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1 <br /> <br /> <br />1 <br /> <br /> <br />6.2 Groundwater Information <br />The data collected from Oxbow Mining, Inc.'s (OMI) groundwater monitoring stations, along <br />with the results of laboratory analyses are presented in Section 4. Minimum and maximum <br />measurements for the baseline year(s) of each resource maybe referenced in OMI's 1998 Annual <br />Hydrology Report. <br />The sealing of all of the abandoned Somerset Mine portals has precluded access into the mine to <br />obtain underground mine water samples from those abandoned workings. As such, monitoring <br />wells H-10 and B-6 have been used to monitor groundwater inflow and quality in order to predict <br />the extent of flooding in the abandoned underground workings since the mine was closed in <br />1985. <br />' From 1987 to 1989, the water level in H-10, a well in Hubbard Creek Canyon, held steady at <br />about elevation 6028 feet, and then in 1992 rose to approximately 6068 feet in elevation. Since <br />then and until 1999, the water level ranged from 6067 feet to 6069 feet in elevation. Monitoring <br />' well H-l0 was monitored in April and October 2000. However, after several attempts in October <br />1999, Apri12000 and October 2000 to measure a water level in well H-10, no water could be <br />measured <br />In monitoring well B-6, located in Bear Creek Canyon, the historical fluctuation of water levels <br />has been different than in well H-10. After initially rising to elevation 6035 feet, the water level <br />fell to elevation 6014 feet in 1990. Water levels then recovered, with a slight dip at elevation <br />6033 feet in 1992, rising to elevation 6051 feet in 1993. The water level ranged from 6038 feet <br />to 6048 feet in 1994 and 1995, and then rose to elevation 6054 feet in 1997. In 1998 the water <br />level ranged between 6052 and 6053 feet in elevation. Monitoring well B-6 was monitored in <br />April and October 2000. Similarly to monitoring well H-10, several attempts in October 1999, <br />Apri12000 and October 2000 to measure a water level in monitoring well B-6, no water could be <br />measured. <br />The lack of water in these wells maybe due to a blockage or another problem in the wells, but <br />could indicate that the water level in the abandoned Somerset Mine has decreased for some <br />unknown reason, as these two wells aze in two different drainages and aze both dry. This <br />decrease is coincident with the time of the mine fire event and pumping from the North Fork into <br />the Sanbom Creek Mine. Flows also ceased just a few months eazlier from Spring 8 (believed to <br />have been from the old Oliver Mine D-seam workings). However, unlike the Oliver Mine, there <br />is no portion of the abandoned B- and C-seam workings of the Somerset Mine that overlies the <br />Sanborn Creek Mine, and there is more than 200 horizontal feet of unmined B-seam coal <br />between the two mines. OMI has continued to monitor both wells in the yeaz 2000 and no water <br />has yet been measured in either well. <br />Monitoring wells SC-1, SC-2 and TC-1 were completed in the Rollins Sandstone, which is 40 to <br />50 feet below the B-Seam. Monitoring data were collected from wells SC-1 and SC-2 prior to <br />any substantial mining in the B-Seam of the Sanborn Creek Mine. Monitoring of TC-1 was <br />begun in June 1997. The water contained in monitoring well TC-1 well appears to be <br />168 <br />