DALLAS -- Dallas officials are testing the waters -- and finding coliform bacteria.
Dallas water users might notice their tap water smells like a swimming pool. City officials are flushing the system with more chlorine than usual after discovering the harmless organisms.
The chlorine level will stay well within limits for all use, including drinking, said Dave Leland, drinking water program manager with the state Health Division.
Dallas tested positive for coliform bacteria throughout the water system. The bacteria, though not harmful to humans, show the possibility of disease-causing pollutants in the water.
No E. coli or fecal coliform were found in Dallas' water supply. Coliform from animal waste can point to the presence of giardia or cryptosporidium in the water, Leland said.
At that point, health officials recommend boiling water. There is no need to boil Dallas water, Leland said.
The positive tests in Dallas came from a film forming on top of water-holding tanks, said City Manager Roger Jordan. These tanks have been cut off from the water system for cleaning.
Dallas water should return to its normal chlorine level by Monday, Jordan said.
Coliforms don't mean Dallas' water treatment is inadequate, Leland said. "No treatment system on the planet is 100 percent effective.
"Drinking water is not completely sterile."
Dallas tests its water more than 15 times a month, Leland said. The coliform just alerts officials to stay watchful. "This is our alarm system."