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Excavation Remediation Report Advanced Environmental Concepts,Inc. <br /> TABLE <br /> it <br /> Analytical Results <br /> Soil ampler <br /> 09-23-9( <br /> 6.0 (ppm) <br /> CONSTITUENT TPH-G MTBE BENZENE TOLUENE ETHYLBENZENE XYLENES <br /> SAMPLE I.D. <br /> W-1 @ 11. 2.7 ND ND ND ND 0.0066 <br /> W-2 @11' ND ND ND ND ND ND <br /> W-3 @11' ND ND ND ND ND ND <br /> DETECTION 005 .005 .005 .005 005 <br /> LIMIT <br /> 5.3 Completion of Monitoring Wells <br /> The 3 confirmation soil borings were each completed as groundwater monitoring wells using <br /> approximately 20 feet of new 2-inch, flush-threaded, Schedule 40 PVC casing installed through the <br /> hollow auger stem. The bottom 10 feet of casing was composed of 0.010-inch factory slotted liner <br /> centered above and below the potentiometric surface to allow for seasonal fluctuations in the water <br /> table and permit sampling of the airAvater interface. Number 2116 Monterey sand was slowly poured <br /> down the annulus while removing 5 feet of auger at a time. The filter pack was installed from the <br /> bottom of the well to 1 foot above the screened internal. A 3 foot seal of hydrated bentonite was <br /> then poured above the sand filter pack to form an impermeable barrier. A cement/bentonite slurry <br /> was used to fill the annular space to within 1 foot of grade level. The wellheads were finished with <br /> stovepipe boxes cemented in place and sloped to minimize water accumulation, <br /> 5.4 Well Development/Sampling/Analyses <br /> r. Each monitoring well was developed using a submersible pump approximately 24-hours after <br /> installation. The wells were pumped until the effluent was clear and free of fine-grained sediments. <br /> Natural equilibrium was allowed to recover prior to measuring the depth to groundwater and <br /> collection of representative samples for analysis. Purged groundwater was pumped into <br /> appropriately labeled DOT approved 55-gailon drums and stored on-site pending results of <br /> laboratory analyses. Measurements of pH, conductivity, temperature, and turbidity were recorded <br /> on field data sheets during the development and purging process. Samples were collected using <br /> a new disposable plastic bailer for each well and decanted to clean 40 ml VOA vials having teflon <br /> septa. Care was exercised to ensure that no air pockets were present in any of the vials. The VOA <br /> vials were then labeled, placed in a protective covering, stored on blue ice, and recorded on the <br /> Chain-Of-Custody Record. Soil and water samples were analyzed by Baseline On-Site Analysis, <br /> a California certified analytical laboratory located in Huntington Beach, for TPH-gasoline, MTBE, <br /> and BTXE according to EPA methods 8015 modified and 8020, respectively. Laboratory results of <br /> water samples collected during September 1998 are presented in Table 10. Reports and Chain-of- <br /> Custody documentation are included within Appendix B of this report. <br /> Project: AEC 96C-1707 11 <br /> •ENVIRONMENTAL CONCEPTS WITH DESIGN IN MIND - <br /> 4400 ASHE ROAD.*206 - BAKERSFIELD.CA 93313 8051831-1646 - FAX 8051831-1771 <br />