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• Alluvium <br />A series of alluvial monitoring wells and piezometers were completed in the Fish Creek alluvium. The wells <br />and piezometers were monitored from the period of October, 1992 to June, 1994. The monitoring frequency for <br />water levels varied from weekly to monthly. Additionally, the wells were surveyed at the time of or as close to <br />the time of measurement as possible to determine if the well had subsided in relation to the mining activity. The <br />updated survey data was useful for determining if the water level in a particular well had fallen or it the entire <br />well Itad subsided and the water level remained fairly constant. The survey data indicates that the majority of <br />ttte alluvial wells subsided 0.1 or 0.2 feet, except for wells GWA6 and GWAP7, which subsided 1.2 and 2.2 feet <br />respectively. The water level data for each of the wells/piezeometers area presented on the tables in this exhibit <br />and shown graphically on the figures. <br />GWA-I is located a[ the west end of the rib separating panels 4 and 5. Development mining occurred in January <br />and September 1992 with the closest longwall mining in December, 1992. Water levels have been consistent <br />with the exception of a period approximately April through August, 1993 when water level peaked <br />approximately 3 feet higher than normal before returning [o its normal level. No significant changes in water <br />quality were noted. <br />GWA-2 is located at the west end of Panel 5 in the area of development mining. It was not directly undermined <br />by longwall mining conducted in the area in December, 1992. Water levels remained constant with the <br />exception of the summer of 1993 when an increase in water level occurred. No significant changes in water <br />quality were noted. <br />• GWA-6 is located at tfte west end of Panel 6. The area was undermined by longwall mining in September and <br />October, 1993. Tlie water level has been consistent with the exception of an increase during [he summer of <br />1993. The water level after undermining was slightly higher than that of the previous year. No significant <br />changes in water quality were noted. <br />GWA-9 is located at the west end of the rib separating Panel 6 from Panel 7. Development mining occurred in <br />July and August, 1993. Longwall [Wining was conducted in September and October, 1993 to the north of the <br />well in Panel 6. Water levels have remained relatively constant except for noted increases during 1993. <br />GWAP-7 is located within Panel 6 near the west end of the panel experienced a decrease in water level of <br />approximately I foot after undermining. All other piezometer levels have remained relatively constant except <br />for seasonal tluctua[ions. <br />Shallow Bedrock <br />Two monitoring wells, GWBI and GWB2 (GWB2 was replaced by GWB2R) were established in a shallow <br />sandstone unit which overlies the mine in [his particular location. During [he monitoring program well GWB2 <br />appears [o leave been destroyed by mining activities. The well was replaced on December 13, 1993 with well <br />GWB2R. Tliis well and its predecessor showed the greatest impacts as measured by water level. Well GWB2 <br />appeared to have been pinched of a shale/sandstone interface. <br />Well GWB2R since the date of installation has continued to recover. The depth to water as of December 20, <br />1995 was measured at 0.31 feet. The latest measurement continues to show the trend of recovery that has been <br />• developing since the installation of the well. The depth to water at the time of installation was measured a[ 35.8 <br />feet. <br />PR 93-03 Ex. 7j I/24/96 <br />