Colors and Smells

Noticeable water problems tend to involve unusual colors, smells, and tastes. Once identified, these aesthetically displeasing elements can be eliminated using a variety of different methods. Federal guidelines are set up to monitor these aesthetic problems.

Taste and Odor

Since taste and odor work together it is often difficult to distinguish the two. Common complaints include:

  1. Strong Chlorine taste or smell - Generally this occurs when the water is treated at the water treatment plant to disinfect it. The addition of chlorine is used to kill off bacteria and other harmful microorganisms (2).
  2. Metallic taste - Some water systems have a high mineral concentration giving the consumer a salty or soda taste. In the case of Iron and Manganese, a strong metallic taste is readily detected (1).
  3. Rotten egg odor - This is usually a result of decaying organic deposits underground . As water flows through these areas, hydrogen sulfide gas is picked up, and when this water reaches the surface or comes out of the faucet, the gas is released into the air. Hydrogen sulfide gas produces the rotten egg odor, can be corrosive to plumbing at high concentrations, and can tarnish silver rapidly. In large enough quantities, it is toxic to aquarium fish. As little as 0.5 PPM (parts per million) can be tasted in drinking water (1,2).
  4. Musty or unnatural smells - These smells are normally a result of organic matter or even some pesticides in the water supply. Even very low amounts can introduce unpleasant odors into the water  (1).
  5. Turpentine taste or odor - This smell can be a result of MTBE contamination in your water. The odor threshold of MTBE is fairly low, so even though you can smell it, the MTBE is more than likely not at a level to cause harmful effects.


"Clean" water should be clear with no noticeable color deposits. Common colors include:

  1. Red or Brown Color - A red, brown or rusty color is generally indicative of iron or manganese in your water. Disadvantages to iron in your water include stains in sinks, or discolored laundry (1,2).
  2. Yellow Color - This coloration occurs in regions where the water has passed through marshlands and then moved through peat soils. In the United States, these conditions occur in the Southeast, Northwest, New England, and Great Lakes regions. It is more commonly found in surface water supplies and shallow wells. Although the yellow color may be displeasing, it presents no health hazard, as it is only small particles suspended in the water (2).
  3. Blue or Green Color - A green or blue color is generally a result of copper in your water supply, or copper pipes and corrosive water (1). The copper can cause staining of your fixtures and your laundry. Copper is regulated in drinking water by the EPA at 1.3 PPM. This is at a low enough concentration that the copper cannot be tasted (the taste threshold is around 5 PPM). Copper can become a problem  if it is higher than 30 PPM in your water. Effects at this dose are vomiting, diarrhea, and general gastrointestinal distress (3). If you are using well water as your primary source of water, and copper is a concern in your area, it would be to your advantage to have your water tested for copper.
  4. Cloudy White or Foamy - Cloudy water is usually due to turbidity. Turbidity is caused by finely divided particles in the water. When light hits the water, it is scattered, giving a cloudy look to the water. The particles may be of either organic or inorganic nature. Neither one causes any harmful effects to the body, although they can cause abrasions to pipes, or possible staining of sinks (2).


Treatment Options

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  1. Siouxland Home Page. A service of Siouxland, an assembly of Midwestern organizations on the Internet.
  2. Water Review Technical Brief, (1991) Volume 6, No. 4; a publication of the Water Quality Research Council.
  3. Toxicological Profile for Copper. U.S. Department of Health and Human Services. Agency for Toxic Substances and Disease Registry. December 1990.

This page was prepared by S.L. Keyser, UCD EXTOXNET FAQ Team
June 1997