Re-Inspection of Sanitary Sewer Conditions Seven Years Later: How Do 2005 Observations and Recommendations Compare to Today?

There are many ways to evaluate sanitary sewer collection systems. Most evaluations include extensive cleaning, CCTV video inspection, and NASSCO PACP defect coding of collection systems. These sewer inspections give a momentary snap shot of the condition of the pipe at the time of the inspection. But, how many times are these systems revisited to assess how the sewer changes over time with respect to structural defects, such as cracks and fractures, or O&M defects, such as roots and debris? This paper focuses on the 2013 re-evaluation of a portion of sanitary collection system in Columbus, Ohio that was previously cleaned, inspected, and evaluated in 2005. The analysis identifies locations within the system that have structurally degraded over time or re-grown heavy roots. This knowledge is expected to help owners and engineers optimize the timing of system improvements to avoid fixing sewer system components too soon or too late.