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09 Au st 2000 AGE-NC Project No. 95-0106 Page 5 of 10 , 2:6 . WELL SURVEY A well survey was'conducted,in August 1998-to gather information regarding the location and use of municipal and domestic wells withinf 2,000 feet of the site. The PHS-EHD;the City of Tracy and the State'of California Water Resources Control•Boar_d records were reviewed. One active, domestic ground water well was identified 1,000 feet southeast of the site,up- and cross-gradient to the subject I property. This well is referred to as the "Lincoln Well". The total depth of this well is 1,020 feet and the current depth to water as of June 1998 in the well casing is 92 feet. No additional wells were determined to be within the search radius of the site. 3.0. PROCEDURES The February 2000 monitoring event was performed,in accordance with San Joaquin County Public Health Services - Environmental Health Division (PHS-EHD) and Regional Water Quality Control Board =Central Valley Region (RWQCB-CVR) guidelines for investigation of underground storage tank (UST) sites. 3.1. MONITORING WELL PURGE PROCEDURES On 24,February 2000, a Solinst water level meter was used to measure the depth to ground water in . each.well relative to the tops. of the well casings. After ground water depth measurements"-were collected, each monitoring well was purged using a two-stage submersible pump. Approximately-3 �. - J to 8 gallons of water were evacuated from each monitoring well {a minimum three well casing , volumes), as appropriate.for each well. Temperature; pH and conductivity weremeasured at 1-gallon or 2-gallon intervals, 'as app ro"Priate, using a Hydac water analyzer to monitor stabilization of these-ground water parameters. Field data logs are included'in"Appendix.A: Purged water was temporarily stored on-site in 55-gallon drums-. . 3.2. COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES. Water samples were collected from each monitoring' well using new disposable bailers after allowingthe wells to achieve aminimum 80% recovery of the pre-purge water volume. The samples. were transferred-into 40-m1 EPA-approved vials containing 0.5 ml 18%'h drochloric acid_ as a ' . .. preservative..The sample.vials were then labeled with the monitoring well designation, date, time of sampling and,the sampler's initials. The samples were transported'in a chilled container under Advanced GeuEnvironmentai,Inc.