This interactive diagram allows the user to follow a drop of water from the source through the treatment process. Water may be treated differently in different communities depending on the quality of the water which enters the plant. Groundwater is water located under ground and typically requires less treatment than water from lakes, rivers, and streams. Users are invited to click on each treatment ... Full description.

Flowing water from rivers and streams is a valuable and plentiful energy resource that people learned to use centuries ago to operate the machinery that was important to their livelihoods. This page features diagrams (some animated) that show the three main principles of water; various types of water wheels; and the modern hydroelectric turbine. There are also animations of various types of mills ... Full description.

In this lesson, students test for visible and invisible pollutants in the air and keep a journal of experimental results, procedures, and conclusions. Using simple materials, they will form groups to set up experiments around the school, keep records, research the history of acid rain, make a mural showing the acid rain cycle, and post a chart displaying the sources of visible pollutants. Full description.

This portal offers an alphabetical selection of links to materials on a variety of sea creatures, especially whales. Topics include research reports, expedition records, maps, datasets, movies, and sound recordings for several species of whales, seals, porpoises, and turtles. Full description.

The site offers an interactive discussion of different vantage points associated with dam building. It describes some of the engineering and environmental issues that go into the process of selecting a site for building a dam and the conditions necessary for electrical generation. Links to classroom and family activities are organized by grade level. Full description.