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The USGS collects and analyzes chemical, physical,
and biological properties of water, sediment and tissue samples from
across the Nation. The NWISWeb discrete
sample data base is a compilation of over 4.2 million historical
water quality analyses in the USGS district data bases through
September 2004. 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 characteristics of 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 EPA
STORET.
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Discrete water samples data are undergoing modernization with this page no longer being updated with the latest data
starting March 11, 2024 