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west Elk Mme • B Seam longwall experience indicates that some inflows continue past "one to two weeks;' but these inflows generally drop to levels of less than 10 gpm, except as noted from the fault system inflows. 9. CDMG staff quantified the maximum mining impact on the North Fork and the probable mining impact on the North Fork for total dissolved solids (TDS), using conservative assumptions. The conclusions reached from this analysis were: "The worst case impact with regards to TDS in the North Fork during the irrigation season would be to raise the TDS level from 130 to 189 mg/L. This is understandable since the total discharge from all the mines, as used in the calculation, is only 7 percent of the flow of the North Fork." • "With the maximum, worst-case impact for TDS being only 189 mg/L, there is no need to calculate the more realistic impact." (p. 16} WWE has reviewed the cited TDS computations. The methodology is reasonable and provides a conservative projection of what could occur in the area. This analysis can be translated to the South of Divide permit revision azea. As discussed in Surface Water Quality Effects, W WE has revisited the TDS loading analysis conducted by CDMG and found that, even under the extreme conditions of 1996 and early 1997, when MCC was forced to dischage lazge quantities of mine water without adequate treatment (in response to lazge inflows from the BEM and 14HG fault inflows), TDS levels in the North Fork were well below those considered to be a concern. 10. "Mine inflows are not normally significant when ephemeral or intermittent streams are undermined. Mine inflows are seldomly, if ever, correlated to the undermining of ephemeral or intermittent streams. Most of the streams to be undermined in the SOD permit area are ephemeral and intermittent. Flow in these streams is concentrated in periods of snowmelt and high intensity precipitation events. The stream gradients are steep and their channels contain little alluvium." (p. 20). In both the current pemtit and South of Divide mining area, many of the streams aze ephemeral, except a portion of the Deep Creek channel in Section 35 and the previously described transbasin diversion of Dry Fork. Their steepness is characterized in Exhibit 55 and SSA, which contrasts pre- and post-mining sediment transport. As described in the section Groundwater Quantity Effects, neither the BEM Fault nor the 14HG Fault inflows aze directly linked to surface inflows. The experience of other mines in the area is useful in assessing possible ground water conditions in the B and E-Seam. The Bear Mine No. 3 C-Seam workings are particularly relevant (see Map 5). During previous inspections of this mine, no noticeable flowing aeeas within the mine were observed. Mine operators reported inflows of less than 20 gpm in 1995 to the Bear No. 3 B-Seam workings (see section entitled Groundwater Quantity Effects). Similar to the Mountain Coal Company F-Seam experience, occasional roof drippers have been observed. Seasonal inflows in the portal areas have been observed, similaz to Mountain Coal Company's experience in the F-Seam. Water has been observed in a pressurized state discharging from fractures just below landslide debris in the portal of the Bear mine in 1986 during a period of high rainfall in the spring season. 205-183 Revived Juue 2005 PRl0, January 2006, March 2006; Rev. May 2006PR10