Scarborough\u2019s Beare Hill Park wasn\u2019t always teeming with lush forests, meadows and wetlands.<\/p>\n
In fact, until just over four decades ago the 200-acre site was once one of the city\u2019s biggest landfills, where the booming metropolis dumped all its waste in big piles that were then plowed under tonnes of soil. By 1982, the dump was full and the city closed it.<\/p>\n
Toronto hasn\u2019t decided yet what it wants to do with its current landfill, Green Lane, near London, Ont., which is\u00a0expected to hit capacity in the next 10 years, but the experience of turning\u00a0Beare Road Landfill into the park it is today \u2014 and that of most other parks built over landfills \u2014 suggests it will be neither easy nor quick.<\/p>\n
\u201cIt does take some effort. It does take money. It does take some planning,\u201d\u00a0said Larry Conrad, a professional engineer and board member with the Solid Waste Association of North America\u2019s Ontario division. \u201cBut there are many examples of successful closures of landfills.\u201d<\/p>\n
A need for perpetual care\u00a0<\/p>\n
\u201cYou can\u2019t just walk away from this thing after closing it,\u201d said Mark Winfield, a professor at York University\u2019s Faculty of Environmental and Urban Change. \u201cSomebody\u2019s going to have to look after it, essentially forever.\u201d<\/p>\n
A landfill that is kept sanitary has two goals: isolate the waste and protect the surrounding environment. When municipalities close landfills, those goals don\u2019t change, regardless of whether it gets a green afterlife like Beare Hill.<\/p>\n
Closing and capping<\/p>\n
For most landfills, and especially large landfill sites like Green Lane which is 318 acres, closures happen in stages. The site is separated into sections then sealed off as they\u2019re filled while it\u2019s operating, because it\u2019s easier to manage than dealing with the whole site all at once at the end.<\/p>\n
Closing sections of a landfill requires capping it, \u201clike putting a lid on top,\u201d said\u00a0Conrad,\u00a0who is also Peel Region\u2019s former manager of waste operations.<\/p>\n
Two of the biggest risks for a closed landfill are emissions, usually methane produced by organic waste decomposing without oxygen, and leachate, which is unavoidable contaminated groundwater\u00a0that has passed through buried garbage and extracted toxic pollutants.<\/p>\n
Almost all closed modern landfills have control systems for gas and leachate,\u00a0including the former Beare Road Landfill site.<\/p>\n
\u201cYou\u2019re capping that material so it\u2019s isolated from the surrounding environment not only from odours,\u201d Conrad added, but also to prevent rain from\u00a0adding to the leachate.<\/p>\n
Typically there\u2019s a system of pipes underground that collects that\u00a0water,\u00a0preventing it from getting out into the natural environment, instead\u00a0sending it to a treatment plant to get cleaned.<\/p>\n
<\/p>\n
Mississauga spent $13 million to transform the former site of the Britannia Landfill\u00a0into the BraeBen Golf Course.<\/p>\n
Andrew Wallace\/Toronto Star<\/p>\n
That \u201clid\u201d on top of all that garbage is typically made up of several layers: impermeable\u00a0barrier systems (like a clay liner or a geomembrane), the drainage system that diverts stormwater and collects leachate for treatment. This is then topped with soil, landscaping and vegetation to prevent erosion and pooling \u2014 like in Beare Hill Park.\u00a0<\/p>\n
It\u2019s a process demanding studies, consultations and applications, so it can take years, and is\u00a0regulated by Ontario\u2019s Ministry of the Environment, Conservation and Parks. The costs to close them fall on the municipality operating the landfill.<\/p>\n
When landfills reach 90 per cent capacity or are within two years of closing, whichever comes first, cities have to submit a detailed closure plan to the province for approval. This plan outlines all closure activities including how to manage\u00a0leachate and gas emissions, post-closure site use, as well as how it will be monitored and maintained long term.<\/p>\n
In the case of\u00a0Beare Road Landfill, all of that, plus the park\u2019s development, took four decades.<\/p>\n
In an email to the Star, ministry spokesperson Gary Wheeler said because each landfill in Ontario is unique, each closure report will be different \u2014 as will its timelines and costs.<\/p>\n
\u201cThe closure report may be refused or returned \u2026 if the proposed work is not protective of the environment or contravenes environmental protection standards,\u201d Wheeler\u00a0said.<\/p>\n
Risks of rotting garbage<\/p>\n
Wheeler noted\u00a0that leachate can seep into groundwater or even migrate beyond the landfill\u2019s property line and contaminate\u00a0oceans, lakes, rivers or streams in neighbouring communities.<\/p>\n
Before the 1980s, landfills were almost an unregulated activity, said Winfield.\u00a0\u201cThey were literally just a hole in the ground. Cities threw whatever in, then bulldozed some dirt over the top.\u201d<\/p>\n
Under current rules, \u201cyou have to pump out the leachates accumulating at the bottom of the landfill,\u201d said Winfield, who is also a former adviser to the federal and provincial environmental commissioners.\u00a0\u201cYou may need to have monitoring wells as well to make sure that there is no leakage.\u201d\u00a0<\/p>\n
<\/p>\n
Mississauga spent $13 million to transform the former site of the Britannia Landfill\u00a0into the BraeBen Golf Course.<\/p>\n
Andrew Wallace\/Toronto Star<\/p>\n
The methane needs to be captured, too, because it\u2019s flammable and a very potent greenhouse gas. Pipe-like wells that stick out of the ground connect to an underground network that collects the methane. Older versions burned the collected gas, like what was once happening at Beare Road.<\/p>\n
\u201cWhat commonly happens now is you collect the gas and clean it,\u201d\u00a0Winfield said.\u00a0\u201cThen you have renewable natural gas, which can be put into the gas grid or used to replace fossil natural gas and stuff that\u2019s come out of the ground.\u201d<\/p>\n
Fuelling the gas grid is what the former Beare Road site did long before Beare Hill Park was built over it. The city\u2019s gas control system in 1996 started collecting landfill gas then transporting it to generate electricity at a nearby power plant. This stopped in\u00a02014 \u201cdue to insufficient gas levels,\u201d a city spokesperson said.<\/p>\n
In 2016, the province approved a \u201cpassive gas management system\u201d to allow the gas from the Beare Road Landfill site to vent through the soil cap ever since. \u201cToday, the site continues to be monitored,\u201d the spokesperson said.\u00a0Meanwhile, the power plant is\u00a0slated for demolition this fall<\/a>.\u00a0<\/p>\n \u201cThat\u2019s normal,\u201d Conrad said. \u201cThere\u2019s a lot of gas in the early life of a landfill site. But as it ages, not a lot generates.\u201d<\/p>\n Some landfills cause problems<\/p>\n But even with all the regulations around closing a landfill, there are no guarantees, according to Theresa McClenaghan, a lawyer and executive director of the Canadian Environmental Law Association, which also works on landfill cases for community groups and First Nations.<\/p>\n McClenaghan said that a closed landfill\u2019s methane has in the past seeped through fractured bedrock or the clay-lined cap and into nearby buildings or homes with disastrous results.<\/p>\n