A rising tide of calls for Mizzou Engineering water expertise
Several public water suppliers struggling to meet tougher federal standards are tapping Mizzou Engineering water quality experts in hopes of finding ways to remove cancer-causing byproducts from their systems.
Mizzou Engineering’s Water Resources Research Center already is working with Columbia and Boonville to discover exactly where and how excess disinfection byproducts (DBPs) that could cause cancer get into their supply systems. Engineering researchers in December started analyzing the Marceline and Trenton public water systems in north central Missouri to lay the foundation for DBP-reducing techniques they hope can be widely employed.
“We’d like to take what we learn in Missouri and apply it throughout the country,” said Tom Clevenger, a civil and environmental engineering professor who serves as the MU Water Resources Research Center’s (MWRRC) director. “Even though the water chemistry differs in different areas, the methodologies we develop will be uniform.”
Water supply systems across the nation have reported DBP violations since new Environmental Protection Agency limits started taking effect in December 2001. DBPs are formed when chlorine—widely used to prevent water-borne diseases—reacts with naturally occurring organic materials, such as decaying leaves.
The new EPA standards reduced the allowable level of one type of DBP, trihalomethanes (THMs), while limiting another type of DBP, haloacetic acids, for the first time, said Terry Timmons, a monitoring section chief for the Missouri Department of Natural Resources public drinking water branch. The regulations create a “double-edged sword” for a number of water supply systems, since some tactics for cutting THMs may increase haloacetic acids, Timmons said.
In 2008, 17 of the 1,730 Missouri public water systems regulated for DBPs violated EPA standards, Timmons said.
A growing number of public water suppliers are turning to the MWRRC for help. Marceline and Trenton hired the MWRRC last fall to sample their water at several points in their supply systems, and a contract with Monroe City is in the works, Clevenger said.
Led by Clevenger as well as engineering Research Associate Professor Robert Reed and Assistant Professor Enos Inniss, the MWRRC research teams will analyze the chemical makeup of water within each community’s treatment plant, water storage towers and distribution system throughout the year. Marceline’s analysis will include samples from water distributed by the Chariton-Linn Public Water Supply District No. 3, which the city supplies, Reed said.
The researchers then will test how certain chemicals affect the water samples in order to identify options for complying with EPA guidelines. For example, the MU research teams will examine how different forms of chlorine and activated carbon, which acts as a molecular sponge to soak up certain chemicals, affect the water within these systems, Reed said.
Differences in water chemistry call for customized disinfection processes, the MU researchers said.
“Some things that work for one city won’t work for another city,” Clevenger said.
In Columbia, Inniss said his team has determined through nearly 800 water samples that the city’s excess DBPs stem from the chemical composition of its well water, rather than from its treatment process or distribution system. That finding will kick off a series of tests to explore how Columbia’s water reacts with different purifying or treatment enhancing chemicals, Inniss said.
“We’ve essentially confirmed with this quarter’s analyses that there needs to be a change in the treatment process,” he said.
Inniss said his research team will continue sampling Columbia’s water at each treatment stage through next June. The year-round profile of Columbia’s water system will help city officials settle on the best methods for reducing THM levels, he said.
The MWRRC has helped the City of Boonville reduce the level of THMs in its drinking water over the last two years by analyzing changes in DBP levels before and after the city modifies its treatment processes.