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1 <br /> analyzed One halogenated hydrocarbon, bromomethane,was detected in soil sample MW4- <br /> 45 at 0 43 µg/g (ppm) No other halogenated organics were detected in any of the samples <br /> analyzed <br />' At the time of monitoung, groundwater depth at the site was approximately 86 feet and <br /> groundwater flow was to the north Groundwater in the down-gradient well (MW-3) and <br /> cross-gradient well (MW-4) was contaminated with benzene (0 4 ppb and 4 1 ppb), <br />' respectively No other hydrocarbons were detected in these wells However, the up-gradient <br /> well (MW-2) was contaminated with TPH-g, benzene, and toluene GeoAudit inferred that <br /> the groundwater flow direction may have vaned in the past, and recommended further <br />' monitoring and assessment of the extent of the contamination plume <br /> I3.0 MONITORING PROCEDURES <br />' 3.1 Water Sampling <br /> On January 4, 1994, groundwater monitoring procedures were conducted at the site The <br /> depth to groundwater in MW-2, NNW-3 and MW-4 was measured to the nearest 0 01 foot <br /> with a Solinist water level meter As in previous monitonng events, no groundwater was <br /> present in MW-1 Aftes measurement of the depths to water, a 4-inch Grundfos submersible <br /> pump was used to surge and purge the wells Between 44 and 52 gallons of water (3 well <br /> volumes) were removed fi om each well to Stabilize temperature, pH and conductivity before <br /> collection of a water sample Stabilization data were collected using Orion pH, conductivity <br /> and temperature meters The purge water was placed in 55-gallon drums and stored on-site <br /> Stabilization data are summarized in Table 1 <br /> I A water sample was collected from each well using a new disposable plastic bailer Each <br /> sample was collected in six 40-m1 EPA vials, placed in a chilled container and transported <br /> to a state-certified laboratory <br /> I3.2 Laboratory Analysis <br /> The water samples were transported to Alpha Analytical Laboratories (AAL) in Ukiah and <br /> analyzed for TPH as gasoline, volatile aromatic compounds (BTE&X), and halogenated <br /> organic compounds (HVOC's) in accordance with EPA methods 8015, 602, and 601, <br /> Irespectively <br /> 4.0 FINDINGS <br /> 4.1 Groundwater Gradient and Direction <br /> I Well casingelevations and groundwater depth data are summarized in Table 2 At the time <br /> g P <br /> 4 <br /> I <br />