Storage - Public Water Systems - page 969

Variability of the water supply, demand, and quality

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Sizing of the facility, since a minimum scale of development exists below which
ASR may not be cost-effective

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Storage zone characteristics

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Applications ASR provides seasonal, long-term, or emergency storage of drinking
water in confined or unconfined aquifers. 5 This technology has other applications be-
yond typical storage purposes, including treatment, groundwater restoration, subsi-
dence reduction, and wellfield enhancement and augmentation. ASR can also have
application where there are large seasonal variations in water availability and there is
limited siting for additional surface storage reservoirs.

Regulatory Issues As an injection practice, ASR wells are regulated by the Un-
derground Injection Control Program, administered by the USEPA under the Safe
Drinking Water Act. Given the concern over aquifer water quality, generally, water
injected into an ASR aquifer should meet potable water standards. Each state has
varying standards and permitting requirements that must be considered for this storage
concept.

Technical Considerations The concept of ASR is to inject and withdraw water
through the same well. This approach allows backflushing of the well to reduce aquifer
clogging and maintains the storage bubble to minimize intermixing of the stored water
with native water. Using this technique, it is not uncommon to store treated drinking
water in freshwater or brackish water aquifers with varying geologic conditions. Se-
lecting the appropriate aquifer is important to reduce loss of stored water, contami-
nation, and intermixing.

REFERENCES

1. Brock, D. A., ''Determination of Optimum Storage in Distribution System Design,'' JAWWA,
p. 1027, August 1963.
2. EPA, ''Manual for Evaluating Public Drinking Water Supplies,'' Superintendent of Docu-
ments, Washington, D.C., 1971.
3. Culp, Russell L., EPA Technical Guidelines for Public Water Systems, Chapter VI, ''Storage,''
NTIS, PB-255-217, U.S. Department of Commerce, Springfield, Va., June, 1976, p. 195.
4. Washington, State Department of Health, Water System Design Manual, June 1999.
5. AWWA Research Foundation, ''Aquifer Storage Recovery of Treated Drinking Water,'' 1996.
6. Wade, J. A., ''Design Guidelines for Distribution Systems as Developed and Used by an
Investor-Owned Utility,'' JAWWA , p. 346, June 1974.
7. Jorgenson, I. B., and Close, S. R., ''Arvada 10-mil gal Treated-Water Storage Reservoir,''
JAWWA , p. 181, April 1976.
8. AW WA Committee Report, ''Multiple Use of Covered Distribution Reservoirs,'' JAWWA ,p.
262, May 1978.
9. Larsen, L. A., ''Cold Weather Operation of Elevated Tanks,'' JAWWA , p. 17, January 1976.
10. AWWA Research Foundation, ''Water Quality Modeling of Distribution System Storage Fa-
cilities,'' 1999.
11. Dellaire, Gene, ''The Floating Cover: Best Way to Cover a Finished-Water Reservoir?,'' ASCE
Civil Engineering , p. 75, June 1975.