City water supply system tapping into Mizzou Engineering expertise

Mizzou Engineering Assistant Professor Enos Inniss, center, leads a research team gathering City of Columbia water samples to help determine the source of cancer-causing byproducts in the supply system. Ben Williams, an MU civil engineering junior at left, and Blaise Brazos, Columbia’s water quality treatment specialist, have helped collect more than 90 samples from city wells. Photo by Vicki Hodder

University of Missouri engineering researchers are in the midst of their first seasonal analysis of Columbia’s well water to help determine the source of cancer-causing byproducts in the city’s water supply system.

City officials announced last spring that Columbia’s drinking water exceeded Environmental Protection Agency limits on trihalomethanes (THMs), a group of disinfection byproducts that are formed when chlorine used to prevent water-borne diseases reacts with naturally occurring organic materials. Long-term exposure to THMs can cause cancer in three or four of every 10,000 people, officials said.

Columbia subsequently hired Mizzou’s Water Resources Research Center for $91,000 to find out where and how these disinfection byproducts (DBPs) enter or are formed in the supply system. The engineering team is sampling Columbia’s water 1,400 times—taking several hundred samples at each treatment stage—to develop a chemical profile of the water for each season of the year, said Enos Inniss, a civil and environmental engineering assistant professor who is leading the research team.

“We want to go to the wells and treatment process and ask where and when the DBPs are entering the system,” Inniss said. “Once we know, the city can make better choices on ways to get the system back into compliance.”

Mizzou’s researchers have taken about 92 samples from Columbia’s 15 motor-driven wells, which supply the city water treatment process, Inniss said. Sampling to create the summer water profile for all the components of Columbia’s water supply system—that is, its wells, treatment plant and distribution system—will be complete by the end of August, he said.

Analysis likely will continue showing high THM levels during the summer sampling, since higher temperatures stimulate the chemical reaction that creates them, Inniss said.

The MU water research team will conduct similar analyses on the water supply system throughout the year. Once a year-round profile of the water system is completed in June 2009, city officials will better be able to determine how to reduce THM levels, the Mizzou researchers said.

Several Missouri water supply systems face similar issues, said CoE Research Associate Professor Robert Reed, who is collaborating with Inniss on the Columbia water analysis project.

Reed has been working for the last two years with the City of Boonville to reduce the level of THMs in its drinking water. Given that the federal limits on THMs are fairly new, many communities lack the expertise required to comply with those standards, Reed said.

That deficiency is something else the MU engineering team hopes to help resolve.

“At the end of the year, we’ll have information that not only the City of Columbia but other people can use to better deal with this problem in the future,” Inniss said.