United States
                    Environmental Protection
                    Agency
Office of Exploratory
Research
Washington DC 20460
                    Research and Development
EPA-600/S6-83-002  Sept. 1983
x°/EPA         Project  Summary

                    Assessment of  Potential
                    Environmental  Problems
                    Concerning  Water Availability
                    G. M. Wesner and B. E. Burris
                      This study analyzes national supply
                    and demand and summarizes data on
                    all water resources regions. Estimates
                    of the potential for wastewater reuse
                    and recycling are also presented. The
                    technology for improving the  water
                    supply through augmentation and con-
                    servation is reviewed, and the  most
                    feasible implementation methods are
                    discussed in detail.  Three  detailed
                    studies of water sensitive regions pre-
                    sented in this report illustrate the
                    regional  nature of the issues,  prob-
                    lems, and research needs. The  areas
                    are San Antonio, Texas, South Coastal
                    area of Southern California,  and the
                    Yadkin-Pee Dee Basin in North Carolina
                    and South Carolina.
                      This Project Summary was developed
                    by EPA's Office of Exploratory Re-
                    search, Washington, DC, to announce
                    key findings of the research project
                    that is fully documented in a separate
                    report of the same title (see Project
                    Report ordering information at back).

                    Introduction
                      This study summarizes water supply
                    and demand data for all water resources
                    regions in the Nation, reviews  the tech-
                    nology for water supply augmentation,
                    presents evaluations of water resources in
                    three widely different areas of the Nation,
                    and analyzes issues, problems and re-
                    search needs in water availability. Critical
                    water problems facing the Nation include
                    inadequate surface water supply and over-
                    draft of ground  water. There are  other
                    water related problems and potential prob-
                    lems in the Nation including pollution of
                    surface and ground waters but the major
                    concern is the inadequate, or marginally
                    adequate, supply in many areas.
Water Use
  Agricultural irrigation is the largest cur-
rent water use in the Nation, and its per-
centage of total water used is projected to
increase by the year 2000.
                    Percent of Total
                  Fresh Water Requirement
                   1975    2000
Agriculture
Steam Electric Power Plants
Manufacturing Industries
Domestic and Commercial
Minerals Industries
Other
50.9
24.6
14.1
8.0
1.9
0.5
54.5
24.2
6.0
11.2
34
0.7
Most of the agricultural use is in the Pacific
Northwest California, and Missouri re-
gions.  Cooling water for steam electric
generating plants is the second  largest
requirement for fresh water with most of
the demand in the  Eastern States. De-
creases projected in fresh water require-
ments for the steam electric  and manu-
facturing industries are the results of pro-
jected  increases  in water recycling. It is
estimated that fresh water supplied to
manufacturing industries in the year 2000
will be used over 1 7 times and fresh water
will be recycled over seven times by steam
electric plants before it is discharged.

Water Supply
  The  two general methods of increasing
the water supply are: (1) augmentation by
increasing the quantity  of water available
to the user, and (2) conservation to reduce
withdrawals and consumption. The fol-
lowing augmentation and  conservation
measures are evaluated in this study.

  • Augmentation
    1. Desalination
    2. Wastewater recycling and reuse
    3. Brackish-saline water use
    4. Transfer and storage

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       5.  Evaporation reduction
       6.  Vegetation management
       7.  Weather modification
       8.  Water rights
       9.  Icebergs

    •  Conservation
       1.  Agricultural irrigation efficiency
       2.  Crop switching
       3.  Cooling water techniques
       4.  Domestic and  commercial con-
          servation devices

   Conclusions
    It is concluded that conservation, waste-
   water recycling  and reuse,  desalination
   and  improved conjunctive use  of ground
   water and surface water supplies offer the
   most immediate potential for  increasing
   water supplies on  a nationwide basis.
   Other methods  may  be  used in  more
   localized areas and others may be more
   widely  used after further research and
   development. The water supply situation
   in the following three water  sensitive re-
   gions is evaluated in detail in this study.
    •  San Antonio, Texas. Ground water is
        presently the sole source of water
        supply for the u rban sections in a five
        county area of South Central Texas
        that includes the City of San Antonio.
    •  South Coastal California. About two-
        thirds of the water supplies for this
        11,000 square mile area in Southern
        California are imported  from the
        Colorado River and  Northern Cali-
        fornia with the other one-third sup-
        plied from  ground water and local
        runoff.
    •  Yadkin-Pee Dee River Basin. Surface
        water and ground water from within
        this river basin  are  the  source  of
        supply for  an  18,000  square mile
        area  in North Carolina and South
        Carolina.
               Information on major issues, trends and
             research needs in water availability for this
             study were collected from several sources
             including:
               1. Recent  reports and review on the
                 National water situation including
                 comments and critiques on Federal
                 water policy and research activities.
               2. Regional reports,  many of which
                 were prepared under  the  Federal
                 Water Resources Planning Act

               3. Reports by various State agencies.
               4. Discussions with local water agency
                 personnel and others during  the
                 work on this project.
               5. Informal discussions with knowledge-
                 able persons in Washington, D.C. to
                 solicit opinions  on major  issues,
                 trends and research needs in water
                 availability.
  It is concluded that many of the prob-
lems and issues are regional in nature. The
issues that exist in all regions of the Nation
are limited or inadequate water supply and
concern for water quality. Inadequate or
marginally  adequate water supply is a
problem  in many areas especially in  the
Western  States. The unresolved question
of water rights on Indian lands and Federal
lands limits the allocation of existing water
supplies  in many areas in the West
  At the  present time the most feasible
methods  of augmenting  water supplies
are conservation, wastewater reuse and
conjunctive  use of  ground and surface
water supplies. Research needs are also
somewhat  regionalized  in  nature.  The
most immediate research needs are those
that will advance the most feasible means
of augmenting  supplies:  conservation,
wastewater reuse, water rights and insti-
tutional arrangements.
               G. M. Wesner andB. E. Burn's are with Culp/Wesner/Culp, Santa Ana, CA 92707.
               Marvin Rogul is the EPA Project Officer (see below).
               The complete report, entitled "Assessment of Potential Environmental Problems
                 Concerning Water Availability," (Order No.  PB 83-226 035; Cost: $11.50,
                 subject to change) will be available only from:
                       National Technical Information Service
                       5285 Port Royal Road
                       Springfield, VA  22161
                       Telephone: 703-487-4650
               The EPA Project Officer can be contacted at:
                       Office of Exploratory Research
                       U.S. Environmental Protection Agency
                       Washington, DC 20460           .
                                                             *US GOVERNMENT PRINTING OFFICE 1983-659-017/7179
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