Persistent herbicides at very low parts per billion level can impact sensitive garden plants such as fava beans.

Dan Goossen, Director of Composting at Chittenden Solid Waste District (CSWD) in Williston, Vermont, and General Manager of Green Mountain Compost, recently posted an update about the continuing risk of compost contamination from persistent herbicides on the US Composting Council’s (USCC) Soilbuilder Blog. The following is excerpted from Goossen’s post: “In 2012, Green Mountain Compost suffered significant losses following the discovery of Aminopyralid (one of the more potent persistent herbicides widely used for agriculture) in the compost sold to its customers. CSWD incurred close to a million dollars in losses responding to and compensating more than 500 customers whose gardens were affected. Some improvements have been made since the incident seven years ago, however, usage of these compounds has not slowed down and the risk of contamination at composting facilities is very real and likely to get worse. Aminopyralid is not currently marketed in the Northeast, but it can still be purchased through online platforms and will be going off patent in January 2021 (meaning greater availability to consumers and likely less product stewardship from producers). The options for lab testing compost and manures for persistent herbicides are more limited than they were even a few years ago. Incidents continue to occur nationwide, but they are underreported due to the potential stigma associated with the compost products.”

Composting facilities need to report incidents whenever they occur, emphasizes Goossen. “If you suspect you have had an incident involving persistent herbicides in your compost contact the USCC and your state pesticide control officials. Many of the persistent herbicides of greatest concern are also up for reregistration and review at the EPA in 2020.”

• Coping With Persistent Herbicides In Composting Feedstocks
  
• Testing For Persistent Herbicides In Feedstocks And Compost
• Composters Defend Against Persistent Herbicides
• Unraveling The Maze Of Persistent Herbicides In Compost
• USCC Persistent Herbicide Reporting Form and Factsheets