Appropriate assessment of the application to vary the water discharge activity permit for Hinkley Point C Final Version 13 November 2020 Foreword NNB Generation Company (HPC) Limited (NNB GenCo) are constructing a new nuclear power station at Hinkley Point in Somerset, known as Hinkley Point C (HPC). The construction and operation of HPC requires various permissions from the Environment Agency (EA), Department of Business Energy and Industrial Strategy (BEIS), and the Marine Management Organisation (MMO) amongst others. Permissions for the building and operation of the power station were granted in 2013. These included a Development Consent Order (DCO), a Water Discharge Activity (WDA) permit, and a Marine Licence (ML). The Company no longer wants to install an Acoustic Fish Deterrent (AFD) system on its marine intake heads and so it is applying to vary its current WDA permit to remove the conditions related to this measure. It will also apply to remove the conditions from the DCO through a material change application and also from the marine licence. The Environment Agency, as a Competent Authority, is required, under the Conservation of Habitats and Species Regulations 2017 (Habitats Regulations), to undertake a Habitats Regulations Assessment (HRA) for any permissions it grants that have the potential to impact upon European designated sites (Natura 2000 sites). These include, Special Areas of Conservation (SACs and candidate SACs), which are designated under the EC Habitats Directive for important high quality habitat sites, and Special Protection Areas (SPAs and potential SPAs), designated under the EC Birds Directive, classified for rare and vulnerable birds (as listed on Annex I of the Directive), and for regularly occurring migratory species. Ramsar sites are wetlands of international importance designated under the Ramsar Convention and Government policy gives Ramsar sites broad equivalence to those designated under the Birds and Habitats Directives. Therefore, Ramsar sites will be included within the assessment. Collectively these are known as Habitats sites. The purpose of this assessment is to ascertain, in view of the conservation objectives of the Habitats sites, whether it can be concluded that the variation to the permit will not adversely affect the integrity of the Habitats sites in question, either alone or in combination with other relevant permissions, plans, or projects. What follows in this document is a record of the Habitats Regulations Assessment required by Regulation 63 of the Conservation of Habitats and Species Regulations 2017 (SI No. 2017/1012), undertaken by the Environment Agency. Information from this assessment may be used by BEIS and the MMO as Regulation 67 of the Habitats Regulations makes provision for coordination where more than one competent authority (CA) is involved. Further Guidance on competent authority co-ordination under the Habitats Regulations issued by Defra (MIEU) in 2012. 2 of 238 Executive summary We have carried out a Habitats Regulations Assessment (HRA) for the proposed variation to remove the requirement for the acoustic fish deterrent, and the EA has led the process to include the Fish Recovery and Return (FRR) system outlet as a discharge point on the permit. The HRA assesses the potential impact of our permissions on achieving the conservation objectives for the Natura 2000 sites, as listed in section 1.4 of this assessment and as identified by Natural England and NRW. The main part of the assessment was concerned with the potential for polluting matter from the FRR system, the entrapment of fish through the intake, and their potential effects on the Habitats sites listed in section 1.4 as HPC is partly within or functionally linked to these designated sites. We have carried out desk-based research of scientific papers including information from technical reports written by the applicant NNBGenCo and their consultant Cefas. However, because of the complex nature of the Habitats sites and the need to make assumptions about precise biological responses to environmental change, we have also used expert judgement to reach our conclusions about effects and impacts. The data, assumptions, and approach we have used in reaching our conclusions has been internally and externally peer-reviewed and endorsed by national experts with particular knowledge of the sites. The main areas of potential concern we focused on included entrainment and impingement of fish and planktonic organisms, loss of prey species, toxic contamination, nutrient enrichment, smothering and habitat loss. These hazards have been assessed in respect of the project itself; and in respect of the combined impact of the project with other permissions, plans or projects in the area. The conclusions below reflect our findings for the sites listed in section 1.4 Relevant Habitats Sites. The results of the screening stage are provided in Annex 5. We applied recent case law when carrying out the screening due to the reliance of mitigation measures in the variation application (see 1.3 below). We have concluded that it was not possible to conclude no adverse effect on the integrity of the Severn Estuary / Môr Hafren SAC and Ramsar site, the River Usk / Afon Wysg SAC and the River Wye / Afon Gwy SAC from the variation for the removal of the requirement for an AFD at HPC alone. We have concluded that there was no adverse effect on the integrity of the remaining sites listed in 1.4 below from the variation for the removal of the requirement for an AFD at HPC either alone or in- combination with other permissions, plans or projects. We have concluded that there was no adverse effect on the integrity of all of the relevant sites listed in 1.4 below from the variation to include the FRR system outlet as a discharge point on the permit at HPC either alone or in-combination with other permissions, plans or projects. We are confident in our approach to the assessment and although there is uncertainty, given the modelled effects, it cannot be certain that there are no adverse effects on the integrity of the designated fish species (listed above) of the Severn Estuary / Môr Hafren SAC and Ramsar site, the River Usk / Afon Wysg SAC and the River Wye / Afon Gwy SAC and that no reasonable scientific doubt about the absence of effects remains as per Case C-127/02, Waddenzee paragraph 61. More recent case law reaffirms this position in particular Case C-258/11, Sweetman and in relation to sites in unfavourable conservation status, Cases 294/17 and 294/18, Dutch nitrogen (see 1.3.3 below). 3 of 238 4 of 238 Contents Appropriate assessment of the application to vary the water discharge activity permit for Hinkley Point C .......................................................................................................................................1 Foreword ...................................................................................................................................2 Executive summary.................................................................................................................3 Contents....................................................................................................................................5 1. Introduction ..........................................................................................................................7 1.1. Requirements of the Habitats Regulations .......................................................................................... 8 1.2. Location of Hinkley Point C .................................................................................................................. 8 1.3. The HRA process ............................................................................................................................... 11 1.4. Relevant Habitats sites....................................................................................................................... 16 1.5. Conservation objectives ..................................................................................................................... 18 2. Appropriate assessment of the proposed removal of AFD requirement .................19 2.1. Overarching assessment for direct effects on fish assemblage and Annex II fish species ............ 21 2.2. The Quantitative Impact Assessment Model..................................................................................... 22 2.3. Uncertainty Analysis ........................................................................................................................... 34 2.4. Further Information ............................................................................................................................. 35 2.5. Annex II species and migratory assemblage assessments ............................................................. 36 2.6. Assemblage of fish species................................................................................................................ 89 2.7. Marine piscivorous birds................................................................................................................... 102 2.8. Marine mammals .............................................................................................................................. 113 2.9. Otter................................................................................................................................................... 127 3. Appropriate Assessment of the inclusion of the FRR