Kepax Pedestrian/Cycle Bridge, Worcester

FEASIBILITY STUDY

Prepared for Worcestershire County Council & Worcester City Council

June 2018

Red Hill House 227 London Road Worcester, WR5 2JG +44 1905 361 361

Document History

Client Name: Worcestershire County Council & Worcester City Council CH2M Reference: 694944.BA.23.00 This document has been issued and amended as follows:

Version Date Description Created By Checked By Approved By

1.0 19/06/2018 FINAL LB MB AJR

Contents

Section Page Document History ...... ii Contents ...... iii Acronyms and Abbreviations ...... v Introduction ...... 1 Feasibility ...... 2 Structure Location...... 2 East side ...... 2 West side ...... 4 Constraints and Requirements ...... 5 Ecology and Environment ...... 5 Existing Services ...... 5 Land Ownership ...... 6 Transport Planning ...... 7 Loading and Headroom...... 8 Parapet Height and Structure Width ...... 8 Approach Gradients, Landings and Path Alignment ...... 9 Construction Issues ...... 9 Interfacing with Existing Infrastructure ...... 9 Site Access ...... 12 Traffic Management and Congestion ...... 16 Flood Risk ...... 16 Geoenvironmental Issues ...... 18 Design Criteria ...... 19 Span Arrangements and Cross Sections ...... 19 Superstructure ...... 19 Substructure ...... 23 Aesthetics ...... 24 Details and Finishes ...... 24 Maintenance ...... 25 Health and Safety ...... 26 Options Comparison ...... 29 Summary of Construction Cost ...... 31 Recommendation for Further Investigations ...... 31 Summary of Preferred Options and Recommendations ...... 32 Appendix A – Ecology Assessment ...... i Appendix B – C2 Plans ...... ii Appendix C – Preliminary Geo-Environmental Study ...... iii Appendix D – Example Drawings ...... iv

III

Table(s) Table 1 - Advantages and Disadvantages Summary of Location Options Table 2 - Summary of potential pollutant pathways to be considered in a Piling Risk Assessment Table 3 - Structure Form Advantages and Disadvantages Table 4 - Options Comparison

Figure(s) Figure 1 - Location Plan source: GIS2 Figure 2 - Gheluvelt Park Historic Map (Epoch 1922-1969) source: GIS2 Figure 3 - Historic Landfill sites map shown in pink hatch source: data.gov.uk Figure 4 - Land Ownership Plan Figure 5 - Public Rights of ways and footpaths Figure 6 – Northern Crossing Point at Hallow Road source: Google.co.uk Figure 7 - Southern Crossing Point at Henwick Road source: Google.co.uk Figure 8 - Plan of Eastern Access Routes Figure 9 - View over pipe culvert Figure 10 - Footpath between overhead cable pylon and ditch drain Figure 11 - Flood levels taken from Flood Information Service on Gov.uk Figure 12 - Flood Map source: Flood Map for Planning Service Figure 13 – Example of a Cable Stayed Bridge - Diglis Bridge Figure 14 – Example of a Truss bridge - Arley Footbridge Figure 15 – Example of a Tied Arch Bridge – Abbey Bridge Figure 16 & 17 - Sustainable Urban Drainage Examples; Infiltration trench and Infiltration basin respectively

Acronyms and Abbreviations

WCC Worcestershire County Council PEA Preliminary Ecology Assessment WPD Western Power Distribution STW Severn Trent Water SUD Sustainable Urban Drainage System SSSI Sites of Special Scientific Interest

Introduction

CH2M have been commissioned by Worcestershire County Council to conduct a feasibility study for a proposed pedestrian and cycle bridge across the River Severn on behalf of Worcester City Council. The location for the proposed structure has been determined by Worcester City and Worcestershire County Councils to improve walking and cycling routes to the north of Worcester city in accordance with the plans set out in Worcestershire’s Local Transport Plan (LTP) 2018-2030. It is envisaged that a new east-west link and pedestrian/cycle crossing of the River Severn would have utility value with the nearby residential areas, university on the west and open green spaces being linked. There is opportunity to create circular leisure walks and bike rides along the river and it is hoped that a new crossing would encourage greater utilisation of the green fields to the west and create new attractive transport links to the university and city centre. The nearest existing pedestrian crossing of the River Severn is Sabrina Bridge approximately 1-mile South of the proposed location and the nearest northern river crossing is at Holt Fleet approximately 5 miles away. Two locations have been considered for the location of the proposed structure as discussed briefly below in Table 1: Location Advantages Disadvantages Location A Existing connections Construction Access Restrictions Gheluvelt Park/St. Johns Close to centres of population Landfill site and contaminated land Landownership held by Local Connections to west bank problematic Authorities Location B Good access for construction Ecological concerns in SSSI area Northwick Potential for further links Negotiations required with private land owners at a higher cost Opportunity to incorporate public education regarding wildlife and Limited connectivity on west bank ecology Table 1 - Advantages and Disadvantages Summary of Location Options

Following a review of the Pre-feasibility Study conducted by Worcestershire County Council, Location “A” has the least design and construction constraints and can be easily tied into the existing footpath network in Gheluvelt Park. This report will focus on the feasibility of Location “A” only. There are many constraints to consider in relation to the precise location of the crossing, these will be discussed in more detail within the following sections.

Feasibility Structure Location The proposed location of the structure is to be between Gheluvelt Park, on the east side of the river, and the disused landfill site, formally owned by Kepax, on the west side of the river and to the north of the City centre, Figure 1.

Proposed Bridge Location

Figure 1 - Location Plan source: GIS2 East side Gheluvelt Park is owned by Worcester City Council and is split into two main areas; the more formal grounds that run from Barbourne Road to Barbourne Brook, and the less formal parkland west of Barbourne Brook to the River Severn, this area was the former location of the Worcester Corporation Water Works, see Figure 2. It is this second area that the report will focus on. The area closer to the river is generally flat and made up of short grassland with small areas of immature trees, shrubbery and sparsely spread outdoor gym equipment around the perimeter of the park. A surfaced path approximately 1.2 m wide skirts around the edge of the parkland creating a circular walk. The north west corner of the park gently slopes away from a Pump House forming two distinct levels to the land that borders the River Severn. A drainage channel running along the northern edge of the park discharges surface water from Barbourne Brook into the River Severn. The brook has a hazardous waters warning sign and is fenced off to prevent access. It is suspected the signs refers to the culvert under the B4482 Bilford Road that was repaired in 2016 after leachate from the former landfill site at Perdiswell had entered the watercourse through the damaged culvert. The signs are still in place and will require further investigation to confirm the nature of the hazard. Although not in immediate vicinity of the proposed structure location, it should be captured on the site risk assessment and may require additional health and safety measures to be put in place. The Pump House and Environmental Centre were constructed in 1857 to draw and filter water from the River Severn. The existing retaining wall at the south-east corner of the park is believed to have been constructed to facilitate the water inlet for the Pump House and the route of the inlet will need to be traced. Although the Pump House building, equipment and adjacent land is not listed or

recognised as having significant historic value, the formal section of the park is a designated war memorial and grade 2 listed due to the landscape design interest and group value of several assets in close proximity. Consultation should be made with Worcester City and Historic England to confirm the listing does not extend to the proposed structures location. An assessment may be required to ensure the inlet pipe is capable of withstanding construction vehicle loading and/or is not damaged during the installation of deep pile foundations for the proposed structure. The structure is to be sited on the higher ground near the retaining wall for two reasons; it is less likely to cause obstruction during flood and the height corresponds more closely with the land to the west bank, limiting the requirement to raise the abutment and approaches by importing fill material to make up the ground to a suitable height. Additional made up ground and lower headroom clearance over the River Severn could present numerous difficulties and have a negative effect on the land drainage both locally and increase the flood risk downstream through Worcester City centre.

Figure 2 - Gheluvelt Park Historic Map (Epoch 1922-1969) source: GIS2

West side On the opposite side of the river, the area of interest is comprised of several features. The Severn Way, National (walking) Trail, extends along the length of the river and passes through an area of willow carr, behind this the land rises to the disused landfill site formally managed by Kepax, Figure 3.

Figure 3 - Historic Landfill sites map shown in pink hatch source: data.gov.uk

The Kepax site is an unnatural raised structure made from household and industrial waste with imported soil used as a capping layer. The land is generally flat with several monitoring stations situated throughout the landfill site and surrounding area that measure conditions of gasses from the degrading waste. The land is accessed by the general public and “goat tracks” can be seen where members of the public frequently walk, however there are no surfaced paths in this area. The land on the west bank is level with the willow carr extending between 40 and 55 m between the river bank and the landfill site. The area is generally wet woodland and has an open drain that dissects the land. There are some further monitoring stations and what appears to be an old covered well in the nearby area. The option to move the structure location south to avoid the area of landfill has been considered however, access would still be required via the landfill site. There are concerns about the height difference between the ground levels either side of the river and the requirement for ramp design. The incorporation of ramps will significantly increase the cost of design and construction and would land the structure in, or very close to the race track of Pitchcroft and will open many security issues with the racetrack. Although Worcester City Council own Pitchcroft Race Course and lease out the track and facilities, it is envisioned the security concerns, potential risk to public safety, additional cost and land uptake required for ramps will cause more complications than at Gheluvelt Park.

Constraints and Requirements Ecology and Environment In October 2017, Worcestershire County Council commissioned their in-house ecology team to undertake a desk-based Ecological Assessment on behalf of Worcester City Council, a copy of which is included within Appendix A of this report. The River Severn is a designated wildlife site and the proposed structure location is within the “buffer” zone of Biodiversity Action Plan (BAP) habitat. The assessment recommends a field Based Preliminary Ecology Assessment (PEA) to confirm specific ecological surveys required including but not limited to; • National Vegetation Classification or Phase 1 Habitat Mapping • Invertebrate and Reptile Survey • Ground Flora Surveys • Otter Survey • Badger Sett Survey • Detailed Bat Activity Survey (including daytime assessment) • Breeding Birds Survey • Invasive Species Survey • Ancient Trees and Hedgerow Survey The assessment also highlighted the following ecological constraints; • The bridge must be designed to not affect water flow as the river is highly sensitive to water pollution. As such the structure is to be designed as a single span over the river with no piers in the watercourse and abutments set well back from the embankments. • The design of cycle ways and footpaths and associated drainage must be sensitive to wildlife to avoid impact by entrapment in drains and severance of habitats by surfacing paths in the presence of reptiles. • The bird breeding season (March-August inclusive) restricts when work can be carried out on vegetation or structures supporting active nests. • Reinstatement of habitat/relocation of certain protected species and/or mitigation measures to reduce the impact of construction, operation and maintenance. Existing Services A statutory undertakers services search was completed for the area at Gheluvelt Park and can found in Appendix C of this report. Services identified; • Severn Trent Water (STW) is present to the west of the river. • Western Power Distribution (WPD) overhead high voltage electrical apparatus crosses the river in close proximity to the proposed location and continues underground both sides of the river. Water STW apparatus roughly follows the line of the Severn Way walking trail. The information received from the statutory undertaker’s return does not show the type or size of equipment. Trial holes will need to be hand dug to determine the size, depth and location of the equipment.

Overhead Power Lines Existing 11 kV overhead cables owned by WPD cross the river within 30 m of the proposed structure location. This will impact on potential crane operations and consideration of this will be required with regards to design and buildability. It is considered that it would be possible to construct the bridge near to the services with appropriate mitigation measures in place through liaison with the service owner. If a crane is required to lift sections of the structure into place. It could be possible for the overhead line to be diverted or temporarily de-energised and earthed during construction to minimise the risk, however this is usually expensive. A crane could be positioned away from the overheads (to the north east of the proposed location) and the reach/swing limited, but the utility owner, WPD, may insist on having a site presence and additional health and safety measures enforced during construction works. It is envisaged that pile driving machinery will be required on both sides of the river to install deep pile foundations in the soft silt sediment ground conditions. The 11 kV overhead lines may be affected by ground vibrations caused during the installation of pile foundations and advice must be sought from the utility owner to mitigate. To add value to the scheme, thought should be given to installing empty ducts in the bridge deck to enable future services to cross the structure and remove the possibility of integral structural damage caused by installation at a later date. If WPD use ducts incorporated in the footbridge design and remove the existing overhead lines, it will improve the aesthetics of the location and surrounding landscape but will be dependent on approvals from WPD. To the west of the river running in a north south direction, 132 kV overheads cut through the middle of the Kepax landfill, however these are considered to be at a safe and sufficient distance from the proposed structure location. The power lines are at a high enough elevation to allow construction machinery to pass safely underneath though line heights and the swing and sag of cables will need confirming by the service provider prior to any construction work commencing. All heavy lifting machinery is proposed to be brought to the site on the eastern side of the river to avoid disturbance on the landfill site and for ease of access. Buried Power Lines The 11 kV overheads that span the river adjacent to the structure location appears to be linked to underground cables. The power cable appears to surface to cross the river on poles and then return to the earth as a buried underground cable. A CAT survey or similar alternative should be conducted and trial holes hand dug to locate prior to construction works commencement. Contact must be made with the service owner to ensure construction vehicles tracking over buried services do not cause any damage to the assets and so that mitigation measures can be implemented on site (such as steel road plates) or the utility company have opportunity to upgrade the level of protection on their equipment. It is anticipated that no service diversions are necessary at this stage and that the hazards can be managed safely on site however, this should be reviewed at the design stage. Land Ownership A search of the landownership records indicates that title WR51603, Gheluvelt Park, is owned by Worcester City Council with the section adjacent to the river leased to Severn Trent and the south west corner leased to a third party. Title WR13079 and title HW93142 are owned by Worcestershire County Council. Title 19650 is owned by a third party and leased to Worcester City Council for a period of 99 years beginning October 16 th 1990, as shown in Figure 4. The land is accessed via a gate near the entrance to the landfill which must be maintained for the purposes of monitoring and controlling gas from the landfill.

Figure 4 - Land Ownership Plan

The river embankment retaining wall to the south east of Gheluvelt Park is believed to be owned and maintained by Worcester City Council when they purchased the Pump House and adjacent land in 2005. Attached to the retaining wall is a flood monitoring station owned and maintained by The Environment Agency. At the base of the retaining wall is an inlet believed to form part of the Pump House system decommissioned in 1995. Further investigation work is required regarding the drainage inlet at the base of the retaining wall should the scheme be developed further. Transport Planning The client for the new structure is to be pedestrians and cyclists. The structure must be designed for inclusivity of all types of pedestrian and cyclists in accordance with BS 8300-1:2018; Design of an Accessible and Inclusive Built Environment. The largest volumes of pedestrian traffic are likely to be from Northwick, Merrimans Hill and the Barbourne areas east of the river and, Hallow and Henwick Grove to the west of the river. It is thought most traffic will be heading towards the city centre to the east and Worcester University St Johns Campus to the west. A detailed traffic analysis will determine the projection of use, likely types of users, and any upgrades required to the wider transport network which will affect the design of the structure. Although the purpose of the new crossing is intended for recreational users making journeys for leisure purposes, goal orientated users making journeys to specific destinations are likely to take the shortest route from A to B, also called the desire line. The design of any proposed new footpaths and cycleways will need to facilitate both types of user and direct routes will reduce pedestrians and cyclists straying from the path. A new footpath route over the landfill will require extensive ground works to surcharge the land and reduce the displacement of the waste below the surface ground level. There is scope to further

increase the footpath links on the Severn Way walking trail. The trail is currently an uneven dirt track running adjacent to the river with pinch points of 0.8 m in places and steep muddy slopes close to the edge of the river embankment. To upgrade the walking trail further investigation works is required to determine the extents and options available. The existing footpaths in Gheluvelt Park will require a status change of use and potential upgrades to facilitate the use by cyclists and either a or Public Path Creation Order will be required under The Highways Act 1980. As the land in the area is owned by Local Authorities, Worcestershire County Council and Worcester City Council, an application for a Public Path Creation Agreement following consultation between the authorities is applicable assuming an agreement is made. Notice of the dedicated footpath must also be published in at least one local newspaper circulating in the area. Loading and Headroom The loading on the structure shall be calculated in accordance with BD 37/01 and Eurocode 1. The minimum air draft (headroom) clearance for structures over a water course is the 1 in 100-year flood level +600 mm. The minimum headroom to soffit level is proposed to be 8 m above average water level. This is based on figures for adjacent bridge structures at Holt and Diglis at summer river levels and will require confirmation from the Canals and Rivers Trust as the River Severn is classed as a navigable water course at the location. The navigation arch levels at Worcester and Diglis bridge are 6.2 m and 8 m respectively and the highest recorded flood level is 5.74 m. The minimum headroom required for pedestrians and cyclists in an enclosed structure is 2.7 m. the minimum headroom for dismounted equestrians and pedestrians is 2.7 m or 3.7 m if mounted. Parapet Height and Structure Width The structure is to be designed for pedestrian and cyclist use. In the interests of safety, it is recommended by Highways England to separate cyclists and pedestrians where possible however, this decision is at the discretion of the Overseeing Organisation. It is proposed for pedestrians and cyclists to share the same space as segregation can be visually intrusive and reduce the manoeuvrability for passing pedestrian traffic and both wheelchair and mobility scooter users. Additionally, there is no evidence to suggest segregation reduces the potential for conflicts and it is not anticipated that the route will take significant volumes of cyclists travelling at high speeds. The requirements for combined use by pedestrians and cyclists in BD 29/17 states the minimum unsegregated total path width is 3.5 m, or when separated by a kerb or railings the minimum total path width is 4.7 m and 5 m respectively. Local Transport Note 2/08 advises an additional 250 mm width be added for comfort of cyclists where a bridge parapet is over 1.2 m. The proposed structure width is to be 4 m. Details of exact dimensions will need to be confirmed at the preliminary design stage. The minimum parapet height required for cyclists and pedestrian use is 1.4 m in accordance with BD 29/17 By comparison, Diglis Bridleway Bridge has an internal path width of 3.5 m between parapets and total structure width of 4 m. Sabrina Pedestrian Cycleway Bridge has an internal path width of 3 m and total structure width of 3.25 m It is important to note Sabrina has a parapet height of 1.2 m which does not meet the current design standards, implying the structure was originally designed for pedestrian use only. Both these structures were designed prior to updates in design guidance and codes, in particular the minimum width of the structures has been increased from 2 m minimum for an unsegregated footbridge designed for pedestrians and cyclists in BD 29/04, to 3.5 m in the 2017 update. The design of the visual aesthetics of the parapet and any guard railings should be designed with the perspective of the user and Inclusive Mobility Guidance.

Approach Gradients, Landings and Path Alignment Approach ramps and the gradient over the structure shall be no steeper than those adopted for the access ramps. Ramp gradients shall be designed to be no more than 1 in 20 in accordance with BD 29/17 Design Criteria for Footbridges. Where compliance creates design difficulties, a relaxation can be made with the acceptance of the Overseeing Organisation, but may not be steeper than 1 in 12. Horizontal landings shall be incorporated into the design of ramps at equal intervals of 2.5 m rise for a 1 in 20 slopes, if the gradient is flatter than 1 in 20 no landings are required, any steeper and further landings are required. The ground levels at Gheluvelt Park and the top of the embankment to the Kepax site appear to be very similar. A full topography survey will be required to confirm levels and enable the detailed design of approaches and ramps if required. On the east side of the river at Gheluvelt Park, the approach ramps and gradient can be incorporated and built into the existing embankment and tied into the existing ground level. The western structure landing on the Kepax site requires more thought and will depend on if ramp access to the Severn Way walking trail is also to be incorporated into the design of the structure. The approach ramps to the structures landing location can be incorporated into the design of the structures abutments to tie into the ground level at the Kepax site. This may present difficulties working in or near contaminated land. Connecting the landfill and structure to the walking trail adjacent to the river will add considerable cost to design and construction and the walking trail will also require extensive upgrade works to the path and river embankments. It is thought the difference in height between the top of the embankment at the edge of the Kepax site to the ground level in the willow carr area is approximately 5 m and the flat area of willow carr extends approximately 25 m from the edge of the Kepax embankment to the edge of river. It is recommended to limit the works in the willow carr as the area is prone to flooding and additional works will be required to create access down the steep embankment from the edge of the landfill. The minimum inside radius of curved or spiral ramps for a cycle path is 5.5 m. All paths, gradient and ramps are to be designed in accordance with BS 8300-1:2018 Design of an Accessible and Inclusive Built Environment, External Environment - Code of Practice and HD 39/16 Footway and Cycleway Design. Construction Issues Interfacing with Existing Infrastructure Gheluvelt Park has existing footpaths running the perimeter of the park, Figure 5. Gheluvelt Park is well maintained with easy access for pedestrians and cyclists from Barbourne Road and flat paved footpaths approximately 1.2 m wide. The land to the west appears to be used heavily by dog walkers. The National Trail, The Severn Way, runs parallel along the length of the river and connects the existing public rights of way 502(B) and 634(A) to the north and south respectively. The National Trail is an uneven dirt path less than 0.8 m wide in places through dense woodland and unsuitable for wheel chair and pushchair access at present. As a part of the bridge design it is recommended to review the access from the west of the proposed site to upgrade the existing network to allow construction vehicle access. The most suitable and direct route is via gated access on the Hallow Road Recycling Centre access road and over the landfill. Beyond the immediate footpath connections, Gheluvelt Park has good existing connections to Pitchcroft and Worcester Racecourse green and residential areas north of the city using the existing footpath network. The western bank has potential to upgrade existing links and improve connections however space constraints will limit the options available. 9

Figure 5 - Public Rights of ways and footpaths

The creation of a new crossing point over the river is likely to have a positive effect to increase the volume of pedestrian and cyclist traffic on the wider existing network. The existing links on the east of the river are close to the edge of Gheluvelt Park and convenient for foot traffic. There are also existing cycle lanes incorporated in the highway on the A38 Barbourne Road and the traffic lights allow enough room for cyclists to cross comfortably. Specialist transport planning surveys and modelling will be required to determine if the existing crossing points and highway network is adequate to cope with an increase in foot traffic and/or any improvements are necessary to both the wider networks links to the east and west of the proposed structure. Upgrading or widening of the footways on Horsford Road and Hallow Road to comply with current standards will be difficult due to the space constraints. The existing footways on Horsford Road are between 0.8 m and 1 m wide and adjacent to private property land with no verges. Widening the footways to accommodate for increased foot traffic may not be possible due to the issues associated with land take on residential properties and the likely possibility of compulsory purchase orders required. Additional considerations may include available verge space and moving or renewing existing assets on the network e.g. streetlighting, drainage, services and/or other street furniture and potential realignment of the carriageway. The wider highway network will need to be assessed by a competent Transport Planner and Highway Engineer to review all available options to determine a safe and economic solution. To the west of the river, it is envisioned the new footpath link will join to Horsford Road. The nearest pedestrian crossing points of the A443 Hallow/Henwick Road are near Monarch Drive, Figure 6, approximately 300 m north of the entrance to Horsford Road, and The traffic lights south west, Figure 7, are over 750 m to the south of Horsford Road. The northern crossing point is a dropped kerb crossing with bollards planted in the island in the centre of the carriageway. The area in the central reserve is not wide enough for a bicycle and the crossing point relies on human awareness to cross live traffic. The southern crossing point is considered much safer with the use of traffic lights, however for foot traffic to reach these traffic lights they must first get past an area of off road parking where vehicles are often parked on the kerb and on the footway.

The parked vehicles often restrict the footpath width making the route too narrow for pedestrians to pass safely and it is thought likely for pedestrians to cross the A443 at a more convenient location rather than to walk some distance to use the traffic lights. The installation of a new pedestrian and cyclist crossing over the river will encourage increased cyclist concentrations at a number of junctions and roads in the surrounding area however, without traffic modelling or an assessment, the extent and direction of foot/cycle traffic will be unknown. A thorough review is required to determine the extents and suitable options for upgrading and/or installing a new crossing point on the A443 Hallow Road with a full road safety audit.

Figure 6 – Northern Crossing Point at Hallow Road source: Google.co.uk

Figure 7 - Southern Crossing Point at Henwick Road source: Google.co.uk

Site Access Access from the east via Gheluvelt Park and the Pump House Environment Centre is obtainable through the Pump House’s gated access and would require permission from Worcester City Council and the Pump House Environment Centre to use. The existing road network to the Pump House provides suitable access for construction vehicles from the A449 Barbourne Road via a designated route. If, however, crane access or abnormal load vehicles are required on site, parking suspensions may be required to restrict off road parking temporarily. Access from the west is difficult and unsuitable for construction vehicles at present. The Severn Way footpath 628(B) in Figure 8, linking the Severn Way walking trail and A443 Horsford Road is comprised of 3 main sections. The first section from Horsford Road to the properties to the north of the site is surfaced hard standing approximately 2.5 m wide at the narrowest point however, the private property access shared by the footpath has a vehicle height restriction barrier suspected to have been installed when the landfill site was in operation. The second section of the footpath from the edge of the property to approximately 200 m before the Severn Way trail is a wide and flat dirt path running parallel with a stream/drain with dense foliage and well established trees lining the edge of the track. The last section connecting to the river trail is narrow with uneven ground conditions, typical of the walking trail, and narrows to approximately 2 m in places.

Figure 8 - Plan of Eastern Access Routes

Construction access from the west of the river will require significant works to allow for construction vehicle traffic. The ground must be stable enough to support construction vehicles and preferably paved to reduce the risk of vehicles becoming embedded in the soft soil conditions of the landfill and walking trails. Three options have been considered as detailed below. 1. Use the access from the east only (via Gheluvelt Park) and construct a temporary crossing, temporary crane to lift materials or make use of pontoons to float construction materials to the western half of the site. The structure will need to be constructed in sections as a cantilever and as such will be overdesigned once the structure is completed. This approach is not uncommon for the design of suspension bridges. The River Severn is well known for its strong currents and regular floods. Further consultation will be required to determine if the use of pontoons or floating material to the western half of the site can be fully considered and the risks assessed. It is an unlikely option as there is currently no suitable landing position on

the western side of the river, and some form of temporary or permanent structure will be required to safely unload materials. 2. Upgrade the existing footpath links to make suitable for construction traffic. The existing footpath network on the western side of the river has pinch points of approx. 0.8 m near the river bank. Extensive de-vegetation works will be required to widen the path and fill material deposited to level uneven ground. Sheet piling may be required to strengthen the river embankments in some areas and prevent the access route from sliding towards the river. A pipe culvert, Figure 9, drains into the river along the walking trail. The culvert will require a structural assessment and potential strengthening works before construction traffic can be permitted. Dependent on results of the structural assessment, this could be as simple as overarching the culvert with concrete fill or as complex as replacing the pipe and redesigning the structure to take construction traffic loads. The culvert is approximately 7 m in length with a 1 m span with the footpath above 4.5 m wide. The asset owner is assumed to be Worcestershire County Council as they are the current land owners of the title WR13079. The width of the path between the existing overhead cable tower and drainage ditch, , is approximately 8 m to the ditch side fence line and would require construction of some form of protection to reduce the risk and/or consequences of damage to the pylons from construction traffic. 3. Create new access point across/around the Kepax landfill area. From discussions with geotechnical and hazardous waste specialists, the creation of a new route via a gated access point south of Hallow Recycling Centre is possible. A route through the land fill will require a large amount of fill compacted over the designated route before excavating back the top layer of fill and laying surfacing. This technique will reduce the amount of settlement before construction vehicles use the route but must be done well in advance before use by construction vehicles. Access for abnormal loads carrying specialist plant and/or materials to the site should be considered and a suitable route determined. There is a known issue at Barbourne Bridge with a weight limit of 40 tonnes, this will affect the deliveries to site and structural strengthening works may be required to upgrade the existing network.

Figure 9 - View over pipe culvert

Figure 10 - Footpath between overhead cable pylon and ditch drain

Traffic Management and Congestion During construction, traffic management, signing, site access and construction traffic access will need to be established and maintained throughout the duration of the works as certain roads are unsuitable for large construction machinery. Parking suspension notices may be required to allow larger construction vehicles and crane machinery to access site via Barbourne Lane, Pitchcroft Lane, Pope Iron Road and Waterworks Road. Aside from unavoidable increased construction traffic on the residential estate, there will be minimal disturbance to the main traffic network during construction. It is suspected the residential properties to the west of the location at Riverview Close and the neighbouring area will not respond well to increased construction traffic. It is believed the capping layer to the landfill was significantly reduced due to complaints from local residents over construction traffic. The deliveries of material to the land fill were stopped and the existing material on site was redistributed over to cap. Post-construction pedestrian and cyclist traffic will increase and as such the existing footpath links should also be upgraded to increase width and capacity to allow foot traffic adequate room to pass safely in opposing directions and to make the path network suitable for cyclist, push chair, mobility scooters and disabled access. If the existing network is upgraded for construction access on the western side of the river, it will be relatively straight forward to convert the access post-construction for cycle/footpath use. Flood Risk The Location suffers from regular flooding and rapidly fluctuating water levels. The Environment Agency have a flood monitoring station in close proximity to the proposed structure location and levels typically vary from 0.55 m to 3.35 m with the highest recorded level at the location as 5.74 m in February 2014, Figure 11.

Figure 11 - Flood levels taken from Flood Information Service on Gov.uk

Figure 12 shows the current flooding zone for the area around the proposed structure. The Installation of a structure and paved footpaths on a flood plain will increase the area of hard standing and decrease the area of permeable surface and flood capacity. This could have a negative effect of flooding downstream and increase flood risk and risk of pollution entering the river both during and post construction phase. Consultation with the Environment Agency will provide further information into the types of mitigation measures that can be incorporated into the design of the structure to minimise or negate flood risk.

Figure 12 - Flood Map source: Flood Map for Planning Service

Geoenvironmental Issues The western part of the site is underlain by landfilled material of unknown origin. It is assumed however, that while the deposited wastes would have likely been routinely compacted during the landfill site’s operation, it is unlikely that the material would have been compacted to any specification. Further, it is unknown whether the site accepted wastes which would degrade over time. As a result, it is anticipated that the site will be susceptible to ground movement which would lead to intolerable movements of any shallow foundations, and as such, a piled foundation solution will be required. However, there are constraints associated with this foundation type; the Environment Agency’s document Piling and Penetrative Ground Improvement Methods on Land Affected by Contamination: Guidance on Pollution Prevention, National Groundwater & Contaminated Land Centre report NC/99/73 (May 2001), describes six scenarios which may potential impact on the environment from piling activities. Table 2 presents a summary of the considerations for adopting a piled foundations solution.

Potential pathway Description

Creation of pollutant Pathways may be created by piles penetrating the basal liner of the landfill (if present), pathways leading to a pathway for downward migration of landfill leachate

Pathway may be created by piles penetrating the capping liner of the landfill (if present), leading to a pathway for the upward migration of landfill gases

Advancing contaminated There is a risk that some forms of displacement piling (such as driven precast piles) may materials during advance a “plug” of contaminated material below the level of the landfilled material

Disposal of contaminated Non-displacement forms of piling, such as CFA (continuous flight auger) bring arisings to arisings the surface. Depending on the nature of the material, this may pose a risk to site operatives during piling operations, and may also be problematic and potentially costly to dispose of

Cementitious fluids Cast in-situ forms of piling may need particular consideration if undertaken near sensitive bleeding from wet surface water or groundwater bodies, as the concrete may bleed cementitious fluids concrete during the curing process.

Aggressive ground Concrete piles may be susceptible to degradation from contact with leachate or soils, conditions within the ultimately reducing their integrity and load-carrying capacity Made Ground Table 2 - Summary of potential pollutant pathways to be considered in a Piling Risk Assessment

It is anticipated that, based on the available data, all of the pathways referred to above are pertinent to the Hallows Road Landfill site. A Piling Risk Assessment would be required, in order to develop a suitable pile design and specification, to deliver the required technical performance, whist mitigating the risk of creating hazards to the environment from piling operations. The historical sewage works, which is no longer present on the site of Gheluvelt Park could potentially have contaminated the site. This area may therefore have Made Ground present, with the potential for metals, inorganic ions (cyanides, sulphates, chlorides etc.), organics, fuel oils, treatment chemicals, asbestos and pathogens (salmonella etc.). It therefore should be recognised that the Made Ground beneath Gheluvelt Park on the east side of the river may also fall within the same EA constraints detailed above. There are several listed buildings recorded in Worcester, the majority are located to the east of the site, however one is located directly north west of the western boundary of the site. (MAgiC, 2018)

Design Criteria Span Arrangements and Cross Sections The Preliminary Desk-based Ecology Assessment produced by Worcestershire County Council on behalf of Worcester City Council, specifies that “The bridge must be designed to not affect the water flow (i.e. a single span bridge with abutments set well back from the bank)” to avoid harming the fish population. The proposed length of the structures span is to be approx. 110 m to land the abutments in, or on the edge of the Kepax landfill site. The longer the span, the closer construction will be to the disused landfill site. Digging and working on or near the land fill presents difficulties disturbing the hazardous waste material and increases the risk of leakage of toxic gasses and liquids into the river and surrounding area. A full topography survey is required to confirm measurements, span length and abutment locations. Although possible, constructing in or near the edge of the land fill will require specialist consultation to monitor and/or remove toxic/dangerous material from the site. A two-span structure of 60 m from Gheluvelt Park to land a pier in the willow carr on the western embankment and a 40 m span to land on the edge of the Kepax site has been considered however, extensive additional work would be required to enable construction vehicle access down the embankment to the willow carr area. Although splitting the structure into two spans could have benefits such as reducing the amount of work and/or number of pile foundations required near the landfill and increase the safety of construction, there will be an increased flood risk and risk of polluting the river when working in the flood plain at a lower ground level and greater disturbance to wildlife and ecology than a single span structure. Some work will still be required on the willow carr area however, a detailed ecology survey would provide more information on the species affected by the proposed works and further consultation would give an indication of the design and construction constraints. Superstructure Structure Form For the purposes of this report the following construction options have been considered, Table 3; Construction Advantages Considerations type Masonry arch • Natural materials • Unachievable span length • Aesthetically pleasing • Maximum span to rise ration of 10:1 Intermediate supports required in the river. • Method of construction (formwork required) • Slow construction • Limiting water capacity when in flood Concrete/Steel • Iconic • Limiting water capacity when in flood Arch • High strength • Difficult to inspect all elements post • Minimal materials construction • Formwork required (if concrete) • Large self-weight and require robust foundations. Beam and Slab • Simple form of construction • Not considered aestheticly pleasing • Low cost • Slenderness ratio should be 20-30 • Simple to design • Maximum span of 80 m before deck • Low maintenance depth and aesthetics significantly • Long life span compromised • Fast construction • Formwork may be required

Construction Advantages Considerations type Truss • High strength • High maintenance • Fast construction • Visually intrusive • Variable span length Tied Arch • Iconic • Heavy sections to lift into place requiring • Aesthetic large crane equipment. • High strength • High cost of construction and materials • Can be installed in sections • Substantial foundations required to take • the large self-weight of the structure • Difficult to perform maintenance • Construction sequence and deformation of the arch. Suspension • Iconic • Two anchorages required to be • Aesthetically pleasing constructed, one in the contaminated • Variable span length land fill site not recommended. • Construction method and lifting of • Difficult to perform maintenance bridge deck sections achievable • Uneconomical for short spans • Installation of tower of western embankment unfeasible. Cable Stayed • Iconic • High cost of construction and materials • Cantilever form of construction and • Difficult to perform maintenance construction sequence • Can be designed with only 1 tower on east of river. • Aesthetically pleasing • Variable span length • Construction method and lifting of bridge deck sections achievable • Greater stiffness • One anchorage required which is achievable in Gheluvelt park Table 3 - Structure Form Advantages and Disadvantages

From the above options, tied arch, cable stay and a truss form of construction will be carried through for consideration. Cable stayed The most iconic and aesthetically pleasing of the suitable available options selected, Figure 13. The form of construction has additional installation and construction sequence benefits. The use of one pylon or tower to be installed on the eastern side at Gheluvelt Park will limit the foundation size required at the Kepax site, reduce the amount of excavation required and hence associated construction issues. The design of the cables is complex with many issues to be considered such as pylon location and design, cable stay arrangement, the cable types and wire configurations, cable protection and inspection and maintenance access.

Figure 13 – Example of a Cable Stayed Bridge - Diglis Bridge

A cable stayed structures deck is often constructed in segments as it is unlikely that the deck could be lifted in one single section. The deck should be designed for each segment to act as a cantilever lifted into place before the suspension cables are attached and tensioned to increase the strength. The next section of deck can then be lifted into place and the process repeated in a similar methodology to that used for the Diglis Bridge. The design for temporary works and temporary actions on the structure during the construction sequence often result in the completed structure being overdesigned to withstand the temporary forces acting during the construction. To accommodate for a crane to lift deck sections, it is likely temporary foundations will be required to support the lifting plant as the ground conditions near the river are suspected to be of poor quality and subject to settlement. The number and length of cables can significantly increase the cost of construction and consideration should be made to minimise the materials and number of attachments required. Truss Truss structures, see Figure 14, are typically installed in steel sections and bolted, welded or riveted together on site. This form of construction is most likely to cause sparks during construction and could be extremely dangerous due to the methane emitting form the land fill. Truss construction is simple and quick to install but requires regular maintenance and can be expensive to repair and maintain when compared to other structure forms.

Figure 14 – Example of a Truss bridge - Arley Footbridge

Steel is prone to corrosion from water damage which causes rust to occur and weaken the structural strength. The design on the steel should avoid or seal crevices and avoid the collection of debris which may trap moisture and increase the rate of corrosion whilst allowing access for maintenance to the members.

Tied Arch The Stockton-On-Tees infinity bridge is a steel tied arch with a span of 120 m and weight of 450 tonnes and was successfully completed in 2009. Its of a similar span to the proposed structure and has been used to inform this report. Tied arch construction, Figure 15, usually involves the assembly of the arch on site as the sections and materials are too large and heavy to transport to site prefabricated. The arches are lifted into place using large cranes in either whole sections, or temporary support towers are erected either side of the structure to support the arch as sections are constructed from the abutments towards the centre as cantilevers. Both erection methods are heavily affected by the wind with difficulties lifting large sections in high winds and vibrations when constructing in segments. Once the main arches are installed, the hangers and deck can then be installed and tensioned as required. One of the main difficulties with large span tied arch construction and design, is the wind loading. The design of the deck should be of a shallow depth to aid the aesthetics of the structure; however, this weakens the structures strength and so the deck should be deigned to the minimum depth allowable for both during and post construction. Tied arches also require large foundations as the forces acting at the connections and foundations are substantial compared to suspension bridge construction. This means installing large piled foundations at both Gheluvelt Park and in the Kepax site in contaminated made up ground.

Figure 15 – Example of a Tied Arch Bridge – Abbey Bridge

The design and shape of the arch arrangement should be suitable for the location. As the location is within the flood plain, it is suggested that all the arch elements should be above the flood level and a deck arch and half through arch forms of construction avoided.

Substructure Due to the ground conditions and location, deep pile foundations will be required to prevent the structure from moving and sliding towards the river. Construction of the foundations in the western embankment will require specialist consultation due to the high risk of releasing contaminants in the landfill through ground disturbance. The release of toxic gasses and/or liquids is dangerous to human life for those working on site and to the surrounding environment and wildlife. Furthermore, these gasses often contain high levels of methane which is highly flammable and could be ignited by sparks from multiple sources during the construction. A potential mitigation measure to limit or reduce the likelihood of igniting flammable gasses is to use controlled flaming. Worcestershire County Council is responsible for inspecting and recording the methane levels at the landfill site and records should be obtained to determine the level of risk. Foundations Foundations and below ground elements may be subject to chemical attack from the contaminants and require mitigation measures at the design stage dependent on the soil make up and acidity. Additionally, the depth of the landfill and details of the base lining is unknown. Potential further issues may arise as a result of puncturing the base lining (if present) and the capping layer and the release of contaminated materials which may require some form of sealing to the top and base of piles. The ground conditions are predicted to be soft sediment near the river with deep silty conditions before reaching an underlying founding stratum of suitable strength soil. The foundations of the

structure will need to be deep piled foundations to transfer superstructure loads to good ground conditions and prevent movement of the structure. Extensive ground investigations will be required to determine the strength and type of soil and hence determine suitable pile foundation types. Piles are expensive to install and can increase the costs of construction by over 20% in certain scenarios. It is important to limit the number of piles to design pragmatically and with great consideration to cost and groups of over five piles or spaced less than three times the pile diameter apart may cause greater settlement. A piling rig is necessary to install piles vertically into the ground. The nearby overhead powerlines may cause concern when lifting the steel or concrete sections into the rigging machine. The location of the pile foundations and length should be designed with consideration to this. The selected type of pile and method of installation should minimise the risks of groundwater pollution and gas migration and a foundation works risk assessment report produced to capture the pollution scenarios that may occur, potential mitigation, proposals for monitoring and specific issues and uncertainties with each method. The requirement for the report will be determined by the planning authority. Furthermore, the method of pile installation may cause significant vibrations and noise disturbance which may affect adjacent properties, structures, embankment stability and existing services. The chosen method of pile installation must consider the ground conditions and risks associated with auguring contaminated land at Gheluvelt Park and disturbance to the surrounding environment. Aesthetics All structures must be designed with consideration for aesthetics, environmental impact and surrounding landscape in accordance with BA 41/98 The Design and Appearance of Bridges. Reducing VVVandalismVandalism The most common forms of vandalism to structures in Worcestershire are graffiti, particularly to subways, fire damage to the soffit of low use road bridges, general litter and padlocks being attached to wire fencing or mesh over river structures. The padlocks rub against the metal parapets increasing the rate of corrosion and can, in special cases, cause a flood risk when blocking the gaps between fence rails. A build-up of padlocks looks untidy, adds increased loading to the structure and are dangerous to remove by hand held cutting machinery. The design of the parapets should consider the public attaching padlocks and how to minimise. The risk of antisocial behaviour in the area is assumed to be quite low at Gheluvelt Park as people frequently use the gym equipment and run through the park both during the day and late evenings. The land is open and visible which detracts antisocial behaviour and litter bins dotted throughout the site reduce the litter in the area. The risk of graffiti and antisocial behaviour can be reduced with clever design decisions, for example, reducing the number and area of vertical surfaces to be tagged and making areas around abutments and bearing shelves difficult to access. Details and Finishes Drainage The bridge deck will be designed with a slight gradient to enable the structure to drain surface run off adequately. Additional drainage may be required dependent on consultation with a highways drainage engineer and results of any assessments required. The construction of a large area of impermeable surfaces will affect the local areas water retention ability when in flood. Any drainage systems must be designed to withstand regular flooding and have an overall neutral effect on water retention and land drainage. The use of sustainable urban drainage systems (SuDS), Figure 16, has risen significantly over the last few decades. These systems work by intercepting the surface run off and delaying the rate at which 24

the water is discharged back into the watercourse and hence decrease the volume and speed at which the water drains back into the water course.

Figure 16 & 17 - Sustainable Urban Drainage Examples; Infiltration trench and Infiltration basin respectively

Walkway Surfaces Walkway surfaces are to be designed in accordance with BD 29/17 Design Criteria for Footbridges and shall be agreed with the Overseeing Organisation as an aspect not covered by standards. Lighting No lighting is currently installed at Gheluvelt Park or in the landfill site and therefore no lighting is necessarily required based on guidance within BD 29/17 Design Criteria for Footbridges. If the installation of lighting is to be considered at a later date, a feasibility study should be conducted to explore issues with the depth and method of installation of ducts through the landfill site, installation of lighting column foundations, existing ecology and light spill, installation of new connections to the electricity network and maintenance and operating costs. Maintenance The structure must be designed to be inspected in accordance with BD 63/17 Inspection of Highway Structures and the requirement to inspect all visible elements to provide information on the physical condition. A General Inspection is required every 24 months unless a Principal Inspection is scheduled at the same time, in which case only a Principal Inspection is required. A Principal Inspection should be scheduled every 6 years unless agreed with the Overseeing Organisation and shall comprise of a close examination within touching distance of all inspectable elements. Provisions shall be made for access equipment and machinery required for the purposes of Principal Inspections. Access for Inspection Typically, access for footbridges over a water course is gained via a pontoon or boat. The nearest boat launch location to gain access via a boat on the river is from Seaborne Leisure at Kempsey according to Boatlunch.co.uk. The minimum headroom to soffit level is to be a minimum of 8 m above average water level. This is based on figures for adjacent bridge structures at Holt and Diglis and will require confirmation from the Canals and Rivers Trust. Consideration could also be made to design in provisions to allow roped access from the underside of the structure. This could be designing the parapets to be roped access friendly or designing in steel climbing loops and clipping locations permanently for roped access, though this may cause issues with corrosion and degradation of the structure and any provisions made for man safe equipment will require annual inspection. 25

Suspension CCablesables and Pylon There are many considerations when designing cable stayed structures, the cables have an expected life span of 120 years. Suspension cables are susceptible to damage from corrosion, fretting and physical damage from impact or vandalism, they are particularly vulnerable at connection points and as such, the cables should be suitably protected to reduce area of surface exposure but still be accessible to inspect. The most effective method of prevention of corrosion is galvanisation of the cables and reducing the areas in which water may collect (i.e. at connection points). Further prevention of damage from wind-rain oscillation and cable fatigue can be applied by the incorporation of isolators or dampers at the base of cable attachments to significantly reduce the oscillation. The location of the pylon and design loading of the structure will need to consider access to the pylon and if the pylon is angled. If a scissor lift or similar alternative is to be used, the structures deck must be able to take the loading and shear forces exerted by the weight of the machinery and accessed safely around the suspension cables. InsInsInspectionIns pection gallery It is common for long span road structures to incorporate inspection galleries and permanent access along the outer edges of the structure for safety of inspection and maintenance. For a 110 m span pedestrian and cycle bridge, the cost of designing and installing a 1 m wide gallery along the length of both sides of the structure would likely outweigh the economic benefits and increase the structures proposed width from 4 m to 6 m. An additional health and safety consideration when designing inspection galleries is restricting access for the public to prevent people from climbing over railings and falling into the river below. Maintaining Steel Steel is typically finished with either a paint protective coating or by galvanisation. Galvanisation protects the underlying steel by coating the exposed steel with a layer of zinc. The zinc acts as a sacrificial anode and it is a more reactive metal and will corrode before the steel, hence protecting the inner steel. Paint protective systems have a typical life of 20 years before the protective coating must be removed and the substrate, repaired where necessary and repainted. The process of repainting a structure in situ is both expensive, time consuming and has a high risk of pollutant materials entering the environment. Although galvanisation has a higher capital cost, the cost of maintenance over the structures lifetime can be more economic. Maintaining concrete The most common defects for reinforced concrete structures are cracking, spalling and delamination of the concrete where the reinforcement has corroded, expanded and “blown off” the concrete at the surface. The most common method for repair is to encapsulate the structure to prevent pollutants entering the surrounding environment and use hydro-demolition to remove the concrete around reinforcement, replace reinforcement if required, and patch repair the concrete to the required finish. Although the cost of the method of repair and equipment required is high, the material and form of construction has a typical life of 80 years before maintenance is required. To reduce deterioration in concrete structures, the design of the concrete mix, steel reinforcement and quality of installation are vital. Different concrete mixes and water, sand, cement and aggregate mixes will have different strengths and properties. Steel reinforcement should have a minimum of 50 mm cover to the outside face of the concrete and the use of vibrating equipment in wet concrete can significantly reduce the amount of trapped air and therefore increase the strength. Health and Safety Designer duties under The Construction Design and Management Regulations (CDM) apply as soon as a designer has been appointed and when designs which may be used for construction work are started. The client shall be made aware of their duties under CDM prior to commencement of any further feasibility or design works are commissioned and a Principal Designer appointed. A brief

consultation with an experienced health and safety professional and Principal Designer representative has been conducted with the following recommendations; • The landfill site and contaminated ground conditions are to be treated as a “red site”. o High risk of settlement and piercing the capping layer releasing leachate and methane. o Obtain methane level records from WCC and locations of any existing flare points on the site and/or if flare points will be required during construction. o Obtain records of capping construction and depth. o Surveys and investigations must be programmed in the winter months when the grass length is short to help identify locations of any sinking areas. o No smoking, drinking or eating on the site at any time unless suitable welfare has been set up with hand washing facilities and a smoking area designated. • Overhead power lines o Required to be grounded, sheathed, switched off or diverted when lifting bridge sections and suspension cables into place. o A safety zone should be modelled and installed throughout the duration of the works in accordance with Guidance Note GS6 – Avoiding Danger from Overhead Power Lines. o The utility owner should be consulted prior to the commencement of detailed design to gather the safe working distances for specific activities, i.e. piling restrictions near overhead powerlines. • Retaining wall at Gheluvelt Park o Structural assessment and ground investigation works will be required to determine the condition and works required to the retaining wall. o Potential additional provisions to prevent cracking and collapse during vibration activities. • Legal o Creation of a new public footpath under section 25 of the Highways Act o Ownership of the structure o Maintaining agent and liability • Information provided o The accuracy of any ground investigations cannot be relied upon. • Public safety o By creation of a new public footpath and cycle way, it is predicted that cyclist traffic on the roads, adjacent residential estates and increase concentrations at junctions. Traffic modelling and a review of the existing road network including a road safety audit should be conducted. • Site access o Access at Gheluvelt park and dates of key events or closures of the park should be noted. o Access for cranes, materials and large construction vehicles and the traffic route should be considered and confirmed. The feasibility of transporting large machinery and steel sections over Barbourne bridge with a 40/44 tonnes weight limit restricting

access form the north of Worcester and tight bending radii of roads through Worcester city centre will require confirmation. o Access for construction machinery from Kepax and the location of the site compound and welfare is to be determined. When planning works to surcharge the landfill for construction access, vehicle turning locations, welfare unit locations, storage areas for materials and access to the structures from all directions for machinery shall be considered. It is a legal offence under the Anti-Pollution Works Regulations 1999 and Environmental Protection Act (EPA) 1990 for polluting matter to enter any controlled waters, i.e. the River Severn.

Options Comparison Table 4 below compares the suitable options. Design factor Tied Arch Truss Cable Stayed • Foundations required for lifting machinery. • Temporary structure support towers to be Temporary Works erected if constructed in two or more • Foundations required for lifting machinery. • Foundations required for lifting machinery. segments. • Excavation supports may be required • Large amounts of excavation required for large foundations and large • Medium amount of excavation required on • Large foundations only required on the side of number/diameter of piles on both sides of both sides of the river. the pylon. the river. • Deep foundations required both sides of • Minimal excavations required in landfill. Foundation • High risk of releasing leachates from the the structure. • Foundations still required on the western side of Requirements landfill site and working in contaminated • High risk of releasing leachates from the the river but can be limited due to the land. landfill site and working in contaminated construction type • Deep and bulky foundations to be able to land. • Minimal risk of exposure to contaminants take large forces and turning moments at connections. • Large crane on one side of the river • Large crane on one side of the river required. required. • Large cranes require large temporary works Construction • Large cranes required both sides of the river • Large cranes require large temporary works foundations Machinery and if constructed in segments. foundations • Site access for crane machinery and delivery equipment • Large pile driving/boring machinery • Site access for crane machinery and vehicles; turning radius and weight limits on the delivery vehicles; turning radius and weight existing network. limits on the existing network. • Largest foundations required • Strong foundations required on both sides • Pile foundations required Foundations of the river • Large foundations on the east side of the river. • Low maintenance • Long lifespan with minimal repairs • High maintenance • High level of difficulty performing • Medium maintenance requirements. Maintenance • High level of difficulty performing maintenance • Specialists required to inspect the tension cables maintenance • Option to install more dampers at a later date usually designed in.

Design factor Tied Arch Truss Cable Stayed • Working at height • Bolting/fixing techniques causing sparks • Lifting of sections and wind movement Construction • Working over fast flowing water • Lifting large sections and wind movement • Installation of cables and tensioning Type Specific • Bolting/fixing techniques causing sparks • Working at height • Working at height Risks • Lifting large sections and wind movement • Working over fast flowing water • Working over fast flowing water • Installation of tensioned hangers • Attractive form of construction • Most intrusive • Most attractive form • Open view over the river from the structure • View over the river obscured by members Aesthetics • Open view over the river from the structure • Working at height • Working at height • Large and eye-catching form • Working over fast flowing water • Working over fast flowing water • Least intrusive form • Specialist inspection equipment required to • Specialist inspection equipment required to Ease of inspect the arch and hangers • Difficult to inspect thoroughly if protective inspect the pylon inspection • Loading for inspection machinery to be paint systems are used. • Loading for inspection machinery to be included included in design calculations in design calculations Table 4 - Options Comparison

Summary of Construction Cost Table 5 details the costs associated with the structure. The costings are based on previous/similar schemes of the same construction and of similar span. The costs are subject to the results of any further investigations required. Structure Type Tied Arch Bridge Truss Bridge Cable Stayed Bridge Cost £2,400,000 £2,100,000 £3,000,000 Foundation Cost £2,700,000 £2,300,000 £1,200,000 Total Cost £5,100,000 £4,400,000 £4,200,000

Whole Life Cost Low High Medium (Order of Magnitude) Table 5 – Summary of Estimated Construction Costs

The costings are purely for the structure type and foundations, they do not include: • Preliminary Works (Ground Investigation, Topographical Survey etc) • Design and Check Costs • Potential Service Diversions • Upgrading / Creating transport links Recommendation for Further Investigations It is recommended that further investigations are carried out to fully develop the proposed option: • Topographical Survey including Lidar Survey Costs: £5,000 Duration: 1 Week Constraints/Assumptions: The topographical survey does not include bed levels and is subject to vegetation coverage

• Ecology Surveys (Preliminary Ecological Appraisal, Bat emergence / re-entry surveys, Bat activity survey, Reptile presence/absence surveys and In-channel examination of river banks for otter and water vole) Costs: £20,000 Duration: Dependant on surveys required, i.e. Bat emergence / re-entry surveys can only be carried out during May to August while the Bat activity survey can only be carried out during May to September. Constraints/Assumptions: The costs associated with the ecology surveys are dependent on the results of the Preliminary Ecological Appraisal and therefore are subject to change.

• Ground Investigation including Boreholes Costs: £25,000 Duration: 8 Weeks Constraints/Assumptions: Ground investigation to be the 1 st phase of a 3 phase investigation with the following phases requirements dependant on the outcome of the 1 st phase. It is assumed that easy access will be available to both sides of the river.

• Archaeological Survey Costs: £10,000 Duration: 2 Weeks Constraints/Assumptions: Cost and duration is dependent on the initial review of the site and the number of trial pits required.

• Traffic Survey and Model Costs: £25,000 Duration: 5 weeks Constraints/Assumptions: Dependant on method of analysis and level of detail required.

• Flood Risk Costs: £10,000 Duration: 2 Weeks Constraints/Assumptions: Assuming the Environment Agency model can be updated

• Network Survey (Plant Access Route / Required Network Improvements) Costs: £25,000 Duration: 4 Weeks Constraints/Assumptions: Costs dependant on the condition of structures on access routes and the number of structural reviews required. Work to follow traffic model and to include network recommendations.

The cost and duration of the works, have been obtained from professionals within their fields and are based on previous similar projects, however these are ‘ball park figures’ and are subject to change dependant on initial review of the location and requirements. Duration of works is for the carrying out of the survey and does not include time required for planning and reporting, which will depend on survey team workloads. The results of these surveys and assessment will be used to update the feasibility report (Cost: £15,000, Duration: 3 weeks) and develop the initial design (Cost: £50,000, Duration: 10 weeks). Again these are provided as indicative costs and are dependant on the extent and detail of the information gained. Summary of Preferred Options and Recommendations In review of the constraints and options discussed within this report, Option A is the most favourable site for the bridge crossing the River Severn between Gheluvelt Park (east side) and the disused Kepax Landfill (west side). The east side of the bridge lands within Gheluvelt Park, the park historically was a water filtration works and therefore the ground conditions are currently regarded as suspect until a full ground investigation is carried out. The west landing point sits within the boundary of the old Kepax Landfill site. The landfill site was capped in 1985, however due to complaints during the capping operation, the thickness of the clay cap is expected to be circa 2 inches (55 mm). It was determined that due to plant access and risks to flooding that the structure would need to span the willow carr area, directly adjacent to the River. It is estimated that the span of the structure will be approx. 110 m (depending on the results of the Ground Investigation). The air draft for boats travelling under the structure will need to be confirmed by the Canals and Rivers trust, however from a review of the surrounding structures it is anticipated to be the greater of either 8 m above summer river level, or the 1 in 100 years flood level (5.74 m) with an additional 600 mm (6.34 m). Three types of structure were considered in depth, as these were the only types capable of spanning the required distance in a single span. These were: • Tied Arch Bridge – Discounted due to large foundations required which substantially increase the total cost of the structure

• Truss Bridge– Discounted due to large foundations required which substantially increase the total cost of the structure • Cable Stayed Bridge – Preferred Option A single pylon (east side) cabled stayed bridge will be able to span the 110 m while reducing the required foundations on the west side of the river within the landfill area. It is anticipated the foundations will need to be piled, with the potential of an end bearing pile as the made ground on both sides of the river will not be able to provide sufficient shaft friction. An estimate of the depth and size of the piled foundation has not been determined, however they are expected to be wider and deeper than the Diglis footbridge foundations. The current estimated cost of construction is £4,200,000 (Bridge Cost - £3,000,000, Foundation Cost - £1,200,000). The cost of the construction has been has put together based on previous schemes of similar type and construction (for example Diglis Bridge which was constructed in 2010 and costed £1,800,000 which is 60 m in span, which is approximately half span). This cost is dependent on the results of the proposed further investigations as specified within ‘Recommendation for Further Investigation’ section and the final design of the structure.

Appendix A – Ecology Assessment

Desk-based Ecological Assessment

Northwick to Hallow, and Ghulvelt to Hallow Road area, Worcester

Completed for Lynsey Keir, Worcestershire County Council

November 2017

Name Position

Author Laura Wood Ecologist

Checked by Cody Levine Principal Ecologist

Project reference Project Contact Revision number Date of issue number Laura Wood 201710/035 01 3rd November 2017 [email protected]

Limitations Severnscape has prepared this report for the sole use of the above named Client or their agents in accordance with our General Terms and Conditions, under which our services are performed. It is expressly stated that no other warranty, expressed or implied, is made as to the professional advice included in this Report or any other services provided by us. This report may not be relied upon by any other party without the prior and express written agreement of Severnscape. The assessments made assume that the sites and facilities will continue to be used for their current purpose without significant change. The conclusions and recommendations contained in this report are based upon information provided by third parties. Information obtained from third parties has not been independently verified by Severnscape.

Contents

1 Introduction ...... 4 1.1 Desk-based Ecological Appraisal ...... 4 1.1.1 Surveyor ...... 4 1.1.2 Survey limitations...... 4 1.2 Site location and description ...... 4 Table 1. Candidate bridge sites...... 4 Figure 1. Potential sites (outlined in red) for a new pedestrian and cycle bridge, north of Worcester City...... 5 2 Methods ...... 6 2.1 Sites designated for conservation and Biodiversity Action Plan Habitats ...... 6 2.2 Notable or protected species ...... 6 3 Results and recommendations ...... 7 3.1 Designated sites and BAP Habitats ...... 7 3.2 Notable or protected species ...... 7 Figure 2. Sites designated for conservation within 1 km of the proposed bridge sites...... 8 Figure 3. Biodiversity Action Plan (BAP) habitat core areas and dispersal extents...... 9 Table 2. Assessment of designated sites within 1 km of the potential bridge site red-line boundaries...... 10 Table 3. Assessment of habitats in potential areas of bridge installation...... 12 Table 4. Assessment of species likely to occur in area of bridge installation...... 15 3.3 Invasive species ...... 19 4 Appendices ...... 20 4.1 Appendix 1 – Local Biological Records Office data ...... 20 Table 5. Records of animal 'species of principal importance' within 1 km of the red line boundary of the northern site (Northwick to Hallow)...... 20 Table 6. Records of animal 'species of principal importance' within 1 km of the red line boundary of the southern site (Gheluvelt to Hallow Road area)...... 23 Table 7. Records of plant 'species of principal importance' within 1 km of the red line boundary of the northern site (Northwick to Hallow)...... 28 Table 8. Records of plant 'species of principal importance' within 1 km of the red line boundary of the southern site (Gheluvelt to Hallow Road area)...... 28 4.2 Appendix 2 – Northwick Marsh SSSI citation ...... 29 4.3 Appendix 3 – Northwick Marsh SSSI Damaging Operations ...... 30

1 Introduction

1.1 Desk-based Ecological Appraisal A desk-based ecological appraisal according with CIEEM guidelines was undertaken in October 2017 as requested by Lynsey Keir for Worcestershire County Council. The objectives of the survey were to establish what habitats and species of conservation interest would be likely to be affected by the installation of a combined cycle and pedestrian bridge over the River Severn to the north of Worcester City and to provide recommendations on appropriate practices to avoid ecological impact. This report is part of a feasibility study to examine the broad implications of a new bridge installation at two candidate sites. 1.1.1 Surveyor The desk-based survey was carried out by Laura Wood from SevernScape Natural and Historical Environment Consultancy, Worcestershire County Council. Laura is experienced in ecological survey and has a thorough understanding of nature conservation legislation, with specific expertise in freshwater ecology. The report was checked by Cody Levine (MCIEEM) who is also an experienced ecologist, with a specialist interest in bat ecology. 1.1.2 Survey limitations It is important to note that a desk-based ecological survey can only address the most obvious features of a site and relies heavily on interpretation of existing habitat and species information. It will typically under-represent the biodiversity of a site. Furthermore, the Worcestershire Biological Records Centre (WBRC) dataset comprises records submitted by amateur and professional naturalists on a voluntary basis. Therefore the dataset cannot be considered a comprehensive compendium of ecological interest within a given area; rather it is simply a 'snapshot' in time recorded by those observers who have shared their records. Absence of data cannot therefore be interpreted as absence of a protected or notable species or habitat, but rather should be considered as an under-recorded or yet-to-be assessed area where further survey might be beneficial. The WBRC database is therefore a 'living' document and should be subject to regular review by users to ensure decisions are based on up-to-date information.

1.2 Site location and description Two potential sites for bridge installation have been identified by the project team (Table 1 and Figure 1). The candidate sites are a short distance apart, spanning the River Severn to the north of Worcester city.

Table 1. Candidate bridge sites. Candidate site Settlement to west Settlement to east National Grid Reference North Hallow Northwick SO83475769 South Hallow Road area Gheluvelt Park / Pitchcroft SO83885655 (Worcester) A new bridge in this area would link riverside rights of way on the east and west banks of the river, facilitating greater public use of the paths.

Figure 1. Potential sites (outlined in red) for a new pedestrian and cycle bridge, north of Worcester City.

2 Methods

2.1 Sites designated for conservation and Biodiversity Action Plan Habitats Sites with statutory and non-statutory designations for conservation were drawn on a map with the red-line boundaries of both candidate bridge sites. Biodiversity Action Plan (BAP) habitats were also plotted, with the buffers around them showing the expected dispersal extents of species within them. The likely ecological implications of both the construction and operational phases of a new bridge development on designated sites and BAP habitats were assessed.

2.2 Notable or protected species Datasets held by Worcestershire Biological Records Centre (WBRC) were searched for records of notable or protected' species found since 2002 within 1 km of the red line boundaries of each candidate site.

1 km was selected as an appropriate radius due to the rural nature of surrounding area (to the south, west and east) and the tendency of aquatic animals to travel along watercourses. A greater distance would have been searched if records of otters (Lutra lutra) and bats had not been returned within 1 km. 'Notable' species are species of 'principal importance' listed under Section 41 of the Natural Environment and Rural Communities Act, 2006. 'Protected' species are those directly protected by wildlife legislation, including: - Conservation of Habitats and Species Regulations 2010: species listed in schedule 2 are protected from deliberate capture, killing, disturbance, or trade. - Wildlife and Countryside Act 1981 as amended: all naturally occurring wild bird species are protected while nesting and inclusion on schedule 1 adds further protection in terms of increased penalties for offenders; inclusion on schedule 5 makes it an offence to intentionally or recklessly kill, injure or take that species or to interfere with places used for shelter or protection; inclusion on schedule 6 protects species from certain methods of taking or killing. - Protection of Badgers Act 1992: protects badgers from wilful killing, injury or taking, ill-treatment, disturbance at a sett and intentional or reckless damage of a sett.

3 Results and recommendations

3.1 Designated sites and BAP Habitats Both candidate bridge sites interact with sites designated for nature conservation (Figure 2). The candidate site to the north directly overlaps with a Site of Special Scientific Interest (SSSI) and therefore is likely to have the greatest constraints with regard to bridge installation. The likely impact of a new bridge on statutory and non- statutory protected sites is assessed in Table 2 and broad habitat categories known to be present are assessed in Table 3.

Core BAP habitats and 'dispersal extent' buffers are shown in Figure 3 with the red- line boundaries of both potential bridge sites. It is clear that the northern site overlaps considerably with these habitats identified for their high value to biodiversity. The south-east corner of the southern site also overlaps with BAP habitat.

Screening / scoping may be advisable to determine whether the scheme could trigger requirements under the Town & Country Planning (EIA) Regulations (2017). In some locations/configurations this desktop scoping exercise has confirmed that there is a considered risk of adverse impact to sensitive ecological receptors.

3.2 Notable or protected species The Worcestershire Biological Records Centre (WBRC) data search returned many records of 'species of principal importance' within 1 km of both potential bridge sites (Appendix 1). The potential impacts of a new bridge on species known, or likely to be, present is assessed in Table 4.

Figure 2. Sites designated for conservation within 1 km of the proposed bridge sites.

Figure 3. Biodiversity Action Plan (BAP) habitat core areas and dispersal extents.

Table 2. Assessment of designated sites within 1 km of the potential bridge site red-line boundaries.

Receptor Assessment Constraints Opportunities Surveys

Statutory Northwick Marshes SSSI A highly sensitive receptor hosting Public engagement and Extensive surveys designations A species-rich marsh in disused brick pits within protected species and scarce habitats. education via interpretation required to establish the River Severn flood plain, supporting interesting See Tables 3 and 4 for protected boards and events, possibly presence / likely botanical and ornithological communities. This species and habitat assessments. with the Pump House absence and locations habitat is very scarce in Worcestershire. See Environment Centre in of protected species. citation in Appendix 2. Floodplain grazing marsh is Disturbance to breeding birds Gheluvelt Park. Commencing with a a priority habitat type included on both UK and the (especially from dogs) is a particular Preliminary Ecological county level Habitat Action Plans. concern. To carefully manage public Appraisal (PEA). access to the SSSI (e.g. by The habitat and species here are very sensitive to Development may not be permitted making access to other areas Hydrological studies disturbance. Improving public access to this area within a SSSI, and adjacent areas must clearer and easier). required to describe is likely to increase the number of people and be carefully protected from the negative impact of increased dogs visiting the SSSI. impacts likely to arise from the To bring meadows adjacent to run-off and ground construction phase and ongoing the SSSI into positive compaction on the The proposed northerly bridge site includes part of increased public access. management by extending the water table within the this SSSI, which would be a major constraint to cattle grazing regime. SSSI. the project. Using fences and gates to control public access is difficult within a flood plain.

Operations that may damage this SSSI are identified in Appendix 3, points 21- 27 are particularly relevant to the bridge proposal. Non-statutory River Severn LWS The river is used by a number of See Tables 3 and 4 for Full ecological surveys designations The UK's longest river flowing north to south protected species which would opportunities specific to will be required at the through Worcester City. The river corridor is potentially be affected by a bridge certain habitats and protected selected bridge site, to subject to pressures along its length including installed at any location. The impacts on species. cover the footprint of development, agriculture, and channelling. habitats and protected species are the bridge, construction considered in Tables 3 and 4. Enhancement for biodiversity access and public Rising in mid-Wales, high rainfall causes the river can be achieved as part of the access. to burst its banks. Both potential bridge sites are Design of the bridge, access paths and bridge project – for example within its floodplain. construction methods must account for by routing pedestrians and A field-based PEA may the sensitivity of this receptor – e.g. by cyclists away from the most influence decisions on It is an important wildlife corridor, being used by a using existing tracks and paths to sensitive areas of bank, the most appropriate number of species (including legally protected access the river bank, not lighting the incorporating nesting / site for a bridge and species) – see Table 4. Some of these species are site during the construction or roosting / hibernation associated access highly sensitive to disturbance (e.g. from lights, operational phases, siting the opportunities for bats, birds routes, and it would people, dogs) and may be affected by increased abutments away from the river bank, and invertebrates. also identify the specific footfall along both banks in addition to disturbance selecting materials with minimal ecological surveys

Receptor Assessment Constraints Opportunities Surveys

at the bridge site itself. maintenance requirements to reduce Public engagement with required prior to making the need for potentially disturbing work nature – see above. a planning application. in the future. Park Meadows GI This habitat and the species that use it Alterations and adjustment to The PEA Part of this Grassland Inventory site is within the may be susceptible to disturbance and the site's management regime recommended above red line boundary of the northern candidate bridge damage from increased footfall along may be possible as part of the should pay particular site. It consists of unimproved neutral grassland the riverside path. bridge project. attention to this GI site, (NVC category MG5) which is a scarce habitat documenting the plant type locally and nationally. MG5 grassland is a UK It is likely to support protected species Public engagement with species found there BAP Priority Habitat. (e.g. badger, otter, great crested newt). nature – see above. and making recommendations for This site is marked on Figure 2 as a point – its full specific species extent should be mapped prior to planning to site a surveys. bridge here. Northwick Marsh GI (see SSSI above) See above See above See above A further six non-statutorily designated sites fall None None None required within a 1 km radius of one or both of the candidate bridge sites (Figure 2). None are directly on the banks of the River Severn or within the LWS = Local proposed red-line boundaries and would be Wildlife Site unlikely to be affected by a new bridge installation.  Laughern Brook LWS GI = Grassland  Worcester and Birmingham Canal LWS Inventory Site  Hallow Mount GI

 Gregory's Bank GI and BAP habitat BAP = Biodiversity  Thornley's Orchard GI and BAP habitat Action Plan  Hanging Hills Meadow GI and BAP habitat

Table 3. Assessment of habitats in potential areas of bridge installation.

Receptor Assessment Constraints Opportunities Surveys

Grassland Both sides of the river are flanked mostly by Valuable grassland assets Potential to put grassland National Vegetation floodplain grassland, some of which is protected could potentially be damaged habitats into positive Classification (NVC) – detailed (Table 2). The southern candidate site has by bridge construction activities management to increase mapping and plant species lists potential access on the east bank via Waterworks and increased numbers of species diversity and to extend for all priority habitats identified Road or Gheluvelt Park (Figure 1), which may pedestrians and cyclists. / contribute to defragmenting with risk of impact (including minimise the need for additional land-take for paths the Grassland Inventory sites floodplain meadows). and the bridge. Within the northern site, areas along the River Severn of grassland are protected (see corridor into Worcester city. NVC or phase 1 habitat The botanical diversity in areas that may be Table 2), which would limit mapping for Gheluvelt Park. affected by the bridge construction works or activities permitted in that area. Gheluvelt Park to the west of increased use by pedestrians and cyclists should The southern site does not the southern bridge site is be mapped prior to finalising the bridge location contain any designated already subject to high footfall, and access routes. protected sites, however the albeit the part adjoining the grassland may still be of high river has less intensive value. management as a nature reserve area. Joining one end of the bridge to the park may reduce ecological concerns for the east bank, although it may also increase the risk of collateral impact by further boosting the number of pedestrians and cyclists on the riverside paths. Thorough surveys of the habitat and species within the park and on the opposite bank that may be affected could help to determine likely impact. Hedgerows Hedgerows are visible on aerial photos along field Existing hedgerow may be To fill gaps in existing A hedgerow survey should be margins within both red line boundaries (Figure 1). protected by the Hedgerow hedgerows. carried out (as part of the PEA A desk-based assessment cannot effectively Regulations (1997). or separately) to evaluate any assess their size or ecological value. If appropriate for the location, hedgerows likely to be subject New hedgerow planting is new hedgerow planting could to works or removal against the potentially restricted by floods, be used to join up existing criteria for 'importance' under which may prevent new plants habitats and to encourage the Hedgerow Regulations establishing. pedestrians and cyclists to (1997). stay on the paths and not to 12

Receptor Assessment Constraints Opportunities Surveys

enter more sensitive habitats. Where an 'important' hedgerow (i.e. a priority habitat) is Once established, new present and likely to be hedgerows may play a role in impacted by the works an NVC regulating water flow at times survey of flood. Riverside Aerial photos show that the river banks are lined Trees may host nesting birds, If tree felling is unavoidable, A PEA should identify and trees with trees with few gaps. The canopy size of some roosting bats, and potentially the deadwood should be assess trees likely to be trees suggests that they are mature. otter holts under waterside retained on site, ideally at the directly impacted by the new Woodland Aerial photos show woodland in the north-west roots. Thorough surveys are outer edge of the floodplain, bridge project (construction corner of the northern bridge site red-line required on any trees that may where it will rot and provide and operational phases). boundary. The Worcestershire Habitat Inventory need to be removed for the valuable habitat for (WHI) identifies this woodland as broadleaved, bridge installation. Felling of invertebrates. If the new bridge installation mixed and yew, with parts of it classified as trees should be avoided where directly affects trees, surveys to Ancient Woodland. possible, and any impact on locate and assess veteran and ancient or veteran trees should ancient trees will be required, Ancient woodland is an irreplaceable habitat. be prevented. also trees with potential to host bat roosts. An NVC survey is Additional lighting spilling onto appropriate for this. trees would disrupt the corridor for commuting bats. Invertebrate and ground flora surveys would help to establish the value of the woodland and inform bridge siting, design and construction activities. Other species that use woodland, including badgers, dormice, breeding birds and otters must also be considered (see Table 4). River Severn See River Severn LWS in Table 2. The river is a very valuable Ecological enhancement of the Otter and water vole surveys habitat and corridor for foraging river bank and the ditches that required before construction to and commuting bats. It is also drain into the river, for plant determine appropriate working important for birds, fish, otters and animal species associated methods to prevent and aquatic invertebrates. with watercourses (e.g. otter, disturbance or injury. See Mitigation and sensitive design water vole, Odonata). species sections in Table 4 would be required to prevent below. adverse impacts – e.g. Education – environmental

Receptor Assessment Constraints Opportunities Surveys

avoidance of damage to the interpretation boards to Work on the river bank, noise and lighting promote engagement with the embankments may also trigger minimisation during construction natural environment. survey work for species and operational phases. associated with other habitat parcels. See Table 4.

Table 4. Assessment of species likely to occur in area of bridge installation. Receptor Assessment Constraints Opportunities Surveys Amphibians Great crested newts (Triturus cristatus) are known If ponds, ditches or hedgerows New scrapes, ditches and The PEA should advise to occur within Northwick Marshes SSSI (Appendix are to be disturbed or damaged ponds could be created within whether or not amphibian 2) within the red-line boundary of the northern amphibian surveys should be the grassland to extend the surveys are required for the bridge site (Appendix 1, Table 5). carried out to inform breeding habitat available to selected bridge site. appropriate working methods amphibians. Ideally these Smooth newts (Lissotriton vulgaris) and common and potentially the need for a would be above regular flood frogs (Rana temporaria) are also recorded within 1 derogation licence. levels. km of the southern potential bridge site (Appendix 1, Table 6), however only one record is along the Within 500 m of the Northwick river corridor. Marshes SSSI bridge / access path design and working Periodic flooding by the river is likely to limit the methods during the suitable terrestrial habitat available to amphibians construction phase should be within the red-line boundary of either potential advised by a competent bridge site, however hedgerow roots may support ecologist. over-wintering newts. Badger There are historical records (Appendix 1) of If directly impacted by the Opportunity to include berry- If the woodland or hedgerows (Meles meles) badgers in close proximity to both potential bridge bridge installation badger setts bearing species in landscaping are impacted by the new bridge sites and the habitats known to be present are may need closure under proposals associated with the installation, a survey for badger highly likely to continue to support badgers. licence from Natural England. bridge to enhance foraging setts should be carried out by a Mitigation may require opportunities for badgers; competent ecologist. retention / creation of suitable opportunities to retain badger foraging habitat and connectivity along the bank. maintenance of habitat connectivity between setts and foraging areas. Bats Bats are very likely to use the habitats identified in All of the habitats identified Potential to improve bat Detailed bat activity surveys (activity) Table 3. have potential to support foraging resources through required (between May and foraging and commuting bats. improved habitat management. October) to determine how the WBRC records (Appendix 1) show five or more bat Bats are sensitive to habitats are used and to inform species in the vicinity, however this figure is disturbance, especially lighting, location and design of the considered to underrepresent the bat diversity which must be accounted for bridge. known to be in the area (e.g. Daubenton's bats during the construction and have not been recorded, but almost certainly operational phases. Bat surveys are restricted to frequent this stretch of river, as they do in nearby the months when bats are Worcester City). active: May to October, although baseline assessments of tree potential are best done when the trees are not in leaf (i.e. winter and early spring).

Receptor Assessment Constraints Opportunities Surveys Bats (roosts) Aerial photos show mature trees on both river Further survey required if any Opportunities to provide A daytime assessment (for banks within both potential bridge sites (see Table tree or structure is affected by enhanced bat roost provision probable bat roosting features) 3). Cracks and cavities within trees have the the new bridge installation. within the bridge or on trees is required if any trees or potential to support bat roosts. nearby. structures are to be removed or Careful and detailed altered. Activity surveys may consideration of lighting is Original and innovative bridge then be required to inform the essential to avoid a negative design could produce a need for a derogation licence impact on bats. fantastic example of a from Natural England. functional conservation Where trees with bat roosts structure. For example a bridge require felling or other works, a in the Netherlands was licence from Natural England designed to host both summer will be required. Mitigation may and winter bat roosts. require replacement bat roosts and maintenance of habitat connectivity. Breeding Northwick Marshes SSSI is known to be an The bird breeding season Enhanced breeding Breeding bird surveys required birds important site for breeding and over-wintering birds (March-August inclusive) opportunities on the bridge prior to any work affecting trees (Table 2 and Appendix 2). restricts when work can be structure (e.g. bird boxes), or grassland. And for all areas carried out on vegetation or above maximum flood height. subject to works within 100 m Other vegetation within both potential bridge sites structures supporting active of the SSSI (due to potential for is also suitable for breeding birds (e.g. hedgerows, nests. Improved management and disturbance of birds during the trees, grassland). habitat creation. operational phase). The management prescription for Northwick Marshes SSSI describes acceptable works within this site and 'potentially damaging' operations that would require consent from Natural England. Fish No records for fish species were returned in the The bridge must be designed Public interpretation features to None required. WBRC database search, however online anglers' to not affect the water flow (i.e. raise awareness of the forums describe this stretch of river as excellent for a single span bridge with ecological value of the LWS coarse fishing. abutments set well back from and the collaborative the bank). conservation efforts being A joint project between the Severn Rivers Trust, undertaken for the Allis Shad the Canal & River Trust, the Environment Agency During construction, care must and other fish species. and Natural England is currently underway to 're- be taken not to deposit dust or open the river' for migrating fish by removing weirs other substances (e.g. or installing fish passes. This project is expected to concrete, paint) in the water. benefit all fish species in the river, including a

Receptor Assessment Constraints Opportunities Surveys number of threated and critically declining species such as Twaite, Allis shad, salmon and the European eel.

A bridge spanning the river without piers or abutments in the water (and altering the flow) is unlikely to negatively impact fish populations, however they are an important consideration during construction due to a high sensitivity to pollution (e.g. dust) in the water. Invertebrates Habitats of specific interest for invertebrates Retention of habitats where The site could easily be Invertebrates covered under include the grassland, mature trees, the river and possible and compensatory enhanced for invertebrates. Section 41 of the NERC Act the traditional orchard south-east of the southern habitat creation or improved See opportunities for scrub may be impacted by works on potential bridge site. habitat management to ensure habitat enhancement in Table a range of habitats (e.g. wet no net loss of diversity. 3. seeps and flushes, ditches, The WBRC holds records of seven 'notable' bare soil, embankments). invertebrate species for the years 2002-2017 within If any trees are to be cut back Survey requirements should be 1 km of the northern site and 15 species within 1 or removed, piles of logs resolved via a PEA when the km of the southern site (Appendix 1). partially buried would provide proposed developmental valuable deadwood habitat for footprint becomes further invertebrates (e.g. beetle refined. larvae) – ideally at the furthest reaches of the floodplain. Baseline surveys of the areas Changing the management that currently offer invertebrate regime for the grassland habitat (e.g. mature trees and outside of the SSSI could grassland) would also enable increase habitat availability for comparison of 'before and after' pollinators. biodiversity. Otter The river corridor offers suitable foraging territory Suitable otter habitat should be Opportunities to provide When a bridge site has been (Lutra lutra) for otters and the woodland within the northern site retained, with a ‘dark buffer’ to improved habitat for otters, provisionally selected, an otter and riverside tree roots may provide holt sites. allow undisturbed use by through habitat management. survey should be carried out otters. Installation of an artificial otter within areas of suitable habitat Within 1 km of both potential bridge sites there are holt would be a suitable low- that will be affected by multiple records of otter sightings (Appendix 1). At the design stage care must cost enhancement. construction activities and be taken not to obstruct greater public access. potential otter routes along the banks – otters often walk along a bank rather than swim, especially when a watercourse is in flood. Reptiles Due to periodic flooding, the terrestrial habitat Grassland that may be lost or Opportunities to provide A competent ecologist should

Receptor Assessment Constraints Opportunities Surveys holds low potential for most reptile species within damaged (e.g. by construction improved reptile habitat – be engaged to carry out reptile the red line boundary, apart from grass snakes vehicle access) should be reptiles would benefit from surveys for the bridge and (Natrix natrix) which usually occur in wetland / surveyed for reptiles, with a positive management of the construction site footprints. aquatic habitats. focus on grass snakes. grassland and river banks. Reptile surveys are restricted to late spring to early autumn. WBRC records for slow worms within 1 km of both By law, widespread reptile sites (Appendix 1) are all outside of the floodplain species such as grass snakes and appear to be in residential gardens. There are may not be deliberately or WBRC grass snake records within the floodplain, recklessly injured or killed, inside the red line boundary of the northerly bridge therefore working methods site. must be designed to avoid harming them, especially during construction.

If riverside paths are to be surfaced it is important to avoid interaction between basking snakes (attracted to tarmac warmed in the sun) and cyclists or dogs. Very wide hard surfaces could functionally sever access between the water and grassland habitats used by grass snakes.

The design of cycle ways and footpaths and associated drainage must be sensitive to wildlife to avoid impact (e.g. entrapment in drains and severance of habitats). Water vole There are no records of water voles on this stretch Habitats to be retained where Opportunities to provide Water voles are highly unlikely (Arvicola of the River Severn. A single record returned from possible with a ‘dark buffer’ to improved habitat for water vole, to be present due to recorded amphibius) WBRC is on the Laughern Brook to the south-west allow undisturbed use by water through habitat presence of antagonistic of the site. vole in future. management/creation and species (i.e. mink). Further control of access by people survey requirements can be and dogs. resolved through subsequent PEA site-based appraisals. If required, water vole surveys may be conducted alongside otter surveys.

3.3 Invasive species In common with many other water courses in the UK, the River Severn in Worcester has large stands of the invasive plant Himalayan balsam (Impatiens glandulifera) along its banks. Japanese knotweed (Fallopia japonica) is also present on the river banks a short distance south in Worcester City. Causing or allowing either of these species to spread is a criminal offence under the Wildlife and Countryside Act (1981) as amended. Therefore suitable precautions and working practices should be devised with the advice of a competent ecologist or environmental consultant and made clear within development plans (e.g. within a Construction Environmental Management Plan [CEMP]).

4 Appendices

4.1 Appendix 1 – Local Biological Records Office data

Table 5. Records of animal 'species of principal importance' within 1 km of the red line boundary of the northern site (Northwick to Hallow). Position relative to Species northern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) Insect - beetle Oedemera Oedemera 2013 1.00 S (Coleoptera) (Oncomera) femoralis (Oncomera) femoralis 2011 0.09 ESE 2011 0.83 SE Insect - Gomphus 2011 1.16 N dragonfly Common Club-tail vulgatissimus (Odonata) 2011 1.22 ESE 2011 1.22 ESE 2016 0.64 N Bombus Brown-banded Carder- (Thoracombus) 2008 0.93 WSW Insect - bee hymenopteran humilis Hylaeus pictipes Little Yellow-face Bee 2008 1.08 SW Insect - moth Spilosoma lubricipeda White Ermine 2015 1.15 SSW Ctenophora Ctenophora 2011 1.39 S Insect - true pectinicornis pectinicornis fly (Diptera) Norellia spinipes Norellia spinipes 2015 0.35 WNW 2011 0.69 NW Amphibian Triturus cristatus Great Crested Newt 2011 1.23 NE 2011 1.23 E Anguis fragilis Slow-worm 2016 0.63 E Reptile 2016 0.69 E 2011 0.69 NW Natrix natrix Grass Snake 2015 1.15 SSW Alcedo atthis Kingfisher 2010 1.15 SSW 2007 0.25 ENE 2011 1.08 SE Cuculus canorus Cuckoo 2011 1.26 NW 2011 1.26 NW Emberiza citrinella Yellowhammer 2006 1.39 NE 2007 0.25 ENE 2007 0.25 ENE Bird 2007 0.25 ENE 2007 0.25 ENE Emberiza schoeniclus Reed Bunting 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2009 1.15 SSW Falco peregrinus Peregrine 2010 1.15 SSW

Position relative to Species northern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) Milvus milvus Red Kite 2011 1.37 SE 2006 0.25 ENE Muscicapa striata Spotted Flycatcher 2006 0.35 ENE 2007 0.25 ENE 2007 0.25 ENE Passer domesticus House Sparrow 2007 0.25 ENE 2011 1.37 SE 2013 0.80 SSW 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE Sturnus vulgaris Starling 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE Turdus iliacus Redwing 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE Turdus philomelos Song Thrush 2007 0.25 ENE 2007 0.25 ENE 2007 0.25 ENE 2011 1.37 SE 2012 1.12 NW 2007 0.25 ENE Turdus pilaris Fieldfare 2007 0.25 ENE 2012 1.19 NW Vanellus vanellus Lapwing 2006 1.39 NE 2003 0.84 E 2003 1.33 NW Mammal Erinaceus europaeus Hedgehog 2003 1.40 SE 2004 1.09 S 2004 1.37 NE

Position relative to Species northern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) 2015 1.08 ENE 2015 1.15 ENE 2016 0.92 SSW 2016 1.03 NE 2016 1.10 S 2016 1.35 S 2004 0.87 SSW 2010 0.99 NNW 2011 0.09 ESE Lutra lutra Otter 2013 1.00 S 2014 1.05 SSW 2014 1.12 SSW 2014 1.34 SE 2004 0.30 Redacted 2004 1.12 Redacted 2009 1.12 Redacted 2010 0.57 Redacted Meles meles Badger 2010 0.60 Redacted 2011 1.43 Redacted 2014 1.52 Redacted 2015 1.17 Redacted 2011 0.99 E Unidentified Myotis bat Myotis sp. 2011 0.99 E species 2016 0.65 NNW Myotis nattereri Natterer's Bat 2011 0.70 NW 2011 0.32 ENE 2011 0.70 NW 2011 0.99 E Nyctalus noctula Noctule 2011 0.99 E 2016 1.37 ENE 2016 1.37 ENE 2003 0.71 SSW 2003 1.33 NE 2005 1.45 SE 2011 0.32 ENE 2011 0.70 NW Pipistrellus pipistrellus Common Pipistrelle 2011 0.99 E 2011 0.99 E 2012 1.12 NW 2012 1.12 NW 2016 0.65 NNW 2016 0.65 NNW

Position relative to Species northern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) 2016 1.37 ENE 2016 1.37 ENE 2003 0.83 SSW 2003 1.21 ESE 2005 1.45 SE 2011 0.32 ENE 2011 0.70 NW 2011 0.99 E Pipistrellus pygmaeus Soprano Pipistrelle 2011 0.99 E 2012 1.12 NW 2016 0.65 NNW 2016 0.65 NNW 2016 1.37 ENE 2016 1.37 ENE 2003 0.71 SSW 2011 0.99 E Plecotus auritus Brown Long-Eared Bat 2011 0.99 E 2012 1.26 NW

Table 6. Records of animal 'species of principal importance' within 1 km of the red line boundary of the southern site (Gheluvelt to Hallow Road area). Position relative to Species southern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) Apteropeda globosa Apteropeda globosa 2016 1.17 SSW Chrysolina oricalcia Chrysolina oricalcia 2015 1.09 S Insect - beetle Hippodamia (Adonia) Adonis' Ladybird 2016 1.37 SW (Coleoptera) variegata Oedemera Oedemera 2013 0.60 NNW (Oncomera) femoralis (Oncomera) femoralis Limenitis camilla White Admiral 2015 1.21 SSW Insect - White Letter butterfly Satyrium w-album 2013 1.17 SSE Hairstreak Common Club-tail 2011 0.66 S Common Club-tail 2011 0.16 ENE Insect - Gomphus Common Club-tail 2011 0.16 ENE dragonfly vulgatissimus (Odonata) Common Club-tail 2011 0.58 NNE Common Club-tail 2011 1.12 WNW Common Club-tail 2011 1.20 ESE Bombus (Psithyrus) Red-tailed (Hill) 2015 1.16 S Insect - rupestris Cuckoo Bee 2015 1.16 S hymenopteran Hylaeus pictipes Little Yellow-face Bee 2008 1.11 NNW Insect - moth Arctia caja Garden Tiger 2014 0.72 ESE

Position relative to Species southern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) Cirrhia icteritia Sallow 2015 1.29 SSW Spilosoma lubricipeda White Ermine 2015 0.78 N Tyria jacobaeae Cinnabar 2011 1.39 ESE Ctenophora Ctenophora 2011 0.54 WSW Insect - true pectinicornis pectinicornis fly (Diptera) Volucella zonaria Volucella zonaria 2015 0.63 SE 2007 1.28 SSW Lissotriton vulgaris Smooth Newt 2015 1.21 SSW 2017 1.20 SSW Amphibian 2012 0.57 SSE Rana temporaria Common Frog 2015 1.21 SSW 2017 1.20 SSW 2015 1.27 NE Anguis fragilis Slow-worm 2016 1.17 NNE Reptile 2016 1.24 NNE Natrix natrix Grass Snake 2015 0.78 N 2010 0.62 S Alcedo atthis Kingfisher 2010 0.78 N 2007 1.26 W Cuculus canorus Cuckoo 2011 0.62 NE 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W Emberiza schoeniclus Reed Bunting 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W 2009 0.78 N Bird Falco peregrinus Peregrine 2009 1.49 SE 2010 0.78 N Falco subbuteo Hobby 2015 1.25 SE Larus argentatus Herring Gull 2013 0.99 WSW Milvus milvus Red Kite 2011 0.42 E 2006 1.25 W Muscicapa striata Spotted Flycatcher 2006 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W Passer domesticus House Sparrow 2007 1.29 SW 2007 1.29 SW 2007 1.29 SW 2011 0.42 E

Position relative to Species southern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) 2013 0.66 NW 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W Sturnus vulgaris Starling 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W Turdus iliacus Redwing 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.29 SW 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W 2007 1.26 W Turdus philomelos Song Thrush 2007 1.26 W 2007 1.26 W 2007 1.29 SW 2007 1.29 SW 2007 1.29 SW 2011 0.42 E 2007 1.26 W Turdus pilaris Fieldfare 2007 1.26 W 2017 1.17 SSW Turdus viscivorus Mistle Thrush 2017 1.18 SSW Arvicola amphibius Water Vole 2014 1.30 SW 2002 0.54 SSE 2002 0.82 S 2003 0.32 S Mammal 2003 1.32 NNE Erinaceus europaeus Hedgehog 2004 0.48 N 2014 1.04 SW 2016 0.58 N 2016 0.72 NNW

Position relative to Species southern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) 2016 1.34 NE 2004 0.85 NNW 2007 0.69 S 2011 1.12 WNW Lutra lutra Otter 2013 0.60 NNW 2014 0.38 E 2014 0.68 N 2014 0.75 NNW 2002 1.25 Redacted 2004 0.97 Redacted 2005 0.31 Redacted 2006 0.93 Redacted 2008 0.47 Redacted 2009 0.64 Redacted 2009 0.68 Redacted 2010 0.97 Redacted Meles meles Badger 2010 1.27 Redacted 2010 1.36 Redacted 2011 0.52 Redacted 2014 0.86 Redacted 2015 0.28 Redacted 2015 0.87 Redacted 2015 0.89 Redacted 2015 1.11 Redacted 2011 0.41 NNW 2011 0.41 NNW 2012 1.34 SW Myotis sp. Unidentified Myotis bat 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2011 0.41 NNW 2011 0.41 NNW Nyctalus noctula Noctule 2011 1.31 W 2012 1.34 SW 2012 1.34 SW Pipistrellus sp. Pipistrelle sp. 2013 1.34 SW 2003 0.73 NW 2004 0.80 SSE 2005 0.42 S Pipistrellus pipistrellus Common Pipistrelle 2007 0.80 SSE 2009 0.80 SSE 2011 0.41 NNW

Position relative to Species southern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) 2011 0.41 NNW 2011 1.31 W 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2014 1.05 SSE 2014 1.05 SSE 2015 1.29 SSW 2017 1.21 SSW 2003 0.13 ENE 2003 0.76 NNW 2005 0.42 S 2007 0.80 SSE 2011 0.41 NNW 2011 0.41 NNW 2011 1.31 W 2012 1.34 SW 2012 1.34 SW Pipistrellus pygmaeus Soprano Pipistrelle 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2012 1.34 SW 2014 1.05 SSE 2017 1.21 SSW 2017 1.43 SSW 2003 0.73 NW 2011 0.41 NNW Plecotus auritus Brown Long-Eared Bat 2011 0.41 NNW 2012 1.34 SW

Table 7. Records of plant 'species of principal importance' within 1 km of the red line boundary of the northern site (Northwick to Hallow). Position relative to Species northern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) Conifer Pinus sylvestris Scots Pine 2013 0.87 SE Geum rivale Water Avens 2008 1.34 SSW Hyacinthoides non-scripta Bluebell 2013 0.87 SE Flowering Populus nigra Black-poplar 2005 0.25 ENE plant Saxifraga granulata Meadow Saxifrage 2004 1.52 SE Tilia platyphyllos Large-Leaved Lime 2012 1.44 SE

Table 8. Records of plant 'species of principal importance' within 1 km of the red line boundary of the southern site (Gheluvelt to Hallow Road area). Position relative to Species southern site Record Taxon Distance to year Latin name Common name centre of site Direction (km) Conifer Pinus sylvestris Scots Pine 2013 0.47 NNE Fern Adiantum capillus-veneris Maidenhair Fern 2015 0.76 SE 2005 1.22 S Blackstonia perfoliata Yellow-wort 2016 1.13 S Geum rivale Water Avens 2008 0.91 W Hyacinthoides non-scripta Bluebell 2013 0.47 NNE Flowering Populus nigra Black-poplar 2005 1.26 W plant 2015 1.21 SSW Ranunculus flammula Lesser Spearwort 2017 1.20 SSW Saxifraga granulata Meadow Saxifrage 2004 0.86 ENE 2003 0.85 S Tilia platyphyllos Large-Leaved Lime 2012 0.76 ENE

4.2 Appendix 2 – Northwick Marsh SSSI citation

4.3 Appendix 3 – Northwick Marsh SSSI Damaging Operations

Appendix B – C2 Plans

Appendix C – Preliminary Geo-Environmental Study

III

TECHNICAL MEMORANDUM Kepax Pedestrian/Cycle Bridge – Preliminary Geotechnical and Geoenvironmental Feasibility Technical Memorandum

PREPARED FOR: Worcester County Council TITLE Geotechnical and Geoenvironmental Feasibility Technical Memorandum PREPARED BY: Nathan Cummins/Tanya Walsh CHECKED BY Elisabeth Andrews REVIEWED BY: Graham Dowlen DATE: 17 May 2018 PROJECT NUMBER: 694944.BA.23.00 REVISION NO.: 0 APPROVED BY: FILE NAME: 20180523_Kepax_Prelim_DS_TW -grd_EAck 1. Introduction CH2M has been commissioned by Worcester County Council (WCC) to conduct a Geotechnical and Geoenvironmental feasibility study for a proposed pedestrian and cycle bridge across the River Severn. The location for the proposed structure has been determined by WCC to improve walking and cycling routes to the north of Worcester city. A new east-west link and pedestrian/cycle crossing of the River Severn would have utility value with the nearby residential areas, university on the west and open green spaces being linked and enable circular leisure walks and bike rides along the river. A new crossing would encourage greater utilisation of the meadow to the west, create new attractive transport links to the university and city centre and encourage more walkers and less vehicular traffic. The nearest existing pedestrian crossing of the River Severn is Sabrina Bridge approximately 1 mile south of the proposed location and the nearest northern river crossing is at Holt Fleet, approximately 5 miles away. The purpose of this technical memorandum is to provide a review of readily available data to identify the significant geotechnical, geological and geoenvironmental issues that may affect the scheme. This memorandum should be considered as a high-level assessment to inform WCC’s consideration of the feasibility of the scheme. In addition, this memorandum includes recommendations for future geotechnical and geoenvironmental phases of work, to further inform the proposed development. Further consideration of the following issues may be needed prior to the commencement of the project, although a review of these is beyond the scope of this memorandum: • Environment; • Geomorphology; • Ecology; • Archaeology; • Utilities; • Land ownership. As the scheme develops and the concept design is finalised, this memorandum and the recommendations herein should be reviewed and updated if the proposed works vary substantially

1 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM from what has been assumed in Section 5Error! Reference source not found. . The following information is appended to this report: • Drawings: o Site Location Plan; o Borehole Location Plan; o Proposed Works; o Historical Map (1922 to 1969); o Geotechnical and Geoenvironmental Preliminary Constraints Plan. • Appendix A contains existing borehole records. 2. Compliance with British Standards and Eurocode 7 Eurocode 7 - Geotechnical design - Part 2: Ground investigation and testing (BS EN 1997-2) requires that a Desk Study is completed prior to Ground Investigation (GI) being undertaken. British Standard, Code of Practice for Ground Investigation (BS 5930:2015) provides guidance on the application of BS EN 1997-2 and states that “The desk study and field reconnaissance should be carried out as the first stage of an investigation to enable an initial ground model to be developed, based upon the available information, and to plan the scope of the initial and subsequent stages of the investigation. A desk study and field reconnaissance should be carried out before a ground investigation programme is designed in accordance with the sequence specified in BS EN 1997-2:2007”. As outlined in Section 1, this report is provided as high-level guidance, and does not constitute a Eurocode 7 compliant desk study. Further recommended work is referred to in Section 12. 3. Site Description The site is located in north Worcester, 1 mile north of Sabrina Bridge and located between Gheluvelt Park on the east side of the river, and the site of a disused landfill site, formally owned by Kepax, on the west side of the river (Ref 7). Gheluvelt Park is owned by Worcester City Council and is split into two main areas; the more formal area that runs from Barbourne Road to Barbourne Brook, and the less formal area west of Barbourne Brook to the R. Severn (Ref 7). Waterworks Road lies to the south of the park, with houses backing onto the park at north. Waterworks Walk runs from north to south through the park. An electricity sub-station is present to the southwest of the park. A borehole location plan (See Drawings – WCC (2013), Hallow Road Landfill Site) provided within a “Freedom of information” request shows that the main crest of the slope lies at an elevation of some 18.3m AOD (above ordnance datum), with the toe at a level in the order of 14.7m AOD. Anecdotally, the landfill site has not been formally capped. In the WCC (2017), “Pre-feasibility into the siting of a new pedestrian/cycling bridge crossing the River Severn, Worcester”, it is stated that the landfill site was decommissioned in December 1985. During the subsequent capping operations, it is reported that local neighbours complained about the nuisance and disruption being caused by the import of capping material. Import operations were ceased, and the available material was spread across the site, resulting in a sub-optimal thickness of capping material being placed. 4. Site Walkover Findings A site walkover was undertaken on the 21 st March 2018 by a Principal Geoenvironmental Engineer and a Senior Engineering Geologist. The weather conditions at the time were clear and sunny. The following descriptions are based on the observations, some of the pertinent ones are presented in Drawings – Geotechnical and Geoenvironmental Preliminary Constraints Plan.

2 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM 4.14.14.1 Hallow Road Landfill Site ––– WestWesternern Extent of Proposed Bridge The western bank of the River Severn comprises the former Hallows Road Landfill site. The site is accessed via Riverview Close located on the western boundary of the Hallow Road Landfill site, and the access road to a local tip/household recycling centre. The site comprises a generally flat area, approximately 0.15km 2 in size. The River Severn lies to the east of the former landfill site. There are also some monitoring stations situated within and adjacent to the landfill site. The eastern extent of the landfill is a circa 3 to 4m high slope falling steeply to the east (approximately 25 degrees). An overgrown ditch is present at the crest of the slope. No water was observed to be present in this ditch at the time of the walkover. Approximately 20m east of the toe of the slope is another circa 0.5m deep ditch which was observed to have flowing water within it at the time of the walkover. Wooden sleepers provide access from the crest to the toe of this slope, the slope is covered with shrubs. At the toe of the slope, a densely wooded area comprising semi-mature trees.; this wooded area extends to the river bank, approximately 55m. 5m further east lies a fence. The Severn Way footpath is present circa 20m from the river bank and extends along the length of the river in a generally north-south orientation. At the proposed location of the bridge, the River Severn is 40m wide and flows from north to south. From the slope toe of the landfill extent to the river, the land is generally flat with a gradual gradient to the east. The Kepax site is an unnatural raised structure made from household and industrial waste with imported soil used as a capping layer for the disused disposal site. The topography of the land is generally flat with several measuring stations dotted throughout the site. Goat tracks can be seen where members of the public walk. The lower terrace area is densely wooded, and has a small slow-flowing ditch. A redundant steel gantry structure and manhole feature are present, which the borehole location plan identifies as a Monitoring Station. 4.24.24.2 Gheluvelt Park East Site ––– Eastern Extent of Proposed Bridge The east side of the River Severn comprises Gheluvelt Park, a public open space. In the approximate location of the proposed bridge, the site lies approximately 4m above the river level, retained by a concrete wall. The western half of the Park has two sealed surface paths that skirt the parkland, although these are of limited width (approx. 1.2m wide). The Pump House Environmental Centre is present to the southwest of the park and in this location, there is visual evidence of buried services in the form of covers e.g. water, electric covers were noted. The area is generally flat and made up of short grassland with small areas of immature trees. The northwest corner of the park gently slopes away from the Pump House, forming two distinct levels to the land that borders the River Severn. The height difference here is between 3 and 5m. 5. Proposed Works A plan of the proposed structure and its location is presented in drawing 90.01 in Appendix A in addition to a Geotechnical and Geoenvironmental Preliminary Constraints Plan. 6. Available Data Sources The following data sources have been reviewed: • British Geological Survey (BGS) for geological maps, existing ground investigation records, memoirs; • Ordnance Survey mapping; • Historical mapping;

3 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM • Natural England; • Worcestershire County Council – existing site information; • Data provided via a freedom of Information Request; • Environment Agency resources. 7. Historical Development A review of online historical maps, by use of the National Library of Scotland, indicates that the sub- areas have remained largely unchanged since the first available OS mapping. Table 1 summarises the main changes. Table 1 – Historical Development - Key developments identified from historical maps between 1886 and 1969 Year Map Scale Key developments

1886 OS 6-inch series East: • The site is occupied by a number of structures (tanks/filters) associated with the “City Water Works”; • A small watercourse meanders through the site, to the north of the structures, and discharges into the River Severn; West: • The west side of the river is undeveloped, being identified as “Liable to Flood”; • There appears to be a network of small water courses/drainage ditches within the site.

1905 OS 6-inch series East: • A small terrace of houses is shown slightly to the south of the outfall of the watercourse; West: • A flood prevention bund has been constructed along part of the river frontage to the south of the proposed bridge location.

1930 OS 6-inch series East: • The watercourse is no longer shown (probably partially culverted), other than a short section immediately prior to the discharge location; West • The flood bund has been extended northwards, adjacent to the river to include the area of the proposed bridge.

1947 OS 6-inch series East: • No change West: • No change

1952 1:25000 maps East: • No change West: • An overhead cable is shown crossing the site in a north-to-south direction. There is a single pylon shown, positioned towards the centre of the site; • The area is no longer recorded as being subject to flooding, however it is possible that such information was no longer recorded on such maps; • A feature referred to as the Kepax Ferry is shown.

1922 1:1,180 WCC East: to Map • A water works containing filter beds and water tanks is shown in the location of 1969 Gheluvelt Park. The building known now as the Pump House is present; • Waterworks Walk dissects the site in an approximate north-south orientation; West:

4 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM

Year Map Scale Key developments • Not present on mapping.

Notably, the WCC “Pre-feasibility into the siting of a new pedestrian/cycling bridge crossing the River Severn, Worcester”, states that “the landfill site was decommissioned in 1985”. Further, the response to the Freedom of Information enquiry described the site as “ old County Council Landfill site that was tipped between 1963 -1985.”. The foregoing historical development of the site has been established by reviewing publicly available factual data. Further work will be required to ascertain the history of the site’s development post 1952, see Section 9.0 Recommendations. 8. Conceptual Ground Model British Geological Survey (BGS) online resources have been utilised to indicate the ground conditions underlying the site, these are: • “Geology of Britain” viewer; • Geological Map Sheet 199; • Existing Ground Investigation logs; • Lexicon – this provides a general indication of the characteristics of underling geologies. 8.18.18.1 Superficial geology Hallow Road Landfill Site ––– Western Extent of Proposed Bridge Geological mapping indicates that superficial geology underlying the western extent of the proposed bridge comprises made ground overlying alluvial deposits. The BGS Lexicon describes the alluvial deposits as “Clay, Silt, Sand and Gravel”. Underlying the alluvium are the Terrace Deposits of the River Severn. Three types of terrace deposits may be present underlying the site: • Power House Terrace Deposits (first terrace). Pebbly, silty sand/sandy silt; sandy gravel, silty clay and peat; • Worcester Member (second terrace). Cross bedded gravels and sands; pebbles mostly Triassic quartzites, together with flints 'Irish Sea erratics' and others, including Jurassic and "Malvernian" clasts; • Holt Heath Sand and Gravel Member (third/Main terrace). Gravel overlain by sand; a high proportion of the gravel includes exotic clasts from Scotland, Lake District and Malvern Hills; third terrace of the River Severn, also known as the 'Main Terrace'; part of the Severn Valley Formation. The subsequent infilling of the site as a former landfill would result in the presence of an unknown depth and probably highly variable Made Ground deposits overlying the superficial deposits. Gheluvelt Park East Site ––– Eastern Extent of Proposed Bridge Sands and gravels are present in the areas surrounding the site boundary, with the present adjacent to the River Severn, and the present overlying this, and therefore may be present within the site. The presence of a historic water works at the current Gheluvent Park site indicates the potential for made ground of unknown depth and composition in addition to the presence of buried structures. The viewer does not record any superficial deposits as being present beneath Gheluvelt Park, to the east of the river. This is assumed to mean that the site has not been geologically logged, rather than there being an absence of superficial deposits

5 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM Summary TTThe following superficial deposits are anticipated to be present on both sides of the river: • Made Ground; • Alluvium; • River Terrace Deposits. 8.28.28.2 Bedrock geology The viewer shows that the bedrock geology underlying the whole of the study area comprises mudstones of the Sidmouth Mudstone Formation part of the Mercia Mudstone Formation of Triassic age. The Sidmouth Mudstone Formation strata are described as “dominantly mudstone and siltstone, red-brown with common grey-green reduction patches and spots. The mudstones are mostly structureless, with a blocky weathering habit, but intervals up to 15m thick of interlaminated mudstone and siltstone occur within parts of the formation. Units of halite up to 400m thick are present at several stratigraphical levels in the thicker basinal sequences of the East Irish Sea, Cheshire, Staffordshire, Cleveland, Worcestershire, Somerset and Dorset, though are most prevalent towards the top. Breccias produced by contemporaneous dissolution of salt are common throughout the formation”. Gypsum/anhydrite also occurs throughout the formation as nodules and veins. 8.38.38.3 AvailAvailableable Borehole Records The BGS’s viewer includes records of historical boreholes to the east of the river, within Gheluvelt Park. There are in excess of 20 exploratory holes recorded within Gheluvelt Park, and appear to be of two eras: some holes are undated, but are reported in imperial units, and relate to the “Worcester, North Sewerage Scheme”. Others are dated 1995, and relate to the Barbourne W.T.W. Redevelopment scheme. The records of the latter era are considered to be the more relevant to the current study. The exploratory borehole logs discussed are included in Appendix A of this report. Borehole BH1 (BGS Record number SO85NW 59), located close to the River Severn, encountered Made Ground from ground level (15.8m AOD) which extended to 4.8m depth (11.0m AOD). The Made Ground was described as “stiff becoming firm reddish brown and dark brown sandy (fine to medium) silty clay with occasional fine to medium subangular gravel of mixed lithologies, brick and coal” and with gravel sized fragments of brick below 1.0m depth. The Made Ground was underlain by a “soft greenish grey sandy to very sandy (fine to course) slightly clayey SILT with occasional to some fine to medium occasionally coarse subangular to subrounded gravel of coal and mixed lithologies”; this material is considered to be alluvium, and attained a thickness of 4.2m in BH1, extending to a depth of 9.0m below ground level (6.8m AOD). The alluvium was underlain by a “medium dense brown to dark brown slightly sandy to sandy fine to coarse subrounded to rounded GRAVEL of mixed lithologies, potentially the Worcester Member.

Other exploratory holes elsewhere within Gheluvelt Park, for example WS5 (BGS Record reference SO85NW 80), located approximately 90m east of BH1, encountered only 1.1m of Made Ground, which was underlain directly by a reddish-brown sand at 14.4m AOD, and was proven to a depth of 3.6m, where a reddish brown sandy silty clay was present (11.9m AOD). There are no boreholes within the Kepax landfill site shown on the BGS viewer. 8.48.48.4 HydroHydrologylogylogylogy It is understood that the River Severn floods onto a lower terrace of the River Severn, on the western bank, periodically. The flood maps viewable through www.data.gov.uk (ref. 9) confirm this, with the area level with the river being a flood Zone 3, and much of the west site being classified as a flood zone 2. Ordnance Survey mapping indicates that the River Severn flows from north to south.

6 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM Barbourne Brook lies to the north of Gheluvelt Park and Ordnance Survey mapping indicates that this flows from east to west. 8.58.58.5 Hydrogeology A groundwater strike was only recorded in one existing exploratory hole at 2.2m bgl. The standing water level in this hole was 1.3m bgl. Due to the close proximity of the sub-areas to Mill Bourne and other watercourses, the groundwater is anticipated to be in continuity with the river levels. The following groundwater designations apply to the geological units within the study area (www.environment-agency.gov.uk/ ): • Superficial deposits: Secondary A aquifer (‘permeable layers capable of supporting water supplies at a local rather than strategic scale, and in some cases forming an important source of base flow to rivers. These are generally aquifers formerly classified as minor aquifers ’). • Bedrock geology: Secondary A aquifer The site does not lie within a groundwater Source Protection Zone. The site lies within an area described as minor aquifer of intermediate to high vulnerability. 8.68.68.6 Previous Ground Investigations WCC provided tabulated data for the boreholes within and outside of the landfill site, however graphical logs were not provided. The pertinent data is summarised in Tables 2 and 3 below; however, it should be noted that there appear to be omissions of certain data. These omissions should be verified, either by examination of the final borehole record logs, and/or by undertaking field monitoring of the wells. 8.78.78.7 Geoenvironmental Monitoring Data A detailed assessment of the available results isn’t possible for the purpose of this technical memorandum; the results are of a significant age, and the format of the results would require a significant amount of processing. Therefore, a brief summary of the pertinent findings of the testing and monitoring data is presented below. Landfill Gas Many of the gas monitoring data were from wells installed within the assumed footprint of the landfill, adjacent to the residential dwellings (installations PW1-12 inclusive). Concentrations of methane were recorded up to 79.1% v/v within installations PW17. The concentrations within PW01–OW12 were significantly lower than those within the installations located in the main body of the landfill. Although high gas concentrations were reported, the gas flow rates were modest, with a highest reported gas flow rate of 2.9l/hr in PW13. Methane concentrations outside the assumed footprint of the landfill were negligible, suggesting that alluvium deposits are unlikely to be a significant source of soil gases. Leachate Data An initial screen of the data from the 11 sampling points has shown that elevated concentrations of the parameters typically associated with general groundwater quality (ammoniacal nitrogen, conductivity, salinity, biochemical oxygen demand and chemical oxygen demand) are all significantly elevated over typical groundwater parameters. In addition, it appears that leachate levels (i.e. meters bgl) within the landfill fluctuate significantly; there are significant differences between the maximum and minimum reported leachate levels within each of the wells which were monitored. However, in the absence of borehole logs, it is not possible to determine whether the installations were installed solely within the landfilled material.

7 TECHNICAL MEMORANDUM

Table 222 ––– Summary of factual borehole data within Hallows RoaRoadd landfill site (Source ––– WCC) Gravelly Brown Clay Sand & Mercia Borehole Waste Installation Clay (Alluvium) Gravel Mudstone Formation at base of borehole Thickness Base of GL Base Top Base Top Top Top Top Top of screen (m) installation

PW05 20.9 13.9 ?? ?? ?? ?? 20.2* 17.1 16.1 ?? ?? MUDSTONE

PW06 21.4 13.4 19.9 13.8 6.1 13.8 ?? ?? ?? ?? ?? Gravelly CLAY

PW07 21.3 12.8 19.9 14.0 5.9 ?? ?? 14.0 ?? ?? ?? GRAVELS

PW08 20.8 12.1 19.6 12.1 7.5 ?? ?? ?? ?? ?? ?? WASTE

Firm reddish brown sandy gravelly PW13 20.5 12.5 20.5 12.6 7.9 12.6 ?? ?? ?? 17.5 12.7 CLAY with occasional cobbles.

PW17 20.8 11.1 20.8 ?? ?? ?? ?? ?? ?? 17.8 11.4 WASTE All units are m AOD unless otherwise stated ?? data not provided * considered to be unreliable data

The data in Table 2 indicates that typically, the site lies at an elevation of 20.5 – 21.5m AOD, with waste deposits attaining a thickness of typically 6 – 8m. The waste typically comprises gravelly clay or sand and gravel. PW05 suggests that alluvium is present at 20.2m AOD; this is anticipated to be incorrect, and alluvium would be anticipated to be present at a lower elevation. It is concluded that there is no basal liner to the landfill, either in the form of an engineered liner (typically compacted clay or manufactured), nor is there a naturally low-permeability material present.

8 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM

Table 333 ––– Summary of factual borehole data outside Hallows RoRoadad landfill site (Source ––– WCC) Gravelly Brown Clay Sand & Mercia Borehole Waste Installation Clay (Alluvium) Gravel Mudstone Formation at base of borehole Thickness Base of GL Base Top Base Top Top Top Top Top of screen (m) installation

M5 25.3 13 - - - 24.4 21.3 1.1 20.2 3.1 - - MUDSTONE

W1 25.9 8.08 25.88 18.48 7.4 18.5 Absent 17.9 11.7 8.7 MUDSTONE

W6 13.9 6.36 13.86 11.06 2.8 11.1 7.9 0.3 7.56 3.2 7.9 6.6 Reddish brown MUDSTONE

W7 13.8 8.82 13.82 11.02 2.8 11. - - - - 10.5 8.8 Grey slightly sandy CLAY (Alluvium) All units are m AOD unless otherwise stated - Data not provided, assumed that strata not present or not encountered

In summary, the data in Table 3 indicates that the alluvium is present at approximately 11m AOD. Alluvium was also designated as the classification of material encountered in boreholes W1 and M5, which are located adjacent on the access road to the tip. This location is a significant height above the landfill, and is considered to be an erroneous classification. The interpretation of the encountered ground conditions would be better made by reviewing the graphical, typed borehole logs.

9 TECHNICAL MEMORANDUM

9. Geoenvironmental Issues The western part of the site lies within the boundaries of the historical landfill, an old County Council landfill known as Hallow Road Landfill, that operated between 1963 and 1985. An extract of one of the Freedom of Information request stated; “the land you are referring to as Kepax Country Park is in fact an old County Council Landfill site that was tipped between 1963 -1985. The landfill site at Hallow is an above ground unlined site and the banks surrounding the landfill act as bunds to stop the migration of landfill gas and leachate into the immediate environment. It has been documented in the past that there have been leachate breakouts on the Northern and Eastern banks of the landfill. It is therefore important that we are able to clearly identify any areas of concern along these banks so that we can remediate as necessary. This therefore reduces the potential of pollution entering the surrounding environment, in particular the surface water ditches around the site .” The western part of the site is underlain by landfilled material of unknown origin. It is assumed however, that while the deposited wastes would have likely been routinely compacted during the landfill site’s operation, it is unlikely that the material would have been compacted to any specification. Further, it is unknown whether the site accepted wastes which would degrade over time. As a result, it is anticipated that the site will be susceptible to ground movement which would lead to intolerable movements of any shallow foundations, and as such, a piled foundation solution will be required. However, there are constraints associated with this foundation type; the Environment Agency’s document ‘Piling and Penetrative Ground Improvement Methods on Land Affected by Contamination: Guidance on Pollution Prevention, National Groundwater & Contaminated Land Centre report NC/99/73’ (May 2001), describes six scenarios which may potential impact on the environment from piling activities. Table 4 presents a summary of the considerations for adopting a piled foundations solution. Table 444 ––– Summary of potential pollutant pathways to be consiconsidereddered in a Piling Risk Assessment Potential Pathway Description

Creation of pollutant Pathways may be created by piles penetrating the basal liner of the landfill (if present), pathways leading to a pathway for downward migration of landfill leachate.

Pathway may be created by piles penetrating the capping liner of the landfill (if present), leading to a pathway for the upward migration of landfill gases.

Advancing contaminated There is a risk that some forms of displacement piling (such as driven precast piles) may materials during drilling advance a “plug” of contaminated material below the level of the landfilled material.

Based on the available data, It is anticipated that all of the pathways referred to above are pertinent to the Hallows Road Landfill site. A Piling Risk Assessment would be required, in order to develop a

10 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM suitable pile design and specification, and deliver the required technical performance, whist mitigating the risk of creating hazards to the environment from piling operations. The historical sewage works, which is no longer present on the site of Gheluvert Park could potentially have contaminated the site. This area may therefore have Made Ground present, with the potential for metals, inorganic ions (cyanides, sulphates, chlorides etc.), organics, fuel oils, treatment chemicals, asbestos and pathogens (salmonella etc.). It therefore should be recognised that the Made Ground beneath Gheluvert Park on the east side of the river may also fall within the same Environment Agency (EA) constraints detailed above. There are several listed buildings recorded in Worcester, the majority are located to the east of the site, however one is located directly northwest of the western boundary of the site. (MAgiC, 2018) 10. Geotechnical Hazards and Design Issues In accordance with BS EN 1997-1:2004, the project is classified as Geotechnical Category 2 as it includes conventional types of structures and foundations with no exceptional risk, difficult soil or loading conditions. A qualitative approach has been used to develop the geotechnical risk register for the site. Using this system, the degree of risk is the expected impact of damage, loss or harm for a given hazard under particular circumstances, and is the product of the likelihood and consequence of that hazard materialising. The scales of likelihood and consequence are shown in Table 5 and 6, and the degrees of risk are summarised in Table 7.

Table 5 Table 6 Scales of Likelihood Scales of Consequence

Likelihood Scale Likelihood Scale

Improbable 1 Insignificant 1

Remote 2 Marginal 2

Occasional 3 Serious 3

Probable 4 Critical 4

Frequent 5 Catastrophic 5

Table 7 Degrees of Risk

Degree of Risk Risk Level Recommended Response

1 to 5 Low risk Broadly acceptable if all reasonably practicable control measures are in place Tolerable only if further mitigation is not reasonably practical and there is need to 6 to 8 Medium risk continue activity with identified controls 9 to 15 High risk Apply further mitigation measures and/or alter method of work to reduce risk further

16 to 25 Very high risk Unacceptable. Re-examine activities to provide lower risk

Table 8 summarises the potential hazards that may be associated with the strata beneath the study area, and the corresponding risk for each.

11 TECHNICAL MEMORANDUM

Table 8 Geotechnical Risk Register Geological Unit Potential Hazard Potential Impact Likelihood Consequence Risk (without mitigation) Made Ground /Landfill Variable foundation conditions Differential settlement of foundation 4 4 16 Poor foundation conditions Ground instability 3 4 12 Contamination Adverse effects on workers and environment 5 4 20 Sulphate bearing material Attack on buried concrete 2 3 6 Piling resulting in c reation of contaminant Release of leachates/gas 2 4 8 pathways Alluvium Compressible strata Total or differential settlement of structures 5 4 20 Risk of flooding Detrimental effect on construction 4 3 12 Variable foundation conditions Differential settlement of foundations 2 4 8 Weak/loose strata Ground instability 5 4 20 High permeability strata Seepage beneath defences 3 3 9 River Terrace Deposits High water table Unstable excavations/uplift of structures 5 4 20

High permeability strata Seepage beneath defences 5 3 15 Former workings Settlement/Made Ground 3 4 12 Gravel and cobbles Obstructions to excavations/piling 2 3 6

Mudstone Poor foundation conditions Global stability/bearing failure of defences 2 4 8

Variable foundation conditions Differential settlement of foundations, variable 4 4 16 construction techniques required Competent, shallow bedrock Obstructions to excavations/piling 1 2 2

Local perched water tables Unstable excavations 3 4 12

Ground heave in clay members Damage to foundations 3 5 15

Loose sand Erosion and gullying 3 4 12

12 TECHNICAL MEMORANDUM 10.110.110.1 Additional Geotechnical Risks • Other risks that will have an impact on the scheme are; • The number of overhead and buried services that were identified during the site walkover; • In addition, both sides of the bridge lie in areas of publicly accessible land and any construction work, including GI, will need to take account of this; • The River Severn is a deep, fast flowing river. Work undertaken in the vicinity of this will require sufficient health and safety protocols in place; • The river will also need to be protected from any contamination as a result of construction works; • Site access to the western extent of the proposed bridge may be via the landfill site, heavy construction traffic will require sufficient ground protection. 11. Engineering Considerations • A significant number of boreholes have been sunk within the confines of Hallow Road landfill site, and it is anticipated that there would have been formal, graphical and typed borehole logs produced, which would include, amongst other details, descriptions of the nature, and thicknesses of, the materials encountered and details of the monitoring installations. The response to the “Freedom of information” requests did not include the borehole records; however, a tabulated summary of the logs was provided by WCC. A more comprehensive assessment of the ground conditions could be made, if a Ground Investigation Factual Report, produced by the ground investigation contractor, was available to review. • It is anticipated that the records would be held by WCC and/or EA; this information should be identified, and a study made of the pertinent information, by a suitably experienced ground specialist. • It is anticipated that chemical testing results would also be available for the soils which are present at the site. These are likely to have been included within the contractor’s Ground Investigation Factual Report; to date, only groundwater, gas and leachate data has been provided. • While ground conditions at the eastern site are unlikely to have altered significantly from those detailed in borehole records held by the BGS, the ground conditions at the proposed bridge abutments will need to be established for foundation design. In addition, GI in line with current Eurocode 7 and British Standards will be required to ensure a compliant design. • Foundation placement over landfill can be problematic due to the varied nature of the material, significant settlement, low bearing capacity in addition to the Geoenvironmental issues noted in Section 9. • Ground conditions within the former Hallows Road Landfill site are likely to have altered as the deposited waste materials decompose and degrade, and as the alluvial deposits consolidate over time, due to the increased loadings imposed by the deposited waste. In addition, specific details of the ground conditions at the proposed bridge abutment will need to be confirmed for foundation design. • The construction of the bund that surrounds the landfill site is unknown. This will require further investigation. 11.111.111.1 Possible Foundation Type Based on the information provided in this report and the nature of the structure, it is considered at this stage that the foundation type will be a pile. A piled foundation would transfer the bridge load

13 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM through weak strata onto more competent strata. The pile may need to be end bearing as it is anticipated that limited shaft friction will be provided by the made ground associated with each end of the bridge. Based on available GI adjacent to the eastern extent of the bridge, soft/loose deposits may be present to depths over 10m below ground level (bgl). Limited data is available for the western extent; available GI undertaken outside or at the edge of the landfill, indicates soft/loose deposits may be present to depths over 8m bgl. Preliminary loads have not been provided at the time of writing this report. A preliminary assessment of the Diglis Bridge construction records has been undertaken which indicates that the natural geology underlying the site is similar to that of the proposed Kepax Bridge, however, Made Ground is not present beneath Diglis Bridge. In addition, the depth of superficial deposits can vary significantly. Given the above, it is not possible to determine the diameter or depth of the piles required, however, it is anticipated that the they will need to be wider and deeper for the Kepax Bridge. 11.211.211.2 Preliminary Construction Costs The form of the proposed bridge is similar to Diglis bridge, with the span being approximately double. As such, the costs associated with the proposed bridge are likely to be great to the extent outlined below: • The bridge span of the Diglis bridge is approximately half of that proposed for Kepax, as such, construction costs for the latter will be circa twice that of the Diglis bridge; • The ground conditions associated with the proposed Kepax bridge and Diglis bridge have not been compared. Given the potential poor nature of the ground conditions for both the eastern and western landing points of Kepax Bridge, it is anticipated that the foundations will be deeper and of a higher chemical resistance. It is considered that the construction costs of the Kepax foundations should be further increased by 25% to account for this. 12. Recommendations Further work required, prior to GI being undertaken is recommended as follows: • A Eurocode compliant Desk Study should be undertaken in order to understand better the Geotechnical and Geoenvironmental conditions affecting the site. It is recommended that the desk study be completed in general accordance with the format provided in Highways Agency (2008) Design Manual for Roads and Bridges, Volume 4, Section 1 Part 1 (HD 22/08): Appendix C Format of Preliminary Sources Study Report (PSSR). An Annex A to Preliminary Sources Study should be provided providing a preliminary scope of GI works required for outline design. In order to compile a PSSR, an Envirocheck Report and UXO Preliminary Risk Assessment will be required. Appendix C provides a template of a PSSR. Drawings associated with the PSSR will be required and may contain the following: o Flood Risk Map; o Geology Map and Existing Ground Investigation Plan; o Historical Land-Use Plan; o Updated Geotechnical and Geoenvironmental Constraints plan with additional hydrogeological constraints incorporated; o Aerial Photography. • BS 5930 does not provide guidance on investigations for contamination or naturally elevated concentrations of potentially hazardous substances (these are dealt with in BS 10175). Nor does it provide guidance on investigations for ground gas (these are dealt with in BS 8576). However, it does provide guidance on the integration of geotechnical investigations with investigations for contamination or ground gas and other types of investigations (e.g.

14 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM archaeological). As such, the template provided in Appendix C will need to be updated in line with these standards; • A full review of the construction drawings and Geotechnical information of the Diglis Bridge, circa 3.5km south of the River Severn, will need to be undertaken to determine the ground/groundwater and loading conditions; these can then be compared to that of the proposed Kepax bridge to ascertain the differences and better target the GI; • Outline anticipated loading conditions of the proposed bridge will also be required to ensure GI is scoped to the appropriate depth; • Available records with respect to both the east and west side of the river will be required from both Worcester City Council and Worcestershire County. These may include, but are not limited to: o Hallow Road landfill; o Water Treatment works; o Available ground and groundwater information; o Existing Ecological surveys and reporting; o Records with respect to existing services; o Details of the bund surrounding the landfill. • Liaison with other disciplines will be required in order to take into consideration constraints to further Geotechnical and Geoenvironmental work, these include, but are not limited to: o Hydrology; o Environment; o Geomorphology; o Ecology; o Archaeology. • Current details on the following will be required: o Utilities; o Land ownership. • Monitoring of existing monitoring installations surrounding the landfill should be undertaken, if permission can be obtained, to inform the assessment of the risks posed by the site in terms of hazardous gas emissions, risk to human health (principally construction workers) and risks to groundwater/River Severn from contaminated leachate. 13. References 1. Barclay. W.J et al. 1997. Geology of the country around Worcester: memoir for 1:50,000 geological sheet 199. British Geological Survey; 2. Bing, 2017. Maps, satellite and OS mapping imagery. www.bing.com/maps/ (accessed May 2018); 3. British Geological Survey, 1993. Sheet 199. Worcester. Solid and Drift. 1:50 000; 4. British Geological Survey, 2018. GeoIndex. www.bgs.ac.uk/geoindex (accessed May 2018); 5. National Library of Scotland, 2017. Side by Side historical mapping. www.maps.nls.uk (accessed May 2018); 6. Natural England, 2018. MAgiC. www.natureonthemap.naturalengland.org.uk/MagicMap (accessed May 2018);

15 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM 7. Worcestershire County Council, 2017, Pre-feasibility into the siting of a new pedestrian/cycling bridge crossing the River Severn, Worcester; 8. Data provided via a freedom of Information Request, accessible through https://www.whatdotheyknow.com/request/kepax_country_park_testing_data 9. https://www.whatdotheyknow.com/request/hallow_road_tip_contracts_and_in 10. What’s in Your Backyard is closed, however the data is viewable through www.data.gov.uk (accessed May 2018).

16 TECHNICAL MEMORANDUM Drawings

17 Key: Wooden Sleeper Steps providing access up/down proﬁled slope

Proposed Bridge Footprint

Severn Way Footpath

Concrete River Wall

Ditch/Drainage Pathway

Overhead Service

Proﬁled slope with shrub cover (~3 m height, ~1:3 slope)

Publically Accessible Land

Semi-mature Tree Cover

River Severn

Visual Evidence of Buried Ser- vices

Potenal Contaminated Land LANDFILL Steps down slope Notes:

1) Background drawing H.R.L.R.S. has been provid- Elevated chamber ed by Worcestershire County Council. Jacobs cannot be held responsible for its contents.

2) To be read in conjuncon with preliminary GHELUVELT PARK geotechnical and geoenvironmental feasibility technical memorandum: May 2018, rev. 1. (former water works) Monitoring 3) Locaon of proposed bridge. Please refer to staon/ drawing 694944.BA.23.00-90.01. gantry Client: Worcestershire County Council

Electrical equipment box

Project: Kepax Pedestrian/Cycle Bridge Electrical sub- Drawing: staon Geotechnical and Geoenvironmental

Preliminary Constraints Plan Overhead Western Power Distri- buon overhead cable. Goes to Drawn: TW 18/05/2018 ground:

Checked: EA 21/05/2018 • East of River Severn—electrical Reviewed: GD 23/05/2018 substaon property, Approved by: • West of River Severn—west of fences. KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM Appendix A Existing Borehole Logs

18 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM SO85NW59 page 1 of 2

19 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM SO85NW59 page 2 of 2

20 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM SO85NW80

21 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM Appendix B Volume 4 Section 1 Part 1 HD 22/08 August 2008: Appendix C Format of Preliminary Sources Study Report (PSSR) 1. INTRODUCTION Title Sheet, clearly indicating the name of the scheme, together with the title, details of the authorship and the version number of the report. The version number and date of the report shall be clearly placed as a footer to every page of the report. Reference to Statement of Intent. Limits of study area and content and note of any previous geotechnical studies in the area. 2. SOURCES OF INFORMATION & DESK STUDY Details of the results of all enquiries made and of all sources used for geotechnical, historical and other general information relevant to the area (Ref.12 and 13). Nil or negative responses should also be reported. 3. FIELD STUDIES Description of any field activities undertaken for this report - walkovers, geomorphological/geological mapping, probing, pitting and testing work, drainage/hydrological studies, geophysical or photographic surveys etc. 4. SITE DESCRIPTION The topography, geology, hydrology, hydrogeology, geomorphology, man-made features and historical development of the area should be investigated together with the geo-environmental and possible contamination issues. Most conveniently presented as a series of plans and overlays. 5. GROUND CONDITIONS Description of soils anticipated, with engineering properties known and predicted; significance of geological formations, ground water conditions etc. 6. PRELIMINARY ENGINEERING ASSESSMENT • For each soil type and/or location preliminary consideration of the design implications including: General - location, classification, earthworks acceptability criteria, groundwater, likely difficulties and problems, areas/features to avoid. • Cuttings – side slopes (short and long term), potential acceptability of material, merits of special drainage or ground treatment, swelling problems. • Embankments – side slopes, characteristics and restrictions on use of particular soils, plant use options, drainage requirements, foundation treatment. • Subgrade – likely CBR values for cutting areas and for potential fill materials in embankments, capping layers and availability of material, drainage requirements. • Structure foundations – alternative types of foundation likely to be applicable, estimates of bearing pressures and settlements, groundwater, problem areas/strata, potential construction difficulties etc.

22 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM • Contaminated land/Soil Chemistry – possibility of harmful elements being present in soil or groundwater, and implications of these on health and safety. Scope for the reuse of marginal/recycled material within the works. • Any existing geotechnical problems; i.e. Slope failures, solution features, mine workings slopes with marginal factors of safety, very soft/highly compressible soils. • Effects of man-made obstacles/site history. 7. COMPARISON OF PROJECT OPTIONS AND RISKS • List all geotechnical, geo-environmental, historical and other factors discovered which are likely to influence the project; i.e. routes, alignment, health and safety or buildability. • An updated Geotechnical Risk Register; in which the risks of the primary hazards are assessed, the consequences of these risks to the project determined, and details of how the risks are to be managed given. CDM implications should be highlighted. • A statement of the preferred routes/options (on geotechnical grounds) should be given if appropriate. 8. DRAWINGS AND PHOTOGRAPHS • Site Plan (usually 1:10,000) with study limits and scheme options. Plans/overlays to show topography, historical development, existing trial holes, geology, geomorphology, hydrogeology, hazards including contaminated ground and man-made features etc. as appropriate. Geological longitudinal sections with cross-sections where appropriate. • Photographs from both the ground and air obtained for the study should be reproduced and referenced to the site plan. ANNEX A TO PRELIMINARY SOURCES STUDY 1. OBJECTIVES and FORMAT OF ANY INVESTIGATION (For example): To provide information to confirm and amplify the geotechnical and geomorphological findings of the Preliminary Sources Study, as reported separately and to obtain detailed knowledge of the soils encountered and their likely behaviour and acceptability. To ascertain ground water conditions and locations of underground workings, if any. Limits of work envisaged. 2. SPECIAL PROBLEMS TO BE INVESTIGATED Location of structures. Sub-soil conditions below areas of high embankment. Aquifers and likely water-bearing strata affecting the works. Rock stability problems. Effects on adjacent properties etc. Any man-made features to be encountered. Contaminated ground. 3. PROPOSED INVESTIGATION Fieldwork - details of exploratory work proposed for specific areas with reasons for choice of investigatory method. Laboratory work - details of proposals with reasons for choice of test and relevance to design. Summarised as tables. Requirement for Factual Data to be supplied in digital form to AGS Format. 4. SITE & WORKING RESTRICTIONS Traffic management, difficult access, Statutory Undertaker’s plant, Network Rail restrictions, flora and fauna, designated sites; e.g. SSSI’s.

23 KEPAX PEDESTRIAN/CYCLE BRIDGE – PRELIMINARY GEOTECHNICAL AND GEOENVIRONMENTAL FEASIBILITY TECHNICAL MEMORANDUM 5. SPECIALIST CONSULTATION Details and reason if proposed. 6. PROGRAMME, COST AND CONTRACT ARRANGEMENTS Anticipated start dates, contract periods, restrictions on programme, cost estimates (VAT excluded) for factual and interpretative work. Arrangements for contract work and supervision of contract. 7. REPORTING Responsibility for reporting (with reasons), format and topics to be covered.

Appendix D – Example Drawings