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EPA Releases Additional Data, Graphs and Documents Stemming From Gold King Mine Incident

(Washington, DC) -- The U.S. Environmental Protection Agency today (Sept. 8, 2015) released new sampling data, data trend graphs, and additional public records relating to the Gold King Mine incident.

The new data posted today are available here.

The data cover:

  • EPA sediment samples collected on 9/1 from locations along the Animas and San Juan Rivers
  • EPA surface water samples collected on 9/2 from locations in the Animas and San Juan Rivers
  • EPA surface water samples collected on 8/31 from locations in the Animas and San Juan Rivers
  • EPA surface water samples collected on 8/27, 8/29, 9/1, 9/3 from locations in the Animas and San Juan Rivers
  • EPA sediment samples collected on 8/31 and 9/1 from locations along the Animas Rivers
  • EPA sediment samples collected on 8/27and 8/28 from locations along the Animas Rivers

What do the trending graphs show?

We have posted graphs to show the trending concentrations of all 24 metals in surface water over time. These trend graphs were created from pre-event and post-event data posted to this website between August 10, 2015 and August 30, 2015. EPA is posting 576 graphs to show the trending concentrations of metals in surface water at the 24 sampling locations where five or more samples have been collected.

The trend graphs were created from pre-event and post-event data that show the conditions of the Animas and San Juan watersheds. Each sample was analyzed for 24 metals, including arsenic, cadmium, lead and mercury. The trend graphs show the concentrations of dissolved metals rather than total metals, based on the pre-event and post-event data. Concentrations are expressed in the dissolved, rather than the total, form of the metal because the dissolved is a better predictor of harm to human health and the environment.

The metals were compared to Recreational Screening Level (RSLs). RSLs, established by EPA, are health-based concentrations for each metal based on exposure during recreational use. (Note that the RSLs for some metals like calcium, potassium, sodium and magnesium are not listed on the trend charts. These are common metals derived from relatively high soluble minerals such as calcite (calcium carbonate) and sodium/potassium salts and therefore no recreational screening levels were calculated.)

For each metal, the trend graphs illustrate that concentrations are significantly lower than RSLs. The graphs also show that concentrations for all 24 metals in surface water are consistent with pre-event conditions. The graphs are available on the surface water sampling map on the main Gold King Mine data page.

What new documents are being released?

EPA is releasing the agency's plan for notifying stakeholders with Gold King Mine updates. EPA is also releasing a memo directing senior agency leadership to review plans for downstream notifications after potential future releases, and an interim guidance memo regarding the agency's work at mine sites across the country.

  • Sept. 4 memo: "Interim Guidance for Continuation of Work and Development of List of Superfund Mining and Mineral Processing Sites"
  • Sept. 4 memo: "Review of Regional and Area Contingency Plans for Downstream Notifications"
  • Sept. 7 planning document: "Gold King Mine Stakeholders Alert and Notification Plan"

These documents are now available here.