Groundwater Protection Program
The responsibilities of the Groundwater Protection Program include groundwater quality monitoring and the interpretation and dissemination of ambient groundwater data, as well as providing technical review of permit applications for the permitting staff. The manager also administers portions of the Clean Water Act Section 106 grant that support other state groundwater protection programs (e.g., the Arkansas Department of Health Wellhead Protection Program). When required, the manager also serves on state or federal committees or other technical work groups addressing existing or emerging groundwater-related issues.
Ambient Groundwater Monitoring
One of the more important functions of the program is the ambient groundwater monitoring program, developed to document existing groundwater quality in various aquifers throughout the state. The program currently utilizes a network of approximately 250 water supply wells (domestic, irrigation, municipal, and industrial) and spring sites within 11 discrete monitoring areas. Sampling is typically conducted in summer when the wells are more active. A full suite of inorganic parameters is analyzed—including trace metals, major cations and anions, total organic carbon, and nutrients—much the same as the chemical parameters measured for the ADEQ ambient surface water network. For selected sites (near industries, landfills, and facilities that manufacture, store, or dispose of organic chemicals), semi-volatile and volatile organic analyses are performed. Because each area of the state is sampled approximately every three years, the data can be used to identify trends and changes in water quality over time. Special groundwater quality sampling is also conducted as required, e.g., to assist with research projects at university geoscience departments in Arkansas.
Arkansas Groundwater – Quality Network
The majority of ambient groundwater quality monitoring in Arkansas is conducted by ADEQ and the United States Geological (USGS) Survey Lower Mississippi-Gulf Water Science Center. A Web-based tool for retrieving and analyzing ADEQ and USGS groundwater quality data can be accessed at the Arkansas Groundwater-Quality Network.
To find groundwater quality monitoring results, use ADEQ’s water quality monitoring data search. ADEQ water quality monitoring data includes surface water and groundwater quality monitoring data.
In general, groundwater quality is good to excellent throughout the state. Exceptions to this are high iron and manganese concentrations that occur in a variety of geologic conditions, and areas of high chloride in localized areas of the Gulf Coastal Plain in eastern Arkansas. Adverse effects due to nonpoint sources, although regional in scope, primarily result in low-level contamination (below established health standards). Point sources or site-specific sources can cause higher levels of contamination but are normally quite localized (usually within site boundaries). Groundwater Section personnel work with other ADEQ divisions and other agencies in crafting guidelines to address both point and nonpoint sources of pollution as required.