Development and use of robust extrapolation and inference-based techniques: NAWQA has done an exemplary job of developing and applying robust extrapolation and inference-based models (e.g., SPARROW and the Watershed Regression for Pesticides or WARP models that are statistical, geospatial, and/or process-based and that support inferences from recent and historical data and projections of the outcome of proposed actions).
Information dissemination: NAWQA’s communication activities have grown in scope and sophistication as the program has evolved. The program now uses multiple media and appealing graphics to communicate its information products and tools, and it has a wealth of publicly available water-quality data in its data warehouse.
NAWQA science informing policy and management decisions: The program has translated and interpreted its high-quality, nationally consistent data with sophisticated tools so that policy and decision makers can use the program’s science to inform efficient decision-making.
Collaboration and cooperation: NAWQA continues to cooperate, coordinate, and collaborate within its own agency as well as with other federal, state, and local agencies in designing and carrying out its programs with a commitment to enhancing its usefulness by making its data and programs relevant to others with interests in water-quality.
Linkages and integration across media, disciplines, and multiple scales: NAWQA has been successful in multidisciplinary research at regional and national scales, collecting and interpreting geographic, hydrologic, biologic, geologic, and climatic data from a range of environmental media (e.g., groundwater, sediments, soils, surface waters, and biota) to help resolve water-quality questions.
changes caused major reductions in the application of some pesticides, with corresponding declines in surface water concentrations of those compounds (Gilliom et al., 2006). The NAWQA program’s findings also highlight how the movement of nitrogen and pesticides from agricultural fields to streams, groundwater, and beyond is controlled by a complex yet identifiable interplay of hydrologic factors (irrigation, drainage, flow paths, precipitation), agricultural practices (compound applied, timing of application), and biological processes (photosynthesis, biological activity) (McCarthy, 2009).1
Water-quality improvements from reductions in pesticide use are not limited to agricultural areas. After a federally-mandated phase-out of the organophosphate insecticide diazinon in outdoor urban settings, the concentration in northeastern and Midwestern streams fell dramatically