2012-04-13_REPORT - C1981038 (5)

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Steven's Gulch Colluvium Groundwater Monitoring Wells: Shallow groundwater monitoring wells, SM -1 and SM -9 (see Map No. 4 -1) are in the Steven's Gulch drainage. The wells are monitored for water quality parameters, water levels, and field parameters to detect impacts associated with mining in the central pod. Required monitoring for wells SM -1 and SM -9 was semi - annually during 2011 for water levels and field parameters when water is available. Well SM -1 is next to areas mined in 1991 and 1992 but has showed no apparent impacts the data collected since that time. Well SM -9 was undermined by Panel C during 1993 but has showed no apparent impacts in the data collected since that time. No anomalous water quality observations were apparent during 2011 at the Stevens Gulch shallow groundwater monitoring wells. Surface Water Monitoring Stations - SPRINGS East Roatcap Creek - Two springs were monitored in the East Roatcap Creek drainage (refer to Table 1 and Map No. 4 -1) during the year. Spring 30 had lowflow during the year. Spring 30 was first undermined in April 1983. Spring 10 -10 was dry during the reporting period. Spring 10 -10 was encompassed by the angle -of- draw of Panel Y during October 1993. Subsidence impacts were not apparent at either of these locations during 2011. West Roatcap Creek - Two springs were monitored in the West Roatcap Creek drainage (refer to Table 1 and Map No. 4 -1) during the year. Spring 32 was monitored ten times during the year. Spring 32 exhibited flows that were below average. Water quality parameters were consistent with last years sampling. Spring 14 -4 was monitored quarterly. Flows were considered normal. No mining occurred during the year in the Spring14- 4 watershed. Stevens Gulch - One spring was monitored within the Stevens Gulch drainage (refer to Table 1 and Map No. 4 -1) during the year. Spring 25 lies below an area of the East mine inactive since 1982. This site had no measurable flows during the year. Spring 25 has been identified as an adjudicated water right within the permit area. Two springs with ponds in the Stevens Gulch drainage, Spring and Pond 13 -5, Spring and Pond 13 -6 were monitored quarterly during the year. Spring and Pond 13 -5 was undermined during the last half of 1992. Spring and Pond 13 -6 was undermined during the end of 1988. Spring 13 -5 was reported to have a seep in April, a small flow in June and dry in September and December. Spring 13 -6 had measurable flow during April and was reported as a dry during June and a seep in September and December Surface Water Monitoring Stations: STREAMS AND DITCHES Overall, adverse impacts attributable to mining were not evident at any of the monitored surface water stations (refer to Table 1 and Map No. 4 -1). Stations SW -5 (Stevens Gulch) and SW -6 (East Roatcap Creek) exhibited flows and water quality parameters consistent with previous years data. No evidence of subsidence impacts in these drainages was apparent. Mining occurred in the Stevens Gulch drainage upstream of site SW -5 during 1993 in Panel C. Panel C mining was designed and conducted to prevent the development of subsidence to protect the waterway and certain structures in the vicinity. Data collected during the year shows these protective measures were successful. Surface Water Monitoring Stations: SMALL AREA EXEMPTIONS The west side of the east mine fan level is defined as a small area exemption since drainage from this area is not conveyed to a sediment pond. One sample point is defined at this location and sampled for conformance with the NPDES discharge alternative limitations requirements associated with discharges occurring because of precipitation events of less than the 10 -year and 24 -hour magnitude. In these instances, settable solids and pH limitation must be met. No samples were collected during 2011 from this SAE point. Coal Member of Mesaverde: All previously monitored drill holes have now collapsed and are no longer monitored. The removal of these monitoring points is explained in TR -34. 3