ET-4E2 (2/10/05 version)
Chemical Integrity: Existing Nitrogen Reduction Targets
Table 1. Existing Nitrogen Reduction Targets
|Target 1: By 2013, implementation of the
Scioto CREP will reduce nitrate-N loading flowing into the Ohio River from the Scioto River basin by 30% (Level 3).
|Baseline: The Scioto River basin discharges
approximately 20,000 metric tons of nitrogen annually to the Ohio River.
Additional details are available in "Assessment of Overland Runoff Nonpoint Source Pollution, 2003".
|Target 2: By 2015, per the Gulf Coast Hypoxia Action Plan, reduce hypoxic zone to less than 1,930 square miles (Level 4)) and nitrogen discharges to the Gulf of Mexico by 30% (Level 3).
Baseline: About 90 percent of the freshwater (3.3
million gallons/second) and nitrates entering the Gulf come from Mississippi
River Basin runoff from agricultural operations. About 56 percent of the
nitrates enter the Mississippi River above the Ohio River. The Ohio River Basin
adds 34%. Nitrogen loading data, by tributary, for the Pennsylvania, West Virginia, Ohio, Kentucky, Indiana, and Illinois portions of the Ohio River basin is available in
"Assessment of Overland Runoff Nonpoint Source Pollution, 2003".
|Target 3: By 2012, reduce nutrient loadings by 30% to Hoover Reservoir in the
Upper Big Walnut watershed, through implementation of 3500 acres of conservation practices and 500 acres of conservation easements (Level 3).
|Baseline: This target is based on protecting drinking water quality for the City of Columbus. Nitrate loadings to the reservoir have been measured since 1982. The average loading is 7 lbs/acre for the 122,000 acre watershed. While nutrient concentrations do not exceed nitrate drinking water MCLs, recent taste and odor producing biological events suggest that nutrient stimulation of these growths may be occurring. The drinking water treatment option of choice is powdered activated carbon (PAC). A 30% nutrient loading reduction will reduce water treatment costs by $125,000/year or $1,875,000 over a 15 year period. It is less expensive to implement the necessary conservation practices to control run-off at the source than it is to continue PAC treatment.