A failure at a water treatment centre that left tens of thousands of Kent households without water was foreseen weeks before it happened and could have been stopped, the regulator has said.
Twenty-four thousand homes in the Tunbridge Wells area were without drinking water for two weeks from 30 November last year due to a failure at the Pembury water treatment centre.
At first there was no water coming from taps, and then the town was put under a boil water notice. South East Water told residents the water from their taps was unsuitable for drinking, giving to pets, brushing teeth, washing children or bathing in with an open wound.
Marcus Rink, the chief inspector at the Drinking Water Inspectorate (DWI), said the problem began on 9 November when there was a “noticeable deterioration” at the plant.
He told MPs at a select committee hearing that the company also failed to do proper testing, which had been requested by the regulator, and that it also failed to install a filter that would stop dangerous heavy metals from entering the water supply.
“It shouldn’t have been a surprise,” he said at the environment, food and rural affairs (Efra) select committee hearing.
The problem occurred because a coagulant chemical used to purify drinking water stopped working. Rink said: “The opinion of my inspectors is had they done the appropriate testing and had they had the appropriate data, the original chemical would have worked.”
South East Water had last conducted appropriate tests in July, he said, and added that the company was “flying blind” and manually collecting data on how the coagulant was working rather than using an electronic system which could have identified problems in real time.
The ageing treatment works, which is the only one which serves Tunbridge Wells, has been under an enforcement notice from the DWI since last year over bacteria and pesticide contamination risks.
During a defensive display at the select committee hearing, the chief executive of the water company, David Hinton, suggested the problem came out of the blue.
He said: “The actual issue that caused this was a change in the raw water chemistry that we hadn’t seen in 20 years.” He referred to this as an “unexpected failure”.
He also blamed the “lifestyle changes” of customers “spending more time at home” since 2020 for pressures on the water supply system and suggested the issue was because of the climate crisis, as a recent drought had depleted the reservoir that feeds the treatment centre.
“Climate change is changing the environment – we should have had a backup chemical,” he said.
Hinton also blamed the regulator’s “infrastructure standards” for the fact that there was only one water supply centre to Tunbridge Wells, adding: “Customers relying on a single asset are always more at risk than those that aren’t so until infrastructure standards are updated that will be the case.”
Rink said the inspectorate has little recourse to take further sanctions against the water company as it issued a boil water notice and informed residents of the risk before it could do so.
He explained: “We enforced against the notice for the company to put a microfiltration unit to stop any residual aluminium leaching into the clean water tank. The company have not fitted that. We have no further sanction to deal with this, the regulations don’t provide us with the relevant facility to do that. We don’t feel we have a potential pathway under the current legislation which allows us to sanction the company’s under sufficiency.”
South East Water has been on the brink of financial collapse, a fate threatening multiple other water companies. Last year it had to ask for a £200m cash injection from its investors after being put on a watchlist by the regulator Ofwat over its financial health.
South East Water has been contacted for comment.
