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will be decontaminated prior to commencing drilling at each <br />hole. Well construction materials will be cleaned as <br />necessary, prior to installation. <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 decontaminated using a steam cleaner. <br />The equipment will be placed on a drying rack for air <br />drying. The decontamination water will stored in containers <br />certified for hazardous materials storage and disposed of in <br />an 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 Dimensions -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 isobutylene standard as per <br />manufacturers instructions. <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 according to manufacturers <br />instructions. <br />Electrical Conductivity- Electrical conductivity meter. <br />Calibration: factory -calibrated annually and periodically <br />calibrated against laboratory prepared standard calibration <br />solution. <br />Water Temperature- Mercury or digital thermometers. <br />Calibration: factory -calibrated once. <br />