Laserfiche WebLink
1. INTRODUCTION <br />The purpose of this report is to provide updated information pertaining to the on-going hydrologic monitoring <br />program developed for the Edna Mine and discuss trends in surface and ground water quality which have become evident <br />over the past decade. The previous report, dated February 1999, reported monitoring activities up through the end of 1998. <br />This report discusses data for parameters which have been collected on an on-going basis for the period 1990 through 1999. <br />The report is divided into several sections including: Hydrologic Monitoring Network; Surface Water; Ground <br />Water; Surface Water-Ground Water Interactions; Quality Assurance; Annual Spring and Seep Survey; Moffat Stability; and <br />Trout Creek Sandstone. A compilation of the raw data is provided in the Appendices. <br />II. HYDROLOGIC MONITORBVG NETWORK <br />The present monitoring network is a modification of the network used during baseline monitoring. Continuous <br />streamFlow records are made 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 streamflow was recorded on Trout Creek below <br />the Moffat mining area at TR-b prior to July 1994. During June 1994, a continuous streamFlow recorder was installed at TR- <br />b. Therefore, monitoring data after June 1994 has been collected on the same schedule as at TR-a. Surface water samples are <br />collected above and below the mine 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 to the Moffat area). Ground water <br />levels and samples are collected from three wells completed in the alluvium along Trout Creek (TR- I.S. TR-3 and TR-4) and <br />from a spoils well (WR-I) located at the base of the West Ridge area. Additional ground water levels are collected from six <br />wells (215W, 215L, 218W, 218L, 8925 and 892L) located in the Moffat area. Finally, the Trout Creek Sandstone water <br />quality is monitored downdip of mining activity via samples taken from Well TCS-I. All of [he monitoring sites are shown <br />on Exhibit 4.6-26 0(the permit document. <br />WATER QUALITY ANALYSES AND SAMPLING FREQUENCY <br />The samples are analyzed for the parameters listed in Table 4.6-54, Section 4.6.8.4 of the permit. Sampling <br />frequency at the various sites is also listed in Table 4.6-54. Parameters measured in the field include: pH, temperature, and <br />specific conductivity. All other parameters measured are analytically derived at an independent laboratory. Surface water <br />data are contained in Appendix A and ground water data are contained in Appendix B. <br />111. SURFACE WATER <br />GAUGING STATIONS <br />Figure I shows the continuous streamFlow records for Trout Creek at TR-a and TR-b. The graphs showing the <br />results of the gauging stations along Trout Creek indicate that the monitoring program is being placed on-line early enough in <br />