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overburden) and the coal ground water system by as much as 2389b (Wadge Coal). With respect to both the overburden and coal seam ground water systems, elevated levels of TDS and individual constituents will be localized. The impact of localized water quality degradation in the coal and overburden aquifers is minimal, given that the aquifers do not yield volumes sufficient for irrigation purposes, baseline ground water quality in these systems is marginal to unsuitable for stock watering and/or irrigation, and there are no wells completed in the overburden or coal units in the mine vicinity. Surface Water Effects The majority of runoff from disturbed areas within the original permit area during the mine life will be diverted to Sediment Ponds 005 and 006, prior to release off site. Effluent from Ponds 005 and 006 flows to unnamed ephemeral gulches, and ultimately Dry Creek. The majority of runoff from disturbed areas in the south extension area during mine lffe will,be diverted to the Sediment Pond 016/016A series or to Sediment Pond 017, prior to discharge. Effluent from the ponds will flow into Hubberson Gulch, and ultimately Dry Creek. Effects of mining on Hubberson Gulch and Dry Creek will involve changes in quantity and quality, which are further described below. A negligible acreage affected by the extreme eastern extension of the south area pits and the neck pits between the north and south mining azeas will drain to Sediment Ponds 009 and 015, and eventually to Sage Creek. Measurable effects on Sage Creek water quality or quantity are not projected, due to the small disturbance acreage and the fact that there will be no spoil water flow to the Sage Creek watershed. The mining and reclamation activities will result in changes to the geomorphic characteristics of ephemeral stream channels within the 005, 006, 016 and 017 drainage basins. Drainage densities and channel frequencies will be reduced, and channel gradients will be slightly increased in some areas; however, the operator has designed and located post-mining drainage channels to minimize erosion, with riprap specified where wazranted. During mining operations and until adequate vegetation is established, runoff and erosion rates within the disturbed area will be higher than pre-mining rates. Seneca Coal Company calculated runoff and erosion sediment yield rates from disturbed areas when designing all sediment ponds. (Tab 13). Sediment leaving the site will be controlled to meet effluent limits placed upon sediment pond discharges in Seneca Coal Company's Colorado Discharge Permit System permit. Baseline flows in Hubberson Gulch exhibit TSS levels from 5 mg/1 to 606 mg/I with an average of Seneca II-W Findings Document 43 November 17, 2004 Permit Revision No. 4