The state Department of Health has not seen an increase in the number of sick people in Aberdeen sinceE. colilevels exceeded drinking standards.
Aberdeen officials announced Wednesday that the city exceeded the drinking water standard for E. coli in June. Because of that, people in an 80-block area of Aberdeen are being urged to boil their drinking water.
“We've called every clinic in Aberdeen and asked them to be alert for people with gastrointestinal symptoms,” state epidemiologist Lon Kightlinger said Wednesday.
Those symptoms, which include diarrhea, vomiting, intestinal cramps and nausea, could be caused by E. coli and coliform contamination in water, he said.
So far, “we have not noticed an increase” in people with those problems visiting Aberdeen clinics, he said.
People would get sick anywhere from 24 to 72 hours after they drank contaminated water, Kightlinger said.
The affected area of Aberdeen is from North Washington Street to North High Street and from Fourth Avenue Northeast to 12th Avenue Northeast.
The city is required to test 30 of its 35 sites each month. The final 10 were tested Tuesday. Those results won't be back until today, said city manager Lynn Lander.
After the city's normal sampling process June 12, a positive E. coli result showed up in water collected at O.M. Tiffany Elementary School. That school is one of the 35 sites the city uses, said Janel Ellingson, superintendent of Aberdeen's water treatment plant.
On Monday, the city resampled the O.M. Tiffany location and two other sites — one upstream and one downstream. E. coli was not found at the O.M. Tiffany location, but it did turn up at one of the other sites, an apartment complex a block north of O.M. Tiffany.
Until further notice, people who live in the 80-block area should boil water for one minute and let it cool before drinking it. They may also use bottled water.
It is safe to bathe in the water.
“Just don't swallow it,” Kightlinger said.
In the affected area, boiled or bottled water should be used for drinking, making ice, brushing teeth, washing dishes and food preparation.
Boiling kills bacteria and other organisms in the water.
All Aberdeen residents are welcome to boil their drinking water. But the 80-block area is the area where officials believe something specific is going on, Ellingson said.
A member of Ellingson's staff, Tim Murray, was collecting chlorine and bacteria samples Wednesday to help narrow down where the problem is, she said.
In addition, the city has increased the amount of chlorine in the water coming from the water treatment plant into town. People should not be alarmed if they notice additional chlorine in their water, Lander said.
A trailer from the South Dakota Association of Rural Water Systems was on its way to Aberdeen on Wednesday. That trailer has the ability to inject a chlorine solution into the water “and will hyperchlorinate the area that we believe is affected,” Ellingson said. The city will also flush that area, she said.
Assistant city engineer Stu Nelson said that people should not panic. Officials believe the problem is in the water distribution system, not the water treatment plant, Nelson said.
City officials said the city has not had a positive test for E. coli for at least 14 years, and possibly longer.
Ellingson said the water should not be a problem for dogs because many pets often drink out of puddles. She also said gardeners who have watered their plants with city water will be fine as long as they wash the produce before eating.
To see if a filter is effective in treating contaminated water, people should look on the package to see if it removes bacteria, Ellingson said.
—Scott Feldman contributed to this report