Campus farms clean of bacteria, UA officials say
After almost three months of heavy chlorination, the UA Campus Agriculture Center's water has been declared clean of coliform bacteria and safe for human consumption.
The University of Arizona Facilities Management took a total of 40 samples in October along with the state requirement of four samples, to make sure the water was clean of coliform.
"All of those (samples) were clean," said Bill Witschi, UA water systems manager.
Since Sept. 10, the water at the agriculture center has been continuously chlorinated to rid the center's water of potentially dangerous bacteria.
Digestion of coliform bacteria can cause diarrhea, cramps, nausea, vomiting, jaundice, headache and fatigue.
Peter Else, the resident director of the center, said the farm's pipes were contaminated, not the university's ground water wells.
Else said they tried to flush the system by heavily chlorinating the water at one to three parts per million. Facilities workers then stopped all chlorination to check for contamination, and found more bacteria.
"The problem was when we tried to discontinue the chlorinating, one or two samples came up positive for coliform," he said.
The center has found that chlorinating the water supply at a level of one half to one part per million has kept the system clean of coliform.
"We're going to be safe and keep a little bit of chlorine in the water to keep the water safe," Else said. "It's chlorinated at about the same level as Tucson city water."
Else said chlorine levels may be increased to one to three parts per million if a repair has to be made on an underground water main. Any damage in the main would raise the chance of contamination.
One to three parts per million is about the same chlorine level as swimming pool water, Else added.
The chlorine level may also be increased if there is rainfall that results in a significant amount of standing water around the area or if any part of the system loses water pressure.
Witschi said while coliform showed up in both McKale Center, 1721 E. Enke Dr., and the Forbes Building, 1140 E. South Campus Dr., during the summer, the incidents were coincidental.
"For some very, very strange reason we had problems at Forbes then later at the CAC," Witschi said. "The CAC has different wells and a different water distribution system."
Witschi said all the water on campus is now chlorinated as a safety precaution.
As for bacteria showing up in the water system again, Witschi said it is unlikely.
"It can come back in the future," he said. "But with chlorine in (the water) it's extremely unlikely."