How Santa Barbara is fixing its sewer system using sound

Oct 15, 2015

Residents and visitors to Santa Barbara could hear some unusual sounds in the coming weeks as the city works to improve its sewer system.

Credit City of Santa Barbara

Walk down a city street in Santa Barbara over the next month or so, and you may hear the tones of an acoustic sewer inspection. A device at one end of the pipe sends sound through the pipe to a receiving device at the other end. 

Manuel Romero is the Wastewater Collection Superintendent for Santa Barbara and said the process takes just a few minutes.

"It measures the energy gap through the airspace above the sewage flow and the pipe wall. And thus any defects or obstructions, for example, roots, or grease or any type of debris, or even offsets, that allows the sound energy to be blocked," said Romero.

In the end, you get a numerical rating that tells you how clear the pipe is.

The city says they've recently seen a higher number of sewage overflows that they would like, so some 2,000 sewer pipes will be tested through November.

They haven't done a cost-benefit analysis, but the project will likely save the city money, said Romero.

He said acoustic inspections won't completely replace traditional methods for surveying and cleaning, but the technology does allow them to skip already clear pipes, giving them more time to focus on the ones that need work.