USGS Water-Quality Information
USGS personnel collect a water-quality sample on the Missouri River. USGS/Photo by Kelly Brady.
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.
Revised September 2006 Franceska D. Wilde, Managing Editor
This report is in pdf format. Download a copy of Adobe Acrobat Reader for free.
Chapter A4 describes preparations and methods for the collection of surface-water, ground-water, and associated quality-control samples. Topics covered in this chapter include procedures to prevent sample contamination, establishing site files, instructions for collecting depth-integrated isokinetic and nonisokinetic samples at flowing-water and still-water sites, and guidelines for collecting formation water from wells having various types of construction and hydraulic and aquifer characteristics.
Sections of Chapter A4. Collection of Water Samples:
Purpose and scope
Requirements and recommendations
Field manual review and revision
4.0. Responsibilities, field preparations, and preventing sample contamination
4.0.1. Responsibilities and field preparations
4.0.2. Preventing sample contamination
4.1. Surface-water sampling
4.1.1. Site files
4.1.2. Selection of surface-water sampling sites
4.1.3. Sampling at flowing-water and still-water sites
4.2. Ground-water sampling
4.2.1. Site inventory and site files
4.2.2. Considerations for collecting representative samples at wells
4.2.3. Well purging
4.2.4. Steps for sampling at wells
4.3. Quality control
4.3.1. Blank samples
4.3.2. Replicate samples
4.3.3. Spike samples
4.3.4. Reference samples
4.3.5. Blind samples
Conversion factors, selected terms, and abbreviations
Selected references and documents
Appendix A4-A. Transit rate and volume guidelines for isokinetic sampling
Appendix A4-B. Instructions related to measuring water levels at wells, and a sample USGS ground-water-quality field form
Appendix A4-C. Quality-control samples collected by field personnel for water-quality studies
Appendix A4-D. Examples from the National Water-Quality Assessment Program related to protocols for collecting blank samples at ground-water sampling sites
Chapter A4 Archive