Frequent Questions Related to Gold King Mine Response
Updated March 16, 2017
How did the release affect the environment and human safety in Colorado?
In Colorado, surface water has returned to pre-event conditions based on data gathered after the Gold King Mine incident. Water quality does not exceed recreational screening levels for human exposure.
However, prior to the Gold King Mine incident EPA’s 2014 Draft Baseline Ecological Risk Assessment (BERA) found that metals emanating from Cement Creek pose severe risks to the aquatic environment for several miles downstream of the mining district. Lesser impairment of the aquatic community is likely to be occurring for at least 30 miles downstream of Silverton.
It is these and other documented environmental impacts that have led EPA to propose the addition of the Bonita Peak Mining District to the National Priorities List (NPL), which is the list of national priorities among the known or threatened releases of hazardous substances, pollutants or contaminants throughout the United States and its territories. By proposing the site to the NPL, additional data will be collected to more fully characterize sources of metals in the Animas River outside of the Cement Creek drainage and to assess risks to human health and the environment.
How did the spill affect the environment and human safety of communities downstream of Colorado?
Surface water on the San Juan River has returned to pre-event conditions based on data gathered after the Gold King Mine incident. Evaluating the impacts of the Gold King Mine release on the San Juan River is complicated by high background concentrations, by influences from storms and natural geology, and from sedimentation and remobilization processes.
Is the San Juan River safe for agriculture?
The San Juan River has historically received pollutants from several sources, including abandoned mines. As a result, San Juan River surface water occasionally exceeds Navajo Nation’s agricultural screening levels for short durations. During the response to the Gold King Mine spill, metal concentrations exceeded Navajo Nation’s agricultural screening levels for short durations. Given the short duration of the exceedances, EPA water quality experts believe the San Juan River is safe for agriculture and irrigation.
Are there any safety precautions for people who live, play or work near Cement Creek, the San Juan River, or the Animas River?
EPA, the state of Colorado and local health authorities continue to caution that there may be higher concentrations of metals in discolored sediment/soil.
People living, playing and working near the affected waterways should avoid discolored sediment/soil. Children under age 6 should be supervised when playing in and around the river to ensure they don't ingest river water or sediment.
As always, untreated water should not be ingested from creeks, streams or rivers.
If people see any unusual discharges from mines, contact local officials immediately.
How did the release affect local wildlife, crops and livestock??
The Colorado Department of Public Health and Environment issued a Sept. 1 fact sheet with the following statement: “The Colorado Department of Public Health and Environment recommends that eating trout from the Animas River at this time is considered safe. CDPHE analyzed fish tissue from rainbow and brown trout from the Animas River. Based on the limited samples available, most of the post (Gold King) event fish tissue analyzed showed metals below detectable levels and all results fall below risk screening levels. Because there is a potential for the fish to concentrate metals in their tissue over time, CDPHE and CPW will continue to monitor levels of metals in Animas River fish. New data will be analyzed and the results will be reported when available.”
Utah’s Department of Environmental Quality has found no health concerns for livestock or crops from the San Juan River in Utah. The toxicologist’s evaluation is available here: https://deq.utah.gov/Topics/Water/goldkingmine/stateofevalu.htm
The San Juan Basin Health Department issued a March 16, 2016 fact sheet that notes, “Overall, levels of heavy metals in soil and water are similar to previous years, and it is unlikely that heavy metals will make their way into crops at levels that are risky to human or livestock health.” The fact sheet also provides guidance for ranchers, farmers and home gardeners for testing the copper, molybdenum and sulfur levels in hay, pastures and gardens. The fact sheet is available here: http://sjbhd.org/wp-content/uploads/2016/03/Spring-Agriculture-FAQs.pdf?f6619c
What screening values is EPA using for water and sediment/soil?
EPA is using conservative recreational screening levels for water that assume adults and children receive all of their daily water intake (2 liters/day) from the river over a 64 day period. Screening levels for soil/sediment assume that adults and children receive their daily soil intake over a 64-day period.
Will EPA monitor the water as sediment is kicked up during spring run-off?
Yes, EPA plans to monitor before, during and after spring run-off to capture water quality conditions during those flow events. Seasonal run-off and storm events routinely increase the sediment load, as observed historically. The sampling is being done in accordance with the Conceptual Monitoring Plan. Read the monitoring plan: https://www.epa.gov/goldkingmine/final-conceptual-monitoring-plan
Does EPA support ongoing water quality monitoring of the Animas and San Juan rivers?
EPA has allocated $2 million in funding to support states’ and tribes’ monitoring plans. Utah, New Mexico, Southern Ute Indian Tribe, Ute Mountain Ute Tribe, Navajo Nation, and Colorado are eligible and may apply those funds to spring monitoring and preparedness planning as well. Some entities have applied and some have not. The agency has also agreed to contribute an additional $628,000, which in combination with the prior $2 million in funding, will enable states and tribes to fund a real-time water-quality monitoring alert system. This real-time monitoring would also serve to ensure successful coordination and implementation of notification and preparedness activities for communities downstream.
The agency is also doing its own monitoring. The agency’s conceptual monitoring plan is designed to gather a robust set of scientific data to consistently evaluate river conditions over time and evaluate impacts to public health and the environment. Under the conceptual monitoring plan, EPA is examining water quality, sediment quality, biological community and fish tissue at 30 locations under a variety of flow and seasonal river conditions. The sampling locations are located within Colorado, Southern Ute Indian Reservation, New Mexico, Ute Mountain Ute Reservation, the Navajo Nation and Utah, spanning Cement Creek, the Animas and San Juan rivers, and the upper section of the San Juan arm of Lake Powell. Learn more about the plan here: https://www.epa.gov/goldkingmine/us-epa-releases-monitoring-plan-evaluate-conditions-animas-and-san-juan-rivers
What is the status of the Interim Water Treatment Plant located at Gladstone, Colorado?
The interim water treatment plant installed at Gladstone in November 2015 is treating ongoing acid mine drainage being discharged from the Gold King Mine. The plant has operated over the winter and will continue through the summer.
EPA is evaluating options for operation of the interim water treatment plant beyond November 2016. Decisions related to water treatment will be made in the context of the cleanup options identified during the Superfund Remedial Investigation/Feasibility Study process.
What are the next steps for the Gold King Mine site?
Response operations at the Gold King Mine will resume as early as possible in the late spring/early summer, dependent upon road conditions and any remaining avalanche hazards around the mine.
The Gold King Mine is one of 48 mining sites in the Bonita Peak Mining District, which the agency recently proposed to be added to the National Priorities List.
What are the next steps regarding a Superfund listing?
The Gold King Mine is one of 48 mining sites in the Bonita Peak Mining District, which the agency recently proposed to be added to the National Priorities List. The agency is accepting comments regarding this proposed listing through June 6.
The remedial investigation is the first step in the site cleaned-up process once a site has been placed on the NPL.
How much will cleanup cost if the Bonita Peak Mining District is added to the NPL?
At this point, it is too early to estimate clean-up cost. Additional site characterization is necessary prior to considering cleanup options and associated costs.
What did EPA do to support Navajo Nation after the incident?
During the Gold King Mine response, EPA spent more than $1.1 million to deliver more than one million gallons of agricultural water and 8,500 bales of hay for livestock to Navajo farmers and ranchers along the San Juan River. EPA’s Region 9 office in San Francisco deployed more than 30 people, the majority of whom were at the Incident Command Post (ICP) in Farmington, New Mexico. The Farmington ICP ran hay and water delivery operations and conducted monitoring activities to ensure that the San Juan River was safe for agricultural and irrigation use under the Nation’s agricultural water supply and livestock screening standards. Sampling data indicated that metals and other constituents in water and sediment returned to pre-event conditions by the middle of August. Indeed, most jurisdictions impacted by the release lifted restrictions by that time. On August 28, 2015 Navajo Nation President Begaye lifted irrigation restrictions for the Chapters of Upper Fruitland, San Juan and Nenahnezad and maintained irrigation and livestock restrictions on most of the San Juan River until October 15, 2015.
The agency has provided $157,000 in funding through a cooperative agreement with Navajo Nation government agencies for costs incurred during the response to the August 2015 Gold King Mine release, and requested additional information from the Navajo Nation about remaining reimbursement requests to determine their eligibility under the EPA's response authorities and federal grant principles.
Navajo Nation is also eligible to apply for a portion of $2.6 million in grant funds, which the agency has allocated to the affected states and tribes to support real-time water monitoring.
EPA continues to sample water and sediment/soil along the San Juan river as part of the agency’s monitoring plan. Learn more about the monitoring plan here. https://www.epa.gov/goldkingmine/final-conceptual-monitoring-plan
There were reports that the water EPA sent to Navajo Nation had a strange smell and oil sheen. Was the water safe?
EPA used water tanks to transport emergency agricultural water to Navajo Nation during the response.
After concerns were raised regarding the quality of water in the tanks, EPA contractors inspected the tanks and collected water samples. One of the tanks, Tank #31L, had some oil residue on the outside but in areas that would not come into contact with water exiting the tank through the discharge valves. Samples from the water tanks were analyzed for volatile organic compounds (VOCs), total organic compound (TOC), semi-volatile organic compounds (VOCs), total metals, phenols, total suspended solids, and total dissolved solids.
The sample results confirm that water inside Tank #31L, as well as the water in the six other tanks sampled, met all applicable EPA standards for drinking water, and Navajo Nation standards for irrigation and livestock consumption. On Sept. 1, 2015, Navajo Nation also confirmed to EPA that the water in the tanks met all applicable Navajo Nation standards based on testing completed by the Tribe.
Information regarding the quality of the water provided in the tanks is available here.
Can you put the amount of water from the Gold King release in perspective?
The Gold King Mine incident on Aug. 5, 2015 released approximately 3 million gallons of acid mine drainage. In comparison, roughly 5.4 million gallons per day of acid mine drainage discharges from the 48 historic mines/mining-related sources in the Bonita Peak Mining District.
How much acid mine drainage leaks out of mines in the west every day?
While there is no current, comprehensive inventory of abandoned hardrock mines in the U.S., a 2011 Government Accountability Office report estimated that at least 161,000 of these mines exist in the 12 western states and Alaska. As there is no current, comprehensive inventory of these mines, EPA does not have data on the total amount of acid mine drainage occurring in the western U.S. each day.
How did this happen?
On August 5, 2015, EPA was conducting an investigation of the Gold King Mine near Silverton, Colorado, to:
- assess the on-going water releases from the mine,
- treat mine water, and
- assess the feasibility of further mine remediation.
While excavating above the old adit (a mine tunnel), pressurized water began leaking above the mine tunnel, spilling about three million gallons of water stored behind the collapsed material into Cement Creek, a tributary of the Animas River.
What is the total volume discharged on August 5?
The spill volume associated with the release on August 5 is calculated to be approximately three million gallons based on flow rates. Current discharge rates from the mine are averaging around 600 gallons per minute. For context, there are multiple mines along the upper Animas, and historically there has been considerable discharge at each mine site. The Red and Bonita Mine, just below Gold King Mine, is currently discharging about 300 gallons per minute.
Where is the leading edge of the plume?
There is no longer a visible leading edge of the Gold King Mine plume. We estimate that the water associated with the release reached Lake Powell sometime on Wednesday afternoon August 12. Lake Powell is a large body of water, and we expect no significant impacts to the lake, the Colorado River or any water bodies downstream.
What is EPA doing to respond?
EPA has deployed a large response team to Durango and Silverton, Colorado and to several locations in New Mexico, Utah and the Navajo Reservation to coordinate with affected states, tribes and communities on various response activities and to address impacts associated with the Gold King Mine wastewater release.
EPA’s primary objectives include working with federal, state, tribal and local authorities to make sure that people continue to have access to safe drinking water, ensure appropriate precautions are in place for recreational use and contact with river water, evaluate impacts to aquatic life and fish populations, and stop the flow of contaminated water into the watershed at the Gold King Mine site.
What work is happening at the site right now?
As water exits the mine, the water flows into a system of four treatment ponds. The treatment ponds provide retention time to allow the addition of lime to neutralize the pH. Substances to treat water are added during the process to settle the metals to the bottom of the retention ponds. One additional retention pond is being added to the treatment system to allow crews to manage the solids that has settled out to date. This additional pond will allow the treatment system to maintain efficiency as the crews are managing the existing ponds. A water treatment system will be installed on site as part of short-term actions for water treatment. Planning is in place for a treatment solution that includes pipes to allow the mine water to flow to a lower mine site with a better location for water treatment to continue into the fall. Longer-term treatment needs and options are being evaluated.
Is EPA currently conducting sediment sampling? If so, when does the agency expect to make those results available?
We are conducting sediment testing in Colorado, New Mexico, Navajo Nation, and Southern Ute Nation. New results are posted on EPA’s website on an ongoing basis.
Are you considering making this a Superfund site?
The Gold King Mine site has never been proposed to be listed on the National Priority List (NPL). At this time we haven’t received any requests from the governor to propose listing this site on the NPL, which we look for as part of the agency’s policy and practice.
What is the process EPA goes through to release water quality data?
EPA is working around the clock to collect and analyze water quality information in order to develop a comprehensive picture of water quality at various locations over time. This is a massive task and it is critical to make sure we are doing all we can to develop the sound science that will support recommendations and decisions that protect the public.
This is a time-consuming process. We are looking to develop and evaluate a full picture of the release event and water quality conditions before, during and following the movement of the plume downstream. EPA is sampling water at several locations in the Animas and San Juan Rivers for a suite of metals and contaminants. The lab work and quality assurance process for generating these data is extensive and designed to make sure we can have confidence in our results. This effort is generating thousands of data points, which must be analyzed by our scientists, placed in the context of other data collected, assessed for trends.
EPA also must evaluate the full set of data collected through the past few days and develop an understanding of the concentrations of metals that were deposited in sediments on the river bed and banks. This analysis will ensure that any recommendations about reopening drinking water intakes and reopening the river for recreational use are based on the science and the process we use to assess risk and ensure public health.
What do the data indicate? What does this mean for the long-term?
EPA is collecting and assessing water quality from the Animas and San Juan Rivers daily. The La Plata County Sheriff lifted the recreation use ban on the Animas River on Friday, August 14. The water quality data we have analyzed thus far continues to be encouraging and point to minimal short-term risks associated with the plume and a return to pre-event baseline conditions in the Animas River in Colorado. In the San Juan River, data indicate the plume dissipated as it traveled downstream, and samples show a smaller rise in acidity and metals levels in the river compared to those in the Animas River. Further downstream, data suggest slight impacts as the plume dissipated and no leading edge was visible. While we are taking samples in Lake Powell near the San Juan River inflow, we expect no adverse impacts to the lake or other locations downstream from the lake.
While this information is encouraging, we need to thoroughly evaluate the full set of data collected over the past few days and develop an understanding of metals levels in water and in sediment deposited in the river before making recommendations. EPA is working with our partners to review all data collected to develop a comprehensive picture of water quality conditions in the river and in the plume itself. This will ensure our decisions are based on sound science.
Our longer-term concern is the effect on the entire watershed of metals deposited in sediments and their release during high-water events and from recreational use over time. These sediments may pose some risk, especially to aquatic life and fish. Because we have been working to assess impacts to water quality in the Animas River for several years, we have good information and data on background conditions in the river. EPA will use this information to assess long-term needs and evaluate our progress in restoring the waters impacted by the Gold King Mine release.
From a scientific perspective, what contaminants have been found and at what concentrations?
Data are posted at https://www.epa.gov/goldkingmine as they become available.
Is EPA planning to build a wastewater treatment plant at the Gold King Mine site?
The agency has not made a final decision about whether to build a wastewater treatment plant at the Gold King Mine site. Agency staff initiated the RFP process for a potential treatment plant immediately after the spill, so that the procurement process would be well underway if that decision were to be made. (It can take several weeks to specify, solicit proposals, conduct technical evaluations, and then mobilize and deploy.) We are currently evaluating proposals.
At the same time, the agency is conducting an analysis to determine if a temporary treatment plant provides a measurable benefit to water quality downstream in the Animas River. The agency is closely coordinating with officials in Colorado, New Mexico, Utah, Southern Ute tribe, Mountain Ute tribe, and Navajo Nation to develop a comprehensive, long-term plan for the Gold King Mine site.
At the time of the Gold King Mine incident, did the work team have a cell phone or satellite phone in case of emergency?
Environmental Restoration's Site Health and Safety Plan required the work team to have a mobile telephone, two-way radios, and vehicle horns/air horn.
At the time of the release, the road was destroyed and the EPA crew was trapped with no cell phone coverage.
The EPA crew radioed to an EPA ERRS contractor who was off-site to notify him of the situation. The contractor contacted a team from the Colorado Division of Reclamation, Mining and Safety (DRMS) who had been assisting EPA at Gold King Mine but who were off-site at that time. EPA and DRMS personnel then communicated via radio and the EPA on-scene coordinator instructed DRMS to make notifications to downstream communities.
Although not required in the work plan, the work team also was equipped with a satellite phone. The day of the release, the subcontractor working with the mine team was given the satellite phone because they were conducting underground operations at the nearby Red and Bonita Mine.
Impacts on Human Health and the Environment
What are the health risks?
The EPA and the Agency for Toxic Substances and Disease Registry (ATSDR) do not anticipate adverse health effects from exposure to the metals detected in the river water samples from skin contact or incidental (unintentional) ingestion. Similarly, the risk of adverse effects to livestock that may have been exposed to metals detected in river water samples from ingestion or skin contact is low. We continue to evaluate water quality at locations impacted by the release.
Although the pH levels in the Animas River between Cement Creek and Durango have returned to baseline levels, washing with soap and water after contact with untreated river water is always sound public health practice. This will minimize exposure to any metals that may be present. We are still reviewing data on pH levels in the San Juan River and will release those as soon as they have been validated.
What is the impact on agriculture?
We are certain that crops are safe for consumption. When the plume came through, irrigation ditches that impacted crops and livestock were shut down. Water quality data we have seen indicate no harmful effects on any agricultural products. Ground water and tap water have both been tested and have returned to pre-event conditions.
How do I know if my drinking water is safe?
In New Mexico: On August 14, 2015 New Mexico Environment Department lifted the ban on the use of private domestic water wells. On August 15, 2015 New Mexico Environment Department lifted the ban on San Juan County’s drinking water system supplied by the Animas and San Juan Rivers.
In Colorado: On August 14, 2015 the city of Durango resumed pumping raw water for drinking water treatment and distribution.
What about wildlife and fish?
The assessment of impacts to wildlife and fish populations in both the Animas and San Juan Rivers is ongoing but information gathered to date is promising. EPA is working with the State of Colorado Division of Parks and Wildlife (CPW), the New Mexico Department of Game Fish, the Navajo Nation and the U.S. Fish and Wildlife Service to investigate reports of impacts to wildlife.
- There were no fish kills along the Animas River during the plume event. Biologists walked and paddled the river looking for dead fish. There was also no evidence of scavenging by birds or other mammals.
- No effects were seen on terrestrial animals – ducks, mammals, etc. Ducks have been seen back on the river since Monday, Aug. 10.
- Colorado Parks and Wildlife biologists placed fingerling rainbow trout in the Animas River in Durango the afternoon of Aug. 6 before the mine-spill plume reached the city. 108 fish were placed at three separate locations in cages. Young fish known as fingerlings were used because they are most sensitive to environmental changes. One fish died, but not due to water quality. The fish remained healthy throughout the event and afterwards. They were removed from the river on Aug. 11.
- After being removed from the river the fish were frozen and taken to Denver, where they’ll be tested for toxicity by the Colorado Department of Health and Environment. Scientists will be looking for deposits of metals in tissue and organs. Those results will not be known for at least two weeks.
- During the week of Aug. 24, CPW biologists will fish the Animas River in Durango to check on populations of wild fish – sculpin, suckers, rainbow trout and brown trout. Some of those fish will also be sent to Denver for testing.
- The Animas River has been affected by acid mine run-off for decades and that has been detrimental to fish populations for many years. CPW has seen a noticeable decline in the number of trout in the river for the last 10 years. There are very few fish found from Silverton to Baker’s Bridge. The bridge is located about 10 miles north of Durango.
While this information is encouraging in terms of short-term impacts to fish, we will be evaluating long-term impacts associated with exposure to the plume and the impacts of deposited sediments over time. EPA will be working with the States of Colorado, New Mexico and the Navajo Nation to evaluate these and other ecological impacts as we move forward.
Are the fish safe to eat?
On September 2, 2015, the Colorado Department of Public Health and the Environment announced that trout from the Animas River meet state standards. https://www.colorado.gov/pacific/cdphe/News/Animas-trout
What is EPA doing to make sure this doesn’t happen again?
EPA has worked successfully to address environmental concerns at hundreds of abandoned mine sites across the West. EPA will thoroughly investigate this incident, and it is committed to applying all lessons learned to its work as it moves forward.
While EPA continues to investigate the root causes of the release of mining waste at the Gold King Mine, all EPA regional offices will immediately cease any field investigation work at mines, including tailings facilities. EPA is in the process of initiating an independent assessment by a sister federal agency or another external entity to examine the factors that led to the Gold King Mine incident. Based on the outcome from that assessment, EPA will determine what actions may be necessary to avoid similar incidents at other sites.
While EPA stops work on existing field investigations and assessments at these mining sites, EPA also is instructing its regional offices to identify existing sites with similarities to the Gold King Mine site, to identify any potential immediate threats and to consider appropriate response actions.
Who, specifically, is responsible for the release?
A Colorado-based EPA team was working at the site with a response contractor and the State of Colorado's Division of Reclamation, Mining and Safety. For EPA Administrator Gina McCarthy's remarks on agency responsibility, go to https://www.epa.gov/goldkingmine.
Will anyone be fired as a result of this incident? If so, who?
EPA and external entities will be thoroughly investigating the full facts regarding this incident and the response, and the agency will respond based on that information.
Is EPA aware of water buildup inside the Sunnyside Mine? Is there any estimate for the volume?
Yes. The Sunnyside Gold Corporation, pursuant to its mining permit and an agreement with the State of Colorado, installed bulkheads in the American Tunnel in several locations in the late 1990s and early 2000s. The American Tunnel drained the Sunnyside Gold Mine workings during the mine’s operating years. When the bulkheads were installed, water elevations rose in the mountain and flooded the Sunnyside Gold mine workings. EPA understands that the water levels in mine pool have been stable for several years. The Colorado Division of Reclamation, Mining and Safety (DRMS) would be a good resource for additional information and estimates on volume.
Does the agency have any concerns about a potential spill from Sunnyside?
We have no information indicating an immediate risk of a release from the Sunnyside Mine. EPA will be working with our partners at DRMS to evaluate the Gold King Mine release and its impact on conditions in the area to determine if additional measures are necessary to address potential discharges.
Were the actions taken at Sunnyside responsible for water that was coming out of Gold King Mine?
The relationship between the water in the Sunnyside Gold Mine and other mines in the area is a complex topic. Many of the mines in the area either intersect the same geologic structures and/or are in close proximity to the same structures. The DRMS has extensive knowledge and details on Sunnyside and other mines in the area, and that information has been the subject of extensive discussion and review with EPA and the Animas River Stakeholder Group (ARSG) over the last several years.
What will EPA be doing to make sure that the mines in the Upper Animas basin are safe?
EPA will be working with our partners at DRMS to evaluate the Gold King Mine release and its impact on conditions in the area to determine if additional measures are necessary to address potential discharges