||Alion Science and Technology, Norfolk, VA.; National Risk Management Research Lab., Cincinnati, OH. Office of Research and Development.; Environmental Protection Agency, Research Triangle Park, NC. National Risk Management Research Lab.
Pesticide spray drift is defined as the movement of spray droplets through the air at the time of application or soon thereafter from the target site to any non-or off-target site, excluding pesticide movements by erosion, migration, volatility, or windblown soil particles after application. EPA established a Drift Reduction Technology (DRT) project under EPAÃ¢â‚¬â„¢s Environmental and Sustainable Technology (ESTE) program, which itself is part of EPAÃ¢â‚¬â„¢s Environmental Technology Verification (ETV) Program. Before the pesticide spray DRT generic verification protocol (GVP) is used for verification testing, the draft protocol requires testing and evaluation. Results from testing will be used to revise the draft DRT GVP. This report describes the evaluation of the draft protocol for pesticide spray DRTs verification at low and high speeds. This report provides stakeholders the validation data in a transparent manner so they can provide U.S. EPA suggestions to revise and improve the GVP. The goal of the DRT project is to test and verify the effectiveness of a variety of spray DRTs, and has the ultimate goal of reducing unintentional exposures during the pesticide application process. In 2007, U.S. EPA completed a draft protocol for the verification of pesticide spray DRTs for row and field crops. Draft Generic Verification Protocol for the Verification of Pesticide Spray Drift Reduction Technologies for Row and Field Crops (http://www.epa.gov/etv/pubs/600etv07021.pdf) was developed by U.S. EPA with input and commentary from stakeholders that included academia, industry, and other government agencies. For the low-and high-speed tests, the validity of and applicability of the pesticide spray DRT protocol were evaluated using two test nozzles and one reference nozzle. The two candidate nozzles tested were an AI11003-VS nozzle (Teejet Technologies, Wheaton, IL) and a ULD 120-04 nozzle (Hypropumps, New York, NY). The reference nozzle used for testing was an ASABE S572 nozzle associated with the fine/medium boundary. Measurements of the droplet size distribution produced by the candidate test systems were compared to the reference spray system based on the ASABE S572 standard for droplet size. Wind tunnel and spray liquid conditions measurements were supplemental measures that established the bounds of the spray size distribution data. Additionally, spray flux and deposition measurements were collected during low-speed tests. The low-speed measurements were conducted by Alion personnel in a low-speed wind tunnel environment in EPAÃ¢â‚¬â„¢s Aerosol Test Facility (ATF) at Research Triangle Park, NC. High-speed tests were conducted in the high-speed wind tunnel (HSWT) at the USDA-ARS in College Station, TX.