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 ------- 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 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 Postage and Fees Paid Environmental Protection Agency EPA 335 Official Business Penalty for Private Use S300 2 IUN AGENCY ICAGO ------- |