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i Ilerman& 1aLIen s Marina Fourth Quarter 2000 CTT-OUndWaWr Montrorwg Y lanuary l2 2001 Page 10 5. SUMMARY/CONCLUSIONS I On DeCLrnber 13 2000 Condor conducted quarterly groundwater and surface water monitoring at lierman & llelen s ;Marina located at 15135 fight Mlle Road in Stockton, California Laboratory analytical results of the groundwater samples collected during the fourth quarter, 2000 monitoring event are generally consistent with historical quarterly groundwater analytical data The concentration of PVI FBF in the groundwater sample collected from MW-2 during the current monitoring event, however, is significantly lower than in the groundwater sarnplcs collected from MW-2 during the previous seven monitoring events Total BTEX and TPH- G concentrations in the groundwater Sample collected from this well during the current monitoring event are significantly lower than in groundwater samples collected from this well during the previous five monitoring events Groundwater elevation measurements collected at the site on September 7, 2000, indicates that the average depth to groundwater was approximately 5 7 feet below the monitor well and water surface measuring points Groundwater elevation contours for December 13, 2000, indicate that the groundwater gradient at the site is generally consistent with the historical groundwater gradient Historical laboratory analytical results indicate that sporadic, trace concentrations of MTBE have been present in the surface water samples collected from the island drainage channel (IDCW and IDCE) In addition, low and/or occasionally elevated concentrations of MTBE have been present in the surface water samples collected from the drainage ditch (DDN and DDS) In the current monitoring event, however, MTBE and the other analytes of interest were not detected at or above the laboratory reported detection limits in any of the surface water samples This represents the first time that none of the analytes of interest have been detected in the same quarterly monitoring event As previously discussed in Section 2, Condor has recommended additional site characterization and monitoring I rather than an active engineered remedial solution for the site based on the results of the soil and groundwater investigation conducted between September I1 and 13, 2000 The results of the soil and groundwater investigation indicated that the MTBE plume generally extended in relatively low concentrations in shallow groundwater beyond the drainage ditch and into the agricultural field to the east of the site The relatively rapid attenuation of MTBE concentrations suggested that the MTBE plume was being truncated by the hydraulic influence exerted by the island drainage channel pumping that occurs at the south portion of the site The next quarterly groundwater and surface water monitoring event is scheduled to be conducted in March, 2001 Please cal l us at(209) 234-0518 with any questions Respectfully submitted, ICONDOR EARI H TECHNOLOGIES, INC Donald F Kress NO 6430 Todd C Hafner California Regist 0 `� Senior Geologist Geologist#6430 V"x' I1Pdclpro3ects11432 H&Fielen'slQuarterly Monitoring Reports12001 -Januaryl4thQuarto0 doe I t 1� CONDOR