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Guidelines for field-measured water-quality properties

July 10, 2023

The “National Field Manual for the Collection of Water-Quality Data” (NFM) provides guidelines and procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation’s surface-water and groundwater resources. This chapter, NFM A6.0, provides guidance and protocols for the measurement of field parameters on site, which include the selection of sites and methods for measurement in groundwater and surface water and procedures for measurement and reporting. It updates and supersedes USGS Techniques of Water-Resources Investigations, book 9, chapter A6.0, version 2.0, by Franceska D. Wilde. Field parameters are routinely measured when water samples are collected, are often measured continually at USGS streamgages, and are regularly measured during laboratory and field experiments. The field methods for measuring field parameters described in this chapter are applicable to most natural waters.

Before 2017, the NFM chapters were released in the USGS Techniques of Water-Resources Investigations series. Effective in 2018, new and revised NFM chapters are being released in the USGS Techniques and Methods series; this series change does not affect the content and format of the NFM. More information is in the general introduction to the NFM (USGS Techniques and Methods, book 9, chapter A0) at The authoritative current versions of NFM chapters are available in the USGS Publications Warehouse at Comments, questions, and suggestions related to the NFM can be addressed to

Publication Year 2023
Title Guidelines for field-measured water-quality properties
DOI 10.3133/tm9A6.0
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Techniques and Methods
Series Number 9-A6.0
Index ID tm9A6.0
Record Source USGS Publications Warehouse
USGS Organization WMA - Observing Systems Division