The U.S. Environmental Protection Agency (EPA) released a proposal that follows up on a 2016 agreement that would require mining companies to show they have the financial wherewithal to clean up their pollution so taxpayers aren’t stuck footing the bill.

The 2016 agreement was reached under court order for the government to enforce a long-ignored provision in the 1980 federal Superfund law.

The requirement would apply to hardrock mining and would cover mines and processing facilities in 38 states, requiring their owners to set aside sufficient money to pay for future clean ups, the Associated Press reported.

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.

Companies would face a combined $7.1 billion financial obligation under the new rule, the EPA estimated. The agency said the amount could be covered through third parties such as surety bonds or self-insured, corporate guarantees.

The National Mining Association blasted the rule as “unnecessary, redundant and poorly constructed,” because existing programs prevent mines from becoming Superfund sites.

The group accused government officials of overstating the potential risks from modern mining techniques, in a rushed attempt to put a new rule in place before President Barack Obama leaves the White House next month.

Echoing the industry’s concerns were U.S. House Natural Resources Committee Chairman Rob Bishop of Utah and Energy Committee Chairman Fred Upton of Michigan. The Republicans said programs in place at the state level already ensure the environment is protected.

In documents released with the new rule, the EPA said that since 1980, at least 52 mines and mine processing sites using modern techniques had spills or other releases of pollution.

There are about 300 hardrock mines in the U.S. Combined they produced about $26.6 billion worth of metals last year, according to mining association Senior Vice President Ashley Burke. Of those mines, the EPA said 221 would be subject to the rule.