It took the oil company to the High Court at Auckland, where it was decided that if Mobil was liable, it would pay the council-controlled organisation $10 million in damages.
But Justice Sarah Katz in February last year decided that Mobil was not contractually obliged to decontaminate the subsurface of the land.
After the event, neither side could agree on what Waterfront Auckland should pay Mobil in costs.
Mobil sought costs and disbursements of $1.42 million, while Waterfront Auckland only accepted liability for $276,730 of that amount.
In a decision released earlier this month, Justice Katz ordered the development agency to pay Mobil $930,691.