Coal mine, Alberta
Generating and harnessing energy from raw materials has an impact on the environment.
While producing energy from renewable sources, such as hydropower, biomass, wind and solar, can cause some damage (e.g., areas of land being flooded to create hydropower reservoirs), extracting non-renewable energy sources, such as crude oil, coal and natural gas, has the greatest impact on the surrounding landscape...
While producing energy from renewable sources, such as hydropower, biomass, wind and solar, can cause some damage (e.g., areas of land being flooded to create hydropower reservoirs), extracting non-renewable energy sources, such as crude oil, coal and natural gas, has the greatest impact on the surrounding landscape.
One strategy to mitigate the environmental damage done by producing these non-renewable energy sources is land reclamation, which involves converting disturbed land to its original state or to an alternative state with a different end use. Here are a few examples of land reclamation projects happening in Alberta.
For those opposed to Alberta’s oil sands development for environmental reasons, tailings ponds are a defining geographic feature of the province, and an ugly black eye on the industry. The large pools of wastewater, sand, salt and hydrocarbons that are left over when oil is extracted from bitumen can last for decades before enough of the leftover silt has settled and the land can be reclaimed. The Alberta government has taken steps to limit the size of tailings ponds and restrict the amount of water that can be used during processing in an effort to phase out new tailings ponds altogether. A new technology could shave decades off the land reclamation process by using a technique that removes water from tailings and leaves only a dry waste product that can be reclaimed in the ground. The process could also decrease greenhouse gas emissions and reduce production costs. This technology is still in the testing stages, but Suncor Energy and CNRL have had succesful trial runs that show promise.
Because coal mining often requires clearing substantial swaths of forests and undergrowth in order to build roads and remove the resource from the ground, restoring a depleted coal mine to its previous state is an ecological priority for industry and government. When the Alberta electricity provider TransAlta closed down its Whitehood Mine in 2010 after nearly 50 years of providing coal to a nearby electric power plant, the company began one of the largest-ever coal mine reclamation projects in the country. That meant removing its power lines, service roads, sediment ponds and irrigation ditches, seeding the land with grasses and planting trees. The company also introduced wetlands and densely wooded areas for wildlife on parts of the former mine site, while other areas became productive agricultural lands for grazing cattle.
Because of its relatively small environmental footprint, natural gas development requires little in the way of reclamation once a gas well stops producing. However, the government requires that inactive gas wells have to be properly suspended once production has ended, any associated pipelines have to be removed, and the land must be restored to its natural state, which includes cleaning up any surface or sub-surface contaminants. Toxic wastewater is a byproduct of some natural gas drilling, especially when hydraulic fracturing is used. This wastewater can pose environmental risks if not handled properly. One of the most common methods of water disposal is through injection wells, which occur most commonly in Alberta’s shale gas regions. These disposal wells are drilled to store wastewater deep underground where it is somewhat protected from migrating into drinking water reservoirs by overhead rock formations. These wells are then sealed off from the surface with several layers of cement and steel casing. However, there is still a risk with these injection wells that they may leak chemicals into groundwater, contaminating drinking water.
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