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Own"� . Mr. Cfirn Angers September 11, 1991 Page 2 0fl July 20, 1991,Spectrum Exploratlon drilled a sob boring at the location of MW-4(FFgure 1). The boring was drilled rasing athick-mounted drill rlg empiaying 8A-Inch Outskfe�Eameter(O.D.), hollow augers. Drilling was Supervised by a Groundwater Technology field geologist who maintalned a log of the eRcourttered materials. A representathre of the SJCEHD,Mr.Harlan Knoll,was present to observe the well Installation. The borehole was drilled to a depth of appradmatuly 60.5 feet below grade. Sof!coxes were retrieved at apPrOdmately s4m Intervals using a Callfomla modified 80ft-spoon sampler attached to the drill rig. A COPY Of the drilling fog Is atterhed(Attachment B). Selected sell samples were collected at approximately 54000 Intervals and retained for possible laboratory analyses. These Sop samples were collected In 2-Inch-diamater by Vnch-long brass tubes. The tubes were sealed with aluminum roll, capped,and sealed with plastic tape. The samples were labeled and placed on ice in an Insulated coder for ftwq ortation to a Callfomla-certified laboratory under chaln-of-custody protocol. Coplas of sil applicable Groundwater Technology standard operating procedures(SOPS)are attached i (Attachment C). Sol!Samples were screened In the field for volatile hydrocarbon vapors using a Portable photo-lonhatlon detector(PID). Based On FID readings,field observation,and proximity to the water table,a soli sampip, was selected for laboratory aratyses. One Boll sample,collected at 49 feet below grade,was analyzed for the Presence of benzene,toluene,ethylbenzene,and xylenes(BTE)q,and for total petroleum hydrocarbons(rFH)-88V8dlne(EFA Msthods 5030/8020/8015). Copies of the analytical report and chaln-of-custody document are attached (Attachment D). Drill cuttings from the wap installation were p P18Ced In three 5$-gallon drums,labeled,and stored DR she. 1! A comPoske sample of the$op cuttings from these drums was collected In a brass liner,using iho same sampling protocols described above for sop samples collected from the wail boring. The grOurdwater monitoring well that was Installed In this borehole was canatnaGted o�2-Inch-dlamster, € 0.0217-Inch machine slotted,Schedule 40 Polyvinyl chloride well Screen and Wank casing. A well filter pack consisting of No. 18 Cisco since sand was placed in the annular apace In the wall from the bottom of the screened ktterval io approximately 30 feet below grade,Wending 5 feet above the screened Irtterval. Alter the Sand had bean placed In the annular space and before a bentorifte seat was added,the wail was developed using a surge block, The groundwater monitoring well was surged for 1$minutes,and then altemately surged and Wed for 15 minutes. The well yielded approximately 35 gallons 0#water before suspended sediments Ir,the extracted wafer attained acceptably few levees. The develepment-T — - I -water was corrtrined In.&b;:jWlondrum,labeled,and stored on site. A Chevron represertative was GROUNDWATER s L— TwnNOLUGy,INC,