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Dan Mathews Page 3 April 17, 2006 of casing, diameter of casing, total depth of well, and perforated interval, and formation completed in. 4. On page 5 of the AHR it is stated that the effect that the mine has on the groundwater hydrology of East Salt Creek has not been detected. Yet data from GW-3 as indicated by Table 5 of the AHR shows neazly a threefold increase in conductivity from the baseline year average to the 2005 year average. There also appeazs to be a significant drop in the water level measured at this well. It is further indicated on page 5 that GW-3 is located outside of the influence of the irrigation of the hay field that affected Well GW-4. Given this information, there does appear to be some effect on the East Salt Creek Alluvium. Further explanation and discussion is warranted in this case under Probable Hydrologic Consequences section of the AHR. 5. There appeazs to be a discrepancy with reference to the baseline data for GW-3 on Table 5 of the AHR (AW-6 = GW-3). Comparison of Figure 4.1-2 with Figure 4.2-2 of the McClane permit and cross-referencing this to Table 2.5-1 of the Munger permit appears to show that MW-2 = GW-3. It is uncleaz if MW-2 equates to AW-6. Please check the reference to baseline data for GW-3 on Table 5 of the AHR, and update Table 5 if appropriate. 6. The McClane permit document indicates that since the proposed mine is located above the alluvial fills no direct disturbance of the alluvial aquifer will result from the actual mining operation. The AHR indicates that the effect that the mine has on the groundwater hydrology has not been detected. However, mine water is dischazged to McClane Creek at outfall 002, which then discharges to East Salt Creek. Because McClane Creek is ephemeral and East Salt Creek is either intermittent or ephemeral, at least the potential exists that the mine discharge could be tributary and at some point impact the East Salt Creek alluvium. This combined with the fact that there has been some question in the past about possible irrigation return flows affecting the quality of data from wells located in the vicinity of the mouth of Munger Canyon, may indicate that an additional monitoring well would be useful. One additional well may be warranted in the East Salt Creek alluvium just below McClane Canyon outside of the influence of the irrigated hay field. This well located below the McClane Canyon mine discharge will aid in identifying the effect if any the mine has on the groundwater hydrology of the East Salt Creek alluvium. 7. In January 2006, the Division received Technical Revision No. 20 for the Munger Canyon Mine, in which the operator is requesting approval to seal several of the alluvial wells that are not currently being monitored. Specifically the application requests sealing wells GW-2, GW-4, GW-7, and GW-S. The Division has reviewed the proposal in conjunction with this AHR review and concurs with the sealing of these wells with exception of GW- 7. If access or right-of--entry is not an issue for GW-7 then the Division recommends that