Senators Cory Gardner, R-Colorado, and Orrin Hatch, R-Utah, on Thursday called for a hearing on a bill that would expedite reimbursements to communities impacted by last year’s Gold King Mine spill.
In a letter to senators Chuck Grassley, R-Iowa, and Patrick Leahy, D-Vermont, the chairman and ranking member of the Senate Judiciary Committee, the pair called for a hearing on Gold King Mine Accountability and Compensation for Taxpayers legislation that they introduced in May.
The bill would require the EPA to fully reimburse communities for expenses caused by the spill. It would also expedite the payout of emergency response costs for tribes, local and state governments. The letter asks for the “swift consideration” of the bill.
It is one of several pieces of legislation pending approval in Congress concerning the spill, as well as good Samaritan legislation for mine reclamation. Sen. Michael Bennet, D-Colorado, introduced a similar EPA reimbursement bill in September last year that would also require the EPA to compensate those affected by the spill.
Here’s the release from US Senator Gardner’s office.
The long-closed site is on about 80 acres just north of Rico. Its leaking St. Louis Tunnel and pond treatment system sit beside the Dolores River, which provides agricultural and municipal water for 27,000 people in two downstream counties, several towns and the Ute Mountain Ute reservation.
But unlike Gold King Mine, the Rico Argentine Mine has had significant pollution-control systems in place. And more control systems are planned, said Paul Peronard, the Environmental Protection Agency’s cleanup coordinator at the mine.
“Here, we have a great understanding of the mineworks and have controls and monitoring in place, so we know where the pressure is,” Peronard said during a June 29 tour. “Based on that, the risk is pretty low.”
The mine is being reclaimed by Atlantic Richfield Co. under a 2011 Superfund order from the EPA. The reclamation program has four major components: new relief wells, more advanced water treatment, real-time monitoring, and a new waste disposal site.
How crews work to prevent a blowoutConstruction and drilling have begun on two new relief wells that will help drain the tunnel and prevent a blowout.
Mine and EPA officials estimate there is 1.7 million to 2.2 million gallons of water backed up in the mine. The contaminated water has high concentrations of manganese, zinc, copper, arsenic and cadmium.
The Rico Argentine mine’s workings come together to continuously drain through the collapsed St. Louis tunnel at a base flow of 400-600 gallons per minute, spiking to 1,000 gallons per minute in the spring.
But in the past few years, officials have noticed that the pressure behind the collapsed tunnel has been increasing each spring, which they attribute to silt, which has constricted the flow of the drainage.
Monitoring devices in the mine tunnel give operators real-time data on the elevation of the of backed-up water and the built-up pressure. Currently, the water level in the tunnel is at 8,860 feet elevation from sea level. A level considered dangerous is 8,871 feet.
A siphon in the tunnel has been pulling water out and piping it to the treatment facility. But officials fear that is not enough, so two new horizontal relief wells are being drilled into the tunnel to pump backed-up water to the treatment facility. The new wells and pumps are scheduled to be operational by the end of summer.
“We are currently getting water out of there, but let’s not miss the point of preventing a blowout, so we’re installing big relief wells as a redundant safety factor. If it backs up to a level we don’t want, we can pump it out more efficiently,” Peronard said.
Water-treatment system is scaled upA pilot water-treatment system that uses biological controls is working better than expected and is being scaled up to treat higher volumes of mine drainage year-round.
The Enhanced Wetland Demonstration Treatment System is one of two in the nation and is the only one at such a high elevation.
Water from the mine flows through a series of treatment cells with bio-reactor substrates of sawdust and organic material that use bacteria to break down heavy metals.
The treated mine water then flows through a series of 11 settling ponds before being released into the Dolores River.
“The water treatment plant is designed to handle the variable flows and water temperatures year-round,” Peronard said.
The biological system is preferred over the previous lime treatment system, he said, because the spent substrate matrix only has to be replaced every 5-15 years. It also can operate during winter without on-site management in the avalanche-prone area…
“The water here needs to be treated forever, so we want to make the costs as low as possible to give the plant longevity and not be a huge money pit,” Peronard said.
A double-lined, solid waste disposal site has been built at the site to permanently store mine wastes from the abandoned lime-treatment system as well as the toxic sludge that is removed from settling ponds. The pit can hold 60,000 cubic yards of waste, and can be expanded to store up to 365,000 cubic yards of waste.
Systems monitored in real timeCritical systems are wired to be monitored in real time, and there are live cameras throughout the plant. Mine managers and the EPA are notified remotely about the water level and pressure behind the collapsed tunnel, and on flow rates from the mine into the water treatment facility.
“We get real-time readings that ping us on the conditions,” Peronard said. “It’s an impressive system that continuously tracks and monitors operations.”
If a problem threatens the Dolores River, an automated notification system alerts county and emergency managers, irrigation managers, sheriff departments and irrigators.
And the historic and current monitoring data is, or soon will be, posted on the EPA website.
“If the public wanted to know the elevation of water behind the tunnel, they can look it up,” Peronard said.
New dam considered as a backupAs an additional precaution against a blowout, the EPA and Atlantic Richfield are considering building a dam just beyond the St. Louis adit that would be capable of capturing up to 2.2 million gallons of water backed up inside the mine.
“If you did have a catastrophic blowout, the dam would knock everything down right there,” Peronard said.
The plans for the dam are in place, and the EPA will make the decision by the end of the summer on whether it is necessary.
Atlantic Richfield is paying for “99 percent” of the costs of the mitigation and reclamation project at the mine, the EPA said, but total costs were not reported. Eventually, a long-term operator will be contracted to maintain the system, and oversight will be handed off to the Colorado Department of Health and Environment.
The tour gave area water managers confidence that the old mine is being controlled.
“It gives me peace of mind that the are doing a good job with the treatment of water and are planning for larger flows,” said Randy McGuire, water-plant manager for the downstream town of Dolores.
“The redundancies designed into the system raises my confidence level,” said Todd Parisi, emergency operations coordinator for Dolores County.
On Friday the EPA mobilized contractors to stabilize the mine and the waste pile…
Wildlife officials shared some good news, saying their testing shows the fish survived with no evidence of die-offs. But the problems are far from over…
The spill drew attention to the thousands of abandoned mines throughout the West that may also pollute rivers.
And on Friday EPA crews returned to the mine to start work stabilizing the entrance. Here’s a report from Dan Elliott writing for the Associated Press. Here’s an excerpt:
Construction crews will return this weekend to the scene of a massive mine-waste spill in southwestern Colorado to stabilize the mine opening with steel and concrete, the U.S. Environmental Protection Agency said Friday.
The EPA said the work is designed to keep rock and dirt from collapsing at the entrance to the Gold King Mine and to make sure it’s safe to enter during future cleanup efforts. The stabilization work will last through October…
In an email to The Associated Press, the EPA said it is very unlikely the work being done at the mine this year would trigger another spill. “The EPA has taken precautions to prevent any unanticipated discharges,” the agency said.
The contractor hired to do this summer’s work, Environmental Restoration LLC, was also on the scene at the time of the August blowout. But the EPA and outside investigators have said it was government officials, not the contractor, who made the decision to begin the work that led to the spill.
The EPA pledged to alert downstream communities if anything goes wrong this summer, using a notification plan put in place after the August blowout. The agency was widely criticized for not alerting all the tribal, state and local governments affected by the spill.
Wastewater is still running from the mine, and if the rate increases during this summer’s work, a temporary treatment plant installed last fall can handle a higher flow, the EPA said.
The $1.8 million plant went into operation in October. Officials said at the time it could handle 800 gallons per minute, while wastewater was flowing from the mine at about 560 gallons per minute.
The plant is scheduled to run through November of this year. Colorado lawmakers have urged the EPA to keep it operating, and the agency said Friday it is looking into that.
Government agencies are just beginning to scratch the surface of costs incurred by a frustratingly hardy, toxic chemical polluting waterways across the U.S.
Air Force officials already expect to spend more than $400 million to study the chemical’s use in a firefighting foam at nearly 200 sites and replace it. Peterson Air Force Base and the Air Force Academy are on that list.
And on a local level, officials for water districts serving Security, Widefield and Fountain say they also may have to pay millions of dollars upgrading their water systems over the next few years to filter it out of tap water.
The tabs are expected to grow, and they don’t include costs associated with cleanup efforts. In one such project, the Air Force will pay $4.3 million to help filter well water across southeast El Paso County.
Nor does that tally include similar assessment efforts being conducted by the Navy and Army as well as clean up efforts in many other communities across the nation. One such study at Fort Carson had yet to start as of Wednesday.
All of it is for a chemical that the Environmental Protection Agency says may cause health ailments at levels no greater than a drop of water in a string of railroad tank cars 10 miles long.
“The fact that it doesn’t go away – it doesn’t degrade naturally, it stays in the environment – is a cause for concern,” said Daniel Medina, who is heading up the Air Force Civil Engineer Center’s response.
The substance, called perfluorinated compounds, or PFCs, remains unregulated by the Environmental Protection Agency. However, the EPA has grown increasingly concerned about the substance.
In May, the EPA’s health advisory level dropped to 70 parts per trillion – leaving every well used by water districts in Security, Widefield and Fountain above the new limit.
The advisory was tailored to ensure it protected the most sensitive population – in this case, developing fetuses and breast-fed and bottle-fed infants. That means people using water below that level should not expect health effects, even if drinking that water over a lifetime, state and federal health officials said at a town hall Thursday.
Communities across the U.S. are grappling with the chemical.
To mitigate residents’ exposure here, local water officials have relied more heavily on surface water pumped in from the Pueblo Reservoir.
Doing so has limited the number of people receiving contaminated tap water to 10,000 to 15,000, said Tyson Ingels, with the Colorado Department of Public Health and Environment’s Water Quality Control Division.
Officials running local water districts are working to drop that number to zero, though it may take time. Projects underway or in development are unlikely to change how many people receive PFC-laden water this summer, water district officials say (see accompanying report).
In the meantime, people receiving water above the EPA’s new limit should consider other water sources – especially women who are pregnant, planning to become pregnant or breastfeeding, as well as infants, a Colorado health department official said Thursday.
The exact source of the PFCs in the Widefield aquifer remains unclear, though an Air Force official recently said that the chemicals possibly originated at Peterson Air Force Base.
From 1970 through the mid-1990s, firefighters at the base used a type of foam laden with the chemicals while training to extinguish high-intensity fires, such as during plane crashes.
Ever since then, firefighter have trained using water in a lined basin. It still has the firefighting foam that contains PFCs, but it is only used in emergency situations, Medina said.
The Air Force has spent more than $137 million through Thursday as part of an effort to study 191 sites across the nation where the foam is believed to have been used, Medina said. They include active duty and National Guard installations, as well as decommissioned bases.
So far, assessments have been completed at 96 percent of those sites, he said.
The Air Force also expects to spend another $271 million incinerating that foam and replacing it with another substance, Medina said. That effort is underway at Peterson, base officials said.
The price tag is expected to grow as more thorough assessments are ordered across the nation.
At Peterson, for example, officials plan to drill monitoring wells to pinpoint the source, and a draft report is due in March 2017.
The Environmental Protection Agency said Friday morning, specifically, it is mobilizing contractors to shore up the mine’s opening and the waste rock pile just outside the adit. The operations are expected to continue through October.
“We anticipate that the interim water treatment plant (below the Gold King) will continue to capture and treat any discharge from the mine,” the EPA said in a news release. “However, should any of this work impact downstream watersheds, EPA will notify stakeholders.”
The work will include installing steel bracing and concrete, the removal of waste sludge stored in the mine’s temporary water treatment plant and an analysis of how to move forward with water treatment in the long run.
With the beginning of the new initiative, the EPA is signaling it has heard the complaints of communities downstream of the mine who say they weren’t notified quickly of the Gold King disaster. The agency says it has an expansive notification plan in place to prevent any further communication issues.
Perhaps the biggest focus, however, of downstream stakeholders has been the still-leaching mine’s temporary water treatment plant. Officials have been worried about the EPA’s commitment to keep open the facility, which has been running since October.
Gov. John Hickenlooper, Sen. Cory Gardner and local leaders for months have urged EPA officials to commit to keep this temporary plant running, and maybe expand it, until a federal Superfund cleanup of old mines is done.
The plant’s future, as of Friday, remained an unknown though the EPA said it has committed to taking a hard look — including public input — about how to proceed in the long-term. The plant will continue to operate as officials investigate alternatives.
Meanwhile the House of Representatives passed a funding bill for mine cleanups today. Here’s a report from Kate Magill writing for The Durango Herald. Here’s an excerpt:
The bill, introduced by Rep. Jody Hice, R-Ga., would create the Energy and Minerals Reclamation Foundation, which would be tasked with obtaining and using funds for the cleanup of abandoned coal mines, hard-rock mines and onshore oil and gas wells.
Hice’s legislation is part of a three-part bill package introduced to address abandoned mine cleanup. The other two bills include the Mining Schools Enhancement Act and the Locatable Minerals Claim Location and Maintenance Fees Act, which also includes good Samaritan language that was added by Rep. Scott Tipton, R-Cortez.
The Foundation Act specifically refers to mines that are located on federally managed lands. If created, the foundation would be a nonprofit corporation that would not be associated with an agency or government establishment. It would be led by a board of directors appointed by the Interior Department secretary.
The purpose of the foundation would be to obtain and administer private donations to be used for the “activities and services of the BLM,” according to the bill. In addition to the cleanup of abandoned mine sites and oil and gas wells, these activities include caring for wildlife habitats, National Conservation Lands, and cultural, recreation and historical resources. The foundation would also raise money for educational and technical resources to help with the management of the Bureau of Land Management.
Though Tipton supported Tuesday’s passage of the Foundation Act, he believes it is just the first step in the process of reclaiming abandoned mines, and it needs to be followed by the passage of good Samaritan legislation, according to Liz Payne, a spokesperson for Tipton.
Payne said it is a positive step to raise money to do site cleanup, but good Samaritan groups need liability coverage, a key component of the language Tipton added to legislation. Such coverage would protect groups that have the technical expertise to reclaim abandoned mine lands from being held completely liable for unforeseen problems such as a mine blowout.
Hice introduced the bill in part because of the Aug. 5 Gold King Mine spill, so that more private sector resources could be dedicated to cleanup efforts.
“By incorporating private sector policies and procedures, H.R. 3844, the Bureau of Land Management Foundation Act, revamps and improves the cleanup of contaminated water in abandoned mine sites,” Hice said in a statement following the passage of the bill.
The bill now goes to the Senate, where it has been assigned to the Energy and Natural Resources Committee.
A proposal to deploy the powerful Superfund program to clean up leaky Colorado mines — including one that unleashed millions of gallons of wastewater last year — isn’t stirring up much passion, despite formidable resistance in the past.
Some people who live in the scenic southwest corner of the state feared a Superfund designation would scare off vital tourist traffic, even though dormant mines have been belching poisonous wastewater into rivers for years.
Others objected on the grounds that it was a federal intrusion. Some worried Superfund status, which delivers federal money up-front for extensive cleanups, would diminish the chances of mining making a comeback.
But as of Wednesday, the U.S. Environmental Protection Agency had received only seven written comments opposing the planned cleanup, and 18 supporting it.
“I’ve gotten more letters to the editor on this topic,” said Mark Esper, editor of the Silverton Standard, a weekly newspaper in the heart of the storied mining district in the San Juan Mountains. “I’m a little bit surprised,” he said.
Since opening the public comment period in April, the EPA said, the agency has received a total of just 33 written comments , with 25 clearly for or against. Others made suggestions about specific sites or commented on other projects.
Monday is the deadline for the public to weigh in.
Opposition to a Superfund designation softened after a 3-million-gallon spill from the Gold King Mine on Aug. 5, 2015, even though it was an EPA-led crew that inadvertently triggered the blowout during a preliminary cleanup operation.
Many people came to believe only the federal government could pull off the sweeping cleanup that will be required, Esper said. The project is expected to cost millions and take years.
Silverton Town Administrator Bill Gardner said the scant comments might signal that residents had their say during months of public meetings.
“I’m hoping that people feel included and that their concerns have been heard,” he said.
Tainted wastewater from the Gold King reached the Animas River in Colorado and the San Juan River in New Mexico and Utah. The EPA estimates the spill sent 880,000 pounds of metals into the Animas, including arsenic, cadmium, copper, lead, mercury, nickel and zinc.
Water utilities shut down their intake valves and farmers stopped drawing from the rivers. The EPA says the water quality quickly returned to pre-spill levels.
After local officials and Colorado Gov. John Hickenlooper endorsed a Superfund cleanup, the EPA proposed the Bonita Peak Mining District Superfund area in April. It encompasses 48 sites that spill a combined 5.4 million gallons of acidic waste daily, the agency said.
The EPA could formally create the Superfund district as early as this fall, after the agency reviews the comments and makes any changes to the plan.
If the area is designated a Superfund site, the EPA would examine the mountains for pollution sources and compile a list of cleanup alternatives. Long-term cleanup work would begin once the EPA chooses an alternative.
Not much happened around the Silverton Caldera in southwestern Colorado between 26 million years ago — when hydrothermal alteration of the caldera’s fractured granitic rocks left behind extensive veins of metal-rich ores — and 1871, when those deposits were discovered by prospectors. That’s when Silverton really started to boom. From 1871 to 1991 — when the Sunnyside Mine on the east side of Bonita Peak, the largest of dozens in the area, closed — an estimated $530 million worth of gold, silver, copper, lead and zinc were extracted from the Silverton Caldera. Most of the prospectors and mining companies that extracted that wealth are long gone, but a legacy of widespread environmental impacts remains…
A map of the results of the water and sediment sampling published by the Arizona Geological Survey indicates that only a handful of samples, mostly in the upper reaches of the watershed in the early days of the spill, had pollutant levels that exceeded maximums established for drinking water standards. While the Animas and San Juan rivers remained closed to use for irrigation, drinking water and recreation for about 10 days, the impact to agriculture along the banks of the river was minimal although future crop yields could suffer from the shutdown of irrigation, according to the University of Arizona researchers, led by Karletta Chief, a hydrologist and tribal extension specialist in the Department of Soil, Water and Environmental Science.
The report also put the 3-million-gallon spill into perspective. Each year, Silverton mines collectively discharge more than 330 million gallons of acid mine drainage into the Animas River watershed — more than 100 times the volume of the Gold King spill. In other words, the Animas River is experiencing a Gold King-sized spill, albeit less concentrated, roughly every three days.
After more than a century of largely unmitigated mining in the West, Gold King is just the latest example of the slow-motion environmental problem that has been unfolding in hundreds of mines and along thousands of kilometers of waterways. The EPA’s involvement in this particular spill, however, is an unusual twist that has brought controversy and attention, but at least, researchers say, it is shining a light on the larger problem of abandoned mine lands and the complexities surrounding their regulation and remediation.
In recent decades, the movement to remediate abandoned mine lands has gained momentum, and geoscientists from many different fields, from environmental scientists and hydrologists to geologists and mining engineers, are bringing their expertise to bear in characterizing abandoned mine sites, monitoring their environmental impacts, and assessing and prioritizing them for reclamation. But regulatory, legislative and funding issues remain — and a looming geoscience workforce crisis may leave future cleanup projects in the lurch.
The Impacts of Abandoned Mine Lands
Today, the U.S. has an estimated 400,000 to 500,000 abandoned mine sites mostly concentrated in eastern coal mining regions, like Pennsylvania and West Virginia, and western hardrock and coal mining regions like Colorado and Wyoming.
“Abandoned mines” are those abandoned before 1977 by owners who pulled up stakes when the veins tapped out or market economics changed, making the mine no longer profitable to work. Prior to 1977, when the Surface Mining Control and Reclamation Act (SMCRA) established the national Abandoned Mine Land Reclamation Program, few regulations held former mine owners accountable for the environmental consequences of abandoning a mine. SMCRA assesses fees on active coal mining operations to pay for remediation of abandoned coal mine sites. There is, however, no similar program for hardrock abandoned mines.
Abandoned mines can range from small prospect pits that merely pock the surface, to deep underground mines with kilometer upon kilometer of adits, shafts, drifts, stopes and tunnels. Such underground cavities often intersected the water table — the surface, or top, of water stored underground — requiring drainage tunnels or pumping during active mining. When mines were abandoned, however, the pumping often stopped, and drainage tunnels — which were graded to allow water, as well as loaded ore cars, to passively flow downslope — continued to drain.
Seeping groundwater can then pool in the mine and possibly escape into the surrounding environment, potentially leading to the most prominent and far-reaching of the many health, safety and environmental dangers posed by abandoned mines: the degradation of water resources by acid mine drainage.
Acid rock drainage can occur naturally, without mining, when rocks containing gold, silver, copper and other valuable metals — which also usually contain pyrite, an iron sulfide that, when exposed to air and water, creates sulfuric acid that further leaches metals from the rock — are exposed via weathering and erosion, fractures or exhumation. But mining accelerates and scales up this natural weathering, exposing vast amounts of fresh rock surfaces both inside and outside the mine to oxygen and water.
Until the 1930s, it was common practice to dump mine tailings directly into streams. When acid mine drainage flows into creeks or streams, it can impact reaches of a watershed far downstream, often leaving trails of iron-hydroxide deposits — “yellow boy” in mining terminology — that stain rocks and riverbanks red, yellow and orange. Today, tens of thousands of kilometers of U.S. rivers and streams are still affected by acid mine drainage.
In addition to water-quality impacts, other hazards that also require mitigation include spoils and tailings piles, open portals and shafts, underground fires, ground subsidence, explosive gases and rusting equipment, just to name a few.
In addition to Gold King, Colorado alone has more than 23,000 other abandoned mines posing varying degrees of threats. More than 6,000 have been remediated by the Colorado Division of Reclamation, Mining and Safety in cooperation with the Colorado Department of Public Health and Environment — but $66 million worth of unfunded projects remain listed on the national database of abandoned mine lands. Other states have similar backlogs.
In Pennsylvania, the state most impacted by acid mine drainage and with a long history of remediating it, abandoned mines discharge 300 million gallons of acid mine drainage per day, affecting more than 8,800 kilometers of streams, says Eric Cavazza, director of the state’s Bureau of Abandoned Mine Reclamation and past president of the National Association of Abandoned Mine Land Programs.
The Watershed Approach
The problem may seem vast and intractable, but the science of acid mine drainage is well understood. And, over the last few decades, a well-stocked toolbox of mitigation techniques has been developed, including treating acid mine drainage waters with lime (calcium carbonate) to buffer the water’s pH to normal levels and channeling mine discharges through settling ponds to allow metals to precipitate.
The bigger challenge is determining where and how to allocate limited resources, says Geoffrey Plumlee, a geochemist with USGS in Denver who testified before Congress in November 2015 on the role geoscientists can play in assessing and prioritizing remediation of abandoned mines.
In his testimony, Plumlee emphasized the importance of involving geoscience expertise at every stage: identifying and assessing sites, determining remediation options, and prioritizing projects based on the potential return. The task is figuring out which sites pose the greatest hazard and possess the greatest potential for improvement, he says.
Plumlee cites the example of Colorado’s Summitville Mine, a hardrock gold mine about 100 kilometers southeast of Silverton, where mining had occurred on and off since the late 1800s. In the 1980s, open-pit mining began using a new cyanide-leaching technique to dissolve gold from lower-grade ores. Almost from the beginning, heavy-metal discharges, pH levels lower than 3, and cyanide leakage plagued the operation.
In 1992, the mining company declared bankruptcy and was unable to meet its remediation responsibilities. In 1994, to prevent a major spill into the Alamosa River, the state of Colorado asked the EPA to designate it a Superfund site and take over cleanup, the cost of which has since exceeded $100 million.
The ore geology at Summitville — massive sulfide-rich volcanic deposits, with no underlying carbonates to help buffer and neutralize acidity — “was basically a geologic recipe for extreme acid rock drainage,” Plumlee says. Meanwhile, the ore geology at other mines can result in discharges near drinking-water quality. Although not all mine drainage is acidic, it can still carry substantial amounts of toxic elements.
“Not all mine drainage is created equal,” Plumlee says. “This is why understanding the geology of the deposits is so important to helping predict mine drainage chemistry.” That is just one way geoscientists can help prioritize different sites for cleanup. Another example of how geoscience may be brought to bear is the interdisciplinary “watershed approach,” exemplified in a 10-year pilot study of the effects of more than a century of historical mining in two watersheds: Boulder Creek in Montana and the Animas River in Colorado, which includes Gold King. In the comprehensive study, which ran from 1997 to 2007, researchers examined “the geology and geochemistry of rock and sediment, the hydrology and water chemistry of streams and groundwater, and the diversity and health of aquatic and terrestrial organisms” in each watershed.
In the study, undertaken when the USGS implemented a new program in cooperation with federal land-management agencies called the Abandoned Mine Lands Initiative, researchers inventoried mine sites, analyzed an array of water, rock and mine waste samples, and characterized the geologic conditions controlling acidity and the release of toxic metals.
The results of the study, published in a 2007 report edited by USGS scientists Stanley E. Church, Paul von Guerard and Susan E. Finger, demonstrated the full potential of a comprehensive geotechnical assessment of watersheds impacted by mining, Plumlee says. Eight years later, that report became a vital resource for the teams investigating the Gold King Mine spill, helping to establish both pre-spill and pre-mining conditions.
Determining the natural conditions that existed in an environment prior to mining is important, Plumlee says, because it provides a baseline for the conditions that are technically feasible to achieve with remediation. This, in turn, can help planners set realistic goals for reclamation plans.
In establishing those conditions, it is important to remember that nature is not always pristine when left to its own devices. In Colorado, for example, the first European settlers gave streams names like Iron Creek, Alum Creek and Bitter Creek: names that alluded to natural acid rock drainage. In 1875, prior to intensive mining, the topographer of the Hayden Expedition noted the “iron-sulfate” waters of Cement Creek and Mineral Creek were not fit for drinking.
In 2011, the Colorado Geological Survey released a study identifying a number of streams whose headwaters, lying at elevations high above where mining impacts are felt, were acidic with high metals concentrations due to the hydrothermally altered metal-sulfide rocks in the surrounding geology. “Natural acid rock drainage has been active in Colorado for thousands, possibly millions of years,” the authors wrote.
In addition to understanding surface geology, knowing a site’s underground history is also crucial for remediation decision-making. Pairing historic documents with modern geoscientific technologies can help uncover that history.
Tools & Technologies
If the Gold King spill did nothing else, it raised awareness that a better understanding of a mine’s underground structure and hydrologic conduits and connections, both man-made and natural, is needed to make effective remediation decisions.
Gold King was part of a complex of mines including the large Sunnyside Mine. During the decommissioning of the Sunnyside Mine in the 1990s, 12 bulkheads — bunker-like structures made of steel and concrete — were installed to seal off the mine. Like plugging a bathtub drain, the bulkheading prevented acid mine drainage from flowing out at the lowest levels of the mine. After bulkheading, the local water table rose 300 meters, flooding the mine.
Although it might seem like flooding a mine would exacerbate the aquatic chemical reactions that result in acid mine drainage, sometimes water is part of the solution.“The idea behind the bulkheads is to raise the groundwater table back to pre-mining levels and remove oxygen from the acid mine drainage equation,” says Kirstin Brown, a geologist with the Colorado Division of Reclamation, Mining and Safety.
Soon after Sunnyside was bulkheaded and the water table rose, however, acid mine drainage at nearby mines — including the Red and Bonita, Mogul, and Gold King, each of which had previously been dry or discharging minimally — began flowing again. The renewed flows of acid mine drainage into Upper Cement Creek and the Animas River were at first actively treated to raise the pH. However, in 2003 and 2004, treatment ceased when disputes among the mine companies over who was responsible for its cost led to litigation, and streamwater quality again declined.
In 2010, in an effort to better understand the flow of mine drainage into Upper Cement Creek, the Bureau of Land Management, the Animas River Stakeholders Group and the Colorado Department of Public Health and Environment contacted the Colorado Division of Reclamation, Mining and Safety about creating a three-dimensional model of how the mine workings might be intersecting the water table.
The task fell to Brown, who worked with the U.S. Office of Surface Mining Reclamation and Enforcement, to learn and use EarthVision software to create the model, which drew on data from historic mine maps, some of which the researchers had to track down and “dig out of people’s basements in Silverton,” she says.
After scanning and georeferencing the old maps, groundwater data was then overlaid on the workings. Researchers can’t see the groundwater surface underground, but they can see where it flows out on the surface. If a mine portal, spring or stream is flowing at the ground surface, it shows researchers a fixed point on the surface of the groundwater table. Researchers also can check groundwater head pressures on some bulkhead gauges to see the current pressure and depth of the water table.
The result was a model that can be manipulated in three dimensions that gives officials the ability to “better visualize and understand the groundwater in the mountain and to help communicate the problem [of acid mine drainage] to the public,” Brown says. The model could also “help make predictions for the best practices for remediation.”
Understanding the hydrology at work in a mine can also allow for the most potent remediation technique: controlling the water at its source to prevent contamination in the first place. Sealing off mine entries with bulkheads can help prevent water from entering mine workings, and the flow of water inside the mountain can be manipulated to direct acid water away from clean water sources, Brown says.
Remediation teams employ other tools and technologies to investigate what’s going on belowground. Salt and dye tracer solutions can be introduced into mine waters to follow the hydrological connections among the workings. Drilling boreholes to send cameras, sensors or other instruments down into a mine is another common technique, often used to check the pressure and depth of a mine pool prior to beginning work.
“We do a lot of mine pool evaluations and mine pool monitoring, which is what didn’t happen at Gold King that resulted in uncontrolled releases of mine water,” Cavazza says. “Before we open up an abandoned underground mine, we almost always drill and put in monitoring wells so we have a good understanding of exactly how large [the mine pool] is, what the volume is, and how to contain and control it if we decide to open it.”
Another way to figure out what’s going on is to go underground with an engineering team, says Brown, adding that this is only done after ground conditions have been assessed, stabilized and deemed safe. Once underground, teams can map faults and fractures, collect information about water quality and water sources underground, and assess how to control those sources, for example, by determining where to place bulkheads.
But, it turns out, it is getting harder and harder these days to find engineers trained to work in mines.
Mining Engineers: A Depleted Resource
Since 1982, the number of accredited mining engineering schools has shrunk from 25 to 14 and for the last decade they have produced fewer than 200 graduates a year.
“Here in Pennsylvania, we have had a very difficult time recruiting new mining engineers to replace our mining engineers who are reaching retirement age,” Cavazza says. “There are fewer mining engineers being trained nationally, and there is probably going to be a continued need for them into the future.”
Last fall, in response to the Gold King spill, three bills were introduced in the U.S. House of Representatives Subcommittee on Energy and Mineral Resources chaired by Rep. Doug Lamborn (R-Colo.), who noted in his opening remarks the importance of having mining engineers on staff at agencies tasked with acid mine drainage cleanup.
“In the Committee’s investigation of the Gold King Mine spill, we discovered that, out of 15,326 employees, [the EPA] has no mining engineers and only 68 geologists, two of [whom] are assigned to [EPA] Region 8 where the spill occurred,” Lamborn said.
One bill, H.R. 3734, the Mining Schools Enhancement Act, would require the Office of Surface Mining Reclamation and Enforcement to direct 70 percent of its research funding to mining schools to help train the next generation of mining engineers.
In addition to mining engineers working on abandoned mine lands cleanup, it is “crucial to have economic and structural geologists who can help the mining engineers interpret and address the complexities of the geology, and hydrologists who can develop the detailed hydrologic models for groundwater flow,” Plumlee adds.
The other two bills introduced last fall, H.R. 3843 and H.R. 3844, propose to assess a maintenance fee on mineral claims for the next seven years, establish a federal “Good Samaritan” law, and establish a foundation that would oversee private gifts and bequests to fund abandoned mine lands remediation projects.
The bills are not the sweeping legislation that has been called for to replace the current law governing hardrock mining — the General Mining Act of 1872. Signed into law by Ulysses S. Grant to promote the settling of the West, it was enacted a century before the environmental movement took hold and made no provision for funding or regulation of remediation. “It’s never been updated, which is a very long time for an environmental law to be on the books,” Cavazza says. But, he says, “some people don’t want it updated.”
The most recent legislation proposing to update the 1872 mining act, H.R. 963, the Hardrock Mining Reform and Reclamation Act of 2015, was referred to subcommittee, where it remains. It would have, among other things, assessed reclamation fees to establish a fund for future cleanups and established a federal Good Samaritan law to waive some liability for private citizens, groups or companies who want to become involved in mine cleanup projects. Opponents contend that while domestic coal producers can pass the additional cost of reclamation fees onto consumers, U.S. mineral producers competing in a global market would suffer a competitive disadvantage if additional fees were imposed.
“There’s really never been the legislative will in Congress to enact a hardrock abandoned mine lands program,” Cavazza says.
Thus, hardrock abandoned mine lands are instead overseen by an alphabet soup of local, state and federal agencies, each with its own rules and guidelines. And funding to remediate a particular site may come from a hodge-podge of sources, including federal, state, and private partners who, in turn, get funding from a variety of sources, including SMCRA, Superfund, and the Clean Water Act Grant Program.
“Currently, no single source of funding, whether it be federal, state, tribal or private, is adequate on its own to address the magnitude of the problem that exists,” the Bureau of Land Management (BLM) and the U.S. Forest Service (USFS) reported in 2007. As of 2011, according to a General Accounting Office report, BLM, USFS, the Environmental Protection Agency and the U.S. Office of Surface Mining Reclamation and Enforcement had spent at least $2.6 billion to reclaim abandoned hardrock mines on federal, state, tribal and private lands.
Some of the private funding comes from corporations or groups — like Trout Unlimited, a nonprofit organization dedicated to conserving trout fisheries — that have a vested interest in cleaning up their local waterways. However, under certain laws anyone involved with mine cleanup in any way over the years can potentially be held responsible for environmental damage, even that which preceded their involvement with cleanup, and be liable for legal damages and cleanup costs.
Thus, Good Samaritan laws offer permits to waive or reduce the liability of private parties that want to participate in environmental cleanup projects. For example, if a group helped remediate a polluted stream that was previously unable to support aquatic life to the point that fish could survive in it, but not necessarily to the point that the water met the standards of the Clean Water Act, Good Samaritan laws might exempt the company from the more stringent requirement.
South Dakota and Pennsylvania are currently the only states with “Good Sam” laws. In Pennsylvania, Cavazza says, the 1999 law increased the number of private parties participating in acid mine drainage cleanup projects. But, he says, he suspects that many potential corporate partners are still dissuaded by legal teams who do not want to risk federal liability.
“I don’t know why you would want to discourage anybody from going in to try to clean something up that they had nothing to do with creating, that they are not in any way liable for, and for which they are providing their own resources,” says Cavazza, who last fall testified in his capacity as past president of the National Association of Abandoned Mine Land Programs (not in his role as a state official) to the benefits of Good Sam laws before the House subcommittee.
The Legacy of Gold King
Whether the Gold King spill will provide the impetus to create a national program for hardrock abandoned mine lands remains to be seen. The case of Gold King is currently mired in litigation and hearings. At the site, the EPA has set up a temporary water treatment plant in the nearby ghost town of Gladstone to treat Gold King discharge before it reaches Cement Creek. Downstream, state and federal public health agencies and other researchers continue to monitor the Animas watershed, especially during spring runoff and high-water events that may mobilize sediments laden with heavy metals.
“Although there appear to be no short-term effects to health or the environment following the Gold King Mine spill,” the University of Arizona researchers wrote last November, “we will not understand the long-term impacts of this highly concentrated release of metals into our environment for quite some time.”
In April, in response to a request from Colorado Governor John Hickenlooper and towns, counties and tribes in the Animas and San Juan watersheds, the EPA proposed listing 48 historic mine sites in the Silverton Caldera as a Superfund site. Some residents of Silverton had long resisted the designation, despite the fact that it would bring additional federal resources for remediation, because it was thought that associating the town’s name with Superfund, often synonymous with hazardous waste, could threaten tourism. But after seeing the Animas run orange, many changed their minds.
If approved, the Superfund site will be called the Bonita Peak Mining District.