A Program Of The

City Of Columbia

Sewer Line Rapid Assessment Tool (SL-RATâ„¢) Improves Inspections, Reduces Cost

CW2020 Employee Newsletter Vol. 4, No. 2

SL RAT inspection

The Wastewater Maintenance Division (WWD) began using the Sewer Line Rapid Assessment Tool (SL-RAT™) by InfoSense last year in its inspection program as part of its long-term effort to reduce the number of sanitary sewer overflows (SSOs) in the system. The SL-RAT™ uses sound waves bounced between two manholes to quickly identify pipes in need of maintenance or repair. It has become a critical piece of equipment for helping the WWD more efficiently deploy maintenance staff and equipment. Since 2014, the City has inspected approximately 317 miles of sewer lines. 

WWD Superintendent Robert Judy noted that, “Since we began using this new technology, we have seen a significant reduction in emergency calls for stoppages.” According to Judy, “The commitment to success by our employees is really what makes this thing work well for us.”  

Sound waves naturally follow a pipe’s curvature. The SL-RAT™ detects problems in a pipe when a portion of the acoustic energy is reflected and absorbed by obstructions, blockages, and defects. The SL-RAT™ can also be rapidly deployed as it does not require a robotic transporter to capture pipe data. This technology has allowed WWD staff to inspect the sewer system more rapidly and with less expense. 

Recently, the WWD deployed a second SL-RAT™ inspection team with a second unit and two additional employees. “We expect this to further improve our inspection and preventive maintenance program into the new fiscal year,” states Judy.