About the Program

The U.S. Geological Survey (USGS) Toxic Substances Hydrology (Toxics) Program was initiated in 1982 to provide objective and reliable scientific information needed to develop policies and practices that help avoid exposure to toxic substances, mitigate environmental deterioration from contaminants, provide cost-effective cleanup and waste-disposal strategies, and reduce future risk of contamination. Contamination of surface water, ground water, soil, sediment, and the atmosphere by toxic substances is among the most significant issues facing the Nation. Contaminants such as excessive nutrients, organic chemicals, metals, and pathogens enter the environment, often inadvertently, via industrial, agricultural, mining, or other human activities. The extent of their migration and their persistence often are difficult to ascertain. Estimates of the costs and time frames for cleanup of contamination and protection of human and environmental health can best be described as astounding, despite continual efforts by governments and industries worldwide to improve environmental technologies.

The Toxics Program conducts: (1) intensive field investigations of representative cases of subsurface contamination at local releases; and (2) watershed- and regional-scale investigations of contamination affecting aquatic ecosystems from nonpoint and distributed point sources. Toxics Program Investigations occur over a wide range of scales -- from intense point sources, such as leaks or discharges from industrial facilities; to multiple, closely spaced releases, such as domestic septic systems; to relatively uniform releases that occur over broad areas with similar land-use practices, such as agricultural and residential land uses.

Fundamental themes that motivate short-term goals and products of TOXICS Program investigations are:

• Process Understanding - Characterize the physical, chemical and biological processes that control contaminant source loading, transport and transformation in the environment with special emphasis on the natural response of hydrologic systems to contamination.
  
• Measurement - Develop methods for environmental measurement of a wide range of physical, chemical and biological properties that control the rates of transport and transformation processes, and measurement of contaminants and their byproducts in environmental samples from different media at levels low enough to explain environmental processing.
  
• Environmental Health - Describe the influence of contaminants on organisms, ecosystems, and the food web, and the potential long-term implications for human and environmental health.
  
• Modeling - Develop simulation models to assess environmental occurrence and potential exposure, by predicting contaminant transport, transformation, persistence, and fate, and to design management strategies, including monitoring networks, best management practices, and new techniques for waste disposal and remediation.