Water pollution is the addition of some substance that causes the quality of water - taste, smell, appearance, cleanliness - to become poorer. It has been an important problem for over 150 years.

This section's case-in-point, Pollution in the Great Lakes, discusses the history of the problem as well as joint U.S. / Canadian efforts to remediate pollution. Go to the shared Environment Canada / EPA site at http://www.on.ec.gc.ca/glimr/data/celebrate-glwqa/. Please write a short essay on the status of the cleanup. Include a section on "work still to be done."

Fertilizers, herbicides and pesticides are critical to maintaining a healthy, abundant food supply. Yet excess amounts of these products runoff from farms into lakes, streams and aquifers. The goal is to prepare products that are environmentally benign.

Lois Swirsky Gold is Director of the Carcinogenic Potency Project, affiliated with the University of California at Berkeley. We discuss her thinking on natural v. synthetic pesticides in this section. The Project's Web site, at http://potency.berkeley.edu/herp.html, contains information on a measure called HERP. What is this? Why is it introduced? How does this relate to Dr. Gold's philosophy about natural v. synthetic pesticides? After reading this section in the text and doing the Web assignment, what is your conclusion on the safety of synthetic v. natural pesticides?

Governmental legislation is one way of attempting to deal with the causes and effects of industrial water pollution.

Worldwide pollution emission data are available. Please go to the United Nations Pollution Release and Transfer Register (PRTR) site at http://www.ecn.cz/prtr-tf/discussion.htm.Find the reference site for your country. Answer the questions below, compared to other countries. In the U.S., the EPA recently published an on-line version of the related information, the Toxics Release Inventory (TRI) for 1999 at the site http://www.epa.gov/triinter/programs/state_programs.htm. Please find your state on the map and print out the data sheet (this requires that you have access to Adobe Acrobat). Summarize the data. That is, what do they tell you about your state's industrial emissions compared to, say, the largest or smallest states? (You'll need to download their sheets.) How do the data compare to the states in various parts of the country, etc? What are some trends?

Hundreds of oil spills occur each year. Many have few long-term consequences, but others are rather serious. Technology exists for cleaning up and recovering some spilled oil.

The Smithsonian Institution has a site at http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/peril_oil_pollution.html. At that site, they claim that major tanker oil spills account for only a small fraction of the total oil that ends up back in the ocean. According to that site, and using other supporting evidence as necessary, discuss why such a relatively minor spill percentage is viewed as so important. Remember to site the data in this and other articles as necessary.

Treatment of municipal water supplies is one of the most common, and important, features of our industrial age.

We'd like you to do a "photo essay" for this final section. Please go to a search engine such as google, metacrawler or altavista. Use the "images" tab do a search for "municipal wastewater treatement plants" and variations on that theme. Import the pictures to your word processor (or print them and paste them). Use the pictures with any necessary commentary in a photo essay on "wastewater treatment". Discuss what each part of the facility in your picture is. Also, identify what plant the picture refers to, and identify the source of the picture.