A health warning sign to be erected on St Kilda Beach near Lawyers Head is not a result of pollution caused by the Tahuna wastewater treatment plant, the Dunedin City Council says.
Council wastewater treatment manager Chris Henderson said the sign, which would go up in the next few weeks, would replace one in John Wilson Ocean Drive at the top of the access track to that end of St Kilda Beach, which could not be seen from the beach.
The 1m by 75cm sign would advise against swimming and collecting shellfish in the area and would be permanent.
''People need to be aware that if they are in contact with the water, they are at risk of getting gastroenteritis.''
He said contamination limits for swimming were breached in the Lawyers Head area several times during summer.
It was unclear why the higher Enterococcus bacteria readings occurred, but it was likely to be because of natural environmental conditions, such as hot weather and a high number of sea birds in the area and not the nearby Tahuna outfall pipe, which discharges treated wastewater more than 1km out to sea.
''The UV disinfection plant at the Tahuna wastewater treatment plant is operational and delivering consistently good results, so the contamination did not come from the Tahuna wastewater outfall.''
No other city beaches were affected.
He said Public Health South and the council's environmental health team believed more people would see the new sign in its position on the beach.
Another health warning sign, at Tomahawk Beach, was still expected to be removed.
The sign was put up as a condition of the Tahuna wastewater treatment plant's coastal discharge permit.
It could not be removed without the approval of the Otago Regional Council and the Southern District Health Board, which first had to be satisfied with consistent test results from the plant over a period of time, Mr Henderson said.
''The intention is still to remove the sign, but that will be subject to a formal process following Tahuna testing.''
