Colorado is set to take on the $2 million-a-year financial burden of a cyanide gold mine that became an environmental disaster.

The Denver Post reports Colorado must pay the $2 million for Summitville Mine, a bill that the EPA has been handling for the last 27 years, starting in 2021 for cleaning a fluctuating flow of up to 2,100 gallons a minute of toxic water that drains down a once-pristine mountainside.

The Colorado Department of Public Health and Environment will run a $18 million industrial water treatment plant there. 

More about Summit via the EPA:

The 1,400-acre Summitville Mine site is a former gold mine in Rio Grande County, Colorado. Gold mining started in the late 1800s. By 1984, the Summitville Consolidated Mining Corporation Inc. began open pit mining for gold, copper and silver. Mining processes, waste disposal practices, and the discharge of large amounts of copper and other metals to Wightman Fork and the Alamosa River contaminated soil, surface water and groundwater with heavy metals. Following cleanup, operation and maintenance activities are ongoing.

The plant houses huge stainless-steel vats of burbling brown sludge. Toxic metals are chemically coaxed and filtered out.

Colorado also must oversee the artificial covering and drainage ditches 1.7 square miles of tundra scarred by open-pit mining.