Some lorry drivers are a major cause of pollution at a Northampton lake where several birds were killed by an oil slick, a civil engineer has claimed.
James B Milne was commissioned by Southfields Residents’ Association to write a report about the Billing Brook water system that feeds four lakes in the Eastern District, including Thorplands Lake where four cygnets died from ingesting oil last month.
He says low rainfall has caused pollution to be more apparent but another is lorry drivers, who accidentally deposit chemicals from their vehicles.
Mr Milne said: “Most of the pollution comes from lorries parked on the side of the roads, especially at weekends when the drivers are forced to take an extended break dictated by European Law.
Fuel oil, engine oil, transmission oil and brake fluid are all dropped by lorries standing for any time and, when it rains, these oils are all washed into the storm drains.
“Added to this, I’ve regularly seen the gratings covering the road gullies lifted up and the drivers tipping rubbish down them.
“All manner of waste has been tipped down these gullies, from plastic bags and food wrappings, to food waste and bottles of what appears to be urine.
“Everything tipped down these drains ends up entering Thorplands Lake.”
Mr Milne said his investigations have concluded that a storm sewer has been connected in error to a culvert that carries away industrial chemicals from Round Spinney Industrial Estate. In effect this sweeps chemicals into the surrounding water courses, mostly Thorplands Lake (also known as Swanhaven Lake).
Therefore, he concludes, the storm sewer must be rerouted into the correct sewer, or else a fully functional petrol and silt separation chamber built before it enters Thorplands Lake. Skips and toilets should also be provided for HGV drivers, he adds.
Liberal Democrat Councillor Dennis Meredith has presented the report to Northampton Borough Council. He said: “One way or another something has to be done if the lakes are going to become a health hazard for local people.”
Councillor Alan Bottwood, cabinet member for the environment, said: “We have received a copy of the report and are hoping to meet with the report’s author to discuss the contents further.”