Pumping stations can discharge sewage under certain conditions

South West Water has the right to discharge untreated sewage into streams after storms or if there are power failures at pumping stations.

But some people are claiming it is happening regularly around the coast.

The Watergate Bay Environmental Tourism Trust, says incidents could harm the county's reputation for clean beaches.

Intense weather

Spokesman Henry Ashworth said: "We are talking about sorting out the last 5%.

"We've got 95% fantastic water quality, but we do have this one little chink in our armour - the pumping stations which discharge into the rivers close to the beaches at certain times of the year or under certain conditions."

"It's very easy to sort this problem out: we just need a final concerted effort to carry it through so Cornwall is completely at the forefront of water quality, as it is the county's finest asset."

But South West Water says discharge will happen only under very extreme weather conditions.

Stephen Swain, communications manager for South West Water, told BBC News Online that untreated sewage is never regularly discharged.

He said: "No sewage treatment system anywhere in the world would cope with extreme and intense weather storm conditions.

"There are safety valves which operate overflow systems, during intense rainfall.

"If that wasn't the case, sewage would back up and end up in people's properties."