The state of Alaska says it has taken hundreds of public comments to heart and will require developers of the stalled Pebble mine to do extensive cleanup and monitoring this summer — and to commit $2 million to ensure disturbed land is eventually restored.

The conditions were announced Tuesday by the Alaska Department of Natural Resources and immediately drew a favorable reaction from Bristol Bay tribes, environmental groups and fishing interests. Pebble said its work this summer will be as DNR has directed, and will protect the public interest.

Pebble Limited Partnership applied in October for a land-use permit to continue monitoring and care of mining claims spread over 266,000 acres in the Bristol Bay region.

The developers aren't planning exploration work this summer, but say they intend to move forward and eventually seek major permits to develop the site. The summer work, with permission now in hand, will include inspections, upkeep of facilities, and reclamation including filling of holes drilled into the earth to remove core samples.

The project has drawn intense scrutiny and opposition from Alaska Native tribes and fishermen for years over concerns the huge proposed gold and copper mine would devastate Bristol Bay's world-class salmon runs.

Pebble has battled various interests in court over the project. Two federal court cases involving the U.S. Environmental Protection Agency are currently on hold.

On Tuesday, DNR said Pebble's new land-use permit with new requirements came after "exhaustive analysis."

The goal is to ensure good stewardship of state lands for a project with high public interest, DNR said.

"You have to be very deliberate and very thoughtful," Commissioner Andy Mack said.

The state routinely requires financial guarantees for large mining projects but for Pebble the amount of land disturbed during exploration was tiny — under 3 acres — not enough to trigger that sort of requirement, according to DNR.

That's because each borehole is just a few inches across. But they dot a large area.

The state attached a $2 million financial assurance to the 2017 permit, a requirement Pebble can meet through a bond, Mack said.

The state estimates it would cost $1.9 million to remove all of Pebble's equipment from state land and another $100,000 to do the inspection and restoration required under this year's permit, Mack said in a letter to Pebble's environmental manager Tim Havey.

DNR issues 500 to 1,000 land-use permits a year, which are usually quietly reviewed and approved.

"Most of them are routine and without any public input at all," Mack said.

But for Pebble, DNR was forced into seeking public review by the Alaska Supreme Court, which in 2015 ruled the agency was violating the state Constitution by allowing extensive work without any public notice or finding that the work was for the common good.

"We are required to do this now by the decision, but we think it is good policy, too," Mack said.

The state received more than 2,000 public comments on Pebble's application to continue basic maintenance, restoration and upkeep.

It considered 1,500 of the comments to be timely and responsive; some of the others were duplicative, DNR said. More than 1,000 were from Alaskans and those are the ones DNR considered most closely in crafting the permit, Mack said.

Since 1988, some 1,355 exploratory holes have been drilled on the Pebble prospect. About 600 have been filled, DNR says.

The new permit requires Pebble to fill another 138 holes, including plugging them below the surface and cutting off any exposed well or pipe, which Bristol Bay residents say have been exposed in the past, creating hazards.

Another 612 boreholes can remain open for the next year, but Pebble must inspect 300 of them, under the permit.

And Pebble remains obligated to fill them all eventually, and reclaim the land, DNR says.

"This includes a significant number of sites that are being used for ongoing monitoring, data collection, and the storage and staging of equipment for reclamation and maintenance," Mack said in the Tuesday letter to Pebble.

Sites not in use need to be put back to as close to natural as possible, as soon as possible, Mack said. DNR will be sending its own staff to inspect this summer as well, rather than rely solely on Pebble's self-reports, he said.

Pebble said the DNR review allows its ongoing work to continue.

"We will continue our site operations in 2017 in full compliance with the State's permit conditions, and in a manner that protects the broader public interest in the lands and resources surrounding the Pebble property," Tom Collier, Pebble CEO, said in a written statement.

Pebble is still reviewing the new permit in a packet of documents that totals 177 pages.

The United Tribes of Bristol Bay, a group formed to advocate for tribal interests related to Pebble mine, praised the new requirements. The $2 million Pebble must commit to ensure the work is done is unprecedented for the project, said Robert Heyano, president of the tribal group.

"We are thankful that the Department of Natural Resources took a hard look at what was happening at the Pebble site, rather than simply rubber stamping these permits as was done in the past," he said in a written statement.

DNR does require large performance bonds for big projects, but typically that comes at a different stage of development.

For instance, the Red Dog zinc mine near Kotzebue has a reclamation bond of more than $500 million, DNR said. But that is a different type of assurance for a project that is developed, unlike Pebble, where work stalled in the exploration phase due to the EPA review and court challenges.

The environmental law firm Trustees for Alaska, the tribal group Nunamata Aulukestai – which had challenged earlier permits for lacking public review — and the Trout Unlimited sportfishing group all praised DNR and Gov. Bill Walker for the new permit.

It includes key accountability measures that are sorely needed to ensure the protection of Bristol Bay, the groups said.