Natural Treatment System Approaches for Enhancing River Quality in Oregon

This paper presents two innovative natural treatment system approaches developed to enhance the water quality in two major rivers in Oregon. One presents an approach for the reduction of phosphorus to 0.1 milligrams per liter (mg/L) and reduction of other nutrients through a system that integrates high rate soil treatment with treatment wetlands and hyporheic discharge. The other illustrates an avenue into nutrient reduction by utilizing a combination of multiple complementary waste-streams to further enhance the nutrient-reducing potential of treatment wetlands and to cool effluent by 3.54°C—equivalent to removing 543 million British thermal units (Btu)/day or 136 million kilocalories (kcal)/day. Soil column and pilot study data are presented.