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depth of the perimeter wall as measured from the ground surface to the pit bottom <br />along the toe of the pit side slope, plus 0.0015 ft3/day/ft2 (5x 10-' cm3/cm2/sec) <br />multiplied by the area of the bottom of the liner system or natural bedrock bounded <br />by the perimeter wall. Appropriate geotechnical evaluations and analyses should be <br />performed to indicate that the Design Standard could be achieved with the proposed <br />design to a reasonable probability. It is recommended that the applicant submit <br />design and construction plans for review to the State Engineer. <br />2.0 Construction Standards <br />The applicant must demonstrate that the constructed liner meets the requirements of <br />the design by performing appropriate quality control observations and tests. The <br />applicant shall provide written documentation of the work performed and results of <br />quality control field and laboratory tests. Tests performed shall meet or exceed the <br />standards established by the American Petroleum Institute (API) and/or the <br />American Society of Testing and Materials (ASTM) as applicable. <br />3.0 Performance Standards <br />The Performance Standard shall be three times the Design Standard as described <br />above. The Performance Standard shall be applied to an initial test of competency of <br />the liner, as well as to the ongoing operation of the reservoir. <br />3.1 Initial Liner Test <br />For mined pits: The unregulated ground water inflow to the reservoir will be tested by <br />evacuating the contents of the reservoir and observing the inflow of water over a <br />period of ninety days. The start of the test will be under essentially dry conditions. <br />For unmined pits: The unregulated ground water inflow to the reservoir will be <br />evaluated by constructing a dewatering sump at the lowest portion of the pit and <br />then dewatering until a steady-state condition is achieved. Once a steady-state <br />condition exists, the amount of the unregulated ground water inflow will be <br />determined. This process will generally require the installation of piezometers to be <br />located on the inside and outside of the lined pit in the unmined area in order to <br />determine whether a steady-state condition has been achieved. <br />A water balance must be done to demonstrate that the balance of the inflows (e.g., <br />precipitation and ground water) and outflows (e.g., evaporation) equals the change <br />in storage volume by a minimum of a 90-day test. Ongoing monitoring of the water <br />balance may also be required as determined by the Division Engineer. The <br />frequency of accounting and monitoring as well as the type and accuracy of the <br />monitoring devices shall be determined after consultation with the Division Engineer. <br />The applicant shall demonstrate that during a 90-day test period the unregulated <br />ground water inflow to the pit does not exceed the Performance Standard. <br />Demonstration of inflows less than the Performance Standard shall be sufficient