ARCHIVED REPORTS_XR0008560 - Laserfiche WebLink

Home Browse Search

Second Quarter 2004 Groundwater Monitoring Repert Eckert Cold Storage,Manteca,California July 26,2004 Page 3 LABORATORY ANALYTICAL RESULTS The groundwater samples collected on June 23, 2004 from monitoring wells MW-4, MW-8, and domestic well DW-1 were analyzed for BTEX, TPH-G, and selected gasoline oxygenates/additives including MTBE by Argon Laboratories of Ccres, California. The current laboratory analytical results, shown in Table 2, below, are generally consistent with historic laboratory analytical results. Historic groundwater monitoring data are included in Attachment C. Laboratory certificates of analyses and the chain-of- custody documentation for the samples are included in Attachment D. Table 2— Groundwater Sample Laboratory Analytical Results (June 23, 2004) GASOLINE OXYGENA'T'ES/ADDITIVES B T E X TPH-G MTBE Other Gasoline oxygenates/Additives Units: 4g/L gg/L pg/L pg/l_ mg/L pg/L pg/L Analytical Method: 8260B 8260E 8260B 8260B 8015M 8260B 8260B Sample I.D. 3471-MW4-6/23/04 <0.5 <0.5 <0.5 <1.0 <0,05 4.3 7.6(1,2-DCA)0 3471-MWS-6/23104 39 0.9 4.7 <1.0 0.41 13 33(TBA);4.6(1,2-DCA)0 3471-DWI-6/23/04 <0.5 <0.5 <0.5 <1.0 <0.05 <0.5 <0.5—<5.0 • Units: Anal ical: mg/L:milligrams per liter,parts per million(ppm) B,T,E,X=benzene,toluene,ethyl benzene,total xylenes pg/L:micrograms per liter,parts per billion(ppb) TPH-G r total petroleum hydrocarbons quantified as gasoline Gasoline oxygenates/additives= methyl tertiary butyl ether(MTBE),ethanol, tertiary-butanol (TBA), di-isopropyl ether (RIPE), ethyl tertiary butyl ether (ETRE), tertiary amyl methyl ether(TAME), 1,2-dibromoethane(EDB), 1,2- dichloroethane(1,2-DCA) �=all other oxygenates/additives were not detected at or above the laboratory reported detection limits FUTURE WORK/RECOMMENDATIONS The SJCEHD has indicated that continued quarterly groundwater monitoring is required at the site. The next quarterly monitoring event is scheduled for September 2004. Condor, on behalf of Eckert Cold Storage, recommends that future groundwater monitoring events not include facility water supply well sampling and analyses. Supply well DW-1 has recently been replaced with a new supply well that is completed to a depth of 430 feet below grade, screened from 230 feet to 430 feet bgs, located approximately 120 feet further down-gradient from the impacted area than DW-1, and sanitary sealed down to 200 feet below grade. Based on an historical absence of a measurable impact at DW-1 and the construction and location of the new supply well, no monitoring of the new supply well, relative to the UST contamination site, should be necessary. 4 W CONDOR