According to official Government figures, getting in the water at almost 200 of the UK's designated bathing beaches carries a heightened risk of infection. Morland Sanders takes to the road in his VW campervan to investigate the causes and asks whether any of our beaches can be guaranteed to be free of pollution.

The Marine Conservation Society's Good Beach Guide 2010 indicates beaches of excellence but also paints a grim picture of water quality at over 40% of British beaches. With over 20,000 sewage overflow pipes around the UK, some spilling untreated sewage onto our beaches, are water companies the ones to blame or is it other factors such as farm waste? And do local authorities do enough to forewarn us of potential health risks?

Our investigation begins in the South West of England – the Jurassic Coast - and the popular holiday destination of Lyme Regis. It's an area of outstanding natural beauty and designated as a World Heritage Site, but its Church Beach also has some of the poorest bathing water quality in the country. Morland Sanders speaks to Dorset District Council to ask why there are no signs on the beach warning visitors that the water quality here has failed to pass the mandatory EU standard.

Around the coast in Cornwall, Morland meets Surfers Against Sewage campaigner Andy Cummins who details his concerns about two popular Newquay beaches. His shocking video diary footage reveals raw sewage being pumped into the river that leads to Godrevy Beach, and sewage related items littering Porthtowan, a Blue Flag beach.

Keep Britain Tidy, the organisation that runs the Blue Flag Awards in the UK, tells the programme it is disappointed to see sewage related debris on its Blue Flag beaches. We also meet a resident from the North East who says his Blue Flag beach, Seaburn, is far from worthy of the accolade – having gathered years of evidence of sewage debris washing onto its shores.

With new tougher EU bathing water quality guidelines coming into force in 2015 the UK has a long way to go to bring itself up to scratch, says the Marine Conservation Society. An estimated 51% of beaches will struggle to meet the excellent criteria and 14% may fail completely.

So if you’re taking to the beach this weekend, take care - it could be an unlucky dip.

• Dorset Council say most of the time their water quality is excellent or good and they have now amended their website and will be putting up more signs for tourists.
• South West Water told us by the end of the year they will have upgraded over 200 of their sewage pipes and will continue to improve others over the next five years. They are also working with councils to look at the various factors which affect water quality at beaches like Porthtowan and Godrevy.
• Water UK told us the water companies are committed to the environmental improvement of their sewage systems.
• Northumbrian Water told us it meets all its legal obligations regarding its sewage overflows and Sunderland Council said it is committed to improving standards at Seaburn beach and puts warning signs up after heavy flows.
• Cornwall Council told us it does a litter pick for three hours everyday on Porthtowan beach.
• Keep Britain Tidy say that they remove Blue Flags from beaches if they believe it to be failing their criteria.

For further information:

Marine Conservation Society's Good Beach Guide

Surfers Against Sewage

DEFRA

Environment Agency

Health Protection Agency

World Health Organisation

Fishing For Litter Scheme

Shellfish Association of Great Britain

Cornwall Seal Sanctuary

Campervan Hire

Dorset Council

Cornwall Council

Sunderland Council

Water UK