Surface Water Monitoring Program
ADEQ monitors Arkansas’s surface water in streams and lakes by collecting samples, which ADEQ’s Technical Services Division (the Lab) analyzes. Chemical, physical, and biological data derived from these samples are used for water quality assessments, designated use attainment decisions, and special projects such as total maximum daily loads (TMDLs) development and watershed characterization.
Ecologists, geologists, and biologists from the Water Quality Planning Branch and inspectors from the Water Inspection Branch use collection procedures that adhere to Arkansas’s Water Quality and Compliance Monitoring Quality Assurance Project Plan. Water Quality data for all ADEQ sampling sites can be downloaded using the Lab’s searchable database.
Streams Monitoring Program
Biological monitoring is an important component of assessing Arkansas’s waters. Often, water quality monitoring alone is not sufficient to determine whether aquatic life is being impaired. Conducting biological surveys is an effective way to determine how pollution from point and nonpoint sources affects ecosystems. Long term monitoring of chemical, physical, and biological data can help increase our knowledge of direct and indirect effects of natural and man-made stressors.
Anthropogenic (human-made) disturbances do not always result in noticeable changes in water chemistry. But physical habitat alteration resulting from human activities can have far-reaching impacts on aquatic life. Changes in flow, increased scouring, retention of organic material, and decreased streambed diversity are a few examples of habitat alteration that have direct consequences for aquatic plants and animals.
At this time, physical habitat data is only available upon request. Contact Tate Wentz at 501-682-0661, for available data.
ADEQ employees collect and chemically analyze water samples for parameters listed in the current State of Arkansas Water Quality Monitoring and Assessment Program, Revision 4, to:
- Identify impaired waters
- Support the evaluation of program effectiveness
- Establish, review, and revise water quality standards
- Establish geographic trends in stream quality
- Refine physical, chemical, and biological assessment tools to improve water quality assessments
- Evaluate water quality and designated use attainment for development of the 303(d) list and 305(b) report
- Characterize the performance of management actions
- Determine appropriate management strategies if designated uses are not being attained
- Assess the effects of point source dischargers upon water quality
- Observe the impact of known nonpoint source pollution trends
- Monitor all waters of the state
- Provide long-term physical, chemical, and biological data, and monitoring of the state’s least-disturbed ecoregion reference waterbodies
Water Quality data can be downloaded using the Technical Service Division’s searchable database.
Fishes represent the top of the aquatic food chain and are important indicators of ecosystem health. Extensive knowledge of the habitat, life history, longevity, and mobility of native species provide insight into long-term and widespread effects of the physical and chemical alteration of water. Fish collection and habitat data are available on ADEQ’s website.
Information on the bioaccumulation of mercury in fish tissue is included under the Mercury in Fish heading in the Lakes Monitoring Program below.
Extensive research has been compiled on the life history, tolerance, and habitat requirements of aquatic macroinvertebrates, making them exceptional indicators of ecosystem health. With limited mobility and relatively short lifespans, these organisms provide insight into localized and current water quality conditions. Aquatic macroinvertebrate data are available on ADEQ’s website.
Periphyton (a complex matrix of algae and heteroptrophic microbes) represents the bottom of the food chain in aquatic ecosystems. While algal communities are important food sources for macroinvertebrates and some fishes, excessive algal growth can not only be an aesthetic nuisance but can also deplete oxygen available to other aquatic organisms. Ecologists collect periphyton samples to better understand relationships between chlorophyll-a and periphyton biomass to water chemistry parameters (e.g., nutrients).
Bacteria (Escherichia coli) are collected from selected sites to determine if primary contact limits are being attained during the critical season (May 1 to September 30). ADEQ uses data from these samples to assess impairment for purposes of the Clean Water Act. The Arkansas Department of Health maintains a list of swim beaches that are closed due to bacteria.
Lakes Monitoring Program
Water planning employees monitor the water quality of 16 of Arkansas’s large public lakes for designated use assessment and trend analysis. This routine monitoring plan began in 2011. Each of these lakes is sampled quarterly at the uppermost portion of the lake and at the dam. Profiles of the water column are recorded in the field. Water samples are collected for ambient monitoring parameters and analyzed by ADEQ’s lab. Water quality data are available online.
- Beaver Lake
- Blue Mountain Lake
- Bull Shoals Lake
- De Queen Lake
- DeGray Lake
- Dierks Lake
- Gillham Lake
- Greers Ferry Lake
- Lake Catherine
- Lake Fort Smith
- Lake Greeson
- Lake Hamilton
- Lake Nimrod
- Lake Ouachita
- Millwood Lake
- Norfolk Lake
Mercury in Fish
Mercury occurs naturally in the environment and can enter water through the breakdown of rocks and soil. Human activities such as mining, burning of fossil fuels, and miscellaneous industrial processes also contribute to mercury released in the environment.
Nearly all fish and macroinvertebrates contain trace amounts of mercury. Once mercury enters into the water, it is broken down by microorganisms. During this process, mercury is combined with methane to form methylmercury, one of the most toxic substances known. A fish’s diet, how long it lives, and how high it is in the food chain are all factors in the bioaccumulation of methylmercury in the fish’s tissue. Bioaccumulation results in relatively higher concentrations of mercury in predators at the top of the food chain, such as predatory fish like bass and fish-eating birds and mammals like herons and raccoons. Mercury levels in these predators can be thousands times greater than the concentrations of mercury found in the water column. Thus, the data for mercury in fish is expressed as mercury concentration in tissue rather than as a water quality value.