2017-02-03_REVISION - C1980004 (6)

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II. SUPPORT FACILITIES — RULE 4.04 Support facilities are discussed under Section 2 of the permit application. A. Construction of support facilities will not result in damage, destruction, or disruption of oil, gas, or water wells or pipelines, coal slurry pipelines, railroads, or utility lines which pass over, under, or through the permit area. Utility lines pass through the permit area but are not affected by the support facilities. Therefore the Division previously approved those activities (4.04(6)). III. HYDROLOGIC BALANCE - RULE 4.05 A. Water Quality Standards and Effluent Limitations All surface drainage from the mine bench/face-up area is directed via the road drainage ditch to a sedimentation pond, to ensure that all discharges meet effluent limits specified in the CDPS discharge permit for the McClane Canyon Mine. A storm water permit also dictates measures for ensuring that all surface runoff water leaving the mine site meets applicable effluent limits. Three small disturbed areas; the office area, topsoil stockpile, and construction dirt stockpile, are not routed to a sediment pond, and are approved as small area exemptions (SAE's). In these areas, sediment control is provided by diversion berms and silt fencing demonstrated to be sufficient to ensure that runoff from the 10 year, 24-hour storm event will meet the settleable solids discharge limit of 0.5 ml/1 (Appendix pages M-2 through M-4xxiii). The silt fences were approved within TR -11 to replace total containment sumps that had previously provided sediment control for the small areas. The silt fencing was installed in 2002. Mine water collected underground in sumps is authorized within the NPDES permit to be pumped to the surface and directly discharged through a pipe to the McClave Drainage without being routed through a sedimentation pond. Mme water discharges have been necessary on occasion since resumption of operations in 2000, and the discharges have been in compliance with applicable discharge permit effluent limits. Drainage and sediment control measures are addressed in Section 2.4.4 of the application text, as well as various exhibits and appendices referenced in the text. The following finding is made pursuant to the three small area exemptions referenced above. 1. The Division proposes to grant small area exemptions (SAE'S) from use of sediment ponds for the office facility area (SAE -1, .78 acres), the topsoil stockpile (SAE -2, .39 acres), and the construction dirt stockpile (SAE -3, .30 acres) due to the limited size of the areas and due to the fact that the operator has demonstrated that ponds and treatment facilities are not necessary for the drainage to meet the effluent limitations of Rule 4.05.2 and applicable State and 21