A state Department of Agriculture investigation found powerful herbicides Dicamba — now banned — and Clopyralid in several compost samples that killed and damaged plants in dozens of gardens and small farms in North Carolina. However, investigators could not identify the original source of contamination.
Policy Watch reported last month that McGill Environmental in Chatham County unknowingly sold the tainted compost under the name “Certified Soilbuilder” to garden shops in the Triad and Triangle, where people purchased the product.
McGill officials speculated some of the contamination came from yard waste that had been sprayed with pesticides. That waste was then collected by municipalities and delivered to McGill to be used as feedstock to make the compost.
Sydney Ross, pesticide operations specialist with the state Department of Agriculture, said the agency received 85 complaints related to contaminated compost from McGill. Two samples detected Dicamba and another taken detected trace amounts of Clopyralid; all other samples taken did not detect the presence of any pesticides.
In its own investigation, McGill found Clopyralid in the compost.
Manufactured by Bayer, Dicamba has a troublesome 50-year history. Farmers previously avoided spraying the herbicide during warm, dry weather because it is prone to drifting and can harm crops and yards that weren’t the target of the spray.
Four years ago, the EPA approved an expansion of its use on soybeans that had been genetically modified to be tolerant of the chemical. As a result, millions of acres were sprayed nationwide, while the number of complaints skyrocketed, mostly from farmers and orchard and vineyard owners who said their crops had been damaged or killed by drift.
In June, a federal court ruled that it is no longer legal to sell Dicamba. However, farmers are allowed to use any of their remaining inventory. Some states have implemented restrictions, though, on how and when Dicamba can be sprayed.
Bayer recently allocated $400 million toward a settlement for alleged crop damage in the Midwest, beginning in 2015.
Manufactured by Dow AgroSciences, and now its spinoff company Corteva, Clopyralid is a persistent and powerful herbicide. Some states and municipalities have banned it outright. But in North Carolina, it can legally be applied to alfalfa and turf fields, as well on right-of-ways.
Without knowing the original source of the pesticides, the agriculture department could not determine if there were violations of state pesticide law. The cases are now closed, Ross said.