Making Every Last Drop Count: REUSING Water IN THE DESERT SOUTHWEST
Thursday, January 1 2009
Arizona's burgeoning population is increasing pressure on the state's limited water resources. Agricultural Research Service scientists at the U.S. Arid-Land Agricultural Research Center (ALARC) in Maricopa, Arizona, are investigating potential solutions.
Reclaim It, Reuse It
Microbiologist Jean McLain and soil chemist Clinton Williams are examining urban use of "reclaimed" water-which is drawn from residential and industrial sewage systems and treated to remove contaminants.
Since September 2006, McLain and Williams have collected soil and water samples from a municipal park that is being irrigated with reclaimed water and tested them for harmful shiga toxinproducing Escherichia coli bacteria. To date, the scientists have not found a single pathogenic strain of E. coli. They did note a small increase in soil salinity-a potential downside to using reclaimed water-but the level observed was too low to harm plant growth.
Williams has also tested for carbamazepine, an epilepsy drug that has been detected in low doses in drinking water. His research has shown that the drug is retained by organic matter found in soil. This suggests that any carbamazepine in reclaimed irrigation water is unlikely to leach beyond the root zone.
