Wichita officials looking at ozone gas to reduce water's odor

February 2003

U.S. Water News Online

WICHITA, Kan. -- A musty smell has lingered in the Wichita's water supply since October, and city officials are turning to ozone gas as a possible remedy.

During the next 30 days, the city plans to experiment with adding ozone gas to the water supply. Ozone, produced by zapping medical-grade oxygen with electricity, is pumped into the drinking water to remove impurities.

If it helps reduce the odor, the Wichita City Council will decide whether to spend $2.1 million a year to regularly treat the water. The cost -- about $1 a month for a typical family -- would be passed on to residents.

``The $1 a month is pretty small,'' said Wichita resident Lorrain Hird, who put a filtration system on her faucet to eliminate the odor, which she described as being like dirt.

The odor in the Cheney Reservoir normally lasts for a few days once or twice each summer. Despite the smell, the water is safe to drink, said David Warren, director of the city's water and sewer department.

The latest episode began in October and has lasted more than three months. This is the first time the city has had an odor problem in its water during the winter.

``It could go on for a week. It could go on for a month,'' Warren said. ``It could stop tomorrow. The frustration is that you can't predict when it will start and when it will end.''

The city suspects the odor is caused by blue-green algae, also called cyanobacteria, fed by farm fertilizer and manure building up in Cheney Reservoir.

Until now, the city has focused on long-term remedies to deal with the algae. Since 1994, Wichita has been working with area farmers to move feedlots and to terrace fields to reduce the chemicals washing into the lake. But it could be years before the efforts pay off, and some residents want the problem solved now.

No one is sure why the problem is occurring now. Algae normally thrive in hot, sunny weather.

Warren suspects eight inches of rain in October might have flushed more phosphorus, a fertilizer component and the algae's favorite snack food, into the reservoir.

Val Smith, an ecologist at the University of Kansas who is studying Wichita's water woes, said that because no water has been released from the Cheney Reservoir since July 2001, phosphorous levels may have built up.

``It is like a bathtub when you close the drain,'' Smith said. ``Stuff comes in and doesn't go away. It just builds up.''

To make sure algae are the culprit, the city is shipping three months' worth of preserved water samples to the university for testing.

In Kansas, about five water supply lakes are prone to blue-green algae blooms, according to Ed Carney of the Kansas Department of Health and Environment.

Winfield, Olathe and Alma all get complaints.

In Lawrence, the blue-green algae got so bad in 1995 and 1996 that the city stopped taking water out of Clinton Reservoir.

So far, only one city in Kansas has solved its taste and odor problems: Emporia, which installed ozone technology about eight years ago at a cost of $1 million. Iola is considering the same technology.

Since Emporia added ozone to its water, odor complaints have stopped, although the extra oxygen sometimes gives the water a milky-white appearance that some residents don't care for.

``I don't think anybody would go back to the other way,'' said Phillip Cooper of the city's maintenance department.


Return to the U.S. Water News Archives page
Or
Return to the U.S. Water News Homepage


Editor@uswaternews.com

 

Forward this article to a friend:

*Your Name:  

*Your Email:  

*Friend's Email:  

Use a comma to separate e-mail addresses:

*Your Comments:

 

 

*Required Fields