Laserfiche WebLink
i <br /> FIELD PROTOCOL <br /> 4 <br />!l I <br /> The static water level and floating product level, if present, in each well that <br /> contained water was measured with an ORS Interphase Probe Model No 1068018 <br /> or Solonist Water Level Indicator, these instruments are accurate to the nearest <br /> I 0 01 foot These groundwater depths were subtracted from wellhead elevations, <br /> including corrections for product thickness, when necessary, for gradient evaluation <br /> by multiplying product thickness (PT) by a correction factor 0 8 and subtracting from <br /> Ithe DTW (Adjusted DTW = DTW - CPT x 0 8]) <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 <br /> well The samples were checked for measurable floating hydrocarbon product All <br />' Teflon° bailers are triple washed with Alconox© and triple rinsed with distilled water <br /> prior to use <br />' Before water samples were collected from the groundwater Monitoring Wells, the <br /> wells were purged until stabilization of the temperature, pH, and conductivity were <br /> obtained Approximately four well casing volumes were purged before those <br /> characteristics stabilized The quantity of water purged from each well was calculated <br /> as follows <br /> 1 well casing volume = 7r'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 /> 748 = conversion constant from cubic feet to <br /> gallons <br />' Gallons of water purged/gallons in 1 well casing volume = well casing volumes <br /> removed <br />' After purging, each well was allowed to recharge to at least 80% of the initial water <br /> level Water samples were collected with a new disposable or Teflon° bailer, and <br /> carefully poured into 40-milliliter (ml) glass vials, which were filled so as to produce <br /> a positive meniscus Each vial was preserved with hydrochloric acid, sealed with a <br /> 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 <br />' transported in iced storage in a thermally-insulated ice chest, accompanied by a Chain <br /> of Custody Record, to a California-certified laboratory <br /> CanowteEnvironmental <br /> PL\W 194 2731REPORT514THQTR 223 [Feb 23 19951 <br /> I <br />