Southern Water has pleaded guilty to releasing untreated sewage, debris and diesel into the sea and inland waters across north Kent.
The Environment Agency (EA) charged the company with a series of pollution incidents which happened at various times between 2019 and 2021.
In July 2019, people reported seeing and smelling oil in Swalecliffe Brook in Whitstable.
EA staff were sent to the scene, laying out absorbent booms to contain what turned out to be diesel from Southern Water’s local wastewater treatment plant.
It had got into the brook and, in turn, the sea, when a generator failed and began leaking.
Then, shortly before the start of the pandemic in 2020, Southern Water polluted another two inland waterways.
Across three days from March 5, untreated sewage was released into Faversham Creek from a separate wastewater station after pumps stopped working.
On the same day, Swalecliffe Brook was hit again, this time with sewage, which, like the diesel, was carried into the sea.
EA officers attended and found swage and debris flowing under the main gates of the treatment plant in Brook Road, over a grass verge and into the water.
An almost identical incident then happened in October 2020, where sewage and other matter travelled out of the main gate of the works, along the road, across the verge and into the brook.
Medway Magistrates’ Court heard that more pollution happened at Southern Water plants in Whitstable, in August 2021, directly into the sea, or via Swalecliffe Brook.
The incidents occurred only weeks after the company was fined a record £90million for thousands of illegal sewage discharges off the south coast, two of which were directly into the sea.
On August 6, the beleaguered Swalecliffe Brook again had untreated sewage pouring into it, and investigators found around 70 dead fish, including eels.
The effluent flowed into the sea, significantly affecting water quality, and led Canterbury City Council to put up signs along beaches at Tankerton and Herne Bay, warning against swimming for nearly a week afterwards.
The EA charged Southern Water with five pollution offences, and the firm pleaded guilty to all the matters at Medway Magistrates’ Court on April 7.
Dawn Theaker, the EA’s water industry regulation manager in the South East, said: “All of these pollution incidents could have been avoided if Southern Water had managed operations more carefully, and had in place the necessary checks to deal with problems when they occurred.
“It is a familiar pattern with water companies. Always catching up with events.
“The EA will keep Southern Water in its sights with more inspections, even tougher regulation and prosecution in the most serious cases.”
Sentencing will take place at the same court on a date to be confirmed.
Since 2015, the EA has concluded more than 70 prosecutions against water and sewerage companies, securing fines of over £153 million.
