Dumping hundreds of thousands of tonnes of sediment from Hinkley Point into the Bristol Channel at Portishead carries a 'very low risk', project leaders say.

Chris Fayers, the 3.2-gigawatt power station’s head of environment, said the material had been tested more than other sediment along the British coastline and is safe for swimmers and marine life.

EDF Energy secured permission in August to dredge and dump material from Hinkley Point C at a private disposal site off Portishead, despite objections from North Somerset Council and Portishead Town Council.

The operation is due to wrap up for the year in the coming weeks.

Mr Fayers told a question and answer session that was webcast on October 14: “We’ve tested the sediment and it poses no risk to human health or the environment.

“There’s international best practice and guidance. We’ve gone beyond that in response to people’s genuine concerns.

“We’ve taken lots of samples. We haven’t just skimmed the surface, we’ve sampled all the way down.

“Dredging is not uncommon in the Severn Estuary. We’re consented for just shy of half a million tonnes of wet material. Over the last 20 years approximately 40million wet tonnes have been disposed of within the estuary.

“All that testing is in the public domain. They’re out there, we aren’t hiding anything. The results are consistent and haven’t shown anything unusual.”

EDF is dredging so it can place structures on the sea bed to cool the power station, which will power six million homes.

The Marine Management Organisation licence says the sediment has to remain in the special area of conservation near the Portbury Wharf salt marsh.

EDF has also applied to dump sediment at Cardiff Grounds after its previous licence lapsed in 2019.

Mr Fayers added: “These sediments have been sampled more than any other sediments around the coast of Britain. They are absolutely within the limits.

“They are absolutely acceptable for disposal in a marine environment.

“We’ve done everything we can. I want to reassure you that it’s OK to swim in the water.”

Member of the public Alex Kirby said the activity in the estuary was “very intense” and the clouds of pollution over Portishead were “really quite disturbing”.

Mr Fayers replied: “It’s a fairly intensive campaign. We will be finished soon for this year. We won’t be dredging over the winter months. It’s better to get it over and done with in a way.”