17 Things You Need to Know About Your Tap Water

When you turn on your faucet to fill a spaghetti pot or sippy cup, do you know what's actually coming out? We got experts to reveal the dangerous contaminants hiding in your tap water—and how to know if your house has a problem.

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The "Erin Brockovich" carcinogen is back in the news


Remember that carcinogenic chemical Erin Brockovich exposed in the drinking water of Hinkley, California, back in the 1990s? (It was featured in the movie of the same name, starring Julia Roberts.) It's called chromium-6, and a recent analysis of federal drinking water data by the Environmental Working Group (EWG), found an unsettling amount of it in sinks across the country. "In the tap water of at least 200 million Americans in all 50 states, chromium-6 has been detected above the minimal risk level," says David Andrews, PhD, an EWG senior scientist. "By and large it can be found in most water at varying concentrations, yet there's no federal drinking water regulation to keep it in check." Although chromium-6 can occur naturally, it is also an industrial chemical with a wide variety of uses. If you want to know if chromium-6 was found in your area's water, check this interactive map compiled by the EWG.

Teflon chemicals could mean trouble


Other unregulated contaminants on the EWG's radar are two "perfluorinated" chemicals long used in many consumer products: PFOA, formerly used to manufacture Teflon, and PFOS, formerly a Scotchgard ingredient. A 2016 EWG analysis of drinking water data from the U.S. Environmental Protection Agency (EPA) found that the water supplies of over 5.2 million homes could be contaminated with these chemicals—which have been linked to developmental and reproductive health problems—at levels higher than those considered safe by the EPA.

Metals, like lead, can lurk in water


Lead is a natural chemical element not generally found in the rivers and lakes that supply a water system. But it can sneak into your water supply via the plumbing—including the pipes that connect homes to water mains as well as the solder, pipes, and fittings, according to the EPA. They recommend that if you have a lead service line, you contact your local water supplier to determine if your H20 should be tested. Some areas of the country also have site-specific problems, adds Raymond M. Hozalski, a professor in the department of Civil, Environmental, and Geo- Engineering at the University of Minnesota. For example, the toxic metal arsenic has been found in groundwater supplies in some parts of Western Minnesota, where treatment options are available to remedy it.

Bacteria, like legionella, can breed in water


"We've seen an increase nationwide in cases of legionella over the last 10 years or so, and there is evidence that it can be transmitted via water supplies," says Hozalski, who explains that the exposure is not through drinking affected water but through showering and breathing in aerosols containing these bacteria. But, he points out, not everyone need be alarmed. "The main concern is for people who are immunocompromised—those with AIDS or lung conditions or those who are undergoing chemotherapy have a higher risk of developing Legionnaires' disease," he says. "Healthy people may just get a flu-like illness called Pontiac fever that goes away after a few days." Homeowners concerned about legionella could increase their hot water heater temperature; setting it to about 122 Fahrenheit could help inactivate the bacteria, according to Dr. Hozalski. But of course cranking up the dial means potential for scalding, especially in households with children, in which case you could have a plumber install a thermostatic mixing valve, which lessens the risk of burns. Otherwise, this is the healthiest temperature for your shower.

Your showerhead could harbor bad gunk


It's easy for bacteria to build up in your showerhead and hose. "I'm at a conference right now where people are cutting open shower hoses and finding all kinds of slime and bacterial growth," says Dr. Hozalski, who adds that changing or cleaning your showerhead periodically can reduce this accumulation. "You could also just let the water run for a few minutes before your shower to clear things out," he adds. (Don't miss the other ways you're probably cleaning your bathroom wrong.)

Flushed pharmaceuticals make it back to the tap


For many years, we've disposed of unused pills by flushing them down the toilet, so it's little surprise that pharmaceuticals are showing up in our water supplies today. "Trace amounts can be detected in lakes and rivers around the country," Dr. Hozalski says. "Ordinarily some are removed as water goes through treatments plants, so the levels coming out of the tap are usually barely detectable, if at all." However some plants aren't designed to remove traces of old drugs, in part because the levels are so low that sophisticated technology would be needed to detect them. "Some people say, 'Oh no, there are birth control pills or antibiotics in my tap water!' And yes, if you really look hard enough you could find extremely low levels on occasion, but I would say the potential health risks are probably negligible," Dr. Hozalski adds. If you have old prescriptions to toss, check with your township about proper disposal—some require that you bring them to a Household Hazardous Waste site.

Discolored fixtures could mean a call to the water company


Homeowners with a private well might see discoloration forming in their plumbing fixtures, which comes from iron or manganese in the water that's oxidizing. "Ordinarily, especially for well water, it doesn't indicate any health risk," says Dr. Hozalski. However, if you have water coming from a municipality, such discoloration would be highly unusual because plants should be removing those elements. "So if your white toilets are turning orange, I would call the water utility and find out what's going. Discoloration from iron and manganese isn't directly a health risk—more of an aesthetic issue—but it does suggest that the water utility isn't doing its job."

Your local utility can send a water report


Fortunately there's an easy way to find out if these contaminants are in your water. If your H20 comes from a public water system, contact your local water supplier and ask for their "Consumer Confidence Report," also known as an "Annual Water Quality Report," which are usually sent to residents annually, according to the EPA. This report details the regulated chemicals, bacteria, and microbes that may be in your water and whether the system meets government drinking water standards. If you have a private well, the EPA recommends regularly testing it for nitrates, total coliforms (for example, bacteria), and any particular contaminants known to be in their watershed. Your local health department might test well water free of charge, adds the EPA, or you could contact a State Certification Officer for a list of water testing labs.

Fluoride is fine


Fluoride, a natural mineral that's present to some degree in almost all water, has been proven to protect against tooth decay by rebuilding and strengthening enamel. But these naturally occurring levels usually aren't enough to boost our dental health, according to the Centers for Disease Control and Prevention, which is why state and local municipalities may add fluoride to drinking water to help keep teeth strong. "Community water fluoridation has been identified as the most cost-effective method of delivering fluoride to all, reducing tooth decay by 25 percent in children and adults," according to the CDC. While there's been some controversy surrounding such community water fluoridation, Dr. Hozalski assures us that the negative effects are nil. "At the levels that fluoride is added, the health risks are basically non-existent, and because of the benefits for dental health, especially for kids, I think it's a good thing," he says.

Chlorine cuts back on bacteria


Water coming into a treatment plant carries a range of pollutants, including pathogenic bacteria from sources including septic systems and animal runoff. One of the chemicals used to clean it up is chlorine, which is added at levels low enough to kill germs but not high enough to make the water unsafe to drink. "Chlorine helps protect against acute gastrointestinal illness and exposure to pathogens," Dr. Hozalski says, "so this disinfection is very important."

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