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Nonpoint Source Characterization and Control
Goal 2: Protecing America's Waters
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Introduction
The National Risk Management Research Laboratory (NRMRL) is researching cost-effective water quality restoration and protection management to establish best management practices (BMPs) for controlling the pollution that affects our water resources. Researchers in nonpoint source characterization and control investigate methods to predict the quantity and quality of stormwater runoff and other diffuse sources of surface water contamination, and to mitigate the loading of contaminants to receiving waters. In fiscal year 2008, EPA’s research addressed three topics:
- Characterization of nonpoint source pollution
- Enhancement of models to simulate stormwater runoff
- Assessment of the performance of conventional and emerging structural controls for stormwater runoff
Emphasis is being placed on characterizing sediments, nutrients, and pathogens—the top three stressors causing water quality impairment. Emerging contaminants are also being studied.
EPA researchers are characterizing pathogens and nutrient runoff from the field application of manure. Scientists are also looking at surface water contamination (via groundwater) from concentrated animal feeding operations and failing on-site treatment systems.
Stormwater runoff modeling research (such as Storm Water Management Model [SWMM]) is developing improved models to simulate runoff characteristics (such as flow and pollutant concentrations/loadings) based on land use and land cover. These simulations can be integrated with water quality models to assess current water quality and forecast future water quality based on the application of management practices and other controls in the watershed.
BMP researchers are evaluating the performance and monitoring of selected structural management practices under controlled conditions. New BMPs and their design are being researched and developed for green infrastructure (e.g., as applied to low-impact development).
In addition, the effectiveness of comprehensive nutrient management plans (CNMPs) are being studied, along with innovative approaches to controlling releases from septic systems. The results of this research are integral to accomplishing successful watershed management. For example, results of BMP research are used in the development of watershed management models such as SUSTAIN (a BMP process and placement tool for urban watersheds) and the modified Soil and Water Assessment Tool (modified SWAT).
Environmental Issue or Problem
Nonpoint source pollution is that which is caused by a wide range of activities, including urban development, agriculture, and forestry. Nonpoint source pollution is the leading remaining cause of water quality problems as reported by the states. The effects of nonpoint source pollutants on our water resources vary and may not always be fully assessed. However, we know that these pollutants have harmful effects on our drinking water supplies, recreation waters, fisheries, and wildlife.
Nonpoint source pollution is caused by rainfall or snow melt moving over and through the ground. As the runoff moves, it picks up and carries natural and human-made pollutants, ultimately depositing them into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water. These pollutants include:
- Excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas
- Oil, grease, and toxic chemicals from urban runoff and energy production
- Sediment from crop and forest lands, eroding stream banks, and improperly managed construction sites
- Salt from irrigation practices and acid drainage from abandoned mines
- Bacteria and nutrients from livestock and pet wastes, and faulty septic systems
- Atmospheric deposition and hydromodification
Long-Term Goal and Annual Performance Goals Addressed
Drinking Water Research Multi-Year Plan (under revision)
Water Quality Research Multi-Year Plan 2009–2014 (PDF) (55 pp, 552 KB, About PDF)
Contact
Alice Gilliland
Assistant Laboratory Director, Water