2013-10-28_REPORT - C1981012 - Laserfiche WebLink

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October 2012 Page 1 -1 1.0 INTRODUCTION New Elk Coal Company (NECC) owns and operates the New Elk underground coal mine and preparation plant in southern Colorado. This report presents the hydrologic monitoring activities conducted at the mine during 2012 and analysis of trends over a twenty -nine year monitoring period (1984 to 2012). The remainder of this section describes the mine site area and the current hydrologic monitoring program. Section 2.0 describes the monitoring methods used for this program while Section 3.0 provides the monitoring data for the year. Section 4.0 discusses mitigative measures taken to minimize disturbance to area hydrologic functions and Section 5.0 describes plans for future hydrologic monitoring activities. Data and information related to this assessment are presented as appendices to this report. Previous production from the New Elk Mine occurred intermittently from the Allen coal seam between 1952 and 1988. The mine was temporarily sealed in 1988 and allowed to flood. Monitoring data including the depth to water and water quality were collected for the mine pool between February 2001 and November 2008. These data are presented previous annual hydrologic reports. Active dewatering of the mine resumed from the East Portal Air Shaft in December 2008 to facilitate entry and rehabilitation of the mine. 1.1 Site Description The New Elk East Portal area is located three miles east of Stonewall and seven miles west of Weston in T33S, R68W in Las Animas County, Colorado. The mine is situated in mountainous terrain with numerous canyons contributing runoff to the drainages of ephemeral, intermittent, and perennial streams of the area (see Map 8, Regional Hydrology, in the permit document). The New Elk Mine is located on the Middle Fork of the Purgatoire River, about 1.5 miles upstream of the confluence of the North Fork. Most surface facilities of the mine are adjacent, and underground mining occurred under and to the north and south of the Purgatoire River, in an area known as the Picketwire Valley. The mine was temporarily closed and sealed in 1989. Dewatering ceased and the lower areas of the mine were gradually flooded. NECC has resumed mining in the Allen and Blue Seams. Development of mains and panels will occur as shown on Map 3 Mine Plan. Mining in the Allen Seam began in January 2012. Mining in the Blue Seam began at the end of 2011 when the rock slopes from the Bates Portal were complete. Currently the mine is on "care and maintenance status ". The Purgatoire River is the primary stream drainage in the area of the mine. The headwaters of the Purgatoire are located on the eastern slope of the Sangre de Cristo Mountain Range west of the mine area. The general direction of stream flow is easterly to the confluence with the Arkansas River, also in Las Animas County. The principal tributary of the Purgatoire River which drains in the vicinity of the mine permit area is Apache Canyon. Apache Canyon drains a watershed of approximately 7,264 areas. Cover in the canyon is primarily woodland with an herbaceous valley bottom. Primary land use is grazing and wildlife habitat. Surface mine features within the Apache Canyon (on the left fork) include two ventilation shafts. Portions of Apache Canyon have been undermined (by room -and- pillar mining). Apache Canyon discharges into the Purgatoire River above the Golden Eagle Mine reclaimed area. Apache Canyon was determined not to meet alluvial valley floor criteria.