Men from the Bay of Plenty Regional Council and University of Waikato tested samples at Motuopuhi Island while a helicopter checked the shoreline for more oil.
Men from the Bay of Plenty Regional Council and University of Waikato tested samples at Motuopuhi Island while a helicopter checked the shoreline for more oil.
Heavy fuel oil is still being cleaned up from Tauranga Harbour after a spill more than three weeks ago - and costs have hit the hundreds of thousands of dollars.
Bay of Plenty Regional Council regional on-scene commander, Adrian Heays, said at last count on Monday, 38.96 tonnes of oily waste had been collected.
Three shags have died since the spill and three oiled penguins have been captured and treated. Two penguins have been released and one is still in care.
The council was investigating the incident and was looking at how Mobil had complied with relevant consents and the Regional Coastal Plan.
Mr Heays said this investigation would determine whether the council would carry out any enforcement action and whether any regulatory change was appropriate.
38.96 tonnes of oily waste had been collected since the spill.
The clean-up was still continuing and was estimated to have cost hundreds of thousands of dollars, he said.
Clean-up is ongoing at the Tauranga Bridge Marina at Berth C, the port wharf sea wall and Maungatapu sea walls. Matakana iwi were also continuing clean up work on the island.
"We're continuing to monitor high-risk sites for oil wash up, including Pilot Bay, Sandy Bay and Matakana " no new oil has been observed at these sites since Sunday.
"We have a good plan, trained staff and equipment caches in place that mean we're well prepared to respond to future oil spills."
Mobil New Zealand public affairs manager Samantha Potts said the estimated amount of fuel that was spilled in the harbour remained at 1500 litres.
Ms Potts said 104 claims had been received, but as the assessment process was still under way Mobil did not have an estimate on costs.
"The claims line remains open and we are receiving a few calls each day, mainly from boat owners.
"Most of the claims relate to the cleaning of boats from the Tauranga Marina - we are paying for the cleaning directly rather than paying owners individually to expedite the process."
The bunker pipeline to the main wharf remains shutdown following the leak for inspections and testing and Mobil did not yet know when it would be up and running again.
"We will not recommence refuelling from the bunker pipeline until we have full confidence in its integrity and that we have done everything we can to minimise the risk of another incident ... we do not expect main wharf bunkering to be operational for several weeks yet."
Ms Potts said Mobil had arranged for technical experts to come to Mount Maunganui, including two pipeline experts from the United States.
She said an assessment of the pipe would be needed to understand the specific cause of the failure, which would take "some weeks".
All costs incurred by the regional council in response to the spill would be reimbursed by Mobil, as well as all "reasonable costs" for cleaning and repair of damage to vessels and directly affected property.
Maungatapu resident Martin Neill, whose property was directly hit by washed up oil and oiled debris, said most of the oil had been cleaned up but residue still remained.
Clean-up crews had been at his property for almost three weeks removing debris.
"We've got a bit of residue coming off the banks now, but it's not bad."
Mr Neill said he had met with Bay of Plenty MP Todd Muller earlier this week about getting a plan in place for an instant response if a spill happened in future.
