What are aggregates?
Aggregates are natural deposits of gravel, sand, clay, earth and bedrock. Bedrock is the solid rock that makes up the Earth’s crust.
Why are aggregates important?
Since ancient times, humans have used stone, gravel, sand, clay and earth to build homes, roads and public structures.
In Ontario today, almost every building, road and structure contains some form of aggregate:
- Building one kilometre of two-lane highway in southern Ontario consumes about 18,000 tonnes of aggregate. That’s about 10,000 cubic metres – enough to fill four Olympic-sized swimming pools.
- An average 185-square-metre (2,000-square-foot) house contains 250 tonnes of aggregate.
- Concrete includes gravel or crushed stone and sand. Concrete is used to construct buildings such as hospitals, condominiums and office towers, as well as water mains, dams, utility poles, subway tunnels and the foundations of houses.
- Aggregates are used in the making of steel, aluminum and plastic.
Glass, coated paper, paint, fertilizer, insulation, toothpaste, makeup and some countertops and flooring also contain aggregates.
Each year, we use about 14 tonnes of aggregate for every person in Ontario.
What are other benefits of aggregates for Ontarians?
The aggregate industry creates jobs directly for about 9,000 people. Another 9,600 people are employed in related industries. In 2010 the industry contributed $1.37 billion to the province’s Gross Domestic Product.
From 2000 to 2009, the Ontario construction industries consumed more than 80 per cent of the aggregates used in the province. The construction industries employed close to 250,000 people and accounted for $44.7 billion
in economic activity.
We also use aggregates in projects that help the environment:
- Sand and gravel are used as filters in water treatment plants that ensure our water is safe to drink. They are also widely used in septic systems. A rural septic filter bed requires 85 tonnes of aggregates.
- Stone and gravel are used to landscape our gardens and public spaces. They also help restore wetland and riverbank habitat, prevent erosion, control stormwater and reduce flooding.
- Limestone filters or “scrubbers” remove pollutants from the exhaust of smokestacks.
What impacts of aggregate operations are people and communities most concerned about?
- The concerns people and local communities may have can depend on the location and design of an aggregate operation. Some of the more common concerns include:
- Noise pollution
- Truck traffic and volume
- Air pollution/dust
- Disturbance to wildlife and habitat
- Effects on water wells and features that depend on water, like wetlands and fish habitat
- Decreased property values
- Quality of life
- Disturbance to environmentally sensitive areas.
How do we manage aggregate operations in Ontario?
The Aggregate Resources Act regulates aggregate operations on Crown lands and most private lands in Ontario. It sets out the framework for reviewing new proposals and establishing operating rules.
Ministry of Natural Resources aggregate inspectors are responsible for ensuring aggregate operators comply with the act, the regulations, the approved site plan for the operation, and the conditions that apply to the operator’s licence or permit.
The Aggregate Resources Act also requires companies to rehabilitate pits and quarries during and after the operation of the site. Land that has been used for aggregate extraction must be restored to its former use or changed to another use compatible with the surrounding land.
