Top AI Performer Selected for 107-Mile Sewer Assessment Program
The City of Phoenix and engineering firm Dibble evaluated five AI vendors and selected SewerAI as the top performer for a 107-mile sewer assessment program, achieving the highest accuracy and lowest cost per linear foot.
Overview
The City of Phoenix operates one of the largest municipal sewer systems in the American Southwest, with a small-diameter rehabilitation program that has grown dramatically over the past three decades — from a $500K annual budget in the 1990s to a $33M program by 2020. In 2024, the City partnered with SewerAI to integrate AI-powered assessment into its quarter-section inspection workflow, with the goal of expanding program scope, improving data quality, and reducing costs across a 100-mile Year 1 pilot.
Historical Rehab Program
The City of Phoenix's small-diameter rehabilitation program has evolved significantly over four decades, reflecting both the growth of the city's infrastructure and the increasing complexity of managing an aging sewer network.
1990–2000: City-Wide Rehab
Budget: $500K–$2M. Various on-call contractors performed city-wide rehabilitation work across the network.
2000–2010: Quarter Section Approach
Budget: $6–7M. The City shifted to a "quarter section" model, prioritizing rehabilitation based on infrastructure age and organizing work geographically to align with maintenance operations.
2010–2020: Manhole Rehab Expansion
Budget: $8M. A dedicated manhole rehabilitation JOC contractor was added to the program, expanding the scope of work beyond pipe lining.
2020–2024: Full-Scale Program
Budget: $33M. The program expanded to four CIPP contractors and five manhole rehab contractors, with warranty inspections added to the scope — representing a more than 60x increase in annual investment compared to the 1990s.
AI Integration Objectives
The City identified five strategic objectives for integrating AI into its sewer assessment program:
- Expand program scope with strategic planning
- Improve collections integration
- Increase quarter section assessment efficiency
- Streamline data transfer
- Reduce program costs
Year 1 Pilot Study
Scope
The Year 1 pilot focused on small-diameter sewer pipe across 100 miles of the network. Quarter sections were aligned with existing maintenance operations to maximize efficiency. Three separate contractors with various CCTV systems participated, testing SewerAI's ability to consolidate and standardize data across a multi-contractor environment.
Results
As of February 28, 181,782 linear feet (34.4 miles) had been assessed across the three contractors:
- Contractor #1: 57,731 LF assessed — 43% requiring lining (24,687 LF), 5% requiring point repairs (2,793 LF)
- Contractor #2: 31,337 LF assessed — 34% requiring lining (10,626 LF)
- Contractor #3: 92,714 LF assessed — 37% requiring lining (34,481 LF), 1% requiring point repairs (595 LF)
- Totals: 181,782 LF assessed — 38% requiring lining (69,794 LF), 2% requiring point repairs (3,388 LF)
Rehab Assessment
Results are on target with rehabilitation expectations. Of the 34.4 miles assessed:
- 38% — CIPP Lining required
- 2% — Open-Cut Point Repairs required
- 60% — No work required
The data confirms that AI-assisted assessment is delivering accurate, actionable rehabilitation recommendations aligned with the City's planning assumptions — enabling more confident capital allocation across the $33M program.