Williston – The Chittenden Solid Waste District has confirmed that initial lab results show the presence of trace amounts of persistent herbicides in certain batches of compost produced at its facilities. CSWD has stopped sales of all of its compost products until it can verify the source of the herbicides in the materials that were delivered to the compost facility and implement additional measures to prevent such material from being incorporated into compost in the future. The municipality is in the process of notifying all known customers of bulk and bagged product of this issue.
The Vermont Health Department has analyzed lab test results provided by CSWD. According to the Health Department, levels of herbicides detected in the compost, ranging from 1.7 – 15.3 parts per billion, are far lower than levels that would increase risk of harm to human health.
“While many customers are reporting no evidence of the presence of persistent herbicides, we are concerned about the impact on those whose gardens have been affected,” said CSWD General Manager Tom Moreau. “We are working with the Vermont Agency of Agriculture to determine how these herbicides, which are regulated by the state, have entered feedstocks to our compost program in apparent violation of their label requirements, and how to prevent it from occurring in the future.”
Lab results indicate traces of Clopyralid and Picloram, two persistent herbicides that target certain annual and perennial broadleaf plants. While the Vermont Agency of Agriculture does not restrict the use of Clopyralid, the manufacturer cancelled residential use on lawns in 2002. Picloram is a restricted-use product, which means that it can be used only by licensed applicators. According to the Agency of Agriculture, there has been no reported commercial use of Picloram in Vermont from 2009 through 2011 on any potential compost feedstock.
“We are baffled at where this could be coming from and are working with the state to track its source,” said Moreau. “We are conducting additional tests to verify initial lab results and consulting with nationally recognized experts on this issue to understand how best to trace the source, prevent it from affecting future batches, and resolve issues that have arisen with our customers.”
Symptoms of contamination include cupped leaves, twisted stems, distorted growing points and reduced fruit set, on broadleaf plants such as tomatoes, potatoes, eggplant, beans, peas, peppers, and sunflowers, which is consistent with herbicide exposure. The issue came to light last week, when CSWD began fielding reports from staff and customers of symptoms indicative of herbicide contamination.
For more detailed information, please view the online fact sheet, which is in the process of being updated, and will continue to be updated as new information is available. CSWD asks that anyone who suspects that their garden has been affected fill out an online report so they can be contacted as developments occur.
Individuals concerned about the safety of eating produce grown in Green Mountain Compost can contact the Health Department weekdays at (800)-439-8550.
Inquiries from commercial growers concerned about how the Vermont Agency of Agriculture is managing the issue, and whether produce may be sold in the marketplace, should contact Cary Giguere, Pesticide Program Section Chief at (802) 828-6531.