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McDowell& Davis Towing <br /> Phase 11 Groundwater Monitoring Well Installation Report <br /> +-r Boring B-3 was drilled southeast of boring B-2 between the two fuel islands to <br /> help provide lateral definition of the contaminants. This boring was drilled to 20 <br /> feet in depth where apparent contaminants had diminished in B-2. No odor or soil <br /> discoloration was encountered. Laboratory soil samples were obtained at 15 and <br /> 20 feet in depth. All samples were reported as "non-detect for the compounds <br /> analyzed" by the analytical laboratory. <br /> Boring B-4 was drilled northeast of boring B-2 to help provide lateral definition of <br /> the contaminants. This boring was drilled to 20 feet in depth where apparent <br /> contaminants had diminished in B-2. No odor or soil discoloration was <br /> encountered. Laboratory soil samples were obtained at 15 and 20 feet in depth. <br /> All samples were reported as "non-detect for the compounds analyzed" by the <br /> analytical laboratory. <br /> Laboratory Soil Sample Results 1/28/00 <br /> c� <br /> Sample I.D. Gasoline I Benzene Toluene E-Benzene I Xylenes MTBE 8260 <br /> B-1-20' ND ND ND ND ND ND NA <br /> B-1-25'' ND ND ND ND ND ND NA <br /> B-1-35' ND ND ND ND ND ND NA <br /> B-140' ND ND ND ND ND ND ND <br /> B-2-15' 2600 860 120000 51000 4000000 87000 NA <br /> �- B-2-25' ND ND 11 ND 48 36 NA <br /> B-2-35' ND ND ND ND ND ND NA <br /> B-2-45' ND ND ND ND ND ND ND <br /> B-3-15' ND ND ND ND ND ND NA <br /> B-3-20" ND ND ND ND ND ND ND <br /> 134-15' ND ND ND ND ND ND NA <br /> 134-20' ND ND ND ND ND ND ND <br /> ND=Non Detect NA=Not Analyzed <br /> Mg/Kg for gasoline µg/Kg for BTEX,MTBE,and 9260 Oxygenated Compounds <br /> On March 20, 2000 San Joaquin County Environmental Health Department reviewed the <br /> analytical results from the investigation with a representative of the Regional Water <br /> Quality Control Board, Central Valley Region. The representative indicated that before <br /> �- the site could be considered for a low-risk closure, a groundwater investigation would <br /> have to be conducted. <br /> '-" 2.0 SCOPE OF WORK <br /> On November 21 & 22, 2000 M. I Kloberdanz & Associates drilled 3 soil borings in the <br /> �- vicinity of the former underground tanks and fuel island using a rig equipped with a <br /> hollow stem auger, sampling spoon, and brass sleeves to collect soil samples for <br /> laboratory analyses (Figure 2). Groundwater was encountered at about 60 feet in all three <br /> borings. <br /> Boring MW-1 was drilled next to former boring B-2 where levels of contamination were <br /> disclosed at 15 feet in depth in March of 2000. Based on gradient studies, from existing <br /> monitoring wells located at a site across the street in September 2000, this location was <br /> suspected to be the down gradient direction from the fuel island. The boring was drilled <br /> to 70 feet in depth with no odor or soil discoloration encountered. Beginning at 50 feet in <br /> 2 <br />