Hold the water, please! 

Test results from the Environmental Protection Agency showed that the water used to make coffee and tea in 12 percent of commercial planes in the U.S. tested positive for coliform in 2012, according to the New York Daily News. 

The findings come years after the EPA launched an effort to reduce bacteria in drinking water on planes. In 2004, the EPA found the water in one in every 10 planes, 15 percent, tested positive for coliform. While that particular kind of bacteria is not known for making people sick, its presence may indicate that more bacteria is present. 

"I would say that's still a high percentage," said Bill Honker, deputy director of the Water Quality Protection Division, EPA Region 6. "So we're expecting to see further improvement by all the airlines in the country."

The Daily News reported that most airlines use bottled water for the drink cart, but coffee and hot tea are often made with the water from airplane's tank. The water on the airplanes are reportedly tested for coliform and E. coli once a year. 

"I think there is more that needs to be done," Honker said.

Coliforms are bacteria that are always present in the digestive tracts of animals, including humans, and are found in their wastes. They are also found in plant and soil material. Some symptoms include diarrhea, gastroenteritis, typhoid fever and urinary tract infections