The Environmental Protection Agency announced Wednesday it would formally designate the district of leaking mines around Silverton as a Superfund.

In a news release, the EPA said the “Bonita Peak Mining District” will be added to the National Priorities List. The project area includes 35 mines, seven tunnels, four tailings ponds and two study areas around the mineral-rich San Juan Mountains.

“Listing the Bonita Peak Mining District is critical to addressing historic mining impacts in San Juan County and our downstream communities,” Martha Rudolph, director of environmental programs for the Colorado Department of Public Health and Environment, said in a prepared statement.

The listing comes just over a year after the EPA, while working at the Gold King Mine, caused a release of mine waste down Cement Creek and into the Animas and San Juan rivers. The spill reversed a nearly two-decade resistance from Silverton and San Juan County to a Superfund listing.

“What a tremendous benchmark for this community and all the communities downstream,” said Silverton Town Administrator Bill Gardner. “There was a lot of hard work by a lot of people, and I believe its resulted in one of the quickest listings in the history of Superfund.”

After the Aug. 5, 2015, blowout, Silverton and San Juan County officials conceded that no other avenues other than a Superfund listing could effectively address the sprawl of mining-related sites dumping metal-laden water into the Animas River watershed. The opposition stemmed from concerns the designation would harm tourism and deter future mining.

Within a year, local, state and federal agencies and invested stakeholders were able to negotiate the particulars of a hefty hazardous cleanup program. Community involvement was a top priority for the small mountain town with a resident population of about 600.

A 60-day public comment period for the proposed listing that began in April elicited more than 50 responses, with most in favor of the EPA stepping in to address Silverton’s legacy of hard-rock mining.

Further downstream on Wednesday, elected officials for the city of Durango and La Plata County lauded news that the mines responsible for degrading water quality in the Animas River would officially become a Superfund site.

“To some extent, I feel like the EPA designation of Bonita Peak may be a silver lining to the orange cloud that floated down the river last year,” County Commissioner Julie Westendorff said. “If we can get some long-term good out of what was certainly a trauma to our community, then I’m glad there is an upside.”

City Councilor Dean Brookie said in contrast to fears that a Superfund site, and its supposed stigma, would adversely affect tourism, he believes cleaner water in the Animas will increase tourism and the economy of the region.

“I’m totally excited in the pursuit of the EPA’s efforts,” Brookie said. “I think it’s going to be very good for the region and the long-term betterment of the river.”

Local environmental advocacy groups, too, praised Wednesday’s announcement.

“It’s a huge step forward in efforts to clean up the Animas watershed and bring the river up to its full potential for water quality, river recreation and public health,” said Trout Unlimited’s Ty Churchwell. “Durango and Silverton depend on clean, quality water to support our outdoor economies and quality of life – it’s the foundation of everything else here in the Animas River Basin.”

Dan Olson, executive director of the San Juan Citizens Alliance, had a similar sentiment.

“We are proud that communities throughout the Animas River watershed have put their shared desire for a healthy river first and look forward to fully engaging in what will likely be a long but productive cleanup process,” he said.

Indeed, the sobering reality that an official listing is only the first step in what is likely to be a decade or two decade-long process of cleaning mining sites around San Juan County followed the otherwise encouraging news.

“It’s a long haul, but in this case, the first step might have been the most difficult one,” said Gardner, referring to the town’s historic opposition to Superfund.

“But there’s a lot of energy to see this through and see it done right. We have no reason but to be hopeful and optimistic about the future.”

Rebecca Thomas, project manager for the Superfund listing, previously said there are “a lot of actions in interim that could have strong environmental impacts for the Animas” while larger, more complex decisions are made.

Some of those issues include identifying potential responsible parties in the district, deciding what are the best long-term treatment options for mine wastewater, and assessing what to do with the massive volumes of drainage backed up behind the American Tunnel.

Yet Wednesday’s announcement was at least some assurance to local officials that those questions will be fully addressed.

“There’s been a lot of hard work and effort by everyone in the community,” said San Juan County administrator Willy Tookey, “And I think the results are going to be real positive for the community and the region. So I’m being very optimistic.”