NaturChem North, which has a Kentucky office in Lawrenceburg, agreed to pay 10 percent of the $194,200 penalty and serve a two-year probation.
Agriculture department attorney Nicole Liberto said the company would have to pay the entire fine immediately if it commits any further violations during that time.
NaturChem was cited for failure to follow state regulations governing the herbicide Atrazine and allowing untrained workers to spray it. Ken Franks, branch manager for the department's Division of Environmental Services, said the weed-control chemical is highly restricted in Kentucky because it can easily sink through the ground and contaminate the water table.
"It does get into the groundwater, so the only labeled use for Atrazine in Kentucky is on corn," Franks said.
Franks said the fine is the steepest penalty levied by the department's regulators in at least five years and is believed to be the highest ever. The chemical was sprayed on rights of way, or land near gas and power lines where NaturChem was allowed to apply herbicides.
The department did not investigate whether there was any contamination from the herbicide, Franks said.
The use of the common herbicide has been severely limited over the last decade, according to the Environmental Protection Agency. The chemical has been found in high levels in ground water in at least 10 states, including Indiana.
The violations occurred in 2001 and 2002. The company has since come into compliance and begun to pay the fine.
NaturChem, which is headquartered in Georgia and South Carolina, applies herbicides for commercial customers such as gas and power companies. Aaron Hayek, who oversees NaturChem's Tennessee and Kentucky offices, said the company was using Atrazine legally in other states when it was cited in Kentucky.
"It just so happens that in the state of Kentucky this particular product cannot be applied," he said. As a result, the company has stopped using the herbicide in the state.