All Wet: How to Identify and Remove Common Water Contaminants

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Of all the elements necessary for human existence, only oxygen is more vital than water. Water carries nutrients to our cells, aids in metabolism, helps our joints move smoothly, flushes waste, replaces the moisture we lose from perspiring, and contributes to glowing skin.

Yet how healthy is water if it’s tainted? If there’s one matter on which every agency from the government on down can agree, it’s that the earth’s water supply is threatened daily by an almost endless list of contaminants.

At first glance, the dilemma is enough to make anyone run straight for the bottled water aisle. But the truth is, while the state of our drinking water may not be cause for celebration, the news isn’t all doom and gloom. “Widespread, fatal, waterborne outbreaks that were routine a century ago have largely been eliminated,” says Erik Olson, senior attorney for the Natural Resources Defense Council (NRDC). “Then, a percentage of every U.S. city’s population died from bad drinking water. Most public health experts will tell you the single greatest health achievement has been the treatment of drinking water to make it safer.”

John Millett, a spokesperson for the Environmental Protection Agency (EPA), says his agency works to ensure the nation’s water supplies remain safe. “The Safe Drinking Water Act amendments of 1996 have provided EPA with a course that reflects the latest science,” he says. “It takes into account the latest risks and benefits and has advanced drinking water safety and regulations in a way that benefits our health over the long term.”

The Safe Drinking Water Act also gave us Consumer Confidence Reports, annual statements required from every public water district detailing the level of contaminants in the water supply. Most utilities are required to mail the report to customers; smaller utilities are permitted to post the reports on a website.

Unfortunately, says Olson, it’s not enough. “What you have is Wright brothers-era technology trying to treat space-age contaminants, and it’s just not up to the task. The United States has underinvested in cleaning up water supplies during the last 100 years.”

Newer technologies are now available, including ozone filters, which super-oxygenate water to kill bacteria; ultraviolet light, which uses light instead of traditional disinfectants to kill bacteria; and reverse osmosis, which percolates water through a microfilter to remove contaminants. These are costly, however, and it will be many years before most public water supplies are effectively updated.

The good news is that options for home filtering systems are many. The bad news is, there’s a lot to filter out. Here’s a look at a few common water contaminants.

Copper and lead

When these elements are found in the water, the problem nearly always results from plumbing with brass attachments or solder-containing lead. The limit set by the EPA for lead–which has been linked to brain and nerve damage, cancer, testicular atrophy, and birth defects–is fifteen parts per billion. For copper, which in high amounts can cause liver and kidney damage, the limit is thirteen parts per million. While the source of the elements can often be found within the home, according to Water Quality Association technical director Joseph Harrison, lead and copper in the water can also be traced to the service connection on the outside of the house and may be exacerbated by the corrosive quality of the water. “Old solder is not the responsibility of the city,” says Harrison, “but the service connection and the corrosive nature of the water that causes the lead to dissolve are.”

If lead or copper is a concern, EPA’s Millett suggests: “Don’t use hot water from your tap to make coffee or formulas for children. Instead, use cold water and heat it.” Also, whenever water sits in the pipes overnight or for longer than six hours, flush out the faucet until the water becomes cold–about five to thirty seconds, he says. “Filters can be effective in removing lead or copper from the water, but be sure the system you purchase is designed to remove those contaminants,” he adds.

Methyl tertiary-butyl ether (MTBE)

MTBE has been used since the late 1970s as a fuel additive to make gas burn more efficiently. While it was initially added in low levels, concentrations became higher in the 1990s to comply with Congress’s Clean Air Act Amendments. In recent years, however, MTBE has been found in water supplies nationwide. “The trouble with MTBE,” says Harrison, “is it loves water. If you spill gas on the ground or even dribble it at a filling station, the MTBE will be attracted to rainwater and will drain with it right into the gutters or groundwater.”


Nitrates are naturally occurring chemicals commonly found in water at low levels. When levels are elevated–often because of nitrates from fertilizers leaching into the soil–they can be hazardous to young children. “Blue baby” syndrome, a blood disorder, can cause vomiting, diarrhea, difficulty in breathing, and even death in infants.

Filters aren’t typically effective in screening nitrates from the water. To find out if your water is affected, contact your local water authority for suggestions about testing (or check the National Ground Water Association’s website). If your water has concentrations of more than ten parts per million and there is a child in the house younger than four months, use only bottled water for formula and other food preparations.


Similar to MTBE, perchlorate is a rocket fuel oxidizer. According to Jessica Leibler, a spokesperson for Clean Water Action in San Francisco, companies that make rockets and/or rocket fuel have dumped the chemical into waterways. Perchlorate can cause adverse health effects by blocking the uptake of iodine by the thyroid, and scientists are trying to determine just how detrimental minute amounts of the compound in drinking water are. Fetuses, infants, and children are particularly vulnerable because thyroid hormone is essential for brain development.


Among the most significant emerging issues affecting our water is the discovery of prescription and over-the-counter drugs in the drinking supply. “Right now, an unlimited amount of pharmaceutical contaminants can stream from a tap without actually being illegal,” says the NRDC’s Olson. “We’re finding traces of drugs in streams, rivers, and lakes because most sewage treatment plants aren’t designed to filter them out. One big source is hog and chicken farms, where animals are treated with huge amounts of antibiotics,” he points out.

A U.S. Geological Survey and National Park Service study of water in Lake Mead and the Las Vegas Wash (a waterway used to transport treated wastewater from the Las Vegas metropolitan area to Lake Mead) detected thirteen compounds in water samples collected between October 2000 and August 2001. The most commonly found compounds included caffeine, carbamazepine (used to treat epilepsy), cotinine (a metabolite of nicotine), and dehydronifedipine (a metabolite of the antianginal Procardia).


In general, pesticides harm the earth and its inhabitants, but when it comes to the truly noxious, atrazine is one of the most insidious. Used primarily on corn crops, atrazine is one of the country’s most widely used pesticides. According to Susan Kegley, staff scientist with Pesticide Action Network, atrazine is particularly troublesome because it’s long lasting and highly water soluble, making it that much more likely to leach into the groundwater. Atrazine has been linked to cancer, miscarriages, stillbirths, and endocrine disruption.


When the chlorine used to disinfect the public water supply comes in contact with organic matter in the water, toxic byproducts occur. Called trihalomethanes (THMs or TTHMs), these chemicals have been linked to cancer, birth defects, and low birth rates. “One of the reasons they’re so insidious,” says Olson, “is you get a significant dosage while showering. In fact, you’re inhaling them.”

The limit for THMs was recently lowered, but Harrison says EPA standards are often set at a level above zero risk. “The EPA has said the maximum for disinfection byproducts formed when chlorine is in the water is eighty micrograms per liter,” Harrison says. “It can’t set it at zero because the agency doesn’t want to discourage cities and towns from adding chlorine, which eliminates pathogens. The lowest practical amount is eighty micrograms per liter, but anything above zero has a risk of causing cancer.”

Safe water options

For guaranteed pure drinking water, bottled water often seems like a safe bet–and generally speaking, it is. All those plastic bottles, however, are costly for the environment. Water vending machines in grocery stores allow consumers to provide their own containers, but the water comes straight from the grocery store tap. While the machines’ filters supposedly purify the water, the Environmental Working Group recently reported that two-thirds of the machines in California could not meet claims of chemical-free water. Consumers were spending 25 to 35 cents a gallon for virtually the same water that cost them half a cent at home.

So how do you ensure pure water without spending a fortune or adding to the growing mass of plastic? Easy answer: home filters.

“Point-of-use filtration is simply a better way to get healthy water,” says Kurt Weingand, Ph.D., a principal clinical scientist with P&G Health Sciences Institute, parent company of Pur water filter products. “You can get filtered water for a tenth of the cost of bottled water.”

Point-of-use systems generally use one or several filters to remove solids, chemicals, and metals. Faucet-mount systems attach to the faucet and filter any water that passes through, while pour-through systems utilize a series of filters within a carafe to purify water poured into it. Prices for faucet-mount systems range from $35 to $107; carafe systems range from $20 to $156. There are also systems that fit beneath the sink and attach to the water pipe as well as those that require an auxiliary faucet mounted on the kitchen sink.

Point-of-entry systems, attached to the water line where it enters the home, filter all the water in the house but are significantly more expensive and may require a professional to install.