Solid Waste & Recycling


Maximizing the benefits of recycling

While the debate regarding waste disposal options rages in Ontario there is no argument that recycling remains the best option for reducing energy consumption and greenhouse gas emissions associated w...

While the debate regarding waste disposal options rages in Ontario there is no argument that recycling remains the best option for reducing energy consumption and greenhouse gas emissions associated with the production a host of materials, products and packaging from raw materials. Numerous comparative energy assessments have demonstrated that neither landfill (with energy recovery from landfill gas) nor incineration (with energy recovery) comes close to recycling in offsetting the energy invested in the manufacture of most products and packaging. (See cover story, page 8.)

As an example, the table provides the energy consumed in producing various materials from raw materials versus from recycled feedstock, as well as the emissions avoided of greenhouse gases associated with producing those materials from recycled feedstock.

However, the benefits of recycling are constrained by the effectiveness of the recovery system for collecting those materials and the efficiency at which those materials can be processed for recycling. With regard to municipal curbside collection of recyclable materials, collection system effectiveness and recycling efficiency are closely related.

Collection effectiveness relates to the quantity of material recovered as a portion of the absolute amount of material available for recovery. As an example, waste audits from seven Ontario municipalities (including Durham, Essex-Windsor, London, North Glengarry, Ottawa, Greater Sudbury and Toronto) yield an overall recovery rate of 87 per cent for old newsprint (ONP), which is indicative of a generally high recovery rate for ONP across the province.

However, recovery rates only tell part of the story. As we turn our attention to recycling efficiency, we consider the yield at which recovered materials are utilized in making new products.

As an example, since 1994 the percentage of actual newsprint in a tonne of old newspapers (ONP) received by Ontario paper mills has dropped from 94 per cent to about 72 per cent in 2005. Over the same period, the proportion cardboard/boxboard in ONP has increased from less than one per cent to almost 5 per cent of a tonne of ONP. Concurrently contaminants in ONP (plastic bottle caps, plastic film, aluminum scraps, etc.) destined for recycled paper mills have also increased.

Cardboard in ONP — called “outthrows” in paper recycling vernacular — tends to darken newsprint. Paper mills then have to add extra bleaching chemicals to compensate. Moreover, outthrows are typically comprised of low quality fibre that’s often saturated with dirt and glues; these overload mill cleaning systems, resulting in higher dirt levels, paper machine deposits, extra downtime and increased processing energy requirements (and increased waste to landfill). Contaminants in ONP must be sent to landfill.

So, while apparent ONP collection rates are up, actual ONP recycling efficiency at the mill is down.

In recent years the number of materials collected by many municipalities has increased while the total tonnage of material recovered has also increased. Concurrently, municipalities are making concerted efforts to reduce collection costs by reducing the number of collection trips they make. One popular approach (to reducing the number of truck trips to collect recyclable materials) is to commingle recyclable materials and collect them as a “single-stream.”

In Ontario, packaging-using industries are legislated to pay 50 per cent of net municipal curbside recycling costs. Hence, there’s significant pressure from these industries on municipalities to become cost efficient. Single-stream collection does reduce collection costs and increases collection efficiency. But here’s the conundrum: increases in municipal collection efficiency can result in recycling inefficiency (i.e., reduced yield); cross-contamination increases costs and reduces the environmental and economic efficiency of recycling the collected materials back into new products.

Positive modifications

The Ontario government recently announced a deposit-refund system for LCBO containers. A key impetus for this program is that the collection of glass packaging in single-stream systems results in breakage, color mixing and cross contamination of collected glass, thereby reducing its utility for recycling into glass packaging and fiberglass. While the current blue-box collection of LCBO containers is approximately 65 per cent, the actual bottle-to-bottle and bottle-to-fiberglass recycling rates are much lower. The majority of blue-box collected glass is down-cycled into lower-end uses such as aggregate replacement. Thus, the forthcoming deposit-refund system will complement the blue box by alleviating the burden of collecting certain materials that are best collected separately for recycling, and should boost paper recycling efficiency.

As we demand higher diversion rates for packaging (and household hazardous/special wastes, waste electronics, etc.) we must keep in mind the larger picture that includes the energy, natural resource and greenhouse gas emissions outcomes for the materials we recover for recycling.

Jo-Anne St. Godard is executive director of the Recycling Council of Ontario. Contact Jo-Anne at

Energy virgin Energy recycled Avoided energy Recycling avoided
(GJ/tonne) (GJ/tonne) (GJ/tonne) emissions
Glass 6.8 4.6 -2.2 -0.1
Aluminum 120.3 16.8 -103.5 -6.5
Steel 25.5 9.7 -15.8 -1.2
PET plastic 34.1 6.4 -27.7 –3.6
Newsprint 15.6 8.7 -6.9 -2.8

Environment Canada and Natural Resources Canada. December 2005. Determination of the Impact of Waste Management Activities on Greenhouse Gas Emissions. Prepared by ICF Consulting.

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