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�. Working to Restore Nature <br /> FIELD PROTOCOL <br /> �► The static water level and floating product level, if present, in each well that contained <br /> water was measured with an ORS Interphase Probe Model No. 1068018 or Solonist Water <br /> Level Indicator; these instruments are accurate to the nearest 0.01 foot. These groundwater <br /> depths were subtracted from wellhead elevations,including corrections for product thickness, <br /> when necessary, for gradient evaluation by multiplying product thickness (PT) by a <br /> correction factor 0.8 and subtracting from the DTW (Adjusted DTW = DTW - {PT x 0.8]). <br /> L. <br /> Water samples collected for subjective evaluation were collected by gently lowering <br /> approximately half the length of a new disposable or Teflon® bailer past the air-water <br /> interface (if possible) and collecting a sample from near the surface of the water in the well. <br /> The samples were checked for measurable floating hydrocarbon product. All Teflon® <br /> r bailers are triple washed with Alconox® and triple rinsed with distilled water prior to use. <br /> Before water samples were collected from the groundwater monitoring wells, the wells were <br /> purged until stabilization of the temperature, pH, and conductivity were obtained. <br /> Approximately four well casing volumes were purged before those characteristics stabilized. <br /> The quantity of water purged from each well was calculated as follows: <br /> 1 well casing volume = irrZh(7.48) where: <br /> �-Awl 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 <br /> 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. <br /> ` Water samples were collected with a new disposable or Teflon®bailer, and carefully poured <br /> into 40-milliliter (ml) glass vials, which were filled so as to produce a positive meniscus. <br /> Each vial was preserved with hydrochloric acid, sealed with a cap containing a Teflon® <br /> septum, and subsequently examined for air bubbles to avoid headspace which would allow <br /> volatilization to occur. The samples were promptly transported in iced storage in a <br /> thermally-insulated ice chest, accompanied by a Chain of Custody Record, to a California- <br /> certified laboratory. <br /> M <br /> ..tii <br /> {� F7132.93/Q14 <br />