Water company Three Valleys has been found guilty of supplying water "unfit for human consumption".

Villagers were put at risk for months before eventually complaining about the colour and taste of what was flowing through their taps.

Three Valleys pleaded guilty to supplying the untreated water in Colney Heath at St Albans Magistrates' Court.

But those who were exposed to the water, which had unacceptably high levels of bacteria, are furious with the punishment - a £12,000 fine.

Colney Heath parish and district councillor Chris Brazier said: "With the profits it makes, a fine of £12,000 is just ridiculous.

"Three Valleys should have been fined something like £500,000 - that would give it the real kick in the backside it deserves."

In 2006, Three Valleys made new connections to three homes in Roestock Lane.

Because records had not been updated the homes were not connected to a proper supply main but to a pipe, which, since 1997 had been carrying untreated water.

After villagers complained, the company tested the water, which was discoloured.

By November 2006, the mistake had been rectified and the homes connected to a pipe carrying treated water.

Prosecuted by the Drinking Water Inspectorate (DWI), Three Valleys admitted supplying unfit water for ten weeks to two of the homes.

The court was told that the third home was not occupied at the time of the offences.

The company was fined £6,000 on each count, and ordered to pay £7,610.30 towards prosecution costs.

Spokeswoman Sally Howe said: "Three Valleys Water accepts the charges. We very much regret this error occurred.

"As soon as we realised our mistake we took immediate action, informed the customers and corrected the problem that same day.

"We have undertaken a thorough investigation and now understand how the problem arose. We have reviewed our records and we are confident this was a one-off event."

Seventy-four-year old villager Derek King, who lives in Roestock Lane, told the Review: "It makes you wonder how safe our water is - we have even had some problems with it this year.

"For a few months after Christmas our water tasted like it had TCP in it - you just could not drink it. But in the last month it has improved."

DWI spokeswoman Sue Pennison said: "Prosecutions are taken forward where there is reliable evidence that water unfit for human consumption was supplied, where the company does not have a defence that it took all reasonable steps and exercised all due diligence, and when such a prosecution is regarded as being in the public interest."