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1 -lo- ' in the pit was prepared to determine whether or not water ' could be stored or would leak out as fast as it naturally flowed in. ' Ground Water Conditions The geology of the Cooley Morrison quarry operation con- ' sists almost entirely of coarse grained metamorphic roc:k of indeterminate thickness. Overlaying the dense, hard racks are thin, isolated deposits of either stream alluvium or slope wash. These surficial deposits vary in thickness from 0 to 20 t feet in the quarry vicinity. Shallow ground water may be f d i h ll i i l i oun n t e a uv um mater a s, part cularly close to the intermittent stream. The quantity of water stored in the sur- ' ficial materials can vary considerably through the year, with the most water being available in the spring and early summer ' months. Ground water can also occur within the dense, meta- morphic rocks but only where the rocks have been fractured by ' faulting or igneous intrusions. Fracturing can occur at any depth, but with greater depth the fractures are generally ' close due to over-burden pressures. Ground water is usually t f d t d i no oun a great epths n a metamorphic rock environment. ' Well yields in mountainous terrain are quite variable, depending upon the presence and thickness of alluvial material ' and the presence of fracture patterns in the hard rocks. Yields are n ll it l i f l l ge era y qu e ow, vary ng rom ess than 1 ga lon per minute to 15 gallons per minute. Because of the geologic ' environment, ground water storage is also small and wells developed in either geologic unit can go dry after a period of ' pumpage. Examination of well logs of wells drilled on the Cooley property indicate that there are two principal zones of ground water production. Production from both wells are from the deeper zones. The shallow ground water is from an upper fracture pattern in the metamorphic rock and probably does not ' j~\ Leonard R ce Cc°s~';~ny Wa:e~ End nee~s Inc