"EPA 600/R-93/105"The report discusses the construction of nine wetland cells at the Oregon State University dairy farm. These wetlands will be used in a long-term project which will attempt to: (1) Develop optimal loading rates for milking parlor wastewater and diluted dairy cow manure, not only for maximum treatment efficiency, but also for adequate treatment of wastewater to allow direct discharge into surface waters; (2) Measure seasonal variation in treatment effectiveness; (3) Develop design criteria for farms with limited wastewater generations; (4) Measure variation in treatment efficiencies between several wetland plant species and develop propagation techniques for wetland plants. Over the next five years, observations and data from these wetlands should help develop better design criteria and economics for form-scale wetlands.