From trash to treasure: Turning former landfills into parks

More than one southwestern Ontario park got its start as a waste site. Such transformations create havens for nature — but they can come with challenges
By Mary Baxter - Published on Aug 12, 2020
East Pond in the Coves in London. (Mary Baxter)



LONDON — Growing up in Westminster Township, Thom McClenaghan played in all sorts of places. The wrecking yard by a large ravine was a regular Sunday retreat — “providing they had the dogs on chains,” says McClenaghan, now 83. The gravel pit, where some kids practised shooting, and the adjacent dump were also popular.

The area, and the stretch of agricultural land between, had been used as a military shooting range from 1901 to 1946. With its three long oxbow ponds — once part of the Thames River — it came to be known locally as the Coves (and, today, McClenaghan serves as president of the Friends of the Coves, a non-profit preservation group). Today, Westminster Township is part of London, and the 710-hectare area forms the Coves sub-watershed; 85.4 hectares were declared an environmentally sensitive area in 1996. More than half of the land is public, including Euston Park, which sits above what was, for a time, a 30-acre dump, one of seven former landfills in the Coves.

Thom McClenaghan standing in front of a sign
Thom McClenaghan is president of the Friends of the Coves, a non-profit preservation group. (Mary Baxter)

As a practice, turning dumps into parks dates back about a century, says Alan MacEachern, an environmental-history professor at Western University. “They're large pieces of land that are underutilized — and maybe under-utilizable,” he says. As residential development springs up and nearby dumps close, leftover land is “inexpensive,” MacEachern explains. Dumps also tend to be in easily accessible, centralized locations. The land that used to be part of the former dump that now forms the Coves’ northeastern entrance, for example, takes about 10 minutes to reach by foot from London’s core.

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Chris De Souza, a Ryerson University urban-planning professor who specializes in the rehabilitation of former industrial properties, or brownfield sites, says that many different types of waste sites have been converted into parks. “Probably the more common are municipal landfills, because they're owned by the government, historically, and they have more inert types of waste,” he says, adding, though, that adequately addressing health and environmental risks can be a challenge with these conversions.

For example, De Souza notes, municipalities commonly vent, cap, and monitor their former dumps to prevent harmful waste from leaching. If they didn’t, he says, “Not only would you get very bad media, but the liability risks are high” — especially when dumps are repurposed into recreational areas.

The sprawling one-time dump beneath Euston Park, in the Coves’ southern section, is both capped and vented. “Everything is permanent,” writes Jay Stanford, the City of London’s director of environment, fleet, and solid waste, in an email. He notes that the cap materials are intended to “reduce rain water from entering deep into the closed landfill” and are topped off with soils to foster vegetative growth. The city annually inspects the mechanical venting system, which is meant to prevent the build-up of methane gas as the landfill's contents decompose.

former dumpsite
A former dump in Euston Park, part of the Coves. (Mary Baxter)

Issues can arise, though: that’s been the case at Sarnia’s Canatara Park, part of which is located on the old Michigan Avenue landfill. The dump was created in 1930, when Sarnia signed a lease with the Canadian National Railway, and active until 1967, say local historians Jim Russell and Jack Fraser. With the assistance of Russell and other volunteers, Fraser has compiled an extensive park history, which is slated to be published by the local historical society.

Sarnia acquired most of the dump property in 1938, although the railway retained a small section where waste was also deposited. The Canada Lands Company turned this final parcel over to the city in the early 2000s after residential development had been ruled out due to contamination; the landfill had been established well before the province introduced environmental laws and oversight, and Imperial continued to dump sludge there until 1944. “Spent clay is what they called it,” says Russell.

Ed Das, 54, lived near the former dump as a child. He remembers seeing fluorescent-green pools of water forming on its crumbling access road after a summertime rain. “If you strayed off the road and into the overgrowth,” he says, “you could see partially buried drums.”

Fraser says the dump was capped with clay in 1980 and reinforced again in 1993 after studies detected hazardous levels of methane gas along its perimeter and diesel fuel seeping underground. In 2001, Sarnia council approved spending $500,000 to remediate the site and allocated $40,000 a year for ongoing monitoring. By 2003, barriers had been introduced to block the underground spread of diesel, according to a 2005 IJC report.

But, in 2008 and 2009, methane levels again became high, triggering additional spending for sampling. Then, in 2013, an oily sheen appeared on a duck pond at the park’s animal farm, north of the former dump. Oil was also found in monitoring wells nearby. This time, council approved spending nearly $70,000 to add sheet-pile barriers to block the spread of an underground diesel plume into a nearby neighbourhood and the park’s Lake Chipican. Recovery wells to pump out the oil were also established. “We have a staff person visit the site on a weekly basis to monitor the system,” explains David Jackson, the general manager of Sarnia's engineering and operations division. The city is currently investigating whether the fluid has spread more, he says in an email: "We are still waiting for the final report from that investigation."

lifeguards on a beach
A lifeguard orientation session at the beach at Canatara Park, in Sarnia. (Mary Baxter)

Sarnia’s mayor, Mike Bradley, suggests remediation efforts were necessary, despite the cost. “The expense on dealing with a legacy of the past was worth it,” he says. “Otherwise, Lake Chipican and Lake Huron would have ended up with the leachate from the former dump — and there was no one else to take responsibility." Brenda Lorenz, a local resident who recently helped found Friends of Canatara Park, agrees: “You can’t do anything about the dump now, but what you have to do — and worry about — is the contamination that is slowly leaching out of that area.”

Today, the tall-grass prairie that she and members of Lambton Wildlife Inc. planted on the dump’s cap in 2017 provides a resting spot for birds migrating through the Huron shore flyway, and habitat for the endangered Butler’s garter snake. There are also mowed pathways and a Frisbee-golf course in that portion of the park.  

Experts say that the Coves is home to more than 70 different species of birds and more than 100 species of animal. With concerns about climate change mounting, it’s critical to maintain areas that have the biodiversity to support wildlife and native flora and fauna, McClenaghan says. In the case of the Coves, the old dumps presented an opportunity, somewhat by default: "These sites,” he notes, “were unusable for any other purpose.”

This is one in a series of stories about issues affecting southwestern Ontario. It's brought to you with the assistance of faculty and students from Western University’s Faculty of Information and Media Studies.

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