Drinking Water Inspectorate warns compliance risk on the rise

New figures from the Drinking Water Inspectorate (DWI) have revealed marginal increases in compliance risks amongst suppliers last year in England and Wales

The DWI’s Drinking Water 2018 report reveals that while figures for public water supply compliance with European standards in England and Wales remain largely static, there have been changes in other areas.

Most notably, the report reveals increases in the compliance risk index (CRI), which is designed to allocate a numerical value to risk.

According to the DWI report, CRI is designed to measure the risk arising from treated water compliance failures.

In 2018, the DWI recorded the CRI for water companies wholly or mainly in England was 3.86, compared to 3.62 in 2017.

In a letter to the environment minister Therese Coffey, the chief inspector of drinking water, Marcus Rink said failures of samples to meet EU, national and other standards taken at treatments works had all contributed to the CRI score.

“The common link between the majority of these failures is they are due to just a handful of assets, which present the majority of risk and contribute greatest to CRI,” said Rink in his letter.

Water companies based wholly or mainly in Wales scored a CRI of 4.15 in 2018, compared to a figure of 2.63 the year before.

“This reflects the continuing and repeated iron and manganese failures compounded by a coliform failure in May in Newton zone,” said Rink in his letter to the Welsh environment minister, Lesley Griffiths.

“My report highlights that consumers in Wales contact water companies about discoloured water almost three times more frequently than consumers, on average, in England and that there has been little progress in reducing numbers of contacts in recent years.”

But the DWI report also shows that the 2018 figure for public water compliance with the EU Drinking Water Director was 99.95 per cent in England and 99.97 per cent in Wales.

Rink said both figures are “certainly good news” and indicate that the “drinking water supply is excellent”.

The report also reveals that Wessex Water had the lowest CRI score of all nine water and sewerage companies in England.

“We can be really proud of this result, which is down to the hard work and focus of the whole business,” said Wessex Water’s head of compliance, Richard Hargrave.

“From those who collect the samples or fix the mains, colleagues in the control room who respond quickly and those who operate our treatment works or write compliance reports – there are many people involved,” he added.

“Being first is great but it’s essential that we don’t get complacent, and next we will identify any learning we can take from the report.”