DEKALB CO., GA (CBS46)—DeKalb County stormwater employees are searching for structural defects in their stormwater system after two massive sewer spills.
According to DeKalb County officials, heavy rainfall at the beginning of March caused a 6.9 million-gallon spill on Meadow Creek Path and there was another 9.2 million-gallon sewer spill at the same site in February.
Both spills caused stormwater intrusions into the wastewater system.
County officials said stormwater intrusions occur when rainwater enters the wastewater system from a structural defect.
The structural defect can include broken or damaged sewer lines, root intrusion, and aging infrastructure.
Officials are working to identify the location of the stormwater intrusion, however, they say this process is challenging because the actual source of the intrusion could be located miles away from the actual spill site.
DeKalb County’s wastewater system includes 2,600 miles of pipes-further than the distance from Atlanta to Los Angeles, according to a DeKalb County spokesperson.
Also, the county has 70,000 manholes and during early March’s rainfall, there was intrusion in 16 of the 70,000 manholes.
DeKalb County CEO Michael Thurmond has said “identifying the source or sources of stormwater intrusion that caused the spills along Meadow Creek Path as a top priority.”
The county is using the following detection methods:
• Helicopter flyovers
• Drones flight investigations
• Ultrasonic tracking
• Sonar testing
• Visual observations while walking miles of sewer pipes during storms
• Flow monitoring
• Smoke testing
“Prior to rain events, DeKalb crews are engaged in proactively monitoring the system, securing resources, and preparing mobile response units. After all sewer spills, DeKalb crews work to mitigate health concerns”, a DeKalb County spokesperson wrote.
In 2017, DeKalb County began its 10-year plan to fix its wastewater system, spending more than $301 million in capital improvements.
The capital improvements included wastewater treatment plant upgrades, sewer pipe rehabilitation, manhole repairs and replacement, and lift station renovations.