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National Water-Quality Assessment Program (NAWQA)
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Representative Accomplishments of NAWQA, Cycle I

One task of the National Research Council's review of the USGS's National Water Quality Assessment (NAWQA) Program was to conduct an assessment of general accomplishments of NAWQA to date. NAWQA has been remarkably productive in its first decade of national monitoring. The NRC found that NAWQA is a well-managed and implemented program. It has significantly contributed to the understanding of the quality of the Nation's water, providing new knowledge to better manage our vital water resources. The Program has become an exemplary institution, illustrating that sound science can be applied at a national scale to resource assessment. The following examples, excerpted from the NRC report, Opportunities to Improve the
U.S. Geological Survey National Water Quality Assessment Program, illustrate a small cross-section of the breadth of contributions NAWQA has already made, and continues to make, to the Nation.

Identification of Unexpectedly Frequent Occurrences of Pesticides in Urban Streams

One somewhat surprising result of studies from streams flowing through agricultural and urban landscapes was the prevalence of insecticides in urban streams. NAWQA documented widespread occurrence of insecticides that are commonly used in homes, gardens, and commercial areas, and some occurred with higher frequency and oftentimes at higher concentrations in urban rather than in agricultural areas.

Integrating Biological Assessments into Water Quality Monitoring

USGS scientists began biological assessments that were integrated with the more traditional physical and chemical measures. This data set will provide a valuable contribution to the ongoing debate on how best to do biological assessment and what that assessment tells us about water quality that was not evident from other methods. Some biological assessments done in Cycle I suggest a threshold response to ecological impacts. This has significant implications for both water management and restoration programs and should be further examined in Cycle II.

Assessment of Linkages Between Changes in Phosphorus Loads and Clean Water Act Policy

One of the major accomplishments of NAWQA to date is the use of historical data on phosphorus loadings to evaluate the effects of various phosphorus-control measures implemented under the Clean Water Act (CWA). Enriched phosphorus levels in surface water can result in eutrophic conditions in lakes and streams, often harming the aquatic environment and impairing its use. An evaluation of NAWQA data shows that phosphorus concentrations are decreasing in many study units, largely as a result of CWA control mechanisms.

Ecological and Human Health Issues

Potential impacts on reproductive, nervous, and immune systems from low-level exposure to environmental contaminants ("endocrine disruptors") has become a growing concern for the protection of wildlife, aquatic organisms, and human health. NAWQA data have provided the first significant glimpse of potential associations among groups of pesticides and hormones in fish on a national scope. These early studies have raised important questions for further assessments.

Emerging and Unexpected Chemical Contaminants in Water: Methyl tert-butyl ether (MTBE)

The broad spectrum laboratory methods used by NAWQA allow USGS scientists to evaluate their sample results for unexpected, non-target compounds that may be present or to look for the occurrence of emerging contaminants. One prominent example, from the 1990s, was the discovery that MTBE was widely occurring in NAWQA and USGS Toxic Substances Hydrology Program monitoring. MTBE was subsequently added to the USGS monitoring list of volatile organic chemicals. These data played a key role initiating EPA and the States' to conduct a more thorough review of MTBE's potential impact on drinking water.

Development of SPARROW

SPARROW (Spatially Referenced Regressions on Watershed Attributes) is a watershed scale model with a mechanistic basis and is a major contribution to water-quality modeling tools and literature. SPARROW was developed by USGS, though not under the NAWQA Program. However, NAWQA's highly visible use of the model is helping to make the model increasingly known and is enabling many parties to use it. The watershed model has many desirable characteristics and can be an important support tool for EPA and the States' total maximum daily load (TMDL) programs.

Information Dissemination in NAWQA

While most of the NAWQA budget and effort is devoted to data collection and interpretation, it is the reporting of the program's findings that is most critical for its ultimate success. A tremendous amount of data and information, at local and national scales, has been made available to researchers, resource management and regulatory agencies, and the general public. NAWQA information is communicated through reports, databases, the Internet, and other digital products and is getting significant use in applied management and policy programs as well as in research and monitoring programs.

Improved Methods and Detection Levels for Chemical Contaminants

NAWQA program personnel have worked to refine and improve existing analytical methods while simultaneously lowering their detection and reporting levels (i.e., concentrations). These improved, lower-level reporting concentrations are an important contribution. As we try to understand contaminant occurrence and cause-and-effect relationships it is important to assess the difference between actual low-level occurrence and "zero" occurrence in the environment. Other organizations are now adopting USGS protocols.

Improved Coordination and Collaboration with Other Federal and State Agencies

NAWQA has become a model of an effective, collaborative Federal program-an attribute policy makers always stress, but seldom achieve. NAWQA has successfully integrated its program both within and outside of the USGS, establishing some exemplary relations with EPA and State governments. EPA, State, and local agencies have found NAWQA of such value that they have furthered the symbiosis by providing funding to USGS to add on to NAWQA to help meet their additional information needs.

Hyporheic Zone Work throughout NAWQA

The hyporheic zone is the interface between ground water and surface water. Active and dynamic exchange of water, organisms, and chemicals occurs between the surface water and the adjacent ground-water system, making the hyporheic zone an important component for understanding both surface- and ground-water quality. NAWQA researchers are advancing our knowledge of hyporheic processes and their effects on water quality, which is important for our long-range management of water resources.


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