Summitville Gold Mine, Colorado

The Summitville Mine is in the San Juan Mountains near Del Norte in Rio Grand County, Colorado. Gold was first discovered at Summitville in 1870, and the area was mined sporadically through the 1950s.

Deadened River

In 1984, Galactic Resources Limited renewed gold mining at the site using the cyanide heap leach method to remove gold from low-grade ore.  Between 1984 and 1992, Galactic Resources produced gold worth an estimated $81 million.  During this time, toxic mine waste that included copper, iron, manganese, zinc, aluminum, and cadmium was dumped into the headwaters of the Alamosa River, causing a massive fish kill in the Alamosa River and the Terrace Reservoir.  Acid mine drainage, which occurs when sulfur-bearing rock is exposed to water, has affected the entire length of the river.

The Alamosa River provides irrigation water for ranchers and farmers in the San Luis Valley in southern Colorado.  The river and nearby wetlands provide important habitat for fish, ducks, and other wildlife, including the endangered whooping crane. Acid mine drainage and toxic mine waste have contaminated the river, killing fish and harming wildlife, possibly damaging crops, and ruining irrigation equipment worth hundreds of thousands of dollars.

Bankruptcy Leaves Legacy of Pollution

In 1992, Galactic Resources declared bankruptcy and abandoned the mine. Shortly afterwards, the State of Colorado asked the U.S. Environmental Protection Agency (EPA) for emergency help in preventing a cyanide-contaminated waste pond from overflowing a spillway.  EPA responded quickly, placing the mine on the National Priorities List of federal Superfund sites.  Cleanup has cost about $185 million so far.  The costs of operating a water treatment plant on site, which may be necessary for decades to come, are estimated at $1.5 million annually.