Concentration of CO2 in the Atmosphere

Alert: Results from CSWD’s expanded testing for herbicides in compost reveal wider picture

August 3, 2012

WILLISTON – The latest test results available from the Chittenden Solid Waste District indicate that the recent issue with trace amounts of herbicides found in some batches of CSWD compost reach beyond their product alone and, indeed, beyond Vermont’s borders.

“All 12 samples of individual horse farm manure and bedding show the presence of one or both of the persistent herbicides” said CSWD General Manager Tom Moreau. “Given that trend, we sampled some horse feed used by the farmers and four of the national brand of bagged products have tested positive for one of the herbicides.”

To date, CSWD has sent to a lab for testing 84 samples of compost, grass clippings, horse manure, leaves and a national brand of horse feed used by local horse farmers who provide manure to CSWD for composting. Six out of seven samples of compost from other brands produced in Vermont tested positive for trace amounts of persistent herbicides picloram and clopyralid between 2.8 and 13.3 parts per billion (ppb). Samples of horse feed returned results of between 104 and 465 ppb of one herbicide. CSWD’s compost has consistently measured less than 16 ppb of one or both herbicides. Click here for test results.

The Vermont Department of health has indicated that they would not expect that the presence of these herbicides would cause any harm to those who consume produce grown in affected compost.

CSWD is working closely with the Vermont Department of Agriculture, which regulates herbicides and is conducting its own investigation, and the University of Vermont College of Agriculture and Life Science to understand the science behind this issue. Of particular interest is an understanding of why certain plants in gardens using CSWD’s compost appear to be affected more than those grown in other brands produced in Vermont, and to determine the best ways to mitigate damage to plants and speed the breakdown of these herbicides.

To date, 507 people have registered their affected gardens with CSWD. Field technicians are conducting confirmation visits seven days a week and have made it to 420 gardens, about 70% of which they have confirmed signs of herbicide damage related to CSWD’s compost. CSWD will begin administering its assistance package early next week.

About CSWD
The Chittenden Solid Waste District (CSWD) is one of several solid waste districts established in 1987 when the Vermont Legislature passed Act 78 solid waste law. Functioning much like a school or water district, Vermont’s solid waste districts are government entities that design regional solutions to the solid waste challenges faced by their member towns. The District’s mission is to provide efficient, economical, and environmentally sound management of solid waste generated by Chittenden County towns and cities and their residents and businesses. Converting natural materials into compost is a core means by which CSWD fulfills its mission.

Contact: Clare Innes
CSWD Communications Coordinator
802-872-8100 x207 –

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