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I 61 detection limit It should be noted that sample 134-15' contained a concentration of 12,000 mg/Kg total petroleum hydrocarbons as diesel (TPHd) which is the greatest concentration observed to date at the site During the UST removals on July 1995, a concentration of 7,900 mg/Kg TPHd was reported for an excavation soil sample (North Wall at 14") which contained 0 008 mg/Kg total xylenes and not detected at or above the method detection limit (ND) of ' 0 005 mg/Kg for benzene, toluene and ethylbenzene Also, it should be noted that benzene, toluene and ethylbenzene have not been previously observed in any of the submitted laboratory samples to date On March 12, 1997 CAPE performed an additional round of groundwater sampling at the site which was observed by the EHD Laboratory analysis of the groundwater sample indicated ND for all fractions of petroleum hydrocarbons and also for the BTEX compounds An updated Table 2 - Summary of Analytical Results (Water) is provided as Attachment IV and ' the laboratory report with chain of custody documentation is included as Attachment V The groundwater depth was observed at 31 05 feet below the top of the well casing The groundwater monitor well sampling and field data sheet is included as Attachment VI ' As referenced in the EHD letter, soils oils from the previous investigation were stored on P P g site On February 14, 1997, one (1) 55-gallon drum of rinsate water and eleven (11) drums of ' soil spoils were removed from the site The drums were transported by Allwaste Transportation and delivered to Morton Recycling, located in Marscopa California, for recycling The shipping paper for the drum transportation and disposal is included as Attachment VII ' In subsequent conversations with the EHD, it was mentioned that the waste manifest for UST rinsate fluids and documentation of excavated soil disposal has not been received by the EHD Approximately 1,300 gallons of liquid waste was removed from the site USTs and delivered to I the PRC Patterson facility in Patterson, California In addition, approximately 360 cubic yards of petroleum hydrocarbon impacted soil was transported to Forward Incorporated, located in Stockton California Attachment VIII contains the waste manifest for liquids and the soil transporter weight tickets In summary, CAPE has performed an additional round of groundwater sampling at the site Iwhich completes a total of three (3) sampling rounds Laboratory analytical results from this third round of sampling supports the conclusion that groundwater has not been impacted by a release of petroleum hydrocarbons from the previously existing USTs Analytical results of soil samples obtained during the Soil and Groundwater Investigation (November 1996) indicated that relatively small volumes of soil are impacted with diesel fuel which remains in- place at two (2) locations The impacted soil is located below the existing building and below a concrete electrical vault and is beyond the access capabilities of conventional excavation equipment Lithological information obtained from the Soil and Groundwater Investigation has indicated that a 3 to 5 foot thick clay barrier is present at a depth of 30 to 35 feet below i Ienvlgsa12403c 411rpt-sum doc 2