A New "Spin" on Site Remediation

Barry Greenaway, McCloskey International Limited,
Special Collaboration


Nestled in the heart of the Greater Toronto Area, the Town of Richmond Hill is not only one of the fastest growing communities in Canada, it is also one of the most affluent. This means that the investment potential of any available property in the town is continually on the rise. For Rick Sova, the owner of Cornerstone Landscaping, the challenge was to help a leading developer in the area to get full value from the property.

Rochon Building Group saw plenty of opportunity in a parcel of 6 ha it had purchased there. Plans were in place for a large residential project. But years ago, long before today's stringent regulations on land use and waste management, the site that Rochon planned to develop had been the property of a construction contractor. The developer found that it had inherited the contractor's dump site. Under a large section of the property lay a daunting mix of rubble, asphalt and assorted demolition debris. Rochon called Cornerstone for a solution.

Rick Sova describes what he found: "One corner of the building site was filled with concrete, curbs, rebar, wiring, steel, wooden beams... pretty much anything the contractor wanted to dispose of," he recalls. "It was completely unusable as a base for building a roadway or parking lot, as the developer had planned. We had no choice but to dig it all out."

Established in Brampton, Ontario, over 21 years ago, Cornerstone Landscaping came into the world as a landscape design/build firm. Over the years, the company has expanded its activities to include, among other ventures, processing its own soil. This experience provided Rick Sova with a solid grounding in screening equipment which, in turn, led Cornerstone into "green" services such as waste processing and recycling operations.

The right idea; the right equipment
At the Richmond Hill dump site, Mr. Sova's approach was not to simply clear out the dump site, but to "mine" it for recyclable materials. With the right equipment, he could reclaim much of the value of the buried materials along with the value of the property itself.

Rick Sova tested his remediation system by bringing in excavators and loaders to dig out the materials, plus a McCloskey 621 trommel to separate the various materials for recycling. "We had the trommel fitted with a vibrating grizzly, which scalped off any materials larger than 10 cm before it entered the hopper," he explains. "The remaining material was screened through the trommel drum with a 5 cm mesh. Screening it this way allowed my crew to separate out the larger materials to be recycled, including anything from 10 to 5 cm in diameter. The remaining material, anything under 5 cm, was fine enough to recover and use to backfill the excavated area."

The sorted materials turned into a number of recycling streams. Chunks of concrete and asphalt were put through a grinder for re-use. Wood waste was chipped for mulch or composting. Metals and clean plastics were sorted for delivery to recycling operations. In the end, Cornerstone had to send only a small percentage of the total material to a landfill site.

The principle is simple enough, but the amount of material to be processed was huge, and the developer was on a timeline. Cornerstone ramped up with additional equipment, including a second 621 trommel Mr. Sova purchased for the project. With the process in full swing, the two trommels were running 10 hr shifts, with four excavators and two wheel loaders operating continuously to feed them, plus two stackers to pile the screened materials.

"Brutal" but successful!
Start to finish, Cornerstone processed close to 38 000 m3 of dirt and debris over a period of 10 weeks.

"We cleaned out a pretty big hole," Mr. Sova admits. "The remediation area covered a full acre, and we excavated a good 9 m deep! As we backfilled the site with the fines, we were also compacting it in 15 cm lifts, and brought the whole thing back up to grade."

"It really was brutal work for those trommels," he continues. "They really took a beating from the kind of material we put through it, over very long duty cycles. But they did the job, and they're still producing for me."

Rick Sova credits the onsite support he received from the McCloskey factory as an important part of his success with the project. "We needed some help getting set up when we first started; we had some very heavy, sharp, nasty material going through! But McCloskey had its people onsite quickly. They also looked after weekly maintenance service and they were always right on schedule."

Building on recycling
The two trommels that Rick Sova took to Richmond Hill are now working at two Cornerstone soil-processing locations in nearby Caledon and Barrie. The 621 trommels both feature McCloskey's "Drum X-Change System", allowing Cornerstone to easily switch out the 5 cm screening drums for 3/8" screens suitable for soils and composting. "Now I've got them making our famous Quadmix specialty and garden soils!", he laughs. Cornerstone's recycling work is actually an integral part of its soil and landscaping business. In the beginning, Rick Sova began grinding and screening his landscape debris to produce his own soil mixes. His soils became a successful venture on their own, including production of private label brands for leading retailers. He takes pride in producing soils with no peat content, just "100% compost."

The resulting demand for soils spurred the expansion of Cornerstone's waste recycling services for other contractors and landscapers. The two sides of the business support each other, and both support the landscaping business. Anytime Cornerstone excavates and grades a jobsite, the material all goes back to the composting facility to be screened, processed, bagged and retailed, instead of just dumping it.

As demand for urban development meets increasing pressures to conserve green spaces, Rick Sova sees another growing opportunity for Cornerstone, recycling compromised properties into valuable real estate.

McCloskey International Limited designs and manufactures innovative trommel screeners, vibrating screeners, stacking conveyors and picking stations. Since 1985, McCloskey International Limited has been exceeding customer expectations with reliable, durable and high performing products. McCloskey equipment is used by topsoil producers, landscape contractors, composting facilities, waste management and recycling operations, and quarry operators to help achieve profitable volumes.

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