Severn Trent has resolved an issue which saw thousands of customers in Derbyshire and Leicestershire told not to use their water because of unusually high levels of chlorine.

Around 3,700 households around Swadlincote and Ashby-de-la-Zouch were told not to use the water from their taps on Friday after abnormal levels of chlorine were found at Castle Donington reservoir. The company issued the ‘do not use’ notice – which advises customers not to use the water for any purpose, including bathing or flushing the toilet – after being alerted to the problem by a monitoring system.

It distributed free bottled water to customers at two supermarkets in the affected areas, while working through the weekend to resolve the problem by flushing the network. Customers were later advised to run their cold taps for a minimum of five minutes and to empty their hot water tanks before being told that it was safe to use the water again. Severn Trent said it was still investigating the cause of the problem, but that over-chlorination from a dosing system was suspected.

“We’re pleased to say that all of our customers in the Derbyshire and Leicestershire area can now use their water supply as normal,” said Severn Trent in a statement.

“We’re really sorry for the inconvenience we know this has caused.  We want to reassure you that the health of our customers is our absolute priority, and this was a precautionary measure due to the levels of chlorine in the water supply.

Some customers would experience discoloured water while the system was restored to normal but they were advised to run their taps for 20 minutes and the water would clear, the statement continued.

“While we appreciate that you may be concerned about water you have already consumed, we’d like to reassure you that if you didn’t notice a strong chlorine taste or smell, or detect anything unusual when drinking it, then it’s unlikely to have caused you any harm.  If you have any further health concerns then we recommend you contact your local health professional.

“We’re investigating what caused the problem and identifying how we will compensate all 3,700 customers, both domestic and business, who were directly affected for an extended period of time.”

This article first appeared in Utility Week’s sister title WWTonline