Municipal Wastewater Reuse for Irrigation

Agricultural irrigation is the major use of water in the seventeen western Reclamation Act states. A small portion of the projected demand in 1980 and 2000 might be supplied through reuse of municipal waste water (respectively about 7,500,000 and 11,900,000 acre-ft per yr of the predicted withdrawals of 175,000,000 and 170,000,000 acre-ft per yr). Data on direct land application of municipal wastewater is discussed particularly for the western states and examples are cited. The estimate for 1962 is about 300,000 acre-ft per yr or not more than 5% of the available wastewater. Diseases associated with sewage irrigation are discussed, the most recent outbreak attributed to the practice in the United States having been reported as occurring in 1919. It is concluded that public health considerations pose no obstacle to crop irrigation with treated municipal wastewater but the trend seems to be toward higher-value uses such as ground-water recharge, golf course irrigation, and recreational lakes.