New Jersey has the bill for all the sinkhole repairs on I-80 near Wharton, and it’s a hefty one.

State DOT officials said construction cost $30 million, plus another $565,000 in overtime costs for some 50 DOT workers. The state also contributed $5 million in grants for impacted businesses. There was also overtime paid to state and local police for months of extra traffic duty.

A DOT spokesperson said they’ve received no federal money yet, but the Federal Highway Administration is reviewing the request for full reimbursement.

“The $30 million price tag does not shock me, and I’m sure we’ll get some help from the federal government,” said state Sen. Anthony Bucco (R), the Senate Republican leader.

Bucco and State Sen. Paul Sarlo (D), the Senate deputy majority leader, have proposed bipartisan legislation to strategically fill in the most dangerous of New Jersey’s 600 abandoned mineshafts.

“We could map out these mines, rate them in terms of risk to our infrastructure, and then begin a fund so we can start the reclamation process,” Bucco said.

Geotechnical engineer Bill Kroth advises that this plan would take significant research, time and money to do properly. Each site could require a different strategy based on the material, age and depth of the mine.

“As far as filling a mine that’s deep in the ground, it’s very hard to get good compaction,” Kroth said. “Filling it in sideways, you basically have to open it up and put lifts in.”

Three sinkholes in three months from abandoned mineshaft collapses near Wharton may have served as a $30 million wakeup call for New Jersey.

“This will be decades and tremendous cost,” Kroth said. “But again, they learned the hard way that you have to do something, you have to start this program. It’s just like a Superfund cleanup site. These have been going on for decades, and we address the worst ones first.”