The Slow and Ongoing Destruction of an Important Aquifer Northwest of Edmonton
The Edmonton Chapter stands with the Onoway River Valley Conservation Association in their 25 years long battle to protect the environmental integrity of the Sturgeon River Valley aquifer. This aquifer is delineated by the extensive sand and gravel deposits along the prehistoric Onoway River Valley pre-glacial channels found under the current Sturgeon River.
“Underground deposits of sand and gravel are the basic constituents of an aquifer. These formations naturally filter and store water that is then slowly released back into the surface water system; they are critical elements in the provision of environmental services essential to life.
As important as these sand and gravel deposits are to aquifers, they also have become valuable commodities, constituent parts in the manufacturing of cement and in providing base materials for roads and sidewalks. Though there are some innovative exceptions, virtually every building, road and sidewalk are built with significant amounts of sand and gravel.
Sand and gravel mining near the Sturgeon River in Sturgeon County and Lac St. Anne area, northwest of Edmonton, began in the 1950’s. Taken individually, these mines are of minimal environmental consequences.
However, as these mining operations expanded and began to mine deep below the local water table, negative impacts added up. Not only are the constituent parts of the aquifer being removed for profit, mining operations are also “de-watering” aquifers to access the sand and gravel deposits. These operations are now de-watering aquifers to facilitate mining 75 feet deep or more, well below the natural water table. Water licenses for as much as 250,000 cubic meters per day have been granted to these operations by Alberta Environment.
Available environmental reports show that a “cone of depression” 10 metres deep and 8 kilometres plus in radius exists under the major sand and gravel mining operation near Calahoo and Villeneuve, north west of Edmonton.
Residential water wells in the area are severely impacted to the point where rural household and farm water wells are no longer viable. Local rural residents now depend on water trucked in to secure water for household uses.
As de-watering lowers the water table, area lakes and other surface water bodies are negatively impacted. De-watering aquifers contributes to the declining levels of these lakes and other surface water bodies. With the permanent dismantling of sand and gravel aquifers, water has fewer places to go during high precipitation events, leading to an increase in probability of flooding events.
Though sand and gravel are now essential commodities for our communities, there are significant environmental costs to their profligate removal from the environment. There are innovative alternatives to sand and gravel that should be explored. The provincial government would be well advised to facilitate and encourage the development of such innovative alternatives, as healthy aquifers are also essential to life and our environment as a whole.
Rod Olstad
Edmonton Chapter-Council of Canadians
and Prairies-NWT representative to the National Council of Canadians Board.
Strip mining well below the water table in the Villeneuve, Alberta area, just north west of Edmonton. This kind of mining requires dewatering the aquifer, which disrupts neighbouring land owners’ water wells often for many kilometres in radius in a “cone of depression”. This practise also disrupts surface water within the radius of the “cone of depression” due to the effects of hydro-stadic pressure.
edmontoncouncilofcanadians.ca 