Water is basic to life and health. Water makes up about 60% of your body’s weight, on average. Every system in your body depends on water to function. Safe drinking water is one of the most valuable resources we have. The United States has one of the safest public water supplies in the world, yet every year, millions of cases of illness associated with public drinking water systems are estimated to occur nationally. The Idaho Department of Environmental Quality, Idaho Department of Health and Welfare, and Idaho’s seven local public health districts protect public health by ensuring drinking water from public water systems in Idaho is safe.

Recreational water use is associated with significant benefits to health and well-being. Despite these benefits, the Centers for Disease Control and Prevention has noted a steady increase in the number of reported outbreaks of diarrheal illness associated with recreational waters; these reports suggest that spread of illness through aquatic venues occurs routinely during the swimming season. The Idaho Division of Public Health works with Idaho’s local public health districts to investigate outbreaks of illness associated with drinking or recreational water. 

Recreational water is any water which is used by a significant number of persons for recreation or play. Recreational waters may be natural bodies of water, such as oceans, lakes, rivers, ponds, and hot springs; artificial bodies of water such as reservoirs; or man-made facilities such as swimming pools, plunge pools, splash parks, water parks, hot tubs, and spas.

Recreational waterborne illnesses (RWIs) are illnesses that result from swallowing, breathing, or having contact with recreational water. RWIs can be caused by microorganisms (e.g., bacteria, protozoa, algae, viruses), other parasites, or chemicals. RWIs can cause a wide variety of problems including upset stomach, diarrhea, rash, difficulty breathing, and infections of the eye, ear, skin, brain, or other organs. The most commonly reported RWI is diarrhea. Other hazards associated with recreational water include drowning, injury, exposure to temperature extremes, and dangerous animals.

Drinking water typically originates as surface water, such as lakes and rivers, or groundwater, such as an aquifer. Drinking water may be obtained directly from private wells or public water systems, or from commercial sources, such as bottled water. Most people in Idaho get their water from a public water system that must meet health-based drinking water standards.

Illnesses acquired from drinking water can be caused by microorganisms (e.g., bacteria, protozoa, algae, viruses), naturally-occurring or man-made chemicals, or naturally-occurring or man-made radioactive compounds. In the United States, the most common causes of reported outbreaks of drinking water-associated illness are bacteria and chemicals. Persons can become ill from swallowing drinking water or from inhaling water from a drinking water supply, for example, while taking a shower.