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C] <br />Water Quality Monitoring Report <br />Forward Landfill <br />and trichlorofluoromethane (TCFM). Constituents exceeding a CNSDAM were place in "tracking <br />mode" and are being evaluated quarterly for temporal trends (discussed below). <br />Historically, low-level concentrations of VOCs have been detected in the samples collected from the <br />Forward Unit. On behalf of Forward Inc., GLA prepared a letter report dated February 14, 2001 <br />(RWQCB Case No. 2209), to assess the source and potential impacts of low-level VOCs in <br />groundwater adjacent to the Forward Landfill. The letter report concluded that the sporadic <br />detection of low-level VOCs in groundwater (and lysimeter samples) at the Forward Unit are most <br />likely due to landfill gas from unlined unit WMU-B. Forward has continued to minimize gas related <br />impacts to groundwater by preventing ponding of water through regular site maintenance. <br />Concentration Limit Thresholds <br />In accordance with RWQCB Order No. 115-2014-0006, the routine inorganic monitoring data <br />obtained from the Forward Unit during the second quarter 2017 monitoring period were <br />compared to intrawell concentration limits (CLs) established for each well. Details on the <br />statistical analysis for the established CLs are presented in Appendix G of the fourth quarter <br />2014 Water Quality Monitoring Report for the Forward Landfill (GLA, 2014). As summarized in <br />Table 2-4, the following CLs were exceeded during the second quarter 2017 monitoring period. <br />MW -3 — barium <br />MW -10 — barium, bicarbonate, calcium, magnesium, nitrate -N, potassium, sodium, <br />strontium <br />• MW -13 — pH <br />MW -15 —nitrate -N <br />MW -17 — barium, calcium, magnesium, potassium, sodium <br />MW -18 — barium, bicarbonate, calcium, magnesium, potassium, sodium, strontium <br />• MW -19 —calcium, potassium, sodium <br />. MW -22 — barium, calcium, chloride, strontium <br />• MW-23R—pH <br />MW -24 —calcium, magnesium, potassium, sodium <br />In a letter dated July 31, 2017, the RWQCB was notified of these CL exceedances. With the <br />exception of pH exceedances in wells MW -13 and MW -23R, all of the constituents exceeding a <br />CL were place in "tracking mode" and are being evaluated quarterly for temporal trends <br />(discussed below). <br />Project No. 5017.1030 I Water Quality Monitoring Report 7 <br />July 2017 <br />