Durham Region’s new two-stream MRF defines the new state-of-the-art
On December 18 a new recycling plant (or “materials recovery facility” — MRF) officially opened in Durham Region, east of Toronto. (See ribbon cutting write-up in Up Front, page 7.) The plant is an exceptional example of a greenfield “design, build, and operate” project involving three partners: the Regional Municipality of Durham (which owns the land and buildings, and will eventually own the equipment); Metro Municipal Recycling Services Inc. — a division of Metro Waste Paper Recovery Inc. (which operates the plant under a renewable five-year contract); and Gottardo Construction Ltd. (which built the plant).
The plant is similar to others built and operated by Metro Waste (see Cover Story sidebar article, page 11) that have achieved high recovery rates, and incorporates lessons learned from previous projects. The $17-million plant will process about 50,000 tonnes per year, with the capacity to process up to 115,000 tpy with the addition of a second shift. The contractor is paid by “tonnes out.”
Solid Waste & Recycling magazine toured the facility at the invitation of Peter Watson shortly after it came online in January. It was clear that Watson, who retired from Durham Region at the end of January, considers the new MRF the crowning achievement of his career.
“I’ve attended many industry conferences over the years and toured facilities in Europe,” stated Watson. “I made many notes about all the things I observed that work best, and incorporated them into the specifications of this plant.”
“Note the tall windows all around the exterior,” Watson says. “They’re 18 feet tall.”
“I got that idea from some European plants,” he continued. “The natural light makes the interior a more pleasant workplace, and safer, but it’s also environmentally sound because it lowers the lighting costs.
The first thing a plant visitor notices, after the windows, is the two large entrances and tip floors beside one another on one side of the building: one for the fibre stream (ONP, boxboard, etc.) and the other for containers (plastics, glass, aluminum, etc.).
“We committed to a two-stream process from the beginning,” says Watson, noting that the “free labor” of residents source-separating their recyclables into two blue boxes (with cardboard and boxboard tied or set beside the boxes) prevents cross-contamination of materials inside the MRF. (For a glimpse into the contamination problems mills experience from single-stream recycling, see Blog article, page 46. For the argument in favor of single-stream recycling, read the Waste Business column on page 36.)
Asked about other cities like Toronto whose MRFs process commingled fibre and container streams, Watson states, “My guess is that if you went for a walk with staff from those cities, they’d admit this is a better system.”
Throughout the plant, the two streams are processed separately, and clean bales of material are the result.
Quebec-based Machinex recycling equipment is ubiquitous throughout the plant, painted a distinctive blue. Even the Pellenc optical sorter is an equipment brand owned by Machinex. The exception we noticed was the large Gorilla baler from Peach Tree, Georgia-based Harris Waste Management Group, Inc.
“I enjoyed watching the trucks arrive with each piece of equipment,” says Watson. “It was like watching the world’s biggest Mechano set being assembled. They had to coordinate the delivery and installation of certain components on the bottom layer at the far end of the building, then work in a deliberate sequence forward and upward.”
The system uses disc screen technology to separate OCC out of the fibre stream. The discs are steel. The production rate is 20-25 tonnes per hour. (These kinds of specs were written right into the region’s contract with Metro.) The flexibility of this design allows for fine-tuning the equipment for periodic fluctuations in material composition and volume.
The container sorting system includes a ferrous magnet, a disc screen, an aluminum eddy current magnet, an air classifier, a plastics perforator-flattener and two Pellenc optical sorters (both used to sort containers). The optical sorters were embedded in the plant design, and funded with a $317,000 grant from Stewardship Ontario.
The processing stages use automation to remove or separate all ferrous metals, aluminum, cardboard and boxboard, newsprint, plastic, glass, etc. Residual materials are removed at various quality control centers (picking lines) along the sorting system.
“Because material is fairly clean coming in, and the equipment is effective, we need fewer workers on the picking line; they mostly remove items that don’t belong, more than separate large volumes of materials,” says Watson. He adds that a firm decision was made at the start to allow no plastic bags in the system (in the blue box or green bin program). The region will allow biodegradable liners when the new certification logo issue is sorted in the next year ahead.
Another notable feature of the plant is that newsprint is sent loose via conveyor to one of two compactors and is then put directly into highway trailers and taken away. This saves money. The tip floors are adequately sized (two days’ capacity) and there are five loading docks for baled material. Everything is done inside, yet the capacity and large bays allow for quick turnaround of vehicles delivering material or hauling it away to markets.
Four of Durham’s eight municipalities (i.e., 185,000 households) currently have weekly collection of blue box and green bin waste, and biweekly collection of waste. The remaining municipalities will move to this system when their current contracts come up for renewal this year. The four municipalities that already have biweekly garbage collection have seen residual waste drop 40 per cent and a 30 per cent jump in recycling. When all eight municipalities are online, the region should enjoy an enviable diversion rate.