A positive test for coliform bacteria in the North Crawford Schools water supply has forced the school to provide bottled water to students, staff and the cafeteria.
North Crawford District Administrator Dr. Dan Davies explained a quarterly water sample taken on Thursday, Nov. 12 was reported to be positive for coliform bacteria. A follow-up sample taken Monday, Nov. 16 was also positive for coliform bacteria.
Davies emphasized the positive samples for coliform bacteria do not indicate the more dangerous E Coli or fecal coliform.
“Coliform is not generally harmful and occurs naturally in the environment,” Davies explained. “It can be an indicator of other potentially harmful bacteria.”
Tony Knipfer, a DNR Water Supply Specialist, said the quarterly water sample tests are a simple pass-fail test for any amount of coliform bacteria. If a follow-up sample is positive, boiled water/bottled water advisory goes into effect. The DNR did not know the results of the Monday sample by Tuesday morning.
However, Davies said the school had a positive test on the Monday sample and responded by shutting down water fountains. The district began providing bottled drinking water for students and staff and large quantities of Culligan bottled water for use by the kitchen staff.
Tap water remains safe for use washing hands, showering and flushing toilets.
The school district intended to treat the entire water supply system Tuesday night by disinfecting it with chlorine. The plan called for flushing the system Wednesday waiting 24 hours to sample the water and then waiting another 24 hours for the results of that sample.
The DNR’s Knipfer explained that five water samples are required in the following month. If all prove negative for the presence of coliform bacteria, the district would resume its quarterly testing schedule. Any positive test would require a four sample test and a return to measures aimed at disinfecting the water supply system.
The DNR water supply specialist noted that a cursory computer check of bacteria testing of water samples in the North Crawford Schools showed a lack of problems going back into the 1990s.