This summer, EPA proposed new measures to reduce runoff from some fields treated with atrazine into nearby watersheds, triggering some questions.
On Sept. 22, the Weed Science Society of American hosted a webinar. It included EPA staffers and scientists who work directly with the agency’s atrazine review process, and they discussed the details on atrazine’s current regulatory review, which is not yet final. The public comment period for EPA’s new proposals ended Oct. 7.
In 2020, EPA increased atrazine’s aquatic ecosystem concentration equivalent level of concern, or CE-LOC, from 3.4 parts per billion to 15 ppb. In June, EPA proposed a return to the 2016 CE-LOC level of 3.4 ppb. Leading farmer-membership groups said EPA’s return to the lower level impairs practical atrazine use on farms near watersheds where EPA’s monitoring shows levels of concern.
EPA proposed a “picklist,” or control requirements, farmers can use to reduce application rates or runoff into watersheds that exceed the new proposed CE-LOC level.
According to EPA staff on the webinar, the required number of control practices from the picklist would depend on EPA’s monitored atrazine concentrations in watersheds susceptibility to runoff concerns. Farm application rates matter. The higher the application rate and the higher the estimated atrazine concentration in the nearby watershed, the greater the number of picklist practices necessary.
EPA staffers presented a map showing watersheds in regions that require some picklist actions. Watersheds in coastal North Carolina, mid-southern South Carolina, south-central Alabama and a half dozen small spots in Georgia would require a ‘pick,’ or some combination of requirements, for growers to use atrazine there.
Looking at the map, much of the Southeast doesn’t fall under the picklist requirements. EPA also proposed new atrazine label requirements, such as:
- Barring application when soils are saturated or above field’s soil-retaining.
- Prohibiting application during rain or when a storm, likely to produce runoff from the treated area, is forecasted to occur within 48 hours following application.
- No aerial applications.
- Restrict annual application rates to 2 pounds of active ingredient or less per acre per year or less for applications to sorghum, field corn and sweet corn.
As part of the Federal Insecticide, Fungicide, and Rodenticide Act, or FIFRA, EPA must review a pesticide’s registration every 15 years. It had a deadline of Oct. 1 to review the 726 pesticide cases registered before October 2007, the agency said in late-summer statement. Of the 726 total cases, 461 are conventional ag pesticides. EPA has completed final or interim decisions for all but 144 of the 726 total pesticide cases.
“Pesticides without finalized review as of this deadline can remain on the market and be used according to the product label. EPA affirms its aggressive plan to review all remaining pesticide cases and issue decisions to protect humans, endangered species, and the environment, while providing pesticide users with predictability about the legal status of pesticides in registration review,” according to the agency.
Along with FIFRA requirements, EPA must comply with reinvigorated obligations under the Endangered Species Act, including for atrazine.