The Water Quality Portal (WQP) is a cooperative service sponsored by the United
States Geological Survey (USGS), the Environmental Protection Agency (EPA) and the
National Water Quality Monitoring Council (NWQMC) that integrates publicly available
water quality data from the USGS National Water Information System (NWIS) and the
EPA STOrage and RETrieval (STORET) Data Warehouse.
The EPA water quality data originate from the STORET Data Warehouse, which
is the EPA's repository of water quality monitoring data collected by water resource
management groups across the country. Organizations, including states, tribes, watershed
groups, other federal agencies, volunteer groups and universities, submit data to
the STORET Warehouse in order to make their data publicly accessible. For more information
about STORET, see the STORET Home Page.
The USGS water quality data originate from the NWISWeb Database. The database
contains current and historical water data from more than 1.5 million sites across
the nation and is used by state and local governments, public and private utilities,
private citizens, and other federal agencies involved with managing our water resources.
For more information on what data are available and how NWIS data are mapped to
the Water Quality Exchange (WQX) format, visit NWIS Water Quality Web Services.
Are the data from the Water Quality Portal (WQP) available through web services?
The WQP provides an easy way to access data stored in various large water quality
databases through form-based queries as well as through standalone web services
(A web service is a computer-to-computer protocol that allows for the direct sharing
of information. Applications such as internet portals can use the web services to
access data from the various databases without needing an authorized database connection).
The WQP provides various input parameters on the form interface including location,
site, result, and date parameters to filter and customize the output result set.
Equivalent data retrievals can be performed using web services, which have the same
input parameters and predefined output formats offered through the form. For more
information see the Web Services Guide.
How often are the data refreshed?
The USGS services are refreshed every 24 hours. The STORET services are refreshed
once a week on Thursday evening.
How much data are available?
As of November 2011, nearly 200 million results from over 5 million monitoring
locations are currently accessible through the portal. The portal reports samples
and results collected from each location since the beginning of the databases.
Why do I have to add "USGS-" in front of my NWIS site id when searching?
Why do I have to add the Organization ID in front of my STORET site id when searching?
The site ids in the STORET and NWIS systems have not been harmonized (unlike the
case with characteristics). Therefore, a site id may be duplicated across the two
systems. Furthermore, the site id within STORET is unable to serve as a unique identifier
for a site because STORET aggregates data from different organizations who have
not harmonized their identifiers. Because of these reasons, the WQP has chosen to
prefix the simple site id in order to make it a suitable unique identifier.
Why is the MonitoringLocationIdentifier not quite the same as the site ID?
The MonitoringLocationIdentifier is meant to be consistent within the WQP in the
sense that any MonitoringLocationIdentifier you get back from the WQP can be re-input
into the WQP as a site id search identifier. However, if you are used to using STORET
or NWIS, this site id will not be consistent with the site id used by STORET or
NWIS. For the reasons why the WQP site id is different from the STORET or NWIS site
id, please see the answer to the question above.
Why will Google Earth display a lot more points than Google Maps when I download
data in KML format?
KML files specify a set of sites that can be displayed in Google Earth, Google Maps,
or any other 3D Earth browser compatible with KML. However, Google Maps currently
has specific limitations to the size and complexity of loaded KML files. Google
Maps can only support a maximum of 1,000 sites, whereas Google Earth can support
much more. (Note: this limit is temporary and is subject to change at any time).
Why do some queries take longer than others? How can I reduce the time it takes
for the WQP to return my dataset?
Some queries take longer to return the resulting dataset than other queries
for various reasons. Large datasets will take longer to return depending on file
size and internet connection speed. Mark the checkbox to compress your dataset to
speed up download time. Using certain filters also affects query run time. Use the
start date filters to reduce the size of the resulting dataset and to reduce query