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Quality assurance objectives have been established to develop and implement procedures <br /> for obtaining and evaluating water quality and field data in an accurate, precise, and <br /> complete manner. In this way, sampling procedures and field measurements provide <br /> information that is comparable and representative. of actual field conditions. Quality <br /> control (QC) is maintained by site-specific field protocols and requiring the analytical <br /> laboratory to perform internal and external QC checks. The goal is to provide data that <br /> are accurate, precise, complete, comparable, and representative. The definitions as <br /> developed by overseeing federal, state, and local agency guidance documents for <br /> accuracy, precision, completeness, comparability, and representativeness are: <br /> * Accuracy — the degree of agreement of a measurement with an <br /> accepted reference or true value. <br /> • precision — a measure of agreement among individual measurements <br /> - under similar conditions. Usually expressed in terms of the standard <br /> deviation. <br /> • Completeness — the amount of valid data obtained from a <br /> measurement system compared to the amount that was expected to meet <br /> the project data goals. <br /> • Comparability — expi:,ss the confidence with which one data set car <br /> be compared to another. <br /> • Representativeness — a sample or group of samples that reflect the <br /> characteristics of the media at the sampling point. it also includes how <br /> - well the sampling point represents the actual parameter variations which <br /> are under study. <br /> Laboratory and field handling procedures of samples are monitored by including QC <br /> samples for analysis with every submitted sample lot from a project site. QC samples <br /> may include any combination of the following: <br /> E <br /> • 'Trip Blanks: Used for purgeable organic compounds only; QC <br /> samples are collected in 40 milliliter (ml) sample vials filled in the <br /> analytical laboratory with organic-free water. Trip blanks are sent to <br /> the project site, and travel with project site samples. Trip blanks are <br /> not opened, and are returned from a project site with the project site <br /> samples for analysis. <br /> EXCELTECH, INC. <br /> Groundwater Sampling Protocol <br /> Latest Revision: May 3, 1991 <br />