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2) Collect one sample per 10,000 tons of identified material for lab testing <br /> a. Test samples for ABA and SPLP <br /> b. First sample should be taken at a depth of at least 2-ft within the pile. <br /> c. Multiple samples should separated by at least 2-ft of distance. <br /> d. Material that has an ABA > 20 will be considered Non-Potentially Acid Forming. Material <br /> that tests with an ABA < 20 will be considered Potentially Acid Forming. <br /> 3) Produce short report of material quantity and quality and keep for records and for regulators <br /> 1 .5.2. Excavation Procedures <br /> 1) Prior to any material excavation, sediment control will be established around the perimeter of <br /> the pile. <br /> 2) Uphill of the pile a runoff diversion structure will be installed. This structure may be a ditch or <br /> berm. Runoff diversion structures will be capable of diverting the 10-YR 24-HR event around the <br /> waste pile. Exhibit G contains a discussion of diversion structures. <br /> 3) Wattles or similar sediment control structures will be placed around the downhill perimeter of the <br /> waste pile area. <br /> 4) Up to two entry/exit points may exist within the sediment control perimeter. <br /> a. Entry/exits will maintain sediment containment by containing either a runoff control ditch <br /> or runoff control berm at least 2-ft in total depth that diverts runoff away from the <br /> entry/exit. <br /> 5) A general stormwater management plan will be maintained for all waste pile excavations. <br /> 6) A CDPHE stormwater discharge permit will be secured for each applicable pile or set of piles as <br /> needed. <br /> 7) Excavation of waste piles will typically be conducted from the top down, removing material in <br /> vertical slices to minimize the area of disturbed pile at any given time. See Map C-2 for an <br /> example. <br /> 1 .5.3. Material handling <br /> 1) All material is to be excavated from the pile area to at least 6-inches below the natural grade or <br /> bedrock depth, whichever is less. <br /> 2) No potentially acid-forming waste pile material may be stockpiled at the waste pile location once <br /> it has been excavated from its original source. All potentially acid-forming waste pile material <br /> must be hauled to the London Mine 110D operation for further processing. <br /> 3) All hauled waste material will be hauled via haul trucks. <br /> London Mountain Clean Up <br /> D-3 Lewicki& Associates <br /> April 2025 <br />