Bacteria blooming in UA's water

By Zach Thomas
Arizona Daily Wildcat
October 31, 1996

Chris Richards
Arizona Daily Wildcat

Faucets like this one in Chemistry and Biological Sciences connect to the campus-wide deionized water system, which has been plagued by bacteria contamination for the past week.


Three different types of bacteria were found in the UA's deionized water system Oct. 22, prompting the university to plan a system-wide hyperchlorination to get rid of the bugs, the UA vice president for research and graduate studies said.

"We have a bacterial bloom in the deionized water system," Michael A. Cusanovich said. "It's not in the drinking water system or the tap water system."

According to Cusanovich, the bacteria is causing problems in individual laboratories campus-wide.

"The bacteria are shedding through the system and plugging up and damaging the filtering systems at the individual lab level," he said.

Cusanovich said he hopes Facilities Management will be able to flush the system with super-chlorinated water "very soon," but that the flush has been delayed due to the process' complex logistics.

"My desire is to do it as soon as possible, but they've got to figure how and what they are going to do and how long it is going to take," he said.

Cusanovich, also a University of Arizona researcher, said bacterial appearances are not uncommon, but not on such a campus-wide scale.

"Within tanks in my own lab, I have blooms from time to time," he said. "This is first time it has actually mucked up the whole system."

The specific bacteria types have yet to be identified, but Cusanovich said UA bacteriologist Charles Gerba hoped to identify them by Friday.

"It's not Legionella," Cusanovich said, citing similar bacterial outbreaks plaguing University Medical Center's water system over the past year.

Cusanovich added the problem has been traced to the deionized system itself, not the system's tap water feeds.

"The tap water that is going in filters at the central plant is fine," he said. "It's probably something that got started in the deionized system which just built up and spread."

Under normal circumstances, deionized water is pure enough to drink, Cusanovich said. He cited the lack of backflow valves on the deionized system which make the water not potable. Backflow valves, used in all tap water systems, prevent water from flowing back into mains.

"They (researchers) are not supposed to drink it," he said.

"We haven't had any reports of any illnesses as a result of this," Cusanovich said, "but I can't tell you that somebody hasn't drunk it at some point."

Ronald LeBlanc, an engineer in the chemical and environmental engineering department, admitted some researchers do use the deionized system to make coffee.

"I definitely advised the parties not to do that," he said in light of the contamination.

The deionized water system carries water with smaller amounts of metals and organic materials in it to UA research facilities than ordinary water, he said.

"It is separate from the tap water system."

The deionized system is fed by tap water which is then purified and filtered before it enters a campus-wide network of pipes.

Cusanovich added that even the water that comes out of deionized taps is typically refiltered before laboratory use.

"Deionizing and filtering does not get you super-high quality water," Cusanovich said, "but it gets a reasonable quality for most uses."

Cusanovich said the bloom is in part a consequence of the high well water temperature during the Arizona summer.

"It is the absolutely perfect bug-growing temperature," he said.

Cusanovich reportedly sent notices to all affected departments Tuesday, which informed the deans of the problem.

LeBlanc said he posted the notices throughout his department, but added that the note was too vague.

"I wish they had been a little more informative in their urgent notice," he said.