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_lq_ The Quaternary terrace deposits consist of Pleistocene aged gravels related to glaciation in the area. Three gravel terrace layers have been mapped in the area and represent previous flood plains of the Animas River. These deposits vary between 1 and 100 feet thick and consist of boulders and cobbles in a silt clay matrix. Quaternary alluvial deposits are primarily located along the Animas River. Thin (less than 3 feet thick) isolated alluvial bodies are located in Carbon Junction Canyon. The proposed operation is in compliance with the requirements of this section. V. Ground Water Hydrology - Rules 2.04.5, 2.04.7, 2.05.6(3) and 4.05 The applicant has supplied sufficient information to describe the quality and quantity of ground water within the permit application (Section 2.04.7(1) and in responses to adequacy concerns received February 15, 1983 and May 4, 1983). The following description of ground water was prepared using information within the permit application, information in the Chimney Rock Coal Company's Martinez Strip Mine permit application, and site observations by MLRD staff. Ground water in the general area of the mine occurs in the Pictured Cliffs Sandstone, the interbedded and lenticular sandstones and coal seams of the Fruitland Formation, the Quaternary Terrace Deposits and alluvium of the Animas River. The Pictured Cliffs Sandstone is a regional sandstone aquifer which overlies and underlies the lowest coal seam to be mined, the "C" seam. No water wells are presently completed in this aquifer in the general area. Springs along Carbon Junction Canyon are, in part, supplied by discharges from this aquifer, given the outcropping and subcropping of this sandstone in the stream valley. Spring flows in Carbon Junction Canyon vary from seeps of less than a gallon per minute to over 5 gallons per minute during dry periods in the fall. flows are expected to vary seasonally, with increased flow rate recorded in spring and early summer. Ground water flow may not be uniform throughout the Pictured Cliffs sandstone. The applicant's consultant had an 18 inch section of core from the Lower Fruitland-Upper Pictured Cliffs transition zone tested in the laboratory. This sample consisted of hard, poorly sorted, clayey, very fine grained sandstone. The porosity of this sandstone averaged 14% and had essentially no permeability. This sample, however, represents a relatively small part of the massive Pictured Cliffs Sandstone and may not be representative of it's entire cross-section. No exploration drill holes penetrate the entire section of the Pictured Cliffs Sandstone. Regionally, the Pictured Cliffs Sandstone in outcrop is a massive, hard, well-sorted, clean, fine to medium grained sandstone (Fassett and Hinds, 1971, and Shomaker, et. al., 1971). This massive section of Pictured Cliffs Sandstone is permeable and could suppo~~t ground water flows.