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From April through August 1974, menhaden processing waste water from an industrial plant near Dulac, Louisiana was partially reclaimed using land treatment by overland flow. The waste was pumped from a primary treatment pond after screening and was spray-discharged at a rate of 5.08 cm (2 in) per week onto a naturally vegetated spoil bank of clay soil material (6 percent slope, 30 m long). The effluent flowed unevenly through the plant cover and litter layer. The effluent, with total organic carbon, nitrogen, and phosphorus concentrations of 800, 600, and 50 mg/1, respectively, was purified by the action of the soil-plant system, reducing the waste nutrient load an average of 58, 51, and 53 percent for C, N, and P, respectively. The soil-plant system removed an average of 814, 581, and 47 kilograms per hectare of carbon, nitrogen, and phosphorus, respectively, over the five month period. Roseau cane, Phragmites communis, the dominant plant on the slope, increased in live standing crop by 55 percent and in nitrogen and phosphorus by 47 and 13 percent, respectively. Levels of groundwater nitrogen just exceeded 10 mg/1 at a depth of 30 cm after five months. Waste total coliform MPN was diminished by 66 percent over the slope. Regression analysis indicates that higher levels of C, N, and P may be removed from the waste if the slope length were increased. Uneven flow of the waste over the spoil bank indicated that mechanical grading and sloping would be necessary to allow greater reclamation of the waste. Because of the suitability of overland flow techniques for waste water treatment, dredge spoil disposal sites in South Louisiana are recommended for advanced waste water treatment where favorable waste effluent composition, climate, and soil-plant systems are available.