Hinkley Point C resumed mud dredging as part of works to install cooling water intakes in the Bristol Channel. The mud is no different from mud elsewhere in the channel and comprehensive testing has shown that it poses no harm to people or the environment.
Our contractors have now completed the main dredging and disposal of mud at the licensed disposal site at Portishead. Some further maintenance dredging will be required in Spring of next year ahead of the placement of the heads for the cooling water system.
An independent report commissioned by the Welsh Government also found that the mud would be deemed suitable for disposal at sea.
Hinkley Point C is one of many companies - over many decades – which has dredged and deposited mud in the Bristol Channel for industrial or construction purposes. Dredging first began in September 2018 when contractors successfully completed the first licensed work to dredge and deposit mud in the Severn Estuary.
The Marine Management Organisation approved licences, along with licence conditions, for dredging and disposal of mud at the Portishead licensed disposal site for the second phase of dredging. We complied with all requirements and fully supported efforts to inform and explain the dredging work to the public.
The mud has to be disposed of within the Severn Area of Conservation (SAC) in order to maintain the balance of sediment and mud in the area. Hinkley Point C made applications to Natural Resources Wales for the use of the Cardiff Grounds licensed disposal site and to the Marine Management Organisation for the use of the Portishead licensed disposal site.
Latest testing results
For this second phase of dredging, the UK Government marine scientific agency (CEFAS) went further than before, testing the mud beyond internationally recognised best practice, with more samples at greater depth and with a greater range of analysis - including tests for pure alpha emitting particles and tritium.
The results confirm previous analysis that the mud is perfectly safe for disposal at sea and poses no risk to humans or the environment. The results also confirmed that the low levels of radioactivity in the mud is predominantly naturally occurring - as found up and down the Severn Estuary, as well as around the coast of Britain. The additional artificial radioactivity from a range of human activities is very low.
Campaigners had asked for specific tests to look for plutonium and tritium which are both radioactive elements primarily found as by-products of nuclear reactors, although they do also occur naturally.
The additional alpha (plutonium) and beta (tritium) tests showed that their presence was “insignificant” which means that the amounts are so low as to be barely detectable, even using the most sensitive monitoring equipment. The results showed that previous tests, using the internationally recognised assessment methodology of gamma spectrometry, had been appropriate to provide a conservative assessment of the very low levels of radioactivity present.
The results in detail from this latest sampling are available online and can be seen via the following links;
Hinkley Point C conducted full Environmental Impact Assessments as part of its disposal licence applications. Those assessments considered the potential impact from dredging and disposal on areas such as the coastal and marine environments, ecology, water quality and navigation.
Summaries of the Environmental Statement report for dredging and disposal at Portishead can be found via the following links. They show that there is no significant environmental impact from either the dredging or disposal activities.
The Marine Management Organisation held a consultation on our application for disposal at Portishead between 12 February and 26 March 2021, with details available on their website.