Air Quality Studies Summary

Air

Air Air Modeling Results TITLE: Modeling Report to Assess Ambient Air Quality Impacts RELEASE DATE: July 2010 PREPARED BY: Applied Environmental Consultants Brief Summary: An air impact analysis was conducted

by Applied Environmental Consultants as part of the Environmental Impact Study to demonstrate the National Ambient Air Quality Standards (NAAQS).

Demonstration of protection of NAAQS was accomplished by comparing the maximum impacts to the applicable standards. The study looked at carbon monoxide (CO), nitrous oxides (NOx), particulate matter less than 10 microns in aerodynamic diameter (PM10), sulfur dioxide (SO2), and particulate matter less than 2.5 microns in aerodynamic diameter (PM2.5) and concluded that all were less than the applicable standards associated with each.

Air studies looked at the potential short- and long-term effects of the Rosemont project on air quality - at the project site and in specific areas of urban Tucson.

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rosemont copper

- a bridge to a sustainable future

TITLE: CALPUFF Modeling Report to Assess Impacts in Class I Areas RELEASE DATE: July 2010 PREPARED BY: Applied Environmental Consultants Brief Summary: Applied Environmental Consultants conducted an evaluation of potential ambient air quality impacts due to emissions from the Rosemont project based on projected emissions from Year 1 and Year 5. Results showed that of the Class I areas studied, the greatest predicted pollutant concentrates and the highest potential for visual impacts are at the Saguaro National Monument East. Even at these “greatest potential� areas, impacts are negligible and infinitesimal compared to impacts from the Tucson urban area.

Air Permit Information TITLE: Executive Summary Air Quality Information Rosemont Copper Project Southeastern Arizona RELEASE DATE: July 2010 PREPARED BY: Applied Environmental Consultants Brief Summary: An application for a Class II Air Quality permit includes all information required for issuance of the air quality permit including site plans, process flow diagrams, equipment descriptions, pollution controls, maximum process rates, maximum emissions of regulated pollutants, and applicable air quality requirements. The Rosemont project also is subject to the National Environmental Policy Act (NEPA) that requires an Environmental Impact Statement (EIS). The information needed to address air quality in the EIS includes some additional information not required for the Class II air quality permit: innovative or non-standard actions that would reduce emissions; emission estimates (including greenhouse gases) on a 5-year cycle throughout the life of the mine; weather and ambient pollution data summary; and air modeling protocol, assumptions, settings, and results. This additional information is outlined in this report.

TITLE: Application for a Class II Permit Rosemont Copper Project Southeastern Arizona RELEASE DATE: July 2010 PREPARED BY: Applied Environmental Consultants Brief Summary: Information necessary for the Pima County Department of Environmental Quality was submitted as part of the Class II Air Quality Permit process. The report covers how the variety of minerals at the site will be processed, the major operations, and the potential to emit pollutants.

Ambient Air and Meteorological Info TITLE: Summary of Ambient Air Quality and Meteorological Data Collected from Startup through March 2009 Volumes 1-4 RELEASE DATE: April 2009 PREPARED BY: Applied Environmental Consultants Brief Summary: The Rosemont project monitoring program summary provides background and baseline air quality and meteorological conditions in support of an application for an air quality permit for the planned operations. The information in this document summarizes the monitoring program and data collected from February 2007 through March 2009.

Miscellaneous TITLE: Rosemont Copper Company Application for Class II Permit Letter RELEASE DATE: September 2010 TITLE: Air Quality Permit Processing in Pima County, Arizona White Paper RELEASE DATE: September 2010

Permits TITLE: Air Quality Activity Permit: Fugitive Dust 6488 RELEASE DATE: August 2010 TITLE: Air Quality Activity Permit: Fugitive Dust 6489 RELEASE DATE: August 2010 TITLE: Air Quality Permit Application received July 20, 2010 (Permit #6112) Letter RELEASE DATE:: September 2010 TITLE: Air Quality Permit Application, Permit No. 6112 RELEASE DATE: October 2010 TITLE: Response to Incomplete Permit Application received October 12, 2010 (Permit #6112) Letter RELEASE DATE: November 2010

TITLE: Emission Inventory Information Years 1, 5, 10, 15, and 20 Rosemont Copper Project Southeastern Arizona RELEASE DATE: July 2010 PREPARED BY: Applied Environmental Consultants Brief Summary: This report summarizes the Rosemont project’s potential to emit the following regulated air pollutants throughout the life of the mine: a) particulate matter, b) particulate matter less than 10 microns in aerodynamic diameter, c) particulate matter less than 2.5 microns in aerodynamic diameter, d) carbon monoxide, e) nitrous oxides, f) sulfur dioxide, g) volatile organic compounds, h) sulfuric acid, i) carbon dioxide, and j) hazardous air pollutants. rosemont copper

- a bridge to a sustainable future

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