Drinking Water Evaluation

What to Test on a Group A Drinking Water System

Now that you have an idea of the problems that could occur, what should you test for? Substances found in drinking water can be classified four ways:

• microbiological
• chemical
• physical
• radiological

Microbiological Tests detect "bugs," or microbes, that are too small to be seen by the naked eye, such as bacteria or protozoans. Many labs test for coliform bacteria, which originate from the same source (feces) as many disease-causing microbes.

Chemical Tests are classified as inorganic or organic. Inorganic chemicals are often associated with rocks, clay, sand, and other earthy materials. Many organic chemicals are of plant or animal origin.

Physical Tests examine the characteristics of water including turbidity, color, taste and odor, and temperature.

Radiological Tests look at characteristics of water including the presence of radium, uranium, and radon.

If your water comes from a Group A public water system you'll want to take the following approach on your tests:

Chemicals

• Test for chlorine if your water tastes like swimming pool water or you smell bleach when you turn on the tap.
• Test for asbestos if you have an older, concrete line, or for lead if you have old copper pipes.
• Test for mercury, cadmium, trihalomethanes, or arsenic only if you have a specific reason to suspect their presence.

Bacteria

• A routine test for E. coli or fecal coliform will indicate possible contamination by human waste. If the coliform test is positive contact your local Health Department. However these test results are already available from you local Health Department or Water System Management Company. You may request a copy of the test results as they are considered public information.

Particulates, Odor, Flavor, and Color

• The presence of these may cause your drinking water to be unpleasant but may not cause health problems. If you are having trouble with odor, taste, staining, or other aesthetic problems, consult with your local Department of Health on the most likely of the several causes listed in the table below.