Two or three herbicides are periodically found in the drinking water of about 60 million Americans living in the Midwest, with the highest levels occurring in the weeks following spring herbicide applications. Reducing the use and health risks associated with corn-soybean herbicides has been a high priority EPA goal for nearly two decades, yet herbicide detection is increasingly common and there has been no major change in average levels found. If anything, the problem is worsening and growing more costly, both for municipal drinking water utilities and rural residents drawing their water from wells or surface water resources.

Approximately 2.5 pounds of herbicides are applied to every acre of corn in the United States for every pound sprayed on soybeans, yet the debate over soybean herbicide use -- and the impacts of Roundup Ready soybeans -- dominates public discussion. Clearly, innovations in corn weed management systems and technology will have to play a major role in reducing the risks associated with herbicides in drinking water. This report analyzes the impacts of three recent changes in corn weed management technology, each introduced with the promise of major reductions in corn herbicide use and risks. Two failed to deliver on the promise of use reduction and one is working, yet is paradoxically in regulatory jeopardy.

Complete Report (with Tables 1-5) (452KB)

Table 1: Herbicides Applied to Corn Acres from 1991 - 2000 based on USDA Pesticide Use Data: Percent National Acres Treated and Acres Treated (54KB)

Table 2: Pounds Applied of Corn Herbicides in 1971, 1982 and 1991 - 2000 based on USDA Pesticide Use Data (49KB)

Table 3: Estimated Impacts of Roundup Ready Corn on Herbicide Use in 1999 and 2000 (45KB)

Table 4: Compliance with the Acetochlor Conditional Registration Agreement's Herbicide Use Reduction Goals, 1992 to 2000 based on USDA Pesticide Use Data (52KB)

Table 5: Impact of the Registration of S-Metolachlor on Corn Herbicide Use, 1997 through 2000 based on USDA Pesticide Use Data (44KB)