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<br /> <br />London Mountain Clean Up <br />July 2025 <br /> <br /> <br />T-2 <br />The operation maintains strict control over potentially acid-forming materials through a comprehensive <br />isolation and removal protocol. No potentially acid-forming waste material is allowed to remain at a site <br />permanently once the isolated pile containing the material has been disturbed. When a waste pile is <br />within sediment control for an area but remains separate from other piles by at least ten feet, that pile <br />will be considered isolated for operational purposes. Once the isolated pile is disturbed for excavation, <br />all of the disturbed potentially acid-forming waste material must be removed from the site and <br />transported for offsite processing and disposal. Non-potentially acid-forming material from an isolated <br />pile may be replaced onsite or hauled offsite depending on reclamation requirements and material <br />suitability. <br />Vegetation and topsoil management procedures recognize the importance of preserving and enhancing <br />the natural growth medium for successful site restoration. Trees present in work areas will be mulched <br />to provide organic matter for soil improvement and erosion control. Topsoil will be stripped to its full <br />depth and carefully salvaged for use in reclamation activities. This salvaged topsoil will be stored either <br />in separate areas near the waste pile being mined or at designated stockpile locations as shown on the <br />referenced project maps. When topsoil is found to underlie potentially acid-forming material, that soil <br />will be hauled to the processing facility for treatment or transported offsite for disposal at a licensed <br />facility to prevent contamination of clean reclamation materials. Any loose native material adjacent to <br />waste piles that has been disturbed during operations will likewise be hauled to the processing facility <br />to ensure no contaminated material remains on site. <br />Stormwater and sediment control measures form a critical component of the environmental protection <br />plan, ensuring that runoff from work areas does not carry sediment or potentially contaminated <br />materials to downstream areas. Prior to any material excavation, comprehensive sediment control will <br />be established around the perimeter of each pile to contain any disturbed materials within the work <br />area. Uphill of each pile, runoff diversion structures will be installed with sufficient capacity to divert the <br />ten-year, twenty-four-hour storm event around the waste pile, preventing clean runoff from becoming <br />contaminated through contact with disturbed materials. These diversion structures may consist of <br />ditches, berms, or combination systems depending on site topography and drainage patterns. <br />Sediment control structures including wattles or similar containment systems will be placed around the <br />downhill perimeter of waste pile areas to capture any sediment that might be mobilized during <br />operations. Up to two entry and exit points may be established within the sediment control perimeter to <br />facilitate equipment access, with each access point maintaining sediment containment through the <br />installation of runoff control ditches or berms at least two feet in total depth that divert runoff away from <br />the entry and exit areas. A comprehensive stormwater management plan will be maintained for all <br />waste pile excavations, with Colorado Department of Public Health and Environment stormwater <br />discharge permits secured for each applicable pile or set of piles as required by state <br />regulations. Further detailed water information can be found in Exhibit G. <br />NA. These rules are addressed in the following sections.