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Mr. Allen Sorenson - August 6, 2010 <br />Page Three <br />AGC therefore is notifying DRMS that it will commence a spray evaporation operation, to be <br />contained within the lined tailing pond interior, upon receipt of a DWR "variance" or <br />"authorization" to carry out such a "consumptive use" activity. While initial logistics are <br />underway to assemble necessary components for this action, we wish to provide you with the <br />information necessary to ensure DRMS is confident the program will be carried out in <br />conformance with prior authorizations as issued to prior site operators. <br />Spray Evaporation System <br />The spray evaporation system will be deployed in a grid-like manner over the footprint area of <br />the tailing impoundment. A nominal 25 gpm pump will extract water from the tailing pond pool <br />(the pump intake will be set at a depth sufficiently elevated to ensure silt/sediment materials will <br />not be disturbed or ingested) via a single, valved manifold to a series of three grid offsets. One <br />grid line will encompass placement on the exposed liner area along the western portion of the <br />impoundment feature (to take advantage of the heat absorption characteristics of the black liner) <br />while the other two lines will be established as floating features over the pond surface. <br />Standard "misting" lawn irrigation sprinkler nozzles (3 gpm @ 25 psi rating) will be utilized. <br />A total of 32 nozzles (8 per bank, each with a 12- to 15-ft. spray radius) is anticipated in the <br />tailing pond system. The system will be made operational for 10 to 12 hours per day (daylight <br />hours). Multiple daily observations/inspections of the system will be made to assess conditions <br />relative to wind-carry, etc. and if there is evidence of any problematic issues, adjustments will be <br />made either through sprinkler head adjustment, system pressure reduction, or complete shut- <br />down of a given bank/line or individual sprinkler head(s). AGC anticipates operating the system <br />except during periods when freezing temperatures substantially inhibit or prohibit operation. <br />Land Application System <br />Upon receipt of a DWR issued "variance" or "authorization" for temporary consumptive use (and <br />DRMS authorization to proceed), AGC will deploy a land application system to further enhance <br />pond volume reduction capability. <br />The proposed system will be deployed with three discrete zones (see accompanying Figure 1: <br />Land Application System), as depicted. Land application areas (i.e., "zones") were selected and <br />grid placement defined with the objective of avoidance of (i) defined drainages; (ii) areas directly <br />contributory to shallow groundwater monitoring wells; (iii) other environmentally sensitive areas; <br />and, (iv) active operational areas. <br />Each of the three zones will be equipped with sub-zones (i.e., banks/lines) that will allow <br />operation at full scale or lesser degrees of application throughout the course of a day. This "in- <br />zone" flexibility will facilitate drain-down and minimize the potential for over-saturation in <br />localized areas. In addition, AGC proposes to sequentially rotate between the three zones on a <br />daily basis. <br />Zone A is to be positioned within the M 1994-117 permit area at a location immediately north of <br />the tailing impoundment and east of the topsoil stockpile. This is an approximately 200' x 100' <br />surface area characterized by intermittent open areas with vegetation comprised of various