Pandora Pond testing resumes, action over blockage in sewer system

Enough sewage is believed to have drained into Napier's inner harbour "to exceed acceptable limits". Photo / File

Investigations into the source of the Pandora Pond contamination resumed yesterday, after testing stopped due to last week's heavy rain.

The popular water spot has been closed since February 21, after a high reading of 475 Enterococci per 100ml. The safe swimming guideline is 280. On Friday levels soared to 770 Enterococci per 100ml.

These elevated bacteria levels mean the pond will remain closed while testing continues.

Hawke's Bay Regional Council coastal scientist Anna Madarasz-Smith said they had undertaken extensive sampling from the Railway Bridge to the Inner Harbour.

Thwe council had not found the contamination source but was working on what the contributing factors were.

"Some avian or bird contamination has been found but that would be expected in an estuary such as Ahuriri and HBRC certainly doesn't have the full picture yet," she said.

The council is also taking action against the Napier City Council over a blockage in the Meeanee Quay sewer system led to the discharge of raw sewage into an Ahuriri waterway,

Sewage is believed to have entered Napier Marina's inner harbour - the fishing boat side of Meeanee Quay, from Westshore Bridge to the harbour mouth, which is relevant to the Ahuriri estuary on an incoming tide.

Napier City Council manager asset strategy Chris Dolley said the blockage on Thames St was caused by gravel and sand.

Wastewater backed up and entered the roading stormwater network though a lifting eye in a manhole near Westshore Bridge.

"At the incident site, it was the view of the operators that no wastewater had entered the inner harbour although it's difficult to be certain," he said.

Sampling by the regional council however confirmed the discharge reached the inner harbour after entering the roadside stormwater drain, which drains into the inner harbour.

Regional council manager resource use Wayne Wright said the quantity of sewage that reached the inner harbour was unknown, but "enough entered the waterway to exceed acceptable limits as per the sample results".

The discharge was discovered by regional council staff on Sunday, March 4. After being advised, Napier City Council staff attended to clean the remains of the discharge, the roadside sumps and gutters, and removed the blockage.

Mr Wright said the council was unable to comment further because enforcement action was pending.

In the week after the closure, the Hawke's Bay Regional Council reported samples from Pandora Pond were clear.

When asked if this contributed to the pond's prolonged closure, a Hawke's Bay District Health Board spokesperson said: "We were aware of the possibility of sewage going into the harbour from this event, and given this information it was prudent to keep the swim warning in place.

"We are awaiting further information from Napier City Council and Hawke's Bay Regional Council to understand this event and its implications.

"The swim warning will remain in place with results continuing to show elevated results of contamination."

Ms Madarasz-Smith said the council would continue to take regular water samples and was working hard with the Hawke's Bay District Health Board and the Napier City Council to fully understand the contamination's source and what is contributing to it.