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vvv CLEARWATER G R o u r Environmental Services chain-of-custody documentation (Kill Reports numbered 70276 and 70309) for the third quarter 2009 groundwater-monitoring event are included as Attachment E . Purge Water Disposal Instrat removed the purge water from the Clearwater Point Richmond yard on October 22, 2009 under Instrat non-hazardous waste manifest #CWG09- 12 (Attachment D) . GROUNDWATER MONITORING RESULTS Groundwater Elevation and Flow The static depth-to-water measurements recorded on October 1 , 2009, ranged from approximately 10.05 feet below ground surface (MW-2) to 11 . 50 feet below ground surface (MW-8) . Depth-to-water measurements and well elevation data were used to generate a groundwater elevation map (Figure 3) . During the third quarter 2009 groundwater-monitoring event, the inferred direction of groundwater flow was to the southeast at a gradient of 0.0036 . The groundwater flow direction and gradient are consistent with previous observations (Figure 4 and Table 2) made for the same period of the hydrologic cycle. Groundwater Quality Parameters Wells MW-8 and IW-3 were observed to have a "slight' hydrocarbon odor, well MW-513 was observed to have "some" hydrocarbon odor, and wells DPW- 1 and AS- I were observed to have a "strong" hydrocarbon odor during the collection of the depth-to-water measurements, purging, and sampling. Hydrocarbon sheen was not observed in any wells sampled. No significant thickness of Light Non-Aqueous Phase Liquid was measured in any wells . The concentrations of dissolved oxygen (DO) observed during the third quarter groundwater- monitoring event ranged from a low of 0. 18 milligrams per liter (mg/L) [IW-3 ] , to a high of 4.95 mg/L (MW-2) [Table 4] . The levels of oxygen-reduction potential (ORP) observed during the third quarter groundwater-monitoring event ranged from a low of —319.7 millivolts (mV), in MW-7, to a high of + 150. 7 mV, in MW-2 (Table 4). All ORP and DO values have decreased since the last monitoring event, most likely caused by the iSOCTm system shutdown and consumption of the remaining oxygen by aerobic microbes . Water quality data, measured on October 1 and 5, 2009, indicate that on-site groundwater is currently slightly anaerobic in all of the wells, except MW- 1 , MW-2 and MW-3 . The groundwater in the monitoring wells contains low concentrations of dissolved oxygen and has low values of slightly positive-to-negative oxidation-reduction potential. Groundwater Sample Analytical Results The iSOCI system was turned off for a rebound test on April 1 , 2009, per SJEHD staff approval. The laboratory reported various concentrations of the contaminants of concern above the laboratory detection limits. The values detected during the October 1 and 5, 2009, sampling event are listed in Table B, below: ZB178N — Barnes Trucking Facility 3 November 2009 Third Quarter 2009 Quarterly Monitoring Report