WSP04567

• File Number: 8273.300
• Description: Colorado River Basin Salinity Control - Federal Agencies - USGS
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1990
• Author: USGS
• Title: Implementation Plan for the National Water Quality Assessment Program
• Water Supply Pro - Doc Type: Report/Study

The results of each of the study-unit investigations
N will be described as' appropriate in technical journals,
....' reports for the general public, and USGS formal and
en informal series reports. A series of interpretative
0) reports presenting results of the investigation will be
prepared at the completion of each period of inten-
sive activity. The flist chapter is reserved for a sum-
mary of key findiitgs. Subsequent chapters may
include an analysis of available water-quality informa-
tion and more detailed discussion of pertinent find-
ings from the intensive activity period and previous
less intensive activity periods.

Regional and National Synthesis of
Study-Unit Results

Regional and national synthesis of information
from selected study units will be the foundation for
comprehensive assessments of the Nation's water
quality. The synthesis activities will consist of compar-
ative studies of specific water-quality issues using
nationally consistent information and will focus on
differences and similarities in observed water-quality
conditions, trends, and causes of these conditions and
trends among the 60 study units. To permit meaning-
ful comparisons a major part of the synthesis activities
will be the characterization of each study unit in terms
of nationally consistent information on water quality,
and factors such as lllnd use, geology, climate, agricul-
tural practices, and hydrology. Some of the synthesis
activities will focus on water-quality issues that affect
large contiguous hydrologic regions. Other synthesis
activities will focus on large noncontiguous areas that
are affected by similar specific water-quality issues or
concerns.

An example of a specific water-quality issue is the
presence of atrazine, one of the most heavily applied
herbicides in the United States. Most of the usage of
atrazine is concentrated in agricultural areas in the
Midwest, along the Mid-Atlantic coast, and in specific
regions of many other States. Thus, a "regional" anal-
ysis of the presence of atrazine to natural and human
factors would focus:on several large noncontiguous
geographical areas of the Nation. Therefore, the
NAWQA approach to synthesis of study-unit investi-
gation results provides a unique opportunity to exam-
ine the presence of this herbicide in ground and
surface water in dimirent parts of the country that are
characterized by distinct differences or similarities in
climate, hydrology, and agricultural practices.

Regional and National Water-Quality Concerns

Some of the national water-quality concerns to be
addressed in the first cycle of NA WQA studies along

with regional and national water-quality policy
questions are given in table 2. These water-quality
concerns are comprehensive and represent a wide
range of difficulty and scope. The regional and
national synthesis of information from study-unit
investigations will significantly contribute to answer-
ing fundamental water-quality questions facing the
Nation. For example, a concern that will likely be
addressed during the early years of the program is the
relation of the presence of pesticides in ground and
surface water to application rates, cropping practices,
and climatic, geologic, and soil factors. Information
on the factors affecting ground- and surface-water
contamination by pesticides will be useful to
water-resource policymakers and managers for:

(1) developing effective water-resource manage-
ment approaches regarding pesticide contamination,

(2) determining the appropriate pesticide
standards for particular geographic regions and
hydrologic settings rather than using rigid nationwide
standards that may overprotect the resource in some
areas and underprotect it in others, and

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(3) developing effective and efficient ways to
monitor water-quality.

By including a large number of study units (60) and
a large part of the United States, the NAWQA Pro-
gram ensures that many critical water-quality con-
cerns in diverse hydrologic and land-use settings can
be evaluated. Water-quality concerns to be covered by
the regional and national synthesis will be reviewed
periodically and refined on the basis of fmdings from
study-unit investigations and other programs, and
advice from USGS coordinating and technical
advisory committees.

The relation among national, regional, study-unit,
and local scales of study are shown in figure 3. This
figure also summarizes the type of information that
will be reported for each scale of study. Because of
the interdependence between the study-unit investi-
gations and the regional and national synthesis of
study-unit investigations results, elements of the pro-
gram are being concurrently planned. Planning activ-
ities are being coordinated at both the regional and
national levels with appropriate Federal, State, and
local interests. Detailed planning of the regional and
national synthesis activities will begin in FY 1990.
These plans will affect ancillary data needs, the
emphasis of the local scale investigations in selected
study units, and to some extent, the staging of
study-unit investigations.

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