Pipelines 2019: Planning and Design

This paper describes the estimation of economic damage arising from a water main break as a means of calculating the economic consequence of failure. This shifts away from factor-based, qualitative approach where factor inputs are grouped into bins, which tend to contribute to a slimmer amount of variance. An element of subjectivity also comes into play in the form of making the cut-offs and determining which factors will influence the risk scores and by how much (in the form of weighted scores). A proposed quantification of damage is presented arising from the significant consequence of a large diameter pipe failure caused by the discharged water. The pipe burst simulation utilizes surface modeling to determine the flooding area caused by a large diameter pipe failure. With the simulation results, the amount of damage is estimated by using the water depth resulting from the discharged water and the building type and size that will be affected. By utilizing cost damage information from U.S. Army Corps of Engineers, the consequence of failure is better represented compared to a qualitative approach where the use of spatial distance and pipe attribute information is commonly used. Examples are presented which simulate different scenarios depending on the urban setting, the intensity of the pipe break, and the emergency response time of the water main break.

The U.S. lacks an overall infrastructure renewal strategy. As a result, many states are forced to develop specific initiatives involving infrastructure asset management practices. For critical water infrastructure systems, states are mitigating the risk and burden of aging water infrastructure and declining water quality concerns by requiring water utilities to develop asset management plans and programs. Michigan was the first state to pass a law requiring that a Water Asset Management Program be implemented by January 1, 2018, and an asset management plan (AMP) is completed and submitted by water systems serving a population greater than 1,000. So what happened when over 500 water systems all needed to submit AMPs following various guidelines? This paper reviews the process and findings and identifies improvements for water utility engineering firms to better support utilities as well as recommendations to improve data and water pipe condition assessment results to better support capital planning needs and affordability concerns.

In 2005, the province of Alberta developed a new strategy for regional wastewater treatment and transmission in Central Alberta. This was done to protect the watershed along a sensitive stretch of the Red Deer River, and to provide wastewater treatment and transmission capacity for a design horizon service population of 350,000. This paper provides an overview of the entire system, starting with the new regulatory framework that set the stage for the system, from the perspective of Alberta Environment and Parks (AEP), the agency that developed the plan. On the design front, this paper compares the differing approaches to the consideration of peaking factors and wet weather flow allowances over the course of the designs of the various systems that occurred over a ten-year period, and how "lessons learned" were applied over time to inform how water conservation, infrastructure renewal, and higher utility servicing costs were addressed in the system designs. Differences in the hydraulic profiles of the systems are also identified along with how approaches to air releases, pressure sustaining valves, and vents in the systems evolved over time. The expansion of wastewater treatment capacity on an existing site will be reviewed. The paper also considers construction and constructability, with consideration to topics such as wetland preservation, the changing break points on affordability of open cut vs. horizontal directional drilling.

The Cumberland City Low Water Transmission Project consisted of more than 24,000 LF of 60- and 36-inch diameter ductile iron water mains. The completion of the Cumberland City Low Transmission Water Main Improvements project creates a dual feed water transmission main for an essential portion of Nashville's distribution system and Phase 1 of the redundant 60-inch feed from the K. R. Harrington Water Treatment Plant. The team provided this great project from routing evaluations through construction in less than 24 months. One of the biggest challenges and blessings was most of the project was located in existing roadways managed by the Tennessee Department of Transportation (TDOT) and Metro Nashville Public Works (NPW). The project also included a crossing of the Stones River and a liner plate tunnel under a Nashville Eastern Railway. While the benefit of the new water transmission main was added resiliency to the east side of the Stones River, the Triple Bottom Line identified $73.4 million dollars of regional gross domestic product (GDP) or added wealth to Davidson County was generated from this $34.3 million dollar investment into the water infrastructure.

There are four main parties in a design/build pipeline project: the owner and his representative; the general contractor; the contractor’s design engineer (the engineer of record); and the pipe manufacturer. The selection of the pipe manufacturer by the design/build team is critical, since besides providing the pipe design calculations if required, layout drawings, and manufacturing the pipeline, the design/build team can depend on the manufacturer’s expertise to provide recommendations and alternatives to resolve unforeseen field related issues. The additional contribution by the pipe manufacturer can be limited or significant depending on the pre-engineering level of the project and the experience of the project team. Three examples of design/build pipeline projects requiring different levels of technical support by the pipe manufacturer, will be presented: the Tuyaux Bonna/American Pipe and Construction Design/Build team for the rehabilitation of 19 miles of 78-inch PCCP with a steel liner; Archer Western/Winzler & Kelly for the construction 9.5 miles of potable and reclaimed water steel pipelines ranging in diameter from 24-inch up to 48 inches; and Kiewit/Parson’s for the construction of 6000 ft. of 120-inch diameter high pressure steel-tunnel-liner penstock requiring specialized steel with very high toughness properties. Lessons learned from the three projects will also be presented.

Montgomery County (Ohio) Environmental Services (MCES) Department is currently in the process of procuring a design-build firm to lead the design and construction of their largest capital improvement project to date. The Sanitary Conveyance and Treatment Improvement Project will include the replacement of MCES’ existing primary pretreatment facility and pumping station and provide new screening, pumping, and pretreatment at their existing Western Regional Water Reclamation Facility (WRWRF). The transport of wastewater flow from the existing pretreatment site to WRWRF will be conveyed by a new 72-inch gravity sewer that will replace an aging force main. This paper discusses the evaluation of the conveyance options to include: adding redundancy through an additional force main or new gravity sewer; multiple trenchless sewer alignments through urban environments; and how alternative project delivery methods could benefit MCES. The progressive design-build project delivery method was selected for this project and will include approximately 7,300-feet of deep sewer installed by microtunneling. This will be the first progressive design-build microtunnel project in the U.S.

The Second San Diego Aqueduct is located within the San Diego County Water Authority’s (SDCWA) right of way that traverses the Scripps Ranch community, south of Miramar Hill. After crossing Interstate 15, the Second Aqueduct, which contains Pipelines 3, 4, and 4A, travels through a residential area, crosses Scripps Ranch Boulevard, and ascends a hill known as “Nob Hill.” Certain operating conditions within the Water Authority’s Second Aqueduct were predicted to produce transient events that could result in water column separation in the vicinity of the high point at Nob Hill. The transient event had the potential of damaging or rupturing Pipelines 3 and 4 and producing a catastrophic event for the Aqueduct system and the residential areas down-slope of the pipelines as they cross Nob Hill. This section of the Second Aqueduct contains the Water Authority’s Pipelines 3 and 4. Both are 72-inch diameter prestressed concrete cylinder pipe (PCCP), with Pipeline 4 having the addition of steel liners. To prevent a potential catastrophic event, SDCWA completed a project to “lower” both existing pipelines, thereby increasing the hydraulic gradient in the pipelines and reducing the potential for a damaging transient pressure event. This paper will discuss the difficulties in combining two, 72-inch diameter PCCP pipelines, along different elevations and slopes, into one 96-inch diameter steel pipeline, tunneled through Nob Hill. Several design and installation issues will be examined.

The Central Arizona Project (CAP) is an aqueduct system that delivers 1.6 million acre-feet of Colorado River water annually from Lake Havasu to approximately 5 million people in Arizona via a series of open channel canals, tunnels, large pipelines, and pumping plants. In the summer and fall of 2018, two critical, 252-inch diameter flexible steel pipelines were dewatered for condition assessments after more than 15 years without an outage. These pipelines convey over 2 billion gallons of water each day, making opportunities for inspection rare and difficult to schedule. Crews must work around the clock during an outage to dewater, inspect, repair, and rewater to quickly put the system back in operation. This paper will present the highlights and challenges of these recent pipeline inspections performed by CAP and Bureau of Reclamation engineers including outage planning, dewatering, inspection procedures, results, and recommendations.

Pipeline route studies are vital to complex, large-diameter pipeline project planning. Route studies can be used to support project stakeholder engagement and decision-making, early permitting coordination, financing, final design, and construction. This paper presents a case study of a robust route study process that considered approximately 380 pipeline alternative routes and their associated characteristics in a simplified yet comprehensive manner. The pipeline is proposed to be a large-diameter water transmission main in a highly urbanized setting. Major project challenges included residential and business impacts, multiple stakeholders, utility conflicts, and potential soil and groundwater contamination. To properly address these project challenges, all reasonable alternative routes were developed and analyzed within the project study area. The pipeline, expected to be 81 inches in diameter, is proposed to transport potable water from the Great Lakes Water Authority’s Water Works Park Water Treatment Plant for approximately seven miles through Detroit to the Northeast Station. The pipeline route analysis incorporated both monetary and non-monetary costs criteria. Using the evaluation process and analysis results, decision-makers were able to easily understand the characteristics of the hundreds of alternative routes and gain confidence that all reasonable alternative routes were closely considered. The results of the analysis were presented in concise, visually appealing graphs that were easily interpreted by all project stakeholders. These processes facilitated the successful and defensible selection of the pipeline route for this important regional drinking water infrastructure project in southeastern Michigan.

The San Antonio Water System (SAWS) serves more than 1.6 million people and over 411,000 sanitary sewer customers in the Greater San Antonio area and it continues to experience rapid growth. In July 2013, SAWS approved a settlement agreement with the U.S. Environmental Protection Agency (EPA) and is currently under a Federal Consent Decree (CD) to reduce sanitary sewer overflows (SSO) over a ten (10) year period. Through this CD, SAWS committed to performing system wide condition and capacity assessments of their sanitary sewer collection system. This paper will describe how Freese and Nichols, Inc. (FNI) analyzed alignment alternatives for approximately 5.2 miles of large diameter, undersized sewer main located in an urban corridor of South San Antonio, dubbed the ‘Main Stem’, that would provide a robust, improved conveyance system with a focus on minimizing impacts to the community.

The Navajo-Gallup Water Supply Project (NGWSP) is a major infrastructure endeavor that will convey a reliable municipal and industrial water supply for future generations on Navajo Nation land and the Four Corners Region. The project will service northwest New Mexico, including the eastern section of the Navajo Nation, the southwestern portion of the Jicarilla Apache Nation (JAN), and the city of Gallup (COG) via approximately 300 miles of pipeline, 19 pumping plants, and 2 water treatment plants. The pipeline will cross various land ownership types (tribal, state, private, and federal) with different regulatory agencies, and unclear jurisdictional boundaries presenting many obstacles for alignment consideration. Additionally, highly corrosive soils and wash crossings influence the pipe material selection while preserving environmental and cultural resources. Public outreach is vital toward earning the public’s buy-in through education of the residents, informing them of the project’s progress. The NGWSP has a congressionally-mandated deadline for completion by December 31, 2024.

Rehabilitation of water distribution pipes using CIPP (cured-in-place-pipe), a fiber-resin composite lining system, is a viable alternative to pipe replacement. This paper will discuss the challenges of using the well-established thermoplastic hydrostatic design bases (HDB) design method for CIPP pressure pipe liners. For example, HBD curves for thermoplastic pipes are developed using 25 mm/1 inch or 50 mm/2 in. extruded tubes. Since CIPP liners are constructed with reinforcement layers and resin the construction of small tubes for HDB testing is not possible. At the University of Waterloo, a new test facility has been constructed to develop HDB curves for CIPP lining systems, as well as, test specimen subjected to pressure cycles. HDB test results for 150 mm/6 in. diameter Insituform's InsituMain CIPP liner will be presented along with short-term burst test results for other commercially available CIPP pressure liner products. The paper will conclude by proposing a standard methodology for HDB testing of CIPP pressure liners and determining the liner pressure class/pressure rating.

Carbon and glass fiber reinforced polymers (FRP) have been used for infrastructure rehabilitation for more than three decades, and applications in pipeline rehabilitation has gained momentum in recent years. The advantages these systems can provide include high strength, light weight, and ability to be installed on essentially any type of pipe material, size, and geometry. Nevertheless, particularly carbon fiber is an expensive material and if an FRP system is not designed properly the difference in the cost may offset the advantages it provides. This paper will present best design practices with respect to utilize FRP systems as a more economical alternative for pipeline rehabilitation. Particularly emphasis will be given to considering the residual strength of the host pipe and using a composite system, which enables achieving high ring stiffness without excessive layers of carbon fiber fabric.

In a pipeline system, a variety of internal and external factors such as pipe age, diameter, depth, soil condition, and water table reduce the serviceability of the pipeline and increase the risk of pipe failure. Multiple trenchless technology methods can be used for water pipe renewal, such as cured-in-place pipe (CIPP), close-fit pipe (CFT), and sliplining (SL). The design of renewal pipe includes considerations for structural, semi-structural, and non-structural applications considering internal and external pressure. Selection of the appropriate renewal method and lining material can lead to a reduction in the cost of the water pipeline renewal project. Pipe-in Liner is a fabric reinforced flexible plastic pipe (FRFPP), which is a cost-effective semi-structural solution to rehabilitate water, oil, gas, and hot water networks. The objective of this paper is to present design and installation specifications of FRFPP as a new solution to renew water pipeline. The semi-structural design uses the support from the old pipe, and the new liner pipe spans the cracks and holes to eliminate leakage as well as enhances the structural capacity of the old pipe. The installation of the renewed pipe requires proper selection of the renewal method, old pipe conditions, proper planning and preparation, surface and sub-surface considerations, and service lateral connections.

This paper details the execution of electromagnetic testing and miscellaneous improvements on a 30-year-old, 10-mile-long pipeline in North Texas. During a short three-week period, 10.5 miles of 72-in. diameter pipe were drained and filled, two 72-inch butterfly valves were installed, over 2,000 joints of prestressed concrete cylinder pipe were internally bonded, and 140 test stations were installed. A team of 65 people was deployed throughout the pipeline right-of-way with crews and equipment working 24 hours a day, 7 days a week. This work was successfully completed due to extensive planning efforts, effective coordination and communication between the project team, and special attention and compliance with confined space safety requirements.

Marina Coast Water District (MCWD) recently completed construction of 7.5 miles of 24-inch diameter high pressure, zinc coated ductile iron transmission main and a 2.0 MG reservoir in the former Fort Ord Army Post as part of the Regional Urban Water Augmentation Project. Unique challenges included excavating in areas potentially containing unexploded ordinance (bombs), poorly graded coarse soil (beach sand), and existing utility systems constructed without record drawings. Additional challenges included establishing land ownership for properties in transition from federal to local agencies, an aggressive project schedule, conflicting permitting requirements, and complying with federal funding requirements. This paper describes the MCWD's approach to mitigating these challenges before construction and overcoming these challenges during construction. Selecting the zinc coating and designing the transmission main for high pressure are also discussed. Finally, the paper reviews the project's successes and failures, lessons learned, and recommendations for working in former military bases.

The Scarborough Trunk Watermain (STWM) project is one of the first undertaken by the city after releasing its Standard Specification TS 7.80 for Large Diameter Watermains. Construction started in the fall of 2018. This paper presents the challenges encountered and overcome during the design of the STWM. The associated high-operating and transient pressures that dictated pipe-material suitability, pipe-wall thickness, and surge protection will be discussed. Specific constructability challenges associated with building a large watermain in a heavily dense urban environment will be presented.

Owners of transmission main projects frequently provide project-specific design guidelines or standard criteria to the design teams for their projects. Large projects may involve several teams, each designing a different portion of the system. Having the design teams follow the owner-established criteria or guidelines provides uniformity between multiple projects and between the various segments of large projects. Occasionally, portions of the design criteria and guidelines prepared for pipeline projects can be confusing and be interpreted different ways. This paper presents a list of criteria that should be considered for inclusion in design guidelines, provides several examples of design criteria and guidelines that may be unclear, and explains how the criteria and guidelines could be improved.

The oil and gas industries are still booming for many West Texas communities, and they rely on water, a finite resource in the Permian Basin. Typically, water delivery systems to oil and gas operations aren’t permanent and don’t focus on efficiency. Our team developed a system that allows water to be conveyed efficiently and safely, encouraging industry growth. Parkhill, Smith, and Cooper (PSC) and Garney Construction teamed to design and construct the $14,500,000 water transmission system to deliver a max flow rate of 250,000 barrels/day (Bbls/day) to support oil and gas operations. The project was fast tracked, so the team had to engineer solutions to deliver this system from concept to operation in fewer than 200 days.

The city of Tucson is a Sonoran Desert community in southern Arizona with a population of nearly 750,000 people and one million people, including the metropolitan areas. “Tucson Water”, a department of the city of Tucson, is a large, complex groundwater system receiving a Colorado River water allocation of approximately 148,000 acre-feet, which the city recharges in a vast recharge and recovery system west of the community. In February of 1999, the city’s largest potable water transmission line, a 96-inch diameter (4,000 mm) prestressed concrete cylinder pipeline (PCCP), failed catastrophically, releasing a flood of water, mud, rock, and debris, crashing into a neighborhood, knocking down block walls, trapping people in homes, floating vehicles out of driveways, and causing extensive damage to private property and homes within the community. This one failure of a pipeline just 11 years old, cost the city approximately five million dollars in private property damage, collateral damage, and litigation, and forced the city to revert back to pumping native groundwater for months, until the transmission line was restored to service. The forthcoming white paper will demonstrate how one water utility recovered from the catastrophic failure of its most critical water transmission line, progressed to one of the most forward-thinking water utilities, and implemented one of the most advanced and longest running asset management programs for PCCP in North America. This “snapshot” presentation of Tucson’s asset management program entitled “Pipeline Protection Program” (PPP), will give a brief overview of the various challenges Tucson faced and highlight the various strategies, tools, and technologies applied, that have collectively prevented any additional catastrophic failures for more than 20 years and counting.

Accommodating future needs is an important consideration for a well-planned pipeline system because of the long-term lifecycles of the infrastructure. However, this process can also result in overdesign with respect to the present. Technology historians have identified several dynamics that are involved in the resolution of this tension between present and future needs. Using these dynamics, this paper proposes an analytical methodology to defensibly balance them. The goal of the approach is to set the vision for the pipeline infrastructure plan in a way that makes the best long-term use of available funding. To quantify this, present worth analysis is used to scrutinize preferred design approaches against other alternatives. The output seeks to identify hidden lifecycle costs from future needs that may warrant approach reconsideration. The methodology is applied to critique past decisions in the design of wastewater collection systems. In addition, it is presented as a viable tool to assist with sustainable decision-making.

Corrosion protection of buried metallic pipelines is not always a straightforward analysis of soil parameters as the predictive factors that influence corrosion are often interactive. This paper is a case study of a proposed watermain installation where the soil analysis showed corrosive soils with the possibility of microbiologically influenced corrosion. Also critical to the pipe material and corrosion protection method selection, was the concern over induced alternating current (AC) stray current corrosion, as the alignment paralleled overhead high voltage AC lines. The basis for the analysis of this pipeline is a newly published risk-based decision model that considers both risk factors for corrosion as well as consequence of failure analysis. The result is a framework to justify corrosion protection methodologies employed for water and wastewater piping. Additionally, this paper considers how various protection methodologies may mitigate or exacerbate corrosion from stray current sources. The corrosion protection methodologies evaluated included polyethylene film, enhanced polyethylene film, sacrificial coating, bonded coating, and bonded coating with cathodic protection.

The Great Lakes Water Authority (GLWA) provides water to approximately 4 million people in 127 communities—nearly 40% of the state of Michigan. Up to 1.7 billion gallons of water per day is conveyed to customers through over 800 miles of large diameter transmission mains. In October 2017, a 48-inch prestressed concrete cylinder pipe (PCCP) operated by GLWA experienced a catastrophic failure, resulting in a service impact to more than 300,000 customers, including three nearby hospitals. The drop in pressure caused by the break resulted in reduced pressure, boil water advisories, and loss of service. GLWA, Oakland County, and member partner public works departments worked around the clock to isolate the main break, open emergency connections, and restore water to as many customers as possible while the main was being repaired. At the time of this failure, GLWA was developing a transmission system integrity plan, which included a risk-based prioritization and long-term asset management plan for all their large diameter pipeline inventory. Due to the risk of this main failing again, and considering the now understood consequences, GLWA decided to complete a comprehensive condition assessment as a pilot study to be used as the basis of the integrity program. This paper will provide background on the transmission main and include a discussion of the 2017 failure. This paper will also provide details on the planning and execution of the water main assessment, which posed several challenges because the pipeline has no redundancy. In order to minimize the likelihood of service impacts, GLWA opted to use inline, free-swimming technologies to complete the assessment. Considering that GLWA is a wholesale water provider to more than 127 member-partner communities, planning and executing the assessment required widespread collaboration between internal and external stakeholders. Several risk mitigation procedures were completed prior to the assessment, including test shutdowns and valve operability assessment. In an effort to maximize the information obtained during this assessment, multiple techniques of varying resolution were employed, including a drone flyover, transient pressure monitoring, inline leak detection, and electromagnetic assessment. GLWA determined that the criticality of this main also warranted the installation of a continuous structural monitoring system that will allow them to make proactive decisions in managing this high-risk main. As GLWA moves forward with a transmission system integrity program, the lessons learned from this assessment will serve as the basis for development of a world class, water sector leading program!

Solaris Midstream of Midland, Texas, was tasked to develop fresh and produced water lines to be used in oil and gas production in an area south of Malaga, New Mexico, along the TX/NM border and in the heart of the Permian Basin. These pipelines would run from a 1-million-barrel or 42-million-gallon fresh water pond and pump station constructed in Texas just south of the TX/NM border and head north through Lea and Eddy Counties in New Mexico to fracking rigs. The intent was to construct a distribution pipeline and network that could pump water to and from various rigs in the region and eliminate the need to truck water to each site. The project alignment spanned over nine miles through arid, undeveloped land. The open terrain simplified layout and installation but caused other complications when it came to mobilizing crews and equipment to the project site. The closest towns where construction crews could stay were over an hour drive from the project site and the site itself started seven miles down a dirt road off a 2-lane highway. Completing design and ordering pipe material in late March 2018, beginning construction/installation in May 2018, and completing this installation by the deadline of July 1, 2018, required intensive coordination between Solaris Midstream (owner), Parnell (engineer), Blackline Energy Services (contractor), and all material and equipment suppliers. The dry, rocky soil conditions throughout the alignment presented another obstacle in maintaining pace for project completion. Aside from a few road and existing utility crossings that required bores, the majority of the alignment was installed by open trenching, required to contain both the 16-inch fresh water line and 12-inch produced water line in a shared trench with minimum 3 feet of cover. The tight schedule, long working days/hours, the rural area, site conditions for the work force, and lack of power or mobile phone coverage all added to the complexity of this project. The 12-inch produced water line was installed for future use. This paper will focus on the design, construction, coordination, challenges, and methods to maintain a steady installation rate over nine miles to complete the 16-inch fresh water line within weeks and to have it and the pump station complete and on-line by July 1, 2018.

Crossing environmentally sensitive areas can present challenges for pipeline design and construction. Identifying environmental constraints early during route analysis and pipeline design is important as they can affect alignments, installation methods, cost, schedule, and ability to gain public support. This paper presents several case studies of pipelines crossing environmentally sensitive areas and highlights the key considerations and steps involved in addressing the environmental constraints. The case studies include a variety of sensitive installations including waterways, wetlands, parks, and a national monument. Common considerations and their application to each unique project will be discussed, such as: involving stakeholders and regulatory personnel early in the process; understanding the permitting and regulatory requirements; engaging specialists in areas where endangered species may be present; evaluating various installation methods including open cut, aerial, and trenchless; and consideration of cost and schedule impacts. Understanding and addressing environmental constraints early in pipeline design provides maximum opportunity for optimized solutions that protect the environment and balance cost, schedule, and other key project drivers.

Large diameter water transmission mains are the backbone of the Baltimore Metropolitan Water District (BMWD) system. These mains transport water from three treatment plants to pumping stations, ground storage reservoirs, elevated tanks, surrounding counties, and finally to smaller distribution mains to customers in Baltimore County and Baltimore City. Approximately 86 miles (454k lf) of these transmission mains are large prestressed concrete cylinder pipe (PCCP). When PCCP fails, the results are devastating to the water system and surrounding areas. After several catastrophic failures of PCCP, the BMWD determined that PCCP water mains 36-inches and larger are critical to the overall integrity of the metropolitan water system and should therefore be a top priority for condition assessment. In the late 2000s, The BMWD established Project 953 to create the groundwork for an inspection, assessment, and preventive maintenance and monitoring program for raw and finished water mains. This project also included a pilot inspection of a 54-inch PCCP water main to demonstrate the technology that could be utilized for future inspections. In 2016, Pure Technologies (Pure) was tasked by the BMWD to develop a more comprehensive condition assessment plan or pipeline risk prioritization (PRP) predicated on the preliminary work done in Project 953 for the next 10-years based on the BMWD’s budget restrictions. A factor-based prioritization model was utilized with pipe attribute failure factors and a set of rules to weigh and calculate the combined risk for segments of large diameter PCCP. These segments were combined into “Data Acquisition Unit (DAQ) Zones”. Each DAQ zone was assigned a priority based on calculated risk factors. Pure began inspections on the highest priority water mains using visual and sounding methods, innovative tools for locating leaks and gas pockets using acoustic based technology, and electromagnetics for identifying broken pre-stressing wires. Three years after the completion of the PRP plan, the BMWD and Pure have inspected 4 of the 14 DAQ Zones and made repairs to the pipelines. It was also during this time that the asset management plan and risk factors underwent revisions due to changes in key personnel. This paper will provide an overview of the PRP, the lessons learned during the last three years of the execution of the program, and showcase how the BMWD in partnership with Pure continues to mold and create a strong asset management plan based on an improved risk management system while mitigating various project challenges.

Water supply systems (WSS) are lifelines of communities as they enable security, health, and economic prosperity. Pipeline infrastructure in many older regions of the U.S. has deteriorated leading to significant leakages and frequent component failures. These issues currently threaten the supply reliability goals of water utilities and it is important to take cognizance of these vulnerabilities and develop appropriate response strategies. In this paper, a framework for optimized near real-time scheduling for operation and control of WSSs is proposed and demonstrated. The operational statuses of different types of valves and pumps that are inclusive of the system will be controlled based on an evolutionary optimization algorithm that is driven near real-time system monitoring data (e. g. tank level values). Energy efficiency and leakage minimization goals may also be accomplished through better control of system operations using monitoring data. The results of the optimization algorithm will lead to improved system operations and sustainable usage of critical resources such as energy and treated water. The proposed approach is demonstrated using a modified version of Anytown WSS. A genetic algorithm optimization code written in MATLAB is integrated with EPANET programming toolkit to enable the modeling of monitoring-data-driven optimal WSS control. This study and its findings would help water utilities in controlling the operations, maintaining reliability, and planning rehabilitation work of their systems.

The city of Springfield is investing approximately $20 million into the Erie Interceptor Express Sewer project, an integral part of their long term combined sewer overflow control plan. It will serve to reduce combined sewer overflows and convey separate sanitary flow to be preferentially treated in the city’s activated sludge treatment plant. The project scope included design and construction of approximately 7,000 linear feet (lf) of 42” gravity sewer; a new 11 mgd pump station (expandable to 19 mgd); approximately 6,000 lf of dual 18” force main (12,000 lf total); decommissioning and demolition of four existing wastewater pump stations and construction of approximately 3,000 lf of 8” gravity connector sewers from the current pump station locations to the new express sewer; connection of the discharge from an existing pump station to the new express sewer; and rehabilitation of approximately 4,100 lf of an existing 36” combined sewer. The project required complex pipeline alignments with involvement by various stakeholders. As a result, there were several changes through the design process as well as other scope modifications to address critical issues with existing infrastructure. The project traverses an urban corridor with varying geology and land uses including former and current industrial sites. A proactive focus on planning and risk identification in the design phase helped to manage costs during construction, despite many challenges during design and unforeseen conditions arising after construction was underway. Specified allowance items in the project bid to account for potential unknowns enabled the city to have minimal change orders during construction. Lessons learned from design, construction, and the bid approach will be shared to best manage unknowns and mitigate change order potential during construction for challenging linear construction projects.

Route selection is a critical process in the preliminary design of linear infrastructure. A weighted ranking analysis of pipeline routes allows for the selection of a project alignment that results in the lowest overall impact based on project-specific variables. Factors that influence and inform a routing analysis can be categorized and subcategorized into project-specific evaluation criteria. Examples of pipeline routing evaluation criteria are environmental impacts, financial impacts, and social impacts. Each of these criteria can contain one or more site specific subcategories such as right of way/easement requirements, cost, utility impacts, cultural/archeological historical impacts, or other named issues of stakeholder importance. An initial screening of potential routes is generally performed to lay the groundwork for a more detailed evaluation. Multiple routes are developed, less attractive routes are eliminated, and the routes that remain after the initial screening process are evaluated using a weighted ranking analysis. Evaluation criteria are given a score based on their relative importance to one another, the criteria are quantified by level of impact, then weighted based on project-specific conditions. The evaluation method will vary depending on the type of project and should be modified as necessary depending on the goals and interests of the owner. The scoring matrix ultimately generates a ranked list of pipeline routes that range from least impactful to most impactful and allows an engineer to recommend a pipeline route with supporting justification. This technical paper will present an alternative pipeline routes case study, show how evaluation criteria influence the scoring of each route, and show how an optimal route is selected based on a weighted ranking analysis. The weighted ranking system will show how the project owner’s goals and interests affect the route selection process (i.e. critical project goals are weighted according to importance), and how this type of analysis can be used to justify a route recommendation. This type of route analysis is both qualitative and quantitative, ultimately providing a source of justification for a critical preliminary design element of pipeline projects.

The city of San Mateo, CA, commissioned Stantec to complete the planning, preliminary design, and final design of the Basins 2 and 3 collection system improvements which will address sanitary sewer overflows within a large section of the city. This paper includes a project narrative followed by pertinent project specifics presenting lessons learned and the key takeaways of the design team. The lessons learned, and topics addressed are largely applicable to all engineering projects regardless of field or nature. Subjects include stakeholder engagement, utility coordination, data reliability and delivery, design and construction schedule, knowledge continuity and a transforming team, and design changes.

Tohopekaliga Water Authority (“TWA”) is facing similar challenges that municipalities are encountering nationwide, including how to proactively assess and identify priority infrastructure for rehabilitation, and how to fund the necessary improvements prior to them becoming emergency repairs. The construction of the existing system infrastructure within TWA’s service area was sub-standard and most of system issues were inherited by TWA in 2007. Over time, the system infrastructure has declined and is currently in a state of disrepair; thus, creating emergency repairs, added costs, and greater impacts to the community. TWA has been proactive in assessing their collection system infrastructure and identifying the top 20% of their system with respect to high consequence gravity interceptors, gravity mains within primary roadways, and mains within known high infiltration areas of their system. Accordingly, TWA is actively pursuing an aggressive rehabilitation program to minimize the escalation of repair costs once they become emergencies. Currently, funding for the rehabilitation projects is coming from funds on-hand, which is a primary constraint to moving forward quickly. Receiving the Water Infrastructure Finance and Innovation Act (WIFIA) funding will allow the sewer main replacement to move forward approximately twice as quickly as the projects would without WIFIA funding. The current frequency of sewer repairs that must be addressed on an emergency basis impact the availability of funds budgeted to address collection system deficiencies identified by the in-house assessment program on a proactive basis (prior to failure). WIFIA funding will expedite assessment in the identified troubled areas and allow known and discovered deficiencies to be addressed prior to failure. This will reduce the current expenditures that are characteristic of emergency repairs; namely expedited mobilization/demobilization, maintenance of traffic, replacement versus rehabilitation, and restoration costs.

Evansville Water and Sewer Utility has a 36-inch potable water PCCP transmission main that serves as one of the backbones of their water system. The Riverside Drive Transmission Main’s condition was largely unknown, and the utility made the decision to perform a comprehensive condition assessment of the main to identify its current condition, make needed repairs, and perform forensic evaluations of the replaced pipe sticks to better understand the triggers for its deteriorated condition. The goal was to understand what lies beneath Riverside Drive and to maintain the pipeline’s integrity. The approach to assessing the main began with identifying inspection technologies capable of providing the most information possible. Electromagnetic technology used to identify broken wire wraps in the main was paired with a leak detection platform. In preparing for the inspections, the utility worked to minimize impacts to critical services and because of the selected technologies, were able to perform the inspections while keeping the main in service. The results of the inspections indicated approximately 5% of the pipeline sticks showed signs of distress in the wire wraps. Working with the inspection company, three sticks were identified for replacement. Once excavated, an external verification of the damage was performed confirming the proper sticks had been identified. The approach will then be to excavate and replace the pipe sticks, saving the worst for a forensic evaluation. Evansville Water and Sewer Utility needed to know why their transmission main is showing signs of distress, in order to take steps to extend the expected remaining useful life.

Denver Water is replacing an existing large diameter pipeline along an 8.5-mile route between a reservoir and a water treatment plant. Property easements for this pipeline were acquired initially more than 80 years ago and, since that time, the land within and around the easements has become extensively developed with homes, businesses, and mature landscapes. Further complicating matters, the impacted property owners are not direct customers of Denver Water. This paper and presentation will present how Denver Water and HDR have developed and executed a public outreach and right-of-way (ROW) program leveraging land agents and design and communication professionals to effectively communicate Denver Water’s project needs, easement rights, and impacts. Approximately 195 commercial and residential properties fall within Denver Water’s easement boundaries for the project, with other surrounding residential neighborhoods and business also being impacted by construction. The Denver Water and HDR team (team) developed a personalized grassroots approach to educating stakeholders on easements and construction impacts. This approach was crucial to Denver Water’s commitment to being a good neighbor while avoiding negative publicity and keeping the project within budget and schedule. The ROW and strategic communications teams collaborated to prioritize communication with impacted property owners within and adjacent to the easement through a variety of methods. One of the most beneficial is through “kitchen table meetings” with each directly impacted land owner to provide one-on-one interactions with the project team to communicate their unique property impacts and rights. The meetings also provided the project team an opportunity to share the benefits of updating aging utility pipelines and the importance of the project overall.

Buried pipelines are susceptible to damage from ground movements triggered by earthquakes, such as liquefaction-induced lateral spreading, landslides, and fault rupture. Given the linear characteristics of water and wastewater pipelines, failure due to ground displacement is most likely to occur at locations of weakness, which for segmented pipelines is typical at joints or fittings linking adjacent sections of pipe. Connections can be characterized as unrestrained (e.g., bell-and-spigot joints), fully restrained (e.g., continuous systems with welded/fused connections), or hybrid segmented joints, which provide the ability to displace axially in response to ground movement before locking up and behaving as a continuous system. The joint type and geometry will contribute significantly to the expected performance of a given pipe system subjected to axial and/or transverse ground movements. Furthermore, the connection force capacity of the joints is an important limit state for predicting failure of pipe systems for which the joint has less strength than the pipe barrel. To support the development of an ASCE/UESI manual of practice (MOP) on Seismic Design of Water and Wastewater Pipelines, this paper presents a framework for establishing the minimum connection force capacity (based on burial conditions and pipe/connection characteristics) required for a particular system to be classified in one of four proposed seismic demand categories defined by the MOP. To predict system response to various levels of ground movement, an analytical model is paired with a statistical approach to compare the survival rate of pipe systems that have performed well in past earthquakes to the expected survival of other systems composed of different materials and mechanical connections. Results will aid seismic capacity classification by providing a basis for establishing connection force capacity coefficients for new and existing systems.

Many water systems have performed poorly in major earthquakes. Water supplies needed to fight fires or for health and safety of the public during post-disaster recovery have been disrupted. Although many water utilities have seismically upgraded their tanks, pump stations, and other “vertical” structures, most U.S. water utilities still have vulnerable watermain networks. Over one thousand watermain failures occurred in each of the 1994 Northridge, 1995 Hyogo-ken Nanbu (Kobe), 2011 Christchurch, and 2011 Tohoku earthquakes. These watermain failures led to depressurization in large areas of the affected water systems and lengthy restoration times. Japan has pioneered the use earthquake-resistant design standards for watermains and the installation of seismic resistant pipe. Watermains built using these earthquake-resistant design standards and seismic resilient pipe systems have been shown to provide excellent seismic performance. Although many U.S. utilities located in areas of high seismicity are beginning to use earthquake-resistant watermains, there is not a uniform U.S. standard that stipulates seismic design requirements for new watermains. To decrease the seismic vulnerability of watermain networks in the United States, the American Society of Civil Engineers’ (ASCE) Utility Engineering and Surveying Institute (UESI), in collaboration with ASCE’s Infrastructure Resilience Division (IRD), is developing a manual of practice (MOP) for water and wastewater pipeline seismic-resistant design. The intention of this MOP is to serve as a pre-standard for seismic design of all new water and wastewater piping in the U.S. and Canada. Detailed, site-specific analysis is warranted for transmission mains and some other critical watermains. However, most pipelines do not require this type of analysis. To simplify the design methodology for the less critical pipelines that comprise the majority of most water system networks, a prescriptive procedure is being developed. The prescriptive procedure will utilize the pipelines level of service (criticality), level of redundancy, the seismicity, and geotechnical hazard exposure to assist the watermain designer in selecting pipeline performance criteria. The pipeline performance criteria will be established in terms of required system flexibility (e.g., joint deflection for segmented pipelines), ductility (e.g., strain capacity), and strength for continuous and segmented pipelines. It is expected that pipe manufacturers would test their pipe products and demonstrate different performance levels. The goal is to ensure that the pipe materials perform as expected after a seismic event. The prescriptive procedure is intended to be a simple, straight forward method that will allow civil engineers to design and specify new pipe without specialized geotechnical and earthquake engineering expertise for most commonly encountered design conditions. This paper describes the proposed prescriptive procedure and presents design examples.

In this study, we developed an improved earthquake-resistant ductile iron pipe (ERDIP) having a large diameter, with the aim of improving workability and reducing installation cost in order to promote the establishment of an earthquake-resistant pipeline. The proposed ERDIP was created with the intent of achieving the same seismic performance as an existing ERDIP, which has performed satisfactorily against large earthquakes. The new pipe joint is a metal touch-type mechanical joint. The metal touch jointing was performed by simply tightening the T-head bolts and nuts until the glands touched the socket flange, thereby eliminating the tightening torque control of the T-head bolt/nut, which is a necessary condition for the AWWA (American Water Works Association) standard mechanical type joint. In addition, a pipe centering tool having a simple structure enabled quick insertion of a pipe spigot to a bell despite the pipe having a large diameter. The use of the new pipe and tool thus reduced pipe assembly time and therefore construction cost.

The present paper extends the experimental and numerical research presented at the ASCE 2018 conference. The paper is numerical, based on a shell finite element simulation of the welded lap joint subjected to internal pressure and structural loading, which accounts for the bell formation process, the corresponding residual stresses, and the presence of initial (geometric) imperfections of the cylindrical pipes. Previous numerical simulations of the experiments presented in the 2018 conference, have shown a very good comparison between the numerical results and test data. The present paper has the following two purposes: (a) extend the numerical results for the case of axial compression loading, in addition to the case of bending; and (b) examine the effects of pressure on the mechanical response of welded lap joints. Towards the above purposes, two 24-inch nominal diameter pipes with thickness equal to 0.135 in. and 0.25 in. will be considered, similar to those tested in the prior experiments. The pipes contain welded lap joints with single and double weld and are pressurized first to a certain level (up to 50% of yield pressure) and subsequently, they are subjected to either axial compression or bending, well into the plastic regime of the steel material. The numerical results are used for elucidating some interesting issues of welded lap joint behavior under severe axial and bending deformation, allowing for determining the ultimate load deformation capacity of those joints in geohazard and seismic areas, where severe ground-induced actions are expected, towards minimizing the risk of failure.

Seismic damages of pipelines at fault crossing have been seen in various places in recent years. Countermeasures against fault offset are difficult, because the amount of fault offset on the order of several meters may occur locally. There have been virtually no cases in which proactive countermeasures were taken for fault crossings. Therefore, the authors have developed “steel pipe for crossing fault (SPF),” which can maintain the water transmission function without cracks or leaks even in the event of large displacement. In order to confirm the performance of SPF, the performance tests were carried out with Cornell University: axial compressive test, axial tensile test, cyclic test, bending test, and split basin test. SPF makes it possible to secure the water transmission function of pipelines, by following large ground displacement locally, like fault offset, ground subsidence, land sliding and lateral flow of soils, and similar problems. This paper introduced the concept, performance tests, and applicable examples in Japan.

Buried water and wastewater pipeline infrastructure located in regions with increased seismic activity are vulnerable to damage from seismically induced geo-hazards. Two types of geohazards are possible: (1) wave propagation hazard; and (2) permanent ground deformation (PGD) hazard. While earthquake-induced transient wave propagation can lead to damage of some pipe systems, permanent ground deformations (PGD) such as those imposed by landslides, liquefaction-induced lateral spreads, and fault rupture have been shown to be particularly damaging to buried pipelines. While pipeline response is dependent on the soil-pipe interaction behavior, the pipeline response related to seismically induced longitudinal PGD is heavily influenced by the frictional resistance that develops from relative displacement between the soil and pipe at the soil-pipe interface. The frictional resistance along the pipeline is dependent on the pipe material, joint geometry, soil type, cover over the pipe, and pipe diameter among other things. The American Society of Civil Engineers (ASCE) is currently developing a manual of practice (MOP) for the Seismic Design of Water and Wastewater Pipelines under the Pipeline Division of the Utility Engineering and Surveying Institute (UESI) in collaboration with ASCE’s Infrastructure Resilience Division (IRD). To aid the MOP development, simple soil-pipe interaction analyses have been undertaken by the task committee to characterize the longitudinal frictional resistance force along continuous and segmented pipelines constructed of different pipe materials. This paper presents a description of the analyses completed, results obtained, and recommendations developed including proposed equations to characterize frictional behavior at the soil-pipe interface and suggested parameters suitable for different pipe materials, joint geometry, soil types, and installation conditions.

Buried pipelines can be exposed to transient and permanent ground movements (e.g., lateral spreading, landslides, differential settlement, and fault rupture) in earthquakes. These movements can be characterized in terms of ground strain as a function of the ground displacement over the length or width which that displacement occurs. These ground strains impose demands for which the pipes must be designed to withstand and ensure they remain functional following an earthquake. This paper identifies and tabulates the range of transient and permanent ground strains pipes may be subjected to, providing guidance to product developers and engineering designers for improving buried pipe performance during earthquakes.