State legislators will decide this week whether to change Maine’s year-old mining law to add protections for water quality and financial safety nets for the state at potential mining sites including Bald Mountain in Aroostook County.

On an 8-4 vote, the Legislature’s Environment and Natural Resources Committee has endorsed the bill, L.D. 1302, with several amendments to bolster water- and air-quality safeguards, financial protections and job creation.

The minority on the committee advocated limited changes, requiring less stringent regulations on water quality and easing mining companies’ responsibilities for cleanup and remediation if a site were closed.

The bill covers metallic mineral mining, known as “hard rock mining,” in which minerals such as zinc, copper, gold and silver are extracted from solid rock.

The process usually entails blasting, crushing and processing the rock with chemicals to separate desirable minerals from what becomes waste rock.

“We did not ban … the whole mining act that we worked so hard on last year,” said Rep. Joan Welsh, D-Rockport, the committee’s House chair. Rather, she said, the committee has added provisions to clarify and solve issues not fully covered by the law.

The proposed changes have drawn criticism from some legislators and mining industry representatives, who have said the added provisions would hamper potential mining operations.

“It will, in essence, stop mining,” said Sen. Thomas Saviello, R-Wilton. “We established a law last year and rules (for permitting) are still being written. This bill, in my mind, throws it on its ear.”

Part of the 2012 law, designed to streamline the permitting process for mining, requires that new rules for proposed mining be written by the state Department of Environmental Protection. Those rules are to be completed in early 2014.

But if L.D. 1302, introduced by Rep. Jeff McCabe, D-Skowhegan, is passed, sweeping changes could be made before the new rules are finished.

Saviello is one of several legislators who said the committee should wait until the DEP rules are released before tinkering with the law.

The amendments recommended by the majority of the Environment and Natural Resources Committee are designed to protect water, air and forests from the negative effects of mining minerals and metals. The changes fall into three general categories: taxpayer protections, water quality and job growth.

“I think it outlines some of the most important requirements for protecting the environment from mining pollution,” said Nick Bennett, staff scientist and watershed project director for the Natural Resources Council of Maine, a environmental group that has been critical of last year’s mining law.

The organization has advocated for more study of mining elsewhere to assess whether Maine is adequately prepared for open-pit mining.

The committee’s minority recommendations are confined mainly to authorizing the DEP to go beyond its own staff to review applications for mines and requiring mining companies to provide waste-rock management plans. It would allow 30 years for treatment of polluted water after a mine’s closure.

One key unresolved issue is acid mine drainage. During mining, natural sulfides are exposed to air and water, creating sulfuric acid that often leaks into surrounding lakes, streams, rivers and groundwater systems. The drainage can cause toxins to leach into watersheds. Once it starts, it can continue for thousands of years.

There are no current applications for open-pit mining in Maine, although New Brunswick-based JD Irving Ltd. has said it is interested in the Bald Mountain site.

According to estimates by the Maine State Chamber of Commerce, that operation holds the potential for creating 700 jobs and generating $630 million in employment income, with an additional $120 million in state and local taxes.

The accuracy of those projections has been widely questioned, particularly by environmental advocates and residents of Maine communities that are still struggling with contamination from closed mines.

But the chance for job growth in struggling Aroostook County has generated considerable support from residents of the region.

Sen. Troy Jackson, D-Allagash, whose home is about 15 miles from Bald Mountain, has been among the more vocal supporters of a streamlined mining application process. However, he has said that any operation must be environmentally sound, and that if it posed any threat to the water or wilderness of the region, he would withdraw his endorsement.

When L.D. 1302 is debated in the House and Senate, it can be modified further before a final vote.

North Cairn can be contacted at 791-6325 or at ncairn@mainetoday.com