A green solution for oily soil

Kensington Condo

 

In the heart of Kensington Market, there’s been a barren stretch of Baldwin St. running east-west amid the jostling produce stands, the skinned goats hanging for sale, the stores with names such as Dementia and Asylum, Madeiros Fish Market and Lucky’s.

This stretch of street had been dominated by the blank wall of George Brown College, a three-building complex dating back to 1926 that stretches north to Nassau St.

Now the college is gone, the building is being converted into a 140-unit condominium, and the blank wall is about to become a stretch of storefronts to match the rhythm of the market.

The condominium units sold out within one-and-a-half months of going on the market in October 1997, a good year and a half before any was ready for occupancy.

As always, there are many reasons why something sells out quickly.  Location was obviously one factor. But the one that interested me most was the marketing strategy. Context Development Inc., the company that undertook the conversion, decided that it was going green, and it marketed the building as an environmentally advanced project.

This approach worked, says Alex Speigel, a partner in the company. Buyers responded.

Among the green initiatives was the way the company dealt with contaminated soil. That’s the one I found most innovative. There were other initiatives, and I’ll tell you about them next week.

One of the college buildings had contained a massive boiler that provided heat to the complex. It was fired by an oil furnace, and the oil tank was located on an earthen floor.

Speigel, an architect, says it’s not unusual for old buildings to have an earthen floor. The foundations were fine, it’s just that a concrete floor was never laid. As you would expect, fuel oil got into the soil. It seeped to a depth of five metres, and spread underneath the foundation footings.

Usually, contaminated soil is dug up and carted away, even if it means, as it would have in this case, demolishing part of the building.

However, Speigel and his partners didn’t want to do that, because it’s not a green solution. You don’t get rid of the problem, you simply transfer it somewhere else.

Bioremediation — using bacteria to break up oil molecules by reacting chemically with them — was a possibility, but normally it takes too long, and delays construction to the point that it’s far cheaper to dig and haul.

That’s where Cynthia Robins, senior environmental consultant with Shaheen & Peaker Ltd. of Etobicoke came in. She recommended Koy-Hong Lee, a biochemist with A GEO Technology Inc. of Toronto, who has concentrated on speeding up the process.

Lee is opposed to using « superbugs,’’ genetically altered bacteria that work faster at breaking down oil. They can be purchased from genetic engineering firms. There are even bacteria that are descendants of those used to clean up the Exxon Valdez oil spill that can be acquired. But they also originated as a « superbug.’’

« We still don’t know enough about (the consequences) of using `superbugs’,’’ he says. Once they’ve done their job, « they’re released into nature,’’ and no one knows what the result will be.

Lee relies on bacteria already living in the soil, and uses enzymes, which are natural catalysts, to speed up the chemical reaction by which the bacteria break down the oil. He mixes « scores’’ of enzymes into a solution, and injects it into the contaminated area. After eliminating the oil, the bacteria revert to their normal state.

Speigel and his partners went for Lee’s enzymes. Lee tested bacteria from the soil for a month, beginning in May, 1998, began injecting the enzymes in June, and by November the soil was clean. The process proved as inexpensive as digging and hauling.

« The beauty of (Lee’s) solution is it doesn’t require a lot of machinery,’’ says Speigel. « We were doing work on the upper floors while they were doing this in the basement. It’s such an elegant solution.’’

Elegant indeed. An apt description.

 

NEXT WEEK: More neat solutions

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