Techniques of Water-Resources Investigations 9-A1-A9
National Field Manual for the Collection of Water-Quality Data
U.S. Geological Survey
Water-Quality Sampling
The U.S. Geological Survey (USGS), a science agency within the U.S. Department of the Interior, is mandated to provide the information needed for accurate assessment, protection, and wise management of the Nation’s water resources. To fulfill this mandate, the USGS collects, and assists others in collecting, the data needed to determine the quality and quantity of our surface and subsurface water bodies. The reliability and timeliness of such data are fundamental to maintaining and protecting our human and environmental health, and are designed to address such questions as:
- Is our water of acceptable quality for drinking or swimming, for irrigation or aquatic habitat?
- Is water quality getting better or worse?
- What is causing the pollution or deterioration of a given lake, stream, or aquifer?
- Are regulatory requirements being met?
- How does the quality of one water body compare with other waters across the state or country?
Challenges to Environmental Monitoring
These questions, while vital to human and environmental health, are not readily answered. Addressing them requires identifying appropriate measurements, taken at appropriate locations, and using appropriate techniques. To meet these requirements, a monitoring design is needed that is based on a clearly articulated purpose and data-quality objectives and that is supported by sound plans for data management and analysis. Moreover, the techniques used and site conditions encountered must be sufficiently documented to (a) ensure that the body of data collected is internally consistent, and (b) determine whether the data are comparable to and compatible with other potentially relevant information.
Data Comparability and Collaboration
Consistent and comparable water-quality monitoring data are needed for describing the status and trends of a water resource; addressing existing and emerging water-quality issues; determining compliance with health standards; and combining the information gathered by different agencies. The USGS and USEPA, through the National Water Quality Monitoring Council, are working with other public and private Organizations to facilitate data sharing by identifying and documenting standardized field and laboratory methods. One outcome of this collaboration is development of a National Environmental Methods Index, a clearinghouse of environmental monitoring methods (see www.nemi.gov).
National Field Manual for the Collection of Water-Quality Data
This Web-based report series is used by the USGS for informing and training its field personnel in the collection of water-quality data. The “NFM” emphasizes the use of science-based decisions and quality assurance by field personnel. These reports prescribe protocols and standards that:
- Promote and enhance the comparability of water data
- Help ensure and document data quality.
- Help to avoid costly duplication of effort and facilitate sharing of data and resources.
- Provide guidelines that are relevant to making informed and effective decisions about the assessment, protection, and management of the Nation’s water resources.
This report is available on the USGS Office of Water-Quality Site.
VIEW the report.

