Southern Water has apologized after millions of plastic pellets washed up on beaches in southern England, admitting it was “highly likely” responsible for what environmental groups are calling a severe pollution incident.

The company, which provides water and sewage services to millions across southern England, said the contamination resulted from a “failure” at one of its treatment facilities.

Environmental monitoring group Strandliners estimated that the spill released millions of pellets along the shores of Camber Sands in East Sussex, calling it “the worst plastic pellet pollution incident we have ever seen here.”

“The impact on the environment and local wildlife can be catastrophic,” the group warned, explaining that birds and marine animals often mistake the toxic beads for food.

Following an internal investigation, Southern Water stated it was “highly likely that the beads have come from our Eastbourne Wastewater Treatment Works,” citing “a failure of a screening filter” that allowed the pellets, used in the wastewater treatment process, to escape into the sea during heavy rainfall.

“We are very sorry this has happened and are doing everything possible to investigate and resolve the problem,” the company said in a statement.

'Thorough investigation' ongoing

Water Minister Emma Hardy said she was “deeply disappointed” and had spoken directly with the company’s CEO. “The immediate priority now needs to be addressing any environmental damage and minimising further impacts,” she stated, noting that the Environment Agency is conducting “a thorough investigation” and considering “what regulatory action should be taken.”

The black “bio-beads", just a few millimeters wide, are commonly used to filter bacteria in wastewater treatment plants. Environmental experts warn that they are difficult to remove once mixed with sand and algae, and when ingested by wildlife, can cause starvation or toxic buildup leading to death.

The Rother District Council, which is leading cleanup efforts, said volunteers and professionals have been working for nearly a week to remove the pellets and hope to complete most of the work by Monday. However, officials warned that more beads are expected to wash ashore with the tides.

The incident adds to growing public anger toward Britain’s water companies, which have faced repeated criticism for discharging sewage into rivers and seas. In response, the government has pledged stricter regulation and tougher sanctions against senior executives in the sector.