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[GreenYes] RE: [ZWIA] Re: LA Zero Waste pans


It’s fairly straight forward.  If MBT produces a product that will generate no methane when landfilled, then the MBT + landfill combo most likely will have less GHG emissions than incineration + ashfill, even after deducting the GHG offsets from natural gas fueled electric power generation.  The MBT system itself would generate some GHGs to run equipment, so I would need to know those emissions to produce actual numbers for the comparison.  But my intuition is that the equipment and operations for incineration plus the amount of fossil fuel content of products that are incinerated have a greater GHG impact than the additional GHG from MBT equipment and operations. 


Same result for all the other environmental impacts in addition to climate change.


Then, if MBT + landfill costs less than incineration + ashfill, it’s a slam dunk that MBT for the residuals is better than incineration with energy recovery.  This, by the way, was the conclusion of that study that we did for Halifax in the early 90s that resulted in the MBT system they have in place there.  The actual costs for the two systems would be out of date, but I’ll bet the cost ratios of the two are still about the same.  So you could check out those studies to get a quick fix on the margin of additional cost imposed by the incineration + ashfill alternative.


Best of luck – you should know that there was at least one representative from Vancouver at the Recycling Council of Ontario’s Energy from Waste forum in November of 2006.  I gave the keynote and talked about the cost benefits of landfill versus incineration for disposal of residuals (given that their overall environmental impacts were about the same).  My impression was that the Vancouver folks were already well down the road to pushing incineration as their MSW disposal alternative.




From: zwia@no.address [mailto:zwia@no.address] On Behalf Of Helen Spiegelman
Sent: Tuesday, January 29, 2008 11:36 AM
To: Jeffrey Morris; matt@no.address; eric@no.address; 'Gillespie Gerry'; ricanthony@no.address; zerowaste_sd@no.address; zwia@no.address; gaia-zero-waste@no.address; GreenYes@no.address; crra_members@no.address
Subject: [ZWIA] Re: LA Zero Waste pans
Importance: High


Apologies for cross-posts... it's hard to know who's on which list above.

Jeff, have you run MBT through your calculator? Here in Metro Vancouver we are being told that WTE is the best solution for "residuals" that have been subject to 70% diversion through composting (food, yard, contaminated paper) and recycling. Can we make a case that investment in MBT for the remaining 30% is a better idea than investment in WTE?


At 10:24 AM 1/29/2008, Jeffrey Morris wrote:

Hey Everyone,
Many of you have obtained the model/calculator for the environmental benefits of recycling and composting from me.  Because of the great dialogue on composting versus incineration on these list serves, I thought I should mention again that the model does include in the environmental benefits of composting the upstream pollution prevention from reduction in the use of synthetic fertilizers and pesticides, and the carbon sequestration benefits of compost applications and the resultant healthier soils and plants. 
The version I sent around assumes that compost use offsets 50% of the average level of synthetic fertilizer and pesticide use on home lawns and gardens.  The model can calculate any level of offset between 0% and 100%.  The model also takes into account the build up of carbon in the soil from the use of compost, both as a result of the addition of carbon in the compost itself and as a result of the increased humus formation as a result of better plant growth. 
I picked the 50% fertilizer and pesticides offset estimate based on the observation that someone who buys compost for their lawn or garden is not likely to continue to buy the same amount of synthetic fertilizers and feed/weed type of products.  One might argue that the offset should be higher.  My usual tactic in the calculation of environmental benefits is to make assumptions that are if anything biased toward the burn or bury proponents.  The results still come out favoring recycling and composting, and it’s then hard to make the case that my analysis is biased toward recycling and composting.  However, one could run the model at 100% offset of synthetic fertilizers to see how much additional benefits accrue from going totally green!
The offset assumption for pesticides is also 50% in the baseline model.  Some of this is from the reduction in purchases of synthetic fertilizers that include herbicides (weed ‘n feed products).  Some is from the reduced need for herbicides and pesticides due to the stronger plants that result from a natural lawn and garden care approach. 
The carbon build up estimate is from EPA/s WARM model and the supporting document Solid Waste Management and Greenhouse Gases: A Life Cycle Assessment of Emissions and Sinks (3rd edition, Sept 2006).  The synthetic fertilizer and pesticide offsets are based on a study that an economist at Seattle Public Utilities, Jenny Bagby, and I did on backyard composting and natural lawn and garden care.  That study has been peer reviewed and accepted for publication in the International Journal of Life Cycle Analysis.  The article is published online awaiting its turn in the queue for publication in the printed journal.  The abstract can be found at .
One other point – the model includes other environmental benefits in addition to climate change benefits from recycling and composting.  It’s important to remember that human toxics and carcinogens, ecosystem toxics, acid rain, smog, ozone depletion, habitat alteration, species biodiversity, and water nitrification impacts are also reduced by recycling and composting.  In total these other impacts are of at least equal if not greater importance than climate change.  
Many thanks and much appreciation to those of you that are out there everyday promoting clean and green behaviors.  At some point we’re bound to reach a tipping point away from our chemically drowned lifestyles.
Best wishes,

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