Aquifer Protection Studies Summary

Aquifer Protection

Aquifer Protection Agency Correspondence TITLE: Initial Hydrology for Rosemont Copper Operations RELEASE DATE: October 2009 PREPARED BY: Arizona Department of Environmental Quality TITLE: Rosemont Copper Co NADS 1 090408 RELEASE DATE: April 2009 PREPARED BY: Arizona Department of Environmental Quality TITLE: Rosemont Copper Co RAIS 041410 RELEASE DATE: April 2010 PREPARED BY: Arizona Department of Environmental Quality TITLE: Incomplete Response to Substantive Deficiencies RELEASE DATE: December 2010 PREPARED BY: Arizona Department of Environmental Quality

Aquifer Protection Permit Application TITLE: Rosemont Copper APP Appl. Volumes. 1-4c RELEASE DATE: February 2009 PREPARED BY: Tetra Tech for submission to ADEQ

Rosemont Response

Aquifer protection studies looked at the flow of water at the Rosemont project site to determine potential long-term impact on the quality and quantity of water in the area.

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TITLE: Response to Notice of Administrative Deficiencies Letter (Transmittal of documents requested in letter April 4, 2009) RELEASE DATE: May 2009 PREPARED BY: Rosemont Copper TITLE: Incomplete Response to Substantive Deficiencies, Inventory Number 106100 RELEASE DATE: January 2010 PREPARED BY: Rosemont Copper

Technical Response Part 1 TITLE: Comprehensive Request for Additional Information (Response to ADEQ) RELEASE DATE: July 2010 PROVIDED BY: Kimberlite Water Quality Permitting and Compliance Services Brief Summary: This July 2010 letter from Kimberlite Water Quality Permitting and Compliance Services (Rosemont’s engineering consultants) responds to an ADEQ letter from April 2010 that made specific requests for additional technical information about the Rosemont operations. The April 2010 ADEQ letter was part of the technical review of Rosemont’s application for an Aquifer Protection Permit, submitted in March 2009.

Tech covers four samples of tailings material that were generated and tested for acid-generation capacity and release of metals. Tests conclude that water outflow will be no more acidic than present groundwater and concentrations of most specific metals were below detection in all of the samples. Overall, the geochemistry studies found little to no probability of pollution of the area aquifers.

TITLE: POC Well Diagram RPI-WS RELEASE DATE: July 2010 TITLE: Revisions to Figure 23 of APP Application RELEASE DATE: July 2010 PREPARED BY: Tetra Tech

TITLE: Site Water Management Update, Volumes 1 - 5 RELEASE DATE: April 2010 PREPARED BY: Tetra Tech

TITLE: Rosemont Well Inventory Update RELEASE DATE: January 2010 PREPARED BY: Tetra Tech

TITLE: Infiltration, Seepage, Fate and Transport Modeling Report RELEASE DATE: February 2010 PREPARED BY: Tetra Tech Brief Summary: The projected amounts and quality of water entering (infiltration) and leaving (seepage) three of Rosemont’s facilities have been thoroughly scrutinized. This report from Tetra Tech presents the results of infiltration and seepage, and fate (altered chemistry) and transport modeling for the proposed Waste Rock Storage Area, the Heap Leach Facility, and the Dry Stack Tailings Facility. Detailed laboratory studies and predictive modeling (including waste rock, heap leach residuals, and dry stack tailings residuals) for the three Rosemont facilities show that they will have little or no impact on the quality or quantity of water within the regional groundwater system. Another site-wide particle tracking model (fate and transport analysis) has been completed by Tetra Tech to confirm that these three facilities will not impact the regional system.

TITLE: Water Level Hydrographs 2007-2010 RELEASE DATE: July 2010 PREPARED BY: Montgomery & Associates

TITLE: Tailings Geochemistry RELEASE DATE: March 2009 PREPARED BY: Tetra Tech Brief Summary: Rosemont’s geochemistry studies evaluated the potential impact to the regional aquifer from water emerging from the project site, especially from the Waste Rock Storage Area, Heap Leach Facility and Dry Stack Tailings Facility. This report from Tetra

TITLE: Geochemical Sample Composite Method RELEASE DATE: November 2009 PREPARED BY: Tetra Tech

TITLE: Groundwater Level Contours and Depth to Water 2010 RELEASE DATE: July 2010 PREPARED BY: Montgomery & Associates TITLE: Summary of Groundwater Level Measurements for Wells, Piezometers and Drill Holes RELEASE DATE: July 2010 PREPARED BY: Montgomery & Associates TITLE: Site Surface Soils Geochemistry RELEASE DATE: January 2010 PREPARED BY: Tetra Tech TITLE: Surface Water Sample Sites, Cienega Creek and Davidson Canyon RELEASE DATE: July 2010 PREPARED BY: Montgomery & Associates

Technical Response Part 2 TITLE: Attachment 1: Groundwater Flow Modeling

Conducted for Simulation of Proposed Rosemont Pit Dewatering and Post-Closure Revised Report RELEASE DATE: August 2010 PREPARED BY: Montgomery & Associates TITLE: Attachment 2: Rosemont Groundwater Flow Model Summary RELEASE DATE: August 2010 PREPARED BY: Montgomery & Associates TITLE: Attachment 3: SRK Consulting Technical Review of Montgomery’s 2009 Groundwater Flow Model RELEASE DATE: August 2010 PREPARED BY: SRK Consulting TITLE: Attachment 4: Rosemont Geochemical Pit Lake Predictive Model Summary RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 5: Rosemont Area-Wide Fate and Transport and DIA Summary RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 6: Rosemont Infiltration, Seepage, Fate and Transport Modeling Report Update RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 7: Technical Review of Tetra Tech’s Feb. 2010 Infiltration, Seepage, and Fate and Transport Modeling Report RELEASE DATE: April 2010 PREPARED BY: SRK Consulting TITLE: Attachment 8: Physical and Mechanical Properties of Tailing and Waste Rockfill Materials RELEASE DATE: August 2010 PREPARED BY: AMEC TITLE: Attachment 9: Rosemont Tailing Geochemistry Sample Sources RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 10: Rosemont Heap Leach Design Responses RELEASE DATE: August 2010 PREPARED BY: Tetra Tech rosemont copper

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TITLE: Attachment 11: Rosemont Flow-Through Drain Design Summary RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 12: PWTS Pond and Settling Basin Design Revisions RELEASE DATE: August 2010 PREPARED BY: M3 Engineering & Technology TITLE: Attachment 13: Rosemont BADCT Analysis for the PWTS Pond RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 14: Rosemont Settling Basin BADCT Analysis RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 15: Rosemont Waste Rock Segregation Plan RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 16: Rosemont APP-Regulated Facility Locations RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 17: Rosemont APP-Regulated Facility Depth to Groundwater RELEASE DATE: August 2010 PREPARED BY: Tetra Tech TITLE: Attachment 18: Non-Municipal Solid Waste Landfill Application Revised RELEASE DATE: August 2010 PREPARED BY: Civil and Environmental Consultants, Inc. TITLE: Comprehensive Request for Additional Information RELEASE DATE: August 2010 PREPARED BY: Kimberlite Water Quality Permitting and Compliance Service Brief Summary: This report from Kimberlite provides responses and supporting information to the remaining comments from the ADEQ April 2010 letter that contained 52 specific requests for additional technical information about the Rosemont project. The August 2010 letter includes the following supplemental 12

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information: • Tetra Tech Groundwater Flow Model summary, dated August 31, 2010.

• Tetra Tech Geochemical Pit Lake Predictive Model Summary, dated August 24, 2010.

• Tetra Tech Area-Wide Fate and Transport and DIA Summary, dated August 31, 2010.

• Civil and Environmental Consultants, Inc. (CEC) NonMunicipal Solid Waste Landfill Application, dated August 2010.