Tests reveal no trace of E. coli
Clearwater officials are still trying to determine how the bacteria appeared earlier in the water supply.
By AARON SHAROCKMAN
Published December 25, 2004
CLEARWATER - For the first time since August, the city's drinking water system does not include traces of E. coli bacteria, testing this month revealed.
City officials, however, remain puzzled on how the bacteria, which can indicate the presence of serious waterborne diseases, appeared in the city's potable water supply at all.
A group of independent experts studying the problem hopes to have some answers next month, city utilities director Andy Neff said.
From September through November, 21 different water samples tested positive for E. coli. The hits have been scattered throughout the city, puzzling city officials who were unable to discern any pattern.
Earlier this month, utilities crews tested 110 drinking water samples from across the city. All, Neff said, were free of E. coli.
"We're certainly happy that we're getting negative results from the sampling program," Neff said. "But we need to understand better what happened back in September. So far, there's no clear signal of a single event that caused anything to happen."
E. coli, a bacteria commonly found in animal and human intestines, can indicate the presence of life-threatening diseases, including cholera, dysentery and typhoid. The E. coli strain that was present in Clearwater's water system was not harmful by itself, Pinellas County Health Department officials said.
And no human cases of waterborne diseases have been reported to health officials, they say.
Neff said a panel of experts has launched an $87,000 audit to identify the cause. One hypothesis, Neff said, is that the busy hurricane season contributed to the positive test samples.
But no other Pinellas County water system has had similar problems.
"It's like finding a needle in many haystacks," Neff said. "But we're continuing to work through information, trying to narrow down the possible causes. For now, we're really sort of focusing on what we can eliminate as a potential source. Once we narrow the scope, hopefully we can better understand what happened."
Along with E. coli hits, earlier samples revealed the presence of coliforms, a broader family of bacteria that includes E. coli. Coliforms indicate biological activity in the system, Neff said, but like the Clearwater E. coli strain, they are not by themselves harmful.
In September, the city issued three localized boil-water notices for residents when multiple samples collected from those areas tested positive for coliforms.
Clearwater receives about 70 percent of its water from Pinellas County Utilities. The other 30 percent comes from the city's own underground well system. Officials have not learned whether the problem is specific to the water source or the filtration and processing system.
It could also be human error.
"There's a lot of work that still needs to be done in terms of the modeling and looking at different scenarios in the water system to determine what could have resulted in getting these samples," Neff said. "It's no small task."
Aaron Sharockman can be reached at 727 445-4160 or asharockman@sptimes.com