Laserfiche WebLink
• I. INTRODUCTION <br />The purpose of this report is to provide updated information on the on-going <br />hydrologic monitoring program developed for the Edna Mine and discuss trends in <br />surface and ground water quality which have become evident over the past decade. <br />The previous report, dated February 1996, reported monitoring activities up through <br />the end of 1995. This report discusses data for parameters which have been <br />collected on an on-going basis from the period beginning in January 1987 through <br />December 1996. <br />The report is divided into several sections including: Hydrologic Monitoring <br />Network; Surface Water; Ground Water; Surface Water-Ground Water Interactions; <br />Quality Assurance; Annual Spring and Seep Survey; Moffat Stability; and Trout Creek <br />Sandstone. A compilation of the raw data is provided in the Appendices. <br />II. HYDROLOGIC MONITORING NETWORK <br />The present monitoring network is a modification of the network used during <br />baseline monitoring. The modifications are mostly simplifications justified by the <br />monitoring records from 1976 through 1987. Continuous streamflow records are made <br />for Trout Creek above the mine (TR-a) from May through October (periods of freezing <br />• sometimes necessitate the records to be of shorter duration). Instantaneous <br />streamflow was recorded on Trout Creek below the Moffat mining area at TR-b prior to <br />July 1999. During June 1999, a continuous streamflow recorder was installed at TR- <br />b. Therefore, monitoring data subsequent to June 1999 is provided on the continuous <br />schedule as at TR-a. Surface water samples are collected above and below the mine <br />at TR-A and TR-D, respectively. Additional surface water sampling sites along Trout <br />Creek are TR-B (located adjacent to the East Ridge area) and TR-C (located adjacent <br />to the Moffat area). Ground water levels and samples are collected from three wells <br />completed in the alluvium along Trout Creek (TR-1.5, TR-3 and TR-9) and from a <br />spoils well (WR-1) located at the base of the West Ridge area. Additional ground <br />water levels are collected from six wells (215W, 215L, 216W, 218 L, 8525 and 892 L) <br />located in the Moffat area. Finally, the Trout Creek Sandstone water quality is <br />monitored downdip of mining activity via samples taken from Well TCS-1. All of the <br />monitoring sites are shown on Exhibit 4.6-26 of the permit document. <br />WATER QUALITY ANALYSES AND SAMPLING FREQUENCY <br />The samples are analyzed for the parameters listed in Table 9.6-59, Section <br />9.6.8.4 of the permit. Sampling frequency at the various sites is also listed in <br />• Table 9.6-59. Parameters measured in the field include: pH, temperature, and <br />specific conductivity. All other parameters measured are analyzed for at an <br />1 <br />