The Environmental Protection Agency has let the U.S. Army Corps of Engineers know that it has a problem with the impact of the Rosemont Mine on local waterways.

"At this time, we respectfully reaffirm our objections on the basis that permit approval will have substantial and unacceptable impacts to 'aquatic resources of national importance' (ARNI), including Cienega Creek and Davidson Canyon," Jared Blumenfeld of the EPA's Region IX wrote to Col. R. Mark Toy of the Corps of Engineers on Monday, Feb. 13.

This could be significant trouble for Rosemont; without a Section 404 permit, there's no mine.

Here's the letter in its entirety:

Colonel R. Mark Toy
District Engineer, Los Angeles District U.S. Army Corps of Engineers
PO Box 532711
Los Angeles, California 90053-2325

Subject: Permit Application No. 200S-00S16-MB for the proposed Rosemont Copper Mine Project, Rosemont Copper Company, Pima County, Arizona

Dear Colonel Toy:

On January 5,2012, the US Environmental Protection Agency (EPA) provided comments in response to your District's Public Notice for a Clean Water Act (CWA) Section 404 permit for the proposed Rosemont Copper Mine (enclosed). The 4,750 acre mine, proposed primarily on Coronado National Forest lands southeast of Tucson, would eliminate and/or significantly degrade hundreds of acres of aquatic and riparian resources including waters of the United States (waters), such as wetlands, springs, seepsandriffle-poolcomplexes. Thesignificanceoftheseimpactstosensitiveandprotectedaquatic resources, and concerns regarding compliance with federal regulations (40 CFR 230), led us to identify the permit action as a candidate for the US Department of the Army and the EP A headquarters review pursuant to our agencies' Memorandum of Agreement implementing CWA Section 404(q).

In coordination with your staff in Tucson, as well as other federal and state agency regulatory authorities, we have been working to identify data gaps and clarify issues related to the many environmental uncertainties this project raises (please see our enclosed detailed comments). However, given the complexity of the project and the lack of any new substantive information provided since our January 5, 2012 letter, the EP A is now moving to preserve the option to seek higher level review of your pending permit decision. At this time, we respectfully reaffirm our objections on the basis that permit approval will have substantial and unacceptable impacts to "aquatic resources of national importance" (ARNI), including Cienega Creek and Davidson Canyon.

In summary, our enclosed comments detail specific deficiencies in the application related to each of the regulatory restrictions on 404 discharges. Of particular concern, the current proposal:

1. includes an inadequate analysis of off-site and on-site alternatives to demonstrate that the proposal is the least environmentally damaging practicable alternative (LEDPA);

2. provides questionable hydrological assessments concluding that impacts to downstream flows, sediment balance, and chemical contamination will not be significantly adverse or violate state standards;

3. provides no biological assessment (BA) to guide a determination whether the permit action would jeopardize the continued existence of any of ten federally listed threatened or endangered species;. would contribute to the significant degradation of Arizona's rare and fragile wetland resources, reduced by one third over the last century alone;

5. provides no plan to compensate for unavoidable impacts to waters of the United States; and

6. could negatively impact recreation, aesthetics, and ecotourism, a $2.95 billion regional economy.

The above considerations, if unresolved, could provide an adequate basis for permit denial under the regulations in any environmental setting impacting waters of the U.S. In this setting, where virtually pristine ecological and recreational public resources-including state designated "Outstanding Waters"-thrive in a desert environment, it is vital that CWA protections are rigorously applied. Based on the information currently available, the EPA finds this project will result in the significant degradation of waters of the U.S., including substantial and unacceptable impacts to ARNI. This letter follows the field level procedures outlined in the August 1992 Memorandum of Agreement between the EPA and the Department of the Army, Part IV, paragraph 3(b) regarding Section 404(q) of the Clean Water Act.

Thank you for your ongoing partnership implementing the programs of the CW A and protecting human health and the environment. Please call me at (415) 972-3572 with any questions, or have your Regulatory Division Chief contact Jason Brush, our Wetlands Office Supervisor, at (415) 972-3483.