Groundwater

Description
Explanation
Map Layers

The Arkansas Groundwater - Quality Network is a web map interface that provides rapid access to the U.S. Geological Survey's (USGS) NWIS and the U.S. Environmental Protection Agency's (EPA) STORET databases of ambient groundwater information. The interface enables users to perform simple graphical analysis and download selected water-quality data.

Description of NWIS and STORET Databases The National Water Information System (NWIS) is part of the USGS's program for disseminating water data it has collected. NWIS includes approximately 57,000 groundwater locations in Arkansas, although many of these locations only contain water-level data.

The STORET (STOrage and RETrieval) Data Warehouse is EPA's national repository for water quality, biological, and physical data collected by federal agencies, states, tribes, local governments, academic groups, watershed and volunteer monitoring organizations, and the public. STORET contains information and water-quality data for approximately 450 groundwater and spring sites in Arkansas, including general chemistry data from ADEQ's ambient groundwater-quality network.

Map Interface The Arkansas Groundwater-Quality Network web map interface uses geospatial capabilities of ArcGIS to retrieve data directly from NWIS and STORET using the National Water Quality Monitoring Council's Water Quality Portal. The Portal provides data in a consistent format utilizing the common format known as the Water Quality Exchange (WQX) to output data from both NWIS and STORET.

Data Retrieval Well and spring sites of interest may be selected geographically using the map interface or by defining a point location and radius around the point.

To select sites using the map interface, the user first selects the site type of interest, wells or springs or both, and the database, STORET or NWIS or both, from the check box menu found within the "Explanation" tab in the map interface menu along the left side of the page. The user may also change the base map background by selecting the desired base map from a list found within the "Map Layers" tab also in the map interface menu. Using the navigation tools along the right side of the page, the user zooms into the area of interest, and clicks the "Retrieve GW Data in Map View" button found within the "Explanation" tab.

Additionally, users may select well and spring locations of interest by entering the latitude and longitude, in decimal degrees or degrees, minutes, and seconds; a search radius, in miles; and clicking the "Retrieve GW Data in Radius" button in the sites tab. After the retrieve data buttons are clicked, the data management page is opened within a new browser window.

Data Management The data management page provides users with the opportunity to select and unselect sites, perform simple graphical analyses, and view and download data.

Users may further refine their site selection by using the pull-down menu to the right of the "Monitoring Location Identifier" heading and clicking on or off the desired check boxes associated with the listed sites.

The pull-down menu to the right of the "Action" heading provides users with the opportunity to perform simple graphical analysis, preview selected site data and/or download selected site data. Graphical analyses of selected site data are limited to equivalent concentrations of the Cations and the Anions, in milliequivalents per liter (meq/L) or milligrams per liter (mg/L). Available graphical analyses include Pie and Bar charts, and Stiff diagrams.

Selected site data may be viewed before downloading by clicking on the radio button associated with "PREVIEW DATA (web)". Selected site data may be downloaded in a tab delimited, comma delimited, or Excel format by clicking on the appropriate radio button associated with the desired format.

Development The Arkansas Groundwater - Quality Network web page was developed by the USGS Arkansas Water Science Center in cooperation with the Arkansas Department of Environmental Quality (ADEQ) using funding provided by an USEPA Exchange Network grant.

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