The Otago Regional Council yesterday appealed for information to identify the source of the spill, and had enacted a pollution response plan to mitigate the environmental impact.
The spill, which involved 400-600 litres of diesel going into the harbour and South Dunedin stormwater network, was described as a serious breach by council compliance manager Tami Sargeant.
“We’re looking at a significant amount of diesel that has been discharged into the stormwater network, and our investigations team are very keen to identify the source and determine what’s happened here.
“Given the volume of the diesel, we think it’s highly likely someone in the community will know how it got into the stormwater system.
"The adverse effects on the environment from a spill like this can be quite severe.”
Nearby resident Mike Aluesi, who fishes regularly in the area, contacted the Otago Daily Times early this week to report fuel pollution in the area, including slick about 100m long, and also reported it to the ORC Pollution Hotline.
Mr Aluesi first saw fuel pollution there on Saturday, and was yesterday concerned that further pollution was entering the harbour, damaging the environment and posing a health risks to fishers and to sea scouts using kayaks nearby.
Ms Sargeant said the pollution response team was using sorbent booms to stop the spread of diesel into the harbour.
There was still diesel contamination in the stormwater network which would make its way to the harbour via the outfall pipe over the coming days.
“The time it takes for the diesel contamination to flush from the network depends on how much rain we get, but the booms will remain in place until the diesel has ceased discharging.”
Dunedin City Council 3 Waters group manager Tom Dyer said the council was disappointed by the situation and staff were working closely with the regional council.
Ms Sargent asked for anyone who had information about the spill to contact the council.
Dr John Jillett, a retired marine biologist who long headed the Portobello marine laboratory complex, was pleased the regional council was investigating this "worrying’’ spike in pollution, which could cause serious environmental damage, he said.
