Laserfiche WebLink
COLORADO DEPARTMENT OFPUBLIC HEALTHAND ENVIRONMENT, Water Quality Control Division <br />Rationale, Page 4, COG-0850000 Coal Mining General Permit <br />-Alkaline Dr <br />t <br />i <br />Coal Preparation Plants and <br />ainage <br />s <br />remen <br />Table III-2c: Alternate Effluent Limitations and Monitoring Requ <br />eas and Western Alkaline Coal Mining <br />d A <br />t <br />i , <br />(additional requirements apply to <br />r <br />a <br />e <br />Coal Preparation Plant Assoc <br />Western Coal Mining, See Section III.A.3 of this rationale) <br />Limitations Monitoring .Sample <br />Parameter 30-Day 7-Day Daily Rationale Frequency 1 ?ype <br />Avg. Avg. Max.. <br />-----Federal Effluent Limitation Guidelines--------------- <br />-------------------------------- <br />G -----------------_ ______ <br />- <br />Weekly Grab <br />p <br />Total Suspended Solids, mg/1 Report NA Re ort Federal EL <br />Totallron, mg/1 <br />Existing Sources (before 5/4/84) Report NA Report Federal ELG Weekl Grab <br />Y <br />New Sources (after S/4/84) Report NA Report <br />ort NA Report Federal ELG <br />l/l Re Weekl Grab <br />p <br />Settleable Solids, m <br />3. Effluent Limitations -Western Alkaline Coal Mining - In addition to the requirements under Part I.B.1 above, western <br />alkaline coal mines are subject to 40 CFR Part 434 Subpart H. This subpart applies to alkaline mine drainage at western <br />coal mining operations from reclamation areas, brushing and grubbing areas, topsoil stockpiling areas, and regraded areas, <br />where the discharge, before any treatment has a pH equal to or greater than 6.0; has a dissolved ~ n c ~~ ~ tration less <br />than 10 mg/L; and has a net alkalinity that is greater than zero. The effluent limitations in this sub art a 1 until the <br />appropriate authority has authorized bond release. <br />a. Sediment Control Plan -The following items apply to those facilities, and specifically those areas outlined above. <br />1. The operator must submit asite-specific Sediment Control Plan to the permitting authority that is designed to <br />prevent an increase in the average annual sediment yield from pre-mined, undisturbed conditions. The Sediment <br />Control Plan must be approved by the permitting authority and be incorporated into the permit as an effluent <br />limitation. The Sediment Control Plan must identify best management practices (BMPs) and also must describe <br />design specifications, construction specifications, maintenance schedules, criteria for inspection, as well as <br />expected performance and longevity of the best management practices. <br />2. Using watershed models, the operator must demonstrate that implementation of the Sediment Control Plan will <br />result in average annual sediment yields that will not be greater than the sediment yield levels from pre-mined, <br />undisturbed conditions. The operator must use the same watershed model that was, or will be, used to acquire the <br />SMCRA permit. <br />3. The operator must design, implement, and maintain BMPs in the manner specified in the Sediment Control Plan. <br />b. De nitions -The following definitions are specific to this subpart. <br />1. Brushing and grubbing area means the area where woody plant materials that woatld interfere with soil salvage <br />operations have been removed or incorporated into the soil that is being salvaged. <br />2. Regraded area means the surface area of a coal mine that has been returned to required contour. <br />3. Topsoil stockpiling area means the area outside the mined-out area where topsoil is temporarily stored for use in <br />reclamation, including containment berms. <br />4. Reclamation area means an area that was previously disturbed as a part of the coal mining operation that is being <br />reclaimed. <br />4. Ej~luent Limitations -Post Mining Areas and Reclamation Areas -Post-mining limitations may apply to outfalls serving <br />reclamation areas, which have been returned to the required contour and on which revegetation (seeding or planting) work <br />has commenced. Limitations may also apply topost mining underground mine areas. Thepermit7ee may request <br />consideration for change from active mining limitations to post-mining limitations when these conditions have been met. <br />a. Post Mining Reclamation Areas -Tables III-3a and III-b apply to this category, subject to 40 CFR Part 434 Subpart <br />E (Post Mining Areas). The following limitations apply to reclamation areas. The federal ELG limitations would apply <br />until bond release. If these wastewaters are combined with other waters under Section III of this rationale, then those <br />limitations shall apply. If this wastewater is combined with post mining underground mine wastewater, then the <br />limitations in Section III.D.2 apply to the combined discharge. If this post mining wastewater is separate, then the <br />following limitations apply. <br />