2021-06-14_REVISION - M2012032 (2)

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��_ b�, LAiRAr SILVER AIPVES located in front of the mill filter building. The apron is not shown on the for- construction drawings but will be included in the as-built drawings submitted to the Division once construction is complete. The concrete apron in front of the mill filter building is 78 feet long and 9-10 feet wide. The thickness of the reinforced concrete is 6 inches. A swale was formed in the concrete apron, which is 6" to 8" deep and leads to a sump on the east side of the building. The apron can contain roughly 1,300 gallons. A level-controlled pump of 300 gpm capacity has been installed in this sump to automatically pump liquids or slurry back to the thickener or the 18,000-gallon slurry tank. b. Process water will not require offsite disposal. There is a water deficit in the mill process and make-up water will need to be added to the milling circuit during operations. c. See response to comment 8.a above. The mine will construct an apron in front of the reagent room to unload trucks. The apron will be similar to the concrete apron currently outside of the mill filter building. Trucks carrying reagents will park on the apron to be unloaded. If a reagent container is damaged while it is being unloaded from the transport vehicle, the apron will contain the volume of material spilled. 9. Please provide information regarding where empty containers or those containing spilt chemicals that are to be returned to the manufacturer or disposed of as hazardous waste be stored while awaiting transport pursuant to Rule 6.4.21(6)(b)(i). Please note that a container is never truly empty and shall remain in secondary containment at all times. Response: DRMS is incorrect in its statement that a container is never empty and requires secondary containment at all times. The Resource Conservation and Recovery Act(RCRA) (40 CFR 261.7) and the Colorado Hazardous Waste Regulations (6 CCR 1007-3, Section 261.7) define a container as empty: "...if all material has been removed from the container that can be removed using the practices commonly used for that type of container (i.e.,pumping or pouring) and: a. There is no more than one inch of residue on the bottom of the container or inner liner; or b. For a container of 119 gallons or less, the remaining residue is not more than 3% by weight of the total capacity of the container; or c. For a container of more than 119 gallons, the remaining residue is not more than 0.3% by weight of the total capacity of the container. If the container held a non-acute hazardous waste, the residue in the empty container is not regulated as hazardous waste. " 71Pa � e