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• • . Duplicate samples for TPH-D analyses were collected, quadruplicate samples for BETX analyses were collected All sample bottles were supplied by Mobile Chem Labs Samples were labeled with information including sample number and date of collection The vials were placed in a foam rubber holder and the 1 liter sample bottles packed with bubble-wrap in an ice chest with 4 blue ice packs A completed Chain of Custody form (attached) was placed in a plastic zip-lock bag attached to the inside lid of the chest The sample chest was transported by truck to CAL INC's office in Vacaville, then picked up by Mobile Chem Labs Mobile Chem Labs, Inc of Lafayette, CA analyzed the groundwater samples from monitoring wells MWA, MW-2 and MW-3 on March 24, 1999 for TPH-D using EPA Method 3550 modified and TPH LUFT TPH-D analyses are reported in micrograms/liter (pg/1) Mobile Chem Labs analyzed the samples for BETX and MTBE using EPA Methods 5030 and TPH LUFT with Method 8020 for BETX distinction These analyses are also reported in lig/l The laboratory analyzed for Total Lead using EPA Method 7420 and reported the results in mg/1 The Certificates of Analyses for the samples are attached The results are summarized in Table 5 in the section on the results of the chemical analyses below RESULTS--HYDROGEOLOGY The depth to the water table in the three monitoring wells was about 11 85 to 11 91 feet below surface grade on March 19, 1999 (assuming the difference in elevation between the surface and the top of the well casing is 0 4 foot) The depth to the water table was about 10 64 to 10 75 feet below surface on September 10, 1998 and 1121 to 11 26 feet on October 30, 1998 This appears contrary to what might be expected That is, the water table should be higher in March than in September or October because March is near the end of the rainy season and September and October are near the end of the dry season iThe site plan, Figure 2, shows contours of the groundwater elevation based on measurements taken on March 19, 1999 They suggest that groundwater flows toward the north under a relatively low hydraulic gradient of 0 001 The figure also shows the groundwater elevation contours for measurements taken on October 30, 1998 The hydraulic gradient and inferred direction of groundwater flow then is similar to, and consistent with, those on March 19 TABLE 5: Groundwater elevation data for monitoring wells MW-1, MW-2 and MW-3 on September 10 and October 30, 1998 and March 19, 1999 Well Date Measured Water Surface Elevation* 1 OC Elevation Depth to Water Number (feet) (feet) (feet) MW-1 9/10/98 1483 2507 1024 MW-2 9/10/98 1477 2509 1032 MW-3 9/10/98 1473 2508 1035 MW-1 9/14/98 1461 2507 1046 MW-2 9/14/98 1466 2509 1043 MW-3 9/14/98 1453 2508 1055 MW-1 9/16198 14 53 2507 1054 MW-2 9/16198 1446 2509 1063 MW-3 9/16/98 1445 2508 1063 MW-1 10/30/98 1426 2507 1081 MW-2 10/30/98 1421 2509 1088 MW-3 10/30/98 1422 2508 1086 MW-1 03/19/99 13 62 2507 1145 MW-2 03/19/99 13 58 2509 1151 MW-3 03/19/99 13 58 2508 1150