2008-01-15_HYDROLOGY - M2004078 - Laserfiche WebLink

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levels have also been adjusted for wells not likely to have been influenced by mining activities based on the distance from the active mine area. • The dissolved iron concentrations have exceeded the SDWS in two of the ten wells sampled from December 2006 through October 2007. A site-wide baseline concentration level is proposed below based on the dissolved iron results. • Sulfate exceeded SDWS in four of the ten wells sampled in December 2006, April 2007, and October 2007. CRMW09 and CRMW16 did not have a sufficient amount of data collected in the 2006 annual report to establish a baseline level. However, with the additional data collected in 2007 a baseline level has been established for these wells. The baseline levels have also been adjusted for wells not likely to have been influenced by mining activities based on the distance from the active mine area. • Total dissolved solids consistently exceeded the SDWS across the site as in the previous years. There has been no significant decrease or increase in the TDS concentrations observed from year to year. 2.3 Additional Parameters Additional parameters analyzed include bicarbonate, calcium, carbonate, magnesium, sodium, total suspended solids (TSS), and turbidity. Baseline levels have been adjusted for wells CRMW09, CRMW16, and other wells where mining activities have been located at a significant distance not anticipated to have influence on the groundwater at these locations. 2.4 Chlorinated Herbicides/1"otal Extractable Hydrocarbons/Aromatic Volatile Orclanics/Organochlorine Compounds There were no reportable detections of total extractable hydrocarbons, chlorinated herbicides, aromatic volatile organics, or organochlorine compounds detected in CRMW 01, CRMW 04, CRMW 06, or CRMW 41. Additional parameter test results and the summary of all laboratory analysis results are contained in the attached tables. Figure 2 shows the location of the monitoring wells and the groundwater elevations measured during the October sampling event. The gradient is northwest toward the South Platte River. The results of this sampling event are consistent with anticipated results when the GWSAP was developed. Further sampling will be completed quarterly in 2008 consistent with the approved GWSAP. 3.0 ANNUAL GROUNDWATER MONITORING RESULTS The groundwater quality monitoring results were tabulated and evaluated based on the Primary and Secondary Drinking Water Standards and additional parameters. These standards are intended as general guidelines for this monitoring activity. The results were compared to current standards along with spatial and temporal trends. A complete listing of test results can be found at the end of this report in Appendix A. The background levels for the parameters listed below were primarily established in October 2006 based on site wide averages and standard deviations. Individual well "baseline° levels have been adjusted based on additional data and the possibility of the groundwater to be influenced at the wells location based on mining activities. These higher levels in the individual wells are considered the baseline/background level of the parameter for the specific well if it has a higher concentration level than the site wide background level. Wells with less than five sampling events were not considered for background level determination when the well average and standard deviation was used. ~~ Annual 2007 Sampling Report -Lupton Lakes -2- January 2008