Atlas of Polluted Rivers in the United States
The EPA keeps records of water quality in rivers at www.epa.gov/ owow/tmdl/atlas/states.html. Look at a state with which you are familiar. Rivers are color coded by the type of pollution that affects them, and the graphs show the types of pollution in more detail. What are the main types of pollution in your state? Why are those types dominant, and what sources might be responsible for them? Now think of a state that you suspect has a completely different type of pollution. (For example, if you are looking at a state with agricultural pollution, what is a state with industrial types of pollution?) Use your browser's "back" button to return to the map of the states, and go to the state you have in mind. Were you right in your guess about what type of pollution was most important there?
