Backers of a Montana initiative aimed at reducing mining pollution said Monday that water quality problems and cleanup costs borne by taxpayers demonstrate current regulations that govern the industry aren't enough.
Montana Trout Unlimited and Earthworks sought to bolster their case for the November ballot initiative with a report documenting pollution and costs from mines operating since 1980.
The mining industry pushed back against the claims and said it shouldn't be judged against past pollution.
The groups said in their report that 11 of the 12 mines they examined had water pollution problems not anticipated by regulators when the projects were originally approved. Among the problems cited were accidental releases of polluted water, violations of water standards and off-site contamination.
Cleanup costs at three of the sites have to date exceeded bonds put up by their owners by a combined $70 million, leaving government agencies to pick up the tab.
"The message is clear that current Montana mining laws do not protect clean water and taxpayers from the negative impact of hard rock mining," said David Brooks with Montana Trout Unlimited.
The ballot initiative would block permits for new mines that require perpetual cleanup of water pollution. Existing permits could not be revoked under the initiative.
Mining companies and their supporters have warned that if passed, the initiative could make it hard to open any new mines in the state.
State regulators said regulations governing mining have seen major changes over the time period covered by the report. Those include a ban on using cyanide to extract gold, tougher bonding requirements and a law that blocks mining executives from starting new mines if they left behind pollution at other sites.
Department of Environmental Quality spokeswoman Kristi Ponozzo said the report was "somewhat misleading" in setting 1980 as the beginning date for the modern mining era. "The Metals Mine Reclamation Act has changed significantly since the '80s," she said.
Brooks said none of the changes directly address the perpetual pollution of waterways from some mines that close and continue to leak contaminated wastewater indefinitely.
Montana Mining Association executive director Tammy Johnson acknowledged the industry's past problems, but she said new mines shouldn't be judged against events elsewhere that in some cases occurred decades ago.
Mining companies "fully embrace sound measures that assure we do not repeat that history," Johnson said.
The mining association on Friday released the results of an economic study it commissioned to highlight the industry's economic importance in Montana. More than 12,000 jobs are supported by hard rock mining with average earnings of about $86,000, according to the study by the University of Montana's Bureau of Business and Economic Research.