TA5 1UD, NNB Generation Company (HPC) Limited: environmental permit application advertisement
Published 2 August 2021
Applies to England
© Crown copyright 2021
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This publication is available at https://www.gov.uk/government/publications/ta5-1ud-nnb-generation-company-hpc-limited-environmental-permit-application-advertisement-eprjp3122gmv009-and-eprjp3122gmv010/ta5-1ud-nnb-generation-company-hpc-limited-environmental-permit-application-advertisement
Details of the application
The Environment Agency has received a variation application for an environmental permit under the Environmental Permitting (England and Wales) Regulations 2016 from NNB Generation Company (HPC) Limited.
Application number
EPR/JP3122GM/V009 and EPR/JP3122GM/V010
Regulated facility type
Water Management Zones and effluent treatment units
Regulated facility address
Construction site at Hinkley Point C power station
Near Bridgwater
Somerset
TA5 1UD
National grid reference discharge point
ST 19315 46475
Receiving environment
Severn Estuary
Effluent type
New trade effluent comprising effluent from cold commissioning activities, including hydro-testing and demineralised water production; existing trade effluent consisting of pumped groundwater and existing trade effluent consisting of tunnelling effluent and muck bay drainage
Volume
Maximum daily discharge of 1,500 cubic metres at a maximum rate of 70 litres per second (new); Maximum daily discharge of 1,728 cubic metres at a maximum rate of 20 litres per second (existing); Maximum daily discharge of 2,592 cubic metres at a maximum rate of 30 litres per second (existing).
This existing permit allows a number of discharges to be made to the Severn Estuary solely during the construction phase at HPC.
Under reference number EPR/JP3122GM/V009
The Company wants to vary this existing construction phase permit to allow the discharge of another type of liquid waste – known as trade effluent. This will result from cold commissioning activities onsite and it will be discharged into the Severn Estuary via a pipe on HPC’s temporary jetty. Cold commissioning simply means testing the performance of certain components and systems, such as pipes, tanks and other structures. The tests will check for leaks and blockages and how the water flows through them before the start of electricity generation.
The Company wants to be able to discharge up to 1,500 cubic metres daily of this trade effluent from their cold commissioning activities to the Severn Estuary at a maximum rate of 70 litres per second.
In order to carry out these tests the Company wants to carry out the following activities:
a) Hydro-testing - this involves filling components and systems with water up to a certain pressure to test for leaks. The company then want to discharge this used water to the Severn Estuary.
b) Flushing – this involves filling and emptying the components and systems several times to check they are clean and flowing correctly. The company then want to discharge this used water to the Severn Estuary.
c) Production of demineralised water - this involves purifying water to be used for the Hydro-testing and flushing described above. The production of this demineralised water results in a by-product which the company also wishes to discharge to the Severn Estuary.
In some cases chemicals will be used for these activities so they may be present in the water that will be discharged into the Severn Estuary. These chemicals are:
1. Hydrazine
2. Un-ionised ammonia
3. Ethanolamine
4. Trisodium Phosphate
Under reference number EPR/JP3122GM/V010
The Company also wants to vary the amount of Ammonia that is currently allowed to be discharged in two liquid waste types already covered by this existing construction phase permit. The two existing activities on this permit are:
a) Activity E2 - Trade effluent (consisting of pumped groundwater) discharged via Outlet 12. The permit allows a maximum daily discharge of 1,728 cubic metres at a maximum rate of 20 litres per second.
b) Activity H - Trade effluent (consisting of tunnelling effluent and muck bay drainage) also discharged via Outlet 12. The permit allows a maximum daily discharge of 2,592 cubic metres at a maximum rate of 30 litres per second.
Outlet 12 is the same discharge point to the Severn Estuary as that which will be used for the trade effluent from cold commissioning activities. It is located on HPC’s temporary jetty.
How to view the application
The application may be viewed online at https://consult.environment-agency.gov.uk/psc/ta5-1ud-nnb-generation-company-hpc-limited-v009.
We are following Government advice to manage the risks of Coronavirus to our organisation, to protect the health, safety and wellbeing of our staff and sustain our critical operations. As a result, please contact us via e-mail at psc-waterquality@environment-agency.gov.uk or contact us on 03708 506 506 to arrange to see the application documents if you do not have internet access.
How to comment on the application
If you have any comments on the application send these by 14 September 2021.
Online: view and comment on the application using Citizen Space at https://consult.environment-agency.gov.uk/psc/ta5-1ud-nnb-generation-company-hpc-limited-v009
Via email: pscpublicresponse@environment-agency.gov.uk
The Environment Agency will normally put any comments it receives on the public register. This includes your name but not your personal contact details. Please tell us if you do not want your response to be public.