This lesson defines soil contamination and its important components. Then you’ll learn about the numerous types and sources of contamination as well as ways by which soil contamination can be prevented.
Soil contamination can be defined as the presence of anthropogenic (meaning derived from humans) substances in the soil in which any combination of the following circumstances or characteristics are true:
- The composition of the soil is different from its normal/natural composition.
- There’s a significant risk of harm to users of the soil as well as anything they place on that soil such as plants, animals, and buildings.
- The contaminants restrict the use of the soil in any one or more ways or lead to the loss of soil function.
- The contaminants leech into surrounding surface or groundwater.
- The contaminants are present in high enough concentrations to be of detriment to one’s health.
In this case these substances aren’t simply contaminants but also pollutants.
Let’s go over some of the possible sources of soil contamination as well as some prevention strategies.
Two General Sources
The sources of soil contamination can be categorized into two very broad categories known as point and non-point sources. Point sources are localized sources of contamination that are readily measurable, like runoff/discharge from a pipe coming out of an industrial plant that contaminates a local field. Non-point sources are diffuse.
That’s to say that they cover large areas or are comprised of numerous simultaneous point sources and are very difficult, if not impossible, to fully measure. A great example of this would be contaminants polluting the soil as a result of atmospheric deposition. For instance, contaminants that deposit onto the soil as a result of emissions from automobile exhaust.
All sorts of industries can contaminate the soil:
So what are the actual types of contaminant we can find in soil as a result of these sources and industries? They include: