DORSET'S beaches have been given a summer boost as they received a clean bill of health in a major study of water quality.

Beaches at West Bay, Portland Harbour, Weymouth, Church Ope Cove, Bowleaze Cove, Ringstead Bay and Durdle Door have all been recommended in the Marine Conservation Society's (MCS) Good Beach Guide 2008, published today.

The guide is based on water quality standards and risk of sewage pollution, with the MCS only recommending beaches that meet strict European guidelines.

The county's beaches have bucked both the national and regional trends, which show a decrease in the number of beaches recommended due to last summer's poor weather.

Last summer all the beaches in West Dorset were recommended apart from Weymouth's main beach, which received only a basic pass for the first time in six years.

MSC coastal pollution officer Thomas Bell said: "Year on year the water quality in Dorset has been remarkably high.

"The testing for the 2008 guide was done from May to September last year, which was the wettest summer on record and when you get that much rain coming down you get a lot of waste washed into the sea.

"That caused bathing water standards to go down nationally but Dorset didn't seem to suffer very much from that effect.

"That may have been to do with the fact there aren't very many storm drains or overflows affecting beaches in the county."

He added: "Most of Dorset is also covered by Wessex Water which have invested a lot of money in treating sewage.

"They have got treatment plants serving nine of the beaches in Dorset and that will have a beneficial effect on bathing water quality."

The Good Beach Guide 2008 also carries information on the RNLI's national beach safety programme and details of beaches patrolled by RNLI lifeguards.

Mr Bell said: "Poor quality bathing water carries health risks, so if this summer is wet then I'd advise people to use the Good Beach Guide, pick bathing beaches with a good record and stay out of the sea for at least 24 hours after heavy storms."

The guide is published online today at www.goodbeachguide.co.uk