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Ms. Christine E. Johnston 1992 AHR Response August 25, 1994 Page 3 4. Data from field parameters indicated that some values were outside the minimum and maximum range. Samples sent to the laboratory require 20 to 30 days to receive results and if a second sample were taken a[ that point in time, it would not correlate [o the prescribed sampling window or other samples previously obtained. As a result, MCC has applied for a revision to the plan to eliminate this second sampling reyuirement. MCC does not have an explanation as to why the minimum and maximum values were exceeded. 5. The total depth of well GP-3 is listed in Exhibit 12 as 32 feet. A static depth of 29.4 feet is within the depth of [he well. We are not sure where your reference l0 22 feet comes from. 6. Historically, well GP-5 has been dry. MCC's monitoring consultant believes that the water level indicator was lodged in [he casing [o give an incorcect measurement. 7. New mine inFlows are measured by using a portably weir, bucket and stop watch, or visual estimate for dispersed flows. All new inFlows are measured as they appear and are the flows indicated on Exhibit 3 of the AHR. Discharge Flows are also monitored as a pumping rate at the portals. This data is the source of the volume measurements used in the water balance calculation. 8. The sites referenced in this comment on Exhibit I resulted from having the old map scanned for utilization as [he base map. These sites are pas[ monitoring and/or drill holy locations which are no longer monitored. These sites have been removed from [he Exhibit 1 Map in the 1993 AHR. 9. It appears that the correct scale on the conductivity measurements from samples acquired from well SOM 128H has not been recorded. MCC has notified their monitoring consultant to be aware of this deficiency at this site. MCC does not know why the TDS currently is between 8000 to 9000 mg/L at SOM 128-H, and can only speculate about the cause. Sedimentary formations are heterogeneous, due [o their environmem of deposition. Field parameters acquired during [he 1991 water year from well UG-90-I indicate [ha[ the Rollins has an average specific conductivity of 4550 umhos/em al that location. The information in Section 2.05.6(3)(b)(iii) on page 2.05-109 describes the specific Rollins Sandstone results from one well, R-I, and general information about Mesa Verde water bearing zones from multiple wells. MCC will sample SOM 128-H upon approval of TR-71. Well SOM 126-H was set to monitor water levels in the Rollins Sandstone. After an initial rise in water levels of over 150 feet during a period of two years, the water level appears to have plateaued. This data is interpreted as the gradual (due to the low transntissivity of the Rollins Sandstone) inflow of groundwater into the well bore. Thy water surface is ezpectecl to slowly rise until the confined potentiometric surface (height) is reached. 10. Monitoring of wells A-I, A-2, and A-3 was discontinued in conjunction with TR 54. The sites are temporarily capped and monitoring will commence again a year prior to undermining. I1. MCC agrees with [he Division that TSS is an indicator of surface water yuality and not groundwater quality. The attached TR contains a request to eliminate TSS from the groundwater quality monitoring program.