The University of Arizona, College of Agriculture
Greater Harmony Between Ariculture and the Environment
Reclaiming Wastewater through Soil Aquifer Treatment
Issue
Water-short areas in the U.S. and around the world have turned to reclaiming wastewater as a
way to increase water supplies. Some treatment methods use chemical additives to help purify the
water. Charles Gerba, a University of Arizona environmental microbiologist, tested a more natural
method currently used in Tucson, and found that it produced high quality nonpotable water
without additives at a low cost.
What has been done?
The soil aquifer treatment used a 37-meter layer of soil as a filter. Wastewater was purified as
it passed through, and was then collected in underground storage tanks. This is a natural,
sustainable system that will not wear out. It takes the place of building a conventional treatment
plant.
Impact
The soil aquifer treatment significantly reduced enteroviruses as they passed through the soil.
Groundwater samples held no Giardia. The two organic compounds present were reduced by
92% and 85% respectively, and total nitrogen leached out 47% during recharge. The project has
now expanded to include the City of Phoenix in Arizona, and Los Angeles and Orange Counties
in California, at the request of those communities.
Funding
City of Tucson, American Water Works Association Research Foundation
U.S. Environmental Protection Agency
Tucson Water
City of Phoenix, Salt River Project
Los Angeles County Sanitation District
Agricultural Research Service
Contact
Charles Gerba, environmental microbiologist,
Department of Soil, Water and Environmental Science
Shantz Bldg., Room 429, PO Box 210038, The University of Arizona
Tucson, AZ 85721
Telephone: (520) 621-6906 Fax: (520) 621-1647
Email: gerba@ag.arizona.edu
This report is one of 29 impact statements submitted by the University
of Arizona College of Agriculture to the USDA's 1999 CSREES Science and Education
Impacts
database in Washington, D.C. An impact statement is a brief summary, in lay terms, of the
economic, environmental and/or social impact of a land-grant program. It states
accomplishments and their payoff to society.
Located at http://ag.arizona.edu/impacts/2000/wastewater.html
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