STORET Database Description
Data in modernized STORET (referred to from now on as STORET) is organized
into five information categories:
Organizations
The group or entity responsible for the data set, either for collecting
and otherwise generating the data, or sponsoring the activity for which
the data set was created;
Projects and Surveys
The activity during and for which the data set was created;
Sites
Also referred to as stations, carry the identification and description
of the physical location at which monitoring occurs;
Samples
Water quality sampling, observation, and measurement activities that occur
at these sites; comprehensive descriptors of the event during which samples
were collected or the measurements performed;
Results
The findings of the sampling events, measurements, and field activities.
Organization
In STORET organizations are the primary owners of data and control access
to it. Organizations own metadata (descriptions of their data). Organizations
own project descriptions, and lists of organizations and people with whom
they work. Organizations control a broad set of lists of their preferences
or usual practices for monitoring activities. These lists may include
aids to data entry (e.g. substances tracked by monitoring activities,
habitat evaluation criteria, and so forth), equipment used in the field,
methods used in their labs, bibliographic references, and many others.
In STORET, organizations control their own data through the use of an
organization-specific identification code provided by EPA, and passwords
controlled locally. The identification code ties together an organization's
projects, stations, and sampling data. To enter or modify an organization's
data, a user must supply the proper password. Without a proper password,
STORET restricts a user's access to "browse-only."
Projects and Surveys
STORET allows an organization to maintain descriptions, in summary form,
of the projects and surveys it conducts. The descriptions contain essential
information concerning purpose, procedures, standards and methods, and
quality goals. The descriptions also include information on individuals
who manage and participate in the projects. Project descriptions permit
linking data quality objectives and other quality control plan items to
a broad spectrum of data. In this way, the needs of users for data quality
descriptors can be met with a minimum of data entry effort.
Each project in STORET can involve one or more sampling stations ("sites"),
and a sampling station can participate in multiple projects. Field activities
and their analytical results are linked directly to all the projects they
support. Projects may in turn be linked to programs, and because programs
may be defined broadly to include the projects of several organizations,
data from any field activity may be easily shared among both organizations
and projects.
Sampling Stations (Sites)
All data concerning field work is keyed to the specific location at which
the field work is conducted, linking water quality measurements to the
place they represent. Each STORET site has a point of reference, whose
latitude and longitude are fully defined. In addition, each site may include
an area boundary, a field of actual monitoring locations, and the descriptions
of any permanent sampling grid or transect found there. For facilities,
additional data may be entered for the individual end-of-pipe locations;
for wells, a field of individual wells may be described.
Precise location definition is very important to environmental analysis,
and EPA data standards for locational data are strictly followed in STORET.
All applicable federal standards (FIPS, NIST, and others) are adhered
to wherever possible as well.
Sites may be part of external reference schemes, and may carry a multitude
of identifiers from each of these schemes. For example, a site in STORET
might have an NPDES number and a state regulatory program code. Any site
which contributes data to a project may be assigned a project-specific
identifier.
STORET gives organizations several options for identifying their stations.
Each station has a unique identifier, assigned at the discretion of the
organization that "owns" the data. An organization can also assign multiple
alias names to its stations. In addition, project managers can assign
a unique name to each participating station that is meaningful within
the context of their project. This allows a station to carry a different
name in each project in which it participates. A site must first have
its reference point defined before it may be assigned to one or more projects
and sample collection may begin. This assures that all results are place-based.
Organizations can maintain information on different types of sampling
stations (e.g., well, spring, stream, ocean). The system provides a common
set of geographic and descriptive information for all stations as well
as information specific to the individual type of sampling station.
To assign a station to a project (i.e., to collect samples) requires
a latitude/longitude coordinate [set] to be entered. STORET then takes
this information -- known as the station's point of record -- and presents
the user with candidate selections for the Federal Information Processing
Standard (FIPS) State, County, and Hydrologic Unit Codes (HUC). STORET
also allows an organization to add the latitude/longitude coordinates
of a series of points to a station description, transforming the station
from a single point to an area or polygon.
An organization can view and copy station descriptions belonging to another
organization. Copying a station description allows an organization to
include that station in its catalog of stations and makes the station
available for assignment to the organization's projects.
Samples (and Station Visits)
Samples are described according to their medium and the intent for which
they were collected. STORET accepts descriptions of the sample collection
process which address the complete spectrum of water monitoring and sampling
of the biological community. How a sample is collected is documented in
STORET by links between a sample and lists of methods and equipment. Lists
are available as part of the system, or client organizations may supply
their own lists.
For large area samples, such as trawls, details such as the lat/long
of its end points, gear deployment depth, and bottom conditions under
the trawl can all be captured.
Samples can be created from other samples, by compositing, splitting,
or subsampling. Each new sample is linked to its "parents" and can be
traced back to all the events which might influence its results. A sample
which is generated by a trawl (a "catch") might be the parent of a sample
which is an individual fish. The fish in turn might be the parent of a
sample which is a specimen of liver tissue, and chemical results for this
liver specimen can thus be traced back to the spatial coordinates of the
original trawl.
Field monitoring activities may be water, air, or sediment sample collection,
biological specimen catch/trap events, or any measurements or observations
obtained at the site. Each field activity is linked to those analytical
results it generates (see results below).
Information gathered in the field through the process of measuring or
observing the environment during the site visit is recorded in STORET
as part of the site visit description. These data may include physical
conditions of the site itself, status of any equipment permanently located
at the site, biological habitat assessments, weather observations, and
simple field-determined physical or chemical data. STORET can be used
to document the frequency with which visits to sampling stations are to
be conducted and to capture the results of a visit (samples collected,
field measurements, and qualitative observations of conditions). Information
about the sampling process, including standard procedures and methods,
deviations from these methods, and sample management, may also be stored.
Station visit and sample information can be associated with a single
station within a particular project.
Results
With STORET, results obtained through analysis of samples and "in situ"
measurements can be recorded and attached to the visit/sample to which
they relate. The system also stores metadata concerning the quality of
results related directly to the results.
Each result is linked to a field monitoring activity. If the activity
was the collection of a water sample, the results are qualified by all
the methods used to collect, handle, store, and process that sample. The
results may be further qualified by the identity of the lab performing
the analytical work, and equipment and methods used in this process. STORET
captures information about the participating laboratories and their qualifications.
It also captures identifying information for the substances or properties
being measured with qualifiers that enable valid data comparisons to be
made. Statistical information concerning confidence intervals may be supplied,
and for results which are not quantified, detection status and quantitation
status may be stored. Results which are counts or percentages may be qualified
by the range of some size or weight variable which they represent.
Biological results are handled in different ways. For a "catch", biota
may be grouped and regrouped repeatedly for counting, weighing, or measuring.
For example, one grouping might be by taxon, and the counts recorded for
purposes of computing taxonomic diversity and richness, while another
grouping might be a user-defined histogram or class frequency table of
fish lengths within a species, and yet another might be to record counts
and weights of only adults, or only gravid females, or any other category
the analyst might request. A catch might be divided so that a group contains
only 1 individual, and a detailed description of it recorded.
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