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'. 02 January 2002 • 'AGE-NC Project No. 95-0185 Page 2 of 5 ' were removed from MW-3 and nine gallons of water were removed from MW-4 (minimum of three casing-volumes per well). Approximately one-half inch of measurable free-phase hydrocarbons were observed in the first bailer removed from monitoring well MW-4. The ground water parameters of ' temperature, pH and conductivity were measured at regular intervals, using an Oakton water analyzer. The ground water parameters stabilized during purging (Appendix A). 1 Purgedwater was stored on-site in 55-gallon Department of Transportation(DOT)-approved drums. ' 2.2. ADVANCEMENT OF SOIL PROBE BORINGS AND GROUND WATER SAMPLING On 26 October 2 00 1, four discrete soil probe borings were advanced at the site. Sets of borings were co-Iocatedto collecte d ground water from discrete depth intervals and minimize cross contamination. Probe boring locations are illustrated on Figure 2. The borings were advanced using AGE's van- mounted Geoprobe 5400 soil probing machine equipped with a 2-inch diameter water sampler on the leading end of the probe rods. ' Borings PI 2A/B were advanced near the location of well MW-2 and borings P 13AB were advanced near the location of the former UST excavation. Probe borings P12A and P13A were advanced to 40 feet bsg and borings P 12B and P 13 B were advanced to 50 feet bsg. ' Grab ground water samples were collected from the probe borings using a Geoprobe water sampling assembly,which was extended to the targeted ground water,then pulled back approximately four feet ' to expose a water sampler screen interval. Ground water was allowed to enter the sampler, and samples were retrieved using a modified tygon tubing bailer. ' After sample retrieval, the sampler was disassembled and cleaned. New PVC tubing was used for each sample. Samples were collected in 40-m1 EPA vials containing 0.5 ml 18 % hydrochloric acid as a preservative, and in 1-liter amber bottles. Samples were then labeled and placed in a chilled ' container for transport under chain-of-custody to Me Campbell Analytical Laboratories, Inc. (MAI) in Pacheco, California. The sampling equipment was washed in an Alconox solution and rinsed with water prior to each sampling run to prevent cross- contamination-2.2. COLLECTION AND ANALYSIS OF MONITORING WELLS GROUND WATER SAMPLES Ground water samples were collected from each monitoring well using the dedicated disposable Advanced GeuEnvirontnental,Inc.