SUMMER'S heavy rain storms and flash flooding could pose a pollution risk on Cumbria's shorelines, including the region's lakes, warn experts.

The Marine Conservation Society has announced a rise in faecal pollution, usually derived from sewage or animal droppings on many of Britain's beaches.

This is due to the fact that many of Britain's bathing beaches have Combined Sewer overflows and storm water outfalls sites on or near the shore. This means that, during periods of heavy rainfall, untreated waste can be diverted from treatment plants and discharged directly into rivers, lakes or coastal waters.

Thomas Bell, Good Beach Guide Officer for the MCS, said: "The water quality monitoring data from May onwards shows periodic surges in faecal pollution at beaches with normally very good water quality. These temporary peaks in faecal bacteria load seem to correlate with big storm events."

Managing Director of Windermere Lake Cruises Nigel Wilkinson, whose firm carries thousands of visitors each year across the lake, said he had noticed raw sewage flowing out of pipes and on to the lake shore.

He said: "There is an outfall on the beach in Bowness Bay which, when there is a storm that causes the water to overflow, causes the sewage to come out on to the beach which is the same beach in Bowness that families use. It is something that we have been bringing to the attention of the Environment Agency for a long time.

"It only occurs when there is very heavy rainfall and the normal sewage system cannot cope on the rare occasions that it happens it is the untreated elements of the sewer.

"Of course, when the drains are overflowing there aren't many people around but it is something that my staff have to walk in and around and ropes dangle in, and it is not very pleasant."

Although the discharge only happens rarely, there is a health risk for lake or sea users if they accidentally swallow the water.

Environment Agency spokesman Tim Fernandes said that sewage levels in bathing waters were frequently checked by the agency but that some outfall was inevitable.

Dr Keith Jones, head of health related Environmental Biology at Lancaster University, said that harmful bacteria such as the E-coli bug could lurk in the polluted water and people could face a health risk if they were to accidentally swallow it.

He said: "The presence of E-coli in the water also shows that other more harmful things are there as well, such as salmonella."

Dr Jones added that the risk of swimmers ,sailors or canoeists becoming ill with gastroenteritis from the contaminated water was much more likely in fresh water than in seawater.