The highlight of the November 7, 2002 Organics Symposium put on by the Ontario Waste Management Association (OWMA) in Burlington was the unique challenge event called "Organicopolis." In this, three m...
The highlight of the November 7, 2002 Organics Symposium put on by the Ontario Waste Management Association (OWMA) in Burlington was the unique challenge event called “Organicopolis.” In this, three municipalities (Toronto, Halton and Hamilton) and their consultants built on existing pilot study information from their communities and presented model organics schemes that could divert as much as 30 per cent more material from landfill.
Some might assume that the idealistic Organicopolis is as realistic as the Emerald City in the Wizard of Oz, but the exercise was interesting and the participants deserve praise for some daring ideas that may yet be put into practice.
The Toronto team, with help from MacViro Consultants, came up with a striking 26 per cent diversion plan. In their “Organicopolis,” single-family homes set out kitchen scraps in green bins collected weekly. Dry recyclables and waste residue are collected on alternate weeks. Collecting residue (which is landfilled) only every second week promotes greater diversion.
Residents of small apartment buildings and condos (less than 50 units) place their organic waste in deep in-ground drop-off depot containers. Leaf and yard waste is collected and windrow composted, then sold.
The Toronto team addressed the problem of high-rises by recommending in-sink garburators for food scraps. These organics are processed at the Organicopolis sewage treatment plant. (In-sink garburators are actually required in high-rises in many American cities.) Organics from single-family homes and smaller apartments are transferred to a new processing facility that uses Enhanced Autothermal Thermophilic Aerobic Digestion (EATAD) technology. In addition this facility receives the sewage treatment plant sludge, thereby eliminating the need for a land-application program. The aerobic treatment process operates at thermophilic temperatures between 70 and 80 Degrees Celsius so pathogen inactivation is complete. The facility produces a granular fertilizer product and a concentrated liquid fertilizer product.
Organics are preprocessed at the EATAD facility in a liquid phase, i.e., as organic pulp. This separates and removes virtually all plastics and other contaminants, so household organics may be collected in small plastic bags (which helps overcome the “yuck” factor). It also allows for the collection of diapers, sanitary products and animal wastes.
The cost of this new system is approximately the same as conventional recycling and landfill because only a single truck is required to collect recyclables, organics and garbage, plus there are savings in biosolids management and landfill costs.
MacViro’s David Merriman says, “The critical assumption is that the fertilizer sales revenues cover the high operating costs of the EATAD facility.”
Organic waste management and fertilizer product sales are independently regulated by the provincial environment ministry and by the federal government via the Canadian Food Inspection Agency. The Toronto-team plan requires that the regulatory agencies eliminate barriers to the production and sale of organic fertilizer products derived from municipal organic residuals.
The Halton team also looked to co-operation from the Organicopolis sewage plant to manage its organics efficiently. They assumed that collected organics are first processed in a hydropulper to separate out plastic bags and grit, then added directly to existing digesters. (This improves the quality of the biosolids that are then applied to land.) Greenhouse gas emissions are reduced and green power is produced.
The Halton team increased diversion from single-family households from 21 to 50 per cent, and for Organicopolis as a whole from 18 to 42 per cent. The cost of processing household organics is estimated at $64 per tonne or $26 per household, significantly less than landfilling the material.
The Hamilton team (with the help of Earth Tech consultants) concentrated on how Organicopolis could get more organics to the curb, noting that participation and capture rates above 90 per cent are required to have organics contribute 30 per cent to overall diversion. They identified a flexible set-out program in which residents either use 120-litre carts provided by the city or their own smaller container bearing a sticker. Their scheme relies on extensive information/education initiatives and a range of “carrots” (e.g., rebates, awards) and “sticks” (e.g., by-law enforcement, full user pay).
In the program’s mature phase, organics and recyclables are collected weekly and residue is only collected bi-weekly. They visualize one or more aerobic co-composting facilities for rural areas and anaerobic digesters for urban locations that generate “green energy” and district heating, as well as potential greenhouse gas reduction credits.
The proposals from the three teams differ, but all recognize the importance of source separation and energy capture. It’s clear that there’s tremendous potential in using garburators and integrating solid waste with the municipal sewage system, especially in large cities with many high-rises. Some combination of all three proposals would be very compelling.
Though the final details will certainly change and evolve, the dream of Organicopolis may soon become a reality if the three teams present their inventive ideas to their municipalities and muster some political will. New challenges require imaginative thinking or as Dorothy said to Toto before they headed for the Emerald City, “We’re not in Kansas anymore.”
In an editorial entitled “The Waxman Decision” (in the August/September 2002 edition) I may inadvertently have created the impression that the judge in the civil case found the testimony of company accountant Steve Wiseman to be “fabricated.” While Madame Justice Sanderson rejected much of Mr. Wiseman’s testimony, she did not say that it was fabricated and I apologize if this impression was created.