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GROUND-WATER i OM10—LING AND SAMPUNG PROCED. URES <br /> 1 Prior to sampling, the depth to water was measured in all monitoring wells using an electronic <br /> t� immersion probe. All measurements were read to the nearest 0.01 foot. If free product was present, <br /> the depth to free product and the depth to water were measured usingan interface robe <br /> p and an <br /> obsen%tion sample was collected with a clear teflon bailer for confirmation. No analytical samples were <br /> Ccollected from monitoring wells containing more than 0.25 inch of free product. <br /> .� The monitoring wells were sampled on October 4, 1990. Prior to purging,each well was checked with <br /> a clear teflon bailer in order to observe the possible presence of floating hydrocarbons. Purging was <br /> accomplished using a stainless steel or teflon bailer. The bailer was thoroughly cleaned prior to each t <br /> sampling using a trisodium phosphate <br /> (TSP)solution followed by a 10%methyl alcohol solution, and <br /> then rinsed twice with potable water. The wells were purged prior to sampling until pH,conductivity, <br /> and temperature slues stabilized. Generally,this resulted in the removal of approximately 3 to 5 w sil <br /> - volumes of ground water from each well during the purging g Process. The water obtained from ur l-Ig } <br /> was placed in labeled 55-gallon drums and stored on-site. The bailer rope was replaced after each <br /> sampling. Samples recovered from each well were.dccanted into two appropriately prepared and <br /> labeled 40-ml volatile organic analysis(VOA)bottles. A travel blank(numbered as 1AW-A)was also <br /> submitted for quality assurance. One travel blank per site will be analyzed. The sample bottles were' <br /> imt:iediatefy placed in an ice chest and mainfained at 4'C until delivery to a State of California licensed <br /> laboratory. Routine chain-of-custody procedures were employed. <br /> L - <br /> f 3 <br /> DU PONT ENVIRONMENTAL REMEDIATION SERVICES <br /> c � <br /> :. - ..- ... -ma4r }�.wn.i-i...'4s -_«..iEYta:i 'N re,+ie-is..w W "��.••. <br /> r <br /> r <br /> t <br /> i <br /> r <br />