Chapter A6. Section 6.6. Alkalinity and acid neutralizing capacity

Techniques of Water-Resources Investigations 09-A6.6
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Alkalinity (determined on a filtered sample) and Acid Neutralizing Capacity (ANC) (determined on a whole-water sample) are measures of the ability of a water sample to neutralize strong acid. Alkalinity and ANC provide information on the suitability of water for uses such as irrigation, determining the efficiency of wastewater processes, determining the presence of contamination by anthropogenic wastes, and maintaining ecosystem health. In addition, alkalinity is used to gain insights on the chemical evolution of an aqueous system. This section of the National Field Manual (NFM) describes the USGS field protocols for alkalinity/ANC determination using either the inflection-point or Gran function plot methods, including calculation of carbonate species, and provides guidance on equipment selection. Newly published and revised chapters will be announced on the USGS Home Page on the World Wide Web under 'New Publications of the U.S. Geological Survey.'

Suggested Citation

Rounds, S.A., 2012, Alkalinity and acid neutralizing capacity (ver. 4.0, September 2012): U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chap. 6.6,

Table of Contents

  • 6.6 Alkalinity and Acid Neutralizing Capacity
  • 6.6.1 Equipment and Supplies
  • 6.6.2 Calibration and Standardization
  • 6.6.3 Collection and Processing
  • 6.6.4 Measurement
  • 6.6.5 Calculations
  • 6.6.6 Troubleshooting
  • 6.6.7 Reporting
  • Selected References
  • Acknowledgments
Publication type Report
Publication Subtype USGS Numbered Series
Title Chapter A6. Section 6.6. Alkalinity and acid neutralizing capacity
Series title Techniques of Water-Resources Investigations
Series number 09-A6.6
DOI 10.3133/twri09A6.6
Edition Version 3, Revised Jul 2006
Year Published 2012
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) U.S. Geological Survey
Description 53 p.
Larger Work Type Report
Larger Work Subtype USGS Numbered Series
Larger Work Title National Field Manual for the Collection of Water-Quality Data. U.S. Geological Survey Techniques of Water-Resources Investigations, Book 9
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