Pipelines 2024: Condition Assessment

Water pipeline condition assessment is pivotal for effective asset management planning. This paper underscores the importance of evaluating the current state of water pipelines, essential for informed decision-making by asset owners. The assessment process typically follows a staged approach, starting with desktop analysis and concluding with thorough field investigations. The selection of assessment tools and methods is crucial, considering factors such as asset vulnerability, budget constraints, and external influences. This paper explores both indirect and direct assessment techniques for water pipelines, each addressing specific aspects of asset evaluation. Additionally, it presents a case study where this integrated approach was applied to assess a concrete composite water pipeline, showcasing the evaluation results. In summary, this paper aids asset owners in comprehending the significance of indirect and direct water pipeline assessments for informed decision-making, mitigating business risk exposure.

Nearly, every water system operator that has worked in the water industry for 5 or more years has experienced some levels of frustration and challenge trying to isolate a part of their water system. Whether it be raw water, finished water, wastewater, or reclaimed water, the number one problem faced by operations and maintenance staff is valve reliability. And, the system water operators are not alone. Consultants, engineers, designers, and civil contractors all struggle with the same challenges. The good news is that it does not have to be that way. There are proven industry best practices, backed by AWWA, that will improve the reliability of your system valves from an initial average of 60% before the first inspection and assessment to above 90% after the initial valve assessment. After identifying and correcting the initial failure modes in a second pass of specific valves, the reliability of your valve inventory can be improved to 99% by employing some corrective maintenance, and 100% in the seldom case, a valve must be replaced. Rarely do valves need to be replaced if the AWWA recommended practices are implemented. As a result, the success rate of any shutdown, whether planned or reactive, CIP, or maintenance driven, will be achieved 100% of the time.

The Great Lakes Water Authority (GLWA) owns and operates the largest Water Resource Recovery Facilities (WRRF) in the United States and the American continent. To ensure reliable treatment of 1,700 million gallons per day (MGD) of wastewater, GLWA needed to assess the condition and potentially rehabilitate more than 30 mi of underground support utilities that have been constructed in the last 90 years. A multi-prong approach was used to assess the condition of the gravity and pressurized sewer, potable and service waters, natural gas, steam, and compressed air systems. Various available tools and methods were evaluated to collect information on the condition of the underground utilities, and a toolbox of applicable methods was developed. Data collected through soil and pipe material tests, visual inspection and surface measurement, flushing and fire hydrants test, valve exercising, acoustic leak detection, tethered CCTV inspection, manhole inspection, and ultrasonic and electromagnetic pipe wall thickness measurements were used to perform risk analysis of the assets. The result of quantitative risk analysis helped prioritize the rehabilitation practices required to improve the resiliency and reliability of the systems and improve their service life while reducing operation interruption. This paper covers the triage process for setting up a practical toolbox for condition assessment of congested and complex underground utilities within the fenced area of a heavily industrial and active facility, followed by a quantitative approach to risk analysis to prioritize improvements. This paper’s shared experience and techniques can be beneficial to facility directors and managers and help them take a more informed and organized approach to condition assessment and prioritization of their underground assets.

Following the 2017 catastrophic break on Great Lakes Water Authority’s (GLWA) 14 Mile Road transmission main, GLWA conducted a wet-live electromagnetic (EM) inspection of 9.3 mi of the prestressed concrete cylinder pipe, which was installed between 1967 and 1973. The EM inspection evaluated all 2,623 pipes along the alignment, which ranged from 60-, 54-, 48- to 42-in. diameter, and identified 100 distressed pipes (a distress rate of 3.8%) with broken wire wraps. One 650 linear foot segment of the 54-in. diameter portion of the alignment had a much higher distress rate of nearly 50%, including several severely distressed pipe segments. Plans for renewal of this distressed section of pipe were made using carbon fiber reinforced polymer (CFRP). The GLWA’s Energy, Research and Innovation group, along with Field Services and the Linear System Integrity Program, made plans to leverage this area of known damage for evaluation and piloting of four different emerging technologies for monitoring and assessing prestressed concrete cylinder pipe (PCCP). Each technology would assess or monitor the same section and the pluses and minuses of each technology would be evaluated in true field setting. First, discrete acoustic sensors were installed at three existing access point manholes along the distressed segment to provide an economic and non-intrusive approach to monitoring for broken wire wraps prior to installation of the CFRP renewal. Second, during the CFRP renewal project, high-fidelity optical sensing fibers in metal tubes (FIMT) were installed (embedded within the CFRP system) to evaluate the advantages and capabilities for each method of measuring pipe structural health. Post-installation of the CFRP, two “outside the pipe” technologies were evaluated, each using external excitations to the pipe wall, with the pipe in service used to assess the pipe condition. The first technology utilized acoustic velocities to calculate the effective pipe stiffness and the effective-to-nominal stiffness ratio for each inspected test segment. The second technology evaluated structural condition of individual pipe segments using the dynamic response of the pipes to excitations at different frequencies. Each piloted technology had advantages and disadvantages. This paper documents the overall implementation as well as applicability of each technology to assessing the condition or monitoring the structural health of PCCP.

Performing inspection work in any major city is no easy feat. Performing inspection work in the District of Columbia, one of the most densely populated cities in the United States that also houses a plethora of federal agencies and national security establishments, presented a multitude of unique complications. Along with more typical roadblocks such as aging infrastructure leading to emergency repairs and unmapped assets discovered in the field, the surrounding stakeholders and property owners affected by the inspection program included foreign embassies, government agencies, and even disgruntled homeowner associations, to name just a few. Along with these challenging circumstances, the procurement timeline resulted in a tremendously accelerated inspection schedule during which 40 mi of inspection work had to be prioritized, performed, reviewed for quality, and invoiced all within the last 5 months of the fiscal year. Through an innovative use of new software tools, collaborative teamwork, and copious amounts of coffee, this seemingly impossible feat was accomplished on time and on budget.

Pre-stressed Concrete Cylinder Pipes (PCCPs) are critical components of water distribution systems, providing a reliable conduit for the transportation of clean water to communities worldwide. However, the structural integrity of PCCPs can be compromised when they experience wire breakages due to various factors, including age, corrosion, and external loading. Accurate estimation of the remaining load-carrying capacity of PCCPs with broken wires is essential for assessing their structural health and making informed decisions regarding maintenance, repair, or replacement. In this paper, the authors present a novel analytical framework based on three-dimensional elasticity and develop a predictive tool, UM Closed-Form Solution App, for estimating the capacity of PCCPs with broken wires. The App integrates mathematical modeling, closed-form solutions, and user-designed functions to provide a comprehensive and user-friendly platform for engineers and asset managers in the field of civil and environmental engineering. A refined finite element (FE) model and two groups of FE results were used to validate the functionality up to include the yield state. This model estimates yield limit, instead of ultimate strength, to improve functionality of the tool. The results show that the UM Closed-Form Solution App represents a significant advancement in the field of PCCP assessment and management, offering a cost-effective alternative tool for infrastructure stakeholders to make informed decisions regarding the rehabilitation and maintenance of PCCPs with broken wires.

The Trinity River Authority of Texas (TRA) is currently conducting a Wastewater Interceptor Condition Assessment Program (Program) for over 100 mi of unlined reinforced concrete pipes (RCP) throughout the Central Regional Wastewater System (CRWS) collection system by means of Multiple Sensor Inspection (MSI). The MSI data will be used to determine the remaining wall thickness of the piping, which in turn will be utilized to calculate the Remaining Useful Life (RUL) of the unlined RCP interceptors within the CRWS collection system. Rather than initiate reactionary multi-million-dollar capital projects due to pipeline failures and after-the-fact maintenance records, TRA has launched a proactive multi-pronged approach to the development of their multi-billion-dollar Capital Improvement Program (CIP). The program development consists of three major components: a condition assessment (the basis of this abstract), a hydraulic modeling update to evaluate capital investment using an optioneering approach, and a detailed linear storage or tunnel storage options analysis. Each of these components will be integrated with optimization driven by Optimatics Optimizer software. TRA has been a power user of the InfoWorks ICM software and related precursor products since 1998. These varying design philosophies drive towards the best or most optimal investment strategy that benefits TRA’s customer cities with the clearest view towards long-term financial considerations and built-in flexibility. The majority of the unlined RCP pipelines within the CRWS collection system are in similar, poor condition due to corrosion from low velocities and elevated levels of hydrogen sulfide. TRA has adopted an integrated condition assessment approach to tackle the challenging task of prioritizing pipeline rehabilitation and replacement. By incorporating the development of risk factors specific to TRA’s concerns and calculated RUL, the Program is establishing a robust, cyclical, and dynamic data and risk management process for asset management-driven decision-making. As part of this integrated approach, optimization technology is being leveraged to develop several rehabilitation scenarios that account for risk as well as overall cost. This program will establish a planning process for identifying specific assets for rehabilitation and/or replacement, a prioritized approach to bundle relevant assets into capital projects, and leverages optimization technology that identifies several scenarios to minimize cost, mitigate risk, and maximize organization value. This paper/presentation will showcase this data-driven integrated condition assessment program that enables automated intelligent decision-making, informs capital planning, and sets the foundation for sustainable and scalable future pipeline condition assessments. In addition to the approach, this paper/presentation shall discuss key outcomes as well as lessons learned that will be applicable to other agencies around the country looking to drive integrated asset management, data management, and/or condition assessment programs.

Regular inspections are crucial for ensuring effective system operation and for planning needed maintenance. Closed-circuit television (CCTV) is widely employed in North America to examine the internal conditions of sewage pipes. Due to the extensive inventory of pipes and associated costs, it is often not practical for municipalities to conduct inspections on each sanitary sewage pipe section. According to the American Society of Civil Engineers (ASCE) Infrastructure Report published in 2021, combined investment needs for water and wastewater systems are estimated to be $150 billion during 2016–2025. Therefore, new solutions are needed to fill the trillion-dollar investment gap to improve the existing water and wastewater infrastructure for the coming years. Machine learning-based prediction model development can be an effective method for predicting the condition of sewer pipes. In this research, sewer pipe inspection data from several municipalities were collected, which included variables, such as pipe material, age, diameter, length, soil type, slope, and Pipeline Assessment and Certification Program (PACP) score. These sewer pipe data exhibit a severe imbalance in pipes’ PACP scores, which is considered the target variable in the development of models. Due to this imbalanced data set, the performance of the sewer prediction model is poor. This paper, therefore, aims to employ oversampling and hyperparameter tuning techniques to treat the imbalanced data and improve the model’s performance. Utility owners and municipal asset managers can utilize the developed models to make more informed decisions on future inspections of sewer pipelines.

Pipe age may well be the most common factor used in making water main rehabilitation and replacement decisions. Data from the largest database of pipe failure records compiled to date suggest that it is often being used incorrectly, resulting in billions of dollars in unnecessary pipe replacement. Prior studies have shown a linear relationship between age and failure risk for the first few decades of pipe life. Many models assume that break rates will rise exponentially, despite a lack of published data. This study analyzes over 10,000,000 pipe-years of monitoring records from 6 utilities in 3 continents, providing sufficient data for the longer term relationship between age and break rate to become clear. The results are unexpected: for most pipe materials, failure rates reach a peak after a few decades, and then begin to decrease. This decrease is deep and prolonged for many pipe materials, offering stretches as long as 50 years where failure rates are lower than when the pipes were just a few decades old. These “golden years” extending beyond their design life may offer decades of unexpected useful life from existing pipelines.

This presentation will highlight three case studies that cover all aspects of pressure pipe condition assessment. It will cover inspection of 20-in. to 36-in. potable water transmission mains in a downtown setting, including multiple interstate crossings. It will cover inspections of miles of 36-in. and 54-in. raw water mains located in rural cross-country easements as well as neighborhood streets. And, it will also cover inspection of the highest risk force mains ranging from 12-in. to 42-in. in a coastal community that desired to create a risk management program. The case studies will detail why certain technologies were selected, the data collected, and how the data were used to calculate the remaining useful life of the asset, and the field lessons learned when deploying the inspection tools.

The Los Angeles County Sanitation Districts (Districts) treats 400 million gallons of wastewater daily at one of their 11 treatment plants. Wastewater flows are transported to the plants through pumping stations and 1,400 mi of sanitary sewer collection systems. Constructed in the 1920s, a portion of the Joint Outfall A Unit 3C Trunk Sewer is composed of a 78-in. diameter semi-elliptical interior vitrified clay tile grouted reinforced concrete pipe sewer. The vitrified clay tiles have fallen into the invert of the sewer, resulting in one to three feet of accumulated debris, thus reducing the capacity of the sewer. The critical sewer reach extends approximately 7,400 ft and is located in an unincorporated area of Los Angeles County. The study evaluates the engineering analysis and design of various rehabilitation methods using hydraulic modeling. Those evaluated include replacement, rehabilitation with cured-in-place-pipe (CIPP), fiberglass reinforced plastic (FRP) liner pipe via sliplining, and internal rehabilitation methods with polyvinyl chloride (PVC) lining system. Critical site constraints include existing curves along the sewer alignment, roadway with congested utilities, railroad crossing, flow diversions to reduce depth and velocity, large bypass to remove all the flow, private properties, and permitting. As part of this evaluation, a decision matrix framework is generated to provide guidance to future engineers on selecting a sewer rehabilitation method. The non-circular FRP liner pipe, and internal rehabilitation method alternatives are selected for the project based on hydraulic modeling, site constraints, constructability, and total cost. The non-circular FRP liner pipe and internal rehabilitation alternatives will provide approximately 87% and 90% of the existing hydraulic capacity with a total cost of approximately $19 million and $25 million, respectively. The overall project is split into two separate phases to rehabilitate the most critical reaches first. Construction for the first phase of the project is tentatively scheduled to be completed in the Fall of 2024 with the second phase scheduled to be completed in the Fall of 2026.

The Ak-Chin Link pipeline is an 8.5-mi-long, 78″ and 84″ diameter prestressed concrete cylinder pipe (PCCP) near Maricopa, Arizona. This pipeline provides the entirety of irrigation supply for 16,000 acres of Ak-Chin Farms. Stantec (Engineer) recommended Ak-Chin Farms to complete an electromagnetic (EM) survey and visual and sounding inspection on the 40-year-old pipe. The 2017 EM survey revealed broken pre-stress wires, indicating a potentially compromised system. However, a thorough analysis demonstrated that despite wire breaks, the pipeline’s steel cylinder is capable to withstand the low operating pressure and overburden loads. Therefore, a partial encasement repair solution was approved to extend the evaluation time. Other work in following years included expanding pipeline access (for future condition assessment), pipeline bonding for continuity, and installation of an impressed current cathodic protection (ICCP) system to protect further prestressed wire breaks. Five years later, the Engineer recommended another condition assessment to determine the pipeline deterioration rate specifically under partially encased pipe sections. Additionally, remote field testing (RFT) was used over 1.5 mi of the pipeline to identify the condition steel cylinder within the PCCP. This paper will not only discuss the results of the two condition assessments conducted in 2017 and 2022, but it will also explore the impacts of steel cylinder corrosion on pipe integrity, particularly within the context of the pipeline’s low operating pressure capped at a maximum of 30 psi. Moreover, we will outline the procedure for establishing repair priority, leveraging the risk curves generated, and the degradation rate prevalent in each pipe segment. This project is a unique case study which highlights efforts to support Ak-Chin Farms to continue meeting their goal to sustainably feed the greater Southwest region.

In 2005, a fast-track repair was required for the failed Homestake Pipeline within the 6,000-ft long Goddard Tunnel passing under the continental divide in western Colorado. This episode led to a 20-year program of assessment, repair, renewal, and replacement. This process has included a 5-year phased condition assessment on the Homestake Pipeline, a 20-year capital improvement plan to extend the service life of this critical facility, adoption of an evolving series of assessment technologies, and implementation of 15 years of renewal projects utilizing four construction methodologies. This comprehensive program has revealed several insights for those undertaking condition assessments and utilizing numerous emerging technologies while actively implementing a long-term renewal program. Among those are the benefit of objective research into the capabilities, limitations, and efficacy of technology tools and strategic use of those tools as part of an overall assessment approach coupled with the importance of independent verification of results from high-technology tools. As a cohesive team, we utilized advanced planning to estimate the cost and operational impacts of shutdowns or facility modifications required to perform the assessment and renewal work. This approach allowed the team to adopt a phased the program with subsequent steps based on results of previous work to improve outcomes and manage costs effectively. Early in the program, the team identified the benefits of holding a formal “lessons-learned” workshop at the completion of each year of assessment and rehabilitation and utilized this process to assist in managing and evolving a long-term renewal program to reprioritize for critical developments, on-board evolving technologies, and stay within budgeting and operational constraints. The continuation of the next 20-year phase of renewal is set to begin in 2025.

The Town of Bradford West Gwillimbury’s (Bradford) has a current population of over 40,000 people, with growth forecasted to exceed well over 50,000 by 2031. Given these growth projections, the Bradford looks to take proactive measures to ensure system resiliency. The Bradford is primarily serviced by two municipal ground water wells, along with treated water from two critical pipelines installed in 2004. These are the Bradford Transmission Line (C301–600 mm [5 km]), and Innisfil-BWG Transmission Main (C303–500 mm [13.8 km]). In 2020, Bradford engaged Pure Technologies to perform an audit-level assessment. The solution included a structural engineering analysis of 18 km length of 500/600 mm diameter pre-stressed concrete bar-wrapped pipes. The engineering analysis concluded that the pipes have a low probability of reaching or exceeding their yield limit by the year 2045. In response, in 2022, Bradford engaged Pure Technologies for a detailed condition assessment and physical inspection of the transmission mains.

In 2020, the City of Houston (City) authorized Lockwood, Andrews, and Newnam, Inc. (LAN) to perform a preliminary engineering report (PER) for 3,900 linear feet of 48-in. prestressed concrete cylinder pipe (PCCP) primarily due to a METRO rail crossing and previous failure. In reviewing records, it became clear that there were other portions of the pipeline that had high potential for impact to the pipeline’s condition. The PER summarized these risks, and after consideration from the City, the assessment limits were increased to approximately 18,400 LF. A final design project was developed and is currently under construction with completion expected within the next 6−8 months. This paper will go through the original project extent, the additional risk areas identified, the impact the change in length caused, and the final package bid under construction. In the end, the original budgetary costs for the project (3,900 LF scope) construction costs are expected to be met with a few increases for professional services coming from other available funding sources.

Pipelines owners have used acoustic wire break (WB) detection to avoid catastrophic failures and understand deterioration rates of their prestressed concrete cylinder pipe (PCCP) for more than 25 years. Recent development has made it possible to get additional insight from acoustic monitoring of pipelines in three ways: first, acoustic fiber optic leak detection, second, distributed wire break monitoring, and third, the locating of events of interest. Field trials were undertaken to evaluate the performance of each technique. For any acoustic sensing technology, it is difficult to quantify detection thresholds in a dynamic operating environment. Factors affecting ambient noise such as diameter, flow, bends, features, proximity to pump station, etc. all have an impact on sensitivity. This paper will discuss the application of each technique, present findings from trials, and planned next steps.

The Great Lakes Water Authority (GLWA) owns and operates the 14 Mile Road Transmission Main, which was constructed between 1967 and 1973 with 42-in. to 54-in. diameter prestressed concrete cylinder pipe (PCCP). This transmission main extends approximately 11 mi, with 8 mi having no redundancy. Since its construction, the pipeline has failed on two occasions: October 23, 2017, and October 31, 2021. In 2019, a free-swimming electromagnetic in-line inspection tool was used to characterize the number and location of broken wire wraps (BWWs) in the PCCP. The inline inspection identified high levels of distress in a concentrated area near the crossing of the GLWA transmission main and a set of high-pressure steel gas pipelines. Subsequent field testing strongly suggested that stray current from the impressed current cathodic protection (CP) system on the gas pipelines contributed to the observed BWWs in the GLWA transmission main. Based on the results of these tests, renewal of this portion of the GLWA main was recommended by HDR Michigan, Inc. (Prime Engineer). An alternatives analysis was performed to determine the most favorable approach for renewal. Renewal operations using carbon fiber reinforced polymer (CFRP) lining per (American Water Works Association) AWWA C305 were completed in 2023 and the transmission main was returned to service. During the course of the repair, significant planning and coordination took place with the GLWA member partners to implement alternative water operations to meet demands.

This paper summarizes a statistical analysis of a database collected by the Water Research Foundation (WRF) of prestressed concrete cylinder pipe (PCCP) failures in North America from 1942 to 2022. This database, with almost 50,000 data points collected, is part of two separate research efforts for Projects #4034 and #5069 and is sourced from utilities in the United States and Canada. These WRF projects examine PCCP failures for trends which were co-sponsored and funded by the USEPA and Great Lakes Water Authority. Failures are grouped into one of the three categories, each with descriptive factors, including age, location, size, pipe type, installation date, etc. Via simple yet comprehensive analytics, failures can be graphed as a function of their descriptive factors and subsequent inferences can be made such as: are there locations of PCCP at higher risk than others, which installation dates/periods have the most failures, does size matter, etc.

While much of the effort on condition assessment of concrete pressure pipe has focused on prestressed concrete cylinder pipe (PCCP) for many years, a significant amount of AWWA C303 bar-wrapped concrete cylinder pipe (BWP) installed across the United States, since the 1940s has also been degrading. Due to increasing awareness on degrading BWP pipelines supported by concerns after high-consequence failures, high-resolution electromagnetic (EM) inspection technologies are now also in demand for BWP to detect defects in the steel cylinder and reinforcing bars. Pipeline inspection vendors have been investing in improving their inspection technologies, tools, and platforms. Currently, two primary inspection technologies are being offered by a few vendors with varying claims of accuracy and resolution: the Remote-Field Technology (RFT) and the Near-Field Technology (NFT). Platforms include modular, non-modular, robotic, and others. Although the theoretical basis of the inspection technologies may be similar, the results are likely affected by many proprietary factors considered by each vendor, such as sensor types and configuration, calibration and inspection procedures, and differences in data processing and interpretation. Many BWP pipelines have been and continue to be inspected with these technologies using different tools and platforms; however, independent field verification of their results has been limited, precluding development of full confidence in their capabilities and limitations. This paper expands the results of a recent blind verification study performed with one of the pipeline inspection vendors, with results from a second inspection vendor on the same test pipes, 30 in. and 36 in. diameter BWP. To allow for direct and fair comparison of results from the two vendors, additional defects were introduced into both test pipes, and the first vendor was invited to rescan the pipes and update their results.

As part of an ongoing comprehensive condition assessment program undertaken by the City of Mesa (COM), Arizona, two 42 in. diameter prestressed concrete cylinder pipes (PCCPs) manufactured in the mid-1970s were excavated for external inspection to verify the results of electromagnetic (EM) inspections performed 2 years ago and update the failure risk and repair priorities of distressed pipes along the pipeline. Inspection of the two pipes revealed brittle wire breakage and discrepancies between the EM-predicted and actual number of broken wires, which led to a detailed investigation to determine the root causes of degradation, evaluate risk, and plan for future actions to maintain pipeline reliability. The investigation included external inspection of all eight previously identified distressed pipes; teardown inspection of one that was selected for replacement; petrographic analysis and laboratory testing of mortar coating quality and condition; mechanical testing of prestressing wires and steel cylinder; and soil corrosivity. This paper demonstrates comprehensive assessment of PCCP using multiple inspection, testing, and analysis methods, including presenting the purpose and results of each component of the investigation as well as synthesis of all results to develop recommendations for future actions to manage the pipeline for continued reliable operation.

To address the challenges of managing an aging cast iron pipeline, this study will discuss how using spatial analysis can facilitate and aid the decision-making process for managing a 20-in. cast iron pipeline in Johnson County, KS. For this, high-resolution condition assessment data in the form of ultrasonic pipe wall thickness measurements were used in a spatial hotspot analysis to evaluate the spatial density of potential clusters of more distressed areas along the pipeline. Leveraging the hotspot analysis results, prioritized extents of pipes were defined by determining contiguous pipe segments of high defect density. This additional step enhanced the decision-making process for prioritizing bulk replacements or other relevant renewal strategies across the pipeline. These prioritized extents provided a roadmap for the team enabling them to allocate resources more efficiently and effectively.

As we seek to be good stewards of our utilities, it is important to maximize the return on our investments (ROI). Daily decisions, from pipe bedding to fastener materials, impact water infrastructure longevity. This paper seeks to provide quick answers to common corrosion engineering questions on water systems. Buried assets are prone to corrosion, yet corrosion practices are often overlooked until they accrue high maintenance costs. The presentation covers some of the most frequent corrosion types in the water industry and provides some examples and recommendations. In addition, this paper discusses how implementing corrosion engineering at any time through the life cycle of the project can expand the life of the asset.

The Greenmount Avenue Water Transmission Main is a 150-year-old 36-in. diameter pit cast iron pipe, a critical asset in the Baltimore’s water distribution system. With aging water main and the history of breaks, the City decided to conduct full condition assessment of this critical supply main, with the primary objective to determine the remaining useful life of the pipeline. Various condition assessment methods used included Forensic Analysis of the pipe coupons, Soil Chemistry Analysis, Visual Inspection of the exterior of the pipeline, and Leak Detection and Closed Circuit Television (CCTV) Inspection. This case study focuses on the methodology, findings, results of the condition assessment, and proposed measures to improve the reliability of this important asset.

The georeferenced alignment of aging pipelines is often inaccurate or unknown. Accurate mapping of pipeline alignment has become increasingly important with modern data-driven pipeline management approaches as utilities look to strategically repair or replace specific pipe sections to extend overall asset life. In practical terms, it has been observed that subsurface utility data classified as Quality Level A and B can lead to a reduction in repair project costs ranging from 10% to 15%. That said, traditional inertial navigation mapping techniques are frequently disruptive and impractical for effectively mapping buried underground infrastructure. Instead, we propose an innovative method utilizing high-performance micro-electro-mechanical systems inertial measurement units (MEMS IMUs) consisting of a gyroscope and accelerometer combination integrated into a rolling spherical in-line inspection tool. This novel approach allows for the accurate mapping of pipelines with minimal disruption to their operation. In this research, we delve into the noise characteristics of commercially available IMUs and their impact on inertial navigation accuracy through a kinematic rolling model. Findings are validated by utilizing real-world pipeline data and comparing our simulated results with utility-provided alignments.

In 2022, the Town of High River, Alberta, started a leak detection program on a series of critical ductile iron (200-, 350-, and 400-mm diameter) and PVC (300-mm) raw watermains and potable distribution mains as well as a steel river crossing. A 2013 flood put much of High River under several feet of water, leading to extensive damage and requiring hundreds of millions of dollars spent on flood mitigation and disaster relief over the past decade. Flooding has the potential to damage a variety of critical infrastructure, including pump stations and buried pipelines. As part of its “build it back better approach,” High River teamed with Pure Technologies and identified and repaired two leaks, reducing lost revenue and ensuring reliability of the system for their growing population. This project will highlight non-disruptive condition assessment approaches for small diameter pipelines managed by small utilities.

This paper presents an approach to evaluate a steel penstock over a century old using initial analyses to identify areas of the pipe that are most susceptible and most impacted by different types of threats to the penstock’s integrity. This starts with understanding how the asset was designed, constructed, operated, and maintained through its life and the available repair and rehabilitation methods. The paper will cover the available information, including historic design, fabrication, and construction practice; the analyses performed under this project and how they were used to support decisions regarding condition assessment methods and limits; the findings of the condition assessments; and lessons learned. Experience and lessons learned from other steel pipeline evaluations that influenced the approach taken for this project will also be presented. The benefits of a programmatic condition assessment approach are reviewed. Penstocks are a specific type of high-pressure pipeline intended to feed a hydroelectric facility for power generation. The presented approach for this penstock is applicable to other steel pipelines of a variety of vintages, including raw water conveyance and potable water transmission lines.

This study introduces an innovative application of ultrasonic technology coupled with finite element modeling for the early detection of damage mechanisms in cast iron pipes that precede catastrophic failure due to cracking. Spun Cast Iron Pipe emerged as the predominant choice for water conveyance in the United States during the period spanning from 1920 to 1950, consequently establishing itself as a pivotal component of the nation’s water infrastructure. However, the deterioration of these pipes over time has presented substantial challenges. It is well-established that corrosion is the principal means of deterioration of cast iron pipes and that stress concentrations near corrosion anomalies reduce structural capacity of the pipe wall and ultimately lead to splitting and failure. Prior research has studied pipe deterioration by creating artificial anomalies on the pipe experimentally or by means of simulation. However, there is limited study for real-world corrosion scenarios and the ensuing crack propagation phenomena. On June 28, 2023, a 20-in. cast iron pipe, previously inspected by ultrasonic technology, failed in Johnson County, Kansas. The inspection had identified 15 distinct regions of wall thinning and anomalies (most likely graphitic corrosion) distributed across the pipe’s length. This information was used to generate a finite element model of the pipe wall, and a study was conducted to determine the model’s capacity to predict the origin and trajectory of cracks witnessed in the forensic evaluation of the failed pipe stick. Accurate understanding and prediction of such failures in cast iron pipe will enable timely maintenance and replacement decisions to ensure the reliability and safety of water transmission systems. This research contributes to the advancement of infrastructure health monitoring and the sustainable pipeline management of urban utilities.

Water pipelines are prone to failure when seismic events occur, posing significant risks to water supply systems. In recent years, innovative earthquake-resistant joint systems have emerged as potential solutions to mitigate these risks. These joint systems allow for axial movements and rotations, enhancing the pipeline’s ability to withstand ground movement. However, a comprehensive understanding of the mechanisms governing these jointed systems remains unclear. In addition, the understanding of the performance of the joint system simultaneously under both bending and tensile loading condition is limited. To address this knowledge gap, this study conducted a series of pipeline experiments which encompassed tension tests, four-point bending, and bi-axial tension tests, all of which were equipped with distributed fiber optic sensors capable of capturing continuous strain profiles along the pipeline. Furthermore, finite element models were meticulously constructed and validated using the collected experimental data. This integration of empirical and numerical data demonstrated a thorough investigation into the failure mechanisms of 8-in. earthquake-resistant ductile iron pipe.

When planning water main replacement programs, pipeline engineers make decisions on which pipes to address using failure risk factors. Pipe material, diameter, length, age, and previous failure history frequently play a role in these decisions. Despite their intuitive and ubiquitous use in making these critical decisions, the actual relationship between these factors and pipe failure rates is not well-documented. Over the past 5 years, a research program led by the University of Waterloo has assembled a large and diverse database of pipe failure records. With contributions from six utilities in North America, Europe, and Asia, this database covers over 10 million pipe-years of records. The records include over 500,000 pipe segments spanning over 30,000 km (over 18,000 mi) of pipe with detailed records of over 150,000 pipe failures. This paper presents broadly applicable statistics regarding pipe failure risk predictors, drawn from this database.

Wastewater professionals working with combined sewers often encounter a variety of non-circular sewer cross sections, including egg-shaped sewers. Equations are developed here to calculate the wetted area, wetted perimeter, and surface width for egg-shaped sewers flowing partially full and support a variety of hydraulic calculations. These equations supplant traditional graphical approaches using geometric and hydraulic element curves in favor of equations better suited to Smart Sewer applications. The equations are validated and provided a concise reference for those working with egg-shaped sewers in combined sewer systems.

Lift stations and force mains are essential in wastewater collections and are required to operate in a highly corrosive environment and are typically subjected to widely fluctuating flows and pressure surges that affect force main integrity. Lift station and force main design seek to avoid common damage modes, including H₂S-induced corrosion and solids accumulation, but rarely benefit from physical assessment of the installed and operating system to evaluate design robustness. Collection and evaluation of physical condition data for the City of Phoenix’s Lift Station 43 (LS 43) force main identified design and operational best practices that can be adopted to improve the service life of any force main. The LS 43 force main is constructed of three 24-in. ductile iron pipes that experienced two breaks associated with air accumulation. A comprehensive assessment was completed, including hydraulic modeling, closed-circuit television (CCTV), and remote field electromagnetic (RFEM) inspection. Hydraulic modeling utilizing different pump states identified areas of negative pressure and gas buildup. The results of hydraulic modeling were confirmed via CCTV assessment, which showed staining on the inside of the force main that indicates the presence of an air pocket. This permanent staining is called a Miscellaneous Water Mark per National Association of Sewer Service Companies (NASSCO) Pipeline Assessment Certification Protocol (PACP) guidelines. The presence of the air pocket indicated that the air release valves (ARVs) were not functioning effectively. This was also confirmed via hydraulic modeling which determined that incorrect placement of ARV caused air to accumulate in the force main. The study identified the factors contributing to air accumulation and remedial measures to address the concern. Additionally, RFEM assessment determined that internal corrosion below the springline was caused by solid accumulation, an infrequently considered damage mode for ductile iron pipe (DIP) in force main service. Suspended solids in wastewater can settle in the force main and develop areas of microbially induced concrete corrosion (MICC). Efforts to allow maximum future capacity in the initial design resulted in low velocities and solids accumulation. Cleaning tools can dislodge the accumulated solids but lift station and force main designs rarely allow for easy launch and retrieval of a cleaning tool. Furthermore, no clear guideline exists on cleaning frequency. The study identified the necessary velocities required to prevent solid accumulation and the frequency and essential design modifications necessary to support regular cleaning. In conclusion, the study has identified best practices to improve lift station and force main hydraulics and service life.

This paper demonstrates the methodology for calculating the hydraulic grade line from free-floating, in-line inspection tools and the subsequent deposit analysis of the hydraulic grade line. Neutrally buoyant, in-line inspection tools measure the pressure along the entire pipeline length under regular operating conditions. Deploying multiple tools with a short time delay allows for localized features to be distinguished from changes to the pipeline operation during the deployment. Identified operational changes during the deployment are corrected before calculating the hydraulic grade line using an elevation profile of the pipeline. The resulting hydraulic grade line represents the pressure-head loss due to friction along the pipeline; locations with steeper pressure-head loss indicate restrictions in the pipeline from the build-up of deposits. The gradient of the hydraulic grade line, pipeline specifications, and inspection flow rate are used with the Hazen–Williams equation to calculate the levels of deposits in several segments along the pipeline.

Release of unpleasant odor to the environment is an easily identified consequence of H₂S production in sewer systems; therefore, air-locking the entrance to municipal wastewater collection networks (e.g., manholes) should reduce the emissions of H₂S gas into the air. However, this will increase the H₂S gas resident time, which unfortunately results in aggravating sewer corrosion. Controlling or eliminating H₂S generation within existing sewage collection systems is the best approach. Two ways to achieve this are by altering the sewer ambient environment and modifying the system’s hydraulic design parameters (e.g., by reducing turbulence). These two options are said to be possible with the Vortex Flow Insert (VFI) system. VFI works by using the drop flow energy of the wastewater to create a vortex that then reduces turbulence potential, typical with plunge drops. The spiral flow is claimed to help create a downdraft into the unit, trapping airborne gases and forcing air into the sewage flow to oxidize odorous gases. After a series of consultation iterations, a large water utility company in western Canada installed VFI in one of its major drop manholes. The 8 m deep drop manhole in question is part of a 1950 trunk sewer system connected to a 600 mm connecting sewer that transfers the 2.6 m drop flow into the drop manhole. Being the first ever VFI in utility’s system, a post-installation experimental study was completed to evaluate the effectiveness of the VFI in reducing odor and corrosion potential in the system. This presentation describes the H₂S generation mechanism, the science behind VFI, design details of the VFI, VFI installation considerations, on-site performance data collection program, data analysis and interpretation of findings, and lessons learned and recommendations for future implementations.

PICA provides a breadth of services to asset managers, and we built a Multi-Sensor Autonomous Inspection Device (MSAID) for low-resolution condition assessment. PICA used this device to help the municipality of Jasper, AB, Canada, gather data on a fire water pipeline. The device was inserted and retrieved through fire hydrants connected to the line. The data collected by the device were used to determine a leak location. This allowed the municipality of Jasper, AB, to repair that specific section that had been causing a significant loss of water. Applications of technology are constantly evolving by becoming more efficient, resilient, and effective. Using a Multi-Sensor Autonomous Inspection Device allowed the Municipality of Jasper, AB, to gain a low-resolution data set without interrupting service.

In any large-diameter condition assessment project, significant hurdles will need to be addressed for a successful project. Some of those hurdles are unique to each project, but many of them are common among condition assessment projects. Drawing on previous experience with these projects, here are a few of the most frequent hurdles that one may encounter and need to be addressed for a successful project. These hurdles include Safety, Budget, Isolation Issues, Drawing Completeness, Pipeline Design, Operational Impacts, Assessment Tooling Selection, City and/or Contractor Support, Public Outreach, and Stakeholder consideration.

Inspection of sewer pipelines on a periodic basis is a necessity for successful operation of collection systems. Operational and structural assessment is required to identify and remedy issues prior to failure occurrence. Beginning in 2017, the City of Los Angeles, Bureau of Sanitation (LA Sanitation and Environment, or LASAN), embarked on a program to systematically inspect and assess the condition of one its oldest, and critically important conveyances, the North Outfall Sewer (NOS) system. Much of its length was inspected using Closed-Circuit Television (CCTV), Light Detection and Ranging (LiDAR), and sonar profiling [combination known as Multi-Sensor Inspection (MSI)]. The cost of MSI inspections limited the length that could be inspected with available funds. LASAN sought a lesser cost option to perform screening level inspections rather than detailed MSI. This paper focuses on the identification and use of a novel untethered, free-floating platform for screening level visual inspections of large sewers.

Prestressed Concrete Cylinder Pipe (PCCP) is widely used to construct large-diameter transmission and feeder Watermains. These assets usually have a high consequence and/or impact of failure, and any unexpected service interruptions from a PCCP failure may place a significant burden on the pipe owner. Hence, it is paramount to inspect and assess PCCP assets using state-of-the-art technologies to estimate the physical condition of the PCCP asset. However, these inspections are a snapshot in time and only provide valuable information on the current physical condition of the PCCP asset. Hence, these inspection results should be leveraged to estimate the PCCP’s remaining useful life (RUL) to aid in making sound decisions in-line with the pipe owner asset management framework. Estimating PCCP’s remaining useful life is a complex process and involves multiple stages given the nature of the PCCP structure that acts as a composite structure. These stages are well-documented in the industry and are associated with different structural limit states (serviceability, yield, and strength limit states) as per the AWWA C304. Hence, to estimate the RUL, an innovative approach was developed that involved developing multiple survivor curves associated with each structural limit state by fitting the best distribution model with an estimated deterioration curve based on prestressing wire count technology. The paper will demonstrate that the methodology of a 36 in. PCCP (LCP type) was assessed using risk margin technology that assessed the prestressing wire break thresholds associated with the different structural limit states (serviceability, yield, and strength limit states) as per AWWA C304. An inspection of the 36 in. PCCP using prestressing wire count technology was plotted on the developed multiple survivor curves and its estimated RUL was estimated based on the current inspected distress status, age, and projecting the time to reach the strength limit state using the multiple surviving curves’ methodology.

Jacobs was competitively contracted by the City of Toronto to execute the condition assessment and detailed rehabilitation design and construction administration project for approximately 8 km of sanitary trunk sewers in Toronto, Ontario. These sewers, which traverse bustling urban areas, recreational zones, and environmentally sensitive lands, presented a unique challenge due to their diverse configurations and sizes. This paper delves into how artificial intelligence (AI) was harnessed as an innovative approach to support the recommended scoping of data-driven investigations and determine condition assessment recommendations for rehabilitation design and construction implementation. This approach ultimately led to a 95% reduction in cost of sewer investigations required to confidently recommend this asset management strategy. Through precise and consistent machine coding and advanced analytical asset management tools, risks were comprehensively evaluated, facilitating proactive intervention and cost-effective planning. The primary project objectives included restoring the remaining useful life (RUL) and serviceability of the sewer system while minimizing public and environmental impact, thereby leaving the client and all stakeholders satisfied.

The use of Artificial Intelligence (AI), Machine Learning (ML), and other advanced analytical tools has already made a profound impact on the ability to collect condition data on gravity sewers and verify its integrity more cost effectively with elevated quality standards than traditional processing techniques. The most prominent tool utilized to date has been Automated Defect Recognition (ADR) which has enabled attaining increased quality in programmed SCA far more efficiently than traditional methods. Recent advancements in cloud computing enable the use of ADR at scale, drastically reducing the amount of time that lapses from CCTV inspection to utilize the data for informed business decisions even when presented with large volumes of data. When coupled with defect cluster analysis tooling, configured to match defect patterns to suggested rehabilitation techniques, the process directly results in relating observed condition to their capital cost ramifications. Intelligent use of ADR has also facilitated accessing large volumes of legacy data from programmed CCTV work with no coding to uncoded inspections from routine maintenance. The collection of sewer condition data in conjunction with age, era, and other readily available exposure data also allows the development of deterioration models that provide considerable insight into the manner and rate of degradation for various cohorts throughout the system. The combination of spatial and temporal knowledge enables the use of other advanced modeling tools, such as Genetic Algorithms, Monte Carlo Simulation, and other advanced analytical techniques to provide Asset Managers with consummate answers to relate how much is spent, on what, over what time frame, and what is the resulting benefit or risk involved.

Utility engineering projects can benefit from the use of Artificial Intelligence (AI) and engineers will require a combination of new skills and application of traditional methods to encourage the advancement of AI. There exist many professional practice standards to assist the professional engineer with their responsibility in engineering reviewing work that can be applied to the collection, review, and interpretation of background data. In recent years, the growth of artificial intelligence has provided may improvements in data collection, review, and interpretation that will require professional engineers to oversee and validate the results. Artificial Intelligence has been seen in recent utility projects in the collection, review, and interpretation of background record information. This paper will look at the challenges facing the professional engineer to satisfy their obligations when it comes to AI used in projects completed under their supervision including references to existing professional practice standards. AI will require new responsibilities for the professional engineer.

Utility companies manage extensive water distribution pipe networks in urban areas, where aging infrastructure presents challenges in efficiently prioritizing rehabilitation and replacement projects. To address this issue, accurately assessing the condition of each pipe segment is essential. While various approaches exist, questions remain regarding their ability to handle the left truncation problem, create pipe-specific condition models, and maintain model interpretability. This study introduces a method that employs the inverse of time between failures (TBF) to represent pipe deterioration conditions. The method utilizes parametric statistical models to construct idealized pipe condition curves and leverages machine learning to capture complex relationships among factors influencing pipe deterioration, ultimately generating unique, pipe-specific models. The results demonstrate that the TBF approach, in conjunction with parametric models, aligns well with domain knowledge-based physical mechanisms. Moreover, machine learning offers the flexibility to include covariates. These findings are expected to offer utility companies a structured, data-driven approach for prioritizing pipe rehabilitation and replacement initiatives, enhancing the efficiency and reliability of infrastructure management.

Operable isolation valves are integral to maintain the integrity of water systems and efficiently manage incidents of service interruptions, whether planned or unforeseen. As part of a proactive water asset management program, the City of Baltimore has implemented a routine valve exercising program to comprehensively assess the location, accessibility, and operational status of valves within the Baltimore Metropolitan Water Distribution System (BMWDS). To better aid in the implementation of such a program, this paper presents a valve criticality analysis for the active isolation valves in the BMWDS to prioritize the most critical valves, thereby enhancing the City’s valve asset management strategies. Rehabilitation work batches were developed for implementation to facilitate addressing the rehabilitation needs of inoperable valves. As of December 2023, most inoperable valves in the top 10% criticality have been reassessed and repaired. The remaining valves are planned for further intervention actions.

Valve Criticality is an analysis of select valve assets in transmission and/or distribution systems. The goal of criticality evaluations is determining the relative importance, typically by calculating a “Total Risk Score” (TRS), of each valve in the system. Effective valve criticality evaluations are dependent on completing a robust valve inventory database (VID), a collection of physical and operational valve characteristics. VID development should be accompanied by a hydraulic model, which can provide automated measurement of valve characteristics on a large scale for data points typically unavailable to the utility. Valve attributes from the VID and model are categorized by their effect on the valve’s probability of failure (POF) or consequence of failure (COF). The product of each valve’s POF and COF scores equates to the valve’s TRS. The end product of the criticality analysis is the utility’s valve inventory ranked by TRS, which supports proactive asset management and effective use of resources.

The main water supply for the City of Toledo (City) is a 9-mi long, 78-in. diameter steel pipeline that was manufactured and installed during WWII. This pipeline has been in continuous service since that time except for shutdowns for condition assessment/asset management purposes. The City has a second raw water pipeline, 60-in. PCCP constructed in the 1970s, but the focus of this paper is on the original 78-in. raw water main steel pipe. In 1992, after the pipeline achieved its original 50-year service life, various condition assessments commenced over the next 25 years. This paper will summarize the overall known condition of the pipeline considering this 25-year history of condition assessments. With the present condition of the pipeline understood, the City desired to know if the pipeline was still safe to operate or if it was nearing the end of its useful service life. The previous condition assessments, improvements, and repairs will be utilized to develop a condition assessment “scoring” which will include both technical as well as subjective criteria. This effort will lead to an asset management task that would then guide the City as how to proceed, e.g., repair, rehabilitate or replace the raw water main. A summary conclusion will be provided as to the next step that the City took regarding this important raw water main.

Physical entry inspections are a practical and well-proven method to obtain critical data on the interior condition of water pipelines. Pipelines are generally part of a buried infrastructure system and are not necessarily thought about as often as they should. The old idiom “out of sight, out of mind” is frequently used when discussing buried pipelines but given the critical nature of their function more emphasis needs to be placed on the need for regular inspections and assessment. Their condition needs to be assessed and maintenance activities performed. However, it can be difficult to inspect some pipelines and safety is always the top concern. Developing a physical entry inspection protocol requires detailed planning. Items that need to be considered include isolation of the pipeline from sources of water, steps to dewater the pipeline, lock-out/tag-out requirements, personnel access locations, ventilation, handling of debris in the pipeline, communications, and rescue/response procedures. These are just a few of the items to be considered. This paper reviews the development of physical entry pipeline inspection protocols for large diameter water pipelines and discusses a case study of an inspection at a large aqueduct system in the southwestern United States.

The City of Calgary has long taken a proactive approach to the management of their large diameter feedermain network. This includes an advanced condition assessment strategy that combines an inspection program and risk analyses to develop a better understanding of the safety and reliability of the network. The program began in 2004, after the 1,200 mm (48-in.) McKnight Feedermain catastrophically failed and released 20 mL (5 mg) of water, flooding a roadway, and disrupting service to over 100,000 customers. An investigation determined that the failure occurred on a pipe section with coating that was eaten away in sulfate rich soils, allowing water to seep in and corrode the steel structure of the pipe. Over the years, successful inspections have allowed the City to proactively repair damaged pipes. This presentation will provide an update on Calgary’s long-term strategy to pipeline management, including historical real-time structural monitoring results of the McKnight Feedermain and proactive leak detection success stories on their large diameter feedermain network. Inspection methods and technologies utilized, including damaged pipes that were identified and repaired prior to failure will be highlighted, along with challenges and recent improvements to the assessment process.

The Waukegan Effluent F-3 Force Main (Force Main) in Illinois, responsible for transporting treated effluent into the Des Plaines River just next to Lake Michigan, has been under proactive condition assessment by the North Shore Water Reclamation District (NSWRD) for two decades. Constructed in 1976, the pipeline has experienced catastrophic failures in 1996 and 1998, prompting repeated condition assessments with varying techniques. The latest condition assessment in December 2022 included an electromagnetic assessment, visual and sounding inspections of the prestressed concrete cylinder pipe (PCCP) and 95 carbon fiber reinforced polymer (CFRP) repairs, remaining useful life analysis, and incorporation of structural risk curves and priorities from a third-party engineering firm. Out of the 1,261 inspected pipes within the pipeline, 68 were identified with distress with 21 being newly compromised and 28 showing an increase in distress since 2018. This paper presents the assessment methods, results, recommendations for both short-term and long-term management of the Force Main, and how NSWRD is using this guidance to ensure the force main’s continued reliability.

When it comes to building a lead service line inventory, a one-size-fits-all approach is not a good fit for most communities. The reality is that most water agencies tend to have incomplete data—often found in a mix of paper records, spreadsheets, databases, PDF documents, and geographic information system (GIS) data. This was the case in Jackson, Mississippi. With little to no available records, a multi-pronged methodology was required. Under the direction of JXN Water, Inc., third-party manager for Jackson’s water distribution system, a service line (SL) inventory was developed using an aggressive potholing inspection program. Consisting of approximately 400 residential locations plus all 55 Jackson Public Schools, the team carried out approximately 1,600 inspections by hydro excavating and testing the lines. An ongoing meter replacement program also provided targeted information to aid inventory development. A key component to the success of this aggressive field program was the public outreach coordination across numerous consultants, contractors, and JXN Water. All the field potholing information obtained was input into a machine learning tool and using predictive modeling was able to guide teams in the next set of inspections. With the use of predictive modeling, the inspections were specifically targeted, resulting in cost savings. This paper will discuss Jackson, Mississippi’s story of successes and lessons learned in building, and maturing, their Lead Service Line Inventory and Replacement Plan. This program is just one important piece to rebuild the community’s trust in their water agency, all the while complying with the EPA’s Lead and Copper Rule Revisions.

As its 40-year-old raw water line nears the end of its design life, the City of Grapevine determined that an inspection of this 20-in. bar-wrapped pipeline (BWP) was necessary. When presented with the opportunity to utilize a new in-line inspection platform with ultrasonic testing capabilities to inspect its raw water line, the City re-evaluated its existing selection and decided to take the leap toward cutting-edge ultrasonic technology (UT). CPM Pipelines, in collaboration with Acquaint, carried out this first-of-its-kind inspection in North America, identifying numerous observations, including offset joints, displaced joints, air pockets, missing concrete, and various other anomalies. Since repairing these small sections of pipe would require extensive shutdown time and no other condition or operational issues have been previously reported, Freese and Nichols (FNI) recommended the City reinspect the pipeline in 5–10 years as the pipeline approaches the end of its 50-year design life.

The Great Lakes Water Authority (GLWA) has implemented a Linear System Integrity Program (LSIP) to manage the risk of their extensive water linear piping network. Understanding the condition of their pipe assets is critical to GLWA’s objective of minimizing service failures and improving the overall resiliency of their transmission system. Through the LSIP, GLWA is using pipe condition assessment to drive targeted improvements to its transmission main system. In order to successfully accomplish their objective, GLWA has developed an extensive framework, which serves as the core to the implementation of the program. The framework allows GLWA to maintain consistency, inform, and engage stakeholders as needed, and allows for clear, repeatable processes. In addition to the framework, GLWA has developed business processes for determination of the most applicable pipe assessment method and renewal techniques.

Jackson, Mississippi, residents have long endured years of water main breaks, boil water notices, and low to no water pressure. In August 2022, flooding caused the OB Curtis water treatment plant to shut down, creating a citywide crisis. Nearly, 150,000 residents and businesses were dependent on a system that was on the brink of catastrophic failure. A federal emergency response necessitated that the Environmental Protection Agency and Department of Justice step in to secure the needed funding and assign a third-party interim manager (TPIM) to oversee the system and restore reliable service. Ted Henifin, P.E., was appointed as TPIM with the job to steer and stabilize the drinking water system—from emergency and chronic system improvements to planned system upgrades and sustainability for Jackson’s water utility for years to come. Due to the lack of available and reliable information, the engineering team promptly started working to digitize nearly 20,000 scanned atlas maps and plan drawings to create a distribution system GIS map. A parallel effort was also taken to create a system-wide hydraulic model which previously did not exist. The mapping and hydraulic model proved to be critical to understand system vulnerabilities and to inform prompt decision making, such as establishing priorities to sustain system operation, identification of the most critical distribution system elements for immediate repair/replacement, and implementation of long-term improvements. The hydraulic model and GIS system mapping also provided the team with vital information to understand how repairs and replacements could be implemented to improve the system resiliency, maintain operation, and not further damage the existing fragile system. Hundreds of pipeline leaks in Jackson’s system from 2″ up to 48″ required immediate action to stabilize the distribution system. Some of these emergency repairs led to additional pipeline leaks forming in other areas as pressures increased in the aging and deteriorated pipes. Such a dire situation required a comprehensive plan to restore Jackson’s entire drinking water system through a phased approach. Our paper will describe the process of mobilizing an emergency response team, development of an implementation plan, lessons learned, contractor and supply chain collaboration, integration of engineering and finance, planning, and sequencing of the work to address immediate critical needs while meeting the ultimate objective of providing the community of Jackson a safe and reliable drinking water system.

As a part of the Cedar Creek Section 2 Pipeline Replacement Project for Tarrant Regional Water District, Black & Veatch performed a condition assessment of existing tunnel support systems on pipeline crossings under two Union Pacific Railroads. This paper provides a summary of the assessment process, findings, and reuse potential of the tunnels at the Midlothian and Mansfield railroad crossings.