Cannery Wastewater Treatment by High-Rate Spray on Grassland

A 12-month study was made on the efficiency of a spray-runoff treatment system for cannery wastes. A total of 133 in. (338 cm) of wastewater was applied to each of four experimental areas. Eighteen percent was lost by evaporation, 61 percent was runoff to surface streams, and 21 percent percolated into the soil. A once-a-day spray schedule resulted in 92 to 99 percent removal of volatile solids and organics, 83 to 90 percent removal of total nitrogen, and 50 to 63 percent removal of total phosphorus. A three-times-a-day spray schedule improved total phosphorus removal on one area to a top level of 88 percent. Capital installation costs were $1,000/acre ($2,470/ha). Operating costs were about $0.05/1,000 gal ($0.013/1,000 l). The design was to handle 3.6 mgd (13,700 cu m/day) on 500 acres (202 ha).