Oil is still being removed from parts of Tauranga Harbour after an oil spill seven weeks ago which has already cost almost $700,000 to clean-up.
Bay of Plenty Regional Council on-scene commander Adrian Heays said it was pleasing to have some areas signed off following the spill from a Mobil-owned pipe at the Port of Tauranga on April 28, but there was still work to be done.
"A minor amount of oil remobilised at Bridge Marina last week, so we have reactivated clean-up efforts with prop washing and booms, recovering oil from the water, waterline scraping and solvent cleaning of dry marina structures. We've been wiping down the pier surface and using divers to clean difficult surfaces under water," he said. At the Port, pile cleaning continues with a final washing off to contain and remove any oil that may be trapped in pockets under the wharf. At Maungatapu and Motuopuhi Island Mobil staff and hapu are checking shorelines, and a remediation plan is being developed for seawalls and jetties.
The clean-up will continue until all areas have reached an acceptable end state, rather than an end date, he said. "Once we get to the point that transferable oil is largely removed from the affected areas we can terminate the response phase of the clean-up. Independent environmental monitoring will continue, and it is expected that Mobil will lead the affected parties through an appropriate recovery and mitigation process," Mr Heays said.
Clean-up operations have finished at the worst affected area, Matakana, and at Rangiwaea Island, Pilot Bay and Sandy Bay. The regional council has invoiced Mobil for a total of $691,766 in clean-up costs so far. Early results from sampling of shellfish on April 29 (three days after the oil spill) showed that levels of oil-related pollutants in the shellfish at Maungatapu Bay were higher than baseline levels on that date.
All other monitoring sites, including the Port, Bridge Marina, town reach and Motuopuhi Island, had results within typical average levels for Tauranga Harbour. "This suggests that initial impacts of the oil spill on shellfish were localised, affecting only heavily-oiled shoreline areas. Current contaminant levels and longer term oil spill impacts on shellfish can't be assessed until at least six weeks of sampling has been completed at the end of June."