Can I Drink the Water?

by Charles Platkin, PhD

used to be simple. It came out of a tap; you drank it; and it was good. Now, with concerns about safety and taste, water is much more complicated. After contacting the experts and scouring the research, here are the answers to the most important water questions.

Where do we get our ?
There are generally two sources of water — ground (underground) and surface (reservoirs, lakes, rivers, etc.), and it’s about a 50-50 split. Larger cities typically use surface water, whereas smaller municipalities use ground. Also, according to James M. Symons, Sc.D., aka Dr. Water, about 80 million people in the United States use water from individual sources (e.g., well water), which is not regulated.

Is tap water safe?
To state the obvious, if water weren’t safe, most of the country would be sick. So, in the short term, most municipalities have safe water. The risk associated with tap water relative to other risks in the world, such as air and traffic accidents, is very low, says Mark Wiesner, Ph.D., P.E., a professor of environmental engineering at Duke University. The primary concern for municipal water facilities is to eliminate pathogens or microbes — the things that can make you sick right away. American water systems are doing a decent job keeping our water supply safe, so we can feel a level of comfort drinking the water from the tap.

Water from your tap is not meant to be sterile, but it is meant to be safe to drink within a reasonable risk. The Environmental Protection Agency (EPA) regulates known contaminants and, through a process known as risk assessment, monitors the frequency and concentration of contaminants. The Safe Drinking Water Act mandates that the agency continually update its list of potential contaminants.

In fact, the EPA has two sets of water-quality goals. The first is the EPA maximum contaminant levels (MCL), which municipalities can’t go above. Then there are the MCLG (maximum contaminant level goals). Here the objective is to determine what the goals would be if cost weren’t an issue. Both these levels are available on the EPA Web site.

However, environmental groups are concerned about the long-term effects of tap water. Can you get cancer or lead poisoning from the water? The fact is that we don’t know — and that’s what’s frightening.

The Environmental Working Group analyzed the nation’s municipal water supply and found over 90 percent compliance with enforceable health standards set by the EPA, demonstrating a commitment on the part of municipalities to comply with safety standards. The problem, according to the group, is the EPA’s failure to establish enforceable health standards or to monitor requirements for other sources of tap water contaminants. Of the 260 contaminants detected in tap water from 42 states, the EPA has set enforceable health limits for only 114; the EPA also has set non-enforceable goals, called secondary standards, for five others.

Of the 141 unregulated contaminants detected in public water supplies from 1998 to 2003, 52 are linked to cancer, 41 to reproductive toxicity, 36 to “developmental toxicity” and 16 to immune system damage, according to chemical listings in seven standard government and industry toxicity references. Despite the potential health risks, any concentration of these chemicals in tap water is legal, no matter how high.

Cities may also be concerned about nitrates and nitrites, too much fluoride, pesticides and a vast number of other organic chemicals, endocrine-disrupting chemicals, etc. “There are so many that it is ludicrous to list what the consumer should avoid, since the consumer can’t actually identify any of them,” says Tim Ford, Ph.D., a professor of microbiology at Montana State University.

The Environmental Working Group database of contaminants — — has a detailed listing of all contaminants you should be concerned about, both those regulated and unregulated by the EPA.

The other issue with regard to municipal tap water is the potential problems created by the chemicals used to clean and disinfect the water. “Long-term effects of disinfection byproducts are hotly debated. Yes, many have been shown to be carcinogenic at high concentrations, but if we didn’t have disinfection, we’d die of infectious disease long before the effects of disinfection byproducts kill us from cancer,” says Ford.

Why is tap water contaminated?
The biggest problem we have with tap water is the source. Because rivers and reservoirs are often polluted with industrial chemicals, farm waste, sewage, pesticides, fertilizer and sediment, municipal water supplies start with a very contaminated supply, which they’re forced to clean up. “We are paying for a lot of current and past sins,” according to Symons.

How is tap water cleaned?
According to Symons, the two primary means for preparing water in this country are disinfection (using primarily chlorine) and filtration. It’s best if the water is clarified (filtered) to remove all particles, because germs hide inside particles. But some municipalities, such as New York City, only chlorinate, he adds.

Why don’t municipalities take additional steps to purify tap water? There’s no point in “sterilizing” water that is then going to be distributed through an aging, leaking distribution system (which currently is almost all of them), says Ford. But most tap water is treated to overcome most of the post-treatment distribution issues that could occur.

Also, one interesting fact about water treatment: According to Wiesner at Duke University, all municipal water is treated to be drinkable; however, only 15 percent goes for residential use (and only 15 percent of that 15 percent is actually used to drink and cook — the rest is used for bathing, gardening, washing cars, etc.). So no matter where you drink, American water is probably safe — from the fire hydrant, hose, a swimming pool, etc.

Is there another country with a superior water supply?
The United States creates regulations based on available data of the risks and hazards, whereas Europe has a precautionary system. If they think there is something that’s going to be wrong — well, they don’t let it out on the market. For instance, synthetic polymers are used to remove viruses from water in the United States, but they’re banned in many European countries because there is not enough health information, says Wiesner.

If I drink tap water, should I use a filter?
One of the weakest points of tap water is the distribution system, and while treatment is supposed to hold up through this process, there can be some deterioration. “It’s not an unreasonable investment to have some sort of carbon filter to remove lead, bacteria and chlorine. It can be a bit safer and also improve the taste. But keep in mind that you’re taking on the responsibility of treating water at the last step of the process — which means you need to maintain the process,” says Wiesner.

If you are thinking about getting a filter for your home, there are several things to consider. First, make sure your filter removes contaminants of concern in your particular tap water. Second, be sure the filter is independently certified by NSF International, a not-for-profit, non-governmental organization (, or a similar independent organization. Third, maintain the filter at least as often as the manufacturer recommends, or hire a maintenance company to maintain it for you. Carefully follow all cleaning, replacement or routine maintenance instructions. “Refrigerators with built-in filters are worrisome. Supply lines will eventually form biofilms and are virtually impossible to clean. There are many, many different filters on the market, but here, maintenance is the key. The simpler they are to clean and replace, the better,” says Ford.

Also, remember that a “point of use” filter on your sink will not remove all contaminants. For example, you can be exposed to trihalomethanes in the shower. Only a “point of entry” device that cleans all the water in your house will take care of all your water taps.

Finally, if you have a weakened immune system, check the Centers for Disease Control Web site and consult with your health care provider for advice about filters.

How can I find out about the quality of the water where I live?
All community water suppliers have to produce what is known as a Consumer Confidence Report once a year and make it available to their customers. You can call to find out where your city’s information is posted or if they can mail you a report, says Aaron Margolin, Ph.D., a water expert and professor of microbiology at the University of New Hampshire. To find out about your city’s water quality, ask your water company for a copy of its annual water-quality report, which is sometimes called a right-to-know report. Then get the brochure called “Making Sense of Your Right to Know Report,” (see or to help you understand the report.

The Environmental Working Group has compiled a great source to check the contamination of drinking water provided by more than 39,751 water utilities in 42 states. For the first time, you can see how your tap water stacks up against other cities and towns throughout the country.

Do you want to test your drinking water?
Although primarily designed for unregulated well water, you can get a test kit from Underwriters Laboratories, a not-for-profit testing company, at for $165 plus some additional charges. The kit tests for 53 contaminants, including bacteria, metals, inorganics and volatile organic compounds.

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