United Utilities has announced that the court hearing in relation to the 2015 cryptosporidium incident at its Franklaw water treatment works has concluded – the root cause was identified as run-off water from agricultural land following severe rainfall.

Routine water quality sampling at the Lancashire works In early August 2015 uncovered traces of cryptosporidium - a microscopic bug which exists widely in nature.

As a precaution, the company issued advice to 300,000 homes and businesses in Blackpool, Chorley, Fylde, Preston, South Ribble and Wyre to boil their water before using it.

Lawyers acting for the company told Preston court the root cause of the incident was rainwater running off agricultural land grazed by livestock. A small amount was able to enter an underground treated water tank through a joint in the structure.

Despite regular inspections in line with industry best practice, it is likely the joint was affected by small ground movements in the tank structure over time. This, coupled with severe weather and significant rainfall on 27 July, led to rainwater run-off entering the underground storage tank at Barnacre, five miles from Franklaw.

Since the incident, United Utilities has enhanced its risk management processes at treatment works, tested supplies in all 364 water storage tanks across the North West, all of which are free of cryptosporidium, and introduced more rigorous structural inspections for storage tanks.

Steve Mogford, Chief Executive of United Utilities, 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 forty years. We have learned valuable lessons from what happened and have put technology and processes in place to guard against a repeat of this type of incident. United Utilities is now a leading company in terms of resilience to cryptosporidium.

“Public safety is always our primary concern and customers can be reassured that the North West’s drinking water is of an extremely high quality. Incidents of the kind that affected Lancashire in summer 2015 are thankfully extremely rare. The fact that we spotted the bug quickly, through our routine sampling, and immediately issued precautionary advice, minimised the risk of any customer falling ill.”

An independent study led by Public Health England, and published in 2016, concluded that there was no evidence of an increase in cases of illness directly attributed to the water supply at the time.

Since the incident United Utilities has put a series of measures in place, including:

• Installation of automatic shutdown at its water treatment works across the North West. This means water that isn’t of the quality fit to use is stopped from entering the water network in the first place. United Utilities will be the first major water company in England and Wales to have this on all of its sites, once completed.
• Developed and implemented a more robust approach to flood testing of all its underground storage tanks which are now considered industry best practice.
• Installed UV treatment at Franklaw water treatment works and at other key strategic sites which can also be supported by mobile rigs if needed.
• Tested water in all 364 underground storage tanks across the North West. All have been found to be free of cryptosporidium. A new, more rigorous structural inspection process for storage tanks has been introduced alongside improved technical training.
• Reviewed risk management processes at water treatment sites and improved automation, telemetry controls and resilience at strategic sites.
• Invested in its fleet of ‘Water on Wheels’ tankers that pump treated drinking water into the local network in the event of a water outage. The company now has 12 tankers on standby at all times, capable of reducing the customer impact of large water supply interruptions and this will grow to 24 by May 2018.
• Launched a new Priority Services scheme for vulnerable customers which provides access to a dedicated service and improved support during any water related incident for those customers with additional needs. More than 35,000 customers have been signed up to the scheme in the past two years.

Click here to listen to a video by United Utilities outline the cause of the incident, its source and improving the water network for the future on the Waterbriefing Watch Channel.