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The Division has granted a number of small area exemptions from the use of <br />sediment ponds and treatment facilities, due to the limited size of the areas in <br />question and the fact that ponds and treatment facilities are not necessary for the <br />drainage from these sites to meet the effluent limitations of Rule 4.05.2 and <br />applicable State and Federal water quality standards for receiving streams, and <br />also due to the fact that no mixing of surface drainage from these areas with a <br />discharge from underground workings will occur. <br />B. Stream Channel Diversions <br />I . The Division approved the diversion of an ephemeral stream draining at least <br />one square mile. Scullion Gulch has been diverted with a large diameter pipe <br />culvert such that it passes beneath the D Portal facilitates area. The decision <br />to approve this diversion was based on a finding that the proposed diversion <br />meets the requirements of 4.05.18 and 4.05.4, applicable local, State, and <br />Federal statutes and regulations, and that the diversion is designed to <br />safeguard the 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.I 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 />The raw water lagoon is a semi-in situ impoundment that collects pumped water <br />from the White River. A dike is constructed to separate Scullion Gulch drainage <br />from the lagoon area. Please see map 90 of the PAP for dike and access road <br />locations. <br />D. Surface and Ground Water Monitoring <br />1. The applicant will conduct monitoring of ground water in a manner approved <br />by the Division. The ground water monitoring plan can be found in Section <br />II.C.31, Vol. I of the permit application (4.05.13(1)). <br />2. The applicant will conduct monitoring of surface water in a manner approved <br />by the Division. The monitoring plan was submitted under 2.05.6(3)(b)(iv) <br />and can be found in Section II.C.2.e of the permit application, Vol. I <br />(4.05.13(2)). Currently, surface water monitoring is limited to monitoring <br />required under the CDPS discharge permit, as necessary to demonstrate <br />compliance with water quality standards and effluent limitations pursuant to <br />Deserado Mine 20 September 19, 2008