DEQ's Drinking Water Program protects public health by ensuring drinking water from public water systems in Idaho is safe. DEQ is authorized to administer Idaho's Drinking Water Program through the federal Safe Drinking Water Act and the Idaho Rules for Public Drinking Water Systems (IDAPA 58.01.08) (pdf on Department of Administration Web site). Approximately 95% of the state's drinking water comes from ground water. Surface water, such as streams, rivers, reservoirs, and springs, supplies the remaining 5%.

In Idaho, there are 1,991 regulated public drinking water systems serving 1,217,786 people. Public water systems, which may be publicly or privately owned, serve at least 25 people or 15 service connections for at least 60 days per year. Many other Idaho citizens get their drinking water from private wells. These wells are not regulated under the Safe Drinking Water Act; well owners are responsible for ensuring their own water is safe.

Drinking water, including bottled water, usually contains at least small amounts of contaminants.  However, the presence of contaminants does not necessarily mean that the water poses a health risk.  The U.S. Environmental Protection Agency (EPA) sets standards for approximately 90 contaminants that specify the maximum amount of each allowed in drinking water. Drinking water supplies are often vulnerable to contamination from land use practices (e.g., farming) and potential contaminant sources (e.g., gas stations) within the vicinity of drinking water wells and intakes. DEQ's Source Water Assessment Program assesses the likelihood of drinking water sources becoming contaminated (usually a short-term "contamination event"); DEQ's Drinking Water Protection Program helps public water systems prepare drinking water protection plans and implement protection measures.

In cooperation with the state's seven district health departments, DEQ provides a variety of technical assistance to public drinking water systems. DEQ works with systems to ensure compliance with minimum state requirements, conducts sanitary surveys and on-site visits, reviews water system plans and specifications, issues monitoring waivers, conducts training sessions, holds public information meetings, publishes the quarterly Idaho Drinking Water Newsletter, and contracts for statewide operator training classes. Public water systems pay an annual fee based on the number of connections, which helps to fund the Drinking Water Program. The remainder of program funding comes from EPA.

Most people in Idaho get their water from a public water system that must meet stringent drinking water standards.  By law, your water company must inform you if your water ever becomes unsafe.  If you have a question about the quality of your drinking water, contact your water company.

Annual compliance reports provide a general yearly overview of drinking water in Idaho, but do not discuss specific public water systems.

If your water comes from one of Idaho's 730 community water systems, you can request a copy of the system's annual Consumer Confidence Report (CCR) from your local utility.  (Not all  of Idaho's 1,991 public water systems are required to publish a CCR; only community water systems.)  The CCR will discuss the quality of your water (based on the last calendar year), any problems or detections of drinking water contaminants, and what is being done to correct the situation.  More on safe drinking water.

If you rely on private well water, it is your responsibility to monitor the quality of your drinking water.  More.