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Ron Thompson Page 2 January 16, 1998 ~~ shows no change when compared to PRS-2 quality. A slight increase in surface water quantity downstream of the mine would no[ be considered a negative impact unless a water right was injured. Two surface water stations are monitored on Ciruela Canyon. CCS-I is located over SW I longwall panel which was mined in the late 1980's. Some Flows were recorded prior to the late 1980's. Only one Flow event at this site has been recorded (1994) since that time. It is possible that during low flow periods. surface water Flow has been impacted due to subsidence, resulting in loss of surface water Flows to [he subsided alluvium and overburden. However, field inspection indicates no visual evidence of subsidence along the stream channel itself. Water monitoring continues under the current plan and should help determine whether subsidence impacts exist a[ this site or whether the lack of monitored flow events is more a function of the ephemeral nature of the stream. The downstream site on Ciruela Canyon (CCS-2) registered flows during February and March, caused mainly by runoff and mine dewatering [o Ciruela Canyon through the Pond 2 treatment facilities. After this time, mine water discharge ceased and no Flow events were recorded. Ground WaterOuantitx Drawdown estimates of bedrock water levels due to mining and subsidence were estimated in the permit to be one foot at up to 2. I miles (I 1,088 feet). Review of the average depth-to-water readings for coal and overburden wells to the north of the mined area indicate drawdowns may be substantially more than predicted (Table A). Declines in overburden well NM-20 of over 80 feet are noted, 130 feet in NM-21 completed in the coal, and 165 feet in overburden well NM-22. Table A Well Zone of Completion Distance from mined area Average depth to water 1994 Average depth to water 1995 Average depth to water 1996 NM-20 Overbrdn 6000 ft 275 ft 320 ft 357 ft NM-21 Coal 4000 ft 664 ft 796 ft N/A NM-22 Overbrdn 10,000 ft 268 ft 374 ft 436 ft Additionally, SF-2, completed in the overburden to the southeast of the mined area has shown over 350 feet of decline benveen 1994 and 1996. It would appear that mining has impacted that bedrock ground water levels beyond what was predicted in the probable hydrologic consequences section of the permit. Over 165 feet of drawdown has apparently occurred at 10,000 ft from the mined area. Alluvial water levels, as indicated in wells PAW-5 upstream of the mine and PAW-6 downstream of the mine continue to show normal variation due to seasonal inFluences and no impact to alluvial water levels can be identified at this time. Ground Water Quality