Water treatment at UA farm will conclude today
After about three weeks of flushing out water pipes to kill bacteria at the Campus Agricultural Center, chlorine pumping will end today to test if the water is clean.
Since late August, the water distribution system at the farming center, located a few miles north of campus, has been contaminated with coliform bacteria, which could cause illness if consumed by humans.
Bill Witschi, University of Arizona water systems manager, said to his knowledge no one has reported illness related to the contamination.
Witschi said bottled water will continue to be supplied for human consumption "until we are 100 percent sure the entire distribution system doesn't have any coliform bacteria."
UA Facilities Management will take 20 water samples from the various locations throughout the farming grounds to see if the chlorine treatment was effective, he said. The first test - taken earlier this month - showed one of 20 samples still contained bacteria.
Peter Else, resident director of the center, said the treatment has taken so long because of the large area of land on North Campbell Avenue that the farms operate on.
About 380 cattle live on the farms and five on-site staff houses in the area use the same water supply. The cattle continued to drink the chlorinated water, and have not been affected, Else said.
"It's been a big project," he said, adding that the "hundreds and hundreds" of hours of work have gone into the treatment.
Else said some sections of the piping were installed as far back as the 1950s, which could have contributed to the problem.
"When you have an old plumbing system like we do, you've got a lot of old pipes," he said.
Old pipes can often raise the likelihood of contamination, Else said.
The contamination at the agricultural center is the third appearance of coliform bacteria at the UA in recent months.
Both McKale Center, 1721 E. Enke Dr., and the Forbes Building, 1140 E. South Campus Dr., shut off their drinking water supply after the same bacteria appeared in routine tests.
The water in both buildings tested clean after two weeks of chlorine treatment.
Witschi said in his 22 years with the UA, he has never seen coliform contamination in the water supply, and could not explain the recent incidents.
"It's awfully coincidental," he said, adding that the Arizona Department of Environmental Quality has reported similar water pollution recently.
He attributed the appearance of the bacteria to frequent rain storms, which can lead to standing water backwashing into pipe systems.
Part of the problem with the infection of bacteria can stem from "dead leg" pipes - lengths of pipe that don't lead anywhere, Witschi said. The coliform can linger in the dead ends where the chlorine treatment can't flow.
To prevent future contamination, facilities management will begin chlorinating the farms periodically. For the first time since 1994, facilities management began constantly treating the UA main campus with chlorine a few months ago.
"It became almost fashionable not to put chlorine in the water," he said.
Tucson water is constantly treated with chlorine.