From: "Lawrence F. London, Jr." <venaurafarm@bellsouth.net>
To: permaculture <permaculture@lists.ibiblio.org>
Subject: Re: [permaculture] [Fwd: [SANET-MG] Convert landfills to compost!]
Date: Wed, 23 Dec 2009 00:14:17 -0500
Armed With A Mind Armed With A Mind wrote:
> One factor to consider with municipal scale composting systems is the
contamination. In the city of Toronto they apparently used to have a
composting system, and residents were free to come pick up finished
product for free. The compost was tested and was found to be
contaminated and unsafe for use in food gardens. I'm not saying that
this should stop such programs but it is something that most do not
think about and some extra step should be put in place to remove the
contaminants if testing shows it to be present.
---<>--<|><+><|>--<>---
If they are recycling yard and landscape waste there is always the risk
of contamination from various categories of pesticides, particulary
herbicides and especially roundup and the less biodegradable products
like chlorpyralid. http://newfarm.rodaleinstitute.org/depts/talking_shop/1203/watilth3.shtml
Compost. The chlorpyralid herbicide problem has receded since
restrictions on chlorpyralid use were put in place. The problem has been
that plant materials that have been in contact with chlorpyralid and
still have the residues on them, pass through the composting process and
kill plants that come into contact with the compost. There have been no
reports of chlorpyralid contaminated composts for two years, so testing
of composts for chlorpyralid is no longer mandatory in the state of
Washington.
Chemical spills, spills of all categrories of pesticides used by
homeowners or landscape contractors, dirt, mulches, potting soils, etc
that might have had these substances applied to them or spilled on them
that might have gotten mixed with the yard and landscape waste, all
possibilities of these scenarios apply when assessing the safety of
recycling yard waste for use by people as an amendment to their food
producing gardens. There are two categories of recyclable biomass
available from municipal waste collection and processing centers,
1) ground, shredded, pulverized landscape waste, usually larger woodier
items including stump, tree trunk, branch and twig grindings, root
systems, the heavier items
2) bark and light woody material, prunings, weeds of all sorts, vines,
grass clippings and leaves; sometimes the leaves are stored and recycled
by themselves
2) is where the problem lies as that group of landscape waste items is
most likely to be contaminated to a greater or lesser degree
The professional lawn and yard, business and industry landscape
maintenance companies are likely users of chemicals for many of their
maintenance tasks, especially herbicides such as roundup, 24d, atrazine,
chlorpyralid but also fungicides and insecticides. All this can end up
in the yard or landscape waste. Contaminated dirt, mulch and potting
soil can also get mixed in.
From what I know grass clippings are the most likely source of
contamination, possibly long term, of municipal compost destined for use
in food producing gardens or production of food crop seedlings or as mulch.
Here's more from the New Farm magazine:
http://newfarm.rodaleinstitute.org/depts/talking_shop/1203/watilth3.shtml
<...>
NOSB snubbed. Author’s note: Several materials recommended by the
National Organic Standards Board (NOSB), an advisory board to the NOP,
were not approved. An ongoing issue throughout the evolution of the NOP
Final Rule has been the NOP refusal to fully implement the
recommendations of the NOSB. The NOSB is made up of volunteer members
from the organic farming, support, and consumer sector, while the NOP is
part of USDA and, in the end, does what the USDA bids.
The NOP zero tolerance problem. Another issue that McEvoy raised is that
the NOP is going with a zero tolerance policy on what the WSDA-OFP has
considered to be minor non-compliance issues having to do with the use
of inert ingredients in various products.
Clarifications of the rules
Treated wood. Wood treated with chromium arsenate can’t be used as new
or replacement items that come into direct contact with certified
organic soil, plants, or animals. The issue of “direct contact” was
discussed. A fence in a pasture is considered not to be in direct
contact, since it is a border. A farrowing pen, a trellis, or a raised
bed structure is considered to be in direct contact.
<...>
Compost. The chlorpyralid herbicide problem has receded since
restrictions on chlorpyralid use were put in place. The problem has been
that plant materials that have been in contact with chlorpyralid and
still have the residues on them, pass through the composting process and
kill plants that come into contact with the compost. There have been no
reports of chlorpyralid contaminated composts for two years, so testing
of composts for chlorpyralid is no longer mandatory in the state of
Washington.