WATER standards must improve at Weston-super- Mare beach next year or tourists could be barred from swimming in the sea.

Every year the Environment Agency carries out water checks at resorts across the UK to ensure the sea is safe for bathers.

The results are passed to the Marine Conservation Society (MCS) to produce an annual Good Beach Guide.

Each beach is given either a recommended rating, a guideline pass, a basic pass or it fails and both Weston's main beach and Uphill only achieved basic this year.

This is the third consecutive year these beaches have been graded basic, which means they only meet the European minimum standard for water quality.

Tests have shown those beaches with basic water standards contain waterborne pathogens in quantities known to cause illness.

The main causes of pollution to bathing water are manure from farmland, animal faeces, human sewage and run-off water from urban areas and domestic misconnections of pipes.

The MCS has now issued a stark warning saying water standards must improve next year ahead of changes due to come into force about the way guidelines are issued.

It says from 2015 new European bathing standards will be introduced whereby results from the past four years will be used to grade each beach.

Those failing to reach the minimum "sufficient standard" will be forced to impose a permanent bathing prohibition or install signs advising against swimming, which would have a major impact on Weston's tourism.

Every year the resort attracts millions of visitors and in high season the majority of families flock to the beach to swim in the sea.

Thomas Bell, MCS coastal pollution officer, said: "Weston main beach and Weston Uphill slipway are two of 20 beaches in the South West predicted by the Government to fail new European bathing water standards to be introduced in 2015.

"The 2010 season's water quality results for both beaches have not, unfortunately, shown improvement in either case.

"Weston main beach is a huge draw for visitors to the town each summer, and Wessex Water is currently working with the Environment Agency to try to pin down the source of the pollution problem using a new and fairly expensive investigative technique called microbial source tracking.

"This involves taking samples of sea water on a regular basis and testing to see whether any faecal bacteria contamination can by pinned to a particular source – typically human sewage and/or livestock waste.

"The problem for Weston is that from 2015 beaches will be graded for water quality using a four year data set rather than a single season's testing as is currently the case.

"The Environment Agency will therefore use results from 2011 to 2014 to grade beaches for the start of summer 2015.

"If Weston Main beach and Uphill Slip way don't show improvement from next summer therefore, the chances of them being graded as 'sufficient' (the new minimum standard) in 2015 start to slip away.

"Failure to meet the 'sufficient' standard would mean, under the new European Bathing Waters Directive, that advice against bathing would have to be posted at the beach and this of course could have enormous consequences for the town.

"MCS therefore expects Wessex Water and the Environment Agency to do everything possible to rectify the water quality issues at Weston over the next year."

The Environment Agency says Weston beach is one of its priority bathing waters for improvement in order to achieve the minimum "sufficient standard."

Spokesman Mike Dunning said: "Burnham, Brean and Berrow beaches all passed the EU Guideline bathing water standard in 2010.

"Weston failed Guideline.

"It was one of 11 south west beaches to fail the higher standard. This compares with 26 guideline failures in 2009."

North Somerset Council says it will continue to work with the Environment Agency and Wessex Water.

Council spokesman Nick Yates said: "We are very proud of the beach at Weston which has won the Quality Coast Award again this year.

"Our miles of golden sand is cleaned on a daily basis and we do have a beach management plan.

"We do work with and will continue to do so, with both the Environment Agency and Wessex Water about water quality.

"We are in an estuary with the second highest tidal flow in the world which means that there is a lot of silt in the water which has always been the case."