Water Pollutants and Sources
Fill in the following table of pollution sources and the pollutants that are
generated at from each.
Source Pathogens Nutrients Sediments Toxic
X X X X
X X X
X X X X
Types of Water Pollution:
1. Point-source Pollutant: One specific source that is easily tracked and identified.
Examples: Anything with a drain pipe.
2. Non-point-source Pollutant: Not one specific source that can be easily tracked or identified.
Examples: All types of runoff, acid rain, etc.
Why is it very difficult to clean up groundwater once it becomes contaminated?
It is underground and difficult to access. Ground water moves very slowly. Aquifers are
Three Main Categories of Freshwater Pollutants
1. Sewage: Organic waste from humans or industry (anything that goes down a drain or toilet
ends up in the same place).
a. Inorganic: chemicals that don’t have carbon in them. Example—acids, fertilizers.
b. Organic: chemicals that contain carbon. Example—fossil fuels, soaps.
c. Eutrophication: out of control growth of algae and plants in ponds and lakes due to
3. Thermal and Radioactive
Thermal pollution is any increase in water temperature due to human activity.
Radioactive pollution is the unwanted presence of radioactive material affecting any
Why water is easily contaminated
a. it supports pathogen life (things that cause disease like to live in water).
b. it is polar—lots of different things can dissolve in water.
c. hydrocarbons (oils) float
On the bottom of this page, describe the basic steps of the sewage treatment process we use in
the United States. Identify the difference between primary and secondary sewage treatment. Diagram
the process as a flowchart.
Primary sewage treatment is mostly a physical process where the water is passed through a series of
screens to get large solids out. Solids are also allowed to settle out due to gravity. Stuff is physically
taken out during primary treatment.
Secondary sewage treatment is both physical and chemical. Things such as oxygen, bacteria, and
chlorine are added to the water in different chambers. Stuff is added to the water during secondary