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FIELD PROTOCOL <br /> The static water level and floating product level, if present, in each well that contained water was measured <br /> with an ORS Interphase Probe Model No. 1068018 or Solonist Water Level Indicator; these instruments are <br /> accurate to the nearest 0.01 foot. These groundwater depths were subtracted from wellhead elevations, <br /> including corrections for product thickness, when necessary, for gradient evaluation by multiplying product <br /> thickness (PT) by a correction factor 0.8 and subtracting from the DTW (Adjusted DTW = DTW - [PT x <br /> 0.8]). <br /> Water samples collected for subjective evaluation were collected by gently lowering approximately half the <br /> length of a new disposable or Teflon®bailer past the air-water interface (if possible) and collecting a sample <br /> from near the surface of the water in the well. The samples were checked for measurable floating <br /> hydrocarbon product. All Teflon® bailers are triple washed with Alconox® and triple rinsed with distilled <br /> water prior to use. <br /> Before water samples were collected from the groundwater monitoring wells, the wells were purged until <br /> stabilization of the temperature, pH, and conductivity were obtained. Approximately three well casing <br /> volumes were purged before those characteristics stabilized. The quantity of water purged from each well <br /> was calculated as follows: <br /> ' 1 well casing volume =pr'h(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 1 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 samples <br /> were collected with a new disposable or Teflon® bailer, and carefully poured into 40-milliliter (ml) glass <br /> vials, which were filled so as to produce a positive meniscus. Each vial was preserved with hydrochloric <br /> acid, sealed with a cap containing a Teflon® septum, and subsequently examined for air bubbles to avoid <br /> headspace, which would allow volatilization to occur. The samples were promptly transported in iced <br /> storage in a thermally insulated ice chest, accompanied by a Chain of Custody Record, to a California- <br /> Certified Laboratory. <br /> • <br /> i <br />