Aggregate FAQ

Stone Cold Facts

These are some of the questions that members of the aggregate industry are commonly asked. Click on each question to reveal the answer.

  • What is aggregate?
    • The short answer is stone, sand and gravel. But that's just scratching the surface. It is the grains of sand that make up our roads and sidewalks. It is in the bricks and concrete blocks that make up the walls of our homes, schools and workplaces. Aggregate also plays a lesser-known yet vital role in our water purification process and can even be found in pharmaceuticals, toothpaste, make-up, paint and paper among other products we use on a daily basis.

      When you think about it, aggregate is quite literally the foundation of our economy and society – which is a very impressive accomplishment for something as small as a grain of sand.
  • How much aggregate do we use each year?
    • Ontario uses approximately 170 million tonnes of stone, sand and gravel per year – more than any other resource. That's 14 tonnes per person.
  • Where is aggregate used?
    • Even if we don't think about how we use stone, sand and gravel on a regular basis, we're still using them every day in some form or another.

      Sure we use sand, stone and gravel to build things like roads, houses, schools, hospitals, playgrounds, baseball diamonds, subway tunnels, and bridge abutments, but beyond these obvious uses is a whole host of lesser-known uses for aggregate. For example, did you know that glass, make-up, paint, toothpaste, household cleaners, pharmaceuticals, baby powder and even chewing gum are also made with some form of aggregate?

      Even things like our water filtration and sewage systems use crushed stone, sand and gravel. It really is everywhere, even if we can't see it at first.
  • How do we choose where to put a quarry or pit?
    • Not every piece of land can be used as a pit or quarry. Only Mother Nature dictates where these resources are located and in what amount. Although we sometimes find sites that are ideally located, the aggregate may not be abundant enough to justify the cost of setting up a fully operational pit or quarry. Furthermore, because stone, sand and gravel sources are naturally occurring, they can be easily lost when houses or other developments are constructed over top of them.

      Our industry sometimes faces opposition when a pit or quarry permit is applied for. Everyone needs aggregate, but who wants a quarry or pit next door to them when they could have a park or even a new shopping centre instead? The reality is that most opposition comes before a pit or quarry is licensed. Once operations begin, neighbours quickly realize that living next to a pit or quarry is quite pleasant. Because aggregates are a non-renewable resource, our industry continually struggles to find conveniently located sites that 1) have an abundant supply of aggregate, 2) are conveniently located to the location they will be used in, and 3) are unconstrained by the myriad of competing land uses that could render the deposit unusable.
  • How close to the source do we use the aggregate we extract and why?
    • Our ever-increasing transportation costs make it best to use aggregate as close to the source as possible. Stone, sand and gravel are bulky and heavy, and the further we transport them, the more expensive they become.

      It's not only the economic cost that rises when we move our pits and quarries further away, there are also environmental and social costs. Imagine the impact of having more trucks on the roads driving longer distances; greenhouse gases increase as does traffic.

      Economically, about one-half of the cost of sand and stone on a job site is the cost of transportation. Since governments, and hence the taxpayer, use over half of the aggregates produced in the province, every taxpayer benefits from keeping the pits and quarries as close to markets as possible.
  • How long does the average pit or quarry stay open?
    • Pits and quarries are, by nature, self-consuming. Once a quarry's stone, sand and gravel have been fully extracted it's no longer necessary to keep it open. Sites can stay open for 35 years or more but many are depleted within 5 years. It all depends on how abundant the resource is and the rate at which the aggregate is extracted.

      Unlike most other industrial uses, the sand and gravel operation is a temporary use that is not only making an important contribution to the economy but is simultaneously in the process of developing lands (and waters) for other uses. These uses can be anything from parks with fish and wildlife habitat to new residential subdivisions.
  • What happens to the pits and quarries once they are fully extracted?
    • The fate of a pit or quarry is often known even before it is ever developed. In fact, a mandatory part of applying for a license to begin extraction is to have a proposed rehabilitation plan in place. There is, however, a public planning process that must be satisfied prior to a new land use being established "post pit". Just because a pit approval is sought it does not mean that the "after use" development is automatically approved.  

      Regardless of what the end use will be for a pit or quarry, the rehabilitation process will still begin the moment topsoil is removed to uncover the aggregate deposits below. The topsoil is removed and preserved along with all its seed sources, returning to the pit or quarry when mining is completed. In this way, our industry is able to ensure the sites are returned to their natural state or are improved upon by turning them into lakes, golf courses or even college campuses.
  • How is this industry environmentally responsible?
    • The aggregate industry is regulated by more than 24 pieces of legislation that protect the environment and future resources. Pits and quarries are what we call temporary land uses, which means that once they are no longer being used to extract aggregate (and even while they are still being used) the producers either return them to their original land use or, in many cases, improve upon it. This practice has made this industry one of the largest creators of wetlands in Ontario. It has also created several well-known attractions such as local golf courses, parks, botanical gardens, and vineyards.

      For more information on Ontario Wetlands please visit:

      Aggregate extraction is actually a very clean and largely mechanical process. The only processing that aggregate requires is crushing, screening, blending and sometimes washing (with water). No chemicals are used in the processing of aggregates.

      The water that's used in aggregate processing is recycled in a closed loop system and is regulated by the Ontario Water Resources Act and controlled through Permits to Take Water.
  • Can aggregate be recycled?
    • Stone, sand and gravel can often be recycled or reused, and this is done whenever possible. Asphalt and concrete are two materials that are amongst the most recycled commodities in North America.
  • Who works in this industry?
    • The aggregate industry employs approximately 7,000 Ontarians directly and another 34,000 in related industries. Sand, gravel and crushed stone provide the basis for Ontario's $30-billion construction industry, which employs 270,000 people.
  • What is the Ontario Stone, Sand & Gravel Association (OSSGA) and what does it stand for?
    • The Ontario Stone, Sand & Gravel Association (OSSGA) is the non-profit industry association representing producers of sand, gravel and crushed stone in the Province of Ontario along with consultants, suppliers, and industry products and services.

      The OSSGA tag line is "Essential materials for building a strong Ontario". - Wetland Sanctuary