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�f 1J SN�H A heavy sheen was observed in well MW 1 However, no product was able to be recovered from the well due to the small amount present Groundwater monitoring data since December 1990 are summarized in Table 1 _ A potentiometnc surface map for the June 2, 1995 monitoring event is presented on Figure 2 Groundwater beneath the site generally flows to the southeast with components to the east and northeast at an average gradient of 0 0073 feet per feet (approximately 38 5 feet per mile) Historically, groundwater elevation data has suggested an irregular groundwater surface beneath the site, possibly due to the heterogeneous nature of the sods and/or the varying well depths Groundwater samples were collected from wells MW2, MW5 and MW6, after purging at least three casing volumes of water No sample was collected from well MW 1 due to the presence of heavy sheen Monitoring wells were purged and sampled in accordance with the field methods included in Attachment 1 Well purge logs are included as Attachment 2 LABORATORY ANALYSIS Groundwater samples were transported under chain of custody protocol to Sequoia Analytical Laboratory in Redwood City, California (ELAP #1210) 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 samples collected from the wells MW2 and MW5 detected the presence of an unidentified hydrocarbon in the TPHd range at concentrations ranging from 140 parts per billion (ppb) to 590 ppb The sample from monitoring well MW5 contained a detectable amount of benzene (1 1 ppb), and TPHg and an unidentified hydrocarbon in the TPHg range (120 ppb) Analytical results of petroleum hydrocarbon constituents are summarized in Table 2 Laboratory data sheets and chain-of-custody documentation are included in Attachment 3 The samples collected from monitoring wells MWS and MW6 detected several HVOCs The HVOCs detected in the sample collected from MW6 included 1,2-Dichlorobenzene (1 8 ppb), 1,4-Dichlorobenzene (0 71 ppb) and 1,1-Dichoroethane (2 0 ppb) The HVOCs detected in the sample collected from MW5 included 1,2-Dichlorobenzene (14 ppb), 1,3-Dichlorobenzene (0 84 ppb), 1,4-Dichlorobenzene (8 2 ppb), cls-1,2-Dichloroethene (1 9 ppb), trans-1,2- Dichloroethene (3 9 ppb), and Trichloroethene (2 5 ppb) No HVOCs were detected in the sample collected from monitoring well MW2 Analytical results of HVOCs are summarized in 1500771QUARTLY12QR-1995 doe 2