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layers follow a 5-degree north-northeast dipping plane consistent with that found in the B and F coal seams. The URP bench is evidently a contiguous extension of the lower stratigraphic members of the mountain plateau to the south. The upper layers of Mesaverde formation have long since broken off and eroded away, leaving the refuse azea bench juxtaposed as shown on Figure 1. The same is true with WEM surface facility bench, which is also a competent extension of the lower layers of the high plateau to the south. Refer to Foundation Investigation Report. Proposed Coal Prepazation Plant. Mount Gunnison Mine, Somerset. CO, prepared by International Engineering Company, Inc., 1976, for further information on the site geology, hydrology, and seismicity. 5.2 Hvdroloey Surface runoff is generally diverted eastwazd into Sylvester Gulch, or westward into the unnamed ravine. During several site investigations (Geo- Hydro, Inc., 1980, and Envirocon, Inc., 1993 and 1995) no visible erosional ruts resulting from concentrated surface runoff on the upper refuse area bench were observed. Groundwater tends to follow along the surface of the sandstone bedrock, at the base of the colluvial overburden. SOM-13 has been monitored continuously since 1980 and static water levels have stayed below the 100 feet depth (see Appendix B). Several ephemeral springs, appazently from this same groundwater table, daylight along the face of the slope leading down to the WEi~I surface facility bench. South and several hundred feet above the upper refuse bench, an ephemeral spring daylights on the steep slope at the head of a stand of old-growth aspen (see Figure 1). The spring does not produce any visible surface runoff, and the groundwater appazently moves deep into the subsurface as indicated by SOM-.13, which is located on the bench at the base of the slope downgradient from the spring. 7