A Guide to Safe Drinking Water for the Home

Use these three steps to ensure the water in your home is safe, clean and refreshing.


Ensure your drinking water is safe by filtering it for common contaminants such as atrazine, chlorine, lead and chromium-6.

Photo By Corbis

Content Tools

Although for most of us the tap water runs out of the faucet clear, tasteless and odorless, our municipalities must work hard to filter an ever-increasing array of both natural and manmade pollutants from our groundwater. And even if it meets legal standards, your tap water may still contain pollutants. Getting informed about drinking water quality is a good idea for everyone, but particularly those of us who live with children, are sensitive to chemicals or have weakened immune systems. 

The Safe Drinking Water Act of 1974 is the main federal law establishing standards for drinking water quality. Under this law, all U.S. municipal tap water is treated to remove pollutants in accordance with federally mandated maximum contaminant levels (MCLs) set by the EPA. State and local governments may also set water safety laws. 

But despite federal, state and local water regulations, contaminants can still make their way into our water supply. The Environmental Working Group (EWG) recently analyzed nearly 20 million records from state water officials and discovered that “testing by water utilities has found 315 pollutants in the tap water Americans drink.” More than half of these detected chemicals aren’t subject to health or safety regulations and can legally be present in any amount. And although federal guidelines do govern the others, 49 of these contaminants were found to exceed set levels in different parts of the country, thus polluting the tap water of 53.6 million Americans.

Because of these kinds of reports, consumer concern about tap water safety has increased in recent years. In a 2011 survey commissioned by the Water Quality Association (WQA), 54 percent of consumers polled were concerned about contaminants in tap water, and 49 percent were concerned or very concerned about their household water supply.

“We are seeing people become more educated about water issues and finding ways to ensure water quality for their families,” says Peter J. Censky, WQA executive director. Although safety regulations do ensure at least a minimal level of cleanliness and safety in municipal water supplies, taking responsibility for the health of our own drinking water is smart. Indeed, even the President’s Cancer Panel recommends the use of home filtering devices to decrease exposure to cancer-causing agents. To ensure you have safe drinking water in your home, take these steps:

Step 1: Learn What’s In Your Tap Water

Every year by July 1, your water supplier will mail you an annual Consumer Confidence Report (also called the Drinking Water Quality Report). You may also be able to find your report on the EPA’s website. The EPA offers online tools to help you learn how to read the report at its Local Drinking Water Information page. You also may find your local and state reports in the EWG’s National Drinking Water Database.

While these reports offer an analysis of your local water at its source, it’s also wise to directly test your tap water at home. Some contaminants, such as lead, could leach through pipes and household plumbing, and therefore not be detected before water enters your home. Relatively inexpensive home water-testing kits are available at hardware stores. You could also obtain professional tests on your water; the EPA recommends contacting your state certification program for a list of certified laboratories.

Step 2: Understand Water Contaminants

Drinking water contaminants come from many sources: Radon, radium and arsenic are naturally occurring, while microorganisms, pesticides and nitrates come from people, animals and industry. Here are a few contaminants to specifically watch out for (read “Water Treatment: 10 Contaminants” later in this article to learn how to eliminate these pollutants):

Chromium-6 (Hexavalent chromium): You may be familiar with this highly toxic chemical from the movie Erin Brockovich. Chromium-6 occurs naturally from the erosion of chromium deposits, but it can also be produced by industrial processes and released into the environment by poor storage or inadequate industrial waste disposal practices. In a 2010 tap water survey, the EWG found this known carcinogen in 31 of the 35 American cities tested—that’s 89 percent. While chromium-3 is an important dietary element, chromium-6 is believed to cause many serious health problems, including cancer. The EPA’s maximum level of chromium was set in 1991, but in 2008, the agency began a rigorous and comprehensive review of chromium-6 health effects based on new science. According to the EPA’s website, “when this human health assessment is finalized, the EPA will carefully review the conclusions and consider all relevant information to determine if the current chromium standards should be revised.” Read more at the EPA’s website.

Atrazine. This common herbicide is thought to potentially cause endocrine disruption, cancer and reproductive disorders. Studies have linked high levels of atrazine in the water supply to birth defects in children, and in one study male frogs exposed to atrazine transformed into fully functioning female frogs. Use of the herbicide is particularly high in the Midwest, where it’s used on crops in spring. Six states—Illinois, Indiana, Iowa, Kansas, Mississippi and Ohio—recently settled a lawsuit against Syngenta, the manufacturer of atrazine, for millions to subsidize the chemical’s removal from the public water supply. Atrazine is among the pollutants discussed in the 2012 water quality documentary Last Call at the Oasis, which features Erin Brockovich and other environmental experts.

Chlorine and chloramines. Chlorine is commonly used by municipalities to help purify the local water supply. However, chlorine can combine with organic matter in water to create chlorination by-products, which could potentially cause cancer, according to NSF International, an independent nonprofit organization that provides standards development, product certification and risk management to help protect the world’s food, water and health. Some municipalities have switched from chlorine to chloramine (a combination of chlorine and arsenic) to treat water. Although the EPA classifies both as safe at levels used in drinking water, both chlorine and chloramine are toxic at high levels and have been associated with health risks. If your local water utility uses chloramines as a disinfectant, make sure the water filtration system you use is certified specifically for chloramines, and not only chlorine, the NSF recommends.

Lead.  Lead is a highly toxic metal. If your home was built before 1986, it’s more likely to have lead pipes, fixtures and solder, according to the EPA. Even legally “lead-free” plumbing in newer homes may contain up to 8 percent lead. No amount of lead exposure is considered safe—drinking lead-contaminated water could result in physical and mental development delays in babies and children. Adults aren’t immune: Watch out for blood pressure increases and kidney problems. Because lead is more likely to enter drinking water through the corrosion of plumbing materials where water has high acidity or low mineral content, the EPA issued the Lead and Copper rule, which requires treatment systems to make drinking water less corrosive to the materials it comes into contact with on its way to consumers’ taps. You can read more about lead exposure at the EPA’s website

Step 3: Select the Best Water Filter

When shopping for a filter, you will find many “technologies,” ranging from carbon to ozone to UV. Don’t worry; the choices are surprisingly easy to navigate. A few overall tips to keep in mind: Some filters use a combination of technologies, while others use just one; any filter you use should be certified by a reputable, independent agency; and check what a filter is certified to do by reading the fine print. Some filters are certified to improve water’s taste, for example, but not to guarantee the removal of specific contaminants. To find the filter most capable of removing specific contaminants, look up the pollutant on the EWG website and find a list of filters certified to effectively remove it.

While many filter technologies exist, those most adept at removing contaminants include carbon or charcoal filtration and reverse osmosis. Carbon filters vary in effectiveness; some remove chlorine only while others remove a range of contaminants, including lead and mercury. You will find carbon filters in carbon block and granulated activated carbon varieties. In general, carbon block filters are more effective. Carbon filters cannot effectively remove many inorganic pollutants such as arsenic, fluoride or nitrate, according to the EWG.

Reverse osmosis filters are adept at removing inorganic contaminants not removed by carbon filters. You can sometimes find combination carbon/reverse osmosis filters, which remove a wide range of organic and inorganic pollutants. However, reverse osmosis filters use three to 20 times the water they produce, so limit their use to drinking and cooking water.

Other filter types you may encounter include ozone and UV (ultraviolet). These are effective at removing or killing bacteria and microorganisms but not chemical contaminants. Ion exchange filters and water softeners lower levels of calcium and magnesium but do not remove contaminants.

You will also find a number of filter styles, which range in price and complexity of installation. Options include pitcher/dispenser, faucet-mounted, faucet-integrated, on-counter, under-sink or whole-house. The best type for your home depends on your budget and the contaminants in your home’s water. Also keep in mind that a growing body of research shows that plastic can leach chemicals into liquids stored in it, so avoiding plastic water storage containers may be best for those with chemical sensitivities. The EWG offers an online “water filter buying guide”.

Letitia L. Star is a healthy living writer whose 1,100 published articles focus on environmental issues, eating well and organic gardening. 

Fluoridation: Is It Safe?

Since 1945, a fluoride compound has been added to U.S. public drinking water to prevent tooth decay. Although the American Dental Association and the Centers for Disease Control and Prevention unreservedly endorse the fluoridation of community water supplies, some groups question its safety. According to Fluoride Action Network, a project of the nonprofit organization American Environmental Health Studies Project, which “seeks to broaden public awareness about the toxicity of fluoride compounds and the health impacts of current fluoride exposures,” ingesting fluoride could result in mild or severe consequences, including impaired endocrine and brain function, and dental fluorosis—a defect in tooth enamel. In 2011, after reviewing findings of the National Academy of Sciences, the U.S. Department of Health and Human Services proposed setting the recommended fluoride level in drinking water at .07 milligrams per liter of water—the lowest end of the current optimal range. To learn about your community’s fluoridation, visit the CDC’s website and click on “My Water’s Fluoride” at the bottom of the page. For a map of U.S. communities that have rejected fluoridation, visit the Fluoride Action Network.

Water Treatment: 10 Contaminants

Below are water treatment technologies certified by NSF International. See the NSF’s full Contaminant Guide list for explanations of more than 50 contaminants.

Potential health risk (through water ingestion): skin, nervous system toxicity
Water treatment: carbon, reverse osmosis

Potential health risk: mammary gland tumors
Water treatment: carbon

Chlorine and Chlorine By-Products
Potential health risk: chlorine can create chlorination by-products, which may cause cancer
Water treatment: carbon

Potential health risk: gastrointestinal illness
Water treatment: carbon, reverse osmosis

Potential health risk: cancer, plus liver and other disorders
Water treatment: carbon, reverse osmosis

Potential health risk: dental fluorosis
Water treatment: reverse osmosis

Potential health risk: kidney and nervous system damage
Water treatment: carbon, reverse osmosis

Mercury (Inorganic)
Potential health risk: kidney and nervous system damage
Water treatment: carbon

Potential health risk: cancer
Water treatment: carbon


basic information about regulated drinking water contaminants

Safe Drinking Water Hotline
(800) 426-4791
information about drinking water programs

Community Right-to-Know Hotline
(800) 424-9346 
uses and releases of industrial chemicals in your state

Environmental Working Group
National Drinking Water Database