What is Civil Engineering ?

Environmental Engineering

Remediation


Hydrophobic soil near Devon, Alberta

Certain soils develop hydrophobic characteristics with time. These soils do not let moisture migrate through the soil making the soil dry and barren. The cause of water repellency or hydrophobicity in soils is not yet known and may be natural (forest fires) or anthropogenic (contamination from petroleum hydrocarbons) in origin. Hydrophobocity is not restricted to a particular soil type and can be associated with coarse grained and fine-grained soils. Once rich, arable soils become hydrophobic they become completely bald and uncultivable. Research is underway to determine the cause of soil hydrophobicity and to develop methods to remediate such soils.

courtesy of Dr. Gopal Achari, UofC

Poplar and cottonwood trees are being used to remediate mild to severe contamination of soil and ground water. The trees help by removing the contaminants using rhizosphere oxygenation and also by enhancing the soil microbes that live on and around the tree roots.

Landfills are "capped" with final layers of clay and top soil and then grass (usually native grasses are used) and trees are planted. Many times recycled materials such as biosolids from the sludge lagoons, mulch from recycled lumber and Christmas trees, and compost are mixed with the soil to enrich it.

At the landfill in NW Calgary, antique farm machinery and picnic benches were planted along with the grass, shrubs, trees and flowers making the site look more like a park than the "nuisance grounds" our grandparents grew up with.