Laserfiche WebLink
butanone(MEK)in the samples collected from wells MW-2A and W-17; and cis-1,2- <br /> dichloroethene(cis-1,2-DCE), tetrachloroethene(PCE), and trichloroethene(TCE) in the <br /> samples collected from upgradient(background) wells MW-22 andMW-23R. In <br /> addition, PCE was measured at an estimated trace concentration(between the method <br /> detection limit [MDL] and the PQL)in the sample collected from well -14. <br /> 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 <br /> in groundwater adjacent to the Forward Landfill. The letter report concluded that the <br /> sporadic detection of low-level VOCs in groundwater(and lysimeter samples) at the <br /> Forward Unit are most likely due to landfill gas from unlined unit WMU-B. The <br /> particular VOCs detected in samples during the current monitoring period appear to <br /> support this conclusion. Forward has continued to minimize gas related impacts to <br /> groundwater by limiting interim fill areas that promote ponding of water. Furthermore, <br /> in accordance with CCR Title 27, Section 20937, Forward continues to install additional <br /> landfill gas extraction wells, as needed. <br /> New Historical Intrawell Maximum Values <br /> As shown in the table below, 17 new historical intrawell maximum values were measured <br /> including eight first-time VOC detections during the fourth quarter 2010 monitoring <br /> event. <br /> New Historical Intrawell Maximum Values <br /> Well Analyte New Value Previous Value <br /> MW-2A Acetone 17 g/L Not Detected <br /> Chromium,Hexavalent 0.009 m L 0.0062 m L <br /> MEK 26 L Not Detected <br /> MW-13 Sulfate 67.7 m L 64.1 m L <br /> MW-17 Acetone 22 L 5.3 µ <br /> MEK 32 2.4µ L <br /> MW-18 Sulfate 94.7 m L 90.4 m L <br /> MW-22 Chloride 54.7 m L 51 m L <br /> cis-1,2-DCE 1.0 Not Detected <br /> Nitrate-N 24.6 m 20.0 m L <br /> Potassium 6.63 m 6.6 m L <br /> Sulfate 116 mg/L 110 m L <br /> PCE 3.4 Not Detected <br /> TCE 8.4 Not Detected <br /> MW-23R cis-1,2-DCE 1.1 Not Detected <br /> PCE 3.3 Not Detected <br /> TCE 8.4 g/L Not Detected <br /> Concentration Limit Thresholds <br /> Data obtained during the fourth quarter 2010 monitoring period were compared to <br /> concentration limits (CLs) as specified in the RPCMP for the Forward Landfill. CLs <br /> were calculated by Herst&Associates and are included in Appendix D. Table 2-4 <br /> D:\2010_0013\FA.4Q10.doc <br /> 6 Geologic Associates <br />