M1977342_AM8_AM-08 Henderson Rec Permit M-1977-342_72046

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Henderson does not have any immediate plans to install additional water quality monitoring wells and/or infrastructure in this area. However, Henderson feels it is sensible to propose an increase to the affected land boundary in this area as well to allow for potential future water quality management program improvements. Like the proposed area below 1-Dam, the proposed reconfiguration of the affected land boundary shifts the boundary eastward, along the property boundary. The net increase to the affected land area will be 141.5 acres (see maps in Exhibit Q. Hydrology and Water Quality The activities proposed in this Amendment, including the construction of roads to install and access additional water quality monitoring wells will not impact the hydrologic balance of the affected land or the surrounding area, nor affect the quality or quantity of water in surface and groundwater systems. The nature of the work and disturbances to the surface for which the amendment is requested (adding roads by using best management and stormwater management practices and adding monitoring wells) do not implicate off-site water quality or quantity impacts or affect the need or end date for water quality treatment. The TOTAL net increase to the affected land area for this Amendment, including areas beneath both 1-Dam and 3-Dam, will be 224 acres. 2.2 Henderson Operations Acreages Henderson's current and permitted and proposed affected land boundary acreages are summarized in Table 2-1. Table 2-1 Proposed Operations Acreages Area Current Permitted Acreage Proposed Acreage Under AM-08 Property Boundary 11,877.5 11,877.5 Private Lands 11,841.8 11,841.8 Federal Lands 35.7 35.7 Affected Land 4,360.2 4,584.2 increase of 224 acres Of the total affected land, 364.2 acres are currently located at the Mine site which is not being altered by this Amendment. 3. RECLAMATION PLAN FOR ADDITION OF AFFECTED LAND The increase in affected lands does not alter the existing reclamation plan for the Mine and Mill. Disturbances will be limited to new monitoring well access roads which would remain in place after reclamation to allow for continued groundwater quality monitoring and would not require an increase to the reclamation cost estimate. Disturbances within the new affected lands boundary area would be reclaimed in the same fashion as the immediately adjacent lands,which have a post- mining land use designation of"Rangeland" as summarized in the original Permit, AM-01, AM- 03, AM-04, and AM-06. Henderson Operations AM-08 to Rec Permit M-1977-342 Climax Molybdenum April 2023 A Freeport-McMoRan Company Page 2