Herbicide Manufacturers Should Accept Responsibility For Residues In Compost

From BioCycle
Journal of Composting &Organics Recycling
July 2001, Page 84

COMPOSTING VIEW
HERBICIDE MANUFACTURERS SHOULD ACCEPT RESPONSIBILITY FOR RESIDUES IN COMPOST
Gabriella Uhlar-Heffner

THE CITY of Seattle, King County and other governmental jurisdictions throughout Washington State and Oregon have become very concerned about the increasingly widespread use of herbicide products in turf and agricultural applications that are making compost products unmarketable due to their persistence. These relatively new herbicide products contain clopyralid (and related herbicide compounds) and are slow to break down during composting and are damaging to nontarget plants at very low concentrations.

These problems pose grave threats to state and local government programs that promote both backyard and centralized composting as the best management method of dealing with yard trimmings. State and local governments and composting facility operators in the Northwest have invested millions of dollars in testing and marketing compost products to the public, nurseries and landscapers in order to improve regional soil quality, reduce water consumption demands and improve water quality. The existence of a class of herbicides that can damage the marketability of compost products is totally contradictory to all of our regional goals for recycling, resource conservation and sustainability.

Other articles in this issue of BioCycle document the ongoing problems that the City of Spokane, Washington State University (WSU) and recently, Pennsylvania State University are experiencing with their compost products being tainted with clopyralid and picloram, a related herbicide. The source of the clopyralid contamination in Spokane was traced specifically to the turf product, Confront, produced and marketed by Dow AgroSciences (Dow). It is heavily applied there by commercial lawn care applicators whose services are widely used by homeowners and golf courses for control of such “noxious” weeds as dandelions and clover. While clopyralid residues have not been detected yet in compost products produced in western Washington or Oregon, this chemical compound is now found in 22 registered herbicide products and most recently even in weed and feed formulations for lawns.

LABELING ON CONFRONT

Dow AgroSciences claims to have fulfilled its labeling obligations with its product Confront since the label reads: “Do not use compost containing grass clippings from turf treated with Confront within the growing season of application.” This label is totally inadequate since this message is only being delivered to the commercial applicator who applies the chemical to lawns and not to the homeowner or lawn maintenance company who collects the grass clippings. While Dow is now proposing that homeowners who have clopyralid-containing products applied to their lawns be told to grass cycle, has any research been done to evaluate the environmental fate of such residuals?

REGISTRATION PROCESS FOR HERBICIDES

The U.S. Environmental Protection Agency’s (EPA) registration process for herbicides should take into account that composting, not landfill disposal, is the waste management method for urban yard trimmings, food scraps and agricultural wastes. Many communities, including King County and the City of Seattle, ban the disposal of yard trimmings with the garbage. Many states prohibit the disposal of yard trimmings in landfills.

Herbicide manufacturers should be required to test their products to determine the fate of herbicide chemical compounds during a normal 60 to 90 day composting process. Tests should replicate both common commercial composting methods and unmanaged small home compost piles. The U.S. Composting Council should be contacted to assist with setting up a sampling and testing protocol to evaluate how quickly a herbicide breaks down during the composting process.

MANUFACTURER’S RESPONSIBILITY

Local and state government representatives from Washington and Oregon met with representatives of Dow AgroSciences in April to express concerns regarding the increasingly widespread use of clopyralid-containing products, such as Confront, and their impact on the marketability of compost. Dow representatives shared product sales information and proposed to conduct a series of bench-scale tests to evaluate how clopyralid residues break down during an idealized composting process. In order for such a study to produce valuable information, it must take into account all of the variability inherent in a full-scale composting operation, ranging from feedstocks to the type of technology employed. It also must address the issue of clopyralid contamination in potentially thousands of backyard compost piles that are not as aggressively managed as commercial composting operations.

In May, in response to a request from the Spokane City Council and the Board of County Commissioners, Dow asked commercial lawn care applicators to temporarily desist from using Confront on residential lawns in the Spokane area until this bench-scale testing program could be carried out. They also have proposed developing an inoculant product that could be sold to composters in order to break down clopyralid. This approach still places the entire burden of testing and disposing of unmarketable compost products on compost producers. The Spokane Regional Compost Facility has 25,500 cubic yards of clopyralid-contaminated compost from the year 2000 and who knows how many thousand cubic yards of unmarketable product from this year since the problem persists. Also, WSU has incurred significant expenses because the university is having to compensate organic farmers for their loss of organic certification of their fields for three years after tainted compost was applied last summer. The loss of organic certification is a serious liability problem to formerly certified organic farms.

Finally, the burden of having to test through bioassays and costly laboratory analytical work plus disposing of herbicide tainted compost products should not fall upon a local government or composting facility owners/operators but rather upon the manufacturer of the herbicide product.

PROPOSED PUBLIC AGENCY ACTIONS

The present herbicide problems in Spokane are the unintended consequences of a turf product of questionable societal value and for which the manufacturer is refusing so far to take full responsibility. The local governments that met with Dow representatives in April are sending letters registering their concerns with national and regional EPA, the Washington Department of Agriculture (which administers its own registration program for pesticides used in the state) and Dow AgroSciences. The local governments and compost producers plan to convene a meeting with the Washington State Department of Agriculture and Region 10 EPA to discuss the possibility of imposing more restrictions on the use of clopyralid-containing herbicide products in order to prevent more widespread compost quality problems in the future.

Gabriella Uhlar-Heffner is with the Seattle (Washington) Public Utilities based in Seattle.

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