The state has reached a deal to take over an old Burnsville landfill after months of unsuccessful negotiations with the landowner nearly led to a costly federal Superfund cleanup.

Freeway Landfill, along Interstate 35W south of the Minnesota River, will be cleaned up by the Minnesota Pollution Control Agency through the state’s Closed Landfill Program. The agreement between the state and the landowner, which was finalized this week, is a victory for the local governments, school districts and businesses that would have had to pay for the cleanup if the state hadn’t taken over the site.

Instead, the state will foot the bill, which is expected to be nearly $65 million.

“From a monetary perspective, it’s extremely important that this landfill end up in the Closed Landfill Program,” said Steve Mielke, director of Dakota County’s physical development division. “We’re very pleased that the landfill owner and the PCA have been able to come to an agreement.”

Freeway Landfill covers about 132 acres, including about 90 that will go to the state along with some buffer land. The state will be responsible for cleaning up all of it, including the approximately 45 acres that the McGowan family, which owns the land, plans to keep.

The cleanup plan involves installing a protective liner that will keep waste from contaminating the river and a drinking water supply that serves Burnsville and nearby Savage.

A mediation agreement finalized Thursday said state bonding dollars would pay for the bulk of the cleanup project. But with the governor’s bonding bill already passed, other funding options may be considered, said MPCA Assistant Commissioner Kirk Koudelka.

Cleanup around a garbage transfer station that Michael McGowan wants to continue operating on the property will be paid for with non-bonding dollars. Per the mediation agreement, Freeway Landfill can opt out of the Closed Landfill Program if that money isn’t secured.

The Legislature created the Closed Landfill Program in 1994 as an alternative to the Environmental Protection Agency’s Superfund cleanup process, which leaves parties that put trash into a landfill — and the landowner — holding the cleanup bill. Those parties end up suing each other, lengthening the cleanup process and adding to its overall cost.

“It’s a very litigious process,” said Burnsville City Administrator Heather Johnston. “It’s a lot of folks that would be touched by it.”

Negotiations between the state and McGowan lasted for months. The EPA initially set an agreement deadline of June 30 of last year, but extended it three times before finally deciding to take over the landfill in December.

“It’s a voluntary program, so the only way it gets into the Closed Landfill Program is if the property owner volunteers to enter it,” Mielke said. “There is a chance that that would not have happened.”

But even after the last EPA deadline, Koudelka said, McGowan and the state kept talking. One of McGowan’s sticking points was being able to continue operating the transfer station. Under the agreement, the station can continue operating even during the cleanup.

In the coming weeks, some additional details and legal issues in the agreement will be worked out, Koudelka said. Once that’s completed — likely in February — the MPCA will conduct an extensive investigation of the site and prepare final designs before beginning the cleanup. The whole process is expected to take about five years.

McGowan could not be reached for comment. He previously told the Star Tribune that he believed the MPCA cleanup was unnecessary.