How much aggregate do we use in Ontario?
Ontarians used an average of 179 million tonnes of aggregates a year from 2000 to 2009. That’s enough to fill 63 stadiums the size of Toronto’s Rogers Centre up to the roof every year. It adds up to about 14 tonnes a year of bedrock, gravel, sand, clay and earth for each person in Ontario.
- Building one kilometre of two-lane highway in southern Ontario requires about 18,000 tonnes of aggregates, or about 10,000 cubic metres - the volume of four Olympic-sized swimming pools.
- An average 185-square-metre (2,000-squarefoot) house contains 250 tonnes of aggregates.
How much do we need for the future?
Ontario’s population is projected to grow by 4.5 million people between 2010 and 2036. The need for more housing and public infrastructure such as roads, public transit, schools and hospitals to serve Ontarians makes it likely that the amount of aggregates we use will continue to rise.
Ontario’s demand for aggregates has been projected to increase with our population to an average of 180 million tonnes a year from 2010 to 2019, and 191 million tonnes a year from 2020 to 2029.
Where do the aggregates we use come from?
Most of the aggregates consumed in Ontario come from pits and quarries in the province. Recycled aggregates from reused asphalt pavement, concrete material and other substitute materials account for about seven per cent of the total. About two per cent is imported.
Almost 95 per cent of the aggregates extracted in the province come from pits and quarries on private land.
The Greater Toronto Area uses about one-third of all the aggregates consumed in the province each year and depends on neighbouring areas for more than half of its supply of aggregates.
What limits the supply of aggregates?
Location
Aggregates are natural deposits of bedrock, gravel, sand, clay and earth that can take millions of years to form. We can only extract them where they occur in the landscape.
Aggregates are heavy and bulky, so moving them long distances makes them more expensive to consumers. It also increases emissions and wear and tear on the roads.
Quality
Aggregates vary in hardness, mineral content, size and shape. These variations affect what they can be used for. For example, rocks containing certain minerals can’t be used to make concrete, and rocks that are not hard enough won’t stand up to the wear and tear of high-traffic roads.
Restrictions on land use
Aggregates are used to construct essential infrastructure and provide us with products and services. But there are many other natural features and land uses that are important to Ontarians. Land use rules in Ontario protect important landscapes, woodlands, wetlands, other natural features and prime agricultural lands. Where deposits of bedrock, gravel and sand lie under these features, extraction may not be allowed.
How can recycling help?
Recycling aggregate makes sense – it can help preserve land, lower our energy consumption, reduce waste and conserve natural resources.
