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20 Apt t[ 1995 <br /> AGE-NC-95-0109 <br /> Page 3 of 8 <br /> O�COZ analyzer,organrcvapors were measured using a Thermo Environmental 580A photo- <br /> ionization detector <br /> Air samples were collected from each monitoring point after the well had been purged for <br /> approximately three to five minutes Each on-site well was purged using an electric pump <br /> Air is then di awn through the field instrument and the measurement is recorded after <br /> stabilization The results of the vapor monitoring are included in Table 2 <br /> 3 3 DRILLING AND SAMPLING OF SOIL BORINGS <br /> Four soil borings were dialled at the site on 13 and 14 March 1995 Borings P6, P7, P8 and <br /> P9 were drilled near vapor wells VW-1, VW-4, VW-2 and VW-6 respectively The locations <br /> of the borings is depicted in Figure 2 <br /> Each soil boring was drilled using a ti uck-mounted Hollow stem auger drill rig equipped with <br /> a split tube sampler The CME-55 drill rig and two-man crew were supplied by Soils <br /> Exploration Services, Inc (SES) of Benicia, California Each boring was continuously cored <br /> and samples were collected at or near each lrthologic change and from areas where field <br /> screening indicated the presence of organic vapors All samples%vere field screened for the <br /> presence of organic vapors using a photo-ionization detector (PID Thermo Environmental <br /> Instruments 580A) All borings were drrlIed to a depth of 55 feet Boring logs are included <br /> in AppendrY A <br /> Samples were collected in clean 2 by 3-inch or 2 by 6-inch brass sleeves The ends of each <br /> sleeve were covered with alumrnurn sheets capped and seaIed \vtth tape Samples were then <br /> placed in a chilled container and transported under chain-of-custody to Geocheni <br /> Environmental Labotatories (GEL) in San Jose, California A total of 16 soil fiom borings <br /> P6, P7, PS and P9 were analyzed for total petroleum hydrocarbons as gasoline (TPH-g) and <br /> for aromatic hydrocarbons (benzene, toluene, ethylbenzene and xylenes BTE&X) in <br /> accor dance with EPA methods 8015m and 8020, r especttvely The selection for analysis was <br /> based upon field measurements of organic vapors using the PID <br /> Duplicate samples fiom each "zone"were also collected for microbe analysis Samples were <br /> tr anspor ted under chain-of-custody to Applied Brotres of Bakersfield and analyzed for <br /> bacterial numbers and specific number of species <br /> 3 4 MONITORING OF GROUND WATER FOR PETROLEUM HYDROCARBONS <br /> As a part of the more hequent Inonrtolrng requitement, wells MW-14 and EW-1 were <br />