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.
|