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Keith: An excellent source of continuing education about the production and beneficial use of biosolids (the material formally known as sewage sludge) is the National Biosolids Partnership (www.biosolids.org), a partnership between EPA, the Water Environment Federation, and many states/municipalities...In addition to its excellent website, NBP's weekly e-newsletter is a good place to start; it doesn't shy away from dealing with the complexities and occasional controversies re biosolids. A recent one included a discussion of Toronto's problem in the context of it entering into a research partnership w/DC's wastewater management authority...in its search for ways to improve its options. My lay-understanding of Toronto's problem is that a) its biosolids don't meet sufficient quality standards (yet) for optimal marketing of them (which is why they've been landfilled), and that b) Canada's climate inherently limits field application of quality biosolids to certain times of the year (i.e., when the ground isn't frozen). By contrast, an increasing percentage of biosolids in the U.S. is beneficially reused (probably two-thirds or more), most often via various forms of compost and/or fertilizer -- with increasing interest in energy-related opportunities (not just burning, but actual production of liquid fuels)....In NYC's case, for example, what used to be ocean-dumped until 1992 is now 100% beneficially reused, with 70% meeting Class A (EPA) standards and over 50% processed locally into fertilizer pellets that are successfully marketed to orange groves in Fl, etc. Some percentage is actually used locally -- for ballfields, roadsides, etc. And a supplemental benefit: system costs for biosolids production and transport to markets have decreased substantially -- from over $100M initially to mid-$50M's at present, and been stable for several years. Also worth noting is Toronto's continuing challenges with the compost generated via its green-bin program....processing, quality, markets, etc. -- as well as costs. The subtle point is this: in U.S. cities/municipalities, most food waste is actually diverted from the solid waste management system via the use of food waste disposers (given that it's 70% water, it's more liquid than solid) which use the sewer system to transport organic waste (human + food) to wastewater treatment plants for processing....with the premise that the additional food waste actually improves the quality of biosolids. Not only does a food waste disposer/WWTP system eliminate truck-based collection costs and environmental impacts, it also improves methane recovery, rodent and odor control, etc.... In Philadelphia, for example, commercial food waste disposers are required as a condition of obtaining a dumpster permit for a restaurant so as to eliminate organic waste from them.... And, given the choice, I'd much rather trust wastewater engineers with managing food waste than solid waste engineers/managers with their focus on compaction, transport, dumping/burning and more compaction. Glad to discuss off-line, including the issues in Toronto and its surrounding cities -- which all are struggling with the same issues -- and point you to dozens of recent studies from around the world that carefully examine these issues, including assessing the life-cycle impacts of various systems for managing food waste....they all concur that food waste disposer-based systems create manageable impacts for well-managed wastewater treatment systems, while offering significant environmental and economic benefits. While I know full well that food waste disposers are considered a "third-rail" issue for some, in the U.S. they are a fact of life -- the majority of U.S. homes have them (for decades), and installed in probably more than 80% of new homes...with growing acceptance internationally, as nations/states/cities struggle with how best to manage food waste and address GHG issues. Thanks for considering... Kendall Christiansen Gaia Strategies kendall@no.address 718.941.9535 The writer has seventeen years experience in solid waste management and recycling systems in NYC -- including chairing NYC's Citywide Recycling Advisory Board for 5+ years -- and serves as senior consultant on environmental affairs to InSinkErator, the leading manufacturer of food waste disposers. (www.insinkerator.com) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "GreenYes" group. To post to this group, send email to GreenYes@no.address To unsubscribe from this group, send email to GreenYes-unsubscribe@no.address For more options, visit this group at http://groups.google.com/group/GreenYes -~----------~----~----~----~------~----~------~--~--- |
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