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FIELD PROTOCOL <br /> �t <br /> The static water level and floating product level, if present, in each well that contained water was <br /> ' measured with an ORS Interphase Probe Model No. 1068018 or Solonist Water Level Indicator; <br /> these instruments are accurate to the nearest 0.01 foot. These groundwater depths were subtracted <br /> from wellhead elevations, including corrections for product thickness, when necessary, for gradient <br /> evaluation by multiplying product thickness (PT) by a correction factor 0.8 and subtracting from <br /> ' the DTW(Adjusted DTW=DTW- [PT x 0.8]). <br /> Water samples collected for subjective evaluation were collected by gently lowering approximately <br /> half the length of a new disposable or Teflon® bailer past the air-water interface (if possible) and <br /> collecting a sample from near the surface of the water in the well. The samples were checked for <br /> ' measurable floating hydrocarbon product. All Teflon® bailers are triple washed with Alconox® <br /> and triple rinsed with distilled water prior to use. <br /> ' Before water samples were collected from the groundwater monitoring wells, the wells were purged <br /> until stabilization of the temperature, pH, and conductivity were obtained. Approximately three <br /> well casing volumes were purged before those characteristics stabilized. The quantity of water <br /> ' purged from each well was calculated as follows: <br /> 1 well casing volume=pA(7.48) where: <br /> r=radius of the well casing in feet. <br /> h=column of water in the well in feet <br /> (depth to bottom -depth to water). <br /> 7.48 = conversion constant from cubic feet to gallons <br /> Gallons of water purged/gallons in I well casing volume =well casing volumes removed. <br /> After purging, each well was allowed to recharge to at least 80% of the initial water level. Water <br /> ' samples were collected with a new disposable or Teflon® bailer, and carefully poured into 40- <br /> milliliter (ml) glass vials, which were filled so as to produce a positive meniscus. Each vial was <br /> preserved with hydrochloric acid, sealed with a cap containing a Teflon®septum, and subsequently <br /> examined for air bubbles to avoid headspace, which would allow volatilization to occur. The <br /> samples were promptly transported in iced storage in a thermally insulated ice chest, accompanied <br /> by a Chain of Custody Record, to a California-Certified Laboratory. <br /> 1 <br />