A PRELIMINARY ANALYSIS OF WATER QUALITY TRADING OPPORTUNITIES IN THE GREAT MIAMI RIVER WATERSHED, OHIO

This preliminary analysis evaluated biophysical and economic aspects of the Great Miami River basin, Ohio to assess nutrient point source-nonpoint source water quality trading opportunities in the watershed. The analysis focused on 1) conducting a nonpoint source modeling analysis to assess agriculture credit supply on the subwatershed level for the Great Miami River watershed using the GIS-interfaced SWAT model; 2) assessing and comparing the costs of point source load reductions via traditional in-plant facility upgrades to the costs of comparable load reductions by agricultural nonpoint source management practices; and 3) analyzing cost savings and load reductions potentially achieved through the proposed point source-nonpoint source trading program. Results indicate that phosphorus credit demand and most of the nitrogen credit demand by point sources can be met by nonpoint sources through the implementation of the no-till management practices on 50% of the row crops in the watershed. It was estimated that on average, point sources would pay 23.37 to reduce one pound of phosphorus with biological nutrient removal compared to 1.08 for agriculture with no-till. For nitrogen, point source unit costs were 4.72/pound compared to 0.45/pound for agriculture. This analysis concluded that water quality trading in the Great Miami River watershed had the potential to provide significant cost savings up to 384.7M over traditional command and control approaches over a 20-year period.