The Keele Valley landfill was the largest landfill in Canada and the third largest in North America during its operation. It was the primary landfill site for the City of Toronto and the regional municipalities of York and Durham from 1983 until 2002, and was owned and operated by the City of Toronto. It was located at the intersection of Keele Street and McNaughton Road in Maple, a community in the northeastern part of the City of Vaughan in Ontario.
In 1985, the initial portion of a landfill gas collection system was installed to reduce emissions and associated odours emanating into the nearby community. This has been used to generate electricity, which it has continued to do since the landfill's closing, sufficient to power 20,000 homes.
The facility is registered in the National Pollutant Release Inventory, with site identification number 7371. The site emitted about 410 kilotonnes of carbon dioxide equivalent greenhouse gases in 2011.
In 2002, the site was identified by the Government of Ontario as an Area of High Aquifer Vulnerability, which would prohibit waste disposal and organic soil conditioning facilities being built or operating there per the Oak Ridges Moraine Conservation Plan. Vaughan's Official Plan Amendment 604 (OPA 604) specified that the site would be redeveloped as an open public space.
Operation The site was originally a large gravel pit which was purchased by the city of Toronto in the 1970s for million. Before its opening, Toronto's trash was sent to the Beare Road Landfill in Scarborough, and Vaughan's trash was sent to a site about 1 kilometre north of Keele Valley, north of Teston Road. When it opened, the Keele Valley Landfill was within an almost entirely rural setting, but the rapid growth of Maple in the 1990s surrounded the site with residential developments. The site opened on 28 November 1983 based on an agreement between Metropolitan Toronto and York Region, under which Toronto was required to dispose of York's waste until 2003 in exchange for establishing the Keele Valley site. The site accepted garbage from the area of Toronto west of Yonge Street, whereas garbage from areas east of Yonge Street was sent to the Brock Road Landfills. The York municipalities of King and Georgina continued to dispose of their waste in local landfill for some time, whereas the others paid dumping fees to the city of Toronto for use of the Keele Valley Landfill. The site was originally scheduled to close in 1993, at which time it was expected to reach its capacity of 20 million tonnes. It overlays a sand aquifer, using a single engineered landfill liner to prevent leachate from entering the aquifer below.
An on-site Household Hazardous Waste depot collected paint, batteries, pesticides, cleaning agents and other hazardous waste in small (residential) quantities. A general recycling depot, to which residents and businesses could bring appliances (refrigerators, stoves, washing machines, etc.), corrugated cardboard, drywall, scrap metal and tires for recycling operated at the site, as did a tire recycling depot. The facility also had a yard waste drop-off area, from which the operators would transport material for composting in large outdoor windrows on a site north of the landfill, at the Avondale Composting Site. It also accepted waste brought by residents of households in York Region, but building contractors abused the privilege by bringing numerous small loads to the landfill, prompting the imposition of a tipping fee in 1990 for pickup trucks and small trailers. Commercial haulers were charged $18 per tonne in 1988, and $97 per tonne in 1990.
The site was a profitable venture for the city of Toronto. In its last year of operation in 2002, it generated $25 million of revenue. It processed 1.57 million tonnes of waste in 1986, and 2.2 million tonnes in 1988, most of which increase was by the private sector. By 2000, it was processing 1.4 million tonnes of garbage from the city of Toronto.
Waste collected The site collected approximately 28 million tonnes of waste throughout its operational lifetime. In 1999 biomedical waste constituted 4,300 tonnes and asbestos constituted 4,900 tonnes of the waste collected that year. The fee for disposing such waste was $50 per tonne before 3 January 2000, and $75 thereafter until the site closing. The cost of clean fill also increased to $20 per tonne on that date.
Hazardous materials, including biomedical waste and asbestos, were treated before final disposal.
The table below shows the concentration of various leachate chemicals at the Keele Valley Landfill based on the October 2000 report Final Report East Taro Landfill. It compares the Keele Valley peak annual average data to the Ontario provincial standards for municipal solid waste (MSW) and Drinking Water Objectives (DWO). Also included are results from a 2002 paper about Keele Valley leachate analysis by Fleming and D. Rowe, and a 1995 paper by R.K. Rowe.
ChemicalConcentrationDWO standardMSW standardKeele ValleyMOE studyFleming & RoweRoweChemical oxygen demand (COD, mg/L as O) n/a6,100–25,0001,410–27,600Biochemical oxygen demand (mg/L as O) n/a3,400–16,4002,330–16,000Total organic carbon (mg/L as C)1,440–7,060Electrical conductivity (mS/cm)10–23Total suspended solids (mg/L)40–370Volatile suspended solids (%)29–65Benzene (μg/L)520<20<0.1–25Cadmium (mg/L)0.0050.050.0240.0002–0.34Chloride (mg/L)2501,500–2,5002,9791,400–3,800173–3,810Lead (mg/L)0.010.60.10.001–331,2-Dichloroethane (μg/L)5nd – <861,4-Dichlorobenzene (μg/L)11010nd – <861,1-Dichloroethylene (μg/L)14nd – 601,2-Dichloroethylene (μg/L) n/and – 900Dichloromethane (μg/L)503,3003,372215–7,100Ethylbenzene (μg/L)2.430–1,400Toluene (μg/L)241,000950485–1,821Tetrachloroethylene (μg/L)30nd – <86Trichloroethylene (μg/L)5050nd – <230Vinyl chloride (μg/L)25555nd – 70o-Xylene (μg/L)30–1,450m- and p-Xylene (μg/L)30070–3,900Sodium (mg/L)200824–2,220Potassium (mg/L)420–1,040pH6.5–8.55.8–7.45.9–6.85.7–6.8Ammonia (mg/L)220–770Phenols (mg/L)Calcium (mg/L)1,539660–2,88062–2,860Total Kjeldahl Nitrogen (mg/L as N)370–1340Nitrate (mg/L)10.00.02–16.00Sulphate (mg/L)50034–290Sulphide (mg/L)0.050.2–10.0Alkalinity (mg/L CaCO3)30–5003,200–8,100Iron (mg/L)0.346–3570.5–1,910Magnesium (mg/L)306–695Manganese (mg/L)0.051.7–20.0Mercury (mg/L)0.0010.00003–0.0025Phosphorus (mg/L)2.5–8.7Zinc (mg/L)5.00.072–5.6Total phenolics (4AAP) (mg/L)0.2–4.5Volatile organic acids (mg/L)2,260–7,420Microbial ATP (ng/L)20 (avg.)Total heterotrophs (no./mL)2–40×108
Landfill gas collection
From 1985, a system to collect and flare gas was installed by its operators to mitigate the potential effects of landfill gas, including methane, which constitutes 47% of landfill gases at this site. This system was installed in progressive stages until 2002 as the waste accumulated in the landfill. In 1993, Eastern Power Developers won a bid to develop an electricity generation station at the landfill, which it built in 1994 at a cost of $30 million. By April 1995, it was in operation, selling electricity to Ontario Hydro's electricity distribution department (now Hydro One and the Independent Electricity System Operator).
The landfill gas was collected from the site and diverted to a central blower and flare station via gas transmission pipes. Most of this gas is then directed to the electricity generating station, which has a peak generation capacity of about 33,000 kilowatts. It generates 274,800,000 kilowatt hour of power annually, delivering 31,370 of continuous power. Five percent of the collected gas is combusted and flared.
It is a combined cycle plant consisting of two 1 MW gas turbines, two boilers which operate on landfill gas and recovered waste heat, and one 30 MW steam turbine. The pipe system extracts 17,005 standard cubic feet per minute (119 million cubic metres annually) of landfill gases from the collection field, which consists of "over 40,000 linear metres of horizontal gas collection trenches and 80 vertical gas collection wells installed within the landfilled waste". Circling the site is a 10,000 linear metre dual header piping system which is used for the transmission of gas from the wells and trenches to the flaring station.
The power plant emits nitric oxide for which it has an emission allowance from the Ontario Emissions Trading Registry. Nitric oxide is an air pollutant which has a participatory role in ozone layer depletion and which may form nitric acid in the atmosphere, resulting in acid rain.
YearEmission allowanceNOSO220030020040020050020062050200716802008146020099202010860201100Total6970
The city of Toronto receives approximately $1 million in royalty payments annually for recovering the landfill gases which are used at the power plant.
Expansion and lawsuit In 1993, Superior-Crawford Sand & Gravel Ltd., which owned most of the adjacent land, promoted the site's expansion, which it had also suggested in 1991. The company conducted feasibility studies for expansion, and actively campaigned for it, claiming that with expansion an additional 52 million tonnes of waste could be accepted at the site for 20 years, starting in 1996. The report, based on research conducted by consultants hired by the company, claimed that Keele Valley was the most suitable site for consideration based on criteria defined by the Interim Waste Authority (IWA). The company's proposal was to expand the landfill site to include 190 hectares of land owned by Superior-Crawford and 60 hectares of other nearby land, most of which was owned by Metropolitan Toronto.
On 20 May 1993, Michael Jeffery, a lawyer for the company, stated that the company would file a lawsuit to challenge the IWA site selection process if Keele Valley expansion was excluded from consideration. By the following week, Superior-Crawford had filed a legal suit contesting the choices of the IWA report for future landfill sites to host the region's garbage, favouring expansion of Keele Valley. It had complained about its exclusion from the original IWA list of 57 potential sites in 1992. The company also mailed pamphlets to 7,000 residents in communities near sites on the IWA short list as part of its campaign. Although expansion of the Keele Valley landfill was not originally a viable option, the legal actions by Superior-Crawford "could very easily change the context", according to Walter Pitman of the IWA. The other viable candidate for a landfill site was the North Vaughan site, adjacent to King City at the northern boundary of Vaughan near Jane Street, which was deemed by Superior-Crawford to be "extremely disruptive" to King City and neighbouring Vaughan residents.