Health warning issued after deliberate sewage leak at popular Adelaide beach

A popular beach in Adelaide’s south has been closed to the public and a health warning issued after a deliberate act of vandalism sent 300,000 litres of sewage spilling into a waterway.

The toxic sludge was released into Christie Creek after someone broke into SA Water’s nearby treatment plant and opened valves.

The incident forced authorities to close a section of the beach today while a major clean-up took place, with crews called in to pump contaminated water out of the creek.

The dangerous act of sabotage is now being investigated by Police and has left residents furious.

“Stupidity on their behalf, absolute because yesterday it was chock a block with people swimming,” a local man told 9NEWS.

“Who does stuff like this deliberately? Who breaks into a sewerage farm after all? You know you have to have a screw loose,” added another.

But health experts are confident beachgoers haven’t been exposed.

“The sludge has been contained to the creek and little or no sludge has entered the water but as a precaution we're advising swimmers to avoid a 200m stretch of water,” SA Health’s Dr David Cunliffe said.

The incident is believed to have occurred sometime between 3.30pm yesterday and 7am today.

SA Water is now investigating exactly how the security breach occurred.

“We're working closely with SA Police on their investigation into the illegal break in. We're also working closely with the EPA to ensure that the creek is properly cleaned,” Dr Daniel Hoefel from SA Water said.

The treatment plant’s security is also under review.

“They all adhere to our Australian standards and we take a multi-barrier approach to our security at our waste water treatment plants,” he added.

The beach is expected to be re-opened tomorrow once authorities receive the results from water tests.