Minneapolis will use drones to survey sewer problems

Aug. 17, 2017
The city is experimenting with the technology as part of its annual smoke testing of the sewers.

MINNEAPOLIS, MI, AUG 17, 2017 -- Some Minneapolis neighborhoods will use drones this fall to look for problems in the city's sewers, according to the Minneapolis Star-Tribune.

As part of its annual smoke testing of sewer lines, which helps crews spot trouble spots underground, the city will experiment with drones for assistance. This is the first time that the city's public works department will use drones in this way.

Officials said they will not be flying the drones over private property, though they did send letters to residents to let them know they may see a drone taking photos from above.

The city uses smoke testing to determine connections between the city's sanitary and stormwater sewer systems, which the city has" taken pains to separate to stop sewage spills during large rainfalls." Officials say the system is now more than 99 percent separated, and that smoke testing is the most effective way to find those remaining connections.

Crews pump smoke into the sanitary sewers and watch rooftops of nearby homes to see where the smoke comes out. If there is no smoke, or if that smoke comes out of a storm sewer opening on the street, there is a leak. The drones will enable the city to see the vents on top of large apartment buildings or in more industrial neighborhoods.

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