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Water Resources--Office of Water Quality

...National Field Manual
Chapter A7. Biological Indicators

(Second Edition, 3/2003)


The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter of the manual includes procedures for the (1)determination of biochemical oxygen demand using a 5-day bioassay test; (2) collection, identification, and enumeration of fecal indicator bacteria; (3) collection of samples and information on two laboratory methods for fecal indicator viruses (coliphages; and (4) collection of samples for protozoan pathogens.

Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters will be posted on the World Wide Web on the USGS page "National Field Manual for the Collection of Water-Quality Data." The URL for this page is (accessed July 18, 2003.

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Last Modified: 9 Sept 03 imc