Concerns have been raised about Cornwall Council’s decision not to carry out an environmental impact assessment of South West Water’s controversial proposals to build a desalination plant at Par Docks.

A solicitor acting on behalf of a group of residents, who oppose the plan, said the council’s decision could lead to a judicial review.

If the plant is approved it would see the installation of two 1.2km above ground pipelines between the desalination plant and Par Waste Water Treatment Works (WWTW) and a 13km underground pipeline between the desalination plant and Restormel Water Treatment Works (WTW), as well as a lagoon and an “integrated construction wetland” around 850m south of Restormel WTW, which would also need to be extended.

Residents of Par and the surrounding area are concerned about the possibility of wastewater and chemicals being discharged into St Austell Bay’s special protected area (SPA), which supports the largest known sub-tidal seagrass bed in Cornwall at 359.1 hectares; one of the largest seagrass beds in the UK.

Due to lack of rainfall and demand for water in 2022/23, South West Water (SWW) had to declare a hosepipe ban due to low levels in its Colliford Reservoir on Bodmin Moor. SWW has identified a series of resilience measures to ensure continued supplies of water to customers during periods of drought. The proposed desalination plant at Par is one of those measures.

READ MORE: South West Water plan to turn sea water into drinking water in Cornwall

SWW asked Cornwall Council if an environmental impact assessment (EIA) was needed for the plant as the scheme does not fall within a clearly defined category of EIA regulations. However, development proposals described under case law require an EIA if they are considered likely to have significant effects on the environment due to nature, size and location.

A “screening opinion” carried out by Cornwall Council has concluded that the proposed plant does not need such an impact assessment, based on EIA Regulations and relevant Government guidance. This has been met with anger by members of the opposing Desalination Information Group.

Richard Buxton Solicitors have been instructed to act on behalf of the group. A spokesperson for the solicitors said: “In our view, the screening opinion is inadequate and fails to consider a number of potential impacts of the proposal.

“Our clients would be entitled to bring judicial review proceedings in respect of any future planning permission granted on the basis of the flawed screening opinion, but we hope that this can be avoided by raising these points at an early stage so that the council can reconsider whether significant effects may arise from this project.”

 

Desalination plant plans by South West Water in Par.

Desalination plant plans by South West Water in Par.

 

In a letter to Cornwall Council, the solicitors state: “There appears to be little or no consideration of possible operational impacts of the desalination plant, including on the adjacent SPA, into which there will be discharges. This is, in itself, a clear error.”

The “production of waste” section of the council’s screening opinion states that “waste brine and supernatant waste from the desalination process are to be transferred to Par WWTW. This will be treated before discharge. The dilution levels of brine leaving the outfall will be lower than that dilution level of the sea it will be discharged into”.

Richard Buxton Solicitors and the Desalination Information Group believe this makes it clear that the project will involve discharging wastewater into the adjacent protected area.

“No consideration appears to have been given to: (1) whether the water will contain anything at all which might affect the conservation objectives of the site, (2) whether discharging lower-salinity water into the SPA may itself potentially affect the conservation objectives of the site. It is not at all clear, for instance that the council has turned its mind to whether lower-salinity water may harm seagrass, maerl beds, seahorses, etc.

“There could also be other residual materials in the discharge water, including other chemicals we understand are used in the desalination process (e.g. chlorine, biocides, etc); again, no consideration is given to whether these may be present in the discharges or have an effect on the SPA.”

The letter adds: “The council should, at minimum, seek expert advice from Natural England on these risks and whether they would expect an assessment of such discharges.”

Cornwall Council says it won’t comment on the concerns raised about a lack of environmental assessment. “We don’t have anything to add to the full decision,” said a spokesperson.