Autonomous underwater vehicle provides high-resolution observations of water quality and much more. Photo (c) Peter Berrini, HDR, Inc., used by permission.

Noteworthy

National & Regional Science:

• Fact Sheet: Integrated Synoptic Surveys Using an Autonomous Underwater Vehicle and Manned Boats
• Press Release: Decades-old Nitrate Found to Affect Stream Water Quality
• Circular 1383-G: USGS Water Science Strategy – Observing, Understanding, Predicting, and Delivering Water Science to the Nation
• OFR 2013-1054: User's Manual for the National Water Information System of the USGS
• Press Release: New water-quality test for preventing unnecessary beach closures

Local Science Features:

• New Hampshire: Concentrations of Chloride and Sodium in Groundwater in New Hampshire From 1960 Through 2011
• Arkansas:
  • –Press Release: No Contamination from Fayetteville Shale Exploration Found in Sampled Wells
  • –USGS Report: Shallow Groundwater Quality and Geochemistry in the Fayetteville Shale Gas-Production Area, North-Central Arkansas, 2011
  • –Journal Article: Geochemical and isotopic variations in shallow groundwater in areas of the Fayetteville shale development, north-central Arkansas 

Past listings...

Water Quality Data

National Water Information System (NWIS)

NWIS provides current and historical water-quality data.

Today's Water Conditions

Water-Quality Watch provides continuous real-time water-quality measurements.

Water-Quality Web Services

Web services automate the sharing of USGS and USEPA water-quality monitoring data.

For More Data

Additional water-quality data resources are available.

USGS in Your Area

USGS Water Science Centers are located in each state.

Chapter A6. Field Measurements

National Field Manual for the Collection of Water-Quality Data (TWRI Book 9)

6.2 Dissolved Oxygen

Revised By Michael E. Lewis

This section of Chapter 6 is available as a pdf file:
6.2, Version 2.1 (dated 6/2006) [685KB PDF]

Download a copy of Adobe Acrobat Reader for free.

[August, 2011 -- This section is being revised to incorporate changes that have been made to the method for computing dissolved-oxygen solubility, as described in Water Quality Technical Memorandum 2011.03 and implemented in version 3 of DOTABLES software http://water.usgs.gov/software/DOTABLES/ ].

Abstract

Accurate data for the concentration of dissolved oxygen in surface and ground waters are essential for documenting changes in environmental water resources that result from natural phenomena and human activities. Dissolved oxygen is necessary in aquatic systems for the survival and growth of many aquatic organisms and is used as an indicator of the health of surface-water bodies. This section of the National Field Manual (NFM) includes U.S. Geological Survey (USGS) guidance and protocols for four methods to determine dissolved-oxygen concentrations: the amperometric, luminescent-sensor, spectrophotometric, and iodometric (Winkler) methods.

Contents

6.2 Dissolved Oxygen

6.2.1 Amperometric and luminescent-sensor methods

6.2.1.A Equipment and supplies

6.2.1.B Calibration

One-point and two-point calibrations

Correction for atmospheric pressure and salinity

Calibration procedures

1. Air-calibration chamber in air

2. Calibration with air-saturated water

3. Air-calibration chamber in water

6.2.1.C Measurement

Surface water

Ground water

6.2.1.D Troubleshooting (amperometric instruments)

6.2.2 Spectrophotometric method

6.2.2.A Equipment and supplies

6.2.2.B Calibration and interferences

6.2.2.C Measurement

6.2.3 Iodometric (Winkler) method

6.2.3.A Equipment and supplies

6.2.3.B Measurement

6.2.4 Reporting

6.2.5 Correction factors for oxygen solubility and salinity

Selected references

Acknowledgments

Return to Chapter A6 Contents Page

Return to Field Manual Table of Contents

Section 6.2 Archived Versions:

• Archive: 6.2, Version dated April 1998 (130KB PDF)
• Archive: 6.2, Version 2.0, dated May 2006 (1.3MB PDF)