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were performed. Aquifer test data is found in Appendix 7-3, Tab 7. Ground water levels are <br />• measured with an electronic water level indicator. Water levels in some shallow alluvial wells <br />are measured directly with a steel tape. <br />Ground Water Quality Sample Handling, Preservation, and Analysis. The ground water <br />parameter list is contained in Appendix 15-2 (Pre-October, 1991 Hydrologic Monitoring <br />Program). The types of samples, preservatives, and bottles used in the monitoring program are <br />contained in Appendix 15-1. Raw/non-acidified and/or raw acidified water samples are taken <br />from the sampling site and placed into specially prepared sample bottles. Dissolved constituent <br />samples are filtered in the field with a 0.45 micron membrane filter. Water samples are chilled <br />by packing the bottles in iced coolers, and then they are promptly taken to an EPA certified <br />laboratory for chemical analysis. <br />All water samples are field tested for pH, temperature, and electrical conductivity at the time <br />they are collected. The pH meter is calibrated before each day's use by performing atwo-point <br />calibration using pH 7.0 and 10.0 buffer solutions. Single point calibration checks are <br />performed in the field. Conductivity meter calibrations are routinely verified using potassium <br />chloride solutions varying in strength from 1000 up to 3000 umhos/cm, depending on the <br />availability of the solutions from select vendors. Field conductivities reported prior to the end <br />of water year 1989 are not temperature compensated. Peabody acquired a new conductivity <br />meter with an automatic temperature compensation probe as of October, 1989. The new <br />conductivity meter is calibrated before each day's use. Sampling protocol is reviewed and <br />maintained in a systematic fashion that delivers reliable data. Peabody will continue to <br />implement improvements in sampling protocol to minimize errors affecting field chemistry <br />measurements and sample collection. <br />Procedures used to collect ground water quality samples are dictated by individual well site <br />conditions such as casing diameter, depth to water, casing storage volume, rate of recovery, <br />and pumping capabilities of sampling equipment. Alluvial and bedrock wells are sampled by <br />purging a minimum volume of water at a constant rate while concurrently measuring field <br />parameters (temperature, pH, and electrical conductivity) for stability, and then collecting the <br />sample once the field parameters have stablized and the minimum volume of water has been <br />purged. The minimum purge volume, purge rate, and sampling device has been established for <br />each monitoring well based an consideration of well site conditions, field parameter <br />measurements, and evaluation of water quality analytical <br />• <br />11 Revised 9/98 <br />