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u . Mr Michael Infurna Page 4 of 7 Drilling and Soil Sampling On November 15 and 19, 1999, Spectrum Exploration (C57 512268) advanced three soil borings NMI, MW2, and MW3, which were subsequently converted into monitoring wells (Figure 4) All work conducted at the site was performed under the supervision of field geologist Sean Garvey, and project manager Greg Stahl, a California Registered Geologist Mr Michael Infurna of San Joaquin County Public Health Services, Environmental Health Division conducted the site inspection and observed field activities A hollow stem auger ng was used to advance the borings Soil samples were collected at 5-foot intervals using an 18-inch long core sampler lined with new 2-inch diameter brass and/or stainless steel sleeves, affording soil identification and subjective evaluation for contamination A flame ionization detector (FID) was used to monitor the presence of volatile organic compounds in the soil The soil samples collected were sealed, labeled, and immediately placed in an iced cooler and transported to Argon Labs (ELAP 2359) under chain of custody protocol Soil samples selected for analysis were based on field observations and screening results Analysis consisted of total petroleum hydrocarbons as diesel (TPHd) and total petroleum hydrocarbons as gasoline (TPHg) using modified EPA method 8015 EPA method 8020 modified was utilized for the analysis of benzene, toluene, ethylbenzene, xylenes(BTEX) Gasoline oxygenate additives were analyzed by EPA method 8260 All drilling and sampling equipment was decontaminated prior to use and between sample collection events to minimize the possibility of cross contamination Soil generated during dnUmg activities was placed on and covered with visqueen Runsate generated during drilling activities was placed into DOT approved 55-gallon drums Both waste streams are currently stored on site pending disposition for proper disposal Well Construction Based on the lnthology and initial depth to groundwater observed m the bonngs, wells NMI, MW2 and MW3 were screened from 10 to 30 feet bgs The wells were constructed of 2-inch diameter, Schedule 40 PVC casing and 0 020 inch slotted screen The filter pack consisted of#3 silica sand The annular seal contained 2 feet of bentonite, which was overlain by neat cement grout Boring/well construction logs are included in Attachment A Well Development and Groundwater Sampling On November 22, 1999, the wellhead elevations of the new monitoring wells were surveyed Water levels were monitored and the wells were developed and sampled Prior to well development, the depth to groundwater was measured in each well and subtracted from the surveyed wellhead elevation to determine groundwater elevation The potentzometnc surface wooer c �rts\summary doc