Water quality inspectorates in England and Wales commend companies for coping with Covid

The Drinking Water Inspectorates for England and Wales have commended the water industry for its maintenance of water quality amid the trials presented by Covid.

In its annual report for 2020 the Drinking Water Inspectorate for England said statistical analysis of the required actual number of samples taken in in 2020 to ensure the absence of faecal contamination in public drinking water “showed no significant difference with 95% certainty.” It commented: “As such, the industry should be commended on their performance in assuring the quality of the water supply at a most challenging time.”

The English inspectorate’s counterpart in Wales said:”During 2020 water was abstracted, treated, sampled, analysed and delivered to a high standard by staff who had to work through the pandemic without interruption and unseen. All those involved should rightly be commended on this.”

The English inspectorate reported that the median Compliance Risk Index (CRI) for England – the measure used to “illustrate the risk arising from failures to meet drinking water standards” – was 1.61 against a commitment by all companies to achieve a CRI of 2.0. so over half of companies are now achieving this demonstrating the high quality of water,” the inspectorate reported.

Wales’ inspectorate, in its report, noted an overall shortfall of 1,567 tests for E. coli across Wales for 2020. It said there was a wide variation in the percentage of samples taken by Welsh companies with 64% of samples not collected from the regulatory compliance sampling point by Dŵr Cymru Welsh Water while for Hafren Dyfrdwy, 30% were uncollected.

It said some of the difference was down to size of the company and hence the number of samples; the remoteness of areas covered; and arrangements for social distancing for samplers and analysts within laboratories. But “innovative solutions” went towards filling this gap it said, without increasing the risk to staff or being part of the wider problem.

The CRI for companies wholly or mainly in Wales was 3.92 – a slight deterioration in from the 3.73 recorded in 2019. It said this was “fundamentally due to legacy within the distribution network,” adding: “in contrast, the water produced and leaving water treatment works in Wales is of a very high standard.”

The Event Risk Index (ERI) is a measure designed to illustrate the risk arising from treated water incidents. Like CRI, it assigns a value to the significance of the event, the proportion of consumers potentially affected and an assessment of the company response.

In 2020 the Event Risk Index (ERI) – a measure that illustrates the risk arising from treated water incidents –  for England was 216. This was an improvement from 727 in 2019 and the lowest annual ERI recorded.

However, there was a “sharp decrease” of 25% in the number of events contributing to ERI from April to the end of the year compared to a six-year average. “It is difficult to prove cause and effect without detailed analysis of every event,” the inspectorate said.

But it points out how water companies stopped most of their work during that period and there was less activity in the network and treatment works. So it concluded: “The improvement of ERI for 2020 must be considered as a balance of improvement by companies but also an effect of the changes in practice due to the pandemic.”

For 2020 the Welsh inspectorate reported the ERI for Wales at five, from 27 in 2019, 32 in 2018 and 55 in 2017. In line with the English inspectorate’s report, it said Wales saw a sharp drop in the number of events contributing to ERI. They fell from 46 in 2019 to 21 in 2020. It said the difference was “obvious”. Echoing its English counterpart it said a “conclusion of cause and effect is not possible,” but given the the drop off in activity by Wales’ water companies it proposed that the decrease in ERI could be “an artefact of the pandemic.”