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<br /> UEARWATER,
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<br /> In accordance with PHS/EHD directives, GeoAudit completed 'installation and
<br /> sampling of three monitoring wells in October, 1993 As reported in GeoAudit's
<br /> November' 1993 report entitled ' "Monitoring `Well Installation and Quarterly
<br /> Report", ''analytical results indicated that gasoline compounds, in low
<br /> ' concentrations, were detected in soil -samples taken in the vicinity of the capillary
<br /> ' fringe in boring MW-2, but not in MW-1, or MW-3 Benzene and/or other volatile I=
<br /> aromatic,hydrocarbons were detected above reporting limits in all samples below 2b
<br /> feet in MW-2 and MW-1 + No aromatics were detected in MW-3 '
<br /> Benzene was detected in water samples from all three wells; with the highest { '
<br /> concentration (560 ppb) in MW-2, which is located directly adjacent to the former
<br /> r tank field Toluene, ethylbenzene, xylene, and TPHg were also detected in both I '
<br /> MW-1 and MW-2,'but not in MW-3 '
<br /> Depth to groundwater was measured on March 30, 1994, with an average- depth of t
<br /> 27 89 feet bgs r Water level and surveying data were used by GeoAudxt to calculate
<br /> the local direction of groundwater movement Cumulative data indicated that I
<br /> groundwater was moving in a north/Westerly direction with an apparently steep
<br /> hydraulic gradient of 0 040 ft/ft
<br /> - r 2.0 RECENT FIELD ACTIVITIES {
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<br /> ' � All �work''''was performed ,according �tCl
<br /> 0 earwater's`I Well Installation �and,,
<br /> (Groundwater ;Sampling ',Protocols,,;and ' under t the ,directives kind: guidelines,,,
<br /> established by the PHS/EHD 'and the Regional Water 'Quality Control Board
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<br /> t 1 'i`Protocols are'attached as Appendix 1 A
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<br />'r 2.7 Soil Borehole Drilhi ig and Soil Sarripling I ; ' '
<br /> Clearwater's workplan was approved, and'permits w&e'obtained from -the PHS/EHD
<br /> b l' , ,r , i t r r a 1 1 , r l 1 f I
<br /> 1k' and the City"of' Stockton Department of Public Works" IA` safety briefingrwasr , � '�'`, {'
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<br /> E I I coriducted' with Mitchell Drilling' of Rancho,Cordova,,,California prior' tolldrilling on., I;i
<br /> �August131,: 1994`, `XCthe'� d ofIthe �bnI6fmg,I all,=personne'l',reviewed' and `signed -the
<br /> Health'(,and,'Safety Planr't(Appendix' B)1 I" Copies of all 'permits' re attached as `
<br /> I I'' ` 1 ` '+I I ; r ,I tr I
<br /> Appendix C
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<br /> Mitchell';Drillirrg;lused 'aJCME',751 drillrig',,to; drill 6rtwo 'eight-i ch ldiameter, soil
<br /> borings, 'designated;MW-4 and MW-5,'both tci`total depths of '4�feet`"below' grade kl I
<br /> Groundwater was'initially measured duririg'Arilling at approximatI611' thirty' feet
<br /> '1,'elow grade A` two-inch inside diameter' continuous core sampler was used' to
<br /> collect soil ,samples' every, five feet from each boring' I Soil samplest'selected fork,
<br /> bl, 'r , , t ; , , ,
<br /> lab'or`atory o nn"L isl,were labeled', documented on ,a,,chain-of-custody form, and
<br /> ;r '�'.placeld',in a,cooler,fortt'ranspo'rt�io Trace'Analysis,,'a,state-eertifaed labor`ato,iy located' -"
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