Southern Water Pleads Guilty to Sea Pollution Offences, Kent

Press release

Southern Water admits sea pollution

Incidents off Kent coastline and others inland – company released sewage into water weeks after getting record £90 million for almost 7,000 illegal discharges

From: Environment Agency Published 27 April 2026

Investigators from the Environment Agency twice found sewage cascading down a road from a Southern Water treatment plant

Southern Water has pleaded guilty to a series of pollution incidents across north Kent, affecting the sea and inland waters.

The Environment Agency charged the company with releasing untreated sewage, sewage debris, diesel and waste matter at various times between 2019 and 2021.

Some of the pollution incidents happened simultaneously at different locations.

In July 2019, people reported seeing – and smelling – oil in Swalecliffe Brook in Whitstable. Environment Agency 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.

The diesel got into the brook and, in turn, the sea, when a generator failed and began leaking. The public were warned to keep themselves and their pets out of the water.

Dawn Theaker, the Environment Agency’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’s a familiar pattern with water companies. Always catching up with events.

“The Environment Agency will keep Southern Water in its sights with more inspections, even tougher regulation and prosecution in the most serious cases.”

Shortly before the start of the pandemic in 2020, Southern Water polluted 2 inland waterways.

Across 3 days from 5 March, untreated sewage was released into Faversham Creek from a separate wastewater station after pumps stopped working.

On the same day, Swalecliffe Brook in Whitstable was hit again, this time with sewage, like the diesel, carried into the sea.

Environment Agency officers again went out. They found sewage and debris flowing under the main gates of the treatment plant in Brook Road, over a grass verge and into the brook.

Then in October 2020, an almost identical incident. Sewage and other matter travelled out of the main gate of the works, along Brook Road, across the verge and into the brook.

Medway magistrates’ court heard more pollution happened at Southern Water plants in Whitstable, in August 2021, into the sea directly, or via Swalecliffe Brook.  The incidents occurred only weeks after the company was fined a record £90m for thousands of illegal sewage discharges off the south coast.

More discharges directly into the sea in the weeks before the long weekend station at either end of the month.

In addition, the beleaguered Swalecliffe Brook had untreated sewage pouring into it on 6 August. Investigators found around 70 dead fish, including eels.

The effluent flowed on to the sea like before, significantly affecting water quality. Canterbury City Council put signs up along beaches at Tankerton and Herne Bay, warning against swimming for nearly a week afterwards.

Weeks after Southern Water was given a £90m fine in 2021 for sewage pollution, dozens of fish died in another incident

The Environment Agency charged Southern Water with 5 offences, all contrary to regulations 12(1)(b) and 38(1)(a) of the Environmental Permitting (England and Wales) Regulations 2016:

• caused a water discharge of sewage effluent into Faversham Creek between 4 and 8 March 2020;
• caused or knowingly permitted a water discharge to coastal waters, poisonous, noxious or polluting matter, namely diesel fuel, on or before 31 July 2019;
• caused or knowingly permitted a water discharge to coastal waters of poisonous, noxious or polluting matter, and/or waste matter and/or sewage waste, namely untreated sewage, between 5 March and 3 October 2020;
• caused or knowingly permitted a water discharge activity, namely the discharge or entry to coastal waters of poisonous, noxious or polluting matter, and/or waste matter and/or sewage waste, namely untreated sewage, on 6 August 2021;
• caused or knowingly permitted water discharge activities, namely the discharge to coastal waters of poisonous, noxious or polluting matter, and/or waste matter and/or sewage waste, namely untreated sewage, between 31 July and 23 August 2021. Southern Water pleaded guilty at Medway magistrates’ court on 7 April to all 5 charges. Sentencing will take place at the same court on a date to be confirmed.

Since 2015, the Environment Agency has concluded more than 70 prosecutions against water and sewerage companies, securing fines of over £153 million.

Contact us:

Journalists only: 0800 141 2743 or communications_se@environment-agency.gov.uk.

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Published 27 April 2026