Why does my water taste or smell different to me?

The three most common smells people inquire about are: Chlorine, MIB/Geosmin, and Dirty Drains.

American Water
Works Association

Chlorine, is a disinfectant that is added to the water to clean and disinfect it to meet drinking water standards. Typically, only a small amount of Chlorine (about 1 part per million) is added to the water to prevent bacteria growth in the distribution system. A simple way to reduce the taste and odor of Chlorine is to fill and chill a pitcher of water in the refrigerator before use. This will allow the chlorine to dissipate and be less noticeable.

MIB/Geosmin, seasonal by-products produced from algae in Arizona's lakes and canals. This taste too can be alleviated by chilling water in the refrigerator or adding a slice of citrus to your glass.

Dirty drains, people commonly mistake smells coming from their drains as “smelly” water. To accurately determine if a smell is coming from your water fill a clean glass with cool water and walk away from the tap to smell it. Most of the time the smell will not be in the glass. Pouring bleach in the drain will kill germs that may be growing in the trap.

The detection of these compounds is dependent upon an individual’s sense of smell. Many people may never detect them, while others who are sensitive or taking certain medications may detect taste or smells at levels below instrument detection levels. 


What are cities doing about the taste and odor?

Many cities take additional steps to improve the aesthetic quality of water by adding activated carbon and then removing it during to the treatment process. These steps help to alleviate tastes and odors from the drinking water sources. The water industry as a whole is continually evaluating new ways to cost effectively treat drinking to water provide a product which both meets the high quality standards and is aesthetically pleasing. 


What law keeps my drinking water safe?

Congress passed the Safe Drinking Water Act (SDWA) in 1974 to protect public health by regulating the nation’s public drinking water supply and protecting sources of drinking water. SDWA is administered by the US Environmental Protection Agency and its state partners. 


Where can I find information about my local water supply?

Since 1999, water suppliers have been required to provide Consumer Confidence Reports (CCRs) to their customers on an annual basis. These reports are due by July 1 each year and include information on any contaminants found in the drinking water, possible health effects, and the water’s source.

You can find additional information on your water supply at:


How often is my water supply tested?

EPA has established pollutant-specific minimum testing schedules for public water systems. Each water system is unique and may require different testing protocol. To find out how frequently your drinking water is tested, contact your local water system or the Arizona Department of Environmental Quality.


What are we concerned about in the water?

Naturally occurring microorganisms (wildlife and soils), radionuclide (underlying rock), nitrates and nitrites (nitrogen compounds used in fertilizers), heavy metals (underground rocks containing arsenic, cadmium, chromium, lead and selenium), and fluoride.


How is my water treated to make it safe?

Water suppliers use a variety of treatment processes to remove contaminants from drinking water. The most commonly used processes include coagulation, filtration, and disinfection. Flocculation removes dirt and other particles suspended in the water, which in turn settle naturally out of the water by sedimentation. Filtration removes all particles from the water including clays and silts and clarifies it. This step enhances the effectiveness of disinfection, which is considered to be one of the major public health advances of the 20th century. Chlorine, chlorinates, or chlorine dioxides are most often used for disinfection because they are highly successful and can maintain a residual concentration in the water system. Physical processes such as ultraviolet light, which kills microorganisms such as viruses, bacteria, and protozoa, are also used.