Results received so far have been consistent with those from a NSW Beachwatch program conducted in the area a decade ago, which indicated elevated levels of antimony and arsenic at Station Creek, which flows from the plant into the Urunga Lagoon.

Council’s deputy general manager for Environment and Planning, Stephen Taylor, said a review of the current test results indicated it was unsafe to swim or fish in the vicinity, and so health warning signs would be posted.

“Obviously this has been an ongoing problem and I am not sure why these signs were not installed 10 years ago,” Mr Taylor said.

“Plans are now well underway for the remediation of the Urunga site and hopefully we will see an improvement in the future.”

A spokesman for NSW Lands, Catchments and Water, said soil testing was continuing on the site and the community would be advised of the chosen remediation strategy before any work commences later this year. There are four options under consideration.

The water test results will provide an important benchmark against which the effectiveness of the remediation efforts can be measured.

Samples from the Sea Lido public swimming area show it is safe for recreational use.