Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Smart Motorways Programme Environmental Assessment Report Appendix 5.1 to 5.7 – Air Quality
Tranche 5 – A1(M) J6 to 8 (Preliminary Design – PCF Stage 3)
HE551539-WSP-EGN-SG-RP-LE-00016
May 2019
Notice
This document and its contents have been prepared and are intended solely for Highways England’s information and use in relation to the Smart Motorways Programme.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Revision history
Job number: 551539 Document ref: HE551539-WSP-EGN-SG-RP-LE-00016 Revision Purpose description Originated Checked Reviewed Approved Date P01 S3 – Draft for review Sioni Hole Bethan David Hoare Jonty Parry 01/03/19 and comment Tuckett Jones P02 S4 – Suitable for stage Sioni Hole Bethan David Hoare Jonty Parry 12/04/19 approval Tuckett Jones
Client signoff
Client Highways England Project SMP Tranche 5 – A1(M) Junctions 6 to 8 Document title Appendix 5.1 to 5.7 – Air Quality Job no. 551539 Document HE551539-WSP-EGN-SG-RP-LE-00016 reference
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table of Contents
5. Appendix 5.1 to 5.7 – Air Quality 1 5.1 Air Quality Assessment Strategy and Methodology Papers 1 5.2 Regulatory / Policy Framework 4 5.3 Baseline, Opportunities and Constraints 14 5.4 Traffic Data and Other Inputs 23 5.5 Model Verification 24 5.6 Assessment of Impact 31 5.7 Compliance Risk Assessment 48
List of Tables
Table 5.1.1 - Ecological Receptors included in the Air Quality Model ...... 2 3 Table 5.1.2 - Comparison of Annual Mean NO2 Concentrations (µg/m ) from Defra Background Mapping and Background Sites ...... 3 Table 5.2.1 - Relevant Air Quality Criteria 3 ...... 5 Table 4.3.2 - Summary of Roadside Annual Mean NO2 Trend Analysis ...... 14 3 Table 5.3.3 - Annual Mean NO2 Diffusion Tube Monitoring Results (µg/m ) within A1(M) junctions 6 - 8 Geographical Study Area 5 ...... 18 Table 5.3.4 - Highways England Diffusion Tube Monitoring Data (2013 - 2014) 6 ...... 20 Table 5.3.5 - Critical loads for Nutrient Nitrogen and Background Nitrogen Deposition7 ...... 22 Table 5.5.1 - Diffusion Tube Sites Excluded From Model Verification 8 ...... 24 Table 5.5.2 - Diffusion Tube Locations Used in Model Verification 9 ...... 24 Table 5.5.3 - Comparison of verified Modelled and Measured NO2 Concentrations 10 ...... 26 Table 5.5.4 - RMSE and Fractional Bias values for unadjusted modelled estimates of NO2 compared to monitored concentrations 11 ...... 28 Table 5.5.5 - Comparison of Modelled and Measured NOx Concentrations 12 ...... 28 Table 5.5.6 - Model Adjustment Factors Applied in each Model Adjustment Area 13 ...... 30 Table 5.5.7 - RMSE and Fractional Bias values for adjusted modelled estimates of NO2 compared to monitored concentrations 14 ...... 30 Table 5.6.1 - Annual Mean NO2 Results for Discrete Human Health Receptors within Proposed Scheme’s Geographical Study Area 15 ...... 31 3 Table 5.6.2 - Annual Mean NOx Results (µg/m ) for Ecological Receptors within the Proposed Scheme’s Geographical Study Area 16 ...... 34 Table 5.6.3 - Nitrogen Deposition Results (kgN/ha/yr) for Ecological Receptors within the A1(M) J6-8 Geographical Study Area 17 ...... 40 Table 5.6.4 - Regional Emissions Results – ‘Cumulative Worst Case’ Scenario 18 ...... 47 Table 5.7.1 - Compliance risk assessment results table – ‘cumulative worst case’ Scenario 19 ...... 48
Supporting Figures
Figure 5.1.1 - Wind Rose Diagram for Luton Airport Metrological Station, 2017...... 2 Figure 5.3.1 - Sandy Roadside Mann-Kendall and Sen Estimate of Annual Mean NO2 Trend 2 ...... 15 Figure 5.3.2 - Cambridge Roadside Mann-Kendall and Sen Estimate of Annual Mean NO2 Trend ...... 16 Figure 5.3.3 - Annual Mean NO2 Future Year Concentration Projections 4 ...... 17
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 5. Appendix 5.1 to 5.7 – Air Quality 5.1 Air Quality Assessment Strategy and Methodology Papers
The full methodology for the Air Quality assessment was agreed with Highways England the Air Quality Assessment Strategy and Methodology Papers (Document references: HE551539-WSP-GEN-SG-RP-ZM-0012 and HE551539-WSP-GEN-SG-RP-ZM-0013). Model Setup - Emission Rates The emission rates used in the local air quality modelling were derived from Interim Advice Note (IAN) 185/15 on speed banding. In accordance with IAN 185/15 the traffic modellers undertook speed pivoting where required including: • Analysis of the performance of modelled traffic speeds on individual road links compared against observed speeds on the same road links; • Adjustment, where required, of modelled traffic speeds on individual road links to better reflect observed speeds; this is known as the “Speed Pivoting” approach; • Assignment of individual road links into a speed-banding category by road type; and • Adjustment, where required, of assigned speed band where changes in speed did not justify a change in speed band (speed change less than 5 kph) or where a speed band change was considered by the traffic modellers to not reflect a valid Proposed Scheme impact. The emission rates for each hour were calculated as follows: • Step 1 – Weekday morning peak (AM), inter peak(IP), evening peak (PM), off peak (OP) hourly flows (in terms of light duty vehicles (LDV) and heavy duty vehicles (HDV)) for each road link were obtained from the traffic model and a speed band assigned to each road link for each period. • Step 2 – The traffic modellers were consulted to confirm which hours the relevant traffic model periods apply to. These were confirmed as: – AM: 07:00 – 10:00 (3 hours); – IP: 10:00 – 16:00 (6 hours); – PM: 16:00 – 19:00 (3 hours); and – OP: 19:00 – 07:00 (12 hours). • Step 3 – Emission rates for each time period were calculated using the using the flow, %HDV speed and road type using the “IAN 185-13 Speed Band Emission Factors v2” spreadsheet tool. • Step 4 – Emissions for each time period were input into the ADMS-Roads model and a “fac” file used to specify which hourly emission rate is used over each hour of the day. Model Setup – Dispersion Hourly sequential meteorological data for 2017 for Luton Airport Meteorological Station were used. The parameters required by the model included: date, time, wind direction (angle wind blowing from), wind speed (at 10m above ground level), surface air temperature (degrees Celsius), and cloud cover (oktas – or eighths of sky covered). The wind rose from Luton Airport metrological station (presented below in Figure 5.1.1) indicates that the dominant wind direction for 2016 was from the south-west.
Environmental Assessment Report 1
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Figure 5.1.1 - Wind Rose Diagram for Luton Airport Metrological Station, 2017.
The meteorological station is situated 15km to the west of the Proposed Scheme, with no significant topographic variation to the modelled region, and is therefore considered to be a good representation. Model Setup – Receptors Table 5.1.1 presents the ecological receptor locations within the Proposed Scheme’s geographical study area included in the air quality model. The locations of human health and ecological receptors are shown in Figure 5.2 Chapter 5: Air Quality. Table 5.1.1 - Ecological Receptors included in the Air Quality Model
ID Distance to Name X Y Local road (m) Authority KW101-121 0 Knebworth Wood SSSI 523157 223173 Stevenage KW201-121 0 523228 223085 Stevenage KW301-121 0 523297 222984 Stevenage KW401-121 0 523343 222893 Stevenage SW101-121 0 Sherrardspark Wood 522463 214222 St Albans SW201-121 0 SSSI 522435 214149 St Albans SW301-121 0 522371 213995 St Albans SW401-121 0 522340 213893 St Albans Background Concentrations
Estimated annual mean background NO2 concentrations for 2017 (the air quality assessment base year) were obtained from the background mapping provided on the Defra UK-AIR website. In 2017, there were no background continuous monitoring station (CMS) sites located in the Proposed Scheme’s geographical study area, with the nearest site situated at Wicken Fen, approximately 50km to the north east of the Propose Scheme, and approximately 45km away from the study area.
Environmental Assessment Report 2
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
In lieu of local continuous analyser monitoring data within the assessment area, background concentrations from available diffusion tube monitoring have been compared to the equivalent Defra background concentrations, Table 5.1.2 presents the results of this comparison. Of the background sites considered, only one site (S12) sits within the ARN, although all are within 5km.
3 Table 5.1.2 - Comparison of Annual Mean NO2 Concentrations (µg/m ) from Defra Background Mapping and Background Sites
Local Site X,Y Grid 2017 2017 %Difference Authority Classification Square Defra Monitored (grid square (ID) (Type) X,Y Back- Back- NO2 – ground ground monitored NO2) / monitored NO2*100) Stevenage Urban 525373 525500 10.8 14.5 -34% (S5) Background 226985 226500 (Diffusion Tube) Stevenage Suburban 522955 522500 11.2 16.6 -48% (S12) Background 223335 223500 (Diffusion Tube) Stevenage Urban 525425 525500 17.5 15.3 14% (S18) Background 224183 224500 (Diffusion Tube) Welwyn Background 526249 526500 11.5 18 -56% Hatfield (Diffusion 211617 211500 (WH11) Tube) Welwyn Background 525852 525500 13.1 17 -30% Hatfield (Diffusion 211187 211500 (WH12) Tube) Welwyn Urban 527150 527500 11.1 17 -53% Hatfield Background 212966 212500 (WH13) (Diffusion Tube) The table above shows that monitored background concentrations are in general greater than the closest Defra modelled background equivalent, although there is some spread in the magnitude of the difference (between 30-56%). Due to the lack of availability of verified continuous analyser data, as well as the limited coverage of the available background diffusion tube monitoring sites, no adjustment has been applied to the Defra background concentrations before use within this assessment. This will ensure a conservative assessment of the verified Proposed Scheme impacts.
Environmental Assessment Report 3
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
5.2 Regulatory / Policy Framework Air Pollutants
Vehicle exhausts contain a number of pollutants including oxides of nitrogen (NOx), carbon monoxide (CO), hydrocarbons, carbon dioxide (CO2) and particles. The quantities of each pollutant emitted depend on the type and quantity of fuel used, engine size, speed of vehicle and abatement equipment fitted. Once emitted, the pollutants disperse and subsequently are diluted in the ambient air. Pollutant concentrations in the air can be measured or modelled and then compared with the ambient air quality criteria (discussed below). The local air quality assessment has focused on the impacts of the air pollutant nitrogen dioxide (NO2) as the air quality criteria for this pollutant is likely to be most difficult to achieve in the vicinity of roads (see Environmental Scoping Report). The regional assessment of emissions considers NOx, carbon dioxide (CO2) and particulate matter (PM10). Nitrogen Dioxide
Nitrogen dioxide (NO2) is a secondary pollutant produced by the oxidation of nitric oxide (NO). NO and NO2 are collectively termed nitrogen oxides (NOx). Almost a third of the 1 UK NOx emissions are from road transport . The majority of NOx emitted from vehicles is in the form of NO, which oxidises rapidly in the presence of ozone (O3) to form NO2. In high concentrations, NO2 can affect the respiratory system and can also enhance the response to allergens in sensitive individuals, whereas NO does not have any observable effect on human health at the range of concentrations found in ambient air. Carbon Dioxide
Carbon dioxide (CO2) is a greenhouse gas and is used as an indicator of the wider scale, non-local effects of transport schemes. CO2 does not affect human health at ambient levels and so is not significant as a local air quality pollutant but is important for its national and international role in climate change. Particulates
PM10 particles are fine particles with an aerodynamic diameter of less than 10 µm. PM10 is composed of a wide range of materials and are formed from combustion (for example, road traffic) and from chemical reactions in the atmosphere. Fine particulates can have adverse health effects when inhaled. Air Quality Regulations There are two types of air quality regulations that apply in England: • Regulations implementing mandatory European Union Directive limit values: The Air Quality Standards Regulations 2010 (SI 2010/64)2; and • Regulations implementing national air quality objectives: Air Quality (England) Regulations 2000 (SI 2000/928) 3 and Air Quality (England) (Amendment) Regulations 2002 (SI 2002/3043)4.
1 NAEI (2015). Pollutant Information: Nitrogen oxides (NOx expressed as NO2). Retrieved from National Atmospheric Emissions Inventory: http://naei.defra.gov.uk/overview/pollutants?pollutant_id=PMFINE 2 The Air Quality Standards Regulations 2010: http://www.legislation.gov.uk/uksi/2010/1001/contents/made 3 The Air Quality (England) Regulations 2000: http://www.legislation.gov.uk/uksi/2000/928/contents/made 4 The Air Quality (England) (Amendment) Regulations 2002: http://www.legislation.gov.uk/uksi/2002/3043/contents/made Environmental Assessment Report 4
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
In 2008, the European Commission adopted Directive 2008/50/EC on ambient air quality and cleaner air for Europe5. This directive merged the Air Quality Framework Directive (96/62/EC) and three of the four pollutant specific daughter directives, and introduced new objectives for PM2.5. The relevant EU Limit Values in the context of this assessment for the protection of human health are presented in Table 5.2.1. The Air Quality Strategy for England, Scotland, Wales and Northern Ireland (AQS)6 provides details of national air quality standards and objectives for a number of local air pollutants, including NO2. The standards are set by expert organisations with regard to scientific and medical evidence on the effects of the particular pollutant on health, and the standards define the level of pollution below which health effects are expected to be protective of the most sensitive members of the population. The objectives are targets for air pollution levels to be achieved by a specified timescale, which take account of the costs and benefits of achieving the standard, either without exception or with a permitted number of exceedances. Local authorities are not legally obliged to achieve the UK AQS objectives. They do, however, have a responsibility (under the Environment Act 1995)7 to review and assess local pollution levels against these objectives and are required to work towards the objectives by drawing up action plans setting out the measures they intend to take in pursuit of them. These standards and objectives are defined in Regulations SI 2000/928 and SI 2002/3043. It should be noted that the AQS air quality criteria only apply in locations where there may be ‘relevant exposure’. These human health objectives are applicable where members of the public may be exposed to pollutant concentrations for periods equal to or exceeding the averaging periods set for these criteria. Locations of relevant exposure include building façades of residential premises, schools, public buildings and medical facilities. Places of work, other than certain community facilities, are excluded. Table 5.2.1 - Relevant Air Quality Criteria 3
Pollutant Criteria Hourly average concentration should not exceed 200 µg/m3 more than NO2 18 times a year. Annual mean concentration should not exceed 40 µg/m3.
NOx Annual mean concentration should not exceed 30 µg/m3. (vegetation)
Ecological Criteria The EU has set limit values for the protection of vegetation for oxides of nitrogen based on the work of the United Nations Economic Commission for Europe (UNECE) and World Health Organisation (WHO) and these limit values have been incorporated into The Air Quality Standards Regulations 2010 (SI 2010/1001).
5 http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2008:152:0001:0044:EN:PDF 6 Defra (2007). The Air Quality Strategy for England, Scotland, Wales and Northern Ireland. Retrieved from: https://www.gov.uk/government/publications/the-air-quality-strategy-for-england-scotland-wales-and-northern-ireland-volume-2 7 Environment Act 1995: http://www.legislation.gov.uk/ukpga/1995/25/contents Environmental Assessment Report 5
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
The limit value for oxides of nitrogen for the protection of vegetation is an annual mean of 30 μg/m3.This is the same as the AQS objective. The limit values for the protection of vegetation apply to locations more than 20 km from towns with more than 250,000 inhabitants or more than 5 km from other built-up areas, industrial installations or motorways. This objective does not apply in those areas where assessment of compliance with the limit value is not required. However, as the UNECE and the WHO has set a critical level for NOx for the protection of vegetation, the policy of the statutory nature conservation agency (in England, Natural England) is to apply the criterion as a benchmark, on a precautionary basis, in internationally designated conservation sites (Ramsar, Special Area of Conservation (SAC), Special Protection Area (SPA) and Sites of Special Scientific Interest (SSSIs)). In addition, critical loads for nitrogen and acid deposition have been set by the UNECE, that represent (according to current knowledge) the exposure below which there should be no significant harmful effects on sensitive elements of the ecosystem. The critical loads vary by type of ecosystem, and are available from the Air Pollution Information System (APIS) website8. National Planning Policy National Planning Policy Framework (NPPF) The National Planning Policy Framework (NPPF) sets out the Government’s requirements of the planning system. The NPPF requires local planning authorities (LPAs) to take account of air quality in plan making, stating at paragraph 124: “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.” National Policy Statement for National Networks (NPS NN) The National Policy Statement for National Networks (NPS NN), prepared by the Department for Transport (DfT)9, provides policy and guidance relating to the development of nationally significant infrastructure projects. NPS NN requires a judgement to be made as to the risk of a project affecting the UK’s ability to comply with the Air Quality Directive (paragraph 5.9 of the NPS NN). Paragraph 5.11 of the NPS NN states “Air quality considerations are likely to be particularly relevant where schemes are proposed: within or adjacent to Air Quality Management Areas (AQMAs); roads identified as being above Limit Values or nature conservation sites; and where changes are sufficient to bring about the need for a new AQMA 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.” Furthermore, paragraph 5.13 of the NPS NN, states “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 with the most recent timescales reported to the European Commission at the time of the decision.”
8 http://www.apis.ac.uk/ 9 Department for Transport, National Policy Statement for National Networks, December 2014 Environmental Assessment Report 6
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Road Investment Strategy (RIS) and Strategic Business Plan (SBP) The DfT Road Investment Strategy (RIS) published in 201510 sets out the DfT’s aspirations for the Strategic Road Network over the next 25 years. It states that by 2040 DfT aspires to a network that will be sustainable with ‘zero breaches of air quality regulations and major reductions in carbon emissions across the network’. Highways England Delivery Plan 2015-2020 The Highways England Delivery Plan 2015-202011 identifies Highways England’s commitment to investing £75 million ‘in a range of projects to reduce pollution and ensure the air around the network is clean and healthy’. Key Performance Indicators (KPIs) and Performance Indicators (PI) are also identified including the following PI performance specification in relation to air quality ‘Suite of PIs to provide additional information about environmental performance. These should, at a minimum, include: - Air Quality’. The Delivery Plan includes a commitment to develop a PI for vehicle derived emissions of carbon dioxide, and other greenhouse gases arising from the use of the Strategic Road Network by March 2016. When Highways England plans works to improve the network, an assessment of the potential for environmental effects of the scheme is undertaken, including consideration of air quality. To ensure consistency and robustness in all air quality assessments, an agreed methodology is set out in Design Manual for Roads and Bridges (DMRB), supplemented by Interim Advice Notes (IANs) where necessary. Highways England Air Quality Strategy The Highways England Air Quality Strategy, published in August 201712 sets out Highway’s England’s approach to improving air quality, utilising a committed fund from the UK Government of £100 million. The focus of the strategy is on exploring innovative ways to improve air quality on and around its network. As part of the strategy Highways England has identified fours priority action areas; policy, planning, monitoring and operational management, and has committed to “where appropriate, design out or mitigate poor air quality for our schemes”. These activities will draw on its expertise and knowledge to explore innovative ways to improve air quality around its network and beyond. Through this work it will deliver a cleaner network and improve the health of its neighbours and customers. Local Planning Policy Stevenage Borough Council (SBC) The Stevenage District Plan, Second Review The Stevenage District Plan13 is a statutory document used by Stevenage Borough Council in planning applications. Within the document, Appendix F refers to sustainability issues which should be considered when planning development. Appendix F - Sustainability Checklist states: "5. Air, Water, Noise, Light - Reduce air pollution and dust both in construction and operation (e.g. low NOx boilers, reduction in traffic volumes, damping and wheel cleaning to avoid dust. […] provide information on pollution levels and sources to allow effective action to be taken (e.g. pollutant monitoring schemes)." Stevenage Borough Local Plan 2011-2031
10 Department for Transport, Road Investment Strategy: for the 2015/16 – 2019/20 Road Period, March 2015 11 Highways England, Highways England Delivery Plan 2015-2020, March 2015 12 https://www.gov.uk/government/publications/highways-england-air-quality-strategy 13 Stevenage Borough Council, The Stevenage District Plan Second Review (2004), available at: http://www.stevenage.gov.uk/content/15953/26379/26389/Adopted-Local-Plan-Composite-Version.pdf, accessed on: 13/09/2018. Environmental Assessment Report 7
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
The Stevenage Borough Local Plan14 is an emerging policy document whose draft was published on January 2016. This plan will guide the future development of Stevenage with a focus on regeneration and growth. It is currently awaiting public review and will replace the Stevenage District Plan once adopted. It states: "Air, light and noise pollution arising from new development can individually and cumulatively have a significantly damaging impact on the countryside, on peoples' living environment and on wildlife." Strategic policies SP1: Presumption in Favour of Sustainable Development and SP2: Sustainable Development in Stevenage address many of the issues associated with sustainable development in Stevenage. SP1outlines preference for developments which are likely to improve social, environmental and economic conditions in the area. SP2 supports SP1 by outlining how the impact of development on climate change can be reduced. It specifies that proposals which demonstrate how they adhere to a list of favourable conditions such as: promoting greener travel; taking a proactive approach to energy usage and avoiding harm from pollution will be granted planning permission. Other policies within the document such as Policy FP6: Hazardous Installations state: "Planning permission for development proposals involving the use, storage or movement of hazardous substances will be granted where: […] b. there are no additional threats to the local environment, particularly air quality, water and wildlife;" Policy FP7: Pollution "All development proposals should minimise, and where possible, reduce air, light and noise pollution. Applications for development where pollution is suspected must contain sufficient information for the Council to make a full assessment of potential hazards and impacts." North Hertfordshire District Council Air Quality Action Plan for the Stevenage Road, Hitchin Air Quality Management Area and the Payne's Park, Hitchin Air Quality Management Area The North Hertfordshire District Council Air Quality Action Plan for the Stevenage Road, Hitchin Air Quality Management Area and the Payne's Park, Hitchin Air Quality Management Area15 was developed at part of the Council's statutory duties required by the Local Quality Management Framework. It outlines the action that will be taken to tackle air quality in North Hertfordshire between 2017 and 2021. Within the plan, the following areas have been prioritised for action: • Freight and delivery management; • Promoting low emission transport; • Vehicle fleet efficiency; • Alternatives to private vehicle use; • Promoting travel alternatives; • Public information; and • Transport planning and infrastructure; • Policy guidance and development • Traffic management; control. North Hertfordshire District Local Plan No.2 with Alterations North Hertfordshire District Council is currently in the process of replacing its existing Local Plan. Relevant saved policies from the 1996 North Hertfordshire District Local Plan16 include:
14 Stevenage Borough Council, Local Plan 2011-2031, Publication draft (2016), available at: http://www.stevenage.gov.uk/content/15953/26379/90035/Draft-Local-Plan-Jan2016-Consultation.pdf, accessed on: 13/09/2018. 15 North Hertfordshire District Council, Air Quality Action Plan for the Stevenage Road, Hitchin Air Quality Management Area and the Payne's Park, Hitchin Air Quality Management Area (2018), Available at: https://www.north-herts.gov.uk/home/environmental-health/pollution/air-quality/air-quality-management- areas, Accessed on: 20/11/2018. 16 Saved Policies Under Planning and Compulsory Purchase Act (2004), Available at: https://www.north-herts.gov.uk/sites/northherts- cms/files/written_statement_sep_2007.pdf, Accessed on: 13/09/2018. Environmental Assessment Report 8
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
"1.13 New assumptions for making population and housing projections have been published, and guidance on the dwelling provision for each County has been agreed by SERPLAN and the Secretary of State. A new strategy is currently (1990) being developed by SERPLAN with the following main themes: conservation of the environment and enhancement of the quality of life; maintenance of economic buoyancy; important roles of London; changes in the way the region is evolving; importance of harmonising land use planning with other policies (transport, housing, agriculture and pollution control); and relationships between the SE Region and adjacent regions, in the UK and Europe." North Hertfordshire District Council Local Plan 2011 - 2031 North Hertfordshire District Council's Local Plan17 is currently in a proposed submission and will replace the current Local Plan once adopted. The document will set targets for development and employment as well as outline policies affecting decisions on planning applications. The Local Plan stresses a need for protecting the local environment stating that there is potential from all development to cause adverse impacts on nearby residents. Policy D3: Protecting Living Conditions states that development proposals which do not cause unacceptable harm to living conditions will be granted planning permission. Supporting this, Policy D4: Air Quality states that: "Planning permission will be granted where development proposals: • Give consideration to the potential or actual impact on local air quality, both during the demolition/ construction phase and as a result of its final occupation and use; • Propose appropriate levels of mitigation to minimise emissions to the atmosphere and their potential effects upon health and the local environment; and • Carry out air pollution impact assessments, where required, to determine the impact on local air quality of the development, otherwise the development may be refused. Where air pollution impact assessments are not required there will still be a requirement on developers to provide appropriate levels of mitigation to address emissions of pollutants to the atmosphere." Further supporting this, Policy NE5: New and Improved Public Open space and Biodiversity states that: "Planning permission will be granted for relevant development proposals that: […] • Incorporate an open space buffer(s) where necessary for landscape, visual, ecological or air quality reasons;" Policy NE12: Renewable and Low Carbon Energy Development: "Proposals for renewable and low carbon energy development which would contribute towards reducing greenhouse gas emissions will be permitted subject to an assessment of the impacts upon:[…] v. Air quality;"
17 North Hertfordshire District Council Local Plan 2011 - 2031 (2016), Available at: https://www.north-herts.gov.uk/sites/northherts- cms/files/Proposed%20Submission%20Local%20Plan.pdf, Accessed on: 13/09/2018. Environmental Assessment Report 9
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Hertsmere Borough Council Hertsmere Borough Council Air Quality Action Plan Progress Report Hertsmere Borough Council's Air Quality Action Plan Progress Report18 is a follow up report to the 2003 Air Quality Action Plan. It was introduced following the designation of 14 AQMAs (Six as of 2018) along with 19 actions to reduce air pollution in the borough. These are: • To look in to the availability of health information (i.e. the exposure of sensitive groups to poor air quality); • To investigate how areas of high pollution or traffic issues can be tackled through local plans/ strategies; • To work with neighbouring authorities on traffic schemes that affect local AQMAs; • To support the larger National and south east scheme that result from the multi modal study that may improve air quality along the motorway network and promote alternative forms of transport; • To encourage major fleet operators in the borough to adopt cleaner vehicle technologies and fuels; • To support Hertfordshire County Council with its aim to encourage alternative modes of transport through various initiatives; • To support local green projects; • To consider air quality in all planning applications, particularly those within or near to any AQMAs; • To encourage developers to minimise increases in air pollution; • To promote the uptake of LPG or compressed natural gas in taxis; • To begin a campaign discouraging the excessive idling of vehicle engines; • Testing taxis to continue; • For the Environmental Health unit to continue having control over part B processes and industry; • To provide residents and companies with advice pertaining to bonfires; • To continue monitoring air quality to the existing quality standard and maintain the annual review of the diffusion tube networks; • To seek an improvement in the availability of cleaner fuels; and • The continual promotion of the Herts and Beds Air Alert Scheme. Hertsmere Local Plan Core Strategy Hertsmere Borough Council’s Core Strategy19 is a statutory document comprising part of the borough's Local Plan which sets out the Council's vision and strategy for Hertsmere until 2027. In regard to air quality, it states: "Although much of the local air pollution is caused by motorway traffic, which remains outside of the control of either Hertsmere or the County Council, air quality is a key consideration in considering planning applications and associated traffic volumes. Consequently, it is important that the Core Strategy seeks to direct new development, which generates large number of journeys, to the most accessible locations. Addressing poor air quality also requires new development to incorporate energy efficient building techniques, as well as promoting alternatives to the car, to reduce greenhouse gas emissions and reduce pollution levels."
18 Hertsmere Borough Council, Air Quality Action Plan Progress Report (2008). Available at https://www.hertsmere.gov.uk/Documents/04-Environment- Refuse--Recycling/Environmental-Health/Pollution-Control/Air-Quality-Action-Plan-Progress.pdf, Accessed on: 21/11/2018. 19 Hertsmere Borough Council, Hertsmere Local Plan Core Strategy (2013), Available at: https://www.hertsmere.gov.uk/Documents/09-Planning--Building- Control/Planning-Policy/Local-Development-Framework/Core-Strategy-DPD-2013.pdf, accessed on: 13/09/2018. Environmental Assessment Report 10
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Adding to that, Policy SP1: Creating Sustainable Development states: "All development across the Borough should: xvi) ensure that pollutants are minimised, including emissions to air, water, soil, light and noise;" Policy SP2: Presumption in Favour of Sustainable Development " When considering development proposals, the Council will take a positive approach that reflects the presumption in favour of sustainable development contained in the National Planning Policy Framework. It will always work proactively with applicants jointly, in particular through the preapplication process, to find solutions which mean that proposals can be approved wherever possible, and to secure development that improves the economic, social and environmental conditions in the area. Planning applications that accord with the policies in this Plan (and, where relevant, with policies in neighbourhood plans) will be approved without delay, unless material considerations indicate otherwise. Where there are no policies relevant to the application or relevant policies are out of date at the time of making the decision then the Council will grant permission unless material considerations indicate otherwise - taking into account whether: a) any adverse impacts of granting permission would significantly and demonstrably outweigh the benefits, when assessed against the policies in the National Planning Policy Framework taken as a whole; or b) specific policies in that Framework indicate that development should be restricted." Bedford Borough Council Air Quality and Air Quality Action Plan Progress Report Bedford Borough Council's Air Quality and Air Quality Action Plan20 was introduced following designation of the town centre as an AQMA due to borough wide exceedances of the annual mean objective for NO2. The plan put forward the following actions designed to tackle air pollution across the borough: • To maintain air quality monitoring throughout the borough and maintain the existing Town Centre AQMA;
• To continue NO2 monitoring in areas where exceedances are likely; • To expand an existing AQMA if required following completion of a local development; • To revise and put into action the AQAP; and • Prepare for the submission of the upcoming progress report. Bedford Borough Council Core Strategy & Rural Issues Plan Bedford Borough Council's Core Strategy & Rural Issues plan21 provides the foundation for Bedford's vision for local development in accordance with its Development Framework. Guidelines. These will provide the means of implementation for the spatial aspects of the community plan. Sustainable development is a considerable focus of the Local Plan with the impact of new developments with respect to the environment, air quality and pollution being of major importance. This is reiterated in the following policies: Policy CP21: Designing in Quality:
20 Bedford Borough Council, Air Quality and Air Quality Action Plan (2013), Available at: https://www.bedford.gov.uk/environment_and_planning/pollution/air_quality/air_quality_review_and_assess/idoc.ashx?docid=18978b0a-a95c-4fb8-8191- 61ec8bc6fd8c&version=-1, Accessed on: 13/09/2018. 21 https://www.bedford.gov.uk/environment_and_planning/planning_town_and_country/planning_policy__its_purpose/core_strategy__rural_issues.aspx, Accessed on 10/09/2018 Environmental Assessment Report 11
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
"All new development should: […] vii) address sustainable design principles including renewable energy resources, energy efficiency, recycling, and sustainable construction practices and • mitigate against the effects of any pollution including air quality, noise, water, light and land contamination; • improve the character and quality of the area" Policy CP26: Climate Change and Pollution "The council will require development to:[…] ii) Have regard to cumulative impacts of development proposals on air quality, in particular in relation to air quality management areas" St Albans City and District Council Air Quality Action Plan for St Albans City and District Council The St Albans City and District Council's Air Quality Action Plan22 was introduced to address monitored exceedances in the air quality objective for NO2. It proposes taking direct action on reducing road traffic pollution from the M25 as well as supporting national initiative to improve air quality and introduces schemes to reduce local air pollution. St Albans District Council Local Plan St Albans District Council published a Local Plan in 1994 which is in the process of being replaced by the new St Albans City & District Local Plan 2020-2036. The saved policies from the original Local Plan currently remain in effect. Policy 8: Design & Environment describes the increasing emphasis on energy conservation and the need for sustainable design to be incorporated into future development. St Albans City & District Council Local Plan Publication Draft St Albans City & District Council Local Plan 2020-203623 is currently undergoing consultation phase and is expected to come into effect in 2020. In regard to air quality, it states: "Planning for major development must include an assessment of air quality impacts from traffic (both from the development and on occupants of the development). Development design and the transport measures associated with the development must include proposals to limit and mitigate impacts. This is particularly the case if there is an effect on a designated Air Quality Management Area (AQMA)." St Albans Local Plan focuses on the need to improve air quality through managing transport impacts. This is to be a major consideration in development design across all districts. Policy L18 - Transport Strategy states: "The policies embedded throughout this Local Plan work in conjunction with HCC and HE led transport planning. Together, they will provide relevant sustainable transport infrastructure and approaches which promote sustainable modes and create a foundation for enabling significant changes in travel behaviour. They encourage and enable shorter journeys to be made by sustainable means, including by walking and cycling, given the wider community benefits of active travel. […] appropriate measures to better use existing roads, reduce congestion and pollution and to ensure the free flow of traffic will be supported. Particular consideration will be given to planning for:
22 St Albans City and District Council, Air Quality Action Plan (2003). Available at: https://www.stalbans.gov.uk/Images/air-qual-action_tcm15-2147.pdf, Accessed on: 21/11/2018. 23 St Albans City & District Council, St Albans City & District Council Local Plan 2020-2036 (2018), Available at: http://www.stalbans.gov.uk/planning/thelocalplan.aspx, accessed on: 10/09/2018. Environmental Assessment Report 12
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
•reductions in transport-related emissions and improvement to air quality. This should include measures to improve air quality along major roads, including enabling the removal of Air Quality Management Area (AQMA) designations" Welwyn Hatfield District Plan Welwyn Hatfield Borough Council's District Plan24 contains the local planning framework, policies and proposals, which will guide the development and use of land in the district and against which the Council considers planning applications. It states: "Clean air is a natural resource which is important to people's quality of life. Air pollution causes damage to health, but most significantly, greenhouse gas emissions cause climate change, with a threat to life at the global level. The main source of air pollution is transport, particularly cars, although some industrial processes are also responsible. Government policy recognises the important relationship between land use planning, transport and pollution control systems in tackling air quality. Policies aimed at reducing congestion and car usage will help to improve air quality; these are covered in the Movement chapter of the Plan. Powers to control major sources of air pollution rest with the Environment Agency and the Council has a duty to produce an air quality management strategy. These powers and duties must operate in conjunction with planning policies. The role of the Plan is to control the location and design of potentially polluting uses of land; the control of emissions is a matter for other agencies." Relating to this, Policy R18 - Air Quality states: "The Council will have regard to the potential effects of a development on local air quality when determining planning applications. Consideration will be given to both the operational characteristics of the development and to the traffic generated by it. Any development within areas designated as Air Quality Management Areas must have regard to guidelines for ensuring air quality is maintained at acceptable levels as set out in the Air Quality Strategy."
24 Welwyn Hatfield Borough Council, Welwyn Hatfield District Plan (2005), Available at: http://www.welhat.gov.uk/developmentplan, accessed on:11/09/2018. Environmental Assessment Report 13
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
5.3 Baseline, Opportunities and Constraints Air Quality Monitoring Continuous Monitoring The Proposed Scheme’s geographical study area contains one air quality CMS site. Data for this CMS site is presented in Table B-2 for the period 2012-2017 (the latest available year). Where relevant, these CMS data have been used in trend analysis and / or comparison with mapped background concentrations.
3 Table 5.3.1 - Annual Mean NO2 Monitoring Data (µg/m ) from Continuous Monitoring Stations
Local Local Distance Site X, Y 2013 2014 2015 2016 Authority Authority from Type ID ARN (m) Stevenage SE16 3 Kerbsid 523581 ND ND 25.9 26.3 e 223936 ND = data not available / monitoring not undertaken;
Exceedances of annual mean NO2 UK AQS objective are highlighted in bold. Trend Analysis
Analysis of trends in annual mean NO2 has been undertaken using the Finnish Meteorological Institute MAKESENS (v1) spreadsheet using the annual mean time series data for the roadside CMS site described in Table 5.3.2. The statistical analysis undertaken includes a Sen’s slope25 estimate of the linear trend, residual concentrations26 which indicate the variation year on year and the Mann-Kendall test statistic (S) to indicate the significance of any trend. In order to conduct a Mann- Kendall test, five or more series of data must be presented for each site. The Mann- Kendall test statistic is expressed as a whole number. For the null hypothesis of a random distribution of the data to be rejected S27 has to be equal to or greater than an absolute value determined from the number of data points (equivalent to a probability of less than 0.1 or 10%). Table 5.3.2 summarises the results of the statistical analysis for each roadside CMS site, which indicates that there have been statistically significant downward trends in annual mean NO2 concentrations at: • Sandy Roadside (a roadside site on the A1 approximately 24km north of the Proposed Scheme); and • Cambridge Roadside (an urban site approximately 35km east of the Proposed Scheme).
Table 4.3.2 - Summary of Roadside Annual Mean NO2 Trend Analysis
Site ID Site Number Required S Sen’s Significant Within Type of Data S Value Value Slope 200m Points of ARN links? Sandy Roadside 9 14 -18 -1.21 Yes No Cambridge Urban 9 14 -32 -1.42 Yes No
25 The “Sen Slope” refers to the equation of the linear trend line and gives the rate of change per year. 26 The difference in the actual monitored concentration compared to the concentration indicated by the trend line. 27 Nielsen, D. M. (Ed.). (2005). Practical handbook of environmental site characterization and ground-water monitoring. CRC press. Environmental Assessment Report 14
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Figure 5.3.1 and Table 5.3.3 show the trends in annual mean NO2 from measured data at each of the CMS sites. The vertical axis indicates concentration in µg/m3. Confidence intervals for data are only plotted where there are 10 or more data points. The linear trend is shown as a solid black line and residual concentrations are shown as a solid light blue line.
Figure 5.3.1 - Sandy Roadside Mann-Kendall and Sen Estimate of Annual Mean NO2 Trend 2
As shown in Figure 5.3.1 above, the Sandy Roadside CMS site has nine data points, spanning 2009-17. The Sen’s slope estimate, illustrated by the solid black line in Figure 5.3.1 above, is - 1.21, which suggests that there was a general decrease in NO2 concentration of 1.21 µg/m3 per year over the nine-year period between 2009 and 2017 at this site. However, the annual mean concentration for 2009 appears spurious in the context of the other monitored concentrations. The plot of residual concentrations (i.e. deviation from the Sen’s estimate each year) shows that there was variation year on year, with the largest coming in 2009 (7.3µg/m3). The 2009 result has therefore been omitted from consideration for the regression analysis. With the 2009 data removed, the magnitude of the Sen’s slope estimate is reduced to - 0.57 (i.e. a decrease of 0.57µg/m3 per year) and the largest remaining residual is - 2.9µg/m3 in 2014. The Mann-Kendal test statistic (S) is expressed as a whole number, and for the site is - 10. For the null hypothesis of a random distribution of the data to be rejected, where the number of data points is eight, the value of S would have to be equal to or greater than an absolute value of twelve (equivalent to a probability of less than 0.1 or 10%). For eight data points, only absolute S values of twelve or more give a reasonably robust indication of a significant monotonic trend, with the sign of the S value indicating the direction of the trend (decreasing). Consequently, there is insufficient evidence to suggest a statistically significant decreasing monotonic trend at the Sandy Roadside site.
Environmental Assessment Report 15
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Figure 5.3.2 - Cambridge Roadside Mann-Kendall and Sen Estimate of Annual Mean NO2 Trend
The Cambridge site has nine data points. The Sen’s slope estimate, illustrated by the solid black line in Figure 5.3.2 above, is -1.42, which suggests that there was a general 3 decrease in NO2 concentration by 1.42 µg/m each year over the nine-year period between 2009 and 2017 at this site. The plot of residual concentrations shows that there was little variation year on year. The Mann-Kendal test statistic (S) is expressed as a whole number, and for the RTA1 site is -32. For the null hypothesis of a random distribution of the data to be rejected, where the number of data points is nine, the value of S would have to be equal to or greater than an absolute value of fourteen (equivalent to a probability of less than 0.1 or 10%). For nine data points, only absolute S values of fourteen or more give a reasonably robust indication of a significant monotonic trend, with the sign of the S value indicating the direction of the trend (decreasing). Consequently, there is evidence of a statistically significant decreasing monotonic trend at the Cambridge site. Future Projections of Nitrogen Dioxide
In 2012, Defra published a report on Long Term NOx and NO2 Trends and an advice note 28 on projecting NO2 concentrations in 2012 . The consequence of the conclusions of Defra’s advice note on long term NO2 trends was that there is a gap between projected vehicle emission reductions and projections of the annual rate of improvements in ambient air quality in Defra’s previously published technical guidance compared to observed trends from monitoring data. The result being that projections in concentrations of NO2 were considered to be overly optimistic in some cases, in particular up to the year 2017. Defra updated their projections in 2014 but a gap still exists between projections and observed trends. A comparison of the different projections has been undertaken for the Cambridge CMS site up to and beyond the Proposed Scheme opening year (2022). The Cambridge CMS is the only monitoring site showing a statistical significant trend in the MAKESENS analysis. As a result, this site is considered the most suitable for assessing the appropriateness of future year NO2 projections for the purposes of this assessment, which is primarily focussed on assessing changes in air quality at sensitive receptors adjacent to motorways. The following projection methods have been compared:
28 http://uk-air.defra.gov.uk/assets/documents/reports/cat05/1108251149_110718_AQ0724_Final_report.pdf Environmental Assessment Report 16
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
• The trend determined from the MAKESENS analysis reported above; 29 • The trend assumed in IAN 170/12v3 on future NOx and NO2 projections ; • The trend assumed in Highways England Interim Alternative Long Term Annual Projection Factors (IAN 170/12 LTTE6) for Annual Mean NO2 and NOx concentrations30; and The analysis shows that the alternative Defra projections from 2012 and IAN 170/12 v3 projections are similar and give the most conservative projections of annual mean NO2. The trend assumed in IAN 170/12v3, are the most conservative and the IAN 170/12 LTTE6 projection is less conservative. For the Cambridge site, the projection from the MAKESENS analysis of the monitoring data is the most optimistic of the projections considered. In the expected opening year (2022) the MAKESENS projection most closely matches the LTTE6.
For the purposes of this assessment, the IAN 170/12 LTTE6 projections have been used, which, based on the measured trend at the Sandy Roadside CMS is likely to provide a good assessment of future year NO2 concentrations at roadside locations adjacent to motorways.
Figure 5.3.3 - Annual Mean NO2 Future Year Concentration Projections 4
Passive Monitoring
Local Authority NO2 Diffusion Tube Data
Annual mean NO2 concentrations measured by Stevenage Borough Council, North Hertfordshire district Council, Hertsmere Borough Council, St Albans City and District Council and Welwyn Hatfield Borough Council at diffusion tube sites within the Proposed Scheme’s geographical study area are shown in Table 5.3.3 for the period 2013 - 2017.
29 http://www.standardsforhighways.co.uk/ha/standards/ians/pdfs/ian170.pdf 30 Highways Agency (2013) Note on HA’s Interim Alternative Long Term Annual Projection Factors (LTTE6) for Annual Mean NO2 and NOx Concentrations Between 2008 and 2030, Draft. Department for Transport Environmental Assessment Report 17
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
3 Table 5.3.3 - Annual Mean NO2 Diffusion Tube Monitoring Results (µg/m ) within A1(M) junctions 6 - 8 Geographical Study Area 5
Local Local Modelled Site Type X, Y 2013 2014 2015 2016 2017 Authority Authority ID ID Stevenage SE16 SV_SE16 Kerbside 523587 - - - 25.9 26.3 223964 3 SV_3 Urban 524637 32.2 22.0 21.0 22.1 22.5 Background 222710 7 SV_7 Roadside 523279 14.6 31.8 30.9 31.5 30.2 225479 10 SV_10 Urban 522014 27.6 26.6 26.5 26.5 27.2 Background 225586 11 SV_11 Urban 522059 16.4 21.9 20.2 20.8 20.3 Background 224837 12 SV_12 Suburban 522962 21.7 19.7 16.2 19.5 16.6 223335 13 SV_13 Urban 523070 22.7 23.9 21.8 22.4 22.2 Background 226070 14 SV_14 Roadside 523586 30.1 32.9 30.0 33.0 31.3 223967 17 SV_17 Roadside 522706 47.8 47.6 46.9 44.4 48.6 226553 19 SV_19 Roadside 522705 35.3 33.5 35.0 37.0 37.0 226572 21 SV_21 Roadside 523126 27.7 27.8 25.0 26.5 25.4 225676 22 SV_22 Roadside 523359 26.6 25.1 23.6 27.0 23.2 224783 23 SV_23 Roadside 523013 - - 36.8 36.3 31.5 226029 31 SV_31 Kerbside 522710 - - 21.1 23.3 22.2 226550 32 SV_32 Roadside 522700 - - 48.1 48.9 - 226550 33 SV_33 Roadside 523008 - - 39.7 40.5 - 226028 North NH59 NH_NH59 Roadside 524621 30.6 29.1 26.4 27.8 26.3 Hertfordshire 234081 NH61 NH_NH61 Roadside 524427 35.1 33.5 29.2 30.4 27.7 233882 NH70 NH_NH70 Roadside 524302 27.4 28.2 25.3 27.3 26.4 233779 NH72 NH_NH72 Roadside 524502 31.8 23.7 30.4 32.1 31.3 233948 NH88 NH_NH88 Kerbside 524448 38.4 42.4 39.0 39.9 40.5 233898 Hertsmere HM61 HM_HM61 Urban 522038 45.0 46.5 43.3 - - Borough Background 200669 Council HM86 HM_HM86 Motorway 522970 43.0 46.7 41.8 - - 199961 St Albans SA120 SA_SA120 Kerbside 520068 34.2 37.4 31.5 30.3 34.8 206594 Welwyn WH1 WH_WH1 Near Road 523439 27.0 27.0 23.0 22.0 22.0 Hatfield 216315 WH2 WH_WH2 Roadside 523656 27.0 25.0 24.0 24.0 - 213133 Environmental Assessment Report 18
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Local Local Modelled Site Type X, Y 2013 2014 2015 2016 2017 Authority Authority ID ID WH7 WH_WH7 Near road 521575 34.0 30.0 30.0 31.0 30.0 208645 WH8 WH_WH8 Near road 522609 23.0 21.0 20.0 20.0 20.0 206718 WH9 WH_WH9 Urban 523519 23.0 22.0 21.0 22.0 21.0 background 209890 WH10 WH_WH1 Urban 523377 25.0 21.0 20.0 22.0 21.0 0 background 209858 WH14 WH_WH1 Kerbside 522013 34.0 29.0 28.0 29.0 28.0 4 209707 WH15 WH_WH1 Urban 522604 19.0 28.0 22.0 24.0 22.0 5 background 210859 WH17 WH_WH1 Near road 523293 - 47.0 34.0 30.0 32.0 7 209165 WH18 WH_WH1 Roadside 524291 - 42.0 35.0 40.0 37.0 8 212986 WH19 WH_WH1 Roadside 522140 - 52.0 55.0 56.0 49.0 9 209519 WH20 WH_WH2 Near road 522504 - - 31.0 31.0 27.0 0 208537 WH22 WH_WH2 Kerbside 521801 - 42.0 37.0 37.0 43.0 2 209471 WH23 WH_WH2 Near road 521998 - 38.0 28.0 22.0 22.0 3 206243 WH24 WH_WH2 Roadside 521178 - 58.0 39.0 44.0 40.0 4 207735 WH25 WH_WH2 Near road 522095 - - - 44.0 46.0 5 209431 WH26 WH_WH2 Near road 522065 - - - 37.0 39.0 6 209328 WH27 WH_WH2 Near road 522065 - - - 37.0 40.0 7 209287 WH29 WH_WH2 Roadside 523276 - - - 44.0 40.0 9 208803 The diffusion tube results in Table 5.3.3 show that exceedances of the annual mean objective occurred in all the years for which data are available between 2013 and 2017 within 200m of the ARN. Diffusion tubes which consistently measured exceedances include SV_17, Stevenage, which is located on the A602 (Hitchin Road), south east of Junction 8. WH_WH19, Welwyn Hatfield on the A1001 (Comet Way) approximately 160m north of its junction with the B197. Diffusion tubes SV_32, SV_33, Stevenage and HM_HM61 and HM_HM86, Hertsmere have recorded historical exceedances but no recent data is available. Diffusion tubes WH_WH17 and WH_WH18, Welwyn Hatfield have also recorded historical exceedances but have both fallen to below AQS objective as of 2017.
Highways England NO2 Diffusion Tube Data
Annualised mean concentrations for 2017 derived from Highways England NO2 diffusion tube surveys undertaken at locations with the Proposed Scheme’s geographical study area between 2013 and 2014 are provided in Table 5.3.4 along with the survey period data capture. The survey locations are shown in Figure 5.2 in Chapter 5: Air Quality.
Environmental Assessment Report 19
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 5.3.4 - Highways England Diffusion Tube Monitoring Data (2013 - 2014) 6
Survey 2017 annual Survey Period Bias Modelled Date Date Annualisation mean Site ID X Y Type Period Data Mean Adjustment ID Commissioned Decommissioned factor (annualised) Capture % (µg/m3) factor (µg/m3) 2014 A1MJ3J7_001_0813 HE_001 522895 203203 Roadside 01/08/2013 01/08/2014 100 43.8 0.88 0.915 35.3 A1MJ3J7_002_0813 HE_002 522679 204394 Roadside 01/08/2013 01/08/2014 100 28.6 0.88 0.915 23.0 A1MJ3J7_003_0813 HE_003 522494 204829 Roadside 01/08/2013 01/08/2014 100 43.8 0.88 0.915 35.3 A1MJ3J7_004_0813 HE_004 521400 206432 Roadside 01/08/2013 01/08/2014 100 27.7 0.88 0.915 22.3 A1MJ3J7_005_0813 HE_005 521488 206755 Roadside 01/08/2013 01/08/2014 100 43.9 0.88 0.915 35.3 A1MJ3J7_006_0813 HE_006 521268 207784 Background 01/08/2013 01/08/2014 100 39.8 0.88 0.915 32.0 A1MJ3J7_007_0813 HE_007 521162 207773 Background 01/08/2013 01/08/2014 100 32.1 0.88 0.915 25.8 A1MJ3J7_008_0813 HE_008 521578 208249 Background 01/08/2013 01/08/2014 100 43.1 0.88 0.915 34.7 A1MJ3J7_009_0813 HE_009 521556 208103 Background 01/08/2013 01/08/2014 100 35.8 0.88 0.915 28.9 A1MJ3J7_010_0813 HE_010 521710 208037 Background 01/08/2013 01/08/2014 92 46.4 0.88 0.910 37.2 A1MJ3J7_011_0813 HE_011 522062 209322 Roadside 01/08/2013 01/08/2014 100 50.5 0.88 0.915 40.7 A1MJ3J7_012_0813 HE_012 522013 209610 Roadside 01/08/2013 01/08/2014 100 40.9 0.88 0.915 32.9 A1MJ3J7_013_0813 HE_013 522078 209408 Background 01/08/2013 01/08/2014 100 56.5 0.88 0.915 45.5 A1MJ3J7_014_0813 HE_014 522404 209783 Roadside 01/08/2013 01/08/2014 100 46.1 0.88 0.915 37.1 A1MJ3J7_015_0813 HE_015 522565 210893 Roadside 01/08/2013 01/08/2014 100 31.0 0.88 0.915 25.0 A1MJ3J7_016_0813 HE_016 523559 20987 Roadside 01/08/2013 01/08/2014 100 28.2 0.88 0.915 22.7 A1MJ3J7_017_0813 HE_017 522398 211426 Roadside 01/08/2013 01/08/2014 100 35.5 0.88 0.915 28.6 A1MJ3J7_018_0813 HE_018 522417 212157 Roadside 01/08/2013 01/08/2014 92 39.7 0.88 0.911 31.8 A1MJ3J7_019_0813 HE_019 522483 212120 Background 01/08/2013 01/08/2014 100 44.8 0.88 0.915 36.1 A1MJ3J7_020_0813 HE_020 522319 212272 Roadside 01/08/2013 01/08/2014 100 25.8 0.88 0.915 20.8 A1MJ3J7_021_0813 HE_021 522758 212633 Roadside 01/08/2013 01/08/2014 92 33.3 0.88 0.921 27.0 A1MJ3J7_022_0813 HE_022 522193 212439 Roadside 01/08/2013 01/08/2014 100 29.7 0.88 0.915 23.9 A1MJ3J7_023_0813 HE_023 522235 213889 Roadside 01/08/2013 01/08/2014 100 36.0 0.88 0.915 29.0 A1MJ3J7_024_0813 HE_024 523245 215398 Background 01/08/2013 01/08/2014 100 30.3 0.88 0.915 24.4
Environmental Assessment Report 20
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Survey 2017 annual Survey Period Bias Modelled Date Date Annualisation mean Site ID X Y Type Period Data Mean Adjustment ID Commissioned Decommissioned factor (annualised) Capture % (µg/m3) factor (µg/m3) 2014 A1MJ3J7_025_0813 HE_025 523381 215659 Background 01/08/2013 01/08/2014 100 32.0 0.88 0.915 25.8 A1MJ3J7_026_0813 HE_026 524378 215169 Background 01/08/2013 01/08/2014 100 36.3 0.88 0.915 29.2 A1MJ3J7_027_0813 HE_027 523349 215999 Background 01/08/2013 01/08/2014 100 36.2 0.88 0.915 29.2 A1MJ3J7_028_0813 HE_028 523467 216361 Background 01/08/2013 01/08/2014 100 31.8 0.88 0.915 25.6 A1MJ3J7_029_0813 HE_029 523859 217361 Roadside 01/08/2013 01/08/2014 100 36.6 0.88 0.915 29.4 A1MJ3J7_030_0813 HE_030 523956 217467 Roadside 01/08/2013 01/08/2014 100 42.8 0.88 0.915 34.4 A1MJ3J7_031_0813 HE_031 524085 217686 Background 01/08/2013 01/08/2014 100 39.3 0.88 0.915 31.6 A1MJ3J7_032_0813 HE_032 522974 223389 Roadside 01/08/2013 01/08/2014 100 32.1 0.88 0.915 25.9 A1MJ3J7_033_0813 HE_033 522035 225130 Roadside 01/08/2013 01/08/2014 100 35.5 0.88 0.915 28.6 A1MJ3J7_034_0813 HE_034 522097 226379 Roadside 01/08/2013 01/08/2014 100 26.2 0.88 0.915 21.1 A1MJ3J7_035_0813 HE_035 522370 226380 Roadside 01/08/2013 01/08/2014 100 32.3 0.88 0.915 26.0 A1MJ3J7_036_0813 HE_036 522767 227595 Roadside 01/08/2013 01/08/2014 58 30.0 0.88 0.940 24.9 A1MJ3J7_037_0813 HE_037 522366 211877 Roadside 01/08/2013 01/08/2014 92 33.4 0.88 0.911 26.8 A1MJ3J7_038_0813 HE_038 524456 217004 Background 01/08/2013 01/08/2014 100 32.2 0.88 0.915 25.9 A1MJ3J7_039_0813 HE_039 522460 224014 Roadside 01/08/2013 01/08/2014 100 27.1 0.88 0.915 21.9 A1MJ3J7_040_0813 HE_040 524617 219945 Background 01/08/2013 01/08/2014 100 24.5 0.88 0.915 19.7 A1MJ3J7_041_0813 HE_041 523327 214881 Background 01/08/2013 01/08/2014 100 23.0 0.88 0.915 18.5 * the diffusion tube is not located within the Proposed Scheme’s geographical study area but it was used in the model verification Exceedances of annual mean NO2 UK AQS objective are highlighted in bold.
Environmental Assessment Report 21
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Designated Ecological Sites There are two relevant designated ecological site within the Proposed Scheme’s geographical study area, Knebworth Wood SSSI and Sherrardspark Wood SSSI; which contain some habitats sensitive to NOx and nitrogen deposition. Critical loads for nitrogen deposition (where available) along with background nitrogen deposition rates and the NOx background concentration at the designated ecological sites considered in the assessment are shown in Table 5.3.5. The SSSI designation is for the presence of Ancient Woodland (both sites) and Acid grassland (Sherrardspark Wood only). Table 5.3.5 - Critical loads for Nutrient Nitrogen and Background Nitrogen Deposition7
Designated Habitat Type Critical Average Average Sites or Species Load (kg Background Background -1 -1 3 N ha yr ) Nitrogen NOx (µg/m ) in Deposition* (kg 2015# N ha-1yr-1)^ Knebworth Ancient 10-15 16.6 20.8 Wood SSSI woodland. Sherrardspar Ancient 10-15 28 23.09 k Wood woodland. SSSI Flora supporting a unique invertebrate habitat. *Nitrogen deposition varies by land cover type, with habitats with a larger surface area of vegetation (such as woodland) having higher deposition. ^The background nitrogen deposition rate was taken from the APIS website (based on a 3-year mean for 2013-15). # Contributions from Motorways and Trunk A-Roads within the grid squares of the background maps have been removed from the mapped concentrations as these sources are explicitly modelled in the assessment.
Environmental Assessment Report 22
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 5.4 Traffic Data and Other Inputs Traffic Modelling – Key Sources for Air Quality Model Coverage The model covers a single continuous study area encompassing the A1(M) from junction 1 to junction 10. The South East Regional Transport Model (SERTM) was used as the starting point for model development. An A1(M) version of the model was derived with additional network and zoning within the A1(M) corridor. The A1(M) model was used for scheme development and assessment, economic as well as environmental assessments for both Air Quality and Noise. The calibration of the model has been updated using additional traffic count data provided by Hertfordshire County Council. The DM scenario includes all RIS1 schemes in the area as well as additional local authority schemes and developments. Engagement Extensive engagement has been undertaken between the air quality and traffic modelling teams. This has included inclusion of the air quality team in traffic model calibration/validation meetings and inclusion of traffic representatives in air quality meetings, including joint presentations to Highways England, and participation of the traffic team in the Air Quality Peer2Peer meetings. The air quality and traffic teams undertook early risk work to help identify any areas of poorer performance in the traffic model which coincided with air quality risk areas (Red and Amber). This then informed further iteration of traffic model calibration/validation for both models. Close collaboration has also been undertaken to iteratively agree speed banding approaches, and to jointly undertake further detailed investigation of initial results to aid understanding and, where necessary, develop traffic data enhancements. Throughout, the traffic and air quality teams have engaged with Highways England’s Senior Responsible Officer (SRO), SMP Environment, SMP Traffic, and the TPG Appraisal Certifying Officers (ACO) to ensure that a statement of “appropriate for assessment” was achieved for both traffic models used in environmental assessment, achieved in June 2017. This statement reflected the proportionate hierarchical ‘calibration and validation model development approach’ that has been developed for the SMP, such that it provides levels of quality for specific areas of the model (i.e. ‘model is high quality along scheme sections (H1), medium quality along the ARN (H2), low to medium in other areas’).
Environmental Assessment Report 23
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
5.5 Model Verification Model verification was undertaken using monitoring sites within 200m of the ARN. A total of 79 diffusion tube monitoring sites within the Proposed Scheme’s geographical study area (within 200 m of ARN) were considered for use in model verification. From these sites, only those representative of sensitive receptor locations and with sufficient data capture were considered suitable for the purposes of model verification. Following detailed analysis of each monitoring location a total of 64 diffusion tube sites were taken forward in the model verification process. Table Table 5.5.1 details the sites removed from the verification process, whilst Table 5.5.2 and Figure 5.2 Chapter 5 Air Quality show the locations of the diffusion tube sites used in verification. Table 5.5.1 - Diffusion Tube Sites Excluded From Model Verification 8 Site ID X,Y Reason for exclusion from verification 522037.53, Located towards the edge of the ARN, for which HM_HM61 200668.91 there is less confidence in modelled traffic conditions. 522970.41, Located towards the edge of the ARN, for which HM_HM86 199960.91 there is less confidence in modelled traffic conditions. 522710, Location changed in following Local Authority SV_31 226550 Reports – unsure of actual location used in this year 522700, SV_32 Data removed from Local Authority Report. 226550 523008, SV_33 Data removed from Local Authority Report. 226027.5 524291, Located towards the edge of the ARN, for which WH_WH18 212986 there is less confidence in modelled traffic conditions. 521801, Located close to a Car Park (significant source of WH_WH22 209471 emission which was not included within the model). 522065, Located close to a roadside of a link which was not WH_WH27 209287 included within the model. 523276, Located towards the edge of the ARN, for which WH_WH29 208803 there is less confidence in modelled traffic conditions. Background Site. Not used in model verification. 521268.19, HE_006 Located close to a Car Park (significant source of 207784.2 emission which was not included within the model). 523558.69, Removed due to uncertainties in monitored co- HE_016 20986.7 ordinates, given in dataset. 524455.62, HE_038 Background Site. Not used in model verification 217004.2 524617, HE_040 Background Site. Not used in model verification 219945 523327.12, HE_041 Background Site. Not used in model verification 214881
Table 5.5.2 - Diffusion Tube Locations Used in Model Verification 9 Site ID Site Location X Y Local Authority NH_NH61 Roadside 524427.12 233882.41 North Hertfordshire NH_NH70 Roadside 524302.19 233779.09 North Hertfordshire NH_NH72 Roadside 524501.88 233948.09 North Hertfordshire NH_NH88 Kerbside 524448 233898 North Hertfordshire SA_SA120 Kerbside 520068.41 206594 St Albans
Environmental Assessment Report 24
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Site ID Site Location X Y Local Authority SV_SE16 Kerbside 523587 223963.7 Stevenage SV_3 Urban background 524636.81 222710.41 Stevenage SV_7 Roadside 523278.5 225479 Stevenage SV_10 Urban background 522014 225586 Stevenage SV_11 Urban background 522058.5 224836.59 Stevenage SV_12 Suburban 522961.81 223335 Stevenage SV_13 Urban background 523070 226070 Stevenage SV_14 Roadside 523586 223967 Stevenage SV_17 Roadside 522706.41 226553.41 Stevenage SV_19 Roadside 522704.81 226571.5 Stevenage SV_21 Roadside 523126 225676.3 Stevenage SV_22 Roadside 523359.19 224782.8 Stevenage SV_23 Roadside 523012.69 226029.41 Stevenage WH_WH7 Near road 521575 208645 Welwyn Hatfield WH_WH8 Near road 522609 206718 Welwyn Hatfield WH_WH9 Urban background 523519 209890 Welwyn Hatfield WH_WH10 Urban background 523377 209858 Welwyn Hatfield WH_WH14 Kerbside 522013 209707 Welwyn Hatfield WH_WH15 Urban background 522604 210859 Welwyn Hatfield WH_WH17 Near road 523293 209164.8 Welwyn Hatfield WH_WH19 Roadside 522140 209518.7 Welwyn Hatfield WH_WH20 Near road 522503.91 208537 Welwyn Hatfield WH_WH23 Near road 521998 206243 Welwyn Hatfield WH_WH24 Roadside 521178 207735 Welwyn Hatfield WH_WH25 Near road 522095 209431 Welwyn Hatfield WH_WH26 Near road 522065 209328 Welwyn Hatfield WH_WH1 Near road 523439 216315 Welwyn Hatfield NH_NH59 Roadside 524620.69 234080.5 North Hertfordshire HE_001 Roadside 522894.59 203202.7 Welwyn Hatfield HE_002 Roadside 522678.59 204393.8 Welwyn Hatfield HE_003 Roadside 522494.41 204829.2 Welwyn Hatfield HE_004 Roadside 521400.09 206432.3 St Albans HE_005 Roadside 521487.81 206755.09 Welwyn Hatfield HE_007 Background 521162.41 207773 Welwyn Hatfield HE_008 Background 521577.69 208248.59 Welwyn Hatfield HE_009 Background 521555.59 208102.7 Welwyn Hatfield HE_010 Background 521710.41 208037.41 Welwyn Hatfield HE_011 Roadside 522061.81 209321.91 Welwyn Hatfield HE_012 Roadside 522013.19 209609.59 Welwyn Hatfield HE_013 Roadside 522078.31 209407.8 Welwyn Hatfield HE_014 Roadside 522404.31 209782.8 Welwyn Hatfield HE_015 Roadside 522564.5 210892.5 Welwyn Hatfield HE_017 Roadside 522398.31 211425.91 Welwyn Hatfield HE_018 Roadside 522416.81 212157.41 Welwyn Hatfield HE_019 Background 522483 212120.09 Welwyn Hatfield
Environmental Assessment Report 25
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Site ID Site Location X Y Local Authority HE_020 Roadside 522319.09 212271.8 Welwyn Hatfield HE_021 Roadside 522757.69 212633.09 Welwyn Hatfield HE_022 Roadside 522193 212439.09 Welwyn Hatfield HE_023 Roadside 522235.09 213888.5 Welwyn Hatfield HE_024 Background 523244.59 215398.2 Welwyn Hatfield HE_025 Background 523381.19 215659.09 Welwyn Hatfield HE_026 Background 524377.81 215168.91 Welwyn Hatfield HE_027 Background 523349.41 215999.09 Welwyn Hatfield HE_028 Background 523466.59 216360.8 Welwyn Hatfield HE_029 Roadside 523858.91 217361.09 Welwyn Hatfield HE_030 Roadside 523955.5 217467.3 North Hertfordshire HE_031 Background 524084.81 217686.2 Welwyn Hatfield HE_032 Roadside 522974.19 223388.59 Stevenage HE_033 Roadside 522035.41 225129.8 Stevenage HE_034 Roadside 522096.91 226378.8 North Hertfordshire HE_035 Roadside 522369.81 226380.2 Stevenage HE_036 Roadside 522767.41 227594.59 North Hertfordshire HE_037 Roadside 522366.41 211877.3 Welwyn Hatfield HE_039 Roadside 522459.5 224014 Stevenage Uncertainty in modelled estimates has been considered by calculating root mean square error (RMSE) and fractional bias statistics. An air quality model can be considered to perform reasonably well where modelled concentrations are within 25% of monitored concentrations in accordance with Defra’s Technical Guidance LAQM.TG(16). The RMSE should ideally be within 10% of the relevant air quality criterion, but is acceptable where it is within 25% of the relevant air quality criterion. The Fractional Bias (FB) has an ideal value of 0, but is acceptable in the range between +2 and -2.
Firstly, unadjusted modelled estimates of total annual mean NO2 concentrations have been compared against monitored annual means. Out of 61 comparisons, 55 modelled estimates were within +/- 25% of monitored without adjustment, as shown in Table 5.5.3 (the percentages in the table are shown in bold where they are greater than 25%). Substantial underestimates of more than 25% are indicated for sites SV_17, WH_WH7, WH_WH24, HE_010, HE_014, and HE_026, whilst no substantial overestimates are indicated. 31 of the comparisons are within +/- 10% of monitored. The results of the unadjusted model verification within the Proposed Scheme’s geographical study area have been used to define 3 model domains, which are listed below and shown in Figure 5.2 Chapter 5: Air Quality.
Table 5.5.3 - Comparison of verified Modelled and Measured NO2 Concentrations 10 Modelled Total NO Modelled – Measured 2 Measured % Site - Unadjusted Measured NO (µg/m3) / Modelled Difference 2 (µg/m3) (µg/m3) Model Domain Stevenage SV_3 26.3 22.03 -0.42 1.02 -1.9% SV_7 30.0 25.70 -4.46 1.17 -14.8% SV_12 20.0 19.70 3.11 0.84 18.7% SV_13 21.0 22.35 0.13 0.99 0.6%
Environmental Assessment Report 26
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Modelled Total NO Modelled – Measured 2 Measured % Site - Unadjusted Measured NO (µg/m3) / Modelled Difference 2 (µg/m3) (µg/m3) SV_14 21.0 27.27 -4.01 1.15 -12.8% SV_17 28.0 37.77 -10.79 1.29 -22.2% SV_19 22.0 43.82 6.78 0.85 18.3% SV_21 32.0 21.43 -3.94 1.18 -15.5% SV_22 49.0 22.89 -0.34 1.01 -1.5% SV_23 27.0 29.69 -1.84 1.06 -5.8% HE_032 24.9 30.04 4.17 0.86 16.1% HE_033 21.9 33.22 4.60 0.86 16.1% HE_034 46.0 21.03 -0.09 1.00 -0.4% HE_035 39.0 25.97 -0.01 1.00 0.0% HE_036 40.7 23.99 -0.87 1.04 -3.5% HE_039 23.9 23.87 2.02 0.92 9.2% Model Domain Tunnels WH_WH25 37.2 40.59 -5.41 1.13 -11.8% WH_WH26 32.9 42.10 3.10 0.93 7.9% HE_011 29.2 42.28 1.62 0.96 4.0% HE_013 29.4 45.87 0.38 0.99 0.8% Model Domain Other SA_SA120 26.3 32.38 -2.45 1.08 -7.0% SV_SE16 34.8 27.88 1.56 0.94 5.9% WH_WH7 22.0 21.72 -8.28 1.38 -27.6% WH_WH8 40.0 17.72 -2.28 1.13 -11.4% WH_WH9 22.0 19.89 -1.11 1.06 -5.3% WH_WH10 35.3 18.73 -2.27 1.12 -10.8% WH_WH14 23.0 23.94 -4.06 1.17 -14.5% WH_WH15 35.3 21.60 -0.40 1.02 -1.8% WH_WH17 22.3 31.47 -0.53 1.02 -1.7% WH_WH19 35.3 43.87 -5.13 1.12 -10.5% WH_WH20 25.8 30.59 3.59 0.88 13.3% WH_WH23 34.7 23.20 1.20 0.95 5.5% WH_WH24 28.9 31.33 -8.67 1.28 -21.7% WH_WH1 37.1 23.84 1.84 0.92 8.4% HE_001 28.6 41.42 6.12 0.85 17.3% HE_002 31.8 21.02 -2.01 1.10 -8.7% HE_003 36.1 35.78 0.48 0.99 1.4% HE_004 20.8 17.43 -4.84 1.28 -21.7% HE_005 27.0 33.93 -1.39 1.04 -3.9% HE_007 29.0 24.72 -1.10 1.04 -4.3% HE_008 24.4 35.65 0.93 0.97 2.7% HE_009 25.8 24.63 -4.23 1.17 -14.6% HE_010 29.2 23.19 -14.00 1.60 -37.6% HE_012 25.6 27.29 -5.63 1.21 -17.1%
Environmental Assessment Report 27
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Modelled Total NO Modelled – Measured 2 Measured % Site - Unadjusted Measured NO (µg/m3) / Modelled Difference 2 (µg/m3) (µg/m3) HE_014 34.4 27.69 -9.39 1.34 -25.3% HE_015 31.6 20.15 -4.81 1.24 -19.3% HE_017 26.8 26.54 -2.03 1.08 -7.1% HE_018 22.5 31.59 -0.22 1.01 -0.7% HE_019 30.2 39.57 3.48 0.91 9.6% HE_020 16.6 19.29 -1.47 1.08 -7.1% HE_021 22.2 26.51 -0.49 1.02 -1.8% HE_023 48.6 24.78 -4.23 1.17 -14.6% HE_024 37.0 27.05 2.66 0.90 10.9% HE_025 25.4 30.74 4.95 0.84 19.2% HE_026 23.2 20.10 -9.12 1.45 -31.2% HE_027 31.5 24.23 -4.93 1.20 -16.9% HE_028 25.9 29.28 3.67 0.87 14.3% HE_029 28.6 37.63 8.18 0.78 27.8% HE_030 21.1 43.32 8.89 0.79 25.8% HE_031 26.0 28.70 -2.92 1.10 -9.2% HE_037 45.5 26.56 -0.23 1.01 -0.8%
Exceedances of the annual mean NO2 standard are shown in bold. The percentages in the table are shown in bold where they are greater than 25% The RMSE and fractional bias values obtained for unadjusted modelled estimates of NO2 compared to monitored concentrations are shown in Table 5.5.4, split by model domain. The RMSE target value according to Defra’s Technical Guidance 3 LAQM.TG(16) for the 40 µg/m objective concentration for annual mean NO2, is for the RMSE to be less than 4 µg/m3 (10% of the objective) but must be not more than 25 % of the objective i.e. 10 µg/m3. These results indicate that the RMSE is above the target and required values in all domains, and that verification is required. Table 5.5.4 - RMSE and Fractional Bias values for unadjusted modelled estimates of NO2 compared to monitored concentrations 11 Model Domain RMSE Fractional bias Stevenage 10.6 -2.5% Tunnels 11.9 -7.7% Other 10.2 0.9%
A further comparison of modelled estimates of road contributed annual mean NOx with the road NOx component derived from monitoring data is presented in Table 5.5.5. This analysis requires the estimation of the monitored road NOx component, which was undertaken using Defra’s NO2 to NOx calculator, version 5.1.
Table 5.5.5 - Comparison of Modelled and Measured NOx Concentrations 12
Measured Modelled Road Modelled – Measured % Site Road NO NO - Unadjusted Measured x x / Modelled Difference (µg/m3) (µg/m3) (µg/m3) Model Domain Stevenage SV_3 16.4 5.0 -11.4 3.28 -47.3% SV_7 29.9 6.6 -23.3 4.51 -45.3% SV_12 8.7 4.7 -3.9 1.84 -32.5%
Environmental Assessment Report 28
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Measured Modelled Road Modelled – Measured % Site Road NO NO - Unadjusted Measured x x / Modelled Difference (µg/m3) (µg/m3) (µg/m3) SV_13 15.5 5.1 -10.5 3.06 -52.1% SV_14 24.9 5.3 -19.5 4.67 -35.1% SV_17 78.3 16.7 -61.7 4.70 -39.8% SV_19 50.2 21.3 -28.8 2.35 -39.2% SV_21 20.0 3.9 -16.1 5.13 -43.9% SV_22 10.3 3.1 -7.2 3.33 -29.5% SV_23 34.8 9.9 -24.9 3.51 -50.0% HE_032 27.1 11.5 -15.5 2.35 -44.6% HE_033 30.0 12.9 -17.2 2.34 -43.3% HE_034 18.0 5.7 -12.2 3.14 -21.0% HE_035 26.0 8.4 -17.6 3.11 -33.2% HE_036 26.0 7.8 -18.2 3.34 -31.2% HE_039 16.3 6.5 -9.8 2.49 -26.9% Model Domain Tunnels WH_WH25 66.3 29.6 -36.7 2.24 -55.4% WH_WH26 49.5 31.6 -17.9 1.57 -36.3% HE_011 53.4 31.8 -21.6 1.68 -40.5% HE_013 65.1 36.7 -28.4 1.78 -43.7% Model Domain Other SA_SA120 41.7 15.1 -26.6 2.76 -44.8% SV_SE16 14.6 7.4 -7.2 1.97 -25.7% WH_WH7 29.6 5.3 -24.3 5.59 -30.6% WH_WH8 9.7 2.2 -7.5 4.36 -45.4% WH_WH9 9.9 3.2 -6.7 3.06 -22.0% WH_WH10 9.9 2.3 -7.6 4.29 -22.0% WH_WH14 25.3 7.1 -18.2 3.57 -35.1% WH_WH15 17.3 6.9 -10.4 2.52 -19.4% WH_WH17 32.5 13.0 -19.4 2.49 -40.6% WH_WH19 73.9 25.5 -48.4 2.90 -40.5% WH_WH20 18.2 10.7 -7.5 1.70 -47.1% WH_WH23 15.0 7.2 -7.7 2.07 -21.4% WH_WH24 53.7 14.2 -39.5 3.77 -38.7% WH_WH1 19.0 9.4 -9.5 2.01 -33.9% HE_001 44.2 24.3 -19.9 1.82 -39.3% HE_002 18.3 6.0 -12.4 3.07 -26.1% HE_003 44.4 18.9 -25.4 2.34 -38.4% HE_004 15.0 2.3 -12.7 6.39 -23.1% HE_005 43.0 16.6 -26.4 2.59 -38.4% HE_007 22.6 8.5 -14.1 2.66 -29.4% HE_008 39.9 17.5 -22.4 2.28 -34.6% HE_009 27.2 7.7 -19.5 3.53 -29.1% HE_010 45.4 6.5 -38.9 6.98 -35.8% HE_012 35.8 9.9 -25.9 3.60 -38.6% HE_014 45.1 10.3 -34.8 4.38 -39.9% HE_015 23.3 5.7 -17.6 4.09 -27.1% HE_017 30.5 10.9 -19.5 2.79 -38.2% HE_018 37.7 15.5 -22.2 2.43 -41.3% HE_019 47.3 23.1 -24.2 2.05 -42.0% HE_020 14.9 5.0 -9.9 2.98 -30.5% HE_021 27.5 11.0 -16.4 2.49 -39.2% HE_022 21.1 5.6 -23.3 3.76 -36.3% HE_023 33.6 10.3 -11.7 3.26 -41.1% Environmental Assessment Report 29
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Measured Modelled Road Modelled – Measured % Site Road NO NO - Unadjusted Measured x x / Modelled Difference (µg/m3) (µg/m3) (µg/m3) HE_024 24.0 12.3 -11.3 1.95 -31.9% HE_025 26.9 15.6 -26.6 1.73 -33.7% HE_026 32.3 5.7 -24.1 5.66 -49.7% HE_027 34.0 9.9 -12.1 3.44 -36.6% HE_028 26.3 14.2 -12.6 1.86 -38.2% HE_029 34.7 22.1 -18.8 1.57 -44.7% HE_030 47.1 28.3 -25.0 1.66 -43.5% HE_031 38.3 13.3 -15.8 2.87 -47.3% HE_037 26.8 11.0 -26.6 2.44 -36.8%
The results of the comparison of modelled and monitored road-NOx indicates that the model exhibits systematic bias in all modelled domains. As such, in order to improve model performance, model adjustment factors were derived in accordance with the methodology described in LAQM.TG16. The model adjustment factors derived and applied to modelled road-NOx contributions with each model domain are described below in Table 5.5.6. Table 5.5.6 - Model Adjustment Factors Applied in each Model Adjustment Area 13
Model Domain Adjustment Factor Applied? Adjustment Factor Stevenage Yes 3.11 Welwyn Tunnels Yes 1.80 Other Yes 2.40 The RMSE and fractional bias values obtained for the adjusted modelled estimates of NO2 compared to monitored concentrations are shown in Table 5.5.7. These results indicate that the RMSE is below the target value in 1 domain, and below the required value in all 3 domains. No further model verification has been applied. Table 5.5.7 - RMSE and Fractional Bias values for adjusted modelled estimates of NO2 compared to monitored concentrations 14 Model Domain RMSE Fractional bias Stevenage 4.1 -0.1% Tunnels 3.2 -0.1% Other 4.9 -0.1%
Environmental Assessment Report 30
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 5.6 Assessment of Impact Local Air Quality Results
Table 5.6.1 - Annual Mean NO2 Results for Discrete Human Health Receptors within Proposed Scheme’s Geographical Study Area 15
Receptor Sector Removed 2017 Base 2022 DM 2022 DS 2022 NO2 2022 NO2 EAR ID Background NO2 NO2 NO2 Change Change Chapter 3 3 3 3 3 2017 NO2 (µg/m ) (µg/m ) (µg/m ) (µg/m ) (µg/m ) Criteria Figure & Map R001 22.31 32.7 30.8 31.0 0.20 Imperceptible Fig.5.2, Map 2 R002 11.01 15.1 13.8 13.9 0.12 Imperceptible Fig.5.2, Map 2 R003 15.99 23.1 21.6 21.8 0.28 Imperceptible Fig.5.2, Map 3 R004 20.4 28.6 25.3 26.0 0.71 Small Fig.5.2, Map 11 R005 24.46 34.8 30.8 31.8 1.02 Small Fig.5.2, Map 11 R006 27.79 39.3 34.7 36.2 1.53 Small Fig.5.2, Map 12 R007 24.76 34.8 30.6 31.9 1.23 Small Fig.5.2, Map 12 R008 20.49 28.8 25.3 25.5 0.20 Imperceptible Fig.5.2, Map 13 R009 15.98 21.8 18.9 19.0 0.11 Imperceptible Fig.5.2, Map 13 R010 13.01 17.8 16.0 16.0 0.02 Imperceptible Fig.5.2, Map 2 R011 15.04 21.0 19.0 19.0 0.02 Imperceptible Fig.5.2, Map 2 R012 9.78 12.8 11.0 11.1 0.09 Imperceptible Fig.5.2, Map 4 R013 16.93 23.2 20.6 20.9 0.30 Imperceptible Fig.5.2, Map 4 R014 14.4 18.6 16.2 16.3 0.15 Imperceptible Fig.5.2, Map 4 R015 16.11 22.3 19.9 20.9 1.05 Small Fig.5.2, Map 6 R016 16.34 22.4 19.6 20.5 0.88 Small Fig.5.2, Map 7 R017 21.23 30.1 26.4 28.2 1.82 Small Fig.5.2, Map 7 R018 13.99 18.5 15.9 16.5 0.57 Small Fig.5.2, Map 8 R019 15.62 20.3 17.5 18.0 0.50 Small Fig.5.2, Map 8 R020 16.37 22.1 19.2 19.5 0.26 Imperceptible Fig.5.2, Map 8 R021 13.48 18.3 15.7 16.3 0.63 Small Fig.5.2, Map 9 R022 17.46 24.7 21.3 22.8 1.45 Small Fig.5.2, Map 9 R023 19.08 27.2 23.6 25.5 1.85 Small Fig.5.2, Map 9
Environmental Assessment Report 31
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Receptor Sector Removed 2017 Base 2022 DM 2022 DS 2022 NO2 2022 NO2 EAR ID Background NO2 NO2 NO2 Change Change Chapter 3 3 3 3 3 2017 NO2 (µg/m ) (µg/m ) (µg/m ) (µg/m ) (µg/m ) Criteria Figure & Map R024 23.34 33.7 29.4 32.4 2.99 Medium Fig.5.2, Map 9 R025 24.54 35.4 30.8 33.2 2.36 Medium Fig.5.2, Map 9 R026 21.66 31.1 27.4 27.2 -0.22 Imperceptible Fig.5.2, Map 10 R027 17.23 24.2 21.4 22.1 0.71 Small Fig.5.2, Map 10 R028 16.15 22.0 19.1 19.5 0.37 Imperceptible Fig.5.2, Map 11 R029 29.5 41.8 37.0 38.6 1.60 Small Fig.5.2, Map 12 R030 16.96 23.1 20.0 20.4 0.34 Imperceptible Fig.5.2, Map 12 R031 26.96 37.9 33.2 34.3 1.05 Small Fig.5.2, Map 12 R032 18.89 26.2 22.9 23.1 0.23 Imperceptible Fig.5.2, Map 12 R033 18.42 25.6 22.3 22.5 0.15 Imperceptible Fig.5.2, Map 13 R034 19.62 27.3 23.8 23.9 0.14 Imperceptible Fig.5.2, Map 14 R035 19.62 27.3 24.1 24.3 0.14 Imperceptible Fig.5.2, Map 14 R036 16.84 23.4 20.3 20.2 -0.12 Imperceptible Fig.5.2, Map 10 R037 14.66 20.0 17.4 17.4 -0.03 Imperceptible Fig.5.2, Map 10 R038 12.65 16.9 14.7 14.7 -0.01 Imperceptible Fig.5.2, Map 10 R039 11.46 15.0 12.9 12.9 0.01 Imperceptible Fig.5.2, Map 10 R040 10.93 14.2 12.2 12.2 0.00 Imperceptible Fig.5.2, Map 10 R041 11.42 15.0 13.1 13.1 -0.03 Imperceptible Fig.5.2, Map 9 R042 9.88 12.8 11.2 11.2 -0.04 Imperceptible Fig.5.2, Map 9 R043 9.94 12.7 11.3 11.0 -0.30 Imperceptible Fig.5.2, Map 9 R044 10.73 13.9 12.7 12.0 -0.64 Small Fig.5.2, Map 9 R045 10.87 14.1 12.9 12.2 -0.71 Small Fig.5.2, Map 9 R046 10 12.7 11.1 10.8 -0.27 Imperceptible Fig.5.2, Map 9 R047 13.6 17.3 14.7 14.7 0.00 Imperceptible Fig.5.2, Map 10 R048 14.78 19.1 16.4 16.3 -0.02 Imperceptible Fig.5.2, Map 10 R049 13.1 16.9 14.4 14.4 -0.01 Imperceptible Fig.5.2, Map 10
Environmental Assessment Report 32
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Receptor Sector Removed 2017 Base 2022 DM 2022 DS 2022 NO2 2022 NO2 EAR ID Background NO2 NO2 NO2 Change Change Chapter 3 3 3 3 3 2017 NO2 (µg/m ) (µg/m ) (µg/m ) (µg/m ) (µg/m ) Criteria Figure & Map R050 13.47 17.4 14.8 14.8 -0.01 Imperceptible Fig.5.2, Map 10 R051 12.97 16.7 14.2 14.2 0.01 Imperceptible Fig.5.2, Map 10 R052 12.52 16.2 13.8 13.6 -0.20 Imperceptible Fig.5.2, Map 9 R053 15.83 21.1 18.1 17.6 -0.56 Small Fig.5.2, Map 9 R054 13.47 17.5 15.2 14.7 -0.57 Small Fig.5.2, Map 9 R055 15.65 20.7 18.2 17.1 -1.11 Small Fig.5.2, Map 9 R056 12.79 16.7 14.5 14.0 -0.51 Small Fig.5.2, Map 9 R057 14.9 19.7 17.3 16.2 -1.04 Small Fig.5.2, Map 9 R058 13.34 17.5 15.1 14.6 -0.47 Small Fig.5.2, Map 8 R059 14.57 19.1 16.9 16.5 -0.41 Small Fig.5.2, Map 8 R060 22.54 30.1 26.6 26.4 -0.22 Imperceptible Fig.5.2, Map 7 R061 18.06 23.9 21.0 20.8 -0.12 Imperceptible Fig.5.2, Map 7 R062 17.5 23.2 20.3 20.1 -0.16 Imperceptible Fig.5.2, Map 7 R063 14.48 18.6 15.9 15.9 -0.02 Imperceptible Fig.5.2, Map 7 R064 14.97 19.6 16.8 16.7 -0.10 Imperceptible Fig.5.2, Map 7 R065 14.88 19.5 16.6 16.6 0.00 Imperceptible Fig.5.2, Map 7 R066 14.65 19.1 16.2 16.2 -0.02 Imperceptible Fig.5.2, Map 7 R067 13.54 17.2 14.7 14.7 0.06 Imperceptible Fig.5.2, Map 7 R068 13.92 17.6 15.0 15.1 0.05 Imperceptible Fig.5.2, Map 7 R069 14.58 18.5 15.8 15.9 0.05 Imperceptible Fig.5.2, Map 7 R070 18.16 24.1 20.8 20.8 0.09 Imperceptible Fig.5.2, Map 7 R071 20.35 27.7 24.3 24.4 0.03 Imperceptible Fig.5.2, Map 7 R072 15.54 20.7 18.0 18.3 0.21 Imperceptible Fig.5.2, Map 7 R073 26.97 38.0 33.7 33.8 0.17 Imperceptible Fig.5.2, Map 7 R074 11.73 15.2 13.1 13.2 0.02 Imperceptible Fig.5.2, Map 6 R075 11.12 14.3 12.5 12.4 -0.08 Imperceptible Fig.5.2, Map 6
Environmental Assessment Report 33
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Receptor Sector Removed 2017 Base 2022 DM 2022 DS 2022 NO2 2022 NO2 EAR ID Background NO2 NO2 NO2 Change Change Chapter 3 3 3 3 3 2017 NO2 (µg/m ) (µg/m ) (µg/m ) (µg/m ) (µg/m ) Criteria Figure & Map R076 8.97 11.4 9.8 9.8 0.02 Imperceptible Fig.5.2, Map 2 R077 16.84 24.0 22.0 22.1 0.12 Imperceptible Fig.5.2, Map 4 R078 10.04 12.7 10.8 10.8 0.03 Imperceptible Fig.5.2, Map 4 R079 12.59 16.5 14.3 14.3 -0.01 Imperceptible Fig.5.2, Map 4 R080 15.2 20.4 17.7 18.0 0.32 Imperceptible Fig.5.2, Map 6 R081 14.42 19.0 16.4 16.6 0.18 Imperceptible Fig.5.2, Map 7 Motorway J1 – J10 A total of 39 receptors were considered along the Motorway between J1 and J10. 3 Annual mean concentrations of NO2 are predicted to be below the 40 µg/m annual NO2 objective at all of these receptors with the core cumulative worst case scenario in operation. Concentrations are predicted to increase at 17 of the 39 receptors. A small impact (+0.5 -1.9 µg/m3) is predicted at 15 receptors and a medium impact (+2.0 – 3.9µg/m3). All 17 receptors are located between J3 and J9 of the A1 (M). The predicted change at these receptors are due to an increase in AADT flow of approximately 22,000 vehicles along the A1 (M), and result in concentrations with the Proposed Scheme in place that range from 15.7 to 38.6 µg/m3. As concentrations are predicted to be below 60 µg/m3 in both the do minimum and do something scenarios in 2020, it is anticipated that the hourly mean NO2 objective (200 µg/m3) is unlikely to be exceeded at these receptors, with and without the Proposed Scheme in operation.
3 Table 5.6.2 - Annual Mean NOx Results (µg/m ) for Ecological Receptors within the Proposed Scheme’s Geographical Study Area 16
Distance 2017 2022 2022 2022 2022 NO Receptor Designated to road Background x Base DM DS NO Change ID Site centre 2017 NO x x NO NO NO Change Criteria (m) x x x KW1_0 Knebworth 4 21.2 118.9 100.8 148.5 47.7 Large Wood SSSI KW1_5 Knebworth 9 21.1 79.2 66.8 82.6 15.8 Large Wood SSSI KW1_10 Knebworth 14 21.0 64.4 54.0 62.1 8.06 Large Wood SSSI KW1_15 Knebworth 19 21.0 56.1 46.9 52.2 5.35 Large Wood SSSI KW1_20 Knebworth 24 20.9 50.7 42.3 46.3 4.00 Medium Wood SSSI KW1_25 Knebworth 29 20.9 46.9 38.9 42.1 3.18 Medium Wood SSSI KW1_30 Knebworth 34 20.8 44.0 36.5 39.1 2.64 Medium Wood SSSI KW1_35 Knebworth 39 20.7 41.7 34.5 36.8 2.25 Medium Wood SSSI
Environmental Assessment Report 34
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance 2017 2022 2022 2022 2022 NO Receptor Designated to road Background x Base DM DS NO Change ID Site centre 2017 NO x x NO NO NO Change Criteria (m) x x x KW1_40 Knebworth 44 20.7 39.9 32.9 34.9 1.97 Small Wood SSSI KW1_45 Knebworth 49 20.6 38.4 31.6 33.4 1.74 Small Wood SSSI KW1_50 Knebworth 54 20.6 37.1 30.5 32.1 1.56 Small Wood SSSI KW1_55 Knebworth 59 20.5 36.0 29.6 31.0 1.42 Small Wood SSSI KW1_60 Knebworth 64 20.5 35.0 28.7 30.0 1.30 Small Wood SSSI KW1_65 Knebworth 69 20.4 34.2 28.0 29.2 1.19 Small Wood SSSI KW1_70 Knebworth 74 20.4 33.4 27.3 28.4 1.10 Small Wood SSSI KW1_75 Knebworth 79 20.3 32.7 26.8 27.8 1.03 Small Wood SSSI KW1_80 Knebworth 84 20.2 32.1 26.2 27.2 0.96 Small Wood SSSI KW1_85 Knebworth 89 20.2 31.6 25.8 26.7 0.90 Small Wood SSSI KW1_90 Knebworth 94 20.1 31.1 25.3 26.2 0.85 Small Wood SSSI KW1_95 Knebworth 99 20.1 30.6 24.9 25.7 0.80 Small Wood SSSI KW1_100 Knebworth 104 20.0 30.2 24.6 25.3 0.76 Small Wood SSSI KW2_0 Knebworth 4 21.0 111.8 113.0 173.1 60.09 Large Wood SSSI KW2_5 Knebworth 9 21.0 76.2 72.6 92.0 19.39 Large Wood SSSI KW2_10 Knebworth 14 20.9 62.7 57.7 67.5 9.82 Large Wood SSSI KW2_15 Knebworth 19 20.9 55.0 49.5 55.9 6.40 Large Wood SSSI KW2_20 Knebworth 24 20.8 50.0 44.1 48.8 4.67 Large Wood SSSI KW2_25 Knebworth 29 20.8 46.3 40.4 44.0 3.64 Medium Wood SSSI KW2_30 Knebworth 34 20.7 43.6 37.6 40.6 2.97 Medium Wood SSSI KW2_35 Knebworth 39 20.7 41.4 35.5 37.9 2.50 Medium Wood SSSI KW2_40 Knebworth 44 20.6 39.7 33.7 35.9 2.15 Medium Wood SSSI KW2_45 Knebworth 49 20.5 38.2 32.3 34.2 1.88 Small Wood SSSI KW2_50 Knebworth 54 20.5 37.0 31.1 32.8 1.66 Small Wood SSSI KW2_55 Knebworth 59 20.4 35.9 30.1 31.6 1.49 Small Wood SSSI KW2_60 Knebworth 64 20.4 35.0 29.2 30.6 1.35 Small Wood SSSI Environmental Assessment Report 35
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance 2017 2022 2022 2022 2022 NO Receptor Designated to road Background x Base DM DS NO Change ID Site centre 2017 NO x x NO NO NO Change Criteria (m) x x x KW2_65 Knebworth 69 20.3 34.2 28.4 29.7 1.23 Small Wood SSSI KW2_70 Knebworth 74 20.3 33.4 27.7 28.9 1.13 Small Wood SSSI KW2_75 Knebworth 79 20.2 32.8 27.1 28.2 1.04 Small Wood SSSI KW2_80 Knebworth 84 20.2 32.2 26.6 27.6 0.97 Small Wood SSSI KW2_85 Knebworth 89 20.1 31.6 26.1 27.0 0.90 Small Wood SSSI KW2_90 Knebworth 94 20.1 31.2 25.6 26.5 0.85 Small Wood SSSI KW2_95 Knebworth 99 20.0 30.7 25.2 26.0 0.80 Small Wood SSSI KW2_100 Knebworth 104 20.0 30.3 24.8 25.6 0.75 Small Wood SSSI KW3_0 Knebworth 4 20.8 115.0 118.1 178.5 60.4 Large Wood SSSI KW3_5 Knebworth 9 20.7 77.8 75.9 95.7 19.9 Large Wood SSSI KW3_10 Knebworth 14 20.6 64.0 60.5 70.6 10.1 Large Wood SSSI KW3_15 Knebworth 19 20.6 56.2 51.9 58.5 6.63 Large Wood SSSI KW3_20 Knebworth 24 20.5 51.0 46.3 51.1 4.87 Large Wood SSSI KW3_25 Knebworth 29 20.5 47.2 42.3 46.1 3.81 Medium Wood SSSI KW3_30 Knebworth 34 20.4 44.4 39.3 42.4 3.10 Medium Wood SSSI KW3_35 Knebworth 39 20.4 42.2 37.0 39.6 2.60 Medium Wood SSSI KW3_40 Knebworth 44 20.3 40.3 35.1 37.3 2.22 Medium Wood SSSI KW3_45 Knebworth 49 20.3 38.8 33.5 35.5 1.94 Small Wood SSSI KW3_50 Knebworth 54 20.2 37.6 32.2 33.9 1.71 Small Wood SSSI KW3_55 Knebworth 59 20.2 36.4 31.1 32.6 1.52 Small Wood SSSI KW3_60 Knebworth 64 20.1 35.5 30.1 31.5 1.37 Small Wood SSSI KW3_65 Knebworth 69 20.1 34.6 29.3 30.5 1.24 Small Wood SSSI KW3_70 Knebworth 74 20.0 33.9 28.5 29.6 1.13 Small Wood SSSI KW3_75 Knebworth 79 20.0 33.2 27.8 28.9 1.04 Small Wood SSSI KW3_80 Knebworth 84 19.9 32.6 27.2 28.2 0.95 Small Wood SSSI KW3_85 Knebworth 89 19.9 32.0 26.7 27.6 0.88 Small Wood SSSI Environmental Assessment Report 36
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance 2017 2022 2022 2022 2022 NO Receptor Designated to road Background x Base DM DS NO Change ID Site centre 2017 NO x x NO NO NO Change Criteria (m) x x x KW3_90 Knebworth 94 19.8 31.5 26.2 27.0 0.82 Small Wood SSSI KW3_95 Knebworth 99 19.8 31.0 25.7 26.5 0.77 Small Wood SSSI KW3_100 Knebworth 104 19.7 30.6 25.3 26.0 0.72 Small Wood SSSI KW4_0 Knebworth 4 20.3 115.6 118.0 177.0 59.01 Large Wood SSSI KW4_5 Knebworth 9 20.3 78.7 76.0 94.9 18.9 Large Wood SSSI KW4_10 Knebworth 14 20.2 64.9 60.7 70.0 9.24 Large Wood SSSI KW4_15 Knebworth 19 20.2 57.0 52.1 58.0 5.84 Large Wood SSSI KW4_20 Knebworth 24 20.1 51.8 46.5 50.7 4.15 Large Wood SSSI KW4_25 Knebworth 29 20.1 47.9 42.5 45.7 3.16 Medium Wood SSSI KW4_30 Knebworth 34 20.0 45.0 39.5 42.0 2.52 Medium Wood SSSI KW4_35 Knebworth 39 20.0 42.7 37.2 39.3 2.07 Medium Wood SSSI KW4_40 Knebworth 44 19.9 40.9 35.3 37.0 1.75 Small Wood SSSI KW4_45 Knebworth 49 19.9 39.3 33.7 35.2 1.51 Small Wood SSSI KW4_50 Knebworth 54 19.8 37.9 32.4 33.7 1.32 Small Wood SSSI KW4_55 Knebworth 59 19.8 36.8 31.3 32.4 1.17 Small Wood SSSI KW4_60 Knebworth 64 19.7 35.8 30.3 31.3 1.05 Small Wood SSSI KW4_65 Knebworth 69 19.7 34.9 29.4 30.4 0.95 Small Wood SSSI KW4_70 Knebworth 74 19.6 34.1 28.6 29.5 0.87 Small Wood SSSI KW4_75 Knebworth 79 19.6 33.4 28.0 28.8 0.80 Small Wood SSSI KW4_80 Knebworth 84 19.5 32.7 27.3 28.1 0.74 Small Wood SSSI KW4_85 Knebworth 89 19.5 32.1 26.8 27.5 0.69 Small Wood SSSI KW4_90 Knebworth 94 19.4 31.6 26.3 26.9 0.65 Small Wood SSSI KW4_95 Knebworth 99 19.4 31.1 25.8 26.4 0.61 Small Wood SSSI KW4_100 Knebworth 104 19.3 30.6 25.4 25.9 0.57 Small Wood SSSI SW1_0 Sherrardspark 4 15.1 43.9 36.8 39.0 2.15 Medium Wood SSSI SW1_5 Sherrardspark 9 15.1 39.7 33.1 34.8 1.68 Small Wood SSSI Environmental Assessment Report 37
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance 2017 2022 2022 2022 2022 NO Receptor Designated to road Background x Base DM DS NO Change ID Site centre 2017 NO x x NO NO NO Change Criteria (m) x x x SW1_10 Sherrardspark 14 15.1 37.6 31.2 32.7 1.47 Small Wood SSSI SW1_15 Sherrardspark 19 15.1 36.1 29.9 31.3 1.34 Small Wood SSSI SW1_20 Sherrardspark 24 15.1 35.0 28.9 30.2 1.24 Small Wood SSSI SW1_25 Sherrardspark 29 15.1 34.0 28.1 29.3 1.16 Small Wood SSSI SW1_30 Sherrardspark 34 15.1 33.2 27.4 28.5 1.09 Small Wood SSSI SW1_35 Sherrardspark 39 15.1 32.5 26.7 27.8 1.04 Small Wood SSSI SW1_40 Sherrardspark 44 15.1 31.8 26.2 27.2 0.99 Small Wood SSSI SW1_45 Sherrardspark 49 15.1 31.2 25.7 26.6 0.95 Small Wood SSSI SW1_50 Sherrardspark 54 15.1 30.7 25.2 26.1 0.91 Small Wood SSSI SW1_55 Sherrardspark 59 15.1 30.2 24.8 25.6 0.87 Small Wood SSSI SW1_60 Sherrardspark 64 15.1 29.7 24.4 25.2 0.84 Small Wood SSSI SW1_65 Sherrardspark 69 15.2 29.3 24.0 24.8 0.81 Small Wood SSSI SW1_70 Sherrardspark 74 15.2 28.9 23.7 24.5 0.78 Small Wood SSSI SW1_75 Sherrardspark 79 15.2 28.5 23.4 24.1 0.76 Small Wood SSSI SW1_80 Sherrardspark 84 15.2 28.2 23.1 23.8 0.73 Small Wood SSSI SW1_85 Sherrardspark 89 15.2 27.9 22.8 23.5 0.71 Small Wood SSSI SW1_90 Sherrardspark 94 15.2 27.6 22.5 23.2 0.69 Small Wood SSSI SW1_95 Sherrards park 99 15.2 27.3 22.3 23.0 0.67 Small Wood SSSI SW1_100 Sherrardspark 104 15.3 27.0 22.1 22.7 0.65 Small Wood SSSI SW2_0 Sherrardspark 4 15.0 52.5 44.4 46.9 2.49 Medium Wood SSSI SW2_5 Sherrardspark 9 15.0 47.1 39.7 41.6 1.95 Small Wood SSSI SW2_10 Sherrardspark 14 15.1 44.1 37.0 38.7 1.70 Small Wood SSSI SW2_15 Sherrardspark 19 15.1 41.9 35.1 36.6 1.54 Small Wood SSSI SW2_20 Sherrardspark 24 15.1 40.1 33.5 34.9 1.42 Small Wood SSSI SW2_25 Sherrardspark 29 15.1 38.6 32.2 33.5 1.32 Small Wood SSSI SW2_30 Sherrardspark 34 15.1 37.3 31.1 32.3 1.24 Small Wood SSSI Environmental Assessment Report 38
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance 2017 2022 2022 2022 2022 NO Receptor Designated to road Background x Base DM DS NO Change ID Site centre 2017 NO x x NO NO NO Change Criteria (m) x x x SW2_35 Sherrardspark 39 15.1 36.2 30.1 31.2 1.17 Small Wood SSSI SW2_40 Sherrardspark 44 15.1 35.2 29.2 30.3 1.11 Small Wood SSSI SW2_45 Sherrardspark 49 15.1 34.3 28.4 29.4 1.06 Small Wood SSSI SW2_50 Sherrardspark 54 15.1 33.5 27.7 28.7 1.01 Small Wood SSSI SW2_55 Sherrardspark 59 15.1 32.8 27.0 28.0 0.97 Small Wood SSSI SW2_60 Sherrardspark 64 15.1 32.1 26.5 27.4 0.93 Small Wood SSSI SW2_65 Sherrardspark 69 15.1 31.5 25.9 26.8 0.89 Small Wood SSSI SW2_70 Sherrardspark 74 15.2 30.9 25.4 26.3 0.86 Small Wood SSSI SW2_75 Sherrardspark 79 15.2 30.4 25.0 25.8 0.83 Small Wood SSSI SW2_80 Sherrardspark 84 15.2 29.9 24.6 25.4 0.80 Small Wood SSSI SW2_85 Sherra rdspark 89 15.2 29.4 24.2 24.9 0.77 Small Wood SSSI SW2_90 Sherrardspark 94 15.2 29.0 23.8 24.6 0.75 Small Wood SSSI SW2_95 Sherrardspark 99 15.2 28.6 23.5 24.2 0.73 Small Wood SSSI SW2_100 Sherrardspark 104 15.2 28.3 23.2 23.9 0.71 Small Woods SSSI SW3_0 Sherrardspark 4 15.0 56.9 48.9 50.7 1.75 Small Wood SSSI SW3_5 Sherrardspark 9 15.1 50.5 42.9 44.6 1.67 Small Wood SSSI SW3_10 Sherrardspark 14 15.1 46.8 39.5 41.1 1.58 Small Wood SSSI SW3_15 Sherrardspark 19 15.1 44.2 37.2 38.7 1.49 Small Wood SSSI SW3_20 Sherrardspark 24 15.1 42.2 35.3 36.7 1.41 Small Wood SSSI SW3_25 Sherrardspark 29 15.1 40.4 33.8 35.1 1.33 Small Wood SSSI SW3_30 Sherrardspark 34 15.1 39.0 32.5 33.8 1.27 Small Wood SSSI SW3_35 Sherrardspark 39 15.1 37.7 31.4 32.6 1.20 Small Wood SSSI SW3_40 Sherrardspark 44 15.1 36.6 30.4 31.5 1.15 Small Wood SSSI SW3_45 Sherrardspark 49 15.1 35.6 29.5 30.6 1.10 Small Wood SSSI SW3_50 Sherrardspark 54 15.1 34.7 28.7 29.8 1.05 Small Wood SSSI SW3_55 Sherrardspark 59 15.1 33.9 28.0 29.0 1.01 Small Wood SSSI Environmental Assessment Report 39
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance 2017 2022 2022 2022 2022 NO Receptor Designated to road Background x Base DM DS NO Change ID Site centre 2017 NO x x NO NO NO Change Criteria (m) x x x SW3_60 Sherrardspark 64 15.1 33.1 27.4 28.4 0.97 Small Wood SSSI SW3_65 Sherrardspark 69 15.2 32.5 26.8 27.7 0.93 Small Wood SSSI SW3_70 Sherrardspark 74 15.2 31.9 26.3 27.2 0.90 Small Wood SSSI SW3_75 Sher rardspark 79 15.2 31.3 25.8 26.6 0.87 Small Wood SSSI SW3_80 Sherrardspark 84 15.2 30.8 25.3 26.1 0.84 Small Wood SSSI SW3_85 Sherrardspark 89 15.2 30.3 24.9 25.7 0.81 Small Wood SSSI SW3_90 Sherrardspark 94 15.2 29.8 24.5 25.3 0.79 Small Wood SSSI SW3_95 Sherrardspark 99 15.2 29.4 24.1 24.9 0.76 Small Wood SSSI SW3_100 Sherrardspark 104 15.2 29.0 23.8 24.5 0.74 Small Wood SSSI Exceedances of annual mean NOX UK AQS objective are highlighted in bold. Table 5.6.3 - Nitrogen Deposition Results (kgN/ha/yr) for Ecological Receptors within the A1(M) J6-8 Geographical Study Area 17 Distance to 2017 Base 2022 DM 2022 DS 2022 NDep Receptor Designated road NDep NDep NDep Change ID Site centre (m) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr ) KW1_0 Knebworth 0 19.5 21.3 1.8 19.5 Wood SSSI KW1_5 Knebworth 5 18.1 18.8 0.7 18.1 Wood SSSI KW1_10 Knebworth 10 17.5 17.9 0.4 17.5 Wood SSSI KW1_15 Knebworth 15 17.2 17.5 0.3 17.2 Wood SSSI KW1_20 Knebworth 20 17.0 17.2 0.2 17.0 Wood SSSI KW1_25 Knebworth 25 16.8 17.0 0.2 16.8 Wood SSSI KW1_30 Knebworth 30 16.7 16.8 0.1 16.7 Wood SSSI KW1_35 Knebworth 35 16.6 16.7 0.1 16.6 Wood SSSI KW1_40 Knebworth 40 16.5 16.6 0.1 16.5 Wood SSSI KW1_45 Knebworth 45 16.4 16.5 0.1 16.4 Wood SSSI KW1_50 Knebworth 50 16.4 16.5 0.1 16.4 Wood SSSI KW1_55 Knebworth 55 16.3 16.4 0.1 16.3 Wood SSSI KW1_60 Knebworth 60 16.3 16.3 0.1 16.3 Wood SSSI
Environmental Assessment Report 40
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance to 2017 Base 2022 DM 2022 DS 2022 NDep Receptor Designated road NDep NDep NDep Change ID Site centre (m) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr ) KW1_65 Knebworth 65 16.2 16.3 0.1 16.2 Wood SSSI KW1_70 Knebworth 70 16.2 16.3 0.1 16.2 Wood SSSI KW1_75 Knebworth 75 16.2 16.2 0.1 16.2 Wood SSSI KW1_80 Knebworth 80 16.1 16.2 0.1 16.1 Wood SSSI KW1_85 Knebworth 85 16.1 16.2 0.1 16.1 Wood SSSI KW1_90 Knebworth 90 16.1 16.1 0.0 16.1 Wood SSSI KW1_95 Knebworth 95 16.1 16.1 0.0 16.1 Wood SSSI KW1_100 Knebworth 100 16.1 16.1 0.0 16.1 Wood SSSI KW2_0 Knebworth 0 20.0 22.1 2.1 20.0 Wood SSSI KW2_5 Knebworth 5 18.4 19.2 0.8 18.4 Wood SSSI KW2_10 Knebworth 10 17.7 18.2 0.5 17.7 Wood SSSI KW2_15 Knebworth 15 17.3 17.6 0.3 17.3 Woods SSSI KW2_20 Knebworth 20 17.1 17.3 0.2 17.1 Wood SSSI KW2_25 Knebworth 25 16.9 17.1 0.2 16.9 Wood SSSI KW2_30 Knebworth 30 16.7 16.9 0.2 16.7 Wood SSSI KW2_35 Knebworth 35 16.6 16.8 0.1 16.6 Wood SSSI KW2_40 Knebworth 40 16.5 16.7 0.1 16.5 Wood SSSI KW2_45 Knebworth 45 16.5 16.6 0.1 16.5 Wood SSSI KW2_50 Knebworth 50 16.4 16.5 0.1 16.4 Wood SSSI KW2_55 Knebworth 55 16.4 16.4 0.1 16.4 Wood SSSI KW2_60 Knebworth 60 16.3 16.4 0.1 16.3 Wood SSSI KW2_65 Knebworth 65 16.3 16.3 0.1 16.3 Wood SSSI KW2_70 Knebworth 70 16.2 16.3 0.1 16.2 Wood SSSI KW2_75 Knebworth 75 16.2 16.2 0.1 16.2 Wood SSSI KW2_80 Knebworth 80 16.2 16.2 0.1 16.2 Wood SSSI KW2_85 Knebworth 85 16.1 16.2 0.0 16.1 Wood SSSI
Environmental Assessment Report 41
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance to 2017 Base 2022 DM 2022 DS 2022 NDep Receptor Designated road NDep NDep NDep Change ID Site centre (m) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr ) KW2_90 Knebworth 90 16.1 16.2 0.0 16.1 Wood SSSI KW2_95 Knebworth 95 16.1 16.1 0.0 16.1 Wood SSSI KW2_100 Knebworth 100 16.1 16.1 0.0 16.1 Wood SSSI KW3_0 Knebworth 0 20.2 22.3 2.1 20.2 Wood SSSI KW3_5 Knebworth 5 18.5 19.4 0.8 18.5 Wood SSSI KW3_10 Knebworth 10 17.9 18.3 0.5 17.9 Wood SSSI KW3_15 Knebworth 15 17.5 17.8 0.3 17.5 Wood SSSI KW3_20 Knebworth 20 17.2 17.4 0.2 17.2 Wood SSSI KW3_25 Knebworth 25 17.0 17.2 0.2 17.0 Wood SSSI KW3_30 Knebworth 30 16.8 17.0 0.2 16.8 Wood SSSI KW3_35 Knebworth 35 16.7 16.8 0.1 16.7 Wood SSSI KW3_40 Knebworth 40 16.6 16.7 0.1 16.6 Wood SSSI KW3_45 Knebworth 45 16.5 16.6 0.1 16.5 Wood SSSI KW3_50 Knebworth 50 16.5 16.6 0.1 16.5 Wood SSSI KW3_55 Knebworth 55 16.4 16.5 0.1 16.4 Wood SSSI KW3_60 Knebworth 60 16.4 16.4 0.1 16.4 Woods SSSI KW3_65 Knebworth 65 16.3 16.4 0.1 16.3 Wood SSSI KW3_70 Knebworth 70 16.3 16.3 0.1 16.3 Wood SSSI KW3_75 Knebworth 75 16.2 16.3 0.1 16.2 Wood SSSI KW3_80 Knebworth 80 16.2 16.2 0.1 16.2 Wood SSSI KW3_85 Knebworth 85 16.2 16.2 0.0 16.2 Wood SSSI KW3_90 Knebworth 90 16.1 16.2 0.0 16.1 Wood SSSI KW3_95 Knebworth 95 16.1 16.2 0.0 16.1 Wood SSSI KW3_100 Knebworth 100 16.1 16.1 0.0 16.1 Wood SSSI KW4_0 Knebworth 0 20.2 22.2 2.1 20.2 Wood SSSI KW4_5 Knebworth 5 18.5 19.3 0.8 18.5 Wood SSSI
Environmental Assessment Report 42
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance to 2017 Base 2022 DM 2022 DS 2022 NDep Receptor Designated road NDep NDep NDep Change ID Site centre (m) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr ) KW4_10 Knebworth 10 17.9 18.3 0.4 17.9 Wood SSSI KW4_15 Knebworth 15 17.5 17.7 0.3 17.5 Wood SSSI KW4_20 Knebworth 20 17.2 17.4 0.2 17.2 Wood SSSI KW4_25 Knebworth 25 17.0 17.2 0.2 17.0 Wood SSSI KW4_30 Knebworth 30 16.8 17.0 0.1 16.8 Wood SSSI KW4_35 Knebworth 35 16.7 16.8 0.1 16.7 Wood SSSI KW4_40 Knebworth 40 16.6 16.7 0.1 16.6 Wood SSSI KW4_45 Knebworth 45 16.5 16.6 0.1 16.5 Wood SSSI KW4_50 Knebworth 50 16.5 16.5 0.1 16.5 Wood SSSI KW4_55 Knebworth 55 16.4 16.5 0.1 16.4 Wood SSSI KW4_60 Knebworth 60 16.4 16.4 0.1 16.4 Wood SSSI KW4_65 Knebworth 65 16.3 16.4 0.1 16.3 Wood SSSI KW4_70 Knebworth 70 16.3 16.3 0.0 16.3 Wood SSSI KW4_75 Knebworth 75 16.2 16.3 0.0 16.2 Wood SSSI KW4_80 Knebworth 80 16.2 16.2 0.0 16.2 Wood SSSI KW4_85 Knebworth 85 16.2 16.2 0.0 16.2 Wood SSSI KW4_90 Knebworth 90 16.1 16.2 0.0 16.1 Wood SSSI KW4_95 Knebworth 95 16.1 16.2 0.0 16.1 Wood SSSI KW4_100 Knebworth 100 16.1 16.1 0.0 16.1 Wood SSSI SW1_0 Sherrardspark 0 29.5 26.4 26.5 0.11 Wood SSSI SW1_5 Sherrardspark 5 29.3 26.2 26.3 0.09 Wood SSSI SW1_10 Sherrardspark 10 29.2 26.1 26.2 0.08 Wood SSSI SW1_15 Sherrardspark 15 29.2 26.1 26.1 0.07 Wood SSSI SW1_20 Sherrardspark 20 29.1 26.0 26.1 0.07 Wood SSSI SW1_25 Sherrardspark 25 29.0 26.0 26.0 0.06 Wood SSSI SW1_30 Sherrardspark 30 29.0 25.9 26.0 0.06 Wood SSSI
Environmental Assessment Report 43
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance to 2017 Base 2022 DM 2022 DS 2022 NDep Receptor Designated road NDep NDep NDep Change ID Site centre (m) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr ) SW1_35 Sherrardspark 35 29.0 25.9 26.0 0.06 Wood SSSI SW1_40 Sherrardspark 40 28.9 25.9 25.9 0.05 Wood SSSI SW1_45 Sherrardspark 45 28.9 25.8 25.9 0.05 Wood SSSI SW1_50 Sherrardspark 50 28.9 25.8 25.9 0.05 Wood SSSI SW1_55 Sherrardspark 55 28.9 25.8 25.8 0.05 Wood SSSI SW1_60 Sherrardspark 60 28.8 25.8 25.8 0.05 Wood SSSI SW1_65 Sherrardspar k 65 28.8 25.8 25.8 0.04 Wood SSSI SW1_70 Sherrardspark 70 28.8 25.7 25.8 0.04 Wood SSSI SW1_75 Sherrardspark 75 28.8 25.7 25.8 0.04 Wood SSSI SW1_80 Sherrardspark 80 28.8 25.7 25.7 0.04 Wood SSSI SW1_85 Sherrardspark 85 28.7 25.7 25.7 0.04 Wood SSSI SW1_90 Sherrardspark 90 28.7 25.7 25.7 0.04 Wood SSSI SW1_95 Sherrardspark 95 28.7 25.7 25.7 0.04 Wood SSSI SW1_100 Sherrardspark 100 28.7 25.6 25.7 0.04 Wood SSSI SW2_0 Sherrardspark 0 29.9 26.8 26.9 0.12 Wood SSSI SW2_5 Sherrardspark 5 29.7 26.6 26.7 0.10 Wood SSSI SW2_10 Sherrardspark 10 29.5 26.4 26.5 0.09 Wood SSSI SW2_15 Sherrardspa rk 15 29.4 26.3 26.4 0.08 Wood SSSI SW2_20 Sherrardspark 20 29.4 26.3 26.3 0.07 Wood SSSI SW2_25 Sherrardspark 25 29.3 26.2 26.3 0.07 Wood SSSI SW2_30 Sherrardspark 30 29.2 26.1 26.2 0.07 Wood SSSI SW2_35 Sherrardspark 35 29.2 26.1 26.1 0.06 Wood SSSI SW2_40 Sherrardspark 40 29.1 26.0 26.1 0.06 Wood SSSI SW2_45 Sherrardspark 45 29.1 26.0 26.0 0.06 Wood SSSI SW2_50 Sherrardspark 50 29.0 26.0 26.0 0.05 Wood SSSI SW2_55 Sherrardspark 55 29.0 25.9 26.0 0.05 Wood SSSI
Environmental Assessment Report 44
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance to 2017 Base 2022 DM 2022 DS 2022 NDep Receptor Designated road NDep NDep NDep Change ID Site centre (m) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr ) SW2_60 Sherrardspark 60 28.9 25.9 25.9 0.05 Wood SSSI SW2_65 Sherrardspark 65 28.9 25.9 25.9 0.05 Wood SSSI SW2_70 Sherrards park 70 28.9 25.8 25.9 0.05 Wood SSSI SW2_75 Sherrardspark 75 28.9 25.8 25.8 0.04 Wood SSSI SW2_80 Sherrardspark 80 28.8 25.8 25.8 0.04 Wood SSSI SW2_85 Sherrardspark 85 28.8 25.8 25.8 0.04 Wood SSSI SW2_90 Sherrardspark 90 28.8 25.7 25.8 0.04 Wood SSSI SW2_95 Sherrardspark 95 28.8 25.7 25.8 0.04 Wood SSSI SW2_100 Sherrardspark 100 28.8 25.7 25.7 0.04 Wood SSSI SW3_0 Sherrardspark 0 30.1 27.0 27.1 0.09 Wood SSSI SW3_5 Sherrardspark 5 29.8 26.7 26.8 0.08 Wood SSSI SW3_10 Sherrardspark 10 29.7 26.6 26.6 0.08 Wood SSSI SW3_15 Sherrardspark 15 29.5 26.4 26.5 0.08 Wood SSSI SW3_20 Sherrard spark 20 29.4 26.4 26.4 0.07 Wood SSSI SW3_25 Sherrardspark 25 29.4 26.3 26.3 0.07 Wood SSSI SW3_30 Sherrardspark 30 29.3 26.2 26.3 0.07 Wood SSSI SW3_35 Sherrardspark 35 29.2 26.1 26.2 0.06 Wood SSSI SW3_40 Sherrardspark 40 29.2 26.1 26.2 0.06 Wood SSSI SW3_45 Sherrardspark 45 29.1 26.0 26.1 0.06 Wood SSSI SW3_50 Sherrardspark 50 29.1 26.0 26.1 0.06 Wood SSSI SW3_55 Sherrardspark 55 29.0 26.0 26.0 0.05 Wood SSSI SW3_60 Sherrardspark 60 29.0 25.9 26.0 0.05 Wood SSSI SW3_65 Sherrardspark 65 29.0 25.9 26.0 0.05 Wood SSSI SW3_70 Sherrardspark 70 28.9 25.9 25.9 0.05 Wood SSSI SW3_75 Sherra rdspark 75 28.9 25.8 25.9 0.05 Wood SSSI SW3_80 Sherrardspark 80 28.9 25.8 25.9 0.04 Wood SSSI
Environmental Assessment Report 45
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Distance to 2017 Base 2022 DM 2022 DS 2022 NDep Receptor Designated road NDep NDep NDep Change ID Site centre (m) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr) (kgN/ha/yr ) SW3_85 Sherrardspark 85 28.9 25.8 25.8 0.04 Wood SSSI SW3_90 Sherrardspark 90 28.8 25.8 25.8 0.04 Wood SSSI SW3_95 Sherrardspark 95 28.8 25.8 25.8 0.04 Wood SSSI SW3_100 Sherrardspark 100 28.8 25.7 25.8 0.04 Wood SSSI
The assessment has shown that the annual mean NOx UK AQS objective of 30 µg/m3 for the protection of vegetation is achieved in the base year (2017) at locations: • Further than 110m back from the road within the Knebworth Wood SSSI; • Further than 90m back from the ARN within the Sherrardspark Wood SSSI. 3 The annual mean NOx UK AQS objective of 30 µg/m for the protection of vegetation is achieved in the opening year (2022) at locations further than 55m back from the road without the Proposed Scheme, and 65m back from the road with the core cumulative worst case scenario within the Knebworth Wood SSSI. The maximum change in annual mean NOx concentrations at this designated ecological site, within 200m of the ARN, is 19.9µg/m3, at the point closest to the road (KW3_5) with the Proposed Scheme. The assessment has shown that there is an increase in expected nitrogen deposition of 0.85kgN/ha/yr (at the roadside – the closest point of the woodland habitat to the Proposed Scheme ARN), where the lower critical load for the habitat is already exceeded. These data have been passed on to the Scheme Ecologist for further assessment. 3 The annual mean NOx UK AQS objective of 30 µg/m for the protection of vegetation is achieved in the opening year (2022) with or without the Proposed Scheme, at locations closest to the road within the Sherrardspark Wood SSSI site. The maximum change in annual mean NOx concentrations at this designated ecological site, within 200m of the ARN, is 1.95µg/m3, at the point closest to the road centreline (SW2_5) with the Proposed Scheme. The assessment has shown that there is an increase in expected nitrogen deposition of 0.1kgN/ha/yr (at the roadside – the closest point of the woodland habitat to the Proposed Scheme ARN), where the lower critical load for the habitat is already exceeded. These data have been passed on to the Scheme Ecologist for further assessment. In line with IAN 174/13, where changes are greater than 0.4 µg/m³, effects are considered to be perceptible and as such nitrogen deposition has been calculated. This is the case at all sites considered. The maximum change in annual nitrogen deposition at the following sites: • Knebworth Wood SSSI, within 200m of the ARN, is 0.85 kg N ha-1 yr-1, at the point closest to the road with the Proposed Scheme. • Sherrardspark Woods SSSI, within 200m of the ARN, is 0.1 kg N ha-1 yr-1, at the point closest to the road with the Proposed Scheme.
Environmental Assessment Report 46
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Regional Emissions Results Table 5.6.4 - Regional Emissions Results – ‘Cumulative Worst Case’ Scenario 18
Year Scenario NOx (t/yr) PM10 CO2 (t/yr) Veh kms (t/yr) travelled /year 2015 Base 114.74 12.56 46971.7 3,892,396 2022 Do-Minimum 79.25 11.29 50361.6 5,402,268 Do-Something 82.38 11.54 50781.0 5,623,289 Change with Do- 3.1 0.2 419.4 221,021 Something %Change from Do- 4.0% 2.2% 0.8% 4.1% Minimum %Change from Base 2.7% 1.9% 0.9% 5.7% 2037* Do-Minimum 49.95 6.23 55593.2 6,020,649 Do-Something 52.39 6.57 57053.4 6,362,670 Change with Do- 2.4 0.3 1460.2 342,021 Something %Change from Do- 4.9% 5.5% 2.6% 5.7% Minimum %Change from Base 2.1% 2.7% 3.1% 8.8% *Predictions for the design year have been calculated using 2030 emissions as this is the limit of the projections within the emissions factor toolkit.
Environmental Assessment Report 47
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
5.7 Compliance Risk Assessment Table 5.7.1 - Compliance risk assessment results table – ‘cumulative worst case’ Scenario 19
Input Data HA Receptor Results
Opening Year NO2 Concentration (Nearest Receptor to Defra’s PCM Data PCM Compliance Info Defra Link) Change Concentration with Equivalent Change Proposed PCM DS Defra Maximum 3 Is it a Projected Annual Annual in NO Scheme (µg/m ) Link Zone / Modelled 2 Compliant NO (T) Compliance Receptor ID Mean DM Mean DS with >0.4? Census Agglomeration 2 Conc in Zone? Year NO NO Proposed ID Zone 2022 2 2 Scheme 6078 Eastern N 26.5 40.3 2023 R031 33.2 34.3 1.1 Y 27.6 8044 Eastern N 26.5 40.3 2023 R036 20.3 20.2 0.1 N 17453 Eastern N 17.5 40.3 2023 R069 15.8 15.9 0.1 N 28412 Eastern N 24.9 40.3 2023 R029 37.0 38.6 1.6 Y 26.5 48767 Eastern N 23.6 40.3 2023 R060 26.6 26.4 -0.2 N 56070 Eastern N 32.1 40.3 2023 R005 30.8 31.8 1.0 Y 33.1 57343 Eastern N 25.1 40.3 2023 R020 19.2 19.5 0.3 N 57468 Eastern N 21.8 40.3 2023 R050 14.8 14.8 0.0 N 57636 Eastern N 22.7 40.3 2023 R048 16.4 16.3 -0.1 N 57900 Eastern N 28.5 40.3 2023 R071 24.3 24.4 0.3 N 99680 Eastern N 20.5 40.3 2023 R026 27.4 27.2 -0.2 N
Environmental Assessment Report 48
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Smart Motorways Programme Environmental Assessment Report Appendix 6.1 – Ecological Survey Report
Tranche 5 – A1(M) J6 to 8 (Preliminary Design – PCF Stage 3)
HE551539-WSP-EGN-SG-RP-LE-00017
April 2019
Notice
This document and its contents have been prepared and are intended solely for Highways England’s information and use in relation to the Smart Motorways Programme.
A1(M) J6-8 SM: Ecological Survey Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Revision history
Job number: 551539 Document ref: HE551539-WSP-EGN-SG-RP-LE-00017 Revision Purpose description Originated Checked Reviewed Approved Date P01 S3 – Draft for review Chris Horley Paul Joyce David Hoare Jonty Parry 05/03/19 and comment P02 S4 – Suitable for stage Chris Horley Andy David Hoare Jonty Parry 12/04/19 approval Bascombe
Client signoff
Client Highways England Project SMP Tranche 5 – A1(M) Junctions 6 to 8 Document title Appendix 6 - Biodiversity Job no. 551539 Document HE551539-WSP-EGN-SG-RP-LE-00017 reference
A1(M) J6-8 SM: Ecological Survey Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table of Contents
1. Introduction 3 1.1 The Proposed Scheme 3 1.2 Purpose of this Report 3 1.3 Scope and Study Area 4 1.4 Report Structure 5 2. Extended Phase 1 Habitat Survey 6 2.1 Summary 6 2.2 Survey Objectives 6 2.3 Scope and Study Area 6 2.4 Legislative Context 6 2.5 Methodology 7 2.6 Survey Limitations 8 2.7 Results 8 2.8 Conclusions and Recommendations 9 3. Great Crested Newt 10 3.1 Summary 10 3.2 Survey Objectives 10 3.3 Scope and Study Area 10 3.4 Legislative Context 11 3.5 Methodology 11 3.6 Survey Limitations 13 3.7 Results 14 3.8 Conclusions and Recommendations 16 4. Roosting Bats 19 4.1 Summary 19 4.2 Survey Objectives 19 4.3 Scope and Study Area 19 4.4 Legislative Context 19 4.5 Methodology 20 4.6 Results 21 4.7 Conclusions and Recommendations 25 5. Otter and Water Vole 26 5.1 Summary 26 5.2 Survey Objectives 26 5.3 Scope and Study Area 26 5.4 Legislative Context 26 5.5 Methodology 27
A1(M) J6-8 SM: Ecological Survey Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
5.6 Survey Limitations 29 5.7 Results 30 5.8 Conclusions and Recommendations 32
List of Tables
Table 1.1 - Professional Competence ...... 3 Table 2.1 - Extended Phase 1 Survey Dates and Areas Included 2 ...... 7 Table 2.2 - Priority Habitat Adjacent to the Proposed Scheme 3 ...... 8 Table 2.3 - Phase 1 habitat types and areas within the highway boundary 4 ...... 8 Table 3.1 - Habitat Suitability Indices for Great Crested Newt 5 ...... 13 Table 3.2 - Waterbodies not included for assessment in 20186 ...... 14 Table 3.3 - Great Crested Newt Desk Study Records 7 ...... 15 Table 3.4 - Habitat Suitability Index Assessment 8 ...... 15 Table 3.5 - Great Crested Newt eDNA Results 9 ...... 16 Table 3.6 - Great Crested Newt Terrestrial Habitat Loss 10 ...... 17 Table 3.7 - Great Crested Newt Opportunities for Enhancement11 ...... 18 Table 4.1 - Un-Surveyed Features for Bats 12 ...... 21 Table 4.2 – Bat Records13 ...... 22 Table 4.3 - Potential Roost Assessment for Bats14 ...... 23 Table 4.4 - Roosting Bat Opportunities for Enhancement 15 ...... 25 Table 5.1 - Otter and Water Vole Survey Dates and Areas Included16 ...... 27 Table 5.2 - Watercourse Suitability for Otter17 ...... 28 Table 5.3 - Watercourse Suitability for Water Voles18 ...... 29 Table 5.4 - Un-Surveyed Watercourse sections19 ...... 30 Table 5.5 - Otter and Water Vole Records20 ...... 30 Table 5.6 - Otter and Water Vole Habitat Suitability Assessment21 ...... 31
Supporting Figures
Figure 1.1 – Proposed Scheme footprint and 2km buffer; Figure 2.1 – Extended phase 1 survey areas; Figure 2.2 – Priority Habitats within 500m; Figure 2.3 – Ancient Woodland within 2km; Figure 3.1a – Water bodies surveyed 2018 (Northern section) Figure 3.1b – Water bodies surveyed 2018 (Southern section) Figure 3.2a – Water bodies not surveyed 2018 (Northern section) Figure 3.2b – Water bodies not surveyed 2018 (Southern section) Figure 4.1 – Structures surveyed for roosting bats; Figure 5.1 – Otter and water vole survey coverage on River Mimram
Appendices
Appendix A – A1(M) Proposed Scheme
Appendix B – Extended Phase 1 Habitat Survey
Appendix C – Great Crested Newt Survey
Appendix D – Potential Bat Roost Assessment
Appendix E – Otter and Water Vole Survey .
A1(M) J6-8 SM: Ecological Survey Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Executive Summary This report provides a high-level appreciation of the ecological surveys undertaken during June 2018 to August 2018 for the A1(M) J6 to J8 Smart Motorway scheme and is provided in support of the Environmental Assessment Report (EAR) and the Outline Environmental Management Plan (OEMP). The findings also provide background information to support any European Protected Species mitigation licence applications and licences for other species. The study area comprises approximately 981,476m² or 98.1ha of soft estate plus varying distances beyond the highway boundary to reflect the protected species being surveyed. A high-level habitat survey was undertaken over the period 20 June 2018 to 21 June 2018 to confirm the occurrence of priority habitat within the soft estate as identified in the Environmental Scoping Report P01.1 (May 2018)31. It also served the purpose of identifying habitats where protected species surveys were to be undertaken as well as the location of invasive species. The protected species surveys were undertaken on the following dates: • Great Crested Newt: Habitat suitability assessments and eDNA sampling from 26 to 29 June 2018; • Bats: Preliminary bat roost inspections on 14 structures on 21 August 2018; • Otter and Water Vole: Walkover survey along the River Mimram in search of evidence for otter and water vole on 22 August 2018; Surveys for the following were not undertaken due to either survey window restrictions, time of year and/or access restrictions: • Great Crested Newt: Presence/absence/population counts. • Bats: Preliminary bat roost inspections could not be sufficiently surveyed from vantage points for 5 structures (A1(M) bridges. Access to the highways soft estate, will be required to for these surveys, which was not granted in 2018, therefore will need to be surveyed in 2019. • Otter and Water Vole: Sections of bankside along the River Mimram which fell within land parcels without agreed landowner access. The surveys concluded that the following protected and/or notable species were present within the soft estate and its immediate environs: • Extended Phase 1 Habitat: Although no access to the soft estate was obtained in 2018, the survey mapped habitats and botanical species present within areas of soft estate and the immediate environs, mainly through vantage points across the Proposed Scheme, where the soft estate could be observed. No evidence of protected and/or notable species was recorded during this survey. In addition, no condition and distinctiveness assessment was carried out during the survey. • Great Crested Newt: The presence of great crested newts has been confirmed through eDNA analysis at six waterbodies, most of which are located within the Watery Grove area of Knebworth Woods SSSI. There are an additional 22 waterbodies that could not be accessed in 2018, and therefore will need to be surveyed in 2019.
31 Highways England, 2018: A1(M) Junction 6-8 Environmental Scoping Report, MP0135-HEX-EGN-ZZ-AS-KK-0001 A1(M) J6-8 SM: Ecological Survey Report 1
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
• Bats: Fourteen structures have been assessed for bat roost potential, and all have been assessed to offer negligible potential for roosting bats. Five structures could not be accessed in 2018. No trees were subject to a preliminary bat roost inspection in 2018. • Otter and Water Vole: The River Mimram was explored for evidence of otter and water vole along sections of the river where access was permitted. No signs or evidence was identified for otter and water vole, although small rodent footprints were recorded in one area. These alone cannot be relied upon to confirm presence of water vole as they can be easily mistaken for other more common rodent species e.g. brown rat. Some short sections of the River Mimram water course could not be accessed in 2018.
A1(M) J6-8 SM: Ecological Survey Report 2
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 6. Introduction 6.1 The Proposed Scheme Highways England has commissioned WSP to design and assess the A1(M) junction 6 to 8 Smart Motorway scheme, referred to in this report as the ‘Proposed Scheme’. 6.2 Purpose of this Report The purpose of this report is to provide the results of desk studies and field based surveys and assessments. Ecological baseline assessments within the potential zone of influence (ZoI) of the proposed works within the highway boundary were carried out in 2018. The report provides the findings of the investigations for the following: Broad habitat mapping; Great crested newt (Triturus cristatus); Roosting bats; and Otter (Lutra lutra) and water vole (Arvicola amphibious); The report also documents: Extended Phase 1 Habitat survey; Habitat Suitability Index (HSI) assessments for great crested newt; Environmental DNA technique (eDNA) surveys for great crested newt; Preliminary bat roost assessments on structures; Habitat suitability assessments for otter and water vole. The information gathered has been used to inform the Proposed Scheme design as documented in the Environmental Assessment Report (EAR) and the Outline Environmental Management Plan (OEMP). The findings also provide background information to support any European Protected Species mitigation licence applications and licences for other species. This report has been produced by qualified and competent experts, as summarised in Table 1.1. In preparing this report, regard has been given to current guidance and best practice, details of which are included within each chapter. Table 20.1 - Professional Competence Grade & Name Expertise and Professional Qualification Company High Speed 2 Phase 2B, 2017-2018 – member of Quality Assurance team which reviewed raw survey data of habitat surveys along the Phase 2B route windows and technical reports. A27 Arundel bypass, 2017-2018 – member of survey team, and lead ecologist for great crested newt surveys, including Consultant the production of technical survey reports. Supporting Chris Ecologist ecologist for the Terrestrial Invertebrate surveys alongside Horley at WSP entomology specialist, including review of technical report. East West Rail Phase 2, 2017 – member of Quality Assurance team responsible for reviewing raw data, GIS data and technical reports. BSc (Hons) Zoology MSc Conservation and Land Management GradCIEEM Membership
A1(M) J6-8 SM: Ecological Survey Report 3
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Grade & Name Expertise and Professional Qualification Company Highways England Smart Motorways Programme, 2010-2018 – responsible for management and delivery of ecological surveys, and Environmental Assessment Reports associated with Smart Motorways schemes on the M3, M4, M6, M27, M1 and M42. A9 Dualling Scheme, 2015-2018 – Led surveys for two dual carriageway upgrade schemes in Scotland, undertaking wintering and breeding bird surveys, and stakeholder engagement meetings regarding birds with Scottish Natural Heritage and the RSPB, and worked with these groups to Associate Paul deliver an ecological impact assessment. Ecologist Joyce HS2 Phase 1A Work Package 54, and Phase 2B, 2017-2018 at WSP – Develop systems to collate, check and store these data to required specifications for the Phase 2B team, and develop a GIS system to allow those designing mitigation to access the most current information available for the Work Package 54 team. In the latter project I led our international team in India to leverage the open source GIS software QGIS, their specialist IT skills and attention to detail to achieve high quality data outputs for the wider Work Package 54 team. BSc (Hons) Zoology PhD Aquatic Ecology 6.3 Scope and Study Area The Proposed Scheme footprint for the surveys has been taken as being within the existing highway boundary between junction 6 and junction 8, as this is the maximum extent of habitat clearance required for the Proposed Scheme as indicated in Figure 1.1 – Appendix A. All proposed works are to be within the highway boundary, with the exception of the site compound(s). While the location of the compound(s) is not currently known, ‘candidate compound sites’ have been identified at three locations in close proximity to the Proposed Scheme. A search radius of 2km from the highway boundary in respect of protected and/or notable species records has been applied. In July 2018, the Highways England Environmental Information System (EnvIS) was accessed for records of protected/notable faunal species and protected and invasive floral species. In addition, a request was made to the Hertfordshire Environmental Records Centre (HERC) for additional records from within 2km of the Proposed Scheme. Historical records from both sources are included, and any older than 10 years have been discounted as they are not considered to be of relevance. In addition, a Priority Habitat site and Ancient Woodland site search was performed using the Magic® website (www.magic.gov.uk) for records of protected and invasive floral species within 500m of the highway boundary. These searches were undertaken in June 2018. The study area for the survey of individual ecological features included within this report are subject to variation and are set out below.
A1(M) J6-8 SM: Ecological Survey Report 4
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Zone of Influence As the Proposed Scheme does not require any land take beyond the existing highway boundary, the ZoI is defined as the Proposed Scheme footprint (refer to paragraph 1.3.1 above), plus the area over which ecological features may be subject to significant effects and impact pathways to the wider environment. The ZoI applied to different ecological features is set out below. Great crested newt – waterbodies within 250m of the carriageway; Roosting bats – structures within the soft estate and immediately adjacent habitat (within 20m of the highway boundary); Otter and water vole – sections of watercourses (reaches) or connected waterbodies where impacts could arise from the Proposed Scheme, 2km upstream and 2km downstream of the works. The Proposed Scheme is considered to be outside of the known range of hazel dormouse Muscardinus avellanarius. Consequently this protected species was not considered in this study. 6.4 Report Structure Chapters 2 to 5 of this report comprise individual survey reports for Extended Phase 1 habitat, great crested newt, roosting bats, otter and water vole (combined), respectively. Each chapter provides: • A summary; • Survey objectives; • Scope and study area; • Legislative context; • Methodology; • Survey limitations; • Results; and • Conclusions and recommendations.
A1(M) J6-8 SM: Ecological Survey Report 5
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 7. Extended Phase 1 Habitat Survey 7.1 Summary
• The whole area (981,476 m² or 98.1 ha) of land within the highway boundary has been subject to an Extended Phase 1 habitat survey; • Most of the habitats within the highway boundary were common and widespread, only five habitats that occurred within the area surveyed are considered to be priority habitat as Habitat of Principal Importance, these comprise; Semi-improved grassland, Lowland mixed deciduous woodland, Hedgerows, Ponds and River; • Most land parcels were accessible on request; however, some areas were either refused or no response was received (see Figure 2.1).
7.2 Survey Objectives The purpose of the broad habitat survey is to provide via an Extended Phase 1 survey high-level Phase 1 mapping, targeted at the identification of suitable habitats for protected and/or notable species. As such, the aim of this chapter is to address the following: • Review existing ecological data to identify and broadly map the habitats within the highway boundary, including potential priority habitat32 that may qualify as Habitat of Principal Importance; • Enable reporting of the area and condition of the affected biodiversity units33; and • Contribute to the baseline information for the Proposed Scheme with regards to the potential for the habitats present to support protected and/or notable species. 7.3 Scope and Study Area All land within the highway boundary has been included in the scope of the survey and comprises the study area. Further detail on the study area is provided in section 1.3 of this report. Areas within the scope of the 2018 survey that could not be included for reasons such as access limitations or for health and safety concerns are detailed within the Survey Limitations (section 2.6) of this report. 7.4 Legislative Context Habitats and Species of Principal Importance for the conservation of biodiversity in England are listed under the provisions of Section 41 of the Natural Environment and Rural Communities (NERC) Act 2006. These include all the habitats and species in England that were identified as requiring action in the now succeeded UK Biodiversity Action Plan (UK BAP), which continues to be regarded as conservation priorities in the subsequent UK Post-2010 Biodiversity Framework.
32 Priority habitats are those identified as being the most threatened and requiring conservation action under the UK Biodiversity Action Plan (UK BAP), replaced in 2012 by the UK Post-2010 Biodiversity Framework. These lists of priority habitats and species still remain as an important reference source and have been subsequently used for the NERC Act 2006 priority lists. 33 Reporting of the area baseline condition of biodiversity units is to take account of Highways England’s Memorandum ‘Supporting Transparency around our Biodiversity Performance’ A1(M) J6-8 SM: Ecological Survey Report 6
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Section 40 of the NERC Act 2006 places a general duty on all public authorities to pay due regard to conservation and enhancement of biodiversity within their decision making, particularly with reference to those habitats and species listed within Section 41 of the Act. These are referred to as ‘priority’ habitats and species within this report. Current Guidance In preparing this report, regard has been given to current guidance and best practice, comprising: Chartered Institute of Ecology and Environmental Management (CIEEM) Guidelines for Ecological Appraisal (2017)34 Joint Nature Conservation Committee (JNCC) Handbook for Phase 1 Habitat Survey (2010) ‘A technique for environmental audit’35 Highway England’s memorandum ‘Supporting Transparency around our Biodiversity Performance’36 7.5 Methodology Desk Study A desk study was undertaken to review existing information on Priority Habitats and invasive plant species within 500m of the highway boundary. Further details of the Desk Study are provided in section 1.3 of this report. Field survey The Extended Phase 1 Habitat Survey was undertaken during daylight hours between the 20 and 21 June 2018. All survey visits were undertaken by two suitably qualified surveyors, ecologists experienced in botanical survey work and the identification of the potential for protected and/or notable species. The habitats have been mapped and are shown in Figure 2.1 – Extended Phase 1 Survey Areas Plan, provided in Appendix B. Table 2.1 summarises the survey dates, in addition to the area covered during each survey. Table 2.1 - Extended Phase 1 Survey Dates and Areas Included 21
Visit Dates Location and Grid Reference Number 1 20 Southern A1(M) section including areas within and adjacent to June Junctions 6 to 7, northbound and southbound between these 2018 junctions. 2 21 Northern A1(M) section including areas within and adjacent to June Junctions 7 to 8, northbound and southbound between these 2018 junctions. The habitats recorded within the study area were assessed for any evidence of and potential for legally protected and notable fauna, in accordance with CIEEM guidance34. These habitats were broadly mapped following the Phase 1 habitat classifications from the JNCC Handbook for Phase 1 Habitat Survey35. Target notes were recorded to identify habitats, species compositions and invasive plant species within the habitats mapped. The following initial assessments were also undertaken as part of this survey: • Initial assessment for the presence of priority habitats and legally protected plant species (Schedule 8 species ); • Initial assessment for the presence of non-native invasive species (Schedule 9 species); • ‘Ground-truthing’ of accessible waterbodies for great crested newt;
34 CIEEM (2017) Guidelines for Preliminary Ecological Appraisal, 2nd edition. Chartered Institute of Ecology and Environmental Management, Winchester. 35 [may be accessed via the following link] http://jncc.defra.gov.uk/PDF/pub10_handbookforphase1habitatsurvey.pdf 36 Chief Highways Engineer Memorandum 422/18 ‘Supporting Transparency around our Biodiversity Performance’ A1(M) J6-8 SM: Ecological Survey Report 7
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
• High-level assessment of potential roosting sites for bats on structures; • High-level assessment of watercourses for otter and water vole; • Search for signs of badger activity and habitat suitability assessment for badger; and • Habitat suitability assessment for dormouse, breeding birds, reptiles and any other protected and/or notable faunal species or groups (e.g. Section 41 Priority Species). 7.6 Survey Limitations There were no areas excluded from the survey, as all areas were mapped using a combination of survey walkover, vantage point observation and desk study online mapping tools. Areas that could not be surveyed via a walkover in 2018, were investigated by way of a desk study and ‘drive by’ survey. No data is considered to be missing with regard to ground truthing habitats throughout the highways boundary, as aerial mapping and driving the A1(M) between junction 6 and 8 provided sufficient visual information on the current state of habitats across the Proposed Scheme. However, it is considered that some detailed species survey information (i.e. presence of badger setts and bat roosts etc.) will be limited because of the restrictions on survey work within the soft estate during the 2018 survey programme. 7.7 Results Desk Study The Magic® data search identified Priority Habitats within 500m of the highway boundary and those Priority habitats connected to habitats occurring within 500m as set out in Table 2.2 and shown on Figure 2.2 – Priority Habitats within 500m Plan in Appendix B. Table 2.2 - Priority Habitat Adjacent to the Proposed Scheme 22 Area occurring within Area occurring within Habitat 500m of highway 500m of highway boundary (m²) boundary (ha) Coastal and floodplain 18,265.1 1.8 grazing marsh Deciduous Woodland 2,003,088.9 200.3 Good quality semi- 239,640.9 23.9 improved grassland No main habitat additional habitats 177,048.2 17.7 present Traditional orchard 3,922.4 0.3 Total 2,441,965.6 244.1
In addition, there is 622,848m² (62.28ha) of Ancient Woodland within 500m of the Proposed Scheme boundary is shown on Figure 2.3 – Ancient Woodland within 500m Plan in Appendix B. Field Surveys The field survey has identified the following total area of the following habitat types based upon the classification provided in Highway England’s memorandum ‘Supporting Transparency around our Biodiversity Performance’ as set out in Table 2.3. Table 2.3 - Phase 1 habitat types and areas within the highway boundary 23 Phase 1 Habitat Description Area (m²) Area (ha) Code
A1(M) J6-8 SM: Ecological Survey Report 8
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
A1.1.1 Broad-leaved woodland 322,154.1 32.2 A1.2.1 Coniferous woodland 0.0 0.0 A1.3.1 Mixed woodland 24,914.3 2.5 A2.1 Scrub - dense/continuous 25,488.8 2.5 A3.1 Broad-leaved Parkland/scattered trees 4,663.2 0.5 B2.2 Neutral grassland - semi-improved 0.0 0.0 B4 Improved grassland 1,726.7 0.2 B6 Poor semi-improved grassland 98,776.5 9.9 C3.1 Other tall herb and fern - ruderal 2,095.7 0.2 F1 Swamp 69.3 0.0 G1 Standing water 637.1 0.1 G2 Running water 165.2 0.0 SJ1.1 Cultivated/disturbed land - arable 395.8 0.0 J1.2 Cultivated/disturbed land - amenity 29,869.5 3.0 grassland J1.3 Cultivated/disturbed land - ephemeral/short 5.1 0.0 perennial J1.4 Introduced shrub 22.4 0.0 J2.3.2 Hedge with trees - species-poor 952.2 0.1 J3.6 Buildings 309.0 0.0 J4 Bare ground 557.1 0.1 J5.1 Hardstanding 433,324.9 43.3 Totals 946,126.9 94.6 Further Surveys The field surveys supported the following conclusions as to the potential for protected and/or notable species or habitats that specific surveys within the zone of influence are required. Further surveys are appropriate for the following species: • Great crested newt; • Roosting bats; and • Otter and water vole. 7.8 Conclusions and Recommendations The surveys show that most of the habitats present within the highway boundary are common and widespread. Three habitats that occur within the highway boundary are considered to be notable as they are Habitats of Principal Importance, these are; Semi- improved grassland, Lowland mixed deciduous woodland, Hedgerows, Ponds and River.
A1(M) J6-8 SM: Ecological Survey Report 9
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 8. Great Crested Newt 8.1 Summary
• Forty-six waterbodies were scoped in to the eDNA surveys; • Twenty-two of these 46 waterbodies were not subject to survey in 2018 due to access restrictions i.e. refusal or no response from landowners; • Twenty-four waterbodies were visited in 2018, with eDNA surveys subsequently being undertaken at 13 of them, and 11 not surveyed due to the waterbody being either dry or not present or unsuitable for breeding great crested newt; • Four of the 46 waterbodies were discovered during the survey work in 2018; • Two waterbodies confirmed as supporting great crested newt within 50m; • Four waterbodies confirmed as supporting great crested newt between 50 and 250m; • No waterbodies will be lost to the Proposed Scheme; • 52% of the identified waterbodies have been surveyed in 2018. • Presence/Absence Surveys and Population Size Estimates for great crested newt have not been undertaken at this time, due to survey window constraints. • There are 28 waterbodies that still require survey work in 2019 (population estimates for the six waterbodies confirmed as supporting great crested newts in 2018, and HSI/eDNA on the 22 waterbodies that could not be surveyed in 2018. 8.2 Survey Objectives The aim of this chapter is to address the following: • Records of great crested newt from EnvIS and HERC (the local records centre) within 2km of the Proposed Scheme; • Provide baseline information on the presence of great crested newt within the ZoI of the Proposed Scheme (waterbodies within 250m of the carriageway); • Propose further surveys for great crested newt; and • Provide initial guidance as to likely mitigation requirements and licensing for great crested newt. 8.3 Scope and Study Area The 2018 survey focused on determining the risk of adversely affecting great crested newt during construction of the Proposed Scheme, based on likely areas of impact. Waterbodies up to 250m from the carriageway have been included in the assessment/survey, comprising the study area. Further detail on the study area is provided in section 1.3 of this report. Waterbodies within the scope of the 2018 survey that could not be included for reasons such as access limitations or for health and safety concerns are detailed within the Survey Limitations (section 3.6) of this report. As no waterbodies will be lost, damaged or degraded as a result of construction or operation of the Proposed Scheme, the risk to great crested newts is limited to loss and/or disturbance of terrestrial habitat. The risk to great crested newts also includes potential for any amphibians to be harmed or disturbed if present in the terrestrial habitat when the works are undertaken.
A1(M) J6-8 SM: Ecological Survey Report 10
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
8.4 Legislative Context The great crested newt is listed on Schedule 5 of the Wildlife and Countryside Act 1981 (as amended). It is also listed on Schedule 2 of The Conservation of Habitats and Species Regulations 2017 (as amended) making it a European Protected Species. This legislation, when taken together, results in a level of protection that prohibits the intentional, deliberate or reckless: • Killing, injuring, taking or disturbance of great crested newts; and • Damaging, destroying or obstructing any place used by great crested newts for the purposes of breeding, sheltering/protection. Great crested newt and common toad (Bufo bufo) are listed under Section 41 of the NERC Act 2006 as Species of Principal Importance for Conservation in England. Section 40 of the same Act requires that local and regional authorities have regard to the conservation of biodiversity in England, when carrying out their normal functions. Current Guidance In preparing this report, regard has been given to current guidance and best practice, comprising: • Great Crested Newt Mitigation Guidelines (2001)37; • Herpetofauna Workers Manual (1998)38; • Great Crested Newt Conservation Handbook (2001)39; • Great Crested Newt Habitat Suitability Index (2010)40; and • Analytical and methodological development for improved surveillance of the Great Crested Newt (2014)41. 8.5 Methodology Desk Study A desk study was undertaken to obtain existing records of great crested newt for the Proposed Scheme and its locality. Further details of the desk study are provided in section 1.3 of this report. Ordnance Survey mapping and aerial photography were reviewed to identify waterbodies and to inform requirements for survey in respect of great crested newt. The Natural England rapid risk assessment tool was used to calculate the notional probability of an offence being committed based upon potential impacts to ponds and/or surrounding habitat, displayed as a risk: Probability Risk < 0.3 green 0.3 to 0.65 amber > 0.65 red The tool considers all waterbodies within 500m of the Proposed Scheme, however surveys of waterbodies between 250-500m are normally only appropriate when the following conditions are met: • The pond has the potential to support a large population of great crested newt;
37 English Nature (2001). Great crested newt mitigation guidelines. English Nature, Peterborough 38 Gent, AH & Gibson, SD (eds.) (1998) Herpetofauna Worker’s Manual. Peterborough: Joint Nature Conservation Committee 39 Langton, T, Beckett, C & Foster, J (2001) Great Crested Newt Conservation Handbook. Froglife, Suffolk 40 Oldham R.S., Keeble J., Swan M.J.S. & Jeffcote M. (2000) Evaluating the suitability of habitat for the Great Crested Newt (Triturus cristatus). Herpetological Journal 10(4), 143-155 41 Biggs J, Ewald N, Valentini A, Gaboriaud C, Griffiths RA, Foster J, Wilkinson J, Arnett A, Williams P and Dunn F (2014) Analytical and methodological development for improved surveillance of the Great Crested Newt. Appendix 5. Technical advice note for field and laboratory sampling of great crested newt (Triturus cristatus) environmental DNA. Freshwater Habitats Trust, Oxford. A1(M) J6-8 SM: Ecological Survey Report 11
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
• The footprint of the Proposed Scheme contains particularly favourable habitat and/or provides the majority of that available; • The Proposed Scheme would have a substantial negative effect on that habitat; and • There is an absence of dispersal barriers. The Natural England rapid risk assessment tool was run on all waterbodies within 500m of the Proposed Scheme, which were scoped in/out based on the following principles: • Waterbodies of ‘red’ or ‘amber’ risk within 250m were automatically scoped in for further survey; • Waterbodies of ‘red’ or ‘amber’ risk between 250-500m were assessed using aerial mapping for habitat quality, connectivity and barriers to dispersal and scoped in or out accordingly; and • Waterbodies identified as ‘green’ risk were scoped out. As a result of the desk study, 46 waterbodies were scoped in for further assessment for their potential to support great crested newt. Each waterbody was assigned a unique reference ID and mapped using GIS. Extended Phase 1 Habitat Survey As part of this survey, waterbodies and other features of interest were ‘ground-truthed’ and accessible areas within the ZoI which were identified to have waterbodies with the potential to support great crested newt were subject to a HSI and eDNA assessment. Field Survey All survey visits were undertaken by suitably qualified surveyors; Chris Horley, Jessica Hinds, Katie Johnson and Genevieve Labram. All ecologists are experienced in survey techniques for great crested newt. A formal assessment of habitat suitability for great crested newt was carried out at each waterbody scoped in. All HSI assessments were completed on the same visit as the eDNA survey for each waterbody between 25 and 29 June 2018. Surveyed waterbodies are shown on Figure 3.1a and 3.1b – Waterbodies Surveyed Plan, provided in Appendix C. ‘Ground-truthing’ Exercise The ‘ground-truthing’ exercise resulted in 11 of the 24 waterbodies being scoped out of further assessment with no further survey required (see Table 3.2). The ground-truthing also resulted in an additional four waterbodies being identified, which had not been apparent using desktop methods. After the ‘ground-truthing’ exercise 13 waterbodies were scoped in for the HSI assessment. Habitat Suitability Index (HSI) Assessments HSI40 is a mathematical model that incorporates ten suitability indices influencing the likelihood of the presence of great crested newt in a waterbody. The output of a HSI assessment is a score between 0 (unsuitable) and 1 (optimal). The HSI is calculated using the following formula: HSI = (SI1 x SI2 x SI3 x SI4 x SI5 x SI6 x SI7 x SI8 x SI9 x SI10)1/10. The Suitability Indices are set out in Table 3.1.
A1(M) J6-8 SM: Ecological Survey Report 12
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 3.1 - Habitat Suitability Indices for Great Crested Newt 24 Suitability Indices Factor SI1 Geographic Location SI2 Pond Area SI3 Permanence SI4 Water Quality SI5 Shade SI6 Waterfowl SI7 Fish SI8 Additional Ponds Within 1 km SI9 Terrestrial Habitat SI10 Macrophyte Cover HSI Pond Suitability Summary Scores < 0.50 = poor 0.50 – 0.59 = below average 0.60 – 0.69 = average 0.70– 0.79 = good > 0.80 = excellent A total of 13 waterbodies were assessed using the standardised HSI. Waterbodies with an HSI value of 0.5 or less are considered to be of ‘poor’ and as such have generally been scoped out of further survey. However, as HSI is an indicative tool with a subjective methodology, professional judgement has been employed with the occasional result of a waterbody with a value less than 0.5 being scoped in. Waterbodies scoped out by HSI are provided in Table 3.2. Following the HSI assessment, a total of 13 waterbodies were scoped in for further survey. Environmental DNA (eDNA) Surveys The eDNA sampling of 13 waterbodies alongside the first traditional survey visit followed the methodology provided by Freshwater Habitats Trust11. The sampling was carried out by licenced great crested newt surveyor; Chris Horley - Natural England WML CL09 – Great Crested Newt Survey Licence: Level 2. Supporting ecologists on site include Katie Johnson, Jessica Hinds and Genevieve Labram. Negative results are only admissible within the period 15 April to 30 June and all samples were taken within this screening window. The samples were sent to an approved laboratory for analysis. The laboratory used was: • NatureMetrics Ltd, CABI site, Bakeham Lane, Egham, Surrey, TW20 9T (Company no. 09243907) 8.6 Survey Limitations As a result of access restrictions, it was not possible to survey 22 waterbodies in 2018, as shown in Table 3.2, and provided in Figure 3.2a and 3.2b – Waterbodies Not Surveyed 2018 Plan. Surveys of these waterbodies should ideally be scheduled in 2019 prior to scheme construction. As such, a total of 24 waterbodies were left within the Zol that could be accessed. The 22 waterbodies not accessed are assumed to have GCN present, as a precautionary measure. Due to significant dry periods during 2018, a large proportion (9 out of 24) of the originally scoped waterbodies within the Zol could not be surveyed as they had completely or partially dried out within the newt breeding season, and one waterbody was no longer present.
A1(M) J6-8 SM: Ecological Survey Report 13
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
In addition, due to the limited time available before the newt survey season window ended, no conventional survey methods were used during 2018. The results of the eDNA will advise on further surveys for the 2019 season. Table 3.2 - Waterbodies not included for assessment in 201825 Distance from Waterbody Grid Reference A1(M) centre Reason ID line (m) 8-GCN-1 TL 23628 15585 200 Access refused 8-GCN-2 TL 23655 15599 200 Access refused 8-GCN-3 TL 23476 15631 45 Low HSI score (flowing water, highly unsuitable) 8-GCN-5 TL 24372 19158 35 Waterbody dry 8-GCN-6 TL 23959 21052 30 Waterbody dry 8-GCN-12 TL 22916 23177 200 No response to access request 8-GCN-13 TL 22124 24523 40 Waterbody dry 8-GCN-15 TL 22096 25015 90 No response to access request 8-GCN-16 TL 22180 25072 130 No response to access request 8-GCN-17 TL 22041 25994 25 No response to access request 8-GCN-18 TL 22265 26137 60 Waterbody dry 8-GCN-19 TL 22029 26143 120 No response to access request 8-GCN-20 TL 21830 26297 240 No response to access request 8-GCN-21 TL 22530 26714 60 No response to access request 8-GCN-22 TL 22379 26796 50 No response to access request 8-GCN-23 TL 22331 26851 115 No response to access request 8-GCN-24 TL 22294 26888 150 No response to access request 8-GCN-25 TL 22254 26936 220 No response to access request 8-GCN-35 TL 22581 26694 150 No response to access request 8-GCN-36 TL 22240 26951 240 No response to access request 8-GCN-37 TL 22488 26733 50 No response to access request 8-GCN-41 TL 22305 26187 90 No response to access request 8-GCN-45 TL 22500 26671 70 No response to access request 8-GCN-50 TL 24182 18210 55 No response to access request 8-GCN-51 TL 24304 18210 40 Waterbody dry 8-GCN-52 TL 24350 19450 35 Waterbody dry 8-GCN-53 TL 24313 19863 35 Waterbody dry 8-GCN-54 TL 24301 19865 30 No waterbody present 8-GCN-59 TL 22108 25055 105 No response to access request 8-GCN-60 TL 22109 25039 100 No response to access request 8-GCN-64 TL 23852 21625 40 Waterbody dry 8-GCN-65 TL 23999 21092 30 Waterbody dry 8-GCN-81 TL 22166 24794 100 No response to access request 8.7 Results Desk Study The HERC returned 15 records of great crested newt within 2km of the Proposed Scheme between 2013 and 2016, as provided in Table 3.3. The closest great crested newt record is approximately 200m from the Proposed Scheme, associated with Knebworth Woods SSSI. Records from EnvIS identified one entry of great crested newt dated 2013 as provided in Table 3.3 approximately 10m from the highway boundary, associated with the Watery Grove area of Knebworth Woods SSSI. Photographs of waterbodies visited in 2018 are presented in Appendix C.
A1(M) J6-8 SM: Ecological Survey Report 14
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Habitat Suitability Index In total, 14 waterbodies were subject to HSI assessment. The HSI values are provided in Table 3.4. eDNA The results of the 13 waterbodies subject to eDNA testing are summarised in Table 3.5. A total of 6 waterbodies tested positive for great crested newt and 7 negative. Table 3.3 - Great Crested Newt Desk Study Records 26 Record Record Distance from Year Approx. Grid Ref Source Type Carriageway (m) HERC Observation 2013 TL2323 0 HERC Observation 2016 TL2213 0 HERC Observation 2016 TL2214 0 EnvIS Sighting 2013 TL 23060 23273 25 HERC Observation 2016 TL2113 220 HERC Observation 2016 TL2113 220 HERC Observation 2015 TL2114 290 HERC Observation 2016 TL2114 290 HERC Observation 2013 TL2223 1050 HERC Observation 2013 TL2223 1050 HERC Observation 2016 TL2410 1290 HERC Observation 2015 TL2410 1290 HERC Observation 2015 TL2410 1290 HERC Observation 2016 TL2410 1290 HERC Observation 2016 TL2617 1750 HERC Observation 2016 TL 2617 1750 Table 3.4 - Habitat Suitability Index Assessment 27 Waterbody Waterbody Approx. Grid Ref HSI Value ID Suitability 8-GCN-03 TL 23476 15631 0.31 Poor 8-GCN-33 TL 21950 26257 0.5 Poor 8-GCN-39 TL 22244 26060 0.65 Average 8-GCN-40 TL 22218 26486 0.68 Average 8-GCN-56 TL 22974 23227 0.79 Good 8-GCN-67 TL 23844 21622 0.30 Poor 8-GCN-69 TL 23182 22909 0.52 Below Average 8-GCN-70 TL 23191 22917 0.70 Good 8-GCN-76 TL 23062 23259 0.64 Average 8-GCN-84 TL 22901 23397 0.73 Good 8-GCN-85 TL 23009 23102 0.93 Excellent 8-GCN-86 TL 23181 22934 0.43 Poor 8-GCN-87 TL 21896 26191 0.69 Average 8-GCN-88 TL 21950 21203 0.61 Average
A1(M) J6-8 SM: Ecological Survey Report 15
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 3.5 - Great Crested Newt eDNA Results 28
Waterbody ID Approx. Grid Ref Result 8-GCN-33 TL 21950 26257 Negative 8-GCN-39 TL 22244 26060 Negative 8-GCN-40 TL 22218 26486 Positive 8-GCN-56 TL 22974 23227 Positive 8-GCN-67 TL 23844 21622 Negative 8-GCN-69 TL 23182 22909 Negative 8-GCN-70 TL 23191 22917 Positive 8-GCN-76 TL 23062 23259 Negative 8-GCN-84 TL 22901 23397 Positive 8-GCN-85 TL 23009 23102 Positive 8-GCN-86 TL 23181 22934 Positive 8-GCN-87 TL 21896 26191 Negative 8-GCN-88 TL 21950 21203 Negative
There are 22 waterbodies that could not be surveyed due to land access in 2018. Surveys of these waterbodies should therefore be scheduled for 2019. It is currently unknown whether access to remaining land parcels (for un-surveyed waterbodies) will be resolved in 2019 (See Figure 3.2a and 3.2b). Until these 22 waterbodies can be surveyed, it should be assumed that great crested newts are present within them, until further surveys in the appropriate season can be completed to prove otherwise. Due to the significantly dry weather in 2018 all waterbodies with remaining water were sampled further for eDNA surveys, except for waterbody “8-GCN-3” which did have water which was flowing, and scored 0.31 (Poor) on the HSI, and therefore deemed highly unsuitable as great crested newt breeding habitat. 8.8 Conclusions and Recommendations Summary Approximately 52% of the identified waterbodies have been surveyed. Fourteen waterbodies were subject to HSI assessment and 13 of those waterbodies were subject to eDNA survey. The remaining waterbodies will need to undergo assessment within the great crested newt survey window in 2019, considered to be March to June (weather dependent). Two waterbodies have been identified within 50m and four between 50m and 250m of the Proposed Scheme which support great crested newt. In addition, 22 waterbodies that could not be assessed (due to access restrictions) are also assumed to support great crested newt. The locations of these waterbodies are shown on Figures 3.1a, 3.1b, 3.2a and 3.2b and provided in Appendix C. The Proposed Scheme will not result in the loss of any waterbodies supporting great crested newts, nor the severance of any links between known breeding ponds. Predicted impacts as a result of the Proposed Scheme would be the loss of terrestrial habitat, likely to be used by great crested newts for shelter and foraging. The loss of terrestrial habitats could potentially result in the killing of, and injury to, individual great crested newts during clearance and construction works (in the absence of mitigation).
A1(M) J6-8 SM: Ecological Survey Report 16
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
It is currently anticipated that the loss of suitable terrestrial habitats within 500m of waterbodies supporting great crested newts will be as shown in Table 3.6. Note, this table does not include the 22 waterbodies not surveyed in 2018, as presence of great crested newts within them has not yet been confirmed. Table 3.6 - Great Crested Newt Terrestrial Habitat Loss 29 Distance of pond(s) supporting great Approximate loss of terrestrial crested newts habitat (ha) within 50m 0.11 between 51m and 250m 2.63 between 251m and 500m 3.80
Works within 50m of a waterbody identified as supporting great crested newt are likely to trigger an offence in the absence of mitigation. Works beyond 50m but within 250m may negatively impact great crested newt; however, the impact is considered of a lower risk. These works may be able to be undertaken using Reasonable Avoidance Measures (RAMs) and not require a mitigation licence from Natural England. However, it is anticipated that a site wide mitigation licence from Natural England will be required. Mitigation It is anticipated that suitable terrestrial habitats to be affected by the Proposed Scheme will be subject to a capture and translocation exercise. Once a mitigation licence has been obtained, great crested newt exclusion fencing would be erected and pitfall traps installed in suitable locations. The window for carrying out this work is taken as March to June (weather dependant). The fencing would facilitate the capture and translocation of great crested newts from land within the footprint of the Proposed Scheme, and would prevent great crested newts from recolonising the area during the construction period. The installation of fencing and pitfalls traps (including necessary vegetation clearance) and other sensitive operations would be undertaken under the direct supervision of a suitably qualified and experienced ecologist, to minimise any potential for harm to great crested newts. Any newts encountered during the fence installation would be moved by hand to an appropriate location (to be agreed) by the supervising ecologist. Regard would be given to night-time temperatures during this period, with fencing installed only where temperatures overnight are over 5oC. Once the fencing and pitfalls traps have been installed, daily checks of the traps would be undertaken by a suitably qualified and experienced ecologist. In line with guidance from Natural England37, trapping would be undertaken for a minimum period of 30 nights for small populations and 60 nights for medium populations in suitable weather conditions (night air temperature of over 5oC with rain at least in the last few days). Once five trapping nights have occurred with no newts captured, it may be considered that sufficient effort will have been expended and the translocation exercise may move onto the destructive search phase. At the destructive search stage, fencing and pitfall traps would be removed under the supervision of the suitably qualified and experienced ecologist. Any areas of suitable terrestrial habitat located within the footprint of the Proposed Scheme would then be subject to a destructive search, involving the systematic removal of areas of grassland, hedgerow, scrub and trees under the direct supervision of the suitably qualified and experienced ecologist. In the event that any great crested newts or other amphibians were encountered at this stage, they would be captured and released in a suitable location (to be agreed). Once all habitats have been removed, it may be concluded that no great crested newts remain within the footprint of the Proposed Scheme, and the development works may proceed.
A1(M) J6-8 SM: Ecological Survey Report 17
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Enhancement opportunities Potential opportunities for enhancements for great crested newt have been identified at the locations provided in Table 3.7. These opportunities may form part of a mitigation strategy for this species (e.g. as part of a licence application), in order to maintain the favourable conservation status of the population. Table 3.7 - Great Crested Newt Opportunities for Enhancement30 Land Approx. Grid Ref Potential Enhancement Opportunity Parcel ID HD408424 TL 23108 22966 Artificial hibernacula, log piles and pond creation in watery grove (Knebworth Woods SSSI)
A1(M) J6-8 SM: Ecological Survey Report 18
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 9. Roosting Bats 9.1 Summary
• Preliminary roost assessments for bats have been undertaken at 14 structures; • No bat roosts were identified within the soft estate; • No bat roosts were identified within 20m of the highway boundary; • Five structures could not be surveyed in 2018 due to no access permitted within the highway boundary i.e. soft estate; • 74% of the identified potential roost sites (structures only) have been subject to Preliminary Roost Assessments.
9.2 Survey Objectives This chapter provides a review of the following: • Existing ecological data to identify Special Areas of Conservation (SACs) with bats as qualifying features within 30km; • Records of bats from EnvIS and the local records centre within 2km of the Proposed Scheme; • Baseline information on the presence of roosting bats within the ZoI of the Proposed Scheme (structures within the soft estate and immediately adjacent habitat); • Further surveys for bats; and • Initial guidance as to likely mitigation requirements and licensing. 9.3 Scope and Study Area The 2018 survey focused on determining the risk of affecting bat species during construction of the Proposed Scheme, based on likely areas of impact. The survey considered all structures within the highway boundary and immediately adjacent habitat, within 20m of the highway boundary. Further detail on the study area is provided in section 1.3 of this report. A total of 5 structures within the scope of the 2018 survey that could not be included for reasons such as access limitations or for health and safety concerns are detailed within the Survey Limitations (section 4.6) of this report. 9.4 Legislative Context All UK bat species are listed on Schedule 5 of the Wildlife and Countryside Act 1981 (as amended). All UK bat species are also listed on Schedule 2 of The Conservation of Habitats and Species Regulations 2017 (as amended) making them European Protected Species. This legislation, when taken together, results in a level of protection that prohibits the intentional, deliberate or reckless killing, injuring, taking or disturbance of bats; and damaging, destroying or obstructing any place used by bats for the purposes of breeding, sheltering/protection. In addition, Barbastelle Bat (Barbastella barbastellus), Bechstein’s Bat (Myotis Bechsteinii), Noctule (Nyctalus noctula), Soprano Pipistrelle (Pipistrellus pygmaeus), Brown Long-eared Bat (Plecotus auritus), Greater Horseshoe (Rhinolophus ferrumequinum) and Lesser Horseshoe (Rhinolophus hipposideros) are listed under Section 41 of the NERC Act 2006 as Species of Principal Importance for Conservation in England. Section 40 of the same Act requires that planning authorities have regard to the conservation of biodiversity in England, when carrying out their normal functions.
A1(M) J6-8 SM: Ecological Survey Report 19
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Current Guidance In preparing this report regard has been given to current guidance and best practice, comprising:
Bat Conservation Trust (BCT) Guidelines (2016)42. 9.5 Methodology Desk Study A search for SACs with bats as qualifying features within 30km of the Proposed Scheme was undertaken using the Magic® website (www.magic.gov.uk). A desk study was undertaken to obtain existing records of bat species within 2km of the Proposed Scheme. Further details of the desk study are provided in section 1.3 of this report. The nature of any proposed works at each structure was determined to identify whether the activity was likely to cause either a loss of or direct impacts to roosts, or a level of disturbance above that of the existing live motorway. Extended Phase 1 Habitat Survey As part of this survey, a high-level assessment was carried out to locate structures with the potential to support roosting bats within the ZoI and to scope out those with ‘negligible’ roosting potential. Field Survey Preliminary Roost Assessment of Structures Preliminary Roost Assessments of structures scoped in during the Extended Phase 1 habitat survey were undertaken on 21 August 2018. All survey visits were undertaken during daylight hours by 2 suitably qualified surveyors (Chris Horley and Genevieve Labram), experienced in searching for signs of bats and bat roosting opportunities. Maps detailing surveyed structures are shown on Figure 4.1 – Structures Surveyed for Roosting Bats, provided in Appendix D. All structures were assessed against the following criteria set out in the current BCT Guidelines42, as follows: • Negligible – Not thought likely to be used as a bat roost; • Low – A structure with one or more potential roost features that may be used by individual bats opportunistically or a tree of sufficient size and age to contain potential roost features but with none seen from the ground or features seen with only very limited roosting potential; • Moderate – A structure or tree with one or more potential roost features that could be used by bats due to their size, shelter, protection, conditions and surrounding habitat, but unlikely to hold a roost of high conservation status; • High – A structure or tree with one or more potential roost features that are obviously suitable for the use by large numbers of bats on a more regular basis and potentially for longer periods of time due to their size, shelter, protection, conditions and the surrounding habitat. Survey Limitations Due to access not being permitted within the highway boundary soft estate, and subsequent restricted views of some structures on the A1(M) roadside, it was not possible to survey 5 bridge structures in 2018, as shown in Table 4.1 and provided in Figure 4.1 – Structures Surveyed for Roosting Bats, provided in Appendix D.
42 Collins J. (ed.) (2016). Bat Surveys for Professional Ecologists: Good Practice Guidelines (3rd edition). The Bat Conservation Trust, London A1(M) J6-8 SM: Ecological Survey Report 20
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Access to the soft estate next to the carriageway will require additional health and safety controls to be put in place, in order to facilitate safe access to survey inaccessible areas of the A1(M). Table 4.1 - Un-Surveyed Features for Bats 31
Un-Surveyed Structure Grid Reference Reason Not Surveyed Feature ID Name Langley No vantage points to provide Sidings suitable coverage of bridge Bridges 10 and South & TL 23556 22470 structure. Inaccessible along 11 Langley TL 23512 22578 A1(M) due to no access permitted Sidings within the highway boundary in North the soft estate Todds No access on Network rail land, Bridges 17 Green TL 22353 26546 and no vantage points suitable for railway detailed observation. No vantage points to provide Coreys Mill suitable coverage of bridge Bridges 18 and South & TL 22523 27064 structure. Inaccessible along 19 Coreys Mill TL 22491 26944 A1(M) due to no access permitted North within the highway boundary in the soft estate 9.6 Results Desk Study The HERC returned 76 records of bat species within 2km of the Proposed Scheme since the year 2009. Some bat records are located close to the A1(M). Details are provided in Table 4.2. Records from EnvIS identified 2 entries of bat species from 2013, as provided in Table 4.2. Photographs of structures visited in 2018 are presented in Appendix D.
A1(M) J6-8 SM: Ecological Survey Report 21
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 4.2 – Bat Records32 Records Grid ref. of Approx. distance Record No. of Species from closest from Source records years record Carriageway (m) EnvIS Common 2 2013 TL 22029 40 Pipistrelle 25035 & (Pipistrellus TL 23610 pipistrellus) 16810 HERC Common 28 2009 - TL2420 240 Pipistrelle 2017 (Pipistrellus pipistrellus) HERC Soprano 10 2011 - TL2226 100 Pipistrelle 2017 (Pipistrellus pygmaeus) HERC Brown Long- 12 2009 - TL2420 240 eared Bat 2016 (Plecotus auritus) HERC Noctule Bat 11 2009 - TL2223 1020 (Nyctalus 2017 noctula) HERC Leisler’s Bat 2 2014 TL2313 670 (Nyctalus leisleri) HERC Natterer’s Bat 3 2011 - TL2317 650 (Myotis 2014 nattereri) HERC Daubenton’s 4 2015 - TL2317 650 Bat (Myotis 2017 daubentonii) HERC Serotine 2 2012 - TL2221 1890 (Eptesicus 2013 serotinus) HERC Western 4 2017 TL2221 1890 Barbastelle (Barbastella barbastellus) Field Survey Preliminary Roost Assessment Preliminary Roost Assessments were undertaken at 14 structures in total; of these 11 were bridges and 3 were subways/underpasses, all bisecting the A1(M). These are detailed in Table 4.3 which includes their location and distance from the carriageway, location type, a description of the Potential Roost Feature (PRF) and the result of the assessment, in accordance with the criteria set out within section 4.5. As a result of the Preliminary Roost Assessment, all 14 structures scored low and are considered to have negligible potential to support roosting bats and therefore further surveys are not deemed necessary.
A1(M) J6-8 SM: Ecological Survey Report 22
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 4.3 - Potential Roost Assessment for Bats33
Structure Distance from Survey Structure Bat Potential after Grid Reference Type Notes ID Carriageway Date Description Ground Assessment Structure TL 22805 14801 Intersects Bridge 21.08.18 Digswell Hill Join of supporting wall and bridge filled Negligible No. 1 A1(M) over Bridge. with white rubber sealant, creating lack A1(M) Concrete cast of spaces for roosting bats. High noise overbridge. and vibration levels. Structure TL 23434 15718 Intersects Bridge 21.08.18 Welwyn Road Lighting underneath, frequent Negligible No. 2 A1(M) under Bridge. disturbance with traffic, high noise and A1(M) Concrete cast vibration. Good state of repair. underbridge. Structure TL 23566 16517 Intersects Bridge 21.08.18 Clock Underbridge. Lighting underneath, frequently Negligible No. 3 A1(M) under Concrete cast disturbed by traffic, high noise and A1(M) underbridge. Brick vibration. Gap located between brick supporting walls. supporting wall and concrete, but not suitable. Structure TL 23861 17315 Intersects Bridge 21.08.18 The Avenue 16 Pillars, no space i.e. no gaps in the Negligible No. 4 A1(M) under Bridge. Concrete concentrate underneath to provide A1(M) cast bridge with roosting opportunities for bats. pillars. Structure TL 24190 18068 Intersects Bridge 21.08.18 Pottersheath Road No street lighting on A1(M). High noise Negligible No. 5 A1(M) over Bridge. Concrete levels, no visible evidence of bats. No A1(M) cast overbridge. suitable roost spaces identified. Structure TL 24343 18622 Intersects Subwa 21.08.18 Ninnings Wood No lighting, no roost spaces or Negligible No. 6 A1(M) y under Subway. crevices to provide opportunities. A1(M) Pedestrian subway A1(M) noise above. tunnel under A1(M) Structure TL 24323 19218 Intersects Bridge 21.08.18 Gypsy Lane No suitable roost spaces identified. Negligible No. 7 A1(M) over Bridge. Concrete Bridge in good state of repair. A1(M) cast overbridge. Structure TL 24223 20223 Intersects Bridge 21.08.18 Park Lane Bridge. No suitable roost spaces identified. Negligible No. 8 A1(M) over Concrete cast A1(M) overbridge. Structure TL 23810 21628 Intersects Bridge 21.08.18 North Lodge 20 pillars, maintenance steel Negligible No. 9 A1(M) under Bridge. Concrete scaffolding underneath, no obvious A1(M) cast overbridge.
A1(M) J6-8 SM: Ecological Survey Report 23
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Structure Distance from Survey Structure Bat Potential after Grid Reference Type Notes ID Carriageway Date Description Ground Assessment roost spaces, no lighting but high noise and vibration from A1(M). Structure TL 22988 25411 Intersects Subwa 21.08.18 Norton Green Lighting within subway, no features Negligible No. 12 A1(M) y under Pedestrian subway considered suitable for roosting bats. A1(M) tunnel under A1(M) Close to Knebworth Woods SSSI. Structure TL 22655 23836 Intersects Bridge 21.08.18 Chadwell Road No lighting, noise or vibration from Negligible No. 13 A1(M) under Bridge. Brick and A1(M). Crevices/spaces present not A1(M) concrete built deep enough to provide roosting bridge. opportunities. Structure TL 22143 24556 Intersects Bridge 21.08.18 Kitching Lane No lighting, noise or vibration from Negligible No. 14 A1(M) under Bridge. Brick and A1(M). No obvious roosting spaces, A1(M) concrete built good state of repair. bridge. Structure TL 21985 25116 Intersects Subwa 21.08.18 Symonds Green No lighting, tunnel without suitable Negligible No. 15 A1(M) y under tunnel under A1(M) roost spaces, in good state of repair. A1(M) Structure TL 22203 26196 Intersects Bridge 21.08.18 Fishers Green No street lighting on A1(M). High noise Negligible No. 16 A1(M) over Bridge. Concrete levels, no visible evidence of bats. No A1(M) cast overbridge. suitable roost spaces identified.
A1(M) J6-8 SM: Ecological Survey Report 24
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
9.7 Conclusions and Recommendations All identified structures were subject to a preliminary roost assessment apart from bridges 10, 11, 17, 18 and 19. These should be subject to survey once access become available, as no vantage points were sufficient to complete an assessment, and would only be completed with sufficient access to the soft estate. In summary, survey work of the identified structures did not identify any potential for bat roosts and hence the Proposed Scheme is highly unlikely to have a potential effect on roosting bats and no licence is required from Natural England. The desk study data indicates that the habitats adjacent to the Proposed Scheme are utilised by a range of commuting and foraging bats, predominately pipistrelle species. Mitigation will be required to avoid adverse impacts to commuting and foraging bats. This would apply both during the construction period, to mitigate for effects arising from temporary construction lighting, and also during the operational period. Measures such as directional lighting to minimise light spill into adjacent habitats should be used, restricting lighting only to where it is required and retaining dark areas for use by bats. An endoscope inspection of trees with potential for bat roosts should be carried out within the soft estate, prior to pruning or felling. In addition, any trees identified as offering suitability to support roosting bats should be soft-felled under supervision, to allow undiscovered bats to escape if at all present. Enhancement opportunities Potential opportunities for enhancements for roosting bats have been identified at the locations provided in Table 4.4. These opportunities may form part of a mitigation strategy for this species, in order to maintain the favourable conservation status of the population. Table 4.4 - Roosting Bat Opportunities for Enhancement 34 Potential Enhancement Land Parcel ID Approx. Grid Ref Opportunity HD408424 TL 23108 22966 Bat box installation on suitable trees HD408424 TL 22790 22068 Bat box installation on suitable trees
A1(M) J6-8 SM: Ecological Survey Report 25
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 10. Otter and Water Vole 10.1 Summary
• Surveys for otter and water vole have been undertaken in 2018 along the River Mimram; • No otter, water vole or evidence of otter or water vole have been identified along the River Mimram, within 2km of the works; • Seven sections of the River Mimram could not be surveyed in 2018 due to access issues i.e. no response from landowners; • Approximately 35% of the identified otter and water vole survey area has been surveyed.
10.2 Survey Objectives The aim of this section is to address the following: • Review existing ecological data to identify records of otter and water vole within 2km of the Proposed Scheme; • Baseline information on the presence of otter and water vole within the ZoI of the Proposed Scheme (sections of watercourses (reaches) or connected waterbodies where impacts could arise as part of the SMP proposals, 2km upstream and 2km downstream); • Further survey requirements for otter and water vole; and • Initial guidance as to likely mitigation requirements and licensing. 10.3 Scope and Study Area The 2018 survey focused on determining the risk of adversely impacting upon otter and water vole during construction of the Proposed Scheme. All reaches (where the road crosses the watercourse) and waterbodies with connectivity to the Proposed Scheme were considered, with the survey effort concentrated upon likely areas of impact. This comprises the study area. Further detail on the study area is provided in section 1.3 of this report. 10.4 Legislative Context Otter and water vole are both listed on Schedule 5 of the Wildlife and Countryside Act 1981 (as amended) which prohibits the intentional, deliberate or reckless: • Killing, injuring, taking of otter or water vole; • Disturbing otter or water vole in a place of shelter or protection; and • Damaging, destroying or obstructing any place used by otter or water vole for the purposes of breeding, sheltering or protection. Otter are also listed on Schedule 2 of The Conservation of Habitats and Species Regulations 2017 (as amended) making it a European Protected Species. As such, is afforded additional protection against disturbance. In addition, both otter and water vole are listed under Section 41 of the NERC Act 2006 as Species of Principal Importance for Conservation in England. Section 40 of the same Act requires that planning authorities have regard to the conservation of biodiversity in England, when carrying out their normal functions.
A1(M) J6-8 SM: Ecological Survey Report 26
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Current Guidance In preparing this report regard has been given to current guidance and best practice, comprising: • Ecology of the European Otter (2003)43; • Fourth Otter Survey of England 2000-200244; and • The Water Vole Mitigation Handbook (2016)45. 10.5 Methodology Desk Study A desk study was undertaken to obtain existing records of otter and water vole within 2km of the Proposed Scheme. Further details of the desk study are provided in section 1.3 of this report. Extended Phase 1 Habitat Survey As part of this survey, a high-level assessment was carried out to identify and map sections of watercourses connected to the Proposed Scheme and to undertake an initial assessment of the potential of these watercourses to support otter and water vole. Field Survey The survey encompassed the River Mimram watercourse only where impacts could arise as a result of the Proposed Scheme, including all reaches where works are proposed (e.g. priority outfalls) and reaches where works are proposed immediately adjacent (e.g. the River Mimram passing underneath the A1(M) motorway via an underbridge, upon which works are proposed). The extent of each reach was taken to be 2km upstream and 2km downstream (of the potential impact point – e.g. location of outfall or underbridge). The surveys for otter and water vole comprised a habitat suitability assessment combined with a presence/absence survey for each species and were undertaken on 22 August 2018, towards the end of the water vole survey window. Field surveys for otter and water vole were undertaken simultaneously due to the similarities in survey methodology and habitats. Surveys involved a detailed search for sightings or field signs of otter and water vole, with all evidence of their presence recorded and mapped. Field signs in relation to otters included: spraints (dung), anal jelly, holts, laying-up sites (couches), bank slides, runs, tunnels, prey remains and footprints. Field signs in relation to water voles include: latrines, droppings, burrows, feeding remains / well grazed ‘lawns’, runs / pathways and footprints. Surveys encompassed habitats up to 10m from the edge of the water, to cover both species. Surveys were undertaken in accordance with best practice guidelines. All survey visits were undertaken by 2 suitably qualified surveyors; Chris Horley and Genevieve Labram, ecologists experienced in assessing habitat suitability and searching for signs of otter and water vole. The River Mimram watercourse is shown on Figure 5.1 – Watercourses Subject to Otter and Water Vole Survey, provided in Appendix E. Table 5.1 summarises the survey dates, in addition to the area covered during each survey. Table 5.1 - Otter and Water Vole Survey Dates and Areas Included35 Visit Number Date Location and Grid Reference 1 22.08.2018 River Mimram, (TL 23502 16155) centre point and 2km upstream and downstream of grid reference
43 Chanin, P. (2003). Ecology of the European Otter. Conserving Natura 2000 Rivers Ecology Series No. 10. English Nature, Peterborough. 44 Crawford, A. (2003). Fourth Otter Survey of England 2000-2002. Environment Agency, Bristol 45 Matthews, F and Chanin, P (Eds) 2016. The Water Vole Mitigation Handbook (the Mammal Society Mitigation Guidance Series). The Mammal Society, London. A1(M) J6-8 SM: Ecological Survey Report 27
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Otter The assessment of habitat suitability for otter was based on best practice survey guidance. Otter are tolerant of a wide range of habitat conditions, and may use habitats for a number of reasons (e.g. shelter, foraging and passing through to other more suitable habitats). Each watercourse was defined as being of high, moderate, low or negligible suitability for otter based on the following criteria set out in Table 5.2. Otters use terrestrial vegetation adjacent to watercourses as corridors for movement through river catchments, with potential for holts to be located away from the immediate banks of the watercourse. As such, the habitat suitability assessment for otter included a survey of all accessible areas of suitable vegetation up to 10m from the banks of the watercourse. Table 5.2 - Watercourse Suitability for Otter36 Habitat Shelter Food Modification & Hydrology Pollutants Suitability Requirements Supply Disturbance High Many suitable Suspected Minor man-made Watercourse ‘Good’ or habitat presence modification of with fast to above features of watercourse moderate chemical adjacent to abundant habitat and flow velocity or watercourse prey; disturbance from and more biological particularly the public e.g. than 1m water fish dog walking deep quality species Moderate Several Suspected Intermediate Watercourse ‘Fair’ suitable habitat presence man-made with slow to chemical features of modification of moderate or adjacent to sufficient watercourse flow velocity biological watercourse prey; habitat or or less than water particularly disturbance from 1m deep quality fish the public e.g. species frequent dog walking Low Few suitable Suspected Major man-made Watercourse ‘Fair’ or habitat scarcity of modification of with slow to below features prey watercourse moderate chemical adjacent to the habitat and flow velocity or watercourse disturbance by and less biological the public e.g. than 1m water frequent dog deep quality walking Negligible No suitable No prey Major man-made Dry with no Low water habitat species modification of indication of quality with features present watercourse a waterbody indications habitat and present on of pollution disturbance by site the public e.g. frequent dog walking
A1(M) J6-8 SM: Ecological Survey Report 28
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Water vole Habitat suitability for water voles was assessed from observing the features of each watercourse, with consideration to the requirements of this species and based upon best practice guidelines45. Water voles require dense growth of herbaceous bankside and emergent vegetation. Each water vole utilises a series of burrows, which can be up to 5m from the edge of the bank into the terrestrial habitat. The habitat suitability assessment took this into consideration during the survey. Each watercourse was defined as being of high, moderate, low or negligible suitability for water vole based on the following criteria set out in Table 5.3. Table 5.3 - Watercourse Suitability for Water Voles37 Habitat Indicators Suitability High Slow flowing watercourse Width <3m wide Depth of at least 1m Moderately steep banks Minimal shading by trees Abundance of emergent and bankside herbaceous vegetation for shelter, food and nesting materials Moderate Consists of a combination of features associated with both high and low habitat suitability, e.g. flow and bank type may be suitable, however heavy grazing and poaching by livestock may reduce cover of herbaceous vegetation and damage suitable habitat for the creation of burrows. Low Heavy shading from overhanging trees and/or shrubs reducing the cover of emergent and bankside vegetation and thus the availability of water vole food plants Widely fluctuating water levels Seasonal drying out of the watercourse channel Banks that are unsuitable for burrowing e.g. flat / poached Negligible No watercourse present Ditch which has completely overgrown and no longer holds water Double hedged ditch that is no longer managed and channel has been filled in Settlement pools or ditches which are visibly polluted and low water quality (due to their purpose of acting as a buffer to collect polluted material from industry). 10.6 Survey Limitations Due to a lack of response from some landowners, it was not possible to survey some sections of the River Mimram watercourse in 2018, as shown in Table 5.4, and provided in Figure 5.1 – Watercourses subject to Otter and Water Vole survey plan. Furthermore, the Proposed Scheme crosses another main river (Stevenage Brook) and one significant ordinary watercourse (Ash Brook). No access was obtained to facilitate survey of these watercourses. Surveys of these watercourses should be scheduled for 2019.
A1(M) J6-8 SM: Ecological Survey Report 29
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 5.4 - Un-Surveyed Watercourse sections38
Un-Surveyed Location/ Start Location/ End Reason Not Watercourse ID Grid Reference Grid Reference Surveyed River Mimram (east) TL 23504 16177 TL 23664 15582 Landowner access issues River Mimram (east) TL 23779 15496 TL 24076 15370 Landowner access issues River Mimram (east) TL 24121 15309 TL 24224 15067 Landowner access issues River Mimram (west) TL 23388 16176 TL 23247 16107 Landowner access issues River Mimram (west) TL 23220 16088 TL 23109 16092 Landowner access issues River Mimram (west) TL 23038 16121 TL 22994 16183 Landowner access issues River Mimram (west) TL 22992 16280 TL 22999 16398 Landowner access issues 10.7 Results Desk Study The HERC returned 1 record of otter and 18 records of water vole within 2km of the Proposed Scheme from the last 10 years, as provided in Table 5.5. The closest otter record is 510m from the highway boundary, associated with the River Mimram. The closest water vole record is 180m from the highway boundary, associated with the River Mimram. Drawing upon EnvIS, no records of otter or water vole were identified. Photographs of the River Mimram visited in 2018 are presented in Appendix E. Records of otter and water vole are also included within the designation for Singlers Marsh Local Nature Reserve (LNR) which is located approximately 520m west of the Proposed Scheme. Water vole surveys are undertaken here by the Herts and Middlesex Wildlife Trust. Water vole still occur from time to time at Singlers Marsh LNR, but breeding is considered unlikely46. Table 5.5 - Otter and Water Vole Records39 Record Record Grid Ref. Distance from Species Year Source (Type) (watercourse) Carriageway (m) HERC Otter Observation 2012 TL2415 510 (Dung) (River Mimram) HERC Water vole Observation 2014 TL2364315850 180 (River Mimram) HERC Water vole Observation 2013 TL2364315850 180 (River Mimram) HERC Water vole Observation 2014 TL2298116221 520 (River Mimram) HERC Water vole Observation 2016 TL2297916238 530 (River Mimram) HERC Water vole Observation 2010 TL2283416707 750 (River Mimram) HERC Water vole Observation 2016 TL2283516701 750 (River Mimram) HERC Water vole Observation 2014 TL2283416707 750 (River Mimram)
46 Welwyn Hatfield Borough Council (2014). Singlers Marsh Local Nature Reserve, Welwyn, Hertfordshire. Management Plan 2012 – 2024. A1(M) J6-8 SM: Ecological Survey Report 30
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Record Record Grid Ref. Distance from Species Year Source (Type) (watercourse) Carriageway (m) HERC Water vole Observation 2015 TL2283416701 750 (River Mimram) HERC Water vole Observation 2013 TL2283416707 750 (River Mimram) HERC Water vole Observation 2012 TL2419414981 970 (River Mimram) HERC Water vole Observation 2013 TL2419414981 970 (River Mimram) HERC Water vole Observation 2015 TL2419514976 980 (River Mimram) HERC Water vole Observation 2010 TL2437214903 1170 (River Mimram) HERC Water vole Observation 2013 TL2233416937 1290 (River Mimram) HERC Water vole Observation 2012 TL2233416937 1290 (River Mimram) HERC Water vole Observation 2014 TL2233416937 1290 (River Mimram) HERC Water vole Observation 2010 TL2233416937 1290 (River Mimram) HERC Water vole Observation 2010 TL2195816842 1630 (River Mimram) Field Survey The habitat suitability assessment split the River Mimram into an east and west section, and further split each section into A, B and C (with the centre point being where the A1(M) crosses the River Mimram). The various sections were identified as offering low to moderate potential for otter and water vole. The results of the habitat survey are presented in Table 5.6. Table 5.6 - Otter and Water Vole Habitat Suitability Assessment40 Watercourse Start Grid End Date Potential Species Name Ref Grid Ref TL Low Otter River Mimram East TL 23502 22.08.18 23719 (Section A) 16155 Moderate Water vole 15532 TL River Mimram East TL 23719 Low Otter 22.08.18 24097 (Section B) 15532 15333 Moderate Water vole TL Moderate Otter River Mimram East TL 24097 22.08.18 24245 (Section C) 15333 Moderate Water vole 15041 TL Low Otter River Mimram West TL 23502 22.08.18 23231 (Section A) 16155 Low Water vole 16098 TL Low Otter River Mimram West TL 23231 22.08.18 23002 (Section B) 16098 Low Water vole 16424 TL River Mimram West TL 23002 Low Otter 22.08.18 22915 (Section C) 16424 16630 Moderate Water vole No signs of otter activity or presence were recorded during the activity surveys, with no potential otter holts or laying up points recorded.
A1(M) J6-8 SM: Ecological Survey Report 31
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Small mammal footprints (rodent) were recorded at grid ref. TL 24097 15333. This evidence was first thought to be a possible water vole field sign, but on closer inspection was thought more likely to be that of a rat. The reason primarily because of the quality of habitat present, and because the prints continued into an artificial pipe within a road bridge. No water vole burrows were evident in this section of the watercourse (East, Section B). See Appendix E for photographs of the River Mimram visited in 2018. Further Surveys Some land parcels were without agreed access, and so some parts of the River Mimram were not surveyed in 2018. These access issues should be resolved and surveys of these should be scheduled for 2019. 10.8 Conclusions and Recommendations Approximately 35% of the River Mimram was surveyed from a length of 2km up and downstream (4km in total). See Figure 5.1 – Watercourses subject to Otter and Water Vole survey plan for survey coverage. No otter/water vole or evidence of otter/water vole have been identified during this survey work, but an update survey will be required in 2019 to access areas that were not accessed in 2018. The Proposed Scheme will not result in fragmentation or isolation of populations of otter/water vole. The Proposed Scheme will not cause direct impacts to the River Mimram, that may be used by otter/ water vole for breeding, shelter and foraging. As such it is considered unlikely that a mitigation/development licence from Natural England will be needed to cover the works. The design of the Proposed Scheme should seek to avoid or minimise the potential for impacts to otter or water vole, although it is not envisaged that key riparian habitats such as along The River Mimram will be lost, as the SMP construction takes place all within the HE boundary. Throughout the construction stage, all potential impacts on otter and/or water vole habitat will need to be considered. Where necessary, work in the vicinity of watercourses may need to be undertaken under the direct supervision of a suitably qualified and experienced ecologist. However, as most of the construction work will take place within the soft estate of the highway boundary, significant adverse impacts to populations of otter and water vole are considered highly unlikely.
A1(M) J6-8 SM: Ecological Survey Report 32
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Appendices
Appendix A – A1(M) Proposed Scheme
Appendix B – Extended Phase 1 Habitat Survey
Appendix C – Great Crested Newt Survey
Appendix D – Potential Bat Roost Assessment
Appendix E – Otter and Water Vole Survey
A1(M) J6-8 SM: Ecological Survey Report 33
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Appendix A. A1(M) Proposed Scheme
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Appendix B. Extended Phase 1 Habitat Survey (Photos of habitats visited in 2018)
Habitat: A1.1.1 – Broad-leaved woodland (semi-natural) Target Note 1 Description: In close proximity to the A1(M), a typical section of immature woodland with public footpath. Grid reference: TL 23592 16481
Habitat: G2 – Running water Target Note 2 Description: River Mimram bisects the A1(M) near junction 6 Grid reference: TL 23649 15703
Habitat: A1.1.1 – Broad-leaved woodland (semi-natural) Target Note 3 Description: Mardley Heath (Local Nature Reserve) is a large wooded area adjacent to the A1(M). Grid reference: TL 24258 18049
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Habitat: B2.2 – Neutral grassland (semi- improved) Target Note 4 Description: Danesbury Park (Local Nature Reserve) is situated adjacent to the A1(M) and outside of the highway boundary Grid reference: TL 23535 16881 Habitat: J1.1 – Cultivated/disturbed land (Arable) Target Note 5 Description: Arable land adjacent to Knebworth Woods (SSSI) near to Junction 7 of the A1(M). Grid reference: TL 23098 22644
Habitat: A1.1.1 – Broad-leaved woodland (semi-natural) Target Note 6 Description: At the edge of Knebworth Woods (SSSI) adjacent to the A1(M), the soft estate would typically look like this. Grid reference: TL 23169 23145 Habitat: G1 – Standing water Target Note 7 Description: Ponds were present throughout the study area in adjacent habitats from the A1(M), particularly in the watery grove area of Knebworth Woods (SSSI). Grid reference: TL 23244 22928
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Habitat: J2.3.2 Hedge with trees (species poor) Target Note 8 Description: Hedgerows were present throughout the study area, particularly around arable fields. Grid reference: TL 22822 23219
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Appendix C. Great Crested Newt Survey (Photos of waterbodies visited in 2018)
Pond ID: 8-GCN-3 HSI: 0.31 (Poor) eDNA: N/A (flowing water)
Grid reference: TL 23476 15631
Pond ID: 8-GCN-5 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference:
TL 24372 19158
Pond ID: 8-GCN-6 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference:
TL 23959 21052
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Pond ID: 8-GCN-13 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference:
TL 22124 24523
Pond ID: 8-GCN-18 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference:
TL 22265 26137
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Pond ID: 8-GCN-33 HSI: 0.5 (Poor) eDNA: Negative
Grid reference: TL 21950 26257
Pond ID: 8-GCN-39 HSI: 0.65 (Average) eDNA: Negative
Grid reference: TL 22244 26060
Pond ID: 8-GCN-40 HSI: 0.68 Average eDNA: Positive (GCN Present)
Grid reference: TL 22218 26486
Pond ID: 8-GCN-51 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference:
TL 24304 18210
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Pond ID: 8-GCN-52 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference:
TL 24350 19450
Pond ID: 8-GCN-53 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference:
TL 24313 19863
Non-existent (Part of 8-GCN-53) Pond ID: 8-GCN-54
Grid reference:
TL 24301 19865 Pond ID: 8-GCN-56 HSI: 0.79 (Good) eDNA: Positive (GCN Present)
Grid reference: TL 22974 23227
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Pond ID: 8-GCN-64 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference: TL 23852 21625
Pond ID: 8-GCN-65 HSI: N/A (Dry) eDNA: N/A (Dry)
Grid reference: TL 23999 21092
Pond ID: 8-GCN-67 HSI: 0.3 (Poor) eDNA: Negative
Grid reference: TL 23844 21622
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Pond ID: 8-GCN-69 HSI: 0.52 (Below Average) eDNA: Negative
Grid reference: TL 23182 22909
Pond ID: 8-GCN-70 HSI: 0.7 (Good) eDNA: Positive (GCN Present)
Grid reference: TL 23191 22917
Pond ID: 8-GCN-76 HSI: 0.64 (Average) eDNA: Negative
Grid reference:
TL 23062 23259
Pond ID: 8-GCN-84 HSI: 0.73 (Good) eDNA: Positive (GCN Present)
Grid reference:
TL 22901 23397
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Pond ID: 8-GCN-85 HSI: 0.93 (Excellent) eDNA: Positive (GCN Present)
Grid reference:
TL 23009 23102
Pond ID: 8-GCN-86 HSI: 0.43 (Poor) eDNA: Positive (GCN Present) Grid reference:
TL 23181 22934
Pond ID: 8-GCN-87 HSI: 0.69 (Average) eDNA: Negative
Grid reference:
TL 21896 26191
Pond ID: 8-GCN-88 HSI: 0.61 (Average) eDNA: Negative
Grid reference:
TL 21950 21203
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Appendix D. Potential Bat Roost Assessment (Photos of structures visited in 2018)
Structure ID: Structure No.1 (Digswell Hill Bridge)
Grid reference: TL 22805 14801
Bat Roost Potential: Negligible
Structure ID: Structure No.2 (A1000 Road Bridge)
Grid reference: TL 23434 15718
Bat Roost Potential: Negligible
Structure ID: Structure No.3 (Great North Road Bridge)
Grid reference: TL 23566 16517
Bat Roost Potential: Negligible
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Structure ID: Structure No.4 (The Avenue Bridge)
Grid reference: TL 23861 17315
Bat Roost Potential: Negligible
Structure ID: Structure No.5 (Pottersheath Road Bridge)
Grid reference: TL 24190 18068
Bat Roost Potential: Negligible
Structure ID: Structure No.6 (Pedestrian Subway near Ninnings wood)
Grid reference: TL 24343 18622
Bat Roost Potential: Negligible
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Structure ID: Structure No.7 (Wych Elm Lane Bridge)
Grid reference: TL 24323 19218
Bat Roost Potential: Negligible
Structure ID: Structure No.8 (Park Lane Bridge)
Grid reference: TL 24223 20223
Bat Roost Potential: Negligible
Structure ID: Structure No.9 (Old Knebworth Lane Bridge)
Grid reference: TL 23810 21628
Bat Roost Potential: Negligible
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Structure ID: Structure No.10 (Roundabout at J7)
Grid reference: TL 23556 22470
Bat Roost Potential: No Survey (No access)
Structure ID: Structure No.11 (Roundabout at J7)
Grid reference: TL 23512 22578
Bat Roost Potential: No Survey (No access)
Structure ID: Structure No.12 (Pedestrian Subway)
Grid reference: TL 22988 25411
Bat Roost Potential: Negligible
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Structure ID: Structure No.13 (Bessemer Drive Bridge)
Grid reference: TL 22655 23836
Bat Roost Potential: Negligible
Structure ID: Structure No.14 (Meadway Bridge)
Grid reference: TL 22143 24556
Bat Roost Potential: Negligible
Structure ID: Structure No.15 (Pedestrian Subway)
Grid reference: TL 21985 25116
Bat Roost Potential: Negligible
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Structure ID: Structure No.16 (Fishers Green Bridge)
Grid reference: TL 22203 26196
Bat Roost Potential: Negligible
Structure ID: Structure No.17
No Photo (No Survey) Grid reference: TL 22353 26546
Bat Roost Potential: No Survey (No access) Structure ID: Structure No.18
No Photo (No Survey) Grid reference: TL 22491 26944
Bat Roost Potential: No Survey (No access) Structure ID: Structure No.19
No Photo (No Survey) Grid reference: TL 22523 27064
Bat Roost Potential: No Survey (No access)
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Appendix E. Otter and Water Vole Survey (Photos of River Mimram visited in 2018)
Watercourse: River Mimram, East of A1(M)
Grid reference: TL 23578 15578
Watercourse: River Mimram, East of A1(M)
Grid reference: TL 23707 15521
Watercourse: River Mimram, East of A1(M)
Grid reference: TL 23744 15517
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Watercourse: River Mimram, East of A1(M)
Grid reference: TL 23972 15477
Watercourse: River Mimram, East of A1(M)
Grid reference: TL 24098 15334
Watercourse: River Mimram, East of A1(M)
Grid reference: TL 24248 15040
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 23486 16156
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 23451 16164
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 23441 16169
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 23234 16096
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 23092 16101
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 23057 16114
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 23002 16232
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 23003 16422
Watercourse: River Mimram, West of A1(M)
Grid reference: TL 22998 16502
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Smart Motorways Programme Environmental Assessment Report Appendix 7.1 – Landscape and Visual
Tranche 5 – A1(M) J6 to 8 (Preliminary Design – PCF Stage 3)
HE55139-WSP-EGN-SG-RP-LE-00018
April 2019
Notice
This document and its contents have been prepared and are intended solely for Highways England’s information and use in relation to the Smart Motorways Programme.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Revision history
Job number: 551539 Document ref: HE55139-WSP-EGN-SG-RP-LE-00018 Revision Purpose description Originated Checked Reviewed Approved Date P01 S3 – Draft for review Andy Cocks Andy David Jonty Parry 25/02/19 and comment Williams Hoare/Catherine Sugden P02 S4 – Suitable for stage Andy Cocks Andy David Jonty Parry 03/04/19 approval Williams Hoare/Catherine Sugden
Client signoff
Client Highways England Project SMP Tranche 5 – A1(M) Junctions 6 to 8 Document title Appendix 7.1 – Landscape and Visual Job no. 551539 Document HE55139-WSP-EGN-SG-RP-LE-00018 reference 11.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table of Contents
7. Landscape and Visual 59 7.1 Visual Effects Schedule 59
List of Tables
Table 7.1.11Visual effects schedule ...... 59
Supporting Figures
No supporting figures
.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 12. Landscape and Visual 10.9 Visual Effects Schedule
11.
Table 7.1.141Visual effects schedule
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) Residential Receptors
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
1A • Cluster 45-85m 50m • Short- • There will • There will • CH: of mid be short be mid- Establishe 240 suburban range term distant d planting 0- residenti filtered adjacent views to the along the 250 al views to views to top of GA01 receptor’s 0 propertie the top works and CCTV length of s located of associated mast the A1(M) along vehicula with the • Taken in will soften Node r constructio the context its Way moveme n of a of existing appearanc Gardens, nt gantry, a views to top e and Welwyn, present CCTV of traffic, it further aid adjacent from mast and 5 is not screening the first floor No. submitted for the western windows highway that a new affected northbou • Views lights to gantry and properties nd edge are the west of CCTV mast of the filtered the slip will result in Impact: A1(M) by the lane a significant Negligible (viewing estate • Given the change in east) soft set back view Effect: vegetati from the Slight (Approx. on, and highway Impact: 20 No. interveni boundary Negligible ng and that Receptor s) vegetati the on presence Effect: outside of the Slight the existing highway A1(M) and Secondary boundar associated Mitigation: y traffic is No (northbo visually requirement und) detracting, identified • The it is not properti submitted es are that the further proposed separat activities ed by a will cause slip lane a existing significant off the deterioratio highway n in view northbo from the und properties
Sensitivi Impact: ty: High Negligible
Effect: Slight
1B • Cluster 45-85m 50m • Short • There will • There will • CH: of range be short be mid- Establishe
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
240 suburban filtered term distant d planting 0- residenti views to adjacent views to the along the 250 al the top views to top of GA28 receptor’s 0 propertie of high works and CCTV length of s located sided associated mast the A1(M) along vehicula with the • Taken in will soften Maran r gantry the context its Avenue, moveme constructio of existing appearanc Welwyn, nt n, CCTV views to top e and adjacent present installation, of traffic, it further aid the from and is not screening western first floor associated submitted for the northbou rear site that a new affected nd edge facing clearances gantry and properties of the windows • These CCTV mast A1(M) • Views works are will result in Impact: (viewing are proposed a significant Negligible east) filtered to the change in by the opposite view Effect: estate side of the (Approx. Slight 17 No. soft motorway Impact: Receptor vegetati (southboun Negligible on, and d) s) interveni • Given Effect: ng that the Slight vegetati presence on of the outside existing Secondary the A1(M) and Mitigation: highway associated No boundar traffic is requirement y visually identified (northbo detracting, und) it is not • Views submitted are that the further proposed disrupte activities d by an will cause existing a 2.0m significant high deterioratio (approx. n in view ) brick from the wall/fen properties ce located Impact: to the Negligible rear of
property boundar Effect: ies Slight interfaci ng the A1(M)
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) Sensitivi ty: High
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
2 • Clock 30-80m 60m • Short • There will • There will • CH: House ranged be short be mid- Establishe 330 Gardens: filtered term distant d planting 0- Cluster of views to filtered filtered along the 340 suburban the views to views to the receptor’s 0 residenti motorwa works top of GA02 length of al y associated • There will the A1(M), propertie present with gantry be a greater together s located on constructio appreciation with along embank n, CCTV of the mitigation Roman ment installation, motorway planting to Road, • Views radar, and and the rear of Welwyn, are associated associated the gantry adjacent filtered site traffic given will soften the by the clearances the amount its western estate • There will of site appearanc slip lane soft be short clearance e and entry to vegetati term necessary further aid the on, and filtered along the screening A1(M) interveni views to highway for the (viewing ng works edge affected east) vegetati associated • Taken in properties. on along with the the context (Approx. the slip constructio of existing Impact: 45 No. lane and n of views to an Negligible Receptor highway highway open boundar lighting s) section of Effect: y along the motorway Slight (northbo slip lane and slip Adverse und) entry lane, a mid-
• distant view Sensitivi Clearance to a new ty: High s and gantry and technology associated constructio technologie n is s, highway proposed lights and along the site line western clearance highway works will edge, on not result in the a significant opposite change side of the existing Impact: slip lane Minor • Given the Adverse set back from Effect: highway Slight edge to Adverse property boundary, and the Secondary presence Mitigation: of the No
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) existing requirement A1(M) and identified associated traffic are visually detracting, it is not submitted that the proposed activity will cause a significant deterioratio n in view from the properties
Impact: Minor Adverse
Effect: Slight Adverse
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
3A • 90-150m 150m • Short- • There will • There will • CH: Residenti mid be short be Establishe 378 al range term obscured, d planting 5- propertie filtered filtered mid-long along the 392 s located views to views to distant receptor’s 5 along the top works filtered length of Great of high associated views to the the A1(M) North sided with gantry top of will soften Road, motorwa constructio GA27, the its Oaklands y traffic n, CCTV CCTV mast appearanc , present installation, and radar e and adjacent from radar, mast further aid the rear proposed • There will screening eastern facing noise be a greater for the southbou first floor barrier, appreciation affected nd edge windows and of the properties of the • Views associated motorway A1(M) are site line and Impact: (viewing filtered clearances associated Negligible west) by the • Given the traffic due to estate set back sight line Effect: soft from clearances (04 No. Slight vegetati highway along the Receptor Adverse s) on, and edge to southbound interveni rear highway ng building edge vegetati facades, • Taken in on and that the context outside the of existing the presence views to the highway of the top of boundar existing motorway y A1(M) and traffic, an (southb associated obscured ound) traffic are mid-long visually distant view detracting, to a new it is not gantry and submitted associated that the technologie proposed s, and sight activity will line cause a clearances significant will not deterioratio result in a n in view significant from the change in properties view
Impact: Impact: Negligible Negligible
Effect: Effect: Slight Slight Adverse Adverse
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n)
Secondary Mitigation: No requirement identified
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
3B • 0-75m 50m • Short • There will • CH: Residenti range be short • There will Establishe 402 al filtered term be a greater d planting 5- property views to appreciatio appreciation along the 406 at no. 9 the top n of of the receptor’s 0 The of high constructio motorway length of Avenue, sided n activity and the A1(M) Oaklands motorwa associated associated will soften , y traffic with the traffic, its adjacent • Views proposed particularly appearanc the are noise high sided e and eastern filtered barrier and vehicles, further aid southbou by the associated due to sight screening nd edge estate site line for the of the soft clearances clearances affected A1(M) vegetati • A noise along the properties (viewing on and barrier will southbound • Views of west) a sit highway high sided garden alongside edge vehicles (1 No. fence an existing • Taken in will remain Receptor fence and the context above the ) will require of existing new noise localised views to the barrier vegetation top of high clearance sided Impact: along the motorway Negligible highway traffic, and boundary, sight line Effect: increasing clearances Slight views of will not Adverse high sided result in a vehicles. significant • Given the change in set back view from highway Impact: edge to Minor property
boundary, and the Effect: presence Slight of the Adverse existing A1(M) and Secondary associated Mitigation: traffic are No visually requirement detracting, identified it is not submitted that the proposed activity will cause a significant deterioratio
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
n in view from the properties
Impact: Minor
Effect: Slight Adverse
Mitigation: A temporary screen fence should be provided following the removal of the vegetation and maintained until the new noise barrier is erected. To reduce the potential impact on existing vegetation the foundation s for the new barrier should be hand dug and pruning of trees favoured over removal. .
4A • Cluster 0-100m 50m • Short- • There will • There will • CH: of range be short be obscured Establishe 450 suburban filtered term filtered mid- d planting 0- residenti views to appreciatio distant along the 465 al the n of views to the receptor’s propertie motorwa constructio top of length of
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
0 s located y and n activity GA03, the A1(M) along the top of associated GA26, will soften northern high with the CCTV and its end of sided new radar masts appearanc Gwynfa vehicles gantry, • Taken in e and Close, • Views CCTV and context of further aid and from radar an existing screening along properti installation appreciation for the The es along s, retained of the affected Brambles The noise motorway views. , Bramble barrier and and Oaklands s are associated associated Impact: , obstruct site traffic, and Negligible adjacent clearances ed by a the existing the 3m high • The 3m noise Effect: eastern (approx. proposed barrier to Slight southbou ) noise works for the top of Adverse nd edge barrier GA03 are embankmen of the to the located on t acting as a A1(M) top of the physical (viewing embank opposite barrier, mid- west) ment side of the distant • Views A1(M) and views to the (Approx. are also will not top of a new 22 No. filtered result in gantry and Receptor by soft any associated s) estate clearance technologie vegetati measures s will not on, and to the result in a interveni receptor’s significant ng interface change vegetati • The on proposed Impact: outside works for Negligible the GA26 are highway located to Effect: boundar the front of Slight y existing Adverse (southb woodland ound) and will not result in Secondary Mitigation: Sensitivi any ty: High clearance No measures requirement
to either of identified the receptor’s interface
associated constructio n Impact: Negligible
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) Effect: Slight Adverse
Mitigation: No requireme nt identified
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
4B • Cluster 0-100m 50m • Short • There will • There will • CH: of range be short be obscured Establishe 450 suburban filtered term filtered mid- d planting 0- residenti views to appreciatio distant along the 465 al the top n of views to the receptor’s 0 propertie of high constructio top of length of s located sided n activity GA03, the A1(M) to the traffic associated GA26, will soften eastern from with the CCTV and its extent of rear new radar masts appearanc The facing gantry, • Taken in e and Crest first floor CCTV and the context further aid and The windows radar of existing screening Avenue, • Views installation views to the for the Oaklands are s, top of high affected , and filtered replaceme sided views Danesbu by the nt noise motorway ry Park estate barrier and traffic, an Impact: adjacent soft associated obscured or Negligible the site vegetati screened western on, and clearances view as a Effect: northbou interveni • The result of a Neutral nd edge ng proposed new noise of the vegetati works for barrier and A1(M) on GA26 are mid-long (viewing outside located on distant view east) the the to a new highway opposite gantry and (10 No. boundar side of the associated Receptor y and A1(M) and technologie s) existing will not s, and sight fence result in line line. any clearances clearance will not Sensitivi measures result in a ty: High to the significant receptor’s change in
interface view • The proposed Impact: works for Negligible GA03 are located to Effect: the Slight highway Adverse side of existing woodland Secondary and will not Mitigation: result in No any requirement clearance identified measures to either of the receptor’s
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
interface • Given the proposed constructio n of the 3m noise barrier, and embankme nt level change, it is not submitted that theconstru ction activities will cause a significant deterioratio n in view from the properties
Impact: Negligible
Effect: Slight Adverse
Mitigation: To reduce the potential impact on existing vegetation the foundation s for the new barrier should be hand dug and pruning of trees favoured over removal. 4C • Cluster 0-100m 50m • Short • There will • There will • CH: of range be short be obscured Establishe 475 suburban filtered term filtered mid- d planting 0- residenti views to appreciatio distant along the
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
480 al the top n of views to the receptor’s 0 propertie of high constructio top of length of s located sided n activity GA03, the A1(M) to the traffic associated GA26, will soften eastern from with the CCTV and its extent of rear new radar masts appearanc Cannonsf facing gantry, • Taken in e and ield Road first floor CCTV and the context further aid adjacent windows radar of existing screening the • Views installation views to the for the eastern are s, top of high affected southbou filtered proposed sided views nd edge by the noise traffic, an of the estate barrier and obscured or Impact: A1(M) soft associated screened Negligible (viewing site vegetati view and west) on, and clearances mid-long Effect: interveni • Given the distant view Neutral (4 No. ng erection of to a new Receptor vegetati the 3m gantry and s) on noise associated outside barrier, technologie the and s, and sight highway embankme line boundar nt level clearances y and change, it will not existing is not result in a boundar submitted significant y fence. that change in associated view Sensitivi constructio ty: High n activities Impact: will cause Negligible a
significant deterioratio Effect: n in view Slight from the Adverse properties Secondary Impact: Mitigation: Negligible No requirement identified Effect: Slight Adverse
Mitigation: To reduce the potential impact on existing vegetation the
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) foundation s for the new barrier should be hand dug and pruning of trees favoured over removal.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
4D • Cluster 0-100m 50m • Short • There will • There will • CH: of static range be short be obscured Establishe 470 caravans filtered term filtered mid- d planting 0- located views to appreciatio distant along the 485 with the top n of views to the receptor’s 0 Danesbu of high constructio top of length of ry Park sided n activity GA03, the A1(M) adjacent traffic associated GA26, will soften the • Views with the CCTV and its western are new radar masts appearanc northbou filtered gantry, • Taken in e and nd edge by the CCTV and the context further aid of the estate radar of existing screening A1(M) soft installation views to the for the (viewing vegetati s, noise top of high affected east) on, and barrier and sided views interveni associated motorway (8 No. ng site traffic, an Impact: No Receptor vegetati clearances obscured or Change s) on • Given the screened outside proposed view as a Effect: the 3m noise result of the Neutral highway barrier, proposed boundar and slight noise barrier y and cutting and mid- boundar level long distant y fence. change, it view to a is not new gantry Sensitivi submitted and ty: High that associated constructio technologie
n activities s, and sight will cause line a clearances significant will not deterioratio result in a n in view significant from the change in properties view
Impact: Impact: Negligible Negligible
Effect: Effect: Slight Slight Adverse Adverse
Mitigation: Secondary To reduce Mitigation: the No potential requirement impact on identified existing vegetation the
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) foundation s for the new barrier should be hand dug and pruning of trees favoured over removal.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
5 • Semi- 15m 60m • Short • There will • There will • CH: Rural range a short- be an Establishe 590 residenti filtered term appreciation d planting 0- al views appreciatio of gaps in along the 595 propertie towards n of vegetation receptor’s 0 s located the vegetation as a result length of along motorwa clearance of widening the A1(M) Darby y as well as clearance will aid Drive and present distant • There will screening at No. 4 in slight obscured be obscured for the Wych cutting views to distant affected Elm • Views high level views to the views Lane, are activities new gantry, Rabley filtered related to CCTV and Impact: Heath, by the the radar masts Negligible adjacent constructio soft above the estate n of a intervening Effect: western vegetati GA05, a roadside Slight northbou on and CCTV vegetation Adverse nd edge interveni mast and • Taken in
of the ng radar mast the context A1(M) vegetati • Given the of existing (viewing on existing views to the east) outside fence motorway the barrier, and (02 No. highway and that appreciation Receptor boundar the of top end s) y and by existing traffic, any the A1(M) and clearance cutting associated as a result slope traffic are of widening • Views partially through this for screened section will Darby by result in no Drive landform, it more than a are is not minor further submitted change in disrupte that the view d by an proposed activity will existing Impact: cause a fence Minor line significant
located deterioratio to the n in view Effect: rear of from the Slight the property Adverse property boundar Impact: Secondary y’s Minor Mitigation: interface Replaceme Effect: nt planting Sensitivi Slight within and ty: High Adverse along highway Mitigation: boundary to To reduce restore
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) the visual potential screen impact on existing vegetation pruning of trees should be favoured over removal.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
6 • Park 80m 50m • Mid • There will • Potential • CH: Wood distant be an awareness Establishe 665 residenti filtered appreciatio to the top of d planting 0- al views to n of gantry along the 705 cottage the vegetation immediately receptor’s 0 and motorwa clearance east. length of semi- y in associated • The only the A1(M) natural slight with sight change in will aid woodland cutting line view may be screening located present clearances an for the on the across for GA06 appreciation affected southern landsca • Given of minor views side of pe that the gaps in Park • Views existing vegetation Impact: No Lane, are set A1(M) and as a result Change Old back associated of widening Knebwort and traffic are clearance, Effect: h, filtered visually but this Neutral adjacent by soft detracting, would not the estate it is not represent a western vegetati submitted significant northbou on and that the change nd edge interveni proposed of the ng activity will Impact: A1(M) vegetati cause a Negligible (viewing on significant
east) outside deterioratio the n in view Effect: Slight (01 No. highway from the Adverse Receptor boundar woodland ) y but awarene Impact: Secondary ss of Negligible Mitigation: traffic Replaceme remains nt planting Effect: particula within and Slight rly in along Adverse winter highway months Mitigation: boundary to To reduce restore Sensitivi the visual ty: High potential screen impact on
existing vegetation pruning of trees should be favoured over removal. 7 • Norton 25-150m 90m • Short- • There will • There will • The set CH: Green mid be near be near back and 970 Farmstea distant distance distance proposed 0- d and views to partially filtered and mitigation 106 Common the filtered and direct views planting
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
00 : Cluster motorwa direct to the along the of y and views of Electrical receptor’s residenti associat constructio Interface length of al ed traffic n activities Cabinet the A1(M), propertie present associated from the Common s and across with the northern Green, Common Commo installation most together Green n Green of GA09, properties with located • Views CCTV and from existing along are set mast and the estate soft Chadwell back Electrical Common vegetation Road, and Interface Green along the adjacent filtered Cabinet • There will property the by soft • The be near boundaries western estate existing distance will aid northbou vegetati A1(M) and filtered and screening nd edge on and associated direct views for the of the interveni traffic are to GA09 affected A1(M) ng existing from the views (viewing vegetati visual northern which, east) on along detractors, most over time the and the properties will not (Approx. Commo constructio and from warrant a 10 No. n Green n activity the footway significant Receptor and will cause across the change in s) outside a Common view the significant Green highway deterioratio • Taken in Impact: boundar n in view context of Negligible y an existing Impact: motorway Effect: Sensitivi Minor and Slight ty: High associated Adverse traffic, Effect: filtered Moderate views to a Adverse new gantry, CCTV mast and Electrical Interface Cabinet will result in a significant change in view
Impact: Minor
Effect: Moderate Adverse
Secondary
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) Mitigation: Infill mixed hedgerow and plant several trees within the existing soft landscape located between the footway and proposed gantry location
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
8 • • • • 1 • 9• • • • • • • CH: Registere 70m 0m Mid- There will There will Given the 124 d range be mid- be filtered transient 00- Common filtered range views to the nature of 126 Land views to filtered top of a views for 00 located the views radar mast footpath between motorwa through and a users and Symonds y and vegetation slightly the Green top of breaks to greater existing Lane and high activities appreciation awareness Clovelly sided associated of the of Way, beyond with the motorway elements Symonds 3m constructio infrastructur of the Green, noise n of GA18, e from motorway approxim barrier a radar where sight from the ately • mast and • line footpath 700m Views associated clearances and back east of are sight line will occur of the further clearances • property,• A1(M) filtered (southboun There will there will boundary by the d) within be an be no (southbo soft the obstructed significant und), and estate constraints mid-range appreciabl a vegetati of the filtered view e change commerc on and existing to the top of in the long ial the noise the new term property interveni barrier gantry • – the ng • • ‘Crooked • • • I vegetati Given the In the mpact: No Billet’ on prominenc pub – context of Change outside e of the the nature (viewing the existing • west) of the view, highway A1(M), the • E • boundar awareness prominent ffect: • ( y of traffic, existing Neutral 02 No. (southb and awareness • Receptor ound) appearanc of the ) • e of • motorway existing • Views corridor and are also overhead electrical • interrupt cabling towers ed by an and a present, it is existing pylon back not pylon dropping submitted and the that there associat Common, will be a ed it is not significant cabling submitted change in running that these view as a north – activities result will cause south • • along a significant It is also the noted that motorwa deterioratio n in view the y Common boundar for Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
y footpath contains (southb users various ound) • pockets of • dense • canopy I Sensitivi mpact: vegetation ty: High Negligible set back • • from the • highway E ffect: Slight boundary Adverse that will Mitigation: further aid to minimise A impacts for temporary footpath screen users fence should be • provided • I following mpact: the Negligible removal of • the vegetation • E and ffect: Slight maintained Adverse until the • new noise • S barrier is econdary erected. Mitigation: To reduce • N the o potential requirement impact on identified. existing vegetation the foundation s for the new barrier should be hand dug and pruning of trees favoured over removal. • 9 • Clusters 20-40m 380m • Mid- • There will • Site line • CH: of range be mid- clearance of Establishe 126 residenti views range vegetation d planting 00- al towards views of will open up along the 130 housing the constructio short gaps receptor’s 00 groups motorwa n activity for views to length of along y are for gantry the top of the
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Minehea screene GA12 from high sided highway d Way, d by the traffic, will aid Symonds existing western however screening Green, bund most proposed for affected located • Views properties noise barrier views adjacent are and the will not be where the the filtered context of visible top of the eastern by the beyond gantry is southbou interveni motorway intervening likely to nd edge ng corridor bund remain of the vegetati will landform. perceptible A1(M) on along become • from upper• (viewing the more There will floor west) outside apparent. also be windows of the • There will filtered (Approx. highway be a views to the Impact: 10 No. boundar perceptible top of GA12 Negligible Receptor y and change on the obstruct from upper s) opposite Effect: ed by a floor side of the Slight bund windows highway Adverse as a result • • • Given the Views of sight existing are also line appreciation obstruct clearance of the ed by a vegetation motorway 2.4m removal and (approx. • Given the associated ) high distance of traffic, and timber properties the set back noise and distance barrier existing between which awareness property runs of the boundaries parallel motorway and the to the and highway, it highway associated is not (southb traffic, this submitted ound) to is not that the the submitted change in souther to be a view would nmost significant be properti effect significant es Impact: Impact: Minor Minor Sensitivi ty: High Effect: Effect: Slight Slight Adverse Adverse
• S econdary Mitigation: No Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) requirement identified.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
10 • Cluster 60m 180m • Mid- • There will • There will • CH: of range be mid- be filtered Establishe 126 residenti views to long range mid-range d planting 00- al the top heavily views to the along the 130 propertie of high filtered top of GA17 receptor’s 00 s along sided views of • Given the length of Brighton traffic constructio existing the Way, beyond n activity appreciation highway Symonds and for the of the will aid Green, over installation motorway screening located existing of GA17 and for affected adjacent screen and associated views the bund associated traffic, the which, eastern • Views sight distance over time, southbou are clearances between will not nd edge filtered • There will property result an of the by not be a boundaries appreciabl A1(M) interveni significant and e change (viewing ng effect on highway, in view west) vegetati views and the on along given the planted Impact: No (Approx. the set back of bund, it is Change 08 No. outside properties not of the from the submitted Receptor Effect: highway highway that the s) Neutral boundar and the change in y and embankme view would obstruct nt level be ed by difference significant the obscuring screen views and Impact: bund existing Negligible vegetation
in the Sensitivi Effect: ty: High intervening landscape Slight Adverse
Impact: Negligible • S econdary Mitigation: Effect: Slight No Adverse requirement identified.
11A • Cluster 50-80m 90m • Mid- • There will • Mid-range • The set CH: of range a be minor filtered back and 137 residenti views appreciatio views to the existing 50- al towards n of top of the planting 139 propertie the constructio new gantry, along the 50 s located motorwa n works the CCTV receptor’s along y and associated and radar length of Kessingl associat with the masts the A1(M) and ed high constructio above will aid Avenue, sided n of GA16, intervening screening Fishers traffic CCTV and bund and for the
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) Green present radar roadside affected North, over masts vegetation views adjacent landsca above will be where the pe and intervening present awareness eastern embank roadside • Given the of the top southbou ment vegetation level of gantry nd edge • Views • Given the change of will remain of the are set distance of the and, over A1(M) back properties embankmen time is not (viewing and and the t, set back submitted west) screene existing of approx. to warrant d by awareness 50m, and a (Approx. interveni of the existing significant 11 No. ng bund features of vegetation, change in Receptor and the it is not view s) further motorway, submitted filtered this is not that the Impact: by submitted change in Negligible interveni to be a view would ng significant be Effect: vegetati effect significant Slight on along Adverse the Impact: Impact: outside Negligible Negligible of the
highway boundar Effect: Effect: y Slight Slight Adverse Adverse
Sensitivi ty: High • S econdary Mitigation: No requirement identified.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
11B • 60m 20m • Mid- • There will • There will • Given the CH: Residenti range be an be mid- distance 138 al semi- appreciatio range views from 50- propertie filtered n and to the top of properties 139 s located views views to the new to the 00 along towards constructio gantry in highway, Stevenag the n activities south east and the e Road, motorwa associated facing change in Todds y and with the windows level over Green, potential installation • There will the slight adjacent awarene of an also be a cutting, it is the ss of the Electrical greater not western top of Interface appreciation submitted edge of high Cabinet of the that the the sided and highway to views A1(M) traffic associated where between (viewing across vegetation vegetation Year 1 and east) landsca clearances clearances Year 15 pe and to the will occur at will result (02 No. over western the end of in a Propertie embank edge of the Stevenage significant s) ment highway, Road change. • Views at the end resulting are set of from the Impact: back Stevenage installation Negligible Road and of an obscure • There will Electrical Effect: d by the also be Interface Slight level minor Cabinet Adverse differenc views, • Given the
e to the particularly existing motorwa from first appreciation y and storey of the vegetati south east motorway on facing and windows, associated Sensitivi to traffic, and ty: High constructio the distance n activities between the related to property the boundary installation and the of a radar highway, it and CCTV is not mast, and submitted GA16 to that the the eastern change in edge of the view would highway be significant Impact: Minor Impact: Minor Effect: Slight Effect:
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Vie wp oin t Descripti ref on Magnitude Magnitude ere (+numbe of impact Magnitude Approxim Approxi of impact nce r of Existin and of impact ate mate and No. properti g view significan and distance Length significan (se es) and and ce of significanc from of ce of e Key sensitiv effect e of effect Scheme exposure effect Fig Represe ity during Winter Year (m) (m) Summer ure ntative constructi 1 Year 15 7.1 Viewpoi on for nt loc atio n) Adverse Slight Adverse
• S econdary Mitigation: No requirement identified.
12.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Smart Motorways Programme Environmental Assessment Report Appendix 8.1 to 8.5 – Noise
Tranche 5 – A1(M) J6 to 8 (Preliminary Design – PCF Stage 3)
HE55139-WSP-EGN-SG-RP-LE-00019
May 2019
Notice
This document and its contents have been prepared and are intended solely for Highways England’s information and use in relation to the Smart Motorways Programme.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Revision history
Job number: 551539 Document ref: HE55139-WSP-EGN-SG-RP-LE-00019 Revision Purpose description Originated Checked Reviewed Approved Date P01 S3 – Draft for review Sarah Whydle Steve Fisher David Jonty Parry 22/02/19 and comment Hoare/Catherine Sugden P02 S4 – Suitable for stage Sarah Whydle Steve Fisher David Jonty Parry 03/04/19 approval Hoare/Catherine Sugden
Client signoff
Client Highways England Project SMP Tranche 5 – A1(M) Junctions 6 to 8 Document title Appendix 8.1 to 8.5 – Noise Job no. 551539 Document HE55139-WSP-EGN-SG-RP-LE-00019 reference
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table of Contents
8. Noise and Vibration 1 8.1 Regulatory and policy framework 1 8.2 Road committed developments included in the traffic model 3 8.3 Noise and vibration calculation and assessment assumptions 4 8.4 Analysis of noise rectification measures 11 8.5 Traffic noise annoyance xvi
List of Tables
Table 8.1.11 - Regulatory and policy framework for construction noise and vibration ...... 1 Table 8.1.22 Regulatory and policy framework for operational noise and vibration...... 2 Table 8.3.13 Noise calculation assumptions ...... 4 Table 8.3.24- Typical construction road activities and equipment used in the construction noise model ...... 8 Table 8.4.15 Indicative whole-life costs of timber barrier in £ per linear metre ...... 12 Table 8.4.26 Noise barrier analysis ...... 13 Table 8.5.17 Changes in traffic noise annoyance ...... xvi
Supporting Figures
No supporting figures
.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 13. Noise and Vibration 14.1 Regulatory and policy framework General Section 5(2) of the Infrastructure Act 2015 and the Highways England Licence seek to minimise the environmental impacts of projects, protect and enhance the quality of the surrounding environment and conform to the principles of sustainable development. In line with this, the Department for Transport’s Road Investment Strategy (RIS) 2015- 2020 aspires to the target that by 2040 over 90% fewer people are affected by noise from the strategic road network (SRN). The target for the first RIS Period, 2015-2020, is to mitigate at least 1,150 noise Important Areas (nIAs), thus expecting to reduce the number of people severely affected by noise from the SRN by at least 250,000. The legislation and policies considered in undertaking this noise assessment are detailed in Table 8.8.1 and 8.1.2 for construction and operation respectively. Table 8.1.142 - Regulatory and policy framework for construction noise and vibration
Regulation / policy Summary of requirements Proposed Scheme response Within the context of Government policy on sustainable Noise Policy Statement development: for England (NPSE) i. Avoid significant adverse National Planning Policy effects as a result of the Assessment of the effects of Framework (NPPF) scheme the Proposed Scheme and Planning Practice ii. Mitigate and minimise comparison with the aims in Guidance - Noise (PPGN) adverse effects as a result noise policy. National Policy Statement of the scheme. for National Networks iii. Contribute to the (NPSNN) rectification of the acoustic environment. Section 61 could be prepared Section 60 – Control of noise on by the Delivery Partner and construction sites. submitted to the local planning Section 61 – Prior consent for authority prior to construction Control of Pollution Act work on construction sites. works starting. 1974 (as amended) Section 71 – Codes of practice for Section 71 – see The Control minimising noise. of Noise (Code of Practice for Section 72 – Best practicable Construction and Open Sites) means. (England) Order 2015 below. Section 79 (1) (g) noise that is prejudicial to health or a nuisance It may apply to some and is emitted from or caused by a construction activities, vehicle, machinery or equipment Environmental Protection however, it is not envisaged in a street is a statutory nuisance; Act 1990 (as amended) that this would apply to the (NB if so should be inspected by Proposed Scheme at this the local authority). stage. Section 79 (9) interpretation of “best practicable means”.
Environmental Assessment Report 1
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Regulation / policy Summary of requirements Proposed Scheme response Significance of effect for The Control of Noise Approves BS 5228:2009+A1:2014 construction noise and (Code of Practice for Part 1 Noise and Part 2 Vibration vibration assessed against the Construction and Open for the purpose of giving guidance criteria in BS 5228-1 and BS Sites) (England) Order on appropriate methods for 5228-2. 2015 minimising noise and vibration. Mitigation measures refer to BS 5228-1 and BS 5228-2. Regulation 5 provides relevant authorities with discretionary powers to undertake or make a grant in respect of the cost of Noise Insulation Consideration of criteria for undertaking noise insulation work Regulations 1975 (as noise insulation from BS 5228- in or to eligible buildings with amended) 1 Annex E. respect to construction noise. This is subject to meeting certain non- numerical criteria given in the Regulation. Table 8.1.243 Regulatory and policy framework for operational noise and vibration Regulation / Proposed Scheme Summary of requirements policy response Environmental Reduction of noise levels Noise (England) in noise Important Areas Take into account Noise Action Plans. Regulations where it is sustainable to 2006 do so. Within the context of Government policy on sustainable development: NPSE i. Avoid significant adverse effects as a Assessment of the effects NPPF result of the scheme of the Proposed Scheme PPGN ii. Mitigate and minimise adverse effects and comparison with the NPSNN as a result of the scheme. aims in noise policy. iii. Contribute to the rectification of the acoustic environment. Avoid or minimise Land Part I Compensation for depreciation caused operational adverse Compensation by use of public works. effects that may Act 1973 depreciate an area of land. Regulation 3 imposes a duty on authorities to undertake or make a grant in respect of the cost of undertaking noise insulation work in or to eligible buildings. This is subject to meeting Assessment of the effects Noise Insulation certain criteria given in the Regulation. of the Proposed Scheme Regulations Regulation 4 provides authorities with against the criteria in 1975 (as discretionary powers to undertake or make a Regulation 3 of the amended) grant in respect of the cost of undertaking Regulations. noise insulation work in or to eligible buildings, subject to meeting certain criteria given in the Regulation. The Highways Provide highway authorities with a Noise Payments discretionary power to provide a noise Assessment of the effects and Movable payment where new roads are to be of the Proposed Scheme Homes constructed or existing ones altered. The against the criteria in the (England) relevant Regulations set out the criteria which Regulations. Regulations should be applied in assessing eligibility for 2000 making such payments.
Environmental Assessment Report 2
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
14.2 Road committed developments included in the traffic model There are seven Highways England and 26 Local Highway Authority schemes that are expected to open within 18 months of each other and the Proposed Scheme, namely: • A14 Cambridge to Huntingdon – Highways England • M1 Junctions 13-16: Smart Motorways – Highways England • A5/M1 J11a Link – Highways England • M25 Junction 25 improvement – Highways England • M25 Junction 28 improvement – Highways England • A428 Black Cat to Caxton Gibbet – Highways England • M11 Junction 7a – Highways England • Bedford Western Bypass – Bedford Borough Council • A421: Junction 13 to Milton Keynes dualling – Central Bedfordshire Council/ Milton Keynes Council • M1 including 11a - A6 link road – Central Bedfordshire Council • Woodside Link – Central Bedfordshire Council • B183 Gilden Way Link (Harlow) – Essex County Council • M11 Junction 8 Slip road improvement – Essex County Council • Stevenage Costco access/ Gunnells Wood Road – Hertfordshire County Council • A602 Improvements - Hertford Road signalization – Hertfordshire County Council • A602 Improvements - A119 Roundabout – Hertfordshire County Council • A602 Improvements - Sacombe Pound Junction – Hertfordshire County Council • A602 Improvements Anchor Lane Roundabout – Hertfordshire County Council • A602 Improvements A10 Junction Ware – Hertfordshire County Council • A414 Colney Heath Longabout Safety Scheme – Hertfordshire County Council • A10 Hoddesdon Dumbell Roundabout - Dinant Link Road – Hertfordshire County Council/ Developer • Dinant Link Road / Amwell Street (Sun Roundabout) – Hertfordshire County Council/ Developer • Capacity improvements associated with Bishops Stortford North development – Hertfordshire County Council/ Developer • Remove the existing Bus Ln on Ware Rd approach to A10 Amwell Roundabout – Hertfordshire County Council • Upgrade of A602 / Gunnels Wood Road / GSK junction to hamburger layout – Hertfordshire County Council • A414 Breakspear Way / Maylands Lane Reallocation, Hemel Hempstead – Hertfordshire County Council • Upgrade to A10/London Road roundabout Buntingford – Hertfordshire County Council • A120 Little Hadham Bypass – Hertfordshire County Council • Turnford Link Road – Hertfordshire County Council • Hertford Road / Ware Road Broxbourne Improvement – Hertfordshire County Council • A505/ A10 Roundabout; A505/ A1198 Roundabout; A10/ Newmarket Road/ Melbourn Street Roundabout Royston – Hertfordshire County Council • Radlett Railfreight, new access junction onto A414 and new spine road connecting to A5183 Radlett Road (south of Frogmore) – Hertfordshire County Council • New link road connecting North Baldock development to North Road and Royston Road – Hertfordshire County Council
Environmental Assessment Report 3
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
14.3 Noise and vibration calculation and assessment assumptions
Table 8.3.144 Noise calculation assumptions
Element Assumption/Limitations Assumptions
Sensitive receptors have been identified through the Ordnance Survey Receptors (OS) AddressBase product.
The height and extent of existing environmental barriers are taken from the EnvIS, AVIS and SMIS databases and imagery from Google Earth Pro (accessed in November 2018).
The condition of existing noise barriers has been taken from a review of the imagery from Google Earth Pro (accessed in December 2018). Existing barriers The temporary removal of an existing noise barrier will be required at two locations; in the vicinity of Oaklands and Symonds Green. A 50m section will be temporarily removed for a period of up to eight weeks at each existing noise barrier, affecting a total of 112 residential receptors and a care home within 100m of the removed barriers.
New noise barriers It is assumed the new noise barriers will be absorptive.
A contraflow system could change noise levels experienced by residents with those experiencing a contraflow on the more distant carriageway having a reduction caused by reduced speed and increased separation distance.
Motorway traffic during Temporary speed limit is set at 50mph. 60mph may be permitted during construction works commissioning works in the final 3 months before road opening. For the purposes of the assessment, a 50mph speed limit without contraflow traffic management is currently being assumed. The traffic management regime is subject to change when the Delivery Partner is appointed as their construction sequencing may differ to the current DF3 assumptions. • Two MS4 installations per off-peak carriageway closure. • Two cantilever gantries installed per single direction carriageway Carriageway closures closure. • One gantry removal per night. No construction traffic noise or vibration is anticipated beyond the motorway and local roads servicing the compound sites. Given the Construction traffic volume of traffic already using the A1(M), any increase in noise level as a result of construction related traffic is considered unlikely to be significant and has therefore been excluded from this assessment.
All lanes (1 to 3) would be resurfaced with low noise surfacing (LNS, Pavement also known as Thin Surface Course) as part of the Proposed Scheme in the opening year (2022) across the length of the Proposed Scheme.
Environmental Assessment Report 4
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Element Assumption/Limitations
All lanes (1 to 3) would be resurfaced with LNS (2037) across the length of the Proposed Scheme, whether or not the Proposed Scheme goes ahead. The corrections applied to the road links within the 3D noise model are as follows:
• Existing LNS provides a -2.5dB correction where speeds are above 75km/h. • New LNS would provide a -3.5dB correction where speeds are above 75km/h. • At speeds below 75km/h LNS is assigned the same correction as a standard hot rolled asphalt surface of -1dB. The road surface correction for standard hot rolled asphalt surfacing is -1dB at speeds <75km/h and -0.5dB at speeds ≥ 75km/h.
LNS would be specified in the Handover Environmental Management Plan (HEMP) requiring an acoustic assessment prior to considering an alternative surface.
A Rigid Concrete Barrier would be located in the central reserve Central reserve between J6 to J8.
Percussive piling will only occur during the week day, although the Outline Environmental Management Plan (OEMP) identifies high Piling works sensitivity locations for the Construction Environmental Management Plan (CEMP) to demonstrate that acceptable construction techniques are available.
There are no bridge demolitions nor any other removal of any massive Demolition works structures
Construction noise levels could be up to 10 dB lower where properties are screened from the works. Significant Observed Adverse Effect Level (SOAEL) values are adopted irrespective of the anticipated ambient noise levels during construction and represent a worst case. However, where the existing ambient noise level is currently above SOAEL then higher values could be employed Construction noise with the agreement of Highways England. assessment Construction works are assumed to be carried out at night to represent a worst-case assessment.
In order to calculate the distance to the construction SOAEL, acoustically absorbent ground cover has been adopted as the intervening ground cover between the Proposed Scheme and closest receptors is predominantly absorptive in the acoustic sense.
Environmental Assessment Report 5
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Element Assumption/Limitations
Road traffic noise levels during construction are frequently lower than prior to the construction works due to the temporary reduction in speed (- 2.5dB for 70mph to 50mph). Upon opening to traffic, the perceived impact would be larger than the short-term assessment due to the cumulative impact of traffic returning to 70mph and the small increase in road traffic noise caused by the Proposed Scheme.
Noise level contours at a height of 4m above ground level have been calculated for the following scenarios: • DM2022 (i.e. without Proposed Scheme); • DM2037 (i.e. without Proposed Scheme); • DS2022 (i.e. with Proposed Scheme); and • DS2037 (i.e. with Proposed Scheme). Calculation points are 1m from external facades of receptors47 except Operational noise for free-field receptors. Predictions have been made at 4m above ground for all sensitive receptors, except for dwellings with only one storey (e.g. bungalows) where 1.5m above ground has been used. The night-time assessment has been undertaken for receptors where traffic noise levels are predicted to exceed 55dB Lnight,outside in any scenario as required by HD 213/11. Limitations
The timings and duration of individual works affecting specific locations Duration of works have been advised based on prior Smart Motorways Programme (SMP) experience.
Construction The location of the construction compound(s) and layout areas are compounds unknown, although candidate areas within 250m have been considered.
The number of noise sensitive receptors within 50m of diversion routes Motorway diversion is a high level estimate based upon sensitive receptors, identified routes through the OS AddressBase product.
Barriers proposed as absorptive are modelled as reflective barriers, giving a conservative outcome. Noise prediction The noise assessment is based upon traffic forecasts for an opening year of 2022.
It is assumed that works will be delivered within performance Construction specifications that prevent the occurrence of excessive disturbance to techniques local residents reflecting BS 5228-1 Annexes C and D. Further details are provided in the section below.
Environmental Assessment Report 6
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Element Assumption/Limitations
Construction plant Construction noise and vibration levels are based upon the values noise provided in BS 5228-1 and from previous SMP experience.
For the purpose of this assessment the factor (Kp) for the type of soil Ground conditions has been taken as 3, in line with the descriptions in BS 5228 2 Table E.2, as a worst case assessment.
The monetary benefits associated with noise barriers is based upon the Monetisation of noise Department for Environment, Food and Rural Affairs (Defra) 2014 impacts report48, but with updated GDP/cap and GDP deflator forecasts up to December 2017.
Construction noise calculations An assessment of construction activities, which are considered indicative of the likely works associated with the Proposed Scheme, has been undertaken. The assessment has included the prediction of noise levels at nearby properties during the construction works. For each construction activity, the number of specific plant items and the predicted percentage ‘on-times’ have been provided based on previous experience by Highways England. The noise levels for the plant items have been taken from source data in BS 5228-1. Table 8.3.2 details the typical road construction activities and equipment used in the construction noise calculations. To convert the hourly construction noise levels to the assessment time periods (07:00 to 19:00 for day-time and 23:00 to 07:00 for night-time), a typical day-time shift will last for 10 hours over the 12 hour assessment period, whereas a night-time shift will last for 6 hours over the 8 hour assessment period. Based on these assumptions, an operational sound power level has been calculated for each activity involving the relevant combination of plant. In order to calculate the distance to the construction SOAEL, acoustically absorbent ground cover has been adopted, as the intervening ground cover between the Proposed Scheme and closest receptors is predominantly absorptive in the acoustic sense. Where appropriate, and in order to provide a robust assessment, construction activities have been assumed to have a 5m area around them where plant actively involved in the construction activity would be located.
Environmental Assessment Report 7
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 8.3.245- Typical construction road activities and equipment used in the construction noise model
Worst case dB L at Source BS No. of Phase Activity Equipment Aeq on-time, 10m 5228-1 items %hour Central Reserve Phase
Central Reserve Barrier Dozer 82 C.5-13 1 20 (RCB) / lane 3
Wheeled excavator 73 C.5-11 1 20 a. Closure existing lane 2 Removal of existing Hand-held circular saw structures and 87 C.5-36 1 5 (petrol) b. 50mph lanes including installation of concrete hard shoulder running RCB
c. Construction of RCB at Wheeled loader 79 C.2-26 1 20 night
Resurfacing Works1
All three lanes are to be Removal of existing Road planer 82 C.5-7 2 60 resurfaced as part of the surface Wheeled excavator 73 C.5-11 4 20 scheme scope and in order for optimum surface to be Hand-held circular saw 87 C.5-36 2 15 achieved, a full carriageway (petrol) closure may be required at Lorry 80 C.2-34 4 10 night. The traffic management regime is Road Roller 80 C.5-19 2 10 subject to change when the Laying new surface Delivery Partner is appointed Vibratory compacter 82 C.5-29 1 10
as their construction sequencing may differ to the Asphalt paver (+ tipper lorry) 75 C.5-33 2 60 current DF3 assumptions.
Environmental Assessment Report 8
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Worst case dB L at Source BS No. of Phase Activity Equipment Aeq on-time, 10m 5228-1 items %hour Verge phase Petrol driven chain saw 86 D.2-14 1 10 (sawing timber) Demolition and clearance Tracked excavator 80 C.5-18 4 50 Lorry 80 C.2-34 4 10 Wheeled excavator 73 C.5-11 4 20 Concrete mixer truck + truck Demolition, clearance and mounted concrete pump + 78 C.4-32 2 10 stripping out of noise barriers boom arm (if required) Hydraulic hammer rig 89 C.3-1 1 10 Gantry installation (assumes Gantry installation percussive piling required). Wheeled mobile crane 70 C.3-30 2 50 Emergency area construction Gas cutter (cutting top of pile) 68 C.3-34 1 20 (assumes percussive piling required) Lorry 80 C.2-34 2 20 Hydraulic hammer rig 89 C.3-1 1 20 Gas cutter (cutting top of pile) 68 C.3-34 1 20 Dozer 77 C.5-12 1 20 Emergency Area Lorry 80 C.2-34 2 10
Road roller 80 C.5-19 2 10 Vibratory compacter 82 C.5-29 1 10 Asphalt paver (+ tipper lorry) 75 C.5-33 2 60 Drainage Works Tracked excavator 80 C.5-18 2 50 Drainage works Wheeled mobile crane 70 C.3-30 1 50
Environmental Assessment Report 9
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Worst case dB L at Source BS No. of Phase Activity Equipment Aeq on-time, 10m 5228-1 items %hour Road marking works Road marking works Lorry 80 C.2-34 2 20 Signage works Signage works Hydraulic hammer rig 89 C.3-1 1 10
Wheeled mobile crane 70 C.3-30 1 50
Gas cutter (cutting top of pile) 68 C.3-34 1 20
Lorry 80 C.2-34 2 20
Compound Dozer 75 C.2-1 2 30 Construction (assumed to be Tracked excavator 77 C.2-2 2 30 Site clearance day-time) Wheeled loader 79 C.2-26 4 30
Articulated dump truck 74 C.2-32 2 30 (tipping fill)
Compound Tracked crusher 84 C.1-15 2 40
construction Dozer 81 C.2-12 2 40
Vibratory roller 74 C.2-39 1 40
Lorry 80 C.2-34 1 50 Compound operation,2 24 hours Generator 61 C.4-76 1 100 Note 1: Motorway Incident Detection and Automatic Signalling (MIDAS) loop installation assumed to be included, where required.
Note 2: Additionally, an assessment of traffic accessing and leaving the construction compound should be undertaken once sufficient detail is available; noting that the impacts of the construction compound on receptors will be of much longer duration than most smart motorway construction activities.
Environmental Assessment Report 10
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
14.4 Analysis of noise rectification measures Background The monetised benefits associated with the acoustic performance of the candidate noise barriers have been determined using the economic methodology described in report Environmental Noise: Valuing impact on: sleep disturbance, annoyance, hypertension, productivity and quiet by Defra (November 2014). The report values the impacts of noise on both health and amenity. The valuation for effects on amenity considers annoyance and sleep disturbance. The valuation for effects on health considers direct acute myocardial infarctions (AMI), stroke and dementia. For the SMP, the benefit of a decrease in noise levels in relation to annoyance, AMI, stroke and dementia is calculated from the predicted day-time noise levels in LA10,18h free-field. The benefit of a decrease in noise levels in relation to sleep disturbance is calculated from the predicted night-time noise levels in Lnight,outside free-field. The graph below shows the road traffic noise marginal value in £ per dB change per household in 2014 prices in relation to LA10,18h noise levels considering an average of 2.3 persons per household. The analysis of the candidate noise barriers used Lnight,outside to value sleep disturbance, and therefore in some cases the benefit may be higher for sleep disturbance than for amenity.
Source: Defra, Transport noise modelling tool (MS Excel Spreadsheet), November 2014.
The valuation of acoustic benefits has considered a 60-year appraisal period after Proposed Scheme opening to be in line with the whole-life cost approach for the costs (see below). In line with the guidance from the Department for Transport, in WebTAG, the impacts of the Proposed Scheme were based on the differences in both the opening year (2022) and the future year (2037) between the Do Something (DS) scenario without mitigation but including any new LNS, and the DS scenario with further mitigation (i.e. including the candidate barrier). The valuation of costs has also used a whole-life cost approach. The whole-life cost approach considers a 60-year appraisal period after Proposed Scheme opening. The costs do not account for traffic management. The table below provides the whole-life cost values used for this assessment.
Environmental Assessment Report 11
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 8.4.146 Indicative whole-life costs of timber barrier in £ per linear metre
Barrier height Whole-life cost in £ per linear m Absorptive timber barrier 2m high £398 Absorptive timber barrier 3m high £467 Absorptive timber barrier 4m high £724
The costs noted in the above table may be revised post Design Fix (DF) 3, based on a review by the Delivery Partner. Therefore, it is possible that some barriers may no longer provide value for money and may be excluded from the design. Both the acoustic benefits and the costs have been converted to present day values using the methodology in WebTAG Unit A1.1 ‘Cost-Benefit Analysis’. This conversion accounts for future inflation and future GDP growth and is adjusted by discounting (i.e. the economic element that considers the preference of having money now rather than in the future). Assessment and Design Evolution Table 8.4.6 sets out the schedule of candidate noise barriers identified in the Environmental Scoping Report at the start of the design process, with a log of decisions that have been made during DF3. This has included testing each barrier’s ‘value for money’. A value for money (VfM) ratio of less than one indicates that the barrier is unlikely to represent a sustainable solution as per the Government’s policy on sustainable development. Some candidate barriers have been shortened or extended as an alternative test to establish if such adjustments affect the value for money analysis. For barriers achieving a VfM of greater than one, further analysis has been undertaken to establish the optimum height and, in some cases, length of the barrier to achieve a balance between value for money and perceivable noise benefits. New proposed barriers are highlighted in green. These barriers have been included in the noise model and assessment presented in the assessment of the Proposed Scheme.
Environmental Assessment Report 12
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 8.4.247 Noise barrier analysis
Number of properties Number of properties experiencing noise experiencing noise Barrier and reduction, opening year reduction, opening year Length Height Benefit, Cost, nIA VfM day-time, LA10, 18h dB night-time, Ln dB Justification (m) (m) £ £ 5 to 5 to 1 to 3 to >10d 1 to 3 to >10d 10d 10d 3dB 5dB B 3dB 5dB B B B £213,72 2 NB1 £1,133,632 6 5.3 158 47 0 0 169 21 0 0 (Absorptive) £250,77 The 3m barrier offers the 537 3 nIA 5442 £1,583,754 9 6.3 126 91 10 0 139 69 0 0 best value for money. £388,78 4 £1,999,356 8 5.1 101 115 32 0 133 93 10 0 £127,36 2 - 0 0.0 0 0 0 0 0 0 0 0 Discounted as the NB2 £149,44 320 3 acoustic VfM is less than - 0 0.0 0 0 0 0 0 0 0 0 1. £231,68 4 £10,345 0 0.0 3 0 0 0 2 0 0 0 2 £56,946 £39,402 1.5 11 0 0 0 8 0 0 0 The 3m high barrier NB3 gives best value for 3 £85,928 £46.233 1.9 12 3 0 0 10 1 0 0 money. Lies to the south (Absorptive) 99 of an existing barrier nIA 5141 4 (ENB2), serves as an £109,718 £71,676 1.5 12 4 0 0 11 3 0 0 extension. 2 £82,889 £81,192 1.02 5 3 1 0 2 3 1 0 3m high barrier gives NB4 best value for money. 3 £135,172 £95,268 1.4 10 0 4 0 7 2 2 0 Lies to the north of an (Absorptive) 204 existing barrier (ENB2), nIA 5141 4 £147,69 serves as an extension £182,741 6 1.2 15 2 3 1 12 0 4 0 similar to that as NNB3. NB5 £199,00 501 2 The 3m high barrier (Absorptive) £196,959 0 1.0 22 7 0 0 19 6 0 0 gives best value for
Environmental Assessment Report 13
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Number of properties Number of properties experiencing noise experiencing noise Barrier and reduction, opening year reduction, opening year Length Height Benefit, Cost, nIA VfM day-time, LA10, 18h dB night-time, Ln dB Justification (m) (m) £ £ 5 to 5 to 1 to 3 to >10d 1 to 3 to >10d 10d 10d 3dB 5dB B 3dB 5dB B B B nIA 5141 £233,50 money. Lies to the south 3 £434,551 0 1.9 23 11 7 0 21 14 2 0 of an existing barrier (ENB1), serves as an £362,00 4 extension. £663,714 0 1.8 24 11 17 0 21 13 12 0 2 £4,733 £78,008 0.1 1 0 0 0 1 0 0 0 Discounted as the NB6 3 £13,601 £91,532 0.2 5 0 0 0 2 0 0 0 196 acoustic VfM is less than nIA 5439 £141,90 1. 4 £29,190 4 0.2 9 0 0 0 6 0 0 0 2 £21,821 £68,854 0.3 9 0 0 0 5 0 0 0 Discounted as the NB7 3 £56,854 £80,791 0.7 24 0 0 0 12 0 0 0 173 acoustic VfM is less than
£125,25 1. 4 £105,793 2 0.8 49 1 0 0 22 0 0 0 £128,95 2 £55,229 2 0.4 14 0 0 0 12 0 0 0 Discounted as the NB8 £151,30 324 3 acoustic VfM is less than £117,405 8 0.8 11 4 0 0 14 1 0 0 nIA 4891 1. £234,57 4 £173,445 6 0.7 5 9 1 0 6 8 1 0 2 £14,230 £72,834 0.2 3 0 0 0 3 0 0 0 Discounted as the NB9 3 £61,689 £85,461 0.7 7 2 0 0 8 0 0 0 183 acoustic VfM is less than nIA 4888 £132,49 1. 4 £89,282 2 0.7 3 6 0 0 4 5 0 0 £391,63 2 4m high barrier gives NB10 £9,960 2 0 5 0 0 0 1 0 0 0 (Absorptive) 991 best value for money. £462,79 There is a step change in nIA 4887 3 £172,575 7 0.4 65 0 0 0 38 0 0 0 value for money due to
Environmental Assessment Report 14
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Number of properties Number of properties experiencing noise experiencing noise Barrier and reduction, opening year reduction, opening year Length Height Benefit, Cost, nIA VfM day-time, LA10, 18h dB night-time, Ln dB Justification (m) (m) £ £ 5 to 5 to 1 to 3 to >10d 1 to 3 to >10d 10d 10d 3dB 5dB B 3dB 5dB B B B an existing embankment limiting acoustic benefit until barrier reaches 4m 4 in height. Lies to the north of an existing £717,48 barrier (ENB5), serves £1,185,840 4 1.7 388 12 0 0 329 7 0 0 as an extension. £130,14 The VFM ratio for this 2 £60,899 6 0.5 16 0 0 0 12 0 0 0 4m high barrier is 1.02, based on standard cost £152,70 3 assumptions. Given the £136,460 9 0.9 36 2 0 0 21 2 0 0 location of this barrier and the proposed height of 4m, the costs associated with this barrier are expected to NB 11 be greater than those 327 nIA 4886 included in the analysis as ‘standard’ and 4 therefore it is considered likely that the barrier would be unlikely to provide value for money and so not be aligned with the Government’s £236,74 policy on sustainable £240,474 8 1.0 59 3 1 0 45 3 0 0 development. £129,74 2 £6,211 8 0.1 1 0 0 0 1 0 0 0 Discounted as the NB12 £152,24 326 3 acoustic VfM is less than £27,439 2 0.2 8 0 0 0 5 0 0 0 nIA 4886 1. £236,02 4 £38,288 4 0.2 8 1 0 0 8 0 0 0
Environmental Assessment Report 15
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
14.5 Traffic noise annoyance
Table 8.5.148 Changes in traffic noise annoyance
Without Proposed With Proposed Scheme Scheme Change in Annoyance Level Number of Number of Residential Residential Properties Properties >0 - <10% 781 1678 10 - <20% 0 89 Increase in annoyance 20 - <30% 0 5 level 30 - <40% 0 0 ≥40% 0 0 No change =0% 114 551 >0 - <10% 4168 2726 10 - <20% 0 10 Decrease in annoyance 20 - <30% 0 2 level 30 - <40% 0 2 ≥40% 0 0
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Smart Motorways Programme Environmental Assessment Report Appendix 9.1
Tranche 5 – A1(M) J6 to 8 (Preliminary Design – PCF Stage 3)
HE55139-WSP-EGN-SG-RP-LE-00031
June 2019
Notice
This document and its contents have been prepared and are intended solely for Highways England’s information and use in relation to the Smart Motorways Programme.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Revision history
Job number: 551539 Document ref: HE551539-WSP-EBD-SG-RP-LE-00031 Revision Purpose description Originated Checked Reviewed Approved Date P01 S3 – Draft for review Amina Joanna David Jonty Parry 10/05/19 and comment Sheikh- Goodwin Hoare/Andy Osman Thornhill P02 S4 – Suitable for stage Amina Joanna David Jonty Parry 07/06/19 approval Sheikh- Goodwin Hoare/Andy Osman Thornhill
Client signoff
Client Highways England Project SMP Tranche 5 – A1(M) Junctions 6-8 Document title Appendix 9.1 Job no. 551539 Document HE55139-WSP-EGN-SG-RP-LE-00031 reference
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table of Contents
1. Introduction 1 2. Assessment Methodology 2 2.1 Overview 2 2.2 Method A: Routine Runoff 2 2.3 Method C: Groundwater 3 2.4 Method D: Spillage Risk 3 3. Assessment Methodology 5 3.1 Method A: Routine Runoff 5 3.2 Method C: Groundwater 13 3.3 Method D: Spillage Risk 16 4. Indicative Priority Outfall Classification 18 4.2 Outfalls 18 4.3 Soakaways 19 5. Outfalls and Soakaways Scoped Out of an Assessment 21 6. Conclusion and Recommendations 23 6.1 Method A: Single Outfall Assessment 23 6.2 Method A: Cumulative Assessment 23 6.3 Method C: Groundwater 23 6.4 Method D: Spillage Risk 23
List of Tables
Table 3.1 - Summary of outfalls that drain to the River Mimram ...... 5 Table 3.2 - Summary of Q95 low flow for the River Mimram ...... 7 Table 3.3 - Summary of Method A assessment of pollution risks to River Mimram (single outfall assessment) ...... 7 Table 3.4 - Summary of Method A assessment of pollution risks to River Mimram (cumulative outfall assessment) ...... 8 Table 3.5 - Summary of outfalls that drain to the Ash Brook ...... 9 Table 3.6 - Summary of Q95 low flow for the Ash Brook ...... 11 Table 3.7 - Summary of Method A assessment of pollution risks to Ash Brook (single outfall assessment) .. 12 Table 3.8 - Summary of Method A assessment of pollution risks to Ash Brook (cumulative outfall assessment) ...... 12 Table 3.9 Summary of Method C assessment of pollution risks of soakaways discharging to ground...... 15 Table 3.10 - Summary of Method D spillage risk assessment for outfalls and soakaways ...... 16 Table 4.1 - Summary of current and indicative priority status for outfalls (single outfall assessment)11 ...... 18 Table 4.2 - Summary of current and indicative priority status for outfalls (cumulative outfall assessment) 12 19 Table 4.3 - Summary of indicative priority status for soakaways13 ...... 19 Table 5.1 - Summary of outfalls and soakaways scoped out of assessment 14...... 21
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Supporting Figures
Figure 3.1 - Catchment boundary used in previous HAWRAT assessment (October 2012) - screenshot taken from https://fehweb.ceh.ac.uk ...... 10 Figure 3.2 - Amended catchment boundary encompassing land to the north - screenshot taken from https://fehweb.ceh.ac.uk ...... 11
Annexes
Annex A: Method A HAWRAT Assessment Outputs Annex B: Method C and Priority Soakaway Outputs Annex C: Method D Spillage Risk Assessment Outputs .
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 14. Introduction Highways England is proposing to upgrade the A1(M) between junction 6 at Welwyn and junction 8 to the north of Stevenage to a Smart Motorway, hereafter referred to as the ‘Proposed Scheme’. A review of predicted traffic flow for the Do Minimum and Do Something scenarios for the design year (2037) indicates that traffic flows within certain sections of the Proposed Scheme (as summarised below) may increase by more than 20% as a result of the Proposed Scheme. Potential risks to the quality of surface water and groundwater receptors that receive runoff from the Proposed Scheme have been assessed using the Highways Agency (now Highways England) Water Risk Assessment Tool (HAWRAT) methods promoted within DMRB HD 45/09 (namely Method A (Routine Runoff), Method C (Groundwater Assessment) and Method D (Spillage Assessment)). Consideration has also been given to the likely Priority Status of affected outfalls in accordance with the Highways Agency Drainage Data Management System (HADDMS) Priority Registers Priority Outfalls Verification User Guide (2010) and Priority Soakaways Verification User Guide (2012). This appendix summarises the findings of the assessment and any recommendations with regard to further assessment or treatment requirements.
Environmental Assessment Report 1
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 15. Assessment Methodology 15.1 Overview The most appropriate method for assessing risks associated with selected outfalls is dependent on the nature of the receiving water environment – namely if the discharge is to a surface water feature or to ground via infiltration. Method A is used to assess potential pollution risks from routine runoff to surface waters, and Method C is used to assess potential pollution risks from routine runoff to groundwater. Method D is used to assess potential pollution risks from accidental spillage, with the same approach used for both risks to surface waters or groundwater. For outfalls that discharge to surface waters, the magnitude of a potential impact to the water environment and the classification of Priority Status in HADDMS is a factor of the Method A and Method D assessments. For outfalls that discharge to ground, a slightly different approach to Method C is taken depending on the purpose of the assessment – namely if the assessment is to inform an Environmental Assessment in accordance with DMRB HD 45/09 or if the assessment is to inform Priority Status classification. Both methods have been considered in this assessment, and both are also considered alongside the findings of Method D to provide the magnitude of a potential impact or the classification of Priority Status in HADDMS. The assessments are considered most applicable to roads that have a two-way 24-hour Annual Average Daily Traffic (AADT) flow of 10,000 cars or greater, as risks to the water environment from roads with a traffic flow of less than 10,000 are generally considered to be low. The assessment focusses on the potential risks associated with the operational phase of the Proposed Scheme and does not consider potential risks during the construction phase. 15.2 Method A: Routine Runoff The Method A assessment comprises two separate elements: the HAWRAT assessment and the Environmental Quality Standards (EQS) assessment. The HAWRAT assessment is a Microsoft Excel application designed to assess the short- term risks related to the intermittent nature of road runoff. It assesses the acute and chronic pollution impacts on aquatic ecology associated with soluble and sediment bound pollutants, respectively. For an individual outfall to pass the HAWRAT assessment, it must pass both the soluble pollutant and sediment pollutant impacts. The assessment is a tiered consequential system which involves up to three assessment stages, outlined as ‘steps’ within the assessment spreadsheet. These are detailed as follows: • Step 1: uses statistical models to determine pollutant concentrations in raw road runoff prior to any treatment or dilution in the receiving watercourse; • Step 2: assesses in-river pollutant concentrations after dilution and dispersion in the receiving watercourse, but without active mitigation, adopting a two-stage tiered process for the assessment of sediment accumulation: o Tier 1 – comprises a simplified assessment that takes into consideration the estimated river width; and if required o Tier 2 – comprises a more detailed assessment to determine flow velocity that takes into consideration bed width, manning’s n, side slope and long slope. • Step 3: considers the in-river pollutant concentrations with active mitigation.
Environmental Assessment Report 2
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
The EQS assessment considers the long-term chronic impacts associated with soluble pollutants. The in-river annual average concentrations for soluble pollutants are calculated and compared with published EQS to assess whether there is likely to be a long-term impact on ecology. The EQS are the maximum permissible annual average concentrations of potentially hazardous chemicals, as defined under the Water Framework Directive (WFD). The long-term risks over the period of one year are assessed through comparison of the annual average concentration of pollutants discharged with the published EQS for those pollutants. With regard to Step 2 of the assessment presented above, only a Tier 1 assessment has been completed as this stage as no site survey work has been undertaken. Review of previous HAWRAT assessments available in HADDMS indicates that no Tier 2 assessments have been completed within the extent of the Proposed Scheme to date, and therefore the more detailed information required to inform the Tier 2 assessment cannot be extracted from previous HAWRAT assessments. Where more than one individual outfall discharges into the same reach of a watercourse, the combined impacts will increase. DMRB HD 45/09 promotes the assessment of potential cumulative effects for outfalls within 1km of each other that drain to the same reach. Where this is the case, each outfall is grouped and assessed cumulatively using the Method A assessment. To aggregate the outfalls, the drained areas are added together. When assessing the combined impact of sediment bound pollutants, outfalls within 100m of one another are assessed. It is assumed that beyond 100m the road runoff sediment, if it settles at all, is likely to be sufficiently dispersed and diluted with natural sediments so as not to have an adverse impact. 15.3 Method C: Groundwater Potential impacts to groundwater quality associated with the infiltration of routine road runoff is assessed in accordance with Method C of DMRB HD 45/09. The assessment considers the source of pollutants and the pathway to a potential receptor, taking into account predicted traffic flow, rainfall characteristics, type of infiltration feature and nature of the underlying geology. The assessment applies different weightings and scores to the elements assessed, generating an overall risk score of Low Risk (overall risk score <150), Medium Risk (overall risk score 150-250) and High Risk (overall risk score >250). The sensitivity of the underlying groundwater resources is not taken into consideration in the DMRB HD 45/09 Method C assessment, although must be considered when reviewing the findings of the assessment and comparing the importance of the receptor alongside the magnitude of the potential risk. The HADDMS Priority Soakaways Verification User Guide promotes a slight variation to the DMRB HD 45/09 Method C assessment for the classification of priority status. The same basic principles are followed, although consideration is also given to the sensitivity of the underlying resource (i.e. Source Protection Zone (SPZ) or Principal Aquifer classification). 15.4 Method D: Spillage Risk Method D of DMRB HD 45/09 assesses the risk of pollution from spillages – i.e. if an accident were to occur. The assessment considers likely spillage rates based on the nature of the road (i.e. presence of slip roads, roundabouts, junctions etc. that can increase risk) and the percentage of the AADT that comprises Heavy Goods Vehicles (HGVs). The assessment takes the form of a risk assessment, where the risk is expressed as the annual probability of a serious pollution incident occurring. This risk is the product of two probabilities: Environmental Assessment Report 3
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
• The probability that an accident will occur, resulting in a serious spillage of a polluting substance on the carriageway; and • The probability that, if such a spillage did occur, the polluting substance would reach the receiving watercourse and cause a serious pollution incident. Typically, an annual probability of 1% (i.e. a 1 in 100 chance of a serious pollution incident occurring in any one year) is considered by DMRB HD 45/09 as an acceptable risk. However, where a road drainage outfall discharges within 1km of a sensitive receptor (such as a nationally designated conservation site or a groundwater aquifer used for potable supply), a higher level of protection is required, such that the risk has no greater annual probability than 0.5%.
Environmental Assessment Report 4
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 16. Assessment Methodology 16.1 Method A: Routine Runoff The DMRB HD 45/09 Method A assessment has been informed by a range of data as summarised below: • Location of existing outfalls: Obtained from information provided by the drainage design engineers; • River flow (Q95): Determined using LowFlows2 software and using a catchment area determined and purchased from Flood Estimation Handbook (FEH) Web Service, and compared with review of the National River Flow Archive and previous HAWRAT assessments available in HADDMS; • Base Flow Index: Catchment descriptors purchased from FEH Web Service; • River water hardness: This information was not available. High CaCO3 levels assumed based on review of previous HAWRAT assessments available in HADDMS and location of watercourses within a chalk catchment; • River width: Obtained from previous HAWRAT assessments available in HADDMS; • Location of designated sites: Obtained from review of MAGIC online mapping; • Traffic flow AADT data for the 2037 Do Something scenario ‘design year’: Obtained from traffic flow analysis provided by the appointed transport engineers completed by HE Supplier Paul Read (Jacobs); and • Impermeable areas: Obtained from information provided by the drainage design engineers. The input data that was used in the assessment of routine runoff using Method A is summarised in Annex A along with a detailed summary of the Method A assessment results. Out of the 19 outfalls serving the Proposed Scheme that discharge to a surface water feature, 8 outfalls have been taken through to single outfall assessments with a further 4 outfalls included within cumulative assessments. These are discussed below, with a further summary of scoped out outfalls provided in Section 5. River Mimram Table 3.1 summarises the outfalls identified to drain directly to the River Mimram (Outfalls 2, 3, 4 and 5) and additional outfalls that are assumed to drain to the River Mimram within 1km via a secondary drainage network or unmarked ditch (Outfalls 1, 6, 7 and 8). The table summarises the predicted change in AADT between the Do Minimum and Do Something scenarios, and the HAWRAT assessments completed for each outfall Table 3.49 - Summary of outfalls that drain to the River Mimram
Change in Outfalls Comments Traffic Flow Outfall 1 - Traffic flow No single outfall assessment completed TL2315_4971d increase 37% on as outfall only serves slip road and AADT (assumed to drain to slip road only but < 10,000. Drainage area included in Mimram) AADT banding cumulative assessment for soluble acute remains less than impacts and EQS assessment as outfall 10,000. assumed to be located within 1km of Mimram. Not included in cumulative assessment for sediment chronic impacts as outfall assumed to be >100m from other outfalls.
Environmental Assessment Report 5
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Change in Outfalls Comments Traffic Flow Outfall 2 - Traffic flow No single outfall assessment completed TL2316_5310e (also increase 37% on as outfall only serves small area of slip known as 5311c & slip road only but road and AADT < 10,000. Drainage area 5311d) (direct AADT banding included in cumulative assessment for discharge to remains less than soluble acute impacts, EQS assessment Mimram) 10,000. and sediment chronic impacts as <100m from other outfalls. Outfall 3 - Traffic flow Single outfall assessment completed. TL2316_5312d increase ≈20% Also included in cumulative assessment (direct discharge to on main for soluble acute impacts, EQS Mimram) carriageway but assessment and sediment chronic change to AADT impacts as <100m from other outfalls. banding. Outfall 4 - Traffic flow Single outfall assessment completed. TL2316_4616b increase ≈20% Also included in cumulative assessment (direct discharge to on main for soluble acute impacts, EQS Mimram) carriageway but assessment and sediment chronic no change to impacts as <100m from other outfalls. AADT banding. Outfall 5 - Traffic flow Single outfall assessment completed. TL2316_4517b increase ≈20% Also included in cumulative assessment (direct discharge to on main for soluble acute impacts, EQS Mimram) carriageway but assessment and sediment chronic no change to impacts as <100m from other outfalls. AADT banding. Outfall 6 - Traffic flow Single outfall assessment completed as TL2316_5147b increase 25% on traffic flow >10,000 AADT. Also included (assumed to drain to slip road only but in cumulative assessment for soluble Mimram) no change to acute impacts and EQS assessment as AADT banding. outfall assumed to be located within 1km of Mimram, but not included in cumulative assessment for sediment chronic impacts as outfall assumed to be >100m from other outfalls. Outfall 7 - Traffic flow Single outfall assessment completed. TL2316_7078b increase 21% on Also included in cumulative assessment (assumed to drain to main carriageway for soluble acute impacts and EQS Mimram) and change to assessment as outfall assumed to be AADT banding. located within 1km of Mimram, but not included in cumulative assessment for sediment chronic impacts as outfall assumed to be >100m from other outfalls. Outfall 8 - Traffic flow Single outfall assessment completed. TL2317_7600a (also increase 22% on Also included in cumulative assessment referred to as 7501c main carriageway for soluble acute impacts and EQS & 7502b) (assumed and change to assessment as outfall assumed to be to drain to Mimram) AADT banding. located within 1km of Mimram, but not included in cumulative assessment for sediment chronic impacts as outfall assumed to be >100m from other outfalls.
Environmental Assessment Report 6
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
As discussed above, the low-flow river flow (Q95) used to inform the Method A assessment was determined using the industry recognised LowFlows2 software and using a catchment area determined from the FEH Web Service. This figure was compared with the following sources of supplementary information: observed flow records held for the Fulling Mill gauging station approximately 1.5km upstream of the Proposed Scheme; observed flow records held for the Panshanger Park gauging station approximately 6.5km downstream of the Proposed Scheme; and the previous HAWRAT assessments available in HADDMS for outfalls draining to the River Mimram. This information is presented in Table 3.2 below. Table 3.50 - Summary of Q95 low flow for the River Mimram
Q95 Source of Information Comments (m3/s) Q95 calculated using 0.214 Average annual Q95 calculated at location of LowFlows2 Proposed Scheme’s crossing of River Mimram. Q95 at Fulling Mill 0.013 Low Q95 flows upstream of Proposed gauging station 1.5km Scheme reported to be attributable to upstream significant losses caused by groundwater abstraction in headwaters of river. Q95 at Panshanger Park 0.217 Groundwater abstraction in headwaters of gauging station 6.5km river still cited as cause of reduced low flows, downstream although reference made to very high baseline component and increasing peak flows due to urbanisation. Q95 used in previous 0.066 Calculated using the Institute of Hydrology HAWRAT assessments report no.108. available in HADDMS A review of the FEH catchment used in previous HAWRAT assessments available in HADDMS for outfalls draining to the River Mimram indicated a similar catchment boundary to that determined to inform this amended assessment for the Proposed Scheme. It was therefore decided to use the same Q95 as calculated for the previous HAWRAT assessments (0.066 m3/s) as this is still considered to be representative of the catchment and account for losses caused by groundwater abstraction. The results of the Method A single outfall and cumulative outfall assessments for the River Mimram are presented in Table 3.3 and Table 3.4 below. A detailed summary of the Method A assessment results is provided in Annex A. Table 51.3 - Summary of Method A assessment of pollution risks to River Mimram (single outfall assessment) for the 2037 Do Something scenario Soluble Pollutants Sediment EQS Assessment Chronic Annual average Annual average Acute impact Acute impact Outfalls Step impact concentration of concentration of assessment assessment assessment copper (µg/l) due zinc (µg/l) due to of copper of zinc of sediment to road runoff road runoff Outfall 3 Step 1 FAIL FAIL FAIL - - TL2316_ Step 2 PASS PASS PASS 0.02 PASS 0.05 PASS 5312d Step 3 No further assessment required Outfall 4 Step 1 FAIL FAIL FAIL - - TL2316_ Step 2 PASS PASS PASS 0.00 PASS 0.01 PASS 4616b Step 3 No further assessment required Outfall 5 Step 1 FAIL FAIL FAIL - - TL2316_ Step 2 PASS PASS PASS 0.01 PASS 0.02 PASS 4517b Step 3 No further assessment required Step 1 FAIL FAIL FAIL - -
Environmental Assessment Report 7
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Soluble Pollutants Sediment EQS Assessment Chronic Annual average Annual average Acute impact Acute impact Outfalls Step impact concentration of concentration of assessment assessment assessment copper (µg/l) due zinc (µg/l) due to of copper of zinc of sediment to road runoff road runoff Outfall 6 Step 2 PASS PASS PASS 0.02 PASS 0.05 PASS TL2316_ 5147b Step 3 No further assessment required Outfall 7 Step 1 FAIL FAIL FAIL - - TL2316_ Step 2 PASS PASS PASS 0.01 PASS 0.02 PASS 7078b Step 3 No further assessment required Outfall 8 Step 1 FAIL FAIL FAIL - - TL2317_ Step 2 PASS PASS PASS 0.04 PASS 0.18 PASS 7600a Step 3 No further assessment required
Table 3.52 - Summary of Method A assessment of pollution risks to River Mimram (cumulative outfall assessment) for the 2037 Do Something scenario
Soluble Pollutants Sediment EQS Assessment Annual average Acute Acute Chronic Annual average concentration of Outfalls Step impact impact impact concentration of copper (µg/l) assessment assessment assessment zinc (µg/l) due due to road of copper of zinc of sediment to road runoff runoff All outfalls Step 1 Step 1 not assessed for cumulative impacts discharging Step 2 PASS PASS PASS 0.19 PASS 0.79 PASS to the River Step 3 No further assessment required Mimram Step 1 assesses the quality of the direct highway runoff against the toxicity thresholds whilst assuming no in-river dilution and no treatment or attenuation. All of the single outfall assessments and cumulative outfall assessment failed Step 1 for both acute impacts of soluble pollutants and the chronic impacts of sediment-bound pollutants. As a result, a Step 2 assessment was undertaken for each outfall. Step 2 assesses the acute impacts of soluble pollutants (zinc and copper) and takes into account the diluting capacity of the receiving watercourse, as well as chronic impacts of sediment-bound pollutants taking into account the likelihood and extent of sediment deposition informed by estimated river width. Step 2 also includes the EQS assessment. All single outfall assessments and the cumulative assessment passed Step 2 for both acute impacts of soluble pollutants and the EQS assessment (including all outfalls within 1km of the River Mimram) and the chronic impacts of sediment-bound pollutants (for outfalls identified to be within 100m of each other) (i.e. all aspects of the Method A HAWRAT assessment were passed). Step 3 (taking mitigation into account) has not been undertaken at this stage as it is considered to not be required based on the understanding that there is no existing treatment in place, and no additional treatment measures are currently proposed as part of the Proposed Scheme. Ash Brook Table 3.5 summarises the outfalls identified to drain directly to the Ash Brook (Outfalls 26 and 27) and additional outfalls that are assumed to drain to the Ash Brook within 1km via a secondary drainage network or unmarked ditch (Outfalls 25, 28 and 29). The table summarises the predicted change in AADT between the Do Minimum and Do Something scenarios, and the HAWRAT assessments completed for each outfall.
Environmental Assessment Report 8
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 3.53 - Summary of outfalls that drain to the Ash Brook Change in Outfalls Comments Traffic Flow No single outfall assessment completed but Traffic flow drainage area included in cumulative Outfall 25 - increase 19% assessment for soluble acute impacts and TL2226_4471b on main EQS assessment as outfall located within (assumed to drain carriageway 1km of Ash Brook. Outfall also included in to ditch that in and no change cumulative assessment for sediment chronic turn discharges to to AADT impacts as outfall assumed to discharge Ash Brook) banding. within 100m of Outfalls 26 and 27, although not confirmed. Traffic flow Single outfall assessment completed. Also Outfall 26 - increase 22% included in cumulative assessment for soluble TL2226_3977e on main acute impacts, EQS assessment and (direct discharge carriageway sediment chronic impacts as <100m from to Ash Brook) and change to other outfalls. AADT banding. Traffic flow Single outfall assessment completed. Also Outfall 27 - increase 48% included in cumulative assessment for soluble TL2226_3978f on slip road acute impacts, EQS assessment and (direct discharge only and sediment chronic impacts as <100m from to Ash Brook) change to other outfalls. AADT banding. No single outfall assessment completed but drainage area included in cumulative Outfall 28 - Traffic flow assessment for soluble acute impacts and TL2227_5704d increase 16% EQS assessment as outfall assumed to be (assumed to drain on main located within 1km of Ash Brook. Outfall not to local drainage carriageway included in cumulative assessment for system that in and no change sediment chronic impacts as outfall first turn discharges to to AADT discharges to local drainage network that is Ash Brook) banding. believed to outfall to Ash Brook further than 100m from other outfalls, although this is not confirmed. No single outfall assessment completed but drainage area included in cumulative Outfall 29 - Traffic flow assessment for soluble acute impacts and TL2226_3977e increase 8% on EQS assessment as outfall assumed to be (assumed to drain main located within 1km of Ash Brook. Outfall not to local drainage carriageway but included in cumulative assessment for system that in change to one- sediment chronic impacts as outfall first turn discharges to way AADT discharges to local drainage network that is Ash Brook) banding. believed to outfall to Ash Brook further than 100m from other outfalls, although this is not confirmed.
Environmental Assessment Report 9
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
As discussed above, the low-flow river flow (Q95) used to inform the Method A assessment was determined using the industry recognised LowFlows2 software and using a catchment area determined from the FEH Web Service, and comparing this to the previous HAWRAT assessments available in HADDMS for outfalls draining to the Ash Brook (noting that there are no known gauging stations on the Ash Brook that can provide observed Q95 flows). The Q95 calculated using the LowFlows2 software was significantly larger than the Q95 previously estimated by the HAWRAT assessment available in HADDMS, noting that this method used the Institute of Hydrology report no.10849. However, the review also indicated significant discrepancies between the expected catchment of the Ash Brook at the location where it is crossed by the Proposed Scheme, and the catchment as indicated by the FEH Web Service that was used in the previous HAWRAT assessments. It appears that the FEH Web Service underestimates the size of the catchment which will in turn lead to an underestimate of the likely low flows. Figure 3.1 illustrates the catchment determined by the FEH Web Service at the location of the Proposed Scheme’s crossing of the Ash Brook, and therefore the catchment that has been used by the previous HAWRAT assessments available in HADDMS for outfalls draining to the Ash Brook at this approximate location. The catchment area measures approximately 2.47km2. Review of Ordnance Survey mapping indicates that this catchment boundary does not include land further to the north which also drains to the Ash Brook prior to the Proposed Scheme’s crossing of the Ash Brook (i.e. upstream of the outfalls being assessed) and which is also expected be included within the catchment. Figure 3.5 - Catchment boundary used in previous HAWRAT assessment (October 2012) - screenshot taken from https://fehweb.ceh.ac.uk
Ash Brook to north of catchment, clearly flowing through catchment to west of Proposed Scheme
Downstream catchment boundary at location of Proposed Scheme outfalls to Ash Brook
Grey shaded area denotes extent of catchment as extracted from FEH Web Service.
Figure 3.2 illustrates the amended catchment which is believed to be more representative of the true catchment that drains to the Ash Brook prior to the Proposed Scheme’s crossing of the Ash Brook. This encompasses additional land to the north of the previous catchment. The amended catchment area measures approximately 11.77 km².
49 Gustard A, Bullock A and Dixon JM (1992). Low flow estimation in the United Kingdom, report No. 108. Institute of Hydrology. Environmental Assessment Report 10
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Figure 3.6 - Amended catchment boundary encompassing land to the north - screenshot taken from https://fehweb.ceh.ac.uk
Extended catchment to north to encompass upstream extent of Ash Brook
Amended downstream catchment boundary considered to be more representative of catchment area at location of Proposed Scheme outfalls to Ash Brook
A summary of the calculated Q95 low flows for the two catchment areas is presented in Table 3.6 below. Table 3.54 - Summary of Q95 low flow for the Ash Brook Source of Information Q95 (M3/S) Comments Q95 used in previous 0.001 m3/s Larger Q95 flow representative of larger HAWRAT assessments catchment area, however flows likely to available in HADDMS overestimate ‘actual’ low flow within the using ‘original’ catchment watercourse due to likely losses area (Figure 3.1) attributable to groundwater abstraction. Q95 calculated using 0.005 m3/s Comparison of difference between low LowFlows2 and ‘original’ flows calculated using Institute of catchment area (Figure Hydrology report no.108 and LowFlows2 3.1) software for original catchment area Q95 calculated using 0.017 m3/s indicates that an amended low of 0.005 LowFlows2 and m3/s would be appropriate for the larger ‘amended’ catchment catchment area and allowing for likely area (Figure 3.2) losses attributable to groundwater abstraction. For the purpose of this amended HAWRAT assessment to inform the Proposed Scheme, a Q95 of 0.005 m3/s has been applied as this is considered appropriate for the larger catchment area whilst taking into account likely losses due to groundwater abstraction. The results of the Method A single outfall assessments and cumulative outfall assessment are presented in Table 3.7 and Table 3.8 below. A detailed summary of the Method A assessment results is provided in Annex A.
Environmental Assessment Report 11
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 3.55 - Summary of Method A assessment of pollution risks to Ash Brook (single outfall assessment) for the 2037 Do Something scenario Soluble Pollutants Sediment EQS Assessment Acute Acute Chronic Annual average Annual average Outfalls Step impact impact impact concentration of concentration of assessment assessment assessment copper (µg/l) due zinc (µg/l) due to of copper of zinc of sediment to road runoff road runoff Outfall 26 Step 1 FAIL FAIL FAIL - - - TL2226_ Step 2 PASS PASS PASS 0.07 PASS 0.22 PASS 3977e Step 3 No further assessment required Outfall 27 Step 1 FAIL FAIL FAIL - - - TL2226_ Step 2 PASS PASS PASS 0.03 PASS 0.10 PASS 3978f Step 3 No further assessment required
Table 3.56 - Summary of Method A assessment of pollution risks to Ash Brook (cumulative outfall assessment) for the 2037 Do Something scenario Soluble Pollutants Sediment EQS Assessment Annual average Acute Acute Chronic Annual average concentration of Outfalls Step impact impact impact concentration of copper (µg/l) assessment assessment assessment zinc (µg/l) due to due to road of copper of zinc of sediment road runoff runoff Outfalls Step 1 Step 1 not assessed for cumulative impacts discharging Step 2 FAIL PASS FAIL 1.54 PASS 5.47 PASS to Ash Brook Step 3 Not undertaken The assessments presented above indicate that all of the single outfall assessments and cumulative outfall assessment failed Step 1 for both acute impacts of soluble pollutants and the chronic impacts of sediment-bound pollutants. As a result, a Step 2 assessment was undertaken for each outfall. The Step 2 assessment indicates that both single outfall assessments passed Step 2 for the acute impacts of soluble pollutants, the EQS assessment and the chronic impacts of sediment-bound pollutants (i.e. all aspects of the Method A HAWRAT assessment). The Step 2 assessment does however indicate that the cumulative assessment of outfalls draining to the Ash Brook failed the acute impact of copper (noting this includes all outfalls within 1km of the Ash Brook) and the chronic impact of sediment-bound pollutants (noting this only included outfalls identified or assumed to be within 100m of each other). Step 3 (taking mitigation into account) has not been undertaken at this stage as it is considered to not be required based on the understanding that there is no existing treatment in place, and no additional treatment measures are currently proposed as part of the Proposed Scheme. A comparison to present-day baseline condition and the 2037 Do Minimum scenario has been undertaken for the cumulative assessment of outfalls draining to the Ash Brook. The present-day baseline condition has a lower AADT traffic banding of ‘≥50,000 to <100,000’. However, the cumulative assessment still indicates failure of the acute impact of copper and the chronic impact of sediment-bound pollutants (i.e. no change to assessment conclusions compared to the 2037 Do Something scenario). This assessment is presented below in Table 3.57.
Environmental Assessment Report 12
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 3.57 - Summary of Method A assessment of pollution risks to Ash Brook (cumulative outfall assessment) for the baseline Do Minimum scenario Soluble Pollutants Sediment EQS Assessment Annual average Acute Acute Chronic Annual average concentration of Outfalls Step impact impact impact concentration of copper (µg/l) assessment assessment assessment zinc (µg/l) due to due to road of copper of zinc of sediment road runoff runoff Outfalls Step 1 Step 1 not assessed for cumulative impacts discharging Step 2 FAIL PASS FAIL 0.89 PASS 2.20 PASS to Ash Brook Step 3 Not undertaken Review of outfall catchment areas indicates that the drainage catchments of Outfalls 25, 28 and 29 (i.e. those that do not drain directly to the Ash Brook or where the drainage outfall location is unclear) contribute the largest areas of the cumulative drainage catchment – namely c.1.65ha (Outfall 25), c.4.28ha (Outfall 28) and c.1.70ha (Outfall 29) of impermeable carriageway surface. This suggests that any improvement works to provide additional treatment would therefore be best located within the Outfall 28 catchment area. However, whilst it is fairly certain that this catchment drains to the Ash Brook and outfalls upstream of the A1(M), the catchment areas of all outfalls north of junction 8 and the alignment of the below ground drainage network is uncertain. Opportunities to provide treatment within the highway boundary may therefore be problematic. 16.2 Method C: Groundwater The DMRB HD 45/09 Method C assessment has been informed by a range of data and parameters as summarised below: • Rainfall volume (annual averages): Obtained from the Met Office website; • Rainfall intensity: Determined from Volume Two of the FEH; • Soakaway geometry and drainage catchment size: Obtained from review of HADDMS asset data and information provided by the drainage design engineers; • Unsaturated zone, Flow type, Effective grain size and Lithology: Determined through review of borehole data available via the British Geological Survey (BGS) online viewer, with comparison with previous HAWRAT assessments available in HADDMS; • Location of SPZs and aquifer designation: Determined from review of MAGIC online mapping; and • Traffic flow AADT data for the 2037 Do Something scenario ‘design year’: Obtained from traffic flow analysis provided by the appointed transport engineers completed by HE Supplier Paul Read (Jacobs). The input data that was used in the assessment of routine runoff using Method C is summarised in Annex B along with a detailed summary of the Method C assessment results. Out of the 9 outfalls serving the Proposed Scheme that discharge to ground via infiltration, 8 outfalls are predicted to experience a greater than 20% increase in traffic flow although all 9 outfalls have been taken through for assessment for completeness. These are discussed below, with a further summary of scoped out outfalls provided in Section 5.
Environmental Assessment Report 13
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table 3.58 - Summary of outfalls that discharge to ground Change In Traffic Outfalls Comments Flow Outfall 9 - Traffic flow Single outfall assessment completed. TL2417_0161c increase 22% on Previous HAWRAT available in main carriageway HADDMS, although changes made to and change to geology flow type as previous AADT banding assessment assumed intergranular flow. Review of borehole logs indicates weathered weak low density chalk close to ground surface, therefore fractured flow type selected. Outfall 10 - Traffic flow Single outfall assessment completed. No TL2418_3158d increase 22% on previous HAWRAT available, but (also referred to as main carriageway HADDMS describes soakaway as 3757b) and change to infiltration trench that is assumed to be AADT banding shallow. Assessment assumes fractured flow type as review of borehole logs indicates weathered weak low density chalk close to ground surface. Outfall 11 - Traffic flow Single outfall assessment completed. TL2418_3786e increase 22% on No previous HAWRAT available and no main carriageway information regarding soakaway and change to structure available in HADDMS. Depth AADT banding of soakaway unknown but assume >15m to groundwater table as borehole logs indicate depth to groundwater 55m below ground level. Assessment assumes fractured flow type as review of borehole logs indicates weathered weak low density chalk within 6m of ground surface. Outfall 12 - Traffic flow Single outfall assessment completed. TL2419_3544b increase 22% on Previous HAWRAT available in (also referred to as main carriageway HADDMS, although changes made to 3645a) and change to geology flow type as previous AADT banding assessment assumed intergranular flow. Review of borehole logs indicates weathered weak low density chalk close to ground surface, therefore fractured flow type selected. Outfall 13 - Traffic flow Single outfall assessment completed. TL2419_3086a increase 22% on Previous HAWRAT available in main carriageway HADDMS, although changes made to and change to geology flow type as previous AADT banding assessment assumed intergranular flow. Review of borehole logs indicates weathered weak low density chalk close to ground surface, therefore fractured flow type selected.
Environmental Assessment Report 14
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Change In Traffic Outfalls Comments Flow Outfall 14 - Traffic flow Single outfall assessment completed. No TL2321_9506d increase 22% on previous HAWRAT available, but (also referred to as main carriageway HADDMS describes soakaway as 0109b) and change to infiltration basin that is assumed to be AADT banding shallow. Assessment assumes mixed fractured and intergranular flow type as review of borehole logs indicates c.9m clay with sand, gravel and flint superficial deposits overlying chalk. Outfall 15 - Traffic flow Single outfall assessment completed. No TL2321_8562l increase 22% on previous HAWRAT available, but main carriageway HADDMS describes soakaway as and change to infiltration trench that is assumed to be AADT banding shallow. Assessment assumes mixed fractured and intergranular flow type as review of borehole logs indicates c.25m clay and sand superficial deposits overlying chalk. Outfall 18 - Traffic flow Single outfall assessment completed. TL2322_3685c increase 22% on No previous HAWRAT available and no main carriageway information regarding soakaway and change to structure available in HADDMS. Depth AADT banding of soakaway unknown, but assumed 5- 15m to groundwater as borehole logs indicate depth to groundwater 17-38m below ground level. Outfall 21 - Traffic flow Single outfall assessment not required TL2224_1656c increase 19% on but completed for all outfalls to ground. main carriageway Previous HAWRAT available in and no change to HADDMS, although changes made to AADT banding geology flow type as previous assessment assumed intergranular flow. Review of borehole logs indicates weathered weak low density chalk close to ground surface, therefore fractured flow type selected. The results of the Method C assessments are presented in Table 3.59 below. Only single outfall assessments are undertaken for the Method C assessments, with no requirement to undertake cumulative assessments. Table 3.59 Summary of Method C assessment of pollution risks of soakaways discharging to ground for the 2037 Do Something scenario Outfalls Overall Risk Overall Risk Other Score Classification Considerations Outfall 9 - TL2417_0161c 245 Medium Risk Located in SPZ3 Outfall 10 - TL2418_3158d 245 Medium Risk Located in SPZ3 Located outside of Outfall 11 - TL2418_3786e 245 Medium Risk SPZ Outfall 12 - TL2419_3544b 245 Medium Risk Located in SPZ3 Outfall 13 - TL2419_3086a 245 Medium Risk Located in SPZ3 Outfall 14 - TL2321_9506d 210 Medium Risk Located in SPZ2 Located in SPZ2 & Outfall 15 - TL2321_8562l 210 Medium Risk SPZ3
Environmental Assessment Report 15
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Outfalls Overall Risk Overall Risk Other Score Classification Considerations Located outside of Outfall 18 - TL2322_3685c 215 Medium Risk SPZ Outfall 21 - TL2224_1656c 230 Medium Risk Located in SPZ3 The Method C assessment identified a Medium Risk of impact to underlying groundwater resources. A comparison to 2037 Do Minimum scenario has been undertaken for the outfalls listed above. This indicates that for all outfalls expect for Outfall 21 there would be an increase in traffic flow that would change the AADT traffic banding from ‘≥50,000 to <100,000’ to ‘≥100,000’ for Outfalls 9, 10, 11, 12, 13, 14 and 15; and an increase in traffic flow that would change the AADT traffic banding from ’≥10,000 to <50,000’ to ‘≥50,000 to <100,000’ for Outfall 18. However, re-running the Method C assessment for the 2037 Do Minimum scenario indicates the same findings as those presented in Table 3.59for the 2037 Do Something scenario – i.e. Medium Risk to underlying groundwater quality. 16.3 Method D: Spillage Risk The DMRB HD 45/09 Method D spillage risk assessment considers the risk posed to the receiving water environment associated with each outfall – with the same assessment completed for both surface water and groundwater receptors. The assessment has been informed by a range of data and parameters as summarised below: • Length of road draining to each outfall: Obtained from information provided by the drainage design engineers; • Road type and junction type: Obtained from the Proposed Scheme general arrangement drawings; • Location: Obtained from Table D1.2 classification in DMRB HD 45/09; • Spillage factor for each junction type: Obtained from Table D1.1 in the DMRB HD 45/09; • Existing measures factor: Obtained from Table 8.1 in the DMRB HD 45/09. A default value of 1 was used for all of the assessments as there are no known existing measures; • Proposed measures factor: Obtained from Table 8.1 in the DMRB HD 45/09. A default value of 1 was used for all of the assessments as there are no proposed measures; • Traffic flow AADT data for the 2037 Do Something scenario ‘design year’: Obtained from traffic flow analysis provided by the appointed transport; and • Percentage of HGVs: Obtained from traffic flow analysis provided by the appointed transport engineers. The input data that was used in the assessment of routine runoff using Method D is summarised in Annex C along with a detailed summary of the Method D assessment results. The results of the Method D assessments are presented in Table 3.60 below. Table 3.60 - Summary of Method D spillage risk assessment for outfalls and soakaways for the 2037 Do Something scenario Outfalls Receiving Annual probability of Acceptability Waterbody serious pollution incident Outfall 3 - River Mimram 0.031% Pass – Risk <1% TL2316_5312d Outfall 4 - River Mimram 0.017% Pass – Risk <1% TL2316_4616b
Environmental Assessment Report 16
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Outfalls Receiving Annual probability of Acceptability Waterbody serious pollution incident Outfall 6 - River Mimram 0.003% Pass – Risk <1% TL2316_5147b Outfall 7 - River Mimram 0.007% Pass – Risk <1% TL2316_7078b Outfall 8 - River Mimram 0.066% Pass – Risk <1% TL2317_7600a Outfall 9 - To ground 0.055% Pass – Risk <0.5% TL2417_0161c Outfall 10 - To ground 0.018% Pass – Risk <0.5% TL2418_3158d Outfall 11 - To ground 0.026% Pass – Risk <0.5% TL2418_3786e Outfall 12 - To ground 0.022% Pass – Risk <0.5% TL2419_3544b Outfall 13 - To ground 0.067% Pass – Risk <0.5% TL2419_3086a Outfall 14 - To ground 0.042% Pass – Risk <0.5% TL2321_9506d Outfall 15 - To ground 0.043% Pass – Risk <0.5% TL2321_8562l Outfall 18 - To ground 0.014% Pass – Risk <0.5% TL2322_3685c Outfall 21 - To ground 0.013% Pass – Risk <0.5% TL2224_1656c Outfall 26 - Ash Brook 0.004% Pass – Risk <1% TL2226_3977e Outfall 27 - Ash Brook 0.001% Pass – Risk <1% TL2226_3978f The results of the Method D assessment indicate an annual probability of less than 1% for all outfalls to surface water and less than 0.5% for all outfalls to groundwater which is below the recommended thresholds.
Environmental Assessment Report 17
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 17. Indicative Priority Outfall Classification The indicative priority status classification of the outfalls and soakaways assessed has been determined by applying the Priority Outfalls Verification User Guide (2010)50 and Priority Soakaways Verification User Guide (2012)51. 17.2 Outfalls The Priority Outfalls Verification User Guide uses the same methods as promoted within DMRB HD 45/09 with priority status determined by review of the Method A and Method D assessments. Table 4.1 provides an overview of the current priority status for single outfall assessments as presented within HADDMS, and the indicative priority status determined using the findings of the 2037 Do Something scenario as presented in the tables above. The assessment indicates that all outfalls assessed (i.e. that are indicated to experience a greater than 20% increase in traffic flow) that drain (or are assumed to drain) to the River Mimram and Ash Brook would be allocated Priority X (Risk Addressed) status. This is the same or better than the priority status as currently presented in HADDMS. Table 4.1 - Summary of current and indicative priority status for outfalls (single outfall assessment)61 Outfalls Receiving Existing Priority Indicative Priority Water Body Status Status Outfall 3 - River Mimram Priority Status X: Priority Status X - TL2316_5312d Risk Addressed Risk Addressed Outfall 4 - River Mimram Outfall has no Priority Status X - TL2316_4616b Priority status Risk Addressed Outfall 5 - River Mimram Priority Status X: Priority Status X: TL2316_4517b Risk Addressed Risk Addressed Outfall 6 - River Mimram Outfall has no Priority Status X - TL2316_5147b Priority status Risk Addressed Outfall 7 - River Mimram Priority D Priority Status X - TL2316_7078b Risk Addressed Outfall 8 - River Mimram Priority D Priority Status X - TL2317_7600a Risk Addressed Outfall 26 - Ash Brook Priority Status X: Priority Status X - TL2226_3977e Risk Addressed Risk Addressed Outfall 27 - Ash Brook Priority Status X: Priority Status X - TL2226_3978f Risk Addressed Risk Addressed Table 4.2 provides an overview of the current priority status for cumulative outfall assessments as presented within HADDMS for outfalls to the River Mimram and Ash Brook, and the indicative priority status determined using the findings of the 2037 Do Something scenario as presented in the tables above. As discussed above, the assessment of acute impacts of soluble pollutants and the EQS assessment included all outfalls that drain (or are assumed to drain) within 1km of the watercourses, and the assessment of chronic impacts of sediment-bound pollutants included all outfalls that drain (or are assumed to drain) within 100m of each other. The assessment indicates that the cumulative assessment of all outfalls that drain to the River Mimram would be allocated Priority X (Risk Addressed) status. There is therefore no change to the priority status as currently presented in HADDMS.
50 HADDMS Priority Registers Priority Outfalls Verification User Guide Priority Outfall User Guide v1.7 05-10-10 MM.doc, 7 October 2010. 51 HADDMS Priority Registers Priority Soakaways Verification User Guide V2a 17_05_2012.doc, 17 May 2012. Environmental Assessment Report 18
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
The assessment indicates that the cumulative assessment of all outfalls that drain to the Ash Brook would be allocated Priority B (High) status due to the failure of the acute impact of copper and chronic impact of sediment accumulation. This differs from the priority status as currently presented in HADDMS, which allocates a Priority X (Risk Addressed) status. However, as discussed in Section 3.1, a comparison has been made between the 2037 Do Something scenario with the baseline Do Minimum scenario that indicates the priority status of the cumulative outfall assessment would be allocated Priority B (High) status for the same reasons as the 2037 Do Something assessment (i.e. no change to the conclusions of the assessments). Table 4.2 - Summary of current and indicative priority status for outfalls (cumulative outfall assessment) 62 Receiving Existing Priority Indicative Outfalls Water Body Status Priority Status Outfalls discharging to Priority Status X: Risk Priority Status X: River Mimram River Mimram with 1km Addressed Risk Addressed. Priority Status X: Risk Addressed Outfalls discharging to Priority Status B: Ash Brook (HADDMS) Ash Brook with 1km High Priority Status B: High (Reassessment) The change in cumulative assessment status for the Ash Brook from Priority X (Risk Addressed) to Priority B (High) is attributable to the inclusion of the catchment draining to Outfall 25 and the catchments north of junction 8 that drains to Outfall 28 and Outfall 29 that were not previously included within the HAWRAT assessment available in HADDMS (i.e. the HAWRAT assessment only included Outfall 26 and Outfall 27). If this wider catchment is removed from the assessment, the cumulative assessment for Outfall 26 and Outfall 27 passes all aspects of HAWRAT for the 2037 Do Something scenario and would therefore still maintain a Priority X (Risk Addressed) status. 17.3 Soakaways The Priority Soakaways Verification User Guide uses a slightly different method to determine risk to the quality of underlying groundwater resources to the Method C promoted by DMRB HD 45/09. The findings of this slightly amended Method C assessment are combined with the Method D assessment to generate the overall priority status. Table 4.3 provides an overview of the current priority status for each outfall as presented within HADDMS, and the indicative priority status determined using the Priority Soakaways Verification methodology applied for the Proposed Scheme. The input data that has been used in this assessment is summarised in Annex B along with a detailed summary of the assessment results. The assessment indicates that all outfalls that drain to ground would be allocated Priority X (Risk Addressed) status. This is the same or better than the priority status as currently presented in HADDMS. Table 4.3 - Summary of current and indicative priority status for soakaways63 Outfalls Existing Priority Status Indicative Priority Status Outfall 9 - Priority Status X: Risk Priority D TL2417_0161c Addressed Outfall 10 - Priority Status X: Risk Priority Status X: Risk TL2418_3158d Addressed Addressed Outfall 11 - Priority Status X: Risk Priority D TL2418_3786e Addressed Outfall 12 - Priority Status X: Risk Priority D TL2419_3544b Addressed
Environmental Assessment Report 19
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Outfalls Existing Priority Status Indicative Priority Status Outfall 13 - Priority Status X: Risk Priority D TL2419_3086a Addressed Outfall 14 - Priority Status X: Risk Priority X - Risk Addressed TL2321_9506d Addressed Outfall 15 - Priority Status X: Risk Priority Status X: Risk TL2321_8562l Addressed Addressed Outfall 18 - Outfall has no Priority Priority Status X: Risk TL2322_3685c status Addressed Outfall 21 - Priority Status X: Risk Priority D TL2224_1656c Addressed
Environmental Assessment Report 20
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 18. Outfalls and Soakaways Scoped Out of an Assessment The single outfall assessments presented above only consider those outfalls where an increase in traffic flow of 20% or greater is predicted between the 2037 Do Minimum scenario and the 2037 Do Something scenario, and where it was judged that a meaningful assessment could be made. Other outfalls located within the extent of the Proposed Scheme were scoped out of this assessment for the following reasons: • The two-way 24-hour AADT for all sections of road draining to the outfall is less than 10,000; • The increase in traffic flow does not change the current AADT banding and an existing HAWRAT assessment is available in HADDMS with Priority X Risk Addressed status; and • The location of the outfall cannot be confirmed and there is too much uncertainty to inform a meaningful HAWRAT assessment. This applies to outfalls that are believed (but not confirmed) to discharge to the wider drainage network serving Stevenage. A summary of outfalls that were scoped out of this assessment is provided in Table 5.1 below. Table 5.1 - Summary of outfalls and soakaways scoped out of assessment 64
Outfalls Receiving Waterbody Reason for No Assessment Outfall 1 - Traffic flow increase >20% but AADT banding TL2315_4971d remains less than 10,000. No single outfall River Mimram (assumed to drain assessment completed but drainage area to Mimram) included in cumulative assessment. Outfall 2 - TL2316_5310e Traffic flow increase >20% but AADT banding (also known as remains less than 10,000. No single outfall River Mimram 5311c & 5311d) assessment completed but drainage area (direct discharge included in cumulative assessment. to Mimram) Traffic flow increase >20% and change to Assumed to discharge to AADT banding. However, the downstream Outfall 16 - unnamed tributary of drainage network is unclear and assumed to TL2322_6620c Stevenage Brook via combine with drainage from wider Stevenage drainage system urban area. Too much uncertainty to complete meaningful HAWRAT assessment. Traffic flow increase >20% but no change to Assumed to discharge to AADT banding. However, the downstream Outfall 17 - unnamed tributary of drainage network is unclear and assumed to TL2322_4281b Stevenage Brook via combine with drainage from wider Stevenage drainage system urban area. Too much uncertainty to complete meaningful HAWRAT assessment. Traffic flow increase slightly less than 20% and no change to AADT banding. The Assumed to discharge to downstream drainage network is also unclear Outfall 19 - unnamed tributary of and assumed to combine with drainage from TL2323_0143b Stevenage Brook via wider Stevenage urban area. Too much drainage system uncertainty to complete meaningful HAWRAT assessment. Traffic flow increase slightly less than 20% Outfall 20 - Assumed to discharge to and no change to AADT banding. The TL2223_7188b unnamed tributary of downstream drainage network is also unclear
Environmental Assessment Report 21
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Outfalls Receiving Waterbody Reason for No Assessment Stevenage Brook via and assumed to combine with drainage from drainage system wider Stevenage urban area. Too much uncertainty to complete meaningful HAWRAT assessment. Traffic flow increase slightly less than 20% and no change to AADT banding. The Assumed to discharge to downstream drainage network is also unclear Outfall 22 - unnamed tributary of and assumed to combine with drainage from TL2224_0999b Stevenage Brook via wider Stevenage urban area. Too much drainage system uncertainty to complete meaningful HAWRAT assessment. Traffic flow increase slightly less than 20% and no change to AADT banding. The Assumed to discharge to downstream drainage network is also unclear Outfall 23 - unnamed tributary of and assumed to combine with drainage from TL2225_1005b Stevenage Brook via wider Stevenage urban area. Too much drainage system uncertainty to complete meaningful HAWRAT assessment. Assumed to discharge to Traffic flow increase slightly less than 20% Outfall 24 - nearby drainage system or and no change to AADT banding. The TL2226_1523b ditch that may be minor downstream drainage network is also tributary of Ippollitts Brook unclear. Traffic flow increase slightly less than 20% Assumed to discharge to Outfall 25 - and no change to AADT banding. No single ditch that in turn discharges TL2226_4471b outfall assessment completed but drainage to Ash Brook area included in cumulative assessment. Traffic flow increase less than 20% and no change to AADT banding. No single outfall Outfall 28 - Assumed to discharge to assessment completed but drainage area TL2227_5704d Ash Brook included in cumulative assessment. The downstream drainage network is also unclear. Traffic flow increase less than 20%. Change to AADT banding but catchment largely located north of Proposed Scheme extent Outfall 29 - Assumed to discharge to and downstream drainage network unclear. TL2226_3977e Ash Brook No single outfall assessment completed but drainage area included in cumulative assessment. Outfall 30 - Downstream drainage Outfall only drains permeable catchment and TL2227_6058b alignment unclear does not drain carriageway. Downstream drainage Traffic flow increase less than 20%. Change alignment unclear. to AADT banding but catchment largely Assumed to drain to Ash located north of Proposed Scheme extent Outfall 31 - Brook although not and downstream drainage network unclear. TL2228_9338b confirmed and located > Not included in cumulative assessment of 1km from other Ash Brook Ash Brook as outfall believed to be >1km outfalls. from other outfalls.
Environmental Assessment Report 22
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 19. Conclusion and Recommendations 19.1 Method A: Single Outfall Assessment The Method A assessment for single outfalls indicates that all outfalls discharging to the River Mimram and Ash Brook that were deemed to require assessment as a result of the Proposed Scheme pass all aspects of the HAWRAT assessment and would be allocated Priority X (Risk Addressed) status. No further action is considered necessary. 19.2 Method A: Cumulative Assessment The Method A cumulative assessment for outfalls discharging to the River Mimram within 1km indicates that all outfalls discharging to the River Mimram pass all aspects of the HAWRAT assessment and would be allocated Priority X (Risk Addressed) status. No further action is considered necessary. The Method A cumulative assessment for outfalls discharging to the Ash Brook within 1km indicates that the outfalls would be allocated Priority B (High) status. This is indicated to be predominantly attributable to the drainage catchment discharging to Outfall 25 to the south of junction 8 and (more so) to the drainage catchments discharging to Outfalls 28 and 29 to the north of junction 8 Comparison of the 2037 Do Something scenario (i.e. with the Proposed Scheme) against the baseline Do Minimum scenario indicates that the overall conclusions of the cumulative assessment are not changed by the Proposed Scheme – i.e. the cumulative assessment for the baseline Do Minimum scenario also indicates a Priority B (High) status. It is, however, recommend that further consideration is given to this identified risk to: a) improve understanding of the drainage network discharging to the Ash Brook (as there remains some uncertainty regarding the catchment sizes and outfall locations); and b) consider opportunities to improve treatment of runoff prior to discharge if this is considered necessary following a more detailed review of the drainage network and risk to the Ash Brook. 19.3 Method C: Groundwater The Method C assessment for outfalls discharging to soakaways indicates a Medium Risk to groundwater resources, although also indicates there is no change to the risk posed to groundwater resources when compared to the baseline Do Minimum scenario. No further action is considered necessary. The Priority Soakaways Verification User Guide also indicates that all outfalls discharging to soakaways would be allocated Priority X (Risk Addressed) status. 19.4 Method D: Spillage Risk The Method D assessment for all outfalls indicates that the risk of spillage is well below the threshold required for outfalls draining to surface water and groundwater. No further action is considered necessary.
Environmental Assessment Report 23
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Annex A: Method A HAWRAT Assessment
Outputs Method A - Single Outfall Assessments
Method A Method A Step 2 Step 1 Dis S ch ol S S Do arg Pe u ol M Ste wn e rm bl u Ann P Imp p 2 Ann Se str in ea e bl Ch Ac ual O erm Ac Chr ual cti ea or ble - e ro ute Ave ut Ba Tr eab ute oni Ave HA on m wit Ar A - ni Imp rag fal sel le Imp c rag DD s aff Str hin ea c A c act e l / ine Are act Imp e MS of uct 1k Dr ut c Im As Con Co
N Pri ic a As act Con
Out R ure m ain e ut pa ses cen mm et ori B Dra ses As cen
fall oa rse wit U/ ed I e ct sm trati ent
w ty u ine sm ses trati Ref d an hin S to m I Se ent on ary
or St d to ent sm on
ere Dr di 100 of the p m di of of
CaCO3/l) ex(BFI)
k at the of ent of /s)
nce ai d m a Ou a p m Co Cop
ng 3
(m)
N us Out Zin of Zinc
In Waterco
ne of De tfal ct a en ppe per
(m th
u fall c Se (µg/
Region d d Out sig l C ct t r (µg/ m (ha) dim l)
Wi fall nat (ha o Zi l)
be (mg ness ent
d ? ed ) p n r Site infall
a Sit p c
R Receiving Flow Base Flow Q95 Har River Climatic e? er All asp ects of Met hod A ass ess me nt pas sed whe n dilut ion of rec eivi ng TL2 wat 316 erc _ J6 our 531 Pri thr ≥5 se 2d orit ou 0, tak (als y X gh 00 en o - S 0.02 0.05 0 F F into refer Ris B 1.2 1.2 Fa Pas Pas Pas - - 3 to No No ai ai acc red k J6 0 5 il s s s Pas Pas <1 l l oun to Ad - s s 00 t. as dre J7 ,0 Spil TL2 ss S 00 lag 316 ed B e _ ass 541 ess 2d) me nt also pas sed . Indi cati ve Pri orit y Sta
tus
X -
Ris
ram k
m
Ad
r Mi r dre
e
arm/Dry v
i sse
Huntingdon R 0.727 0.066 High 7.2 W d.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
All asp ects of Met hod A ass ess me nt pas sed whe n dilut ion of rec eivi ng wat erc our ≥1 se No 0, tak J6 TL2 pri 00 0.00 0.01 en thr 316 0 F F into orit ou 0.4 0.4 Fa Pas Pas Pas - - 4 _ to No No ai ai acc y gh 1 0 il s s s Pas Pas 461 <5 oun N l l 6b sta 0, s s t. B tus 00 Spil
0 lag e ass ess me nt also pas sed . Indi cati ve Pri orit y Sta
tus
X -
Ris
ram k
m
Ad
r Mi r
dre
e
arm/Dry v
i sse
Huntingdon R 0.727 0.066 High 7.2 W d.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
All asp ects of Met hod A ass ess me nt pas sed whe n dilut ion of rec eivi ng wat erc our Pri ≥1 se orit 0, tak y X J6 TL2 00 0.01 0.02 en - thr 316 0 F F into Ris ou 0.4 0.4 Fa Pas Pas Pas - - 5 _ to No No ai ai acc k gh 1 0 il s s s Pas Pas 451 <5 oun Ad N l l 7b 0, s s t. dre B 00 Spil ss 0 lag ed e ass ess me nt also pas sed . Indi cati ve Pri orit y Sta
tus
X -
Ris
ram k
m
Ad
r Mi r
dre
e
arm/Dry v
i sse
Huntingdon R 0.727 0.066 High 7.2 W d.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
All asp ects of Met hod A ass ess me nt pas sed whe n dilut ion of rec eivi ng wat erc our ≥1 se No 0, tak J6 TL2 pri 00 0.02 0.05 en on 316 0 F F into orit sli 1.5 0.3 Fa Pas Pas Pas - - 6 _ to No No ai ai acc y p 6 8 il s s s Pas Pas 514 <5 oun N l l 7b sta 0, s s t. B tus 00 Spil
0 lag e ass ess me nt also pas sed . Indi cati ve Pri
orit d) d)
e y Sta tus
X -
Ris
ram (assum ram k
m
Ad
r Mi r
dre
e
arm/Dry v
i sse
Huntingdon R 0.727 0.066 High 7.2 W d.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
All asp ects of Met hod A ass ess me nt pas sed whe n dilut ion of rec eivi ng wat erc ≥5 our 0, se 00 tak TL2 J6 0.01 0.02 en Pri 316 - 0 F F into orit 0.3 0.2 Fa Pas Pas Pas - - 7 _ J7 to No No ai ai acc y 8 7 il s s s Pas Pas 707 S <1 l l oun D s s 8b B 00 t. Spil ,0 lag 00 e
ass ess me nt also pas sed . Indi cati ve Pri
orit d) d)
e y Sta tus X -
Ris
ram (assum ram k
m
Ad
r Mi r
dre
e
v
i sse
Huntington R 0.727 0.066 High 7.2 Warm/Dry Warm/Dry d.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
All asp ects of Met hod A ass ess me nt pas sed whe n dilut ion of rec eivi ng TL2 wat 317 erc J6 _76 our - 00a se J8 (als tak N >1 o Pri 0.04 0.18 en B 00 F F refe orit 1.7 1.2 Fa Pas Pas Pas - - into 8 J6 ,0 No No ai ai rred y 5 0 il s s s Pas Pas acc - 00 l l to D s s oun J8 + as t. S 750 Spil B 1c & lag
750 e 2b) ass ess me nt also pas sed . Indi cati ve
Prio d) d)
e rity Stat us X -
Ris
k
Add
res
sed
Huntington (assum Mimram River 0.727 High 7.2 Warm/Dry Warm/Dry .
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
All asp ects of Met hod A ass ess me nt pas sed whe n dilut ion of rec eivi ng wat erc J7 our Pri - ≥5 se orit J8 0, tak y X N 00 en TL2 - B 0.07 0.22 0 F F into 226 Ris J8 0.4 0.6 Fa Pas Pas Pas - - 26 to No No ai ai acc _39 k off 3 5 il s s s Pas Pas <1 l l oun 77e Ad sli s s 00 t. dre p ,0 Spil ss N 00 lag ed B e
ass ess me nt also pas sed . Indi cati ve Pri orit y Sta tus
X -
Ris
k
Ad
dre
sse
Huntingdon Brook Ash 0.661 0.005 High 2 Warm/Dry Warm/Dry d.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
All asp ects of Met hod A ass ess me nt pas sed whe n dilut ion of rec eivi ng wat erc our Pri ≥1 se orit 0, tak y X J8 TL2 00 0.03 0.10 en - off 226 0 F F into Ris sli 0.1 0.2 Fa Pas Pas Pas - - 27 _ to No No ai ai acc k p 9 5 il s s s Pas Pas 397 <5 oun Ad N l l 8f 0, s s t. dre B 00 Spil ss 0 lag ed e ass ess me nt also pas sed . Indi cati ve Pri orit y Sta tus
X -
Ris
k
Ad
dre
arm/Dry
sse
Huntingdon Brook Ash 0.661 0.005 High 2 W d.
Method A - Cumulative Outfall Assessment - River Mimram
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Method A Step 2
Permeable th Discharge in Permeable Step 2
SMP Baseline Impermeable d Downstream Impermeable Step 2 Acute Step 2 Acute Step 2 Annual Step 2 Annual
HADDMS Baseline Area or within 1km Area Chronic s)
Outfall / Priority Sections of Area Drained Traffic Wi Structure Area Drained Impact Impact Average Average 3/
Outfall Priority Drained to U/S of a Drained to Impact Commentary
(m) ness (mg ness
Network Status Road Drained to the Outfall Banding (BFI) ex within 100m to the Outfall Assessment Assessment Concentration Concentration
(m
Traffic
infall Site infall
d d
Reference Status the Outfall Region Designated the Outfall Assessment
Climatic
Banding
CaCO3/l) a
Number (Cumulative) (ha) Flow Q95 of Outfall? (ha) of Copper of Zinc of Copper (µg/l) of Zinc (µg/l)
Base Flow Base
In River
(ha) R Site? (ha) of Sediment
(Cumulative) Har
No priority J6 onslip SB >100,000 1 TL2315_4971d 2.28 0.77 status J6 offslip SB + Step 1 not completed for cumulative assessment. TL2316_5310e Priority X - 2 (known as 5311c Risk J6 offslip SB 0.45 0.60 < 10,000 Outfalls 2, 3, 4 and 5 discharge & 5311d) Addressed directly to River Mimram as outfall TL2316_5312d Priority X - cluster. Previous assessed as J6 through SB ≥50,000
3 (referred to as Risk 1.20 1.25 Priority X - Risk Addressed. This
J6-J7 SB assessment also assumes that
<100,000
TL2316_5412d) Addressed 4.83
Outfalls 1, 6, 7 and 8 also
No Priority Priority X - ≥50,000 8.53 (soluble) (soluble) 4 TL2316_4616b J6 through NB 0.41 0.40 discharge to River Mimram -
Status Risk <100,000 No No Pass Pass Pass 0.19 - Pass 0.79 - Pass 7.2
High located within 1km of Outfalls 2, 3 4
0.727 0.066 Priority X - Addressed arm/Dry 2.56 (sediment) 2.24 ≥50,000 + 100,000
W and 5. Only outfalls 2, 3, 4 and 5 > 5 TL2316_4517b Risk J6 through NB 0.51 0.00 Huntingdon (sediment) included in sediment assessment. Addressed <100,000
No Priority ≥10,000 6 TL2316_5147b J6 onslip NB 1.56 0.38 All aspects of Method A Status <50,000 assessment passed when dilution ≥50,000 7 TL2316_7078b Priority D J6-J7 SB 0.38 0.27 of receiving watercourse taken into <100,000 account. TL2317_7600a Indicative Priority Status X - Risk J6-J7 NB >100,000 8 (referred to as Priority D 1.75 1.20 Addressed. J6-J7 SB + 7501c & 7502b) Method A - Cumulative Outfall Assessment - Ash Brook
Method A Step 2
Impermeable Permeable th Discharge in Permeable Step 2
SMP Current d Downstream Impermeable Step 2 Acute Step 2 Acute Step 2 Annual Step 2 Annual
HADDMS Current Sections Area Area or within 1km Area Chronic
Outfall / Priority Traffic /s) Structure Area Drained Impact Impact Average Average
Wi 3
Outfall Priority of Road Drained to Drained to U/S of a Drained to Impact Commentary
(m) ness (mg ness
Network Status Banding (BFI) ex within 100m of to the Outfall Assessment Assessment Concentration Concentration
(m
Traffic
infall Site infall
d d
Reference Status Drained the Outfall the Outfall Region Designated the Outfall Assessment
Climatic
Banding
CaCO3/l) a
Number (Cumulative) Flow Q95 Outfall? (ha) of Copper of Zinc of Copper (µg/l) of Zinc (µg/l)
Base Flow Base
In River
(ha) (ha) R Site? (ha) of Sediment
(Cumulative) Har
No priority J7-J8 NB ≥50,000 25 TL2226_4471b 1.65 0.94 status J7-J8 SB <100,000 J7-J8 NB Priority X - J8 offslip ≥50,000 Step 1 not completed for 26 TL2226_3977e Risk 0.43 0.65 NB - to be <100,000 cumulative assessment. Addressed confirmed Priority X - Outfalls 26 and 27 discharge J8 offslip ≥10,000 27 TL2226_3978f Risk 0.19 0.25 directly to Ash Book as outfall
NB
<50,000 cluster. Previously assessed as
Addressed 1.83
Priority X - Risk Addressed. This Priority X - J8 offslip 8.25 (soluble) (soluble)
revised assessment also assumes
Risk SB 2 No No Fail Pass Fail 1.54 - Pass 5.47 - Pass
High that Outfalls 25, 29 and 29 also
0.661 0.005
Addressed J8 through arm/Dry 2.27 (sediment) 1.83 100,000 + 100,000
W discharge to Ash Brook - located > NB Huntingdon (sediment) within 1km of Outfalls 26 and 27. Np priority J8 through ≥50,000 28 4.28 unknown status SB <100,000 TL2227_5704d Failure of EQS indicates Priority J8 On-slip B Status for cumulative outfalls. NB Attributable to inclusion of Outfalls J8-J9 NB 25, 28 and 29.
No priority J8 offslip ≥50,000 29 TL2226_3977e 1.70 unknown status SB <100,000
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Annex B: Method C and Priority Soakaway
Outputs Method C - Outfall Assessments
Rainf SMP Imperm Descri Depth Basel Secti all Outf eable Soaka to HADDM ine ons Traffi ption volu Rainfall all / Area Water S Outfall Priori of c me way Flow siz Lithol Sc Netw Drained of intensit Table Risk Referen ty Road Band (annu geom Type e ogy ore ork to the (Unsatu ce Statu Drai ing geolog al y Num Outfall etry rated s ned avera ber (ha) y zone) ges) Chalk with no mapped superfic ial deposit s. Borehol es indicate weathe red low density chalk with thin layer of clay Single Fin with Concen point, Heavily e flints, trated deep J6-J7 Depth consolid sa <1% with (>47 servin Medi TL2417 - Priorit NB >100, to water ated nd clay 9 2.63 chalk at <740 mm g high 245 um 0161c y D J6-J7 000 table sediment an miner FEH 1 road Risk SB 1.8m >15 m ary d als hour area bgl. deposits bel rainfall (>5,00 High ow probabi 0 m2) lity that shallow, weathe red low density chalk will have high permea bility and include fissures & fracture s. Chalk overlain by mixed area of superfic ial clay with flint combin ed with Single Fin sands Concen point, TL2418_ Heavily e Priorit and trated deep 3158d J6-J7 Depth consolid sa <1% y X - gravels. (>47 servin Medi (also NB >100, to water ated nd clay 10 Risk 0.53 Borehol <740 mm g high 245 um referred J6-J7 000 table sediment an miner Addre FEH 1 road Risk to as SB es >15 m ary d als ssed hour area 3757b) indicate deposits bel rainfall) (>5,00 chalk ow 2.55m 0 m2) bgl. Chalk describ ed as slightly weathe red, weak with low
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
density. High probabi lity that chalk will have high permea bility and include fissures & fracture s. Chalk overlain by layer of clay with flint combin ed with sands and gravels. Borehol es indicate chalk 6- 7m bgl. Chalk describ ed as Single Fin weathe Concen point, Heavily e red, trated deep J6-J7 Depth consolid sa <1% weak (>47 servin Medi TL2418_ Priorit NB >100, to water ated nd clay 11 0.74 with <740 mm g high 245 um 3786e y D J6-J7 000 table sediment an miner FEH 1 road Risk SB extrem >15 m ary d als hour area ely low deposits bel rainfall) (>5,00 density. ow High 0 m2) probabi lity that chalk will have high permea bility. Deep borehol e to north indicate s rest water level at 55m bgl. Chalk with no mapped superfic ial deposit s. Borehol es suggest varying Single Fin superfic Concen point, TL2419_ Heavily e ial trated deep 3544b J6-J7 Depth consolid sa <1% cover (>47 servin Medi (also Priorit NB >100, to water ated nd clay 12 0.90 from 0 <740 mm g high 245 um referred y D J6-J7 000 table sediment an miner FEH 1 road Risk to as SB to >5m. >15 m ary d als hour area 3645a) Chalk deposits bel rainfall) (>5,00 describ ow ed as 0 m2) weathe red, very weak with low density. High probabi lity that
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
chalk will have high permea bility and include fissures & fracture s. Chalk with no mapped superfic ial deposit s. Borehol es suggest varying superfic ial cover of clay with flints and gravel from 0 Single to 5m. Fin Concen point, Chalk Heavily e trated deep J6-J7 describ Depth consolid sa <1% (>47 servin Medi TL2419_ Priorit NB >100, ed as to water ated nd clay 13 2.89 <740 mm g high 245 um 3086a y D J6-J7 000 modera table sediment an miner FEH 1 road Risk SB >15 m ary d als tely hour area deposits bel weathe rainfall) (>5,00 ow red, 0 m2) very weak with low density. High probabi lity that chalk will have high permea bility and include fissures & fracture s. Chalk overlain by mixture of clay with sand, gravel and flints. Borehol Single e Fin Concen point, TL2321_9 records e Priorit trated deep 506d J6-J7 indicate Depth sa >15% y X - (>47 servin Consolid Medi (also NB >100, chalk to water nd clay 14 Risk 1.90 <740 mm g high ated 210 um referred J6-J7 000 >5m table an miner Addre FEH 1 road deposits Risk SB >15 m d als to as ssed below hour area bel 0109b) ground rainfall (>5,00 ow (max 0 m2 depth of borehol es). Deeper borehol e further south indicate s
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
modera tely weathe red very weak low density chalk 9.10m bgl. Chalk overlain by clay and Single sands. Fin Concen point, Borehol e Priorit trated deep J6-J7 es Depth sa >15% y X - (>47 servin Consolid Medi TL2321_ NB >100, indicate to water nd clay 15 Risk 0.95 <740 mm g high ated 210 um 8562l J6-J7 000 weathe table an miner Addre FEH 1 road deposits Risk SB >15 m d als ssed red very hour area bel weak rainfall) (>5,00 ow low 0 m2) density chalk at 24.90m bgl. Chalk overlain by clay, sands and gravels. Borehol es indicate weathe red weak low density chalk at 15.30m bgl. Borehol es Single indicate Fin Concen point, J7 water e trated deep No On- ≥50,0 level at Depth sa >15% (>47 servin Consolid Medi TL2322_3 priorit slip 00 17.90m, to water nd clay 18 1.48 <740 mm g high ated 215 um 685c y NB <100, althoug table 5 an miner FEH 1 road deposits Risk status J7-J8 000 to <15m d als h other hour area NB bel tests rainfall (>5,00 ow indicate 0 m2) no ground water at 38m bgl. Depth of soakaw ay unknow n. Assume ground water betwee n 5- 15m of soakaw ay base. Chalk overlai n by clay Single with Fin Concen point, Unconsol flints. e trated deep idated or J7-J8 ≥50,0 Weath Depth sa <1% (>47 servin non- Medi TL2224_ Priorit NB 00 ered to water nd clay 21 0.56 <740 mm g high fractured 230 um 1656c y D J7-J8 <100, weak table an miner FEH 1 road consolida Risk SB 000 very >15 m d als hour area ted low bel rainfall (>5,00 deposits density ow 0 m2) chalk located 3-6m bgl.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Priority Soakaways Verification User Guide Method
SMP Imperm Descri Basel Secti Haza Outf eable Tot Priori HADDM ine ons Traffi ption Aquifer Depth Rain rd all / Area Design al ty S Outfall Priori of c Flow to fall Ran Netw Drained of SPZ vulnera Referen ty Road Band ation Type Ground Volu Sc king Statu ork to the ce Statu Drai ing geolog bility water me Syst Num Outfall ore s s ned y em ber (ha) Flow domina Priorit J6-J7 Depth Princip ntly in D y X - TL2417_0 Priorit NB >100, As SPZ None to water <74 9 2.63 al fissures 145 (Low Risk 161c y D J6-J7 000 above 3 defined table 0 Aquifer / ) Addre SB >15 m disconti ssed nuities Flow TL2418_ Priorit domina Priorit 3158d J6-J7 Depth y X - Princip ntly in D y X - (also NB >100, As SPZ None to water <74 10 Risk 0.53 al fissures 145 (Low Risk referred J6-J7 000 above 3 defined table 0 Addre Aquifer / ) Addre to as SB >15 m ssed disconti ssed 3757b) nuities Flow domina Priorit J6-J7 Depth Out Princip ntly in D y X - TL2418_ Priorit NB >100, As None to water <74 11 0.74 side al fissures 115 (Low Risk 3786e y D J6-J7 000 above defined table 0 SPZ Aquifer / ) Addre SB >15 m disconti ssed nuities Flow TL2419_ domina Priorit 3544b J6-J7 Depth Princip ntly in D y X - (also Priorit NB >100, As SPZ None to water <74 12 0.90 al fissures 145 (Low Risk referred y D J6-J7 000 above 3 defined table 0 Aquifer / ) Addre to as SB >15 m disconti ssed 3645a) nuities Flow domina Priorit J6-J7 Depth Princip ntly in D y X - TL2419_ Priorit NB >100, As SPZ None to water <74 13 2.89 al fissures 145 (Low Risk 3086a y D J6-J7 000 above 3 defined table 0 Aquifer / ) Addre SB >15 m disconti ssed nuities TL2321_9 Priorit Intergra Priorit 506d J6-J7 Depth y X - Princip nular D y X - (also NB >100, As SPZ None to water <74 14 Risk 1.90 al Flow 145 (Low Risk referred J6-J7 000 above 2 defined table 0 Addre Aquifer Significa ) Addre SB >15 m to as ssed nt ssed 0109b) Priorit Intergra Priorit J6-J7 SPZ Depth y X - Princip nular D y X - TL2321_ NB >100, As 2 & None to water <74 15 Risk 0.95 al Flow 145 (Low Risk 8562l J6-J7 000 above SPZ defined table 0 Addre Aquifer Significa ) Addre SB 3 >15 m ssed nt ssed J7 No Intergra Depth Priorit On- ≥50,0 Out Princip nular to water D y X - TL2322_3 priorit slip 00 As None <74 18 1.48 side al Flow table 5 90 (Low Risk 685c y NB <100, above defined 0 SPZ Aquifer Significa to <15 ) Addre J7-J8 000 status nt m ssed NB Flow domina Priorit J7-J8 ≥50,0 Depth Princip ntly in D y X - TL2224_ Priorit NB 00 As SPZ None to water <74 21 0.56 al fissures 130 (Low Risk 1656c y D J7-J8 <100, above 3 defined table 0 Aquifer / ) Addre SB 000 >15 m disconti ssed nuities
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report Annex C: Method D Spillage Risk
Assessment Outputs
Outfall 3 Outfall 4 Outfall 6 Outfall 7 Outfall 8 Outfall 9 Outfall 10 Outfall 11 Outfall 12 Outfall 13 Outfall 14 Outfall 15 Outfall 18 Outfall 21 Outfall 26 Outfall 27 TL2316_4TL2316 TL2224_1656c TL2316_5312d TL2316_5147b TL2316_7078b TL2317_7600a TL2417_0161c TL2418_3158d TL2418_3786e TL2419_3544b TL2419_3086a TL2321_9506d TL2321_8562l TL2322_3685c TL2226_3977e TL2317_7600a b Surface Surface Surface Surface Surface Groundwater Surface Water body type Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Surface watercourse watercourse watercourse watercourse watercourse watercourse watercourse Length of road draining to 639 467.4 598.2 159.3 715.6 1192.1 400.8 558.4 484.7 1460.3 922 948.2 595.8 100 200 350 100 65.1 170 outfall (m) Road Type (A-road or M M M M M M M M M M M M M M M M M M M Motorway) If A road, is site urban or Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural Rural rural? No Slip Junction type No junction No junction Slip Road No junction No junction No junction No junction No junction No junction No junction No junction No junction Slip Road Slip Road No junction Slip Road Slip Road junction Road Location < 1 hour <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr <1hr
Traffic flow (AADT two way) 55497 46671 14463 55479 116236 116236 116236 116236 116236 116236 116236 116236 52210 52210 9881 96859 52210 10260 10260
% HGV 11 10 4 10 10 10 10 10 10 10 10 10 9 9 5 10 9 8 8 Spillage factor 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.43 0.43 0.36 0.36 0.43 0.43 (no/109HGVkm/year) Risk of accidental spillage 0.00051 0.00029 0.00005 0.00012 0.00109 0.00182 0.00061 0.00085 0.00074 0.00223 0.00141 0.00145 0.00037 0.00007 0.00002 0.00045 0.00006 0.00001 0.00002
Probability factor 0.6 0.6 0.6 0.6 0.6 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.6 0.6 0.6
Risk of pollution incident 0.00031 0.00017 0.00003 0.00007 0.0007 0.00055 0.00018 0.00026 0.00022 0.00067 0.00042 0.00043 0.00011 0.0000221 0.00000 0.00013 0.00004 0.00001 0.0000 Risk of pollution incident (combined for more than 0.00014 0.00004 one road type) 0.013% Risk of pollution incident 0.031% 0.017% 0.003% 0.007% 0.066% 0.055% 0.018% 0.026% 0.022% 0.067% 0.042% 0.043% 0.014% 0.004% 0.001% Is risk greater than 0.01 (1%) No No No No No No No for surface water? Is risk greater than 0.05 (5%) No No No No No No No No No for groundwater?
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Smart Motorways Programme Environmental Assessment Report Appendix 10 – Assessment of Combined and Cumulative Effects
Tranche 5 – A1(M) J6 to 8 (Preliminary Design – PCF Stage 3)
HE55139-WSP-EGN-SG-RP-LE-00020
May 2019
Notice
This document and its contents have been prepared and are intended solely for Highways England’s information and use in relation to the Smart Motorways Programme.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Revision history
Job number: 551539 Document ref: HE55139-WSP-EGN-SG-RP-LE-00020 Revision Purpose description Originated Checked Reviewed Approved Date P01 S3 – Draft for review Leon Bailey Catherine David Hoare Jonty Parry 01/03/19 and comment Sugden P02 S4 – Suitable for stage Leon Bailey Catherine David Hoare Jonty Parry 03/04/19 approval Sugden
Client signoff
Client Highways England Project SMP Tranche 5 – A1(M) Junctions 6 to 8 Document title Appendix 10 - Assessment of Combined and Cumulative Effects Job no. 551539 Document HE55139-WSP-EGN-SG-RP-LE-00020 reference
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Table of Contents
10. Assessment of Combined and Cumulative Effects 42 10.1 Relevant Development Proposals for the Cumulative Effects Assessment 42
.
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report 20. Assessment of Combined and Cumulative Effects 19.5 Relevant Development Proposals for the Cumulative Effects Assessment
Proposed Land Total Size (ha/no. Local Planning ID Development Use Type of dwellings) Authority
Welwyn Hatfield CD1 22 The Avenue, Welwyn AL6 0PP C-Housing 12 dwellings Borough Council
Land at Chadwell Road, Norton Stevenage Borough CD2 C- Housing 14 dwellings Green, Stevenage Hertfordshire. Council Land south of Cockernhoe and Mixed use – A1- North Hertfordshire CD3 east of Wigmore, Brick Kiln Lane, A5, C3. D1 and 1050 dwellings District Council Cockernhoe D2 Land At Roundwood, Back Lane, North Hertfordshire CD4 C - Housing 360 dwellings Graveley District Council Former Shredded Wheat Factory, 827 dwellings and Mixed use – A1, Welwyn Hatfield CD5 Bridge Road, Welwyn Garden 1.4ha employment B1,C1-C3, D2 Borough Council City, AL8 6UN area 10 Danesbury Park Road, Welwyn Hatfield CD6 C- Housing 1 dwelling Welwyn, AL6 9SE Borough Council 14 The Avenue, Oaklands, Welwyn Hatfield CD7 C- Housing 1 dwelling Welwyn, AL6 0PN Borough Council Plot 2, 12 The Avenue, Welwyn, Welwyn Hatfield CD8 C- Housing 2 dwellings AL6 0PW Borough Council 15 Wendover Drive, Welwyn, AL6 Welwyn Hatfield CD9 C- Housing 2 dwellings 9LT Borough Council 200 dwellings and DuPont (UK) Ltd Wedgwood Way Mixed use – A1- Stevenage Borough CD10 0.09ha Stevenage Herts SG1 4QN A3, C, D1 Council employment area Matalan Retail Park Danestrete Mixed use – A1- Stevenage Borough CD11 526 dwellings Stevenage Herts A5 and C Council The Frythe, 5 Digswell Hill, Welwyn Hatfield CD12 C- Housing 54 dwellings Welwyn, AL6 9AR Borough Council Comet Hatfield, St Albans Road Welwyn Hatfield CD13 C – Housing 301 dwellings West, Hatfield, AL10 9RH Borough Council Rank Xerox Ltd, Bessemer Road, Welwyn Hatfield CD14 C – Housing 235 dwellings Welwyn Garden City, AL7 1HE Borough Council 8-10 Wendover Drive Welwyn Welwyn Hatfield CD15 C – Housing 5 dwellings AL6 9LT Borough Council 12 Great North Road Welwyn AL6 Welwyn Hatfield CD16 C – Housing 3 dwellings 0PL Borough Council 2 Wendover Drive Welwyn AL6 Welwyn Hatfield CD17 C – Housing 2 dwellings 9LT Borough Council Land between Gragil And 29, North Hertfordshire CD18 C – Housing 2 dwellings Danesbury Park Road, Welwyn District Council
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Proposed Land Total Size (ha/no. Local Planning ID Development Use Type of dwellings) Authority 2 Bowman Trading Estate Stevenage Borough CD19 Bessemer Drive Stevenage Herts C – Housing 4 dwellings Council SG1 2DL Land south and north west of Mixed use – A1- 1,400 dwellings Cockernhoe and east of Wigmore North Hertfordshire CD20 A5, D1-D2 and and 1ha (Stubbocks Walk), Brick Kiln District Council C3 employment area Lane, Cockernhoe Ratcliff Tail Lifts Ltd site Welwyn Hatfield CD21 Bessemer Road Welwyn Garden C – Housing 110 dwellings Borough Council City AL7 1ET Land At QEII Nursery and MRI Centre off William Close William Welwyn Hatfield CD22 C – Housing 41 dwellings Close Welwyn Garden City AL7 Borough Council 4ER Accord House 28 Bridge Road Welwyn Hatfield CD23 East Welwyn Garden City AL7 C – Housing 25 dwellings Borough Council 1HX 37 Broadwater Road Welwyn Welwyn Hatfield CD24 C – Housing 24 dwellings Garden City AL7 3AX Borough Council Former Xerox Site Bessemer Welwyn Hatfield CD25 Road Welwyn Garden City AL7 C – Housing 16 dwellings Borough Council 1HE 15 dwellings and 45 Town Centre, Hatfield, AL10 Welwyn Hatfield CD26 A1 and C 0.03ha 0JJ Borough Council employment area Mill Green Mill Green Lane Welwyn Hatfield CD27 C – Housing 9 dwellings Hatfield AL9 5NQ Borough Council Land at Waterbeach, Bericot Way Welwyn Hatfield CD28 and Shackleton Way Welwyn C – Housing 21 dwellings Borough Council Garden City AL7 2PT Unit 3C Bridgefields Welwyn 0.67ha Welwyn Hatfield CD29 B1 and B8 Garden City AL7 1RX employment area Borough Council Essendon Country Club Bedwell Welwyn Hatfield CD30 C – Housing 20 dwellings Park Essendon Hatfield AL9 6HN Borough Council 12 Harpsfield Broadway Hatfield 8 residential units Welwyn Hatfield CD31 A1, B1 and C AL10 9TF and 0.06ha Borough Council Hatfield Business Park Hatfield Welwyn Hatfield CD32 C – Housing 1100 dwellings AL10 9SL Borough Council 12 North Road Stevenage Herts Stevenage Borough CD33 C- Housing 21 dwellings SG1 4AL Council Land To The North Of Stevenage Stevenage Borough CD34 C- Housing 800 dwellings Stevenage Herts SG1 4DE Council Plot 2000 Gunnels Wood Road 0.4ha employment Stevenage Borough CD35 B1 and A1 Stevenage Herts SG1 2BE area Council Former Norton School Playing Fields To The North Of Principal North Hertfordshire CD36 C – Housing 45 dwellings Court Letchworth Garden City District Council Hertfordshire Mixed Use – A1- Land west of A1(M) Stevenage Stevenage Borough CD37 A3, B1,B2, 5000 dwellings Herts Council D1,D2 and C
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Proposed Land Total Size (ha/no. Local Planning ID Development Use Type of dwellings) Authority
3.27ha Welwyn Hatfield CD38 Hatfield Business Park, Hatfield B1 and B2 use employment area Borough Council
Stevenage Borough CD39 Vincent Court C – Housing 37 dwellings Council Schemes included within the uncertainty log A14 Cambridge to Huntingdon CD40 Road N/A RIS1 Scheme (single design option) M1 Junctions 13-16: Smart CD41 Road N/A RIS1 Scheme Motorways (single design option) CD42 A5/M1 J11a Link Road N/A RIS1 Scheme CD43 M25 Junction 25 improvement Road N/A RIS1 Scheme
CD44 M25 Junction 28 improvement Road N/A RIS1 Scheme
CD45 M11 Junction 7 junction upgrade Road N/A RIS1 Scheme
CD46 A428 Black Cat to Caxton Gibbet Road N/A RIS1 Scheme
CD47 M11 Junction 7a Road N/A RIS1 Scheme
Bedford Borough CD48 Bedford Western Bypass Road N/A Council Central Bedfordshire A421: Junction 13 to Milton CD49 Road N/A Council/ Milton Keynes Keynes dualling Council Central Bedfordshire CD50 M1 jnc 11a - A6 link road Road N/A Council Central Bedfordshire CD51 Woodside Link Road N/A Council
CD52 B183 Gilden Way Link (Harlow) Road N/A Essex County Council
M11 Junction 8 Slip road CD53 Road N/A Essex County Council improvement Stevenage Costco access/ Hertfordshire County CD54 Road N/A Gunnells Wood Road Council A602 Improvements -Hertford Hertfordshire County CD55 Road N/A Road signalization Council A602 Improvements - A119 Hertfordshire County CD56 Road N/A roundabout, Council A602 Improvements - Sacombe Hertfordshire County CD57 Road N/A Pound junction, Council A602 Improvements Anchor Lane Hertfordshire County CD58 Road N/A roundabout Council A602 Improvements A10 junction Hertfordshire County CD59 Road N/A Ware Council
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Proposed Land Total Size (ha/no. Local Planning ID Development Use Type of dwellings) Authority A414 Colney Heath longabout Hertfordshire County CD60 Road N/A safety scheme Council A10 Hoddesdon_Dumbell Hertfordshire County CD61 Road N/A Roundabout - Dinant Link Road Council/ Developer Dinant Link Road / Amwell Street Hertfordshire County CD62 Road N/A (Sun Roundabout) Council/ Developer Capacity improvements associated with Bishops Stortford Hertfordshire County CD63 Road N/A North development Council/ Developer) (various locations) Remove the existing Bus Ln on Hertfordshire County CD64 Ware Rd approach to A10 Amwell Road N/A Council Rbt Upgrade of A602 / Gunnels Wood Hertfordshire County CD65 Road / GSK junction to Road N/A Council hamburger layout A414 Breakspear Way / Maylands Hertfordshire County CD66 Lane Reallocation, Hemel Road N/A Council Hempstead Upgrade to A10/London Road Hertfordshire County CD67 Road N/A roundabout Buntingford Council Hertfordshire County CD68 A120 Little Hadham Bypass Road N/A Council
Hertfordshire County CD69 Turnford Link Road Road N/A Council
Hertford Road / Ware Road Hertfordshire County CD70 Road N/A Broxbourne Improvement Council A505 /A10 Roundabout; A505 /A1198 Roundabout; Hertfordshire County CD71 Road N/A A10/Newmarket Road / Melbourn Council Street Roundabout Royston Radlett Railfreight, new access junction onto A414 and new spine Hertfordshire County CD72 Road N/A road connecting to A5183 Radlett Council Road (south of Frogmore)
New link road connecting North Hertfordshire County CD73 Baldock development to North Road N/A Council Road and Royston Road
Hertfordshire County CD74 Second Stort Crossing (Gilston) Road N/A Council
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Proposed Land Total Size (ha/no. Local Planning ID Development Use Type of dwellings) Authority Pirton Road / A505 / Upper Tilehouse St/ Wratten Rd , Hitchin Hertfordshire County CD75 Road N/A & Upper Tilehouse St / A602/ Council Paynes Park
Baldock Southern link road Hertfordshire County CD76 Road N/A Council
B197 Graveley Rd / North road Hertfordshire County CD77 Road N/A Council Lytton Way redesign (town Hertfordshire County CD78 Road N/A centre) Council Wellfield Road/Comet Way Hertfordshire County CD79 Roundabout & Coopers Green Road N/A Council Lane Roundabout Hatfield 800 dwellings A2-A5 and C – within this Stevenage Borough CD80 North of Stevenage Housing in Local administrative area Council Plan and retail Stevenage Borough CD81 The Oval neighbourhood centre C- Housing 275 dwellings Council Stevenage Borough CD82 Stevenage West C – Housing 1350 dwellings Council Stevenage Borough CD83 South East of Stevenage 1 C – Housing 550 dwellings Council
Welwyn Hatfield CD84 S of WGC C – Housing 1200 dwellings Borough Council
Welwyn Hatfield CD85 North West of Hatfield C – Housing 1550 dwellings Borough Council
East Hertfordshire CD86 East of Stevenage C – Housing 600 dwellings District Council
East Hertfordshire CD87 Land East of Welwyn Garden City C – Housing 1350 dwellings District Council
North Hertfordshire CD88 The Gilston Area C- Housing 3050 dwellings District Council
Welwyn Hatfield CD89 Symondshyde C- Housing 1000 dwellings Borough Council
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Proposed Land Total Size (ha/no. Local Planning ID Development Use Type of dwellings) Authority
North Hertfordshire CD90 North of Baldock C- Housing 2500 dwellings District Council
North Hertfordshire CD91 North of Stevenage C- Housing 900 dwellings District Council
North Hertfordshire CD92 North of Great Ashby C- Housing 930 dwellings District Council
North Hertfordshire CD93 Land East of Luton C- Housing 2100 dwellings District Council
North Hertfordshire CD94 Land at Highover Farm C- Housing 700 dwellings District Council
North Hertfordshire CD95 Land north of Letchworth C- Housing 900 dwellings District Council
East Hertfordshire CD96 Land North and East of Ware C- Housing 1000 dwellings District Council
North Hertfordshire CD97 Land south of Little Wymondley C- Housing 300 dwellings District Council Strategic rail Proposed Rail Freight freight Interchange, Public Open Space interchange St Albans City and CD99 419ha And Community Forest Sites, comprising District Council North Orbital Road, St Albans intermodal areas, Class B8, B1/B2. CD10 The Wine Society, Gunnels Wood Stevenage Borough B1 and B8 0.7ha 0 Road, Stevenage, SG1 2BG Council Units 1-5, 8-25, A-Q & Comark CD10 House, Gunnels Wood Park, Stevenage Borough B1, B2 and B8 2.95ha 1 Gunnels Wood Road, Stevenage, Council SG1 2BH CD10 AVC, Bessemer Drive, Stevenage Borough B1, B2 and B8 1.2ha 2 Stevenage, SG1 2DT Council CD10 Broadwater Rd West (Spen HIll Unknown – Local Welwyn Hatfield 2.01ha 3 Tesco dev) plan Borough Council CD10 Unknown – Local Welwyn Hatfield North West Hatfield 1.74ha 4 plan Borough Council CD10 Unit 1 Quadrant Park, Mundells, Welwyn Hatfield B2 0.25ha 5 Welwyn Garden City, AL7 1FS Borough Council
Environmental Assessment Report
Smart Motorways Programme A1(M) Junction 6 to 8 Environmental Assessment Report
Environmental Assessment Report