2018-08-07_REVISION - M1988108 - Laserfiche WebLink

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PERMIT#:M-1988-108 INSPECTOR'S INITIALS:MAC INSPECTION DATE:February 27,2018 The Mining Plan calls for trucking 50 to 70 tons of solid waste from the processing plant's lime flue gas scrubbing system to the pit.The solid waste is authorized to be disposed of in excavated chambers located adjacent to the pit.The waste disposal chambers are to be excavated into the shale and the solid wastes are to be capped with compacted shale fines at 4 to 5 foot vertical lifts. During the inspection,the Operator informed the Division the solid wastes from the processing plant were being end-dumped onto the mine slopes from the top of the pit.The practice of placing unconsolidated fines (solid waste) onto the pit slopes is not approved in the Mining Plan.The solid wastes which are end-dumped onto the mine slopes are dispersed across the entire length of the slope and enter into the standing water on the pit floor.The purpose of encapsulating the solid waste was to prevent leachate from potentially impacting groundwater quality. The approved Reclamation Plan calls for backfilling the mine slopes with overburden to establish the final slopes of 2.5H:1V and does not allow for slopes to be established by backfilling solid waste from the plant.The Division has concerns regarding the long-term stability of the mine slopes as well potential impacts to the hydrologic balance.The failure to follow the Mining and Reclamation Plans has been cited as a problem and will require corrective action from the Operator; additional details regarding the corrective action may be found on the first page of this report.The Operator will be required to submit a Technical Revision which addresses the following items: a) Provide an engineering analysis which demonstrates the slopes which have been backfilled with solid wastes are stable as required by Rule 3.1.5(3)and 3.1.5(9). b) Develop an appropriate geochemical evaluation of the solid waste which is being disposed of at the mine site.This type of evaluation is necessary to determine the intended fate of all disposed solid wastes.The geochemical evaluation shall identify the sample collection methods as well as the analytical detection methods which will be utilized. c) Demonstrate compliance with applicable federal and Colorado water quality laws and regulations as required by Rule 3.1.6.The Operator may demonstrate compliance by providing the results of any applicable water quality analysis which has been performed at the mine, including stormwater discharge sampling. If water quality data is not available to demonstrate impacts to the hydrologic balance have been minimized, then the Operator shall develop a comprehensive water quality sampling program which identifies sampling and analytical protocols to be used. Storage Area The 75 acre storage area lies immediately south of the processing plant and was added to the permit area through Amendment No. 2. The storage area was to contain a clay pad on which Realite Plus materials were to be stored.According to the current Operator,a clay pad was never constructed and the area was not used to store Realite Plus materials as intended. The Operator is utilizing the area to store coal, which is used in the processing plant, as well as lightweight aggregate product stockpiles.Approximately 7.4 acres of the 75 acre parcel are being used for stockpiles.Surface water runoff from the stockpile storage area was to be routed to a pond designed to contain a 100-year 24-hour storm event.The stormwater pond was not constructed and there is no containment of stormwater from the stockpile area. The footprint of a redi-mix plant is located immediately to the south of the stockpile storage area and accounts for approximately 3 acres of the 75 acre parcel.The redi-mix plant has been removed and all that remains is the concrete foundation.The redi-mix plant is not an approved component of the mining operation nd the financial warranty does not account for reclamation of this area. Page 3 of 9