Assessing a Critical Bucks County Transmission Main with DRI™
How Bucks County Water & Sewer Authority gained a clearer picture of pipeline condition, structural integrity and remaining service life with minimal disruption.
Project Overview
Bucks County Water & Sewer Authority (BCWSA) serves more than 500,000 residents in southeastern Pennsylvania.
As part of its asset management program, BCWSA needed to better understand the condition of an approximately 50-year-old ductile iron transmission main located near the Pennsylvania Turnpike and a cemetery.
A failure in this corridor could create significant operational, traffic and community impacts. BCWSA therefore wanted to identify potential leaks, assess structural integrity and better understand the remaining useful life of the pipeline.
BCWSA retained RJN Group to conduct the assessment using its Advanced Vibroacoustic Analysis (AVA) service, powered by KenWave Dynamic Response Imaging™ (DRI™).
The Challenge: Understanding the Condition of an Aging Critical Main
Pipeline age alone does not indicate actual structural condition.
For BCWSA, the challenge was determining what was happening along approximately 8,000 feet of buried ductile iron transmission main without relying on age-based assumptions or undertaking extensive intrusive investigation.
The assessment needed to answer several important questions:
- Were active leaks present?
- How much wall loss had occurred?
- Were any sections approaching a structural threshold?
- What pipe classes were actually installed along the alignment?
- How much useful service life remained?
- Could the Authority continue operating the pipeline with confidence?
The location added another layer of complexity. Portions of the main run adjacent to the heavily travelled Pennsylvania Turnpike, making excavation, traffic control and disruptive inspection methods undesirable.
Reliable as-built information was also unavailable, creating uncertainty about the classes of ductile iron pipe installed along the route.
The Solution: Non-Invasive Condition Assessment Using DRI™
RJN deployed Advanced Vibroacoustic Analysis powered by KenWave’s DRI™ solution.
DRI™ uses controlled vibroacoustic signals introduced into the pipeline through existing appurtenances or strategically located access points. The response of the pipeline is analyzed to identify changes associated with structural stiffness, wall thinning and potential leakage.
For the Bucks County project, RJN collected measurements using 13 existing appurtenances and 10 newly created access points.
Measurement intervals were generally 500 feet or less. Along the section adjacent to the Pennsylvania Turnpike, spacing was reduced to approximately 300 feet to help mitigate the influence of traffic noise.
The assessment generated a detailed wall-thickness profile at approximately 2-metre resolution, providing condition information at a scale significantly finer than the spacing between access points.
More Than 8,000 Feet Assessed in Three Days
One of the significant advantages of the approach was the ability to assess a substantial length of transmission main quickly while minimizing disruption.
RJN completed approximately 8,055 feet of inspection in three days.
Only minor traffic control was required over a limited portion of the alignment.
This allowed BCWSA to obtain detailed structural condition information without taking the transmission main out of service or undertaking extensive excavation along the route.
Resolving Uncertainty About the Existing Pipe
The assessment also provided information that was not available from BCWSA’s historical records.
Because reliable as-built documentation was unavailable, the exact classes of ductile iron pipe installed along the alignment were uncertain.
The inspection identified three different pipe classes within the assessed section:
- Class 50
- Class 51
- Class 52
Understanding the pipe class was important because it allowed the measured condition to be evaluated against the appropriate structural characteristics of the installed pipeline.
In this way, the assessment helped BCWSA resolve both condition uncertainty and asset-information uncertainty.
The Results: A Pipeline in Strong Structural Condition
The results showed that the transmission main was in substantially better condition than its age alone might have suggested.
83% of the assessed pipeline was classified in good condition, with less than 10% wall loss.
The remaining 17% was in moderate condition, with wall loss between 10% and 18%.
No assessed sections were reported in poor condition.
Key Findings
83%
of the pipeline had less than 10% wall loss
17%
had wall loss between 10% and 18%
0 leaks
were detected during the assessment
3 pipe classes
were identified along the alignment
8,055 ft
of transmission main was assessed
3 days
of field inspection
The analysis also indicated that all assessed pipe segments retained ample wall thickness and remained well above the pipe’s tensile failure threshold.
Based on the observed condition, the project concluded that the transmission main had many decades of remaining service life, barring unexpected changes in operating or environmental conditions.
From Age-Based Assumptions to Condition-Based Decisions
The significance of the project goes beyond confirming that the pipeline was in good condition.
Before the assessment, BCWSA was managing uncertainty around a critical transmission main approximately five decades old and located in a difficult corridor.
After the assessment, the Authority had detailed information about:
- Actual wall loss
- Structural capacity
- Leakage
- Pipe class
- Condition variation along the alignment
- Remaining service-life expectations
That information changes the capital planning conversation.
Instead of assuming that an older pipeline represents an immediate replacement priority, BCWSA can use measured condition to determine where intervention is actually warranted and where continued operation and monitoring are appropriate.
RJN subsequently recommended that the pipelines be reassessed in approximately five to ten years to determine whether wall-thickness deterioration rates have changed.
The result is a more defensible, condition-based approach to managing a critical buried asset.
Delivering DRI™ Through an Experienced Local Partner
The Bucks County project also demonstrates how KenWave works with experienced engineering and condition-assessment partners to bring DRI™ to utilities.
RJN managed the field deployment and worked directly with BCWSA, combining its engineering and infrastructure expertise with the structural condition information provided through KenWave DRI™.
This delivery model allows utilities to access advanced pipeline condition assessment while maintaining established relationships with trusted engineering partners.
“The AVA inspection results resolved uncertainties about the condition of this critical pipeline… We are pleased with the outcome and with the professionalism demonstrated by the RJN personnel involved in the project.”
John W. Butler
Chief Operations Officer
Bucks County Water & Sewer Authority
Better Condition Data. More Confident Capital Decisions.
Critical pipelines do not necessarily need to be replaced because they are old.
They need to be understood.
KenWave DRI™ provides utilities with detailed structural condition information from outside the pipe, helping asset managers understand where deterioration exists, how severe it is and where capital investment is truly required.
For BCWSA, that meant replacing uncertainty around a 50-year-old transmission main with evidence that the asset remained structurally sound and had substantial remaining service life.
Learn how DRI™ can support condition-based decisions across your water transmission and distribution network.
Why Utilities Are Turning to Dynamic Response Imaging™?
✅ Non-invasive, external platform
🔧 Works through valves, hydrants, and access points
- 🛰️ Detects wall thinning, pipe class changes, leaks
- 📏 5–20 ft sub-pipe stick resolution
🧠 Ideal for sub-transmission and hard-to-inspect pipes
📊 Supports capital planning with real-world data
Partnered with Leading Utilities & Consultants Globally
