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fi <br /> 4.3.2 FIELD MEASUREMENTS <br /> Elecirical conductivity, temperature, and pH measurements will be made during the <br /> collection of each groundwater sample. A pH meter with a combination gel-filled <br /> electrode or equivalent will be used for field pH determinations. A combination <br /> electrical conductivity-temperature-salinity meter or equivalent measuring device will be <br /> used to determine the conductivity and temperature. All instruments will be calibrated <br /> daily during field activities to maintain accuracy. <br /> The measurements will be made as follows: <br /> • The cell or container used to collect the purge water obtained during well <br /> sampling will be rinsed with sample water before filling. <br /> • Probes will be thoroughly rinsed with distilled water before measurement, <br /> then submerged in the flow-through cell and measurements taken. <br /> • All field measurements will be recorded in the field data sheet notebook <br /> along with the sample location, time, and date of measurement. <br /> After measurements are made, the probes will be decontaminated by <br /> rinsing with distilled water. <br /> HNu readings will be taken during field activities as described in the Site Safety Plan <br /> (Appendix A). In addition, the HNu will be used to monitor vapors from the drill <br /> cuttings and soil samples. HNu readings will be recorded in the drilling log. <br /> 4.33 EQUIPMENT DECONTAMINATION <br /> Near the drilling locations, an area will be established for equipment decontamination. <br /> Personnel decontamination is addressed in the Site Safety Plan (Appendix A). <br /> The auger and rear portion of the drill rig will be steam-cleaned before drilling each <br /> soil boring. The entire drill rig will be steam-cleaned before it leaves the drill site, if <br /> requested by the field hydrologist. Weli casing and screens will be steam-cleaned <br /> before they are placed in the wells or will arrive on site already cleaned and wrapped. <br /> All soil and water sampling equipment will be cleaned prior to use, between use, and <br /> before it leaves the site. Cleaning will consist of a deterget,, wash followed by rinses <br /> with water, isopropanol, and deionized water. Decontamination wastewater will be <br /> contained and disposed of as described in Section 3.5.2. Equipment will be air-dried. <br /> SF0316051WPWW.51 4-7 <br /> -„p3 _ I <br />