UK oil refinery broke pollution permit conditions 58 times, documents show

Stanlow refinery in Ellesmere Port, Cheshire, one of the UK's biggest oil refineries, spilled pollution into local rivers and the Mersey Estuary on dozens of occasions in 2023 and 2024, documents shared exclusively with the BBC suggest. The documents were obtained by investigative journalists from SourceMaterial. The Environment Agency (EA) has confirmed it is investigating the breaches.

Reports from the EA show that in 2023 and 2024 permitted levels for chemical releases were exceeded hundreds of times. The regulator determined this meant EET Fuels broke its permit conditions 58 times over the two-year period, which could amount to an offence. The spills included toxic chemicals such as cyanide, benzene and heavy oils into the air and waterways including Thornton Brook and the River Gowy, which connect to the Mersey Estuary.

EA documents detail how sulphur dioxide was released into the air at seven times permitted levels, cyanide into waterways like the Gowy at more than eight times permitted levels, and oil at more than thirteen times the allowed levels. In one incident in July 2023, the company breached its permit after rainwater containing oil leaked from the site, an event the EA classed as "significant". The EA's report noted a "significant number" of complaints from locals about the smell, and further investigations indicated the oil had contaminated groundwater supplies.

EET Fuels said it "takes its environmental responsibilities extremely seriously". The company, formerly known as Essar, pleaded guilty in 2026 to 12 charges of breaching environmental law between 2018 and 2020. It bought the refinery from Shell in 2011 for £842m.

The Mersey Estuary is a Site of Special Scientific Interest (SSSI), home to endangered species including dolphins, and a breeding ground for rare birds. Charlotte Harris, chief executive of Cheshire Wildlife Trust, said species like dunlin, black-tailed godwit and redshank "will travel all around the world to feed and roost in the land around the River Mersey". She said the Atlantic salmon has returned to the river and the critically endangered European eel travels up the Mersey and into the River Gowy to breed each year.