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Does your park leak methane? - Toronto Star

February 23, 2011
Paul Moloney
Urban Affairs Reporter
Toronto Star

Some former dumps still do, but the city has blown a reserve fund to monitor them.

Wadlow Park in East York, site of this happy Canada Day scene last year, is being monitored for both landfill gases and leachate.

Some 34 of the 160 former landfills in Toronto leak methane, and 12 discharge leachates. They’re monitored and controlled, but critics say draining a special reserve fund that pays for that could be a problem.

It costs about $6 million a year to look after the old dump sites. Concerns are being raised over the fact that $23 million set aside for that purpose is being diverted to clean up a single site for the Pan Am Games aquatic centre in Scarborough.

The change means city council will have to make annual contributions from the operating budget in future.

“The fact there’s no money in the bank to continue this monitoring raises the question, ‘What are the health implications?’” said Franz Hartmann, executive director of the Toronto Environmental Alliance.

Councillor Gord Perks, a former campaigner for the alliance, said it would be better to retain the reserve fund. But he’s not worried about the older landfills, where decomposition has ended and there is no longer production of landfill gases: a mix of methane and carbon dioxide.

“Let’s put it this way: The risks diminish over time,” Perks said. “I don’t want people to think there are a lot of unmitigated risks lying around. That’s not the case.”

Before Toronto began trucking trash out of town, the city disposed of it right here at home.

Your local park may have started out life as a landfill. For example, the Riverdale landfill ran for one year, 1960, in what is now Riverdale Park.

Perks noted that at three of the largest former landfills — Keele Valley, Brock West and Beare Road, the gas is used to make electricity.

In 2002, the city looked at capturing gas from smaller landfills such as Riverdale but concluded the volume of gas being emitted was too small to make it worthwhile.

The safety concern with methane is that it could move through cracks in the soil and settle in someone’s basement, causing an explosion risk. The fix often is to sink a pipe to let the gas escape into the atmosphere.

“Methane is trying to escape up, so it will follow cracks in the soil,” said Peter Crockett, the city’s executive director of technical services. “In some cases, we’ll put a pipe into the ground that will provide access for the methane to escape into the atmosphere.”

Crockett said some landfills also produce leachate — liquid effluent — that could contaminate groundwater but is instead diverted into the sewer system for treatment.

The city currently has control systems in place on 44 newer landfills, while the older ones pose less risk, he said.

“The older the site, the more dormant it is,” Crockett said. “They do not, quite frankly, require significant repair. If we see soil slumping in an area where cover (over the old garbage) is less than it should be, we’ll do a repair.

“But because of their age, and the stability that comes with age, a visual inspection is a pretty reliable way to make sure there isn’t anything untoward.”

The Ontario environment ministry, which regulates landfills, has no problem with the city’s monitoring program, said ministry spokesperson Kate Jordan.

The depletion of the reserve fund just means council will have to find $6 million or so every year, said Councillor Denzil Minnan-Wong, chair of the public works and infrastructure committee.

“It’s pay-as-you-go,” Minnan-Wong said, adding that would only be a problem if a large, unexpected problem arose that would be expensive to solve.

“There’s nothing really to worry about, only within the context of if there’s a big cost in any one year that’s unanticipated.”

Minnan-Wong said he’s unaware of any looming issues.

“If the city’s doing its job of monitoring and testing, one would assume the public doesn’t have anything to worry about.”

As originally published here: http://www.thestar.com/news/article/943206--old-landfills-don-t-fade-away

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