City ‘smoke testing’ wastewater lines

If you think you’ve been seeing unusual puffs of smoke over the past two weeks, you’re not seeing things.

The City of Atlanta is smoke testing their wastewater lines in certain areas of town where they believe storm water is infiltrating the system.

Just what is smoke testing? Well, it’s a very lowtech solution to a difficult to find problem. A blower is connected to a sewer manhole that injects a huge volume of smoke. The smoke meanders it way through the lines, and if there is a hole in the line the smoke will show up.

Already the testing has netted results, even though the complete report hasn’t been turned in to City staff. City Manager David Cockrell said, “We’ve watched smoke coming out of the ground in a ditches covered with grass that we would have never been able to find otherwise. We’ve also seen smoke leeching from manhole rings and lids.”

Storm water infiltrating the sewage system is a real problem. The City of Atlanta maintains nearly 72 miles of underground gravity sewer lines. So the problems of infiltration can quickly add up, inundating the City’s wastewater plant during heavy rains.

“The wastewater plant typically treats around 850,000 gallons of raw sewage every day, and our goal is to maintain as close to that level as possible during storm events” Cockrell said.

The areas where smoke testing is being performed is U.S. Highway 59 and Hwy 995 and the Indian Hills subdivision.

Cockrell said he expects to see the final report in the coming weeks and repairs will begin immediately after turning the report over to the City Council.