Sewer Cleaning & MaintenanceIntermediate 26 min read

Sewer Cleaning & Maintenance: System Optimization

Risk-based preventive maintenance program design, mechanical vs. chemical root control strategy, an introduction to PACP defect coding for CCTV interpretation, and when cleaning/inspection findings warrant trenchless rehabilitation.

Every utility eventually learns the same lesson the hard way: you cannot clean every mile of pipe in the system every year, and you should not try to. A collection system with 300 miles of gravity sewer and a cleaning crew that can realistically cover 40–60 miles per year has to make deliberate, defensible choices about where that effort goes — and getting that allocation wrong means chronic segments keep overflowing while low-risk pipe gets cleaned needlessly. As a Class 3 operator, you are expected to design that allocation logic, not just execute a schedule someone else built.

Designing a Risk-Based Preventive Maintenance Program

A mature preventive maintenance (PM) program does not clean the whole system on one uniform interval. Instead, it ranks segments by risk — a combination of two factors:

Likelihood of a problem — informed by cleaning history, blockage/SSO histo

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