City of Columbia MobileMobile device users, tell us how we can improve your experience.
City of Columbia MobileMobile device users, tell us how we can improve your experience.
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. Research led the utility to switch disinfection methods in August 2009 which has lowered the level of total trihalomethanes by 50 percent. Other treatment methods are currently being researched.
Watch a video about the Columbia water system.
The City of Columbia's is in compliance with all water quality standards set by the Environmental Protection Agency. The last two total trihalomethane quarterly samples in 2008 were 39.0 and 39.5 micrograms per liter. The maximum contaminant level is 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.
Columbia received a Notice of Violation from the Missouri Department of Natural Resources in 2008 that the water exceeded the Maximum Contaminant Level for Total Trihalomethanes (TTHM).
Columbia Water & Light moved to a chloramine disinfection system in August 2009 and the level of total trihalomethanes dropped by almost 50%. Both the Missouri Department of Natural Resources and the Columbia City Council approved switching to this disinfection method because research showed that the chloramine disinfection process would slow the formation of total trihalomethanes. The cost of the equipment to switch to chloramines was $180,000 which came from the Columbia Water & Light reserve fund. Other treatment options to lower total trihalomethanes are being researched during a study being conducted by an outside firm.
Chloramines are formed when ammonia is added to chlorinated water. Chloramines slow the formation of trihalomethanes. The chloramine 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 switched to this disinfection system in August 2009. The amount of ammonia added to the water is a very small amount. It is the equivalent of 6 grains of table salt in a gallon of water.
Chloraminated water is safe for drinking, bathing, cooking, gardening and other household tasks. As with chlorine, the chloramine should be removed from the water when used in kidney dialysis machines. Patients undergoing dialysis should check with their doctors about the dialysis filtering method being used. Chloramine must also be removed before using the water in fish tanks. Products for chloramine removal are available through aquarium supply stores.
Approximately two milligrams per liter. For comparison, this would be similar to adding six grains of table salt to a one gallon container of water.
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.
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 switched to the chloramine disinfection method as approved by the Missouri Department of Natural Resources.
The formation of trihalomethanes is a complex chemical reaction. The University of Missouri’s Water Resources Research Center took over 1,400 water samples to analyze the situation with disinfection by-products. The data presented to the city suggested a different approach to treating the water. In August, the city switched disinfection methods. A study is also being conducted by an outside firm on other treatment options at the water plant.
FINAL REPORT: Download the Water Resources Research Center's final report on disinfection by-products in Columbia's water system.
As suggested and approved by the Missouri Department of Natural Resources, the University of Missouri’s Water Resources Research Center collected 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 chlorine treatment process is not reducing the formation potential. Download the first quarter status report (October 2008)
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. Download the third quarter status report (March 2009)
The Water Resources Research Center has been studying the chloramine disinfection method for Columbia's water. The third quarter report shows the data from these tests. Switching to chloramines led to a 50% drop in the level of trihalomethanes. Download the second quarter status report ( January 2009 )
During the fourth quarter of research, the Water Resources Research Center did more research on the effects of chloramine disinfection. Results from this quarter matched previous studies that showed the disinfection by products were lowered by about 50%. Other treatment methods were also mentioned in the report to help control disinfection by-products. Download the fourth quarter status report (July 2009)
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
privacy & use policy
linking policy
download plugins
about this site
multi-language
contact the webmaster
