Pipelines 2018: Planning and Design

Intake facilities have more impact on the operation, maintenance, and value of a water system than any other component. The location, type of inlet structure, and conveyance conduit directly controls water quality and quantity, which controls the design of the treatment and delivery facilities. Further, intake facilities typically represent the largest unit cost ($/MGD capacity) than any other component in a water supply system. Before any consideration can be given to the intake location and design, the water quality and quantity parameters must be determined. For the Great Lakes’ intakes, water quality is usually a more significant issue than the available quantity, and the best source of water may not be the closest. Intake facilities include three primary components: the inlet structure, pipeline, and shore facilities. A case study will be presented to illustrate the challenges, such as icing, ship traffic, invasive mollusks, and marine construction. This new intake system consisted of 6,900 feet (2,103 m) of pipe, two submerged timber cribs, and two stop-log chambers. Approximately 2,000 feet (610 m) of the pipeline was installed by tunneling with the remaining installed by trenching.

The Luce Bayou Interbasin Transfer Project (LBITP) was commissioned by the Coastal Water Authority (CWA) as a regional water supply project to convey water from the Trinity River to Lake Houston. The LBITP consists of a raw water intake structure and pump station, approximately 3 miles of dual 96-inch diameter transmission pipeline, pig retrieval station, flow distribution basin, sedimentation basin, and approximately 24 miles of canal. The pig retrieval station consists of an underground vault housing expanded pipe sections to install steel cables for stopping the pipe cleaning pig valves and decant line. The vault is covered by a metal building with removable sections to facilitate access. Downstream of the vault, a concrete wye structure serves two purposes: (1) it contains grooves for stop logs to stop the pig once it exits the vault and provides open access for pig retrieval, and (2) it centers the flow of water and sediment entering the flow distribution basin. Design considerations included vault covering with a removable building, a Victaulic coupling system, a pig stopping system, and a flow distribution system design confirmed with computational fluid dynamic (CFD) modeling.

In the U.S. oil and gas world, produced water (or sometimes called saltwater) is a major bi-product of drilling and completion of a well. Saltwater is a naturally occurring component down in the far depths of the earth that comes to the surface as a result of drilling and completing an oil and gas well. After a well has been drilled, high volumes of water are injected into the well to pressurize, fracture, and stimulate the production of oil and gas from the very far depths of the well, and bring it to the surface where it is sold to market. The saltwater bi-product must be safely disposed of either by trucking offsite to a disposal location or by piping it offsite to a disposal center. In most cases, piping of the water is more economically feasible than trucking the water offsite. If the water cannot be safely disposed of offsite, a well must be shut in resulting in thousands of dollars of lost revenue. Therefore, it is imperative to any producer that owns and operates a saltwater gathering system to properly design, plan, optimize, and operate the gathering system to avoid shutting in a well, and loss of revenue. Most saltwater gathering systems are large and complex requiring extensive work to insure the system runs efficiently and smoothly to not require a well to be shut in because the system cannot handle the saltwater that is produced from the well. In order to more efficiently design, plan, optimize, and operate a complex saltwater gathering system, a hydraulic modeling software system is a great asset and benefit to any producer who wants to insure they have an accurate and reliable tool. The purpose of this paper is to provide real world applications of using a hydraulic modeling software, to design, plan, optimize, and operate a 200,000 bpd produced water gathering system.

The Region of Peel is implementing new design and construction standards for sanitary sewers. One of the first projects to implement the standards is the twinning of the East Brampton Trunk Sewer. The project includes approximately 5.4 km of new 1500 mm to 1800 mm diameter sanitary sewer and several custom chambers to enhance operational flexibility. Components of the standards implemented include pipe specification, pressure testing of large diameter piping and chambers, waterproofing and corrosion protection of precast and cast-in-place concrete structures, and man access considerations. This paper describes the approach taken in implementing the new standards and the challenges, resolutions, and lessons learned during construction of the project.

The Southwest Edmonton Connector (SWEC) project is meant to replace one of ATCO Pipelines existing vintage high-pressure pipelines with 21 km of 508 mm diameter pipeline. The Whitemud Creek Crossing is a horizontally directionally drilled installation beneath a 30 m deep ravine lined with unstable slopes with existing infrastructure. Along this ravine are exposed seams of coal that were extensively mined which created hundreds of meters of room and pillar mine works which extend in all directions centralized at the Whitemud Creek. An extensive geotechnical investigation was planned and executed which included seismic tomography to determine the potential for voids and presence of existing mine works. A ground improvement plan was developed and executed with a total of 105 grout holes. Borepath design, hydrofracture, and pipe stress analysis were supplemented with a parametric study using the finite element method to optimize the pipe wall thickness within the limits of the ground improvement zone. This paper outlines the design and construction methodology utilized to successfully complete the 700 m long crossing of the Whitemud Creek.

The Iowa formula is one of the most traditional methods used to estimate the deflection of a buried flexible pipe. Separate sewer system pipelines, set in one trench, can be found at intersections these in one trench often located at crossroads. The traditional Iowa formula however, does not account for the deformation of two pipes placed in one trench, this information critical for road and other infrastructure design. This paper presents the results from testing a new method to set up separate sewer pipelines when buried in parallel in sand. The results have been used to validate an improvement to the Iowa method used to calculate the deformation of flexible pipes set in one trench, one over the other, or when the pipes intersect at different levels, again within one trench. The improved method was tested by lab experiments through the application of a series of loads on two pipes laid in one trench, using a hydraulic rig to simulate road traffic (live loads), this compared to the results when setting one pipe in a trench. Two PVC pipes and the soil properties of the trench were examined. The results have been compared to experimental data, the two pipe system integrity validated against the standard requirements for flexible pipes buried in soil.

Pipeline bridge crossings are the nexus of two prevalent forms of infrastructure and must be evaluated and designed with both in mind. Bridge crossings present a unique set of design challenges compared to a traditional underground piping system. These include thermal gradients, external bracing, weathering resistance, bridge movement, and other factors that all influence the design process. While extensive design guidance exists from ASCE and other organizations with regard to stress analysis of the piping itself, the same depth of information is absent with regard to overall pipeline system design. This paper will present an overview of methodologies for pipeline system design of bridge crossings using either ductile iron pipe or welded steel pipe (the two most commonly used piping materials for both large and small diameter bridge crossings). Advantages and disadvantages of each material and the various joints available for both will be highlighted and reviewed.

The South Hartford CSO Tunnel (South Tunnel) project is a significant component of the Metropolitan District’s SSO/CSO control program in Hartford, CT. The South Tunnel is a 4-mi.-long, 18-ft internal diameter wet weather tunnel that will eliminate sanitary sewer overflows (SSOs) and control combined sewer overflows (CSOs). Sewer diversion structures will be constructed at each CSO and SSO to replicate or intercept overflows and divert them to near-surface consolidation sewers. These consolidation sewers will in turn, discharge to one of eight hydraulic tangential vortex drop shafts which will convey the flow to the deep rock tunnel. Once in the tunnel, the sewer overflows will be stored and then pumped to receive proper treatment. The project was split into five construction contracts totalling approximately $410 MM. Advanced utility relocation and electrical upgrades have been completed. Construction of the deep rock tunnel, shafts, and deep rock connector tunnels are underway. The 35-ft diameter launch shaft has been excavated. The 70-ft diameter pump station shaft has been excavated to 80 ft below grade. The tunnel boring machine (TBM) has arrived onsite and is being assembled. By July 2018, the launch shaft, pump station shaft, fifteen drilled shafts, and the starter and tail tunnels should all be excavated and the TBM should be beginning its journey. This paper and presentation will focus on the design basis, progress to date, and lessons learned.

The Toronto Ashbridges Bay Treatment Plant Outfall (ABTPO) project is anticipated to be the largest wastewater treatment plant effluent outfall in Canada. This paper describes the design criteria and design approach for a major component of the ABTPO: the riser pipes and ports. A 10-step construction sequence was established for efficient and safe riser pipe and port installation. Alternative materials were evaluated based on materials strength properties, flow resistance, constructability, and corrosion resistance. Biological fouling mitigation alternatives for the riser pipes and ports were evaluated for both microfouling (biofilm) and macrofouling (zebra mussels) potential. Other important design considerations include field investigations, geotechnical conditions, external and internal design pressure scenarios, pipe wall thickness selection, riser-to-tunnel connection details, and riser pipe and port joint connection methods. Performance requirements for marine construction methods such as marine navigation, drilling operations, surveying, riser pipe annulus grouting methods, and leakage testing were also established.

In support of its goal to secure a long-term and sustainable water supply, the town of Castle Rock, Colorado, successfully negotiated inclusion in the regional WISE (water infrastructure and supply efficiency) project requiring the construction of a water transmission line to the South Metro WISE Authority project. The five miles of waterline was constructed within an existing Xcel Energy utility easement from the Parker Water District distribution system at Outter Marker Road to the Ray Waterman Regional Water Treatment Center. Material selection for the 5-mi 36-in. connecting line presented a significant challenge considering the overhead Xcel Energy power line along the alignment. Any metallic components of the line would require cathodic protection. The undulating terrain and rocky soils presented further challenges, including road and drainage basin crossings, requiring three horizontal directional drills (HDD), ranging from 700 to 1,700 ft in length. Installation was completed using a hybrid PVC approach, consisting of fused PVC pipe for all trenchless and restrained pipe and bell-and-spigot PVC for all else. This paper will detail the project’s design and construction phases, expanding on the material options debated, and how the combination of fused and belled PVC joints minimized cathodic protection requirements and overall project costs.

This paper discusses pipe material specification used by the city of Toronto to construct large diameter (generally diameter 750 to 2,250 mm) transmission mains. Lower diameter distribution mains are generally constructed using PVC and ductile iron. Prior to 2013, Toronto only used to permit welded steel concrete encased pipe for large diameter transmission mains. However, after 2013, Toronto permitted other pipe materials for transmission mains. Pipe materials such as prestressed concrete pressure pipe, HDPE, PVC, ductile iron, stainless steel have been used for large diameter transmission mains in various municipalities in Ontario. Each pipe material has individual pros and cons, which can be mitigated depending on the circumstances. While opening up the pipe material, it was felt that a specification for the transmission main pipe material was essential to ensure 80–100 year service life of the transmission main irrespective of the pipe material. This paper will present the process used to develop the new Toronto Large-Diameter Watermain Standard Specifications, the risk-assessment method used to determine localized allowable materials and joints, restrictions, and Toronto’s special requirements. The paper will summarize Toronto technical standard TS7.80, a public resource available to all.

Multiphase flow regimes such as liquid slugging in gas flow or gas blow through in liquid flow can produce high thrust forces particularly at elbows. In addition, a frequently neglected issue is the potential pipeline collapses caused by a unique multiphase condition of column separation. This paper presents the methods in calculating resistive force on elbows and summarizes the components of the thrust load produced by either pressure or momentum changes. This important distinction seems to be important in understanding the real causes of the pipe dynamic loads and consequently, in the design of the structural support for the pipe system. The second part of the paper focuses on the evaluation of pipeline collapse due to negative internal gauge pressure produced during column separation. The results presented in the paper provide guidance and sense of magnitudes on dynamic pipe loads experienced in transient multiphase flow.

The sequence of tightening bolts and controlling torque are very important to the assembly of flanged pipe joint connections. Among other factors, proper-flanged joint closure depends on applying the correct amount of gasket load and achieving uniform load around the joint. Since the load applied to the joint by the bolts is difficult to measure directly, torque is used as a convenient way to approximate the desired load. This paper will review torque calculations as they apply to ANSI/AWWA C207 flanges and the new AWWA web-based interactive tool, including examples for torque calculations as described in the recently published, AWWA Manual M11, Steel Pipe—A Guide for Design and Installation, 5^th Edition.

Trenchless construction techniques eliminate the need to open-cut roadways, railroads, canals, city street intersections, and other locations where trenches for pipe and casing installations are inconvenient or can impact the general public’s safety. Large diameter (24 inch and greater casing) trenchless techniques include microtunneling, pipe jacking, auger boring, and pipe ramming. Steel casing is often the product of choice for these techniques due to its strength, toughness, flexibility, resistance to high jacking forces, and butt-welded joints. Mechanical interlocking joints have steadily gained acceptance and use as a substitute for butt welded joints on steel casing pipe. The interlocking joints eliminate the need for time-intensive field butt welding and the associated higher cost. Fully machined interlocking connectors manufactured per ASTM A1097 are preinstalled in the factory and when joined in the field, are flush with the outside diameter of the pipe providing no additional drag or increased jacking force requirements. This paper will discuss the use and installation of mechanical interlocking field joints for casing installations with case histories. The paper will assist engineers and owners with casing design and specification considerations, and discuss the efficiencies gained with the various styles of innovative mechanical interlocking joints.

When the Board of Directors at DC Water and Sewer Authority (DC Water) decided to start designing projects with in-house staff, DC Water identified the resources necessary to create something from nothing. After five years of increasing capabilities DC Water has an entirely self-sufficient design team. The team started with a supervisor and five employees from other parts of the organization. Today there are 18 individuals on the team, including surveyors, CAD technicians, engineers, supervisors, and an administrative assistant. This team produces bid packages for one of the Board's key performance indicators: replace 1% of linear water infrastructure every year. The team also produces designs for various sewer rehabilitation projects and emergency responses. Creation of this team required multiple change efforts, working like a step function; every couple of years a new set of required skills and capabilities were added to the team's responsibilities. Working in partnership with consulting engineers yielded a successful model even though ultimate success meant fewer projects would be designed by those consulting engineers. This paper and presentation will share the step function of skills we used to create the group over the course of several years. It will also share the challenges we experienced and the solutions to some of those challenges. The paper and presentation will also explore the benefits and downsides to having a design team within the owner organization. Lastly, the paper will share ideas on how to do it better next time. If any other utility owners are considering a similar change, they can use the information provided to evaluate their options, manage risks, and possibly avoid some of the growing pains. Hint: you won't avoid all the problems and it never gets easy.

This paper will discuss the challenges of designing pipe from a deep tunnel pump station and the solutions developed in the design to accommodate them. The LMRDP CSO Tunnel Dewatering Pump Station will dewater a nine (9) mile long, 30-foot diameter tunnel with a storage capacity of about 240 MG. Located 250 feet below grade, the cavern-style pump station piping required complex design considerations including differential head in discharge piping, space limitations in the tunnel and shafts, pipe coatings and linings for buried and exposed piping, constructability, and pipe joint design for buried pipe in fill and piping in the tunnel and shafts. The improvements are part of the Metropolitan St. Louis Sewer District’s (MSD) implementation of Project Clear, a program to reduce combined sewer overflows (CSO), and eliminate sanitary system overflows (SSO) in compliance with their EPA consent decree. The 100 MGD pump station will contain four (4) 20 MGD pumps, three (3) 10 MGD pumps, and two (2) 5 MGD pumps, with the ability to accommodate a future capacity of 150 MGD. Discharge piping within the pump station and shaft consists of eleven (11) pipes ranging from 30-inch to 4-inch diameter. Buried forcemains are 54-inch and 24-inch. Suction pipes range from 84-inch to 30-inch diameter.

To make way for the redevelopment of Denver Water’s 35 acre Operations Complex, a 54-inch reinforced concrete cylinder pipe (RCCP) water transmission conduit required relocation, including the addition of an isolation valve and two new 90-degree bends to realign around planned buildings. The joints in the 1930s-era pipe were not restrained so the design required extensive analysis of thrust forces and evaluation of thrust restraint alternatives to prevent movement in the existing joints of the 80 year old Conduit No. 18 pipeline operating at 200 psi. The upstream end of the relocation connected to a section of pipeline that passed below multiple active railroad tracks. Relocation to replace the existing pipe under the railroad was not feasible. Traditional thrust blocks were not feasible due to site constraints and subsurface conditions. To address the thrust restraint, the segment beneath the railroad was sliplined with steel pipe designed to carry the full thrust of internal pressure and external loads from the rail traffic. This paper discusses the thrust force analysis, thrust restraint alternatives that were considered, and site constraints that had to be accommodated to develop a successful solution for the necessary relocation.

The Washburn Second Feedermain Project is a 900 mm (36 in) diameter potable water feedermain that will extend a total of 3,923 m (2.4 mi) and will provide additional supply and redundancy to Halton Region’s (Ontario, Canada) water network. The new 900 mm (36 in) diameter feedermain interconnects with the existing 1,050 mm (42 in) diameter Washburn Feedermain which is currently the primary supply of water to the Washburn Reservoir and Pumping Station. The interconnection between large diameter critical feedermains presents several design, construction, and commissioning challenges. This paper presents the process and challenges associated with designing, constructing, and commissioning the interconnections between the existing and new large diameter feedermains.

The need for urban sewers continues to grow due to numerous causes, such as population growth, climate change, and the desire to prevent sewage from discharging to the environment. To meet this need, many owners are installing tunnels as part of the solution. Surges and other transients, which are predominantly a wet weather feature, are more common in large-diameter sewers in deep tunnels than near-surface sewers. While the hydraulic drivers of surges and transients are well-documented and generally well-understood, the role of air in inducing these surges and geysers is less so. Pneumatically-induced hydraulic surges can result in geysers, which are violent eruptions of sewage that occur at the ground surface. These geysers can result in numerous potential health and safety concerns, such as damage to infrastructure, discharges of sewage to the environment, displacement of protective manhole covers, trip/fall hazards, etc. Through the use of real-world examples, this paper examines the causes and effects of pneumatically-induced hydraulic surges and geysers in sewers. The associated presentation includes several videos of real-world geysers, as well as modeling result animations from surges in tunnel systems. These videos and animations provide the practitioner with a solid grasp of the causes and effects of air in tunnel systems under wet weather events.

The Zone 4 Feedermain project was identified in Halton Region’s (Ontario, Canada) 2011 Sustainable Halton Water and Wastewater Master Plan. It is required to supply water to the proposed Zone 4 Reservoir near No. 5 Side Road and Trafalgar Road in the town of Halton Hills which will serve Zone 4 in the town of Milton and ultimately south Georgetown (town of Halton Hills). The feedermains comprise approximately 3,100 m of 1,200 mm diameter prestressed concrete pressure pipes (PCPP), 7,070 m of twin 900 mm diameter PCPP, and 2,760 m of 900 mm diameter PCPP. This paper showcases an innovative design of adopting a twin watermain pipe system to serve both the short term and long term operating needs of Halton Region. The twin pipe design enabled Halton Region to maximize the use of their existing infrastructure, while providing the network with system redundancy to meet future requirements.

AECOM, on behalf of the city of Calgary Water Supply Division completed a comprehensive system wide hydraulic transient analysis of two pressure zones, including the second largest zone within the system. The study objectives were to determine areas at risk of and mitigation for high and low transient pressures. Primary goals of effective transient management are to: 1) maintain the structural integrity of system components—control extreme pressure variations and lower magnitude cyclic loading that can damage piping and equipment; 2) protect the quality of the delivered water—reduce the potential for intrusion contamination under negative pressures as well as reduce extreme velocity changes that can loosen biofilms from the pipe walls; and 3) improve operations—ensure controlled valve and pump operations, reduce breaks and long term wear on system components, improve management of air within pipelines, prioritize inspection and maintenance of protection equipment, and improve hydraulic performance. Study components included an investigation and analysis phase. A risk based approach was followed for the evaluation of transient management for the system. This identified portions of the distribution network that are vulnerable to watermain structural integrity and water quality risk by correlating transient model results for high and low surge pressures with watermain condition rating across the zones. This facilitated intelligent decision making with respect to enhanced transient protection. In addition, the study developed best practices for management of transients, including transient friendly operational practices, maintenance prioritization, prioritization of water system rehabilitation, and operational response to major transient events.

With increasing pressure from the general public to provide safe, reliable, long-lasting infrastructure, large diameter feedermains that deliver potable water supply to large municipal populations are under scrutiny. Design decisions to provide robust long life infrastructure require proper evaluation of design loads and loading combinations. These often include internal pressure and external loads, environment conditions including seismic activity, soil types, and geotechnical hazards, and pipeline settlement concerns. Designers of large diameter feedermains often avoid large and costly cast-in-place reinforced concrete thrust blocks in favor of internally restrained field joints designed to transmit tension forces from one pipe to the next. Current technology for field joining of individual pipes includes field welding, flanging, and grooving. Welded and flanged connections provide a rigid connection at the joints, however many designers are uncomfortable placing flanged connections underground because of potential leakage that may go undetected. Grooved technology, pioneered in World War I to provide fuel and water to the battlefields of Europe is nearly 100 years old but, heretofore, has not been widely used until recently to join segments of large diameter feedermains. Both flexible and rigid joints can be supplied using grooved technology. This paper will provide a case study of a large diameter feedermain design and construction to include alternative analysis, material, and joint selection strategies with focus on grooved technology to provide thrust restraint yet flexibility at field connections. Geometric considerations for grooved technology will be presented. A typical AWWA Manual M11 harnessed joint design to provide flexibility will be compared to restrained flexible joint technology. Example problems will be presented.

Schoharie Reservoir is part of the Catskill System, and one of three systems that supply water to the city of New York. Approximately 35% of the city’s average daily demand is provided by the Catskill System, of which about 25% is supplied by the Schoharie Reservoir. The construction of Gilboa Dam was completed in 1926 and is comprised of a 700-ft-long earth embankment with a concrete core wall, and a 1,324-ft-long cyclopean concrete spillway with a maximum height of 160 ft. Like many reservoirs in the northeast, the capacity of the release works became restricted due to the age of the mechanical equipment, silting at outlet locations, and changes in release needs since the time of original reservoir construction. The final design of the low level outlet (LLO) was completed in June of 2014 and the project was bid in late fall of 2014 followed by award to SRJV and notice to proceed for construction in June of 2015. The project is scheduled to be completed in June of 2020 and when completed will represent one of the largest microtunnel boring machine project installations with wet retrieval ever accomplished in the United States. The 2100 linear feet of 108-in diameter Permalok steel casing will be installed in the tunnel while maintaining normal operating conditions of the Schoharie Reservoir at all times. This paper places particular emphasis on the practical applications from the view point of the owner, engineer, and manufacturer. Areas of interest include planning and design of the tunnel, the selection of tunnel lining materials, the Permalok steel casing manufacturing process, and key tunnel planning, design, and construction elements.

King County’s Mercer and Enatai interceptors were built in the 1960s and extend over 14,000 ft from Mercer Island into the Enatai neighborhood of Bellevue, Washington. Some parts of the system are reaching the end of their useful lives, and future peak flows are projected to exceed the system’s capacity. To address these deficiencies, the Mercer Enatai project team completed a complex alternatives analysis, which began its evaluation with over 945 potential pipeline alternatives and ultimately ended with one selected alternative. The alternatives analysis process began with the brainstorming of conceptual alignment options across the three distinct areas of the project: Mercer Island, East Channel (Lake Washington), and Bellevue. The existing North Mercer interceptor is primarily a subaqueous pipeline located within Lake Washington along the northern shoreline of Mercer Island. Any new pipeline on Mercer Island would have either significant challenges in constructing in the water in Lake Washington or on land that has experienced significant development since the 1960s, including the construction of Interstate 90 through the northern part of Mercer Island. The East Channel in Lake Washington is 1400 ft wide and separates Mercer Island from Bellevue. The existing Enatai siphon carries flows across the channel and traverses along the lake bottom and under the East Channel I-90 bridge. Any new pipeline across the channel would need to meet the complex constructability, hydraulic, and Army Corps 404 and WSDOT permitting requirements. The last pipeline segment is located in Bellevue in the Enatai neighborhood, a Native American term meaning “across the water”. Aptly named, the existing Enatai interceptor carries flows from across the channel and from Bellevue, along the southern end of the Enatai neighborhood, and through the environmentally sensitive Mercer Slough. The last 2,000 ft of this pipeline segment is also supported on piles due to the soft ground, and runs under the I-90 corridor, which is also supported on piles in this area. A new pipeline alignment through Bellevue would have significant challenges in constructing in the water through the Mercer Slough or on land through the Enatai hillside. This presentation explores the complex challenges of this project, and the extensive alternatives analysis process that started with over 945 potential alternatives.

The Central Arizona Project (CAP) recently completed relining two 12-ft diameter steel pipes and associated manifold systems at the Mark Wilmer Pumping Plant on Lake Havasu in western Arizona, using the construction manager at risk (CMAR) project delivery method. The Mark Wilmer Pumping Plant withdraws about 1.6 million acre-feet (ac-ft) of water each year from the Colorado River and via six pumps lifts the water through two 12-ft diameter steel pipes about 850 ft to the Buckskin Mountain Tunnel. The pumps are arranged in two-sets of three units which allows isolation of three pumps, a single manifold, and a single discharge pipe for maintenance while still operating the other three units and associated valves and piping. The two 144-in diameter steel discharge pipes are each about 2,300 ft long with slopes that vary from about 9° to 45°. The discharge pipes and manifolds were installed with the construction of the pumping plant in the early 1980s, and the pipes and manifolds lined with a hot-applied-cold-tar-enamel (HACTE) in 1982. In 1986, the plant was commissioned and has been moving water for over 30 years. In 2016, the right pipe and manifold was relined, and in 2017 the left pipe and manifold was relined. As part of CAP’s ongoing asset management program, the manifolds and discharge pipes have been inspected multiple times, and while it was apparent the HACTE was failing, CAP performed spot repairs of the lining as outages and internal man-power allowed. In 2012, it became evident the lining had reached its end and more than just spot repairs would be required to protect the integrity of the steel pipe. A project was developed to remove the HACTE and replace it with a modern coating system. Due to the physical extremes of the work and short outage window, it was decided to use an outside contractor to perform the work, and rather than use the traditional design-bid-build delivery method, CAP decided to use the CMAR approach. This paper will examine the initial development of the project surrounding the decision to use CMAR, outline the contractor selection process and the pros/cons surrounding that process, discuss the role the selected contractor played in the design (pre-construction services) of the new coatings system, then look at the development (negotiations) of the guaranteed maximum price (GMP), and finally review the delivery of the project. A brief discussion of CMAR versus design-bid-build and how the CAP approaches each will also be included.

Terrain analysis is commonly recognized within the pipeline industry as providing an important set of data for pipeline planning and pipeline asset management. Unfortunately, the concept of a functional terrain analysis program is often misunderstood, in terms of both what is meant by the term “functional” and what constitutes an appropriate terrain analysis. A functional terrain analysis incorporates both detailed desktop mapping and subsequent field investigations to identify terrain features that can affect the initial placement and subsequently the integrity of an existing pipeline. Desktop mapping refers to the delineation of terrain features based on (1) soil materials, (2) overburden thickness/depth to bedrock, (3) underlying soil materials, (4) slope, (5) drainage, and (6) geological modifying processes. One of the misunderstood components of a terrain analysis is the concept of scale. Too often, terrain analysis uses only publically available data, which is not appropriate for a functional terrain analysis to support pipeline activities. Publically available datasets are generally at scales of 1:24,000, 1:50,000, 1:100,000, 1:250,000, or smaller. What is needed for appropriate planning and integrity management is detailed, operational-scaled data. So how do we get “operational-scaled” data to support planning and asset management? This paper will focus on how terrain analysis is completed, the concept of scale, and new state-of-the-art “softcopy” tools. The paper will discuss types of data, such as digital stereo imagery and LiDAR, which can be used to aid in and improve terrain analysis. The paper will also provide examples of how terrain analysis helps to improve pipeline planning and how terrain data can be used to assist in stress analysis and stress corrosion cracking (SCC) analysis.

Rarely is your water delivery system more vulnerable than during a shutdown, planned or unplanned. When work is being performed on large diameter transmission lines, the stakes are high and you cannot plan too much to ensure things go well. This paper presents case studies of large diameter water transmission pipeline shutdowns. In developing the case studies, a clear understanding of the risk is first developed with consideration to different design and construction approaches to specialized work of this nature. In reviewing the case studies together, lessons learned are identified and several industry best practices are outlined to help develop a toolbox and go into future shutdowns more prepared and better equipped to maximize the likelihood of success.

The city of Enid, located in northwest Oklahoma, is outgrowing their existing ground water supply and initiated a surface water supply program to begin supplementing the existing ground water by 2021 to provide a long-term solution to increasing demands. The water supply project will provide 19.5 MGD, via 36-in pipeline, from the proposed surface water source, Kaw Lake, approximately seventy (70) miles to the east of Enid. In 2017, the city began Phase 2 of this project which includes an alignment study, route selection, and hydraulic analysis. In order to meet the proposed in-service date, Phase 2 needed to be complete in one year requiring a quarter mile of alignment design per day. This paper will elaborate on the team organization and walk through strategies developed to deliver the project on time. The analysis methods and lessons learned during the alignment selection of the raw water transmission pipeline will also be discussed. The alignment selection was within the confines of quarter mile wide corridor identified in Phase 1. Alignment alternatives were produced on the basis of minimizing known potential environmental impacts, potential impact to landowners, constructability concerns, topographic characteristics that negatively impact hydraulic profile, and maximizing permanent easement access. Field walks of all the alignment alternatives were conducted to gather additional information on the potential identified alignments such as wetlands, structures, and existing utilities. The total length covered in the field walks was close to 140 mi equating to approximately 1 million steps for the project team. Additionally, the paper will detail the intricacies of pipeline construction on properties owned by sovereign governments (Native American tribes). Cost estimating was included in the alignment selection based on corridor characteristics linked with data obtained on recent market trends. A triple bottom line analysis was used to aid in determining the recommended alignment based upon social, economic, and environmental concerns. This alignment selection will provide the basis of design for the city’s Raw Water Supply project.

Sanitary flow in the city of Daytona Beach’s beachside sanitary sewer collection system is estimated to increase 129% by the year 2035. This level of growth would significantly exceed the capacity of the existing system, which has been served by a 24-in subaqueous force main crossing the Halifax River since the mid-1980s. A 2016 capacity analysis report (CAR) recommended replacing the aging force main to provide additional flow capacity and improved reliability. In late July 2017, 2,300 linear feet (LF) of 30-in DR21 fusible polyvinyl chloride (FPVC) force main was successfully installed via horizontal directional drill (HDD). The drill crossed under the Halifax River to avoid environmentally sensitive areas and traversed a million-dollar river front property, community sports complex, and marina. The new force main enables the city to manage increasing system demands and accommodate planning for two (2) new resort-style hotels. This paper discusses force main planning, design, permitting, and installation with a specific focus on HDD design and material selection. This paper also reviews contractor qualifications, the bidding process, project challenges, and lessons learned.

The city of Modesto's North Valley Regional Recycled Water Program is one of the largest water recycling projects in the country, constructing a 32 million gallons per day (121,100 cubic meters per day), 3,000-horsepower (2,200 kW) pump station, 7 mi (11.2 km) of 42-in (1.06 m) diameter pipeline with a 2,800-ft (0.9 km) horizontal directional drill, a jack and bore highway crossing, and an outfall structure to the federally owned Delta Mendota Canal. Funding this major project came with aggressive schedule requirements. To meet these requirements, Modesto chose a new approach: design-build. Using this approach, Modesto was able to finish the project a year faster compared to traditional design-bid-build. This paper describes Modesto's approach to leveraging the benefits of design-build while including requirements important to Modesto. It describes the design-build procurement process, from developing a procurement strategy to implementing a two-stage selection process, and ultimately selecting a design-builder. The paper also discusses the lessons learned, such as the need to involve the design-build team early on and to balance cost and non-cost evaluation criteria. Finally, it discusses the project's successes and failures and makes specific recommendations to avoid potential pitfalls while harnessing the benefits of design-build. The project was deemed substantially complete in December 2017.

During force main construction in Downtown Norfolk, Virginia, the general contractor wanted to avoid an especially challenging segment of open-cut installation adjacent to a high-end shopping mall. After considering and excluding several ideas, a 1,000-LF 30-in horizontal directional drill (HDD) was proposed at no cost to the project. Although this project was a typical design-bid-build, the proposal to perform a HDD in the middle of construction initiated a pseudo design-build effort. The complicated nature of Downtown Norfolk’s subsurface required historical reviews of land reclamation and advanced geotechnical considerations to address potential risks. Primarily was the proposed HDD path location alongside the oldest structure in Norfolk: St. Paul’s colonial-era historic church constructed in the 1730s. This paper explains the vetting strategies of the expeditious design and proactive observation measures implemented to reduce risk. It also details how the contractor, engineer, and owner collaboratively negotiated this major change in work and garnered buy-in from City officials and local stakeholders. In addition, the financial and contractual terms of the change order are presented to show how all parties came together for the mutual benefit of the project and implemented this change at no cost to the project.

Design-build delivery opportunities for pipeline projects are increasing dramatically in the water and wastewater sector. As an informative example of successful delivery of a design-build pipeline, we will discuss the city of Modesto (City) North Valley Regional Recycled Water Program (NVRRWP) Pipeline in Modesto, California. The pipeline will convey highly-treated wastewater from the City’s tertiary treatment plant and serve as an important regional solution to address water supply shortages faced by agricultural customers. This case study will explore various keys to successful delivery of the 7 mi (11.2 km), 42-in (1.06 m) diameter recycled water pipeline that included a 2,800 ft (853 m) long horizontal directionally drilled (HDD) trenchless crossing of the San Joaquin River in an environmentally sensitive area with seismically sensitive soils, including: 1) development of a successful design-build proposal: we will share strategies on how to structure an effective design-build team and prepare a winning proposal; 2) delivery strategies to fast-track schedule including early procurement and contract packages; 3) addressing open cut and trenchless design and construction issues that included balancing pipe/embedment design optimization in poor soils areas, geotechnical/seismic challenges through the San Joaquin floodplain, and schedule delays due to high San Joaquin River levels; 4) satisfying challenging environmental and regulatory agency permit conditions for the HDD crossing of the San Joaquin River using a collaborative approach between owner, contractor, designer, and agencies.

After nearly four years of construction on several sections of the integrated pipeline (IPL) project in north Texas consisting of approximately 60 mi of 108-in steel pipeline using imported granular embedment, the existing soil conditions in IPL Sections 10 and 11 provided the contractor the opportunity to use native excavated material for a sustainable construction solution to importing embedment material. Most of the these completed sections of the IPL project were constructed in soils that were not conducive for use as pipe embedment without extensive screening and processing in the form of controlled low strength material (CLSM) for fat clay soils or crushing and screening of limestone. IPL Sections 10 and 11 which consists of approximately 12.5 mi of 84-in raw water steel pipeline in Ellis, Johnson, and Tarrant Counties partly runs through sandy soils that can be processed and mixed with cement to make cement stabilized sand (CSS). IPL Sections 10 and 11 begins in fat clay soils in the south and ends in the north and west in sandy soils. There are several sand borrow sites in the area including one that the pipeline runs through. This sand borrow site was active prior to construction of the pipeline. The contractor proposed using the native sandy soil excavated along the pipe alignment for CSS in lieu of gravel embedment. This paper highlights the steps taken to evaluate the use of the native sand for making CSS for pipe embedment: triaxial testing to determine Young’s modulus properties of various CSS sand mixes ranging from 1% to 5% cement content; determine modulus of soil reaction, E', values for each CSS mix design to confirm it’s suitability for a standard trench width; and require contractor to demonstrate that CSS could be produced from a pug mill with consistent quality that had optimum moisture determined as part of the triaxial testing process. By using native sandy soils excavated along the pipeline for producing CSS for the pipe embedment, the contractor was able to greatly reduce the number of embedment deliveries to the project site and reduce the amount of spoil material that had to be hauled off. This directly reduced the impact to existing roads and the environment.

This paper analyzes the performance of project delivery methods for water and wastewater infrastructure projects. Aging infrastructure, population growth, and more stringent environmental regulations have been some of the main drivers highlighting the need to upgrade existing drinking water and wastewater treatment facilities, and build new ones. Industry leaders and decision-makers are looking at innovative technological and project delivery solutions to achieve this colossal but urgent challenge. Water and wastewater facilities have traditionally been constructed, retrofitted, and rehabilitated using the design-bid-build (DBB) process, which is adequate for projects where the work is well defined and has relatively low uncertainty and complexity. However, DBB might not be ideal for more complex facilities where the potential for integration between the different stakeholders may result in innovative solutions and improved efficiencies. Therefore, alternative project delivery methods (APDM) such as design-build (DB) and construction manager at risk (CMAR) have been on the rise recently, mostly due to improved project cost and schedule outcomes. In fact, the project performance impacts of APDM have been quantified for the transportation and building sectors; this paper’s objective is to quantify delivery methods’ performance for the water infrastructure sector. The paper discusses a national data collection effort and analysis focusing on water and wastewater projects. Early results show improved cost and schedule performance associated with APDM. These findings can assist stakeholders in selecting the appropriate delivery method for their water and wastewater project.

Birmingham, the U.K.’s second largest city, has for a century relied on water gravitating from the Welsh mountains. With the need to enhance the security of supplies to the city and to enable the older infrastructure to be taken out of service to facilitate inspection and maintenance, an alternative water source to provide up to 250 million litres per day (Ml/d) was necessary. 250 Ml/d = 66 million U.S. gallons per day (mgd). This case study covers the process of determining the best balance of cost, engineering risk, environmental impact, and operational flexibility for selection of a new river abstraction point and a 25 km (16 mi) long pipeline. Several aspects of the project make it a challenge: the intermittent proposed planned use; the need to remain in hot standby for emergency use; the highly constrained access to the River Severn; the wide variation in the river channel; national heritage and environmental sensitivities; the unavoidable topography and the high pumping heads—up to 30 bar (430 psi); and the presence of zebra mussels (invasive species) in the River Severn. An overview and methodology for the evaluation of over 20 potential sites and 8 pipe routes is presented.

The city of Toronto has initiated a $2.0 billion project, referred to as the Don River and Central Waterfront (DR&CW) Project, to reduce wet weather flow (WWF) overflows and ultimately improve water quality in the Inner Harbour of Lake Ontario, the Don River, and Taylor-Massey Creek. The DR&CW Project encompasses construction of 22 kilometers (km) of WWF storage tunnels, offline storage tanks, 50 connections, a new pump station, and a high rate treatment facility. Design of the first stage of the DR&CW Project, the Coxwell Bypass Tunnel (CBT), is complete and tendered. The framework for delivery and preliminary design for the subsequent stages of the DR&CW Project has been established. The CBT involves construction of five tunnel construction shafts, 11 drop shaft connections, and 10.5 km of 6.3 meter (m) diameter tunnel approximately 50 m deep through shale rock. This paper briefly outlines the scope and purpose of the DR&CW Project. More importantly, the paper examines the changes made during design of the CBT to integrate the CBT with parallel projects and improve the overall planning, sequencing, and delivery of the project.

Steel fibers have been used recently in concrete pipe mix in attempt to reduce or eliminate the need for steel reinforced cage, which could reduce the production cost significantly and enhance the concrete pipe resistance for shear and radial failures. However, producing pipe with wall thickness specified by ASTM C76 may not be practical as buried pipes could carry more loads through soil structure interaction. The objective of this study is to evaluate the performance of concrete pipe with diameter of 1200 mm and reduced thickness to 50% of that specified by ASTM standard. The pipe was reinforced using hooked end steel fibers with a dosage of 9 kg/m³. The pipe was instrumented using string transducers to measure the horizontal and vertical deflections. Also, strain gauges mounted on the inner crown, inner springline, outer springline, and inner invert were used to monitor the strain response. The pipe was tested under three-edge bearing load in accordance with ASTM standard. The tested pipe experienced flexural failure as the cracks propagated longitudinally at the high-tension zones. Other failure modes such as radial and shear associated with large pipe diameters were not observed. Also, the tested pipe surpassed the minimum deflection ratio specified for the flexible pipe, which is 2% of the internal diameter. The presence of steel fiber increased the strain capacity of the concrete pipe prior to cracks appearing on pipe wall surface. The tested pipe could be used for the gravity pipe applications.

Laboratory testing to evaluate buried pipe systems under deep burial is needed to evaluate the response of a variety of culvert and sewer pipe products for a range of deterioration conditions and backfill soils. The cost and the time associated with experiments on highway and sewer structures in the field are significant. Until recently no facilities have existed to evaluate larger diameter pipes, to test pipes in saturated ground, or to allow the behavior of pipe joints at deep burial to be investigated. A new deep burial testing facility that is 3 m wide, 5 m long, and 4.6 m deep has been constructed at Queen's University to permit deep burial testing on pipes with diameters up to 3.05 m. The test pit is sealed, so that deep burial experiments can be conducted in saturated ground, permitting seminal studies of soil erosion caused by groundwater flow into the leaking joints of sewer pipes or perforations in deteriorated culverts. Selected results from a commissioning test on a 3.05 m diameter steel reinforced polyethylene pipe are provided.

Ground movement due to blow-out (unconfined shear failure) can develop when conducting pipe installation by horizontal directional drilling through sand, and this can endanger pavements, sidewalks, and other buried infrastructure. This paper presents and compares the three methods used to monitor ground movements in experiments conducted at Queen’s University to investigate horizontal borehole instability due to excessive mud pressures. Particle image velocimetry is a method widely used to monitor displacements in different geotechnical and structural applications, and a new post-processing procedure for the Geo-PIV software is introduced to reduce displacement errors associated with application to three dimensional problems. SfM-MVS (structure for motion and multi-view stereo) and LiDAR (light detection and ranging) was also used to record surface geometry before and after each experiment, to permit comparisons with the deformation data from Geo-PIV. The advantages and disadvantages of these monitoring methods are then discussed. Finally, the progressive development of ground heave with changes in mud pressure in the horizontal borehole will be illustrated. These findings can be of significant value for specialists analyzing ground heave during drilling projects through sand.

Shallowly buried pipes are used as culverts crossing under roads and railways, and for pipelines along main roads. To investigate the load distribution on shallow buried pipes and develop recommendations for their design a research project was funded by the Ministry of the Environment in the state of North-Rhine Westfalia, Germany. The research program consisted of experimental full-scale tests in a large testing facility (6 m×6 m×15 m) at Institute for Underground Infrastructure (IKT), finite element analyses (FEA), and the verification of the loading approaches and calculation schemes used in current German standards. During the experiments various pipe materials were used including concrete, ductile iron, and polyethylene. The main goals were to determine: the vertical and horizontal earth pressure; the stress distribution induced by vehicle loads; the influence of wheel positions and load configuration; the influence of the pavement type; and, the general behavior of the pipe-soil system under impact loads. The main results are as follows: for shallowly buried pipes, the pipe crown is the zone of critical stresses. Soil stresses in tests were similar for the concrete pipe, but lower for flexible pipes when compared with theoretical approaches. Pipe deflections were lower than expected. A time dependent increase of pipe stresses was observed. The pavement type is of significant influence for the pipe stresses. The longitudinal behavior under live loads depends on the pipe type. Soil stresses increase under cyclic loading. The pure Boussinesq approach has been modified in the German code for structural calculation. A load distribution model has been developed instead to consider the supporting behavior of the side fill.

This paper presents two-dimensional finite element analysis performed on corrugated steel culverts, whose inverts are badly deteriorated and treated with concrete paving for rehabilitation. In the study, the culvert analysis and design software (CANDE) was employed to perform the plane-stress analysis of the buried circular pipe and pipe-arch culverts. Thrust, bending moment, and deflection responses of the deteriorated culverts were compared with those of the invert-paved culverts. For each computer simulation, a half-mesh was constructed at level 2 CANDE and then imported into level 3 CANDE to use its versatility. An extreme deterioration with 95% metal loss was simulated by introducing reduced cross-sectional properties (thickness and modulus of elasticity) over the bottom portion as opposed to the remaining part of the culverts. Similarly, concrete paving was simulated while assuming the culvert invert consists of concrete alone. The results showed that through invert-paving deflections decrease and thrust force becomes more uniform while bending moment increases over the invert. While this plane-stress analysis may not be able to sufficiently predict the actual responses of metal culverts in the field, it can serve as a rapid analysis tool to understand the structural benefits that a local improvement made over the invert can offer to the entire culvert structure.

Interlocking pipe joints have been utilized in the trenchless technology industry for over 20 years. This technology allows a pipe segment with a notched male end to be joined to a pipe segment with a notched female end by pressing them together using axial force, eliminating the need for circumferential welding of the segments. Although industry familiarity with these joints is well established, the mechanics of the interlocking process has received little attention in the literature. This paper provides insights into the mechanical behavior of the interlocking, press-fit joints that secure steel pipe casings in auger boring and pipe jacking construction. Four male/female pairs of 914.4 mm outer diameter specimens were assembled to determine engagement forces; these four pairs were then disassembled to determine disengagement forces. The axial forces required to engage the joints ranged from 205 to 320 kN, and the forces to disengage the joints ranged from 254 to 365 kN. The experimental results showed that on average, the disengagement force exceeded the engagement force by 15%. Nonlinear finite element analysis (FEA) of the locking mechanism was implemented resulting in important insights into joint behavior, mechanics, and design. The press-fit geometric parameters (joint thickness, diametral interference, inner and outer diameters, and joint length) along with material and contact properties that define the computational model were studied to gain insights that could consequently lead improved interlocking joint designs.

Pipeline design criteria and performance objectives have advanced with the better understanding of expected damage and consequences. Municipal agencies are being tasked with building systems to meet operational concerns following the maximum considered earthquake. Accepting deformations and exceeding yield stress is common in building seismic design. With properly specified materials, pipeline seismic design can benefit from a similar approach. There are few standards available for engineers to use when designing water pipelines for large deformation due to earthquakes. Typical water industry design practice considers a stress-based design approach, where the pipeline is sized to meet an allowable elastic stress limit. Finite element modelling can utilize steel’s non-linear properties for seismic design. Generally, the optimum behavior for analyses to seismic load conditions is a “round-house” shape stress-strain curve above yield. Using API line pipe, designers can improve designs to accommodate large ground deformation with more predictable performance. ASCE is currently developing a Manual of Practice for Seismic Design of Water and Wastewater Pipelines. These standards encourage engineers adapt available tools when modelling complex soil structure interactions and developing cost efficient, reliable pipeline seismic designs. This paper presents history of pipeline seismic design including a look ahead at the new UESI Manual of Practice, available design methodologies for large PGD, and Portland Water Bureau’s specification to accommodate large ground deformation at the Willamette River Crossing design build project.

The Los Angeles Water System is implementing a Seismic Resilience Program as part of a larger plan to improve the city’s seismic resilience. The Water System Resilience Program comprehensively covers all aspects of water system business, but a key component to the program is developing a seismic resilient pipe network (SRPN). A SRPN is designed and constructed to accommodate earthquake damage with ability to continue providing water or limit water outage times tolerable to community recovery efforts. The challenges to creating a SRPN is described through the transmission and distribution subsystems and their importance for providing water delivery, quality, quantity, fire protection, and functionality services. Assessing the risks for fire following earthquake, post-earthquake emergency water deliveries, and identifying critical facilities and their locations throughout the city are important to defining the resilient pipe layout. Resilient pipe materials useful for creating a SRPN are described and examples presented to show how to implement a SRPN to support community resilience goals.

Welded lap joints are commonly used in large-diameter steel pipelines for water transmission. Their structural performance constitutes a key issue for safeguarding pipeline structural integrity with no loss of pressure containment, required even after a severe seismic event. Full-scale experiments are presented herein, and are part of an extensive project sponsored and coordinated by Northwest Pipe Co. on the structural performance of welded lap joints under severe ground-induced (seismic) actions. In the companion paper “Numerical Simulation of Steel Lap Welded Pipe Joint Behavior in Seismic Conditions” numerical simulation of the experiments are presented. The paper describes a series of large-scale experiments on welded lap joints in 25.75 in outside diameter steel pipes, with wall thickness of 0.135 in (3 specimens) or 0.250 in (3 specimens). The specimens were internally pressurized to 40% of yield pressure, and then subjected to four-point bending. Measurements of the bending load, characteristic displacements, and local strains at the joint area are reported. In all tests, the welded lap joints tested were capable of sustaining remarkable bending deformation, without any loss of pressure containment. This behavior supports the argument that welded lap joints, if appropriately constructed, can be used in seismic areas where severe and permanent ground-induced actions in the pipeline may occur.

The present paper reports numerical calculations which complement experimental work reported in the companion paper entitled “Experimental Results of Steel Lap Welded Joints in Seismic Conditions”, also presented in ASCE 2018 Pipelines Conference. Nonlinear finite element simulation tools are employed to investigate the bending capacity of internally-pressurized welded-lap 24-in-diameter pipeline joints, considering two thicknesses (0.135 in and 0.250 in). The work presented in this paper: (a) simulates numerically the seven large-scale experiments presented in detail in the companion paper; (b) elucidates some interesting issues of welded lap joint behavior under severe bending deformation. In the final part of the paper, based on the above experimental and numerical results, a discussion is offered on the design of welded lap joints in pipelines constructed in seismic areas.