Three million gallons of acidic mine drainage flooded into the Animas River basin 10 years ago, turning the southern Colorado river a mustard yellow and making international headlines. Caused by federal contractors working to treat pollution from the Gold King Mine, the accidental release of water laden with heavy metals prompted the creation of a Superfund site and a reckoning with lingering environmental harms from the area’s mining legacy, including hundreds of abandoned mines high in the San Juan mountains. A decade later, community members and Environmental Protection Agency staff are still grappling with the long-term cleanup of the area’s mines and tailings piles.

Other water contamination news:

• Newsweek: Map shows thousands more areas where groundwater could be contaminated
• Action News Now (Chico, Calif.): Tehama County Major Crimes Task Force seizes more than 5,000 marijuana plants, hazardous chemicals from illegal marijuana grow site
• Science of the Total Environment: Pyrethroid-driven toxicity and its relationships with urban land use: Findings from 15 years of statewide monitoring in California watersheds