Almost a dozen beaches in Northern Ireland have been slammed for their water quality following an investigation into the threat posed by unregulated sewage overflow pipes across the UK.

Newcastle and Ballyholme beaches in Co Down and Carnlough beach in Co Antrim were among 11 beaches identified by the Marine Conservation Society (MCS) as having poor or very basic standards of water quality which have sewage overflow or outfall.

Other beaches highlighted for having only basic water quality were Ballycastle, Waterfoot and Portrush's Curran Strand in Co Antrim. Crawfordsburn and Helen’s Bay also received basic passes from the organisation.

Details of the location of thousands of sewer pipes around the UK were obtained by the MCS following a Freedom of Information request.

A major report in yesterday’s Sunday Times revealed the locations of many of the offending pipes which, it claimed, were jeopardising water quality by dumping raw sewage into coastal waters and rivers.

“There is no limit on the amount of sewage that can come out of these overflows, they represent a licence to pollute,” said Thomas Bell, coastal pollution officer of the Marine Conservation Society (MCS).

According to the Sunday Times article, Newcastle has three sewage overflow outlets, and failed the EU’s basic water quality standards last year. Ballyholme and Carnlough also saw a decline in beach cleanliness and failed the basic water quality standards.

Kelly Andrews, co-chair of The Green Party in Northern Ireland, said problems involving sewage outflows were not new to the province.

“It is imperative that we have good water quality for our marine life and for tourism and swimmers. Everyone needs to see clean beaches,” she said.

“Northern Ireland prides itself on its wonderful scenery and nice environment, but it’s a contradiction if it’s not as clean and wonderful as it should be.”

Yesterday’s report said that there are around 500 regulated sewer overflows on Britain’s beaches which are supposed to operate only after heavy rain, but that swimmers and surfers have complained that these are operating more regularly to relieve pressure on overworked sewage systems.

Among the other overflows highlighted were:

l More than 60 operated by South West Water, including pipes on the River Torridge, which flows to a popular Devon beach.

l More than 250 outlets operated by Yorkshire Water, including sewage flowing into the North Sea.

l Sewage overflows on the River Don, where thousands of fish were killed by sewage pollution in 2006.

l An overflow operated by United Utilities near Manchester, which was blamed for polluting a fishery in 2005.

Despite a £10bn investment programme by water companies since the industry was privatised, about one in four beaches still fails to qualify for the European Union’s top category.

The Sunday Times reported that the water industry says it is replacing many of the sewage overflows that cause problems and added that they are used only when necessary to expel sewage and flood water.