What are the sources of water pollution in your area?
One of the largest pollutants could be city sewage.
Call the local sanitation utility to find what is done to sewage before it is dumped back into the stream or river.
Visit a sewage treatment plant.
Where does the water you drink come from?
Does it come from a river?
A lake?
Underground?
Call the city water department to find out.
Ask to visit the water treatment plant.
Does a river run through the city where you live?
Look on a map and see whether you can find any large cities that do not have rivers.
List them.
Where would their sewage go?
Where would their water supply be?
Do you know your watershed?
If a drop of rain falls on your rooftop, where does it eventually go?
Trace its path.
Map out the major streams and rivers that make up your watershed.