2011-05-17_REVISION - C1981008 (2)

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9. Rule 3.03.2(2) Pollution of Ground Water The Division will determine the degree of pollution of ground water. The Division has considered, among other things, the results of inspections and monitoring conducted pursuant to Rules 4.05 and 5.02, to determine whether pollution of ground water is occurring. In addition, the Division reviewed information on the effects of mining activities upon ground water quantity. The permittee complied with the requirements of Rules 4.05.13(2). Monitoring programs, approved by the Division, were developed and administered (Permit, Chapter G, and Annual Hydrologic Reports). In April of 1986, Enron Coal Company was permitted to reduce monitoring activity to that of sediment discharges. Thereafter, well water analyses (including water levels) were neither required nor performed. (Permit, page M-40A) (Water quality samples were taken in 1997 to evaluate current conditions.) The Division conducted a review of ground water quantity in 1996 and concluded that there had been no significant adverse impacts to ground water quantity [1995 Annual Hydrologic Report Meeker Area Mines (C-81-032)]. Flows have been observed from wells (French drains) developed in wet (both prior to mine development and post reclamation) areas in the vicinity of Northern #1 and Rienau #2 portals (Annual Hydrologic Reports and Division monthly inspections). No loss of flows has been noted in Curtis Creek in the vicinity of the Rienau #2 mine (workings below the elevation of Curtis Creek). Flows from the wells developed at the Northern #1 and Rienau #2 portal sites were noted during the 19 November 1997, 14 August 1997, and 22 May 1997 inspections; at Northern #1 during the 31 July 1997 and 17 June 1997 inspections; and Rienau # 2 during the December 19, 1997, inspection. An artesian well near the Northern # 1 mine, developed before mining, was flowing at the time of a March 28, 1997, inspection. The applicant states in the application that impacts to quantity of ground water anticipated were not realized, probably due to termination of mining well short of plans at both mine sites, and no longwall mining at the Rienau # 2 mine. According to the Application and information in the Permit, the mining method was room and pillar. No subsidence was experienced that fractured overlying sandstones (Application, page 17). The Division finds that the quantity of ground water has recovered and is within the Potential Hydrologic Consequences (Permit, Paragraph 4.2, Page G-86-88). Ground water quality data for the two seams that were mined [FF seam at Northern # 1 (Permit, Table G-21 and page G-90h) and G seam at Rienau # 2 (Permit, Table G-21 and page G-90e); Table 21 of the Application] is presented at Documents 21 and 22. The Division, in 1985, concluded that ground water sampling could be suspended (Technical Revision 1 to the Permit). With regard to the FF seam at Northern # 1, parameter values of 1985 sampling were within baseline limit values except for pH (9.5, below the baseline minimum of 11.91). All parameters of the 1997 sampling (from the developed well) except magnesium [52 milligrams /liter (mg/1) vs the baseline maximum of 39], a pH of 7.1 versus a baseline minimum of 11.91) and sodium (28 mg/1 versus a baseline minimum of 119) were within FF seam baseline limits. 25 20 January 1998