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-''' . <br />- -i <br />STATE OF COLORADO <br />Roy Romer, Governor <br />DEPARTMENT OF NATURAL RESOURCES <br />MINED LAND RECLAMATION DIVISION <br />DAVID C. SHELTON, Dlreetor <br />DATE: May 29, 1987 <br />T0: Steve Renner <br />FROM: John T. Doerfer •.1' ~/ <br />RE: 1986 ANNUAL HYDROLOGIC REPORT, MARR STRIP MINE, FILE N0. C-80-006 <br />As you requested, I have reviewed the surface water sections of the 1986 <br />Annual Hydrologic Report (AHR) submitted by Kerr Coal Company for the Marr <br />Strip Mine on February 27, 1986. My comments following review are provided <br />below: <br />1. A review of field data presented in Appendix 5 indicates specific <br />conductance at site 315 (720 pit) varies widely between weekly <br />observations during the March through June period. How can this <br />variability be explained? <br />2. Individual sample lab data reports are provided in Appendix 6 and <br />copies of field data coding forms are provided in Appendix 5. <br />Although this raw data should be included in the report, a <br />statistical summary of the mean, minimum, maximum and standard <br />deviation would also provide useful information. Tables 14 and 10 in <br />the permit document report surface water data by sorting stations <br />into groups of "Affected area" (ponds) and "Baseline" (stream <br />sites). A similar representation of recently collected data (1986) <br />to the baseline monitoring (1980) would allow a comparison of <br />constituent means and maximums to denote changes, if any, due to <br />mining during the period. No quantitative discussions of the data <br />are provided in the 1986 AHR, only generalized interpretations. In <br />order to meet the objectives of the continuing monitoring program, I <br />would suggest this type of data analysis and reporting be included by <br />Kerr Coal Company in future AHRs. <br />3. A review of Appendix 5 indicates that streamf~ow data for station 314 <br />(Upper Bush Draw) is not reported on every occasion that streamflow <br />is evident at station 306 (Lower Bush Draw). Oftentimes other field <br />data is collected at station 314 which would indicate flow is <br />present. How can this condition be explained? <br />In order to assist the analysis and interpretation of the water <br />chemistry conditions, an estimate of streamflow should be reported <br />whenever samples are taken. Flow data for the stream stations could <br />be plotted and included in the report, as has been done for pond <br />discharges in Appendix 7, to improve future AHRs. <br />/lal <br />cc: Michael Savage <br />423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203-2273 Tel. (303) 866-3567 <br />0122E <br />