Corporate report

Environment Agency response to Hinkley Point C Development Consent Order Material Change consultation

Published 7 May 2024

Applies to England

1. Foreword

In responding, our primary aim is to ensure that the new nuclear power station at Hinkley Point C (HPC), and its associated developments, will be constructed, operated and decommissioned to high environmental standards. We seek continued engagement with you to achieve this.

We consider that many of the areas you will need to take into account have been identified in your consultation, although further detail and assessments will follow. We recognise that this information represents your first stage of public consultation and that you plan further engagement in the future. It is worth clarifying that we are not yet in a position to comment fully on any initial conclusions or statements included in your consultation; once further evidence and assessments are provided we will be in a position to do so.

We, together with Natural England and the Marine Management Organisation - as Defra Group – and with Natural Resources Wales, recognise the complex nature of the proposal and that it is important that we are engaged and involved in providing advice in advance of the Development Consent Order (DCO) application. It is essential that the programme reflects our requirements and enables us to plan the use of our specialist resources.

This response does not represent our final view in relation to any future DCO application, or Environmental Permit applications made to us. Our final views will be based on all relevant information included in the applications and the latest guidance available at that time.

We will continue to provide our advice and guidance in response to your project as your detailed proposals continue to develop. For further discussions, please contact nuclear@environment-agency.gov.uk

Ben Shayler

Area Environment Manager (Regulated Industry)

2. Executive Summary

We are responding to EDF’s Hinkley Point C company, New nuclear build (NNB) Generation Company (HPC) Ltd, pre-application consultation to materially change the original DCO.

Our response provides advice on HPC’s obligations in providing an Environmental Impact Assessment, Habitats Regulations Assessment, Water Framework Directive Compliance Assessment, flood risk assessments (FRAs), environmental permits, and other areas within our remit. This is based on the information available in the consultation document and the prevailing legislation, policy, and guidance, in particular the Overarching National Policy Statement for Energy and the National Policy Statement for Nuclear Power Generation. Our advice will respond to new information and any successor National Policy Statements and is without prejudice to future applications.

In reviewing the consultation documents, we consider that many of the areas you need to take into account have been identified. Many of the assessments which underpin these areas have not yet been provided and as such the impacts and proposed suitability of mitigations and compensation cannot be assessed at this time.

In summary our main concerns include:

• we are currently unable to agree with the calculated level of harm from removing the acoustic fish deterrent (AFD)
• more justification is required for the scale and proposed delivery timescales of the compensation package
• the lack of finalised Flood Risk Assessment (including flood risk modelling), Water Framework Directive and other environmental assessments required to agree the suitability of Pawlett Hams, the marine habitats, and fish pass removal/easement proposals

We have included the detailed matters that need to be considered in Appendix A. These material considerations will need to be resolved before submission of a Material Changes application.

3. Response

3.1 Our role on Nuclear Sites

We are the environmental regulator for nuclear sites in England. We decide under the Environmental Permitting Regulations whether environmental permits should be issued to operators of nuclear sites, and what conditions the permits should contain, to properly protect people and the environment. We enforce the conditions of the permits to ensure that operators comply with the requirements of their permits and can take action, including prosecution, if they do not.

We provide advice to other bodies making decisions about nuclear sites, including the Planning Inspectorate (PINS), where their decisions are related to our responsibilities, such as flood risks.

More widely we provide advice to Government and other bodies about nuclear sites and the environment. We also advise potential operators of nuclear sites so that they know and understand our requirements and expectations of them.

Our regulation on nuclear sites includes disposals and discharge of radioactive wastes, the discharge of cooling and process water, the disposal of non-radioactive wastes and the operation of standby generation plant. Together with the Office for Nuclear Regulation, we are responsible for making sure that any new nuclear power stations built in England meet high standards of safety, security, environmental protection, and waste management.

3.2 Statutory consultee

We are a statutory consultee in the planning process which means that planning authorities must ask us about proposed developments. We advise on the effects of development on people and the environment. Key aspects of developments that we consider include flood risk, discharges to air and water, the amount of water required for operation and construction, the amount of waste produced by the development and how it is managed and minimised.

This document sets out our advice to HPC about the proposals they have set out in the documentation supporting this consultation.

3.3 Our response

From the limited information available for this consultation, we have focused our comments on the environmental issues relating to the removal of the AFD and the proposed habitat creation proposals. This response does not represent our final view in relation to any future Development Consent Order application. Our final views will be based on all relevant information included in the applications and the latest guidance available at that time.

4. Removal of acoustic fish deterrent

4.1 Background

HPC applied for permits from the Environment Agency to build and operate Hinkley Point C in 2011. These are permits to:

• dispose of and discharge radioactive wastes
• operate standby power supply systems using diesel generators
• discharge cooling water and liquid effluents into the Bristol Channel (this included conditions relating to 3 complementary fish protection measures submitted as part of the application and cooling water system design)

We consulted on draft decisions on the applications in autumn 2012 and granted 3 operational environmental permits to the company for Hinkley Point C in March 2013.

In February 2019 we received an application for a permit variation from NNB Generation Company (HPC) Ltd. The company wanted to change how Hinkley Point C nuclear power station takes and discharges cooling water from the Severn Estuary. They wanted to remove the reference to one of the fish protection measures in the existing permit – the AFD from the intake pipes for the cooling water. The purpose of the AFD, together with other measures, is to reduce the number of fish which could be drawn into the cooling water system and killed.

We held a public consultation in 2019 to seek comments on the permit application.

We produced a habitats regulation assessment (HRA) as part of the permit determination. We were unable to conclude that removing the AFD would have no adverse effect on some of the protected species in the Severn Estuary Special Area of Conservation (SAC), Severn Estuary Ramsar, River Wye SAC and River Usk SAC.

In August 2020, NNB Generation Company (HPC) Ltd considered (deemed) that we had refused their permit variation because we had not finished ‘determining’ their application.

In September 2020, the company appealed to the Secretary of State (SoS) for the Department for Environment Food and Rural Affairs (Defra).

PINS normally hears and makes decisions on permit appeals. In this instance, the Defra SoS decided they would make the final decision.

In June 2021 PINS led the appeal inquiry. As an independent regulator the Environment Agency takes a proportionate approach but must be robust and confident in the assessments and decisions it makes. We carefully considered the grounds that NNB Generation Company (HPC) Ltd set out and we responded to the appeal accordingly. The main parties made their closing statements about the appeal on 24 June 2021. The PINS inspector produced a report presenting recommendations for final determination by the Defra SoS.

On 2 September 2022, the Defra SoS dismissed NNB Generation Company (HPC) Ltd’s appeal to remove the AFD conditions from the original permit.

The decision was based on the PINS Inspector’s recommendations from the inquiry. The decision is set out in a letter from the Secretary of State and in the Inspector’s report. In deciding to reject the appeal the Secretary of State “agrees with the Inspector’s conclusions that, in the absence of an AFD, it cannot be concluded that there would not be adverse effects on the integrity of the Severn Estuary SAC, Severn Estuary Ramsar site, the River Usk SAC and the River Wye SAC”.

These areas are home to rare and declining wildlife. The report states that even low-level impacts on a population at risk can be significant and that there are uncertainties in the data and calculations of the potential impacts on these species. You can:

• read the SoS’s decision letter and the PINS inspector’s report
• read about the permit application and appeal on our consultation website
• read documents about the public inquiry, including the programme, on the Defra file sharing service

NNB Generation (HPC) Company Limited applied to the Environment Agency to change its operational water discharge activity permit for Hinkley Point C in December 2022.

The water discharge activity permit is a permit to discharge returned abstracted seawater from the cooling water system, fish recovery and return system, and other liquid trade effluents (including treated sewage effluent) to the Bristol Channel.

The permit application submitted to the Environment Agency proposed the following changes:

• remove all references to the AFD
• remove all references to the effects of abstracting cooling water because the Environment Agency does not regulate this from the open sea
• add the discharge of seawater and biomass from the fish recovery and return system

In July 2023, the Environment Agency issued a variation to the operational water discharge activity permit to remove reference to the AFD. The decision document can be viewed on Summary of decision: Hinkley Point C water discharge activity permit variation: EPR/HP3228XT/V005. The varied permit includes limits and conditions to make sure that people and the environment are protected from the water discharges under normal operation.

The AFD remains on the marine licence granted by the Marine Management Organisation and the DCO for planning, which regulate the intake and abstraction from the nuclear power station at Hinkley Point C.

5. Habitat Creation

Natural England is the Statutory Nature Conservation Body (SNCB) for England and Natural Resources Wales is the SNCB for Wales under the Habitats Regulations. They are statutory consultees in the DCO process and will provide advice to PINS on the applicant’s Environmental Impact Assessment and HRA.

Although Natural England and Natural Resources Wales will lead in HRA advice, the Environment Agency is a statutory consultee in the DCO material change process. Our advice to PINS will be informed by the applicants’ HRA and Environmental Impact Assessment that will consider the likely significant effects on the environment. We will also provide advice under our general duty to ‘maintain, improve and develop’ freshwater fisheries.

5.1 General principles  

We agree that the measures identified could form part of an appropriate compensatory package. We advise that the advice note provided by NRW and NE in March 2023 continues to be considered during the further development of the compensatory measures and the Adaptive Management and Monitoring Plan (AMMP). There are several issues to resolve, and we advise that a Statement of Common Ground approach is adopted as soon as possible in advance of the DCO material change application.

5.2 The level of harm  

We are currently unable to agree with the calculation of the level of harm without further clarification of the methods used.  

We do not believe that scaling the monitoring results for HPB to HPC is an appropriate way to quantify the risk to adult shad. The latest tracking evidence suggests that adult shad are more likely to be impinged at HPC than the scaled results from HPB suggest.    

For salmon, we cannot agree that the mean predicted impingement is a realistic estimate of the harm due to data deficiency in sampling. However, in the presence of a robust adaptive management plan, this should not in itself prevent the delivery of a suitable compensation package.   

The inclusion and consideration of uncertainty in the assessed level of harm will lead to a reduced risk of additional compensation being triggered as part of adaptive management.

5.3 Sufficiency of the compensation package

More justification is needed on how the shortlist of compensatory measures were selected from the long list and how they are sufficient to ensure the coherence of the national sites network (NSN).  

The compensation package does not appear to consider the delay between the operation of HPC and the functioning of the compensatory measures. Compensation should be in place ‘in time’ to provide fully the ecological functions that they are intended to compensate for.   

Where delivery ‘in time’ is not fully achievable, compensatory packages must consider additional measures for the interim. These additional measures could be identified through re-evaluating the long list of proposed compensation. Full justification for not including any additional measures must be provided.  

5.4 Habitat Creation  

A production to biomass ratio (P:B) of 2 to 4 has been applied to estimate production losses due to impingement. No justification is given as to why:  

• these ratios have been selected
• the upper P:B ratio of 4 is expected to be ‘highly conservative’
• it is appropriate to use a P:B ratio that has previously been applied to invertebrate losses and not just fish

Full justification is needed as to why offsetting as little as 15.7% (comprehensive impingement monitoring programme 1, CIMP1) and 39.9% (CIMP2) of the mean fish production losses is sufficient to offset the adverse effects predicted and maintain the overall coherence of the national sites network.  

Compensation associated with Salem power station has been cited (Balletto and others, 2005). In this instance the operator quadrupled the amount of compensatory habitat that was calculated using a P:B ratio. It is unclear why has a similar approach not been adopted. 

5.5 Pawlett Hams        

We are unable to agree with the suitability of Pawlett Hams until flood risk assessment (including flood risk modelling) has been completed and submitted to us for review. Further advice is detailed in the section ‘hydraulic modelling’. Any listed features of the Bridgwater Bay site of special scientific interest (SSSI) lost through the creation of the proposed saltmarsh must be compensated for appropriately. 

The Environment Agency own land both at The Island and Pawlett Hams. We would welcome early conversation regarding this issue.

6. Fish pass easement/removal  

The proposal is to remove, or provide easement on, 3 short-listed weirs out of a long list of 5. No clear justification has been provided on why this is considered sufficient to offset the adverse effects predicted and maintain the overall coherence of the national sites network. Flood risk assessments (including flood modelling) and Water Framework Directive assessments will need to be undertaken. Asset ownership and maintenance of any structures should also be assessed.

We strongly recommend that the creation or improvement of spawning and nursery habitats are included in addition to weir removal or easement.  

6.1 Adaptive Management and Monitoring Plan (AMMP)  

We are unable to agree to the sufficiency of any of the compensatory measures without a robust AMMP in place.  

We have not seen any detail on the AMMP in the consultation documents that would provide us with confidence that action could or would be taken if impingement was bigger than expected or the compensatory measures did not function as predicted.  

The AMMP should as a minimum:  

• have appropriate stakeholder involvement
• develop appropriate monitoring, including metrics, frequency, and duration
• establish meaningful trigger points that will result in positive action
• define and evaluate how the success of the compensation package will be measured in relation to the functionality and coherence of the national site network
• establish the baseline where the compensatory measures are enhancing an existing habitat to demonstrate the additional benefit delivered
• provide alternative measures should it be shown that the compensation is not providing the expected ecological function, or impacts are greater than predicted

6.2 Eels  

An assessment under the Eels Regulations must be carried out as part of the DCO application. Additional measures to those proposed as part of the derogation package might be required.  

6.3 Flood Risk

The advice in the following flood risk section is targeted for the proposals at Pawlett Hams and The Island. We will also have flood risk requirements for the fish pass removal/ easement works but will not be able to provide detailed advice until the locations and proposals have been confirmed.

No timescale has been provided for the production of the necessary Flood Risk Assessments or hydraulic modelling. It is essential to note that these documents may take some time to produce and must be agreed upon in advance of the DCO submission to avoid delays to the project. Any proposals which would result in increased flood risk to people and property may be unacceptable. The preliminary environmental information report (PEIR) asserts that creation of saltmarsh will help regulate water levels and reduce flood risk, but this assumption cannot be demonstrated without the correct evidence base being submitted. Climate change allowances and sensitivity testing will be necessary within the modelling because coastal saltmarshes are sensitive to sea level rise.

6.4 Hydraulic Modelling

Impacts to flood risk and geomorphology should be fully assessed. Please be aware that existing flood modelling in the area is being updated during detailed design of the Bridgwater Tidal Barrier to account for changes in the coastal flood boundary data and operational barrier rules. We therefore recommend engaging with the Environment Agency while this work is being undertaken to keep up to date with the latest available modelling.

Changes to the tidal prism and potential erosion at Burnham on Sea and impacts to Brue Pill and Stert Island must be fully investigated. The buffer zone needs to be extended to include Bridgwater Tidal Barrier (BTB) and Burnham, Brue Pill, and Stert Island. Upstream and downstream model boundaries (Buffer Zone) must be agreed:

• to include model runs with and without Bridgwater Tidal Barrier and Burnham on Sea beach
• to check the impacts of the work on the BTB and other tidal defences along the coast and tidal reaches of the Parrett, and the impact on Burnham Beach.

Please note that previous studies suggested that allowing water to enter Pawlett Hams would result in sand being eroded from Burnham Beach. There are bank improvement works planned on the opposite side of the river to the Pawlett scheme which are part of the Barrier project and potential impacts to water levels could be far reaching and impact the existing gate and bank design of the barrier scheme.

At the Island, we require modelling to assess the impacts on the banks from Huntspill Outfall to the Hams new defences. If there is greater tidal impact on the existing banks, we would require the existing banks from the island to be improved downstream to the Hams such that they are the same design as that being provided for the new Hams banks (6m crest width, 1:4 side slopes).

We will require modelling to be completed which addresses the following matters:

• tidal modelling will need to demonstrate there is no impact on the existing defences from the Huntspill outfall to Burnham beaches
• location of breaches - modelled scenarios are required to show how the breach configuration has been chosen as the best option
• impact on downstream defences must be demonstrated
• impact on and interaction with Steart breach must be demonstrated
• new embankments shall have a minimum of 6m top width and with 1:4 side slopes, considering the high level of settlement that is likely to occur here

6.5 Monitoring Requirements

If maintenance is not carried out there is risk of failure and increased flood risk to third party land, properties, and communities. To capture the impacts that may result from the scheme a monitoring programme must be instigated at both Pawlett Hams and The Island. This should include 2 years baseline monitoring followed by an extensive 10-year post breach monitoring programme to pick up any changes resulting from the scheme. Triggers should also be identified with actions to be taken to remedy impacts:

• wave and water levels at both sites
• water levels on the Parrett and at both sites
• flow rates within the Parrett and at both sites
• erosion rates on breaches in case of unzipping – through aerial photography/visual inspections
• lidar/aerial photography/bathymetry checking for erosion and sedimentation changes within the breaches and River Parrett channel, both sub and intertidal
• laser scanning to monitor impacts on bank adjacent to breaches
• lidar and aerial photography as well as beach surveys of Burnham beach due to concerns over beach lowering as a result of changes in the tidal prism
• impacts to Stert Island and Brue Pill and Burnham beach should be monitored as possible far-reaching impacts

The monitoring programme needs to be fully scoped and incorporated into a final monitoring and management strategy that deals with data collection, data management and analysis, and remedial measures that are triggered by the programme. This monitoring and management strategy must be approved before works begin.

6.6  Management Requirements

It is unclear how the existing and new defences are to be maintained. For example:

• we note that the existing online defences are to be removed but our preference would be for them to be retained. We need to know who would be responsible for maintaining them. If they fail they could detrimentally impact the site and the water levels in the estuary
• who will be responsible for inspecting and maintaining the raised road down to White House Farm?
• who is going to be responsible for inspecting and maintaining the new defences that will protect against tidal intrusion into Pawlett and the surrounding area?
• how will the existing defences south of the larger Pawlett Hams breach be accessed when White House Road is removed? Vehicular access for maintenance may be needed along the defence itself, clarification will be required

All new banks and other new assets will need a maintenance liability of 5 years to allow for establishment and settlement.

7. Contact the Environment Agency

If you have any queries email nuclear@environment-agency.gov.uk.