Taste & Odor (T & O)

Taste and odor problems that may typically be detected by consumers are related to seasonal events, localized degraded water quality, chlorine taste and odor, or internal problems. Determine if the problem is noticed in cold water, hot water, or both. Also figure out which faucets are affected. A problem that is detected in multiple faucets, both cold and hot, is likely an external problem, i.e. originating in the water entering the residence. Conversely, issues that can be internal to the residence include ice cube odors and hydrogen sulfide (rotten egg) odor originating from the hot water system.

Seasonal T & O Events


Likely descriptions are that the water smells earthy, musty, river-like, grassy, or other "natural" descriptors.
  • These types of odors are caused by seasonal changes of water quality in the Fox River due to the presence of naturally occurring compounds that impart different odors to the water. This affects the aesthetic quality of the water only. The water is completely safe for human consumption. The water treatment process is continually adjusted to minimize T & O effects to the drinking water supply.
  • Storing tap water in a closed glass container in the refrigerator will help improve the taste and odor of the water.

Localized Degraded Water Quality


May result from low flow/usage in the area or high water age where the chlorine residual has greatly dissipated. This is likely to be the cause when T & O complaints have not been reported in other areas. Localized flushing will be scheduled to move fresh water into the affected area, which will improve the aesthetic water quality.

Internal Odor Issues


  • Rotten egg odor: Occasionally a customer will experience a rotten egg odor in the hot water. Sulfur-reducing bacteria can create hydrogen sulfide, causing the odor. This usually indicates a problem with the water heater; consult a plumber for assistance.
  • Ice cube odors and cubes causing unpleasant taste in water: Ice cubes can take on odors from the freezer/freezer contents. Also, harmless bacteria can grow in the ice-maker water line and cause odors. "Freezer smell" and "off flavors" are not harmful and can be lessened by cleaning and defrosting the freezer and ice cube trays.
  • Sewage-like odor: This type of odor usually emanates from the drain of the water fixture. Household plumbing systems sometimes give off odors due to biological growths, dry P-traps, etc. This can be verified by performing the following steps:
    • Run the cold water for 30 seconds.
    • Run water into a clean glass.
    • Smell the poured water while standing away from the sink drain.
The water should not have any unusual or sewage-like odor. Pouring some household bleach into the drain will help neutralize odor-causing material. If odor persists, consult a plumber.