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Columbia Water & Light is owned and operated by the citizens of Columbia. The water utility makes every effort to provide quality water. For more than three decades Columbia’s water met or exceeded all standards set by the Environmental Protection Agency. Columbia’s water is tested more frequently and more thoroughly than is required by law. More than 4,000 tests are run each year on samples from 40 locations throughout Columbia. Through this testing the utility staff became aware of elevated levels of Total Trihalomethanes and is working to insure that Columbia’s water continues to be a high quality resource for our community.
third quarter status report: March 2009
second quarter status report: January 2009
first quarter status report: October 2008
The City of Columbia is now in compliance with the standards set by the Environmental Protection Agency for trihalomethanes. The most recent compliance sample (February 2009) showed that the level of trihalomethanes is at 75.3 micrograms per liter which makes the running annual average to 71.2 micrograms per liter. This is below the maximum contaminant level set by the Environmental Protection Agency of 80 micrograms per liter.
Trihalomethanes are a by-product of the disinfection process. They are formed when chlorine breaks down organic material in the water. Chlorine is added to the water to kill bacteria, viruses, and other organisms that could cause serious waterborne illnesses and death.
In 2007, Columbia’s water exceeded the Maximum Contaminant Level for Total Trihalomethanes (TTHM) and received a Notice of Violation from the Missouri Department of Natural Resources in April 2008.The average reported concentration for 2007 was 82.3 micrograms per liter. The average reported concentration for 2008 was 71.8 micrograms per liter. The Maximum Contaminant Level for Total Trihalomethanes is 80 micrograms per liter. In 2004, the Environmental Protection Agency lowered the Maximum Contaminant Level from 100 micrograms per liter to 80 micrograms per liter.
The levels of trihalomethanes have fluctuated and seasonally the levels have gone up over the years. The EPA lowered the Maximum Contaminant Level in 2004. Also the water distribution system has grown substantially since the plant was built and it takes longer for the water to reach the furthest parts of the distribution system. This means there is more time for the chemical reaction between the organic material and the chlorine to form trihalomethanes. In order to keep the levels of trihalomethanes low, the city has approval from the Missouri Department of Natural Resources to change the disinfection method.
The formation of trihalomethanes is a complex chemical reaction. The University of Missouri’s Water Resources Research Center has been consulted and will take over 1,400 water samples to help determine a solution. Due to previous samples of the water showing elevated levels of Total Trihalomethanes, the city must continue to look for ways to keep the levels well below the maximum contaminant level on a permanent basis. The data being presented to the city so far suggests that a different approach to treating the water must be pursued.
Columbia Water & Light has been working with the University of Missouri’s Water Resources Research Center and the Missouri Department of Natural Resources to add ammonia to the disinfection process which slows the formation potential of trihalomethanes. The Missouri Department of Natural Resources and the City Council has approved switching to this disinfection method.
Depending on the new equipment deliver schedule, Columbia Water & Light could switch to chloramines in late July or August. The estimated cost of adding ammonia to the water treatment process is less than $200,000. This money will come from the Columbia Water & Light reserve fund. Other long-term solutions, like changing the filtering process to remove more organic material will also be researched during a water treatment plant study conducted by an outside firm.
Chloramines are formed when ammonia is added to chlorinated water. Chloramines stop the formation of trihalomethanes. The chloramines treatment process has been used by water systems for almost 90 years and over 68 million people in the United States drink chloraminated water. Columbia Water & Light will go to this disinfection system in late July or August. depending on the equipment delivery date. A letter will be sent to water customers detailing the switch to the chloramine disinfection method before the system is converted.
Chloraminated water is safe for drinking and other general household activities. When water is ingested, the digestive process neutralizes the chloramines before they reach the bloodstream. However, chloraminated water going directly into the bloodstream can present problems. Both kidney dialysis patients and pet fish will be taking the water directly into their blood streams so additional measures should be taken to avoid complications.
Although water is considered to have no taste, there are subtle differences. Some people notice the difference between chlorinated water and chloraminated water. Mainly people report that they do not notice the taste or odor of chlorine as much with chloraminated water.
As suggested and approved by the Missouri Department of Natural Resources, the University of Missouri’s Water Resources Research Center has started collecting data to pinpoint problem areas. The first quarter report showed that there is a formation potential for Trihalomethanes in the wells but there is little variation between the wells. The results also show that the treatment process is not reducing the formation potential.
During the second quarter of research there were water samples taken at eight different locations throughout the distribution system. This data shows that the Trihalomethanes form quickly after the chlorine is added at the water treatment plant. They continue to form in the distribution system but at a slower rate. To effectively lower the amount of Trihalomethanes, a different approach to treating the water must be pursued.
The Water Resources Research Center has been studying the addition of ammonia to Columbia's water. The third quarter report shows the data from these tests. Adding ammonia led to a 50% drop in the level of trihalomethanes. The Water Resources Research Center will continue to take samples from Columbia's water system this summer and will provide one more report to the city.
Columbia is now in compliance with the standards set by the Environmental Protection Agency (EPA) for trihalomethanes. There is not an immediate danger in consuming water with elevated levels of trihalomethanes. They present problems over a long period of time. Long-term exposure to levels of trihalomethanes that exceed the Maximum Contaminant Level is a health concern. Consuming two liters of water per day for over 70 years could result in three to four cancers per 10,000 people, according to the Missouri Department of Natural Resources. They also report that there is no conclusive evidence that trihalomethanes are a health problem for pregnant women and the child they are carrying. Some research has been done but the studies did not take into account other health risks. According to the Environmental Protection Agency, people drinking water exceeding the standards for trihalomethanes over a long period of time might also experience problems with their liver, kidneys or central nervous system.
According to some of our resources, water customers can use activated carbon filters in a granulated form to remove trihalomethanes. Columbia Water & Light can not formally endorse these products since activated carbon filters have to be replaced as recommended otherwise other problems with the water can occur, like bacterial growth. You can find activated carbon filters in refrigerator bottles or install them in your home’s water supply. Make sure you follow the guidelines for changing the filters if you choose to use one.
No.
The Missouri Department of Natural Resources does not recommend reverse osmosis systems to remove Trihalomethanes. Activated carbon filters can remove trihalomethanes. Columbia Water & Light can not formally endorse activated carbon filters since they have to be replaced as recommended otherwise other problems with the water can occur, like bacterial growth.
Columbia Water & Light
P.O. Box 6015
E-mail: wlmail@GoColumbiaMo.com
Phone: 573-874-7325
Missouri Department of Natural Resources Northeast Regional Office
660-385-8000
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