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~OLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Qantiry Controf Divisioa
<br />2nrionnle -Page 7, Permit Na. CO-0038776
<br />For Outfall 017, with the change stream standards, chronic WET would now apply. Previously, MCC was required to
<br />monitor for acute WET using Daphnia magna and Pime hales romelus ~ they were consistently compliant with this
<br />permit requirement until the fenal quarter of 2002, a test ai a or ap nia magna. With this failure, the permittee
<br />conducted accelerated tests. Those tests resulted in failure for Daphnia magna, and established a pattern of toxicity.
<br />MCC had Wright Water Engineers (WWE) determine the factors(s) causing the pattern of toxicity for Daphnia magna.
<br />Sampling and analysis was erformed for metals, inorganics, semi-volah a/volatile organics, and the results did not
<br />indicate toxicity from any ofahe ammeters measured. MCC completed the Preliminary Toxicity Identification (PTI)
<br />in November 2002, the results o~which were inconclusive, but suggested that the toxicity was due to elevated levels in
<br />TDS, and alkalinity in particular.
<br />To further investigate the issue, split samples were collected by MCC, and sent to separate laboratories for parallel
<br />Toxicity Identi~canon Evaluations (TIE), and additional tests to be conducted by one the labs So assess whether
<br />alkalinity couCd be responsible for the toxicity. The conclusion of the study identified TDS/alkalinity as the significant
<br />factor in the mortality of Daphnia.
<br />Additionally, Mountain Coal Company conducted an Aquatic Impairment Study (February, 2003) ors the North Fork of
<br />the Gunnison River to determine the impacts to this stream from Outjall 017. The finding was Yhat the results of the
<br />study did not reveal any sign ficant impacts resulting from this discharge.
<br />The current implementation of WET testing in permits allows (or consideration of various approaches to provide some
<br />relief from routine WET testing when it is demonstrated the WET test failures are caused by TDS and where there are
<br />no signi cant impacts to the receiving water. Relief from WET testing requirements can be considered when TDS
<br />remova from an effluent may not be cost effective.
<br />Based upon this information, the Division considers this request o(WET testing from chronic to acute using Daphnia
<br />magna, appropriate. To further attest to the presence of TDS/alkalinity, the test method for outfall 017 will remove
<br />alkalinity as an Interference; because with a high alkalinity, other causes of toxicity cannot be determined.
<br />This renewal permit continues She exempfion from WET testing for Outfalls 004 and 016 when discharges consist of
<br />only surface runoff wafer. When surface mnoff water only was discharged, such shall be noted on the appropriate
<br />DMRs.
<br />iii. Acute WET Limits: Because of demonstrated toxicity in mine water discharged by several permittees, the Division
<br />e fever t ere is reasonable potential for the discharge to interfere with attainment of applicable water quality
<br />classi~tcations or standards. Therefore, an acute toxicity limit has been continued in the permit for Outfalls 004, 011
<br />012,D13,016,and017.
<br />The permittee is required to conduct quarterly monitoring consistent with the fireqquency specifications in the Colorado
<br />Water Oualiry Control Division Biomonitorin Guidance Document, dated July 1, 1993, the results of which are to e
<br />reporte as an o, w is is t e concentration at w tc 71ao or more of the organisms die. If the LCsa occurs in a
<br />concentration of lsess than or equal to 100% effluent, the permittee is required to comply with the specifications
<br />identified in Part I.A. of the permit.
<br />Alkalinity will be adJJ'usted to a level <-1,500 mq/1, which will correspond to a maximum "no effects" level based the
<br />breakpoint o((mortafi'ty for Da hnia ma na. AIT other conditions ojthe Acute WET test will remain consistent with the
<br />guidance. This applies only tot is specter, and not Pimeohales oramelus.
<br />iv. General Informa8on: The permittee should read the WET testing section of Part LA. of the permit carefully. The
<br />permitpermit ou~est reguir~ ents asjd the required follow-up actions the perminee must take to resolve a toxicity
<br />v. Outfa[Is 005 007, 008, 009, 014, 015 and 018 at the West Elk Mine facility do not receive a significant volume of toxic
<br />or industrial wastes and, in accordance with Regulation No. 61 Section 61.8(21(b)(i)(B) of the "Colorado Discharge
<br />Permit System Regulations", the discharges do not have the reasonable potential to cause, or measurably contribute
<br />to, an excursion above any narrafive standards ffor water quality. Therefore, WET testing is not a requirement for
<br />these Outfalls. However, the Division reserves the rtQht to reopen the permit to include WET testing, should facility
<br />conditions change or tf new information becomes available.
<br />incident. a permitree s oul read, a ong with the documents listed in Part I.A. o the permit, the Colorado Water
<br />uali Conrrol Division Biomonitorin Guidance Document dated July 1, 1993. his document out Inesines t
<br />use y t e ivision in suc areas as granting re ie om WET testing, moth ing test methods and changing test
<br />s ecies. The permitlee should 6e aware that some of the conditions outlined a ove may be subject to change if the
<br />facility experiences a change in discharge, as outlined in Parr ILA.2. of the permit. Such changes sha116e reported to
<br />the Division immediately.
<br />stormwater: stormwater from active or inactive coal mining operations that has been contaminated • by contact with any
<br />over ur en, raw material, intermediate products, finished products, byypproducts or waste products located on the site of such
<br />operations is required to be covered by a Colorado Discharge Permit System (CDPS) ermit to order to be discharged fo State
<br />waters. This covesge may be obtained under either a CDPS Industrial Wastewater Discharge Permit or a CDPS stormwater
<br />Discharge Permit. For facdmes that have individual CDPS permits for discharge of rocess water, any applicable stormwater
<br />provisions can then be included in individual CDPS permits. The individual permit or discharge of process water for the West
<br />Elk Mine, CDPS permit (No. CO-0038776) contains stormwater pprovisions that di er {tom fheprovistons of the pprocess water
<br />portion, and are set out in Part LD.2 of the permit. Under the terms of the combined individual permit, tY7ountain Coal
<br />Company, LLC will be authorized to discharge stormwater associated with industrial activity into waters of the State of
<br />Colorado.
<br />The terms and conditions of this permit, as related to stormwater discharges, include:
<br />a. Se a ation o stormwater Dischar es: All discharges covered by the stormwater portion of this permit shall be composed
<br />entireyo stormwater except as fscussedatPartlD.2.d.ofthepermit). stormwater, which mixes with process water, is
<br />subject to process wafer conrrols. Discharges from sources other than stormwater must be addressed by the process
<br />water controls in this CDPS permit.
<br />Last Revvert: 4/l9/2004 6~
<br />3.03 I • 43Z Jr ~CCRkS'r rqk
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