Drinking Water Concerns
Are there reasons to be concerned about the 
safety of your drinking water

High quality water is more than the dream of the conservationists, more than a
political slogan; high quality water, in the right quantity at the right place
at the right time, is essential to health, recreation, and economic growth.
Edmund S. Muskie, U.S. Senator; speech, March 1, 1966

Introduction To Water Quality:
Water has been called the universal solvent because so many substances will dissolve in it. Water also can carry many materials in suspension. Unfortunately, water is not particularly selective in which compounds become dissolved or suspended. The water that dissolves your coffee or tea and sugar in the morning or that you use to reconstitute your orange juice or infant's formula might also have dissolved some atoms of lead from the pipes in your home or picked up a microgram of 2,4 D from the farm upstream from the filtration plant. If your water is chlorinated it almost certainly contains a few micrograms of chloroform (a byproduct of the disinfection process).

The question you need to ask is not, "does my tap water contain contaminants" - all water outside of laboratory distilled, deionized water does. The real questions are, "what are the contaminates in my water, what are their concentration levels, and do they pose short or long term health risks at those levels."

Finding answers to these questions is not easy. The answers depend on where you live (country, city, surrounding land use, etc.), the primary source of your drinking water (confined or unconfined aquifer or surface water), your water supplier (private or community well, small or large municipal water system), and what is happening at any moment as your water travels from its source through the treatment/distribution system to your faucet.

Water that is reasonably contaminant free (and safe) one moment can become dangerously contaminated the next because of accident, neglect, or some natural event.  One of the most notorious recent examples of water that was safe one day and dangerous the next was during the summer of 1993 in Milwaukee when one-fourth of the people living in the metro area (over 400,000) became ill with cryptosporidiosis (discussed below). According to the 1996 Houston Chronicle series, Tapwater at Risk , the contamination of Milwaukee's water supply was a combination of natural events (heavy rains) and accident (improperly installed monitoring equipment) that allowed the parasite to pass though the city's purification system and into the distribution system. In August of 1998 the citizens of Sydney Australia were told that Cryptosporidia had been detected in their municipal water supply. There are over a month of stories detailing the contamination of Sydney's water supply archived on The website of Professor Haas at Drexel University (Professor Haas also maintains a collection point for information on outbreaks of infectious disease in drinking water all over the world). Fortunately, despite a two-day delay in informing the population, there were apparently no reported cases of death or illness linked to the contamination.

Most government entities and water providers are extremely interested in supplying safe water to their citizens and/or customers. Consequently, barring accidents, the majority of dangerous contaminants that are liable to be in the drinking water of most Americans (and people from other developed countries) are typically present in minute amounts. They may contribute to health problems only after many years of exposure, making identification of the cause difficult, if not impossible. Examples of this type of contaminant are lead (that is usually dissolved out of distribution pipes or plumbing fixtures in the home) which causes intellectual deficits in children, and trihalomethanes (a byproducts of chlorine disinfection) that have been linked to a slight, but significant, increase in the chance of getting certain cancers after 20 - 50 years of drinking chlorinated water. I have collected a list of sites that focus on water safety regulations in the U.S.

Water treatment is not a simple issue.  It is, rather, a delicate balancing act. There is an ongoing and vigorous debate among the various groups interested in drinking water safety concerning the costs, the benefits, and the risks of every aspect of the water treatment and distribution business. Anything that is done to treat municipal water costs money, provides the benefit of water that has reduced levels of the targeted contaminants, and decreases risk of disease from the targeted contaminants. The treatment process may also add substances to the water that would increases risks of other disease for the people who drink the water. You can view a list of sites that discuss these issues, or read about a situation in Peru where the risks of water treatment vs. the risks of no treatment were misjudged with disastrous results.  Another good article.

I suspect that in your reading you will find that in the United States and other countries, there are many committed people who are doing  a good job to ensure that the water delivered to your home is safe for drinking.  These are scientists who are trying to figure out the effects of various chemicals and pathogens on the human body or discover better treatment technologies, government regulators who try to identify, monitor, and regulate the amount of certain contaminants allowed in water, and professionals in the water industry who strive to deliver safe, quality water to their customers.

You will also discover that 'the system' does not always work.  Accidents happen, mistakes are made, systems wear out, toxic chemicals are released into the environment to find their way into the surface and ground water, regulators fail to regulate, population growth in a region puts more stress on a water system than it can handle, and any number of other weak links in the chain of processes that must function properly to deliver safe water to your faucet.  

The web sites concerning general water quality issues are a good place to begin your research. The top couple of references contain a wealth of information.

So, are there reasons to be concerned about your drinking water safety?  Your answer to that question must depend on the results of your own research. The site links listed below and information in the other pages at this site contain a tremendous amount of information on water quality. You might also want to contact your water provider and obtain a "Treated Water Quality Summary Report" (The Water Quality Report from Denver Water is a good example of what to request - note: to view the actual contaminant levels, Select the report for 2001 and click on " Roundup" or "Tables" at the very bottom of the page ). If you use well water you should have your water tested periodically to make certain that it is contaminant free.

From everything I have read, people in the US who have the most reasons to be concerned about their water are those served by small water treatment plants - particularly in agricultural regions of the country or areas with a number of industrial plants.  Also, anyone using water from a shallow well should keep a close eye on their water's quality - again, the most common areas of concern would be in agricultural or industrial areas.  This is, of course, not to say that all small water treatment plants or shallow wells will have contaminated water. Nor does it mean that all water from large municipal treatment plants or deep wells will be contaminant free.  The Environmental Protection Agency's Safe drinking water Query Form will allow you to locate your drinking water supplier and view its violations and enforcement history since 1993.

Am I concerned about the safety of my tap water?  Concerned, yes --- Panicked, no. I live in Denver, Colorado, and my family and I use municipal water supplied by Denver Water. The taste of their water is excellent (hardly a taste of residual chlorine) and all of the harmful chemicals for which they test fall well below the Environmental Protection Agency Maximum Contaminant Level (or MCL) (most are below the levels of detection). Despite the good taste and safe test results of our water, my research into drinking water issues convinced me to purchase a high quality water filter for the following reasons:

• I do not like the idea of me or my family drinking even a little bit of chloroform on a daily daily basis over the course of a lifetime (the chlorination of Denver water produces between 8 and 53 micrograms of chloroform per liter of water - these levels are produced by nearly any treatment facility that adds chlorine disinfectant to surface water);
• We live in an old home and I am concerned about lead in the pipe solder and plumbing fixtures possibly leaching into the water;
• I want to ensure the safety of my family in the event of some accident in the water purification/distribution system;
• Even good quality chlorinated water tastes much better with the residual chlorine removed; and
• I figured that with contaminants constantly increasing in our environment, removing one of the potential sources of harmful chemicals or disease causing organisms was something positive that I could do very easily for my family. The information that I have read about possible effects of contaminants on children and pregnancy was particularly sobering.

Children and the Risks of Contaminated Water:
The following excerpt from a report entitled Just Add Water from the Environmental Working Group by Brian A. Cohen, Richard Wiles, Erik D. Olson, and Chris Campbell, should help families recognize the importance of drinking pure, contaminant free water.

• Drinking water standards have many other shortcomings beyond their failure to regulate common drinking water contaminants such as radon, Cryptosporidium and pesticides like cyanazine. One of the most serious is the fact that most current federal drinking water standards do not make any specific accommodation for the special risks and heavy consumption of water by infants and young children.
  
• One-year-olds drink more than twice as much water relative to their size as adults. Measured in terms of total fluid intake, an adult would have to drink 35 cans of soda per day to match the drinking habits of the average one-year-old. Because of this, infants and young children are exposed to more water-borne contaminants, relative to their size, than adults. (emphasis mine) This higher exposure combined with the increased vulnerability of infants to many chemical and microbiological contaminants, means infants and young children face increased risks from virtually all contaminants in drinking water, and that current standards almost always do not provide adequate protections for this vulnerable portion of the population.
  
• In October of 1995, the EPA announced a new policy to protect infants and children from exposure to toxic substances. At that time, EPA Administrator Carol Browner noted that the policy:
  "...will, for the first time, ensure that we consistently and explicitly evaluate environmental health risks of infants and children in all risk assessments, risk characterizations, and environmental and public health standards that we set for the nation." (EPA 1995)
  
• In justifying the need for this new policy the EPA cited two National Academy of Sciences studies (NRC 1993, NRC 1994) that called for major policy changes at the EPA to integrate explicit protections for children when evaluating health risks from environmental contaminants.
  
• To date, just two (lead and nitrate) of the more than eighty drinking water standards have been set explicitly to protect infants and children from immediate or long term health risk. No standards have been modified since the EPA policy was announced.
  
• Similarly, drinking water standards do not account for multiple contaminants in a single glass of water. Instead, they are set as though people are exposed to one contaminant at a time, which very often is not the case.

(End of excerpt)

Risks to Children*:     National Resources Defense Council - Our Children At Risk     EPA - Children’s Environmental Health, Children and Drinking Water Standards,                  Contaminants to Which Children May Be Particularly Sensitive  Several contaminants are of particular concern to children: Lead - Discussed in detail here. Nitrates - A common pollutant in water in the Midwest or other agricultural regions.  High levels of     nitrites or nitrates in the water supply can interfere with infants' ability to absorb oxygen and can     lead to "blue-baby" syndrome (methemoglobinemia), which can result in death. EPA has set     drinking water standards for nitrates and nitrites. Pesticides - Malignancies {in children} linked to pesticides in case reports or case-control studies     include leukemia, neuroblastoma, Wilms' tumor, soft-tissue sarcoma, Ewing's sarcoma, non-     Hodgkin's lymphoma, and cancers of the brain, colorectum, and testes. Although these studies     have been limited by nonspecific pesticide exposure information, small numbers of exposed     subjects, and the potential for case-response bias, it is noteworthy that many of the reported     increased risks are of greater magnitude than those observed in studies of pesticide-exposed     adults, suggesting that children may be particularly sensitive to the carcinogenic effects of     pesticides.  Zahm SH, Ward MH., Pesticides and childhood cancer, in Environ Health, in Perspect    1998 Jun;106 Suppl 3:893-908.       A related article,  Cancer Risk and Parental Pesticide Application in Children of Agricultural... Biological Contaminants - E. coli, giardia and cryptosporidia cysts can all cause gastro-     intestinal problems where dehydration from diarrhea and vomiting may be more severe and rapid     than in adults.  These contaminants can cause death.  In 1998, EPA established the Interim     Enhanced Surface Water Treatment Rule, which strengthens control over microbial contaminants,     including the pathogen, Cryptosporidium. By 2002, public water systems using surface water (or     ground water under the direct influence of surface water) and serving more than 10,000 peopl must     comply with the rule. States must adopt the new standards by 2001.  In some people, particularly     children under 5 years of age and the elderly, E. coli 0157:H7 infection can also cause a     complication called hemolytic uremic syndrome, in which the red blood cells are destroyed and the     kidneys fail. About 2% of infections lead to this complication. Disinfection Byproducts (DBPs) - According to the EPA, the risk varies depending on the DBP.     Some epidemiological studies may indicate a link between certain DBPs and a slight increased     risk of reproductive and developmental effects.       It would make sense that if drinking water contaminated with moderate levels of DBPs over a         lifetime increases the risk of some cancers, it would be an excellent idea to remove as many of         these compounds from the drinking water as soon in life as possible and continue the removal         through adulthood. For additional information on the special sensitivity of children to drinking water contaminants, visit     the EPA's excellent site: Children and Drinking Water Standards.

To better understand how the health risks of water contaminants are determined,  I would encourage you to read this discussion.

Risks to the Elderly and/or Immunocompromised*: Although both populations are affected by all of the contaminants listed above, they are at special     risk of serious injury or death from biological, pathogenic contaminants.  If there is any chance that     their drinking water has been contaminated with harmful bacteria, or cysts, their drinking water     should be disinfected immediately (boiling would be a good option), or they should drink a good     quality of bottled water until the water is safe.  Since it can take as long as 24 hours to be notified     of a contaminant risk, a better plan than continually wondering if the water were safe would be to     invest in a high quality filtration system that is NSF certified to remove cysts.  The PDF file,     Protecting Vulnerable People from Drinking Water Diseases and Illnesses, from the Campaign for     Safe and Affordable Drinking Water (CSADW), containg some good information about these     risks. In some people, particularly children under 5 years of age and the elderly, E. coli 0157:H7 infection     can also cause a complication called hemolytic uremic syndrome, in which the red blood cells are     destroyed and the kidneys fail.

Water Treatment Strategies for High Risk Groups* If there are members of these high-risk groups living in your home, it would be an excellent plan to     consider a permanent water treatment strategy , since: There is always a "lag time" between the discovery of pathogens in a water supply by water     officials and notification of the public. There are disinfection byproducts at some level in nearly all water that is chlorinated.  The     highest levels are usually found in chlorinated water (municipal or private) from a surface source or     water from an unconfined aquifer.  Water from confined aquifers typically does not have to be     chlorinated as heavily (if at all) as water from the other sources.  This water also usually contains a     lower level of the organic material (leaf fragments, etc.) that interacts with chlorine to form the     disinfection byproducts than does surface water or water from an unconfined aquifer. A high percentage of homes have the potential for lead to leach into the drinking water from the     plumbing pipes and fixtures - this problem is discussed in detail on the previous page. In agricultural regions, there is a good reason to expect nitrate, pesticide, and possibly bacterial     contamination, particularly in private wells using water from unconfined aquifers (or in surface     water).  Surface water is also likely to contain cryptosporidia or giardia cysts.  Wells in these     regions should be tested, and water quality reports should be studied carefully to see if these     contaminants exist in the drinking water. The simplest and most economical long- term solution to reduce the majority of the above      contaminants (except nitrates) and chronic bacterial or viral contamination to safe levels      is a NSF certified, high-quality, Solid Block, Activated Carbon (SBAC) filtration system      with a  sub-micron pore size.     - These systems will significantly reduce the chlorine, any DBPs, cysts, asbestos, and a wide      range of pesticides and other organic contaminants from your drinking and cooking water.  Most      SBAC filtration systems also remove lead effectively, and some are designed to remove      mercury, but check with the manufacturer to make certain.   - Although these filters are not recommended for continual use with bacterially contaminated water,      the pore size is small enough to reduce the levels of many types of bacteria that might      accidentally contaminate a normally safe water supply.     - NSF does not certify filtration systems for bacterial removal, so make certain that the manufacturer      of any SBAC system you are considering provides independent lab tests that demonstrate      effective reduction of E. Coli. If nitrates or arsenic are known (or suspected) to be in the water, in addition to the other      contaminants listed above, a high-quality, Reverse Osmosis (RO) system would be the most     economical long-term solution.  Any system you purchase should have a good activated carbon     solid block post-filtration system to remove any contaminants not removed by the RO membranes.  Distillation is also an excellent method treating water that has contaminants not removed by     activated carbon, but it is more expensive than reverse osmosis.

It is possible, though thankfully rare, for harmful bacteria or other pathogens to find their way into      drinking water from a municipal water source or private well. If these organisms are in the water      illness can occur.  If tap water is regularly suspected to contain harmful pathogens, there are      several point of use treatment options that can be considered for home drinking water if on a      municipal water system*.      distillation      ozone treatment      solid block activated carbon or reverse osmosis filtration (to reduce non-living contaminants          and turbidity) followed by UV treatment to kill the pathogens. Distillation and ozone are probably more expensive options than filtration and UV treatment.   If you are on on a well and suspect (or have found) biological contamination, point of entry disinfection might be the most economical solution for bacterial or viral contamination. Bottled water is a good emergency source of safe drinking water, but often, by the time a problem has been discovered and an emergency boil order has been issued, many people have already been exposed to the contaminated water.  A better solution when you suspect municipal water (or well water for that matter) is or may become unsafe, is to install and maintain a permanent treatment system for all water consumed in the home (including tooth brushing).  Individual-size bottles can then be carefully cleaned and filled with the treated water to drink away from the home.

Copyright © 2005 Randy Johnson. All rights reserved.