CLIENT United Utilities

CONTRACT TITLE WwTW Outfall Replacement River Crossing

CONTRACT NUMBER UU Project Number: 80043568

OPERATING UNIT Advance-plus

ADDITIONAL ENVIRONMENTAL REQUIREMENTS KENDAL WWTW OUTFALL REPLACEMENT RIVER CROSSING

Glenn Entwistle

02/07/2020

ACCEPTED BY CLIENT AUTHOR REVIEWER APPROVER (if applicable)

DOCUMENT No. KEND-ADP-ZZ-XX-MS-W-0003

CURRENT REVISION CURRENT STATUS CODE SECURITY CLASSIFICATION

C01 A1 Project Confidential

REVISION HISTORY

REVISION STATUS CODE DATE REVISION DESCRIPTION

P01 S3 10/07/2020 Initial Draft for Review

P02 S3 20/07/2020 Update following review

P03 S3 23/07/2020 Update following Site Layout Updates

C01 A1 24/11/2020 Final Issue Controlled Copy Distribution List EDIT THIS TABLE TO MATCH THE ACTUAL PROJECT TEAM – MAKE SURE YOU INCLUDE ALL KEY MANAGEMENT/ SUPERVISORS AS THEY WILL BRIEF THE REQUIREMENTS TO OTHERS E.G. OPERATIVES WHO HAVE RESPONSIBILITIES UNDER THIS METHOD STATEMENT

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CONTROLLED JOB TITLE COPY NO. 01 Project Manager 02 Project File 03 United Utilities 04 05 06 07 08 09 10 11

Additional Environmental Requirements/Considerations for MTBM Method

Contents Purpose ...... 3 Location ...... 3 Statutory Designations ...... 4 Flood Risk ...... 6 Public Rights of Way (PRoW) ...... 8 Ecology and Biosecurity ...... 10 Construction Management ...... 12

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Purpose The purpose of this plan is to identify any potential environmental and planning requirements and considerations which will need to be satisfied before construction commences, and then managed during construction, to ensure compliance with Regulator requirements and to prevent environmental incidents.

Following the previous failed attempt, the original proposal was to reinstate the outfall pipeline via open-cut methodology following an alternative route to the west of the original pipeline route. However, the works are now proposed to be delivered using a micro tunnel boring machine (MTBM) launch from the south of the river and received to the south of Kendal WwTW, as detailed on the images below.

Location

The working area will encompass a launch shaft and compound area to the south of the River Kent, and a reception shaft to the north of the River Kent and the south of Kendal WwTW. The southern compound and working area will be accessed via temporary haul road to the south-east of the compound from Road, and the reception shaft will be accessed via the existing access to Kendal WwTW, using the existing site access road, ands a ramp down to the working area – as detailed on plans UURKO-MAE-XX-XX-DR-C-0006_P01-2 (North) and UURKO-MAE-XX-XX-DR-C-0007_P01-1 (South) and as per below.

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North South

Statutory Designations The River Kent itself is designated as a Site of Special Scientific Interest (SSSI) (River Kent and Tributaries) and also a Special Area of Conversation (SAC) (River Kent). The river is designated due to the densities of white-clawed crayfish throughout its system, in addition to this, the river also qualifies due to the presence of Freshwater Pearl Mussel and Bullhead, as well as Ranunculion fluitantis and Callitricho-Batrachion vegetation found in the river. The river is also Salmonid.

The previous attempt and proposed offline pipeline route both required open cut excavation across the River Kent to install the new section on pipe. As such there would be significant impacts to the species named above, requiring both fish rescue and removal of white-clawed crayfish. The MTBM methodology entirely removes the need to enter the river and affect the riverbed, reducing the direct impact upon the above species.

In addition to this, indirect impacts upon the river associated with the construction of a cofferdam, such as scour and erosion of the southern bank, as a result of hydrological impacts are also avoided.

Although the risk of direct impact upon Crayfish, Bulllhead and Salmonids is removed through the MTBM method, the potential for indirect impacts from noise and vibrations remains and is subject to review to see what measures can be taken to minimise these impacts.

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To the south of the River Kent, and west of the southern working area and compound, is located the Watercrook Roman fort and civil settlement Scheduled Monument. Roman forts are rare nationally and are extremely rare south of the Severn Trent line. As one of a small group of Roman military monuments, which are important in representing army strategy and therefore government policy, forts are of particular significance to our understanding of the period. All Roman forts with surviving archaeological potential are considered to be nationally important. The Roman fort and civilian settlement immediately north west of Watercrook Farm is highly representative of its period and is reasonably well-preserved. Excavation has revealed extensive archaeological deposits associated with complex phases of occupation and use. The significance of the fort is increased by its association with its civilian settlement. Taken as a whole, the monument provides insight into the Roman military occupation of northern and the complex relationship between Roman forts and native settlement and commercial activity.

The proposed line of the MTBM and new pipeline is to the east of the Scheduled Monument and as such no excavations or tunnelling is required within the boundary of the Monument. At its nearest point, the southern working area and compound are approximately 36m to the south-east, and the nearest line of the MTBM route is approximately 15m to the east.

The site is approximately 1.7km to the east of the boundary of the National Park.

Further Actions:

1) Habitats Regulations Assessment required to assess the likelihood of significant impact upon the SAC to confirm the proposed methodology is suitable and acceptable to Natural England, Environment Agency and County Council. 2) Review of previous tunnelling works beneath the River Derwent to be undertaken to identify potential impacts and any mitigation measures to reduce the indirect impacts of noise and vibration.

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3) To consult with MTBM contractor to establish if they have any representative noise and vibration data for tunnelling in similar ground conditions (i.e. very strong limestone, sandy gravel, and medium density sandy gravel). 4) Historic England to be notified of proposed methodology and route.

Flood Risk The loss of the original section of pipe across the River Kent was caused by Storm Desmond in December 2015, and the area is known to flood (as indicated on the EA Flood Map presented below). In particular, the area immediately around the river is designated as Flood Zone 3 (1 in 100 or greater annual probability of flooding), and the area to the north of the river as Flood Zone 2 (between 1 in 100 (0.1%) and 1 in 1000 (1%) annual probability of flooding). The proposed southern working area and compound are both located predominantly within Flood Zone 1, with the western edge of the compound in Flood Zone 2. The temporary access from Natland Lane Road is within Flood Zone 1.

The closest upstream monitoring station is located at Victoria Bridge Kendal, approximately 2.75km upstream following the River Kent. This site maintains a continuous update of river water level and historical data for the previous 150 days. The river has three weirs spanning the river between the site location upstream to Victoria Bridge. The highest recorded level at this monitoring point is approximately 3.88m, and when levels reach 2m here, flooding is likely. The usual water level range is between 1.18-1.92m, and the typical water level over the last 12 months has been between 1.18- 2.99m. The proposed working area is covered by the EA Flood Warning System.

The highest river level recorded during Storm Desmond in 2015 was 44.7m AOD at – datum will need to be related to at site, but the difference is envisaged to be centimetres. A decision will need to be made on whether the shaft rings will be constructed to the Storm Desmond flood level, or the flood level identified in the Flood Risk Assessment (as per below section).

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Although the southern working area (launch shaft) appears to be outside of 8m from the top of the banks of the River Kent, the exact measurement from the top of the riverbank is not known. However, the northern shaft working area appears to be in the riverbank so a Bespoke Flood Risk Activity Permit is likely to be required for the works on this basis, and the application should be made including both working areas and the compound.

An Environment Agency Flood Risk Activity Permit Exemption exists for “Service crossings below the bed of a main river not involving an open cut technique (FRA3)” – with this exemption you can install a service crossing below the bed of a main river using techniques like directional drilling but not using an open cut technique. The conditions of this exemption are as follows:

 the service crossing is within 10 degrees of perpendicular to the direction of flow in the main river  the service crossing is at least 1.5m below the riverbed along its whole length, and the same height is maintained for at least 5m beyond each bank (measured from the top)  the distance from the launch and reception pits to the landward side of each bank of the main river is: o 8m or more in the case of a non-tidal main river o 16m or more in the case of a tidal main river  the service crossing does not pass through any bank, culvert, remote defence or river control works on the main river or through any sea defence  the service crossing is 50m or more upstream of any impoundment or artificially raised channel  you erect permanent hazard markers on both banks of the main river  you remove from the flood plain all excavated material not re-used on the site of the works  your works do not disturb the bed and banks of the main river

If the above conditions cannot be complied with, a Bespoke Environmental Flood Risk Activity Permit (FRAP) will be required. The determination period for a FRAP can be between 2-4 months.

A Flood Risk Assessment of both working areas will be required to support both the HRA and the FRAP due to the locations being proposed within EA Flood Zone 2 both in the northern and southern working areas.

To mitigate the risk of flooding, the top of both the launch and reception shaft segments would be raised above the 30 year flood level (this is to be informed by the Flood Risk Assessment, and to take in to account the proposed flood mitigation measures being implemented in the area by the EA in the coming months, and the impact of these on future flood levels and locations).

A Site Flood Plan will be developed and will form part of the daily briefings for any works being undertaken within the flood risk area and it will also be displayed on site at all times. Weather forecasts will also be monitored on a daily basis and determine flood risk and whether the next phase of works should proceed. In the event of a flood warning being issued, all mobile plant / machinery or any potentially hazardous material will be moved outside of the floodplain in advance of a flood event.

Further Actions:

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1) River levels to be monitored in the months preceding the works commencing and historic averages and worst-case scenarios for the timing of the works obtained. 2) Flood Risk Assessment required for both launch and reception shaft. To take in to account modelling of resultant flood risk following implementation of EA mitigation measures. 3) EA to be consulted on the requirement to apply for a Bespoke Flood Risk Activity Permit. 4) Prior to site setup and construction commencing, Site Manager to sign up to EA Flood Alert service. 5) Site Flood/Contingency Plan to be produced detailing the action to be taken in the event of flood warnings being issued once construction has commenced.

Public Rights of Way (PRoW) There are 3no PRoW in close proximity to the proposed working areas and compounds. As illustrated with thick green lines on the figure below: one PRoW runs along the bank on the northern peninsula of the River Kent, another runs along the southern bank and joins Watercrook Lane, and a third runs adjacent to Natland Road before finally joining it.

Due to the proposed reception shaft location between the River Kent and Kendal WwTW it is envisaged that the PRoW along the northern peninsula will have to be either closed, or diverted to the north of Kendal WwTW (as illustrated by the green dashed line below) on the grounds of safety given the reduced space between the edge of the working area and the river once works commence.

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It is not envisaged that the footpath along the southern bank of the river which joins Watercrook Lane will be impacted, as all works and compound are to be located to the south of Watercrook Lane and to the east of where there PRoW leaves the Lane and heads south-west across the field. Acoustic fencing may be required along the heras facing bordering the PRoW, as well as the orientation facing the property to the east, to reduce potential noise impacts and nuisance.

The PRoW which runs adjacent to Natland Road consists of a hardstanding area which appears to be used for laydown (as shown on the image below). As such it is not envisaged that this would need to be closed or diverted, but this should be discussed and agreed with Cumbria County Council. As there is also an existing entrance from the highway to this area, and the access from this laydown area to the compound will not be from the highway, the need for Planning Permission for the temporary access is not envisaged as being required, but this should be confirmed with Cumbria County Council.

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Access to the northern working area will be via existing access to Kendal WwTW from Wattsfield Road (as pictured below).

Further Actions:

1) PRoW closures or diversions for the northern peninsula and for the access from Natland Road to be discussed and agreed with Cumbria County Council. 2) Planning Permission requirements for the temporary access to the southern compound to be discussed and agreed with Cumbria County Council. 3) The need and degree of noise mitigation at the southern compound to prevent impacts upon users of the PRoW and the residents of the properties to west and more so the east, to be determined.

Ecology and Biosecurity Trees

As previously stated, a Habitat Regulations Assessment (HRA) will be required to assess the likelihood of significant effect of the works upon the SAC and to obtain Regulator approval for the works.

The proposed location of the reception shaft and working area on the north bank of the River Kent, and the access to this location from Kendal WwTW will require the removal of at least 3no trees, potentially more. A tree survey and impact assessment is required to confirm which trees will require removal and what measures will be required to protect the retained trees. A review of the Planning Portal has not identified any Tree Preservation Orders (TPOs) in this area, but this should be confirmed with the Tree Officer at Cumbria County Council.

Bat survey and nesting bird surveys may also be required before trees can be felled or pruned.

Spoil from the reception shaft working area is proposed to be stored within Kendal WwTW whilst awaiting collection for recycling or re-use as backfill. From satellite imagery, there appears to have

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been trees planted recently in the area adjacent to the site entrance, and this area should be avoided when storing spoil.

There are no trees present in the proposed location of the southern working area and compound. However, some pruning and removal may be required at the access point from the laydown area off Natland Road – this area should be included in the Tree Survey and Impact Assessment.

Biosecurity

The HRA submitted for the original crossing attempt identified “the presence of Himalayan Balsam, dominant in some areas” with reference to the River Kent SSSI. Although no works are required in the channel of the River Kent, invasive plant species such as Himalayan Balsam, Japanese Knotweed and Giant Hogweed are all known to grown along river banks and there is a risk one or more of these plants could be present in the proposed northern working area. It is recommended that this area is subject to survey (preferably during a time when the plant is in flower) to identify potential implications. If any invasive species are identified, these will be fenced off and avoided where possible, if this is not possible, a dedicate Invasive Plant Management Plan should be implemented. As good practice, all boots, machines and tools should be cleaned prior to entering the working area.

Due to location of the southern working area and compound being in a field some distance from the river, there are not envisaged to be any issues regarding invasive plants.

The access point from Natland Road for the compound should be subject to survey at the same time as the northern working area to confirm presence and further requirements.

As the works no longer require entry in to the River Kent the risk of biosecurity issues such as the introduction of invasive species is much reduced, but all works in the northern working area will comply with the “Check, Clean, Dry” campaign to stop the spread of invasive aquatic species.

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Further Actions:

1) Tree Survey and Arb Impact Assessment to be completed to identify the presence of TPOs or Conservation Areas, which trees will require removal and what protection is required for the trees to be retained. 2) Trees to be felled or pruned or which are in the zone of influence of the works to be surveyed for potential roosting bats and nesting birds. 3) Invasive Plant survey to be completed focussing on the northern working area and the access from Natland Road, and recommendations developed as necessary.

Construction Management During site setup and construction works, good environmental management is to be maintained at all times to reduce the potential for environmental incidents.

Dewatering

The dewatering of trenches will be required during shaft construction. Due to the proximity of the reception shaft to the River Kent, this will be dewatered to Kendal WwTW for treatment prior to discharge. Dewatering of the launch shaft will be via pumping into a temporary lagoon, this will be constructed in the farmers field adjacent to the main compound (South Drive Shaft Set Up) and will consist of a shallow pit 10m x 10m x 0.5m deep to allow the pumped water to permeate back into the ground / adjacent river. Depending on the volumes of groundwater anticipated and the forecast duration of pumping, an Abstraction Licence may be required for this activity.

All forms of pumping on site will be managed via Permit to Pump process and monitored throughout.

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Due to the proximity of the northern working area to the River Kent and the potential for run-off, silt fencing will be installed around the bottom of the working area to prevent silty run-off entering the River Kent.

Slurry Management

Excavated material is removed / pumped from the tunnel face to the surface via a closed slurry system. The slurry proposed will consist of predominately water which becomes thicker /heavier as the drive progresses with any clay content within the excavated material or with the addition of an additive / bentonite to transport the gravels back to the separation plant.

At the separation plant the slurry will be passed over a primary rotating Calyball screen which will remove all the larger excavated material out for the slurry. The slurry then passes over a vibrating screen taking material < 1.5mm out of the slurry which is then passed through the hydro cyclones to remove the silts and fine sands. The slurry is then deposited into the tank for recirculation.

As the slurry thickens it will be pumped offline from the slurry transport circuit to a centrifuge to remove any suspended clay/silt allowing the slurry to be utilised to complete the drive.

Arisings from all plant will be discharged into a muck skip or bin and retained temporarily before disposal off site.

Slurry at the TBM face is controlled and monitored from the surface control cabin via the TBM operator. The pressures are monitored live and if there is any pressure drop on the slurry, which would indicate a leak, then the feed is cut and controlled until it can be determined if it’s due to a leak or changes in ground conditions. If the ground is all inert then the slurry will be inert and it will have no effect on the river, as we are expecting to be tunnelling through rock or sandy gravels. There will be no risk or clay or silt entering the river. Any lubricants or additives used in the process will be inert and biodegradable and managed via this method. The slurry separation plant will be located +10m from the River Kent and outside of Flood Zone 2.

Topsoil/Spoil Storage

Topsoil and spoil from the excavation of the shafts will be stored either within the southern compound area, or at a location within Kendal WwTW agreed with UU Ops. Where possible, spoil will be re-used as backfill material. Where this isn’t possible, spoil will be removed from site for recycling.

Further Actions:

1) The need for an Abstraction Licence for groundwater dewatering to be discussed and agreed with the EA.

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