Water Resources--Office of Water Quality

National Field Manual

6.7 TURBIDITY

Version 2.1, dated 9/2005 (509 kb pdf)

Abstract

Turbidity is one of the indicators used to assess the environmental health of water bodies. Turbidity is caused by the presence of suspended and dissolved matter, such as clay, silt, finely divided organic matter, plankton and other microscopic organisms, organic acids, and dyes. This section of the National Field Manual (NFM) describes the USGS protocols for determining turbidity in surface and ground waters, including extensive guidance for equipment selection and data reporting. It includes the revised approach to turbidity measurement and reporting that was implemented by the U.S. Geological Survey (USGS) in October 2004 to account for technological advances and consequent measurement complexities.

6.7 - Turbidity

By Chauncey W. Anderson

6.7.1 Equipment
6.7.2 Calibration
6.7.3 Measurement
6.7.4 Quality-assurance procedures
6.7.5 Data reporting and interpretation
6.7.6 Troubleshooting
Selected References

Additional information on turbidity is available from the following links:
- Turbidity parameter codes and methods codes (January 2007) -- Excel spreadsheet (If a pop-up window appears, click "No.")
- U.S. Geological Survey Implements New Turbidity Data-Reporting Procedures--Information Sheet
- Revision of NFM Chapter 6, Section 6.7--USGS Water-Quality Technical Memorandum 2004.03

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Maintainer: Office of Water Quality
Last Modified: 21Feb07 imc
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Archive of 6.7 Turbidity, ver. 1, dated 4/98
Archive of 6.7 Turbidity, ver. 2.0, dated 8/2004
URL: http://water.usgs.gov/owq/FieldManual/Chapter6/Ch6_contents.html