Daily News Archive

Contaminating Herbicide Causes City To Give Up Compost Distribution
(Beyond Pesticides, November 11, 2003)
The tradional compost distribution that the Solid Waste Divison of Lawrence, KS holds each fall is cancelled this year due to herbicide contamination, according to Lawrence Waste Reduction & Recycling (WRR). The town's compost was found to contain unacceptably high levels of the herbicide clopyralid, a chemical that remains lethal up to 18 months after initial use. "The reason we wanted to test this year's compost prior to distribution was the prevalence of clopyralid found in municipal compost facilities in California, Washington, Oregon, and Pennsylvania. We wanted to know if this particular herbicide was being used locally on residential lawns - to such an extent that it could potentially cause plant damage when used as compost for backyard gardens," says Mollie Mangerich, operations supervisor for WRR. "We sent a composite sample to a laboratory in Moscow, Idaho and it came back with the result of clopyralid found at 52 parts per billion (ppb) in our compost - a level which can be harmful to susceptible plants such as tomatoes, potatoes, peppers, peas, beans and sunflowers - plants often grown in backyard gardens and nurseries."

Other states have taken action as well. In March 2002, Washington state banned use of the chemical on residential turf after studies detected clopyralid in compost made from recycled grass, straw, and manure in California, Washington, Pennsylvania, and New Zealand. See the March 6, 2002 edition of Daily News for more information.

Several months later, during July 2002, Dow Chemical Company, manufacturer of clopyralid-containing herbicides including Confront, actually petitioned the U.S. Environmental Protection Agency (EPA) to delete all residential use from the label of clopyralid products. Additionally, the new label requires professional applicators to notify property managers not to compost clippings from treated grass. Dow's requested action neither addressed the most significant uses of clopyralid products nor provided complete warning of all the dangers presented by the product.

The vast majority of product is applied by commercial and agricultural applicators, and clippings from commercial turf (the majority of turf in some states) frequently wind up in municipal compost programs. Unless the herbicide is completely banned, compost and recycling companies told the Los Angeles Times that their businesses could go bankrupt. "You cannot have a system that mandates recycling of green waste and license a garden chemical that makes the waste unrecyclable," said Gabriella Uhlar-Heffner, solid waste manager for Seattle's public utility company.

The label change to clopyralid products is a phase-out, so although most products will show the new label, there may still be some products gracing garden store shelves that don't include the new warnings. Therefore, it is important to act responsibly on the consumer level. Environmentalists say it is best to avoid toxic herbicides altogether and practice safe lawn care techniques. A good IPM program combines monitoring, proper landscape design, mechanical and cultural methods, and includes the use of heat, herbicidal soaps, and corn gluten meal. Biological control of weeds, using beneficial insects or pathogens is also an excellent approach. These techniques add to the health of the soil rather than adding toxic chemicals, and also allow for safe composting.