Most Texans, at one time or another, have experienced a foul taste in their drinking water. It may
have been a musty, earthy, moldy, or woody taste that is fairly common in surface water supplies across the United
Your local utility usually issues a notice that the water is experiencing the typical run of taste
and odor, but the water is safe to drink. They are correct, assuming all other regulations are met; the water is safe
What causes this unpleasant taste in the water during different periods of the year? Though
some taste and odor issues may be attributed to industrial causes, normally they are derived from a natural base.
Many people explained the problem as “the lake turning over” which in some part is correct, but the real culprit was
probably due to the presence of algae.
There are many different types of algae. Diatoms, greens, blue-green and actinomycetes flourish in
the early part of the year when spring rains cause large amounts of runoff to flow into reservoirs. The runoff carries
nutrients, which are the food source for algae. As the days become longer, the sunshine and nutrients allow algae to
When blue green algae end their lifecycle they emit an oily substance called geosmin. Very small
amounts of released geosmin result in the musty earthy taste encountered.
Naturally-based taste and odor problems have plagued water utilities for many years. Utility
operators have employed numerous methods to control or minimize the intensity of taste and odor issues. The
application of varied treatment techniques throughout the water purification process include the use of potassium
permanganate, activated carbon, ozone, chlorine dioxide, copper sulfate, and numerous other compounds.
However, as they say, an ounce of prevention is worth a pound of cure. The best way to eliminate
taste and odor issues is to prevent the formation of the organisms that cause the problem. One answer is watershed
management strategies. These strategies limit the use of nutrients that feed algae in areas surrounding certain lakes,
rivers, and streams.
For example, a homeowner with a lake-side address proudly spreads fertilizer on their lawn. The
grass and ground absorb a large amount of the fertilizer. However, during heavy rains, the excess chemical is washed
directly into the lake. The fertilizer now provides nutrients to the algae growing in the lake. The alga begins to
bloom and the taste of the local water changes.
Though sensitivity to taste and odors in water varies remarkably between consumers, every customer
expects the water coming into their home to be safe to consume, pleasant in taste, and clear in appearance.
So what can you do if your water has an offensive taste or odor? Point-of-use devices
especially made for the home such as water filtering pitchers or filters attached directly to your faucet may assist in
filtering out some of the taste and odor experienced. Keeping drinking water cooled also reduces the intensity of the
taste. Refrigerators that provide ice and water in the door are now available with replaceable carbon-based filter
systems that will also help with taste and odor.