The bureau also said that standards are inconsistent from one agency to another regarding the reopening of the flooded, abandoned hard-rock mines scattered throughout much of Colorado and the western U.S.

Senate Environment and Public Works Committee Chairman James Inhofe (R-Okla.) blasted the EPA and its contractors for ignoring risks that led to the blowout. He said, “The Dept. of the Interior’s report of the Gold King mine incident raises significant new questions about the events leading up the spill.”

EPA has publicly taken responsibility for the incident. But some observers say that Reclamation’s conclusions underscore the problems abandoned hard-rock mines present and that the criticism of EPA is misdirected. Jim Lyon, National Wildlife Federation vice president of conservation policy, says, “While it’s clear that EPA made some mistakes with this, what’s unfair is that EPA is actually one of the few agencies out there trying to abate these things.” Lyon says the spill’s major lesson is that the U.S. lacks a comprehensive, well-financed cleanup program for its more than 500,000 unclaimed, abandoned mines. “It’s a patchwork effort that is seriously underfunded.”

Several witnesses at an Oct. 21 House subcommittee hearing called for legislation to limit Clean Water Act liability for environmental contractors or volunteer groups acting as “Good Samaritans” to clean up mines. Some lawmakers, such as Sen. Cory Gardner (R-Colo.), have said they plan to sponsor a bill along those lines this session. But similar efforts have failed in the past.

Environmental groups say that, even if such a bill were to become law, what is really needed is more federal funding. Requiring hard-rock mining companies to pay into a cleanup fund—similar to the fee paid by the coal industry—also would help, they add.