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6 . 0 Sampling and Drilling Equipment Decontamination <br /> All equipment used for drilling, well materials and sampling <br /> soil and groundwater will be decontaminated prior to use. <br /> All equipment used for collection of more than one sample, <br /> such as bailers and spoons, will be decontaminated between <br /> each use to prevent cross contamination between samples. <br /> Drilling equipment will be decontaminated prior to <br /> commencing drilling at each hole. <br /> Equipment and well material decontamination will be <br /> conducted on an impermeable surface and all decontamination <br /> effluent will be contained. All surfaces of the equipment <br /> will be thoroughly rinsed with potable water. The equipment <br /> will be placed on a drying rack for air drying. The <br /> decontamination water will stored in containers certified <br /> for hazardous materials storage and disposed of in an <br /> approved manner. <br /> Sample equipment to be used for pesticides and organic <br /> analysis will be washed in a nonphosphate detergent (Alconox <br /> or equivalent ) and rinsed with tap water, followed by <br /> deionized water and finally with acetone. If the equipment <br /> is for metals analysis, the initial rinse will be conducted <br /> with 0. 1 N nitric acid followed by tap water and deionized <br /> water. <br /> 7. 0 Field Equipment Calibration and Maintenance <br /> The following measuring equipment may be used during the <br /> Remedial Investigation. Equipment is grouped by field <br /> activity. Calibration procedures and frequency are listed <br /> for each piece. <br /> Soil Borings and Well Installation- Steel and coated cloth <br /> tape. Calibration: none. <br /> Water Level Measurements in Wells- Steel surveyors tape. <br /> Calibration: manufacturer supplied temperature correction <br /> will be applied as applicable for field conditions . <br /> Electrical well sounders. Calibration: check against steel <br /> surveyor' s tape. <br /> Organic Vapors- Photoionization detector. Calibration: <br /> Daily field Calibration using a benzene standard. <br /> Groundwater pH Measurement- Digital pH meter. Calibration: <br /> standard pH solutions of 4, 7, and 10 will be utilized for <br /> daily field calibration. <br />