Hundreds of thousands across areas including Blackpool, Chorley and Preston affected by warning after utility finds cryptosporidium bug at treatment works

This article is more than 5 years old

This article is more than 5 years old

More than 300,000 households in Lancashire will have to boil drinking water into next week following the discovery of a microscopic bug.

The water firm United Utilities issued the public health warning after discovering “low” traces of cryptosporidium in its water supply.

The parasite can cause gastroenteritis and is commonly associated with diarrhoea, vomiting and nausea.

The warning was issued on Thursday afternoon to United Utilities customers across large parts of Lancashire including Blackpool, Chorley, Fylde, Preston, South Ribble and Wyre.

The water firm is advising the customers to boil their water for all drinking, food preparation and teeth brushing as a precaution until further notice. Residents can continue to use tap water without boiling for general domestic purposes such as bathing, flushing toilets or washing clothes.

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Martin Padley, the chief scientific officer of United Utilities, said on Thursday: “The advice is being given purely as a precautionary measure as we carry out additional tests today. We apologise for the inconvenience but the health of our customers is absolutely paramount.”

Dr Derek Gatherer, an expert in diseases and viruses at Lancaster University, said it was too early to say whether the case would lead to an outbreak of cryptosporidium – but said people should not be too concerned if they follow the advice about boiling tap water.

“It’s very unlikely that we will get any serious clinical implications because most people won’t notice they have it – apart from a short burst of diarrhoea – it’s just with the elderly and the young it can cause more serious symptoms,” he said.

Gatherer said it was highly unlikely to reach the “worst case scenario” of the 1998 Sydney water crisis, when traces of cryptosporidium and giardia were found in water between July and September in several major surburban areas.