There is no disputing how important the mining industry is to Minnesota. Long part of our history, it remains a major source of jobs and economic development for our neighbors on the Iron Range.

But equally important to Minnesotans are the concept of corporate responsibility and our track record of responsible economic stewardship.

And as we contemplate opening up the Iron Range, Boundary Waters and the rest of northern Minnesota to nonferrous metallic mineral -- or sulfide -- mining, we need to protect both our bottom line and our natural treasures.

Sulfide mining extracts copper, nickel and other metals from sulfide ores. The danger with sulfide mining, unlike iron ore mining, is that rainfall on the exposed areas can create sulfuric acid, which will contaminate lakes, rivers and groundwater.

Once water becomes acidic, it leaches out and disperses heavy metals into lakes and streams, killing fish and wildlife and damaging entire ecosystems. An EPA report earlier this year stated that sulfide mining was responsible for 41 percent of all toxic pollution discharges in the country in 2010.

Although Minnesota's existing rules governing mining have some teeth, there are glaring gaps that need to be addressed. That's why I, along with several colleagues in the Senate and the House, have introduced the Financial Assurance Bill.

For years, companies have routinely understated the cleanup costs of nonferrous metallic mineral mines. Often it takes years after these mines have shut down for the damage they inflict to become apparent. To get out of these exorbitant costs, the companies will simply declare bankruptcy and leave the taxpayers holding the tab.

For instance, in Montana, the Zortman-Landusky Mine left residents with a $33 million bill. In Colorado, Summitville Mine's tab is $185 million and growing.

In South Dakota, unpredicted acid drainage problems and failed containment liners left local streams unable to support aquatic life. The company declared bankruptcy in 1999 and left taxpayers on the hook for millions of dollars in cleanup costs.

The proposed Financial Assurance Bill would require companies wanting permits for nonferrous metallic mineral mines to provide to the state financial security that could be used to pay for the costs of necessary reclamation or cleanup of the sites.

This legislation is important to protect the rest of us from the costs of cleanup if the mining company does not do its job, and it also provides an incentive for mining companies to keep people on their payrolls to do these jobs, if necessary.

This is standard language in other environmental laws. It is designed to avoid corporate "shell games," where corporations use subsidiaries or acquisition transactions to avoid liability.

The bill also requires financial assurance to cover the cost of any long-term water treatment needs; no mining companies may be released from their obligations until all water quality issues are resolved.

Future Minnesota Management and Budget commissioners would have more authority under this legislation to determine what form of financial assurance is acceptable. We've witnessed the accounting scandals that have contributed to our recent economic woes.

We need to give the state real muscle in setting the rules in our relations with any mining company that wishes to cut open our land. No more "financial tests," self-insurance or corporate guarantees.

With the risk that sulfide mining poses to the environment, financial assurance needs to be in the form of cash or cash equivalents. Making the MMB commissioner the final arbiter will protect Minnesotans' interests.

With this legislation and these protections for the Minnesota taxpayers, the state doesn't have to choose between economic development and jobs on the Iron Range and our pristine natural treasures.

We must never lose sight that this type of mining could come at a very high cost -- both financial and environmental.

----------

Mindy Greiling, DFL-Roseville, is a member of the Minnesota House.