An investigation into a suspected diesel spill at a popular New Plymouth beach is trying to pinpoint the source of the pollution, Taranaki's environmental watchdog says.
About 11.30am on Monday the Taranaki Regional Council (TRC) was alerted to a hydrocarbon spill coming from the stream at the western end of Ngamotu Beach, near Port Taranaki, and took immediate action.
TRC response staff reacted quickly, placing booms at the stream mouth, and along the water edge of the harbour marina, to stem the flow of what was believed to be about 100 litres of diesel fuel.
The public were advised to stay away from the beach during the clean up process as the pollutant drifted out into the harbour, causing a light sheen on the water surface near the lee breakwater.
TRC compliance manager and on-scene commander Bruce Pope said it was expected Ngamotu Beach would reopen to the public at midday after final checks were made.
Pope said an investigation into how the pollution occurred and where the hydrocarbon came from was continuing.
No residue came ashore in the incoming tide last night, Pope said.
Pope said incidents like this could be avoided if people were careful.
"Everyone at work, or at home needs to take special care not to mishandle any material that has the potential to cause significant environmental effects," he said.
A two day learn to sail training camp, organised by the New Plymouth Yacht Club, was not affected.