Photo by : CBC (2012)
When an oil spill occurs on land, it prevents the absorption of water by the soil, as we know water and oil is immiscible,oil spills on agricultural locations and grasslands have the effect of choking off plant life. When an oil spill occurs in these environments, the main priority are to prevent the oil from leeching into groundwater and from entering groundwater supplies as this can be detrimental to the human population and also to animals.
An oil spill on the land may penetrate underground and move downward reaching eventually the groundwater. However, such vertical movement may be slowed done if not prevented by the presence of paved surfaces, natural clay layers or other natural or anthropogenic barriers. Oil may also move laterally along less permeable layers (including surface pavements) or with groundwater and surface waters, eventually causing underground pollution.
Berms and trenches can be used to contain an oil spill, as long as their use does not allow the oil to leach into the soil. Where there is no danger to the water table, the contaminated area can be flooded, which “floats” the oil or moves it to the water’s surface, as it is typically lighter than water. This technique allows for recovery via vacuums and skimmers. Other possible techniques include mechanical removal of contaminated soil , also bioremediation.
These negative effects are due to the environmental discharge of various organic compounds that make up crude oil and oil distillate products, the majority of which include various individual hydrocarbons. Hydrocarbons are made exclusively from carbon and hydrogen atoms which bind together in various ways, resulting in paraffins (or normal alkanes), isoparaffins (isoalkanes), aromatics (such as benzene or various PAHs), cycloalkanes and unsaturated alkanes (alkenes and alkanes). Other individual compounds that are present in crude oil and oil discharges include (apart from carbon and hydrogen) sulfur, nitrogen and/or oxygen atoms.
Oil spills are all man made, and it is up to us to prevent such disasters from taking place. Be sure to come back next week for more information on oil spills!
References : http://www.environmentalpollutioncenters.org/oil-spill/