Richter consulting, LLc. 

The U.S. 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.

This does not mean that there's nothing to be concerned about. Constant vigilance, research, and new investment are essential. Some drinking water may contain lead or dangerous levels of arsenic. Private wells, like municipal water supplies, need regular monitoring. Keeping the water supply safe is an ongoing concern of the government—and of the people.

Public drinking water

Your local water supplier is required by law to notify you if there's any reason your water is unsafe. Furthermore, the Safe Water Drinking Act requires all water suppliers to issue their customers an annual report on the source and quality of the water—including a list of contaminant levels. Municipal water is tested for micro-organisms, organic and inorganic chemicals, disinfectants, disinfectant by-products, and radioactive substances. If your copy of the report has not come in the mail, call your water company.

Though your water company is responsible for keeping the water safe, lead can get into the supply after the water has left the treatment plant. Arsenic may also be a problem in some areas, mainly the Southwest.

A well of your own

About 40 million Americans and 4 million Canadians get their water from private wells. If you are one of them, water safety becomes your own responsibility.

Any water system can be affected temporarily by spills, agricultural runoff, including pesticides, and short-term treatment problems. And private wells can contain lead or arsenic. Your local health department can tell you which contaminants are typically found in your area. It can also supply a list of certified labs to test the water for you. You can also call the EPA Safe Drinking Water Hotline for a list of labs (see below).

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.

You may want a filtration system even if your water is safe—simply to improve the taste or to remove excess minerals. The National Sanitation Foundation (NSF), an independent, nonprofit organization, is a good source of information on filters. It tests products and certifies that they meet certain standards.

What to do: If you discover that your water has Cryptosporidium, particularly if someone in your household has a weakened immune system (due to chemotherapy, for instance, or infection with HIV), boil the water for a minute or two. Some filtration systems remove parasites. NSF can tell you which filter to buy.

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 thus 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.

To test for lead, which is important if a woman in your household is pregnant or if you have infants or small children, call the local health department or your water company, which may offer free testing, or contact the EPA. 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. (You send a first-draw sample to the lab, and another sample after running the water for a specific time, so it's possible to tell which pipes are the source of any lead.) Be sure you use a government-certified lab.

If you do 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 below). If the 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 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.

By-products of chlorination: Most Americans (80%) drink chlorinated water. Chlorine kills many 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 kills only some viruses, such as polio and the Coxsackie virus. Chlorine 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. A few years ago the EPA set new limits on the amount of such by-products permitted in water.

According to the EPA, chloramine is increasingly replacing inorganic chlorine for treating water in the U.S.; it is less likely to produce potentially harmful by-products. Ask your water company what it is using.

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 it. Constant low levels of arsenic increase the risk of bladder, lung, and skin cancer. Currently, under a standard set almost 50 years ago, the allowable level of arsenic is 50 parts per billion. These levels, according to the National Academy of Sciences, pose a lifetime cancer risk of 1 in 100 if you drink about two quarts of water a day. (No food additive that posed such a high risk would be allowed on the market.)

Unless you live in central California, Nevada, New Mexico, or Arizona, it's unlikely that your water has high levels of arsenic.

What to do: If you live in one of those areas, ask your local utility about the arsenic content of your water. If you have a private well, call the EPA for a list of labs that can check this for you. If your water proves to have a high arsenic content (higher than 10 parts per billion, which is the standard set by the World Health Organization), consider installing a distilling device or reverse osmosis filter.

If you choose to use bottled water to avoid arsenic, be sure you obtain a certificate from the supplier that the arsenic content in what you're buying is below 10 parts per billion (equal to 10 micrograms per liter).

Filtering the water

If you are simply trying to improve the taste of your water, a filtering pitcher will do. But if you are trying to remove lead, arsenic, or specific contaminants, you may want a permanent installation. Before you buy, be sure you know which contaminants the system will filter out. NSF is an excellent source of information.

Water filtration systems come in two basic types, ranging from cheap to expensive:

• Point-of-entry systems are installed on the main water supply and treat most or all the water entering a house. These include water softeners, which remove calcium and magnesium. There's no harm in drinking softened water, and it does not cause heart disease, as has been alleged. But the softer the water, the more likely it is to leach lead from the pipes.
• Point-of-use systems include faucet-mounted filters, faucets with built-in filters, pitchers, and under-the-sink filters.

Whether it's installed under the sink or at point-of-entry, the most effective filter is a reverse-osmosis system, which filters out lead and other toxic metals and other contaminants. This type of filter can be expensive ($500 to $1,000 or more) and the cartridges have to be replaced every year at a cost of up to $200.

Faucet-mounted systems and faucets with built-in filters work well against specific contaminants (check the labels and NSF certificates), as do most countertop pitchers. Simpler systems such as these represent a small investment, but replacement filters can cost as much as $100 a year.

Distilling the water

For about $100 to $500, you can get a countertop distiller that will boil water and condense the vapor. Distilling reduces levels of all chemicals in water, including heavy metals such as lead. Some units kill microorganisms. Some also remove chlorine by-products. Distilled water is tasteless and devoid of potentially beneficial minerals, but there's no harm in drinking it.

Note 1: Distillers and reverse-osmosis filters remove fluoride. If you use one, make sure your toothpaste contains fluoride, and consider fluoride treatments for children in the household.

Note 2: With any filtration or distilling system, change filters as directed; otherwise you risk increasing contamination.

Why not switch to bottled water?

Bottled water, in spite of its phenomenal popularity, may not be safer or more healthful than tap water. Some studies have found that tap water tends to have lower bacterial counts than bottled, and that some bottled waters are out of line with standards for tap water. Some bottles, however, are just packaged tap water.

In addition, bottled water is costly and bulky. Plastic containers are not as weighty as glass, but they can affect the water inside. Clear polyethylene plastic has little or no effect. Thick opaque containers can impart a plastic flavor. Big rigid polycarbonate water-cooler jugs can leave chemical residues.

If you care about conservation of resources, tap water is by far the best choice, according to the World Wide Fund for Nature. Millions of tons of plastic are used every year to make water bottles; disposing of these bottles contributes to air pollution.

FDA regulates bottled-water safety using EPA water standards and establishes definitions for labeling. If you buy bottled water, you're probably better off buying brands bottled by members of the International Bottled Water Association; NSF inspects their plants.

For more information

• Environmental Protection Agency (EPA): Safe Drinking Water Hotline: 800-426-4791.
• NSF International: phone toll-free in U.S., 800-NSF-MARK; otherwise 734-769-8010. For questions on consumer products, call 877-867-3435.
• Natural Resources Defense Council: phone 212-727-2700.
• Food and Drug Administration (FDA): phone 888-INFO-FDA.
• International Bottled Water Association (IBWA): its members (accounting for 80% of the water bottled in the U.S.) must test annually for contaminants and are open to unannounced inspections by NSF. Phone 703-683-5213 or its information hotline at 800-WATER11.

UC Berkeley Wellness Letter, Updated January 2005