Quick action to contain and recover fuel-soaked earth and water near the ruptured oil pipeline at Ruakaka appears to have prevented widespread contamination.
Refining New Zealand has been in charge of collecting and removing the material and monitoring the site for hydrocarbons, in preparation for a complex operation to remove and replace a short section of failed pipeline.
Northland Regional Council staff have also been monitoring the effects of the leak and the recovery process to ensure it carried out appropriately and a suitable remediation plan is implemented.
At this stage that is the council's primary focus, a spokesman said.
"The council remains satisfied the clean-up and repair operation is being carried out appropriately in the circumstances."