2018-08-08_PERMIT FILE - C1982056A (10)

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EXHIBIT 14 HYDROLOGIC MONITORING PLAN-FOIDEL CREEK LIFE OF MINE PERMIT Twentymile Coal, LLC (TC) will conduct a comprehensive program of hydrologic monitoring throughout the period of active underground mining operations. This monitoring program is designed to detect changes in the hydrologic balance and to define the effects of mining and subsidence on bedrock, alluvial and stream hydrologic systems. Monitoring data collected from the Foidel Creek Mine and adjacent areas will be recorded and filed at the company offices. This data will be reported to the Colorado Division of Reclamation, Mining, and Safety (CDRMS) in the form of an annual report, as required. Reporting of effluent water quality will be made in the Discharge Monitoring Reports and will be submitted to the Colorado Department of Public Health and Environment - Water Quality Control Division and to the CDRMS in accordance with applicable requirements under the Mine's CDPS Permits. Tile Annual Hydrologic Monitoring Report will be submitted to the CDRMS by February 28 of each year. It will interpret the previous water year's data and long-term trends for the potentially affected area(s). The plan for hydrologic monitoring encompasses nine basic components: 1. Bedrock ground water monitoring 2. Alluvial ground water monitoring 3. Surface water monitoring 4. Effluent monitoring(NPDES sites) 5. Spring monitoring 6. Mine discharge monitoring 7. Mine inflow monitoring 8. Mine discharge impact monitoring Designated monitoring sites are listed in Table 1, Hydrologic Monitoring Sites and their locations are shown on Map 13A, Hydrologic Monitoring Plan. Monitoring frequency is also summarized in Table A. The parameter lists for water samples are shown in Table B, Hydrologic Monitoring Parameter List. Measurements of field parameters (temperature, specific conductance and pH) will be taken using standard instrumentation, which will be periodically calibrated to assure accuracy. Water quality samples will be preserved according to accepted procedures, and samples will be delivered to the laboratory within the accepted holding times. All water samples will be analyzed by a qualified laboratory using standard EPA measurement methods and ASTM test procedures. Bedrock and Alluvial Ground Water Monitoring Ground water monitoring will be conducted to detect the effects of mining on ground water quality and quantity. Ground water will be monitored in the Foidel Creek Mine Permit Area with the bedrock and alluvial wells listed in Table A, Hydrologic Monitoring Sites. The locations of the wells are depicted on Map 13A, Hydrologic Monitoring Plan. Monitoring at the designated"Points of Compliance"(Twentymile Sandstone—97013TM; Wadge Overburden—008-77-58; Fish Creek Alluvium — 008-AU3; Trout Creek Alluvium—008-AT-1; Foidel Creek Alluvium—008-AV-2) will be used to assess compliance with the applicable groundwater quality standard for TDS of 1.25 x background levels, as defined by CDPHE-WQCC Regulation 41, Basic Standards for Groundwater under the category "Potentially Usable Quality". Bedrock and alluvial ground water monitoring will consist of water level measurements, field water quality readings, and periodic collection of water quality samples from the selected bedrock and alluvial monitoring wells. Bedrock aquifers to be monitored will be the Wadge Overburden, the Twentymile Sandstone and the Trout Creek Sandstone. Alluvial aquifers to be monitored are located along Fish, Foidel, Middle, and Trout Creeks. Additional data from well transects at the AVF areas of Foidel and Fish Creek have been previously submitted in the permit application for Colorado Yampa Coal Company's Mine 3, Permit C-84-062, and the information is presented in Exhibit 42b. Most of the bedrock wells are scheduled to be monitored on a semi-annual basis, with both water level/field readings and full suite analyses of water samples. For alluvial wells, except 008-AV-1, water level and field RN 17-07 Exh 14-1 02/15/18