Hundreds of fish have been killed after sewage escaped into a lake at a popular nature park.
The dead creatures were found floating on the fishing lake at Walton Colliery Nature Park earlier this month.
Bream, pike and tench were starved of oxygen at the Wakefield Council-owned site after sewage spilled in from a nearby pumping station.
Fishing has been suspended by Walton Angling Club until stocks are replenished by the Environment Agency.
Environment Agency officer Martin Rogers said: “The Environment Agency has been investigating an incident of pollution at the Walton Colliery lake following reports of dead fish earlier this month.
“Sewage from a pumping station had entered the watercourse and this had a devastating effect on the fish population, including bream, tench and pike.
“Water quality tests showed that dissolved oxygen levels were very low. We responded by requiring Yorkshire Water to provide floating aerators and pumps and since then we have seen the quality of water improve to original conditions. We are continuing to monitor the situation.”
The lake will be restocked with fish once the water is no longer contaminated.
The council’s service director of Environment and Streetscene, Glynn Humphries, said it happened on Saturday, October 5, after a suspected sewage spill from Yorkshire Water’s Elmwood Avenue, Shay Lane, pumping station into Drain Beck.
He added that Walton Angling Club decided to suspend fishing until further notice.
Yorkshire Water were contacted but they had not reponded by the time the Express went to print.