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Gold King Mine Data, August 19, 2015

Data from Gold King Mine Response

EPA sediment samples collected from nine locations on Monday August 10th, Wednesday August 12th, and Thursday August 13 along the Animas and San Juan Rivers have been validated.

EPA has done a review of the data which included a comparison to screening levels for exposure during recreational use to determine if the metal concentrations are consistent with pre-event levels.

The metal concentrations of the samples were below soil / sediment recreational screening levels. Based upon the sediment sampling results, sediment sample concentrations are trending toward pre-event conditions.


EPA sediment samples collected on Tuesday August 11th at locations along the Animas and San Juan Rivers have been validated.

EPA has done a review of the data which included a comparison to screening levels for exposure during recreational use to determine if the metal concentrations are consistent with pre-event levels.

The metal concentrations of the samples were below soil / sediment recreational screening levels. Based upon the sediment sampling results, sediment sample concentrations are trending toward pre-event conditions.


EPA has released additional water quality data from August 13-15, 2015, on the San Juan River between Farmington, New Mexico and Mexican Hat, Utah.

To assess the impacts of the release at the Gold King Mine, water quality samples were collected from Navajo Nation at numerous intervals beginning on August 7, 2015. The August 7 2015 data was collected for baseline purposes to understand river conditions at the Hogback, New Mexico monitoring location prior to the impact of the upstream contaminants from the Gold King Mine release.

To assess the impacts of the release at the Gold King Mine, water quality samples were collected from August 13-15, 2015 at eleven locations for 24 metals. Each surface water sample was analyzed for metals including arsenic, cadmium, lead and mercury.

Based on U.S. Environmental Protection Agency (EPA) surface water data collected from a sampling station near Hogback, New Mexico from August 7-15, San Juan River water quality in Navajo Nation has returned to pre-event conditions.

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