Pollution alert as 200,000 litres of waste leaks into Welsh river

One of Britain's most environmentally sensitive rivers, hailed as the world's finest for fly-fishing grayling, has been hit by a second chemical spill in two years, just as fish stocks were recovering.

More than 200,000 litres of industrial waste poured into the river Dee in north Wales, killing fish and forcing water companies to stop using the river for drinking water.

The leak from the rubber chemicals company Flexsys involved industrial effluent believed to contain phenol, which can cause burning and irritation if it touches skin.

About 225,000 litres of the effluent flowed into Trefnant Brook at Cefn Mawr, near Wrexham, then into the Dee, part of a network that supplies drinking water to more than two million people in Wales.

Janet Williams, a member of the Campaign for the Protection of Rural Wales (CPRW), saw the spill. "The stench was terrible and the fumes were irritating to the skin," she said.

"The Trefant had turned a murky grey. Another person who was also walking in the area told me he had seen dead fish. The Dee was designated a water protection zone and there should have been safeguards to stop this. I am devastated. The valley is such a beautiful and special place."

Two years ago, more than 100,000 fish were killed by pollution on the Dee, also noted for its spring salmon run, sea trout and coarse fishing, and officials said it would take years for stocks to recover.

The countryside council for Wales wants the whole of the Dee declared a site of special scientific interest. A spokes-man said the Dee was home to rare species such as the otter, Atlantic salmon and lamprey. He said the 2000 spill killed many mature fish and although they had been replaced by young ones, stocks were still vulnerable.

The Dee rises on Garnwedden mountain in Snowdonia to the west of Bala lake, joined there by the river Tryweryn. It flows east through Corwen and Llangollen, then north to Chester, Flint and the Dee estuary to the Irish Sea.

Yesterday Martin Watkins, an Environment Agency spokesman, said early indications suggested the effect on fish was not as bad as the incident in 2000. The source of that leak has not been identified. "A large plug of the chemical flowed into the water but it will dilute as it makes its way downstream," he said.

"There are a lot of areas on the Dee that are home to flora and fauna which don't appear in significant numbers in other rivers. Fish stocks, including salmon, have been recovering and might be getting up to their pre-Industrial Revolution levels. It is too early to say how much damage this leak will do."

Flexsys could face an unlimited fine if it is successfully prosecuted. The company suspended operations and tried to protect the river as soon as the leak was spotted, a spokesman said yesterday.

An abstraction point at Bangor-on-Dee, Clwyd, was closed by 9am on Sunday, with the company using clean water from storage. The spokesman said the leak was contained within an hour and a half and the company was working with the Environment Agency to discover how it happened.

Dee Valley Water, which extracts 85 per cent of its supplies from the Dee, told customers their water was safe. Welsh Water said its supplies were abstracted some distance from the leak.

Helen Mrowiec, deputy director of CPRW, said the leak should not have happened when the river was so carefully regulated. "The chemicals could get into the food chain and concentrate in fish food so there could still be an impact on the ecosystem," she said.

"Ecologically, the Dee is one of the most important rivers in Wales and it is one of the most tightly regulated, so any pollution incident is one too many."