Aggregate Extraction Near Shorelines: The Hidden Impact
Along a stretch of the Nottawasaga River south of Wasaga Beach, a gravel pit operation has been running for over 30 years. The pit sits 200 metres from the riverbank, separated from the water by a thin strip of trees. During spring runoff, sediment plumes from the pit are visible in the river. Downstream, residents have noticed changes in water clarity and complain about dust that coats their properties on dry summer days. The pit operator holds all the required provincial licences and meets the conditions set by the Ministry of Natural Resources and Forestry. The neighbours say that is not enough.
Aggregate extraction, the mining of sand, gravel, and crushed stone, is one of the most land-intensive industries in Ontario. The province produces approximately 175 million tonnes of aggregate annually, making it one of the largest consumers of aggregate in Canada. Much of this material is extracted from deposits that formed along ancient shorelines and river valleys, which means the pits and quarries often sit close to the same waterways and lakeshores where people live, recreate, and depend on clean water.
Where the Pits Are
Ontario's aggregate resources are concentrated in specific geological formations, particularly the glacial deposits that line the shores of the Great Lakes and the river valleys that drain into them. The Oak Ridges Moraine, which runs across south-central Ontario, is one of the province's richest aggregate sources. It is also a critical groundwater recharge area that feeds streams, rivers, and lakes across the region.
In Simcoe County, Dufferin County, and the Niagara region, aggregate operations are clustered near waterways and within the watersheds of major lakes. The proximity is not coincidental. The same geological processes that created the shorelines and river valleys also deposited the sand and gravel that the industry extracts.
Under the Aggregate Resources Act, pits and quarries require a licence from the provincial government. The licensing process includes a review of potential impacts on natural heritage, water resources, and neighbouring land uses. Conditions are attached to licences to mitigate these impacts. But critics argue that the licensing process gives too much weight to the economic value of the resource and too little to the environmental and community costs of extraction.
Impacts on Water
The most significant impact of aggregate extraction near shorelines and waterways is on water. Pit operations that dig below the water table create ponds that are connected to the local groundwater system. Contaminants introduced during extraction, including fuel spills, equipment fluids, and fine sediment, can migrate through groundwater to nearby surface waters.
Sediment is the most pervasive issue. Aggregate washing operations generate large volumes of fine sediment that must be managed on site. When containment measures fail, or when stormwater runoff carries exposed material off-site, the sediment enters streams and rivers. Fine sediment smothers fish spawning habitat, reduces water clarity, and can carry nutrients and contaminants that contribute to algal growth in downstream waterbodies.
Groundwater quantity is another concern. Large-scale extraction that removes material below the water table can alter groundwater flow patterns, potentially affecting wells, wetlands, and baseflow to streams in the surrounding area. In areas where residential properties depend on private wells, any change to groundwater conditions can have direct consequences for drinking water supply.
Community and Quality of Life
For communities near aggregate operations, the impacts extend beyond water quality. Truck traffic is one of the most common complaints. A single aggregate operation can generate hundreds of truck trips per day on rural roads that were not built for heavy commercial traffic. The trucks create noise, dust, road damage, and safety concerns, particularly on routes shared with school buses, cyclists, and farm equipment.
Dust from aggregate operations can travel significant distances, particularly during dry periods. Properties downwind of active pits report dust accumulation on homes, vehicles, and gardens. The health effects of long-term exposure to fine particulate matter from aggregate operations are a subject of ongoing research, but residents living near pits frequently report respiratory complaints and concerns about air quality.
Property values are also affected. Studies in Ontario and elsewhere have documented measurable declines in residential property values near active aggregate operations. The combination of noise, dust, truck traffic, and visual impact makes properties near pits less attractive to buyers, which affects the financial well-being of neighbouring homeowners.
The Regulatory Framework
Ontario's Aggregate Resources Act and its associated regulations set the rules for aggregate extraction. The act requires operators to prepare site plans that address extraction limits, setbacks from property boundaries and watercourses, rehabilitation requirements, and mitigation measures for environmental impacts. The Ministry of Natural Resources and Forestry is responsible for licensing and compliance.
The rehabilitation requirement is one of the most important provisions. Operators are required to progressively rehabilitate extracted areas, typically by restoring them to a natural or agricultural state. In theory, a well-rehabilitated pit can become productive land again. In practice, rehabilitation is often delayed, incomplete, or conducted to a standard that falls short of restoring the site's pre-extraction ecological function.
Conservation authorities also play a role, particularly when extraction occurs near waterways or within regulated areas. A conservation authority permit may be required for operations that could affect flooding, erosion, or water quality. However, conservation authority oversight of aggregate operations varies by jurisdiction, and some authorities lack the resources to monitor compliance effectively.
The Bigger Picture
Aggregate is essential to modern life. It is used in every road, building, and piece of infrastructure in the province. Ontario's growth, particularly the construction of new housing, highways, and transit systems, requires enormous quantities of sand, gravel, and stone. The industry is right to point out that the material has to come from somewhere.
But the current approach to aggregate management in Ontario treats extraction primarily as an economic activity to be facilitated, rather than as a land use to be carefully managed alongside competing interests. Communities near shorelines and waterways bear a disproportionate share of the costs, while the benefits of cheap aggregate flow to the broader economy.
A more balanced approach would include stronger setback requirements from waterways and shorelines, more rigorous monitoring of water quality impacts, better enforcement of rehabilitation requirements, and meaningful environmental assessment of new and expanded operations. It would also involve honest conversations about the true cost of aggregate, including the environmental and community costs that are currently externalized to neighbouring landowners.
For the residents along the Nottawasaga River, those conversations are overdue. They have been living with the dust, the trucks, and the sediment plumes for 30 years. They would like someone to ask whether the price of cheap gravel is worth what their community has paid for it.
