From the University of Denver Water Law Review (Haley McCullouch):
There are three laws that generally govern mining law in the United States: the 1872 Mining Law, the Clean Water Act, and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). These laws lack concrete measures to prevent mine spills from occurring as well as reliable methods to ensure that all mines receive the necessary attention in the case of a spill (or better yet, to prevent one). In addition, these laws can create liabilities and disincentives on parties who might otherwise be willing to come in and remediate the mine on their own. However, some states are turning towards a non-traditional form of legislation: Good Samaritan laws, in which citizens, companies, and organizations would be not liable in the case they decide to take on the task of cleaning up acid mine drainage.
The abandoned mine problem in the United States is striking. Specifically, hard rock mines (including metals like gold, silver, iron, copper, and zinc) are predominant in the West as a result of the discovery of gold and silver during the era of western expansion. Up until the 1970s, the federal government engaged in little oversight on mining across much of the West. During the mining era, there were few expectations about environmental safeguards, and as a result, historic mining operations often went largely unregulated. Before the 1970s, it was common for mining companies to abandon mine sites after mineral extraction was completed or no longer profitable. The land was often left exposed, with waste materials in piles or dumped into mine cavities and pits. At the time, mining companies had no requirement to restore mine lands to their original condition. Today, it is almost impossible to hold these mine owners financially responsible because records of original ownership have been lost and accountable individuals have long passed away. There are over 500,000 abandoned hardrock mine sites across the nation, and the cost for cleaning up these inactive mines is estimated to be between $33 and 72 billion dollars. Today, these abandoned mines are capable of polluting adjacent streams, lakes, and groundwater with high volumes of toxic waste. In doing so, contamination from spills has the potential to—and often does—harm marine ecosystems, poison local drinking water, and pose serious health risks to local communities.