DEMINERALIZATION OF SALINE WATERS 267 
It is obvious that in areas where no industries exist and where 
there are no local sources of energy, production of fresh water 
from saline supplies utilizing waste heat is not possible. However, 
it may be entirely possible to develop industries in some such 
regions by the installation of small multipurpose plants designed 
to produce power, steam for industrial purposes, and fresh water 
as needed for industrial and other uses. For areas lacking con- 
ventional fuels, nuclear energy might be utilized as a source of 
heat for such a combination plant. Although not now attractive 
cost-wise for demineralization alone in the United States, the 
development of practical reactors designed for power generation 
with provision for heat recovery would open many arid regions 
for selective industries, especially those having low unit water 
consumption. The recoverable heat from such units could be 
utilized for saline water conversion in a number of separation 
processes. Such a multipurpose project offers an intriguing ap- 
proach to the problem of water supply in many arid and semi- 
arid areas. 
The need for saline water conversion is not limited to coastal 
areas. Many inland areas which do not have adequate fresh 
water have saline sources available. Many inland water sources 
usually considered to be fresh water are in reality fresh only 
seasonally, and for parts of each year should be classified as 
saline. 
Most tidal rivers are subject to variations in quality on account 
of penetrations of salt water upstream during periods of low 
river flow. Many inland streams are intermittently too saline to 
permit using the water for irrigation, industrial uses, or for human 
consumption. Ground waters often contain high concentrations 
of dissolved salts, impairing their use for various purposes. Many 
of these waters are far less saline than sea water, and therefore 
can be demineralized more cheaply. 
In addition, exchanges of water near coastal points of use with 
water being diverted there from inland fresh water sources may 
be feasible in some areas. As set forth in a recent report by the 
Secretary of the Interior (5), this would result in indirect benefits 
from saline water conversion to certain regions too far from the 
sea for economical direct service with converted sea water. 
