The Environmental Protection Agency has ordered Sunnyside Gold Corp., the company that owned Silverton’s last operating mine, to investigate the groundwater around one of its mines. The order comes just weeks after the corporation declared further study of mine pollution in the Animas River headwaters would be “wasteful and is not required.”

On Thursday, the EPA sent Sunnyside Gold a unilateral administrative order to investigate the groundwater system around Sunnyside Mine, one of the largest mining networks in the area.

The EPA believes previous mining operations have significantly altered the groundwater system, and as a result, have caused other mines to discharge waste and contaminate the headwaters of the Animas River.

Rebecca Thomas, EPA project manager, told The Durango Herald on Thursday the company is being held liable for investigations, as well as the cost, “based on (Sunnyside Gold’s) past ownership and actions in the mining district.”

Included in the order is a list of actions the EPA wants Sunnyside Gold to perform this summer, including drilling a well into the American Tunnel and monitoring some of the bulkheads in the area.

Depending on the findings of those investigations, the EPA then has the authority to order Sunnyside Gold to conduct further operations, if necessary, to understand the way groundwater works in the upper Cement Creek area.

“Until we can understand how water flows through that system, it will be difficult to put forward a plan to address contamination,” Thomas said.

Sunnyside Gold reclamation director Kevin Roach said the company needs to review the administrative order.

Roach said Sunnyside Gold is “not the cause of water quality issues in the Animas River, and its activities in the area, including spending $30 million on reclamation over the past 30 years, have resulted in less metals in the Animas basin than would have otherwise been the case.”

“We are hoping that our remaining assets can be efficiently utilized in timely, proven and effective solutions to improve water quality, rather than pointless studies or litigation,” he said.

Sunnyside Gold – now owned by international mining conglomerate Kinross Gold Corp. – started mining at the historic Sunnyside Mine in 1985 but shuttered Silverton’s last operating mine in 1991.

Over the years, Sunnyside Gold performed millions of dollars worth of cleanup projects. In the 1990s, the company entered an agreement with the state to place three bulkheads to stop mine drainage from the Sunnyside Mine.

The agreement released Sunnyside of its liability for pollution under the Clean Water Act but not responsibilities associated with a Superfund listing, officials have said.

The road to a Superfund listing, long opposed by the community of Silverton, began in earnest on Aug. 5, 2015, when the EPA accidentally triggered a blowout at the Gold King Mine, releasing a torrent of mine waste into the Animas and San Juan rivers.

The impetus for the EPA’s work in the first place was because the Gold King Mine, over the past few years, was discharging more waste tainted with potentially toxic heavy metals.

Many people familiar with the region believe Sunnyside Gold’s bulkheads backed water up at its mine workings, causing adjacent mines, specifically the Gold King – historically a dry mine – to start discharging wastewater.

The area around the Sunnyside and Gold King mines is considered one of the worst contributors to mine pollution in the Animas River, which has caused degraded water quality and has affected aquatic life.

Sunnyside Gold has adamantly denied these claims.

Recently, Sunnyside released two reports, arguing “further study would be wasteful and is not required” in understanding the mines around Silverton.

Sunnyside Gold spokesman Larry Perino wrote in a March 7 email that the company “is not factually, equitably or legally liable for water quality issues in the area.”

Sunnyside was also denied earlier this month in its attempt to reduce the size of the Superfund site, with the U.S. Court of Appeals D.C. Circuit dismissing the company’s petition to remove mine sites from the listing.

Thomas said Sunnyside Gold has been identified as a “potentially responsible party” – a term the EPA uses for companies it deems financially responsible in a Superfund cleanup.

Thomas said Sunnyside Gold’s consent decree with the state is a completely different matter than orders under a Superfund listing. She said the company has a few days to begin initial negotiations over Thursday’s order.

jromeo@durangoherald.com