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i ~,tt~ L. i i• Surface materials consist generally of fill in the canyon bottom witls shallow topsoil, residual soil andJor exposed rock on the canyon walls. Much of the fill, especially near the mouth of the canyon, was undoubtedly placed years ago during operation of the old underground mine. The south canyon wall (north facing) generally has a G-inch to 18-inch layer of top- soil and supports an extensive vegetation cover with only limited exposed rock. The environment of the north canyon wall (south facing) is considerably drier. These slopes hold little topsoil, support only limited vegetation, and contain considerable exposed bedrock. Streeter Canyon is drained by Streeter Creek which ap- pears to be an intermittent stream. At the time of our site investigation, there was only local minor flow east of the waste dump. Most of the water originated from seeps in the south canyon wall and appeared to be related to recently excavated cuts. Due to haul road grading and other earthwork, much of the natural drainage in the canyon has been altered. Accord- ing to the Draft Environmental Impact Statement, Streeter Creek has a drainage area of 2.12 square miles, an average precipitation of 21.55 inches, and an estimated yearly run- off of 0.39 inches. 3.2 Existing Underground ,'dines L I~ The room and pillar mining which has ceased and which currently underlays the dump was known as the Ned Wing M1tinc. The Ned Wing M1fine is reported to have mined a height of some 8 ft. with coal still being left in the roof. Eased on sample calculations in type areas of the available underground lay- outs, extraction of between SOo and GOm were achieved. The overburden cover ranges from approximately 20 ft. to some 340 ft. on the northern side of Streeter Canyon. The majority of ,[KF~