How do I know if my water is safe to drink?

Generally speaking, drinking water in the State of Utah has been shown to be of exceptional quality. Some localized areas of Utah (desert areas, mining districts) have particular problems associated with geological or man-made contamination, but over-all, decades of water testing have shown Utah’s drinking water to be safe.

If your drinking water comes from a public source, then the municipality or water system is required by law to test the water frequently for chemicals or bacteria that may be harmful to you. They are also required to publish annually a Consumer Confidence Report, which lists the results of the analytical testing which has been performed during the previous year.

If your drinking water comes from a well or other non-public source, then any analytical testing is your responsibility. It may be a good idea to test your water on a regular basis (for example, in the summer and in the winter) to make certain that your water is safe to drink.

Your source water is one area of concern; the other major area of concern lies within your own house. This means that your in-house piping, faucets, and hot water heater may cause, or contribute to, a water problem. Please see subsequent questions for discussions about these sources.

Testing for contaminants in drinking water can be an expensive process if you don’t know what to test for. Here are some suggestions for testing your water:

Bacterial Testing
Unless your drinking water source lies next to a huge industry, or any other obvious source of specific chemical pollution, the bacterial content of your water is the most likely health hazard. Testing for coliform bacteria is probably the most prudent – and first – contaminant to test for in an unknown water source.

The State of Utah uses the testing of coliform bacteria as its sole criterion for determining whether water is bacterially contaminated. The coliform group contains many kinds of common bacteria, including those naturally occurring in soil. Although many groups of coliforms are non-hazardous to human health, their presence in drinking water generally indicates that contamination has occurred in some way. Fecal coliforms, which are a sub-set of coliform bacteria, occur naturally only in the gut of warm-blooded animals. E. coli is a well-known fecal coliform.

A water sample which tests positive for total coliform may or may not be hazardous to your health, but it fails the state standard. A sample which tests positive for fecal coliform or E. coli is an indication that the water has come in contact with fecal matter, and is a serious health hazard.

Chemistry Testing
Chemical contamination of drinking water is not common, but there are some chemical constituents that you may want to consider testing. For example, high amounts of calcium and magnesium cause hard water. Soil which has been sprayed for pesticides or herbicides has the potential to contaminate groundwater. Older homes may have piping which deteriorates over time, leaching metals such as zinc, copper, and lead into the drinking water. Excessive use of fertilizer may cause large amounts of nutrients (such as nitrogen and phosphorus compounds) to appear in groundwater. Fuel spills have also been known to generate groundwater contaminants.

Because the above cases are unusual, chemical testing of water on a routine basis by individuals is not done very frequently. However, specific qualities of your water which you find disagreeable may warrant chemical testing.

So, what is safe water?

Complaints about water quality usually fall into two categories. First, and the most important, is contamination by chemical or bacterial constituents which may cause human health problems, that is, things which would cause the water to be unsafe to drink. Second, there is contamination caused by chemical or bacterial sources which results in aesthetic problems: the water smelling or tasting funny, or the water causing stains on bathroom fixtures. The water may not necessarily be unsafe to your health, but the drinking water quality is sufficiently poor that you don’t want to drink it.

The distinction between the two is important.

So, in the State of Utah, safe water is defined as water which meets the standards of the National Primary Drinking Water Regulations. These regulations protect public health by limiting the levels of contaminants in drinking water. A list of these regulated compounds and the Maximum Contaminant Levels (MCLs) is available at www.epa.gov/safewater/mcl

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