captain jack mill

T1N R73 W, SE 1/4 SEC. 12

The Captain Jack Mill site is located at the headwaters of upper Left Hand Creek about 1.5 miles south of Ward in Boulder County, Colorado. The site is in a narrow valley known as California Gulch. Mining for gold and silver in the region began in 1860 and ended in 1992. At the time of listing, the site included the Big Five Mine (the upper mine), Captain Jack Ltd. Mill, the Black Jack Mine, and other mines and waste features in the immediate surrounding area. The Big Five Mine, located about 500 feet upstream from the Captain Jack Mill, consisted of a discharging adit (tunnel), a large waste rock pile and a settling pond. The mill works area included several constructed ponds previously used for settlings tailings from the mill operations. In September 1986, the Mine Safety Health Administration found improper storage of chemicals at the mill buildings. EPA removed several drums of chemicals and concentrated mine wastes in March 1987. The Colorado Mined Land Reclamation Board received reports of dumping of mine and mill wastes into Left Hand Creek in October 1992. At the same time, a milky white substance was reported in Left Hand Creek. Tailings-like material was observed entering Left Hand Creek from the unlined tailings ponds, turning the creek a milky gray color for about six miles downstream. Sampling of the discharge to the creek found high levels of zinc, cadmium, copper and lead. The Left Hand Water District shut off their drinking water intake 15 miles downstream on Left Hand Creek. CDPHE issued a Notice of Violation and a Cease and Desist Order. The Colorado Department of Minerals and Geology (CDMG) obtained a restraining order to prevent further mill operations. CDMG determined in 1993 that there was a threat to the environment from the tailings through blowing dust, surface flooding, overflow of the tailings pond and subsurface groundwater percolation. They also determined that there were improperly stored drums and explosives. A 1997 EPA inspection found elevated levels of heavy metals in the soils from the Big Five Mine waste pile and settling pond and in the unlined tailings lagoons at the Captain Jack Mill. EPA also confirmed the findings of earlier elevated levels of metals in the Big Five adit drainage.