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r <br /> McDowe!!&Davis Towing <br /> Subsurface Soil&Groundwater Investigation <br /> Page: 6 <br /> All sampling equipment including the pump, bailer, and cables, used by sampling <br /> personnel, will be disassembled, if appropriate, and steam-cleaned prior to <br /> commencement of sampling. These procedures will also be followed between <br /> each well, sampling point and at the end of the sampling day. De-ionized or <br /> organic-free water (also provided by the laboratory) will then be introduced into <br /> the pump or bailer as a final stage of cleaning. This water will then be pumped or <br /> gently poured into sample vials to be used as pump or bailer blanks. These blanks <br /> will be tested only if their corresponding samples are found to contain <br /> contaminants. <br /> Immediately prior to sampling, water levels and well depth measurements will be <br /> taken in all wells at the site. Each well will be evacuated using a stainless steel <br /> bladder pump, which does not introduce air into the water column, or a Teflon <br /> bailer. The pH, temperature, and electrical conductivity of the water will be <br /> monitored as the well is evacuated. These parameters will be noted on a field log. <br /> Instruments calibrated to known standards will be used to monitor these <br /> parameters. At least 5 well volumes will be evacuated from each well, and more, <br /> if necessary, until the above parameters have stabilized. Wells that are de- <br /> watered before evacuation of 5 well volumes have been accomplished will be <br /> sampled upon 80 percent recovery of the initial water level. The wells or other <br /> sampling points will be sampled in order of the least to the most contaminated, as <br /> best known or estimated. The samples will be pumped from a stainless steel <br /> bladder pump or carefully poured from a Teflon bailer into clean glass vials with <br /> Teflon-lined screw caps and half gallon plastic containers provided by the <br /> laboratory. Care will be taken to ensure that no air space exists in the vials by <br /> inverting to check for bubbles and re-sampling if necessary. <br /> The samples will be analyzed or extracted within 14 days according to their EPA <br /> methods. Water samples collected for analysis will be analyzed by EPA method <br /> 8021B for BTX&E, EPA 8260 for Oxygenated Compounds and method 5030 for <br /> gasoline. The minimum detection limits used for each analyte will be .0005 mg/l <br /> for BTX&E, .001 mg/l for 8260, and 0.05 mg/1 for gasoline. Analysis will be <br /> conducted by GeoAnalytical Laboratories, Inc <br /> Prepared by: ioar <br /> 8' µ <br /> ails? <br /> Michael J loberdanz, REA, HS <br /> California Registered Environmental Assessor#02157 b <br /> r�� <br /> California Registered Environmental Health Specialist#4783 arp L► <br />