Laserfiche WebLink
%ftwoo V <br /> GROUNDWATER SAMPLING PROCEDURES <br /> Equipment Cleaning <br /> Ail water samples are placed in precleaned laboratory-supplied bottles. Sample bottles and <br /> caps remain sealed until actual usage at the site. All equipment which comes in contact with <br /> the well or groundwater is thoroughly cleaned with a trisodium phosphate (TSP) solution <br /> and rinsed with deionized or distilled water before use at the site. This cleaning procedure is <br /> followed between each well sampled. Wells are sampled in approximate order of increasing <br /> contamination. If a teflon cord is used, the cord is cleaned. If a nylon or cotton cord is <br /> used, a new cord is used in each well All equipment blanks are collected prior to sampling. <br /> The blanks are analyzed periodically to ensure proper cleaning. <br /> Water Level Measurements <br /> Depth to groundwater is measured in each well using a sealed sampling tape or scaled <br /> electric sounder prior to purging or sampling. If the well is known or suspected of <br /> containing free-phase petroleum hydrocarbons, an optical interface probe is used to measure <br /> the hydrocarbon thickness and groundwater level. Measurements are collected and recorded <br /> to the nearest 0.01 foot. <br /> Bailer Sheen Check <br /> If no measurable free-phase petroleum hydrocarbons are detected, a clear acrylic bailer is <br /> used to determine the presence of a sheen. Any observed film as well as odor and color of <br /> the water is recorded. <br /> Groundwater Sampling <br /> Prior to groundwater sampling, each well is purged of "standing" groundwater. Either a <br /> bailer, hand pump, or submersible pump is used to purge the well. The amount of purging <br /> is dependent on the well yield. In a high yield formation, samples will be collected when <br /> normal field measurement, including temperature, pH, and specific conductance stabilize, <br /> provided a minimum of three well-casing volumes of water have been removed. Field <br /> measurements will be taken after purging each well volume. In low yield formations, the <br /> well is purged such that the "standing" water is removed and the well is allowed to recharge. <br /> (Normal field measurements will be periodically recorded during the purging process.) In <br /> EXCELTECH, INC. <br /> Groundwater Sampling Protocol <br /> Latest Revision: March 28, 1990 <br />