The Arizona Department of Environmental Quality is opposed to the Environmental Protection Agency’s new rule requiring hardrock mining companies provide financial assurances (insurance policies) to address environmental cleanup costs resulting from unintended spills or releases of hazardous substances. ADEQ argues the new rule is not needed, “because hardrock mining is already regulated by mature, sophisticated state and federal programs.”

It’s disappointing that the state agency tasked with protecting our environment would be opposed to a rule that protects taxpayers from such financial cleanup costs.

Pima County and Southern Arizona have a lot at stake when it comes to the environmental impacts of hardrock mining. The U.S. Forest Service recently issued a Record of Decision for the proposed Rosemont mine in the Santa Rita Mountains. According to the decision, the next steps are for corporate owner Hudbay to submit for review a revised mine plan of operations and a reclamation plan, to negotiate a reclamation bond (one such insurance policy), and to obtain all required certifications under the Clean Water Act. In addition, state permits already approved for the Rosemont mine may have to be amended to incorporate changes to the mine design resulting from the Forest Service’s decision.

I have long been in opposition to the Rosemont mine proposal. Nothing can justify placing such a massive industrial facility in one of the few wild and natural valleys left in Southern Arizona. There is plenty of capacity in existing copper mining districts of Arizona, which already have infrastructure in place for expansion. Even if Hudbay complies with all current state and federal regulations, and its mine is designed to the highest degree to prevent unintended impacts to water, health and the environment, studies have shown accidents will likely happen.

A 2006 study of 70 environmental impact statements for modern-era hard rock mines found that water contamination risks have consistently been underestimated during the design process, which resulted in inadequate measures to mitigate these impacts. A 2012 study of 14 active copper mines in the U.S., accounting for 90 percent of U.S. copper production, nine of which are in Arizona, found that all mines had at least one failure. The majority had multiple failures, including pipeline and tailing spills, and failure to contain mine seepage. The downstream effect of these mines is clearly apparent in Arizona’s streams and aquifers. And if Clean Water Act protections are removed from certain streams, as recently advocated by Gov. Doug Ducey, insurance policies addressing spills may be taxpayers’ only recourse.

The U.S is one of few nations that does not tax the value of minerals extracted from federal lands, with the exception of coal. If a royalty or severance tax was applied to Rosemont’s gross revenue estimates for extracting copper and other minerals at the coal tax rate of 12.5 percent, $1.7 billion could be generated to address taxpayer cleanup costs. Since there is no such federal tax, we must rely on reclamation bonds and financial assurances to cover costs of unanticipated accidents that most certainly will occur. These must be significantly high enough to cover the high cost of cleanup.

Rosemont mine would be built directly upstream of Davidson Canyon, Cienega Creek and the larger Cienega Watershed; a watershed that provides up to 20 percent of Tucson’s groundwater. Since Rosemont mine is far from a done deal, we as a community still have time to advocate for the health of our air, water and wild places. As chair of the Pima County Board of Supervisors, I can assure you that Pima County will continue to take every opportunity to participate in state and federal permitting processes for Rosemont, as well as any other mine that could have detrimental impacts to our health. We also will continue to support expansion of existing mines and new mines that demonstrate meaningful respect for our community.

Sharon Bronson is chairwoman of the Pima County Board of Supervisors. Reach her at district3@pima.gov