A WORRIED mum believes her water supply has cau-sed her children to vomit, turned their clothes yellow and induced mouth ulcers.

Sara Mills, of Wooburn Green Lane, says a letter from Thames Water warning of increased iron levels, prompted her to question the cause of her kids' health problems.

Last week the company said the discoloured water posed no health risk, but issued bottled water to residents and warned them not to drink from taps.

Around 257 homes have been affected in Beaconsfield, Wooburn Green and Loudwater.

The 35-year-old mum-of-two said: "It is getting worse and worse. The water is disgusting."

Mrs Mills said her two girls, aged five and 20 months, have been experiencing stomach problems since late May which have caused them to vomit.

But despite taking them to the doctors, she says no explanation has been provided. Stool samples taken from the children have failed to find a cause.

Thames Water said the "elevated" iron levels were down to old galvanised pipes reacting with the new water supply.

So far, tests have indicated that 300 to 500 microgrammes per litre of iron are present in the water. This is below the 2,000 microgram level for health risks according to the World Health Organisation.

But Mrs Mills has called on Thames Water to conduct new tests at her home.

"It doesn't look or smell right," she said.

Thames Water said it had conducted a survey of pipes at Mrs Mills' property and has decided to replace them.

A spokesman said: "In terms of quality of water at that property, we are going to be taking a sample as a priority.

"Numerous samples have been taken on the same road and they have fallen within the safe limit."