PROBLEMS FROM DEVELOPMENT 57 



water as well as fresh water toward the areas of deepest water 

 levels, and as the basin filled with this mixed water, under- 

 flow across the Newport-Inglewood barrier would diminish 

 because of reduced hydraulic gradient. 



Geologic conditions appear to be favorable, however, for 

 artificial recharge in the sand-dune areas along part of the 

 coast of the West Basin. It has been pointed out that such 

 recharge would create a ground-water "mound" that would 

 stop the advance of sea water from the coast, and thus pro- 

 tect the rest of the basin from intrusion. The sewage effluent 

 from Los Angeles has been proposed as a possible source of 

 water for this recharge. After treatment, and after percolat- 

 ing through the equivalent of a sand filter, these waters 

 would likely be found to be quite safe for use when pumped 

 from wells. 



Pumping from storage in fresh ground-water reservoirs in 

 a few areas has created conditions favorable for the incursion 

 of inferior water from other aquifers. In some cases, the con- 

 taminant water has come in through wells perforated in both 

 water-bearing formations, but in others it has evidently reached 

 the fresh-water reservoir without such aid. Encroachment of 

 bad water from other formations li has been observed in the 

 ground-water reservoir developed by El Paso, Tex. Deteriora- 

 tion in quality of supplies, due to leakage through Avells, has 

 been noted along the west slope of San Joaquin Valley (page 

 43) but is likely to occur there in any case as depletion of stor- 

 age progresses. 



El Paso, Tex. 15 Two different types of water are available 



i* As distinct from occurrences of brines "native" to certain formations, which 

 are commonplace and may yield products of commercial value as in the 

 Saginaw Valley, Mich., and at Searles Lake, Calif. 



is References: Sayre, A. N., and P. P. Livingston, Ground-water Resources of 

 the El Paso Area, Texas, U.S. Geol. Survey Water Supply 

 Paper 919, 1945, 190 pp. 

 Scalapino, R. A., "Ground-water Resources of the El Paso 

 Area, Texas," Texas Board of Water Engineers, Progress 

 rept. 6, 1949, 22 pp. 



