Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 16
1
Overview
INTRODUCTION
Realizing that the protection and enhancement of the quality
of the nation's surface water and ground water resources had
become a priority concern, and that the effective management of
these resources requires information on current water quality
conditions and trends in their condition, the USGS began to
develop a national water quality assessment in 1984. In FY
1986, Congress appropriated funds to initiate the National Water
Quality Assessment (NAWQA) pilot program to test and refine
the concept and approaches for such an undertaking, and to
evaluate the potential use and cost of a fully implemented
program.
The overall goals of the NAWQA program are to:
1. provide a nationally consistent description of current
water quality conditions for a large part of the nation's water
resources;
2. define long-term trends (or lack of trends) in water
quality; and
3. identify, describe, and explain, to the extent possible, the
major factors that affect observed water quality conditions and
trends.
The program is to be executed through a large set of separate
investigations of river basins and aquifer systems, referred to as
study units. The USGS postulated that by performing NAWQA
as an aggregation of many individual study units, the assessment
would provide results that would be useful in understanding and
managing the water resources of the study unit, and in an-
swering national-scale questions about current conditions, trends,
and factors that affect water quality. Further, the program is to
focus on conditions that are large scale and persistent in time.
16
OCR for page 17
Qver~fe~
77
Emphasis ~10 be placed on reglonsl dcgradst10n of watcr
qualky sucb as might occur from both nonpoint and polot
sources of contsminan1~
In addltlon 10 collectlog ~ster quality dsts, 1he N^WQ^
program ~ deslgocd 101ske advantage of watcr quslRy lnforma-
don compllcd by 01her sgcnclcs for various purpose~ lhus, ono
of thc first sctlvlilos ~libln csch study unl1 ls to collsic sod
lDtccpre1 1hc svallsblc dsts 10 (1) provldc an lul11~1 dcscclptloD
of ~s1cr quslRy condldons, (2) dcvclop hypothcscs about major
factors lnfluenclng ~ster quslRy, and (~) define dsts needs.
Bccausc of thc cmpbash on 1rc~ds ln ~ster qual~y, 1hc
progrsm ls 10 bc pcrenalst rccogolzlag 1ha1 thc cmcrgcacc of
nc~ hYdroloelc knowlcd~c, 1mprovcd mc1hods of mcasuromcn1,
, ,~ ~ ^, . ~ . , . ^ , .,
snd changes 1~1hO lypcs OI cODl~mlDBnlS 01 concern mlgn~
rcqulrc 1ba1 1hc progrsm bc appropclatcly modlflcd. Thc pro-
gram ls 10 plBCC 8 high cmphasls on repcthlon of mcssurcmcnts
over dmc snd on documcnts110n of 1hc methods of dsis coUcc-
don sud snslysk sod of 1bc locs110ns snd characicrk11cs of
data-collcc110n sliest
Accordlng to 1hC USGS, ~ fulLscalc NAWQA progrsm w1H
provldc useful lnformsilon 10 dcclslonmakcrs who set policy,
promul~stc rcgulstlons' cs1abllsh pclorlilcs, or manage watcr
rcsourccs. As s1~1ed by 1hc uSGS' ~nformailon on 1hc status'
1hc 1rcuds, and 1hc causes of watcr quslRy condldons across 1bc
country should bc psrtlcularly usoful to 01hcr sgcnclcs who src
involved ln (1) ldentlfylng key substances for posslblc rc~uls110n
for which rcscarch ls nccdcd on 1oxlclty, human c~posurc, sud
drlnklug-wstcr 1rcatablU1y; (~) sllocs11ng budgotsry rcsourccs
among compctlng types of ~stcr qualRy problems; (~) dctcr-
mlulng whcthcr dcslrcd goals for ~stcr qualky lmprovcmcn1 arc
bclng met; (4) dcslgnlng monltorlng programs ln dlffcrcnt parts
of thc country gn 1crms of 1hc consbtucnts snslyzcd, ssmpllng
locs110ns, ssmpllns fccquency, snd 1lming of ssmplingt (5)
tsrgctlng rc~ula110ns for sclcctcd ~stcr qusllty constituents to
psrtlcular gcogrsphlc rcglons or hydrologic scttlngs; (6) dctcf-
mlnlng 1hc rcla11vc cffccts on watcr qualky of various types of
point snd nonpolnt sources; (7) ldcntlfylng squlfcrs rcqulrlng
dlffcrcnt 1ypcs snd dc~rces of ~stcr qusllty proicctlon; sod, (~)
cvalustlng managemcnt prsctlccs ln 1crms of thclr largc-scalc
cffccts on thc v~stcr qusllty of rivcr baslns snd squlfcr systcms"
(Illrsch, ct sl~ 1988\
Four surfacc ~'stcr snd tbrcc ground watcr pHot proicct~
rcprcscutlng a dlvcrshy of hydrologlc cnvlron mcnts and ~sicr
quallty condlilons' ~crc sclcctcd by thc USGS ln 1986 to tcst
and rcflnc thc ssscssmcnt conccpts of N ~ W ~ A. lhc surfacc
watcr pllot proiccts scloctcd 1ncludcd thc uppcr IDlnois Rivcr
OCR for page 18
18
NAWQA Pilot Program
basin in Illinois, Wisconsin, and Indiana; the Kentucky River
basin in Kentucky; the lower Kansas River basin in Kansas and
Nebraska; and the Yakima River basin in Washington. For the
three ground water pilot projects, the USGS selected the Carson
basin in western Nevada and eastern California, the Central
Oklahoma aquifer in Oklahoma, and the Delmarva Peninsula in
Delaware, Maryland, and Virginia. A local liaison committee
was established for each pilot project (study unit) consisting of
representatives from federal, state, and local agencies and pri-
vate organizations involved in water and land management
within the area of the project. The charge to each liaison com-
mittee was to assist the USGS by ensuring that the scientific
information collected by the pilot project was relevant to local
and regional interests. To advise the USGS on the overall pilot
project program, a National Coordinating Work Group (see
Appendix D) also was created with members representing various
federal agencies and nonfederal organizations having an involve-
ment or interest in water quality information.
The committee's assignment to evaluate NAWQA began with
a meeting in October 1988. At this meeting, USGS personnel
reported that over the prior four years, NAWQA had undergone
considerable development, and as a result, a number of refine-
ments and modifications of the basic plan had been incor-
porated. In fact, the USGS expressed the view that NAWQA
would continue to evolve, with certain aspects being further
refined and modified, over the next several years. The com-
mittee was invited by the USGS to become a part of this evolu-
tionary process by making suggestions for improvement or
simply by challenging any of the various elements of NAWQA.
To assist the committee in its assignment, USGS personnel
presented a series of briefings covering the details of all the
various elements of NAWQA. During the course of its review,
the committee also examined many publications and documents
provided by the USGS (see Appendix B) and evaluated the
potential usefulness of NAWQA in meeting national, state, and
local needs for water quality information by interviewing repre-
sentatives of various government agencies (see Appendix E) and
the private sector. Additionally, the committee visited, in small
teams, five of the seven sites selected as pilot projects: the
Carson basin aquifer, Upper Illinois River basin, Yakima River
basin, Kentucky River basin, and Central Oklahoma basin
aquifer. Meetings were held with USGS project personnel and
the local liaison committee. A committee representative also
attended several meetings of the National Coordinating Work
Group.
OCR for page 19
Overview
19
The committee, in its deliberations, reviewed all the elements
of NAWQA and as a result, identified areas of concern and
made suggestions for change. These concerns and suggestions,
along with other comments, both positive and negative, were
communicated to USGS by the committee through an interim
report dated September 25, 1989 (see Appendix A). A major
conclusion of the committee, as expressed in the interim report,
was "that a national-scale, long-term water quality assessment is
in the best interest of the country."
This final report addresses those elements of NAWQA dis-
cussed in the interim report, but in greater detail. It also eval-
uates other considerations deemed important by the committee in
designing and implementing a long-term assessment of the qual-
ity of the nation's surface and ground waters which, in turn,
will produce useful information for those involved in making
decisions regarding the management of the nation's water
resources. Unfortunately, because the scheduled 4-year study
period for the seven pilot projects had not elapsed at the time of
the preparation of this report, the committee did not have access
to any final products to review, with the exception of five
retrospective reports. This has limited the committee's ability to
evaluate the anticipated results and usefulness of NAWQA.
Therefore, the committee's findings and recommendations are
based on the review of many draft documents, briefings by
USGS personnel, and the committee's own experience and knowl-
edge of surface and ground water quality monitoring and assess-
ments.
NEED FOR A NATIONAL ASSESSMENT
OF WATER QUALITY
The committee is convinced that there is a genuine need for
a long-term, large spatial scale national assessment of water
quality in the United States. Human health and environmental
health are inextricably linked to our nation's water quality. As
our population continues to grow, our water resources are be-
coming more intensively developed, and more potential con-
taminants are being produced. Water quality has become an
increasingly important component of our political, economic,
social, and environmental decisionmaking. Because such deci-
sionmaking affects the quality of each individual's life, as well
as public and private expenditures of billions of dollars, it
cannot proceed without adequate information and understanding.
OCR for page 20
20
NAPTHA Pilot Program
Many significant past and future decisions involving water
quality are of national or regional scope. This broad scope arises
for several reasons. First, hydrologic boundaries do not follow
political boundaries. Therefore, water quality issues are often
interjurisdictional. For example, many hydrologic systems, e.g.,
river basins, lakes, or aquifers, are large and fall within or are
adjacent to more than one political unit. These systems are
dynamic, flowing systems through which changes propagate over
space and time, so that upstream decisions affect downstream
users. Second, a number of important water quality problems
are widespread throughout the nation. Examples include storm-
water runoff quality control and municipal and industrial
wastewater treatment. These problems are so widespread that it
is often more efficient to make some decisions about them at the
national or regional level. Finally, some water quality problems
are characterized by long time scales, so that decisions made at
one point in time carry impacts far into the future. To the
extent that higher levels of government provide continuity over
time, these issues may require a national or regional approach.
There are many examples of water quality issues requiring or
benefiting from national or regional attention and decision-
making for one or more of the reasons just discussed. These
include evaluating past and guiding future investments in waste-
water treatment works; determining the relative contribution of
point and nonpoint sources to the loading of contaminants to
surface and ground waters; identifying and controlling the water
quality impacts of acid deposition, agricultural chemical use
(especially pesticides), and tonics; evaluating the effectiveness of
federal, state, regional, and local environmental regulations; and
controlling eutrophication of inland and coastal water bodies.
The future is likely to bring even more issues requiring a large-
scale focus, such as determining the value of instream water uses
relative to water resources development. This issue has implica-
tions for general environmental policy, Indian and non-Indian
water rights, and the preservation of threatened and endangered
species, among others, and will require attention at many levels
of government.
Sound decisionmaking about these and many other water
quality issues requires that we identify problem areas before
they reach crisis proportions, understand the causes of such
problems, and are able to predict adequately the effects of
changes in water quality and the impacts of attempts to improve
or protect water quality. In other words, we need (1) data
quantifying hydrologic, chemical, biological, and other
OCR for page 21
Overview
21
relevant parameters in space and time; (2) information about the
past and present states of the system obtained by collating,
organizing. and interpreting the available data: and. {3) knowl-
_ _ _ . ~ ~ . . . — . · . , · , , _ _
edge about the cause and ettect relatlonsnlps Between varlaoles
and their evolution over space and time capability. All three are
important and build on each other, but ultimately knowledge
and understanding, which are essential for predictive capability,
must be the goal of any program that supports water quality
decision making.
As we define it, then, a water quality "assessment" must do
much more than "monitor." In our usage, monitoring is a data-
collection activity typically directed toward assuring compliance
with a regulation or statute, detecting the presence of known
contaminants, or operating control facilities and systems. Assess-
ment, on the other hand, goes well beyond monitoring and data
collection to include the analysis, interpretation, and synthesis of
data and theory to enhance our understanding of the environ-
ment. While data collection activities are necessary, and indeed
are one important component of an assessment program, we are
convinced that the strongest current need is for a true national
assessment, focusing on enhancing knowledge and understanding.
There are several timely examples of the value of such an
assessment. One is the issue of pesticides in surface and ground
waters. The distribution, mobility, and fate of pesticides in the
aquatic environment are controlled by a complex set of physical,
geochemical, and biological processes. Mere detection provides
no information about sources, pathways, or fate. In addition,
detection of a pesticide in one environment typically provides
little information about the presence of the same pesticide in
another hydrogeochemical environment. For example, aldicarb is
often associated with high ground water tables and sandy,
mineral soils, where its fate and transport are controlled and its
mobility limited by sorption on mineral surfaces and microbio-
logical degradation under fully saturated conditions. However,
in the presence of a large unsaturated zone and/or more organic
soils, aldicarb may behave quite differently because of the
potential for partitioning into the soil gas and organic solids.
Designing management practices to control contamination by this
pesticide and then evaluating those practices cannot be ac-
complished without understanding the mechanisms responsible
for its fate and transport.
A second example is the presence of selenium in agricultural
drainage waters in such places as the San Joaquin Valley in
California. Effective control and management will be possible
OCR for page 22
22
NAPTHA Pilot Program
only after the complex hydrologic interactions between surface
and ground waters are understood and the geochemistry of
selenium sorption and oxidation-reduction reactions is delineated.
An extensive, in-depth study has been required in order to
interpret the initial detections of selenium and to develop poten-
tial control and management options (Gilliom, et al., 1989~.
Two different (and often competing philosophical ap-
proaches can be used to address a complex problem such as a
national assessment of water quality. In a purely statistical
approach, the collection and analysis of data are based on statis-
tical theory. In other words, variable behavior and the relation-
ships between variables are assumed to be dominated by random
uncertainty. In a process-oriented approach, sampling and data
analysis are largely driven by deterministic models of the rele-
vant physical processes. It must be stressed that these descrip-
tions represent the extremes of a spectrum of approaches. In
practice, it is rare to find an approach that is purely statistical
or purely process oriented. Statistical approaches are most
effective when they exploit an understanding of relevant physi-
cal processes, and statistical methods are essential tools for
process modeling in the face of data uncertainty and model
simplifications. Nonetheless, it is useful to distinguish between
these two basic approaches, since the challenge in any given
situation is to find the appropriate mix.
Because the committee is convinced of the need to develop a
much greater understanding of our nation's water quality, it has
reached the conclusion that a national assessment must take a
strong process-oriented approach. While data uncertainty and
conceptual simplifications must be properly addressed, the assess-
ment must maintain a strong focus on elucidating cause and
effect relationships and developing models that articulate those
relationships.
In order to meet the goals of a national water quality assess-
ment, the assessment must also be long term. First, because of
the extraordinary complexity of the physical, chemical, and
biological processes controlling water quality, any assessment of
the state of water quality in the U. S. must evolve over time,
probably iteratively, as our understanding and data bases in-
crease. Second, the processes controlling water quality take place
over a wide range of time scales. For example, ground water
flow rates are very small, and a "snapshot in time," or even
several closely spaced snapshots, would provide relatively little
information about change. Similarly, the impacts of global
climate change on water quality are likely to occur on time
scales of decades. On the other hand, mixing processes in moun-
OCR for page 23
Overview
23
lain streams are very rapid, so that a single sample, or even a
few samples, could easily miss important events. In either case,
a static, one-time assessment would have no lasting value, but a
long-term assessment would have a better chance of detecting the
true water quality and its changes.
Both the complexity of water quality processes and the wide
range of relevant time scales imply that adaptability is an ex-
tremely important characteristic of a successful water quality
assessment. As new knowledge is gained, new methods devel-
oped, or new contaminants discovered or introduced in the
environment, or as an existing condition evolves over time, an
assessment program must respond and change. A flexible long-
term assessment would make that responsiveness possible.
A national water quality assessment necessarily warrants a
large-scale undertaking. Because of the complexity and spatial
diversity of water quality issues, a national-level aggregation and
integration would be invaluable in maximizing information
gained from local experience. Such integration would enhance
the ability to generalize from local experience and to adapt
knowledge learned from one location to another. Because of
complexity and diversity, multiple lines of evidence are often
required to develop necessary understanding. A large-scale
assessment makes it possible to develop such lines of evidence.
Finally, while there is much completed and ongoing research
focusing on cause and effect water quality relationships, this
research tends to be directed toward smaller-scale (often labora-
tory-scale) understanding. Relatively less is known about the
behavior of large systems, such as entire river basins or aquifer
systems. For this reason, a national assessment would! be a
particularly timely undertaking for scientific reasons alone.
Because of the many advantages of a large-scale, long-term
water quality assessment, there is tremendous value in devel-
oping consistent, compatible, reliable, and accessible water qual-
ity data bases. Unfortunately, there is often relatively little
consistency between data sets gathered for local or regional
purposes. Consequently, generalization and inference at the
national level or across state boundaries or from year to year is
very difficult. The USGS study of the effects of changes in
municipal wastewater treatment on water quality in the Upper
Illinois River Basin provides an excellent example of the dif-
ficulties caused by inconsistent data bases (see Appendix B. #57~.
To summarize, implementing a national water quality assess-
ment using consistent data collection, analysis, and reporting
procedures is essential if we as a nation are to effectively and
efficiently maintain, manage, and control our water resources.
OCR for page 24
24
NAUSEA Pilot Program
Such an assessment must go well beyond mere monitoring and
data collection to focus on developing understanding of cause
and effect relationships. It should be process oriented, long
term, highly adaptable, and of large spatial scale.
While the committee is convinced of the need for a national
assessment, this is an enormously difficult challenge because of
the immense scale of our nationts waters, the diversity of both
the natural hydrologic systems and the human activities that
affect those systems, and the complexity of the physical,
chemical, and biological processes that govern water quality.
There is a vast scope to the types of water bodies of importance,
encompassing rivers and streams, estuaries, lakes and reservoirs,
and ground water aquifers. These water bodies are combined
into hydrologic systems with complex interactions between
components. They range in size from small streams to extensive
aquifers. Important processes occur on scales ranging from
microscopic to global and encompass a broad array of scientific
disciplines, including hydrology, geology, chemistry, micro-
biology, ecology, engineering, and more. Water quality problems
range from naturally occurring radon in ground water to the
impacts of wastewater discharge on downstream water users.
There are many implications of such a vast scope. First of
all, except in a few special cases, uniform national assessments
are precluded. Understanding must almost always be developed
on regional or smaller scales and a national picture must be
assembled as a composite of these smaller-scale assessments.
Rigorous probabilistic generalizations at the national scale are
possible only for a small subset of relatively simple problems
that do not require cause and effect analysis, e.g., number of
stream miles with low average dissolved oxygen concentrations.
Second, a national assessment must be a multidisciplinary under-
taking and a work environment and management structure must
be established that fosters interactions between different dis-
ciplines. For example, the traditional separateness of surface
and ground water hydrologists, as well as of physical and life
scientists, must be overcome. Third, there is an existing struc-
ture for collecting and interpreting a large amount of water
quality data. This effort is highly dispersed across many dif-
ferent public and private organizations and involves data col-
lected for a wide variety of different purposes. Careful coor-
dination is essential to avoid duplication of effort and maximum
utilization of resources and existing knowledge, and to ensure
consistency. Finally, federal agencies have very little experience
implementing a truly national assessment of any particular water
quality issue, let alone a national assessment of water quality as
a whole.
OCR for page 25
Overview
25
Therefore, such an assessment cannot proceed quickly and will
require adequate resources. Conceptual approaches, models, and
other technology will need to be developed as an assessment
proceeds. At no point can a national assessment become a rou-
tine task. Consequently, the success of a national assessment will
be highly dependent on the quality of the people directing and
implementing it. Staff must be very capable, well educated,
broadly experienced, creative, and motivated.
To conclude, then, the committee is convinced of the need
for a national assessment of water quality. However, such an
assessment will face a number of difficulties. It will be of vast
scope, it will be highly multidisciplinary, it will need to be well
coordinated with the activities of many different organizations,
and it will require many experienced, high-quality personnel
provided with adequate time and resources. Uniform national
analyses or rigorous probabilistic generalizations cannot be
expected when a national scope is achieved by assembling a
composite of regional or smaller-scale analyses.
Representative terms from entire chapter:
national assessment
