Asarco will pay $40,000 in civil penalties under a consent judgment for illegally discharging more than one million gallons of water mixed with mill tailings into the Gila River in separate incidents two years ago.
The first incident happened in June 2012 near Highway 177 in the Town of Kearny in Pinal County when a water line ruptured at the Asarco Ray Complex’s Belgravia Unit and spilled about 846,000 gallons. In the second incident, in August 2012, a water line ruptured about 50 feet away from the earlier site and about 373,000 gallons were spilled.
ADEQ issued Asarco Notices of Violation on Sept. 6, 2012 and Nov. 11, 2012 for discharging without a permit in violation of the federal Clean Water Act, which is administered by the state under the Arizona Pollutant Discharge Elimination System program. The incidents also caused violations of the state’s surface water quality standards that require the water to be free of oil, grease and other pollutants that cause a deposit on a shoreline or aquatic vegetation or change the color of the surface water from natural background levels.
At the time of the violations, the Belgravia Unit stored residual mill tailings atop a water supply pipe. Two natural drainages flow through the unit and discharge to the Gila River.
In October 2013, ADEQ negotiated a Consent Order with ASARCO, LLC which included a compliance schedule to address these incidents and other water quality violations. Activities to address the issues at the Belgravia Unit were completed in April 2014.
“These discharges should have been prevented,” said ADEQ Director Henry Darwin. “Since these incidents ASARCO has made improvements to the Belgravia Unit, which they finished earlier this year, by relocating the tailings and replacing the existing pipeline to prevent future releases.”
The settlement is subject to court approval.