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i i assumed, a flow of 25 GPM is calculated. A thousand square feet would therefore contribute 250 GPM. The actual cross-sectional area which is presently contibuting water to the AVF is not known. The present quality of all water in this drainage is greatly influenced by the marine shales in both the Mancos and the Dakota formations. Total dissolved solids (TDS) range from 4000 to 6000 mg/1, sulfate being the dominant ion. After reviewing the coal and wall rock chemical analyses, an independent geochemist concluded that seepage produced from the impoundment would not contain any toxic constituents. Additionally, the natural buffering capacity of the native materials would most likely eliminate any acid-forming potential that may exist. It was also concluded that the resultant TDS would not be significantly different than the local Mancos groundwater, particularly since the bulk of the water to be stored and used within the system will be of a quality considerably better than that of the Mancos. Considering the present water quality and it's apparent insignificant impact on the down gradient AVF, impact from impoundment seepage should not be a factor in the hydrologic balance and function of the AVF. Reduction in surface and groundwater flow by the seepage collection pond could actually result in better quality water within the AVF. Because the hydrologic relationship between the AVF and adjacent bedrock is only partially understood, Storm King will commit to maintaining the existing downgradient monitoring wells and adding one well east of OW-11 within or adjacent to the actual channel which drains the impoundment area. This new well will be drilled at least one year prior to construction of the impoundment to allow for establishment of an adequate baseline. Also, Storm King will install additional wells in this area should water quality and/or quantity detected by these wells vary significantly from what is expected. These wells will be located and monitored so as to clarify the extent of any change. Additionally, several geotechnical wells were drilled within this drainage and were used to construct the potentiometric surface map in Figure 3.3-17. If an unusual situation should occur, these wells can be activated to further define the extent of any change. MLR Comment: "4) The applicant must provide a description of the methods that will be used to restore the essential hydrologic functions of the AVF at the slot storage area. Since it appears that the essential hydrologic functions off this portion of the AVF are those which make the area flood irrigable, the applicant must submit a plan for restoration of the soil profile and ditch system in this area."