A water company has released untreated waste water into the sea 100m off a Blue Flag beach to prevent widespread flooding.

A fault at Southern Water’s pumping station in Sea Road, Littlehampton, threatened a back up in the town’s sewer system.

To prevent homes and firms flooding and people losing water supplies the company released waste water through an outfall out to sea all day yesterday.

The company was forced to take the action after a sheared bolt in the pumping station’s mechanisms caused it to fail and waste water to back up.

The Environment Agency has launched a full investigation.

Clean water campaigners claim the release of untreated waste could cause ailments ranging from sore throats, eye infections and upset stomachs to hepatitis.

A Southern Water spokesman said waste water would normally be pumped away for treatment.

But to prevent flooding and to “ensure customers can continue to use their toilets, washing machines and showers” untreated water was pumped out to sea.

A temporary pumping station has been set up, bypassing the damaged valve so the treatment works can operate as normal until it is repaired.

A second team was stationed on the beach to clear up any debris washed back to the shore.

He said it was impossible to say how much waste water was released into the sea.

Hugo Tagholm, chief executive of Surfers Against Sewage, said: “Any discharge of untreated sewage can pose serious health problems to water users.

“The World Health Organisation recommends that water users avoid the area for 24 to 48 hours after a serious pollution incident.

“If this is a technical fault then that is unavoidable. In any industry that can happen.”

Last night an Environment Agency spokesman said: “Our officers are on site to establish the facts and we are working to ensure that the incident is brought to a close as quickly as possible.

“We are also providing water quality results to allow the council to update their public warning information.”