Is Your Drinking Water Safe?

By Keith Mulvihill

E coli. Cryptosporidium Giardia. Do you know what's lurking in the water that comes from your kitchen faucet. Millions of us are so wary of drinking the stuff that we're willing to spend almost $5 billion each year trying to clean it up or avoid it completely-installing home filtering systems and buying cases of bottled water.

Are we paranoid? The tap water available to most Americans through municipal supply systems has been treated under the Safe Drinking Water Act. Most of the time, our water is just fine.

But not all of the time. Treatment plants have breakdowns; old pipes leach lead; private wells or smaller water-supply sources can be contaminated. "We can't take the safety of our drinking water for granted," says Carol M. Browner, administrator of the U.S. Environmental Protection Agency(EPA). In fact, the EPA recommends that at least five million people consider avoiding tap water entirely: those who are infected with HIV, cancer patients on chemotherapy drugs, and organ-transplant recipients taking immunosuppressive drugs.

Other scientists say even the rest of us have good reason for concern. "Approximately forty-five million Americans in thousands of communities drink water that is polluted with fecal matter, parasites, disease causing microbes, and pesticides-at levels that violate Safe Drinking Water Act standards," says Ken Cook, president of the Environmental Working Group, a non profit organization based in Washington, DC. Studies have shown that such contaminants may increase the risk of cancer, gastrointestinal disease, and miscarriage.

Experts are particularly worried about the impact on children. One recent study by the Harvard School of Public Health found a 10 percent increase in gastrointestinal emergency visits for children between the ages of 3 and 13 within four days after significant increases in water cloudiness even though testing indicated the water was well within safety standards.

"Children drink more water than adults, relative to their size," notes Joel Schwartz, Ph.D., an environmental epidemiologist at the Harvard School of Public Health. "Because of this, infants and young children are more vulnerable to water borne contaminants."

'Time of year is a factor too. During the summer, for instance, warm weather allows more micro organisms to grow, so treatment centers add more chlorine to kill them-and more chlorine creates higher levels of dangerous by-products called trihalomethanes ('l`HMs). Last summer, city officials in Chesapeake, VA. monitored THM levels on a weekly basis; in late July, they exceeded new Federal limits taking effect this month by as much as 60 percent.

Why worry? "There is increasing evidence of a link between bladder cancer, and possibly rectal and colon cancer, and long-term exposure to chlorinated by products," says Kenneth Canter, Ph.D., an epidemiologist at the National Cancer Institute. THMs-even at levels below the regulated limits-have also been linked to miscarriage.

There is some good news: This month the EPA begins a new effort to tighten contamination standards and give consumers more information about what's in their water. For the first time, treatment facilities that serve communities with 10,000 people or more will be required to improve their filtering of cryptosporidium, a parasite that in Milwaukee in 1993 caused more than 100 deaths and made more than 400,000 people ill. The new regulations also will tighten standards to limit other harmful microbes such as giardia, bacteria, and viruses.

In addition, all municipal water suppliers will be required to mail (and publish in .local newspapers) annual water-quality statements. These Consumer Confidence Reports will list amounts of contaminants and tell you whether your water measures up to government standards .

One particularly important change: In the past, water utilities have been allowed to report contaminant levels averaged over a year, which may be misleading because pollutants (like THMs) can be worse during some months. Now, the EPA also is requiring that consumers be told the highest and lowest levels for the year. You'll then be able to determine whether you should install a filter in your home, or take some other action to clean up polluters in your community.

"We must be vigilant about a resource that is so fundamental to our lives and the lives of our children," says Browner. '"The best: way to ensure the protection of public health is to put information about local pollution into the hands of citizens.