Drinking Water From Lakes
They are called "Seasonal Lake Changes," and they happen every year, causing some drinking water supplies to have a noticeable, earthy or musty taste and odor.
According to the EPA, there are 182 million people whose water comes from surface water sources, like lakes and reservoirs. And every year, when the season changes and the temperatures drop, millions of people know what it means to have unusual tasting drinking water.
Here's what happens every year in surface water sources like lakes and reservoirs: In summer, the heat from the sun causes the surface water of the lake to become warm, while the deeper water remains cool, and the lake becomes "thermally stratified." Blue-green algae begin to grow in the warmer surface water while the deeper water becomes stagnant.
As blue-green algae grow, they release compounds that cause unusual taste and odor in drinking water. By early fall, growth of blue-green algae peaks, and as temperatures cool, so does the surface water of the lake, making this layer more dense. The surface water begins to mix with the cooler, deeper water. The stagnant water and sediment begin to mix together as well. At this time the lake is said to "turnover" or to become "de-stratified," causing a secondary algae bloom. This natural process causes a noticeable change in the taste and odor of drinking water coming from surface sources.
"Many scientists believe that taste, odor, and quality-related problems with drinking water will continue to rise," said Dr. David Walker, Research Scientist, University of Arizona. "In several cases, water treatment facilities can't afford to or are otherwise caught off-guard and do not adequately remove taste and odor compounds from drinking water," Walker continued. "While seasonal lake changes are not harmful, the good news is that people can easily and inexpensively do something to improve the taste of their drinking water. Simply attach a water filter to your faucet."
September 28, 2005 7:04 AM | Category: Water