Summary

Balancing the continuous supply of domestic wastewater from effluent treatment plants with fluctuating crop water demands requires unique irrigation design strategies. A key design consideration when utilizing disinfected secondary treated city water is to maximize the re-use of effluent in winter months, when forage crop water demands are low, yet still produce minimal deep percolation. Twenty-seven center pivots in Palmdale, California required new custom-designed sprinkler packages to dispose of approximately 7,000 gallons per minute of treated wastewater. Through innovative design efforts, extensive testing and field experimentation, a standardized package has been adopted by the County Sanitation District of Los Angeles County that enables a highly efficient application of re-use city wastewater without groundwater degradation throughout the year.