Agency continuing to treat discharge at Colorado plant


SHIPROCK — A small number of residents of Navajo Nation chapters along the San Juan River listened to an update on Thursday by the U.S. Environmental Protection Agency about ongoing cleanup work in the Bonita Peak Mining District in Colorado.

The Bonita Peak Mining District consists of 48 historic mines, including the Gold King Mine, which released more than three million gallons of wastewater on Aug. 5, 2015.

The wastewater flowed into a tributary of the Animas River and eventually into the San Juan River, which is used for agricultural activities on the Navajo Nation.

Rebecca Thomas, team lead for the mining district, told those who attended the community meeting at the Shiprock Chapter house that the EPA continues to treat discharge from the mine at the Interim Water Treatment Plant in Gladstone, Colorado.

In June, the EPA released a proposed plan for interim response actions to address the environmental cleanup for 26 mine locations within the district, Thomas said.

Public comments submitted for the proposed plan are under review, and responses are being developed, she added. The agency also is drafting ecological risk assessments for fish and animals located in the district.

"We collected sufficient data to complete our risk assessment," Thomas said adding the agency is working with personnel from the Navajo Nation government to complete the studies.

Because the area has a complex system of mines, the EPA continues to work with the San Juan County Historical Society in Silverton, Colorado, to review maps, some dating as far back as the late 1800s, she said.

Monitoring activities also are being conducted by the state of Colorado, the U.S. Forest Service and the Bureau of Land Management.

The agency anticipates releasing the aquatic risk assessment in the new year, as well as issuing the interim record of decision and beginning interim actions. It also will continue conducting cultural surveys and consultations, Thomas said.

The meeting in Shiprock followed a similar gathering in Silverton on Wednesday.

Nenahnezad resident Joe Ramone said he remembers watching television in August 2015 and seeing the Animas River colored bright yellow from the spill. Ramone reminded the EPA personnel that the spill took its toll on farms and livestock on the Navajo Nation. He asked whether testing is being done on livestock since they drink water from the San Juan River.

Steve Austin, a senior hydrologist with the Navajo Nation EPA, explained that federal funding to the tribe is not allocated for such studies, but Karletta Chief, a hydrology professor at the University of Arizona, has been examining the effect on agriculture.

During the meeting, Austin talked about monitoring and testing done on the San Juan River by the Navajo Nation EPA.

Another member of the crowd asked if the U.S. EPA is examining the spill's effects on human health. Thomas said the agency is developing a human health risk assessment for the mining district since recreational use continues there.

She said officials are working with the Southern Ute Indian Tribe to examine how tribal members interact with the area, including collecting plants and other natural resources.

Noel Lyn Smith covers the Navajo Nation for The Daily Times. She can be reached at 505-564-4636 or by email at

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