Half of Soda Fountains Studied Squirt Fecal Bacteria


Feel like a nice refreshing cold beverage at one of your favorite places? Be warned that whether you soda is self served or is served to you, almost half of all sodas dispensed from a sample of 30 machines in the Roanoke Valley in Virginia had coliform bacteria which is a bacteria banned in drinking water by the U.S. Environmental Protection Agency (EPA) because it indicates the possibility of fecal contamination.

“The EPA regulates our drinking supply, and there can be some bacteria, but one of the things that is not allowed is coliform bacteria,” said Renee D. Godard who is the co author of the study as well as apofessor of biology at Hollins.

“We can’t have that in our drinking supply. But they’re coming out of these soda fountain machines,” she said. The soda machines had turned into a bacteria metropolis with Escherichia coli (E. coli), species of Klebsiella, Staphylococcus, Stenotrophomonas, Candida, and Serratia.

“About 70 percent of the beverages had bacteria and 48 percent of them had coliform bacteria,” explained Godard, though only 20 percent of the sodas sampled had coliform bacteria that exceeded the EPA limit for drinking water.


The good news is that the tap water and ice from the machines didn’t test positive for bacteria, and the team was able to rule out the remote chance of a valley-wide contamination of the water supply.
The researchers tested a variety of brands soft drinks including diet, regular and water even water and discovered they were all contaminated leading Godard and her team to believe that it wasn’t the soda, but the machine that was growing bacteria.

Researchers are not sure where the bacteria came from and few people were observed in the restaurants touching the nozzles of the soda fountain machines and interviews with manages stated the nozzles were cleaned daily however, only manager reported rinsing the plastic tubing within the machines on a regular basis.

This leads Godard to think that it could only take one contamination of the nozzle for the bacteria to grow up into the plastic tubing and start spreading throughout the machine. “Our best guess is they’re actually establishing themselves on the lining of the plastic tubing. The reason we say that is in other areas, such as hospitals, it is known that bacteria can establish themselves on plastic tubing for machines,” said Godard.

Godard said she hopes the news will lead restaurant owners to rinse out their machines more often. “But my guess is that most restaurant owners wouldn’t have the vaguest idea about how to flush those machines, or that they would even need too,” she says.

Microbiologists not involved in the study weren’t surprised of coliform colonies in the soda fountain machines. “Wherever man is there will be representation of feces,” said Philip Tierno, director of Clinical Microbiology and Immunology at New York University Langone Medical Center. “We’re basically bathed in feces as a society,” he said.