A new pollution alert has been sounded over a town centre pond - for the second time within weeks.
The pond in Horsham Park was first contaminated with diesel following a spillage from a nearby railway goods yard in March. Now foul sewage has also polluted the water.
Concerns are being raised by the Friends of Horsham Park who are demanding answers over how the pollution has occurred and what is being done to stop it happening again
Friends’ chairman Sally Sanderson said an “underlying problem related to the drainage network has been ongoing for years and needs to be addressed.”
The Friends are demanding to know from Southern Water what plans it has “for ensuring the pond is restored to a condition that is fit for wildlife and for the residents of Horsham to enjoy.
Sally added: “This pond also feeds streams that flow into rivers so is a source of wider contamination in West Sussex.”
Swans and other wildlife at the pond were affected by the diesel spill and one of the birds had to be taken to The Swan Sanctuary at Shepperton for treatment.
John Potts from the Copthorne-based Swans and Friends Bird Rescue said: “The pond is very polluted and has been for years.”
He said it was so bad that the diesel-covered swan taken to Shepperton had since been taken to Warnham Nature Reserve “because that has clean water.”
He was called out to help swans, moorhens and ducks in the pond on around 30 occasions last year. He has called for a separator to be installed which would take out oil and road contaminants from the pond water.
Volunteer wildlife observer David Leadbetter, who contacted Friends and Bird Rescue after the diesel spillage, said that a new floating boom seemed to be working well in the pond and showed “the extent of the muck entering from the single top inlet, the worst of multiple inlets. From my observations heavy rain can make it lose performance.”
Meanwhile, a spokeswoman for Horsham District Council warned people not to go into the water in the pond.
She added: “We are pleased to report that there are now no significant signs of oil contamination in Horsham Park pond as a result of the clean-up operation which began on March 12 following a diesel oil spillage from Network Rail’s premises.
“We are continuing to exert pressure on Southern Water to assess the drainage system and provide reassurance that such an incident cannot happen again.
“A report from an environmental consultant indicated that there has been an incident of foul sewage entering the pond and we are therefore urging Southern Water to fix this problem.
“Although the pond is not designed for the public to enter, we would remind people to not go into the water.”
A spokesman for Southern Water said: “We have been working with Horsham District Council to investigate diesel pollution in the pond and also sewage present in the water.
“We are satisfied that all our assets are working correctly.”