The Drinking Water Inspectorate (DWI) has urged United Utilities to carry out a full review of its emergency and contingency plans in light of the cryptosporidium outbreak in 2015.
The incident, which directly affected 712,000 residents and consumers in North Lancashire, was the largest of its kind in Britain since 1989, according to DWI’s investigation report published on 25 October.
In addition to reviewing procedures, the DWI recommended United Utilities implements a programme of work to ensure all its treated water-retaining tanks and reservoirs are “properly maintained and secured”.
The report suggested consumers received “unclear” information, which left them “confused” when advice was first published and when it was lifted.
It said the company had made “every effort” to communicate with consumers, but argued it could have “communicated better”.
Recommending United Utilities reviews its plans for issuing protective advice to consumers, it said households should be given written advice within 24 hours of an emergency, as well as access to alternative sources of supply.
The DWI also recommended the use of a temporary treatment plant during a contamination outbreak and a review of cryptosporidium sampling equipment.
Chief inspector Marcus Rink, said: “My conclusion was that the company supplied water that was unwholesome as a direct result of actions and decisions made by the company, and that if a consumer were aware of the presence of the parasite they would have rejected it for consumption.”
On 6 August 2015 United Utilities advised customers in Preston, Blackpool, the Fylde Coast and the area south of Preston to boil water before drinking it after it identified the presence of cryptosporidium in water supplied from its Franklaw water treatment works.
Some customers were unable to drink tap water for up to a month after the discovery. The company pleaded guilty to supplying water unfit for human consumption at Preston Magistrates’ Court on 19 July 2017.
The honorary recorder for Preston, Judge Mark Brown, concluded at the sentencing hearing on 10 October, that the event had a major impact on the day to day consumption of water in Lancashire causing widespread inconvenience and anxiety.
The court heard animal waste had seeped into underground tanks and contaminated the water supply with cryptosporidium parasite. United Utilities was fined £300,000 for providing water unfit for human consumption.
Meanwhile, DWI’s report ruled out previous claims that a dead pheasant caused the incident.
A spokesperson for United Utilities, said: “We have learned lessons from what happened and have put technology and processes in place to guard against a repeat of this type of incident.
“Public health is always our primary concern, and customers can be reassured that the North West’s drinking water is of an extremely high quality.”
They added: “Since October 2015 we had already started implementing many of the recommendations in the DWI’s report. We are now leading the UK water industry in terms of resilience to cryptosporidium.”
Speaking at Utility Week’s Congress event in Birmingham earlier this month, Steve Mogford, chief executive of United Utilities said the company had emerged “stronger” from the incident.
He said it had cost United Utilities around £25 million, but as “a consequence” the company has invested another £100 million across its estate “in applying the lessons more widely around systems and networks”.
United Utilities will hold a series of seminars for the water industry throughout November to “ensure the sector learns from the incident”.