|
January 7, 2003
Omaha World-HeraldTwo weeks' notice: Your water will change
by Nancy Gaarder, Omaha World-HeraldTo meet tougher federal standards that reduce the potential for suspected cancer-causing agents to form, the Metropolitan Utilities District is changing the way it treats water.
For most of M.U.D.'s 176,000 customers, the change simply means that their water may taste and smell better.
Chemist Marian Feltes checks for contaminants in water at the Metropolitan Utilities District treatment plant. M.U.D. will go online with its new treatment process Jan. 21.
But dialysis centers and people who own aquariums will need to alter the way they pretreat their water. Some laboratories and industries may also need to pretreat water.
The change goes into effect Jan. 21.
Even though some people need to take precautions with how they use the water, it will be safe for anyone to drink, said Tom Wurtz, M.U.D. general manager. The body's digestive system neutralizes the additive that M.U.D. will be using, he said.
"It is very safe to drink," said Jack Hoffbuhr, executive director of the American Water Works Association.
Under the new process, M.U.D. will begin using ammonia in addition to chlorine to disinfect water. The combination of ammonia and chlorine is called chloramine. Chloramines are an approved method of treating water, according to the Environmental Protection Agency.
About 20 percent of water utilities use chloramines and some have been using them for decades, Hoffbuhr said. Both Lincoln and Council Bluffs use chloramines.
The other 80 percent of utilities use other water treatments, including chlorine only, which is what M.U.D. has been using, granular activated carbon to membrane filters.
Because chloramines are toxic when they enter the bloodstream, M.U.D. has alerted local dialysis centers of the change. Water from the dialysis process comes in contact with the blood through a permeable membrane.
Ed Egger, director of communications for Gambro Healthcare, which operates several clinics in Omaha, said the clinics have had plenty of time to make the needed changes.
The Douglas-Sarpy County Extension Office has been researching chloramines to provide an independent assessment of the change, said Sharon Skipton, extension educator. The organization has compiled a pamphlet on chloramines. To get a copy, call the office (444.7804), stop by or log on to its website.
Click here to go to the University of Nebraska Extension Office site for more information on chloramines. E-mail questions.
Hardy houseplants and outdoor landscaping should be fine. If you have the kind of plants that require leaving your tap water out overnight before watering them, you may want to pretreat your water, Skipton said. That is because the chlorine will no longer evaporate from your water.
Skipton said the primary impact will be on those with aquariums.
Kyle Haeffner, owner of the Fish Store in Lincoln, recommends that aquarium owners simply add the appropriate chemical to their tanks. That, he said, is more reliable than trusting the carbon filter on your faucet to be working properly.
If you want to filter the chloramines out of your water, you can put a carbon filter on your tap or home water system. You will need to follow the manufacturer's instructions closely because at some point the filter will become exhausted and ineffective.
One question people may have involves the safety of mixing chlorine and ammonia. Most people know that mixing the two at home produces a toxic gas. That is not a problem with chloramines, according to M.U.D., because the concentration of the materials is much smaller than it would be if you mixed the chemicals accidentally at home. Also, because chloramine is dissolved into the water, it is not available to the air as a gas.
The ammonia is being added by M.U.D. as a way of resolving a Catch-22 that comes with the use of chlorine.
Chlorine makes dirty water safe to drink by killing harmful organisms that can cause such diseases as typhoid and cholera. But chlorine binds with naturally occurring organisms in water to form trihalomethanes, which are suspected of causing cancer. There may also be a link between trihalomethanes and birth defects, but that has not been confirmed.
The dirtier water is, and the more chlorine in it, the higher the potential for trihalomethanes to form. (This is a problem for utilities that draw water from rivers and lakes, not aquifers.)
Furthermore, chlorine evaporates easily, and once it has evaporated, it no longer is there to disinfect water. Because of that, water companies give their treated water a final shot of chlorine before it leaves their plants. That is to guarantee that enough chlorine remains in the water to do its job through hundreds of miles of pipeline. M.U.D., for example, has 2,300 miles of pipe.
With chloramines, the ammonia binds to the chlorine molecule and stabilizes it. That means two things: Less chlorine is needed to treat water, and the chlorine that is in the water will not evaporate nearly as easily.
The amount of trihalomethanes in Omaha's water varies from month to month. Typically, trihalomethanes are at their highest in M.U.D.'s water during the spring runoff. That's because so much organic matter is being flushed from fields into the Missouri River.
The EPA has reduced the average amount of trihalomethanes allowed in water to 80 parts per billion, down from 100 parts per billion. The change took effect in December 2001, and state health officials granted M.U.D. an extension to bring its new treatment process on line. M.U.D. has been averaging 74 parts per billion.
M.U.D. has spent about $3.7 million bringing the new system online and will spend about $200,000 a year operating it.
Because M.U.D. has so many miles of pipeline, it may take a week to 10 days for the newly treated water to reach everyone's tap.