Pollution tests in the River Ouse at Lewes have found sewage bugs at 75 times safe-swimming levels.
The tests were taken by the Environment Agency following the collapse of a huge storm sewer storage tank at Ham Lane.
Under European laws, beaches designated for bathing must contain bacteria such as E coli at no more than 2,000 colonies per 100 millilitres of water. The agency tests found a massive 150,000 colonies of E coli.
The results were revealed this week by Lewes Rowing Club, which began investigating sewage levels after Southern Water’s storage tank burst open just before Christmas, spilling out 900,000 litres of rain and sewage overflow removed from the town’s drains. Southern Water set up an emergency system with nine temporary tanks and a pipeline that discharges into the Ouse beneath the bypass. The storm sewage is screened to remove solids.
Brendon Parsons, Secretary of Lewes Rowing Club, said: “These tests confirm our members’ suspicions. Levels were very high downstream of the discharge, but they were also above the European bathing limit upstream, showing the general level of pollution.
“Southern Water says it is ridiculous to compare the Ouse with a designated bathing beach, but that will be little comfort to our members or anyone else who catches a bug from paddling or swimming in the river. This is a national park and leisure activities are intended to expand on the Ouse. If nothing improves they will have to put up signs that say: ‘Come for a swim, leave with the runs’.”
The collapse of the tank is being investigated by the Environment Agency. A second tank, holding two million litres, was built beneath the town by Southern Water following the floods in 2000. Southern Water is allowed to discharge into the Ouse when the tanks fill up during exceptional rainfall.
Mr Parsons said: “Without these tanks, we might well be wading through sewage in the streets so the company deserves credit.
“But as we all know, exceptional rainfall is no longer exceptional and climate change looks like making it commonplace.
“Sadly, the tests will come as no surprise to anyone in the water industry because not a single UK river is designated as safe for bathing.
“Apparently a lot of sewage comes from septic tanks and farms where rain washes cow and sheep mess into the river.
“But the whole system of dumping sewage in a river that is the heart-blood of our home seems medieval, and they have found better ways in countries like Germany, where many rivers are designated for swimming. Let’s take the loo out of Lewes.”
The full results of the tests will be published on the Pennant News section of the rowing club’s website at: lewesrowingclub.co.uk
A Southern Water spokesman said: “We are experiencing the wettest winter on record and our emergency releases of stormwater into rivers and the sea protect homes from flooding and are consented by the Environment Agency.
“The River Ouse is not a designated bathing water, of which there are currently 83 in Southern Water’s region, and so is not subject to the same water quality standards.
“These only apply to designated bathing waters during the summer months.
“The Health Protection Agency says rivers should not be considered of bathing water quality.
“It warns that there will always be micro-organisms present in river water as it is also affected by run-off from roads, farming and industry.”