in the of the traffic. vegetation north of the A33 foreground. Impact: Negligible adverse would be noticeable. Newly Sensitivity: Moderate Effect: Slight adverse planted trees and shrubs within the roundabout and north of the A33 would have
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Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) no appreciable beneficial visual effect at this stage. Impact: No change Effect: Neutral Users of The footway runs along the A33, The shared footway and After removal of construction New tree and shrub planting shared therefore the road, Redbridge cycleway would be directly activity and construction would enhance the Amenity footway and Flyover and Redbridge impacted by construction compound, the overall view Green Space, but changes in cycleway Roundabout are in the activity and a construction would be the same. Newly the overall view would not be south of foreground. compound would be located planted trees and shrubs perceptible. Redbridge Sensitivity: Moderate south of it. within the roundabout and the Impact: No change flyover (F4) Impact: Minor adverse Amenity Green Space would Effect: Neutral Effect: Slight adverse have no appreciable beneficial visual effect at this stage. Impact: No change Effect: Neutral Users of Due to their location, Redbridge The footways, footbridge After removal of construction New tree and shrub planting footways Flyover and the junction are the and Redbridge Roundabout activity, the overall view would enhance the Amenity within main elements in the views from would be directly impacted would be the same. Loss of Green Space, and create an roundabout the footways, footbridge and by construction activity. vegetation north of the A33 attractive and safe area for and amenity space. Impact: Minor adverse would be noticeable. Newly the local community. footbridge Sensitivity: Moderate Effect: Slight adverse planted trees and shrubs Impact: Negligible beneficial (F5), and within the roundabout and Effect: Slight beneficial users of north of the A33 would have Redbridge no appreciable beneficial Roundabout visual effect at this stage. Amenity Impact: Negligible adverse Space (A1) Effect: Slight adverse
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Landscape Baseline description and value Description of change, Description of change, Description of change, receptor magnitude of impact and magnitude of impact and magnitude of impact and significance of effect significance of effect during significance of effect during during construction operation (Winter Year 1) operation (Summer Year 15) People at There are lateral views of the Construction activity would After removal of construction No change in view. Redbridge northern section of the A33 be visible but would be set activity, the overall view Impact: No change Community intersected from the Proposed within the context of existing would be the same. Effect: Neutral School (P1) Scheme and of the junction view of traffic. Impact: No change between the A33 and Old Impact: Negligible adverse Effect: Neutral Redbridge Road from the Effect: Neutral southern edge of the football field at Redbridge Community School. Sensitivity: Moderate
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Appendix G. Geology and Soils - Preliminary Conceptual Site Model: Potential Pollutant Linkages Assessment Methodology
G.1 Soils Assessment
To aid assessment of the risk to human health from potentially contaminated soils in the study area, the results of the laboratory contamination data have been screened against generic assessment criteria (GAC) for public open space (residential) which is considered appropriate for this development. There are certain soil properties that can affect the mobility, migration and availability of contaminants. These properties are important to assess in advance of the assessment, so that each result can be interpreted in the correct context. Particularly relevant to potential hydrocarbon contamination, is the soil organic matter (SOM) which can affect exposure pathways involving absorption and inhalation of hydrocarbon vapours and the leachability of these substances. GACs based upon 1% organic matter have been used for the assessment. This is considered conservative as when organic content increases, the mobility of organic contaminants decreases.
At the time of writing there are two sets of relevant publically available generic assessment criteria:
Category 4 Screening Levels (C4SLs) have been published by Defra for use in the assessment of ‘Contaminated Land’ under Part 2A of the Environmental Protection Act 1995. The Statutory Guidance (Defra, 2012) includes four categories of contaminated land, ranging from Category 4 (low risk) to Category 1 (significant / high risk). C4SLs are low risk levels which are not representative of significant possibility of significant harm (SPoSH) and as such, if the C4SLs are not exceeded, land can be demonstrated as being in Category 4 and cannot be determined as contaminated land. These guideline values adopted a Low Level of Toxicological Concern (LLTC) as the benchmark for toxicological impact; and
Suitable 4 Use Levels (S4ULs) have been published by Land Quality Management Limited (LQM)/ Chartered Institute of Environmental Health (CIEH) and are underpinned by a ‘minimal or tolerable risk’ basis as defined in Science Report (SR2) (EA, 2009a) rather than LLTC. These values are more conservative (i.e. lower) than C4SLs and were published to replace previously available LQM/CIEH generic assessment criteria with values based on new modelling assumptions and end uses (public open space near residential housing and public open space parks) introduced during the C4SL project.
The laboratory contamination results have been assessed against both C4SLs and S4ULs for the identified end uses.
G.2 Waste Soil Classification
It is usually preferable to re-use soil on site if possible, so off-site disposal is usually considered only if no suitable alternative use can be found for the material. If waste soil must be disposed off- site, a waste assessment would be needed in order to determine the disposal options. Waste assessment is a two stage process, with the first stage involving assessing whether materials meet the definition of Hazardous Waste as laid out in the Environment Agency Technical Guidance WM3, and the second stage involving assessing disposal options based on Waste Acceptance Criteria (WAC).
The waste assessment provides indicative information with respect to potential disposal routes if waste soil is required to be disposed off-site to landfill. For the limited amount of sampling available in this report, this does not form a comprehensive site waste management plan, but the assessment provides a brief, initial understanding of potential issues with respect to waste soil disposal that may need to be taken in to consideration during the works if waste soil is required to
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be disposed off-site. Prior to the actual disposal of any soil from the site (if needed), further assessment would be required. This is likely to include further analysis of soil samples representative of the actual waste and assessment and liaison with the receiving landfill.
Based on the List of Waste Regulations (LWR) Landfill Regulations 2002, and subsequent amendments, excavated waste soils may be classified as either:
Inert waste, if there is no reason to believe they may be contaminated, or if the leachate levels and overall contaminant concentrations are below the Inert Waste Limit Values;
Non-hazardous waste, suitable for disposal in a non-hazardous waste landfill, if the waste is not classified as Hazardous Waste under the Hazardous Waste Regulations (HWR), but leachate levels or overall contaminant concentrations exceed the Inert Waste Limit Values;
Stable, non-reactive hazardous waste, suitable for disposal in specific cells of a non- hazardous waste landfill, if the waste is classified as Hazardous Waste under LWR but leachate levels and overall contaminant concentrations are below the Stable, Non-Reactive Hazardous Waste Limit Values;
Hazardous waste, suitable for disposal in a hazardous waste landfill, if the waste is classified as Hazardous Waste under the HWR and LWR, but leachate levels and overall contaminant concentrations exceed the Stable, Non- Reactive Hazardous Waste Limit Values but are below the Hazardous Waste Limit Values; and
Hazardous waste, not suitable for disposal at a hazardous waste landfill if the waste is classified as hazardous waste under the HWR and LWR and leachate values exceed the Hazardous Waste Limit Values. Such material would require pre-treatment prior to disposal to hazardous waste landfill or other disposal means.
All inert non-hazardous and hazardous waste requires some form of pre-treatment prior to disposal to reduce the volume of waste going to landfill and the impact of waste when landfilled. Pre-treatment may include source segregation, off-site sorting and off-site processing. The pre- treatment must be a physical, thermal, chemical or biological process and must aim to change the characteristics of the waste. The pre-treatment must reduce the waste volume, reduce its hazardous nature, facilitate its handling, or enhance its recovery. Separating wastes on site ('source segregation') is equivalent to later sorting of mixed wastes. Both treatment methods are acceptable as long as a reasonable amount of the sorted or separated materials are diverted from landfill.
G.3 WM3 Assessment
In order to determine whether waste soils would meet the definition of Hazardous Waste, as laid out in the Environment Agency Technical Guidance WM3, the following steps are necessary:
Steps to classify the waste:
1. Check if the waste needs to be classified;
2. Identify the code or codes that may apply to the waste; and
3. Identify the assessment needed to select the correct code.
4. Steps to assess the waste:
5. Determine the chemical composition of the waste;
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6. Identify if the substances in the waste are ’hazardous substances’ or ’Persistent Organic Pollutants’;
7. Assess the hazardous properties of the waste; and
8. Assign the classification code and describe the classification code.
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Appendix H. Geology and Soils - Preliminary Conceptual Site Model and Risk Assessment
H.1 Methodology
The method for risk evaluation has been based on guidance by CIRIA, 2001 ‘C552: Contaminated Land Risk Assessment - A Guide to Good Practice’, which is a qualitative method of interpreting the risks based on the magnitudes of both the potential consequence (severity) and the probability (likelihood) of the risk occurring.
The risk matrix (Table ) and description of risk, Table H.1, Table H.2 and Table H.3 have been used to estimate a risk rating for each potential pollutant linkage.
Table H.1 Classification of Consequence (CIRIA, 2001)
Classification Definition Severe Acute risk to human health likely to result in “significant harm” as defined by EPA 1990 Part 2A. Short term risk to sensitive water resource. Catastrophic damage to buildings/property. A short term risk to a particular ecosystem or organism forming part of that system. Medium Chronic damage to Human Health. Pollution of sensitive water resource. Significant change to an ecosystem or organism forming part of ecosystem. Mild Pollution of non-sensitive water resources. Significant damage to crops, buildings, structures and services. Damage to sensitive buildings/structures/ services or the environment. Minor Harm, which may not be significant and may result in financial loss, or expenditure to resolve. No permanent health effects to human health (preventable by Personal Protective Equipment (PPE)). Easily repairable effects of damage to buildings, structures and services.
Table H.2 Estimation of Likelihood
Classification Definition High There is a pollution linkage and an event that either appears very likely in the Likelihood short term and almost inevitable over the long term, or there is evidence at the receptor of harm or pollution. Likely There is a pollutant linkage and all the elements are present and in the right place, which means that it is probable that an event would occur. Circumstances are such that an event is not inevitable, but possible in the short term and likely over the long term. Low There is a pollution linkage and circumstances are possible under which an Likelihood event could occur. However, it is by no means certain that even over a longer period that such an event would take place, and is even less likely in the shorter term. Unlikely There is a pollution linkage but circumstances are such that it is improbable that an event would occur even in the very long term.
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Table H.3 Risk Description
Risk Risk Description Very High There is a high likelihood of the event occurring and having severe consequences. If the risk is realised it is likely to result in a substantial liability. High Likely that an event with medium or even severe consequences could arise. If the risk is realised it may result in a substantial liability. Moderate It is possible that an event could occur and it is either unlikely and consequences may be severe or if it were to occur it is likely that consequences would be relatively mild. Investigation would normally be required to clarify the risk and determine the potential liability. Low Risk It is possible that an event could occur but it is likely that the consequences would be at worst mild. Very Low It is unlikely that an event could occur, and if it happened the consequences are likely to be at worst mild.
The risk matrix below has been used to estimate a risk for each potential source–pathway– receptor linkage identified.
Table H.4 Estimation of risk (risk matrix)
Consequence (Severity) Risk Matrix Severe Medium Mild Minor
High Very Moderate Likelihood High Moderate High /low
Likely Moderate
) High Moderate Low /low
Low Moderate Likelihood Moderate Low Very Low /low
Unlikely Moderate Low Very Low Very Low
/low
Probability(likelihood
The estimation of risk is based on desktop and limited ground investigation data and the magnitude of actual chemical results from the ground investigation.
H.2 Sources, Pathways and Receptors
The potential sources, and receptors presented below have been identified from the baseline assessment contained within this chapter.
H.2.1 Potential Sources of contamination
The potential sources of contamination have been identified at the Proposed Scheme the surrounding area including current and historical sources. These are:
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made ground (within Proposed Scheme area) associated with development of existing highway, potential artificial ground and infilled former canal;
potential contamination from current road use (within Proposed Scheme area);
landfills - Redbridge Lane and Saltings (within the study area); and
electricity sub-stations, garages, an unspecified works site/factory, a vehicle hire business and a construction hire business (within the study area).
H.2.2 Potential Pathways
The identified potential pathways specific to the Proposed Scheme are:
dermal contact, ingestion and inhalation of soils/dust and groundwater;
inhalation of soils from windblown dust
leaching of contamination from soils via rainwater infiltration;
vertical and lateral migration of contamination via groundwater;
surface run-off of contaminants;
direct contact (infrastructure and below ground services);
inhalation of gases or contaminant vapour; and
accumulation and migration or harmful gas and/or vapours.
H.2.3 Potential Receptors
Potential receptors to contamination exposure for the Proposed Scheme are:
Human Health – construction workers, maintenance workers current and future site users and nearby site users;
Groundwater (secondary A aquifer - River Terrace Deposits, Wittering Formation and Earnley Sand Formation).
Surface water (River Test);
Ecologically Important Sites (Solent Maritime and Solent and Southampton Water sites (Habitats Directive Site, Birds Directive Site, Special Area of Conservation (SAC), Special Protection Area (SPA) and Ramsar site) and Lower Test Valley Site of SSSI; and
Buildings and services – potentially aggressive ground conditions in the made ground may damage buried structures.
The below Preliminary CSM in Table H.5, assesses potential risk from the above sources to receptors identified within the study area. As only limited GI data has been received at the time of writing this report, therefore only a preliminary risk assessment can be produced. This risk assessment is based on limited soils data, no groundwater data and only one round of gas data.
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Table H.5: Conceptual Site Model: Potential Pollutant Linkages
Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score)
Made ground Direct contact, Human Health It is considered a low likelihood that construction workers will come Moderate/Low (within ingestion and – Construction into contact with contamination within the made ground. Based on soils proposed inhalation Workers and groundwater data from the GI, no significant contamination was scheme area) identified. It is possible, however that contamination may be present associated that wasn’t identified during the GI. The consequences of exposure to with potential contamination is considered medium. development of existing Direct contact, Human Health It is considered a low likelihood that future maintenance workers will Moderate/Low highway, ingestion and – Future come into contact with contaminated made ground and shallow potentially inhalation maintenance groundwater depending on the work they are undertaking. Based on artificial workers soils and groundwater data from the GI, no significant contamination ground and was identified. The consequences of exposure to potential infilled former contamination is considered medium. canal Direct contact, Human Health It is considered unlikely that current and future site users will be Low ingestion and – Current and impacted by potential contamination as the presence of hardstanding inhalation Future site users in the final roadway development will severely limit this exposure pathway although inhalation of dusts etc. exposure from any non- vegetated verges may be possible. Based on soils and groundwater data from the GI, no significant contamination was identified. The consequences of exposure to potential contamination is considered medium.
Inhalation of Human Health It is considered unlikely that nearby site users will be impacted by Low soils from – Nearby site potential contamination as the presence of hardstanding in the final windblown dust users roadway development will severely limit this exposure pathway although inhalation of dusts etc. exposure from any non-vegetated
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Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score) verges may be possible. Based on soils data from the GI, no significant contamination was identified. The consequences of exposure to potential contamination is considered medium.
Leaching of Groundwater It is considered a low likelihood that the Secondary A Aquifer would Moderate/Low contamination be impacted by mobilisation of contaminants during construction. The from soils via Secondary A consequences of this are considered medium, without mitigation. rainwater Aquifer (River Based on soils data from the GI, no significant contamination was infiltration and Terrace identified. It is possible that contamination may be present that was not migration Deposits and identified during the GI. through Bedrock Aquifer) groundwater
Surface run off Surface Water It is considered a low likelihood that the river test would be impacted Moderate/Low of (River Test – if potential contaminants are mobilised during construction, given the contaminants primary river) distance of the river from the site. The consequences of this are (River Test) considered medium, without mitigation. Based on data from the GI, no significant contamination was identified.
Direct contact Buildings and It is considered a low likelihood that structures and buried services Moderate/Low and Services would be impacted by existing contamination in soils and groundwater accumulation if present. There is also the potential for gas accumulation within and migration enclosed spaces. The gas risk assessment has classified the risk as or harmful gas low, and no significant contamination was identified during the GI. It is and/or vapours possible that contamination may be present that was not identified during the GI. The consequences are considered medium.
Leaching of Ecologically It is considered unlikely that the ecological sites would be impacted if Moderate/Low contamination Important Sites potential contaminants are mobilised during construction, given the from soils via distance of the sites from the proposed scheme. The consequences of
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Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score) rainwater this are considered severe, given the sensitivity of the receptor. Based infiltration and on data from the GI, no significant contamination was identified. migration through groundwater.
Potential Direct contact, Human Health It is considered a low likelihood that construction workers will come Moderate/Low contamination ingestion and – Construction into contact with contamination from vehicle use. Based on soils and from current inhalation Workers groundwater data from the GI, no significant contamination was vehicle use identified. It is possible, however that contamination may be present that wasn’t identified during the GI. The consequences of exposure to potential contamination is considered medium.
Direct contact, Human Health It is considered a low likelihood that future maintenance workers will Moderate/Low ingestion and – Future come into contact with soils and shallow groundwater contamination (if inhalation maintenance present) depending on the work they are undertaking. Based on data workers from the GI, no significant contamination was identified. The consequences of exposure to potential contamination is considered medium.
Direct contact, Human Health It is considered unlikely that current and future site users will be Low ingestion – Current and impacted by potential contamination as the presence of hardstanding Future site users in the final roadway development will severely limit this exposure pathway although inhalation of dusts etc. exposure from any non- vegetated verges may be possible. Based on data from the GI, no significant contamination was identified. The consequences of exposure to potential contamination is considered medium.
Inhalation of Human Health It is considered unlikely that nearby site users will be impacted by Low soils from – Nearby site potential contamination as the presence of hardstanding in the final
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Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score) windblown dust users roadway development will severely limit this exposure pathway although inhalation of dusts etc. exposure from any non-vegetated verges may be possible. Based on data from the GI, no significant contamination was identified. The consequences of exposure to potential contamination is considered medium.
Leaching of Groundwater It is considered a low likelihood that the Secondary A Aquifer would Moderate/Low contamination be impacted if potential contaminants are mobilised during from soils via Secondary A construction. The consequences of this are considered medium, rainwater Aquifer (River without mitigation. Based on data from the GI, no significant infiltration and Terrace contamination was identified. migration Deposits and through Bedrock Aquifer) groundwater
Surface run off Surface Water It is considered a low likelihood that the River Test would be Moderate/Low of (River Test – impacted if potential contaminants are mobilised during construction, contaminants primary river) given the distance of the river from the site. The consequences of this (River Test) are considered medium, without mitigation. Based on data from the GI, no significant contamination was identified.
Direct Contact Buildings and It is considered likely that structures and buried services would be Moderate/Low Services impacted by existing contamination in soils and groundwater if present. The consequences are considered medium.
Leaching of Ecologically It is considered a low likelihood that the ecological sites would be Moderate contamination Important Sites impacted if potential contaminants are mobilised during construction, from soils via given the distance of the sites from the proposed scheme. The rainwater consequences of this are considered severe, given the sensitivity of infiltration and the receptors. Based on data from the GI, no significant contamination
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Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score) migration was identified. through groundwater.
Electricity Direct contact, Human Health It is considered unlikely that construction workers will come into Low Substations, ingestion and – Construction contact with contamination on site from surrounding electricity Garages, inhalation Workers substations, garages, vehicle hire and construction businesses, vehicle hire depending on the work they are undertaking. Based on data from the business and GI, no significant contamination was identified. The consequences of construction exposure to potential contamination is considered medium. hire business (within the Direct contact, Human Health It is considered unlikely that future maintenance workers will come Low study area) ingestion and – Future into contact with contamination on site from surrounding electricity inhalation maintenance substations, garages, vehicle hire and construction businesses,
workers depending on the work they are undertaking. Based on data from the GI, no significant contamination was identified. The consequences of exposure to potential contamination is considered medium.
Direct contact, Human Health It is considered unlikely that current and future site users will be Low ingestion and – Current and impacted by potential contamination as the presence of hardstanding inhalation Future site users in the final roadway development will severely limit this exposure pathway although inhalation of dusts etc. exposure from any non- vegetated verges may be possible. Based on preliminary soils data from the GI, no significant contamination was identified, with the exception of asbestos detected in the area of the northern subway. The consequences of exposure to potential contamination is considered medium.
Inhalation of Human Health It is considered unlikely that nearby site users will be impacted by Low soils from – Nearby site potential contamination as the presence of hardstanding in the final
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Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score) windblown dust users roadway development will severely limit this exposure pathway although inhalation of dusts etc. exposure from any non-vegetated verges may be possible. Based on preliminary soils data from the GI, no significant contamination was identified, with the exception of asbestos detected in the area of the northern subway. The consequences of exposure to potential contamination is considered medium.
Leaching of Groundwater It is considered a unlikely that the Secondary A Aquifer would be Low contamination impacted due to mobilisation of contaminants during construction. The from soils via Secondary A consequences of this are considered medium, without mitigation. rainwater Aquifer (River Based data from the GI, no significant contamination was identified. infiltration and Terrace migration Deposits and through Bedrock Aquifer) groundwater
Surface run off Surface Water It is considered unlikely that the River Test would be impacted if Low of (River Test – potential contaminants within the site area are mobilised during contaminants primary river) construction, given the distance of the river from the site. The (River Test) consequences of this are considered medium, without mitigation. Based on data from the GI, no significant contamination was identified.
Direct contact Buildings and It is considered unlikely that structures and buried services would be Low and Services impacted by existing contamination in soils and groundwater. The accumulation consequences are considered medium. and migration or harmful gas and/or vapours
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Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score)
Leaching of Ecologically It is considered unlikely that the ecological sites would be impacted if Moderate/Low contamination Important Sites potential contaminants are mobilised during construction, given the from soils via distance of the sites from the proposed scheme. The consequences of rainwater this are considered severe, given the sensitivity of the receptor. Based infiltration and on data from the GI, no significant contamination was identified. migration through groundwater.
Landfills - Direct contact, Human Health It is considered unlikely that construction workers will come into Low Redbridge ingestion and – Construction contact with contamination on site from landfills within the study area, Lane and inhalation Workers given their distances from the proposed scheme and the works they Saltings will be undertaking. Based on data from the GI, no significant (within the contamination was identified. The consequences of exposure to study area) potential contamination is considered medium.
Direct contact, Human Health It is considered unlikely that future maintenance workers will come Low ingestion and – Future into contact with contamination on site from landfills within the study inhalation maintenance area, given their distances from the proposed scheme depending on workers the work they are undertaking. Based on soils data from the GI, no significant contamination was identified. The consequences of exposure to potential contamination is considered medium.
Direct contact, Human Health It is considered unlikely that current and future site users will be Low ingestion and – Current and impacted by potential contamination as the presence of hardstanding inhalation Future site users in the final roadway development will severely limit this exposure pathway although inhalation of dusts etc. exposure from any non- vegetated verges may be possible. Based on data from the GI, no significant contamination was identified. The consequences of
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Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score) exposure to potential contamination is considered medium.
Inhalation of Human Health It is considered unlikely that nearby site users will be impacted by Low soils from – Nearby site potential contamination as the presence of hardstanding in the final windblown dust users roadway development will severely limit this exposure pathway although inhalation of dusts etc. exposure from any non-vegetated verges may be possible. Based on data from the GI, no significant contamination was identified. The consequences of exposure to potential contamination is considered medium.
Leaching of Groundwater It is considered a low likelihood that the Secondary A Aquifer would Moderate/Low contamination be impacted if potential contaminants are mobilised during from soils via Secondary A construction. The consequences of this are considered medium, rainwater Aquifer (River without mitigation. Based on data from the GI, no significant infiltration and Terrace contamination was identified. migration Deposits and through Bedrock Aquifer) groundwater
Surface run off Surface Water It is considered low likelihood that the River Test would be impacted Moderate/Low of (River Test – if potential contaminants within the site area are mobilised during contaminants primary river) construction, given the distance of the river from the site. The (River Test) consequences of this are considered medium, without mitigation. Based on preliminary soils data from the GI, no significant contamination was identified. It is possible contamination maybe identified from the outstanding GI data. No groundwater data is available at this stage.
Direct contact Buildings and It is considered a low likelihood that structures and buried services Moderate/Low and would be impacted by any existing contamination in soils and
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Source Pathway Receptor Potential Pollutant Linkage Risk Rating (Score) accumulation Services groundwater if present. No significant contamination was identified and migration during the GI. The consequences are considered medium. or harmful gas and/or vapours
Leaching of Ecologically It is considered unlikely that the ecological sites would be impacted if Moderate/Low contamination Important Sites potential contaminants are mobilised during construction. The from soils via consequences of this are considered severe, given the sensitivity of rainwater the receptor. Based on data from the GI, no significant contamination infiltration and was identified. migration through groundwater.
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Appendix I. Baseline Noise Monitoring Survey
I.1 Introduction
A baseline noise monitoring survey was undertaken between 24th November to 6th December 2017 and consisted of monitoring at a total of four locations in the vicinity of the Proposed Scheme.
Noise monitoring equipment was deployed at two long-term locations, 8 Old Redbridge Road (LT1) and 4 Coniston Road (LT2), where the equipment remained unattended for several days. Monitoring at these locations was undertaken under free-field conditions.
Short-term measurements were undertaken at two locations, following the shortened measurement procedure as described in CRTN (DfT, 1988). This monitoring was undertaken at the northern façade Clover Nooke (ST1) and the western façade of Redbridge Tower (ST2). Monitoring was undertaken at the facades of these properties.
The baseline noise monitoring locations are shown in Figure 11.1 ‘Baseline Noise Monitoring Locations’.
Two daytime noise surveys were conducted at Redbridge Tower (ST2) over two days. The first was undertaken on 24th November 2017, while the second was undertaken on 6th December 2017. In the first noise survey, noise levels were measured 1m away from the northern façade of the building. In the second noise survey, due to restrictions in monitoring position encountered during the second survey, noise levels were measured in a free-field position which was considered representative of the façade incident position of the first noise survey. A correction factor of +3dB was applied to the free-field noise levels which were then combined with the façade incident noise levels from the first noise survey to obtain the averaged noise levels presented below.
I.2 Weather Conditions
Weather conditions experienced during the short-term attended survey were not adversely affected by rain or strong winds and were considered suitable conditions for noise monitoring.
Noise levels associated with the following periods were omitted due to unfavourable weather conditions, based on weather observation available through the Met Office WOW website9: th Between 11:00 and 17:00 on 25 November 2017 th At 22:00 on 25 November 2017 th At 00:00 on 26 November 2017 th Between 10:00 and 15:00 on 26 November 2017 th th Between 23:00 on 26 November and 20:00 on 27 November 2017 th th Between 21:00 on 27 November 2017 and 00:00 on 28 November 2017 th Between 04:00 and 07:00 on 28 November 2017 th Between 10:00 and 15:00 on 28 November 2017 th At 04:00 on 29 November 2017
9 http://wow.metoffice.gov.uk
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I.3 Observations and Equipment
Road traffic noise was observed to be the dominant noise source at all noise monitoring locations during the survey.
Road construction work was observed close to the southern façade of Redbridge Towers (ST2). This construction noise was only audible only at the ST2 monitoring location. Road traffic noise remained dominant at ST2 and any contribution from construction noise was not considered to have significantly influenced the measured baseline noise levels.
Table I.1 lists the particulars of noise monitoring kits used at each location.
Table I.1: Noise monitoring equipment (Survey 1)
Ref. Location Sound Level Meter Pre-amplifier Microphone Calibrator LT1 8 Old Redbridge Rion NL-52 Rion NH-25 Rion UC-59 Rion NC-74 Road s/n 00642983 s/n 43011 s/n 06690 s/n 00830793 LT2 4 Coniston Road Rion NL-32 Rion NH-21 Rion UC-53A s/n 00482614 s/n 27718 s/n 321546 ST1 Clover Nooke Cirrus CR:811B Cirrus Cirrus Cirrus s/n C19301FD MV:200C MK:224 CR:511E s/n 2027 s/n 201290A s/n 40145 ST2 Redbridge Cirrus CR:811B Cirrus Cirrus Cirrus Towers s/n C17206FD MV:200C MK:224 CR:511E s/n 2740 s/n 20046250 s/n 43254
Equipment failures occurred at both of the long-term noise monitoring locations during the survey. The batteries of the noise monitoring kit deployed at LT1 – 8 Old Redbridge Road were replaced during the survey but did eventually fail, resulting in the equipment ceasing to log data after 17:00 on 28th November 2017.
Noise monitoring kit at LT2 – 4 Coniston Road monitoring location malfunctioned and did not log any data. It was replaced with another kit on 28th November 2017, which continued to log data until approximately 05:00 on 29th November 2017. The particulars of the replacement kit are listed in Table I.2.
Table I.2: Noise monitoring equipment (Survey 1 - LT2)
Ref. Location Sound Level Meter Pre-amplifier Microphone Calibrator LT2 4 Coniston Road Rion NL-52 Rion NH-25 Rion UC-59 Rion NC-74 s/n 00220558 s/n 10558 s/n 06710 s/n 00830793
Noise monitoring kits deployed at long-term monitoring locations LT1 and LT2 were collected on 6th December 2017. A second short-term measurement was undertaken at a free-filed position representative to the façade incidence position at location ST1 – Clover Nooke. The previously used monitoring location at the façade of the property was unavailable on 06 December.
A night noise survey was undertaken between 1st and 2nd February 2018, which consisted of unattended noise monitoring at long-term location LT1 – 8 Old Redbridge Road and 3-hour attended monitoring at short-term locations ST1 – Clover Nooke and ST2 – Redbridge Towers.
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Table I.3 lists the particulars of noise monitoring kits used at each location in the night noise survey.
Table I.3: Night noise monitoring equipment (Survey 2)
Ref. Location Sound Level Meter Pre-amplifier Microphone Calibrator LT1 8 Old Redbridge Cirrus CR:811B Cirrus Cirrus Cirrus Road s/n C17206FD MV:200C MK:224 CR:511E s/n 2740 s/n 20046250 s/n 43254 ST1 Clover Nooke Cirrus CR:811B Cirrus Cirrus ST2 Redbridge s/n C19301FD MV:200C MK:224 Towers s/n 2027 s/n 201290A
I.4 Measured Baseline Noise Levels
Table I.4 presents the measured noise level data at the long-term location LT1 – 8 Old Redbridge Road.
Table I.4: Measured noise levels at monitoring location LT1 – 8 Old Redbridge Road
Date and Start Time LAeq,1h LAmax,1h LA1,1h LA10,1h LA90,1h Friday, 24/11/2017 18:00 57.5 73.9 60.5 58.7 55.9 Friday, 24/11/2017 19:00 55.8 69.5 60.5 56.9 53.9 Friday, 24/11/2017 20:00 54.6 68.6 58.2 56.0 52.6 Friday, 24/11/2017 21:00 53.5 64.1 57.3 55.1 51.5 Friday, 24/11/2017 22:00 54.1 70.8 59.0 55.7 51.2 Friday, 24/11/2017 23:00 51.7 60.8 55.8 53.5 48.7 Saturday, 25/11/2017 00:00 50.3 61.9 55.9 52.7 46.6 Saturday, 25/11/2017 01:00 49.2 60.7 54.9 51.9 44.7 Saturday, 25/11/2017 02:00 48.2 59.2 53.9 50.7 43.8 Saturday, 25/11/2017 03:00 47.8 59.1 53.4 50.4 43.0 Saturday, 25/11/2017 04:00 48.9 63.2 54.2 51.0 44.9 Saturday, 25/11/2017 05:00 51.9 63.2 56.0 53.8 48.8 Saturday, 25/11/2017 06:00 53.2 66.4 57.4 54.8 50.7 Saturday, 25/11/2017 07:00 54.2 67.3 58.2 55.5 52.1 Saturday, 25/11/2017 08:00 55.4 74.2 59.3 56.3 52.9 Saturday, 25/11/2017 09:00 56.2 82.2 61.1 55.4 51.5 Saturday, 25/11/2017 10:00 55.3 70.5 58.7 56.3 53.5 Saturday, 25/11/2017 11:00 57.6 73.9 61.9 58.9 55.4 Saturday, 25/11/2017 12:00 57.7 79.3 63.0 58.7 55.7 Saturday, 25/11/2017 13:00 56.9 66.6 60.0 58.2 55.3 Saturday, 25/11/2017 14:00 58.0 70.7 61.9 59.3 56.1 Saturday, 25/11/2017 15:00 57.4 72.7 61.6 58.6 55.4 Saturday, 25/11/2017 16:00 57.6 74.8 62.4 58.7 55.5
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Date and Start Time LAeq,1h LAmax,1h LA1,1h LA10,1h LA90,1h Saturday, 25/11/2017 17:00 54.9 79.6 60.1 55.6 52.7 Saturday, 25/11/2017 18:00 54.3 64.8 57.0 55.4 52.8 Saturday, 25/11/2017 19:00 54.8 70.7 58.4 55.9 52.9 Saturday, 25/11/2017 20:00 53.2 67.0 56.6 54.7 51.0 Saturday, 25/11/2017 21:00 51.8 62.8 55.6 53.5 49.4 Saturday, 25/11/2017 22:00 52.3 66.4 55.9 53.8 50.1 Saturday, 25/11/2017 23:00 52.0 67.0 57.0 53.8 49.1 Sunday, 26/11/2017 00:00 50.2 64.3 55.0 52.5 46.5 Sunday, 26/11/2017 01:00 48.2 70.3 54.9 50.4 43.0 Sunday, 26/11/2017 02:00 46.1 56.0 51.6 48.7 41.1 Sunday, 26/11/2017 03:00 45.1 58.4 51.2 47.8 39.6 Sunday, 26/11/2017 04:00 45.4 60.0 51.3 47.8 40.8 Sunday, 26/11/2017 05:00 48.1 58.5 53.0 50.2 44.1 Sunday, 26/11/2017 06:00 50.5 69.6 55.5 52.5 47.1 Sunday, 26/11/2017 07:00 51.0 68.6 56.1 52.8 48.0 Sunday, 26/11/2017 08:00 51.4 69.7 56.2 52.8 48.8 Sunday, 26/11/2017 09:00 54.5 77.9 59.9 55.4 51.7 Sunday, 26/11/2017 10:00 58.1 80.0 63.0 57.9 54.8 Sunday, 26/11/2017 11:00 56.6 73.1 59.2 57.7 55.0 Sunday, 26/11/2017 12:00 56.9 71.4 61.3 58.1 55.1 Sunday, 26/11/2017 13:00 57.5 76.3 62.3 58.7 54.4 Sunday, 26/11/2017 14:00 57.0 83.6 62.3 56.5 53.2 Sunday, 26/11/2017 15:00 55.1 76.5 61.0 55.9 52.9 Sunday, 26/11/2017 16:00 55.1 72.3 59.9 56.1 53.0 Sunday, 26/11/2017 17:00 54.3 74.0 58.4 55.2 52.5 Sunday, 26/11/2017 18:00 52.8 71.8 58.2 53.7 50.5 Sunday, 26/11/2017 19:00 51.3 67.0 56.1 52.9 48.7 Sunday, 26/11/2017 20:00 50.1 69.0 55.3 51.7 47.3 Sunday, 26/11/2017 21:00 48.9 64.6 53.6 50.7 46.2 Sunday, 26/11/2017 22:00 47.5 62.5 52.8 49.5 44.3 Sunday, 26/11/2017 23:00 46.4 60.4 52.5 48.7 41.8 Monday, 27/11/2017 00:00 44.8 57.0 51.0 47.6 39.9 Monday, 27/11/2017 01:00 46.6 57.7 52.7 49.4 40.7 Monday, 27/11/2017 02:00 48.0 64.9 54.8 50.7 42.2 Monday, 27/11/2017 03:00 51.4 64.9 57.5 54.1 46.1 Monday, 27/11/2017 04:00 51.1 67.0 56.1 53.5 47.2 Monday, 27/11/2017 05:00 53.8 69.9 58.0 55.5 51.0 Monday, 27/11/2017 06:00 56.6 70.2 60.3 58.1 54.4
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Date and Start Time LAeq,1h LAmax,1h LA1,1h LA10,1h LA90,1h Monday, 27/11/2017 07:00 57.6 75.7 61.2 58.8 55.9 Monday, 27/11/2017 08:00 59.2 76.4 62.4 60.0 57.5 Monday, 27/11/2017 09:00 58.8 82.5 62.5 59.8 57.1 Monday, 27/11/2017 10:00 57.9 70.2 62.6 59.1 56.1 Monday, 27/11/2017 11:00 57.1 70.3 60.6 58.4 55.4 Monday, 27/11/2017 12:00 57.5 72.7 61.4 58.6 55.9 Monday, 27/11/2017 13:00 59.4 76.9 62.9 60.4 56.8 Monday, 27/11/2017 14:00 58.7 83.0 62.2 58.5 54.9 Monday, 27/11/2017 15:00 57.4 74.7 61.1 58.6 55.7 Monday, 27/11/2017 16:00 57.4 77.8 62.4 58.6 55.5 Monday, 27/11/2017 17:00 56.7 70.0 60.1 57.8 55.2 Monday, 27/11/2017 18:00 55.7 70.9 58.8 56.8 54.1 Monday, 27/11/2017 19:00 53.8 75.1 58.6 55.2 51.5 Monday, 27/11/2017 20:00 53.1 68.5 57.7 54.8 50.5 Monday, 27/11/2017 21:00 52.2 67.3 56.7 53.8 49.5 Monday, 27/11/2017 22:00 50.3 61.5 54.9 52.2 47.3 Monday, 27/11/2017 23:00 48.7 60.7 53.7 50.6 45.4 Tuesday, 28/11/2017 00:00 45.7 62.2 52.1 48.5 40.8 Tuesday, 28/11/2017 01:00 46.1 64.0 53.1 48.7 41.3 Tuesday, 28/11/2017 02:00 45.4 62.7 52.5 48.4 39.5 Tuesday, 28/11/2017 03:00 46.4 61.3 53.0 49.2 41.2 Tuesday, 28/11/2017 04:00 50.8 61.5 54.9 52.2 46.9 Tuesday, 28/11/2017 05:00 54.4 67.4 58.6 55.7 52.2 Tuesday, 28/11/2017 06:00 57.1 68.4 60.1 58.3 55.5 Tuesday, 28/11/2017 07:00 57.5 71.8 62.1 58.4 55.9 Tuesday, 28/11/2017 08:00 55.9 76.1 59.8 56.8 54.4 Tuesday, 28/11/2017 09:00 57.3 67.2 60.5 58.3 55.7 Tuesday, 28/11/2017 10:00 58.3 74.9 62.7 59.4 56.6 Tuesday, 28/11/2017 11:00 58.4 76.5 63.8 59.7 56.2 Tuesday, 28/11/2017 12:00 59.9 84.8 68.3 60.7 56.3 Tuesday, 28/11/2017 13:00 59.2 80.8 67.1 59.9 56.2 Tuesday, 28/11/2017 14:00 58.7 78.5 64.7 59.4 56.3 Tuesday, 28/11/2017 15:00 58.4 77.7 65.4 59.6 55.8 Tuesday, 28/11/2017 16:00 57.1 81.2 62.7 57.8 54.8 Thursday, 01/02/2018 18:00 57.5 67.4 60.1 58.8 56.4 Thursday, 01/02/2018 19:00 58.1 81.9 61.8 59.0 56.1 Thursday, 01/02/2018 20:00 56.4 73.8 59.8 58.0 54.7 Thursday, 01/02/2018 21:00 55.1 62.5 58.2 56.8 53.3
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Date and Start Time LAeq,1h LAmax,1h LA1,1h LA10,1h LA90,1h Thursday, 01/02/2018 22:00 53.9 75.0 58.0 55.3 51.2 Thursday, 01/02/2018 23:00 51.5 63.9 55.8 53.6 48.7 Friday, 02/02/2018 00:00 48.8 61.3 53.7 51.0 44.4 Friday, 02/02/2018 01:00 48.5 64.2 53.9 51.1 43.9 Friday, 02/02/2018 02:00 49.8 61.7 55.8 52.7 44.8 Friday, 02/02/2018 03:00 50.3 63.9 55.2 52.8 46.1 Friday, 02/02/2018 04:00 53.1 63.2 57.5 55.3 50.2 Friday, 02/02/2018 05:00 56.2 66.4 59.4 57.9 54.0 Friday, 02/02/2018 06:00 58.5 70.8 61.3 59.9 57.0 Friday, 02/02/2018 07:00 60.1 72.1 63.7 61.4 58.9
Table I.5 presents the measured noise level data at the long-term location LT2 – 4 Coniston Road.
Table I.5: Measured noise levels at monitoring location LT2 – 4 Coniston Road
Date and Start Time LAeq,1h LAmax,1h LA1,1h LA10,1h LA90,1h Tuesday, 28/11/2017 19:00 57.8 72.7 62.6 59.4 55.2 Tuesday, 28/11/2017 20:00 56.9 77.6 62.4 58.7 53.5 Tuesday, 28/11/2017 21:00 55.7 79.0 60.7 57.5 52.2 Tuesday, 28/11/2017 22:00 54.5 69.8 59.1 56.6 50.5 Tuesday, 28/11/2017 23:00 52.6 64.0 58.5 55.2 48.2 Wednesday, 29/11/2017 00:00 51.4 70.5 57.8 54.2 45.9 Wednesday, 29/11/2017 01:00 50.4 67.5 57.8 53.7 44.0 Wednesday, 29/11/2017 02:00 51.0 64.6 58.2 54.1 45.0 Wednesday, 29/11/2017 03:00 51.9 68.5 58.6 54.8 46.5 Wednesday, 29/11/2017 04:00 54.9 66.3 60.6 57.8 50.4 Table I.6 presents the measured noise level data at the short-term location ST1 – Clover Nooke.
Table I.6: Measured noise levels at monitoring location ST1 – 4 Clover Nooke
Date and Start Time LAeq,1h LAmax,1h LA1,1h LA10,1h LA90,1h Friday, 24/11/2017 13:15 67.7 84.5 73.2 69.5 64.9 Friday, 24/11/2017 14:00 68.5 93.8 75.6 69.5 64.6 Friday, 24/11/2017 15:00 67.8 87.5 73.1 69.4 65.1 Wednesday, 06/12/2017 13:05 67.6 91.9 72.2 68.7 63.6 Wednesday, 06/12/2017 14:00 66.3 82.0 71.1 68.5 63.5 Wednesday, 06/12/2017 15:00 66.2 79.2 70.4 68.4 63.4 Thursday, 01/02/2018 23:13 62.0 73.1 65.8 63.9 57.0 Friday, 02/02/2018 00:50 59.6 80.0 61.9 59.3 50.4 Friday, 02/02/2018 01:00 59.7 74.2 64.3 61.8 50.4
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Table I.7 presents the measured noise level data at the short-term location ST2 – Redbridge Towers.
Table I.7: Measured noise levels at monitoring location ST2 – Redbridge Towers
Date and Start Time LAeq,1h LAmax,1h LA1,1h LA10,1h LA90,1h Friday, 24/11/2017 13:00 63.3 85.6 68.8 64.9 60.8 Friday, 24/11/2017 14:00 63.0 83.3 69.3 64.2 60.3 Friday, 24/11/2017 15:00 63.2 91.7 67.3 64.0 60.6 Thursday, 01/02/2018 23:48 61.5 70.4 64.6 63.1 58.2 Friday, 02/02/2018 00:00 60.0 69.2 63.4 61.7 56.5 Friday, 02/02/2018 01:38 57.5 72.7 60.7 59.3 52.2
Figure I.1 shows the noise monitoring equipment deployed at the long-term location LT1 – 8 Old Redbridge Road.
Figure 1: Noise monitoring kit setup at LT1 – 8 Old Redbridge Road
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Figure I.2 shows the noise monitoring equipment deployed at the long-term location LT2 – 4 Coniston Road.
Figure I.2: Noise monitoring kit setup at LT2 – 4 Coniston Road
Figure I.2: Noise monitoring kit setup at LT2 – 4 Coniston Road
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Figure I.3 shows the noise monitoring equipment deployed at the short-term location ST1 – Clover Nooke in a façade incidence position.
Figure I.3: Noise monitoring kit setup at ST1 – Clover Nooke (façade incidence)
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Figure I.4 shows the noise monitoring equipment deployed at the short-term location ST1 – Clover Nooke in a free-field position.
Figure I.4: Noise monitoring kit setup at ST1 – Clover Nooke (free-field)
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Figure I.5 shows the noise monitoring equipment deployed at the short-term location ST2 – Redbridge Towers.
Figure I.5: Noise monitoring kit setup at ST2 – Redbridge Towers
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Appendix K. Water Framework Directive Compliance (Screening) Note
K.1 Introduction
Redbridge Roundabout is located in the west of the city of Southampton at the intersection of the M271, Redbridge Road (A33) and A35. The roundabout is an important entry point for traffic travelling into the city centre or to/from Southampton Port. Congestion during peak times is severely hampering access to these key locations. A scheme to ease congestion has been proposed which will involve: widening the road network on the south side of the Redbridge roundabout, improving footways, removing the southern subway, relocating toucan crossings, and providing a new footbridge. The impact of the Proposed Scheme on flood risk, hydromorphology and groundwater has been assessed and the results presented in the Road Drainage and Water Environment Chapter. This Appendix provides an assessment of the Proposed Scheme on the Water Framework Directive (WFD) status of the River Test which is located approximately 300m west of the Redbridge Roundabout. Surface water drainage assessments have now determined that the drainage area of the Redbridge roundabout is connected to the Millbrook piped watercourse via an outfall to the southwest which then flows parallel to the Old Redbridge Road before discharging into the River Test at an outfall under the Redbridge flyover. At this point the Test is tidal.
The River Test drains a predominantly rural catchment in Hampshire flowing for 64km from its source near Ashe to Southampton where it joins the River Itchen. The bedrock geology of the catchment is dominated to the north by chalk which feeds the groundwater baseflows to the rivers. In its fluvial lengths the river is classified as a chalk stream and Sites of Special Scientific Interest (SSSIs) supporting a diversity of associated mammal, fish, invertebrate and plant habitats. Major urban areas, such as Southampton, are concentrated along the coast where the underlying geology is predominantly clay.
The Environment Agency requires an assessment of the impact of any works/modification to water bodies in the U.K. under the European Union (EU) WFD 2000. The primary aim of the WFD is to improve/maintain the Ecological Status/Potential of all water bodies. Ecological Status/Potential comprises a series of biological, physico-chemical and hydromorphological ‘quality elements’. The following WFD compliance (screening) note provides an overview of the compliance of the Proposed Scheme against the legislation considering the baseline conditions and potential impacts from the M271 Redbridge roundabout improvements. In particular, the following sections of the appendix provide a summary (screening) of the WFD compliance for the additional surface water drainage discharged to the River Test by improvements. No new structures (e.g. a replacement headwall on the banks of the River Test) are needed to be built.
K.2 Assessment Background
The WFD (2000/60/EC) is a significant piece of EU water legislation that came into force in 2000, with the overarching objective of enabling all water bodies in Europe to attain good or high ecological status/potential. In addition, under the legislation, any modification to a water body should not lead to deterioration in the status of a water body or any of the quality elements. The Environment Agency is a competent authority in England for delivering the WFD.
The WFD outlines a number of objectives including:
Prevent deterioration in the status of water bodies;
Aim to achieve GES and good surface water chemical status in water bodies by 2015, 2021 or 2027 (depending on feasibility);
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For water bodies designated as artificial or heavily modified, aim to achieve GEP by 2015, 2021 or 2027 (depending on feasibility);
Comply with objectives and standards for protected areas where relevant; and,
Reduce pollution from priority substances and cease discharges, emissions and losses of priority hazardous substances.
Where a scheme is considered to cause deterioration, or where it could contribute to a failure of the water body to meet Good, then an Article 4.7 assessment is required. Should a modification or change meet all of the conditions set out in Article 4.7 then it is considered as being WFD compliant.
K.3 Study Area
For the purposes of this WFD compliance note, a study area has been defined which includes the northern tidal extent of the River Test to Testwood and the southwestern tidal channel at Eling as part of the Environment Agency Southampton Water Operational Catchment. Please note, this study area differs from the areas analysed for flood risk and groundwater assessments. The surface water drainage from Redbridge roundabout has not been shown to have hydrological connections to any other waterbodies so the WFD assessment does not include additional adjacent catchments.
Figure K.1 Water Framework Directive study area (Natural England, 2017)
K.4 Methodology
A desk-based review of existing information has been undertaken to support the WFD compliance note. The WFD assessment follows key guidance provided by the Environment Agency and UKTAG, including the ‘Clearing the Waters for All’ guidance (2017) and Advice Note 18: The Water Framework Directive (The Planning Inspectorate, 2017). A sequence for undertaking an
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assessment of the compliance under the WFD has been developed in line with the guidance. Taking this into account this compliance note includes the following:
Identification of baseline conditions of the biological, physico-chemical and hydromorphological quality elements;
Identification of potential impacts from the Proposed Scheme on quality elements;
Assessment of the Proposed Scheme against WFD status objectives, other EU legislation and overall compliance.
K.5 Water Framework Directive Compliance
The study area lies within the Southampton Water transitional (estuarine) WFD water body, which is currently achieving Moderate Status (Environment Agency, 2018)1.
Table K.1 provides an overview of the existing waterbody characteristics within the study area. An assessment of the potential impacts of the additional discharge from the Proposed Scheme at Redbridge Roundabout is then made against each quality element parameter with supporting information provided in subsequent sections.
Table K.1: Overview of Southampton
Quality Element Baseline Impact Assessment Biological quality elements Overall – Moderate Overall impact – No Objective – Good by 2027 significant impact at a WFD water body scale Composition and abundance Good status. No species Works will not impact aquatic of aquatic flora details given in the WFD flora at local or water body information provided for Cycle scale. 2 (2016). Composition and abundance Good status No significant change in of benthic invertebrate fauna hydrological regimes or water quality expected as part of the works, so no impact on benthic invertebrate community is expected. Composition, abundance and Good status No significant change in age of structure of fish fauna hydrological regimes or water quality expected as part of the works, so no impact on fish habitat or passage is expected. Physico-chemical quality Overall - Good Overall impact – No elements Chemical status - Good significant impact at a WFD water body scale Thermal conditions No data Works unlikely to lead to any significant changes on a local or WFD water body scale. Oxygenation conditions Dissolved oxygen – High No significant change in status hydrological regimes or water quality expected as part of the
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Quality Element Baseline Impact Assessment Salinity No data – located within tidal works and therefore unlikely extent to lead to any significant impacts on the WFD water Acidification status No data body. Nutrient conditions Phosphate – No data Works unlikely to lead to any Ammonia – Moderate significant changes on a WFD water body scale. Hydromorphological quality Support Good Overall impact – No elements significant impact at a WFD water body scale Quantity and dynamics of Hydrological regime – No significant change in water flow supports good. hydrological regimes or water quality expected as part of the works and therefore unlikely to lead to any significant impacts on the WFD water body. Connection to groundwater Proposed construction works Works are unlikely to lead to bodies are over 200m to the east and any indirect changes. do not include waterbody modifications. River continuity Hydromorphological Proposed construction works designation is HMWB are over 200m to the east and do not include waterbody modifications. Works are unlikely to lead to any indirect changes on a WFD water body scale. River depth and width Hydromorphological Proposed construction works variation designation is HMWB are over 200m to the east and do not include waterbody modifications. Works are unlikely to lead to any indirect changes on a WFD water body scale. Structure and substrate of the Hydromorphological Proposed construction works river bed designation is HMWB are over 200m to the east and do not include waterbody modifications. Works are unlikely to lead to any indirect changes on a WFD water body scale. Structure of the riparian zone Redbridge is predominantly Proposed construction works an urbanised area and the are over 200m to the east and waterbody designation is do not include bankside HMWB. modifications. Works are unlikely to lead to any indirect changes on a WFD water
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Quality Element Baseline Impact Assessment body scale. 1Derived from the water body spatial data worksheet available from: www.environment- agency.gov.uk [Accessed April 2018].
The Southampton Water transitional WFD water body is a Heavily Modified Water Body and has specific assigned mitigation measures to mitigate or remediate diffuse pollution impacts. The chemical status for Southampton Water is currently recorded as Fail with an objective status of Good in 2027 following mitigation measures assessment. The mitigation measures include riparian management strategies in the catchment to implement agricultural diffuse pollution measures.
The existing catchment area for surface water drainage local to Redbridge roundabout is estimated to be 1.73ha, of which 1.44ha are impermeable surfaces. Following the modifications in the Proposed Scheme, the surface water drainage area is predicted to increase to 1.77ha, of which 1.53ha are impermeable surfaces. As a result, the negligible increase in road runoff from the very small addition of paved impermeable surfaces is unlikely to affect dissolved organic nitrogen levels in the River Test, or include tributyltin; thereby not preventing the Southampton Water water body from achieving Good status.
An assessment of potential pollution impacts from spillages has also been undertaken for the Proposed Scheme taking account of annual average daily traffic use (AADT), road length and the percentage of heavy good vehicles transporting harmful loads (Appendix N) The results of the spillage assessment confirm that the annual probability of a serious pollution event occurring is 0.07%. According to DMRB guidelines (Volume 11, Section 3, Part 10, 45/09 Annex I), the acceptable risk of a serious pollution event occurring is when the annual probability is predicted to be less than 1%.
The WFD water body is protected by the Shellfish Water Directive and Nitrates Directive. The following sections provide an overview of the potential impacts on these EU directives:
Nitrates Directive – the study area is not located within a Surface Water or Groundwater Nitrate Vulnerable Zone, but is located within a Eutrophic Waters Nitrate Vulnerable Zone (based on 2017 data). Since the Proposed Scheme is predicted to reduce peak discharges to the Millbrook Pipe and outfall after flow control attenuation (Surface Water Drainage Strategy Report (Jacobs, 2017b)), it is not expected that the new road layout would contribute substantial additional flow and associated pollutants to the River Test. As a result, the proposals are considered compliant with the legislation.
Shellfish Water Directive – the study area is located within an area designated for the protection of shellfish growth and production and subsumed into the WFD in order to reduce pollution and improve water quality. Due to the anticipated negligible increase in surface water run off generated by the Proposed Scheme, in combination with dilution effects from the Southampton Water waterbody and more significant industrial and port pollution sources, it is unlikely that the additional Redbridge roundabout run off would be detected above baseline. As a result, the proposals are considered compliant with the legislation. This WFD Compliance Note has provided an overview (screening) of the potential impacts of the proposed scheme on the WFD water bodies within the study area. Highways England Water Risk Assessment Tool (HEWRAT) is not directly applicable to estuaries. Table K.2 provides an overview of the compliance of the Proposed Scheme against the WFD objectives detailed in Section K.1. The proposals are considered to be complaint with the legislation and would not cause a deterioration nor prevent the WFD water body from achieving Good in the future.
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Table K.2: Overall Water Framework Directive compliance
WFD objective Scheme compliance Deterioration in the The assessment has concluded that the proposed works status/potential of the water would not lead to a deterioration in the specific quality body elements or the overall WFD water body status. Ability of the water body to The scheme would be unlikely to affect the ability of the achieve Good Status/Potential WFD water body to achieve Good Status. Impact on the WFD objectives of Additional WFD water bodies have not been considered in other water bodies within the the assessment as there is no apparent hydrological link same River Basin District with the Proposed Scheme; other waterbodies would be unlikely to be negatively impacted by the proposals. Impact on implementation of the The scheme would be unlikely to affect the implementation WFD mitigation measures and of the catchment WFD mitigation measures and would not other EU legislation affect any other EU legislation.
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Appendix L. Flood Risk Assessment
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Appendix M. Method C Assessment of Pollution Impacts from Routine on Ground Waters
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Appendix N. Method D Assessment of Pollution Impacts from Spillages
N.1 Groundwater
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N.2 Surface Water
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