[USCC] Fw: Sludge Watch ==> Questioning the Compost Supply Chain - Thisrecycling of wastes is risky

[The Rubins]

Food for thought for all you composters out there.  How worried are you 
about these trace constituents in biosolids and biosolids based commposts? 
By the way, you can probably detect many of these constituents in other 
composting feedstocks as well.  Analytical methodologies that are used today 
are quite sensitive.

Cheers

Alan


----- Original Message ----- 
From: "Maureen Reilly" <maureen.reilly at sympatico.ca>
To: <Sludgewatch-l at list.web.net>
Sent: Saturday, May 05, 2007 2:26 PM
Subject: Sludge Watch ==> Questioning the Compost Supply Chain - 
Thisrecycling of wastes is risky


> Sludgewatch Admin:
>
>
> This is a very important story. It summarizes the problem...companies paid 
> to 'recycle' wastes with few if any quality standards. Its a recipe for 
> disaster.
>
> ....................................................
>
>
> Questioning the compost supply chain
> As politicians increasingly use composting to solve municipal waste and 
> recycling issues, what happens to the pesticides, herbicides and 
> pharmaceuticals that may have gone into the mix along with the lettuce 
> leaves
>
> Deborah K. Rich, Special to The Chronicle
>
> Saturday, May 5, 2007
>
>
> If soil, which breaks down fallen plant and animal materials, can be 
> likened to the Earth's liver, then composting is becoming the liver of 
> modern society -- tasked with processing and reducing lawn clippings, food 
> scraps, manure and sewage. Given the chemicals we spray on our lawns, feed 
> our livestock and swallow to keep us happy and functioning, are we asking 
> too much of our collective microbial liver? Can composting detoxify 
> chemicals, or are we spreading heavy metals, pesticides and drug residues 
> in our gardens?
>
> The answers to these questions are uncertain.
>
> Composting is the mixing and management of organic waste (plant and animal 
> materials and byproducts) to achieve ratios of carbon to nitrogen that 
> accelerate and maximize microbial degradation of organic matter. By 
> harnessing the power of microbes, municipalities can reduce and recycle 
> plant and animal waste even where land and time are too scarce to 
> accommodate the soil's comparatively slow rate of decomposition. "By 
> composting, you are duplicating what nature would do given the chance," 
> says Dale Arnold, director of quality control and research at Kellogg 
> Garden Products. Kellogg sells compost and other soil amendments to 3,500 
> independent retail nurseries, as well as Home Depot and Lowe's. "Nature 
> takes a long, long time to make compost. All we're doing is speeding up 
> that natural cycle."
>
> Yard trimmings, wood waste from construction, animal manure, agricultural 
> byproducts and biosolids from sewage treatment plants are the primary 
> feedstock for the roughly 170 composters and waste processors that operate 
> in California.
>
> All are valuable sources of carbon and plant nutrients, and these 
> materials, once composted, can be used to maintain and improve soil health 
> and productivity. Adding composted organic materials to soil improves soil 
> fertility and structure, thereby lessening dependence on synthetic 
> nitrogen and counterbalancing the heavy drawdown of nutrients and the 
> successive degradation of soils that result from continuous farming and 
> gardening. Soils high in organic matter are more porous, more drought 
> resistant and less prone to erosion than are soils lacking organic matter.
>
> Chemicals remain
>
> Often these feedstock materials enter the composting process still laden 
> with chemicals. Yet standards for finished compost, which vary from state 
> to state, generally require regular testing only for heavy metals and 
> pathogen indicators. Seldom do states ask that producers test their 
> compost for residual pesticide or pharmaceutical compounds.
>
> Unlike farmers composting manure and plant residues for their own use, 
> gardeners purchasing compost at a nursery seldom know what went into the 
> compost, where the feedstock came from or what chemicals were on them.
>
> "Compost," says William Brinton, founder and president of Woods End 
> Laboratories in Maine and a pioneer of modern compost production and 
> testing systems in the United States, "has become anonymous and 
> untraceable; a single compost product can now contain a mixture of unknown 
> ingredients from all over a county or a state."
>
> The compost supply chain is poised to become even more difficult to trace 
> as city and state politicians turn to composting as a means to meet their 
> solid-waste reduction goals. "Composting now is being driven by recycling 
> mandates set by politicians," Brinton says. "When I got my start in the 
> composting world in the '70s, our motivation was to create products that 
> nourished the soil. That was the goal, and then we worked backwards and 
> asked how do we take ingredients like manure and crop residues and make 
> wonderful compost for the soil?
>
> "Now it's the cart pulling the horse: The recycling cart is pulling the 
> compost horse. I'm not saying the goals of making good soil amendments and 
> recycling are incompatible. I'm saying that this sets up the challenge to 
> maintain the integrity of compost, a challenge that will become more 
> intense as the industry grows even larger."
>
> Aside from the standards set by the National Organic Program for compost 
> used in organic food production systems, national standards exist only for 
> composts made from solids captured in the treatment of sewage at municipal 
> wastewater treatment facilities. In 1993, the EPA developed heavy metals 
> and pathogen standards that sewage solids -- also known as sewage sludge 
> or biosolids -- must meet before they can be spread on land. Subsequently, 
> these same standards were extended to compost made from biosolids and sold 
> to wholesalers and retailers.
>
> The California Integrated Waste Management Board regulates composting in 
> the state and requires that all compost produced in California meet the 
> heavy metal and pathogen indicator standards set by the EPA for biosolids, 
> regardless of feedstock source. California does not require testing for 
> chemical residues such as pesticides, antibiotics or hormones.
>
> Heavy metals, many of which -- like lead, arsenic and cadmium -- are toxic 
> to humans at low levels, aren't subject to microbial degradation in soil 
> or compost systems. Preventing their buildup in soil requires restricting 
> how much is added to the soil in biosolids, compost or any other soil 
> treatment.
>
> Some scientists are concerned whether heavy metals standards developed for 
> land application of biosolids are appropriate for compost because compost 
> is often applied at much higher rates than those allowed for sewage 
> sludge.
>
> "I think it is a very different story when you are applying compost 
> heavily over a short term than when you are applying smaller amounts of 
> sewage sludge over the long term because the bioavailability of these 
> compounds is very different when they're freshly applied and fresh 
> material," says Tom Richard of the department of agricultural and 
> biological engineering at Pennsylvania State University. "There is a lot 
> of organic-matter cycling going on, and these minerals will go through 
> more available phases as they cycle round."
>
> To qualify for unrestricted use on organic farms, compost must have lead, 
> cadmium and arsenic levels two to four times below those permitted by EPA 
> standards for the highest-quality biosolids.
>
> Drugs break down
>
> Unlike heavy metals, human and animal drugs have been repeatedly shown to 
> break down in both soil and compost. "In general, drugs, once they hit 
> manure, are metabolized relatively quickly," says Michael Payne, dairy 
> program coordinator for the Western Institute of Food Safety and Security. 
> "When you add a proper compost step, you even accelerate that because of 
> the heat."
>
> A recent study of composting examined its ability to break down 10 
> pharmaceutical and personal-care product residues in biosolids collected 
> from a wastewater treatment plant in San Diego. Fatih Büyüksönmez, of San 
> Diego State University's department of civil and environmental 
> engineering, found that composting for 45 days reduced residues of 9 out 
> of 10 products by at least 85 percent.
>
> Hormone residue in sewage and animal waste appears to be similarly reduced 
> by the composting process; they are natural compounds and highly 
> susceptible to microbial degradation. But how low a level of hormone 
> residue is safe is unclear. Scientists are finding that even very low 
> levels of hormones -- 
> washed into streams in municipal and dairy wastewater -- can significantly 
> affect fish and amphibians. Research is also linking hormones to increases 
> in a variety of human diseases, including some cancers.
>
> A study published in 2005 by Heldur Hakk of the USDA's Agricultural 
> Research Service found that composting reduced the incidence of estrogen 
> (17B-estradiol) and testosterone in chicken manure by 84 to 90 percent in 
> 139 days.
>
> In his discussion of results, Hakk cautions that the rate of hormone 
> degradation will be affected by how well the compost is aerated, and by 
> the moisture level, porosity and particle size of the compost.
>
> Time makes a big difference
>
> Time, says Brinton of Woods End Laboratories, is another key variable in 
> the reduction of hormones through composting, and of antibiotics and other 
> drugs as well.
>
> "If you use very short turnaround systems, the breakdown of these drugs is 
> a concern,'' Brinton says. "Most composters are composting 60 days at 
> least, and some composters are waiting six to eight months because they 
> know the compost only gets better and better. Every once in a while I hear 
> of a five-day compost system, and that's just not long enough. Most states 
> say you can meet EPA law in five days with in-vessel composting, or 15 
> days for other systems, but then you need to store it for 30 days. So some 
> safeguard is built in."
>
> Scientists probably have a better understanding of how pesticides break 
> down during composting than they do of any other class of man-made 
> chemicals. When interest in composting yard waste as a means of keeping it 
> out of landfills surged in the late 1980s, many state and local public 
> agencies studied how well composting reduced pesticide residue.
>
> Compost pesticide residue consistently proved to be so low that most 
> composters today only occasionally conduct tests to verify that pesticide 
> residue is reduced to the point where the compost will not be toxic to 
> plants.
>
> But the low incidence of pesticides in compost isn't proof that compost 
> can handle society's worst chemicals. The successful elimination of 
> pesticide residue in compost is due at least as much to regulatory action 
> as it is to microbial activity. Since the 1970s, the EPA has banned or 
> restricted use of pesticides that persist in the environment. Chlorinated 
> compounds, like DDT, resist microbial breakdown in both soil and compost. 
> The food residue thresholds authorized by the EPA for each pesticide help 
> as well, placing, by default, a ceiling on the amount of pesticide 
> entering composting systems.
>
> The safeguards aren't foolproof. In 1999, 2000 and 2001, clopyralid -- an 
> herbicide used to control broad-leaved weeds in turfgrass, and hay, wheat 
> and other crops -- persisted in composted lawn clippings at levels high 
> enough to cause damage to garden and nursery plants in eastern Washington 
> and Idaho. Studies found not only that clopyralid breaks down very slowly 
> in compost, but also that it is highly toxic to some plants, including 
> sunflowers, legumes, tomatoes and potatoes, even at residue levels well 
> below those allowed for use on turf and grass crops. Washington and 
> California banned the use of clopyralid on residential lawns and 
> restricted use of clopyralid by commercial applicators in 2002. Since 
> then, no further damage from clopyralid residues in compost has been 
> reported.
>
> Even with pesticides that break down rapidly in compost, questions remain. 
> Only a small amount of pesticide "disappearance" during composting is due 
> to mineralization, whereby the compound is reduced to water and other 
> inorganic compounds. Much of the pesticide volatilizes, vaporizing into a 
> gas. Depending upon the compound, the vaporized pesticide may or may not 
> pose environmental risks. Another large portion of the pesticide is 
> absorbed (or bound) to organic matter in the compost. While bound, the 
> pesticide is unavailable for uptake by plants; however, as the organic 
> matter breaks down further over time, the pesticide may again become 
> bioavailable.
>
> As our dependence on compost to both reduce our organic wastes as well as 
> to maintain the health of our soils grows, composting without a more 
> complete understanding of the fate of chemicals in compost becomes 
> increasingly risky.
>
> "I believe that composting is the best tool that we have for handling many 
> of the different types of organic materials that we use," says Richard of 
> Pennsylvania State University. "It can reduce their impact significantly 
> and at lower cost than other options that we have, and we really do need 
> to have a society that does a better job of recycling its organic matter.
>
> "But we need to look pretty hard at a lot of these different compounds. We 
> are depending on composting to handle increasing amounts of the 50 
> percent-plus of our waste stream that is organic. To not be studying these 
> emerging questions seems to be pretty naive."
>
> Monterey writer Deborah K. Rich is a frequent contributor to Home&Garden. 
> E-mail her at home at sfchronicle.com.
>
> http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/05/05/HOGD3PJOUT1.DTL
>
> This article appeared on page F - 5 of the San Francisco Chronicle
>
>
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