After the oil sands have been mined, oil is separated from the sand and sent for further processing. “Tailings” are the leftover liquid mixture of mostly water and clay, some sand and residual oil.
The total area of existing tailings ponds is 182 km² including associated structures such as ditches and dykes. The total surface area of all fluid tailings is 77 km².
Settling or tailings ponds are large engineered dam and dyke systems designed to contain and settle the water, sand, fine clays, silts, residual bitumen and other by-products of the oil sands mining and extraction process.
In addition to acting as storage facilities, tailings ponds are settling basins that enable water to be separated, recycled and used over and over. Oil sands producers recycle 80–95% of water used, reducing use of fresh water from the Athabasca River and other sources.
Dyke Water Management
Dyke water comes from dyke constriction and surface water run-off. For example, ditches around tailings facilities capture this water that is pumped into tailings ponds.
This combination of water and clay has taken decades to consolodate and dry out. New technologies are accelerating the timing of consolidiation.
The Government of Alberta requires all oil sands operators to have plans in place to convert fine tailings to reclaimable landscapes.
Bitumen can be found on the surface of most tailings ponds. This can pose a threat to waterfowl that land on the pond. Several mechanisms are in place to deter birds from landing, including cannons and radar/laser deterrent systems, like those used at airports.
Wapisiw Lookout is Suncor's first tailings pond, put into service at the company's mining project in the 1960s. Formerly known as Pond 1, the area is the first tailings pond to be reclaimed to a solid surface. It is currently undergoing reclamation and will include both wetland and dry landscapes.