Essar, the company that runs the Stanlow oil refinery in Ellesmere Port, has pleaded guilty to 12 charges brought by the Environment Agency for violating environmental laws nearly 500 times over a four-year period. Four of the offences included discharging higher-than-permitted levels of cyanide into the Manchester Ship Canal, a nearby river and a local brook. The company has apologised and taken steps to address the causes of these breaches.