Many Colorado citizens are concerned about the impending difficulties related to old mines and the problems that arise due to their closing and inadequate care during or after. There are more than 300 mines in the Silverton Caldera alone. They have all increased the exposure of mineralized formations to groundwater. The EPA approach of dam-and-treat is failing. This has led to communities being forced on the National Priorities List (NPL), which affects local economies. Moreover, as of August 2019, mining companies are still refusing to assess or manage cleanup work ordered by the U.S. Environmental Protection Agency as part of a Superfund project in the Southwestern region of Colorado.
The Bonita Peak Superfund project now includes mines such as the Gold King Mine (GKM), Sunnyside Mine (SSM), and the American Tunnel system. Most notably, the Gold King Mine was the source of a 2015 spill that contaminated the Animas River watershed in Colorado, affecting the San Juan and Colorado River that flows into New Mexico and Utah. The mine was responsible for releasing many heavy metals and toxic elements into the Animas River Watershed, such as cadmium, lead, arsenic, beryllium, zinc, and copper.
Officials have said that EPA-led contractors “inadvertently” triggered the spill while excavating at the mine’s bulkheads. The GKM was responsible for releasing many toxic elements into the Animas River watershed. The GKM, SSM, and EPA were well aware of this before the incident. Given this disheartening reality, stronger measures need to be taken. Specifically, the Environmental Protection Agency, in conjunction with the State of Colorado, must adopt stricter regulations for Superfund programs that commit to better strategies of financing local engineers to help authorities address current crises and prevent future mining disasters.
Unfortunately, identifying the problems is only the first step–finding a logical solution must follow. The EPA took responsibility for the spill but defended their inadequate implementation of dam-and-treat practices by stating they are better at dealing with the clean-up than creating the messes. The response from the EPA may indicate the real problem with the agency and how it handles local disaster sites or waits until a crisis occurs to claim federal funding. The EPA track record shows that it is not qualified to assess or do this type of clean-up properly. Steve Fiscor explains that because of the EPA’s “dam and treat” approach to mine discharge, it was “only a matter of time before something like the GKM spill happens again.” Indeed, trying the same technique over and over is not a recipe for success, if the technique ends in failure. The situation must dictate which solution needs to be implemented, because every situation is different.
Putting the problem in context is the first step to formulating a solution. Watersheds can be large systems which can encompass thousands of miles and contain brooks, rivers, lakes, reservoirs, and groundwater that are hundreds of miles inland. Conversely, some watersheds can be small, such a single valley or small lake. Water from hundreds, and often thousands, of creeks and streams flow from mountains to rivers that eventually fill into bigger bodies of water at lower elevations. As the water flows, it can and more often does, pick up pollutants that have adverse effects on the ecology of the watershed and, ultimately, on the reservoirs, bays, or ocean where it ends up.
However, not all water flows to the sea nonstop. For example, when rain falls on arid soil, it can soak into the ground or rushed away in flash floods. Either way, this groundwater remains in the soil, where it will eventually trickle into nearby streams. Some water permeates much deeper into underground reservoirs called aquifers. These river and underground water systems are connected to each other, so what affects one will affect the other. The Animas River watershed encompasses over 140 square miles of mineral-rich soil in the Silverton Caldera. The EPA has claimed that the mining operations that ran from 1871 to 1991 “have had an impact on aquatic life and tributaries from naturally occurring and mining-related heavy metals.” The EPA assessments in the region of Cement Creek indicating that it qualified for the National Priorities List because of mining-related operations follow this premise.
The discovery of the GKM problem was made serendipitous by contractors working at GKM. The accident, which was favorable to the EPA and officials in charge of getting superfund money, seemed to be an “ends justify the means” scenario. Unfortunately, the community and environment had to deal with the aftermath. On August 5, 2015, Environmental Restoration, the contractors working on a system for a drainage remediation project for the EPA, ruptured the plug in a tunnel at the entrance to the 7th level of the GKM on Cement creek. Three million gallons of sludge emptied into Cement Creek and the Animas River. This created a yellow-orange discharge that, according to the EPA, was quickly diluted and never toxic to humans.
The mines in Silverton and the surrounding areas, including the GKM, pour over 5 million gallons of contaminated waste into the Animas’ headspring every day. Fiscor explains that when talking about the EPA that “the agency and its contractors were unprepared for a worst-case scenario and when it occurred, they failed to handle it appropriately.” It is clear that from the start and throughout, the EPA had no idea what was happening at the GKM site. They didn’t know how to handle the complex system of mining tunnels filling with rainwater throughout the region.
Todd Hennis, the owner of the GKM, sees the EPA and Kinross Gold, owner of Sunnyside Gold Corporation, at fault. According to Hennis, the problem lies inside the Bonita Peak, which started when the Sunnyside began the bulk-heading process on the American Tunnel System, from 1996 to 2003. The EPA and Kinross Gold installed concrete bulkheads or dividing barriers in the American Tunnel at the Sunnyside Gold Mine to prevent drainage. According to Hennis, “the engineered concrete structures are working but are causing much greater amounts of water to back up inside the mountain known as Bonita Peak.” Kinross has denied the allegations and insisted that the bulkheads meet standards set by the EPA. Even if that is true, and the bulkheads do meet standards, it does not mean that there is not acidic water building up in these mines.
The GKM spill could be a canary in the coal mine, warning the region of an even more significant impending threat. Silverton and the surrounding area are scheduled to get a federal cleanup of their leaking historic mines under the EPA’s Superfund program or Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Those funds have yielded few results and more sludge to manage. According to the EPA, metals from the GKM spill “may have” contributed to exceedances of state and tribal water quality during the spring 2016 snowmelt.
The EPA is not doing the research that is needed in what is a poorly-understood network of mine openings and natural crevices that allow water to leak from tunnel complex to tunnel complex inside the mountain. It should go without saying that the higher the water level rises in these mines, the higher the pressure, which will result in more leaks in unpredictable places. Simply throwing money at the problem in complex systems such as groundwater and mining discharge will not solve the problem. More often than not, writing a blank check for an undefined problem makes the situation worse.
From an engineering standpoint, the solutions are complicated but possible and require vigilance. Mark Gibson, an environmental specialist, says that engineers with success in these situations have “rejected bulk-heading and implemented hydrological controls above the portals to prevent inflows into the old workings.” The engineers used a source control approach that kept contaminated water from seeping into the mine. Source control is a technique such as constructing rock structures at the top of these mines that act as “plumbing” to drain the runoff away from the mineral deposits that contaminate the water. The engineers were prepared and planned for the worst possible outcomes, and they planned to treat the problem rather than the symptoms.
The Superfund designation is a frightening situation for residents who see it as damaging to the economy. Colorado has eight Superfund sites related to mining operations that have appeared on the NPL for decades. Only one has been remediated correctly. Some sites in Colorado have been successfully cleaned up. However, in those cases, engineers led the teams on the project while the EPA listened.
What is more, the EPA is tasked with the mission of plugging leaks created by plugging leaks that caused the Gold King blowout in the first place. The EPA also has the mission of figuring out how to process all that water to make it clean for wildlife and the community. One possible solution is to change the groundwater potential of Hydrogen or pH value. The combination of water, oxygen, and bacteria, which eat the sulfide ore, is creating the acidic water. Eliminating one element would work, but removing rainwater or the oxygen in it would be complicated and extremely expensive, if even possible. Adding chemicals to the rainwater when it trickles down to neutralize the pH value could prevent the mine water from becoming toxic.
After the spill, the EPA built a treatment facility. The facility is at the bottom of the gulch, which is below the Gold King mine adit. To solve the problem, these facilities circulate the contaminated water through a system where lime is added to reduce the acidity of the sludge and chemicals are added to aid in the precipitation of metals in the sludge. The “water” is then pumped into semi-porous bags sitting in sectioned pits. In the bags the metals precipitate out, sinking to the bottom of the bag. Then, the filtered water bleeds out of the bag into the pits, where it is pumped back to the facility to be recirculated until it meets water standards. Finally, it is diverted through a pipe into Cement creek.
In the end, the EPA did not follow procedure or take into account the complexity of the issue. The Animas River Watershed is a crucial element to the ecosystem. It’s the responsibility of Colorado and the EPA to preserve it for future generations. This can be accomplished by using federal funding. The EPA could allocate this funding to local engineers who have a better track record of dealing with technical problems like mining disasters. Having a better understanding about how to control the source of the problem and prevent disasters from starting in the first place is not just beneficial to society. We need to preserve our environment for future generations.
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Sean Carroll spent four years in the United States Marine Corps stationed at Camp Pendleton, CA, and served in Ramadi, Iraq as part of Operation Iraqi Freedom in 2004. He is currently studying history at a local college.
