If you search for "bottled water" on the web, you may get over a million matches. Select two sites to explore, one provided by a supplier and one provided as a source of consumer information. The former may flood you with statistics about the benefits of bottled water; the latter may raise questions such as, "Is bottled water safer" or "Is it worth the cost?" Both can be expected to catch your interest. For each site, list the title, author, URL, and two things that you learned about water.

Each state has different concerns about its surface and ground water.
a. Draw up a list of the issues in your state. For example, you might mention agricultural run off, leaking storage tanks, or pollution from other human activities.
b. Read the fact sheet for your state provided by the Office of Water at the EPA. What does the sheet say about the surface and ground water quality?
c. EPA notes that some states have lakes, rivers and streams that support no aquatic life. What percent of the surface water falls in this category in your state?

Three dimensional representations of molecules can be viewed on the web with the aid of CHIME, plug-in that you can download and install for free. Here are representations of ethanol, ethylene glycol and sucrose. Can you identify the places in each compound where hydrogen bonding occurs? Has your mental picture of these molecules changed after seeing these 3-D representations? Explain.

Table 5.6 is merely a starting point for the wealth of information available about possible pollutants in drinking water. At the Office of Ground Water and Drinking Water at the EPA, you can access a consumer fact sheet on each of these pollutants, as well as dozens more. Look up one listed in Table 5.6 and find out how the pollutant gets into the water supply, and how you would know if it were in your drinking water. Is your state listed as one of the top state that releases the contaminant?

Note: Cadmium, chromium, lead, mercury, and nitrate/nitrite ions are found under the section on "Inorganic Chemicals". Benzene is listed under "Volatile Organic Chemicals". There are no trihalomethanes such as CHCl₃ currently listed, but you can find a variety of other chlorinated compounds found in water such as carbon tetrachloride and dichloromethane. Both a Consumer Version and a Technical Version is available, and the latter is recommended.

The gasoline additive MTBE (methyl tertiary butyl ether) was discussed in Chapter 4 as one of the mandated oxygenates in certain metropolitan areas to reduce air pollution. There is some concern that MTBE from this use may be accumulating in surface and ground water, with the potential to compromise the quality of drinking water supplies. Search on the web to find the latest information about MTBE.

Find out whether lead, mercury, or cadmium ions are a significant problem in drinking water where you live. You might begin with the map of local drinking water systems provided by EPA's Office of Ground Water and Drinking Water. Your local water utility company or state drinking water program should be able to provide information as well. Additionally, you may be able to find articles in your local newspaper.
a. If these ions are present, what are some likely sources?
b. Are their concentrations above the MCLG or MCL?

Not all water pollutants are toxic or cause cancer. Some, such as endocrine disrupters (a class of chemicals mentioned at the outset of this section) are dangerous for other reasons. What are endocrine disrupters? What are they suspected of doing in both humans and animals? And how do they get in drinking water? A search on the web for "endocrine disrupters" will provide answers as well as material that should raise more questions in your mind. After reviewing material on the web, answer the questions just posed. Then list three more questions of your own, recognizing that their answers may still be a topic of current debate.

Note: A first-rate web site that you may wish to visit is The Why? Files, sponsored by the National Institute for Science Education. Published there is a news story entitled, "Endocrine Disrupters".