New Software Protects Florida Drinking Water From Pesticide

June 27, 1997

GAINESVILLE–A new computer software program developed by a University of Florida graduate student will help protect Florida’s drinking water from pesticide contamination and could have worldwide application.

More than 80 percent of Florida’s drinking water comes from underground sources, says Cornelis G. Hoogeweg, soil and water science graduate research assistant with the UF’s Institute of Food and Agricultural Sciences (UF/IFAS). But pesticides and other chemicals used in the production of Florida agricultural crops could contaminate groundwater supplies. In fact, several pesticides already have been detected in ground and surface waters.

“The pesticide contamination prediction system-called SEAMS (Soil Environmental and Agricultural Management System)is user-friendly,” Hoogeweg said. “So friendly, in fact, that users-farmers, policy makers, educators, regulators and researchers who need a tool to predict pesticide behavior in a three-dimensional world don’t even need to own a computer. The reason is, Florida’s county extension agents are being trained to run the computer simulation program for them.”

The three-day training began June 24 at UF. The software will be released in September, when the U.S. Environmental Protection Agency (EPA) and 55 of Florida’s 67 counties will receive it. Counties that do not have their soil maps digitized will not receive the software.

SEAMS builds on, and combines features from, several different computerized programs: the Chemical Movement in Layered Soils model, the Geographic Information Systems (GIS), ArcView, a weather generation program (WGEN), and Florida’s county-by-county digitized soils databases.

“It’s a great screening tool if you need a quick analysis of groundwater vulnerability to pesticide,” he says. “It’s better than EPA’s present system-an index method to quantify groundwater vulnerability-because it takes individual pesticide properties and drinking water standards into consideration. As for EPA’s other two screening models, SEAMS does an equally good job and requires less input data.”

Users can select from several pesticide classes: growth regulators, fungicides, fumigants, herbicides, insecticides, miticides and nematicides. The list is automatically updated for each crop. Based on the selected crop and treatment, a list of recommended pesticides for the site appears. More than one pesticide at a time can be selected. Five pesticide application parameters are also selected: minimum and maximum application rate, application depth, and application beginning and end dates.

The software prompts the user to select land-use types, such as fallow, row crops and small grains; management practices, such as straight row, conservation tillage, contoured, terraced or a combination; and crop cover conditions to estimate runoff and infiltration of precipitation.

Pesticide leaching appears as maps or as the probability of exceeding EPA’s health advisory levels. The maps, created by GIS, don’t need much interpretation, he says. “They’re very clear. Green is safe and red is hazardous.”

The program is so simple that if a user has not properly selected an application area, a warning window pops up with the message: “Bummer. No Application Areas Selected.”

Right now, the list is valid only for Florida, but that’s because only the pesticides registered for use in Florida have been incorporated into the model. The model could easily be retrofitted for use elsewhere.

“This software can be used anywhere in the world that has digitized soil maps and the type of soil data used in the model,” said Arthur Hornsby, UF/IFAS soil and water science professor.