Pipelines 2022: Condition Assessment

The assess-and-fix approach was developed as an economical alternative assessment and rehabilitation strategy to optimize short- and long-term investment into water mains with a lower failure consequence, typically, distribution mains ≤300 mm (12″). As presented in AWWA M77, it introduces the concept of utilizing electromagnetic tool condition assessment techniques in a contiguous program operation with cleaning and lining to tailor the rehabilitation technique selection to the specific needs of the main. While the technologies that support an assess and fix approach are a collection of mature, well understood technologies and the potential economic benefits can be profound (e.g., the same level of investment could increase annual rehabilitation coverage by 40%–50% on a length basis), widespread implementation progress has been impeded by a lack of understanding of the framework required to support program implementation from a logistical perspective.

Certain pipeline asset conditions require a custom engineered, data-driven solution that integrates past information with immediate field engineering reacting to as-found conditions before and during planned inspections. This paper provides a case study of a midwestern US power generation facility (also referred to as the owner) where internal inspections performed in 2014 revealed the 96″ circulating water (CW) carbon steel pipelines suffered from material deterioration responsible for collateral damage in the downstream condenser. Specifically, severe tuberculation and scaling of the pipelines’ interior surfaces led to fouling of the condenser tubes. In some locations, up to 30% CW pipe wall loss was observed. In 2020, the owner decided to reestablish the structural integrity of its CW system and in turn eliminate fouling of its condensers while providing reasonable assurance as to the future operability of these lines. The approach to deliver on these objectives required up-front planning and design considering multiple rehabilitation scenarios, phased construction scope definition, in-outage condition assessment, and in-outage decision-making as a response to as-found conditions. The results of in-outage condition assessment revealed that the 96-in. CW pipeline had experienced more wall loss in several areas than previously anticipated. This led to a change in the design of the repair. Through a collaborative approach used by the project team, successful cleaning, inspection, and rehabilitation was completed on the first of multiple phases of this project. Collaboration on this project included on-site design engineering support for real-time evaluation of inspection results, allowing for adjusted design based on as-found conditions. The rehabilitation was aided by contingency repair plans that encompassed different levels of potential degradation. This paper provides in-depth information about implementing investigate-design-build (IDB) efforts within the same pipeline shutdown and insight on project phase-out over multiple years.

This paper describes reconstruction of two failed small diameter pipes: one completely corroded and failed 20 in. diameter pre-stressed concrete cylinder pipe (PCCP) in a vault and one 16 in. diameter PCCP punctured during excavation work. The 20 in. diameter buried PCCP power plant blowdown pipeline enters a vault and connects to a tee supported on a saddle. In May 2020, the pipe connection to the tee experienced failure, with the bottom half of the pipe falling on the vault floor and filling the vault with water. Since the blowdown line is an essential part of the plant’s operations, the plant requested an emergency carbon fiber reinforced polymer (CFRP) repair on the section as the pipe could not be removed and replaced in a timely manner. The only access to the repair area was through the vault. The buried 16 in. diameter PCCP is a part of the discharge pipeline in another power plant. In May 2020, during a culvert rehabilitation work at ground level, the buried pipe was punctured as a result of excavation activities, and the pipeline had to be taken out of service for repair. Because of the diameter of the pipe, the only access to the repair area was from the outside. CFRP repairs typically require a mold or form for wet layup installation prior to curing to attain the desired shape. As the entire PCCP section for 20 in. pipe inside the vault had degraded and had to be removed, there was no form available to apply leak-proof CFRP liner between the PCCP and the tee. For the 16 in. pipe, the absence of access from the inside hindered plugging the hole and wrapping the pipe with external CFRP. With some atypical application of CFRP (rebuilding of the 20 in. pipe piece with internal and external CFRP, and use of precured CFRP for 16 in. pipe), the repairs were successfully completed in a short time to enable the plants to get back to operation.

In 2020, a water treatment plant, which supplies drinking water to two municipalities in the Dallas metropolitan area, experienced issues with a degrading 48-in. (1.2 m) diameter centrifugally spun reinforced concrete pipe. The pipeline location, at the bottom of a 13-ft-deep (3.96 m) pipe trench in the plant’s high service pump station and beneath two other large diameter pipes in this trench, made it nearly impossible to perform a “remove-and-replace” repair. Thus, an external repair using a unidirectional glass fiber reinforced polymer (GFRP) became the most economical solution. This allowed for continued use of this 70-year-old asset by providing structural reinforcement around several lateral connections (to high service pumps) and a 48-in. (1.2 m) diameter tee. The project was completed within two weeks, leading to high savings for the client. However, the external repairs presented their own unique set of challenges. Elements such as steel saddles, flanges, and crotch plates created obstructions. As a result, special detailing was required to address these existing conditions while maintaining the structural integrity of the GFRP repairs.

On February 12, 2021, the city of Baltimore DPW received notification of water leaking from a 60-year-old 48-in. prestressed concrete cylinder pipe (PCCP) water main located under the southbound ramp of the I-83 interstate. The city notified EBA Engineering, Inc. (EBA) under its contract to provide urgent needs water engineering services. EBA and its subconsultant Arcadis performed a condition assessment and evaluated repair options. The team recommended QuakeWrap’s carbon fiber reinforced polymer (CFRP) system for this critical, emergency repair. A five-layer CFRP lining system was proposed by QuakeWrap in compliance with AWWA-C305. The challenges associated with this emergency repair included a fully-structural design and installation in short timeframe despite the 1-ft wide hole and limited access to the repair point through a pipe section with a steep slope. The strong collaboration among the owner, engineering, and construction teams resulted in a smooth planning, design, and execution.

Carbon and glass fiber reinforced polymers (CFRP/GFRP) have been used for rehabilitation of pipelines since late 1990s, and the technology has been gaining more acceptance in the pipeline industry due to the advantages it provides such as ultra-high strength, corrosion resistance, ability to install on any shape and material of pipe, and long service life with minimal or no maintenance. The majority of pipeline rehabilitation projects with the fiber reinforced polymer (FRP) technology are comprised of internal or external repair of pressure pipes in dry or low-moisture condition. Recent advances in formulating hydrophobic (and occasionally hydrophilic) adhesives, as well as under-water cure saturants, have provided the opportunity to repair piping systems that are underwater (mostly oil and gas pipes) or large diameter pipes without the need for bypassing the flow (mostly in wastewater conveyance). Nevertheless, repairing a pipeline that is submerged or in live flow imposes certain challenges with respect to design, materials, and installation, which may require divers that are trained to install the product with special equipment. QuakeWrap has been developing FRP systems that are suitable to install in submerged and live flow conditions for the past eight years after receiving a request from the Indonesian oil conglomerate Pertamina Oil, which tested this CFRP system installed underwater, and the results were encouraging. These efforts have continued to improve its external FRP wrapping system (SuperLaminate-X) over the years to achieve stronger adhesion and performance with improved resins, fabrics, and installation practices. Recently, a specialty installation contractor, Bulldog Diving, has performed mock installations of this CFRP system to repair a defective pipe in their training tank (approximately 10 ft. deep). The defective pipe sample (with a 1-in. hole) wrapped with this FRP system underwater, and then was sent to manufacturer’s R&D lab for pressure testing, which yielded failure at 600 psi by means of a leak through the edges in compliance with the failure mode set forth by ASME PCC-2 Part 4. The next step in wet applications of this FRP repair system is installing precured patches along a 48-in. sewer pipe in the Washington, DC, sewer system. The manufacturer and Bulldog Diving have successfully tested this repair system and are currently preparing for the actual pilot installation. Attendees of this presentation will learn about the development of submerged and underwater pipe repairs with a highly engineered FRP system installed with a unique procedure by divers.

DC Water owns and operates a variety of aerial sewer crossings throughout Washington, DC. One such crossing is in the National Arboretum where an aerial sewer crosses over Hickey Run. Inspection of this sewer crossing revealed that the foundation for the sewer crossing had become compromised. In detail, the upstream abutment had spalled concrete, and there was an eroded void beneath the-footer (no pile) and the exposed backside that was subject to the surged flow of the creek along the eroded embankment. As the consequence of failure of this sewer was very high, DC Water recommended emergency repair in lieu of a planned capital improvement project and was given the blessing of the Department of Energy & Environment (DOEE) for a “permitting later and urgent repair first” special green light. The components of this emergency repair to the aerial sewer crossing included the installation of micropiles for stabilization of the existing foundation, tying these micropiles into a newly placed concrete enlargement of the foundation, concrete repairs on the pipeline encasement, five (5) new concrete pier on pile to replace in situ piers, toe protection and embankment retrofit, installation of carbon fiber reinforced polymer (CFRP) on the pipeline encasement to strengthen the unsupported span overtop of the creek, and installation of glass fiber reinforced polymer (GFRP) and topcoat for future corrosion protection. In sum, a comprehensive asset management approach was implemented by DC Water to extend the life of this critical asset.

An Indiana Department of Transportation (INDOT) and city of Indianapolis (City) project planned to replace the Kessler Boulevard bridge over the White River in Indianapolis, Indiana. The bridge replacement was planned to be completed over two construction seasons under a phased traffic approach. The phased approach would allow two lanes of traffic during construction of either phase. Citizens Energy Group (Citizens) owned and maintained an existing 16-in. diameter cast iron water main that was installed in 1957 and located in the northern half of the bridge. Phase 1, which was planned for the 2021 construction season, was completed first. Citizens evaluated different alternatives with one looking at horizontal directionally drilling a new high-density polyethylene (HDPE) water main below the White River. This alternative was not viable as a pressure pipe would not be allowed through the existing levee. Citizens determined the best alternative for relocating and replacing the water main would be installing it back in the bridge as part of the INDOT/city bridge replacement project. This paper focuses on the challenges of completing this project, including (1) water main design alternatives’ evaluation, (2) design coordination and environmental concerns, (3) construction phasing, (4) temporary service requirements, and (5) construction challenges.

The city of Houston’s Northeast Transmission Line (NETL) consists of 16.5 mi of large diameter welded steel pipe (WSP), ranging in size from 54-in. to 120-in., with the majority being 108-in., with an ultimate carrying capacity of 365 MGD. The $450 million NETL will provide water from the Northeast Water Purification Plant to the city of Houston, four regional water authorities, and a number of municipal utility districts (MUDs), and will service over 900,000 homes throughout Harris County. The NETL is being constructed in three phases through 13 independent contracts, utilizing both open-cut pipe installation as well as tunneling. This paper will provide a review of the pipe specifications and design topics, followed by details of the art of WSP manufacture, including cylinder fabrication and application of linings and coatings. Topics pertinent to the safe transportation and handling of the pipe will also be discussed. Various issues related to the successful installation and construction of the pipeline, such as stulling, backfill, joint welding, and completion, with an eye on lessons learned will be provided for the benefit of engineers and contractors involved in projects of this magnitude.

The current state of America’s infrastructure is in need of either replacement or rehabilitation. Most of the time, these assets are addressed by a formal structured process of planning, design, bidding, and construction. However, many times there is not enough time to perform this formal, and many times lengthy, process when the need to address these assets is urgent. Whether there are recent pipe breaks, available funds that need to be spent by a certain time or working within a constraint of an active construction project, cured-in-place pipe (CIPP) solutions provide an engineer, owner, and general contractor the ability to address deteriorating infrastructure in a timely and cost-effective way all while restoring the infrastructure to a fully structural condition. This presentation will discuss the various factors that lead to deciding to incorporate CIPP for a 42-in. force main within a wastewater treatment plant and how it was CIPP that led to the best solution for total project cost and schedule. The audience will gain a deeper understanding of the main drivers of a project, other than the technical design, and how these driving factors allowed for the most efficient way to move the project forward to completion.

Citizens Energy Group (Citizens), a public charitable trust, owns and operates the Indianapolis wastewater collection system comprised of roughly 3,000 mi of 8″ to 120″ sewers in Indianapolis, Indiana. Their approach to system rehabilitation is proactive, rehabilitating sewers and manholes through targeted projects before there is a problem. Citizens partnered with Granite Inliner, a rehabilitation solutions provider, for the Lafayette and White River Large Diameter Sewer Rehabilitation Project. The project consisted of 4,100′ of 42″–54″, 35′ deep sanitary interceptor sewer cleaning and cured-in-place-pipe lining (CIPP). It was located within 200′ of the White River, required an 8 MGD dry weather bypass, and crossed a golf course, two thoroughfares, heavily wooded areas, and an apartment building construction jobsite. The effort began in 2019 with a research assignment through Citizens’ Contractor Planning Partnership. Citizens and Inliner worked collaboratively to plan every detail of the project, thereby minimizing risk and ensuring readiness to proceed. Construction was completed in 2021 and came in within budget.

Cured-in-place pipe (CIPP) is a widely accepted rehabilitation technology that has been in use since the 1970s, though primarily in gravity sewer applications. Recently it has gained greater acceptance as a rehabilitation solution for pressure pipe applications. When CIPP is used in potable water applications, maintaining long-term watertight service connections is a critical design consideration. Common industry practice relies on the ability of the CIPP liner to bond or adhere to the interior surface of the pipe at the service connection. This paper will focus on advancements to the method of internal service reinstatement using a mechanical fitting that is inserted robotically into the service after lining to create a watertight seal that eliminates the reliance of adhesion between the host pipe and CIPP liner. This paper will also provide details on a recent pilot project in Pleasant Grove, Utah, that utilized CIPP lining and mechanical service connection fittings.

The District of Columbia Water and Sewer Authority (DC Water) must repair the century-old sewers located in an environmentally sensitive area. The sewers are located on lands managed by US National Park Service (NPS) and in a District-owned urban forest. The land is part of Rock Creek Park—a true gem in our nation’s capital. The existing sewers were constructed with clay pipe and brick manholes in 1907 and 1908. A 2011 CCTV assessment showed structural deficiencies and infiltration. An environmental assessment (EA), wetland and floodplain statement of findings (SOF), and the finding of no significant impact (FONSI) were prepared per National Environmental Policy Act (NEPA). The SOF and EA considered alternatives that were evaluated to characterize impacts to wildlife, vegetation, wetland, floodplain, and other resources. During the permit process there were several failures. Emergency repairs were made to stop dry weather overflows, wet weather damage, and exfiltration. When emergency repairs were complete, the permit process started where it left off with the sewer needing a permanent solution. Now that the permitting process is complete, the sewer system will be rehabilitated using CIPP. Rehabilitation requires four heavy equipment (HE) vehicular access paths inside the park. The HE paths are constrained by a narrow limit of disturbance that impacts use of construction equipment. Walk-in paths allow equipment such as wheelbarrows. Stream improvements are required near exposed sewer assets. The assets in these areas have a high risk of structural damage and deformation, as well as groundwater and stormwater infiltration. In conjunction with the asset protection measures, banks will be stabilized from scour to protect the currently exposed sewers. Because the project is located in a very active community, we undertook significant community outreach efforts. Several community meetings were held, often attracting more than 100 residents. The neighborhood includes an embassy, a museum, condominium and apartment buildings, and numerous high value single family residences. The traditional low-bid procurement was replaced with quality based selection (QBS). DC Water evaluated technical proposals from contractors and selected contractors with experience and qualifications matching the project needs. The project also includes an incentive for saving trees.

The goal for any construction project is to achieve high quality, stay under budget, and on time. This is even more true for trenchless rehabilitation projects in which the nature of incorporating a trenchless technology is to improve project schedules and reduce overall project costs. These goals are shared by the owner, engineer, contractor, and every stakeholder for the project. There are a multitude of reasons why a trenchless technology is chosen for a particular project. Site conditions such as pipe location, limited access, and groundwater fluctuations are among the many reasons why a trenchless rehabilitation technique is a best solution for addressing critical water main infrastructure. Furthermore, there are benefits to using a trenchless technology when facing adversity during the construction phase. The audience will take away invaluable perspectives to understand how the various stages of the project influence each other and can further improve the design and project documents.

The American Water Works Association (AWWA) publishes standards for the design, manufacture, and construction of water pipelines and facilities for the water supply industry. AWWA has approved the development of a new standard for the installation of concrete pressure pipe. The new draft standard is currently underway, and final approval of the standard is anticipated to be complete in mid to late 2022. AWWA standards are intended to represent a consensus of the water supply industry that the product described will provide satisfactory service. The new AWWA standard is intended to be used in conjunction with other AWWA standards and manuals, and covers the following concrete pressure pipes: (1) reinforced concrete cylinder pipe (RCCP), AWWA C300; (2) prestressed concrete cylinder pipe (PCCP), AWWA C301; (3) reinforced concrete noncylinder pipe (RCNP), AWWA C302; and (4) bar-wrapped steel cylinder pipe (BWSCP), AWWA C303. The new standard includes subsections for the following categories: (1) general information, (2) references, (3) definitions, (4) preliminary information, (5) delivery and handling, (6) trench construction, (7) pipe installation, and (8) verification. The new standard uses new terminology and definitions for bedding, backfill, and embedment being used in other recent AWWA standards for pipelines. It also provides thorough discussions of such topics as pre-construction submittals, alignment and grade, trench excavation, joint assembly, thrust restraint, flushing, disinfection, highway and railroad crossings, subaqueous crossings, corrosion protection, repair of pipe, inspection, and field testing. The new standard is intended to reduce the number of defects in installation, and to be used as a guide for owners, design engineers, constructors, and inspectors in the proper installation of concrete pressure pipe. This paper will include the highlights for the new standard and guidelines for the use of the standard.

Following a series of historic floods in the Houston, TX, area, a 60-in. (1.5 m) reinforced concrete pipe (RCP) storm sewer installed in the 1950s collapsed on the site of a high school sports facility. The failure resulted in a 100-ft (30 m) long sinkhole near a softball field scheduled for major renovations. The school district knew the pipe existed in the area but was unsure of the exact alignment or condition. The collapsed pipe segments were immediately replaced, and the school district initiated an evaluation of the remainder of the pipe to ensure the planned ball field construction would not be impacted and for public safety on the field. The evaluation consisted of review of failed pipe removed and closed-circuit television (CCTV) of the remaining pipe. Based upon observations of the failed pipe, this pipe does not meet the requirements of the current standards for RCP, and it is unclear what design and manufacturing techniques were used. It was also apparent that the pipe contained elliptical reinforcing, with distinct “TOP” markings. Many of these markings were found to be located near the springline of the pipe in their installed positions.

Wastewater pipeline construction projects, like any other public utility projects, are susceptible to delays, and the Kingdom of Saudi Arabia (KSA) is no exception. In many cases, such delays cause environmental issues and affect commuters, local businesses, project cost, and the public and workers’ health and safety. There is a growing need to identify and study the relative significance of the major causes of delays in wastewater pipeline construction projects in the KSA. A questionnaire survey was conducted to assess the importance of 30 potential delay causes based on the perceptions of a select sample of clients, consultants, and contractors. These 30 potential delay factors corresponded to eight main delay categories. The survey data was analyzed using the relative importance index and was then further examined for agreement between the three groups. The top five delay causes identified were labor supply, equipment availability and failure, unforeseen ground conditions, labor productivity, and improper planning. The analysis showed disagreements between clients and contractors as well as between consultants and contractors with regard to the rankings of both individual delay causes and factor categories. The results of this survey will be used in future work to develop decision support systems for wastewater pipeline construction projects. It is anticipated that altogether these studies will contribute to improving the sustainability of wastewater pipeline construction projects in the future.

In 2020, the city of Turlock, California, constructed 7.5 mi of 42-in.-diameter, low-pressure, recycled water, steel pipeline. The design included three 54-in. microtunnel drives below two environmentally sensitive drainages and one culvert. Attempts at stabilization of the launch portal for the first tunnel with grouting were not satisfactory until dewatering wells were added adjacent to the portal. The portals for the second tunnel were stabilized using a guillotine-type (double wall) system. Despite tunneling through unanticipated woody material (buried tree-trunks), the second tunnel was completed successfully. The project included a value-engineering option of mutually shared cost savings from contractor ideas accepted by the city. Through value engineering, the third microtunnel was eliminated, and instead the pipeline casing was installed with pipe jacking through extensively dewatered sandy soil with an excavator bucket. This paper summarizes microtunneling challenges, remedies and value engineering, and related recommendations for future projects.

In 1915, the city of Baltimore entrusted one of the founders of Whitman Requardt and Associates, Ezra Whitman, with the task of designing the new Montebello Water Filtration Plant. Montebello would provide clean drinking water for all of Baltimore. In turn, Mr. Whitman relied on the Lockjoint Pipe Company to design and manufacture 108″ (2,700 mm) diameter concrete pipe to act as a finished water conduit for the new Montebello Water Filtration Plant. The pipe, designed to maintain 80 ft (24 m) of head and weighing 11 t (10 MT) each, was manufactured nearby. One hundred years later, the city of Baltimore returned to Whitman Requardt to update the Montebello plant. As part of the modernization, Whitman Requardt planned on cutting into the existing 9′ diameter reinforced concrete pressure pipe, removing a venturi meter and replacing it with an ultrasonic flow meter in a vault. Allan Myers successfully bid on the project and chose to provide new 108″ (2,700 mm) prestressed embedded concrete cylinder pipe to replace a portion of the circa 1915 concrete line. The 1915 pipe was constructed with a joint similar to a single offset reinforced concrete pipe but included a copper expansion band overlapped with reinforcement, and the whole assembly was finished with poured and troweled cement mortar. Replicating this joint to make a connection would have proved very difficult. The pipe manufacturer, Allan Myers, and Whitman Requardt discussed several options to create a watertight seal. This paper will give a brief history of the Montebello facility, give an overview of the improvements being made, and will discuss various options considered to make watertight connections to the existing finished water pipe and the means and methods used by Allan Myers to successfully make this connection on both ends of the cut-in.

A 24-in. prestressed concrete cylinder pipe (PCCP) between pump stations in north Dover, DE, and downtown Dover, constructed as part of the original network to convey wastewater to the Kent County Resource Recovery Facility had significant point failures in the past ten years, resulting in substantial damage to surrounding roadways and communities. The county identified 15,000 LF of sewer force main that needed immediate rehabilitation and renewal to prevent future failures. Located below Route 13, a key access road to the state capital, universities, businesses, and major tourist destinations, combined with buried utilities that had to be maintained throughout construction, and with work set to begin during the heavy tourist season and continuing into the holiday season, the project faced challenges that could only be overcome using the correct construction methods and materials. This paper will explore the benefits of using the appropriate rehabilitation technique and construction materials, including trenchless technologies such as sliplining, and jack-and-bore, with a combination of some traditional open-cut installations. Use of the appropriate pipe materials and their suitability for the selected renewal methods will also be discussed. Construction-related topics unique to the rehab method and materials will also be a focus of the discussions.

This paper will discuss the design and construction oversight of a city of Houston wastewater lift station elimination project. Three existing lift stations, Dairy Ashford, Kirkwood, and Harvest Moon, were to be eliminated by the construction of a new, larger capacity Harvest Moon lift station and approximately 13,900 linear feet of gravity sanitary sewer and force main pipe. Five different methods were utilized for the construction of the flow diversion piping and lift station structure to accommodate the various right of way sizes and to mitigate adverse conditions encountered during the construction phase. The success of this project is a direct result of the versatility of the project team, their ability to fashion the many hats of underground construction technologies, and to manage the ambiguity encountered throughout the project’s construction phase.

Natural hazards pose significant threats to the integrity of pipeline networks. Rapid post-disaster reconstruction is crucial for both the safety and survival of communities. However, sudden increases in reconstruction costs following natural hazards often hamper the rapid reconstruction and rehabilitation of pipeline networks. It is essential to investigate the post-disaster fluctuations in pipe costs for a timely reconstruction of pipeline networks. The objective of this research is to quantify the pipe cost fluctuations after the 2021 Texas winter storm using cumulative sum control charts and seasonal autoregressive integrated moving average (SARIMA). The results indicate that the disaster triggered statistically significant increases in pipe costs, including corrugated steel pipe costs, polyvinyl-chloride (PVC) pipe costs, ductile-iron pipe costs, and copper water tubing pipe costs. The findings of this research can assist reconstruction engineers and capital planners in quantifying post-disaster cost fluctuations, identifying vulnerable pipe costs to disasters, and enhancing pipeline reconstruction plans.

Sustainability has become a trend in recent years in stormwater infrastructure management and will need to be practiced in perpetuity. Trenchless rehabilitation technologies are sustainable and innovative techniques for the renewal of stormwater drainages. Sliplining is a trenchless technology solution for rehabilitation of large diameter stormwater drainages that provide structural support for severely damaged host pipes. Trenchless sliplining is installed by inserting a smaller new pipe into a host pipe. This technology requires grouting the annular space between the two pipes and sealing the ends. Environmental costs include all the costs associated with the rehabilitation of stormwater drainages considering the complete life cycle, starting from the production of raw materials to the final disposal of the products. Construction cost is the original cost, including the direct and indirect costs of the project. The available information of the bid tabs and materials, manufacturing, processes, transportation, and disposal are used to analyze the environmental and construction costs associated with a trenchless sliplining renewal project. The objective of this paper is to conduct the environmental and construction cost analysis of sliplining using HDPE pipe for culverts. The environmental cost analysis was carried in SimaPro using TRACI method. Results show that carbon dioxide and ozone are the major emissions in sliplining renewal process that can lead to global warming and smog, respectively. Also, environmental costs consist of 7% of the total environmental and construction costs of a sliplining project in large diameter culverts. It can be concluded that the environmental costs of sliplining is an important component when considering sustainable stormwater infrastructure management. This study can be useful for analyzing the environmental and construction costs of other trenchless renewals for large diameter culverts with different project conditions.

Approximately 80% of a water utility’s investment is contained in its underground infrastructure. Many times, these out of sight, out of mind facilities are assimilated to the “Forgotten City.” Precedent is placed on new plants, boosters, tanks, and even office buildings where intense analysis is placed on constructing these projects to guarantee to the utility an efficient, resilient, and sustainable asset will be in place. Unfortunately, however, underground transmission and distribution pipelines are looked upon as a straight line on an engineering drawing with little engineering forethought as to how these facilities can save costs to the utility, during construction and into the future regarding operating and capital expenditures. This presentation outlines proven components that should be analyzed and reviewed prior to material selection of pipeline materials to afford the utility a comprehensive view of how it can most efficiently and effectively serve customers within their system.

In 2017, CDM Smith’s Austin, Texas, office was hired to design a 10-mi transmission line for Bell County WCID #1, a utility district that provides water to Fort Hood, city of Killeen, city of Copperas Cove, city of Harker Heights, and city of Belton. Prior to the design and construction of the transmission line a new treatment plant was designed and put out for bid in the spring of 2017. The transmission line project was designed and bid in two phases. Phase 1 consisted of approximately 22,150 linear feet of new 36-in. potable water C900 PVC transmission main, and Phase 2 consisted of approximately 30,500 linear feet of 36-in. potable water C900 PVC transmission main. The Phase 2 transmission line alignment passed through a river crossing and was installed by horizontal directional drilling. This paper will discuss the design and construction of the horizontal directional drill section of the transmission line.

With the gradual congestion of underground utility pipelines, the traditional open-cut method of installation is becoming problematic and almost infeasible in most conditions, increasing the need for the adoption of horizontal directional drilling (HDD) as a preferred method of installation of underground utility infrastructure. HDD is arguably one of the fastest-growing and the most popular methods of underground trenchless technology construction because of its ability to install larger diameter pipes, the ability to be used in most soil conditions, its steering ability, and less support equipment required compared to other trenchless technology techniques. Despite the numerous unique benefits provided by this innovative construction method, it has not experienced widespread adoption in the utility construction industry. Research needs exist to determine the reason for this limited adoption and implementation. Thus, this study provides a review of the factors impacting the application of HDD for utility pipeline projects. The benefits and drivers of the HDD applications are highlighted followed by a synthesis of the risks and barriers influencing the widespread adoption and implementation of HDD for utility pipeline projects. The findings of the study will be used to develop and evaluate an explanatory framework that can be used by stakeholders in the utility engineering community to enhance the adoption and implementation of HDD for utility pipeline projects.

Pneumatic hammers are often used to assist during horizontal directional drill (HDD) pullback operations when difficulties are encountered during pipe installation. When properly used, pneumatic hammers have proven to be a valuable resource in HDD operations; however, the use of pneumatic hammers should be carefully evaluated to avoid pipe damage or girth weld failure. Pneumatic hammers apply a cyclic load on the pipe cross-sectional area. The cyclic nature of the loading should be analyzed to evaluate the duration the hammer can be used to reduce the potential of fatigue failure. This paper explores the cyclic loading applied by pneumatic hammers during HDD pullback operations and presents a step-by-step fatigue analysis to determine the limitations (if any) of using pneumatic hammers for any given HDD installation, with particular focus on steel pipe. The analysis allows the user to input several variables such as geometric parameters, pneumatic hammer loading capacity, hammer frequency, and derating factors for girth welds, to evaluate an appropriate size for a pneumatic hammer and for how long to operate it.

The city of Fort Lauderdale experienced a series of breaks along its aging sewer transmission main, spilling millions of gallons of sewage into the city’s waterways. To solve the problem, the city decided to replace its main transmission line by constructing over 7 mi (11 km) of pressure force main to serve as a redundant line with a flow capacity of 64 million gallons per day (MGD) (3.37 m³/s) of sewage discharging into its wastewater treatment plant. The new line was constructed mostly with trenchless technologies to minimize disruptions through downtown Fort Lauderdale commercial areas and minimize traffic impacts across major county and state roadways. The 65-million-dollar utility project was fast-tracked; it was designed, permitted, constructed, and placed into operation in under 18 months. The entire project was built within highly developed urban corridors, downtown areas, and business districts.

Long distance gravity sewer installs by horizontal directional drilling (HDD) are considered to be some of the most challenging and risky HDDs out there. The small margin for error can quickly lead to out of spec sections of the borehole or at worse an unsuccessful HDD. This paper will examine the design, pre-planning, and execution that led to a successful 2,300 LF (701.04 m) install of 20″ HDPE gravity sewer by HDD. The crossing was installed at a max depth of 82′ deep in solid rock just south of Cincinnati, OH. To further add complexity, a 65′ manhole was installed in the middle of the HDD alignment after the HDD was completed.

The Citizens Energy Group’s finished water from the White River Water Treatment Plant to the Riverside Reservoir is transported through a 48-in. and a 60-in. conduit. The 48-in. was installed in approximately 1909 and is approximately 4,270 ft in length. The 60-in. was installed approximately in 1929 and is approximately 4,475 ft in length. The capacity of the 48-in. is 39.2 MGD and the 60-in. is 68.1 MGD flowing by gravity. These two conduits provide a redundancy to the Riverside Pump Station, which pumps 30–35 MGD from the Riverside Reservoir. Based on a conditional assessment of each pipe, both conduits are currently in a condition that warrants a rehabilitation. All access points have been located and mapped including GPS coordinates with depths were used to generate a pipe profile. A majority of the pipeline was televised. A rehabilitation plan was developed in two phases. The first phase was to provide security to all access points by raising manhole lids and replacing the castings with a new sealed, bolted, and locked inner lids. Other security measures include fencing and locking gates. The next phase of rehabilitation includes the lining of each conduit. Since either conduit is sized to match or exceed the pumps at the Riverside Station, the conduits will be taken out of service separately due to the redundancy or double capacity of the conduits without affecting the flow at the Riverside Pump Station. The 48-in. conduit has a cross section shape like a guitar pick and will be rehabilitated first. Many methods of lining were evaluated during this process with the requirement to be NSF approved material due to the finished water. Once completed there will be two rehabilitated and structurally sound conduits that will offer capacity and redundancy to the Riverside Pump Station for years to come.

A city with a vibrant past, the city of Laredo was established by Spanish explorers in 1755. Though it began as a humble Western farming settlement, it has had a colorful history of occupation and defense during the Mexican-American War and continues to this day as a major travel point between the countries. Today it is the United States’ largest inland port of entry. In 2018, the city, along with a Laredo based civil engineering firm, began planning and designing the installation of approximately 5,500 linear feet of 30- and 36-in. fusible polyvinyl chloride (FPVCP) gravity sewer interceptor as part of the Eastern Chacon Creek Interceptor and Drainage Improvements Project. This new gravity sewer pipeline was critical to the city’s future growth and long-term sewer collection system capacity, as it continues to function as a hub of commerce and tourism with a slow but consistent rate of permanent residential growth. Existing site conditions, access limitations, encroaching homes and structures, narrow easements, flood plain, environmental impact, and required depth of the new line along an existing creek bottom made not only the preliminary design considerations but also the construction/installation challenging. The city received favorable bids in October 2020 and with the invaluable cooperation and coordination between the city, engineering firm, and the contractor they were able to successfully construct a new asset that will serve the city for years to come. The new interceptor will provide sewer service to 5,320 acres in South Laredo that will accommodate future development for the foreseeable future, eliminates a costly lift station, and with little to no maintenance/infiltration concerns.

The city of Houston (the City), the fourth largest city in United States, is not very old. The oldest water infrastructure in the city dates to the 1930s, and most of the main transmission system is no older than the 1970s. This is the story of a 60-in. transmission line constructed around 1970, known as the “North 60.” This line conveys water to the downtown and western areas of the city, making it one of the city’s most critical pipelines. The line stretches about 10 mi of which the first 3 mi is constructed of steel pipe and 7 mi of prestressed concrete cylinder pipe (PCCP). Over the course of its life so far, several significant events have revealed its vulnerability and highlighted the benefit of proactive condition assessment and planning. The condition assessments involved manned entry observations along with electromagnetic survey, and a real-time acoustic monitoring system, and concluded that over 90% of the pipe sections are in good condition, however, have identified distress in approximately 10% of the pipe located location randomly throughout the line. Each distressed pipe was rated based on its level of risk and approximately 4% have required either replacement or a structural repair. The PCCP portion of the line suffered a major failure in 2003, followed by a series of assessment and rehabilitation projects. Most recently, in 2021, 16 pipe segments were repaired internally using carbon fiber liners. This paper discusses the planning, shutdown, and repair to these 16 pipe segments.

With aging, pipelines have become prone to structural failures, blockages, and overflows, which need immediate attention. Compared with conventional open-cut methods, trenchless technologies are cost-effective solutions for renewal of deteriorated pipelines. The development of infrastructure, concerns about impacts on environmental, and economic trends are affecting society, resulting in the advancement of technology for an eco-friendly and cost-effective pipeline rehabilitation. The objective of this paper is to compare life cycle cost analysis (LCCA) and life cycle assessment of spray applied pipe liners (SAPL), cured-in-place pipe (CIPP), sliplining, and pipe bursting methods using literature review and case studies. The results of this study will provide an estimate of not just the capital and installation costs, but indirect costs of these methods based on their design life to choose a particular technique for various project conditions.

A significant percentage of the pipelines in the United States were installed in the early to mid-20th century, and many still in service have exceeded their intended design life. As a result, there are significant needs for pipeline rehabilitation or renewal. Selecting an appropriate rehabilitation methodology is a complex decision in which pipe material, diameter, and design loading must be considered. The primary drivers in determining the most appropriate rehabilitation or replacement method include cost, scheduling, service life of the repair, impacts to existing operations, constructability, impacts to surrounding communities, surface preparation, allowable diameter reduction, safety, and the ability to accommodate misalignments. The Westminster Boulevard Force Main Replacement project, currently under construction, involves the replacement of two parallel sewer force mains using a combination of open trench, slip-lining, and cured-in-place-pipe (CIPP). These technologies were carefully selected after considering numerous technologies and demonstrate that a holistic approach to choosing a rehabilitation method assists owners and engineers in making better informed decisions.

Leakage through joints in rigid sewers or corrosion-induced perforations in corrugated steel culverts can result in ingress of groundwater and erosion of the surrounding fill. The loss of ground support may then compromise the ability of the sewer or culvert to support earth or vehicle loads. A new test facility at Queen’s University has been developed to undertake erosion experiments to measure the impact of erosion on sewer and culvert behavior. Use of the 5 m long, 3 m wide, and 4.5 m deep test pit to investigate the response of large diameter pipes under deep burial has been described previously, and this paper describes its use for erosion experiments. This is illustrated by outlining a test conducted on a corrugated steel pipe with 0.9 m diameter and perforations along the haunches. This test pipe was instrumented with optical fiber sensors around crests and valleys of the corrugated plate. It was then placed in the pit and backfilled with sand. After initial burial, wheel pair loading on the ground surface was applied through a steel plate, and strains were measured around the pipe circumference. Those strains then were used to obtain the distributions of hoop thrust and circumferential bending moment for this “intact soil” condition. The test pit permits experiments in saturated ground, and after raising the level of the groundwater, leakage through the perforations commenced, causing erosion of the surrounding fill. After lowering the groundwater level to stop the erosion, surface loading was again applied, and the resulting strains measured for the steel culvert with this deteriorated (eroded soil) condition. Comparisons of the pre-erosion and post-erosion responses reveal that there are very significant changes in the patterns and magnitudes of circumferential bending moment, with a large bending moment developing where the soil support was removed by erosion.

Today’s water utility asset managers are faced with decisions that inherently define the nation’s standard of living with regard to how best to maintain large diameter water pipes. Pipes have a life cycle that is not always well-defined or easily understood due to their unseen nature; hence, they are often replaced per leak rates or according to roadway surface management. This can result in the decommissioning of pipes that still have years of functional life remaining. In fact, some experts say that 90% of this type of pipe is replaced too early; this translates to tens of millions of dollars wasted each year nationwide. This paper presents the results of a study seeking to best define water main economic life by harnessing newly developed pipeline performance models, trained from data collected from across North America in an unprecedented manner as part of the PIPEiD Project. The models were used to drive a fuzzy logic-based algorithm for pipeline renewal project selection and timing based on economic life, which would then greatly reduce overall life cycle cost over the planning window.

Pipelines buried beneath roadways experience deformation due to traffic loading throughout their service life. For a jointed cast iron pipeline, traffic loading causes displacement and rotation at each joint. When rehabilitating buried cast iron pipes using trenchless technology, the repair is designed to withstand the imposed displacement and rotation. Introducing a circumferential crack to the host pipe represents an extreme scenario for a repair. A finite element model is developed to evaluate cast iron pipeline deformations caused by HS-20 truck loads applied at the ground surface. The loading is applied to the pipe as a distributed load using Boussinesq’s solution for point loads on a semi-infinite elastic half-space. The pipe-soil interaction is modeled as soil springs with linear-elastic behavior. The cast iron joints are modeled with axial, shear, and rotational springs using previously published data based on laboratory testing of field-sampled cast iron joints. The present model is then compared with analytical solutions, past finite element analyses, and past experimental data to verify and validate deformed shape, rotation at the joints and circumferential crack, and relative offset at the circumferential crack. Following validation, properties of a cured-in-place pipe repair are applied to the model and the predicted offsets and rotations tabulated. The results can inform full-scale testing procedures, justifying the experiment geometry, input loads, and corresponding displacements necessary to evaluate the performance of new pipeline repair technologies over a simulated design life.

Spray applied pipe lining (SAPL) is used by Departments of Transportation (DOTs) as a trenchless technology method to renew deteriorated gravity storm conduits and culverts. Cementitious SAPLs can increase the structural capacity of the deteriorated culverts. Previous studies have shown that the cementitious pipes are able to heal the hairline cracks (crack width of less than 0.01 in.). After crack formation, the healing process, also called autogenous healing, initiates by exposing the un-hydrated cementitious particles in the liner matrix to moisture. Currently, loads that generate 0.01-in. crack width is used as a benchmark for the liner thickness design. The goal of this paper is to measure the corresponding truck load that generates the 0.01 in. crack width on cementitious SAPL through a set of large-scale laboratory testing. To achieve this goal, three 60-in. diameter invert-deteriorated corrugated metal pipes (CMPs) were buried under 2 ft of soil cover in a soil box. Then, CMPs were renewed with cementitious SAPL and were subjected to the static vertical load using a hydraulic actuator. During the load application on the soil surface, the crown of the SAPLs were monitored by high resolution digital cameras, and the crack widths were measured using the digital image processing method. The results showed that thicker SAPL liner can resist larger amount of live load with lower crack opening width.

Through a soil box laboratory testing, the objective of this paper is to provide installation details for application of structural polymeric spray applied pipe liners (SAPLs) in pipe and culvert renewals. SAPL is a trenchless pipe renewal technology, which uses spray applied polymeric materials to line the deteriorated pipes internally, improves the structural integrity of the old pipes, and extends their design life. This paper will demonstrate the procedure for installation of polymeric SAPL inside deteriorated corrugated metal pipes (CMP_S) and provide the installation details of instruments involved in the SAPL structural evaluation test setup.

Polymeric spray applied pipe lining (SAPL) is a trenchless technology renewal method that can structurally renew gravity storm conduits and culverts. Polymeric SAPL is a cost-effective method that compared with other trenchless renewal techniques accommodates complex geometries with robotic applications. This paper evaluates structural capacity of six large diameter fully deteriorated corrugated metal pipes (CMPs) renewed with various thicknesses of the elastomeric polyurea SAPL in both arch and circular shapes. These pipes are buried into a soil box under 2 ft of soil cover and are subjected to a vertical static load, simulating a truck load on a roadway. The structural capacity of these pipes is compared to show the impact of pipe shape on the load capacity of renewed culvert pipes. The results showed that the application of elastomeric polyurea SAPL can significantly increase the load carrying capacity of the fully deteriorated CMPs. In addition, it was found that the circular culvert can resist higher live load than their equivalent size pipe arch.

The underground water and wastewater infrastructure is an essential element of the urban infrastructure system. Most of the US water and wastewater and underground infrastructure has exceeded its design life and is continuously deteriorating to the catastrophe situation; thus, there is an urgent need to develop a method or technology to restore the existing underground infrastructure. The trenchless technology renewal method of spray-applied pipe lining (SAPL) is one of the cost-effective and versatile methods with minimum ground access requirements. SAPL is applied inside of a pipeline for either corrosion protection or to increase the load bearing capacity of existing pipelines and to create a new standalone polymeric pipe within the existing pipe. The objective of this paper is to evaluate Nukote PP300 Polymeric SAPL as a new application to structurally renew and enhance the design life of deteriorated gravity pipes. To achieve this objective, soil box testing is performed on deteriorated corrugated metal pipe (CMP) renewed with spray-in-place thermoset plastic liners under actual loading conditions. A three-point bending test is performed to evaluate the flexural properties, and a tensile test is conducted to determine the properties of material in tension, which are important material characteristics to understand the liner performance in field conditions.