WASHINGTON – Colorado U.S. Sen. Michael Bennet joined with his Democratic colleagues from New Mexico on Thursday to unveil a bill to reform the nation’s hard-rock mining laws in response to the Gold King Mine spill.

Bennet, Sens. Martin Heinrich and Tom Udall, and Rep. Ben Ray Luján, all Democrats, announced their legislation on the three-month anniversary of the Gold King Mine blowout.

“After you see something like this spill into the Animas River, a policy of sitting on our hands and doing nothing is just unacceptable,” Bennet said during a news conference call.

The proposed legislation – the Hardrock Mining and Reclamation Act of 2015 – will make mining companies pay royalties for extracting resources from public lands. The money would be used to help clean up abandoned mines that are continuing to leak waste into waterways, and ensure that future spills like the Gold King Mine disaster are not rectified at the expense of taxpayers.

“In the Southwest, water is simply our most precious resource, so you can imagine what kind of impact the Gold King Mine spill had on our community,” Heinrich said.

A blowout at the Silverton-area mine spilled 3 million gallons of heavy-metal tainted wastewater into the Animas and San Juan rivers.

Separately, the Environmental Protection Agency’s inspector general said it was broadening its investigation of the spill – which an EPA-led crew triggered – to include more than a dozen new lines of inquiry.

The proposed legislation would implement a royalty fee on new mines and would be based on the gross income of production. The royalty level, which would be set by the secretary of the Interior Department, would be no less than 2 percent and no more than 5 percent. The bill would also set an abandoned mine reclamation fee of 0.6 percent to 2 percent, which is estimated to bring in $100 million annually to contribute to the cleanup of abandoned mines.

The revenue acquired from royalty payments would be deposited into a Hardrock Minerals Reclamation Fund, created under the bill, which would then allocate the funding to federal, state and tribal agencies for cleanup projects.

It would remain distinct from the Superfund program, which pays to remediate a range of toxic waste sites including mines.

The lawmakers also proposed a separate royalty on minerals extracted from new mines on federal land that would go into the cleanup fund. The lawmakers said they don’t know how much money it would generate because mining companies currently aren’t required to report their production.

Bennet and his colleagues agreed that it was time for the hard-rock mining industry to pay its share. They pointed out that the royalty fees would be a fraction of the coal, oil and gas industries’ rate of 12½ percent.

“Every other extractive industry pays royalties,” Bennet said. “Hard-rock mining companies should pay as well.”

Bennet added that Colorado has already spent $12 million over the last few years to clean up some of the more serious leaks. The EPA estimates that 230 mines in Colorado are currently leaking toxic chemicals into the state’s waterways, and that it would cost tens of billions of dollars to effectively clean up all mines in the West.

The proposed bill would serve as the first major change to the General Mining Act of 1872 since it first became law. The Mining Act, passed 143 years ago, continues to govern mining operations on public lands and allows companies to extract minerals from these grounds royalty-free.

Luján is co-sponsor of a similar mining reform bill already introduced in the House. Sens. Ron Wyden, D-Ore., and Edward Markey, D-Mass., are also co-sponsors of the legislation.

The EPA inspector general said some of the new questions in its investigation were raised by Congress and others by a review of the spill by the Interior Department.

The new questions include whether the agency was following its own rules when it triggered the blowout, as well as what kind of legal protection EPA gave the contractor and whether that affected the way the work was done.

Conservation Lands Foundation, a nonprofit based in Durango that works to protect National Conservation Lands, applauded the senators’ efforts to reform the 1872 mining law.

“The Animas River attracts visitors and residents from all over the world,” Dave Welz, the Conservation Land’s spokesman said in a statement.

“As someone who has fished and rafted it for two decades, the Gold King Mine blowout was a huge wake up call. We thank Sens. Bennet, Udall and Heinrich and Rep. Luján for their leadership in ensuring that mining companies do not leave American taxpayers on the hook when it comes to protecting rural Western communities’ clean water and economies from the toxic legacy of abandoned mines.”

Trout Unlimited, an environmental nonprofit, also lauded congressional proposals.

“We need a sense of urgency in addressing this toxic threat to our rivers and communities,” said Ty Churchwell, the group’s San Juan Mountains project coordinator. “We hope Congress moves quickly on this legislation.”

egraham@durangoherald.com. Edward Graham is a student at American University in Washington, D.C., and an intern for The Durango Herald. The Associated Press contributed to this story.