The Environmental Protection Agency said it plans to require mining companies to show they have the financial wherewithal to clean up their pollution so taxpayers don't have to.
The proposal follows a 2016 agreement reached under court order for the government to enforce a long-ignored provision in the 1980 federal Superfund law. The requirement would cover mines and processing facilities in 38 states, requiring owners to set aside sufficient funds.
The EPA is considering similar requirements for chemical manufacturers, power generation companies and the petroleum refining and coal manufacturing industries.
From 2010 to 2014, the EPA spent $1.1 billion on cleanup work at abandoned hardrock mining and processing sites across the U.S.
The new rule "would move the financial burden from taxpayers and ensure that industry assumes responsibility for these cleanups," EPA Assistant Administrator Mathy Stanislaus said.
Contaminated water from mine sites can flow into rivers and other waterways, harming aquatic life and threatening drinking water supplies. Companies in the past avoided cleanup costs in many cases by declaring bankruptcy.