Urgent changes to the Resource Management Act are being called for so that councils and ratepayers are not left out of pocket in prosecution cases such as the Mobil major oil spill.

Earlier this week, Mobil Oil NZ was fined $288,000 after 3000 to 4000 litres of heavy fuel oil was discharged into Tauranga Harbour last year during the refuelling of a vessel berthed at the port.

Fuel escaped from two holes in a corroded lateral pipeline flagged for repair in 2013.

Mobil paid $1.8 million to remedy the effects of the spill, including reimbursing the Bay of Plenty Regional Council almost $1.2 million for costs associated with the clean-up and $627,104 in other claims.


But despite 90 per cent of the fine going to the regional council, the council and ratepayers have been left at least $90,000 out of pocket.

Bay of Plenty Regional Council pollution prevention manager Nick Zaman said there was a "glaring gap" in the Resource Management Act (RMA), which meant there was no cost-recovery mechanism to recoup the costs of investigation and prosecution.

Mr Zaman said final costs were still being calculated, but it had cost at least $350,000 to carry out the investigation and pursue the prosecution.

Tauranga District Court Judge Jeff Smith said he was constrained under the RMA from awarding costs to the council after taking into account past similar prosecution cases, and clearly a review of the Act was needed.

Proposed changes to the RMA are currently before a parliamentary select committee.

A $288,000 fine was "quite significant" when compared with the $300,000 fine for the Rena spill but the maximum penalty of $600,000 under the RMA for an offending company was insufficient when compared to what could potentially be awarded under other legislation, Mr Zaman said.

Tauranga Bridge Marina Travelift co-owner/manager Bruce Goodchap said the law was "crazy" if it meant the council could not recoup the costs but that could not be sheeted home to Mobil.

"Mobil were fantastic. They did everything they possibly could to assist us with the clean-up, and got us up and running again pretty smartly. We never put in a claim," said Mr Goodchap.

Carlton Bidois, deputy chairman of Ngati Ranginui iwi, earlier said the RMA needed "more teeth" to ensure ratepayers were not out of pocket, and cultural impacts resulting from these types of incidents were effectively addressed.

A Ministry for the Environment spokesperson said fines and cost-recovery issues were not among the key drivers for changes to the RMA.

Changes in 2009 raised the maximum fine that could be imposed by courts to $300,000 for individuals and $600,000 for companies.

When asked if this would mean that ratepayers were left out of pocket, the spokesperson said it was important to note that fines might be paid in whole or in part to a local authority, determined by the court.

"We are currently considering increases to instant fines regime for excluding stock from water bodies. We expected this to be part of the reforms to pass into law later this year.

"There are no further plans to address issues of cost recovery in the foreseeable future."