April 16, 2010

WATTERS ENVIRONMENTAL GROUP

Reusable materials such as bathtubs were removed by York Region Habitat for Humanity volunteers prior to demolition.

FEATURE | Demolition/Environmental Engineering

Demolition in Newmarket, Ontario is helping build affordable housing

DAN O’REILLY

correspondent

Future riders on York Region’s VIVA rapid bus system in Newmarket, Ont., north of Toronto, won’t be the only beneficiaries of a massive and challenging demolition now nearing completion.

Twenty four residential and commercial buildings along a 1.8-kilometre stretch of Davis Drive from Yonge Street to near the Southlake Hospital have been knocked down for the construction of two dedicated rapid bus lanes.

Prior to demolition reusable materials such as bathtubs, cupboards, and lumber were removed by York Region Habitat for Humanity volunteers for sales at their retail outlet with money going to assist the non-profit organization build four new homes.

Significant heritage elements were also saved by the Newmarket Historical Society, says Robert Watters, president of Watters Environmental Group Inc., the consultant overseeing the project for York Region and VIVA.

The heritage and housing organizations became involved as part of the planning principles, says Watters.

“We were focused on environmental responsibility and were guided by the 3Rs (reduce, reuse, recycle),” he says.

The project’s four demolition contractors also had to buy into it, he says. They include JMX Environmental Inc., Maram, the Cannington Group and Priestly Demolition.

WATTERS ENVIROMENTAL GROUP

Twenty four residential and commercial buildings along Davis Drive have been knocked down for the construction of two dedicated rapid bus lanes.

Describing the project as a demolition doesn’t really convey its full complexity which has a number of other diverse elements besides the recycling.

The work has to be co-ordinated to minimize disruption to Davis Drive and once the buildings were knocked down there was significant soil remediation, Watters says.

A two-stage environmental assessment was conducted in the early stages of the project. After poring through historical records, the consultants drilled holes at approximately half the sites looking for evidence of environmental contaminants such as hydrocarbons. Many of the properties had, at one time, been occupied by gas stations and dry cleaners, says Watters. “We had to go quite a depth in some places.”

Complicating the assessment was the fact the contamination wasn’t consistent. On some of the sites, polluted layers of soil were sandwiched by clean ones. And because pollution does seep on to other lands, some test holes had to be drilled into the middle of Davis Drive.

“We tried to do that in the quiet part of the night,” he says.

In addition to the environment assessment, there was also a detailed asbestos analysis by the four contractors. Many of the older buildings contained now-banned building substances such as asbestos, insulation, PCBs and other hazardous material, says Watters.

No buildings could be torn down until reusable and heritage items and the hazardous substances removed.

Even then, the contractors were still required to carefully separate and segregate the building materials to ensure a targeted 85 per cent diversion rate from landfills.

Once the demolition was completed, the soil remediation process got underway. Rather than simply trucking all the material to landfill, the clean and polluted layers were separated, and clean fill was stockpiled at a nearby VIVA-owned property. Later it was returned to the sites. Follow up verification testing also had to be conducted.

Although most of the demolition is finished, there is still a considerable amount of remediation to be conducted, including sections of Davis Drive.

While that will cause some inconvenience to drivers, it will save time having to rip up the street when the construction of the bus lanes gets underway, says Watters.

That is expected to occur near the end of this year or in the spring of 2012, says VIVA communications spokesperson Dale Albers.

Tenders have already been issued and are scheduled to close at the end of April.

A two-year $50-million expansion of the Keith Bridge over the Holland River to prepare the street for the widening is currently underway. The bus lanes are scheduled to be in place in 2014, says Albers.

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