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J I► • Working To Restore Nature Groundwater samples were collected from wells MW1, MW2, MW5, and MW6, after purging at least three casing volumes of water or purging dry Monitoring wells were purged and sampled according to RESNA's Quality Assurance/Quality Control Plan (on file with PHS/EHD) Well purge logs are included as Attachment 1 LABORATORY ANALYSIS- - -- Groundwater samples were transported under chain of custody protocol to Sequoia Analytical Laboratory in Redwood City, California (ELAP #1894) for analysis of benzene, toluene, ethylbenzene, and xylenes (BTEX) utilizing EPA method 8020, total petroleum hydrocarbons as gasoline (TPHg) and as diesel (TPHd) utilizing EPA method 8015 modified, and halogenated volatile organics (HVOCs) utilizing EPA method 8010 Laboratory analyses of the sample collected from well MW 1 detected the presence of petroleum hydrocarbons, as follows benzene (550 parts per billion [ppb]), toluene (30 ppb), ethylbenzene (180 ppb), xylenes (460 ppb), TPHg (18,000 ppb), and a non-diesel mix in the TPHd range was reported at 32,000 ppb Laboratory analyses of the sample collected from well MW2 detected the presence of a non-diesel mix in the TPHd range at 810 ppb The sample from monitoring well MW-5 contained a detectable amount of benzene (2 0 ppb), xylenes (0 74 ppb), TPHg (180 ppb), and a non-diesel mix of 72 0 ppb in the TPHd range No petroleum hydrocarbon analytes • were detected above method detection limits in the sample collected from monitoring well MW6 Analytical results of petroleum hydrocarbon constituents are summarized in Table 2 Laboratory data sheets and chain-of-custody documentation are included in Attachment 2 Laboratory analyses of the sample collected from well MW 1 contained detectable concentrations of several HVOCs, 1,3-Dichlorobenzene (10 ppb), 1,4-Dichlorobenzene (82 ppb), 1,2- Dichlorobenzene (160 ppb), 1,1-Dichloroethane (5 7 ppb), 1,2-Dichloroethane (6 8 ppb), and cis-1,2-Dichloroethene (13 ppb) The sample collected from monitoring well MW2 detected only one HVOC constituents, chlorobenzene at 0 84 ppb Analyses of the sample collected from monitoring well MW5 also detected several HVOCs including 1,3-Dichlorobenzene (1 7 ppb), 1,4-Dichlorobenzene (12 ppb), 1,2-Dichlorobenzene (22 ppb), 1,1-Dichloroethane (0 71 ppb), cis-1,2-Dichloroethene (2 7 ppb), trans-1,2-Dichloroethene (5 4 ppb), and trichloroethene (4 6 ppb) No HVOCs were detected in the sample collected from monitoring well MW6 Analytical results of HVOCs are summanzed in Table 3 Laboratory data sheets and chain-of- custody documentation are presented in Attachment 2 �ti 1500771QUARTLY12QR-1994 FN] 2