Publicly owned Waterfront Auckland must pay Mobil almost $1 million in courts costs for its failed attempt to get the oil company to foot the bill for cleaning up a heavily contaminated area of Wynyard Quarter.

Mobil Oil leased two properties in the tank farm at the western end of Ports of Auckland for more than 50 years.

When Mobil's lease for the two sites ended in 2011, it was found the land they were situated on had been heavily contaminated.

Waterfront Auckland took the oil company to the High Court, where it was decided that if Mobil was liable, it would pay the council-controlled organisation $10 million in damages.

It was eventually decided that Mobil was not contractually obliged to decontaminate the subsurface of the land.