One of the 30 monthly tests of Aberdeen's water supply had to be taken again in May, but the issue was not significant, said Janel Ellingson, superintendent of Aberdeen's water treatment plant.
Bacteria was found in one of the tests for total bacteria the city does each month. There was no sign of fecal bacteria.
Another test was done at the site, which turned out fine, Ellingson said. When a positive total bacteria result is found, two other sites are also tested — above and below the area in question.
“They were all three clear,” Ellingson said.
Finding bacteria in one test out of 30 does not constitute a problem, said city manager Lynn Lander. No fecal bacteria have been found in Aberdeen's water this year, Ellingson said.
The situation was different a year ago, when Aberdeen twice exceeded drinking water standards for E. coli. E. coli carries health concerns because it is a bacteria that has a fecal source.
The water involved came from O.M. Tiffany Elementary School and an apartment complex north of the school. The Annual Water Quality Report recently mailed by the city points out that Aberdeen has been back in compliance since June 30, 2012.
Like other cities, Aberdeen is required to sample its water for bacteria under the federal Safe Drinking Water Act.
Ellingson believes that the the E. coli problem last year did not really involve the city's water system. It had more to do with the facilities where water samples are taken, she said.
Those facilities include schools and businesses.
“So, if you don't run your water all summer and we go there to take a test, it's probably your facility that has the problem, not our distribution system,” Lander said.
Water from most of Aberdeen's schools are sampled as part of the water testing, Ellingson said. Samples are taken from 35 sites over the course of a year. Thirty of those are chosen each month.
A couple of changes have been made as a result of last year's water safety problems, Ellingson said.
The city rerouted the water for the apartment building involved so that it receives fresher water. It's a more direct connection than the building had in the past.
The schools, including Tiffany, have also implemented a flushing program, Ellingson said. Maintenance people at the schools are flushing water through the building, she said.
In addition, information is shared from a meeting the utility department has every Monday morning. At that meeting, workers discuss their plans for the week. A copy of that plan is given to Ellingson and other water employees.
That way they know if work will be done that might disrupt the flow in that area. That might affect the time a sample will be taken.
“If we're going to sample in that area — if that's one of the areas we need to do — we'll either sample before they get there or we'll make sure that we sample after they’re finished with the work, so that the likelihood of contamination is decreased,” Ellingson said. “Because once they're finished, the area should be flushed out and ready to go.”
Ten of the 30 monthly samples are taken each week. The city tries to scatter those samples around the city.
“So that each week we sample, we get kind of a good representation throughout town rather than just one area,” she said.