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From BioCycle Journal of Composting &Organics Recycling Febuary 2002, Page 51 |
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CONTINUING COVERAGE
CLOPYRALID DEVELOPMENTS IN WASHINGTON STATE
Update discusses results of several research projects as well as the status of the state Department of Agriculture’s rulemaking to restrict some uses of clopyralid.
Gabriella Uhlar-Heffner
COVERAGE of clopyralid contamination in compost in Washington state first began in BioCycle in September 2000. That article, “Dealing With Herbicide Residues In Compost,” discussed clopyralid contamination in composts at two Washington state facilities – Washington State University (WSU) in Pullman and an operation in Spokane. Eighteen months later, clopyralid contamination in compost has been documented to be a problem across all of Washington state.
In October, the Washington State Department of Agriculture (WSDA) undertook a voluntary testing program at five major composting facilities in western Washington and four composting facilities in eastern Washington (not including the city of Spokane’s facility or the one operated by WSU in Pullman, which still have ongoing problems with clopyralid in final products). Samples were taken of both incoming feedstocks and final compost products. Varying levels of clopyralid were found in all but one sample with a detection limit of one part per billion. The accompanying article, “Investigating The Prevalence and Fate of Clopyralid in Compost,” provides the results and analysis from the WSDA sampling.
WSDA is making these testing results available only by a Freedom of Information Act request (even though the barrage of December/early January news coverage in western Washington — following an article on clopyralid and compost in the Los Angeles Times — named the facilities where the samples were taken). Two of the sites, Pierce County Recycling, Composting and Disposal, LLC (PCRCD) and the Cedar Grove Composting Facility, have issued clopyralid advisory statements to purchasers of their bulk products. Both facilities also are conducting bioassays on batches of compost product and are seeking to isolate feedstocks with a high likelihood of having clopyralid residues from those that most likely are clopyralid free. Cedar Grove is continuing to produce a bagged compost product, which is labeled as being “organically certified” and therefore clopyralid free. The impact such publicity will have on the sales of compost product for the spring planting season will start to show by March.
WSU researchers have been doing ongoing testing of a wide range of agricultural products and residuals such as animal bedding, manures, straw and timothy hay and found varying levels of clopyralid (results of WSU sampling studies also are in the accompanying article cited above). Composting facilities in western Washington are now refusing to accept manures and animal bedding as feedstocks since there is a high likelihood of manures and straw being contaminated with the chemical, which is passed through the urine and manure of livestock feed straw or hay from fields where a clopyralid containing pesticide has been applied.
WSDA TECHNICAL ADVISORY COMMITTEE
WSDA convened a Technical Advisory Committee on the clopyralid problem at the end of November 2001. The committee is a stakeholder group comprised of many different interest groups such as large agricultural grower organizations (wheat, timothy hay, mint), forestry interests, the Friends of Farms and Forests, Dow Agro-Sciences, the commercial applicators (lawn care companies and golf course associations), chemical distributors, local governments including the city of Seattle, King County and city of Spokane, the composting industry (Cedar Grove, PCRCD, Norcal), and representatives of the Conservation Districts and sustainable/organic farming community. WSDA’s strategy is to put in place restrictions on clopyralid use in applications where there is a high likelihood that the residuals and products could end up in a composting facility.
The rules will address the use of clopyralid containing pesticides in three major areas — turf (residential and commercial business lawns, public parks, golf courses), cereal grains (e.g., wheat and oats) and grass hay. Rules also may be put in place for use of clopyralid containing herbicides on pasture and Christmas tree farms if problems are documented to exist. Rules will not be proposed for restricting clopyralid use on asparagus and mint simply because the farmer has a high degree of control over preventing residuals from these fields from entering an off-site composting facility. Likewise, the use of clopyralid on forestry lands will not be addressed since organic residuals are left on-site and do not enter composting facilities.
WSDA has made it very clear that it will make clopyralid-containing pesticides “state restricted use,” meaning that only certified applicators will be able to purchase and use the product. This should head off the sale and distribution of a slew of new “weed and feed” products containing clopyralid that could be purchased by uncertified applicators through retail outlets. It still may be possible for homeowners to purchase clopyralid-containing pesticides in bulk through distributors as long as they sign a statement saying that they understand it cannot be used in a variety of situations such as lawn care.
RESTRICTIONS ON CLOPYRALID USE
Restrictions shall be placed on the use of clopyralid containing turf products though it is still unclear whether WSDA shall opt for an all out ban on turf use in all areas (residential, commercial, public parks and golf courses) or it will instead only allow spot applications of a clopyralid containing herbicide if homeowners are instructed that the grass clippings need to be managed on site. The issue of translocation of clopyralid residues from treated grass to adjacent shrubs and trees has still not been resolved so this communication to the homeowner regarding on-site management should pertain to the leaves and shrub prunings as well as grass clippings. The solution shall not be as simple as telling the homeowner to grasscycle and to do backyard composting, which is not effective for reducing most pesticides anyway.
The type of restrictions to put in place for use on crops like wheat and timothy hay is far less clear since the grower associations are unwilling to develop any proposal, such as lower application rates, different timing of application or a tagging/notification system that follows a product as it is sold to a broker and then to an end user. According to the Wheat Growers Association, only about two percent of straw coming off grain fields would have clopyralid, which is applied for control of the Canadian thistle. In contrast, most of the timothy hay produced in the state of Washington could contain clopyralid residues since 90 percent of it is exported to Japan where it must be certified as being “weed free.”
The growers say that the label on products such as Curtail and Stinger are adequate since extensive warnings are already in place. These state: “Do not use plant residues, including hay or straw from treated areas, or manure from animals that have grazed or consumed forage from treated areas for composting or mulching where susceptible plants may be grown in the following season” as well as “Do not spread manure from animals that have grazed or consumed forage or hay from treated areas on land used for growing susceptible broadleaf crops.” However, while this label may apply to “plant residues” left on the field, it does not specifically apply to products like wheat straw or timothy hay that could end up as animal feed, or to straw that could be used as animal bedding. The original label warnings on Curtail or Stinger certainly do not accompany these products as they are sold to a broker and then to an end user and then go to a composting facility. Crafting a notification and tracking system to accompanying these products to different end users is certainly a difficult proposition, but one which will need to be attempted if no changes are required for pesticide use, application and timing on the part of the grower.
NO COMMITMENT FROM PESTICIDE MAKER
Dow Agro-Sciences, the manufacturer of clopyralid, has not made any commitment to decreasing the use of clopyralid containing pesticides, particularly for lawn use where there are plenty of cultural practice and chemical alternatives. Dow funded a major turf study with WSU in Puyallup to measure how the levels of clopyralid decreased in grass clippings over a ten week time period after granular and sprayed applications of a clopyralid containing formulation. Basically, the study showed that at ten weeks, the levels of clopyralid still found in turf after subsequent mowings would be too high to be received by a composting facility. Dow also funded a series of bench-scale tests of the grass clippings by the Woods End Research Laboratory under a range of composting conditions (aerated and unaerated) with different microbes introduced into the process to help with the degradation of clopyralid. No significant degradation of clopyralid was observed in any of the bench-scale test variations.
Many local government and composting industry representatives on the Technical Advisory Committee are urging WSDA to: Make clopyralid a state restricted-use pesticide; Track all sales and use of clopyralid in the state (currently WSDA has no formal tracking system for pesticide sales and use in the state); Eliminate all turf applications; Require treated hay and straw to be tagged and disclosed upon sale; Minimize clopyralid use in agriculture by restricting its use to noxious weeds where there are not other effective control mechanisms; and Evaluate and revise any proposed rules to ensure their effectiveness.
WSDA is planning to release its draft rule for public comment by early to mid-February with a 30 day public comment and public hearing process. The department anticipates adopting an emergency rule by April 1, 2002, with it being effective immediately. Since emergency rules are only in effect for 120 days, a permanent rule would need to be in place by July 1, 2002. The reason for WSDA not making the permanent rule effective by April 1 is that it has to conduct a Small Business Economic Impact Assessment for any new rulemaking process. Such an analysis would consist of a survey of commercial applicators and growers regarding the economic impact of restricting the use of clopyralid-containing pesticides. It is unclear if WSDA will consider the economic impact of not having these restrictions on the composting industry, organic and sustainable agriculture, and farming interests such as dairies, which may not be able to manage their manure through on-site or off-site composting. It is also unclear how the results of such an economic analysis will affect the permanent rule or what mitigation measures would be considered.
For copies of the draft rule, contact Cliff Weed, WSDA Pesticide Management Division, P.O. Box 42589, Olympia, WA 98504-2589; cweed@agr.wa.gov; fax 360-902-2040.
Gabriella Uhlar-Heffner is with the Seattle (Washington) Public Utilities. Uhlar-Heffner will copresent a session on Persistent Herbicides In Compost Feedstocks at the BioCycle West Coast Conference 2002, March 4-6 in San Francisco.
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