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Leadville, Colorado Mine Drainage Response

News and Documents
Drilling rig above Leadville Mine Drainage TunnelTruck-mounted drill rig begins drilling down to Leadville Mine Drainage Tunnel
EPA activities at the Gaw Shaft and Leadville Mine Drainage Tunnel

Collapses in the Leadville Mine Drainage Tunnel (LMDT) have caused water from hundreds of underground mines in the historic Leadville Mining District to back up in the mine workings and groundwater surrounding the tunnel. EPA estimates that between 500 million to one billion gallons of water is currently blocked. There is potential for a sudden release that could send a large amount of water containing elevated levels of zinc, lead and other metals through the tunnel into the Arkansas River.

In a short-term effort to alleviate concerns about a potential catastrophic failure of the Leadville Mine Drainage Tunnel, EPA is:

  • Pumping water from a nearby in the Gaw Shaft to pump water from the mine workings.
  • Constructing a relief well directly into the Leadville Mine Drainage Tunnel to pump water from the tunnel and transport it via pipeline to the Bureau of Reclamation's water treatment plant.

    EPA began pumping water from the Gaw Shaft on February 27, 2008.

    This pumping is a temporary, short-term effort to lower seepage from mine workings in Lower California Gulch. EPA is testing the water being removed from the shaft and has determined that it does not require treatment. The Gaw Shaft is located about one mile downgradient from the Leadville Mine Drainage Tunnel. While these mine workings are connected to the LMDT, it is not clear that pumping at the Gaw Shaft will have a significant impact on the water blocked in the tunnel.

    Trenching to excavate route for LMDT pipelineTrenching work along LMDT pipeline route
    EPA began continuously pumping and transporting water from the LMDT to the Bureau of Reclamation treatment plant on June 24, 2008.
    This is a significant step in the plan to pump, pipe and treat water from the tunnel in the safest and most efficient way possible. The LMDT is 350 feet beneath the ground. The relief well is now pumping water from behind blockages in the tunnel at a rate of approximately 1,000 gallons per minute; the water is being transported via pipeline to the U.S. Bureau of Reclamation's treatment plant where it will be treated to remove contamination prior to release into the Arkansas River.

    EPA is also working with federal, state and local partners on long-term solutions to permanently address any potential risks associated with water in the tunnel.

    Updates on EPA activities are posted below: About PDF files

    June 10 Progress Report (57K)

    May 12 Progress Report (57K)

    April 24 Progress Report (57K)

    April 18 Progress Report (57K)

    April 1 Progress Report (57K)

    March 6 Progress Report (56K)

    March 5 Progress Report (56K)

    March 4 Progress Report (56K)

    February 28 Progress Report (56K)

    February 27 Progress Report (55K)

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