Now Reading
What’s in Your Water?



— July 15, 2017

What’s in Your Water?

  • It may look clean, but appearances can be deceiving

For most Americans most of the time, water is just something that comes from the tap—you don’t have to think twice about it. But tap water isn’t always as pure as it seems. “The biggest problem with drinking water in America is that safe water is not being provided to everyone,” says David Andrews, Ph.D., senior scientist at the Environmental Working Group ( “The infrastructure that delivers drinking water and the regulations that ensure water is safe are completely outdated. Unregulated contaminants such as perchlorate, PFOA, hexavalent chromium and 1,4-dioxane can be found in worrisome concentrations.” And those aren’t the only possible contaminants.

It’s in toothpaste. Fluoride has been controversial since the 1940s when it was introduced into water supplies as a way to reduce cavities in children. Public health authorities support it but dissenters say it is a form of mass-medication. What’s more, fluoridated toothpaste has been on the scene since 1955. The Fluoride Action Network ( says high levels of fluoride have been linked to osteoporosis, thyroid disorders and impaired brain development in children.

The bad ‘organic.’ Volatile organic compounds, or VOCs, are compounds that can easily vaporize or turn into gas from water. The EPA says VOCs are present in roughly one-fifth of the nation’s water supplies. They can enter groundwater from petroleum spills, chemical leaks or the dumping of solvents or cleaners. (The EPA lists VOCs and their possible long-term health effects at national-primary-drinking-water-regulations#Organic)

Poolside problem. If your water smells like a hotel pool, most likely chlorine is present. Chlorine is used in sewage and sanitation plants and is added to tap water to prevent bacteria growth. But it also produces hydrochloric acid in your gut and can damage healthy cells, as well as impair memory and balance.

Lead spread. Lead from corroded water lines entered the homes of Flint, Michigan, residents after the city switched water sources from Lake Huron to the Flint River in 2014. A class-action lawsuit states that Michigan’s Department of Environmental Quality improperly treated the water, resulting in child health problems including delayed puberty, learning disabilities, brain damage, and premature births. Older homes are more likely to have lead in the plumbing. If you live in a home that was built before 1986, you should consider installing a filter that removes lead.

They’re alive! The EPA includes bacteria and virus levels in its Maximum Contaminant Levels regulations. Polioviruses and enteroviruses can be ingested with drinking water and live in the intestines. Legionella, E. coli and H. pylori are some of the bacteria that may be present in untreated water; water may also carry the Giardia protozoan parasite. Giardia and bacteria can cause cramps, diarrhea or nausea, and young children or the elderly are at risk for more serious illness.

Arsenic, but not old lace: Cue the old-movie music: This deadly poison might be lurking in your water tap. How? Arsenic naturally occurs in soil. It may also be left after orchard spraying and coal ash dumping, and lurks in pressure-treated wood— and can leach from any of these sources into your water system. (Don’t toss woodstove ashes in the yard or build raised garden beds with treated wood.)

Raising internal havoc. A Harvard study published in Environmental Science and Technology Letters found high levels of polyfluoroalkyl and perfluoroalkyl substances (PFASs) in water supplies across the US. PFASs have been found in food wrappers, cookware, and other commercial products, and have been linked to disruption of hormones as well as obesity and cancer.

Over a Barrel
Rainwater is free, of course. But before you start the rain dance and set up the collection tanks, check; some states have strict requirements for rainwater collection (for instance, Oregon only allows rainwater collection from rooftops). On the other hand, California is one of several states that offer tax credits for certain types of water collection systems, including rain barrels. Rainwater is not as pure as you think; pollutants such as asbestos, lead, dust and living organisms can enter your collection system. A large portion of roof contaminants are rinsed off during the first minutes of a strong rainfall, so a first-flush diverter could keep the water collection tank cleaner. One type of diverter redirects a certain amount of water away from the tank, and a second type begins to fill the tank only after the rate of rainfall reaches a certain point. But rainwater should always be tested and filtered accordingly. One safe-rainwater system has been developed in Israel, where a Jerusalemite science teacher, Amir Yechieli, created a system that uses gravity to remove impurities from the rainwater that falls on roofs. Water is collected in opaque tanks (algae can only form if water is exposed to sunlight), allowed to settle and passed through carbon filters so the water is drinkable. More than 140 schools in Israel use the system, and Yechieli helped install systems at three California schools in 2016.

What’s in Your Water?

You can call your local water utility company and ask them to send you a Consumer Confidence Report. “There is a difference between what is legal and what is safe, and attention should be given to contaminants detected above health-based values,” Andrews explains. “Often utilities will only list the federal legal standard, but it would be most helpful to compare the levels detected to the public health goal values published in California.” You can also check out the EWG’s Tap Water Database and Water Filter Buying Guide at whats-in-yourwater.php.

Fighting Contamination with Filtration

You could lug home cases of bottled water, although at least one major study, commissioned by the World Wildlife Fund, says it is no better for you. A smarter strategy is to filter the stuff from the tap. Your filtration options include: Carbon. Granulated activated carbon usually will remove chlorine and sediment, and improve the taste and odor of water. Some filters will remove asbestos, lead, VOCs and other pollutants, but not arsenic, fluoride and other common contaminants. Carbon “block” or compressed carbon filters are usually more effective than granulated activated carbon filters. Ceramic. Water is poured into one side of a ceramic holder that has a filter with tiny holes throughout. Sediment and larger particles are captured, and the cleaner water is allowed to pass through to the holding section of the container.

LA Ups Its Game
The City of Angels needs to quench the thirst of 4 billion people in less than 500 square miles. That’s more than 450 million gallons of water per day. The LA Department of Water and Power looked to UV treatment as a cost-effective and more planet-friendly option. Ultraviolet (UV) rays destroy pathogens in water by destroying the DNA of the microorganisms. The treatment doesn’t affect the color, taste or smell of the water, and it doesn’t zap chemicals. So LADWP uses a combination of treatments including those utilizing ozone and chlorine, ensuring that LA residents won’t be ingesting pollutants such as lead, trihalomethane, chromium-6 and pharmaceutical drugs.

Deionization. Using a process called electrolysis, water passes over electrically charged plates and is separated into acidic and alkaline streams of moisture. This process does not remove organic compounds or other non-ionic particles such as VOCs. The resulting low-acid water is softer and better for skin and hair. Ion exchange. In this process, contaminants are exchanged with other not-so-bad materials. Water softeners use this method, swapping calcium and magnesium levels with sodium. It isn’t advisable for people or animals to drink water treated with a softening system, nor to water plants with it. Distillers. Distilled water systems boil water and condense the steam into a clean tank or container. This removes contaminants such as fluoride, asbestos, arsenic and heavy metals. Reverse Osmosis. Osmosis occurs when a weaker saline solution moves toward a stronger saline solution. Reverse osmosis (RO) uses energy to push the stronger solution through a membrane that catches larger particles, salts, bacteria, and materials including arsenic, asbestos and fluoride and allows pure water to flow through. Because RO filters use more water than they produce, they are usually used for drinking and cooking water. UV. Ultraviolet light water treatment systems are fairly new to the market, offering a greener solution to chlorination. UV systems protect against organisms that may be resistant to chlorine, such as Giardia and Cryptosporidium. However, it is ineffective against heavy metals, petroleum, drugs, and other pollutants. Possible filtration delivery systems include: Pitcher. The most inexpensive method, pitcher filters require no installation and the filters are easily replaced. Filters, which typically use activated charcoal, need to be replaced regularly and filtering is slow. Faucet-mounted or -integrated. These filters mount on standard faucets, and the user can switch from tap to filtered water with a lever. The filtering rate can affect water flow and may not fit all faucets. Filter changes can be frequent depending on water quality. Faucet-integrated models may require plumbing knowledge. Countertop or floor-standing. These models, which may require manual filling, use gravity flow to filter water, with a valve or tap at the bottom. Some gravity-flow filters use solid carbon filters to remove bacteria, herbicides, pesticides, and VOCs. An additional filter may be available to remove fluoride or other pollutants. Under-sink. These models are connected to the plumbing lines and sometimes have a separate tap to dispense filtered water. Whole-house. These models are best for filtering all water used inside the house.

May I Pour You Some Fog?
The Stenocara beetle of southern Africa’s Namib Desert lives in one of the driest places in the world—less than a half-inch of rain per year—so water-collecting requires creativity. Its back and forewings are covered with hydrophilic (water-attracting) bumps and hydrophobic (water-repelling) grooves. The beetle positions itself with its rear end up, creating the largest surface possible to attract moisture from the light fog that drifts across the desert in the early morning. Droplets form and run off the bumps and collect in the grooves, and are channeled directly into the beetle’s mouth. Inspired by the desert beetle, The NBD Nano team came up with a design in 2012, which never made it to production, for a self-filling water bottle that drew moisture from the air. Scientists at the University of Sydney have created a synthetic material consisting of a hydrophilic layer and a hydrophobic layer; the goal is to eventually use it to coat the roofs of homes and direct condensation into a holding tank. Teams at MIT and University of California, Berkeley, have created a solar “box” that can collect water from the air, heat it to a vapor using the sun and converting it to liquid with a condenser, potentially providing clean drinking water to desert communities. And researchers at Virginia Polytechnic Institute have come up with an idea that might help pilots in cold weather: They realized that if they mimicked the beetle’s control of dew droplets, they could possibly prevent frost buildup on airplanes.

© Copyright 2019 Discover Life Magazine. All rights reserved.