Sewage leaks along a Kent coastline have been described as an "environmental and financial disaster" by furious council bosses.

Waste water was released into the sea between Margate Main Sands and Joss Bay in Broadstairs last week, after Foreness Pumping Station was struck by lightning.

Southern Water has been carrying out clean-up operations, as warnings against taking a dip at 11 beaches between the two towns remain in place.

About 200 protesters took to the streets on Sunday afternoon, marching from the district council offices in Cecil Street, Margate, to the pumping station in Prince’s Walk.

Now Thanet District Council Ash Ashbee has penned a stinging letter to Southern Water CEO Ian McAulay, demanding he guarantee this situation will not happen again.

“I write to you to express my utter dismay at the failure of your waste water pumping station at Foreness Point on Wednesday night,” the Conservative said.

“Given the repetitive failure of this plant for more than a decade, I do not accept that an act of God is in any way an excuse for this latest environmental and financial disaster in our district.

“Surely your company has an emergency protocol in place to mitigate against any such eventuality at what is a critical part of your infrastructure.

“Yet again, we find ourselves in the same catastrophic situation with beaches closed and businesses that are struggling to recover from the pandemic losing tens of thousands of pounds in trade.

“On behalf of the residents and businesses of Thanet, I request that Southern Water recognises its failures and compensates both the council for the costs incurred with the clean-up operation and all local businesses for their loss of trade.”

Council bosses say the warnings issued following last week’s incident will be lifted only once inspections, which take place after high tide, confirm it is safe to do so. They say evidence from the checks is showing an “improving picture”, as they harbour hopes the advice will be lifted soon.

Protest organiser Tim Garratt, of campaign group Acorn Margate, told KentOnline: “We had about 200 people. It shows the level of anger in the area.

“We didn’t get any opposition from anyone. People are sick of it. This seems to be a yearly occurrence and it feels like people have had enough.

“It smells like sewage has been poured around the area, particularly as you get closer to the pumping station area around Walpole Bay.

“We noticed that as we were marching – it seems to have got into all of the seaweed. The last time this happened it took weeks to clean up.

“Southern Water have to clean up their act.”

The activists were demanding Southern Water pays compensation to businesses impacted by the subsequent reduction in tourism to the Thanet coast.

They also believe the company’s customers in the district “who pay for water treatment, management and appropriate disposal” should be reimbursed.

Meanwhile, they are urging the firm to invest in infrastructure at Foreness to ensure the events of last week are not repeated.

Advice against entering the sea is in place at Minnis Bay, West Bay, St Mildred’s Bay, Westbrook Bay, Margate Main Sands, Walpole Bay, Palm Bay, Foreness, Botany Bay, Kingsgate Bay and Joss Bay. Signs have been erected at the beaches warning of the conditions.

Following the incident on Wednesday night, South Thanet MP Craig Mackinlay called for the Environment Agency to “come down hard” on Southern Water.

The Tory said: “Southern Water blame a lightning strike for the failure.

“I appreciate the act-of-God nature of it, but the question I am asking is whether there were industry-standard mitigations against such an event - like lightning conductors, sufficient power supply back-ups and if the pumping station is at all fit for purpose.

“This is not the first time that Southern Water has let us all down - there was a failure at the Broadstairs pumping station in February resulting in effluent washing up on Joss Bay.

“This latest event is significantly worse. This simply won’t do.

“I hope the Environment Agency uses the full extent of its powers to come down hard on a company that seemingly cares little about its own corporate reputation, the businesses affected and the tourist appeal that our Blue Flag beaches have as key assets of our area.”

In 2016, Southern Water was fined £2 million after untreated sewage polluted the sea at Margate four years earlier.

The pumping station was said to have been overwhelmed following a heavy storm, before detritus like tissues, sanitary pads, condoms and wipes were discovered along the coast.

And in 2019, the company was fined a further £126 million after serious failures were discovered in its sewage treatment sites. This came after a probe led by regulator Ofwat revealed the firm did not manage equipment used to clean and treat waste water.

Southern Water’s head of pollution and flooding resilience, Dr Nick Mills, insists the firm is “dedicated to protecting the environment”. He also stresses that release of waste water into the sea needed to happen to protect nearby homes and businesses from flooding.

“The release that happened overnight on June 16 was caused by a combination of heavy rainfall and a lightning strike, which caused a short power failure and affected systems on site at our Margate pumping station,” he added.

“Back-up generators are in place. As part of our preparations for the predicted thunderstorms and heavy rainfall we also had a team standing by in the area.

“These precautionary measures meant we were able to immediately begin work restoring the site to full operation.”

Dr Mills says an investigation into the incident has been launched by Southern Water.

He also notes that a compensation scheme for businesses is available to make a claim for lost funds.

“No pollution is acceptable to us or our customers and we apologise for the impact the latest incident has had on local residents, businesses and the environment,” Dr Mills continued.

This morning, Southern Water have said the “changing nature of the tides and winds” have made it hard to predict where debris will be washed up.

Clean up work will continue “until we are satisfied that all the beaches can be fully enjoyed again”.

The spokesman said Mr McAulay will be responding to invitations to meet with district council members and Mr Mackinlay.

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