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
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, and the STEWARDS data are refreshed once a week on
How much data are available?
As of February 2014, over 228 million results from over
monitoring locations are currently accessible through the
portal. The portal reports samples and results collected
from each location since the beginning of the
Why do I have to add "USGS-" or other
organization identifiers in fornt of my NWIS site id
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 the Mapping tool when I download data in KML
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. Due to technical limitations in web
mapping technology, we have limited the maximum number of
sites that can be mapped on the WQP Map tool to 250,000,
which is large enough to encompass the vast majority of
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. The "Sampling Parameter" section of
the query page, which requires working through 100x more
data that site-dependent queries, can ofter slow query
response. 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 run time.