3. The Environmental Impacts of Aggregate Extraction
With the exception of those who work in the building trades, the closest most of us ever come to “virgin” aggregate (that is, aggregate that comes straight from an aggregate mine and has not been reclaimed from rubble or other debris) is at home building stores. While a bag of stones or gravel may look fairly benign, the process of getting it to us is anything but benign. Aggregate is mined from the earth, either dug out of pits or blasted out of quarries. This process has many significant environmental impacts.
Creating the pits or quarries requires the removal of virtually all natural vegetation, top soil and subsoil to reach the aggregate underneath. Not only does this lead to a loss of existing animal wildlife, it also leads to a huge loss of biodiversity as plants and aquatic habitats are destroyed. Moreover, adjacent eco-systems are affected by noise, dust, pollution and contaminated water.
Pits and quarries disrupt the existing movement of surface water and groundwater; they interrupt natural water recharge and can lead to reduced quantity and quality of drinking water for residents and wildlife near or downstream from a quarry site.
Most old pits and quarries are not being properly rehabilitated. As noted in one study “less than half of the land disturbed for aggregate production between 1992 and 2001 has actually been rehabilitated.” The province classifies pits and quarries as “interim uses of the land” and requires 100% rehabilitation of pits and quarries. Clearly this requirement is not being met. Destroyed ecosystems and source water aquifers are irreplaceable. This is not an interim land use. The landscape is blotted with destructive pits and quarries, and species of all kinds endure permanent negative impacts.
A more detailed picture of the environmental impact of aggregate mining is outlined in a 2005 legal challenge to the expansion of an existing quarry in the Niagara Escarpment. The report focuses on the following potential environmental impacts:
- Potential impairment of water quality on the site, including harm to the aquifer
- The water quality of residential wells close by could be harmed
- The water level of on-site lakes could be reduced, detrimentally affecting provincially specific wetlands
- Heightened summer water temperature in an on-site lake could have a detrimental impact on the
viability of cold water fish in an adjacent stream
Potential harm to on-site and off-site wetlands
- Loss of habitat for the Jefferson Salamander, which is designated as threatened under the federal Species at Risk Act
- Potential loss and fragmentation of continuous natural environment
Of course, each pit or quarry has unique characteristics and impacts, but every pit or quarry will degrade the natural environment. For pits or quarries situated on lands designated as ecologically significant, this degradation has an even greater adverse impact.
For communities, the displacement of water resources is one of the biggest concerns pits and quarries pose. However, there are many other concerns. Beyond the physical changes to the landscape, the daily barrage of noise, dust and exhaust produced by hundreds of dump trucks hauling aggregate can have serious effects on the health of people living nearby.
Winfield, M and A. Taylor. Rebalancing the Load: The need for an aggregates conservation strategy for Ontario, 2005. The
Pembina Institute, pgs 8-9.
Castrilli, J. Application to the Lieutenant Governor in Council regarding Dufferin Aggregates application to expand their Milton Quarry prepared for Coalition on the Niagara Escarpment (CONE) and Protect Our Water and Environmental Resources (POWER). 2005.