The Red & Bonita Mine consists of approximately 1.25 acres of waste rock and suspected tailings material, and an estimated 3,000 foot long adit that drains at approximately 300 gallons per minute throughout the year into Cement Creek. The mine site is located in San Juan County, Colorado, approximately seven miles north of the Town of Silverton, Colorado, at 10,893 feet above mean sea level (AMSL). The mine was opened in the late 1890s and has not operated for almost 100 years. Since 2005, adit discharge rates have been observed to be increasing from approximately 200 to 300 gpm. The pH of discharge water is approximately 4 su, and it contains high concentrations of several metals including aluminum, cadmium, lead, manganese and zinc. The discharge from the adit represents a significant percentage of the zinc load to the Animas River, which is impacting aquatic life for several miles below the confluence of Cement Creek and the Animas River.
