ARCHIVED REPORTS_QUARTERLY GROUNDWATER MONITORING AND REMEDIATION STATUS REPORT AND UPDATED SITE CONCEPTUAL MODEL 2009

Home Browse Search

Table 2 Groundwater Analytical Results Chevron Facility#306620 (Former Unocal#5098) 5606 Pacific Avenue Stockton,California EXPLANATIONS: Groundwater laboratory analytical results prior to January 26,2007,were complied from reports prepared by ENSR Corporation. For concentrations reported above laboratory reporting limits since August 5,2003,please refer to Table 3. 12-06-94 1,2-Dichloropropane was detected in well MW-1 (5.3 µg/L) 02-08-95 1,2-Dichloropropane was detected in well MW-1 (1.3 gg/L) 06-21-95 1,2-Dichloropropane was detected in wells MW-1 (1.6µg/L)and MW-4(1.3 4g/L); Methylene chloride was detected in wells MW-3 (4.8 µg/L)and MW-4(2.4 gg/L) 12-19-95 Samples taken were analyzed outside of their holding time. 03-11-96 Chloroform was detected in wells MW-1 (3.7µg/L),MW-5(3.0µg/L),and MW-6(1.3 µg/L) 06-19-96 1,2-Dichloropropane was detected in well MW-1 (1.2µg/L) 12-05-96 Chloroform was detected in well MW-1 (2.6µg/L) 12-10-97 Chloroform was detected in wells MW-1 (1.6 4g/L)and MW-5(1.2 µg/L) 09-16-98 1,2-Dichloropropane was detected in wells MW-1 (1.2µg/L)and VEW-5(3.4 gg/L) 09-16-98 p-Isopropyltoluene was detected in wells MW-1 (1.5 µg/L),VEW-4(8.4 µg/L),and VEW-5(6.2µg/L) 09-16-99 p-Isopropyltoluene was detected in well MW-2(1.1 gg/L) 09-19-00 Tetrachloroethene was detected in well MW-18(1.4 pg/L); p-isopropyltoluene was detected in well MW-19D(l.l gg/L); Several wells contained methylene chloride,a laboratory contaminant 12-13-00 Methylene chloride,a laboratory contaminant, was detected in well MW-13 (25.0 gg/L); Several wells contained chloroform in low concentrations;The chloroform is believed to be derived from the tap water used to decontaminate the pump and hose system 09-25-01 Tetrachloroethene was detected in wells MW-27(4.1 µg/L)and MW-18(1.6 pg/L) p-Isopropyltoluene was detected in well MW-813 @ 45'(25 gg/kg) 09-22-02 Tertiary Butyl Alcohol was detected in wells MW-3 (70µg/L),MW-4(19µg/L),MW-14A(5.6 pg/L),MW-25S(37 gg/L),and MW-25D(38µg/L). Chloroform was detected in well MW-1 (3.0µg/L)and Tetrachloroethene was detected in wells MW-18 (0.85 gg/L),MW-21S(0.58 4g/L), and MW-27(2.3 µg/L). 12-03-02 p-Isopropyltoluene(19µg/L)and Styrene(1.5 µg/L)were detected in well MW-11. Vinal chloride was detected in well MW-17(2.6 gg/L),Tetrachloroethene was detected in wells MW-18(0.92 µg/L),MW-23D(0.82 µg/L), Trichloroethene was detected in well MW-27(1.8µg/L). 08-05-03 p-Isopropyltoluene was detected in wells MW-2(2.9µg/L),MW-11 (3.8µg/L)and MW-25D(0.62µg/L.). Styrene(1.0µg/L) was detected in well MW-11. Wells MW-18(0.52 gg/L.),MW-21S(0.65 gg/L)and MW-27(3.6 gg/L)also contained Tetrachloroethene. Well MW-27 contained Trichloroethene(0.98 µg/L). I Received revised laboratory report on June 7,2007,updated tables to reflect new data. z Laboratory report indicates estimated value. Abbreviations and Notations: -- =Not Analyzed MTBE =Methyl Tertiary Butyl Ether (µg/L) =Micrograms per liter n-BUTYL =n-Butylbenzene n-PB =n-Propylbenzene (D) =Duplicate sec-BB =sec-B utyl benzene 1,2,4-TMB = 1,2,4-Trimethylbenzene ND =Not Detected EDB =Ethylene dibromide/1,2-Dibromoethane 1,3,5-TMB = 1,3,5-Trimethylbenzene NAP '=Naphthalene 1,2-DCA= 1,2-Dichloroethane IPB =Isopropylbenzene 306620.xls/#385833 105 As of 01/17/09