It is the second time in two weeks that contamination levels in the bay have exceeded safe standards.
Wellington City Council is urging people to stay clear of the water in the area until further notice.
Water-quality monitoring this week has found that the presence of enterococci – an indicator of microbiological pollution, including sewage – in Owhiro Bay is at a level likely to cause a health hazard.
The Council has taken the action following consultation with Regional Public Health staff.
City Council Infrastructure Director Stavros Michael says the source of the contamination is not obvious. However Council staff are today checking sewer mains in the Todman Street area in Brooklyn, at the top of the Owhiro Bay catchment, where it is suspected a pipe break may be causing sewage to leak into the stormwater system.
Staff are doing dye tests and using CCTV cameras to check the mains. If a fracture is found, repair work will be done as a matter of urgency.
The presence of enterococci in the water indicates it is unsuitable for swimming or recreational contact. Health problems that can be associated with the ingestion of contaminated water include diarrhoea, stomach cramps and vomiting. In addition, cuts and skin lesions can become infected.
Wellington City Council will keep Owhiro Bay beach closed till at least tomorrow (Wednesday 11.02.10). We closed it last Friday after continuing high contamination readings in the bay. The contamination levels have dropped over the weekend but still aren't down to acceptable levels.
While Council staff have cleared a blockage in a private sewer in nearby Severn Street that we believe was contributing to the pollution, we're still doing repairs on a sewer main break in Todman Street, Brooklyn, and leak detection work on mains along Owhiro Bay Parade and on rising mains in the area.