Wastewater irrigation of poplars minimizes surface water degradation

摘要

The City of Woodburn, Oregon, designed and installed a 34-hectare (ha) (84.1-acre) poplar plantation to beneficially reuse wastewater treatment plant effluent. The City chose this approach as a cost-effective and environmentally attractive method ofreducing discharges to the Pudding River in the summer when the total maximum daily load restriction for ammonia is most stringent. Consequently, in July and August, the treatment plant pumps 5.034 cubic meters per day (m~3/day) (1.33 million gallons per day (mgd)j to a poplar plantation instead of the Pudding River. In the final development phase, this is expected to increase to 11,393 m~3/day (3.01 mgd) irrigating 300 acres. The overall system monitoring and management program was developed based onOregon Department of Environmental Quality guidelines for land application of municipal effluent. Irrigation scheduling is based on National Pollutant Discharge Elimination System permit requirements. Nutrient loading is based on agronomic requirements.The capital cost estimate for the 320 acre reuse farm and all reuse equipment is 4,610,200 dollar. The operations and maintenance cost per year is approximately 120,900 dollar. This paper demonstrates that automated irrigation management and scheduling for a poplar tree plantation is an innovative, cost-effective method of wastewater management that protects public health by enhancing water quality and the environment.