Contaminants Found in Tap Water

Approximately two-thirds of your body weight is water. Your blood is 82 percent water, and both your brain and muscles are 75 percent water. The major ingredient of all fluids in the body is water. Water is the key to life, and to think that contaminants in tap water have little or no bearing on your short term and long term health picture is to ignore reality.

In 2003 the nonprofit Natural Resources Defense Council (NRDC) completed a study of the drinking water in 19 of America’s largest cities. The NRDC found that due to a combination of pollution and deteriorating equipment and pipes, the public water supplies in these cities contained contaminant levels exceeding EPA limits (either legal limits or unenforceable suggested limits) and may pose health risks to some residents.

The risks from contamination found in public and private drinking water are significant. "Exposure to the contaminants can cause a number of health problems, ranging from nausea and stomach pain to developmental problems and cancer," notes Physicians for Social Responsibility (PSR). PSR estimates that up to 900,000 people get sick and 900 die in the United States per year from contaminated public and private drinking water.

The NRDC also noted that even if public water may test fine at its source, it may still pick up contaminants on the way to your house. Contaminants that sneaked into city water supplies studied by the NRDC include rocket fuel, arsenic, lead, fecal waste, and chemical by-products created during water treatment. The NRDC also observed that while tap water can contain a vast array of contaminants, a handful of particularly harmful contaminants surfaced repeatedly in its study. Those contaminants were:

lead pathogens (germs) such as Cryptosporidium chlorination by-products, e.g. THMs and haloacetic acids

arsenic naturally occurring radioactive radon the pesticide atrazine the rocket fuel perchlorate.

Main Problems with Tap Water

Chlorine and Chloramine

Chlorine is a greenish yellow gas which combines directly with nearly all elements. It is not found in a free state in nature but is found largely in seawater where it exists as sodium chloride (NaCl). It is recovered as a reactive, corrosive, pale green chlorine gas from brine (a solution of sodium chloride in water) by electrolyis. Chlorine is a respiratory irritant. The gas irritates the mucous membranes and the liquid burns the skin. As little as 3.5 ppm (parts per million) can be detected as an odor, and 1000 ppm is likely to be fatal after a few deep breaths. It was used as a war gas in 1915.

The experimental use of chlorine to treat water began in the 1890s to combat water-borne diseases such as cholera and typhoid. The use of chlorine to treat water quickly gained wide acceptance because of low cost and high efficiency in killing just about everything hazardous in the water. Chlorine allowed population centers to spring up and thrive without any epidemic outbreaks.

The problem with chlorine, however, is that it is a known poison and the safety of drinking this poison over your lifetime is highly uncertain. Also, chlorine reacts with water-borne decaying organic matter like leaves, bark, and sediment to create a family of chemicals called trihalomethanes and other highly toxic substances. Trihalomethanes, or THMs, include chemicals such as chloroform, bromoform, and dichlorobromethane. All of these chemicals are extremely carcinogenic even in minute amounts.

“Cancer rates for people on chlorinated water systems is 93% higher than for those on non-chlorinated water systems.” ~U.S. Council on Environmental Quality

Chloramine, a chlorine/ammonia compound, is another substance now used in many larger municipalities such as Los Angeles. In systems where the level of chlorine is at the highest acceptable level but need still more disinfection, the utility will then add chloramine. Chloramine is represented as totally safe. However, utilities which use ti provide a disclaimer to not give chloramine-treated water to your animals or use it in your fish tanks (because it kills fish)!

Fluoride

Fluoride is any of a number of naturally occurring compounds derived from the element fluorine and another element. In North America, fluoride has been added to the drinking water in an effort to reduce tooth decay. The United States began adding fluoride to public water supplies during the time of World War II ostensibly to reduce cavities in children's teeth This practice has become somewhat controversial due to disagreements about side effects and long term effects.

In 1973, British Columbia was considering mandatory fluoridation. They gave the job of researching and reporting the topic to Richard Foulkes, M.D. Foulkes then wrote a 1900 page report recommending that legislation be passed to make fluoride mandatory in Canada. Based on that work, Canada began to fluoridate.

Then something happened. Little by little, Foulkes found out that the statistics that his researchers had based their findings on were largely falsified. It took Foulkes several years to uncover the truth, but by 1992, he shocked the country by backing down from his original recommendation:

"I now hold a different view. …the fluoridation of community water supplies can no longer be held to be either safe or effective in the reduction of dental caries….Therefore, the practice should be abandoned."- Foulkes, 1992

Excessive ingestion of fluoride during the early childhood years may damage the tooth-forming cells, leading to a defect in the enamel known as dental fluorosis.

Teeth impacted by fluorosis have visible discoloration, ranging from white spots to brown and black stains. Teeth with fluorosis also have an increased porosity of the enamel. In the milder forms, the porosity is mostly limited to the sub-surface enamel. In the more advanced forms, the porosity impacts the surface enamel as well, resulting in extensive pitting, chipping, fracturing, and decay of the teeth. The discoloration induced by fluorosis—particularly in its advanced forms—can cause significant embarrassment and stress to the impacted child, resulting in adverse effects on esteem, emotional health, and career success.

According to the Centers for Disease Control, 32 percent of American children now have some form of dental fluorosis, with 2 to 4 percent of children having the moderate to severe stages. (Click here for the report.)

While proponents of water fluoridation dismiss dental fluorosis as being simply a "cosmetic effect," recent research indicates that the rate of bone fracture among children with fluorosis (even in the mild forms) is higher than the bone fracture rates among children with no fluorosis.

As noted by Dr. Hardy Limeback, Head of Preventive Dentistry at the University of Toronto, "It is illogical to assume that tooth enamel is the only tissue affected by low daily doses of fluoride ingestion." In a Toronto Star interview with Michael Downey, Limeback said, "Children under three should never use fluoridated toothpaste. Or drink fluoridated water."

Biological Contaminants

Bacteria

Tap water may also contain bacteria, including pathogens (germs) such as cryptosporidium, a microscopic disease-carrying protozoan. This organism presents health concerns, especially to individuals with weakened immune systems, including HIV/AIDS patients, the frail elderly, children, and people who have undergone organ transplants or cancer chemotherapy or have certain chronic diseases.

If you are on a municipal system with chlorination or chloramine, theoretically you are protected against bacteria. However, if the level of chlorination isn't high enough from the municipal source to your tap, bacteria can re-infect the water anywhere along the distribution system. The piping system—whether it's the mains or your house plumbing—has bacterial growth in it happening all the time.

If you are on a spring or a well, with no chlorine, then you are very vulnerable to bacterial contamination. Even the most pure sources cannot prevent occasional contamination from animals either dying or defecating in the source, or from neighboring pollution (i.e. from septic tanks) traveling from an adjoining watershed to contaminate the source. Also, the pipes are again a source of bacteria.

Tests for water contaminants

Many people do periodic testing on their well or spring source and rely on this method to assure themselves that they have good water. What they don't realize is that there are a few problems with testing.

First, the test is only good for the moment the sample was taken. Bacteria can have "blooms," if the conditions are right, which potentially occur hours, days, or weeks after the testing and therefore remain undetected. Other casual contamination can occur from animal or human sources, as mentioned above, which the test never detected because the sample was taken before the contamination occurred.

Second, testing can be very expensive to do, depending on what is being tested for. Most basic tests cover bacteria such as E. coli, levels of sediment and decaying organic matter, and amount of total dissolved solids (mineral levels such as calcium, magnesium, iron, and sulfur). With any extra testing the price goes up per test. Lead, asbestos, and specific chemical contaminants are more difficult and therefore much more expensive to test for.

Cysts

This group includes microscopic worms, parasites, and protozoa. The biggest offenders are giardia and cryptosporidia which cause major diarrhea, dehydration, intestinal disorders, and even death in people with compromised immune systems. Water experts estimate that over 63 percent of water problems in the United States today are directly caused by giardia and cryptosporidia.

Cryptosporidium is three to five microns in size, and giardia is from seven to fourteen microns. When the environment becomes inhospitable (like the presence of chlorine or the absence of water), both parasites can go into the cystic form (like a hard, round impermeable microscopic egg). The cyst form is chlorine resistant and very hard to kill.

Municipal utilities are unable to completely remove these cysts. Cysts have been found in most major municipal water systems in the United States. Milwaukee, Wisconsin had a huge outbreak of cryptosporidia in 1993 that killed over 100 people. San Francisco, California has repeatedly tested positive for giardia in its chlorinated water that traveled hundreds of miles from the Sierras.

Heavy Metal Contaminants

Lead

Lead is a cumulative toxin that stays in the tissue permanently, especially in brain tissue. Lead will cause permanent brain damage and decreased intelligence in infants and children. It affects a person in relation to their body weight. Therefore, an exposed adult can fend off the toxic effects for some time but in children, brain and developmental damage occur quickly and permanently.

Lead pipes and lead solder in the distribution system are the main sources of lead pollution as enters drinking water supplies from the corrosion of pipes or faucets. The Boston Globe estimates that 98 percent of all households have lead in their plumbing. Houses older than twenty years and less than five years are most at risk. Also, houses in areas of soft (low mineral levels) water tend to corrode the lead from the pipes more easily.

Arsenic

Arsenic is a toxic element that in water is colorless, odorless, and tasteless. Arsenic finds its way into public water from mining and industrial processes or natural processes. The only way to identify its presence in water is to have the water specifically tested for arsenic.

Arsenic can increase the likelihood of health problems in people who drink water contaminated with it. Arsenic is a known human carcinogen that causes cancer of the skin, bladder, lungs, kidneys, and liver. It also causes increased risk of cardiovascular disease, peripheral neuropathy, skin hyperpigmentation, and diabetes. Major exposure occurs when drinking or cooking with contaminated water. Additional exposure may occur when showering, bathing, and brushing teeth.

The United States Environmental Protection Agency (EPA) has the arsenic limit set for drinking water at 10 ppb (parts per billion). That standard became effective in 2006.

According to National Academy of Sciences estimates, one out of 333 people who drink water containing 10 parts per billion will get cancer (based on drinking two liters of water per day over the course of a lifetime). That's an extremely high cancer risk. The EPA, which sets the arsenic standard, normally assigns standards for toxins and contaminants that represent no more than a one-in-10,000 risk factor for cancer.

While arsenic levels in drinking water may fluctuate over time, what is most significant from the standpoint of cancer risk is long-term exposure.

Chemical Pollution

Industrial and Commercial

Chemicals are, for the most part, odorless, colorless, and tasteless—and therefore undetectable. Chlorine is the most predominant chemical in our water. Some of the most dangerous chemicals are present only in trace amounts (parts per billion), but they are highly toxic even at these minute levels. Sources are usually industrial or commercial, like leaking underground storage tanks for gasoline or industrial solvents such as trichloroethane (TCE). These leaking toxins end up in the groundwater or in the municipal supply through breaks or cracks in the main water pipes. The biggest family of these toxics are volatile organic contaminants (VOCs), including various plastics, gasolines, and petroleum products. The rocket fuel perchlorate is present in the water supplies of more than 10 million Americans.

Herbicides and Pesticides

Next is the herbicidal group such as dioxin (2-4D) and lindane, used as a defoliant in modern logging operation and found in many wild and rural areas. Along with the herbicides comes the pesticidal group such as dichlorodiphenyltrichloroethane (DDT), malathione, and other toxics used in insect eradication and control. The pesticide atrazine affects the water of more than 1 million Americans,

DDT is probably the most notorious pesticide. It is a colorless chemical pesticide which was used to eradicate disease-carrying and crop-eating insects. It was first isolated in Germany in 1874, but not until 1939 did the Swiss Nobel Prize-winning chemist Paul Müller recognize it as a potent nerve poison on insects. First used heavily in World War II for preinvasion spraying, DDT was disseminated in great quantities thereafter throughout the world to combat yellow fever, typhus, elephantiasis, and other insect-vectored diseases. In India, DDT reduced malaria from 75 million cases to fewer than 5 million cases in a decade. Crops and livestock sprayed with DDT sometimes as much as doubled their yields. DDT was believed to be harmless to humans, and before its dangers became known, crops and people alike were sprayed with the chemical to protect against bothersome insects. The EPA banned DDT in the United States in 1973 because it considered DDT a potential human cancer risk based on the results of animal studies.

Herbicides and pesticides that are used to kill unwanted animals and plants, for instance on farms or in suburban yards, may be collected by rainwater runoff and carried into streams, especially if these substances are applied too lavishly. Some of these chemicals are biodegradable and quickly decay into harmless or less harmful forms, while others are nonbiodegradable and remain dangerous for a long time.

Many drinking water supplies are contaminated with pesticides from widespread agricultural use. More than 14 million Americans drink water contaminated with pesticides, and the EPA estimates that 10 percent of wells contain pesticides. Nitrates, a pollutant often derived from fertilizer runoff, can cause methemoglobinemia in infants, a potentially lethal form of anemia that is also called blue baby syndrome.

Other Chemicals

Also, the THMs mentioned before are a big pollutant because of the amount of chlorination used nationwide. They are a separate class of chemical from chlorine itself. By-products of the chlorination process such as trihalomethanes and haloacetic acids may cause cancer and, potentially, reproductive problems and miscarriage. Polychlorinated biphenyls (PCBs), a class of chemicals once widely used in electrical equipment such as transformers, can get into the environment through oil spills and can reach toxic levels as organisms eat one another. Long term exposure to PCBs by people has been associated with a wide variety of health problems including some types of cancer, impaired intelligence, and problems with the physical development and behavior in young children. The Fox River in Northeast Wisconsin has a significant PCB problem caused by pulp and paper mills along its banks releasing PCBs into the river even though the practise was halted in the early 1970s.

These chemical wastes are hazardous because they are either toxic (poisonous), reactive (capable of producing explosive or toxic gases), corrosive (capable of corroding steel), or ignitable (flammable). If improperly treated or stored, hazardous wastes can pollute water supplies.

In June 23, 1969 the Cuyahoga River in Cleveland, Ohio, was so polluted with hazardous wastes that it caught fire and burned. Flames climbed as high as five stories until fireboats brought it under control. The fire was attributed to wastes dumped into the river by the waterfront industries. Cleveland at the time was not particularly impressed. The Chief of Police was not called. The regular crew, which was always dispersing oil slicks and watching for river fires, had it under control in under half an hour. The only picture (left), taken after the fire was pretty much out, ran in two local papers the next day, but the only story was brief and buried.

Jonathan H. Adler: Burning rivers in industrialized areas were common through the late 19th and early 20th century. Rivers and harbors once burned in Michigan, New York, Maryland, and Pennsylvania, among other states. The Cuyahoga's first reported conflagration happened well over a century ago. ... Over time, the fire hazard became great enough to threaten local shipping. Oil and debris on the river caught fire at least a half-dozen times before 1950, often causing substantial damage to docks, ships, and other industrial properties along the crooked river's banks.

Asbestos

Asbestos is another potential carcinogen that can come either from water with naturally occurring asbestos (such as in areas that have a lot of serpentine rock) or from asbestos-lined water pipes. Thousands of miles of these pipes were laid throughout the United States in the 1950s and have yet to be replaced.

Asbestos is so small that it is unfeasible to remove it at the water treatment plant. To build such a removal facility is prohibitively expensive and would clog up the plant within five years of being in operation.

Check out your city's tapwater from the Environmental Working Group. For more information, click here.

Select your state:

Or enter your 5-digit ZIP code:

    

Or search for a City, State:

    select ... Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware Washington, DC Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming

EPA—Generally Low Standards

Overall, the NRDC’s study revealed a relatively small number of cities in outright violation of national standards. This fact does not imply low contaminant levels, but rather weak standards. In short, the EPA has written most standards in a way that most cities will not be in violation. For example, recent studies show that there is no safe level of cancer-causing arsenic in drinking water. Nonetheless, today’s standard, put in place in 2006, is 10 parts per billion (ppb). The EPA found that 3 ppb was a feasible standard, but the agency set the standard at 10 ppb because of concerns about treatment costs to water utilities.

Prior to 2006, the standard had been at 50 ppb. That standard had been established in 1942 when arsenic was unknown as a carcinogen. In the last days of the Clinton Administration, the EPA proposed the standard of 10 ppb, and the Bush Administration attempted to thwart the implementation of the new standard. However, in September of 2006, the National Academy of Sciences (NAS) advised that arsenic was even more dangerous than they had originally thought. The NAS found that at the 10 ppb EPA standard, the lifetime fatal cancer risk is about 1 in 333—more than 30 times higher than what the EPA says is usually the highest acceptable risk. Nonetheless, arsenic is still present in the drinking water of 22 million Americans, hovering at average levels of 5 ppb—half the new national standard.

Arsenic has been found in Nature since Antiquity. Aristotle makes reference to sandarach (arsenic trisulfide) in the 4th century B.C. In the 1st century A.D., Pliny stated that sandarach is found in gold and silver mines and arsenic (arsenic trioxide) is composed of the same matter as sandarach. By the 11th century three species of arsenic were known, the white, yellow and red—since then recognized as arsenic trioxide, arsenic trisulfide (orpiment) and arsenic disulfide (realgar), respectively. Albertus Magnus is reputed in the 13th century to be the discoverer of metallic arsenic. However, his documentation is considered vague. It was not until 1649 that J. Schroder clearly reported the preparation of metallic arsenic by reducing arsenic trioxide with charcoal. Thirty-four years later, N. Lemery also observed that metallic arsenic was produced by heating arsenic trioxide with soap and potash. By the 18th century the properties of metallic arsenic were sufficiently known to classify it as semimetal.

The table below shows the lifetime risks of dying of cancer from arsenic in tap water, based on the risk estimates in the 1999 report Arsenic in Drinking Water by the National Academy of Sciences. In September 2001, the NAS updated the report and concluded that even these estimates were too low.

Arsenic Level in Tap Water (in parts per billion, or ppb)	Approximate Total Cancer Risk (assuming 2 liters consumed/day)
0.5 ppb	1 in 10,000
1 ppb	1 in 5,000
3 ppb	1 in 1,667
4 ppb	1 in 1,250
5 ppb	1 in 1,000
10 ppb	1 in 500
20 ppb	1 in 250
25 ppb	1 in 200
50 ppb	1 in 100

Finally, NRDC’s study revealed an increase in the frequency of periodic spikes in contamination in many cities, indicating that aging equipment and infrastructure may be inadequate to handle today’s contaminant loads or spills. On occasion, these risks were substantial. For example, in Washington, D.C., levels of trihalomethanes— which potentially cause cancer, birth defects, and miscarriages—peaked at more than double the EPA standard. (It is noteworthy that while Washington, D.C., recently changed its treatment to mitigate such spikes, many other cities continue to suffer from them.) With most EPA chemical standards (such as arsenic, haloacetic acids, and trihalomethanes), a spike above the EPA standard does not trigger a violation. Only an average level over the standard is considered a violation. In recent years, Atlanta, Baltimore, and Washington, D.C., issued boil-water alerts as a result of turbidity peaks or other problems. While aggressive action in each city significantly lowered those levels, spikes in contaminants may pose immediate health problems to particularly susceptible people.

Vulnerable Consumers

For people who have immediate concerns about tap water safety, NRDC adopted the EPA recommendations as follows: people with serious immune system problems (such as people on cancer chemotherapy or people with HIV/AIDS) should consult with their health-care providers about drinking tap water in order to avoid the risk of infection from contaminated water. Pregnant women and infants may also be at special risk from certain contaminants common in many cities’ tap water, like lead and chlorine by-products.

It's up to us to take personal responsibility to safeguard the water we use to drink and prepare our food. That responsibility starts at at the tap. According to the NRDC, removing all contaminants just before consuming the water is the most logical, efficient and economical solution to the problem of contamination. In this manner, there is no possibility for re-contamination, from a holding tank for example, after purifying the water.