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Why Test Your Drinking Water?

Contaminants in drinking water can come from many sources, both naturally occuring and human-caused. Water may look, taste and smell good, but many contaminants cannot be detected by our senses. Analysis conducted by a certified drinking water laboratory can detect very low levels of contaminants that could affect the health of you and your loved ones.

Contaminants can cause both acute and chronic health issues, especially for infants, the elderly, and those with other health problems. Alaskans that use private water sources are responsible for ensuring its safety. In addition to contaminants that can directly affect your health, some water problems could reduce the efficiency of your appliances and ultimately cause system problems that could indirectly affect health.

Periodic testing of your private water source is the ONLY way to know for sure what is in your water. This information can give you the peace of mind that your water is safe for your family, or give you the information you need to make appropriate treatment and pollution prevention decisions.

Poor Water Quality

It is recommended to test your water annually, preferably in the spring, for contaminants like bacteria and nitrates. Getting a baseline test for other contaminants is also a good idea if you have never had your water tested before. Other good times to test your water are after replacement or repair to your water system, after spring break-up or a flood event, if you notice any changes to your water or if you suspect that nearby land use changes may be affecting your water.

Below are some of the most commonly tested for contaminants in drinking water.


The alkalinity of water results from high levels of ions such as carbonates, bicarbonates, and hydroxides. The alkalinity of water has the capacity to neutralize acid. Highly alkaline water often has an acrid, soda taste. Alkaline water can result in dry skin.


Arsenic naturally occurs in air, water, soil, animals, and plants. Arsenic commonly comes into contact with drinking water via natural deposits in the ground or from industrial sources (present in soaps, drugs, paints, etc.) and agricultural practices (i.e. in fertilizers). Arsenic is tasteless and odorless. Arsenic is highly toxic. Long-term exposure to drinking water containing arsenic will cause skin, urinary bladder, lung, and kidney cancer. It is also known to assist in the development of diabetes. High amounts of arsenic have been found in groundwater wells in Fairbanks area and on the Kenai Peninsula.  For more information:

World Health Organization - “Arsenic in Drinking Water

EPA  -  “Arsenic in Drinking Water”

EPA - Water Quality Fact Sheet: Arsenic


Copper occurs naturally in air, water, soil, rock, sediment, animals, and plants. It has an important role in our diet, assisting our bodies’ enzymatic activity and metabolism. There are no known diseases associated with high levels of copper intake, but it could cause slight irritation in the intestine and stomach and extreme exposure could cause nausea, diarrhea, and vomiting. Copper can also cause blue-green staining on sinks, plumbing, etc. For more information:

Wisconsin Department of Natural Resources – “Copper and Your Health

Fecal Coliform - Escherichia coli (E. coli)

E. coli is a part of the fecal coliform group which comes from the digestive systems and feces of warm-blooded animals. There are both harmless and harmful forms of E. coli. The harmful forms can cause dysentery, diarrhea, and hepatitis.

Hard Water

Water is “hard” when it contains high levels of dissolved minerals such as calcium and magnesium. On the other end of the spectrum, soft water contains little or no dissolved minerals. When water moves through rock and soil it picks up trace amounts of minerals and increases in hardness. Hard water is not known to cause health problems but it can leave mineral deposits on pipes (reducing pipe diameter) and cause soap curds. Some more recent studies suggest that some magnesium and calcium intake via hard water can actually help with disease prevention (i.e. cardiovascular disease).


Iron commonly forms as a result of high oxygen content in water. Deep aquifers or wells with low oxygen content are at less risk of iron formation. At the levels commonly found in drinking water, iron is not a health threat. Iron does cause an unpleasant taste and stain (laundry, sinks, etc).  Iron can clog filters, systems, and screens resulting in expensive repairs.  For more information:

Iron in Drinking Water” – A Pacific Northwest Extension publication

Langelier Index

The Langelier Index is a method of calculating the level of calcium carbonate saturated in water. Calcium carbonate can deposit, dissolve, or be in equilibrium with water. If the Langelier Index reads positive than the calcium carbonate will deposit, and if the Langelier Index reads negative than the calcium carbonate will dissolve. A zero reading indicates that the water and calcium carbonate are at a state of equilibrium.


Lead is common both in residential piping and the environment. An accumulation of lead can damage the kidneys, red blood cells, and the brain and cause high blood pressure. Pregnant woman, children, and fetuses are at the most risk. .  For more information:

Center for Disease Control - “Lead in Water: Questions and Answers

The National Lead Hotline: 1-800-424-LEAD (E.S.T.)


Manganese occurs naturally in rocks, soil, and ground water but can also result from pollution sources underground. It can change the taste, odor, and color (brownish-red) of water. Exposure to elevated levels over a number of years can be toxic to the nervous system. .  For more information:

Connecticut Department of Public Health – “Manganese in Drinking Water


Nitrogen in the ground water comes in the forms of nitrate, ammonia, and nitrite. It can get in your well water from wastewater, animal waste, flooded sewers, fertilizers, private septic systems, polluted storm water runoff, decaying plants, and agricultural runoff. It can be extremely toxic, especially to kids under six months old and to aquatic life. Infants exposed to nitrate can acquire methemoglobinemia, also known as blue baby syndrome. .  For more information:

Information for you about Nitrate and Nitrite & Ground Water


pH levels indicate how basic or acidic your water is. Water with a low pH (<6.5) is commonly soft, acidic, and corrosive. It may contain elevated levels of toxic metals, can cause corrosion to piping, and cause blue-green staining, and a sour or metallic taste in water. Water with high pH (> 8.5) is commonly hard. There a generally no associate health risks, but the water may taste bitter, soap will not lather, and deposit build up on pipes, dishes, etc. can result.


Sodium occurs naturally in some drinking water or can result from salt water intrusion (if near the ocean). High levels of sodium intake can result in high blood pressure. Note that sodium is added to water in the water softening process because it is used to replace high calcium and magnesium levels in “hard” water.

Total Coliform

Coliform comes from the digestive systems of warm-blooded animals. Not all coliform bacteria are bad, but if you test for “total coliforms” and levels are unusually high, then it is more likely that harmful bacteria are present in your water.

Total Dissolved Solids (TDS)

“Dissolved Solids” refer to the salts, minerals, metals, etc that have been dissolved into the water. TDS can come from sources such as urban run-off, sewage, water treatment chemicals, piping, salt deposits, mineral springs, etc. TDS can consist of both inorganic salts and organic matter (i.e. sodium, magnesium, potassium, calcium, sulfates, chlorides, and bicarbonates). High levels of TDS can make water undrinkable or extremely bad tasting, commonly salty or bitter.

Additional Resources

Water on Tap: What you Need to Know” – This EPA packet contains a broad amount of information regarding well water; extremely comprehensive.

Drinking Water from Household Wells” – This useful packet, also from the EPA, has answers to an array of different questions regarding well water.

Drinking Water: Testing for Quality” - University of Nebraska NebGuide

"Wellcare Information Sheets" - Water Systems Council -  Scroll down for factsheets on dozens of potential ground water contaminants.

"Testing Water Supplies Near Gas Drilling Activity" - PennState Extension, a great resource for questions about drinking water concerns near natural gas activity.