2024-03-28_REVISION - M2015030 (2)

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Chavers Mining Resource DRMS Permit No.M-2015-030 Amendment No.2(AM-02) March 2024 Page 7 reasonably possible about the backfill materials received at the Site to ensure that those materials are free of contaminants. All backfill materials will be inspected upon entry to the Site and while being unloaded using visual and/or olfactory methods to ensure no potentially contaminated materials are received. If evidence of possible contamination is observed, loads will be rejected and material will not be allowed to be left on-site by the contractor. No contaminated materials will be accepted or allowed on-site. Any asphalt or concrete materials received will continue to be diverted to the recycled aggregate materials operation at the Site. • Backfilling Process: The reclamation plan for the Chavers Mining Resource is to backfill the Site at least to the minimum requirement of one(1) foot above the historic high measured water table elevation, but not to exceed pre-mining elevations. After an area of the property has been mined of sand and gravel,backfilling operations will begin once they can be safely conducted. ASCI will conduct backfill operations concurrent with mining operations whenever possible. The exposed pit area will constantly shift as concurrent mining and backfill operations occur, but ASCI will not exceed an exposed active mining and backfill pit area of approximately 26 acres at any one-time. The time to complete backfill will vary upon market conditions but is anticipated to be completed within approximately three(3) years after mining is complete. Groundwater will continuously be pumped until backfill above static water level is complete. Backfill material will be imported to the Site with articulated dump trucks and/or highway dump trucks. Backfill material will be temporarily stored at backfill staging areas around the excavation(e.g., typically no longer than one to two weeks) or processed as part of the recycling operation on-site prior to being placed in the pit. Backfill material will be pushed into the excavation and/or placed and spread in one(1) to two (2)-foot lifts using haul trucks, bulldozers, excavators, and/or loaders. Compaction will take place during the filling process, as haul trucks and heavy equipment traverse over the fill material. Temporary excavation slopes and temporary stockpiled material slopes may range from 1:1 to 3:1 depending on soil conditions in the mine. All slopes will be maintained for site safety and to minimize material erosion. Backfill will be complete when the entire Site is within approximately 1 - 2 feet of final grade as indicated by ASCI survey (rough grade). • Grading and Topsoil: Once the backfill is near rough grade across the Site, the surface contours of the affected area will be graded to approximately twelve(12) inches below the final grade across the Site. After contour grading is complete, a minimum topsoil cover twelve (12) inches thick will be placed on top of the backfill to reach topographic elevations at least one (1) foot above the historic groundwater high,but not to exceed pre- mining elevations (i.e., final grade). The final grade will control water runoff, erosion, and siltation to protect all areas outside the mine and allow surface drainage to flow gently as sheet flow to the northeast, consistent with pre-development drainage.