“We are aware of a tomo (sinkhole) that has formed near the Onemana Wastewater Treatment Plant, and we suspect treated wastewater may have entered a local wetland, potentially entering a stream that flows to the beach area,” the council said.
As a proactive step, the council said it is erecting signage by the Onemana Drive carpark.
This will advise people not to swim, fish or collect shellfish in the area around where the stream discharges.
This warning will be in place until further notice.
The council said it was also turning off the irrigation disposal closest to the sinkhole area as a precaution.
The Thames-Coromandel District Council made a public post urging locals not to swim, fish, or collect shellfish south of the Onemana Drive carpark. Photo / Thames-Coromandel District Council
In addition, it was carrying out sampling at and near the sinkhole site and stream discharge area.
Officials will also carry out regular monitoring of the site to ensure no further deterioration or land movement occurs.
The council said it was going to treat the wastewater ponds to deal with a recent algae bloom.
Signs warning of pollution on Wellington’s south coast as a result of the Moa Point Wastewater Treatment Plant failure. Photo / Mark Mitchell
This incident comes after a significant Wellington sewage spill this month.
The Moa Point treatment plant suffered a “catastrophic” failure, which sent raw sewage into the sea.
The plant was flooded by raw sewage, causing it to shut down and be evacuated. As a result, raw sewage was instead being pumped out into the ocean on Wellington’s south coast.
When asked how bad the failure was on a scale of one to 100, Wellington Water chief executive Pat Dougherty gave it a 90.
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