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Water-Quality Data for the Nation
Real-time water-quality data are returned directly from field instruments.
Instantaneous data are recorded at 5-minute to 1-hour intervals
and uploaded to the data base every 4 hours.
Retrieve water-quality data from field and/or laboratory analysis of water,
biological tissue, stream sediments, and other environmental samples.
Tutorial explaining how to perform a water quality retrieval and understand the results
The USGS collects and analyzes chemical, physical, and biological
properties of water, sediment and tissue samples from across the
discrete sample data base is a compilation of over 4.2
million historical water quality analyses in the USGS district data
bases through September 2003. The discrete sample data is a large and
complex set of data that has been collected by a variety of projects
ranging from national programs to studies in small watersheds. Users
should review the help notes and particularly
the Data retrieval
precautions before beginning any retrieval or analysis of data from
this data set. Additions of more current data, modifications to
ancillary information, and enhanced retrieval options to help users
find and appropriately use the data they need are planned for a future
release of NWISWeb.
At selected surface-water and ground-water sites, the USGS
maintains instruments that continuously record physical and chemical
the water including pH, specific conductance, temperature, dissolved
oxygen, and percent dissolved-oxygen saturation. Supporting data such as
air temperature and barometric pressure are also available at some sites.
At sites where this information is transmitted automatically, data
are available from the
real-time data system.
You may find additional water-quality data of interest in