Water flows through a series of retention ponds built to contain the Gold King mine wastewater after the
accident occured near Silverton, Colorado. (AP Photo/Brennan Linsley)

The EPA took ownership of the incident and defended its poor performance, saying it’s more accustomed to cleaning up messes, than creating them. That response may identify the real problem more clearly than the agency intended. If it were judged on its past performance, one could easily determine that the EPA is not qualified to handle this type of remediation work. Those who are most familiar with the agency’s dam-and-treat approach to mine discharge knew it was only a matter of time before something like this occurred again.

Gold King mine owner Todd Hennis has been quite vocal about the incident. He sees the EPA as part of the problem and he also blames the Sunnyside Gold Corp. and its owner Kinross Gold for installing bulkheads in the American Tunnel at the Sunnyside mine. The engineered concrete structures are working, but he believes the bulkeads are causing much greater amounts of water to back up inside the mountain known as Bonita Peak. Sunnyside disagrees. They said the concrete bulkheads meet regulatory standards. They followed proper procedures in closing the mine in a region where many others have simply walked away from the properties.

Meanwhile, water quality in the Upper Animas (UA) district is deteriorating. If Hennis is right, the Gold King spill could be a warning signal that a much larger release is imminent. Installing a water treatment facility and dewatering the Sunnyside mine would be an expensive proposition. That or a variation and some hydrological source control in the upper reaches of the UA drainage, however, might be what the district needs to avoid a Superfund designation or remove the designation if that’s the EPA’s next move.

The Superfund designation could become a nightmare scenario for local residents. Colorado has at least eight Superfund sites tied to hard rock mining that have been on the National Priorities List (NPL) for 30 years or more and only one has been cleaned up.

Similar sites in the region have been successfully remediated. The difference is that a mining company and its engineers took the lead on the project not the EPA. They used a source control approach that kept water from infiltrating the abandoned mine. They were committed to solving the problem and they were prepared for worst case scenarios.

What Was the EPA Doing?
The UA watershed covers approximately 140 square miles of one of the richest mineralized zones in the United States, the Silverton Caldera. Mining activities began in Silverton around 1870 and ended in 1991. More than 300 former mines have been identified in the area and they have all increased the exposure of mineralized formations to ground water.

The EPA began conducting Superfund Site Assessments in the region in the 1990s. They identified impact to aquatic life in the UA and its tributaries from both naturally occurring and mining-related heavy metals. The agency also recognized a community-based collaborative effort that was under way at that time to address those impacts. The EPA agreed to postpone adding the site to the Superfund NPL, as long as progress was being made to improve the water quality of the Animas River.

The Animas River continued to improve until 2005. Then water quality for at least 20 miles below the confluence with Cement Creek began to decline significantly. In 2008, EPA’s Superfund Site Assessment program began investigations in Upper Cement Creek focused on evaluating whether that area alone would qualify for NPL. This evaluation indicated it would. After receiving additional community input, the EPA again postponed the decision.

Since that time, the EPA has continued and broadened its investigations of conditions at the UA Mining District site. Last year, the agency decided to reopen the Gold King mine portal. “It was late in the season when they started to open it,” Hennis said. “They decided they did not have time to finish the portal work and treat the discharge water, so they backfilled the No. 7 Level portal site to prevent a blowout during the winter. That is what we believe led to the blowout in August. They were doing the right thing, but like the Titanic, a combination of minor problems culminated in a major incident.”

The Debate Over the Sunnyside Mine Pool
The Silverton Caldera is also home to the historic Sunnyside gold mine, which had about 100 miles of mine workings. According to Hennis, the mountain, Bonita Peak, is fractured, folded, fissured, and filled with exploration drill holes, and it’s unreasonable to expect bulk-heading to work in these geologic conditions.

The problem lies inside of Bonita Peak, according to Hennis, and it started when Sunnyside began the bulk-heading process on the American Tunnel between 1996 and 2003. He believes the head on the mine pool is much higher than anyone anticipated. “The pressure on the lowermost bulkheads has to be extraordinary,” Hennis said. “If a seismic event were to occur with that much hydrostatic pressure and faults lubricated with water, the discharge will be much greater than this one.”

Discharges from the Mogul mine (another mine in the region he owns) began to increase in 2000–2001. “Despite everyone being cognizant of what was happening, the state of Colorado allowed Sunnyside to finish bulk-heading the mine and walk away,” Hennis said. “The state signed away any ability to regulate the Sunnyside mine pool.”

By carefully and incrementally lowering the Sunnyside mine pool, Hennis believes all of these peripheral UA discharges will return to minor amounts or zero, which was the pre-existing conditions prior to the bulkheading of the Sunnyside mine. He also wants to see a processing facility installed at Gladstone near the American Tunnel portal that could treat Cement Creek.

At the time Sunnyside was bulk-heading the mine, the mine was owned by Echo Bay Mines. In 2003, Kinross Gold purchased Echo Bay Mines. After the Gold King spill and in response to Hennis’ allegations, Sunnyside Gold Corp. issued a statement explaining that it is not involved whatsoever with this situation; it never owned or operated Gold King and did not take part in work being done there. The company said the following:
“The Sunnyside mine workings have no physical connection to the Gold King and such a connection never existed. Sunnyside is not the cause of the water buildup at Gold King.

“In fact, Sunnyside, with oversight and approval of all relevant agencies, installed a series of bulkheads to isolate its mine workings from other workings in the area and to prevent water flow from the Sunnyside mine workings to the Animas Basin. The bulkheads installed at Sunnyside are engineered concrete structures. While the stateapproved bulk-heading was always expected to return the local water table toward historic natural levels, it did not cause the water buildup at Gold King.

“As the EPA has taken responsibility for the discharge, it is unfortunate that the representative of Gold King mine is trying to deflect responsibility from what has clearly been the location of the incident, which is Gold King mine. The spurious allegations made against Sunnyside are not based on fact.”

Mark Gibson, an environmental specialist with Kyklos Engineering, worked on the Idarado reclamation project and said the results speak for themselves. “It was a statedirected Superfund site,” Gibson said. “There was a dispute on how to deal with zinc contamination and provide an aquatic life habitat on all sides of the drainages.” He has since been involved in several dozen Superfund site disputes and as many hard rock mine cleanups.

When they were originally looking at reclaiming the Idarado mine, the regulators proposed a $150 million mitigation strategy that involved a series of dam impoundments and active treatment systems. “If they would have been allowed to do that, the Idarado property would have been turned into a huge dam impoundment, creating liabilities forever,” Gibson said. “That’s not solving the problems. They are treating the symptoms.”

He believes in source control, which is all manner of techniques to build rock plumbing at the very top stretches of the drainage to minimize the infiltration of runoff. “A great deal of the problem can be eliminated by preventing water from touching mineralized deposits,” Gibson said. “It’s the opposite of dam-and-treat. It prevents the eventualities we see today with the EPA.”

The Idarado remediation plan was put forward by a mining company and endorsed by every environmental group involved and the local governments, according to Gibson. “A Federal Consent Decree was amended to specify source control and avoid dam-and-treat,” he said. “It took all of the these efforts to reverse this ridiculous decision to dam-and-treat instead of focusing on source control. The regulator portrayed source control as experimental, iffy, unproven theories for mine remediation. And, now more than 20 years later, it’s working and the EPA dam-and-treat plans are failing.”

The loadings on the San Miguel (Telluride) side of the drainage have been reduced by 50%. The plan eliminated the need for active treatment, Gibson explained. “The residual leakage, if there is any, is treated by small passive ponds that use infiltration to reduce the metals loading,” Gibson said.

“On the Red Mountain side, the source control plan has only been half as effective as the Telluride side,” Gibson said. “The zinc levels have been reduced by 25%, a factor of two away from the goal. The problem is coming from the historic mines on Red Mountain pass in the vicinity of the Gold King mine.” Gibson believes source control would minimize water infiltration in the UA drainage.

The future of these sites in this region may not necessarily be dictated by the EPA. Gibson believes that this is an opportunity for sane minds to take control of the situation and solve the problem. “If the EPA were left to its own devices, it will continue as it has in the past,” Gibson said. “It will place the region on the Superfund NPL and create a white-collar welfare program for environmental consultants.”

Gibson said he could see the historic mines in that region paying for mine remediation. “The mineral deposits could be leveraged over the long term, using the money to help pay for remediation,” Gibson said. “There are methods of the third-party financing with local governments.” Rather than bringing mining back to Colorado, miners could be put back work for environmental remediation.