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The Division has granted a number of small area exemptions (SAES) from the use <br /> of sediment ponds and treatment facilities, due to the limited size of the areas in <br /> question and due to the fact that ponds and treatment facilities are not necessary <br /> for the drainage from these sites to meet the effluent limitations of Rule 4.05.2 <br /> and applicable State and Federal water quality standards for receiving streams; <br /> and also due to the fact that no mixing of surface drainage from these areas with a <br /> discharge from underground workings will occur. The small areas to be <br /> exempted are listed in Section IV.J.S of the application. Sedimentation <br /> demonstrations for the SAE's are provided in Illustration 44, of Volume 12, and <br /> the locations are shown on Map 147 (4.05.2(3)(b)(i)). <br /> B. Diversions and Conveyance of Overland Flow <br /> 1. The Division approved the diversion of an ephemeral stream draining at least one <br /> square mile. Scullion Gulch has been diverted with a large diameter pipe culvert <br /> such that it passes beneath the D Portal facilities area. The decision to approve <br /> this diversion is based on a finding that the diversion meets the requirements of <br /> 4.05.18 and 4.05.4, applicable local, State, and Federal statutes and regulations <br /> and is designed to safeguard public safety and to minimize adverse impacts to the <br /> hydrologic balance (4.05.4(1) and (4)). <br /> C. Sedimentation Ponds <br /> Sediment ponds are discussed under Section IV.J.1 Volume IV of the permit <br /> application. <br /> The applicant uses sedimentation ponds in all disturbed drainages to control the <br /> increased sediment loads within the ephemeral drainages on the mine site. All <br /> sediment ponds are designed to contain or treat the 10-year, 24-hour event and <br /> safely pass the 25-year, 24-hour event, at a minimum. <br /> An alluvial well field near the confluence of Scullion Gulch and the White River <br /> was originally developed to supply water for mine operations. The 1984 <br /> completion of Kenney Reservoir east of Rangely, Colorado inundated much of the <br /> alluvial well field. Because the alluvial surface is almost completely submerged <br /> by the reservoir,recharge to the alluvium is now instantaneous. Due to inundation <br /> of the well field by the reservoir, and due to high salinity of the alluvial well <br /> water, the operator pumps water directly from the White River into an adjacent <br /> lagoon formed by the Kenney Reservoir. Approval to pump directly from the raw <br /> water lagoon to the raw water system was affirmed in Permit Renewal No. 2 in <br /> 1994. Only one alluvial well, Qal-5, located at the mouth of Scullion Gulch, <br /> Remains in use as monitoring well. <br /> The raw water lagoon is a semi-in situ impoundment that collects water from the <br /> White River. The Division approved (MR-55) the construction of a dike that <br /> separates Scullion Gulch drainage from the lagoon area. The location of the dike <br /> xxvi <br />