Mersey Flood Risk Management Scheme Phase 3B Woolston

ES Addendum Non-Technical Summary

MARCH 2016

We are the Environment Agency. We protect and improve the environment and make it a better place for people and wildlife. We operate at the place where environmental change has its greatest impact on people’s lives. We reduce the risks to people and properties from flooding; make sure there is enough water for people and wildlife; protect and improve air, land and water quality and apply the environmental standards within which industry can operate. Acting to reduce climate change and helping people and wildlife adapt to its consequences are at the heart of all that we do. We cannot do this alone. We work closely with a wide range of partners including government, business, local authorities, other agencies, civil society groups and the communities we serve.

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EIA Quality Mark

This Environmental Statement, and the Environmental Impact Assessment (EEIA) carried out to identify the significant environmental effects of the proposed development, was undertaken in line with the EIA Quality Mark Commitments.

The EIA Quality Mark is a voluntary scheme, operated by the Institute of Environmental Management and Assessment (IEMA), through which EIA activity is indepenndently reviewed, on an annual basis, to ensure it delivers excellence in the following areas:

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Non-Technical Summary – Contents

1 INTRODUCTION 1 2 BACKGROUND 3 3 CONSIDERATION OF ALTERNATIVES 4 4 DESCRIPTION OF THE PROPOSED DEVELOPMENT 7 5 ECOLOGY 10 6 LANDSCAPE AND VISUAL AMENITY 11 7 CULTURAL HERITAGE 13 8 LAND USE AND RECREATION 14 9 TRAFFIC AND TRANSPORT 15 10 WATER ENVIRONMENT 17 11 CONTAMINATED LAND 18 12 NOISE AND AIR QUALITY 20 13 CUMULATIVE EFFECTS 21 14 SUMMARY OF EFFECTS 22

Figures

Figure 1 Site Location Figure 2 MR1 General Arrangement Figure 3 MR2 General Arrangement Figure 4 Viaduct General Arrangement Figure 5 MR1 Upstream Reinstatement Figure 6 MR1 Downstream Reinstatement Figure 7 MR2 Reinstatement Figure 8 Thelwall Viaduct Landscape Reinstatement Figure 9 Photomontage

NTS i Mersey Warrington ES Addendum FRMSPhase 3B - Woolston Non-Technical Summary

NON-TECHNICAL SUMMARY

1 INTRODUCTION

1.1 About this Document

1.1.1 The Environment Agency (EA) submitted a planning application to Warrington Borough Council (WBC) to construct a Flood Risk Management Scheme (FRMS) in several phases. The planning application was granted consent on 19 April 2012 but at that time provided full details only for the earlier phases.

1.1.2 The FRMS, when complete, would reduce the risk of flooding to people, property and the environment to a 1% chance of flooding in any one year for the Howley, Latchford, Padgate, Bruche and Woolston areas of Warrington, . The earliest phases of the FRMS are now either complete or due to be completed soon. The next phase due for construction is Phase 3B Woolston, to which this Non Technical Summary (NTS) relates. Details of the final stage, Orford Road, are not included in this NTS.

1.1.3 The proposals for Phase 3B Woolston were largely included in the original 2012 planning application for the scheme as a whole. However, due to technical difficulties with construction at the rear of Edward Gardens, and because the original planning consent relating to this Phase had expired, it was agreed with WBC that the best way forward would be to submit a new planning application.

1.1.4 The location of the Phase 3B works to which this NTS relates is shown on Figure 1.

1.1.5 The original planning application was accompanied by an Environmental Statement (ES), which considered the environmental effects of the whole scheme. The ES is still relevant for the Phase 3B application; however as there are changes to the working method and some minor changes in flood defence alignment, it was agreed with WBC that an ES Addendum should be prepared. The Addendum highlights those environmental topics in the original ES where there is a change and provides a revised description and assessment as necessary.

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Mersey Warrington ES Addendum FRMSPhase 3B - Woolston Non-Technical Summary

1.1.6 As an ES Addendum has been prepared, it is also necessary to prepare a revised NTS. This revised NTS provides

• the background to the proposed development; • a description of the proposed development; and • a summary of environmental effects; and • a conclusion.

1.1.7 As this NTS provides an update to the original NTS, it only highlights those environmental topics where some change has occurred, but for ease of reference a brief summary of the background to and implementation of the scheme to date is also provided.

1.2 Contact Details

1.2.1 If you would like any further information or wish to discuss the contents of this document, please contact:

Chris Stone EA Project Manager (01925 542419) Connor McIlwrath EA Environmental Project Manager (01925 542229)

1.2.2 Alternatively write to them at:

Environment Agency Richard Fairclough House Knutsford Road Warrington WA4 1HG or via email at: [email protected]

1.2.3 If you have any comments relating to the planning application these should be directed to the Development Control team at Warrington Borough Council.

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Mersey Warrington ES Addendum FRMSPhase 3B - Woolston Non-Technical Summary

2 BACKGROUND

2.1 The over-arching objective of Mersey Warrington FRMS is ‘To deliver a comprehensive scheme to manage the risk to people, property and the environment from flooding over the next 100 years’. This objective has not changed from the original NTS.

2.2 However, further investigation of the Phase 3B site, modelling of likely flood levels and consideration of the flood defence alignment has resulted in slight changes to the proposals as envisaged in the original ES/ NTS. In addition, EA has consulted extensively with public agencies, land owners, residents, businesses and others in respect of the details of the scheme and this has influenced the development of the project. The changes and how the proposed design solution was arrived at are described below.

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3 CONSIDERATION OF ALTERNATIVES

3.1 Detailed consideration of options for Phase 3B were considered at length following granting of the original consent. Options for land downstream of Weir (MR1 downstream) considered the need to allow landowners access to build a hydro-electric power scheme at the New Control Structure (Woolston Weir) and also to avoid a private sewerage installation. Options for land upstream of Weir Lane (MR1 upstream) were more challenging due to the riverbank being unstable. There were few options available for the flood defences at Lane industrial Estate, as there is very limited space between existing buildings and the river.

3.2 A fuller description of all options considered is provided below.

Woolston Weir (MR1 upstream)

3.3 The original ES was based on a scheme which brought the flood defences close to the river side of garden boundaries along Weir Lane/ Edward Gardens. After this option had been developed in outline, the collapse of a section of the existing riverbank resulted in the closure of a riverside footpath and the need for a solution to deal with the unstable ground.

3.4 Subsequent ground investigation shows that the riverbank along this reach cannot support the weight of heavy construction machinery or a flood defence wall. Alternative options making use of ground stabilisation and/ or lightweight construction techniques were considered, but the safety issues were such that none of the available options were considered acceptable. In particular, engineers think that construction and heavy plant access should not be allowed in a strip up to 15m wide from the top of the river bank.

3.5 As an alternative, EA considered taking flood defences through the rear gardens of the Weir Lane/ Edward Gardens properties (ie beyond the 15m safety strip) but it proved impossible to find an alignment that was acceptable to both landowners and EA. In particular, it was impossible to give landowners easy access to the riverside part of their gardens whilst at the same time meeting EA’s requirement to avoid use of manually-operated floodgates wherever possible.

3.6 EA then considered if it would be possible to bring the flood defence along the riverbank to the rear of 55 Weir Lane to 44 Edward Gardens, continuing

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upstream to the proposed tie-in to high ground at the United Utilities outfall rear of Edward Gardens. This alignment would have avoided the area of most severe river bank instability. These upstream defences would have involved flood defence walls being built between property boundaries and some areas of ground raising on roads and private drives. Again, it proved impossible to find an alignment that would suit all parties.

3.7 The only remaining option was a sheet piled flood defence wall running on the river side of the closed footpath. Due to the instability of the riverbank, the piles would have to be supported by a layer of rock placed along the bank and into the river. Because of access difficulties and the 15m restriction on the riverbank for heavy equipment, all piling would be carried out from floating pontoons moored in the river. This option was adopted as the preferred option for the upstream section of M3R1 in summer 2015. The alignment of the proposed works can be seen in Figure 2.

Woolston Weir (MR1 downstream)

3.8 Downstream of Weir Lane, options were constrained by the need to maintain vehicle access for property owners on a narrow track past Lock Cottage to Weir Lodge (both residential properties) and continuing to the New Control Structure (Woolston Weir). In addition to access for residents, occasional access is also required for a large crane to clear the river-borne debris that can accumulate on the Guard Weir. EA considered use of a flood defence wall along one side of the track but detailed consideration of the site and access requirements proved that this alignment was unfeasible.

3.9 Potential solutions also had to take account of Peel Energy’s approved scheme for a hydro-electric power generating scheme (see WBC planning application ref 2013/21750, granted consent on 26 July 2013). The hydro-electric generation scheme requires construction/ maintenance access to be available on Weir Lane between Lock Cottage/ Weir Lodge and the riverbank, using the existing track to access a compound located within open land to the west of Weir Lodge.

3.10 EA considered raising the footpath level slightly along the north side of the New Cut, then placing a flood embankment across the former canal and tying in the higher ground near the New Control Structure. This option was abandoned because it would have left Weir Lodge without flood defences and because of concerns from the New Cut Heritage & Ecology Trail Group.

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3.11 The solution finally chosen is to bring a flood embankment along the south side of the New Cut, outside the boundary of Weir Lodge, tying the embankment in to the higher ground near the New Control Structure. A short additional length of flood embankment would run from the New Cut to Weir Lane connecting to a new flood defence wall which would continue around Weir Lodge. Flood gates would be installed in the wall which would be operated by the landowners.

3.12 This alignment leaves Lock Cottage on the ‘wet’ side of the proposed flood defence; further flood modelling has shown that Lock Cottage’s threshold is above the 1:100 year flood level (including the 300mm freeboard depth) and so no formal flood defences are proposed. However, some localised raising of the road surface on Weir Lane will be carried out and this will in itself provide a flood defence for Lock Cottage.

Bridge Lane Industrial Estate (MR2)

3.13 Given that existing buildings at the Bridge Lane Industrial Estate are very close to the river’s edge, there were very few options available for locating the flood defence structure. Although the defence needed to be located between the industrial buildings and the river’s edge, EA faced a challenge of finding a suitable location which did not limit the operation or development opportunities of the industrial estate.

3.14 Sheet piles were the only practicable option for the majority of the length of the wall because of their narrowness, because a seepage cut-off was required beneath the flood defence wall (to prevent water from leaking under the wall) and because there were concerns about riverbank stability with any other design.

3.15 At the upstream and downstream tie-ins to higher land there is more space and so localised ground raising will be used instead of sheet piles. See Figure 3 for the general arrangement of the proposed works.

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4 DESCRIPTION OF THE PROPOSED DEVELOPMENT

4.1 The proposed development is located on land on the north bank of the , between Bridge Lane Industrial Estate and Woolston. For the purposes of environmental assessment, the study area extends beyond the immediate working area, and also includes the contractor’s temporary compounds and access routes (including use of highways) and surrounding land. For this Phase, construction access limitations mean that an area of land immediately upstream of the M6 Thelwall Viaduct will be used as a temporary compound and equipment and materials will be delivered to the Woolston site via the River Mersey, as shown in Figure 4.

4.2 Phase 3B consists of two separate areas of flood defence:

• MR1 Flood wall (upstream) and land raising/ embankment (downstream) at Woolston; and • MR2 Flood wall and land raising at Bridge Lane Industrial Estate.

4.3 A description of the defences is given below and the general layout of the scheme is shown on Figures 2 (MR1), 3 (MR2) and 4 (Thelwall).

MR1 (Upstream) Proposals

4.4 The flood wall at MR1 (upstream) will be approximately 190m long and will consist of a sheet piled wall up to 1.27m high relative to local ground level. The sheet piles would be clad on the landward (dry) side with horizontal closeboard timber (oak) and a coping to match. The piles will be located on the river side of an existing footpath which is temporarily closed due to bank instability. MR1 ties in to naturally higher ground at its upstream end; at its downstream end the sheet piles will tie in to Weir Lane.

4.5 Because the unstable river bank at MR1 cannot take the weight of equipment used to push in the piles, the piling rig will be located on pontoons in the River Mersey. A barge will be used to deliver the pontoons, piling rig, the sheet piles, rock and other materials and equipment to the MR1 working area.

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4.6 The collapsed riverbank footpath will be re-built 1.8m wide with a verge 0.5 – 1.5m wide between it and the nearby house boundaries. The footpath would have a firm gravel surface so that WBC can lay a tarmac surface at a later date.

4.7 A layer of rock would be placed on the river bank and within the river to give physical support to the sheet piles and to protect the river bank. The visible part of the river bank (ie above the normal water level of the river) would be soiled and seeded; soiled filled ‘socks’ will be placed just above normal water level and will be planted with suitable native plants. These measures will encourage rapid re-vegetation of the river bank.

4.8 Along rear garden boundaries of Weir Lane/ Edward Gardens, hedges or fencing would be retained and protected. The reinstated layout of MR1 is shown on Figure 5.

MR1 (Downstream) Proposals

4.9 A new earth embankment at flood defence level would be built along the south side of the New Cut from Weir Lane to higher ground near the New Control Structure. The earth embankment will extend into the base of the New Cut but will not fill it in. Timber post & rail fencing would prevent access to the new flood embankment from both ends. The flood embankment would be constructed with a 3m wide crest and 1:3 side slopes. A drain from Weir Lodge garden would be installed, to prevent water from ponding within the garden. The new flood embankment would be seeded with a suitable grasses/ wildflowers mix.

4.10 A further area of approx. 1000m2 near to the New Control Structure would be used as a satellite contractor compound. The compound would have a stoned surface and be fenced off and secured when not in use. The stone and fencing would be removed following completion and the land would be soiled and seeded. The reinstated layout of MR1 is shown on Figure 5.

MR2 Proposals

4.11 MR2 would involve a sheet piled flood defence wall of 400m in length located within a narrow strip of land between the Industrial Estate buildings and the River Mersey. The wall would be up to 1.10m above local ground level with an earth embankment/ ramp connecting to higher land on the existing river embankment. A hardwood timber coping would be fitted to the upper edge.

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4.12 A new security fence would also be located along the riverward side of the flood defence wall, offering increased security to the occupiers of the Industrial Estate. The reinstated layout of MR2 is shown on Figure 7. A satellite contractor compound would be located on existing hard standing within the Industrial Estate.

Thelwall Proposals

4.13 Construction for MR1 and MR2 will be served by a temporary contractor compound, located near Thelwall Viaduct on land formerly used as an inert materials landfill (now closed). The land has no current use and is covered with rough grassland and scrub. The compound location is to the east of a highway embankment supporting the M6 southbound Thelwall Viaduct and to the south of A57 Manchester Road at the J21 junction of the M6.

4.14 The compound would share use of a private access track to a materials processing facility (operated by W Maher Ltd) and other infrastructure. The access track is located on land between the A57 and Woolston Deposit Ground No. 1 and runs parallel to the M6 Thelwall Viaduct.

4.15 The Thelwall compound would be approximately 2940m2 in extent and would be provided with a stoned surface and security fencing. The compound would provide offices, staff & visitor parking, and a plant, equipment and materials storage facility for the Phase 3B MR1 upstream works. In particular it would be used as a delivery and storage area for sheet piles, rock armour, the piling rig, a crane and other heavy plant required for construction.

4.16 In addition, a further area will be used on the river’s edge between the Thelwall Viaduct and a Bailey bridge. A temporary landing platform would be built out into the river so that a barge, pontoons and materials and equipment could be transferred by a crane. The barge and pontoons would shuttle up and down the river, delivering equipment and materials to the MR1 working location. The Bailey bridge is a private crossing used only by the materials processing facility.

4.17 This area is currently used as a vehicle turning area and is fenced with barriers to prevent unauthorised vehicle access. The Mersey Way long distance trail runs along the northern bank of the River Mersey at this point although the section from Statham Lane to Woolston is temporarily closed due to bank instability.

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4.18 The barge and pontoons to be used for the construction of MR1 Upstream will be delivered via the Irlam Container facility, into the Ship Canal and from there to the River Mersey and the loading platform at Thelwall Viaduct. The craft would then be used to ferry plant and materials to the working area.

4.19 The contractor compound will remain in use until all MR1 upstream works have been completed, following which the compound facilities would be removed and the stoned area reinstated as agreed with the landowner as shown on Figure 8. The temporary launching platform would also be removed and the riverbank reinstated. 5 ECOLOGY

5.1 Ecological surveys were carried out for the original ES and these have been updated in 2015. The updated surveys now also include the land at Thelwall Viaduct and the revised alignment for MR1 near the New Cut.

5.2 Badger activity has been recorded within the study area. The activity is being monitored and appropriate mitigation methods will be put in place following further investigations to prevent significant impacts on the badgers.

5.3 In addition to the habitats recorded in the original ES (2011), a December 2015 survey of the revised MR1 study area recorded some trees with potential ecological interest. These include Oak, Silver Birch, Ash, Poplar and Sycamore. Two trees of particular interest include:

• on the southern bank of New Cut, a multi-stemmed Ash with no visible cavities. Parts of the tree are diseased; and • a young Alder on land south of the New Cut. There are some rot holes that might provide summer roost habitat for bats.

5.4 Before construction starts, more surveys will be carried out to ensure that no bats or their roost sites, otters or other protected species are endangered. The area will also be checked for foreign invasive plants such as Giant hogweed.

5.5 The noise caused by pushing in sheet piles could cause harm to fish (salmon are known to use the river) and other creatures in the water. Some of the noise would be muffled by the river bank itself but it is difficult to say by how much with any certainty. Working practices would therefore be adjusted to reduce the

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severity of any effects of noise pollution on fish, for example push piling will be used in more sensitive locations and piling will be avoided when salmon are known to be migrating up the river.

5.6 There would be minor short term effects on ecology during construction, of the sort normally associated with flood defence schemes such as temporary disturbance or loss of riverside habitats. These effects can be controlled by careful management of the works. Replacement seeding/ planting and fitting of bat and bird boxes will have a small beneficial effect. The assessment of the effects of the scheme therefore remains the same as in the original ES. 6 LANDSCAPE AND VISUAL AMENITY

6.1 Since the original ES was produced, the alignment of the flood defences has changed at Woolston (MR1) and most engineering work would be carried out from pontoons in the river. The pontoons would be moved by a barge down to Woolston from a temporary site compound and launching point at Thelwall Viaduct. The changes to the alignment mean that an area of land around the New Cut close to Weir Lane would now be included in the scheme, together with the land temporarily required at Thelwall Viaduct.

6.2 There are no changes affecting landscape and visual amenity at Bridge Lane Industrial Estate (MR2)

6.3 The changes at MR1 mean that some new locations will have views of the scheme. These include properties on Timberscombe Gardens, Lincoln Close, and walkers on the Mersey Way. In addition, some people who would have had views of the original scheme will have a change in those views under the revised scheme. These include occupants of Lock Cottage and Weir Lodge, people living on Weir Lane and Edward Gardens, and walkers on nearby public footpaths.

6.4 These changes have been considered and it is thought that there would not be any important permanent change in landscape amenity or views of the scheme, as compared to the original scheme. There would be some temporary changes (as compared to the original scheme) because the new riverbank and flood embankment at MR1 would seem very new and would not blend in with the nearby trees and shrubs straightaway. These effects would lessen quite quickly as new seeding and planting begins to grow. For walkers, the newly reinstated

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footpaths would also feel less natural, but again this effect would lessen with time. It is thought that by the 15th year after completion of the scheme it would have completely blended in to its surroundings.

6.5 A photomontage of MR1 upstream is shown in Figure 9; the figure shows the scheme area before the works start, immediately on completion and after a period of years when new seeding and planting has grown. The figure is based on the full landscape reinstatement scheme for both MR1 and MR2; the landscape scheme is shown in Figures 5, 6 & 7. As a minimum, EA will re-plant one new tree for every existing tree that has been felled, either within the scheme area or elsewhere as agreed with Warrington Borough Council.

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7 CULTURAL HERITAGE

7.1 The original assessment of effects on cultural heritage near the MR1 & MR2 works was reviewed in 2015 in the light of the proposed new alignment at Woolston and the works for the temporary launching platform at Thelwall Viaduct.

7.2 The Project Design (which describes all the activities that will have to be undertaken to protect the cultural heritage of the working area) was also reviewed and slightly revised.

7.3 The new assessment said that there was no change to the assessment of low risk of causing damage to cultural heritage as described in the original ES.

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8 LAND USE AND RECREATION

8.1 A check was carried out to see if any Public Rights of Way (PRoW) would be affected by the revisions to the scheme and the following will have to be temporarily closed and/ or diverted during the scheme:

• 329/25a –(Mersey Way) a short section running east from Weir Lane will need to be diverted; • 329/25 - (Mersey Way) a short section between the Thelwall Viaduct and the Woolston Deposit Ground no. 1 Bailey bridge will need to be diverted.

8.2 Both 329/25a and 329/25 are currently closed due to bank instability and a temporary diversion route is in operation for 329/25a. 329/25a would re-open once the flood defence works are complete; it is not known what Warrington BC intends for the long-term future of 329/25. Some small areas of open space used by the public may be temporarily closed off for contractor compounds. This was the case in the original ES, though the locations have changed slightly. There is no change from the original ES in the effects on recreational facilities. Overall, there is no change to the effects of the scheme on land use and recreation as predicted in the original ES.

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9 TRAFFIC AND TRANSPORT

9.1 Most traffic and transportation effects are caused by heavy goods vehicles (HGVs) delivering equipment and materials to the working areas. The revised scheme uses a different arrangement of compounds than that in the original ES and also will use the River Mersey as a delivery route for sheet piles, rock and large plant such as a piling rig or excavator. The original ES also only dealt in detail with the earlier Phases of the flood defence scheme. These changes meant that a complete review of the likely effects of the scheme was necessary to see what changes there might be.

9.2 The review assumed that a 12 month construction period, starting in June 2016, would be required. Based on this timetable, it was estimated that the busiest period for construction traffic would be February 2017, when the scheme as a whole would cause about 9 HGV trips per hour. The review also estimated when the most intense construction traffic would occur at various locations. The results are set out below:

• East of Thelwall - maximum HGV trips per day 58, with a maximum per hour of 6 (forecast to occur in December 2016); • Weir Lane – maximum HGV trips per day 23, with a maximum per hour of 3 (forecast to occur in October / November 2016); and • Bridge Lane – maximum HGV trips per day 22, with a maximum per hour of 2 (forecast to occur between September 2016 and April 2017).

9.3 EA proposes to reduce the impact of this extra pressure on the highway network by having its construction contractor prepare a Construction Traffic Management Plan (CTMP). The CTMP will include detailed arrangements for routing and timing of HGV deliveries, maintenance of access for residents to driveways, parking arrangements, etc. The CTMP will be based on continuing discussion between EA and local businesses, residents, Highways England, Warrington Borough Council and other interested parties.

9.4 With the CTMP in place, the traffic effects of the scheme during construction are considered to be very small.

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9.5 Once the scheme is built there will be no effects on traffic and transportation. There will be a need for occasional inspections of the flood defences but these will be carried out on foot.

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10 WATER ENVIRONMENT

10.1 The original ES considered the potential effects of the scheme on the River Mersey from a point near Edward Gardens, Woolston and downstream to Warrington town centre. The new scheme also affects the river near the Thelwall Viaduct and so a review was carried out to see if the scheme would still be acceptable with respect to the effects it would have on the water environment.

10.2 The new scheme will slightly reduce the amount of water that the River Mersey can hold (because of placing of rock reinforcement along the riverbank) but this effect is tiny when considered in the context of the total volume of the River Mersey.

10.3 There is a risk that construction, either of the Thelwall Viaduct launching platform or of the flood defence wall at MR1 (Woolston) could release sediment into the river. However the Mersey is a lowland river that already carries a lot of sediment; any additional load would not be important and should not affect fish that are already used to high levels of sediment.

10.4 The works near Thelwall Viaduct would be temporary, short-lived and would affect a very small part of the river.

10.5 No change is proposed to the measures described in the previous assessment for minimizing the effects of the works on the River Mersey. These consist of following best site management guidance.

10.6 The review decided that overall there is no change in the effects of the revised scheme as compared to the original one.

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11 CONTAMINATED LAND

11.1 The original ES considered the risk of finding land contaminated by various pollutants when carrying out the works. These pollutants can be harmful to staff working on the site, or if disturbed during excavations and building work they can leak into groundwater or the River Mersey. The pollutants can also be harmful to plants and animals in the wider environment.

11.2 The design of the flood defences took into account the nature of the soils and underlying rock upon which they would be constructed. The design included measures to prevent seepage through them, the ground, or around them. The design also took account of possible changes in groundwater levels although it is thought unlikely that the flood defence works will make any groundwater level changes.

11.3 Samples were tested for various possible substances which could be harmful to human health. Asbestos was found at MR2 and some groundwater tests showed raised levels of arsenic, copper and mercury. An assessment of the contamination risk concluded that the levels would not make the site unsuitable for a flood defence. Nonetheless, it is good practice to attempt to reduce any risk from contamination and so measures will be put in place to:

• Reduce potential human health risks for local residents and construction workers; • Reduce/ prevent contamination of water; • Protect buildings from chemical attack; and • Dispose of potentially contaminated material (if any is found).

11.4 These measures will include:

• Use of good working practices and personal protective equipment as appropriate; • Materials that require removal will be analysed before disposal to a properly licenced landfill; • Preparation of plans to manage contamination risk on site on a day-to-day basis and also an emergency response plan to be implemented in the case of an incident; • Contractor to comply with EA pollution prevention guidance;

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• Chemical analysis of any suspected contaminated materials; • Separate storage of any suspected materials to prevent cross-contamination.

11.5 The review decided that overall there is no change in the effects of the revised scheme as compared to the original one.

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12 NOISE AND AIR QUALITY

12.1 When the original ES was prepared, little detail was available on construction methods for Phase 3B. The generic construction methods described in the original ES and plant/ equipment required have now been updated to allow a more accurate assessment of effects.

12.2 The predicted level of noise from the majority of the works has been found to be above that presented in the original ES. The appointed contractor will therefore be required to consider measures to reduce this level as described in the original ES and implement ‘Best Practicable Means’ to minimise the impacts of construction. Measures to minimise impacts could include: screening, temporary noise barriers, shrouding for equipment or use of alternative methods of construction, plant or equipment.

12.3 Noise from the works could harm fish and other creatures in the water. Methods to be adopted that will reduce the effects on fish are described in the Ecology section above.

12.4 Vibration during construction of the works may affect properties at Weir Lane, Edward Gardens and Bridge Lane Industrial Estate. Condition surveys will be undertaken before work starts of all properties potentially affected by the works so that any changes can be assessed.

12.5 Works will only be carried out near the industrial estate’s café and the Dance Studio during August when these premises are closed for holidays, to avoid disruption to the businesses.

12.6 A public liaison system will be set up to allow residents to raise any concerns and complaints and to keep them informed of up-coming noisy operations.

12.7 Piling works within the vicinity of Thelwall Viaduct will be monitored and use low- impact techniques to ensure works do not cause any damage to its structure.

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13 CUMULATIVE EFFECTS

13.1 Overall, although the details of the scheme have changed slightly, the ES Addendum for the Phase 3B scheme said that there was no change from the effects as predicted in the original ES. The risk of the approved hydroelectric scheme being constructed at the same time as the EA flood defence works is thought to be very low.

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Mersey Warrington ES Addendum FRMSPhase 3B - Woolston Non-Technical Summary

14 SUMMARY OF EFFECTS

14.1 There will be very limited changes in effects as compared to the original ES. Those effects considered to have altered due to the proposed changes to the works are on landscape and visual amenity, traffic, and noise and air quality. The effects considered to have changed since the original ES relate mainly to the construction phase, and all are therefore temporary. Measures have been proposed to reduce the disruption caused by these effects. With these measures in place, these effects can be reduced so that no important negative environmental effects will be experienced. The construction of the scheme will, by its very nature, bring about positive effects because it will greatly reduce the risk of flooding for residential and commercial properties. It will also make safe a collapsed riverbank, so allowing a Public Right of Way to be re-opened.

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