United Utilities fined £300,000 for providing water unfit for human consumption

Animal waste seeped into underground tank, contaminating drinking water supplies with cryptosporidium parasite, court hears

Up to 700,000 people could not drink tap water in their homes for three weeks after the bug was found at the Franklaw water treatment works in Preston (Getty)

Water firm United Utilities has been fined £300,000 for providing water unfit for human consumption in Lancashire in the summer of 2015.

The UK's largest listed water company will also have to pay £150,000 costs for the prosecution.

A court heard that animal waste seeped into an underground tank, contaminating drinking water supplies with the cryptosporidium parasite, which can cause diarrhoea and abdominal cramps.

Up to 700,000 people were told they should boil water before drinking it and some could not drink tap water in their homes for a month after the bug was found at the Franklaw water treatment works in Preston.

The incident prompted supermarkets in the area to limit the amount of bottled water per customer, following panic buying.

Sentencing, honorary recorder of Preston Judge Mark Brown said: “The event was completely ended by early September. However, it's likely that in the minds of many customers there would have been ongoing concerns because confidence had been affected.”

United Utilities pleaded guilty to the charge in July.

Speaking after the sentencing on Tuesday, the firm's chief executive Steve Mogford said: “We are very sorry for the impact this had on our customers.

“I know from first-hand the inconvenience this incident caused, having lived in Lancashire for 40 years.

He said the company had learned "valuable lessons" from the incident and had implemented new procedures to prevent similar contaminations happening in future.

The court heard there were inherent hazards at the reservoir, including a neighbouring farm, and structural defects at the site led to cryptosporidium getting into the water after a heavy downpour of rain.

The parasite was noticed after it was picked up by a filter system at the Franklaw site on 5 August.

The warning for customers to boil their water was issued the next day and stayed in place until early September.

The court heard there was a “huge” impact on the public.

Mr Banwell said one dentist's surgery had to cancel 100 procedures as a result and could only deal with appointments which were emergencies or did not require water.

He added: “No doubt the need to boil water was of significant inconvenience to everybody.”

The court heard ultraviolet irradiation, a treatment which inactivates the parasite, had since been installed after a £100m investment by the company.

Lisa Roberts QC, defending, said the costs would not be transferred back on to customers.

She said: “So far as the company is concerned, it deeply regrets the incident in the summer of 2015 which gave rise to this.

“It takes its responsibilities to customers very seriously and places their safety at the very forefront of the business.”

Additional reporting by PA