Severn Trent has warned thousands of customers not to use water while it investigates problems with high levels of chlorine in its supply.
The water company said it is investigating an issue at the Castle Donington reservoir in Derbyshire.
It has told residents in the DE11, DE65 and DE73 areas of Derbyshire not to use water for anything, including drinking and bathing.
A total of 3,700 properties could be affected.
Updates on this story and more from Derbyshire
Severn Trent, which uses chlorine in its filtration process to make water clean enough for drinking, said it does not know how long it will take to resolve the problem.
“It looks like there’s been over-chlorination,” a spokesman said.
“Once we’ve got through this incident and we’ve flushed the water through the system, we can go back, take a look and see exactly what happened.
“A Do Not Use notice means that customers shouldn’t use their water supply for anything – including drinking, preparing food and bathing.”
What’s wrong with the BBC? This entry passed through the Full-Text RSS service – if this is your content and you’re reading it on someone else’s site, please read the FAQ at fivefilters.org/content-only/faq.php#publishers.
Source:: BBC UK