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10 October 1997 AGE NC Project No. 97-0298 Page 2 of 5 2.3. GROUND WATER DEPTH AND FLOW DIRECTION Ground water was not encountered during removal of the UST. Based upon the San Joaquin County Flood Control Map entitled Lines of Equal Depth in Water Wells-Fall 1993, ground water depth in the area of the site is approximately 65 feet below surface grade(bsg). The regional flow direction in the Lodi area is toward the southwest; however ground water flow direction can vary locally. 2.4. WELL SURVEY A well survey was conducted to gather information regarding the location and use of municipal and domestic wells within 2,000 feet of the site. The PHS-EHD and the State of California Water Resources Control Board records were reviewed. The City of Lodi Well No. 2 (CW-2) is located 30 feet south of the site and City of Lodi Well No. 4 (CW-4) is located approximately 1,800 feet south of the site. Well CW-4 has been decommissioned and a replacement well has been installed in eastern Lodi. Well CW-2 has been monitored for chlorinated hydrocarbons for approximately the past ten years. Additional domestic ground water wells were discovered directly south of the search range. 3.0. PROCEDURES 3.1. SOIL PROBE BORINGS On 24 February 1997, three soil probe borings were advanced at the site. Figure 2 depicts the locations of the probe borings. The probe borings were advanced using AGE's van-mounted Geoprobe 5400 soil probing machine. Probe boring P 1 was advanced to a depth of 60 feet bsg directly south of the former UST excavation. Probe boring P2, located 25 feet south of the former UST excavation, was advanced to a depth of 43 feet bsg, where refusal was encountered. Probe boring P3 was advanced in the northern portion of the former UST excavation and meet refusal at 20 feet bsg. Discrete soil samples were collected from each probe boring at 5-foot intervals beginning at a depth of 5 feet bsg. The samples were collected using a 1.375-inch diameter, two-foot long, piston type sampler loaded with four pre-cleaned 6-inch brass sleeves. The sampling equipment was washed in an Alconox solution and rinsed with water prior to each sampling run to prevent cross- contamination.