Water and Wastewater Commission learns cause of foamy water

On Jan. 22, residents in South Austin reported foamy water in their taps following the Austin Fire Department’s extinguishing of a church fire.

At the Feb. 12 meeting of the Water and Wastewater Commission, Rick Coronado, the assistant director of Austin Water, told commissioners that the foam was a benign substance. “Essentially it’s a soap in the water,” he said.

The water utility sent samples of the foamy water to a third-party lab and also performed some in-house testing.

“All the bacteriological tests were fine,” Coronado said. Other tests were positive for surfactants, which are carbon compounds that lower the surface tension between two liquids and are used by firefighters as foaming agents. Tests taken the day following the initial reports did not show any sign of surfactants.

The soap is a Class A foam that the fire department adds to water in order to help it penetrate and soak into building materials more thoroughly. The reason the foam escaped into the city water lines, Coronado explained, is that the engine that was fighting the fire was still connected to a fire hydrant that was over-pressurized, causing the foam to back-feed into the distribution system.

The foam event lasted for less than an hour, according to both the Fire Department and the pressure data collected by Austin Water. Due to the short duration of the event, the foam nearby residents saw was heavily diluted and there were no reports of illness. “We did not see any comments that they were sick,” said Coronado.

Austin Water used reverse 911 calls, door hangers and social media outreach to inform residents not to drink the water while the pipes were being flushed.

By the next day, Austin Water declared that the water was again potable. To avoid any potential ill health effects, however, the utility provided two days’ worth of bottled drinking water to nearby Kocurek Elementary School.

An event like this is rare, Coronado said, adding that he has never experienced such a thing in his tenure with Austin Water. Still, he said the Fire Department has updated some of its procedures and will incorporate training in the academy to prevent future incidences of foamy water in the taps.

The Austin Monitor’s work is made possible by donations from the community. Though our reporting covers donors from time to time, we are careful to keep business and editorial efforts separate while maintaining transparency. A complete list of donors is available here, and our code of ethics is explained here.