The growing number of municipal and commercial composting operations has been one of the few bright spots in the environmental landscape, from San Francisco's curbside composting service to this industrial-scale composting facility in Delaware. But Josh Harkinson in Mother Jones has harshed our green-tinged buzz.
Thanks to fractured or lax regulations as well as the ubiquitous contamination of our environment by industrial chemicals (particularly heavy metals and pesticides), there's a distressingly real risk of toxic chemicals making it into commercial and municipal compost. And it's a particular problem for organic growers:
Pesticide-laced compost has presented a quandary for the USDA's National Organic Program ever since California regulators traced residues of dichlorophenyl-dichloroethylene, a breakdown product of DDT, and bifenthrin, an ant killer, to compost in pots of organic wheatgrass in Northern California grocery stores (the levels were not high enough to make anyone sick). DDT was banned for most uses in the early '70s and bifenthrin is classified as a possible human carcinogen and is highly toxic to fish. The NOP initially proposed setting a strict upper limit for bifenthrin levels in compost but abandoned the idea when wider tests revealed that many brands of commercial compost wouldn't pass. Regulators ultimately decided to allow any level of contamination in compost so long as "residual pesticide levels do not contribute to the contamination of crops, soil, or water."