A water company has been fined almost £8m for a series of pollution-related offences over six years.

South West Water pleaded guilty at Plymouth Magistrates’ Court after an investigation by the Environment Agency into incidents between 2015 and 2021 in Bodmin, Harlyn, Playing Place, and Polperro in Cornwall, and Plymouth in Devon.

Sentencing, Judge Jo Matson described the pollution as “horrendous” and “very significant”.

The water company said in a statement after sentencing: “We apologise for what happened in the past.”

Of the 18 charges, 17 were for illegal discharge activities including sewage discharges and one is for failing to take reasonable remedial measures following a failure at a sewage pumping station.

The firm was fined £7,867,733 and ordered to pay £329,993 in costs.

It is the latest to be imposed on South West Water after it was fined £1.8m over a parasite outbreak in July and fined more than £2.1 after admitting causing pollution in the region in 2023.

Judge Matson said she had made clear in the 2023 case “incidents of pollution by water companies will not be tolerated and must be taken very seriously by these courts”.

“I have taken into account that these incidents pre-date that sentence and I have also taken into account the changes that South West Water have made since then,” she said.

“Only time will tell if those changes are successful, I certainly hope that will be the case.”

She noted the water company had adopted wording that said “one pollution is too many”.

“It goes without saying that must be the case,” she said.

“However, in this case there were hundreds of incidents of sewage spills on to our beaches and into our waterways and sea and untreated sewage gushed through the harbour wall into the harbour at Polperro on a bank holiday weekend.”

The firm needed to make sure “horrendous, very significant incidents of pollution such as these never happen again”, she added.

The fine is the the largest to be imposed on South West Water in a case pursued by the Environment Agency, it said.

Clarissa Newell, environment manager for Devon and Cornwall, said: “There’s been a clear message today to show that pollution will not be tolerated.

“Today we’ve seen offences where alarms have not been responded to and data has been collected but not thought through.”

She said it had “taken a long time for these offences to come to court” due to the nature of the investigation.

“We will get challenged by South West Water every step of the way so every piece of science we use has to be done with calibrated instruments and with qualified people,” she said.

South West Water said the case related to “historic matters between 2015 and 2021” and the majority of spills involved “the use of overflows in storm conditions”.

“We’re investing £760m to tackle storm overflows and have reduced spills by 17% in the last year alone, with spill duration down by 25%,” the company said.

It added “significant improvements” had been made at the sites where pollution occurred.

“We remain focused on the future as we deliver record levels of investment to achieve cleaner rivers and seas across the South West by 2040, a decade ahead of national targets,” it said.

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