Pipelines 2016: Out of Sight, Out of Mind, Not Out of Risk

This paper summarizes various trade-off studies carried out during the pre-feasibility phase of a desalinated seawater pipeline system intended to minimize the capital expenditure (CAPEX), achieve a reasonable operation expenditure (OPEX) and comply with the “fit for purpose” concept required by the owner. The trade-off studies and analyses carried out include: pipeline route optimization; economical diameter selection and telescoping pipe wall thicknesses; optimum number of pump stations; selection of internal liner; and whether a closed or an open system is being designed, among others. The value of this work is to show that completing the minimum necessary assessments, regardless of assumptions or opinions, unless it is something evident, is fundamental to support a robust and economical design. Furthermore, completing these studies was not exceedingly expensive as some people may have thought. In fact, time period in which the flow assurance work was developed for the different trade-off studies described in this paper was approximately 3-4 months. Finally, the work was reviewed by an independent consultant firm contracted by the owner. The results of this assessment are discussed too.

The objective of this paper/presentation is to: 1) present how Sullivan’s Island developed the turnkey engineering and construction program to aggressively reduce inflow and infiltration (I&I) flows into their sewer system; 2) relate the details of implementation; 3) share the impact on flow reduction and benefit to extending sewer service life (leakage was reduced by 47% and years remaining service life were increased by an average of 18 years per pipe); and 4) discuss engineering, rehabilitation technology implementation improvements, and construction management lessons learned.

Buried pipelines suffer axial and bending force under earthquakes and ground displacements, and during the process, deformations and damages usually occur at the pipeline’s joints. Based on the pulling-out test and bending test, this paper is aimed at carrying out stretch-bending test on the rubber gasket joint in the ductile cast iron pipeline, which is commonly used in the water supply system. By applying different eccentric tensions (eccentricities are 25, 50, and 180 mm respectively) to the joint of two pipes, the relationship between axial pulling force and displacement, moment, and rotation angles were obtained meanwhile nonlinear mechanical characteristics and failure state of pipe joints were analyzed. Conclusions are drawn as follows: The deformation at joint is coupling response of axial displacement and bending deformation, which shows nonlinear behavior and pronounced variability. The damage state is pull-out of the joint by the tension with small eccentricity mainly due to the tension. The damage state is bell broken by the tension with large eccentricity mostly owing to the bending.

This paper presents an evaluation of and compares the observed annular fluid pressures to the predicted annular fluid pressures as related the risk of hydraulic fracture of subsurface soils observed during the construction of a landmark direct pipe (DP) installation under a U.S. Army Corps of Engineers (U.S. ACE) regulated hurricane protection levee in Port Arthur, Texas. It also provides an evaluation of the relationship between annular fluid pressure and the thrust and face contact forces observed during construction. The Sabine Neches waterway and hurricane flood protection levee crossing in Port Arthur, Texas was completed in April 2015 using DP trenchless construction. With an as-built horizontal length of approximately 3,457 feet, the 48-inch-diameter DP became the largest DP crossing completed to date in North America. It also is the first DP crossing permitted by the U.S. ACE to cross a U.S. ACE-regulated levee and the first DP to incorporate annular pressure monitoring to document the annular pressures and associated risk of hydraulic fracture of subsurface soils during construction.

Aromatic polyurethane coatings are commonly used to protect steel water pipelines from corrosion while they are buried underground. However, during construction of a large pipeline project, coated sections of pipe may be stored above ground for extended periods and the polymer coating can suffer rapid and substantial changes in outward appearance due to sunlight, moisture, pollution, and heat. These changes in surface appearance can cause concerns about the ability of the coatings to function as a long term corrosion barrier although that protection is imparted by the whole thickness of a coating. The purpose of this investigation is to study the effect of UV, moisture and heat on four polyurethane coating formulations on both the visibly obvious appearance changes and on the likely corrosion protection. Candidate polyurethane coatings were subjected to laboratory weathering testing that causes very rapid degradation compared to natural environments. Quantitative testing of corrosion protection by electrochemical impedance spectroscopy has been done in concert with measurement of coating thickness loss and appearance changes (color, gloss). Appearance change is obvious and rapid but corrosion protection remains at very high levels. A longer term program is underway in which the same coatings are exposed to natural weathering in Florida and Texas so that the changes to the coatings in the real world may be correlated to the much more rapid results possible from accelerated laboratory testing.

Lake Texoma, a 2.5 million acre man-made reservoir stores roughly 28 percent of the North Texas Municipal Water District’s raw water supply (NTMWD 2016). The owner was forced by Federal regulation (the Lacey Act of 1900, SS 42.a.1, pg.2) to stop its pumping operations after the discovery of zebra mussels, an invasive species, within the Red River Basin. In September 2011, the owner hired a consultant to consider alternative ways to access their raw water capacity in Lake Texoma. The development of the a raw water pipeline project was the most feasible means to access this much needed capacity, while maintaining regulation and preventing the spread of zebra mussels into the Trinity River Basin. This project was facilitated through the construction manager at risk (CMAR) delivery method, due to the District’s dire need to regain access to water. Through a selection process the CMAR was selected in January 2012. The CMAR Team was responsible for the entirety of the project delivery, including oversight, management, scheduling, and portions of the construction. The project was taken from concept to delivery in less than 26 months including both the design and construction phases.

A significant portion of the wastewater lines in the United States are nearing the end of their useful life. A substantial reinvestment is needed in the upcoming decades to replace or rehabilitate the wastewater infrastructure. Currently the traditional method for delivering wastewater pipeline engineering and construction projects is design-bid-build (DBB). The traditional DBB delivery system is a sequential low-integration process and can lead to inefficiencies and adverse relationships between stakeholders. Alternative project delivery methods (APDM) such as job order contracting (JOC) have been introduced to increase stakeholder integration and ultimately enhance project performance. APDM cost performance impacts have been studied in the horizontal and vertical construction industries. However, the cost performance of JOC projects in the pipeline engineering and construction industry has not been quantitatively studied. This paper fills this gap by providing a study on the cost performance of 25 JOC wastewater pipeline projects delivered in Phoenix, AZ. A thorough literature review led to the development of a data collection survey used to gather quantitative cost performance data from completed wastewater pipeline projects. The data shows that the City of Phoenix uses JOC primarily for wastewater projects under $1 million, with the majority being between $500,000 and $750,000. The major contribution of this study is demonstrating the ability of JOC to offer cost certainty when delivering wastewater pipeline projects, with an average cost growth of -4.6%. The results can aid decision makers when choosing the appropriate delivery method for their wastewater pipeline projects.

Fabricated reducing elbows are a key component of water projects where available space and hydraulics require a smooth concurrent change in direction and velocity of flow. For example, this requirement can occur on the suction side of pumps, especially within small footprint pumping stations. They are also a specialty item that requires complex geometrical and engineering considerations. Over the years, the design of reducing elbows has been addressed by many agencies and is currently addressed in the American Water Works Association (AWWA) C208, Dimensions for Fabricated Steel Water Pipe Fittings, which presents basic layout geometry. However, no guidance on implementation, fabrication, detailed design, or welding details is included. The authors recently reviewed reducing elbow shop drawings prepared by a major pump manufacturer and found layout errors that would have caused major fit up problems which would have resulted in rejected fittings and a significant project delay. The cause of the problem was the difficulty the fabricator had in understanding and implementing the AWWA layout geometry. Failure to recognize that the design and fabrication of cone-cylinder and cone-cone intersections require an in depth understanding of the geometry will cause costly errors. Selection of proper welding details requires a high degree of skill on the part of the fabricator to complete the design and to make it function reliably as a safe, integral part of a conveyance system, as intended by the designer. This paper addresses several areas of reducing elbow design and fabrication that are not well covered elsewhere, including a procedure for layout, the mathematical derivation of the fundamental equations that appear in AWWA C208, developed views of reducing elbow components, and suggested welding details. It will demonstrate that reducing elbows could be fabricated from a single truncated right cone, cut into segments and reassembled, and that developed cone components can be nested, for efficient use of materials. An example problem, illustrating layout and fabrication, including welding details of a reducing elbow is presented to assist the reader. The goal of this paper is to provide a go-to document with detailed technical guidance to the designer and fabricator of reducing elbows.

The Southern Delivery System (SDS) Segment S4A Central Project was the final section in Colorado Springs Utilities’ 66-inch, 45 mile long SDS raw water pipeline from Pueblo Reservoir to the new water treatment plant in Colorado Springs. Segment S4AC consisted of a 7,200 foot long pipeline segment that crossed Interstate 25, BNSF and UPRR railroad tracks, Fountain Creek, and a wide expanse of low-lying flood plain and was originally designed as a conventional design-bid-build project before Colorado Springs Utilities determined that they wished to change procurement and project delivery and spur innovation by soliciting design-build proposals from qualified teams. The resulting design-build project consisted of a single one mile long tunnel that crossed all problematic elements and avoided major third party and environmental impacts. The geotechnical/geophysical investigation showed that, due to shallow groundwater in coarse alluvium, the least risky option was tunneling deep and long, driving the tunnel through Pierre Shale bedrock and extending the length across the entire flood plain. The 42-foot diameter 85-feet deep launch shaft was constructed on the west side of the alignment. From this shaft, the 105-inch diameter open-faced tunnel boring machine (TBM) tunneled east using steel ribs and wood lagging to support the ground and provide reaction for the tunnel boring machine to develop thrust during mining. The tunnel ended at a 30-foot diameter 65-foot deep receiving shaft constructed at the east side of the alignment. Several challenges occurred during the tunnel construction that were overcome by the design-build team involving Garney Construction as the general contractor, Michels Tunneling as the tunnel subcontractor, Dewberry engineers as the prime civil consultant, and Brierley Associates as the geotechnical tunnel subconsultant. To help meet an aggressive construction schedule, a second tunnel header was excavated from the receiving shaft and headed west concurrently with the primary TBM excavation located at the launch shaft and headed east. Another challenge was correcting and adjusting the tunnel for line and grade offsets. The design team redesigned the carrier pipe profile approximately every 2 to 3 weeks as as-built tunnel survey information became available, by incorporating joint bevels and utilizing the available tunnel envelope. This provided sufficient lead time for the contractor to modify the pre-fabricated steel pipe sections to accommodate the tunnel geometry. Other challenges included annular space grout design and application, developing effective shaft backfill methodology, and mitigating potential alluvial groundwater impacts. Colorado Springs Utilities estimates that this design-build single-tunnel approach, completed in April 2015, saved approximately $10 million over the previous combination tunnel and open-cut trenching solution.

Buried steel structures, such as onshore pipelines, are frequently suffered from corrosion due to their direct contact with corrosive soils, resulting in high maintenance cost and even leading to catastrophes in some cases if without timely repair. Selection of the high demanding protections for these structural steels depends on the soil corrosivity, which in practice is often determined by using two soil characteristics: resistivity and acidity (pH). Even though these two parameters are widely accepted for characterizing the soil corrosivity, they often do not correlate directly to the soil corrosivity or corrosion rate of the buried steels. In this study, we propose a new approach using the state-of-the-art electrochemical instruments to characterize corrosivity of different soils. The combined corrosion characteristics of the buried steels: a) corrosion resistance and b) corrosion potential, were used to form more sophisticated and accurate criteria for the determination of the soil corrosivity. The tests results demonstrated that the new approach led to better correlation between soil resistivity and steel corrosion in soils over conventional methods. Moreover, a parametric study was conducted including critical soil factors, such as soil types, moisture content/percentage, compactness and galvanic effects. The findings of this study will enable engineers to better assess soil corrosivity for determination of steel corrosion.

Electricity to pump water through a system is often the utility’s second-highest cost, behind only salaries and wages. Numerous factors affect the cost and amount of electric power required to operate a utility system. Those factors include the volume of water delivered, the efficiency of the pumps, the cost of electricity, the friction associated with the pipe wall, head loss through pipe, valves and around fittings, the diameter of the pipe, and other factors. This paper will show users how to calculate the cost to operate a particular system constructed of particular materials while operating at a certain level, and then compare that model to an identical system comprised of different pipe materials and different types of isolation valves.

Combined, the San Pedro Bay Ports of Los Angeles and Long Beach are the tenth largest port in the world. The combined Ports account for about 40 percent of the imports into the United States from Asia, and are a huge economic driver for both California and the nation. Approximately 40% of the Ports’ imported goods flow by rail to the interior of the U.S., with the remainder generally moved by truck to and from California’s factories and warehouses. Anyone who has driven the highways of Southern California, especially commuting from the Inland Empire towards Los Angeles, will quickly note the two right-hand lanes lined with trucks as far as the eye can see. And in spite of the reductions of truck diesel emissions through the Ports’ “clean truck” programs, recent evaluations have shown high levels of respiratory impacts along the major freight corridors. Given these circumstances, and the densely built urban landscape that stretches for miles from the Ports, how can they and the nation grow import/export capabilities without compounding the negative impacts of freight movement on the surrounding communities? By automating freight movement underground, with minimal interference of existing transportation modes during construction, using linear electric motors to power the containers to nodes centralized to warehouse districts, and trucks only for last-mile delivery. By combining the freight pipeline with a patented efficient ship berthing system, the entire network can be built as a privately-financed public-private partnership using existing transportation expenditures and no taxes. Governor Jerry Brown’s executive order B-32-15 now makes this $18B proposal more “probable” than “possible”. This paper will present the foundational supporting megatrends forcing the project toward reality, the combination of technology that makes it economically possible, the strategy for crossing myriad jurisdictions through four counties, and the accelerating political and private developments toward supporting construction of the nation’s first large-scale freight pipeline.

This paper discusses meeting the evolving challenges to enable the relocation of a 90 inch embedded concrete cylinder pipeline without service interruption by means of a design build delivery vehicle to tap and divert the flow of the potable water transmission line operating at 250 psi. The challenges, among others, included: establishing the frame work and costs of the contract while defining a changing scope of work and design parameters during project negotiation and execution; organizing, scheduling and coordinating project activities; verifying and confirming site conditions, pipe geometry, design parameters and characteristics; geotechnical exploration and control; tapping and plugging fitting design and fabrication; design and functional testing of equipment; and sequencing bypassing and plugging operations.

The Southern Delivery System (SDS) is a regional project that will convey Arkansas River water stored in Pueblo Reservoir to Colorado Springs, the City of Fountain, Security Water District, and Pueblo West Metropolitan District by April 2016. Core components of the project include a connection to Pueblo Dam, 45 miles (72-km) of predominately 66-inch (1.7M) diameter raw water pipeline, three raw water pump stations (RWPS) with total connected horsepower of 26,000, a 50 million gallons per day (MGD) (189.3 ML/D) water treatment plant (WTP) and finished water pump station, 4 miles (6.4-km) of large diameter finished water pipeline, and environmental mitigation to meet regulatory requirements. Completion of SDS will mark the achievement of a planning process that began more than two decades ago to secure a new reliable drinking water supply to meet current demands and future water needs for generations. In 2010, well before construction started on major SDS components, the program manager, MWH, and managing owner, Colorado Springs Utilities (CSU), began developing a comprehensive plan for commissioning, startup, and placement of SDS into service. This early plan served as a roadmap to inform and guide project managers, designers, and contractors through the initial planning, design, construction, and startup phases of the project. This paper details the challenges of starting up a large, complex water infrastructure project and the unique tools and techniques implemented to achieve value-based performance, resulting in on-time and under-budget delivery of the project.

Tarrant Regional Water District (TRWD) and Dallas Water Utilities (DWU), in their continuous efforts to pursue sustainable excellence, have chosen to partner in the design, construction, and implementation of sustainable initiatives for their $2.5 billion dollar integrated pipeline project (IPL). The IPL will connect a new water source, Lake Palestine, to both TRWD and DWU water transmission systems. In addition, the project will double the transmission capacity on TRWD’s Cedar Creek and Richland Chambers systems through approximately 150 miles of 108-inch diameter pipeline. IPL facilities include several lake and booster pump stations, balancing reservoirs, and flow control facilities that interconnect the IPL with TRWD and DWU’s existing systems. The project is currently under construction and its first phase is anticipated to be completed by 2018. The IPL Team’s sustainable program was implemented from the beginning of the project’s design efforts. It consisted of evaluation and implementation of multiple sustainable initiatives; one of them being the owners’ decision to pursue envision rating of the project. A team was assembled to prepare and submit an application to the Institute of Sustainable Infrastructure (ISI). The application was completed in March 2016 and the project received a Gold award, one of the most prestigious awards given by the Institute of Sustainable Infrastructure (ISI). This paper describes the methodology used by the IPL envision application team and presents the rating results. The paper also presents some of the challenges encountered with the implementation of the rating system. The paper concludes with a list of lessons learned from preparing an application on a complex linear project like the integrated pipeline project.

Recent research has shown that air pockets in wastewater transmission systems can exacerbate pipeline conditions, such as the corrosive environment as well as surge issues, which can lead to pipeline damage and reduced efficiency. Air pockets can decrease flow capacity, they can create significant head losses and energy losses, and they can promote serious corrosion, as well as trigger or enhance pressure surges. Due to increased concern for energy conservation, additional research has investigated the effects of air pockets on flow efficiency and energy consumption. Conclusions are that air pockets have a very significant impact on energy efficiency, especially in wastewater force mains. The issue of hydrogen sulfide corrosion in wastewater pipelines has been a topic of significant importance for many years. The EPA and other organizations have published a numerous papers, pamphlets, and reports on the subject. These studies and reports attribute at least a portion of hydrogen sulfide corrosion to air pockets. This is particularly true for pressurized wastewater systems. Several of these reports have been presented at recent ASCE Pipeline Conferences. Most of these papers referred to detection, monitoring, evaluation, assessment and management of corrosion, but very little has been presented in the way of prevention. Many have highlighted the contribution of air pockets to hydrogen sulfide corrosion, but they do not discuss ways of preventing air pocket accumulation in wastewater pumping systems. For many years, it was commonly accepted by surge experts that air pockets dampen surges. However, more recent research has concluded that air pockets, depending on size and locations along a pipeline, can exacerbate or even create surges. Surge events, especially in force mains weakened by corrosion, can cause extensive damage to pipelines, resulting in soil and water pollution, and intrusion of health endangering pathogens into drinking water transmission systems. Even though there has been a great deal mistrust regarding the use air valves for wastewater applications, modern, innovative air valves are reliable and efficient, and are an extremely cost efficient and readily available device for preventing the accumulation of air pockets and reducing the potential damage from corrosion and surge events in wastewater pumping systems.

This paper presents recent advancements of pipe penetrating radar (PPR) inspection technology through two selected case studies. The Bear Creek Trunk Sewer in Surrey, BC, Canada is a 2845 m long, 600 mm to 900 mm diameter reinforced concrete and asbestos cement line. The pipe was installed in 1972 and there are known corrosion, erosion, sedimentation, and odor issues. The objective of the PPR survey was to determine the condition and remaining service life of this pipe by mapping its wall thickness, rebar cover and detecting voids and/or other anomalies within or outside the pipe wall. PPR results confirmed minimal corrosion at the crown and 95 mm to 97 mm remaining wall thickness with little variation over the inspected length. Rebar cover appeared to be sufficient with no void type anomalies on any of the inspected lines. The Taggart Outfall in Portland, Oregon is a 3 m diameter, brick lined combined sewer that was built in 1906 and experienced wet weather overflows in the past. There was very little information available about the construction methods and the condition of this pipe. In order to design the most appropriate rehabilitation strategy the knowledge of voids outside the sewer was critical. Over 1829 m of high resolution PPR line data were collected via manned entry. Due to the highly complex nature of the geophysical data, data processing and interpretation was a critical component of this project. PPR data revealed voids both outside and within the pipe wall and thus provided engineers the information needed to take the appropriate approach to rehabilitate the pipe. With limited available funding and budget constraints becoming more prevalent, timing of rehabilitation and overall intelligent asset management is more critical than ever. PPR provides engineers and utility owners the information to accurately estimate the remaining life left in a pipeline, refine timing of repairs, and ultimately better allocate funding for asset management.

Natural gas pipelines are critical component of U.S. energy infrastructure. The safety of these pipelines plays a key role in the gas industry. Therefore, understanding pipeline failure characteristics and consequences is a very important criterion in decisions making process associated with future design and maintenance of natural gas pipelines. The oil and gas industry spends billions of dollars annually for the corrosion-related issues due to aging and deterioration processes in pipeline networks. Therefore, pipeline operators need to constantly evaluate and update their corrosion prevention strategies. The loss due to corrosion failures is the main motivation for the oil and gas industry to develop accurate maintenance models based on failure frequency. Statistical pipeline failure models and proper maintenance decisions play a significant role in reducing the failure rates of the pipelines and ultimately enhance the cost effectiveness and safety of the pipelines. This paper fulfilled the following two objectives: (1) failure mode characteristics identification, and (2) model development to address the failure rate and reliability. The pipeline failure incident data used for this study was collected from eleven largest natural gas transmission pipeline operators’ data from 2001 to 2011. The pipeline networks were divided into two major modes: internal and external corrosion. Internal corrosion refers to the failure inside the pipe due to the liquid characteristics and operating conditions whereas external corrosion refers to the failure due to surrounding environment outside the pipeline. Two major applied stochastic models, homogeneous Poisson process (HPP) and non-homogeneous Poisson process (NHPP), were tested to analyze the reliability trend within categorized installation times. The outcome of the tests on the reliability models shows that the reliability should be modeled with NHPP and the trend is dominantly deteriorating for external and internal corrosion with a few exceptions on stationary and improving. It was also shown that decades of installation and the number of previous failures are the two significant pipeline failure characteristics. The result of this study assists decision-making process in the oil and gas industry to predict the expected number of failures in future transmission pipeline operation more accurately and facilitates the utilization of proper preventive maintenance strategies.

Steel corrosion is known as one of the major structural defects for steel structures such as pipelines. Although various of methods such as measuring weight loss and electrochemical approaches have been utilized for steel corrosion detection, the lack of real-time corrosion measurement approaches limits their application. The high resolution of fiber Bragg grating (FBG) sensor and its ability to provide real-time monitoring make it a potential candidate for steel corrosion detection. In this paper, a corrosion detection approach is developed using FBG sensors. The relationship between corrosion pattern and sensor signal is investigated and validated through experiments. With validation, the results of this study could be extended to multiple types of application such as pipeline, storage tank, etc.

This paper presents the results of utilizing available current capacity of a bar-wrapped concrete cylinder pipeline’s cathodic protection system to provide corrosion control to a paralleling pipeline. The parallel pipeline consists of the same material and runs within 20 feet of the other. Cathodic protection is a means of corrosion control, which mitigates the electrochemical reaction that occurs on steel structures placed in contact with a corrosive environment. The proper installation and maintenance of a cathodic protection system is essential in extending the useful life of critical water transmission mains used by water districts across the country. Metallic pipelines installed without cathodic protection are subject to costly leaks and breaks as a result of corrosion. This paper presents the results of the evaluation performed on the paralleling bar-wrapped concrete cylinder pipelines to observe the effect of bonding the pipelines into the same cathodic protection system.

The presence in the right of way of existing third party buried utilities often constitutes risk on pipeline projects. These utilities are encountered frequently on projects that traverse population centers where significant buried utility infrastructure is already present. If those utilities are imperfectly known, or unknown, they can adversely impact both design and construction. The discovery of a buried third party utility in an unexpected location in the right of way during construction can lead to downtime, redesign, additional construction costs, and notably, safety issues. Implementation of a utility risk management program using the techniques that will be discussed herein largely eliminates these issues.

Zinc has been used to protect ferrous materials against corrosion for many years. Metallized arc-spray zinc coatings are now available on ductile iron pipe produced in the United States. Zinc-coated ductile iron pipe has been widely accepted and specified in the 18 months it has been available. This paper will present an overview of corrosion principles, how zinc is applied to ductile iron pipe, how zinc inhibits the corrosion of ferrous materials, and additional enhancements that, in combination with zinc, further extend the life of an already long-lasting product. The paper will also briefly highlight the performance characteristics of ductile iron pipe related to pressure, surge, flow characteristics, thrust restraint, and sustainability.

In November 2014, PICA Corporation was selected to perform an inline inspection of a 12” 10,033 ft ductile iron forcemain for Gull Lake Sewer and Water Authority (GLSWA) located just east of Kalamazoo, MI. The inspection was conducted under the State of Michigan’s Stormwater, Asset Management and Wastewater (SAW) program. The pipeline was originally installed in 1982 and traverses a rural part of town. GLSWA had experienced some failures in the past and wanted to get the actual remaining wall-thickness of the pipeline by utilizing PICA’s remote field testing inspection tool, the SeeSnake. With an early onset of winter and frigid conditions many hurdles and obstacles had to be resolved to perform the inspection. This paper will detail how both GLSWA and PICA overcame them and will include verified defect accuracy (axially and clock position) inspection results.

The San Jose–Santa Clara Regional Wastewater Facility (RWF) adopted a five-year capital improvement program (CIP) that includes a multi-year yard piping and road improvement project to repair or replace pipes or portions of pipes deemed to be highest priority by virtue of their criticality and/or physical condition. The objective of the project was to provide a prioritized list of critical pipes for subsequent inspection as part of a future phase of work. The work involved selecting pipelines for inspection based on the output from a risk. The project also included development of a condition assessment protocol to provide decision-making guidance to prioritize pipe for inspection, determine appropriate inspection technologies, and provide recommended timelines for inspection.

Aging infrastructure, and pipelines installed and operated under poor conditions in pressurized drinking water networks are highly susceptible to the threat of leaks; these leaks pose economical, health, and environmental threats. To allow early repair and condition monitoring, multiple researchers tried to address the issue of leak detection and leak location pinpointing using either biological, hardware-based, or software-based solutions. The previous models came short in identifying practical and cost-effective models for combining real-time monitoring, identification, and location predicting. The research presented in this article proposes a model for a real time monitoring system capable of pinpointing the location of single event leaks in pressurized water pipelines. The model relies on wireless accelerometers placed within the network on the exterior of the pipelines. The vibration signals derived from each accelerometer was assessed and analyzed by the model to identify the monitoring index (MI) at each sensor on the pipeline. A leak was identified when the value of the monitoring index spiked above the acceptable ranges identified through an experimental procedure for each sensor. The value of the monitoring index on the left and right of the suspected leak is processed and utilized along with the distance between the two sensors. This allowed the model to identify the original source of the signal i.e. the leak location within a maximum range of ± 25 cm. The leak location was determined by means of a regression equation developed from experimental data for each sensor. Experiments were performed on one inch cast iron pipelines, one inch and two inch PVC pipelines using single event leaks and the results were displayed.

With the adoption of asset management principles in recent years, there has been a renewed interest in performing condition assessment of aging infrastructure. Given the limited availability of resources, utilities are looking for cost-effective approaches which allow them to prioritize their assets in need of rehabilitation. A programmatic approach to condition assessment offers several advantages including an increase in the cost efficiency of inspection and assessment activities. This paper describes the elements of a programmatic approach to condition assessment and its major advantages and limitations. The paper makes the case for deriving cost efficiency through this approach, and highlights other benefits a utility may realize by adopting a programmatic approach to condition assessment. Additionally, the paper provides general guidelines for establishing a condition assessment program. A case study is included to illustrate application of this approach.

The Town of Flower Mound is located in Denton and Tarrant Counties of north Texas and has a population of approximately 68,000 people. The backbone of the Flower Mound water distribution system is a 20- and 30-inch water main which was constructed in the early 1970’s using bar wrapped pipe (BWP) and mortar lined steel pipe. The Town recently elected to proactively assess the condition of the pipeline to determine if its remaining useful life could exceed the original 50 year design life. To accomplish such a task, a comprehensive condition assessment approach was developed to provide actionable information pertaining to each individual pipe section in the 4.5 mile long water main. The Town of Flower Mound intends to make specific localized repairs based on the condition assessment of the pipeline to extend its remaining useful life and more efficiently manage the pipeline. This paper will provide an overview of the process used to assess the condition of the 20-inch and 30-inch critical water main for the Town of Flower Mound and present the results of the inspections and recommendations. More so, it will demonstrate how the Town of Flower Mound is effectively managing their finances and risk, while continuing to provide the community with a safe and reliable delivery of quality water.

Water distribution networks have significant impact on public health. Based on the 2013 ASCE’s report card, 21st century estimated to be the end of effective life for the majority of water distribution networks in the United States. It is essential to implement accurate and cost-effective models to estimate deterioration rates along with remaining useful life (RUL) of the pipelines to select and perform necessary intervention plans to prevent disastrous failures. This study aims to present a computational model to predict the RUL of water pipelines utilizing artificial neural network (ANN) model. Literature reveals that condition, length, diameter, and breakage rate are the most important factors in prediction of RUL. Based on the available data from the city of Montreal, the condition of pipelines is identified and used as the inputs for ANN model in addition to physical data. Since the model shows robustness and accuracy in estimating RUL, it can support municipality of Montreal in future planning.

As piping infrastructure gets older there must be a systematic way to cost effectively operate, maintain, and upgrade systems when needed. Condition assessment has become an integral part of the management schema, but what does that really mean? It becomes a balancing act between risk management and finite resources. Not all condition assessment tools can or should be applied in every situation. The purpose of this paper is to provide the approach in deciding what type of tools should be used for various situations. The pipe material, size/diameter, construction configuration (bends and access ways), operating parameters, and length of the pipeline may limit what tools can be used for inspection. The higher the risk profile of an asset, the higher the resolution of the tool is necessary to provide adequate granularity with more detailed precision of the asset condition. The higher the resolution typically results in a higher cost of the condition assessment so all considerations need to be evaluated. Example case studies can also help explain the type of tool and technology that is used for different types of inspections. Along with WaterOne in Lenexa, Kansas, many agencies have developed their own approach to what tools they select for various asset risk profiles. These tested and proven approaches in tool selection and risk management can assist other agencies managing their limited resources and capital budgets.

The paper presents a case study involving condition assessment and remaining service life analysis of a 3.8-mile long 24-inch diameter interceptor outfall (sewer) asbestos-cement (AC) pipe line which had been in service for 38 years. The study involved laboratory testing of pipe samples taken at different locations along the pipeline. Laboratory testing included direct measurements of residual strength using crushing strength tests and evaluation of the extent of degradation of companion pipe coupon samples using several techniques including pH indicator, hardness testing and energy dispersive X-ray spectroscopy. Laboratory testing showed pipe degradation at the pipe crown caused by long-term hydrogen sulfide corrosion. Degradation was more severe for pipe sections obtained closer to the downstream end of the pipeline. Based on the results of laboratory testing, service life analysis was conducted using Schlick’s combined load theory failure criterion. The results of the service life analysis indicated that the estimated time to failure varied significantly and was a strong function of location within the pipeline.

The Central Arizona Project (CAP) operates and maintains several pipelines as part of the aqueduct system that delivers almost 1,950 million gallons of Colorado River water per day, to Maricopa, Pinal, and Pima Counties in central and southern Arizona. The water is delivered to municipalities, Native American Communities, and agricultural users; about 5 million people (roughly 80% of the population of Arizona) are provided water by the aqueduct system. The system traverses rugged mountains, desolate deserts, and highly populated urban areas as it conveys water from Lake Havasu at the western edge of the state to the southern boundary of the San Xavier Indian Reservation south of Tucson. The approximately 350 mile long aqueduct system is composed of about 300 miles of open channel canals, about 10 miles of tunnels, and roughly 40 miles of pipelines; 14 pumping plants along the system provide the required lift to raise the water over 3,000 feet from the lake to the final operating reservoir. While it is fairly easy to inspect a canal, performing a manned inspection of the main transmission pipes in the system is more difficult for a myriad of reasons – not the least of which is scheduling an outage to remove the pipe from service and scheduling maintenance personnel to support the inspection. Whenever there is an outage, the maintenance crews are trying to take advantage of the outage to perform inspection/repairs on other components of the aqueduct. This paper will be a review of two of the most recent pipeline inspections performed by CAP engineers, an approximately 7 mile long 78-inch pipe and an approximately 7 mile long 72-inch pipe. The paper will discuss planning outages, dewatering of the pipes, lock-out/tag-out for safety, the required surface support for the inspection team, inspection tools, inspection protocol, subsequent repairs, documenting the inspection results, and lessons learned.

The City of Bellingham, WA currently operates a water supply system that was constructed in 1939 to take raw water from Lake Whatcom and convey it to the City’s 24 MGD drinking water treatment plant. The system has reliably served the City over that time, but is in need of key repairs to maintain the assets and extend their useful service life. Making those repairs will be challenging given the age of the infrastructure and the level of system redundancy originally designed. A thorough condition assessment was an important part of the City’s approach to characterize the assets, identify the key repairs needed, and prioritize them against available budget and resources. The 5-mile intake system consists of: 66-inch wood stave intake pipe, 78-inch hand dug tunnel, and 48-inch/68-inch concrete cylinder supply pipelines. Underwater laser profiling, commercial diving inspection, topside corrosion studies, and deep tunnel man entry were used to evaluate the condition of the existing assets and identify critical repair and replacement needs. This paper will include an overview of the approach, existing components, data gathered, and study conclusions.

This paper presents the planning and implementation needed to safely and effectively conduct manned entry off-tether and out of line of sight pipeline and tunnel inspections for the El Monte raw water supply, a 13 mile long pipe system that had not been inspected since constructed in the 1940s. It varies in diameter from 18” to 72” diameter, in depth from 15’ to 300’, and is constructed of 5 different materials with many different styles of manways, vents, and sags/blowoffs that affected the inspection design. Due to geography and in ability to locate manways and blowoffs, inspections varied in length from 3000’ long single point entries (deadhead) to 1.5 mile long tunnel inspections. These works were conducted in California in 2014 and 2015 using specially modified pipe carts and BMX bikes. We will review record plan review, pipeline dewatering, steep slope management, submerged section safety, ventilation and air exchange calculations, emergency air supply, communications, pump lock-out tag-out management, confined space entry, deep hole entry, entry and exit planning, bike and cart modifications, lighting, inspection documentation tools, and inspection methods.

Pipelines that transport energy products exist along corridors throughout the United States and Canada. Pipeline corridors intersect fluvial systems where the pipeline is typically installed below the sediment surface to alleviate the influence (force) of flowing water on the pipeline. Pipeline corridors also traverse hills and valleys where slope movement could have a negative impact on pipeline integrity. Pipeline integrity management includes assessment of sites where conditions may subject the pipeline to adverse conditions. A method is presented whereby geomorphology and geotechnical methods were used to assess 1,124 water and slope crossing sites for 2,700 miles of pipelines. The method maximizes the use of available data from public agencies and internet sources. Geomorphic, geologic, karst, seismic, soil, hydrologic, and contour map information were used to characterize physical/environmental conditions. From this initial background assessment, sites were identified for field evaluation based on erosion/slope failure potential. Following completion of the field work the combined background and field digital data were used to assign an erosion potential rating for each water and slope crossing. The erosion potential was rated in five categories ranging from very low to very high. The erosion potential rating and field measured depth of cover were used to assign a pipeline exposure potential rating for each site. The exposure potential was similarly rated from very low to very high. The digital approach to collecting, analyzing, and reporting the data provided an effective and efficient means of evaluating large areas with complex conditions. This enables pipeline monitoring, maintenance, and capital improvements to be planned and prioritized. The digital mapping generated is a useful tool for tracking conditions over time and can be updated as conditions change in the future.

The majority of ductile iron (DI) pipelines were installed in the United States in the mid-late 20^th century. Most of these pipes are in a sustainable working condition; however, any failure of these pipelines could be problematic due to the social, political, and environmental impacts of the failure. To facilitate better decision making for capital expenditures and to address the risk associated with these assets, the failure mechanisms of DI pipe must be understood. In addition, for planning and capital budgeting, it is important to determine the current condition of a deteriorated pipeline and its risk of failure. For the case study, the structural evaluation of damaged 60.96-cm (24-inch) DI pipes is discussed considering external corrosion of the pipe (the most common failure mode of DI pipe). This paper provides a clear and concise picture of how to determine the remaining strength of damaged DI pipelines by considering different pipe and soil interaction. The number size and severity of defects were randomly selected based on our previous field verification. This helps clients to determine which tool needs to be selected for condition assessment of their pipeline and will allow decision makers to enhance their asset management strategy based on inspection results and advanced computational modeling.

Fiber reinforced polymer (FRP) rehabilitation systems have validated efficacy in structural rehabilitation of pipelines since the first installation in the early 1990s. The hand applied layers of carbon and glass FRPs allow for time efficient installations in confined spaces, around obstacles, and without hot work. Installations are not always perfect, but the impact of imperfections on the structural performance is not clear. This paper discusses the criticality of defects and recommended remediation based on hydrostatic watertightness tests on the following defects: gaps between fabric widths, voids between carbon fiber reinforced polymer (CFRP) layers, improper saturation, and misalignment of fibers.

Water utilities are faced with significant challenges to maintain supplies of potable water. These challenges become more acute in cities where the pressures of increasing urbanization are coupled with extensive and critical transmission networks to deliver water over large distances. Traditionally the response to these challenges has been to build bigger and faster, but is there also a place in the mix for smarter systems that stream highly granular data and therefore intelligence to Operators to enable them to proactively manage their networks to avoid catastrophic failures? Increasingly the answer is not “yes maybe” but “yes there must be”. Smart systems monitor critical pipelines continuously, automatically, accurately and intelligently, and there is an increasingly critical role for “smart” technology to inform the decision making process and provide the degree of protection/mitigation demanded by customers and operators alike. This paper reviews a number of case studies where water companies and utilities have used smart systems to make real time operational decisions and manage their infrastructure more efficiently.

A team lead by Arcadis, U.S. (Arcadis) was retained by the City of San Diego (City) to determine the condition and years remaining service life of the City’s 75-year old raw water transmission main, the El Monte pipeline. As this pipeline ages, the City has taken a proactive approach to investigate this critical infrastructure in numerous phases. This is the first time the pipeline’s condition has been fully evaluated and the assessment consists of non-intrusive and intrusive assessment and inspection methods along its 12.2-mile long alignment. Based on inspection results, the risk of failure was assessed based on the likelihood and consequence of failure. Internal and external inspection findings, as well as the environment the pipeline is located in determined overall risk. Priority repair levels (high, medium, and low) were assigned along the pipeline corresponding to years remaining service life based on the severity and/or extent of defects found. Planning level cost opinions were developed for high and medium priority repairs totaling approximately $11 million.

Ground penetrating radar (GPR) has developed lately as an effective leak detection technique in water distribution systems (WDS). Using electromagnetic waves, GPR identifies leak locations through detecting water circulation from leaks causing voids or anomalies in pipe depth caused by changes of dielectric constant of surrounding soil. The literature covering GPR in leak detection is diverse and scattered, albeit, no solid recommendations have been delivered so far. This paper provides a comparative study of methods presented in literature to detect leaks in WDS using GPR. Analysis results are grouped under three test types; namely, outdoor field tests, numerical simulations, and, laboratory experiments. The conditions of which are discussed in details along the advantages and limitations of each test type. The principal analysis methods are presented ranging from simple visual inspection to more complicated focusing algorithms and velocity maps. GPR effectiveness as a reliable tool for leak detection can be confirmed under controlled testing conditions. Nevertheless, more experimental work is required to establish a best practice for detecting leaks using GPR for actual cases.

The City of Phoenix has recently launched an assessment program for its force main assets. The initial focus is a pilot study of the Ahwatukee lift station 40 force main, a triple barrel 24-inch ductile iron force main. Barrel 1 was originally constructed in 1974, with Barrels 2 and 3 installed in 1998. Each barrel is 3.1 miles long. The pipes traverse developed areas along the Interstate 10 corridor in Phoenix, AZ. The assessment pilot program developed inspected all three barrels using Pure Technologies’ (Pure) SmartBall platform for acoustic anomalies (AA) for gas pockets and leaks. Barrel 1, the older of the pipes which had experienced one leak, was also assessed using a combination of technologies including PICA’s See Snake remote field electromagnetic (RFEM) inspection, and Pure’s SmartBall platform with pipe wall assessment (PWA). RFEM and PWA were collected on the same 3.1 miles of 24-inch ductile iron force main constructed primarily in 1974. Permanent and temporary physical and operational modifications were required to complete the assessments. All obstructions along the alignment of Barrel 1 were removed, deployment fittings and valves were installed, and extensive pigging was performed on Barrel 1. The approximate cost of pipe preparation and support for the RFEM and PWA inspections were $24/foot and $2/foot, respectively. The disparity in costs between the RFEM and PWA inspection technology vendor costs was less significant, at $9/foot and $7/foot for RFEM and PWA, respectively. Analysis of these data allowed a direct comparison of the accuracy, precision and agreement between the two technologies. AA results identified no detectible leaks on any of the three barrels. One AA result consistent with a gas pocket was identified on Barrel 1. PWA results for Barrel 1 identified 41% of the pipe segments to have anomalies. RFEM results identified and detailed 50% of the pipe segments to have a total of 1,180 defects, including 20 locations where there was less than 10% remaining wall thickness on 11 pipe segments. The difference in total damage reported and locations of reported damage may be related to the difference in fundamental detection physics whereby RFEM directly measures loss of ferromagnetic material and PWA detects the change of the magnetic susceptibility of a material when subjected to a mechanical stress. An overall positive correlation rate of approximately 54% was observed. Approximately 21% of pipes were reported to have an anomaly based on PWA data, and correlated to a pipe with wall loss reported based RFEM data. Approximately 33% of pipes were reported to have no anomaly based on PWA data, and correlated to a pipe with no wall loss based on RFEM data. The results of these assessments are being used to develop rehabilitation plans for Barrel 1. Excavation and physical validation where defects were reported are in progress and are expected to determine the extent to which the emerging PWA technology can identify distressed pipes.

New alternatives to pipeline renewal have steadily been evolving over the past 15 years and are now beginning to change the paradigm of the go-to pipeline renewal and/or rehabilitation method(s) for pipe sizes 30-inches and larger. One such alternative is the centrifugally cast in place concrete liners. These highly engineered cementitious lining systems are currently being designed to perform not only inside of a rigid pipe structure as conventional engineering thought might well suggest, but are frequently being designed to perform inside flexible pipe structures as well. This paper discusses the real world performance considerations that must go into the design and development of this new generation of cementitious lining systems that addresses all of the performance parameters beyond the obvious ones of liner stiffness, liner bending strength, and material compressive strength. It correlates how buried pipes interact with the surrounding soil(s) (soil-structure interaction theory) and how this relationship will evolve over time; which must be recognized by the design engineer seeking to use this new type of material in his/her proposed renewal design for these larger size structures. This paper will also provide a discussion of the empirically-proven design approach taken to arrive at the required wall thickness of these type of liners in both rigid and flexible pipe structures; and, not only those of circular geometry, but those of the more complex pipe geometries typically employed in storm and sanitary sewer pipes.

Drinking water utility break and leak rates are routinely used as an indication of the condition of the distribution system and to help inform distribution system renewal rates. With no national database of water main breaks there is no nationally accepted average break rate. However, there are a number of surveys and evaluations that help inform our understanding of a national break rate. Many of the available surveys identify break rates in the range of 20 to 30 breaks per 100 miles per year. A 2010 research study suggested that a main break rate of 15 breaks per 100 miles per year was a suitable goal for an optimized North American distribution system. This suggested metric still seems justified and appropriate, although there are many instances where achieving this break rate might be extremely challenging. There are no compelling data that strongly support a significant ongoing and general increase or decrease in break rate. Break rate data can be extremely valuable in analyzing and understanding stresses on a distribution system.

In early 2012, the City of Regina started a risk assessment program for its critical trunk mains in its water supply/distribution system. The program included the rating of initial condition and failure consequence ratings of the mains, and the development of a risk model for the system. It also recommended an annual condition assessment program, which combines desktop analysis and field inspections to maximize knowledge of the trunk’s condition in the most effective manner. As an initial and simplified step, pipe condition in the risk model was estimated based on pipe age, size and material. However, the foundation of a condition assessment program should be built on the applied loadings on the trunks versus the residual resistance strength of the trunks as determined in the condition assessment program, as this is the true measure of failure probability. Considering the high cost of a condition assessment program, an initial assessment project was conducted to rationalize both the economics and degree of certainty associated with different inspection techniques in order to develop an optimum program for the long term. This paper presents the framework developed for managing the risk of the City’s trunk mains, which includes an asset criticality model with trunks ranked based on their relative consequence of failure, a condition assessment strategy that maximizes the use of existing failure records and in-direct assessment data, and a set of decision criteria that can be used to identify and prioritize inspection, maintenance, and capital requirements for a comprehensive mitigation plan for the trunks. Also presented in the paper were the results of the initial assessment project. Both traditional and advanced techniques were deployed to inspect the condition of two trunk sections. The inspection indicated severe internal pits and potential external coating deficiencies/pipe corrosion. Field excavation was performed to verify the inspection results.

Choosing the correct pipeline for a certain application in water or wastewater networks can play a vital role in reducing short-term operations cost for the utility as well as long-term benefits of improved asset lifespan. Wide variety of pipe materials available to choose from can leave the decision makers for pipe selection confused, especially in absence of comparative performance evaluation. This paper proposes a process for knowledge accumulation and sharing for pipeline performance through the life cycle. The study presented herein is the analysis of nationwide survey on pipeline performance in terms of operation and maintenance (O&M) costs, failure rates and characteristics as well as user perception and opinions for pressure pipe applications (4” and larger diameter) in drinking water and force main pipeline networks. The pipe performance for different pipelines including reinforced concrete cylinder pipe (C300), prestressed concrete cylinder pipe (C301), bar-wrapped concrete cylinder pipe (C303), Asbestos cement (AC), HDPE, PVC, steel, ductile iron (DI), cast iron (CI), Fiberglass etc. have been analyzed in the diameter ranges of 4”-14”, 16”-36” & larger than 36”. The complete performance analysis of a pipe can only be carried out with several other parameters, but the main aim of this study is to determine O&M costs, number of failures per mile and age at failure along with overall experience of a wide spectrum of industry experts from utilities and various service providers with different pipelines. The study also incorporates results from focus group workshop that was conducted to review the findings and analysis from the survey responses. The focus group meeting also gave a chance to the experts to give their inputs on performance factors that were not collected through close-ended questions in the survey. The results obtained allow characterizing and understanding in further depth the behavior of these pressure pipelines.

This paper describes the development and successful applications of a robust closed-circuit television (CCTV), LiDAR and sonar based pipe inspection system to gather quantitative data for critical underground pipe condition assessment. The system that can be deployed on a remotely operated vehicle (ROV) or on a float produces accurate cross-sectional analysis and sediment volume. This capacity is increasingly critical in large diameter pipes with high level of flow. The system employs a time of flight LiDAR with sub centimetre distance resolution. Results from recent projects are discussed, in detail in this paper. The Townline Road and Gladys Avenue Trunk sewers in Abbotsford, British Columbia, Canada are critical lines in the municipality’s waste-water system. These reinforced concrete interceptors range between 525 mm (20 inches) and 1050 mm (41.3 inches) diameters with highly variable flow conditions. Hard to access, off-street manholes created challenges during deployment. The robust, yet modular SewerVUE multi-sensor pipe inspection system (MPIS) was repeatedly reconfigured during the project to accommodate the challenging site conditions. The sonar results provided accurate sediment volumes and cross sectional restrictions. LiDAR data and a proprietary 4 in 1 visualization module complemented the deliverables. The avenue Lenine combined sewer in Saint Denis, a northern suburb of Paris, France is a critical interceptor in the city’s collection system. This 1400 mm (55.1 inches) diameter reinforced concrete pipe experiences wet weather overflows during extreme rainfall events. The primary objective of the survey was to quantitatively measure sediment volume and distribution within a 2134 m (7646 ft) long section. This paper presents the methodology and the results of the inspection. Advanced pipe condition assessment technologies, such as the CCTV, LIDAR and sonar system described in this paper are cost-effective, and quantitative methods that provide critical information for optimal operation and maintenance of pipe infrastructure. The reported results can also help better refine estimated remaining service life of an interceptor, accurately determine the overall severity of pipe degradation, as well as provide a basis for improved cost allocation and timing of rehabilitation efforts.

We are in the era of big data. Many pipeline owners are beginning to understand the array of data that is available and are beginning to leverage this data for asset management decision making; they know the fundamental principles of data analysis and they are starting to use a multitude of strategies to optimize long term management of pipeline assets.

Over the last thirty years, PCCP water and wastewater mains have been subject to a wide range of condition assessment techniques. In the past fifteen years, electromagnetic internal inspections and acoustic monitoring have become standard practice for critical large diameter PCCP water and wastewater mains. Electromagnetic inspections provide a baseline count of broken prestressing wire wraps for each pipe section, while acoustic monitoring identifies and locates wire breaks on an on-going basis. Together they allow clients to manage their PCCP in near-real time, enabling PCCP owners to understand the condition of their pipeline on a day-to-day basis and intervene when appropriate based on the specific number of wire breaks on a single pipe section and its corresponding structural state. In 2012, a study on the electromagnetic inspections and acoustic monitoring databases, provided by Pure Technologies, investigated the incidence of distressed PCCP and the rate of wire breaks recorded on individual pipe sections. Over the past three years, a more extensive database has been developed within Pure Technologies allowing for more comprehensive study, including investigation of the specific characteristics of deteriorated, active, and repaired pipes. This paper will review the data from approximately 3,000 miles of electromagnetic inspection and over 700 miles of PCCP currently being acoustically monitored with fiber optic cable. The paper will analyze a database of 44,000 individual wire breaks in over 185,000 prestressed concrete cylinder pipes. Although the database includes systems from all over the world, this paper will focus on data from inspections and acoustic monitoring systems located in the U.S. and Canada. The goal of the paper is to review and update the results of electromagnetic inspections and the acoustic monitoring database to analyze the performance of PCCP water transmission mains and sewer force mains. The study will evaluate the occurrence and rate of wire breaks within PCCP of various specifications and within different pipelines and loadings. The findings will be presented on a statistical basis, with associated confidence or likelihood for each conclusion. The data will also be evaluated for the suitability of working within a predictive model. The predictive model will estimate the possibility of pipe failures over future time horizons. The predictive model supports decisions related to the development of cost effective, long-term management strategies and planning capital replacement needs. The findings will help clients better manage their pipelines and further the industry’s knowledge.

The purpose of this paper is to present a collaborative effort between the National Association of Sewer Service Companies (NASSCO) and Oklahoma State University (OSU). This effort is known as one-voice and the goal is to develop a unified national inventory of underground sewer condition assessment data. Currently there is no uniform or consistent means of sharing sewer data on an industry wide basis. The outcomes of one-voice will allow sewer stakeholders to have access to existing sewer condition data from across the nation. One-voice may also be used to justify additional or new funding for sewer infrastructure from local, state, and federal agencies as well as to develop in-depth understanding of pipe deterioration mechanism. The focus of this paper is to report the progress-to-date of one-voice with the emphasis on the development of data quality protocols based on the four existing pipe inspection datasets collected across the nation. In addition, this paper identified problematic issues with current commercial pipe rating software certified by the pipeline assessment and certification program (PACP), including compatibility issues and pipe rating indexes. The rating systems in the current PACP certified data collection software underestimates pipe ratings in some cases. The contribution of the paper to the body of knowledge is a new data quality assurance process that ensures high quality sewer inspection data available for analysis.

Prestressed concrete cylinder pipes (PCCP) has been used in many large water and wastewater utilities since early 1940s. As it ages, its deterioration continues and the industry is now experiencing more and more PCCP failures. Since most PCCPs are large-diameter pipes with high pressure, their failures could cause catastrophic consequences. To mitigate such failures, it is critical to know the condition of the pipe and take proactive measures such as repair, rehabilitation, or replacement before the pipe fails. In current practice, many numerical models are available for structural analysis of PCCP. However, such models have limitations due to the assumptions that all broken wires have no contribution to structural integrity, thus all broken wires are not considered in the model. Such assumptions could overestimate the damage of broken wires and misjudge “good” pipes as “bad” pipes, causing unnecessary waste of limited funding. This paper presents the validation of a more robust numerical model that could consider the structural contribution of broken wires. The field data of a 48-inch PCCP from Washington Suburban Sanitary Commission (WSSC) was collected and used for model validation. The results show that the model can simulate PCCP’s actual failure very well, demonstrating its good applicability in real practice. This model can be used in practice for more effective management of PCCP pipelines.

Performance prediction modeling is a crucial step in assessing the remaining service life of pipelines. Sound infrastructure deterioration models are essential for accurately predicting future performance that, in turn, are key tools for effective maintenance, repair and rehabilitation decision making. Force main pipes present a particular challenge in performance prediction modeling. Consequences of failure are higher for force mains relative to gravity pipes which increases the risk associated with these assets. However, unlike for gravity pipes, there are no industry standards for inspection and condition assessment for force mains. Furthermore, accessibility issues for inspections add to this challenge. This paper presents a novel approach for predicting the remaining economic service life of force mains. Under the water environmental research foundation (WERF)’s strategic asset management (SAM) challenge, there was a planned three-phase development of this performance prediction model. This three phase approach has been conducted with success for assessing the remaining life of gravity pipes in the past. Currently, 9 utilities nationally distributed have provided data and support for this research. A data standard of 96 parameters was developed to capture the physical, operational, structural, environmental, financial, and other factors effecting the performance. This data standard was reviewed by various participating utilities and service providers for completeness and accuracy. The performance of the force mains was assessed by incorporating the single and combined effects of these parameters on performance. This performance index assesses the performance in terms of: integrity, corrosion, surface wear, joint, lining, blockage, and capacity. This performance index is used for the long term prediction of performance. However, due to limited availability of historical performance data, an advanced integrated method for probabilistic performance modeling to construct workable transition probabilities for predicting long-term performance has been developed. A selection process within this method chooses a suitable prediction model for a given situation in terms of available historical data. Prediction models using time and state dependent data have been developed for this integrated method for reliable long-term performance prediction. Reliability of performance assessments and long-term predictions are tested with the developed verification and validation (Ve&Va) framework. Ve&Va framework incorporates piloting the performance index and prediction models with artificial, field, and forensic data collected from participating utilities. The deterioration model and the supporting data will be integrated with the PIPEiD (pipeline infrastructure database) for effective dissemination and outreach.

A method based on the distributed fiber optic strain sensors is presented to monitor the structural performance of the extreme large diameter prestressed concrete cylinder pipes (PCCPs). The distributed sensors are proposed to mount on the surface of PCCP, and their readings are used to evaluate the cracking of the mortar cover and structural behavior of PCCP. To verify the feasibility of the proposed method, a series of prototype tests were performed on a large diameter PCCP (DN3800×5000/P0.6) with internal water pressure up to 1.6 MPa. Two kinds of distributed fiber optic sensors, i.e. steel wire strengthened strain cable (SWSC) and poly-elastic strain cable (PESC), were used in the tests. The surface bonding and embedding approaches were investigated for sensor installation in the experiments. The distributed measurements were in good agreement with the numerical simulations. When the internal pressure reached 1.0 MPa, the mortar cracking was detected from the distributed strain measurements with PESCs. It indicates that the distributed fiber optic strain sensors would not miss the localized behavior, such as cracking, that the conventional strain gauges cannot detect. The experimental results demonstrate that the distributed fiber optic sensors can provide the warning sign of early damage in large diameter PCCP.

Numerous water sector management practitioners have stated an urgent need to have a unified platform for the nation’s water pipeline infrastructure data and information that is universally accessible and useful. Such a platform, PIPEiD (pipeline infrastructure database), is envisioned to provide access to the data sources, tools, and models that enable the analysis, simulation, visualization, and evaluation of the behavior of pipeline infrastructure. PIPEiD will assist the users in more effective management of these assets for sustainability and resiliency. Virginia Tech, WERF, Washington Suburban Sanitary Commission, Denver Water, and American Water jointly sponsored three workshops to sharpen the PIPEiD (pipeline infrastructure database) vision and mission, both of which are focused on enhancing the practice of drinking water, wastewater, and stormwater pipeline asset management. With invited researchers from academia, utilities, regulators, organizations, and industry, the workshop identified opportunities and knowledge gaps relative to critical areas of sustainable and resilient pipeline infrastructure systems and other pipe associated assets. The goal of the workshop was to develop a prioritization that can guide fundamental and applied research at institutions and entities funding research in water pipeline infrastructure. A key question discussed at the workshop was “how to develop data standards, model specifications, and decision support tools for advanced pipeline asset management to allow for higher reliability and improve performance, cost-effectiveness, risk management, efficiency, sustainability, security, and resiliency.” This paper presents the workshop outcome focused on the design and development of a national database platform to allow a practitioner to address all three major water pipeline infrastructure management levels: strategic, tactical, and operational, and for water utilities of all sizes.

Existing utilities of all kinds are depicted on planning and design documents for the use of the design engineer. The intent of the depiction is to assist the design engineer in (a) understanding the physical characteristics, availability, and restrictions of the space to develop and design the project and (b) judging the risk that a particular utility may present for a particular project feature or phase. Engineers can choose to address that risk in several ways: designing the project in such a way so that there is no design element of the project in conflict with the utility; requiring the utility to relocate; or designing protections for the utility during construction activities. However, utility depictions and the environment in which the utility exists are uncertain. This uncertainty makes judgements on reducing risk difficult. ASCE 38 was developed to allow the engineer some degree of confidence that the utility location information is accurate, but this location information and its attribute of utility quality level (as per ASCE 38) are not sufficient for complete risk evaluation. Other uncertainties about utilities exist beyond location that should be evaluated by the design engineer. These uncertainties may include a utilities’ size; ability to withstand stress; soil and bedding characteristics; and structural devices such as thrust blocks and other restraints. Other risk factors that affect design include a utilities’ product, operating pressure, function (e.g. main water supply for a hospital), ability to recover from a catastrophic event, and so on. New software programs, especially 3D modeling ones, have a mechanism to expand a programmed shape like a square or round cylinder that mimics the anticipated shape of the utility beyond the location of that utility. This concept is termed a “soft” clash detection. However, due the uncertainties of location, size, condition, structures, and other factors as outlined above, a symmetrical risk envelope may not be the best solution from a risk mitigation standpoint. Knowledge of utility system design, utility operational and maintenance constraints, project construction practices, achieved utility quality level, and system and community resilience are necessary to judge the best shape and extent of any risk envelope placed around utility elements. Determining the shape and extent of these utility risk envelopes is a new development in the field of utility engineering that will allow the design engineer to exercise better judgement in utility risk elimination and reduction.

This paper aims to provide a high-level structure for asset managers to choose appropriate technologies. It will describe an example of where this structure was recently used and how it is going to be applied in subsequent decisions. The water service center (WSC) in Flint, Michigan has aging infrastructure and a limited capital budget. The current asset management program is reactive in nature, making it more challenging to spend WSC’s limited funds in the right place at the right time. Focusing on their linear assets (buried pipes), the WSC would like to improve its asset management program, to be able to determine which pipes need the most attention and come up with a rehabilitation or replacement plan based on their limited capital improvement budget. The method chosen by the WSC was to separate all data sets into different tiers of information, forming a pyramid. Each tier becomes progressively more detailed as higher resolution investigation methods are applied. Higher resolution and more detail come at a cost because these types of investigations are generally more expensive per unit length, can be invasive and might require disruption of pipe service. The philosophy behind the pyramid approach is to use the lower tiers to find system-wide trends and identify mains that have high risk and consequence of failure. Subsequent tiers are used to improve confidence and resolution in the data. It is recommended that higher tier technologies are only applied if the information from the previous tier suggests that additional testing is needed or if more information is required to make an informed decision.

Growth projections indicate that the Regional Municipality of Peel (the Region) will need to supply over 2.5 million residential and commercial customers with a reliable and high quality supply of drinking water over the next 20 years. In order to achieve these customer levels of services while balancing cost and risk of service, the Region utilized a risk based approach to managing its transmission and sub transmission pipes (water supply pipes) to inform decisions related to maintenance, renewal and capital programming activities with the end goal of achieving established customer level of service targets for water supply. The outcomes of the risk assessment allowed the Region to identify critical water supply pipes; support business justification for short, medium and long term expenditures; use net present value (NPV) economic analysis to identify the lowest cost mitigation options; and develop a consistent and transparent risk based approach to managing its transmission and sub transmission mains.

In order to successfully implement an asset management program, an accurate and reliable deterioration model for assets should be available. Deterioration models are considered as the basis for predicting and prioritizing future maintenance, rehabilitation, or replacement activities of assets. Sewer agencies are seeking different methods to prioritize inspection of sewer pipes in presence of financial constraints and deteriorating pipelines. This paper presents the development of a defect based deterioration model using Bayesian belief network (BBN) in sewer pipelines to be used in inspection prioritization. Different types of defects found in an existing sewage network were collected from closed circuit television (CCTV) inspection reports and used in creating the model to determine the likelihood of a sewage pipeline to be in a certain condition state. The BBN is used to generate dependency between different defects and their effect on the overall condition of the pipe. Monte-Carlo simulation (MCS) was introduced to eliminate the uncertainties that could arise in the model due to independent events that would be propagated through the BBN to assess the final dependent posterior probabilities. BBN is considered as an efficient tool because it deals with inherent uncertainties and handles complex interdependencies using conditional probabilities. The developed model could be used as a decision support tool by which decision makers could plan inspection of deteriorated sections.

Sophisticated smart water technologies are changing the way water networks are monitored and controlled. Smart water solutions improve the efficiency, longevity, and reliability of a utility’s underlying physical assets by better measuring, collecting, analysing, and acting upon a wide range of network events. By generating knowledge, a utility can address some of its largest challenges such as leakage, energy efficiency, regulatory compliance, and customer service. Syrinix and several Californian utilities carried out research into transients and their effects and this abstract details some of the key findings from the studies.

Very often, condition assessments of asbestos cement (AC) pipe will produce contradictory results. A phenolphthalein stain test may indicate advanced material degradation, but ring crushing tests will produce strength values exceeding original specifications. The stain-test data will exhibit considerable variability, with far-from-uniform degradation, even on the inside of pipes, where the environment is presumed to be relatively uniform. Samples taken from broken pipes will often appear un-degraded, yet something produced the break. This paper discusses findings from an exhaustive statistical and physical condition analysis of a large urban water utility, where 24 years of break data and 96 samples were analyzed to guide decisions regarding 1100 miles of AC pipe. Among the findings are: (1) the role of carbonation in AC pipe degradation; (2) the influence of external loading, particularly the shrink-swell potential of soils in causing breaks; and (3) how break history predicts future breaks for both young and old mains. This paper also addresses the efficacy of acoustic-velocity tests for assessing the integrity of AC pipes. The method appears promising, avoiding the need to extract samples from live mains. This paper is based on a recently published water research foundation report 4480, “Development of an Effective AC Pipe Management Strategy for Utilities.”

Washington, DC has several neighborhoods within the coastal low lying wetlands. A system of large masonry sewer tunnels were constructed in the beginning of 1900’s prior to establishment of modern soil mechanic theory in 1930. This network of tunnels plays critical role in controlling the surface water flow as well as sanitary discharge for the flourishing neighborhoods of the nation’s capital. The existing flat terrain became established neighborhoods’ after massive manmade fills. In this presentation, we will demonstrate with these two cases, how the uniform soil load around the old masonry tunnel/pipes provides a hoop prestress force “compression ring” to a masonry pipe for the arch structures. One case is a deliberate residential construction right above a 22’-0” wide x23’-6” high brick tunnel circa 1905. This sewer tunnel carries a 3,500 MGD combined sewerage overflow (CSO) in a 15 year rain event, with 5-ft surcharge. Excavation on top of the sewer tunnel for the basement of the new building does not increase in the total load on the sewer (as explained by the building designer), yet proved to be more detrimental than the pre-construction load of the soil removed for the basement construction. In another case, a commercial building with underground garage was constructed adjacent to a 7ft concrete masonry pipe. The deep excavation with sheeting and shoring was about 20-ft clear from the adjacent pipe. The sheeting and shoring did not perform well during a heavy rain event, resulting in soil erosion at the base of the excavation. The sample analysis presented in this paper demonstrate that alteration to the surrounding soil pressure adversely impacts the masonry tunnel.

Predicting and mitigating the effects of entrapped gas on surge is very important in the design and operation of water pipelines. This paper presents a special technique developed in modeling entrapped air pocket in surge analysis using commonly available liquid pipeline hydraulics software. An innovative approach in the modeling of air properties is introduced. The surge pressure spike during high pressure air pocket venting are demonstrated and compared with experimental data collected from literature and previous researches. The results demonstrate that the modeling technique presented in this paper is reliable and accurate in predicting surge behavior associated with entrapped air in water. The paper also presents the modeling of air venting surge for a real engineering pipeline system. The methods introduced in the paper enables the reliable modeling of a complicated hydraulics issue using simple single phase hydraulics tools.

Much like many of the cities in the Western United States, specifically Arizona; the majority of Tucson’s water pipelines average 30 years old. Contrast that with large municipalities east of the Mississippi that have average pipes in their system that are still performing quite well at over 100 years old, and many might question why a City like Tucson would invest in an assessment program specifically for their asbestos cement pipe (ACP). Tucson Water provides water for more than 730,000 customers and growing. Tucson, Arizona is located in the Sonoran Desert about 100 miles south of the capital city of Phoenix, and about 60 miles north of the Mexico border. The City officially dates back to 1775. Due to a large military base, mining, and the University of Arizona (U of A, founded 1885), the City has been growing for quite some time, but the retirement population starting in the 1970’s has resulted in significant growth over the last 40 years. While Tucson Water has ACP dating back to the 1930s in their system, the majority of their 2,200 miles of ACP was installed during the past 50 years. To address this enormous, aging inventory of ACP in their system, Tucson Water has developed a collaborative public, private, and academia program team designed to manage, track and study every ACP failure that occurs in its system. Initiated in 2014, Tucson Water hired a local corrosion company to assist with the corrosion testing of its ACP, and most recently included to its team experts from the U of A construction materials lab. The nuts and bolts of the program is that when an ACP failure occurs, Tucson Water staff enters the failure event and type into Tucson Water’s online pipeline risk management (PRMS) database developed specifically for condition assessment, that initiates a process flow system for pipe, soil, and water samples to be collected from the location of the event. Each of the samples is tested; pipe by U of A, soil by the local corrosion company, and water sample by Tucson Water staff. As the testing is completed, the data is entered into predetermined fields in a database that can be tracked and queried by Tucson Water staff. Those queries can then be used to search for failure trends in a GIS/geospatial map, including failure types that can ultimately lead to identifying the root causes of failure. Examples of root causes of pipe failure could include acidic soils, aggressive waters, differential settling, poor construction, and operational concerns. Ultimately capital planning decision for repair, rehabilitation, and replacement can be made. This paper will include show how Tucson Water is adding to their already proactive large diameter pipeline condition assessment program. This will include steps from the program inception and some examples of laboratory testing of AC pipe inherent within the program. In addition, this paper will demonstrate how collaboration of public, private, and academia resulted in a viable program for one of the nation’s largest ACP inventories in a single water system.

Since electromagnetic inspection using remote field eddy current transformer coupling (RFEC/TC) became commercially available and viable as an inspection technology for prestressed concrete cylinder pipe (PCCP) in the late 1990s, technology providers have relied on calibration of pipes as a means of improving accuracy of results. Calibration is a controlled procedure which simulates the inspection tool’s signal response associated with various combinations of broken prestressing wires. Calibration ideally requires at least two pipes with nearly identical properties to the inspected pipe be removed from the ground and destructively tested. The costs and coordination required to safely perform PCCP calibration while limiting operational impacts render calibration impractical as a means of obtaining higher quality electromagnetic inspection results for most PCCP owners. The limitations of quantifying wire breaks using electromagnetic signals for embedded cylinder pipe (ECP) PCCP without shorting straps is well known and documented in the literature (Engindeniz et al. 2015 and Zarghamee et al. 2012). While the electromagnetic signal can be very sensitive to a single wire break in this type of pipe, the technology tends to over-report wire break quantities for this specific pipe configuration and design. Calibration of the electromagnetic signal to actual wire break quantities is particularly important for this type of pipe, but even with calibration, over reporting of wire break quantities has been reported. A protocol has been demonstrated on City of Phoenix (City) PCCP for improving accuracy of electromagnetic inspection results without calibration. Select pipes with structurally concerning wire break quantities or those reported as “distressed across (DA),” meaning the wire break quantities could not be estimated through electromagnetic inspection were excavated and evaluated for replacement based on external visual assessment and continuity testing. Electrical continuity testing is a non-destructive assessment method using voltage differences between adjacent prestressing wires to measure whether a wire is broken from outside the pipe. If needed, replacement was completed during the same shutdown as the external assessment. Continuity testing was used as a calibration for other City PCCP with similar properties. The protocol has been demonstrated on inspection of over 50 miles of PCCP in the City, including continuity testing or destructive testing of 16 pipes. The testing performed verified the ability of RFEC/TC electromagnetic inspection in non-shorting strap ECP-type PCCP to detect small quantities of broken wires, non-detection of wire breaks near the joint, and over-estimation of wire breaks in the pipe barrel away from the joint. Field verification of the revised wire break quantities reported by the inspection technology vendor after the continuity-testing-based calibration is being considered as a next step in the assessment process.

The San Diego County Water Authority operates and maintains the San Diego region’s aqueduct transmission system, which consists of approximately 483 kilometers [300 miles] of large-diameter pipelines, delivering water for over 3 million residents via its 24 member agencies. The Water Authority’s asset management program is charged with ensuring the safe and effective operation of these pipeline assets, and ensuring that the lifespan of its assets is managed efficiently. With a significant proportion of its infrastructure approaching the end of its useful life, the water authority utilizes a rolling 5-year condition assessment plan to strategically assess the remaining life of its assets. This focus is aimed at ensuring it maintains its mission of providing a safe and reliable supply of water to the San Diego region. This paper will examine the steps taken by the Water Authority to gather comprehensive condition assessment data on over 195 kilometers [120 miles] of its most critical pipes, and how it presents this data to assist in performing critical pipeline risk assessments and providing recommendations for pipeline rehabilitation.

Water network performance assessment is a challenging concern that is facing worldwide municipalities. The necessity of providing continuous potable water under tight budget places extra pressure on municipalities and triggers the need for proper performance assessment. Accordingly, this research opts to develop a water networks performance assessment (WNPA) model to precisely assess the performance of the water networks’ components. The model revolves through two key indices: (1) Pipes Performance Index (PPI) and (2) accessories performance index (API). These indictors reflect the status of network components, their deterioration levels and propose consequence preventative actions. Furthermore, WNPA utilized a fuzzy analytical network process (FANP) to identify and evaluate the weights of functional performance criteria (physical, operational, quality of service, and environmental) for the pipes and accessories. It also exploits both the preference ranking organization method of enrichment evaluation (PROMETHEE) and simple multi attribute utility theory (MAUT) to compute the functional and global performance indices for the network components. In order to compute the weights, data are collected through water network experts. WNPA is applied to a Canadian water sub-network in which the results showed that most of existing pipes and accessories are in a medium state, which is well-aligned with the actual results. Thus, it can be concluded that WNPA proved to be a promising tool with high capability in assessing the performance of water networks’ components.

Known for hot and dry summers, Texas saw one of the hottest and driest years on record in 2011. This was part of a multi-year drought which resulted in dwindling water supplies and amplified water restrictions. As a result, the City of Abilene, located approximately 150 miles west of Fort Worth, saw their primary surface water source drop to one of the lowest ever recorded levels. This trigged the need to develop additional water supply, so in 2013 the city embarked on a fast-paced project to increase water storage in Lake Fort Phantom Hill. The project included facility improvements and an outfall pipeline at the Hamby water reclamation facility (WRF). These improvements allowed water to be treated and discharged directly into the lake. This paper describes the design and construction of the five mile pipeline and outfall structure. The authors discuss key design items including pipe sizing, deep burial versus shallow burial, and hydraulic analysis. The pipeline design and construction were successfully completed within one year.

The Panama Canal expansion is a $5.25-billion project sponsored by the Panama Canal Authority, which includes $3.2 billion for the design and construction of the third set of locks. Buried beneath the new sets of locks’ footprint are 80,000 feet of ductile iron pipe, providing potable water, dewatering and fire protection service to the new locks’ facilities and the surrounding communities. This paper will discuss the pipe design, selection, design/build challenges encountered during the process and how it affected the pipe manufacturing and scheduling. It will demonstrate how the use of 3D modeling software was used to coordinate the ductile iron pipe with other buried utilities. It will present a unique installation of 30-inch and 24-inch potable water flanged ductile iron pipe crossing underneath the lock structure that required a 450 psi hydrostatic test on the 30-inch pipeline after installation. Due to the unique high performance requirement, which reached beyond normal testing criteria for water piping, special design and testing for the joint system was developed for this project. The paper will also describe how teamwork and cooperation among the designer, the contractor and the equipment manufacturer/supplier were essential for the successful construction and operation of the ductile iron piping component of the overall megaproject.

Pipeline systems in power plants have a unique set of factors quite different from pipeline systems in municipalities. Typical municipalities have hundreds of miles of pipelines and focus on the inspection of this underground infrastructure has historically been a regular practice of the maintenance of this system. In contrast, a typical power plant may have less than a mile of large diameter circulating water pipelines. Since large diameter pipelines comprise only one component of many systems managed within a power plant, in many generating stations regular inspection of these pipelines has not been a standard practice. While power plants have historically taken a reactive approach to management of their pipelines, the recent increase in leaks and failures in their large diameter circulating water pipelines is highlighting a need for proactive approach to pipeline management.

Sewerage infrastructure is either lacking or laid in an unorganised manner in most of the cities and rural areas of India. The untreated sewage is either percolating to ground or routing to natural water bodies. Holistic planning for sewerage infrastructure requires survey and investigation, population projections, estimated sewage generation, existing infrastructure and obstruction features. The preparation for proposed sewerage infrastructure improvements includes analysis of attributed information to develop optimized designs. Geographic information system data along with comprehensive hydraulic modelling software may be used to analyse various iterations and achieve techno economic solutions with reduced time input. The major consideration while planning should focus on longevity of the overall system. This includes selection of suitable materials of construction, techniques for implementation of new components and rehabilitation/augmentation of existing infrastructure along with efficient operation and maintenance. Tackling existing sewerage infrastructure is even more challenging due to unavailability of basic data required to assess its compatibility with thriving growth. The sewerage system of Delhi needs improvement in view of 50% of its area being unsewered and inefficient. Existing sewerage infrastructure has insufficient capacity along with having outlived its design life. The concerned executing agency of Delhi, Delhi Jal Board (DJB) has taken various initiatives including preparation of a sewerage master plan for Delhi (SMP-2031), and adopting an integration approach considering present and planned infrastructure. This paper represents a case study on the approach adopted in Delhi, for establishing a holistic and efficient sewerage system.

In the interest of further diversifying their water supply, New Braunfels Utilities (NBU), a growing water provider, developed a new well field in the Trinity Aquifer. Integration of this new source into an expanding system and pipeline network required an analysis of how the water could be transferred through the system to high demand areas, in conjunction with the existing operating parameters and other water supply sources utilized by NBU. A modeling analysis of the existing distribution pipeline network and future operations was developed to determine the optimal approach to move water through the system. Different options were evaluated to distribute the additional water throughout the system, while maintaining operational flexibility for NBU to supply water through their different supply sources. Examining the quantitative means and methods to move this new water source throughout NBU’s system proved extremely beneficial to NBU and demonstrated the impacts a new water source can have on system operations both short and long term. This paper will discuss the unique requirements of integrating a new water supply into a growing water distribution system, as well as the specific benefits and value that modeling and field testing provides to owners and the Public.

San Diego County Water Authority (SDCWA), like most of California, is in desperate need for new reliable water supplies. In 2012, SDCWA signed a long-term purchase agreement for water from the Carlsbad seawater desalination plant (desalination plant). The 54 million gallon per day (MGD) desalination plant is the largest desalination plant in the Western Hemisphere. In order to move this new 54 MGD supply into the SDCWA system the Carlsbad desalination conveyance pipeline (conveyance pipeline) and several other improvements to the agency’s system were required. This paper provides details on how SDCWA worked with the private developer, Poseidon Water and the design-builder, Kiewit Shea Desalination Joint Venture to build a new 10 mile, 54-inch pipeline, at a cost of $150 million, that would convey water from a new water supply source, the Pacific Ocean. A complex water purchase agreement and design-build/engineering procurement contract were used to construct the desalination plant. The conveyance pipeline was required to be designed to SDCWA standards and meet all regulatory requirements. The authors from the engineer of record for the project have provided their opinions on both the project successes and the lessons learned on the project. Most importantly the authors described how all parties worked together to deliver this very important regional project.

The Navajo Gallup water supply project reach 24.1/25 project will convey water from the San Juan River to four Navajo Nation (Nation) communities in northwest New Mexico. These Native American communities are among the most water-underserved in the United States. The project includes 13.7 miles of 14- and 10-inch pipeline and a pump station with a capacity of 1,500 gallons per minute. The Nation elected to use PVC for the transmission line, and also utilized fused PVC pipe (FPVCP) for the first time. FPVCP was used for joint restraint sections and for sections of the line where pipe joints were undesirable. This included arroyo crossings, locations of potential contamination, and areas of potential down-surge pressures. This paper will discuss the rationale, benefits, costs, and trade-offs of using FPVCP to provide thrust restraint, reduce risk of pipe failure due to soil erosion, and mitigate risk of contamination at pipe joints. Both advantages and disadvantages of FPVCP will be discussed, as well as lessons learned during construction and design aspects that may be improved upon in future designs using FPVCP as part of typical buried PVC pipe systems.

As the demand for oil and gas infrastructure continues throughout the United States, transmission infrastructure such as pipelines continues to be a crucial part of the equation. With the recent trend of heightened opposition to pipeline transmission development, there have become additional risks, whether actual or perceived, that require additional engineering and analysis during the siting process. This paper will discuss such risks, design considerations, and case studies (where applicable) related to: groundwater; geology and pipeline routing in karst areas; obstacles encountered during horizontal directional drilling (HDD) and the need for geotechnical analysis; Executive Order 13690 on floodplains; and potential for future pipe exposure and fluvial geomorphological studies, among other environmental and cultural resource siting considerations. Although this paper focuses on oil and gas pipeline infrastructure projects, the same approach can be utilized for various other linear infrastructure projects.

Companies install hundreds of miles of pipeline throughout the US. A faster, cheaper and more accurate method of doing open-ditch as-builts would reduce costs, limit liability and improve the company’s operational processes. Currently, in order to satisfy their needs, as well as federal and state regulations, surveyors are hired to GPS as-built the pipe and its key components. This process can take as long as 20 days at a cost of approximately $6-17 per foot. On top of that what the company receives is not standardized and takes additional processing to load into enterprise systems. AsBilt LLC is in the process of building a new patented approach (US 9,230,453 B2) that will solve the problems in performing open-ditch as-builts such as that required for the pipeline shown in Figure 1. It will halve the current per foot cost of open ditch pipeline as-builting, the turn-around time will be shorter, and the presented data will correspond directly with the company’s deliverable standards for automatic upload.

In 1998, Tualatin Valley Water District (TVWD), Beaverton Oregon and the City of Hillsboro Oregon (Hillsboro) began work to identify an additional water supply for their service areas, including more than 84,000 service connections. In 1986, Washington County Oregon initiated a Major Street Improvements Project to improve safety, mobility and address the demands of a growing population in southern Washington County, including 124^th Avenue. The intersection of these two planning efforts provides the basis for combining a road project and a critical pipeline segment into a successful design effort: constructing a major new road and 15,000 feet of large diameter waterline known as the 124th Avenue Project. But, the 124th project is only the beginning. By including the 124^th pipe ten years before it is needed, and not having identified more than 30 additional miles of pipeline alignment, it was imperative to identify potential pipe alignment corridors (“Secure the Corridors”), for the remainder of the water supply project. This paper will describe: How combining the road project and the initial 15,000 feet of pipe, 10 years before being needed, is an advantage; How TVWD and Hillsboro approached the critical task of identifying more than 30 miles of alignments and siting for critical facilities, while completing plans for 124^th Avenue; How working with local stakeholders, local elected officials and staff, regulatory agencies and the public to identify pipe alignments, potential restrictions AND opportunity projects helped save costs and present a cooperative project to the public; How TVWD and Hillsboro are proactive in seeking input from government and citizens to determine acceptance of the WWSP and alignments.

This paper presents feasibility of using open-cut and tunneling for building an underground freight transportation (UFT) system from Port of Houston to a distribution center south of Dallas, Texas. This 250-mile project, if built, will be one of the longest planned Underground Transportation projects. UFT uses close-fitting capsules carrying freight through underground pipelines between terminals. The construction of a UFT project involves using either open-cut or trenchless method. This paper will provide an analysis of applicability, constructability to approach in which the construction method can be selected; and parameters which need to be considered for the cost analysis. For defining which section of project is applicable for trenchless or open-cut methods, the entire route was divided into three segments. This case study considers using highway right-of-ways with a 26 ft diameter for “single twin-track tunnel” as tunneling method, and 17 ft for “double single-track tunnels” as open-cut method.

The reason for the data collection is to provide information needed to plan for future expansion of The University of Alabama campus, with respect to its hydronic pipe network. This is accomplished by providing the data needed to minimize conflicts with newly designed underground utilities and by identifying areas of potential expansion of the existing pipe network. This paper discusses how data was collected and how new data will be collected in order to keep the information up to date. ASCE’s subsurface utility engineering (SUE) quality levels were applied to existing pipeline locations. The location of newly installed pipe was provided by an engineering consulting firm. The consulting firm, which provides the University with test reports for all welded underground pipe, began providing the corresponding GPS data. This will supply a steady stream of data regarding future underground pipe installations, which makes updating the utility plan easier. The information has already proven useful. While completing the utility plan, the information collected was used on an upcoming road project to assist in new utility location and to pinpoint areas that required demolition of existing utilities before the start of the project.

Asset management of pipeline infrastructure entails accurate prediction of the condition of the system to operate and maintain at the lowest overall costs. The key components involved in a comprehensive asset management of the pipeline infrastructure are data management, model implementation and information visualization. In this paper, a centralized web-based platform is developed where the models and tools can run, retrieve the data and publish the results to visualize and query the information. The paper depicts various aspects involved in developing a web-based application for two different utilities that store, collect and analyze the data in dissimilar methods. A pipe performance index model to evaluate the performance of the pipelines is demonstrated with Washington Suburban Sanitary Commission (WSSC) and Hampton Roads Sanitation District (HRSD) data. Consequently, the model is published as geo-processing services through ESRI ArcGIS Server. A visualization tool is developed for individual utilities that interacts with the geo-processing services and renders a web-based interactive map to visualize the model results.

Freight transportation by trucks constitutes approximately 80% of total freight transportation in Texas and it is expected to approximately double by the year 2040. Social and environmental costs are adverse impacts of moving freights by trucks. Automated underground freight transportation (UFT) significantly reduces these negative impacts and is more sustainable method of freight transportation. UFT includes close-fitting capsules carrying freight through underground pipelines between terminals. Being able to use a part of the underground space of the existing right-of-way of highways, especially interstate highways, will greatly facilitate the construction of pipelines and reduce their construction costs. The application of UFT in Texas and comparison of routes and methods were discussed through establishing a stakeholder committee. This paper presents results of the stakeholder committee selection, meetings and small group discussions for this project. A survey of stakeholder committee provided their support and feasibility of the UFT system, which will be presented in this paper.

Map projection linear distortion is manifested as a difference in distance between a pair of projected (map grid) coordinates and the true horizontal distance at the surface of the Earth. Such differences often exceed a few hundred parts per million (ppm) for published coordinate systems (such as state plane and UTM). It can be problematic for various geospatial products and services, such as engineering plans, construction staking, as-built surveys, property boundary plats, and facilities management systems. Although this distortion cannot be eliminated, it can be optimally reduced using low distortion projections (LDPs): conformal map projections for minimizing linear distortion. A method for designing LDPs is shown that yields optimal results even for large areas of variable elevation, and it can provide distortion more than an order of magnitude lower than the traditional method of scaling State Plane coordinates “to ground.” Importantly, LDPs are based on common existing projection types, so they are fully compatible with engineering, surveying, and GIS data (an additional advantage over scaled State Plane). Because they are rigorously georeferenced, LDP datasets can directly represent conditions “at ground” in GIS and CAD platforms without resorting to best-fit approximate transformations.

The Tarrant Regional Water District (TRWD) with the City of Dallas Water Utilities (DWU), are currently engaged in the planning, design and implementation of a 350 MGD raw water transmission system, which will run across north central Texas from Lake Palestine to Lake Benbrook, with connections to Cedar Creek reservoir, Richland Chambers reservoir and a Dallas delivery point. Collectively, the system consists of approximately 145 miles of 84-inch to 108-inch pipeline, a 5-mile, 120-inch, diameter tunnel, six 100-350 MGD pump stations, one 450 MG balancing reservoir and ancillary facilities. The program developed by TRWD to accomplish these improvements is called the Integrated Pipeline Project (IPL). The IPL program consists of approximately 30 capital improvement projects phased over a 20 year time frame. Phase 1 includes nine projects of which six are in construction. TRWD has developed an extensive geographic information system (GIS) database to manage data flow among numerous consultants, design engineers and internal stakeholders during the planning and design of the IPL. Recognizing the need for timely and accurate as-built record drawings in construction, TRWD developed a process of real time as-built (RTAB) data collection; making survey-grade GPS locations of constructed pipeline assets available in a GIS in near real-time. The RTAB process compiles design drawings, pipe manufacturer lay sheets, and survey-grade field collected data into a comprehensive GIS database which can be used to review and manage the pipeline construction before the pipeline is buried, as well as generate record drawings, O&M map books and other asset management tools when construction is complete. This paper and presentation describes the development, requirements, and use of TRWD’s RTAB process as applied to a cross country water transmission pipeline.

The Arkansas valley conduit (AVC) project was conceived as part of the U.S. Bureau of Reclamation (Reclamation) Fryingpan-Arkansas (Fry-Ark) Project. The Fry-Ark project was originally authorized and constructed in the 1960’s; however, the AVC project was not financially feasible at that time. Planning-level designs of the AVC project are presently underway and are being managed by Reclamation. The Southeastern Colorado Water Conservancy District (SECWCD) is the project sponsor and when completed, the AVC will serve 50,000 people in about 40 communities with drinking water in southeastern Colorado. The project consists of a new connection to a joint use pipeline near Pueblo Dam, a water treatment facility, booster pumping stations, and approximately 250 miles of transmission pipeline and spurs, ranging in size from 36-inches down to 4-inches. This paper provides an overview of the utility, survey and mapping data collection process to support Reclamation’s design of the pipeline and associated facilities. Important design data is gathered and integrated into relational databases and GIS formats to provide the design team ready access to utility location, surveying, right-of-way (ROW), property and easement mapping data for the pipeline. This approach provides key design data on an integrated platform, allowing for timely decisions to advance the pipeline design within the established corridor. The data collection and integration process is supporting the determination of land ownership and easement acquisition needs; minimizing overall project risks by identifying potential utility conflicts; reducing cost uncertainty at the planning and future final design levels; and ultimately will reduce potential conflicts and substantiate potential utility related construction costs for the AVC project.

The City of Gillette is located in northeastern Wyoming and is known as the Energy Capitol of the World due to the oil and gas industry in the area. Burns & McDonnell was hired to design and perform program and construction management for the Gillette Madison pipeline project which will provide the City of Gillette a water source through 2060. The project consists of 52 miles of 42 and 30-inch transmission main, 6-miles of 18-inch blending waterline, a tank, a pump station, a well field, well piping and a hypochlorite facility. There were many jurisdictional issues with the pipeline permitting and agency approval during the design and construction of the project. This case study provides the challenges and solutions for the Gillette Madison pipeline project.

Design of large diameter tunnel crossings of high traffic volume roads, railroads, and creeks or rivers requires incorporating standard tunnel design standards with multiple agency design standards, coordination with these agencies, and oftentimes requiring permitting or encroachment agreements. The design of several large diameter tunnels was required for the 150 mile integrated pipeline (IPL) project. The IPL Project is a water delivery system made possible through a partnership of the Tarrant Regional Water District and the City of Dallas. Each currently supplies water to over four million people in the Dallas Fort Worth area. IPL sections 12, 13, and 14 consist of approximately 30 miles of 108-inch pipe with a total of fourteen (14) tunnel crossings with a minimum tunnel outer diameter of 144 inches. One of the crossings is Interstate 35E which has a diameter of 168 inches. This paper will highlight the design requirements and the coordination involved for design and construction of these tunnel crossings. Each tunnel crossing was designed to meet minimum depth requirements and to minimize the tunnel shaft depths at either end of the tunnel. Settlement for each tunnel crossing was evaluated to determine appropriate tunnel diameter based on controlling agency loading requirements. Permit and operational requirements of the carrier pipe and tunnel also dictated several key design features, but the means and methods of construction were left up to the tunneling contractor. This paper will also summarize construction challenges and lessons learned during construction. Most tunnel crossings were less than 200 feet in length, but three crossings exceeded 600 feet in length. Lessons learned from the installation of a tunnel 600 feet in length led to design changes in the 805 feet Interstate 35E tunnel. All other tunnel crossings were designed with 144-inch diameter which only allowed for the carrier pipe to be welded to each pipe joint outside of the tunnel and pushed into place. Increasing the diameter of the Interstate 35E tunnel provides more flexibility for the contractor to address any issues during installation of the carrier pipe in the tunnel.

A critical factor that contributes to inefficiencies in the design and construction of civil infrastructure projects is the lack of accurate, complete information about utility facilities that might be in conflict with the project. 3D design software is dramatically changing the way agencies design and build civil infrastructure projects. Most 3D design and construction processes focus on earthwork and grading automated machine guidance (AMG) applications. However, current AMG processes and protocols, including data exchange, provide very limited support for underground facilities. The U.S. Department of Transportation recently completed a research project that examined issues that agencies face in managing utilities in 3D design and construction workflows. This paper summarizes the research findings. The research included a documentation of business practices and lessons learned from a review of selected case studies; an analysis of implementation strategies and return on investment (ROI); and a review of the use of radio frequency identification (RFID) technology to mark and manage underground utility installations, along with a discussion of benefits and costs.

Throughout the world, public agencies and private entities are struggling to efficiently manage various infrastructure assets. A major component of our infrastructure consists of utilities that are routed along highways. However, a key challenge resides in obtaining accurate inventories and location maps for utilities. New geospatial technologies such as mobile lidar provide significant opportunities to develop advanced geospatial databases to support asset management in a safe and efficient manner. In many cases, this technology can be combined with other subsurface imaging technologies to provide a more complete survey of utilities. This paper will discuss how recently developed guidelines for the use of mobile lidar in transportation applications can be effectively utilized to improve utility asset management within transportation agencies and beyond. It will also describe the development of an interactive, eLearning website to support the implementation of these guidelines.

The adequate performance of geotechnical assets, such as natural and artificial slopes, embankments, and other geotechnical structures along pipeline corridors, is fundamental to ensure the safe and effective operation of the pipeline. Ideally, the frequent monitoring of the conditions of the geotechnical assets allows detecting potential problems early, making it easier to correct them as part of an asset maintenance program. In practice, however, the extensive and often inaccessible locations of such assets along a pipeline can make the monitoring task very challenging. We test the feasibility of using photogrammetric methods from a manned and unmanned aerial vehicle platform, to detect ground movements, as a diagnostic test for monitoring geotechnical assets. Photogrammetric methods based on “structure from motion” algorithms are used to generate three-dimensional point cloud models of the terrain, which can be compared between data acquisitions of the same location at different times, to infer ground movements. Preliminary results from our field tests in Alaska show the potential to detect ground displacements on the order of several to a few tens of centimeters. Such information can be used in a geotechnical context to assess slope performance and the potential for collapse, but also to directly monitor pipeline deformation. Additional validation and testing is required for the method to be operational; a brief discussion of current and future work on validation and method evaluation provides a direction for future research in this area.

This paper describes complex permitting requirements and site conditions for a project which included a 64-inch (1625 mm) effluent force main from the St. Joseph, Missouri water protection facility to the Missouri River and is of interest to facility and pipeline owners and operators as well as designers of facilities and pipelines. The force main has a maximum capacity of 108 mgd (408825 M³/day) and is used when river levels are elevated and gravity flow through the treatment facility and levee is not possible. Previously, when the river level was elevated and the levee sluice gate closed, the City would rent temporary pumps and piping and stage them on top of the levee in order to pump treated effluent over the levee and to the river. The temporary pumping was costly and was required in 5 of 8 years at one point. The force main was constructed across KCP&L power line easements, Bartlett Grain Company property, Union Pacific Railroad property, and South St. Joseph drainage and Levee district property and is all contained within the U.S. Army Corps of Engineers critical area of the levee. The force main includes a 500 foot (152400 mm) long, hand excavated tunnel under multiple railroad tracks, a crossing up and over an existing levee, and a discharge structure on the river side of the levee. The force main tunnel is located within the critical area of the levee and under Union Pacific Railroad tracks and required resolving conflicting permitting requirements from multiple parties. The force main was designed during the flood of 2011, however, it was constructed during the drought of 2012. The drought lowered the water table by ten feet, and through value engineering and contractor partnering, the force main design, layout, and profile were changed during construction, saving the city over $400,000 in construction costs.

The Southgate Water and Southgate Sanitation Districts (Districts) are a quasi-municipal special district located in the south Denver suburbs. The Districts function separately from one another, working independently to provide water distribution and wastewater collection systems to more than 80,000 residents. Service areas for these systems cover four cities, two counties, two fire districts, different storm water authorities, and a wide variety of other local stakeholders including homeowners’ associations and special development districts. Project design and construction within the Districts present significant permitting and coordination challenges, as they always border and/or cross over multiple jurisdictional boundaries. Because the functional goal of each agency is different, project requirements and specifications are frequently in disagreement, or even direct conflict with one another. While the stakeholders recognize the importance of reliable water/sewer service, the red tape can lead to project delays, costs, and project immobility. The purpose of this case study is to discuss effective management of both development and capital projects using experience gained from completing dozens of successful projects within the Districts’ boundaries. The following topics will be discussed: A brief history of the Southgate Water District and Southgate Sanitation Districts; An overview of the relationships between the Districts and the various jurisdictions within their service areas; and Several project-specific examples of conflicting interests regarding waterline, sanitary sewer, stormwater, and roadway improvement projects.

The estimated worth of the Water Authority’s infrastructure is over $5 billion. Effective management of these assets yields savings, a smaller increase in water rates over time, and improved system reliability. The Water Authority accomplishes this through an asset management program. The purpose of the program is to ensure the most benefit from assets by maximizing their value over their lifecycle. This includes managing the construction, operation, maintenance, rehabilitation, replacement, and surplus of each asset to occur at the optimal time. Accurate pipeline data and survey information is critical for an effective risk-based asset management program. The most fundamental aspect of the asset management program is the asset registry (asset management database) defining what assets the Water Authority has and where the assets are. The Water Authority has built a spatial database over time to include all assets comprising of over 60,000 pipe sections with over 60 characteristics for each section. The primary driver of this spatial information is survey data. Although this process took the Water Authority years to compile the data, owners with limited data should not be intimidated. There are several simple things that owners can do to start building a comprehensive asset registry for better asset management. This paper will discuss the benefits of a database, the stepped approach the Water Authority has taken on data collection, ideas to capture data for new assets, and the importance of survey data.

The City of Cambridge, Massachusetts recently completed the phased construction of over one mile of reinforced concrete pipe (RCP) up to 54-inch diameter and reinforced concrete box culvert (RCB) up to 12- x 5-foot as part of its CAM 004 combined sewer separation program. Installation occurred at shallow depth of cover complicating many pipeline crossings including a commuter railway corridor, three state-operated sewer interceptors, and arrays of duct banks and utilities. These crossings occurred on state owned parkways congested with traffic, roads with dense private utilities, and office complexes sensitive to outages. The mile long corridor required eight new easements through valuable commercial developments, State- land and railways. The problems facing each crossing are identified, and the design approach along with construction changes are detailed. This project exemplifies how to construct large diameter pipelines via the open-cut method in dense urban corridors.

The quality and thoroughness of topographic, utility location, property, and control surveys prepared for design of a linear infrastructure project is the foundation for a successful design and minimal field changes and change orders. Multiple North American Datum (NAD) surveys established locally, statewide, and nationally have been known to have varying base elevation differences. In addition, agency surveys and monuments can vary between agencies and United States Geological Surveys (USGS). The location of existing wet and dry utility infrastructure is paramount information needed by design engineers to finalize contract documents. Property surveys are required during design to establish property lines and corners and ownership information that are necessary to determine needed permanent and final easements and right-of-way for construction and ultimately operation and maintenance. During design, control surveys are needed to confirm existing monuments and establish new monuments that will be used for construction staking and asset management. This paper will present the requirements for these design surveys, the methods used and actual project experiences that will provide lessons learned to help existing and future designers, contractors and owners mitigate project overruns resulting from incorrect, inaccurate, or missing survey information and data.

Complete, accurate, and thorough surveys were performed during design allowing the design engineers to produce a quality set of contract documents, the construction manager and contractor will need surveying monuments and control staking to manage, inspect, and construct the infrastructure project. Monitoring settlement in adjacent utilities or structures can also be required. This paper will present the level of surveying accuracy and the amount of surveying information needed for the construction team to complete construction on-time, within budget limits and the specified level of quality. In addition, this paper will provide the reader and audience with actual case studies of project successes and lessons learned to help them improve future construction project delivery.

GIS maps are utilized by engineers, technicians, administrative staff, contractors, and customers to locate utilities for various purposes such as utility marking, maintenance and emergency responses, design, and planning activities. The accuracy of GIS maps varies dependent on the source of the data. Low quality GIS maps will cause end users to not rely upon the data in GIS. A process must be developed to ensure the continuous improvement of the data for GIS maps. Major investments by utilities have occurred to encourage the use of GIS in the field with the use of handheld technology. Accurate data will encourage the use of GIS maps by all users. Quality assurance checks of the data should occur to identify any changes that have occurred in the field, but not communicated to GIS.

A major concern during installation or rehabilitation of buried pipelines are ground movements during construction. Unexpected ground movements, such as settlement or uplift, may be the result of geotechnical conditions, proximity to other structures and utility lines, contractor methodologies, and/or poor designs. Near-continuous monitoring of ground movements during construction is important to quickly identify and mitigate potential problems. A common method for detecting ground movement is to routinely measure the coordinates of discrete points along the ground surface during construction using high-accuracy survey equipment, such as automatic levels, total stations, and GNSS receivers. It is then possible to determine if the position of these points are changing with time. Although these survey equipment provide coordinates with millimeter- to centimeter-level accuracies, the equipment and often the surveyor must physically occupy the discrete points along a construction corridor in order to take the measurements. This paper presents a procedure for measuring and monitoring ground changes by utilizing digital photographs taken from an inexpensive, consumer-grade camera mounted on a small unmanned aircraft system (sUAS). The digital photographs were aligned and processed using a computer vision procedure known as Structure-from-Motion (SfM), which results in ortho-rectified, mosaicked aerial images and high-resolution digital elevation models (DEMs) of the construction site. After a series of UAS flights over time, the resulting DEMs from this method were differenced in order to detect and quantify ground movements. In an effort to define accuracy, results of the UAS-based measurements were then compared with measurements taken from a total station survey. The comparison yielded a vertical RMSD of 2 cm at the 95% confidence level.

The question that was answered by the authors as part of ASCE Pipelines 2015 conference was “Can a Design Engineer Rely on D/t Ratio as a Rational Indicator to Manage Stresses and Strains in Welded Steel Pipe during Handling?” During the brief five minute Q&A, a few in the audience challenged the need for the analyses presented by the authors; there was no time available for the authors to provide a response. The intent of this paper is to address this issue fully and expand the review to the remaining design criteria within AWWA M11 to answer the question posed in the title of the paper.

The Logan CSO (combined sewer overflow) interceptor project, awarded to Garney construction in September 2014, includes the installation of 10,000 linear feet of combined gravity sewer, ranging from 96-inch to 24-inch in diameter, to convey flow from 13 combined sewer overflows to a future basin site. Due to the urban surrounding, approximately 80% of the interceptor sewer was installed inside of an existing improved concrete C channel that was constructed in the early 20^th century. The challenges in constructing such a unique project were no small task and took an extraordinary amount of planning and preparation. In this case study, the decision making and construction management for such a unique and challenging project will be dissected to provide a thorough understanding of the operation that takes the design and produces it into a usable system.

Colorado Springs Utilities and other regional partners are currently constructing a new water delivery and treatment system known as the Southern Delivery System (SDS) in southern Colorado. A major component of SDS is a raw water transmission system that comprises approximately 50 miles of predominately 66-inch diameter pipeline and three large raw water pump stations with ultimate capacities ranging from 78 to 100 million-gallons-per-day (MGD). Major construction of the pump stations was completed in the fall of 2015, which was followed by extensive field hydraulic testing to verify the design and optimize operations. The first phase of field hydraulic testing recorded steady-state system hydraulic characteristics (i.e., system curves). Although this is common practice for large water transmission systems, for SDS, establishment of accurate system characteristics was a critical component of automatic control algorithms designed to select the most efficient combination of pumps and speeds for a given flow rate. The second phase of testing focused on the hydraulic transient (surge) mitigation system, which is a critical component of the raw water transmission system. The surge design was verified during startup testing by operating the system at various flow rates up to the peak capacity, followed by a simulated power outage that caused uncontrolled stopping of all pumps simultaneously. Data was recorded using high resolution pressure transmitters located at critical locations and compared to the design values. A final area of testing that is often overlooked is pump startup. In a long pipeline system, such as SDS, the system must overcome the inertia of water mass, which manifests as additional head resistance during pump startup. During field testing acceleration of the water was monitored from startup to steady-state to better understand the change in head resistance and associated hydraulic transients. This paper presents the results of field testing completed during the startup phase with a specific focus on how the results compared to detailed analyses completed during design of the system.

Many U.S. utilities rely upon iron pipe to deliver water through their distribution network. It has only been in the past 50 years that other products have penetrated in the water utilities. The industry has turned to various cementitious and plastic materials largely to overcome aggressive soil and water that can be corrosive to the metallic pipes. This paper will discuss a current water research foundation (WaterRF) study on the development and testing of a new structurally enhanced polyvinyl chloride (PVC) pipe called iPVC. The pipe was developed in South Korea by Pyungwha Pipe Industry Inc. (PPI) and currently is used for water distribution systems in Japan and China as well as South Korea. The evaluation is achieved by series of selective testing on the pipe, including impact, stiffness, tensile, short-term hydraulic burst pressure, fatigue, and bedding test. The evaluations will also include pilot installation and operation of the pipe as part of an active system. This paper will discuss the results of testing and evaluation process including the field installation performance of the iPVC in the St. Louis County, Missouri by Missouri American Water. Prior to the evaluation, the iPVC pipe has passed the National Sanitation Foundation, NSF 61 certification and complied with the American Water Works Association (AWWA) C-900 standard.

Half the United States’ population lives in an area of moderate to high risk of seismic activity. Buried water lines are doubly important following a seismic event. Water is the first defense against fires, a major cause of additional destruction following an earthquake. Water is also essential for public health and the sustenance of life. We can exist without power for days, and many have done so, but when our supply of clean water is interrupted, we must soon restore it. This paper presents a new joint assembly for fire hydrants, valves, and ductile iron pipe that provides for longitudinal joint expansion and contraction within limits of positive restraint, and radial joint deflection. Performance characteristics of the joint assembly will be noted and discussed; the performance of ductile iron pipe, valves, and fire hydrants during seismic activity will be presented; and a video showing joint functionality will be included.

Knife gate valves (KGVs) are frequently used in pipeline systems as on-off valves and to enable isolation and servicing of other system components. This type of valve operates by lowering a steel plate between two seal rings that are integral to the valve body. This paper presents an evaluation of performance problems with 2,130 mm (84 in) diameter KGVs, including seal-ring clearance and opening tolerance issues. Loads that act on the knife gate valve include self-weight, internal water pressure, tension from the bolts connecting the valve to the adjacent pipe, and gasket compression loads. We present the results of extensive non-linear finite element analysis, including contact between the pipe flanges, rubber gaskets, and the valve body. The model was used to evaluate valve deformation and determine the root cause of the observed performance issues. A favorable comparison of the model results and measured deformations is presented. We show how modeling was used to guide the design of a modification which resulted in satisfactory valve performance and provide some recommendations about design of valves of this type.

In 2012, the Louisville Water Company (LWC) formulated and approved a capital improvement plan (CIP) to provide redundancy to the Cities of Prospect and Goshen in its eastern extended service area. The City of Prospect was on the eastern boundary of LWC’s service area, and LWC acquired the Goshen Utilities service area in 2002. Goshen had been one of LWC’s wholesale customers. This area of the system has grown since the acquisition and, with its expanding high-end residential contingent, has large irrigation demands. The implementation of the capital improvement work was progressing at a slow pace due to other pressing needs in the service area. In 2014, the primary 12-inch water main carrying potable water into the Goshen system failed. The location and depth of this break intensified the effects within the system. As LWC raced to find a way to reroute the supply into the system, management watched as tank levels dropped and boil water advisories were issued. This paper will discuss issues encountered, actions and quick thinking by LWC personnel to avoid complete loss of service, and the capital improvements that were implemented to prevent an issue of this magnitude in the future.

Finite element simulation of the structural performance of stiffened lap welded pipeline joints was performed, subjected to severe axial and bending loading conditions, resulting from ground-induced actions, in the presence of internal pressure. The pipe, the welded lap joint and its reinforcement were modelled in FE program ABAQUS with shell and solid finite elements, accounting for geometric nonlinearities, such as large deformations and buckling, as well as the nonlinear behavior of steel pipe material beyond the elastic regime. This paper describes the joint assembly, the resultant benefits shown in the FE modelling to the seismic resilience with the added joint strength, as well as the parameters required for specifying the stiffened joint in design. FE Results are presented for lap welded joints (unstiffened and stiffened) in a steel pipe with diameter-to-thickness ratio of the parent pipe equal to 180, subjected to axial loading, longitudinal bending, and internal pressure. Lap joints with double welds are considered on the inside of the joint, the outside of the joint and on both sides of the stiffened joint. For each loading case, the load-deformation relationship is determined, and local strains are measured in critical locations for different levels of loading. Local buckling (bulging) under compression is simulated explicitly through the finite element solution, whereas the possibility of tensile failure is detected through monitoring the value of the maximum tensile strain. The numerical results focus on the mechanical behaviour of a 66-inch-nominal-diameter pipe with 0.37-inch thickness, and refer to both global structural response and the evolution of local strains in critical locations. At the time of drafting this paper, HDR, Inc. is preparing to conduct a physical testing of the stiffened joint to affirm the performance and define the manufacturing requirements.

This paper presents a theoretical basis for the rerounding effect of internal pressure on deflection and stresses in buried pipe. The nonlinear differential equations governing pipe-soil interaction of deflected buried flexible or semi-rigid pipe surrounded by soil of known stiffness subjected to internal pressure is derived. The solution of the problem provides a rerounding factor that reduces the installation-induced deflections and bending stresses in the pipe wall. The rerounding factor derived expresses the extent of stress reduction from rerounding on internal pressure, pipe bending and axial stiffness, and soil stiffness. The rerounding factor provides an analytical method to determine the stresses in a flexible buried pipe subjected to combined effects of earth load and internal pressure. It is hence applicable to metallic pipe, fiberglass pipe, HDPE pipe, CFRP liners as well as semi-rigid concrete pipe, such as bar-wrapped pipe.

A design standard which makes it possible to evaluate the effect of the tsunami migration force acting on surface pipeline facilities and to plan appropriate countermeasures has not yet been well developed due to a lack of relevant data concerning tsunamis. The most common method of calculating the tsunami force acting on a submerged structure, i.e., the equivalent pressure method, is based on the assumption that the tsunami force acting on a structure is equivalent to the hydrostatic water pressure acting on that structure at a factored water depth. However, it is not certain that the same method can be applied to surface pipeline facilities. In order to confirm the applicability of the equivalent pressure method to surface pipeline facilities, we carried out a numerical simulation of the fluid–structure interaction and compared the results with those obtained by the equivalent pressure method. This paper discusses the applicability of the equivalent pressure method to surface pipeline facilities based on the comparison.

The City of Scranton, Arkansas, was in immediate need of a new water source. The existing supplier was unable to convey enough water to meet demand. Rather than develop a new water source and build treatment facilities, the city opted to buy water wholesale from another utility, the Clarksville Light and Water Company (CL&W). In order to convey the water from CL&W, new transmission facilities were required including attaching 8,600 linear feet of ductile iron pipe to the longest bridge in Arkansas spanning the Arkansas River. The project team included the Engineer, McGoodwin, Williams, and Yates, and Contractor, JL-Bryson, Inc., with support from manufacturers, EBAA Iron and US Pipe. Attachment of the waterline to an existing bridge presented design challenges different from buried waterline construction. The owner of the bridge, the Arkansas State Highway and Transportation Department (AHTD), would not allow the bridge to be used for thrust restraint of the pipeline. The AHTD further required that the pipeline could not restrict longitudinal movement of the bridge girders. The design also needed to accommodate changes in length due to thermal expansion and contraction of the waterline and the bridge structure. Over the entire length of the bridge crossing, approximately 4 feet of expansion and contraction was expected from the anticipated range of temperatures. Additionally, restrained joint pipe was selected, and the “slack” or available movement in the pipe joints between fully homed and engagement of joint restraint needed to be removed to prevent deflection or snaking of the waterline. This paper discusses methods used to prevent snaking of the exposed waterline, prevent transfer of thrust forces to the bridge, and the use of force balanced expansion joints to accommodate thermal expansion and contraction.

This research explores how waterhammer pressures initiated at a particular point within a building’s piping network affects other pipes in the system including the service pipelines supplying the building’s piping. In addition the paper also investigates how the transient pressure induced in a water distribution system affects a building’s piping network. The numerical results shows that pressure surges are amplified while traveling toward smaller pipe sizes but they are dampened when they are moving to a zone with larger pipe diameters. This paper concludes that larger waterhammer pressures generally remain trapped in the smaller pipes within the building networks and do not significantly affect either the supply pipelines of the water distribution systems feeding them. However a moderate pressure surge induced in water distribution system may be significantly amplified inside house piping networks particularly when they are arrested at dead ends within the building.

In 2008, Atlanta Gas Light Company presented a 10-year rider program to the Georgia Public Service Commission that, once approved, allowed for the installation of large diameter pipelines in and around Metropolitan Atlanta. These pipelines are being installed to reinforce the natural gas distribution and transmission systems to guarantee that there will be abundant supply for customers on peak winter days now and in the future. With so many miles of pipelines being installed in a congested urban setting, a specialized project team was created. This team established an enhanced delivery process consisting of improved project management, land acquisition and GIS as-built data collection procedures that will ensure that our pipelines are installed to safely serve our customers for decades to come. In a world that demands safety, we are convinced that our processes protect people, property and pipelines.

Much like medical stents for a heart patient, air valves properly applied to a pipeline are a pressure relief mechanism that can mean the difference between an emergency and peace of mind. A design approach that reduced by almost one third the cost of air valves on a well field pipeline for a Texas Panhandle city is making engineers and owners take notice. Parkhill, Smith, and Cooper (PSC) engineers initially used an air valve manufacturer’s software to get the manufacturer’s recommendations for the pipeline. The manufacturer’s program called for 117 air valves, which would be prohibitively costly. So PSC used hydraulic modeling, to perform transient analysis, which showed that 48 combination air valves ranging from 4 to 12 inches in size would be sufficient. The air release valve recommended by the manufacturer’s software would have cost over $1.2 million; whereas the air valves defined with hydraulic modeling, would cost under $880,000. The project piqued the interest of the El Paso Water Utilities and the American Council of Engineering Companies, which requested a presentation in February 2015, comparing the costs of each type of work. Using hydraulic modeling rather than manufacturers’ recommendations for air valve placement can significantly reduce capital cost on your project while still protecting your pipeline.

A case study showing the growing risk to pipeline infrastructure from erosion and channel degradation. In November of 2011, Burns and McDonnell was contacted about an exposed natural gas pipeline in a residential neighborhood of Arlington, Texas. The natural gas pipeline was a 20-inch diameter high pressure line within close proximity to adjacent houses. The pipeline was exposed as it crosses Key Branch just northeast of the intersection of Woodside Drive and West Mayfield Road in Arlington, Texas. The channel had eroded over the decade the pipeline was in place resulting in the pipeline exposure. The client wanted Burns and McDonnell to provide alternatives to fix the exposure and protect the pipeline long term.

It is well understood in the civil engineering industry that the economy of flexible pipe systems relies almost entirely on the pipe-soil structural interaction. As correctly noted by one of our generation’s preeminent steel pipe design researchers, Dr. Reynold Watkins, the design of flexible pipes is largely dependent on the surrounding soils. The selection of flexible pipe materials and the design of the flexible pipeline system begins with and depends almost entirely on the ground conditions through which the pipeline will be constructed. The Tarrant Regional Water District (TRWD) and Dallas Water Utilities (DWU) began design of the Integrated Pipeline Project (IPL) in 2008 and have been advancing the art and science of large diameter pipeline project delivery ever since. The $2.3 billion IPL is a joint project between DWU and TRWD and will, when completed, include 150 miles of pipeline from Lake Palestine to Lake Benbrook. The pipeline crosses a number of challenging obstacles and passes through a number of highly variable ground conditions, from rippable (soft) rock to running, saturated sands and everything in between. The 13-mile long alignment of IPL Section 15-2 crosses the Waxahachie Creek valley west of IH-45 before following a long, gentle ridgeline roughly between Ennis and Waxahachie, Texas. The pipeline crosses some very design-challenging soils, including the notorious, heave-susceptible Blackland Prairie. The geotechnical/geophysical program prepared by the Program Team noted a number of “Areas of Geologic Concern” in Section 15-2, most notably in the “Waxahachie Creek Bottoms,” an alluvial valley with a broad floodplain and shallow, water-bearing sands within and just beneath the “typical” trench profile. The design team worked collaboratively with the pipeline owners and their program management team to develop best-value design and construction procurement approaches to deliver the project in a way that fairly attributed and mitigated the ground condition risks while assuring the best life-cycle value for the owners. This paper describes the project constraints faced and approaches taken to mitigate both design and construction risks. These approaches included clearly defining the design intent that was predicated on assumed ground/trench conditions and the following construction inspection and management practices: Clear delineation of areas of geotechnical concern in the bidding documents; Clear definition of the ground conditions assumptions made in pipe and trench envelope design in the bidding documents; Definitive pre-construction validation of ground conditions ahead of material procurement; Validation of in-situ trench conditions during pipeline installation; Provisions for alternative trench and backfill envelopes in both the bid schedule and plan and specifications that equitably mitigate bidding and construction cost risks related to ground conditions.

In Japan, a sheet-pile method is often used to install pipelines with large diameter into the ground because of narrow work sites and high groundwater levels. However, voids develop in the ground associated with the extraction of sheet-piles. Therefore, the ground around the buried pipes rapidly deforms, and the earth pressure acting on the pipes changes. In this paper, in order to investigate the mechanical behavior of the buried pipe during sheet-pile extraction, two-dimensional analyses by discrete element method were conducted. In this analysis, sheet-piles with three kinds of embedded length was installed, and flexible pipe having diameter of 1.0 m was modeled and backfilled in sand or cohesive soil. The result of the analyses indicated that the sheet-pile extraction led to the development of a loose area in the ground. The loose area resulted in settlement and deflection of the flexible pipe. Especially in the case of cohesive soil, the settlement and deflection were larger than expected.

The Paradise Whitney interceptor project for the Clark County Water Reclamation District will relieve capacity deficiencies for the existing sewer interceptors and provide capacity for the future. The whole PWI project was divided into three packages. The subject of this paper will discuss design challenges and sustainability provisions for Project 669 (Package 2) portion of the project, the first package out to bid. Project No. 669 includes construction of approximately 27,138 linear feet of new sanitary sewer interceptor utilizing trenchless methods for eight reaches totaling 13,964 linear feet and open cut methods for 13,174 linear feet. The gravity sewer ranges in inside diameter from 66- to 84-in., some with 76-in. steel casing. The project presented numerous design challenges including community and business impacts, complicated geology, close proximity to existing underground utilities, limited surface access, and other factors forcing trenchless drive lengths up to 1,500 ft. The tunnels were constructed utilizing trenchless methods that included earth pressure balance machines and micro-tunnel machines; ground improvement was required on many of the drives. Construction of this project began in late 2014 and is expected to be complete in 2016 with a total construction budget of $62.3 M. Sustainability provisions included fiberglass reinforced pipe (FRP) and polymer concrete manholes.

This paper details the procedure for pressure-induced thrust restraint design of concrete pressure pipelines with tied joints at elbows, tees, and end-caps through several examples following the current AWWA manual of practice M9. The paper discusses the problems that led to the development of the procedure, the design philosophy, and the development of a simplified approach for thrust restraint design. It discusses the assumptions embedded in the simplified approach. It presents the calculation flow diagram and describes the steps in the calculation for three different examples. These examples are selected for discussion in the order of their complexity: an end cap, a simple bend with welded joints, and a bend with mechanically harnessed joints. Through the use of examples, the paper shows how the calculation for each step is performed. Applicability of the procedure developed in the current AWWA Manual of Practice M9 to thrust restraint design of other pipes is briefly discussed.

In accordance with a Federal Consent Decree, Citizens Energy Group is implementing a long term control plan to address combined sewer overflows (CSOs) in Indianapolis. Included in the “DigIndy” plan are provisions for a series of CSO diversion structures, consolidation sewers, drop shafts, and a 28-mile long network of six 18-foot diameter tunnels. Beginning near the Indiana State Fairgrounds on the north, and ending on the south side of Indianapolis, DigIndy will be the largest public works project in the city’s history. The tunnel system will capture up to 95 percent of CSOs along seven Indianapolis waterways, reducing overflows to less than four per year, the maximum allowed by the US Environmental Protection Agency (EPA). With a volume of more than 250 million gallons, the tunnel system will extend along Fall Creek, White River, Pogues Run, Pleasant Run and Bean Creek to create a collective, underground storage and transport facility for combined sewer overflows. All CSOs captured, stored, and transported in the tunnel system will be treated at one of the City’s advanced wastewater treatment plants. The White River Tunnel is designed to be approximately 5.3 miles, capture 9 combined sewer overflows in 7 vertical drop shafts and contain nearly 5,000 feet of consolidation sewer at the near surface. When incorporated with other improvements in the White River watershed, White River Tunnel will achieve 95 percent CSO capture and limit overflows to an average of 4 events per year. The Fall Creek Tunnel is designed to be approximately 3.7 miles, capture 26 combined sewer overflows in 13 vertical drop shafts and contain nearly 5,100 feet of consolidation sewer at the near surface. When incorporated with other improvements in the fall creek watershed, fall creek tunnel will achieve 97 percent CSO capture and limit overflows to an average of 2 events per year. Sizes of the near surface consolidation sewers range from 24-inch to 108-inch and are planned to be installed through various construction methods including traditional open cut and trenchless bore and jack. The paper and presentation will discuss the overall tunnel system and highlight the near surface sites constructed to date. Also the challenges of managing design of a large system with multiple construction packages, coordination with multiple stakeholders and community neighborhoods, and managing project risks and schedule.

The City of Grand Rapids started Phase I of the combined sewer overflow (CSO) program in 1989 with a 30-million gallon retention basin to hold storm and sanitary water during significant rain events. Phase II of this effort, the 52 contract Westside CSO Program began in 1990 and ended in 1998. Phase III, the Eastside CSO Program began in 2004 which was comprised of 35 contracts and was recently completed in July of 2015. With the completion of this project and approximately $400 million spent, all 59 identified overflows are now eliminated, which prior to separation would overflow approximately five to eight times per year. Approximately 120 miles of new sewer pipelines were placed through commercial and business districts, residential and historic neighborhoods as well as in wetland areas and adjacent to and under creeks and railroads. Pipes have been installed in a variety of methods including pipe jacking, bore and jack, cast-in-place, open cut and pipe rehabilitation such as CIPP lining. Many sustainable or “green” infrastructure solutions and low impact development designs have been incorporated into these traditionally “gray” infrastructure projects.

Using finite element simulation tools, which account for both geometric and material nonlinearities, the bending capacity of mitered steel pipe bends is investigated. First, numerical results are reported on the elastic behaviour of two steel typical grade 40 steel mitered elbows with D/t values equal to 192 and 240, with the purpose of calculating flexibility and stress intensity factors. Furthermore, the elastic-plastic response of the two bends is also examined towards identifying their ultimate capacity and the corresponding mode of failure. Internal pressure effects on the structural response are also examined. The present paper addresses some important features of mitered steel pipe elbow response that may arise in geohazard areas, towards safeguarding the structural integrity of steel water pipelines subjected to severe ground-induced actions.

Large diameter gravity trunk sewer pipelines are a critical component of municipal infrastructure. Weaving a large, critical piece of infrastructure through city streets and easements has significant challenges that must be considered heavily in the planning, routing and preliminary design of the project. Similarly, pipeline owners face challenges in the operation and maintenance of the trunk sewer including inflow and infiltration, damage from corrosion and difficulty accessing the line in deep locations.

The Port of New York and New Jersey (PANYNJ) owns one of the most heavily used water transportation corridors in the World. It takes in nearly 1/3 of all the Eastern US shipping trade. The Anchorage Channel is the main “road-way” into the Metro New York Harbor from the Verrazano Narrows Bridge to the channel’s confluence with the Port Jersey Channel. In 2014, $125 Billion Dollars worth of goods and commodities were shipped into this Port. In the late 1990’s the Port Authority recognized that cargo volumes could double within the next 20 years and along with that the usage fees generated by the increased cargo. To accommodate the larger “mega” ships that were being designed and built for the 21^st Century for these increased loads, the Anchorage Channel needed to be dredged to accommodate ships with drafts exceeding 50 feet.

The horizontal auger boring (HAB) method of trenchless pipe installation has been around for 80 years, having started in the 1930s in the coal mining industry. Although auger boring fundamentals are the foundation for most of the trenchless methods, and although the trenchless industry has been very dynamic and expanded rapidly, for the last 20 years the auger boring and pipe jacking (AB and PJ) sector of the trenchless industry has not been receiving the recognition and visibility it had in the late 1980s and early 1990s. Because of this, the Trenchless Technology Center (TTC) conducted a school at Louisiana Tech University to reignite and reunite the AB industry by making a substantial investment to develop a permanent training and research facility. The field operations included two side by side auger boring machines (48 and 36 inches). A soil box measuring 36 feet long and 44 feet wide was built on the opposite side of the auger boring machines and filled with different types of soil including clay, dry sand, wet sand and gravel. Steel pipe joints, 20 feet long, were used in the field operations. One boring installation used 24-inch pipe joints that required traditional welding and the other used 30-inch Permalok steel interlocking pipe. During the boring operation, settlements were observed on top of the soil box.

Several types of concrete pressure pipes are manufactured and used in the North American water/wastewater industry. These include: two types of prestressed concrete cylinder pipe (PCCP), namely lined cylinder pipe (LCP) and embedded cylinder pipe (ECP), reinforced concrete cylinder pipe (CCP), reinforced concrete non-cylinder pipe (RCP), and concrete bar-wrapped cylinder pipe (BWCP). Each of these pipe types use different composition of materials and configuration, and also use different manufacturing and design standards. The structural design of the pipe wall for each of these types of pipelines should consider the interaction of axial forces and bending moments anticipated in the pipeline and their combined effects. Considering the axial loads, longitudinal bending moment capacities of the pipe section can be computed for the specific limit state condition being evaluated. For example, concrete pressure pipe design manual M9 considers cylinder yield limit state and ultimate strength limit state for thrust restraint design, and cracked and un-cracked pipe sections for design of pipes supported on piers. The depth of neutral axis for each of these four cases is different, and needs to be computed based on the representative strain and stress diagram considered. Admittedly, the computation of the neutral axis for a specific geometry of pipe cross-section is a simple exercise of applied mathematics when the underlying strain and stress distributions are defined clearly. For composite concrete pipe cross-sections, however, the calculations are somewhat complex to perform, due to differences in composite cross-sections, materials, strain diagrams, stress diagrams, and the simplifying assumptions. Availability of the different software tools developed by American Concrete Pressure Pipe Association (ACCPA) for the design of PCCP and for the design thrust restraints somewhat alleviates this concern, but documentation for these tools is limited. In order to address possible design conditions, materials, and cross-sections, author has developed computational steps and expressions for performing the neutral axis computations pertaining to different stress/strain states and cross-sections considered in the concrete pressure pipe design manual M9. This paper documents the general approach utilized and presents expressions developed for embedded cylinder pipe (ECP) sections.

Extensive laboratory tests were conducted in the test box at the University of Kansas (KU) to measure the response of SRHDPE pipes. The laboratory tests conducted have some limitations, for examples, on installation conditions. To provide information that can improve the understanding of the short-term and long-term behavior of the pipe, field tests were conducted. Strain gages to measure steel and plastic strains, displacement transducers to measure the changes in diameter of the pipe, pressure cells around the pipe to measure the distribution of the pressure were installed and data were collected both during the installation and loading of the pipe. In this paper, the deflection of the pipe under a test truck loading is presented. Based on the field testing on the SRHDPE pipes, it can be concluded that (1) the deflections measured under the test truck for the SRHDPE pipe were much smaller than the permissible deflection of 7.5 % according to the KDOT pipe and culvert specification (2007) during installation, (2) modified Iowa formula over predicted the deflection of the pipe under the applied load, and (3) the relation proposed by Masada (2000) can be used to determine ratio of the horizontal to vertical deflection of a buried SRHDPE pipe.

How do you cross beneath an urban arterial, three Union Pacific Railroad spur tracks, an industrial manufacturer, and a river flanked by a levee on each side all at once with minimal disruption, in a reasonable amount of time, using a cost effective installation technique? That was the challenge faced by the City of Sioux City, Iowa to relocate their sanitary double barrel inverted siphon to clear the way for expansion of Interstate I-29 through the heart of the City’s industrial core. The answer: horizontal directional drilling or HDD. Eight-hundred feet separate entry and exit connection points at an installation depth of 60 feet. Using a “maxi-rig” that can deliver 330,000 lbs. of thrust-pullforce, two twin 36 inch diameter casings were installed with nested 24, and 30 inch carrier pipes; all Fusible PVC pipe. An overview of the design process and construction of the installation is presented.

Use of welded steel pipe in the water industry was born in the mid-1800s with the invention of the Bessemer process for making steel. Revolutionary developments in the steel industry have since occurred even in the past 20 years that produce tougher and cleaner steel. Standard steel specifications have also evolved to reflect these improvements. Pipeline engineers utilize these standard specifications and enhance them with added requirements. Development of standardized specifications has helped manage costs and improve availability of steel to pipe manufacturers. Some supplemental requirements, while well intended, can significantly increase steel cost and may complicate or delay steel availability. The benefits of these requirements need to be evaluated against added cost and potential for delay. The authors share the history of steel used in the pipeline industry, review benefits of current manufacturing practices, present standard steel specifications, and the impacts of varying from the standards. Engineers will walk away with a better understanding of steel specifications.

The Big Horn Regional Joint Powers Board (BHRJPB) is comprised of six municipalities and rural water districts in the Big Horn Basin of Wyoming. The BHRJPB manages this large regional water system that wholesales water to 15 consecutive public water supplies. Some systems receive total supply, some supplemental supply and some emergency supply per their needs. The cost of this regional system was approximately $44 million.

In early 2015, Lafayette Utilities System (LUS) in Lafayette, Louisiana, completed plans and was finalizing the specification for a sewer force main, which would include approximately 9,000 linear feet of ductile iron pipe with no alternate materials specified. However, three areas were exceptions. These areas would be installed using horizontal directional drilling (HDD) and two pipe materials were evaluated: HDPE and flexible restrained joint ductile iron pipe. This paper will discuss the decision to use ductile iron pipe for the HDD portion of the project, as this was not an installation methodology the utility was familiar with. The major emphasis of the paper, however, will be on the successful HDD installation of three separate sections of flexible restrained joint ductile iron pipe. There will also be a discussion of the experiences each of these sections of 1,140 feet, 940 feet, and 740 feet delivered.

Oklahoma City uses the Atoka pipeline system to transfer raw water from the Atoka Reservoir in southeast Oklahoma to the Stanley Draper Reservoir located in the southeast part of the City. This system consists of six pumping stations and a 100-mile-long/60-inch-diameter prestressed concrete pipeline. The original 60-inch transmission pipeline, surge control system, and pump stations were constructed in 1963 and became operational in 1964. The existing surge protection system consists of a combination of one-way steel tanks (major surge facilities) and air vacuum valves (minor surge facilities) located along the pipeline alignment. Rehabilitation of the six pumping stations was completed and commissioned in mid 2011. A condition assessment of the existing major and minor surge control facilities for this pipeline was performed and it was determined that most of the facilities are very near or past their expected service lives and need to be replaced. Surge modeling was performed to analyze three alternative surge protection systems. A matrix evaluation was developed to compare the conventional option with a bladder-type surge tank option. The matrix evaluation considered site requirements, reliability, operation/maintenance requirements and lifecycle costs. This paper will cover the critical factors that should be considered when evaluating surge protection system for a large diameter pipeline and lessons learned from this project.

When request for proposals go out to construct a pipeline project, usually there are several if not many line items that eventually determine the project cost. However, when bid documents are received by the owner or engineer, many times the per foot bid for the pipeline material is all that is considered. The scope of this paper will focus upon “the total cost equation” which looks at other factors which should be taken into account before the bid analysis is finalized. When utilizing the “total cost equation” to analyze bid proposals for differing pipeline materials, it has been found from actual field data the cost differential between those materials can be much different than the initial per foot bid of the material when taking into account respective factors that are directly related to installation. Using the “total cost equation”, one can determine final project costs related to differing materials. This approach has shown the initial per foot cost of the respective materials is often deceiving, but unfortunately used by many owners and engineers to select pipeline material. In order to best serve a utility owner in the selection of pipeline material for a specific project, several if not many factors relating to the successful installation of that pipeline should be taken into account. Beyond the initial per foot cost of the pipeline material, some other immediate costs exist such as bedding, tapping saddles, line locator wire, corrosion protection and materials to prevent leakage. Additionally, longer term present worth costs such as energy and life cycle should be considered. Prior to a final decision on the selection of pipeline material for a particular project, the “total cost equation” should be applied and the components of the equation incorporated into the final material selection process.

Several types of air valves are commercially available including manual air release valves, automatic air release valves, air/vacuum valves, combination air valves, vacuum relief/air inlet valves, and surge control assemblies. This paper includes a discussion regarding sizing and spacing of air valves, different methods and features for freeze protection, and tips regarding how to specify various types of air valves. Sources of valuable information and guidelines regarding air valves are described. Unique features of air valves used for waste water vs. clean water are discussed. The paper also includes tips for designing air valve enclosures, common problems with air valves, and a perspective from staff responsible for accessing and maintaining air valves. Drawings illustrating several types of air valve assemblies are presented and discussed. The information presented should be of interest to pipeline designers, specification authors, operating personnel, and maintenance personnel.

Relief interceptor segment 1C is part of the Central Regional Wastewater System (CRWS) Elm Fork Interceptor, located in Dallas, TX. The interceptor was constructed in 1981 and consists of approximately 13,000 linear feet of 66-inch diameter reinforced concrete pipe. Segments 1C, along with the parallel 72-inch EF-6 interceptor are both within the floodplain of the Elm Fork of the Trinity River and pass through jogging trails, a golf course, and gun range. A 2011 condition assessment identified numerous areas with significant deterioration in the pipe crown. The initial hydraulic analysis of the interceptor revealed that approximately 36% of the pipe length would be undersized by 2020 and 97% would be undersized by 2060. System flow projections were then updated that reduced peak flow rates from previous estimates. The reduced flow projections triggered an investigation of rehabilitation options to extend the useful service life of the interceptor. The urban site constraints and high groundwater table presented unique challenges for interceptor rehabilitation. The paper and presentation will discuss costs, schedule, permitting, traffic, and business impacts associated with the interceptor and the decision to rehabilitate.

The Joint Water Commission (JWC) is an agency made up of 4 member governments to develop, maintain, operate and share facilities to serve a population of approximately 250,000 residents west of downtown Portland, Oregon. The agency lead and managing partner is the City of Hillsboro. The JWC system consists of a raw water intake, approximately 75 mgd water treatment facility, 40 million gallons of storage, the southern transmission line (STL)—a 42” welded steel pipeline, and the northern transmission line (NTL)—a 54 to 72” welded steel transmission line. The system ranges in age from 11 to 35 years. The focus of this paper will be the NTL which was installed in 2004. On February 15, 2014, the JWC suffered a catastrophic failure of a 54” butterfly valve on their 72”NTL which serves 3 water member utilities. The JWC needed a plan to overcome construction and procurement challenges and quickly and permanently repair the pipeline as the spring and summer water demand period was approaching. HDR was contracted to assist in assessing damage, developing a work plan, locating materials to be procured, and act as an extension to the JWC Staff. The team performed an evaluation of the problem and developed a list of materials that would be needed to make the repair. The list included pipe, couplings, gaskets, looses flanges and a new valve. It quickly became apparent that the lead time on the new valve would drive the schedule. Various options were considered to replace the valve including other types of valves and reaching out to other agencies on the west coast that had systems of similar size. Through a combined effort of multiple agencies, manufacturers, suppliers and contractors the repair was completed in 6 weeks, approximately 6 weeks less than the projected delivery time of a new valve and the NTL was back in service before the increase in demands. This presentation will detail the design and construction of this large diameter pipeline repair including looking for suspected causes of failure.

The conventional construction method for underground pipelines is open cut. This method has many problems such as high “social costs.” To avoid and resolve these problems, trenchless technology piping has been established and developed since the mid-1980s. However, the pipe has been designed as if it is constructed by the open-cut method even for trenchless pipes. Pipelines installed by trenchless technology have been over-designed, to say the least. In this study, finite element analysis results for soil pressure and deformation of the pipe, installed by the open-cut method and trenchless technology, were verified with the data measured from an experimental site. This paper shows that numerical simulation based on finite element method is an appropriate approach to study soil/structure interaction problems for underground pipeline engineering if, for the backfill material and subgrade surrounding the pipe, a constitutive model is selected judiciously and physical parameters are tested carefully.

The City of Revere, MA experienced a catastrophic failure of critical sewer infrastructure in August 2013. The 100-year old, 18” vitrified clay sewer, located in the heart of downtown, collects 30% of the sanitary flow city-wide. During routine CCTV inspection and cleaning, a collapse occurred in the 20’ deep conduit. The pipes’ significance in the collection system required immediate bypass pumping which was operated 24-hours a day by City Public Works staff. Immediately, alternatives were analyzed to determine the best approach to repair the pipe quickly and easily while minimizing disruption to the community. To complicate an already difficult situation, above the collapse were two large diameter (16” and 24”) water mains owned and operated by the Massachusetts Water Resources Authority (MWRA). In addition to repairing the collapse, the City needed to ensure that adjacent pipe reaches and sewer structure maintained their structural integrity, to prevent subsequent collapses during construction or in the future. Alternatives evaluated included pipe bursting, pipe jacking, directional drilling, CIPP lining, direct bury, etc., with particular attention paid to the requirements imposed by MWRA to protect their critical water mains. Ultimately a combination of repair methods were cobbled together to comprehensively rehabilitate approximately 800 feet of sewer infrastructure along Winthrop Avenue including spot replacement of sewer, CIPP lining, service lateral lining, manhole rehabilitation and grouting. This paper will detail the significant challenges faced by engineers and contractors during the eight month project including heavy traffic, extreme weather and timely funding, and will describe how a combination of trenchless technologies were used to rehabilitate the century-old infrastructure.

Cascade Water Alliance (Cascade) provides safe, clean, and reliable water supply to seven municipalities in the Puget Sound Region (Washington). In 2009, Cascade purchased the White River Project from Puget Sound Energy (PSE) with the full expectation that the water rights could and would be converted from a hydroelectric and recreational water right to a domestic and recreational water supply. The White River Project consists of an upstream flow diversion headworks facility that diverts flow out of the White River to fill Lake Tapps and the lower conveyance system (LCS) facilities. These facilities provide flow out of the lake and drop approximately 500 feet in elevation prior to discharge back into the White River. Substantial capital improvements are necessary to convert the over 100-year old hydropower facility to a water supply project. The Project Team’s initial work has been focused on ensuring that the existing facilities can operate under conditions that the facilities were not originally designed for, as well as under a wide range of flow conditions. Condition assessment field inspections of the LCS facilities required the lake to be drawn down almost 40 feet which was a two month process alone. The inspections identified immediate rehabilitation and replacement projects that were required at the intake structure and in the discharge bay, as well as other urgent (0-1 years), near term (5 to 10 years), and future needs (25+ years).

Pipelines connecting cities sometimes pass through mountainous or hilly areas. In these areas they are frequently buried along/under the road with banking structure. In past earthquakes, some pipelines buried under the roads which were constructed in the slopes of mountains with that structure were exposed by the failures of embankment. However the influence of that failure to the pipeline is not yet studied sufficiently. Therefore, the failure of embankment slope is analyzed in this research by using smoothed particle hydrodynamics (SPH) and other methods and the failure’s influences to the pipeline are discussed on the most appropriate analytical results obtained. As a result, it is confirmed that the SPH Method (applying the finite element conversion to SPH particles: strain-based criterion) is the most appropriate method to analyze the effect of slope failure to the pipeline which is buried under the slope. Several remarkable findings from the analytical results by this method are described.

A seemingly benign cave-in between two residential buildings appeared to be a simple emergency sewer repair. The fifty year old 12-inch cast iron gravity sanitary sewer main carried half the flows from the service area to the pumping station. Little did we expect that this would turn into a major repair involving multiple engineering disciplines. The utility engineer investigated the cave-in through CCTV and review of the as-built plans. It was discovered that the area had unstable soil conditions and the pipe was constructed on a wood pile system ten feet below grade. The pipe required emergency repairs. During the point repair the pile system was confirmed along with poor soil conditions. A geotechnical engineer was engaged to examine the conditions of the existing piles and soils. The piles appeared to be in good condition, while the cross members that supported the pipe had failed. Tests were performed on the existing piles and were found to be structurally sound. The engineer recommended that the pipe support system be rehabilitated and supplemented with a 2 to 5 foot stone base. A rehabilitation design was created by the structural engineer for the pile system. The project incorporated the complete replacement of 315 linear feet 12-inch gravity sewer, rehabilitation of the pile support system and restoration of the site. The lessons learned included; that the cooperation and integration of multiple engineering disciplines was essential to the success of the project, and the utilization of innovative materials to rehabilitate the pile system provided a sound foundation for additional service life.

The San Diego County Water Authority has been using carbon fiber reinforced polymer (CFRP) to repair prestressed concrete cylinder pipes (PCCP) since 2003. The Water Authority has completed 11 separate CFRP projects and has tracked design changes, costs, and subsequent inspections associated with these repairs. In addition, the Water Authority was able to destructively test a CFRP repair. Over the last decade the Water Authority has several lessons learned and collected practical information that can help owners evaluating and undertaking CFRP repairs. This paper will document the Water Authority’s history with CFRP, design changes, and discuss the CFRP destructive test and PCCP wire continuity testing conducted in 2013. In addition, the paper will provide lessons learned for owners evaluating and undertaking CFRP repairs.

In 2014, a five (5) story residential house was constructed in a residential area of Washington D.C. directly over the top of DC Water’s North East Boundary Trunk Sewer (NEBTS) without prior knowledge of DC Water. Based on the project drawings provided, there was only approximately 2 feet of soil between the bottom of the basement and the top of the sewer. This paper will discuss the emergency response put into action by DC Water, the analysis performed on the distressed pipe, and the various challenges involved in the emergency repair of a 22-feet diameter, century old brick sewer located in a busy mixed residential/commercial area.

This paper outlines the inspection, condition assessment, and rehabilitation of the St. James interceptor siphon crossing beneath the Assiniboine River in Winnipeg Manitoba, Canada. The St. James interceptor siphon, constructed in 1963, services approximately 2,200 hectares of northwest Winnipeg, and conveys peak dry flows of up to 713 L/s. The twin 600 and 500 mm steel siphons were inspected using a number of advanced condition assessment tools including: Sonar in 2012 and remote field eddy current technology (RFEC) in the fall of 2014. After full flow by-passes were able to be put in place in early 2015, CCTV inspections were also conducted to prepare for lining operations. The RFEC inspection was part of a larger program to inspect 19 high risk river crossings throughout the City to quantify failure risk and prioritize for rehabilitation where necessary. The RFEC data gathered during the inspections indicated that portions of the 500 mm siphon had deteriorated to the point of having no effective remaining wall thickness. While the 600 mm siphon appeared to be in much better condition, localized defects were found that were of legitimate concern to its reliability. While the exact cause of the extensive preferential deterioration within the 500 mm siphon is unknown, correlations between the vertical profile of the siphon and the RFEC data indicated the localised buildup of hydrogen sulphide (H₂S) within the 500 mm siphon under normal operating conditions due to the presence of a localized high spot in the middle of the river. Whereas the larger 600 mm siphon maintains an air gap along the siphon, allowing it to expel any gas buildup during normal operation of the siphon. The deployment of inspection tools and completion of the rehabilitation work was complicated by the configuration of the upstream sewer system which receives flows from two distinct trunk sewers. A complex gravity flow diversion concept was developed by AECOM and tendered for installation with the rehabilitation of each siphon; permitting each siphon to be isolated individually during normal dry weather flow. Due to the vertical profile, diameter, and length of the siphons (205 m), Cured-in-place-pipe (CIPP) was selected as the preferred rehabilitation method. The siphons have minimal rise on the downstream end (approximately 0.3 m) and the presence of concrete anchors allowed dewatering of the pipes with minimal effort and a low risk of floatation. The use of water inversion/curing processes and a full length temperature monitoring system permitted curing of the liners in a very complex heat sink for CIPP curing. The siphons were successfully rehabilitated in the fall of 2015 under very challenging conditions without incident.

Steel liners for rehabilitation of existing large-diameter pipelines with rigid-wall construction have been used since the 1980’s and more recently for rehabilitation and upgrading the pressure capacity of existing steel pipelines with flexible wall-construction. The steel liners are installed, in lengths compatible with the host pipe’s lengths and joined with single lap-welded joints, using procedures similar to tunnel steel-liners. The annular space between the host pipe and the steel liner is filled with cement mortar by either pressure grouting from inside through grout ports or from outside using the slickline (steel tubing) method in the annular space. The steel liners are designed, in most applications, for internal pressure with a minimum wall thicknesses to accommodate handling and installation loads including back grout pressure. The steel liner cylinders are fabricated as either complete (full circle) cylinders with a diameter of approximately 150-mm (6-inch) less than the host pipe diameter or collapsible folded-and-strapped cylinders (cylinders are rolled but the longitudinal seam is left un-welded to fold the cylinder and reduce the diameter for ease of installation) with a diameter, after spring back, of approximately 75-mm (3-inch) less than the host pipe diameter. Complete description and fabrication methods of the tunnel liners and advantages and disadvantages of both types of steel liners will be provided. There are no standard procedures for the design of the steel liners for rehabilitation projects and it is usually left up to the owners and its consultants to check the steel-liner designs based on assumed design-condition scenarios. All design concepts assume that the host pipe will be completely deteriorated and will not contribute to the structural performance of the steel liner; The design checks performed for a 1800-mm (72-inch) diameter steel liner with field single lap-welded joints for the rehabilitation of 30 km (19 miles) of 1950-mm (78-inch) diameter prestressed concrete cylinder pipe (PCCP), with rigid-wall construction, design/build project will be presented; fabrication and testing procedures of the cylinders and the lap-welded joint design will also be discussed. The recent use of steel liners to rehabilitate or upgrade the pressure capacity of existing steel pipelines will also be discussed. Recommendations for additional design provisions for the steel liners for rehabilitation will be given.

The North Texas Municipal Water District (NTMWD) is a water conservation and reclamation district created by an act of the Texas Legislature in 1951. Today NTMWD’s Regional water system provides drinking water to over 1.6 million people in the 55 cities, towns, special utility districts, and water supply corporations. Along with distribution to end-users, NTMWD owns and operates the transmission pipelines, pumps, storage reservoirs and treatment plants to serve its members and customers. In 1982 construction was completed on the North Plano 42-inch Pipeline. The pipeline includes approximately five miles of 42-inch prestressed concrete cylinder pipe (PCCP), and is capable of delivering over 40 MGD. In June 2011, a leak was discovered in the area where 475 lineal feet of the North Plano Pipeline crosses an interstate highway. NTMWD coordinated with the City of Plano to remove the pipeline from service for 24 hours, during which time they installed a tapping sleeve with a 24-inch flanged outlet on the 42-inch PCCP to provide internal access. After gaining access to the pipe an internal inspection was conducted to locate the leak and make a temporary repair. With the help of industry partners, NTMWD looked at several options to provide the permanent long-term repair. These included replacement, carbon fiber repair of the entire 475 lineal-feet segment and carbon fiber repair of high-priority spot locations identified by NTMWD. Disruption to the surrounding environment, traffic patterns and cost were all factors in the options analysis process. In addition, the long term reliability of the repaired segment(s) was a major driver for the selected option. After an exhaustive process, the third option was selected because it provided a precision structural upgrade to the exact locations identified to be in need of repair. Following this, detailed plans were created and put out to bid by qualified CFRP suppliers and installers. A construction contract was awarded to repair approximately 34 feet of 42-inch PCCP with carbon-fiber reinforced polymer. The project was successfully implemented within the allocated budget and timeline. Attendees will learn about NTWMD’s approach to asset management and how a leaking transmission pipe segment under a major interstate highway impacted its operations. In addition, a detailed viewpoint of the options analysis, decision-making and bid processes took place. Owner, consultant and specialty contractor input will be included in the paper and presentation which will provide insight on discovery, planning and implementation of the rehabilitation project.

The Gwinnett County Department of Water Resources (DWR) provides drinking water for approximately 750,000 Gwinnett County residents, with a total of 225 mgd of water production capacity and a 2015 average day demand of 120 mgd. The County distribution system features include two major pressure zones (Central and North), 10 water storage tanks, and 14 booster pump stations. The north zone transient model (NZTM) was commissioned in Fall 2014 in order to deliver a predictive transient modeling analysis tool that could be used by DWR to mitigate the risk of pressure surge in its distribution system The work also included the analysis of several worst-case scenarios and the provision of surge protection recommendations to address simulated transient response deficiencies. The field monitoring strategy was developed to monitor north zone piping network pressures continuously for a 30-day period. The field plan included the installation of ten (10) transient pressure data loggers, including four (4) high-frequency (100 Hz) loggers and six (6) lower frequency (1 HZ) loggers. Having a full set of data from ten monitors allowed the project team to assign transient responses in the distribution system to specific events at the pump stations rather than knowing only that a transient occurred without being able to assign a cause. In some cases, however, there were events that occurred that were not easily assigned system changes found in SCADA logs. The level of comprehensive data analysis in the current study is possible only because of the recent technology breakthroughs in data collection and storage technology. The field data was used to calibrate a skeletonized version of the existing DWR transient model which was subsequently used to simulate more extreme events than those measured and to develop recommendations for new surge control measures.

Facing an impractical transmission line leak repair, Public Utility District No. 1 of Skagit County (Skagit PUD) in Mount Vernon, WA was able to get local, state and federal agencies working together to complete a 2-year project in 3-months to provide reliable water supply for the dry 2015 summer. A new 1,200 foot 36-inch pipeline was planned, permitted, designed, fabricated and constructed to reinstate the Sedro Woolley transmission line and return to normal system operations. Skagit PUD supplies 65,000 customers through two transmission lines, the Judy Reservoir to Mount Vernon (JRMV) and the Judy Reservoir to Sedro Woolley (JRSW) Transmission Lines. Approximately 4 MGD flows through the JRSW transmission line, which was compromised in early 2015. The leaking portion of the JRSW pipeline was located on a 60% hillside, which presented challenges for repair, leading to the replacement of an existing 20-inch reinforced concrete cylinder pipeline with a new 36-inch steel pipeline. Skagit PUD made several attempts to locate the leak and repair the pipeline, but due to the steepness of the slope, soil instability and presence of nearby structures, repair was not feasible. During the leak exploration, a 12-inch blowoff pipe failed requiring shut down of the pipeline; water to the Sedro Woolley service area was rerouted through Mount Vernon. Skagit PUD decided to bypass the area and construct a new 1,200 foot 36-inch replacement pipeline on a new alignment. Due to increasing summer demand, the District needed the pipeline replaced expeditiously and water restored by June 30^th. HDR was contracted in April 2015, with three months to restore service. With the extremely tight schedule, several tasks were completed concurrently, including routing, surveying, permitting, design, and geotechnical work. HDR prepared pre-purchase specifications and completed the preliminary design of the pipeline in approximately 2-3 weeks. Skagit PUD staff worked with local agencies, tribes, USACE, and WDFW to obtain Section 404 and HPA permits in two weeks. Pipeline construction was completed and commissioned in a month, 5 days ahead of schedule. Completing the project on schedule required daily coordination with Skagit PUD staff. Due to the emergency nature, this could be considered an “alternative delivery” project, where the owner and engineer jointly developed the plans, specifications, and permitting documents simultaneously. In lieu of a traditional review process, as individual drawings and specs sections were completed, they were reviewed by Skagit PUD. Concurrently, Skagit PUD contacted suppliers to obtain specialty or long-lead items, such as valves, and pre-purchased the item for delivery to the contractor. Addenda were issued throughout the bidding process to advance the drawings as information became available. For example, the pre-purchased pipeline was based on an assumed length, however the shop drawings were not completed until midway through contractor bidding. As the shop drawings were completed, modifications to the final design were resolved by the owner and designer, which facilitated a faster construction pace. This paper will present on the emergency driven “just- in-time” alternative delivery method used to deliver this important emergency repair in a timely manner.

Kansas City Water Services Department (KCWSD) provides potable water distribution, wastewater collection, and stormwater management piping systems in Kansas City, Missouri, serving 170,000 residential and commercial locations and 32 wholesale customers. KCWSD is focused on continual capital improvement, and updating and expanding piping systems to meet the demands of the community. The blue river runs south to north through a significant portion of the KCWSD service area, with water and sewer infrastructure crossing the river at multiple locations throughout the city. Normally a gentle, meandering stream, flows can reach significant velocities during periods of high rainfall and runoff. Over the last 50 years these types of events have led to a shift in the streams alignment exposing a 30-inch pre-stressed concrete cylinder pipe. As a result of significant environmental and permitting issues, KCWSD elected to utilize horizontal directional drilling (HDD) to replace the line. Even with the application of trenchless installation, the site provided many challenges, including limited alignment geometry, constrained work areas, and extremely restricted pipe laydown room. Additionally, the water line is located on land owned by the federal government that due to previous industrial uses contains potentially contaminated soils and ground water. This paper presents the design considerations, including the pipe material selection process, HDD plan and profile design, and extensive environmental planning. It will detail how the attention to detail during the design process allowed for a successful installation that met all of the stringent environmental requirements.

Buried pipelines may be subjected to external live load effects not considered in the initial design during normal operation or during nearby construction activities. External live loads may be in the form of truck loads, construction equipment loads, material stockpiles, blasting waves, or impact of a heavy load dropped over the pipeline. External live load effects may result in damage to the buried pipeline or in failure of previously distressed pipe pieces. This paper discusses various types of external live loads that may be applied to buried pipelines after installation that were not considered in the initial design of the pipe and demonstrates how the effects of such loads can be quantified and mitigated. Further, it discusses evaluation of pipe capacity to support live loads, distribution of surface loads through the soil to the buried pipe, and methods of mitigating the effects of live loads on the pipeline. The paper examines advanced analysis methods used to evaluate the effects of dynamic impact loads and to evaluate the capacity of prestressed concrete cylinder pipe (PCCP) containing broken prestressing wires. It also considers various pipeline materials including concrete, steel, high density polyethylene (HDPE), and fiberglass. Lastly, the paper presents example applications on evaluation and mitigation of live load effects on small and large diameter pipelines.

As with any technology, internal repair of pipelines using carbon fiber reinforced polymer (CFRP) composites has evolved since its first use in the United States in late 1990s, and the current state of the art in design, installation, and quality assurance reflects experiences gained in many projects in the last two decades and the results of extensive research sponsored by Water Research Foundation, several utilities and manufacturers during preparation of the AWWA Standard for CFRP Renewal and Strengthening of PCCP. Changes in practice over the years included development of a load and resistance factor design procedure (LRFD) that accounts for durability and sustained load effects, consideration of design limit states related to strength and stability of CFRP liner as the host pipe continues to degrade, optimization of design layups, improvements in termination details, development of a new watertightness test and acceptance criteria, characterization of curing characteristics, bonding understanding of CFRP bond strength on different substrates, and improvements in quality control and quality assurance procedures. This paper presents the advances throughout the evolution of this repair method and summarizes the current state of the art. It also discusses the expected performance of previously installed CFRP liners that may not satisfy all of the current requirements of the AWWA Standard, and describes potential remediation methods. With the AWWA Standard now nearly complete, the users of this repair method should have the assurance that they are not using an experimental repair of unknown performance, but a well-researched one with negligible likelihood of a major surprise when the repair materials, design, and installation conform to the requirements of the AWWA standard.

The high service pump station (HSPS) 1-1 located at North Texas Municipal Water District’s (NTMWD) Wylie water treatment plant (WTP) 1 is the original high service pump station constructed in 1955. Recent years have seen a substantial investment made by the NTMWD in revamping this plant. Due to changes in the NTWMD’s transmission system, today’s firm high service pumping capacity from the WTP 1 is lower than the treatment plant capacity. The conditions of the 60-year old facility will struggle to meet the future demands. In an effort to maximize use of the existing infrastructure the project team reviewed the pumping capacity and demands of NTWMD’s entire water transmission system from 2015 to 2040 and beyond. It was determined that the other HSPSs at NTMWD’s Wylie WTP could meet some demands currently served by the HSPS 1-1. An approach to add three major piping connections ranging in size from 72- to 14-inch will allow other existing systems to supply the small demands. The existing priming system associated with the horizontal split case (HSC) pumps has proven to be unreliable over the long-term and restricted NTMWD’s ability to utilize clearwell storage. The team analyzed options to maximize the storage capacity of the existing 8 MG of clearwell storage. Options included lowering the pump room floor to utilize HSC pumps or installing vertical turbine (VT) pumps. A review of structural systems, constructability, cost, operation and maintenance lead the team to ultimately choose VT pumps for the project. The project team is working to solve the problem of how to construct VT pumps with barrels inside the pump building originally designed for bottom-suction HSC pumps. The building has limited access points for personnel and pumping equipment. The pump barrels will be below the current finished floor and the team has addressed the unique structural challenges presented by this installation. The WTP 1 and HSPS 1-1 can be shut-down for construction, however this will be limited a single calendar year. The project will require unique solutions to reduce construction time as much as possible including the use of pre-purchasing equipment. This paper will review the steps taken during planning and design to repurpose the pump station and piping connections to utilize the full capacity of the treatment plant, the transition from HSC pumps to VT pumps, the construction limitations and planning associated with major construction within an existing structure.

With the aim of alleviating the endemic water shortage, the San Diego County Water Authority (SDCWA) initiated the Carlsbad Desalination Project. This project was slated to begin delivering fresh drinking water to businesses and residents by the end of 2015. The plant was designed to convert more than 100 million gallons a day (MGD) of raw seawater into 54 MGD of desalinated drinkable water. This is the first of 12 such plants due to be constructed in California. One unique aspect of this project was the 2,000 LF of large diameter fiberglass pipe which was required for construction in certain areas within the facility. This fiberglass pipe ranged in diameter from 24” to 72”. Designing and building the pipeline involved a number of unique challenges. The pipe had to be buried at depths up to 18 feet, sometimes six feet below groundwater level. This required the pipe to withstand the soil and AASHTO H20 traffic loading as well as resist buckling from the external water pressures. The highly corrosive nature of both the seawater and the chemically treated permeate water, with pH values ranging between 2.5 and 10.5, placed severe demands on pipe, joints and fittings. As a potable water application, the pipe requirements included compliance to the AWWA C950 and ASTM D3517 standards as well as NSF-certification and phthalate free resins. The project specification called for a minimum 30-year service life. The contractor, Kiewit Shea Desalination (KSD), outlined an aggressive construction schedule, requiring the fast-paced production of pipe and fittings to specification. As the chosen supplier of Flowtite filament wound fiberglass pipe for the project, the Thompson pipe group arranged to have the pipe produced in Louisiana. The installation of the large diameter fiberglass pipe included many different joint types and installation methods. The pipe manufacturer provided on-site field crews and technical support throughout the phases of the contract as a construction partner. With pre-cut fiberglass lamination kits shipped from the pipe manufacturer, field butt-wraps were performed in place. In other areas on the project, the contractor took advantage of the Flowtite fiberglass pressure rated couplings eliminating many of the 72” field wraps on the project, which shaved valuable time from the tight installation schedule. In addition to the traditional direct bury installation method, 350 LF of 72” fiberglass pipe was installed using a “jack and bore” application. The pipe manfacturer’s engineers worked with the contractor to design a system to fit within the casing of the jacking tunnel. Using the pressure rated couplings, the pipe sections could be joined together within the tunnel, simplifying the installation process and saving even more time. This project was a difficult project due to the aggressive construction schedule as well as the field quality control requirements. This paper will review this unique project from the aspect of construction, installation and inspection.

The City of West Palm Beach, Florida, public utilities department (City) provides water and wastewater services to 120,000 people in West Palm Beach and the Town of Palm Beach (Town). The City’s wastewater collection system includes gravity sewers, force mains, and more than 120 lift stations, with all flows eventually being conveyed to the East Central Regional Water Reclamation Facility through a single force main. The force main is constructed of 42-inch and 48-inch prestressed concrete cylinder pipe (PCCP). The force main was constructed in the mid-1970s under two separate contracts. Price Brothers provided 11,000 feet of 42-inch pipe and 4,800 feet of 48-inch lined cylinder pipe (LCP) for Contract 1 (east of Interstate 95); Interpace manufactured the remaining 13,600 feet of 48-inch embedded cylinder pipe (ECP) for Contract 2 (west of I-95). The history of prestressing wire failures for pipe manufactured by Interpace is well documented. Although the force main has provided nearly 40 years of continuous service, the City recognized the vulnerability of their conveyance system with no redundant pipeline in place. Because the force main passes through the City’s drinking water catchment area, the devastating impacts on public health if a pipe failure and sewage spill occurred made it clear that proactive management of this critical asset was needed. The City engaged Jacobs and Pure Technologies to work together to perform a condition assessment of the entire force main and then develop a rehabilitation plan to address any issues. A condition assessment investigation plan was developed for using Pure’s in-pipe sensing devices to detect leaks, gas pockets, and broken prestressing wires. No leaks were detected, and a limited number of gas pockets were identified. Of greatest concern, however, was the significant number of individual pipe segments (169 total or 23%) of the Interpace 48-inch pipe that had broken wire wrap distress, ranging from 5 to 100 broken wire wraps in a segment. By comparison, few segments of the Price Brothers pipe were found to have broken wire wraps. Based on the degree of wire distress in the 48-inch Interpace pipe segments, the City elected to move quickly to evaluate alternatives for rehabilitation; select a solution; and proceed with design and construction to ensure reliable service, safeguard the City’s water supply, and protect the local environment. This paper will present the results of the condition assessment; a technical overview of rehabilitation alternatives and the selected approach (using cured-in-place-pipe technology); site-specific constraints for performing the work in a highly developed part of the City, including crossing a high-end golf course; techniques and lessons learned for public communications and stakeholder engagement; and project costs.

A segment of a 96-inch diameter prestressed concrete cylinder pipe (PCCP) raw water transmission line operated by the Santa Clara Valley Water District (SCVWD) suddenly ruptured near Casa De Fruta in Santa Clara County, California on August 1, 2015. The failure resulted in the loss of over 20 million gallons of water and the shutdown of the San Felipe System impacted water supplies to both Santa Clara and San Benito Counties for over a month. The emergency repair involved the replacement of the failed pipe segment with a section of cement mortar lined steel pipe, and also included the repair of two distressed pipe segments using carbon fiber reinforced polymer (CFRP). The failed section of PCCP was installed by the U.S. Bureau of Reclamation (Reclamation) in the mid-1980s as part of the San Felipe system of the central valley project. SCVWD is responsible for the maintenance and operation of the system of about 40 miles of the San Felipe system, which consists of tunnels and pipelines ranging from 96-inches to 144 inches in diameter. A 2007 electromagnetic inspection of the Santa Clara Conduit conducted by Reclamation found 15 pipe sections with broken prestressing wires ranging from 5 to 30 wire breaks. Up to 30 wire breaks were found on the now ruptured segment of pipe. Plans made to re-inspect this area within 5 years of the 2007 inspection never materialized due to operational constraints as well as emerging concerns about the possible spread of Zebra Mussels that were present in the Hollister Conduit portion of the San Felipe system. The rapid degradation of this pipe section raised a lot of questions and concerns amongst SCVWD and reclamation staff, regarding the root cause of the failure and the long-term management strategy for PCCP. With assistance from engineering consultants and Reclamation staff, a thorough investigation ensued to determine the cause of the pipe failure. SCVWD is using information from this failure and experience managing PCCP to re-evaluate its current pipeline maintenance program strategies and policies as it pertains to PCCP. The intent of this paper is to provide the reader with an overview of failure and a discussion of the policy issues and changes needed to safely and effectively manage PCCP.

Many documents and guidelines have been written regarding the design of horizontal directional drill (HDD) pipeline installations, but these sources do not address important information that should be collected during the entire trenchless installation process. Only documented observations and drilling parameters can be used to evaluate potential risks associated with the subsurface conditions and drilling practices being utilized. This documentation is also needed to refine drilling practices if difficulties are encountered and can be used to determine the best path forward to mitigate risks. This paper will describe in detail the important and vital role the engineer can play during HDD construction to assist the project team if unanticipated conditions arise, promote successful installations for the owner/operator, and to document subsurface and other conditions that could reduce uncertainty regarding contractual obligations and payment. The paper will also provide examples demonstrating how thorough construction documentation may be utilized to evaluate and mitigate construction risk before problems are encountered and how this documentation may be used to realize efficiencies and keep projects on schedule. Even though this paper focuses on HDD projects, it is our hope the principles discussed within can be applied to other trenchless pipeline installation methods.

DC water utilized a GIS-based renewal and replacement planning system (RRPS) tool as part of a 2014-2015 effort to evaluate sewer system condition and failure risk over time to optimize rehabilitation and replacement funding. To evaluate level of service metrics, risk over time was calculated for each sewer pipe based on GIS-evaluated criticality and condition data collected for 18% of the system. Percent of maximum risk (PMR) was used to compare funding scenarios. PMR indicates how close the average system condition is to the maximum failure risk if all pipes were in the worst condition category. The initial system-wide condition was determined to be a 3.34 out of a possible score of 5, and the initial PMR was 73%. To meet level-of-service goals over a 20-year planning horizon, the target condition was set to below a 3.0, for a target PMR of approximately 50%.

This paper reviews the preliminary design, detailed design and rehabilitation of two large diameter non-circular trunk sewers in Winnipeg Manitoba, Canada. The existing egg shaped, combined sewer trunks were constructed from brick and cast-in-place concrete with sizes of 2030 mm high x 1630 mm wide and 2980 mm high x 1980 mm wide, respectively. The original construction of the oldest pipe (the 2030 mm high egg) dates back to the 1880’s. Previous condition assessment programs highlighted significant deterioration of the pipelines including loss of invert in the concrete host pipe and reverse curvature at the crown in the brick sewer. Given their size and hydraulic significance, their rehabilitation was a high priority in the overall sewer condition upgrading program. A number of rehabilitation methods were considered as part of the preliminary design process, including segmental lining with glass reinforced polymer (GRP) composites, cured-in-place pipe (CIPP), spiral wound PVC, and bonded glass and carbon fibre reinforced polymer (FRP) systems. Each lining product/system was reviewed for its long term structural performance, constructability, quality assurance requirements, flow bypass requirements during installation, and the capital and life cycle costs of the rehabilitation. While a majority of the products reviewed had a long performance history, hand applied, bonded FRP liners are a relatively new concept and required considerable development of non-traditional rehabilitation design concepts. Bonded FRP’s have been deployed successfully in the water market in recent years on critical pipelines; however, the protocol to assess their viability for gravity sewer applications required development to facilitate consideration as an alternative to more traditional rehabilitation technologies. The introduction of multiple competitive alternatives for rehabilitation of pipelines of this size is complex and in this case delivered significant financial benefits to the owner. The paper reviews the preliminary and detailed design process, the procurement process used to assess equal but very different designs and the eventual implementation of the successful alternative, a segmental GRP liner, to deliver a new design life to these two critical sewer elements.

Gilboa Dam, located in upstate New York, impounds Schoharie Creek and forms the Schoharie Reservoir, the northernmost reservoir in the Catskill System of the New York City water supply. To ensure the dam’s continued long-term performance and reliability, the New York City Department of Environmental Protection (NYCDEP) embarked on a reconstruction program to extend the dam’s service life under the current New York State Department of Environment Conservation (NYSDEC) dam safety guidelines. NYCDEP will construct a low-level outlet (LLO) to facilitate the ability to drain the reservoir and meet proposed conservation releases. The LLO consists of two 9-foot diameter tunnels (a water leg and a land leg), ultimately terminating at a new chamber that will release water to the Schoharie Creek downstream. The two tunnels are approximately 2,160 linear feet combined, and will be completed using trenchless microtunneling construction methods, with microtunnel boring machine (MTBM) wet retrieval when the water leg is mined into the receiving site at the reservoir’s bottom. This paper reviews the overall project and then focuses on selected trenchless construction methods for large-diameter microtunneling, MTBM wet retrieval, and underwater construction.

There is no one trenchless technology or pipeline material section perfect for all applications. Determining the most beneficial technique for the rehabilitation of a pressurized, potable waterline represents a huge challenge faced by many designers and owners. Trenchless rehabilitation/renewal methods including pipe material options are expanding and developing in the quickly emerging market. Understanding the different technologies, the project requirements, available products, and the client’s goals are critical to the overall success of the project. Making technology and material selections that are in the best interest of the owner, the project, and the public is an important first step. This paper will provide a case study of the City of Westminster’s Lowell waterline replacement project. We will investigate and review different trenchless technologies, evaluate the selection method, review different pipe material options, discuss additional project complexities, and follow the project through construction and startup, while providing insight and lessons learned on this successful project.

This paper discusses how the challenges of valve replacement were met by the use of design build performance based contracts and in service welding and tapping and plugging techniques. The project requirements were such that the work was to be performed during a limited period of programed a coal gasification plant shut downs from May 5 through June 15. The challenges involved: detailed welding and quality control procedures for the installation of the tapping fittings on a line transmitting liquid carbon dioxide operating at low temperatures and high pressures; using hot diesel oil to purge the highly toxic gas in the isolated section of pipe where the valve was located; special venting methods to dissipate the hydrogen sulfide contained in the carbon dioxide; implementing safe working methods; work located at a remote site and unfavorable climatic conditions. The project was accomplishment by means of the close coordination of two specialty contractors having performance based design build contracts which were completed on schedule and within budget without incidents of any sort.

Trenchless rehabilitations have often been used for repairing aging irrigation pipes. However, in the Japanese design standard for irrigation pipes, the design of the rehabilitations is not prescribed. Many of past studies have not dealt with the mechanical behavior of rehabilitated pipes under eccentric loading, and the behavior has not been understood. In this study, for investigating the mechanical behavior of the rehabilitated pipes under eccentric loading, model experiments and FE-analyses were conducted. In the experiments, the rehabilitated pipes were modeled by placing the aluminum segments around the polyvinyl chloride (PVC) pipes, and the pipes were loaded with the air-bag. The results indicated that the only liners under eccentric loading deformed in oblique directions with the shift of the loading positions. On the other hand, the deformations of the liners with the host pipes were dependent on both the directions of loads acting on the liners and the damage states of the host pipes.

This project is located at the NASA Stennis Space Center is America’s premier rocket engine test complex, where engines for all manned Apollo and space shuttle flights were tested. The main components to this project included replacing a high pressure water cooling system including two complex 102”-112” manifolds connected by a 96” high pressure water transmission pipeline. The first manifold was located at a pump station which feeds water through the transmission pipeline to a second manifold located under the rocket stand. The manifold delivers water up through the rocket stand to spray nozzles that cool the rocket motors. There were over 238 welded pipe connections including over 40 field fabricated compound miters assembled into the existing structure. All field welding was required to meet 100% radiographic inspection including strict assembly tolerances. This paper explores several key challenges experienced during the project including; Adapting fabricated fittings to an existing structure and accommodate pipe alignment through existing penetration openings. Sequencing assembly to minimize re-fabrication of complex fittings. Material delivery schedule and logistics in a changing work environment. The combination of these issues created a mix of difficult conditions which could only be overcome through constant problem solving and cooperation by all parties.

Water main breaks are the most visible consequences of deteriorating water infrastructure. The impact of leaks and their subsequent repair interrupt customer service and directly add cost to water utilities operation. These deteriorating pipes tend to leak and carry a higher risks of catastrophic failure. In many distribution and transmission main networks, leaks can run for extended periods of time without surfacing, adding to subsurface damage and loss of water intended to serve the customer. To minimize water loss and maintain customer levels of service, water system managers turn their attention to leak detection and efficient response time. In 2009, American Water agreed to participate with Echologics on the development of fixed leak detection technology for water distribution systems, using acoustic technology. Additionally, Echologics undertook a program to develop an acoustic-based fixed leak detection technology for use on large diameter water transmission mains constructed of common materials such as pre-stressed concrete cylinder pipe, steel, asbestos cement, cast iron, and ductile iron. After successful field trials, the first commercial hydrant-based fixed leak detection system was installed in 2014. The field trials successfully identified the inception of a leak and tracked its relatively rapid progression over several weeks. The leak was repaired before the pipeline ruptured. In the six months after the first commercial system was installed, it detected 44 leaks, most of which had not surfaced before repairs were made. A transmission fixed leak detection system was installed in Nevada to monitor a large diameter transmission main. The system identified a suspected leak, and has continuously monitored it over an extended period of time. The acoustic profile of the leak remains stable allowing the utility to select the right time to intervene and investigate. These fixed leak detection monitoring technologies drastically improve the way water main leaks are identified, prioritized, and repaired: reduce the risks of catastrophic pipe failures; monitor leak progression, and prioritize field crew schedules; identify non-revenue water from non-surfacing leaks; improve customer service through proactive planning and notification; reduce pipe repair costs including reduction for emergency (overtime) repairs.

This paper describes the water pipeline replacement program for the City of Palo Alto, California water department. The city has about 236 miles of pipe, including older cast iron pipe installed nearly 100 years ago; mostly asbestos cement pipe installed 40 to 70 years ago, and ductile iron, HDPE, PVC, concrete cylinder pipe and mortar lined and coated steel pipe. A pipeline replacement program was developed that factors in ongoing pipe aging issues and pipe seismic vulnerability. The program uses a benefit cost test, for each pipe, to establish the cost effectiveness of pipe replacement, individually for aging, and individually for seismic issues. The benefit cost ratios are added together to develop a city-wide balanced pipe replacement program. By adopting this type of model, a water utility can develop a rational cost effective approach to water pipe replacement. For Palo Alto, the model shows that the annual capital expenditures could be re-allocated to higher priority pipeline replacement, and in fact, a case could be made to slow down the pipe replacement program.

In highly urbanized areas, replacement of aged pipelines by traditional cut-and-cover methods creates numerous negative impacts to the surrounding community and environment due to the destructive and disruptive nature of the replacement method. Fortunately, engineers have multiple alternative methods for improving aged pipelines that help minimize the destructive and disruptive impacts of pipeline replacement. The engineer must consider both open-cut and non-destructive trenchless methods during evaluation of pipeline replacement. Oftentimes, a combination of methods of will provide the least disturbance to the surrounding community and environment while providing the client with a cost-effective and timely solution to meet their present and future needs. Trinity River Authority of Texas, Northern Region (Authority), engaged AECOM to assess and evaluate methods to economically replace 19,440 lineal feet of existing 10- through 36-inch sanitary sewer lines within the Authority’s West Fork Interceptor of the Central Regional Wastewater System. Through field investigations, closed circuit television inspection and analysis of alternative replacement/rehabilitation methods, AECOM developed a plan for the Authority to improve aging pipelines and me8t the projected 2060 flow capacity requirements. The plan also aimed to minimize impacts to the communities and environment serviced by the interceptor system and reduce the Authority’s pipeline maintenance.

Staff at the City of Casselberry, Florida have planned, designed and managed construction of the largest asbestos cement (AC) pipe bursting project in the US. The City wanted to evaluate constructing the pipe bursting projects with municipal forces to identify any efficiency in self performing the work. The City elected to perform an in-house demonstration project for AC pipe bursting with assistance from TT Technologies, McElroy Manufacturing, ISCO Industries and the Alliance for PE Pipe. The City selected a suitable site for replacement of approximately 600 LF of 6” AC pipe with 6” HDPE. Preliminary design included project site evaluation, existing pipe access and staging area. Data collection defining the existing pipe conditions started in order to develop a detailed pipe bursting plan that provided locations of entrance/exit pit, service connections, fire hydrants and mainline connections. Two trial pipe bursting runs were required to provide a level of comfort for the staff who would be performing a third pipe bursting run as a demonstration project for the surrounding communities. This paper will detail the steps necessary to ensure success for any pipe bursting project, no matter what the size. City staff worked with McElroy Manufacturing and ISCO Industries in the week preceding the scheduled burst to perform certified butt fusions. City staff worked closely with TT Technologies staff to work with the equipment required to perform pipe bursting. City staff performed every action required to plan, design and successfully construct a pipe bursting project in full compliance with Environmental Protection Agency (EPA)’s current regulations surrounding AC pipe bursting.

Advanced fiber reinforced polymer (FRP) systems have been widely used for the structural strengthening and rehabilitation of existing buildings and bridges for decades. Such as the engineering community has accepted these systems as viable, long-term strengthening solutions for structural bridge and building elements, so too have they accepted them for the rehabilitation and strengthening of pipelines. This relatively novel FRP technology is extremely conducive to application in pipeline rehabilitation and strengthening; its unidirectional strength properties and malleable form make precision design and installation of the system efficient and cost-effective in many applications. As the design of FRP pipeline strengthening systems becomes more refined, so too must the inspection methods used to assure these systems’ proper installation and post-installation performance. Various experiences have been compiled from nuclear, industrial, and municipal installations on steel, reinforced concrete, and pre-stressed concrete cylinder piping. Resulting conclusions and best-practices on processes ranging from monitoring of in-field environmental conditions, to critical points of structural observation during installation, and proper methods of post-cure imperfection detection and remediation will be defined and presented within this paper. The aim of this work will be to inform end-users and installers alike of necessary inspection and observation steps required during installations to ensure the safe and proper performance of FRP pipeline strengthening systems.

The Goleta West Sanitary District (GWSD) had a need to upgrade their 840 mm (33 inch) Mesa Road Trunk sewer to a new 1050 mm (42 inch) sewer. The original trunk sewer, constructed in the 1960’s, was also routed through wetlands and so the new trunk would relocate the new sewer in Mesa Road (a main access to the University of California in Santa Barbara “USCSB” campus). Design began by CDM Smith in 2009 and was originally intended to be constructed using open trench construction. Based on geotechnical data supplied by Fugro West, Inc., which indicated poor soils and high groundwater in certain areas, it was decided that a large portion of the project 488 m (1,600 feet) could be constructed using microtunneling and Hobas pipe, so the design shifted to include this concept in final design. The project also includes a large amount of open trench construction 238 m (780 feet) which required an extensive permitting effort, but this paper only addresses the tunneled portion of work.

Utility owners rely on their large-diameter transmission mains to serve as the backbones to their distribution systems. The consequences of their failure and other critical mains include disruption to service for a large number of customers, personal property damage, and traffic disruptions just to name a few. Replacing these pipes before they fail can reduce these consequences; however, replacement is not always the best alternative. There are several considerations that need to be reviewed before the decision to replace is made, including physical location (middle of a 4-lane highway, under a railroad, etc.), as well as other social and environmental concerns. In lieu of replacement, water main rehabilitation techniques are becoming viable options for extending the useful life of high consequence mains. The purpose of this paper is to: outline the rehabilitation methods and materials applicable to high consequence mains; present a strategy for selecting rehabilitation methods; and present a few case studies from recent projects where rehabilitation methods were used in lieu of replacement. The types of rehabilitation methods that will be discussed include: slip lining with close-fit liners and grouted-in-place pipes; cured-in-place pipe (CIPP) liners; carbon fiber reinforced polymer (CFRP) wraps and liners; other spot and joint repair systems and seals; and spray-on coatings and liners. The advantages and limitations of each method will be outlined and a strategy for selecting the appropriate methods will be presented based on selection criteria such as: structural requirements; service and branch connection reinstatements; flow capacity needs; pipe accessibility; contractor availability; diameter and length requirements; etc. Transmission and other critical mains vary in material of construction depending on several factors, including hydraulics and site conditions. Typical pipe materials include cast iron (CI), ductile iron (DI), prestressed concrete cylinder pipe (PCCP), and steel. Common failure modes for each of these types of pipes vary significantly, ranging from leaking joints to catastrophic failures due to prestressed wire failures and external corrosion. Given these variations in potential failure modes, the types of rehabilitation also vary. Two case studies will be presented that include rehabilitation on various pipe materials including concrete pressure pipe, steel, and cast iron, each experiencing a different potential mode of failure, as highlighted previously. The purpose of discussing these particular case studies is to expand upon the idea of how different types of pipes experience different modes of failure and how rehabilitation techniques can be tailored depending on the pipe material, site conditions, and potential failure mode.

The Metropolitan Water District of Southern California Metropolitan currently owns and operates the Etiwanda pipeline. The Etiwanda pipeline serves as the penstock to the Etiwanda Hydroelectric Power Plant. An inspection in 2008 revealed extensive damage to the cement mortar lining of the 12-foot diameter welded steel pipe. The damage was so significant that the mortar lining needed to be removed and replaced with a new lining. To repair the pipe several lining alternatives were considered. The linings considered were: Cement mortar lining, reinforced cement mortar lining, polyurethane and epoxy. After evaluating the usage of the pipeline it was determined that only flexible linings should be considered. Metropolitan then studied other similar construction projects where flexible lining was installed in the field. It discovered there was very little precedence for lining such a large diameter pipe in place with polyurethane or epoxy. For this reason Metropolitan decided to initiate a pilot lining project in the Etiwanda Pipeline. The pilot project was approximately 2,800 feet long. This pilot project required the contractor to install various types of linings, using various surface preparations, and in various thicknesses. This project demonstrated that both polyurethane and epoxy can be installed properly in a buried pipeline in the field. The installation demonstrated that a required minimum temperature of 70 degrees and a maximum humidity of 35% can be held for 48 hours inside a 12 foot diameter pipe. The installation also demonstrated that the white metal blast can be obtained and sustained for 48 hours. These conditions allow the pipe to be lined with either polyurethane or epoxy. The polyurethane is the preferred liner because it has virtually no cure time.

Mormon Flat Dam is one of four hydroelectric projects on Salt River, Arizona. The smaller hydroelectric generating unit on this dam utilizes a 120-in. (3048 mm) diameter 5/8-inch (16 mm) thick riveted steel penstock. Ultrasonic testing results indicated that the penstock had lost as much as 50% of its thickness in certain areas. After considering various alternatives, SRP’s engineers chose to repair the pipe with carbon FRP. The repair area included two 96-inch (2440 mm) pipes about 15 feet long (4.57 m) that merged into a single 120-inch (3048 mm) 45-ft long (13.72 m) segment. The geometry of the Y-connection complicated the repair. A drop in elevation of nearly 20 feet (6.1 m) halfway through the repair section provided additional challenges to the project. The pipe surface was prepared by removal of nearly ½-inch (13 mm) thick coal tar before blasting the surface to a near-white condition. The rivets proved to be longer than anticipated, adding further difficulty in smoothing those regions for a gradual transmission in profile. The strengthening of the pipe included application of 5 layers of FRP based on the design-build contract. A total of 11,000 ft² (1022 m²) of carbon FRP was installed within the allotted 3-week time frame. A final abrasive resistant coating was then sprayed over the FRP for additional protection against any small debris that may enter the penstock. The repair is expected to provide a long-lasting maintenance-free penstock for the dam.

This paper presents Santa Clara Valley Water District’s (SCVWD) approach to addressing their first high profile water main failure including their application of failure investigation, emergency condition assessment, pipe replacement, and the use of carbon fiber-reinforced polymer (CFRP) for structural rehabilitation.

The Gongbei Tunnel is currently being constructed in Zhuhai, with a combination of curved pipe jacking roof for ground support and ground freezing waterproof applied, to guarantee the tunnel traverse under the Gongbei Port. This pipe roof is comprised 36 steel curved jacking pipe strings of 1620 mm diameter with 355mm~358mm gap between adjacent strings. The pipe jacking construction has been faced with various challenges due to the site conditions of multiple soft soil and high groundwater pressure. These challenges include risks of excessive soil deformation, possibility of path deviation, excessive jacking force, leaking of pipe joint seals and failure of gasketed launch seal and reception. This paper will provide an overview of this project and summarize the most challenging aspects they faced. The relevant techniques applied during construction, such as selection of pipe jacking machine, controlling trajectory of close curved pipe jacking, sealing test of pipe joint, pipe jacking mud in rich salt multiple formations and pipe jacking reception device under high underground water pressure are introduced in detail last.

During the past 5 years, technologies related to inspection, assessment and trenchless renewal of the wastewater conveyance system enterprise have grown and improved dramatically. These changes come with the challenge of processing enormous quantities of detailed data information regarding the condition of each asset. For sanitary sewers, this includes information associated with the structural, hydraulic, and maintenance-related conditions. This paper will present a summary of a tiered (or step-wise) approach that has been used by a number of cities and wastewater utilities to elevate their sewer renewal and improvement programs using a risk-based methodology to select the best trenchless solution(s). The presentation will highlight how utilities are using asset management platforms to process and manage data from sources such as CCTV, sonar imaging, 2-D laser profile, 3-D imaging, flow, H2S, and pipe-penetrating radar and apply predictive models to identify highest risk assets based on likelihood and consequence of failure. The paper will also help conference attendees answer the following basic questions: When and how should field diagnostic testing and inspection technologies be used to find and fix high-risk assets (when is “enough” enough)? What software platforms are needed or available to post-process this information efficiently? Can I use the results of an asset management program to pick the appropriate trenchless technology? What are realistic cost metrics to implement such a program and what kind of savings can I expect over traditional approaches? What additional I/T resources are needed?

When the Connecticut Department of Transportation (CTDOT) examined a 50 year old 8’-10” span by 6’-1” rise steel structural plate pipe arch that carries an unnamed brook under I-91 in Middletown, CT, they found a corroded structure that had served its purpose since the original construction of the interstate in 1964. It was, however, decidedly in need of immediate repair or replacement. The CTDOT considered various options and decided to line it with an aluminum tunnel liner plate pipe arch. It would be designed using AASHTO LRFD structural design methodology. The CTDOT immediately awarded a contract to Arborio Corporation using the emergency declaration process. Installation included the full removal of the invert, along roughly one-third of the length, while all travel lanes and the shoulders of the Interstate remained operational 20’ above the work. The tunnel liner plate method allowed for safe construction practices and a full structural rehabilitation. The estimated savings using this method is in excess of $3M.

The utilization of carbon fiber reinforced polymer (CFRP) to strengthen prestressed concrete cylinder pipe (PCCP) is a relatively young pipe rehabilitation technology, dating back to the mid-1990s. However, in the early 2000s numerous agencies with distressed PCCP started to utilize this technology to spot repair severely distressed sections of PCCP in their systems. Miami-Dade Water and Sewer Department (WASD) sustained several failures on various PCCP lines. To help prevent future failures, they initiated an inspection program of all large diameter (≥36-inch) PCCP lines in 2010. They proceeded to rehabilitate the severely distressed pipe sections with CFRP. As WASD continues to repair additional pipe sections, an inspection of the previous CFRP repairs is performed. During these post-installation inspections, various deficiencies in the CFRP system were observed in several pipelines. Typically, the CFRP system is designed to provide a 50-year life; however, only a limited warranty is issued by the manufacturers. This paper will focus on the importance of post-installation inspection of CFRP repairs and describe the observed deficiencies. Additionally, the paper will discuss apparent short comings in typical CFRP specifications.

Continuous functioning of water pipeline systems in the face of a multitude of threats is imperative to economic prosperity and human survival. This general capability is often referred to as system resilience. While there have been some efforts devoted to incorporating resilience in the design of new water pipeline systems, limited attention has been given to resilience in rehabilitation planning of existing water systems, except in regions that are prone to natural hazards such as earthquakes. This paper presents a rehabilitation planning framework that considers system resilience as one of the principal objectives. Resilience is defined as the ability of the system to withstand stresses and cope with failures. While past performance data is leveraged to estimate the integrity (or robustness) of the system, various rehabilitation planning alternatives are evaluated based on the redundancy that they add to the system. The proposed framework is demonstrated using asset data and past performance data of 10-years obtained from a coastal water utility. This paper provides general guidance to utility managers and design engineers in embedding resilience in the rehabilitation planning and design of water pipeline systems.

The Val Vista water transmission main rehabilitation 2014 Project was a construction manager at risk (CMAR) project for the City of Phoenix (City), which included both pre-construction and construction services for the rehabilitation of 6,262 linear feet of existing prestressed concrete cylinder pipe (PCCP). This pipeline delivers approximately 220 million gallons per day of potable water to as much as sixty percent of the City’s population. As the City’s most critical pipeline, maintaining its uninterrupted service is critical. Work on this main could only occur during low demand months from November through April and required extensive coordination with all water production facilities across the City. To gain access to the pipeline, located twenty feet below grade, access portals were created by excavating and installing specialized slide rail shoring. Two existing twenty foot segments of pipe were demolished to allow access to the interior of the pipeline. Once this portal development was established the rehabilitation of the existing 90-inch pipeline could commence. The trenchless technique for slip lining the transmission main is accomplished by installing new steel pipe liners. For this project, 84-inch solid-can and 87-inch split-can liners were installed. Once the liners were installed and welded together, pressure grouting of the annular space between the liner and the existing pipe was completed. After annular space grout was complete, a cement mortar lining (CML) was applied to the new liner pipe. This process essentially creates a new pipe within the host pipe. After the CML was completed, closure pipe segments were installed where the existing segments were originally demolished, and then protected with a structural encasement. The portals were then backfilled using a combination of low strength CLSM, native materials, and select fill. The disinfection, flushing, and startup of the main was then performed. Final surface restorations included asphalt paving, curb & gutter, and landscape replacement, in the affected areas.

Seismic events may drastically damage buried pipelines affecting economy and public safety. ASCE provides design guidelines for analysis of buried pipelines under different seismic loads. This study evaluated performance of steel pipelines under seismic loads when embedded in different backfills using a 3D finite-element model (FEM). Results were compared with ASCE design guidelines and the effects of different model parameters were evaluated. These parameters included soil-pipe interface, boundary conditions, and model dimensions. After setting the model parameters to match the maximum pipe stress predicted by ASCE design guidelines, effect of using a controlled low strength material (CLSM), in lieu of compacted soil, as a backfill material was evaluated. The same model was also used to evaluate the effect of having a fixed connection at one end of the pipeline since ASCE design guidelines are based on the assumption of infinitely long pipelines. It was concluded that a 3D FEM model with carefully selected parameters can match the ASCE design guidelines and further be used to test the effect of various scenarios which cannot be evaluated using these guidelines.

The Santa Clara Valley Water District (District) initiated the Penitencia delivery main and penitencia force main seismic retrofit project (Project) to improve the seismic resilience of three critical water supply/delivery pipelines that serve the District’s Penitencia water treatment plant (WTP) in San Jose, California. The most important objective of the project was to retrofit the pipelines to protect the life-safety of nearby residents and the noble elementary school. The Project planning phase began in 2013 and final design was completed in December 2015. Construction is scheduled to start in April 2016 and is scheduled to be complete in December 2017. This project included the following key innovations: design for large landslide displacement: the landslide and seismic hazard evaluation estimated the landslide displacement as 7.7 feet (seismic) and 1.7 feet (creep) for a total displacement of 9.4 feet over the 50-year design life. sophisticated finite element modeling: The project team developed the design with a sophisticated 3-D model of the landslide and pipeline interactions. Full scale testing of joint and collar performance: Kubota Corporation performed a full-scale test of the 60-inch and 72-inch pipelines to verify the maximum rotation and moment capacities. Novel application of earthquake resistant ductile iron pipe: There have been a few pilot project installations of small diameter earthquake resistant ductile iron pipe (ERDIP) in the United States to date; however, the 60-inch, 66-inch, and 72-inch pipelines will be the first large diameter installation of ERDIP in the US. This project is unique because it required designing for a large displacement along the axis of pipelines which load the pipelines in compression. This project also has a high visibility within the community because of the risk of failure and proximity of the project within the residential neighborhood.

An evaluation of the performance of restrained joint ductile iron pipelines after seismic events with emphasis on returning the system to service for the promotion of the public welfare. Experience has determined that restrained joint ductile iron pipe has a lower vulnerability to ground deformation incurred during seismic events realizing a piping system that can be returned to service with minimum remediation. Public welfare is achieved through the prompt return to service of waste water and potable water conveyance systems as well as the short term return to service of fire protection systems. The discussion addresses continuing evaluation efforts through monitored pipeline installations. The subject addresses the performance of ductile iron pipe manufactured in accordance with ANSI/AWWA C151/A21.51 with restrained rubber gasket joints in accordance with the applicable sections of ANSI/AWWA C111/A21.11.