January 23, 2018
How Safe Is Your Drinking Water?

How Safe Is Your Drinking Water?

by Berkeley Wellness

The US and Canada, as well as most other industrialized nations, have a right to be proud of their drinking water. Safe public water is one of the triumphs of the last century.

But as the recent water crisis in Flint, Mich., has made tragically clear, there’s still plenty of cause for concern. Some municipal water supplies may contain lead—as has been the case in Flint—or unsafe levels of arsenic, microorganisms, or other pollutants. Private wells, too, need regular monitoring to ensure the water is safe for human consumption. Keeping the water supply safe requires constant vigilance, not just on the part of the officials and agencies who oversee drinking-water safety, but, increasingly, by all of us.

Here’s what you should know about your drinking water, from who regulates it to when and how to test it (and for what contaminants) to what you can do to improve your water’s safety, taste, or both.

Public drinking water

Thefederal Safe Drinking Water Act was passed in 1974 to protect the nation's supply of public drinking water. It gives the EPA the authority to set standards and enforce regulations that protect the public's health against the effects of contaminants, whether they're naturally occurring or man-made. That authority involves more than just regulating how water is treated. It extends to protecting the sources of public water, such as lakes, rivers, reservoirs, and public wells; setting minimum standards for training and certifying water system operators; and funding water system improvements.

The law also recognizes the importance of providing information to the public about the water coming from their taps. Under the law, your local supplier must notify you if for any reason your water may not be safe. That notification needs to include what the problem is, what's being done to correct it, and what steps you can take to protect your and your family's health.

In addition, water suppliers are required by the EPA to issue an annual Consumer Confidence Report, or CCR, that's made available to all of their customers. Individual states can set requirements for what needs to go into the report. But each must contain, at a minimum, such information as where the water comes from, what the risks are of that source being contaminated before the water even gets into the supply line, what contaminants were found in the water during the previous year’s testing, and what is being done to protect the public from the potential health hazards of those contaminants.

The law says the report needs to go to every paying customer no later than July 1 each year. Initially, that meant it needed to be mailed. As of 2013, however, customers can opt to receive the report by email or view it online via a URL provided by the supplier. However you opt to receive it, the law requires that the report go to everyone without charge.

You are legally entitled to receive this information, so if you don't get your copy of the report by July 1, call your water company and ask how you can get it. You can also try searching for it online using the EPA's CCR finder tool.

Private well water

About 15 million American households get their water from private wells. Private drinking water wells are not regulated by the EPA. So if you have one, the safety of its water is your responsibility.

Any water system can be affected temporarily by spills, agricultural runoff (including pesticides and fertilizers), failed septic tanks, or leaks from underground storage tanks. Private wells can also become contaminated from flooding and severe storms such as hurricanes. And wells can contain lead or arsenic.

Whether you've acquired a property with a well or have had a new one put in, you should have the water tested before you use it for the first time and then at least annually after that. Your local health department can tell you which contaminants are typically found in your area, and can refer you to a certified water testing lab. Some health departments offer free inspections themselves. You can also call the EPA's Safe Drinking Water Hotline for a list of certified labs, or use the agency’s online search tool.

There are some circumstances under which you might want to test your water more often. Those include:

  • Nearby mining or drilling operations
  • Intensive agriculture going on in your area
  • Water that appears cloudy, frothy, or colored
  • A smell of gasoline or fuel oil, especially if you or your neighbors use underground storage tanks
  • Scaly residues left behind after using the water

If your water proves substandard, you can use a filtration system—anything from a filtering pitcher to an elaborate point-of-entry system that filters all the water coming into your house. You can also consider bottled water. (For more on both options, see boxes below.) You may want to filter your water even if it is safe, simply to improve the taste or to remove excess minerals.

Choosing a Home Water Filter

Which type of filter you need depends largely on what you are trying to remove.

Pollutants in drinking water: organic and inorganic

Pollutants in water are classified as organic (living organisms such as parasites, bacteria, and viruses) or inorganic (nonliving things including metals, such as lead, and chemical elements, such as arsenic). Both types can cause serious illness in humans.

Organic pollutants often come from human or animal waste that makes its way into the source for drinking water, either directly or indirectly. Drainage and normal runoff can carry fecal matter into the water. So can sewage, especially untreated or unfiltered sewage that's dumped or spilled into the water upstream.

Some inorganic pollutants occur naturally and can enter the water from the surrounding soil. Others may enter as runoff from human activities such as farming or mining. And some, like lead, can enter the water after it has been treated, through man-made pipes or other materials that may leach lead.

Organic pollutants: Microorganisms

Giardia and Cryptosporidium, both of which come from animal and human waste, are single-celled parasites that can cause serious illness and even death. Infection with either can cause intestinal symptoms such as cramping, nausea, vomiting, and severe diarrhea. Headaches are another symptom commonly associated with Giardia.

EPA rules mandate that the filtration and treatment process eliminate or kill 99% of Cryptosporidium and 99.9% of the Giardia in the water supply. Municipal water systems usually do a good job of controlling such parasites and of warning the public if the water becomes contaminated.

Other pathogens that can get into the water include bacteria such as Legionella, which can cause a type of respiratory illness called Legionnaires' disease; E. coli, a bacteria that's present in the intestines of humans and animals; and enteroviruses, small viruses that also contaminate water and can cause diseases ranging from gastrointestinal problems to meningitis.

What to do: If your water has been contaminated by Cryptosporidium or another pathogen, your supplier must notify you of the contamination within a prescribed time period. The supplier needs to tell you not only what is being done to remove the contaminant, but also what you need to do to make the water safe for you and your family. Follow any instructions about boiling the water before using it for cooking, drinking, cleaning vegetables, or bathing, especially if someone in your household has a weakened immune system (due to chemotherapy, for instance, or immune-suppressing drugs).

Some water filtration systems will remove Cryptosporidium and other parasites. Look for filters that are certified for specific parasite removal by NSF International, an independent, nonprofit group that tests products, including water filters, and certifies that they meet certain standards. Or check the CDC's guide to water filters.

Inorganic pollutants

Lead. The dangers of lead poisoning are well known, especially for children and pregnant women. Lead gets into water via plumbing: service lines, pipes, solder, and brass faucets (especially when they’re new). Even lead-free copper pipes may be soldered with lead. Soft water (that is, with low mineral content) is more acidic than hard water and so is more likely to leach lead out of pipes. Lead was banned from plumbing pipes in 1986 (though the ban did not take effect in some states until 1988), but even the newest faucets may still contain some lead.

Testing for lead is especially important if a woman in your household is pregnant or if you have infants or small children. Your local health department or water company may offer free testing; call to find out. If they don't, ask for a referral to a government-certified lab, or contact the EPA to find one. Testing is usually inexpensive and can reveal whether the problem, if any, comes from the service line outside or from pipes and faucets in your house.

What to do: If you have a high level of lead (over 15 parts per billion in the first-draw sample, or 5 parts per billion in later samples), consider installing a point-of-entry or under-the-sink reverse-osmosis filtration device (see box above). If later samples show high lead, notify your water supplier.

For less severe problems, use a filtering pitcher or a faucet-mounted filter. Check the NSF certification on the filter to make sure it removes lead.

If the lead comes from the faucet, let the water run for one minute before drinking it or cooking with it, particularly if the water hasn’t been run for several hours. And don’t use hot water from the tap for cooking, drinking, or mixing infant formula. Hot water dissolves lead more quickly than cold. You can also replace your faucets with low-lead ones.

To learn more about protecting children from exposure to lead, see these informational fact sheets from the CDC.

Byproducts of chlorination. Many Americans drink chlorinated water. Chlorine kills harmful microorganisms, including those that cause cholera, typhoid, dysentery, hepatitis, and other waterborne diseases. Thus chlorination has saved countless lives and is one reason for the great increase in life expectancy since 1900.

But chlorination has its downside. While it’s effective against bacteria, it doesn't kill all viruses, only some, including the poliovirus and the Coxsackie virus (which causes hand, foot, and mouth disease). Chlorine also undergoes many changes when added to water. It turns into hypochlorous acid, which combines with practically anything, including bacteria (they die in the process, which is how disinfection works). In very large amounts, the by-products of chlorine increase the risk of cancer.

Whether these chlorine by-products are harmful in trace amounts has been under study for many years. According to the CDC and the EPA, the amount of chlorine permitted in drinking water is below the level that should raise concern. The regulated amount of chlorine is less than 4 mg/liter and does not cause harmful health effects.

Some individuals with certain health conditions, for example people with asthma or contact dermatitis, may be more sensitive to chlorine. If you are concerned, talk with your doctor about what you should do.

Some municipal water systems now use chloramine, a chemical compound that contains chlorine and ammonia, instead of chlorine for disinfecting water. Chloramine is considered safe for this purpose when used in the prescribed amounts. It lasts longer than chlorine, which sometimes loses its effectiveness in pipes. And chloramine also produces lower levels of byproducts that may cause illness in some people.

What to do: To find out whether your water supplier uses chlorine or chloramine to disinfect the water supply, check your annual CCR.

Arsenic. This natural element, highly poisonous in large amounts, can leach into the water from the ground or from industrial waste, and it can be expensive for water systems to eliminate. Constant low levels of arsenic increase the risk of bladder, lung, and skin cancer.

In 2002, the EPA reduced the permissible level of arsenic in food or drinking water to 10 parts per billion (ppb), far less than the previous cap of 50 ppb. Individual states can mandate even lower arsenic levels if they choose to. For example, in 2006 New Jersey lowered the acceptable level of arsenic to 5 ppb.

What to do: If you live in central California, Nevada, New Mexico, or Arizona—the places in which arsenic contamination is most likely—ask your local utility about the arsenic content of your water. If you have a private well, consult the EPA to find a certified lab that can check this for you. If your water proves to have a high arsenic content (more than 10 parts per billion), consider installing a distilling device or reverse osmosis filter (see box above).

If you live elsewhere, it’s unlikely that your water has high levels of arsenic. Still, if you own your own well, check with your local health department to find out if arsenic is a potential problem in your area. If it is, consider having your water tested.

Why Bottled Water Isn't Better

Bottled water, in spite of its phenomenal popularity, may be neither safer nor more healthful than tap water. And it's a disaster for the environment.

Resources for more information

Environmental Protection Agency (EPA): Safe Drinking Water Hotline: 800-426-4791.



Food and Drug Administration (FDA): phone 888-INFO-FDA (888-463-6332).

International Bottled Water Association: phone 703-683-5213; toll-free information hotline at 800-WATER11.

Natural Resources Defense Council: phone 212-727- 2700.

NSF International: For questions on consumer products, call 800-673-8010 or submit an online inquiry. For easy access to a wealth of consumer resources, including information about NSF certified water filters, start on the NSF Consumer Resources home page.