Persistent Herbicide Update

by James McSweeney

Many of you are aware that Green Mountain Compost (GMC), formerly Intervale Compost, has ceased sales and recalled compost from retail outlets due to the presence of two persistent herbicides in some of this spring’s product. The composting community is extremely concerned by the contaminations at GMC and is actively rooting out all potential sources of contamination, with support from the VT Agency of Agriculture and the Agency of Natural Resources, as well as a nationwide support network.

Highfields has had no reports of garden injury from use of our compost and we've seen flourishing results in our own staff's gardens, including in the crops that are most susceptible to the Dow Chemical herbicides present at GMC, Picloram and Chlopyralid. We feel extremely confident in the qualities and benefits of using our product.  We have taken an extremely conservative approach to our incoming materials for the last 10 years, including not accepting grass clippings (one of the primary materials implicated in herbicide contamination at other composting facilities) and floral products.  We will continue to be vigilant in the sourcing and handling of materials received at our facility for composting.

 In addition, we are taking the following safeguards:

  • Plant bioassays using both standard compost and vermi-compost – these are plant tests utilizing sensitive broad-leafed crops that are good indicators of herbicide contamination.
  • Outreach and education to our manure generators to mitigate contamination at it's possible sources – we are working with the farms that supply us with manures to trace their hay and bedding straw back to their source of origin to confirm that these products are free of persistent herbicides.  We are grateful for the partnership of these farms in this effort.
  • Chemical analysis for the presence of these two herbicides in our compost and incoming feedstocks
  • When toxic contaminants show up in products that are otherwise the basis of modern sustainable agricultural systems such as composts, something is broken upstream which needs immediate attention.  Compost is not the problem, our collective tolerance for toxic materials in the food system is.  Compost is only an indicator of broader problems and the herbicides showing up are a mere fraction of the total herbicides now persisting in the environment and farm soils.
  • We believe that in order to build a food system worthy of our grandchildren and great-grandchildren, we must stop poisoning and landfilling their inheritance. 

We are urging regulators to implement long-term solutions, because whether it is in compost or in the soil or groundwater, toxics deteriorate resources that are vital to our local economy and very way of life. Our hearts go out to GMC and to all those who lost their gardens, and we look forward to a time when no composter, farmer, or gardener in Vermont will have to worry about these issues.

Thank you for your support of our facility, organization, and campaign to build a more sustainable, toxics-free food system from the ground up.

NOTE: If you are a composter who takes horse manure, we recommend you perform the following plant bioassays developed at Washington State University: WSU Persistent Herbicide Bioassay