RKT-MOR · Failure Atlas · Index · Revised 14 March 2026

A pictorial field guide to what we read in the camera.

Every CCTV survey we run is coded against the NASSCO Pipeline Assessment Certification Program (PACP).1 The five plates below are the morphologies we read most often under pre-1940 Buffalo sewer laterals — in descending order of frequency on our books since 2018. Each plate is a labeled cross-section diagram, a real photograph, the PACP coding, the typical underlying cause, and the method we'd recommend.

Five wall-mounted morphology plates in the Reuter & Knapp shop, each pinned to a corkboard with cross-section diagrams and CCTV-still annotations. Plate I · Atlas wall, shop interior · 22 February 2026

Frequency · 2018–2025 surveys (n=1,872)

What we see, in proportion.

PlateMorphologyPACP code% of surveys
ARoot intrusionRFJ / RBL62%
BJoint offsetJOM / JOL34%
CBelly / sagSAM / SAL22%
DLongitudinal crackCL14%
ETotal collapseBBA / X4%

Sums > 100% because most laterals show two or three coexisting morphologies. Source: Reuter & Knapp internal survey database, 2018-01 through 2025-12.

RKT-MOR-A · PACP RFJ/RBL

Plate A — Root intrusion

The most common failure mode under Buffalo's tree-lined streets. A lateral root mass — typically silver maple, Norway maple, or American elm — enters at the bell joint and progressively occludes flow. CIPP-treatable at any severity that doesn't physically prevent inversion.

62% of surveys→ CIPP
RKT-MOR-B · PACP JOM/JOL

Plate B — Joint offset

Differential settlement under the foundation step or the curb has shifted one bell relative to the next. Mild offsets line cleanly; severe offsets exceed the bursting head's tolerance and require open-cut.

34% of surveys→ CIPP or burst
RKT-MOR-C · PACP SAM/SAL

Plate C — Belly / sag

A vertical low spot in the lateral where standing water collects between flushes. Symptom: recurring slow drain in the basement-floor cleanout. Caused by failed bedding under expansive clay soils.

22% of surveys→ Burst or open-cut
RKT-MOR-D · PACP CL

Plate D — Longitudinal crack

A crack running parallel to the pipe's axis. Almost always under traffic load — a driveway, a sidewalk, a curb cut. Bores stay continuous so CIPP works; the crack itself stops being a failure once the liner closes against the host wall.

14% of surveys→ CIPP
RKT-MOR-E · PACP BBA/X

Plate E — Total collapse

The pipe wall has failed and a section of bore is missing. Trenchless rehabilitation is no longer an option for that segment; the lateral is replaced by burst or open-cut, depending on the surrounding geometry.

4% of surveys→ Burst or open-cut
CCTV survey →

A note on the limits of this atlas

The five plates above describe the lateral as a structural object. They do not describe upstream household plumbing problems (a venting issue under a kitchen sink can produce identical symptoms to a downstream lateral problem; the survey will distinguish them), they do not describe storm-leader failures (a separate run with separate failure modes), and they do not describe the city-side main connection (BSA's responsibility, not ours). For a complete diagnosis, the survey is the document, not this atlas. The atlas is for understanding what the survey is going to report.

References

  1. National Association of Sewer Service Companies. Pipeline Assessment Certification Program (PACP) Reference Manual, v8.0. nassco.org/programs/pacp
  2. NASSCO. Lateral Assessment Certification Program (LACP). nassco.org/programs/lacp
  3. U.S. EPA. State of Technology for Rehabilitation of Wastewater Collection Systems, EPA/600/R-10/078. nepis.epa.gov