ET-4G2 (2/10/05 version)
Chemical Integrity: Existing Pesticide Reduction Targets
Target 1: By 2012, reduce atrazine 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). The percentage reduction in atrazine is tied to the recommended sediment reductions for the same watershed, as atrazine attaches to soil particles.
Baseline: Atrazine has risen above allowable drinking water limits in Hoover reservoir (a drinking water source for the City of Columbus during the past 17 years of monitoring. The drinking water treatment option of choice is powdered activated carbon (PAC) requiring approximately 1.5 mg/l PAC per 1 ug/L of atrazine reduced. Each year $500,000 is budgeted for atrazine removal during drinking water treatment, but actual cost varies based on atrazine concentrations. A 30% atrazine loading reduction will reduce water treatment costs by $375,000/year or $5,625,000 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.