Nearly one week ago a work crew from the Environmental Protection Agency breeched a rockfall and released a torrent of water containing mine waste from the Gold King Mine near Silverton, Colorado. Their initial reports aid that about a million gallons had be released but that figure was too low. The EPA now says that it believes that the surge released measured three million gallons after analyzing data from a stream gauge downstream from the release.
The yellow plume that marked the surge as is progressed through the various waterways is dissipating. The EPA and the various states warn that the river water should not be used by livestock or humans. The agency does not anticipate any decisions on reopening recreational activities on the rivers until August 17 at the earliest.
The EPA has constructed four sediment ponds at the Gold King Mine where it is treating the continuing runoff from the mine. After treatment to reduce acidity and settle sediment, the water being released into Cement Creek has a pH of 5.5, according to the Utah Department of Environmental Quality. Utah continues to monitor the quality of the water in the San Juan River as it enters the state.
According to sampling done by the EPA on various points along the Animas River Wednesday and Thursday last week, levels of lead, arsenic, beryllium, cadmium and mercury were extremely high compared with acceptable levels set by the agency, which are technically called “maximum contaminant levels” or “action levels for treatment.”
One of the samples of mercury was nearly 10 times higher than the EPA acceptable levels. Samples of beryllium and cadmium were 33 times higher, and one of the arsenic levels was more than 800 times higher.
The concerns in Utah include the effect of the contamination upon Lake Powell, which is the second largest reservoir in the United States. The Friends of Lake Powell state that “Over 20 million people living in the Southwest U.S. depend upon Lake Powell for an ensured water supply and their economic well being.”
Colorado, New Mexico and Utah have all established programs to test well water along the rivers to see if any of the contamination has reached them. Communities that draw drinking water from the Animas or the San Juan have stopped using the rivers and are relying upon other sources. Arizona is preparing to monitor the water below the Glenn Canyon Dam, which creates Lake Powell.