National Water-Quality Assessment (NAWQA) Project
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Estimation Methods:
Beginning 2015, the provider of the surveyed pesticide data used to derive the county-level use estimates discontinued making estimates for seed treatment application of pesticides because of complexity and uncertainty. Pesticide use estimates prior to 2015 include estimates with seed treatment application.
The USGS agricultural pesticide-use estimates are supported by funding from the USGS National Water Quality Program for the purpose of better understanding pesticides in freshwater and their impact on water availability nationwide. The USGS recently updated its plan to publish pesticide-use estimates. Final annual pesticide-use estimates, for approximately 400 compounds, from 2018-22 will be published in 2025. After that, preliminary estimates will be published annually and later updated with final estimates once the USDA Census of Agriculture is released (every five years). The total number of pesticides included in the analysis will fluctuate annually, based on data availability from our pesticide use survey contract provider.
The tables, maps, and graphs provided on this Web site provide estimates of agricultural pesticide use in the conterminous United States for numerous pesticides. The tables report agricultural pesticide use at the county level and are based on farm surveys of pesticide use and estimates of harvested crop acres. The maps show agricultural pesticide use on a finer scale and are created by allocating the county-level estimates to agricultural land within each county. A graph accompanies each map and shows annual national use by major crop for the mapped pesticide for each year.
These pesticide-use estimates are suitable for evaluating national and regional patterns and trends of annual pesticide use. The reliability of estimates, however, generally decreases with scale and these estimates and maps are not intended for detailed evaluations, such as comparing within or between specific individual counties.(More Details)