DENVER – A 3 million-gallon spill from the Gold King Mine above Silverton last year may have dumped more than 880,000 pounds of metals into the Animas River, the U.S. Environmental Protection Agency has reported.
Some of the metals reached the San Juan River, which the Animas joins in New Mexico, but most settled into the Animas riverbed before that, the EPA said in a preliminary report on the metals.
Utah officials have said some contaminants reached their state, but the report, released Friday, didn’t address that.
The report didn’t identify the metals but said researchers were looking at cadmium, copper, lead, mercury, nickel and zinc. Tests done after the spill also found arsenic in the wastewater.
The EPA said most of the metals consisted of small particles and came from Cement Creek, a tributary that carried the water from the mine to the Animas.
Officials have said contaminants in the rivers returned to pre-spill levels shortly after the incident.
An EPA-led cleanup crew inadvertently triggered the spill on Aug. 5 while doing preliminary cleanup work at the inactive mine.
The spill provoked a storm of criticism from Congress, especially from majority Republicans, who have also accused the agency of trying to impose unreasonable controls on water and air pollution.
The mountains north of Silverton are pocked with dozens of idle mines like Gold King, which release a steady flows of tainted wastewater every day.
The report released Friday said the amount of metals carried downstream by the Gold King spill is similar to the quantity released into that part of the Animas during one day of high runoff from melting snow in the springtime.
The report said the researchers found “hot spots” of metals in the Animas and San Juan that weren’t related to the Gold King spill and said they might warrant further study.
The EPA installed a temporary water-treatment plant last fall to remove metals from the water still flowing out of the Gold King. The agency is weighing long-term cleanup plans.