2012-06-28_REPORT - C1982057 - Laserfiche WebLink

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and annual variability are more clearly evident. Water level measurements are taken with an electrical water level indicator, or in the case of a few shallow alluvial wells, directly from a steel tape. Site information, including sampling frequencies, is presented in Table 3, Summary of Ground Water Monitoring Wells. Ground water level monitoring frequencies are listed in Table I of Appendix 15 -3a in the Seneca II -w PAP. Ground Water Level Summary. This year, water levels at all wells fell within their historic ranges, with the following exceptions. Wadge overburden well WOV17, Wadge coal well WW17, Sage Creek overburden well WSOV25, Sage Creek coal well WSC25, Wolf Creek overburden well WWCOV25 and Wolf Creek coal well -WWC25 all displayed the highest water levels on record this spring. All W -25 series wells were drilled in 2004 and exist in the south pit area downgradient of the last mining area at this mine. In addition, Dry Creek alluvial well DCAL -02 also had its highest water level on record this year. However, monitoring of this well by SCC began in 2008. Most aquifers at Seneca II -W exhibit a typical seasonal fluctuation. Water levels are highest after the spring runoff, which recharges the aquifer. Often, bedrock aquifers exhibit a lag time between spring runoff and highest water levels. Water levels then decrease as late summer or fall approaches. Ground Water Quality. Table 3, Summary of Ground Water Monitoring Wells, describes the wells that have been sampled in the past and site characteristics. Table 4a and 4b show the new (2010) ground water parameter lists. Analyses have been performed by ACZ Laboratory in Steamboat Springs, Colorado since May 31, 1983. ACZ Laboratory performs all analyses by EPA or equivalent methods. Samples are delivered the day of collection to the lab in an iced cooler. Monitoring frequencies for ground water quality may be found in Table 1 of Appendix 15 -3a in the Seneca II -W PAP. 3