A water company has been fined £330,000 after raw sewage escaped into a stream in Hampshire for up to 20 hours, killing about 2,000 fish including brown trout.
Waste flowed into Shawford Lake Stream on the edge of the South Downs because of faulty equipment at a pumping station.
Though a warning sounded in a Southern Water control room just after 7am, a team was not dispatched to fix the problem until lunchtime.
YMCA Fairthorne Manor, an outdoor activity centre popular for school trips, had to stop water activities for 10 days after the incident and cancel more than 1,000 sessions.
Speaking after the hearing at Southampton magistrates court, the Environment Agency said the stream was left cloudy and ammonia levels in the water were 25 times the legal limit.
It said investigators believed the illegal flow of contaminated matter continued for between five and 20 hours and pools of dirty water were found in local fields.
Dawn Theaker, an environment manager in Hampshire for the Environment Agency, said: “Yet again, we have a water company failing to properly respond to alarms when things go wrong at facilities they operate, allowing sewage to flow uncontrolled into fields and a stream.”
Rebecca Vanstone, prosecuting, told the court: “At approximately 11:48am on 21 July 2019, a member of the public reported there was a burst sewer and unfiltered sewage was entering the stream.”
The court heard an alarm in the control room had gone off at 7.18am. “It was almost five hours after that that action was then taken,” said Vanstone. “Southern Water simply say they don’t know why.”
Vanstone said brown trout, bullheads, brook lampreys and sticklebacks were killed.
Dominic Kay KC, for Southern Water, said the company had “genuine remorse” and told the court: “Very, very significant changes have been made.”
He said a specialist subcontractor had set up a pump incorrectly but he accepted the problem was compounded by a failure to respond to the alarm.
District judge Nicholas Wattam said: “The local ecology was significantly affected and over 2,000 fish were killed. This cannot be categorised as a minor incident.”
Southern Water pleaded guilty to one breach of the Environmental Permitting (England and Wales) Regulations.
Richard Manning, its general counsel and company secretary, acknowledged it had been an “unacceptable” incident.
He said: “As soon as we became aware of this event, we took action to reduce its impact on the local area, and have since cooperated fully with the Environment Agency’s investigation.”