Small oil spill at Marsden Point refinery caused by faulty fuel line

Yesterday's oil spill at Marsden Point was nothing on the scale of this one at neighbouring Northport in late 2015. Photo / File

An absorbent boom was used to soak up an oil leak in Whangārei Harbour caused by a faulty Refining NZ fuel line.

The leak discovered off Marsden Point around 10am today produced a surface ''sheen'' rather than a ''slick'' and was quickly identified as being very small, a Refining NZ spokesman said.

''Whilst the cause of the leak and the quantity of fuel oil involved is not yet known, it is clear that the leak was small and very slow, and of less than one day in duration,'' he said.

''We are confident that the relatively small amount of fuel oil involved, and the resulting sheen, will disperse quickly given the prevailing wind and tide patterns, with little or no environmental impact.

''There are no restrictions on shipping or other activity in the harbour resulting from this incident.''

On the three-tiered scale of emergency - one being something the Refinery can handle with its own resources, two needing to be led or helped by Northland Regional Council (NRC) and three requiring Maritime New Zealand to take charge — this spill was a ''one''.

Fourteen trained refinery staff were involved in the oil-skimming operation on the barge ... with an NRC boat and staff present in an observer capacity.

Local hapu and iwi were notified and, as well as notifying the NRC, the refinery was in contact with Department of Conservation during the management of the incident.

An investigation is underway into the cause of the leak in the pipe used to refuel ships.