TA5 1UD, NNB Generation Company (HPC) Limited, EPR/HP3228XT/V005: environmental permit proposed decision advertisement

Closed 25 May 2023

Opened 25 Apr 2023

Feedback updated 1 Aug 2023

We asked

This outcome summary is available as a bilingual English/Welsh document in the 'Files' section below.

NNB Generation Company (Hinkley Point C) Limited applied to the Environment Agency to change its water discharge activity permit 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.

We asked for your comments during a consultation on the application from 24 January to 2 March 2023 (see Consultation), and on our proposed decision and draft permit from 25 April to 25 May 2023.

When we consulted, we explained that the consultations were not about the need for nuclear power, UK energy policy or policy relating to the siting of nuclear power stations.

During the consultations we shared information and explained our proposed decision. We emphasised that we would not make any final decisions until we had considered all relevant responses to the consultation.

You said

We received 245 responses from organisations and members of the public

  • For our consultation on the permit application, we received 50 responses
  • For our consultation on the proposed decision and draft permit, we received 193 responses

All responses to our consultation (if the respondent gave permission) are published on this page.

Information about which organisations responded and how each response has been considered is included in our final decision document.

The Hinkley C project team would like to thank everyone who responded to the consultations and attended the online engagement meetings.

We did

We have assessed the permit application, reviewed the evidence and carefully considered the responses we received from both consultations.

Our final decision is that we should grant the permit variation the operator has requested. We have added new limits and conditions in the permit to protect people and the environment.

The previous permit version (EPR/HP3228XT/V004) regulated the operational water discharge activities from Hinkley Point C – they are discharges of these non-radioactive liquid effluents:

  • returned cooling water from the turbine condensers
  • trade process effluents from the various plant systems (including those that maintain water purity and chemistry to keep the best operating conditions and maximise efficiency)
  • treated sewage effluent (from staff welfare facilities)

The final varied permit will also now regulate the returned seawater through a fish recovery and return system.

As a result of our assessment on the impact of the fish recovery and return system discharge, we have included limits on volume, rate and the total biomass discharged from the fish recovery and return system outlet.

We have removed all conditions (or parts of conditions) relating to the acoustic fish deterrent (AFD).

We have concluded that there would be no adverse effect on the integrity of the relevant European designated sites (in relation to pollution from regulated discharges to waters) if there is no AFD in place. This includes those sites functionally linked to the Severn Estuary. The discharges will not result in the condition of relevant SSSIs deteriorating or prevent them from improving or recovering.

We have also concluded that the permit variation will not cause the current status of the water bodies to deteriorate or prevent them from achieving their objectives. 

The final varied permit includes the requirement to use an additional operating technique and an improvement condition. It also includes 2 pre-operational conditions which need Environment Agency approval before the proposed power station can be commissioned or begin to operate. These are included to make sure that NNB Generation Company (Hinkley Point C) Limited builds and operates the proposed power station according to the commitments made in its permit variation application.

The final permit, decision document and public summary are published below and on GOV.UK

Read more about our work regulating Hinkley.

Published responses

View submitted responses where consent has been given to publish the response.


This Overview is available in Welsh translation in the 'Related' section below.

We want your comments on the proposed decision we have made for this permit for

Hinkley Point C Power Station
Hinkley Point
Near Bridgwater


If you have any relevant information you feel we have missed, you can provide your comments.

Our consultation does not relate to the UK EPR™ design. It is not about the need for nuclear power, UK energy policy, the siting of nuclear power stations, nor the safety and security of the design. Here are the aspects and issues we can and cannot take account of.

We can take account of

  • relevant environmental regulatory requirements and technical standards
  • information on local population and sensitive sites
  • comments on whether the right process is being used for the activity, for example, whether the technology is the right one
  • the potential for the land around the site to have an effect on air quality and what pollution control may be needed
  • information that we have not been made aware of in the application, or corrections to incorrect information in the application

We cannot take account of

  • issues beyond those in the relevant environmental regulations
  • anything outside the remit of the environmental permitting regulations, for example, the proposed location of the site, which is done by the local authority through land use planning
  • whether a site should have a formal designation under the conservation of habitats and species regulations or other conservation legislation
  • whether the activity should be allowed or not as a matter of principle – for example, we will not consider whether nuclear power generation is an appropriate process or whether alternative methods of generating electricity should be used instead
  • land use issues or sustainability challenges, even if it is argued that changing the location of the activity would improve its environmental performance
  • the impact of noise and odour from traffic travelling to and from the site
  • the legally defined process we follow to determine a permit
  • comments about the government’s energy policy


  • Anyone from any background


  • Water quality
  • Nuclear
  • Environmental permitting