Drinking Water Contaminants
What, besides water, might come out of your faucet


    A. Introduction
    B. Materials Dissolved in Water
        1. Inorganic Compounds
           a.. Metal and Metalloid Positive Ions
              (lead, mercury, calcium, magnesium, etc.)
           b. Negative Ions (nitrates, sulfates, etc.)
        2. Organic Compounds
           a. Synthetic Organic Chemicals
           b. Trihalomethanes - Disinfection Byproducts
    C. Materials Suspended in Water
        1. Pathogens (Viruses, Bacteria, Cryptosporidia, and other Protozoans
        2. Asbestos
        3. Other Suspended Solids
    D. Excerpt from Popular Science Interview with EPA's Carol Browner

Web Links to Selected Topics
    A. Sites with Information About Water Contamination Issues
       The sites are arranged by specific contaminant.
    B. Abstracts of scientific journal papers describing the health effects of chlorine disinfection byproducts
    C. Links to Other Pages of this Site

Since water is capable of dissolving or suspending a tremendous variety of materials there is simply no way to get "pure" water (H2O and nothing but H2O) out of your faucet. All water, outside of a research laboratory, will have some other stuff in it. Even distilled water you purchase in plastic bottles at the store will eventually have some carbon dioxide (CO2) from the air dissolved in it forming a weak acid (carbonic acid), and worse, there will probably be some dissolved plastic molecules in it as well.

Are all water contaminants bad for our health? Not at all. Many of the naturally occurring compounds in water are benign or even good for our health. Some minerals, like calcium and magnesium are essential to human health, and some reports indicate that drinking water can provide an important dietary source for these minerals. Most of the discussion and links below will focus on the undesirable or dangerous water contaminants.  The environmental Protection Agency has established Maximum Contaminant Levels (MCLs) for some of the most common and/or potentially dangerous of the identified water pollutants.

The materials besides H2O that might be in your drinking water can be categorized as shown below (only the most common or dangerous examples in each group are listed here, since there is a nearly infinite number of possible contaminants). This is a highly simplified list, but I did not want to get into a lot of chemistry and technical ideas and terms here. At some point I may create a page with more technical details for those who are interested, although anyone who is interested probably already knows far more than I do about the subject.

Where appropriate, in the lists of contaminants below, I have indicated in {MCL=} the Maximum Contaminant Level (MCL) established by the Environmental Protection Agency (EPA). The units are usually milligrams of the contaminant per liter of water.

  Materials dissolved in water:

  Materials suspended in water: Of the extremely large number of things that can possibly be suspended in water, only those that are dangerous to health or that affect drinking water quality will be listed here.  If there are enough tiny particles suspended in water it becomes cloudy or turbid.  Light bounces off the suspended particles giving the water a milky or muddy appearance.

To conclude the discussion on contaminants, you might find the opening exchange of Popular Science's exclusive interview with Carol Browner, administrator of the U.S. Environmental Protection Agency interesting  (The Popular Science web page was reorganized, and their "Water Report" from which this exchange was extracted was apparently deleted).

Popular Science: Why do Americans now buy so much bottled water?

Carol Browner: I think it's because of a lack of information, quite frankly. People have heard things, they're scared, and there's a product on their grocery store shelf. So it seems as if buying it is the way to get some information, the way to have some control over the situation.

What it also says to me is that the consumer is willing to make an investment in safe drinking water, and that we have to prove to them that investing in their tap water is what makes sense.

I would say that people in this country have every reason right now to ask questions. I wouldn't take for granted the safety of this nation's drinking water anymore. There's a series of problems from emerging threats like microbials. There's an infrastructure problem. We should just be honest about that. (emphasis mine)

PS: Could you comment further on this trend of people wanting to do things themselves, for example, buying bottle water instead of investing in the quality of their tap water?

CB: There is a lot of evidence that people have concerns and they want to do something themselves, whether it's buying bottled water or one of those filters to put on a water pitcher. I am very hopeful that the more we can provide people with information about what's actually being found in the source water and what actions are being taken to treat it, the more people will feel confident in their drinking water and have a greater willingness to invest in their local water system.

(bookmark this page if you would like to return to it later)

A list of sites with information about the water contaminants discussed above can be viewed by clicking here.

If, after browsing the web pages below and those listed on other pages of this site, you have further questions, comments, new web pages to add, or if you are interested in information about drinking water filtration systems, please let me know.

Click on a Topic Below to View the Related Discussion and Links.

The following pages contain a summary of the information on drinking water quality that I have ferreted out and compiled over the past couple of years.

 Concerns About Drinking Water Safety and Quality.
    Children and the Risks of Contaminated Water.
 How to Improve the Quality of Your Drinking Water.
    My Recommendation   for Quality Water Purification Systems.

The following is a list of what I would consider Essential Sites. They will provide you with a wealth of important information about drinking water safety and quality.

 Water on Tap: A Consumer's Guide to the Nation's Drinking Water and Drinking Water and Health, both from the U. S. Environmental Protection Agency (EPA).
 Tapwater at Risk This extensive, three-part newspaper series published in 1996 explores the safety of the nation's tap water, explains the dangers threatening our water and describes what communities can do to protect it.
 Drinking water quality and health - A good , brief overview of drinking water quality.
 Drinking Water Help by William Ottaway, BS, Meng - A very informative site about water contaminants and water treatment solutions
 Important information about lead in drinking water, particularly if you have children.
 The American Water Works Association's The Story of Drinking Water - Basic but informative site - geared toward children. For a more in-depth look at water, go to - H2O - The Mystery, Art, and Science of Water which includes  The Chemistry of Water by Professor Jill Granger.
 The definitive site for Cryptosporidium/Coccidial Research - Includes a list of waterborne and foodborne outbreaks of Cryptosporidium parvum from 1983 through the Sydney Australia outbreak in late July through August 1998
 Information on Endocrine Disrupters - Endocrine Disrupters - All the better to confuse you with and WWF Canada's Web Guide to Endocrine Disrupting Chemicals
 The American Water Works Association White Papers - Water quality issues from the water treatment industry perspective

Links By Subject
You can view the entire file sorted by subject (260K) or the smaller individual files below.

Children and Water Contaminants --- Drinking Water Contaminants --- Education Sites --- Emergency Drinking Water -- General Water Quality Information --- Health and Water --- Journal Abstracts --- Regulations and Violations --- Risk Analysis and Contaminants --- Site Search Engines --- Water Treatment Options

Links By Category
  You can view the entire file sorted by category (270K)   or the smaller individual files below.

Environmental Sites --- Federal and National Sites --- Journals, Newsletters, etc. --- News Groups, Magazines, Books, etc. --- Organizations, Manufacturers, Certification --- Miscellaneous Sites --- Water Treatment Facilities --- University Related Sites and Extension Services --- International Sites --- State Related Sites