Pipelines 2011: A Sound Conduit for Sharing Solutions

The Scranton Sewer Authority (Authority) received an Order for Compliance from the Environmental Protection Agency (EPA). At the time, the sewer system was under private management. The Authority took immediate steps on a variety of fronts to address the Order, including reestablishing local operations and management control, as well as addressing each element of the Order. A portion of the Order dealt with requirements relating to the existing NPDES Permit. A Special Condition of the NPDES Permit required a physical identification of the combined sewer system, including the following for each outfall: (1) Location of the discharge point (2) Description of the regulator system (3) Description of the outfall structure (4) Field verification of deteriorated sewers and other areas of concern The Order required a large number of concurrent activities. Organizing cost effective and prompt actions under the tight time constraints of the Order necessitated innovative approaches to undertake the physical inspections. Inventory, inspection and condition assessment of the physical components of the system were the initial steps to asset management. The comprehensive regulator inspection program included detailed field investigations and documentation of the condition of the CSO regulators and adjacent piping. Specialized inspection crews were utilized to provide confined space entry and detailed inspection services of internal equipment. Inspection crew members entered the regulators to record dimensions, evaluate the condition of equipment, and provide digital photography. Following the detailed inspections of the regulators, the sewers immediately adjacent to the regulators were televised with a remotely-controlled and independently-illuminated zoom camera. This camera was utilized to provide zoomed images of the adjacent piping to locate cracked, misaligned, or collapsed sewers, and blockages. A comprehensive report was provided to the Authority. This presentation will include an overview of the requirements of the Order for Compliance, implementation of the inspection program, technology utilized for the inspections, and findings. It will also present the management response to the Order and some recommendations for other permittees encountering similar orders.

Damages and defects in prestressed concrete pipes (PCCP), such as prestressing wire breaks and cracks, reduce the stiffness and thereby natural frequencies of the pipe. A finite element method (FEM) is used to evaluate the natural frequencies and mode shapes of PCCP. In our previous study, it was shown that the variation of natural frequencies due to wire break is small. Therefore, structural health monitoring (SHM) of PCCP is performed by considering the mode shapes and variation of curvature of mode shapes due to wire breaks. for damage identification, mode shapes and curvature of mode shapes of undamaged and damaged PCCP are compared. The severity of damage is presented by increasing the number of broken prestressing wires. The results are obtained for 48 inch PCCP lined cylinder pipe (LCP) under 17, 35 and 50 number of wire breaks. The proposed model is applied to obtain the effects of wire breaks on resonance response of PCCP. Based upon the obtained results, suggestions for future work are presented and discussed.

Water infrastructure is a complex system that is comprised of many variables that have an effect on the overall condition and/or performance of the pipe. Accurate performance prediction of a water pipe plays an essential role in the utility asset management process and capital investment planning. This paper presents a weighted factor and fuzzy inference methodology in developing a novel performance index for metallic drinking water pipelines. With the uncertainties and imprecision in utility data along with the ambiguity in the affect pipe parameters have in determining the performance of a water pipe a method needs to be employed that can account for these impediments. Current utility and expert knowledge is also crucial as much of our infrastructure is just starting to see the major effects of pipeline deterioration. With the use of continuous membership functions and rule statements, the fuzzy inference methodology demonstrates to be well suited in generating water pipeline performance values over the weighted factor model. Overall, the water pipe performance models are based on four modules including current pipe integrity, internal stress, external stress and external corrosion. By including over 30 input parameters these models are robust in nature and consider the critical aspects in determining pipeline performance.

The Portland Water Bureau (Bureau) is striving to provide the highest quality water, customer service and stewardship of the critical infrastructure, fiscal, and natural resources. In order to be proactive in management of its assets, the Bureau decided to develop an Asset Management Plan (AMP) for its distribution system pipes. An AMP is a long-range planning document that provides a framework for documenting the assets owned and managed, understanding the risk exposed, and forecasting financial commitment required sustain the services. It is also a plan of action or guidance on how the Bureau intends to manage the assets — address risks, strategize maintenance and replacement, and budget program needs. This paper highlights the content of the current AMP for pipes and how the Bureau managed its pipes.

All water utilities are faced with similar challenges — aging infrastructure and increasing costs to run and maintain our water systems. Stretched budgets push us to find ways to reduce costs; however this needs to be done without compromising system performance. The US EPA's Statement of Policy on Sustainability (USEPA 2010) highlights the importance of planning in the development of sustainable water infrastructure stating "drinking water and wastewater systems should use robust and comprehensive planning processes to pursue water infrastructure investments that are cost-effective over their life cycle, are resource efficient, and are consistent with community sustainability goals." Asset records provide information relating to pipe age and material and in most cases a utility will also be aware of locations or time periods where installation techniques and materials were inferior, or locations where soil conditions have led to an increased rate of deterioration. Water system operators are aware of areas where breaks frequently occur and this will be reflected in repair and maintenance records. It is common practice for utilities to utilize this data relating to age, material, maintenance history, and past failures when prioritizing mains for replacement. Comprehensive condition assessment can give a utility greater understanding of the likelihood of failure of pipes specific to their own system. If replacement of an asset is postponed and failure occurs, the utility may pay a significantly larger amount of money to replace the asset under emergency conditions and they will likely be the subject of unwanted public and media scrutiny. In addition to determining the likelihood or probability of failure through condition assessment, utilities are now looking at consequence of failure as another metric by which pipe replacements can be prioritized. The key to measuring consequence of failure is to understand which assets are likely to cause the most disruption in the event of failure. Hydraulic modeling packages have been developed in response to the need to understand the consequence of pipe failure. Using a calibrated hydraulic model of a water system together with valve data from a utility's GIS, these packages allow a modeler to determine the consequence of pipe failure by simulating break and isolation conditions for every pipe in the network. Understanding the potential consequences and the likelihood of pipe failure allows development of a risk score for all pipes in the network. The ultimate step in the pipe replacement planning process is to optimize pipe replacements based on their risk score, ensuring rehabilitation budgets are spent wisely while minimizing a system's vulnerability to pipe failure. Powerful optimization tools allow utilities to simultaneously evaluate and trade-off multiple drivers such as reducing risk of pipe breaks, reducing leakage, improving system hydraulic performance, minimizing disruption to busy traffic routes and coordinating pipe replacements with planned road works.

Cracks are the most recognized indication of damage in Prestressed Concrete Noncylinder Pipe (NCP) due to corrosion, hydrogen embrittlement, overloading and pipe's defects. In this paper, an extended form of the finite element method (XFEM) is used to study crack initiation, growth and life prediction analysis of NCP. Using XFEM enables to model the pipe without explicitly meshing the crack surfaces, and hence crack growth simulations can be carried out without the need for remeshing. for structural monitoring, stresses and strains of the damaged NCP are evaluated. The crack propagation of a damaged NCP is investigated due to increasing the internal pressure of the pipe. The proposed model is applied to obtain the location and minimum internal pressure associated with visible cracking in the pipe. Based upon the obtained results, suggestions for future work are presented and discussed.

Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) microanalysis technique has distinct advantages in providing high resolution images for identification of microscopic structure changes in hydrated cement matrix and the chemical compositions. Therefore, this technique can be a very useful tool for characterization of asbestos cement (AC) pipe deterioration. Microscopic structural changes in AC pipes can be related to leaching, chemical and biological processes, which include the free lime leaching, secondary gypsum and ettringite formation, acid attack, and the microorganism induced deterioration. These processes have resulted in losses of free lime, cracks in cement matrix, dissolution of Ca-bearing minerals and increased porosity in the cement paste. Carbonation, as calcite precipitation, on the other hand, is more often observed on the outer surface of the pipe in an alkaline soil environment, and may help to protect AC pipes. This paper is focused on the SEM evidence of these deterioration processes. With the elemental composition data from EDX technique, SEM can be used to quantitatively evaluate AC pipe deterioration. A four stage of deterioration of AC pipes in drinking water distribution system is proposed based on the morphology and elemental compositions of the pipe samples. The understanding of degradation mechanisms provides a scientific basis for the development of operational practices and management strategies that can be used to extend the service life of AC pipes.

The Great man Made River Project is one of the largest water projects in the world. It consists of 4000 Km (2485 miles) of mainly four meter diameter (158-inch) prestressed concrete cylinder pipe (PCCP) and can convey over 6 million cubic meters of water per day from well fields deep in the Sahara Desert to the populated areas on the coast. After experiencing failures on their pipeline between 1999 and 2001, the Great Man-Made River Authority (GMRA) conducted an aggressive rehabilitation program and implemented various technologies to assess the condition of remaining pipe sections. These failures were caused by chloride induced corrosion of the prestressing wire and affected only some of the pipes that were not coated with coal tar epoxy in Phase I of the project. These constitute only a small proportion of the projects pipes but affect an important section of the Phase I supply line. In parallel to the rehabilitation program, the Authority retrofitted 1000Km (620 miles) of the pipeline with a Cathodic Protection system to prevent future corrosion of the prestressing wire. Initially the pipeline was inspected using electromagnetic techniques to determine the extent of the problem. Once the rehabilitation program was underway acoustic monitoring was introduced to monitor sections of pipe that were under operation while other sections were being replaced or repaired. Site excavations of distressed pipes revealed that many of the adjacent pipes were also affected by corrosion that had still not resulted in broken wires. This was confirmed by acoustic monitoring which accurately detects wire breaks as they occur under operation. Increased demand also meant that the necessary dewatering of the pipeline to undertake electromagnetic inspections was no longer an option. Both these factors have led the Authority to rely primarily on acoustic monitoring during the operation of the pipeline. Developments in this technology has enabled the Authority to increase the scope of monitoring from 3Km (1.8 miles) in 2000 to current 800Km (500 miles) in 2010 with a projected 1200Km (746 miles) in 2012. Over the past ten years a wealth of monitoring data has been collected which has been an essential element of GMRA's Pipe Risk Management System. Initial analysis of this data in 2007 revealed there was a marked decrease in the rates of deterioration after the installation of cathodic protection. However it was not clear at that time if this reduction in deterioration rates would be maintained over a longer time span. Long term monitoring of a much larger section of the pipeline between early 2007 to the end of 2010 have enabled the Authority to make a more accurate assessment of the pipeline integrity. This paper will concentrate on the analysis of data over a ten year period to evaluate the effectiveness of the following; the initial rehabilitation program, the retrofitted cathodic protection system and the inspection and monitoring technologies used. Ultimately it will provide conclusions regarding the overall integrity of the system.

This paper presents on-going research work titled "A Web-based Interactive National Database of Condition Assessment and Renewal Engineering Technologies for Water and Wastewater Pipelines." This project is funded by the Water Environmental Research Foundation (WERF) through the Environmental Protection Agency's Aging Water Infrastructure Research Program, a research agenda that supports efforts to put the nation's aging infrastructure on a pathway toward sustainability. The development of this research program stems from EPA's Sustainable Water Infrastructure Initiative. This research project will evaluate existing, new, and emerging technologies that address the nation's aging water and wastewater infrastructure.

Steel pipelines are the one of the most economic and safe transport systems for water, and are often our population centers' only means of receiving goods which are vital to day-to-day existence. As a means of long-distance transport, pipelines have to fulfill high demands of safety, and reliability. Most metallic pipelines, regardless of what they transport, are designed with a typical life span of 25 – 50 years. When they begin to fail, the pipelines slowly form leaks at construction joints, corroded areas and small structural cracks. These leaks can gradually progress to a catastrophic failure if gone undetected or can result in substantial water loss over extended periods of time. Pipeline leak detection systems (LDS) are beneficial because they can enhance productivity and system reliability by means of reduced downtime and reduced inspection time through pinpointing and localizing the leak locations. LDS Systems are therefore an important aspect of pipeline technology that are primarily used to assist Pipeline Owners in detecting leaks. But what happens after leaks have been detected in steel pipelines and require immediate repair? This paper will present the importance of the correlation between efficient leak detection and pipeline repair. The general guidelines for the proper design and installation of fiber wrap strengthening systems for steel pipelines will also be presented. Discussion will center upon case histories and best practices to avoid over or under-designing the retrofit, and how to best implement the proper installation of these CFRP systems. The case studies will be explored in detail to evaluate the performance of past and present designs, both for municipal and industrial clients.

Municipalities have challenges funding both emergency and planned infrastructure repairs. Challenges come from time and value requirements predetermined for use of O&M funding, and time requirements needed to secure capital funding. O&M budgets are a great source of ready to go funds. Should an operations manager's organizational costs not be impacted by use of these funds for an emergency repair, then O&M funding may make sense for smaller projects. However, O&M funding value limitations will likely not support the higher costs associated with renewal projects. Although every agency differs, each agency has limitations for use of O&M dollars. For example, O&M funding may be limited to projects having a useful life of less than 5 years and project costs below $50,000. From this, it becomes obvious why O&M funding is a better fit to support maintenance operations rather than infrastructure renewals. The vast majority of infrastructure renewals exceed the time and value requirements set for use of O&M funding. As a result, Municipalities must obtain Capital funding to address both emergency and planned renewals. This paper discusses the ways in which municipal agencies have been able to successfully utilize capital improvement allocations for carbon-fiber-reinforced-polymer (CFRP) renewal of pipelines by recognizing this technology as a long term method for asset management for renewal of both buried and above ground infrastructure. The methods discussed are prequalification of materials and installers, award of on-call contracts, and methods for projecting the costs of future renewals for long term budget allocations.

The Philadelphia (Pennsylvania) Water Department delivers drinking water and operates all storm and sanitary sewers within the city of Philadelphia. This 142-square-mile area contains 3,400 miles of publicly owned sanitary sewers, storm sewers, and a large area of combined sewers. As measurement technology has matured, the department has enhanced its systems for managing its infrastructure. In some areas, these changes have been dramatic. These include use of remote video equipment to inspect city sewers, online monitoring of levels and flows throughout the system, and geographic mapping tools that make it easier to locate specific pipes. Each of these programs requires large databases that require maintenance and application integration. To manage this information, the department has developed a comprehensive set of interfaces available throughout the citywide corporate network that address specific needs and provides for analysis that cuts across several systems.

In water and wastewater asset management, the Environmental Protection Agency has long emphasized the significant role of risk assessment to measure the criticality of an asset. Critical assets are defined as assets with a high probability of failure (old, poor condition, etc.) and high consequences if they do fail (major expense, system failure, safety concerns, etc.). In practice, the consequences of failure are typically estimated by experts through the Delphi method. However, the estimation of the probability of failure has been a challenging problem as it requires the analysis of the utility owned data such as condition assessment data, and repair and replacement records. The most common predictor of estimating the probability of failure for sewer pipes is by determining the remaining life. However, using the calendar age of a sewer pipe completely ignores different aging patterns of pipes under different operational and environmental conditions. This paper introduces a new method using the "real age" of a pipe in estimating the remaining life. Unlike calendar age, real age represents the adjusted age given the unique location and current operational conditions (grease condition, root problem, sludge problem, etc.). Depending on unique deterioration patterns of an individual pipe, the real age could be higher or lower than its calendar age. A variable selection process prior to a model development is conducted to ensure that the final model is lean but well performed. A case study using actual sewer pipe data collected from a sewer utility organization is discussed to show the differences of the estimated remaining life based on calendar age and real age.

The Western Virginia Water Authority is a mid-sized utility located in Southwest Virginia providing water and sewer service to approximately 186,000 people. Similar to most municipalities, the Authority collected data in the field on paper for various field activities such as manhole inspections, incident investigations, planned maintenance and repairs & rehabilitations. This data was then entered by hand into assorted silos such as spreadsheets, databases and an address based CMMS. The system was prone to duplicative data entry and errors. In 2009, a business decision was made to consolidate all available asset and inspection data in one system and to focus on data analysis rather than on the mechanics of data import and management. Software was adopted to better manage the data and a mobile component of the software was implemented to allow seamless field data entry. The implementation involved initially reviewing the current paper forms and the data needed for monthly reports for management and examining the existing business processes. Once done, the initial electronic forms were created and refined with Field Crew input. The implementation was a "Bottom Up" process not "Top Down" to ensure that Field Crews were integral in the process and felt ownership of the final product. This paper will examine the advantages and disadvantages of using mobile software for field data collection along with the challenges and realities of the implementation process. It will also discuss how the collected data is used for data analysis and reporting in the office to make informed and defensible asset management decisions.

Golder Associates Inc. has conducted several condition assessments of prestressed concrete cylinder pipe (PCCP) used in the cooling water systems of energy generation facilities. This paper presents observations from these condition assessment projects. A vital component to the operation of energy generation facilities is the cooling water system. The cooling water system conveys cool water from a river or basin through the plant's condensers to condense steam produced in the process of power generation. The heated water is then returned to the river or basin, or sent through cooling towers to dissipate the gained heat. To work effectively, these systems typically operate with high flows (greater than 200,000 gpm) and low pressures (less than 60 psi) in large diameter pipelines (typically 54 to 120 in). These systems may provide cooling water to one or more units, and redundancy is not typical. Thus, the isolation of these systems for evaluation or repair may require the temporary shutdown of one or several units, resulting in significant costs associated with purchasing replacement power. Many utilities operating energy generation facilities constructed in the 1970s and 1980s have not included these cooling water systems in their general plant evaluation and maintenance schedule, and these systems have often operated continuously for over 30 years. Due to the increased awareness of plant personnel, and the age of their buried infrastructure, these systems are now being evaluated. Condition assessment of these systems is similar to other pipelines with tasks such as document review, physical evaluation and condition summary, but also requires detailed planning to coincide with planned unit outages, and in some cases requires significant coordination with other facilities to allow for several unit outages at the same time. Pipeline condition assessments conducted have identified a wide range of conditions for the 30- to 40-year-old PCCP used in cooling water systems, ranging from pristine pipe, to pipe that has technically failed. Factors contributing to the distress observed in the pipelines include the manufacturing practices (particularly the use of class IV prestressing wire), installation practices, nearby stray electric currents, groundwater quality and interaction, and operational stresses. Recommendations from these condition assessments have also varied greatly, from continued evaluation, instituting operational controls, or even complete replacement of distressed portions of the line.

This paper presents the benefits of a well-managed, long-term asset management program in determining the current condition and predicting future deterioration of prestressed concrete cylinder pipe (PCCP). More than 10 years of inspection and monitoring data were analyzed, accumulated from Palo Verde Nuclear Generating Station (PVNGS), operated by the Arizona Public Service Company (APS). Pipe segments were inspected every 3 years on average. These data were analyzed to determine the current condition of the PCCP assets, and to develop statistical models of future deterioration of the pipeline and future deterioration rates of distressed pipes in different repair priorities by tracking individual deterioration zones throughout the inspection history. Using established risk and uncertainty analysis techniques, future repair priorities are forecast. The frequency of inspections and quality of the data collected allowed us to develop meaningful predictive statistical models of deterioration in PCCP assets. Starting from the detailed data on distress levels in the pipelines, the models forecast future progression of distress, including the total number of distressed pipes, total number of highly distressed pipes requiring repair or replacement, areas of severe distress, areas of rapid deterioration, and specific pipe segments reaching severe distress level in a specific future time period. The inspection data and results of this study were incorporated into a Geographic Information System (GIS). Such information is of paramount importance for effective PCCP asset management.

Asset management is a core activity for public utilities; however, the extent and efficiency of how it is performed varies from utility to utility. Utilities are familiar with the benefits of using risk-based decisions to help establish investment priorities. The popular industry definition of asset risk is the "likelihood of failure" (LOF) multiplied times the "consequence of failure" (COF). This paper presents a discussion of multiple ways to produce asset condition scores; an array of asset aggregation combinations; and multiple mathematical methods of aggregating assets scores. The differing scoring results from these methods and the corresponding prioritization influence are illustrated for hierarchy levels or asset groupings. The paper discusses the sensitivity of the risk scoring results based on the granularity of the individual asset scores and how the scoring integration process affects asset prioritization. A recommended LOF mathematical integration scoring method and an example application are discussed.

This paper presents a summary of the research performed for Water Research Foundation on the evaluation of condition assessment and remaining service life prediction/failure margin analysis technologies in use for prestressed concrete cylinder pipe (PCCP). The project involved a literature review, an industry survey, and a workshop. The literature review integrated the published experiences with all condition assessment and monitoring technologies. The industry survey included design, distribution, and compilation of responses to a questionnaire sent to water utilities, technology stakeholders, and consultants to document their experiences. The workshop provided a venue to discuss utility experiences and utility needs. The results of the literature review, industry survey, and workshop were used to develop a Best Practices Guidance Manual that identifies a method of prioritizing pipelines for condition assessment; condition assessment, monitoring, and failure margin analysis technologies that are in existence or near deployment; benefits and limitations of existing technologies; gaps in knowledge; what works and what does not work in management of a pipeline; and further research and field work needed to improve condition assessment and pipeline management.

The comprehensive condition assessment of wastewater force mains has historically proven difficult for operators of collection systems since unlike potable water transmission mains, wastewater force mains generally lack redundancy and therefore, the ability to shut down the pipeline for a comprehensive assessment. Thorough inspections often require significant expenditures in order to bypass the wastewater flow via temporary pumping or a piped diversion. By conducting a desktop force main assessment, pipelines can be identified with a high likelihood and consequence of failure based on several criteria including flow transmitted, failure history, age, etc. While this desktop assessment provides an initial screening to identify high risk force mains, it cannot provide the comprehensive condition assessment that is needed to properly manage these critical assets. Since traditional inspection techniques used in the gravity sewer system (i.e. visual based technologies) do not always transfer easily to their wastewater pressure pipe counterparts, a different set of inspection tools is required for force mains. Acoustical anomaly detection tools have been used for several years to identify leaks and gas pockets in force mains but these are only a part of a full condition assessment for a pipeline. Further information is required to fully assess a force main including internal and external corrosion, which according to the Water Environment Research Foundation's Guidelines for the Inspection of Force Mains, are the primary causes of force main failure. A comprehensive internal and external pipe wall corrosion assessment has traditionally been a difficult task in force main condition assessment limiting inspections to a small number of test pit locations along the alignment of the pipeline. Recent advances in both tethered and non-tethered inspection technologies have made the full condition assessment of the full force main alignment possible. This paper/presentation will discuss the challenges and successes of conducting a comprehensive force main condition assessment including the use of existing and new techniques/technologies to provide collection system owners with the necessary information for the long term management of their assets. Data and examples of actual condition assessments will be presented and discussed.

Condition assessment is a foundation of a long term asset management program. However, it can also be logistically difficult, inherently subjective, and at times, even cost prohibitive. This is especially true when dealing with pressurized infrastructure including wastewater force mains. In order to be successful, each project requires a thorough understanding of available methods and technologies; the physical attributes of the collection and conveyance system; its operating parameters; and close coordination with the Owner's engineering and operations staff. One proposed, and cost-effective condition assessment program approach includes a strategic combination of traditional and innovative inspection methods. Operations include field corrosion evaluations such as soil corrosion studies, discrete pipe wall thickness inspections, and corrosion pitting analyses. Other non-destructive methods include the internal deployment of Remote Field Eddy Current (RFEC) and/or Acoustic Leak Detection (ALD) inspection technologies to determine continuous pipe wall thicknesses or to detect the presence of active leaks and air pockets of potentially corrosive gases. This paper will describe the practical development of a wastewater force main evaluation program including the approach; selection and implementation of inspection methodologies; identification of specific challenges and alternatives; and the presentation of a case study from an on-going evaluation program including inspection results, data analysis, and lessons learned.

Fast set, high solids polyurethane has been used as a coating for the interior and exterior of steel water transmission pipelines since the late 1980s, but it wasn't until 1999 that the American Water Works Association (AWWA) approved Standard C222 for polyurethane coating of steel pipe and fittings. Over the course of the following decade, the coating system gained wide acceptance for water transmission pipelines among many major water utilities. In 1997, Denver Water installed 8,090 lineal feet of 108-inch diameter steel water pipe with an interior coating of 20 mil thick polyurethane. As this was the utility's first use of polyurethane, Denver Water has undertaken testing of the pipe polyurethane lining during scheduled shut downs of the pipeline in 1999, 2002, 2006, 2009 and 2011. This paper presents what Denver Water learned from its field inspection and testing program of this early-generation polyurethane lining system. Physical and visual testing has thus far yielded favorable results, proving the integrity of the polyurethane lining after fourteen years of service.

Asbestos cement (AC) water mains were installed in the United States and Canada, from approximately 1940 to the early 1980's. According to the American Water Works Association, approximately 18% of the installed mains are AC, while EPA (2000) estimated a somewhat lower number at 15% of the total mains in the United States. While much of the installed AC pipe is in excellent condition, it has been noted by utilities that operate this type of pipe that some areas are prone to degradation. As the pipe ages, it is also noted that burst rates can begin to increase in frequency (Hu and Hubble, 2007). Condition assessment of Asbestos Cement pipes has been problematic for many utilities. Currently, the primary method used is to dig to the pipe and extract physical samples for testing of physical properties. Due to the cost, and problems with the statistical significance of thus method, few utilities have a full picture of the condition of their asbestos cement assets. The acoustical method relies on measuring how quickly an acoustical signal is transmitted along a section of pipe, using easy-to-access measurement locations such as fire hydrants and control valves. Changes to the signal-specifically changes to its transmission or propagation velocity-can be related to changes in the pipe wall stiffness. Echologics has recently undertaken extensive implementation and testing of the technology on asbestos cement pipes with Las Vegas Valley Water District. Studies and testing have also been performed in Richmond BC, Ottawa ON, and Tacoma WA. This paper will describe an acoustical method to determine the remaining structural wall stiffness of asbestos cement pipes. A review of the asset management procedures being used for AC pipes in Las Vegas will also be presented. This paper will outline several factors regarding the need for AC pipe assessment, including current EPA and California standards for asbestos

The City of Fort Collins Utilities Department (FCU) is in its second phase of a comprehensive asset management planning and implementation effort addressing its water, wastewater, storm water, and electrical utility assets. Key drivers for this effort included aging infrastructure, a need for more defensible budgets and rates due to limited funding, regulatory and legislative changes, and workforce transitions. This case study will highlight key features of effective asset management planning completed to date, and focus on completed efforts that have made progress to enhance asset management to promote sustainable infrastructure stability and more effective management of the utility's water, wastewater, and stormwater pipes. During 2009, FCU completed high level strategic planning efforts to determine its vision and key objectives for enhanced asset management. With this vision in mind, a comprehensive gap analysis was performed to examine FCU's current practices relative to international best practices in asset management. Collaborative efforts to examine key gaps and prioritize enhancement efforts led to a detailed "roadmap" of recommended next steps, including assessing the condition and criticality of pipes, towards enhanced asset management for FCU. During 2010, efforts focused on implementing the early tasks laid out in the asset management enhancement roadmap, including strategy enhancements, improved asset data management and investment planning, and associated business process improvements. Specific efforts that have been completed and will be presented include: (1) Asset management capabilities assessment and enhancement roadmap development (2) Levels of service target and guiding policies development (3) Extensive analysis and asset risk scoring of water, wastewater, and storm water pipelines and GIS mapping of these characterizations (4) 100-year risk-based financial forecasting for future inspection and repair/replacement of the pipelines over their expected life cycle In addition to highlighting key technical elements of efforts completed to date, this case study will discuss key success factors, challenges, and lessons learned by FCU staff as they embarked on this process. Understanding FCU's approach and experiences to date should benefit any organization interested in embarking on a more structured, comprehensive, and sustainable approach to enhanced linear asset management.

Bellevue Utilities owns and operates a wastewater collection system that serves over 135,000 residents in the City of Bellevue and surrounding communities. Bellevue Utilities is responsible for operating and maintaining over 500 miles of sewer main and over 30,000 service stubs (that portion of the side sewer which lies within the City-owned right-of-way). A large portion of the sewer pipeline system was constructed from the 1940's through the1960's. Although the Bellevue sewer pipeline system is younger than many other wastewater systems in the United States, some pipelines within the system are beginning to show the effects of age. In order to address the aging sewer pipeline system, plan for the future and maintain services levels expected by Bellevue Utilities customers, Bellevue Utilities is enhancing its condition assessment program and pipeline repair and rehabilitation program. Because the number of known defects has been increasing, defects are being prioritized for repair on the basis of risk, the estimated probability of failure multiplied by the failure consequences. So far, Bellevue Utilities has been able to address sewer pipeline defects primarily with point repairs. However, the increasing number of defects and observed condition of some of the Utilities sewer pipelines indicates that Bellevue Utilities will need to consider other methods such as pipeline rehabilitation and replacement in the future.

After many years of service and ongoing deterioration, Australia's infrastructure water pipelines including water pipes, sewers and stormwater pipes, are demanding timely and appropriate rehabilitation programs to ensure their serviceability. Asset management technology and understanding of pipe deterioration are constantly improving. But there is lack of a training program in most higher education providers and research institutions of Australia to update current asset managers and engineers as well as graduates with such latest, practical and state of art asset management skills and knowledge. In this paper, a training program for asset management of infrastructure water pipelines is proposed. The training program is designed to fulfill four key learning tasks: student-centred learning, learning diversity, student learning assessment and practical outcomes. The training program focuses on four important skill and knowledge areas: data collection program, risk management program, optimal rehabilitation program and project management. Furthermore, E-learning technology is explored to enhance student learning.

The public has to be involved in the decision making process of infrastructure projects. But the public involvement methods are more superficially used and the development decisions are often not satisfactory to the public. Therefore, a more rigorous method is needed to integrate the public or stakeholders' opinions. This paper proposes a rigor matrix to assess the quality of the decision making process and enhance the public involvement effectiveness for infrastructure projects. Focused interviews were conducted with practitioners to scrutinize the matrix's components to ensure its applicability. Rigor indices were calculated to quantify the quality of integration decisions. Finally, the rigor matrix was tested on a protested sewerage system project to explain its usefulness by comparing the actual and simulated scores. The results show that the rigor matrix and rigor indices can systematically explain and measure integration quality. This tool makes the decision making process more transparent and enhances the trust between the government and the public.

This paper describes a public outreach effort conducted by the King County Wastewater Treatment Division (WTD) in four shoreline communities in the City of Seattle, WA. A public outreach plan was developed to support planning and siting for new wastewater facilities for Combined Sewer Overflow (CSO) control. Despite similarities in project communities and both approach and timing of outreach activities, public reaction varied, apparently dependent upon proposed facility location, with park land creating the greatest level of opposition and requiring the most effort to address. The project team adjusted the outreach plan and added resources to accommodate response level and information needs in each project community after alternatives were presented. We conclude that project managers need to allow sufficient schedule and scope for extensive public outreach when new facilities are sited in urban areas, especially parks and open spaces, and to identify community-specific outreach strategies throughout the project.

The paper examines the structural response of buried butt-welded steel pipelines, crossing active strike-slip tectonic faults, which are vertical and perpendicular to the pipeline axis. The interacting soil-pipeline system is simulated with finite elements, accounting for large strains and displacements, nonlinear material behaviour, as well as for contact and friction on the soil-pipe interface. Steel pipelines of various diameter-to-thickness ratios, and typical steel material for pipeline applications (API 5L grade X65) are considered. The paper investigates the effects of various soil and pipeline parameters on the mechanical response of the pipeline, with emphasis on pipe wall "kinking" or fracture. The effects of cohesive and non-cohesive soils are also investigated. Furthermore, the influence of internal pressure on the structural response of the steel pipeline is examined. The numerical results are aimed at determining the fault displacement at which the pipeline failure occurs, they are presented in a graphical form showing the critical fault displacement, the corresponding critical strain versus the pipe diameter-to-thickness ratio, and can be used for efficient pipeline design against significant ground-induced deformations due to active strike-slip faults.

The constrained modulus (M_s) of soil has been used to predict the deflection and the buckling potential of buried flexible pipe. Since the constrained modulus (M_s) of soil increases with depth, M_s could have significant value in calculations for deep burial conditions. The standard laboratory test used to determine the constrained modulus is limited to sand size particles and smaller for practical reasons. Gravel size crushed rock is a desirable material for buried pipe support. However, large scale tests to measure strength properties of gravel particles are impractical because of the expense and lack of standard procedures for cohesionless soils. Thus, only presumptive values of the constrained modulus (Ms) for crushed rock are available. As discussed in a companion paper (Gemperline and Gemperline 2011), a large-scale confined modulus laboratory test was developed to quantify M_s values for gravel size particles. The test was performed on different clean, uniform samples of crushed rock. Each sample was tested at low, medium, and high densities. The tests were incrementally loaded to a pressure simulating about 150 feet of fill. The stress-strain curve was found to be linear with load, resulting in a constant value of constrained modulus for each soil at a specific density. The constrained modulus was also found to be directly dependent on placement density. The constrained modulus ranged between approximately 2000 lb/in² and 10,000 lb/in². The low density tests had constrained modulus values between 2000 lb/in² and 4000 lb/in². The high density tests had constrained modulus values between 5000 lb/in² and 10,000 lb/in². The constrained modulus values representing compacted crushed rock compare favorably with published empirical and presumptive values. The constrained modulus values representing dumped conditions are 200 to 400 percent higher than published empirical and presumptive values. Higher M_s values may be possible using rounded to sub-rounded particles with a wider range of particle sizes. Further testing should verify this assumption.

Permanent ground deformations associated with earthquakes, liquefaction and landslides can introduce substantial axial and bending strains on buried pipeline systems. The analysis of the strains is largely dependent on the force imposed on the pipeline by relative displacement between the pipeline and surrounding soil. To advance state-of-the-art for soil continuum models, it is necessary to develop better simulation of soil-pipeline interaction. In this study, finite element analyses (FEA) of the soil-pipe interactions under lateral movement in dry sand are investigated. Mohr-Coulomb strength parameters applied in FEA are developed from direct shear test data and a subroutine was introduced to represent strain softening. The results show excellent agreement with large-scale 2D experimental results and the results are used to construct a dimensionless chart for various depth-to-diameter ratios for dry sand. The favorable agreement between analytical and experimental results marks a transition from characterizing engineering behavior through experimental results to characterizing that behavior on the basis of computational simulation. The guideline based on experimental results for estimating force induced by soil-pipeline interaction can be replicated with FEA.

Seattle Public Utilities (SPU) in Washington State owns and operates two major water supply pipelines extending from the Tolt Reservoir in the foothills of the Cascade Mountain Range to the City of Seattle. These pipelines measure about 56 kilometers (km) in length and supply the City with about 30 percent of its water supply. The first pipe, designated Tolt Pipeline 1 (TPL1), is a 1.7-meter (m) diameter, concrete cylinder pipeline that was constructed in 1960. The second pipe, designated Tolt Pipeline 2 (TPL2), is a 2.3-m diameter, steel pipeline that was constructed in 1998. TPL2 was field mortar lined and is tape coated. Together they are referred to as the Tolt Pipeline. Since 2000, SPU has documented slope movements starting with ground surface tension cracks along a 150-m long stretch of the Tolt Pipeline. Within this stretch, the pipelines are buried about 1 to 3 m below a paved roadway surface. According to geologic and LiDAR (Light Detection and Ranging) mapping, the pipelines are located within a large, ancient landslide complex. Various studies and mitigation measures have been implemented since 2000, and currently SPU is evaluating additional mitigation measures due to continuing slope movements.

Constrained modulus (M_s) has recently found use in predicting deflection and buckling of buried pipe. Crushed rock and gravel are preferred materials for buried pipe support and previously only presumptive values of M_s were available. A one-dimensional compression test procedure to measure the M_s of coarse-grained soils (maximum particle sizes ranging from 0.5 inch to 1.5 inch) has been developed. A test specimen is placed in a 17.5 inch inside diameter, 17.3 inch high Teflon^TM lined steel pipe operating as a floating ring. A series of increasingly greater axial loads is applied, and axial deformation is measured. M_s is then calculated for each incremental pressure. Samples may be tested at low, medium, and high densities at varying degrees of saturation. Thirty-five tests were completed on five clean, crushed rock samples, one river rock sample, and one crushed concrete sample obtained from different sources in the Colorado area. Proper testing procedures and equipment, including friction and scale effects adjustment factors, were developed. It is demonstrated that M_s of hard, uniformly graded and shaped crushed rock,river rock and crushed concrete: (1) Is not greatly dependent on stress level; (2) Is strongly dependent on placement compaction effort; (3) Is weakly dependent on placement moisture condition; (4) Varies significantly with changes in crushed rock particle characteristics.

Each US Army Corps of Engineers' (USACE) district has established stringent requirements for installing pipeline crossings of levees so construction or repairs do not adversely affect ongoing flood control efforts and public safety. So when a new or existing pipeline's path must cross a levee, deciding how to cross it—up and over or down and under—takes a comprehensive evaluation of the levee's performance and overall stability to address protection requirements of the USACE as well as the pipeline owner's objective. Pipeline crossings in different settings and levee governing districts will require different approaches. The key to choosing the approach that best meets the needs of the USACE and pipeline owners in today's world is the early analysis of the situation. When prepared in advance, pipeline owners can work in a more timely collaboration with the USACE to find an engineering design that protects the public safety and supports their business objectives.

Current restrained joint design theories for different pipe materials depend on two primary mechanisms, frictional and lateral earth pressure, to resist the horizontal unbalanced thrust forces at a horizontal bend, valve, tee or other similar source of thrust in a buried pressure pipeline. The frictional resistance mechanism relies on the friction and adhesion resistance at the pipe-soil interface, while the lateral pressure resistance in current practice is generally assumed to be from passive pressure resistance. The contribution of frictional resistance in resisting the thrust forces in a horizontal bend was the subject of a paper presented by the task committee at the ASCE Pipelines 2010 conference. A similar, critical examination of the contribution of the lateral earth pressure resistance to resist the unbalanced thrust forces in a horizontal bend will be the primary objective of this paper. As thrust acts on a buried pipeline, the pipe in the vicinity of the source of thrust moves both longitudinally and laterally, relative to the axis of the pipeline. The lateral earth pressure component of resistance arises from the lateral component of the pipe movement into the surrounding soil. The lateral pressure component is directly considered in AWWA design manuals for some pipe materials, but not others. When lateral earth pressure is directly considered, it is generally assumed to be derived from passive resistance; other forms of lateral resistance mechanisms, such as bearing capacity/lateral flow of soil around the pipe, are not considered. This paper examines the theoretical and experimental basis for the current design approaches related to the use of lateral earth pressure for the thrust restraint design. It will assess recent developments in soil-structure interaction and load-deformation behavior and their possible use in establishing a common and rational approach to incorporating the lateral earth pressure component into thrust restraint design.

The New York City Department of Environmental Protection (NYCDEP) has been successfully using hot tapping and line stopping techniques at its sewage pumping station in Manhattan and water pollution control plant (WPCP) located in Brooklyn. These important installations provide a public service to a major sector of the population in the largest city in the United States thereby requiring that operations continue during their rehabilitation and reconstruction. This paper discusses the method and benefits derived from effectively applying the Hot Tapping and Plugging procedure. It was selected as the best alternative to address the need to maintain service and to protect the marine environment during repair and rehabilitation programs of pipelines and appurtenances within the pumping station and (WPCP) mentioned above. Discussion will also include how the method may be applied as a viable option to realize other types of work related to modification of various types of transmission pipe lines.

There is a lack of software interoperability, standard definitions, standard reports, standard codes, standard data storage, and standard information presentation practices. With the advent of GIS databases integrated with enterprise-level Asset Management Systems, there is an opportunity to capture and effectively utilize critical "as built" baseline condition data to obtain actionable information throughout the life-cycle of the asset. But this is only viable with consistent and compatible, "standardized" data collection. Currently, few standards exist for condition assessment data collection with buried pipes, and none are sufficiently comprehensive to enable the development of performance based design or "verifiable" implementation of artificial intelligence based prediction models. With the development and adoption of such standards to ensure data integrity, data collected by various operators, working for various companies, using various types of equipment and software, at different times, and even across multiple utilities, can be scientifically analyzed together.

This paper presents a case study of a Prestressed Concrete Cylinder Pipe (PCCP) system that is experiencing deterioration and a failure resulting from internal corrosion. The corrosion mechanism is Sulfuric Acid attack due to Hydrogen Sulfide gas (H2S) generated from the wastewater. The PCCP pipeline is located in Regina, Saskatchewan, Canada and was constructed in 1979. The nominal inside diameter is 1350 mm (54") and the pipeline was designed as a sewage force main. In 1999, approximately 75 m (246 feet) of the pipe failed and was replaced with HDPE pipe. In 2008, an internal inspection was conducted downstream of the failed section. The inspection was conducted using man entry and by close circuit television (CCTV). The inspection found five (5) pipe sections under severe corrosion attack where the interior concrete surfaces near the crown of the pipe had deteriorated exposing the reinforcing. Another nine (9) sections also showed early signs of H2S attack. A post inspection hydraulic analysis indicated the deteriorating pipe section does not flow full, and the hydraulic regime along this section is supercritical transitioning to subcritical resulting in a hydraulic jump forming within the pipe. The wastewater contains high concentration of sulfides. The turbulent flow conditions at the hydraulic jump exacerbate the release of H₂S gas from the aqueous phase to the air phase. The H₂S gas collects near the crown of the pipe and initiates corrosion attack on the concrete surface. A rehabilitation strategy was developed to extend the service life of the PCCP force main.

In the summer of 2009 the City of Mercer Island, Washington, began construction on the Sewer Lake Line and Pump Station No. 4 Replacement Project that would replace a portion of the failing sanitary sewers that surround Mercer Island in Lake Washington. The project's original design included the open cut installation of three sewer lines; a 250 mm (10-inch) ductile iron (DI) force main, a 400 mm (16-inch) DI gravity sewer, and a 200 mm (8-inch) DI gravity sewer. The sewer lines were designed to extend from the pump station approximately 41 m (135 feet) into the lake, crossing beneath an active 250 mm (10-inch) asbestos cement sewer line. During construction, the Contractor requested that they be allowed to install the three sewer lines within a single 1500 mm (60-inch) steel casing installed by microtunneling. The City and its' project consultants performed a detailed risk analysis in response to the request, comparing the risks of installing the lake tap with microtunneling versus the 11 m (35-foot) deep open cut construction of the three pipelines that had been specified. This paper discusses how the project team weighed the risks involved with using an alternatively-proposed trenchless method of construction, and the contractual issues that were overcome to successfully execute a change order while managing those risks. The paper also presents the details of the construction of the lake tap in Lake Washington, the challenges of modifying the existing design of the pump station to accommodate the microtunneling equipment, and the details of the successful installation of the three sewer lines.

The City of Greensboro Water Resources Department, Greensboro, NC, had been contracting with a local contractor for several years to pipe burst deteriorated gravity sewer lines with pneumatic equipment. During this same period, the utility had been upgrading miles of old 4-inch cast iron water distribution lines by traditional open cut replacement. The ability of static pipe bursting machines to install multiple product pipe options presented the utility with an opportunity to move into water main pipe bursting in lieu of open cut replacement. This case study highlights the pilot program project that includes 1200 feet of 4-inch cast iron, burst and replaced with 6-inch Fusible PVC^TM in the Allendale neighborhood. In addition, the project called for the installation of 4-inch fusible PVC pipe through directional drilling along Wendover Avenue to enable the transfer of services from the existing location under the roadway and allow for the pipe bursting of a 12-inch cast iron water transmission line. The 12-inch line was replaced with restrained joint ductile iron pipe. As a result of this pilot project, the Greensboro City Council approved the Water Resources Department budget for FY 2009/10, which included a major expansion of the City's rehabilitation program to include pipe bursting of substandard waterlines. Additional water pipe materials and diameters are also being considered for bursting. This project demonstrates a high level of cooperation between the water utility, pipe manufacturer and trenchless equipment manufacturer to develop a municipal pipe bursting program. It serves as a model for other utilities in terms of an approach to developing achievable solutions to rehabilitation and replacement projects.

Seattle Public Utilities has determined that a combined sewer constructed in 1923 is undersized. The sewer is located under a busy street near the core of the City. Approximately 450 feet of the existing clay sewer is 24 inches in diameter, and 1300 feet is 18 inches in diameter. A hydraulic analysis indicated that in order to minimize surcharging and surface flooding, the sewer should be approximately 30 inches in diameter. The depth of the sewer varies from 8 feet to 30 feet. Pipe bursting was considered, but due to the geotechnical conditions and significant upsizing, the risk of encountering difficulty was determined to be excessive. Pipe reaming was selected as the preferred alternative. The length of the sewer to be replaced and the degree of upsizing appears to be on the "cutting edge" of trenchless technology.

The Massachusetts Water Resources Authority (MWRA) provides water to over 2.2 million people and 51 communities serving greater Boston and central Massachusetts. They are undertaking a $57 million construction project to rehabilitate the 13.4-mile long, 11.5-foot diameter Hultman Aqueduct, including: inspection and repair of the existing aqueduct pipe and construction of several large diameter valve chambers to house connections between the existing Aqueduct and the new Metro West Tunnel. This paper will focus on the planning, inspection, and repair of the inside of the Hultman Aqueduct that has been completed to date for the first 10 miles. Because the Aqueduct could not be inspected and the exact extent of repairs quantified before the construction contract was awarded, a number of challenges needed to be considered. Before construction was awarded, the MWRA and its consultant needed to develop an inspection plan before any entry into the Aqueduct could be performed. Unique aspects of inspecting this major structure included limited points of access (typically 2 miles between access points), the need for inspecting and making repairs while working inside confined spaces, and the need to implement the repairs in a timely manner all make this project challenging. The inspection required the MWRA's consultant and the contractor to work cooperatively together to conduct the inspection inside the Aqueduct to locate defects and problems that need to be repaired, devise practical repair details, and implement methods and procedures that will eliminate existing leaks and extend the useful life of the Aqueduct.

Horizontal directional drilling (HDD) was used to complete two very difficult portions of pipeline construction and installation for the Port of Portland (Port) Portland International Airport (PDX) Deicing Collection and Treatment System Enhancement Project in Portland, Oregon. The PDX Deicing Project added surface runoff treatment to the existing deicing system at the Portland Airport. The project consisted of more than 8 miles of piping on Port-governed property. HDD was selected for two of the most difficult areas of pipeline construction which included a new outfall into the Columbia River and a significant active airfield crossing. The Columbia River outfall HDD installation presented several unique challenges. The installation included 1,100 feet of 30 inch polyethylene pipe. The HDD rig and boring operation was land-based while the pipe was installed using water-based floatation and insertion. Other challenges included tight in-water environmental constraints on construction techniques, activity on protected water with endangered species, crossing of an Army Corps of Engineers levee, and the need for underwater construction. The active airfield HDD installation crossed active runways, taxiways, and ramp areas, and presented several unique challenges. The installation included a 24 inch and 6 inch fusible polyvinylchloride pipe dual insertion, installed in a single 3,800 foot bore. This installation also had tight environmental challenges regarding fusion and layout areas, a significant depth of bore required under working runway and taxiway crossings, and consideration of Transportation Security Administration airfield security requirements. This paper will detail the design and construction efforts associated with both of these HDD installations and the lessons learned from both of these very challenging yet different uses of HDD methodology.

The City of Richmond, Virginia (VA) is currently completing rehabilitation and/or replacement of two of the four existing transmission mains conveying treated drinking water from the water treatment plant to the water distribution system. The first transmission main is identified as the Treated Water Conduit. The Treated Water Conduit is a one mile long, 54 inch diameter cast-in-place concrete pipe with 50 million gallons per day (mgd) capacity and is being rehabilitated in some sections by installation of a 48 inch diameter steel slipliner and is being replaced in other sections with a 60 inch diameter ductile iron pipe. The second transmission main identified as the Korah 3 Main, is a five mile long, 36 inch diameter prestressed concrete cylinder pipe (PCCP) with 27 mgd capacity. Defective sections of this main are being replaced with 36 inch diameter ductile iron pipe. A three phase, four year project schedule was developed to complete the work in periods of low seasonal treated water demand and to comply with time of year limitations of environmental permits. Construction of two phases is complete. This paper discusses the details of the project construction schedule with emphasis on the phases of construction and sequencing.

The City of Houston maintains hundreds of miles of large diameter water transmission lines, many of which are the main source of water to vast service areas. In the unforeseen event that a vital section of the hundreds of miles of the water line is damaged and requires immediate repair, there are several considerations to recognize in providing the proper repair recommendations as expeditiously as possible. This paper presents a single challenging incident of an existing 66-inch steel water main in a tunnel section that was damaged during 20-inch x 20-inch concrete pile driving construction activities, not associated with the water line. As a result of a direct impact and potential damage to the 66-inch water main, it was important to first immediately notify the entities involved to help recognize the importance of maintaining service to vital costumers. Once the importance of this water line remaining in service was identified, immediate coordination with all entities involved was initiated to discuss the scope of work needed to expose the water main to assess the potential damage. Due to the importance of this water main remaining in operation, several options were evaluated to assess the damage potentially caused without having to isolate the water main and terminating the distribution of water. All entities directly involved agreed the most viable option was to carefully excavate the location in conflict in order to better assess the damage and evaluate the recommended repairs. The location in conflict was part of a 1,104 linear foot ring beam and steel channel laggings tunnel section constructed under state highways and underneath a detention facility. This location of the potential damage presented possible issues and construction constraints. Additionally, the unknown condition of the 66-inch water main had to be taken into account prior to any excavation to expose the area; therefore, simply providing recommendation in excavating to observe the potential damage was a challenge. Once the damage to the 66-inch water main was assessed and it was identified that the water main can remain in operation, final repair recommendations were provided and performed. In understanding the damage, immediate repairs were performed and long term recommendations were provided.

A successful buried pipe installation depends on obtaining the proper soil support for the pipe. The amount of support depends on the level of compaction of the soil. A Target Value is used to evaluate the level of compaction of the soil. Typically, the Target Value is the percent compaction of the soil. To obtain the percent compaction, an in-place density test is compared to a laboratory test that determines the maximum dry density of the soil (e.g. percent standard Proctor). However, the density of gravel-size cohesionless materials used for pipe bedding, embedment, and backfill is difficult to measure in the field and in the laboratory. Materials such as pea gravel, crushed rock, and recycled concrete present unique measurement problems, particularly in pipeline trenches. For these materials, the Target Value can be a property of the soil that is more convenient to measure than density. Tests using devices to measure soil properties such as stiffness, modulus, or impact resistance are now available and can be used in combination with a Control Strip. A Control Strip is a test section that is compacted before construction begins and is used to establish control values that are used to evaluate the level of compaction. One of the measurement devices is selected and employed during the construction of the Control Strip and is used to establish a Control Strip Maximum (CSM) value. The CSM then serves as a reference for the Target Value. ASTM has recently adopted several such procedures to measure the in-place properties of soils that can be used to evaluate compaction. These include the Clegg Hammer, the GeoGauge, the Time Domain Reflectometer, the 18 lb Dynamic Cone Penetrometer, and the 5 lb Dynamic Cone Penetrometer. A Control Strip can also be used with devices that measure density, such as nuclear gauges, without establishing calibration curves necessary to get the exact value. In some circumstances, the Target Value could even be a wet density. For some cohesionless soils, determining the percent compaction (or the percent Relative Density) may still be the most appropriate method. A new ASTM procedure using a vibrating hammer has been developed to measure the maximum density of cohesionless soils. This test is intended to replace the vibrating table method and can be used to determine either percent compaction or percent Relative Density.

In 2006–07, Parsons was contracted by The Williams Companies, Inc. to perform in-depth inspections of two aerial crossings for a natural gas pipeline southwest of Houston, Texas, over the Colorado and Brazos rivers. Each crossing consists of a single cable-supported 30—inch diameter line, carrying a half-billion cubic feet per day. Originating in the Gulf of Mexico, the Williams' Transcontinental Gas Pipeline supplies gas to the northeast United States, including New York City. Inspection of these bridges in 2006–07 found extensive corrosion of the main load-carrying galvanized steel bridge rope cables in the area where they pass through the cast-steel saddles atop the towers. Advanced ferrous corrosion and multiple wire breaks were found to justify a significant load-carrying reduction of these main cables and associated reduction in factor of safety of these bridges. In order to ensure reliable service for an additional 50 years, several options were considered. Rehabilitation and main cable replacement was the selected, preferred alternative based on reliability, cost-effectiveness, safety during construction, and the ability to maintain the pipe in service during construction operations. This paper describes the inspection findings, structural analysis, rehabilitation design and detailing, load transfer methodology, and construction aspects of the project.

Today's pipeline projects are complex, faced with challenging constraints, regulatory requirements, volatile costs, multiple jurisdictions and high expectations by all stakeholders. The project delivery methods vary, but Construction Management (CM) services add value and needed resources to the delivery of the end product. Owners often retain third-party construction management services for difficult projects such as the Aurora Prairie Waters Project which included an alluvial well field, an aquifer recharge and recovery basin, over 37 miles of 60" diameter steel pipe, three 50 million gallons per day raw water pump stations and a water purification facility. Other owners retain consultants used in a Construction Management Staff Augmentation role for their multiple project deliveries. As CM for both 3^rd Party and Staff Augmentation delivery methods, the authors provide insight to the following project specific challenges during construction: (1) Environmental Controls and Oversight (2) Owner Controlled Insurance Program (OCIP) (3) In-plant Fabrication Inspection (4) As-built information and use of hand held GPS survey measurements (5) Project Controls Administration (6) Multijurisdictional Installations and Permit Requirements (7) Coordination with the Designer and/or Program Manager (8) Public Involvement and Land Acquisition The key to successful project construction is in CM teamwork. Owner and consultant staff can be used to deliver the construction project, though each may have their own methods of performing work and their own tools which are used. This paper discusses how using CM which is specifically tailored to match the needs of the project can control costs for owners throughout the project. The authors begin defining some CM terms and then describing instances when an owner should consider bringing in consultant services. The value delivered to owners is shared from the authors' experience with pipeline construction providing owners, developers and engineers a framework for developing successful CM services while optimizing use of existing staff.

The District of Columbia Water and Sewer Authority (DC Water) was faced with repair of a degrading aerial sewer located in an environmentally sensitive area. The sewer is located over Klingle Creek in US National Park Service land. The sewer is an 18-in sanitary terra cotta line encased in 30-in wide by 30-in deep degrading concrete with support columns and footings position in the steam bed and banks. Significant erosion at the stream bed undermined the stream bed footings. This caused the design span to double and put the aerial sewer in jeopardy. Mitigation options included realignment, replacement, renewal, and footing support updates. The importance of the sewer to accommodate public demand was not well supported by options requiring environmental impact reports or special permits, such as replacement, realignment, and stream bed alterations. Although initial project discussions considered realignment and replacement as viable options, DC Water recognized the urgency for an alternative that did not require extended planning and permitting. The pipe owner contacted Analytical Engineering to provide an FRP (fiber reinforced polymer) repair alternative. Analytical recommend the use of the Tyfo CFRP (carbon fiber reinforced polymer) system for strengthening the exiting encased crossing while eliminating the need for stream bed supports and alterations. The use of the Tyfo CFRP system for external rehabilitation of the crossing also eliminated the need for dewatering the pipeline, which provided significant cost and time savings to the owner. Additionally, the CFRP system is environmentally compliant with no impacts on high water flows contacting the crossing. The work was completed by Fibrwrap Construction with no spillage and no incidents which would have negatively affected the creek area. This renewal option not only solved the environmental issues and extended schedules required of other options, but was did so at a fraction of their costs.

A coal fired Power Generation Facility in the Baltimore relies on a large diameter circulation pipeline stretching half a mile from the boiler to the cooling towers. The line was constructed with mainly 102" Prestressed Concrete Cylinder Pipe (PCCP) containing problematic class IV wire. The plant started experiencing breaks in the nineties with costly repairs and even more costly lost revenue. The plant engineers then devised a proactive inspection and preventive repair program that managed to mitigate breaks but still forced longer outages and costly repairs using post-tensioning loops or concrete encasements. In 2007, a solution was presented which included the use of Fiber Reinforced Polymer, or Fiber Wrap. The advanced composite system was applied on the interior of the pipelines at this facility first in the fall of 2007. After that first successful experience, internal repairs utilizing Fiber Wrap became common practice for dealing with distressed pipes as they were detected year after year. The Power Generation facility went beyond the year to year approach and in 2009 decided to strengthen the entire length under the switchyard to completely eliminate the chance that a break or a leak would shut down the entire plant. The scope of work for this Project, completed in early 2010, was 55 sections, 20 ft long and 102" diameter to complete in 30 days. The project included a very short window for surface preparation of 10 days. The completion of the Fiber Wrap installation and top coating was reached on day 24 of the project, well ahead of a very challenging schedule. Alternative methods of mitigating this critical pipeline problem could have cost up to 5 times the Fiber Wrap option and would have caused major construction to take place under rail lines. The application of Fiber Wrap can be completed in 10–15% of the time required to replace pipelines of this nature. For over a decade Fiber Wrap has been utilized to strengthen and renew pipelines in varying degrees of distress and degradation in the municipal water and power generation market. The process is viable when there is an inability to excavate and a trenchless method must be utilized. Fiber Wrap liners lend themselves well to trenchless rehabilitation where a fully structural solution is a requirement. The Fiber Wrap designs may consider various loading combinations from internal pressure to external loads such as vehicular traffic, or in some cases, train traffic. The Fiber Wrap liner used as a segmental repair in combination with electromagnetic wire break testing for PCCP or Ultra Sonic(UT) testing for steel wall thickness loss may be a more economically feasible repair method when pipeline owners are working with limited rehabilitation budgets. The case study will present a clear contrast of various methods of pipeline repair considering the associated costs of down time, environmental impact, safety and capacity loss. Using the Power Generation facility project as a detailed case study this paper will assist pipeline owners in determining if and when to consider the use of Fiber Wrap. It will present a concise and objective comparison and contrast to traditional pipeline upgrade meant to provide Conference attendees usable information to assist in making these critical operational and financial decisions.

This paper looks at the structural design and buoyancy issues in connection with a 1200mm (48") diameter steel drinking water pipeline between Manchester and Liverpool as it encountered a 1500m (1 mile) long layer of peat up to 7m (23 ft) deep. The peat covered a layer of soft clay with a varying water table. Several construction techniques were tried with varying degrees of success. These included laying pipe beneath the peat within the clay layer; laying on gabion piers at a suitable spacing and finally, laying on a stone infill over the clay as a platform beneath the peat. The design considerations looked at pipe structural integrity, buoyancy, sinking and the impact on the flow of water to and from a lowland raised bog adjacent to the pipe route. With the works taking nearly 12 weeks to complete 1500m compared to the rest of the pipeline which achieved rates of up to 3.5km a week, the difficulties encountered are seen in perspective. The paper evaluates how the UK buried pipe structural design standard BS EN 1295 is not appropriate for these site conditions and provides some empirical evidence as to the excessive conservatism within the standard.

Mandated by the federal court-ordered Boston Harbor cleanup, the control of combined sewer overflow into Boston Harbor continues to be a primary focus of the Massachusetts Water Resources Authority (MWRA). The East Boston Branch Sewer Relief Project required nearly $90 million of design and construction to replace, relieve or rehabilitate 4.5 miles of the existing MWRA interceptor system serving East Boston. These upgrades increased the in-system storage and capacity to deliver wet weather flows. A combination of cured-in-place pipe lining, microtunneling, pipe bursting and open cut excavation methods were used to complete the upgrades. The result is a 79% reduction by volume in combined sewer overflows to Chelsea Creek and Boston's Inner Harbor. Designing and constructing a project of this size in East Boston proved to be a challenging task with its busy streets, complex system of overhead and subsurface utilities, and unique geologic history. East Boston is densely populated with a mixture of commercial properties, residential houses, as well as the busy Logan International Airport and associated support services. Coordinating construction activities with the community proved to be challenging. These issues included noise control, traffic management and pre and post construction surveys. Working in a dense urban environment made a difficult construction project even more challenging. Now that the project is complete, this paper serves as a way to look back and chronicle the project and lessons learned that can be applied to improve design and construction of future sewer rehabilitation projects. A significant amount of time was spent to develop the contract documents, and yet during construction there were major hurdles to overcome. By analyzing the hurdles and associated changes, and sharing our approach to addressing the issues, the information can be used to aid future projects. This paper will look closely at issues investigated over the life of the project from design through construction. These include risk management both planned and implemented, changes in pipe installation methods (e.g., changing from open cut to microtunneling, change from pneumatic to static pipe bursting), construction shaft locations and sizing, utility relocations, and alignment modifications during construction to facilitate construction and mitigate the court ordered schedule. The paper will also examine how the owner, the designer, and the contractor chose to make these changes, whether or not they were successful and whether changes during design could have been anticipated to address these issues differently.

PPI-BoreAid is a free online tool that allows users to perform preliminary pipe design analysis for polyethylene (PE) pipes installed using a horizontal directional drill (HDD). It allows users to determine suitable PE pipe dimension ratios (DR) to satisfy installation and in-service loads required in ASTM F1962 and Chapter 12 of the Handbook of Plastics Pipe Institute (PPI) Polyethylene Pipe Design, 2nd edition. During PPI-Boreaid development, several conservative aspects of the current PE pipe design methodology and PE pipe properties were noted. This paper discusses the requirement for the development of PPI-BoreAid as a preliminary PE pipe design tool, and provides suggested changes to the aforementioned documents. Sample calculations are presented to demonstrate how the new application can be used to select a suitable PE pipe for a site specific HDD project.

Water utilities across the United States are rapidly realizing that their existing buried infrastructure has a finite useful life. Many are embarking on aggressive pipeline condition assessment and renewal programs. As utility budgets continue to decrease,it is imperative to find the most cost effective methods to preserve and extend the life of existing assets. Prior to initiating the construction phase of a renewal program, utilities must analyze their existing water distribution systems, develop long term strategies, and reach consensus on appropriate renewal methods and materials. A first step in any water pipeline renewal program is to develop a realistic set of goals and objectives. Several factors can influence the program objectives such as, main break/leak frequency, existing system materials, poor flow capacities, chronic discolored water, etc. These issues, as well as many other factors will likely be considered as the goals and objectives are developed. A thorough review of the original installation records will help determine the system composition. Classification of pipe types, pipe sizes, and determining installation dates are among the more important tasks associated with this step of program development. A review of pipe performance history is equally important. By correlating break and leak historical information with infrastructure composition and installation dates, trends in pipeline performance will likely become evident. These activities will lead to prioritizing where the overall renewal program needs to focus. This presentation includes an overview of the application of following potable water pipeline renewal processes: (1) 1,800 linear feet of 8-inch diameter cured-in-place-pipe (CIPP) on cast iron pipe (CIP) (2) 44 linear feet of 24-inch diameter carbon fiber internal point repair on ductile iron pipe (DIP) (3) Large diameter elastomeric internal joint seals on 84-inch prestressed concrete cylinder pipe (PCCP)

Replace, rehabilitate, or simply eliminate? Utilities often struggle to determine the best approach to upgrade existing infrastructure. The approach becomes more complex when the existing infrastructure is located on fully operating Military installations adjacent to wetlands and water bodies. This paper provides an overview of the approach used to improve wastewater assets acquired by the Beaufort-Jasper Water & Sewer Authority (BJWSA) on two local Military installations. Additionally, the paper will provide an overview of why and how the BJWSA acquired aging infrastructure on the Military bases, and the effects the Military's constraints had on selecting the "best" approaches. As part of a federal utility privatization initiative, the BJWSA competed for and acquired water and wastewater systems located on four Military installations. Consequently, the BJWSA completed an Initial System Modification (ISM) assessment defining projects to be funded by the Utility Privatization (UP) Contract so that the assets are brought up to an acceptable condition. Since being awarded the UP Contract, the BJWSA has implemented a design and construction program for a number of ISM projects that includes strict adherence to each Military installation's security, safety, environmental, and cultural resources protection requirements. Jacobs Engineering Group, Inc. performed pipe rehabilitation services about of 40,000 linear feet (LF) of sewer at the Marine Corps Recruiting Depot at Parris Island (MCRD-PI) and 3,000 LF of sewer at the Naval Hospital. Services included sewer cleaning, smoke testing, CCTV inspection and defect identification, manhole inspection and evaluation. A computerized assessment program was implemented to help manage the data. The sewers at the Naval Hospital have been re-lined using cured-in-place pipe (CIPP) and the sewers at MCRD-PI are slated to be rehabilitated using multiple methods, including CIPP and pipe bursting, beginning in spring, 2011. However, the sewer rehabilitation project represents just one part of an overall ISM program that is anticipated to cost about $14 million and be completed by late 2011. A key point of this paper is that the BJWSA's acquisition of the MCRD-PI Military installation not only improved aging wastewater assets on the bases, but did so without disruption to the day-to-day operations

The City of Fort Worth will complete the construction in April 2011 on a 12-mile reclaimed water pipeline extending from the Village Creek Water Reclamation Center (VCWRC) in Fort Worth to the south end of the Dallas/Fort Worth (D/FW) International Airport. The pipeline alignment was determined based on the close proximity to the initial wholesale customers including the Cities of Arlington, Euless, and Dallas/Fort Worth International Airport as well as future expansion. This resulted in the majority of the pipeline being designed within existing right-of-ways creating numerous conflicts that had to be resolved within the limited working room allowed. To overcome these challenges three 30-inch diameter horizontal directional drills (HDD) were designed, one of which being the longest large diameter ductile iron pipe HDD in the state of Texas. The first horizontal directional drill was approximately 1,005 LF of 30-inch ductile iron pipe to allow the pipeline to cross the West Fork of the Trinity River. The location of the crossing located adjacent to the VCWRC is on land owned by the City which allowed for adequate room to construct and string the pipeline but also resulted in high operating and surge pressures especially considering the depth necessary to cross the river. The second horizontal directional drill was approximately 955 LF of 20-inch PVC carrier pipe inside 30-inch steel casing pipe to cross S.H. 360. The pipeline alignment was shifted north outside of F.A.A. Boulevard right-of-way to prevent the road from being closed during construction requiring permanent and temporary construction easements on both sides of the freeway. F.A.A. Boulevard has not been constructed on the east side of S.H. 360 but the right-of-way has been dedicated allowing this area to be used for stringing the pipeline and staging for the drill. The design of this drill was challenging due to the deep and narrow highway depression, the minimal construction area on private property, and varying geologic soil conditions located within the Woodbine Formation including the possibility of large crystalline boulders. The third horizontal directional drill was approximately 1,015 LF of 20-inch PVC carrier pipe inside 30-inch steel casing pipe to cross S.H. 183. The pipeline alignment parallels an existing natural gas transmission main leading to a gas well pad site at D/FW International Airport. This resulted in limited construction space between the gas pad site and Texas Department of Transportation (TxDOT) right-of-way which required a temporary easement on private property during drilling in order to string the pipeline. The predominant challenge for this drill was due to the deep and wide highway right-of-way created by the on and off ramps at the intersection of S.H. 360 and S.H. 183.

The Tawakoni Pipeline is part of a new transmission pipeline system from Lake Tawakoni and Lake Fork to Dallas Water Utilities' Eastside Water Treatment Plant. This paper looks at the logistical challenges of delivering 144" PCCP pipe sections to a 16-mile pipeline corridor. The logistics analysis, which included a local pipe manufacturer (Hanson) and experienced construction managers, looked at delivery routes from the fabrication facility to the trench corridor. Considerations included load limits, bridge heights, and traffic interference. The preferred routes were used to communicate with state and county officials to anticipate impacts to public roads. Mitigation of these impacts could then be added to the bid documents so that general contractors would include appropriate allowances for road maintenance and rebuilding. Haul road requirements between pipeline corridor access points were also reviewed. Expectations of the pipe manufacturer for appropriate road conditions to allow trenchside delivery were also developed, again allowing for appropriate allowances in the bid documents. The paper concludes by describing how awareness of delivery logistics and requirements will improve bidders' understanding of the requirements and therefore improve bid conditions and results.

This paper proposes quality assurance procedures to be followed prior to, during, and after repair of concrete pressure pipes with carbon fiber reinforced polymer (CFRP) liners. A design framework for such repairs was recently proposed (Zarghamee et al. 2010). In this paper, the importance of and requirements for prequalification of the engineer, manufacturer, installer, and inspector; on-site verification of quality of construction, including material preparation, installation, curing, and post-installation inspection; and testing of CFRP are presented. The available guidelines for CFRP repair of other concrete structures are reviewed, existing requirements that are particularly important for repair of pipelines are highlighted, and modifications and additions to these requirements are discussed. Required physical and mechanical tests on the CFRP liner and associated testing standards are listed, and evaluation of the test results is presented.

The City of Salem, Oregon became concerned about the condition and reliability of their 75-year old, 36-inch diameter water supply main following high water losses and the reoccurring need to repair leaking pipe joints. The pipeline of concern is over seven miles long, consists of both steel and reinforced concrete "pressure" pipe sections, and is one of two large parallel water mains which supply drinking water to the City of Salem (City). This paper discusses methods used and challenges encountered during the inspection and evaluation of this large diameter pipeline and rationale developed for recommendations to extend the service life of this infrastructure. A comprehensive external and internal inspection of the buried pipeline was conducted by Murray, Smith & Associates (MSA) in the fall of 2009. Several test pits were excavated to expose portions of the pipe for external inspection and assessment. From these excavations, test leads and test stations were connected to the steel pipe to conduct pipeline continuity testing, soil resistivity testing and an over-the-line pipe-to-soil electrical potential survey as part of a corrosion evaluation. Internal pipeline inspection included the use of video equipment to observe pipe joint condition, access port locations, areas of corrosion and other anomalies. The pipeline was inspected for leakage using flow data and sonic leak detection methods. These assessment techniques have efficiently provided the City with a thorough understanding of their supply main's condition, materials, and "as-built" components. Criteria were developed to prioritize the pipe rehabilitation work, focusing City resources on the highest priority issues. These criteria included the risk to human life and infrastructure due to pipe failure, the cost of water loss, the type of retrofit required, and the accessibility to the pipeline. Several trenchless pipe rehabilitation options were determined to be feasible, as was pipe replacement. By applying these criteria to the evaluation findings, a cost-effective pipe rehabilitation and replacement program may be implemented to lessen the risk of pipeline failure and extend the service life of this valuable City infrastructure. The techniques employed for the City of Salem's pipeline assessment were also used recently on a similar project for the City of Everett, Washington and builds upon prior work completed for the Joint Water Commission, Hillsboro, Oregon; the City of Beaverton, Oregon; and others.

The Spring Valley Outfall is an approximately 8.7-mile gravity sewer, owned by the County of San Diego, constructed in 1962-63 that conveys sewage from the Spring Valley Sanitation District to the City of San Diego Metropolitan Wastewater System. This project focused on a 2,000-foot length of the outfall located in the community of Bonita, San Diego County. The pipe begins at a driving range manhole and runs westerly under the Sweetwater River terminating on private property. The majority of this pipeline is within the river preserve containing dense vegetation, marsh, horse trails, protected species and other unfavorable conditions for open trench construction. Photos 1 and 2 show the vegetation density within the river preserve. The existing pipeline consists of 39" Reinforced Concrete Pipe (RCP) constructed at slopes ranging from 0.25% to 0.30% with depths ranging from approximately 14 to 18 feet and manhole spacing from 100 feet to 1,100 feet. The flow rate at ultimate build-out is estimated at 26 Million Gallons per Day (MGD), or approximately 75% of capacity; the maximum allowed by the County. Closed Circuit Television (CCTV) data from October, 2007 showed hydrogen sulfide had deteriorated the interior of the concrete pipe in some locations. There was some minor joint separation and visible infiltration mainly around manholes.

Ever-tightening budgets are forcing water system owners to rehabilitate their major water transmission mains with permanent solutions, a key approach in their asset management programs. Halifax Water was recently faced with a deteriorating Prestressed Concrete Cylinder Pipe (PCCP) water transmission main that needed rehabilitation or replacement. This transmission main is located under Kearney Lake Road, a main high traffic level corridor on the west side of Halifax. The use of Spirally Welded Steel Pipe (WSP) with a unique O-ring rubber-gasket joint, allowed Halifax Water to successfully rehabilitate 4,920 LF (1.5 km) of a 48-inch (1200 mm) host PCCP primary transmission main by sliplining. This fully structural lining system provided a structurally independent solution designed to last 100 years. This paper details the innovative use of polyurethane lined and coated Steel Pipe with the unique joint that eliminated liner pipe bells and ensured that maximum internal flow area was provided by the lining system.

King County Washington Wastewater Treatment Division (WTD) is building a new wastewater treatment plant (36 MGD average wet weather flow (AWWF) membrane bioreactor or MBR) to serve the northeast portion of its service territory in the metropolitan area of Seattle, Washington. The project includes an associated 13-mile-long conveyance system (four tunnel segments) that will discharge effluent to Puget Sound, a marine estuary in western Washington. This presentation will cover the design considerations and construction of the marine outfall, which consisted of 417 feet of 84-inch-diameter polyurethane-lined and coated steel pipe and twin parallel 63-inch-diameter, mostly bottom-laid HDPE (5,018 feet and 4,768 feet). Each of these outfall pipes includes 250-foot-long diffuser sections, which are staggered to provide an effective 500-foot-long diffuser. The flanged steel pipe was constructed using cut and cover from the shoreline to an existing grade depth of -4 feet mean lower low water (MLLW). This section was sheet pile shored to limit the trench width in an eelgrass bed. The first 494 feet of the HDPE pipes were also installed using cut and cover with 237 feet of trench shored and 257 feet side-sloped. The remaining twin parallel HDPE pipes were bottom laid, installed using controlled submergence and have concrete or coated ductile iron collars to provide differing degrees of ballast depending on the slope conditions. The presentation will review pipe materials and construction methods used for the project and the benefits of each. Material selection was done to assure a performance specification of a 75-year design life. The project was a success for the WTD and design-build team finishing 22 months ahead of the required date for 8 million dollars (20 percent) less than engineer's estimate. The project won 10 regional, national and international peer awards including Engineering News Record's Best of the Best Projects for 2009 in the Heavy Civil/Public Works category.

King County Washington Wastewater Treatment Division (WTD) is building a new wastewater treatment plant (36 MGD average wet weather flow, membrane bioreactor or MBR) to serve the northeast portion of its service territory around the Seattle, Washington metropolitan area. The project includes an associated 13 mile long conveyance system (four tunnel segments) that will discharge effluent to Puget Sound, a marine estuary in western Washington. The discharge for the conveyance system is a 5,435 foot long marine outfall placed from shore out to –600 feet of water. This paper will cover the use of design-build as a procurement method for the marine outfall including: (1) Advantages of using design-build versus design-bid-build. (2) Design-build procurement precautions. (3) Pre-design studies. (4) Permit procurement process. (5) Request for Qualifications / Request for Proposal Development. (6) Evaluation of proposals. (7) Geotechnical risk sharing. (8) Material price escalation risk sharing. (9) Negotiation of terms and conditions. (10) Partnering. The project was a success for the WTD and the design-build team. It was finished 22 months ahead of the required date for 8 million dollars (20%) less than engineer's estimate. The project won 10 regional, national and international peer awards including Engineering News Record's Best of the Best Projects for 2009 in the Heavy Civil/Public Works category.

On March 2^nd, 2010, a failure occurred on a 54 inch pre-stressed concrete cylinder pipe in Miami, Florida. This failure precipitated a move by the Miami-Dade Water and Sewer Department (WASD) to find and implement the best available inspection and repair/replacement technologies to address potentially damaging deficiencies in the large diameter buried pipe of its water distribution system. Through a combination of efforts that included contact with peers, interaction with vendors, on-line research, engineers at WASD pulled together a comprehensive team of what it considers to be "best-in-class" industry experts in NDE Services, Engineering Consultation, and Repair/Replacement Contracting to work together with the department to achieve the high degree of affordable system reliability being sought. This paper documents strategies pursued over the course of the last 18 months where successful inspections, evaluations, and replacements were made within brief windows of opportunity. The reliability and maintenance of pipelines are critical aspects of a water distribution system. Non-destructive evaluation of the Pre-stressed Concrete Cylinder Pipe (PCCP) used in these pipelines enables selective repair or replacement of distressed sections, and can alleviate the prohibitive cost of complete replacement. To detect distressed pipe sections in PCCP, a non-destructive technology using electromagnetics is currently being used. The inspection technique combines remote field eddy current and transformer coupling effects to interrogate pre-stressing wire integrity from inside the pipe. The inspection system is designed to access even large pipes through small-diameter manholes. In general, the majority of pipes are not at immediate risk of failure. The objective for engineers at WASD is to determine and identify those pipe sections that are at an unacceptably high risk of failure and repair/replace them before a failure occurs. By combining regular inspections that gather condition-based data for each asset and a risk analysis, WASD develops an understanding of past events, current events, and what events are likely to happen in the future on their water pipelines.

This paper describes the development of Pipe Penetrating Radar (PPR), the underground in-pipe application of GPR, a non-destructive testing method that can detect defects and cavities within and outside mainline diameter (>18 in / 450mm) non-metallic (concrete, PVC, HDPE, etc.) underground pipes. The method uses two or more high frequency GPR antennae carried by a robot into underground pipes. The radar data is transmitted to the surface via fibre optic cable and is recorded together with the output from CCTV (and optionally sonar and laser). Proprietary software analyzes the data and pinpoints defects or cavities within and outside the pipe. Thus the testing can identify existing pipe and pipe bedding symptoms that can be addressed to prevent catastrophic failure due to sinkhole development and can provide useful information about the remaining service life of the pipe. The key innovative aspect is the unique ability to map pipe wall thickness and deterioration including cracks and voids outside the pipe, enabling accurate predictability of needed intervention or the timing of replacement. This reliable non-destructive testing method significantly impacts subsurface infrastructure condition based asset management by supplying previously unattainable measurable conditions.

There is growing awareness in the water industry of the magnitude of transmission main water loss. Additionally, there is a tremendous opportunity to improve water efficiency by managing this water loss effectively. The IWA standard Water Audit framework represents decades of effort in establishing best practices for water loss management, and has now been adopted by the AWWA as well, making this a globally recognized standard. This framework, however, has largely ignored transmission mains, on the assumption that they rarely leak. This paper presents aggregate data representing all in-line leak location surveys on large diameter water mains conducted to-date, by all providers worldwide. This data spans over 2,000 miles of inspections conducted by tethered acoustic devices, and tells a very different story of transmission mains, demonstrating that actual transmission main leakage is close to 100 times the levels previously assumed. Breakdowns of the data are provided by various predictive factors, such as pipe age and material. Case studies of water loss management programs are presented from cities around the world. A cost / benefits model for transmission main leakage control is presented, and applied to these projects. The results of this analysis show that transmission main leakage offers an economical opportunity for water efficiency gains, making it a key component of water loss control programs.

Most of North America's oldest water mains are constructed of ferrous material, in particular cast iron, ductile iron, and steel. As utilities rarely have funds to replace all of these pipelines at the end of their design life, utilities are forced to carefully target their replacement and rehabilitation budgets. Critical for this targeting of funds is the availability of accurate knowledge of the actual pipeline conditions, in particular assessing the condition of the pipe wall and its impact on the remaining useful life of the pipeline. With this clear and impending need, a variety of technologies are becoming available for pipe wall assessment. This paper details developments and advances over the past two years in several technologies for pipe wall assessment. The results provided by each technology are outlined, as well as how these results can be used to assess progression along the failure paths of various types of pipelines. The tools are grouped in a systematic way, illustrating how they fit into three fundamental philosophies towards condition assessment. Examples of their application are provided for tools advanced beyond the R&D phase.

When Clean Water Services discovered inoperable valves and deteriorated connections along a critical sewer force main, evaluation and remediation ensued. The force mains consist of two 24-inch diameter lines, 46,000 feet long. Made of polyvinyl chloride (PVC), the mains transition to ductile iron (DI) at creek crossings. Twenty eight air release vaults are located along the alignment. Murray, Smith & Associates, Inc. inspected the vaults and force mains and measured soil resistivity. The metallic components within the air release vaults were experiencing corrosion. The corrosion was occurring at threaded connections, on the galvanized steel door hardware and on the vault lids. Microbiologically induced corrosion (MIC) was occurring inside pipes. Galvanic protection and impressed current systems were recommended. This presentation discusses the causes and potential cures for a problem that will become increasingly frequent as older ductile iron pipe with metallic fittings and appurtenances begin to show deterioration due to corrosion.

Two regional Subsurface Utility Engineering (SUE) projects performed for the Oregon Department of Transportation and the Washington State Department of Transportation demonstrate how SUE can effectively be used to locate and map underground utility facilities. The field investigation results led to the development of a two-dimensional map and/or three-dimensional model that facilitated roadway and stormwater facility designs. The model also served as a tool that easily identified utility conflicts and problem areas to be addressed either through redesign or relocation. This information led to effective utility coordination that minimized conflicts, facilitated required relocation design, and increased cooperation and collaboration between utilities and public agencies. The process saved time, money and roadway construction contractor claims. Documentation of varying SUE quality levels per CI/ASCE 38-02 Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data is also discussed.

The design of intelligent infrastructure that can be permanently installed to detect leaks in buried pipelines. This paper will describe the background theory and practical application of a fiber optic based technology that uses Brillouin acoustic scattering to detect subtle changes in temperature in the cable. The technique may also be used to detect changes in strain in the pipe. The fiber optic cable is either buried under the pipe (for fluid leak detection), or bonded to the surface of the pipe (for strain monitoring). When the fluid in the pipe leaks, it will alter the thermal environment of the cable under the pipe, and this change can be accurately detected and pinpointed. The use of Brillouin scattering as opposed to Raman scattering allows extremely long distances of pipe to be monitored in this fashion. This paper will outline the background Physics of the method, and provide results from a case study for leak detection of a brine pipeline.

The difficulties in locating leaks in plastic pipes are well-documented. The frequency of noise generated by leaks and plastic pipes are generally much lower in frequency and amplitude than a similarly on a metallic pipe. The practical difficulties are so well-documented that very few leak detection technicians will even attempt to use leak noise correlators on plastic pipe. The Leakfinder RT correlator has earned a reputation for excellent performance on plastic pipe, however without the knowledge of proper feel procedures, correlation of leaks in plastic pipe will generally be unsuccessful. This paper will outline the physics of acoustics on plastic pipe and transmission mains, in order to give a fundamental background on the issues regarding leak detection on plastic pipes and large diameter pipes, as the issues are similar. The issues of frequency content, attenuation of acoustic waves, and velocity of the acoustic waves will be covered. Following this, we will present the results from several recent studies where successful leak locations were performed on plastic pipe. These include case studies from Numerous leaks were found on the system, and some novel measurement techniques were used to make the correlation technology successful. The techniques developed have application to other water systems as an example project of leak detection on plastic, the technical methods that must be used, and the limitations encountered.

This paper describes a simple soil-structure interaction model of a buried segmented concrete pipeline that can be used for indirect health monitoring during Permanent Ground Deformation (PGD). Buried pipelines are difficult to inspect visually, and thus accurate health monitoring systems can improve the efficiency and effectiveness of repair efforts immediately following an earthquake. A Winkler pipeline model is developed for indirect health monitoring that incorporates the two primary modes of failure observed in pipeline experiments, namely telescoping and rotation at the joints. Very approximate estimates of the model parameters are made, and the model results are compared to experimental results. In general the model captures both the magnitude and patterns of joint deformation. However, the model yields axial forces that are two orders of magnitude higher than the measured values. This suggests that the first order approximation of the joint as an elastic beam is inaccurate. Structural testing of the joints both in axial compression and rotation will provide more accurate refinement of the joint model.

"Why build a sewer in a lake? Why make it buoyant? Where has it been done before? Will it work? Will it last? Can we maintain it?" City of Lake Oswego officials and their engineering consultant asked and answered these and many other questions while designing and constructing the innovative pipeline, completed in May 2011 after a 10-year planning, design, and construction process. Total program cost for the six projects is $90 million to replace undersized, deteriorating lines with a system designed to last at least 100 years. Its centerpiece is a buoyant gravity HDPE sewer (10,000 feet 22-inch to 42-inch outside diameter, with 12,000 feet of smaller, air-filled HDPE buoyancy pipe, all DR 11 and 13.5), held to proper grade 11 to 18 feet beneath the lake surface by 428 ground anchors and tethers. A serpentine alignment provides thermal expansion loops to maintain grade despite wide-ranging water temperature which causes the pipeline to lengthen and shorten +/– 14 feet over its 2-mile length. Stainless steel manholes are also buoyant and submerged, with access via removable caissons. Several manholes on upland tributary trunk sewers were converted to debris sumps to trap sand/gravel/sediment where it can be easily removed rather than accumulating in the in-lake system. Pile-support systems (354 18-inch steel pipe piles supporting 7,000 feet of HDPE sewer) and CIPP rehabilitation (6,000 feet of 18-inch to 36-inch) are also used for significant reaches. While much of the work was constructed with the lake full, final connections, and associated excavations, were made with the lake drawn down 24 feet and with extensive bypass and lake drawdown pumping/piping systems. This paper reviews the drivers for the project, the alternative solutions considered, and the development, design, installation, and maintenance of the buoyant system, including some of the numerous challenges overcome. Visit loisnew.com and view the professionally-produced "webisodes" to gain additional insight into this remarkable project.

Several years ago, the Capital Planning and Hydraulics group at the Louisville Water Company (LWC) recognized the need and foresaw the advantages of a system-wide hydraulic model. In 2005, LWC purchased hydraulic modeling software that leveraged its existing GIS system. A combination of items including personnel changes, substandard hardware, software compatibility issues, and a lack of full support from upper management slowed development of the system-wide hydraulic model. In 2009, management support for the system-wide hydraulic model was reinvigorated as the development of a system-wide model was recommended in the LWC 2011–2030 Facility Plan. Creation of the system-wide hydraulic model commenced following the purchase of new hardware, resolution of the software issues, and advanced training for key personnel. In December 2009, LWC and Hydromax USA participated in a 7 day data gathering operation for flow and pressure at 15 locations using a 1-minute measurement interval throughout LWC's service area. LWC supplemented this data with pressure monitoring data recorders at an additional 8 fire hydrant locations and pressure, flow, and/or level monitoring at 73 other booster pump station, master meter, and storage tank locations using LWC's SCADA system. This data was instrumental in the calibration of the system-wide hydraulic model. The creation and calibration of the system-wide hydraulic model was completed in 2010. LWC will examine the future use of the hydraulic model in evaluating the effects of proposed system improvements allowing LWC to make sound capital investments and evaluation of operation and maintenance decisions.

ASTM F 1962, Standard Guide for Use of Maxi-Horizontal Directional Drilling for Placement of Polyethylene Pipe or Conduit Under Obstacles, Including River Crossings, provides a procedure for estimating pull loads and stresses on polyethylene pipe as a function of the drill path and buoyant weight of the pipe in the drill hole. The original equations were developed assuming a level grade, or that the HDD entry and exit elevations are the same. A previous paper has therefore extended the equations and methodology of ASTM F 1962 to address the installation of polyethylene pipe for the case of a non-level grade, but restricted the analysis to the installation of pipe in the absence of anti-buoyancy measures. The present paper further extends the analysis to include the use of ballast for a non-level grade and helps provide a better understanding of the factors influencing the pull loads in the maxi-HDD installation of pipelines.

The Middlesex Water Company (MWC) is a 113-year-old, publically traded company providing water, wastewater and related utility services to a population of nearly 400,000 in central New Jersey and Delaware. In mid 2010, MWC completed the planning, design and construction of a new 24-inch, 5,800-foot-long water main to replace an existing 24-inch cast iron water main that was more than 100 years old. The existing water main conveyed water from MWC's northern distribution system near the city of Perth Amboy, across the 4,800-foot-wide Raritan River, and into MWC's South River Basin system in southern Middlesex County. Due to the age, corrosivity and unstable nature of the surrounding environment, the existing main experienced several breaks, requiring costly emergency repairs on an increasing frequency. These outages caused major operations disruptions, and repairs were costly due to access impediments associated with the river, soft sediments adjacent to and under the river and regulatory considerations associated with adjacent wetlands and river navigation. Alternative construction methods for crossing the Raritan River were evaluated, and options included open-cut trenching, microtunneling, pipe jacking, conventional tunneling, and horizontal direction drilling (HDD). Factoring in construction schedule, cost, sustainability, impacts to the environment and marine traffic, and permitting requirements, horizontal directional drilling (HDD) using fusible polyvinylchloride pipe (FPVCP) was recommended for the river crossing. The final design consisted of a HDD crossing approximately 5,365 feet in length using 24-inch FPVCP. The length and diameter of the crossing and subsurface conditions encountered during construction classifies this project as high-risk. This paper describes various elements that were considered during the project's planning, design and construction phases. These include those associated with the geotechnical investigation, preparation of construction drawings and specifications, HDD construction techniques, staging and fusing of the FPVCP.

In 2010, the ASCE Task Committee presented a draft white paper that included preliminary details of a proposed preliminary framework for the design of thrust blocks and thrust restraint systems to improve current practice. The concepts included in the proposed preliminary framework were formulated by reviewing the historical work and current practice for the design of thrust blocks and thrust restraint systems. Since the publication of the draft white paper, the committee expanded the concepts outlined in the white paper to further explore the development of a unified design practice applicable to all pipe materials, using simplified yet rational assumptions, to solve the thrust restraint problems in buried pipelines. Justifying the need for a new framework for the design of thrust blocks, the white paper noted the shortcomings in current practice: improper handling of (a) the frictional resistance between the thrust block and the soil, and (b) the lateral (passive) soil pressure against the thrust block face. While the primary resistance against the unbalanced thrust force is provided by the lateral (passive) soil pressure against the thrust block face, the frictional resistance between the thrust block and the surrounding soil could be significant in some cases. Accounting for the frictional resistance would help optimize the design, resulting in smaller thrust blocks. All current AWWA design manuals estimate lateral (passive) resistance based on "allowable lateral soil bearing pressures" published for different types of soils; however, the values of these allowable pressures vary widely among the design manuals for different pipe materials. The use of inconsistent terminology and inconsistent recommendations for soil parameters among design guidelines for different pipe materials, without adequate explanation or justification, can cause significant misunderstanding and confusion. The lateral resistance should be calculated accounting for the tolerable movement of a thrust block, which could indeed depend to some extent on the pipe material characteristics, joint designs, and beam stiffness. This paper presents an expanded framework for the design of a thrust block for a horizontal bend in a buried pipeline, documenting the progress made to advance the development of a potentially unified approach. The proposed approach considers the tolerable movement of the pipe, the structural integrity concerns of the adjoining pipe segments and joints, the characteristics of the soil, and an appropriate factor of safety. This improved approach provides a common, yet rational, tool for the design of thrust blocks for all pipe materials.

To meet regulatory requirements, a possible 156-inch diameter transmission main was evaluated as one alternative for a 22 mile long urban pipeline through the City of Houston. This paper will focus on the investigation of a number of constructability and operational issues a pipe of this size posed. Issues to be presented will include the hydraulic analysis to determine the pipe size options along with issues related to maintaining a competitive environment to minimize cost of the pipeline while reducing construction duration requirements.

For any material, a basic understanding of physical and mechanical properties forms the foundation upon which the best engineering design decisions can be made regarding the use ofthat material. This concept certainly applies to all current piping materials, including the plastic materials that have gained widespread acceptance and use in the range of buried pipeline applications. This paper examines the basic differences between the two most commonly used buried pipeline plastics — polyvinyl chloride (PVC) and high density polyethylene (HDPE). The differences will be traced back to their respective molecular compositions and structures, which provide a clear explanation and understanding of their variations in performance behavior. The discussion includes their impact on pipe applications and performance optimization. The physical properties covered and explained include molecular weight, molecular bonding forces, molecular structure (morphology), glass transition temperature, melt temperature, specific gravity, hardness, and resistance to some of the more common chemical environments. The mechanical properties examined include tensile strength, long-term stress capacity, modulus of elasticity, viscoelastic creep, thermal expansion/contraction, and static fracture toughness.

Northwest Pipe Company is a manufacturer of both steel pipe and bar-wrapped steel-cylinder concrete pressure pipe. While there are similarities between the two pipe materials, the AWWA C303 standard for bar-wrapped concrete pipe does not currently allow the Rolled Groove gasket joint, a rubber sealing system widely used in steel pipes manufactured with complete-penetration butt welded seams per AWWA C200. In an effort to study the viability of including the Rolled Groove joint into Bar-wrapped concrete pipe, the services of researchers from the University of Texas at Arlington were retained to aid with design and analysis of a prototype joint, S303^TM. Additionally, full scale tests on a 54-inch S303 prototype joint were conducted to verify its ability to perform to established acceptance criteria. This paper presents discussions on the Finite Element Modeling (FEM) and the full scale testing.

The history of steel bell and spigot joints with fiber-center lead gasket for concrete pressure pipe in California dates back to 1933, and the modern joints with O-ring gaskets for concrete and steel pressure pipelines to 1940. The performance of these gasketed joints in the seismically active region of California has been excellent. There have been isolated occurrences of damage to both unrestrained gasketed joints and welded restrained joints. The damage generally occurred at the end of concrete encasements or at structures or near bends. Several case studies will evaluate the effect of three large recent earthquakes on nearby pipelines. This paper will show that the empirical evidence suggests that gasketed joints of concrete pressure pipe and intermediate diameter steel pipe perform well in earthquakes and they should be considered for pipeline projects in seismically active regions. Recommendations will be made regarding measures that may reduce the risk of damage to pipelines using gasketed joints.

A set of guidelines for the use of mini-horizontal directional drilling (mini-HDD) has recently been developed by the Plastics Pipe Institute. Technical Report TR-46, Guidelines for Use of Mini-Horizontal Directional Drilling for Placement of High Density Polyethylene Pipe, represents a comprehensive set of information supporting the placement of HDPE pipe by mini-HDD equipment. The new document is intended to provide information analogous to that provided in ASTM F 1962, Standard Guide for Use of Maxi-Horizontal Directional Drilling for Placement of Polyethylene Pipe or Conduit Under Obstacles, Including River Crossings, but at a level appropriate for the less complex mini-HDD technology and typical project characteristics. TR-46 contains guidelines ranging from preliminary site investigation to pipe selection (design) to implementation. The document reflects the latest industry information, but also includes new information and an HDPE pipe selection methodology not readily available elsewhere.. It is anticipated that TR-46 will become widely used for mini-HDD pipeline installations, serving a similar role as ASTM F 1962 for maxi-HDD applications. The present guidelines may also be used for some midi-HDD installations, depending on the application and the judgment of the contractor or engineer.

Horizontal directional drilling is widely used for the installation of Polyethylene (PE) Pipes. The pull distances achievable in these applications are in most cases limited by the PE pipe's safe pull stress. Historically, the safe pull stress has been established by applying a reduction factor to the tensile yield stress determined by test method ASTM D638, "Test Method for Tensile Properties of Plastics". The most commonly used reduction factor of 0.4 is based on the observation that little permanent deformation remains when PE is unloaded from 40% of its yield stress. Additional reduction factors to account for material creep under timewise constant stress are estimated from creep tests. Based on successful field experience, this methodology has worked well; nevertheless, a more precise test that accounts for loading conditions similar to the actual field application would provide better engineering values. Additionally, standards allowing the use of PE4710 materials for the manufacture of PE pipe were introduced in 2005 and 2006. Because PE4710 materials have a higher tensile strength than PE3408 materials, they are expected to have higher safe pull strengths than those currently in use. This paper discusses the use of a test procedure that applies a loading history representative of actual field conditions during directional drilling installations. Test results are presented for PE4710 pipe materials and the consequences of loading history on the final post-installation deformation state of PE pipe are discussed. Additionally, the original method employed to determine safe pull stresses did not evaluate fusion joints that are present in directionally drilled applications and subject to the same stress as the PE pipe. This paper presents test results for pipe fusion joints to confirm that the increased pull strength for PE4710 HDPE pipes is suitable for field produced fused pipes. These results and comparisons will be useful in the design of current trenchless projects, as well as setting design requirements for the PE4710 pipe materials in AWWA manuals and other industry guidance.

In 2004, our design team began a four-year project with the City of Bellingham, Washington (City) to design, permit, and construct a replacement for the City's Alternative Outfall. The Alternative Outfall serves as a second outfall for the Post Point Wastewater Treatment Plant (WWTP) when peak flows exceed the capacity of the 1520 mm (60-inch) Primary Outfall. The old 760 mm (30-inch) diameter Alternative Outfall was undersized, had numerous joint failures, and the end of the 150 meter (500 ft) long outfall had become aspirated with sediment due to extended periods of no flow. The design team developed several options to repair the pipeline, including sliplining, pipe ramming, and replacement with a larger pipeline. After careful evaluation, the City decided to replace the existing pipeline with a stronger, higher capacity 1400 mm (54-inch) diameter pipeline outfall protruding farther from the shoreline into Bellingham Bay. To minimize ecological impacts to a large and very healthy eelgrass (Zostera marina) bed, the outfall alignment was shifted to pass through a thinner section of the eelgrass, reducing overall impact. The project team also developed an extensive eelgrass mitigation plan for this alignment. The design team worked closely with the Washington Department of Fish and Wildlife and the Washington State Department of Natural Resources to implement several innovative procedures to aid in eelgrass mitigation, including an experimental clamshell dredge removal method and the first large-scale use on the western U.S. coast of the Transplanting Eelgrass Remotely with Frames (TERFs; developed by Short et al. [2002]) methodology. Divers were also deployed to remove and transplant eelgrass using more traditional methods. During construction, difficulties were encountered sinking the pipeline, sealing the 1400 mm (54-inch) rubber check valve, and stabilizing the marine backfill. This paper discusses some of the design considerations, construction challenges, the lessons learned in working in a sensitive marine environment, and the preliminary results of the experimental eelgrass transplanting methods.

The City of Austin, TX is building a new water treatment plant, Water Treatment Plant No. 4 (WTP4), to provide added treatment and transmission capacity necessary to meet projected increases in demand on a schedule that accounts for increased water conservation. The WTP4 will have a 50 million gallons per day (MGD) initial capacity, be expandable to 300 MGD in the future and will provide the City with increased system redundancy and reliability. Raw water supply for WTP4 comes from a deep water intake facility located in Lake Travis. The intake facility consists of three large custom designed intake screens, which are located at three different elevations and separated horizontally by approximately 80 ft. Each of the screens is designed to withdraw 300 MGD flow. The three screens are interconnected by a 160 ft long, 9-ft diameter steel pipe manifold, which is installed along the sloping lake bottom. Lake water will be drawn through the sides of the screens, then flow through the sloping steel pipe manifold, and enter a 9-ft diameter steel riser pipe embedded 70 ft into the lake bottom, and eventually reach the water treatment plant via a series of tunnels and a pump station. The water depth at the intake area varies between 60 ft to 190 ft. This paper will focus on the unique challenges that were associated with the planning and design of the 9-ft diameter riser pipe at the "lake tap" and the complex 9-ft diameter steel pipe manifold. Some of the major challenges included: (a) constructability and logistics of the pipeline installation under great water depth, (b) design of riser pipe to facilitate the "lake tap" construction; (c) reliable anchorage of the steel pipe with minimum cost; (d) safety concerns and risk management during construction, and (e) corrosion protection of steel pipe in submerged environment.

In practice, the hydraulic transient analyst will inevitable be posed with the following question, "Is a surge analysis required?" The discussion herein proposes an easy way to make this decision. In hydraulic modeling, the St. Venant Equation is used to characterize the relationships between hydraulic head, flow rate time, and distance along the pipeline. A term within the St. Venant Equation holds the answer to "the question." This acceleration term is characterized by the momentum equation. The use of acceleration will help the analyst understand the sensitivity of the model to hydraulic transients which will potentially save time and effort as well as help the analyst avoid the use of an overly complex model for an analysis. The acceleration term considers the inter-relationship(s) between the velocity change, the time change, as well as the length of the pipeline system. This paper will show where this acceleration term is within the St. Venant Equation and explain how it can be coupled with various assumptions to answer "the question". Along with the acceleration head parameter, the transient analyst can utilize a matrix along decision criteria, which are developed within the paper, to assess if the transient behavior of the system warrants consideration for full dynamic "surge" modeling. This matrix will also help with the decision of what type of hydraulic model to use. Is a steady state model adequate? Is a quasi-dynamic or fully dynamic model required? The use of the acceleration term will be introduced as a decision tool for this line of questions as well. The concept (model simply for results and/or model to fit) will be fleshed out within the paper and a discussion with proposed decision criteria for both questions: "Is a surge analysis required?" as well as "What type of model should I be using?" will be presented.

Thrust restraint design of buried pipelines is dependent on the pipe-soil interaction at the pipe-soil interface, pipe bend configuration, pipe and soil properties, and internal and external loading. It is generally recognized that a buried pipe has to move against the soil, in order to develop maximum aggregate friction, adhesion and lateral (passive) resistance forces, which in combination resist the unbalanced thrust forces. Pipe movements (axial and transverse) cause additional pipe stresses (axial, bending and shear) on the pipe at or near the unbalanced forces, and these additional effects are currently not considered in American Water Works Association (AWWA) pipe design manuals, except to a certain extent in the recently revised M9 procedure which uses significantly improved assumptions. In 2010, the ASCE task committee on thrust restraint design of buried pipelines presented a draft white paper on the subject and proposed a preliminary framework for the design of thrust blocks and thrust restraint systems to improve current practice. Recognizing the different joint types used in practice, the proposed framework consisted two distinct design solutions for: continuous (welded, fused or flanged) pipelines; and segmented (discrete) pipelines. Continuous pipelines consist of welded steel (WSP) and concrete pressure (CPP) pipelines with welded joints and polyethylene (PE) and polyvinyl chloride (PVC) pipelines with fused joints. Since the publication of the white paper, this task committee has undertaken a series of exercises to evaluate and compare current practice in detail and to evaluate alternate approaches in order to advance the development of a potentially unified approach. As part of this effort, the committee undertook a case study for the comparison of restraint length and resulting stresses in buried continuous steel pipelines utilizing the analyses procedures outlined in AWWA M9, M11 and the simplified procedure published by Robertson (1980) for Reinforced Thermosetting Resin (RTR) pipes. This paper presents the results of this case study containing bend displacements and additional bending stresses calculated using two WSP examples.

The Brightwater Conveyance Project for King County Wastewater Treatment Division in Washington State includes four soft ground tunnels totaling nearly 21 km (13 miles) with interior diameters ranging from 4 to 5.5 m (13 to 18 feet) and equipped with one-pass concrete segmental linings and secondary pipe linings. Two of the tunnel sections, BT-1 and BT-2, are combined tunnels housing separate pipelines for sewage influent, effluent, reclaimed water, and influent storage. The other two tunnels, BT-3 and BT-4, are fitted with secondary linings in areas of net internal pressure. Pipeline and secondary lining design considered material selection, corrosion protection, installation constraints and operations and maintenance parameters. Complex installation included multiple pipelines with tight tolerance constraints; pipe support and restraint; and tunnel backfill / structural slab placement.

When designing large diameter water transmission pipelines, some engineers rely on design rules-of-thumb or a previous project as a template, without recognizing the inherent differences of each project. For large-scale water supply projects, mistakes in hydraulic design, especially underestimating friction headlosses, can be magnified resulting in reduced system capacities, catastrophic failures, or potential litigation. One of the most common mistakes in hydraulic design of large-diameter pipelines is underestimating pipe resistance and friction headlosses. The Hazen-Williams equation is the most widely used method for calculating headlosses in pipelines because it is simple and easy to use. However, the Hazen-Williams equation is empirical and, for large-diameter pipelines, has a limited range of applicability. Conversely, the Darcy-Weisbach equation provides a better approximation of friction headlosses since it takes into account the pipe roughness and Reynolds Number for different pipe materials, and is valid for all pipe sizes and turbulent flow ranges. Although there is an abundance of evidence of the limitations of the Hazen-Williams equation, it is continually misused in the engineering industry. There are many other design issues that can cause serious performance problems with large-diameter pipeline projects if not taken into consideration during design. Additional common hydraulic design pitfalls include: underestimating effects of sediment and biological material in raw water sources, not accounting for aging of pipeline materials, inadequate pipe pressure class design, improper placement and sizing of air valves, lack of accurate transient and surge analysis, inadequate flow and pressure field measurement, and potential need for pipeline maintenance and cleaning. There have been numerous publications on the topic of hydraulic design and proper calculation of pipeline friction headlosses. However, the focus of this paper is to provide analysis through case studies of several major water supply systems that reaffirms the importance of utilizing proper hydraulic considerations. Common hydraulic design oversights and short-cuts can often result in capacity and maintenance problems for large water supply systems.

Virginia Natural Gas, a wholly owned subsidiary of AGL Resources (NYSE:AGL), provides retail natural gas sales and distribution services to 271,000 residential, commercial and industrial customers in southeastern Virginia. With roots that stretch back to 1850, Norfolk-based Virginia Natural Gas is one of the fastest growing natural gas distribution companies in the country and is known for its outstanding customer service. AGL Resources, an Atlanta-based energy services company, serves approximately 2.3 million customers in six states. The company also owns Houston-based Sequent Energy Management, an asset manager serving natural gas wholesale customers throughout North America. As an 85-percent owner in the SouthStar partnership, AGL Resources markets natural gas to consumers in Georgia under the Georgia Natural Gas brand. The company also owns and operates Jefferson Island Storage & Hub, a high-deliverability natural gas storage facility near the Henry Hub in Louisiana. In 2010, Virginia Natural Gas, completed the most complex infrastructure project ever undertaken by the company, a 21-mile, 24-inch pipeline called "the most important energy investment" in Virginia. The project is also known as the Hampton Roads Crossing (HRX) Pipeline.

As part of the greater Harris County reduction of groundwater usage, construction of a new Transmission Waterline (Northeast Waterline) was envisioned to transmit surface water from the Northeast Water Purification Plant (NEWPP) to four Regional Water Authorities, Municipal Utility Districts (MUDs), and the City of Houston. Upon completion, the proposed Northeast Waterline will be capable of providing up to 418 million-gallons-per-day (MGD) at 6- to 8-fps. The Northeast Waterline size was based on 2050 demands. Various hydraulic modeling scenarios were created to assess dual pipelines, pipeline diameters up to 156-inches, operating conditions including normal (< 100 psi) and increased (> 100 psi) NEWPP operating pressures, inline pumping, and normally open or closed system interconnections. After the Northeast Waterline size was recommended, water quality was evaluated using 2020 demands to determine whether water quality could be an issue when the Northeast Waterline is first placed in-service, before full design flows are in place. The City's current largest transmission main is 96-inches and highest water plant operating pressure is approximately 98-psi. Hydraulic model evaluation paired down the scenarios to balance pipeline diameter and NEWPP operating pressure. This paper will discuss the preparation efforts and considerations taken by the City of Houston and Lockwood, Andrews, & Newnam, Inc. in performing developing a recommended NEWPP waterline system to meet the system requirements and demands of potential participants both near term and at ultimate design.

For the Texas Gulf Coast, the conversion to surface water is imperative to reduce depletion of aquifers levels that provide the majority of the potable water supply to the region. The Lone Star Ground Water Conservation District has set policy requiring the county's large volume water users to meet various criteria for conversion from groundwater to surface water. The City of Conroe is one of these users, located 40 miles north of Houston, Texas, and has to convert 30% of their usage to surface water by the year 2016 and 61% by the year 2025. The City of Conroe has contracted with a local water authority to receive surface water and is evaluating various surface water take points for optimal usage and system operation. The City has an elevation difference of approximately 170 feet from the northern to the southern end of town, creating challenges in pressure control throughout the water distribution system. The City has developed "pseudo" pressure planes through closing and throttling various manual system valves. To address this, the City would like to develop true pressure planes with a series of automated pressure reducing valves and emergency service valves controlled by SCADA. The City would like to have the pressure planes incorporated into their system by the 2016 surface water conversion deadline. This system will allow the City to operate the pressure planes with flexibility for the surface water conversion. To plan the conversion and meet the criteria, the City of Conroe retained Lockwood, Andrews, and Newnam (LAN) to provide engineering services and planning strategies and solutions for the surface water conversion. Hydraulic modeling was utilized to analyze the system and plan the integration of surface water into a groundwater system. LAN also developed Design Standards, Specifications, and conceptual Guidelines for the necessary valves and associated SCADA for the City of Conroe's future automated system. This paper will focus on the methods and strategies utilized by the City of Conroe and LAN to plan for the surface water conversion.

The City of Omaha entered into a Consent Decree with the State of Nebraska Department of Environmental Quality (NDEQ) to reduce the volume of combined sewer overflows (CSOs) from their combined sewer system (CSS) to receiving streams by October 1, 2024. In response to the Consent Decree, the City of Omaha, in conjunction with the Program Management Team (PMT) comprised of CH2M Hill, HDR Engineering, and Lamp Rynearson Associates, developed the City of Omaha CSO Program Long Term Control Plan (LTCP). The purpose of the CSO Program is to reduce CSOs from the CSS. Sewer Separation is one component included in the CSO Program. This paper will provide an understanding of the City of Omaha CSO Program, including an overview of the $1.66 Billion Program that includes 72 sewer separation projects, and 15 Major Projects consisting of lift stations, force mains, wastewater treatment plant improvements, high rate treatment plants, system storage, and conveyance tunnels that are to be completed over a 15 year timetable. The specifics of the paper will focus on the sewer separation planning aspects of the Program in order to provide design consistency and project delivery. These planning efforts included the development of protocols, procedures, guidance, and standards documents. These documents provide guidance and direction to Project Teams in completing sewer separation design activities.

Thrust restraint design of buried pipelines is dependent on the driving force distribution as well as pipe-soil interaction at the pipe-soil interface, which can be quite complex. The characteristics of the pipe-soil interaction are dependent on the piping configuration, pipe and soil mass properties, and internal and external loading, among other factors. It is generally recognized that a buried pipe has to move against the soil in order to develop maximum aggregate friction, adhesion, and lateral (passive) resistance forces, which in combination resist the unbalanced thrust forces. However, the design equations that are currently in use in the water/wastewater industry have been based on simplified assumptions that do not fully address the interfacial behavior, notwithstanding the recent AWWA M9 update. Pipe deformations or movements, in particular, can also cause additional pipe stresses (axial, bending and shear) on the pipe and/or deflection in the joints at or near the unbalanced forces. These additional effects are typically not considered in the designs of water/wastewater pipelines using most of the current AWWA pipe design manuals. In addition, with numerous joint configurations having varying capabilities of axial and rotational movement (flexibility) along with the complex behavior of the pipe-soil interaction, the amount of movement the pipe bends can safely be subjected to without causing excessive stresses on the pipe or joint itself is generally unknown. In 2010, the ASCE task committee on thrust restraint design of buried pipelines presented a draft White Paper that presented historical work, current practice and a preliminary framework for the design of thrust blocks and thrust restraint systems to improve current practice. Recognizing the widely different joint types used in practice, the white paper suggested this framework might eventually consist of two distinct design solutions: continuous (welded, fused or flanged) pipelines; and segmented (discrete) pipelines. This paper presents some further work of the task committee towards improving understanding concerning the behavior and design of thrust restraint systems employing restrained joints for segmented pipelines. While this paper offers some more basic information and issues, it does not presume to dictate a common restrained length calculation method, nor does it dictate a specific new strength analysis for all the various varieties of segmented piping materials and joint restraints, including those used with concrete, ductile iron, fiberglass, polyvinyl chloride (PVC), and steel pipelines. Also, while it only focuses on horizontal bend situations, and with a case study of ductile iron piping (DIP) with only some quite adverse differential loading and support conditions, it does however present some principles that might eventually be extended to more detailed examinations of more well-supported bends and other thrust situations.

A large diameter steel pipe was tested under static soil loads at the Center for Underground Infrastructure Research and Education (CUIRE) laboratory at UT Arlington. The 19.75 ft (6 m), 73.75-in. (1873 mm) outside diameter, steel pipe with diameter to thickness ratio (D/t) of 230 was placed inside a concrete load cell and currently is being backfilled with native clayey soils obtained from the Integrated Pipeline (IPL) project site in the North Texas. The backfill soil was first tested in the geotechnical laboratory and currently is being placed while compacted to one foot above the crown of the pipe. Additional load equivalent to nine feet of native soil will be added incrementally. Vertical pressures at crown and bottom of the pipe and horizontal pressures at the springline of the pipe will be recorded as loading is increased. Also, changes in vertical as well as horizontal diameters of the pipe will be measured during and after installation of the pipe. The purpose of the test is to study behavior of a large diameter steel pipe under native backfill and calibrate the related Finite Element Model (FEM). This paper describes details of the test and presents the preliminary results obtained. Based on the results of this test and accompanied FEM, appropriate recommendations for using native soils for trench backfill materials will be made, providing cost saving measures and sustainable construction methods.

The design of thrust restraint for piping systems, especially of large diameter (greater than 24-inch diameter) gasketed push-on joint piping systems, can become complicated as the forces involved in larger diameters reduce the restraint options available to a designer. This is due to larger thrust forces amplifying the pipeline stresses, movements and corresponding soil reactions. Most thrust restraint publications do not address non-standard environments that commonly occur in design. Some of the scenarios that a designer might encounter that require special consideration are fixed leg-flexible leg alignments, pipe telescoping, in-line valves, and limited joint deflection of restrained joints. The purpose of this paper is to address thrust restraint scenarios which require non-standard design considerations, to present potential solutions for such, and to present various phenomena encountered in large diameter pressure systems operating at 100 psi or more, which is typical of most municipal water and wastewater systems. This paper is not intended to address welded/fused-type joint systems, but to address the unrestrained push-joint and restrained-joint type piping systems.

Southern Nevada receives nearly 90 percent of its water supply from the Colorado River, currently facing the worst drought on record. To ensure a more reliable long term water supply for the Las Vegas Valley, the Southern Nevada Water Authority (SNWA or "Authority") is planning to develop water resources in east-central Nevada. The Groundwater Development (GWD) Project is proposed to ultimately consist of a pipeline and power conveyance system and well fields. The main pipeline system, made up of welded steel pipe ranging in size from 66-inches to 96-inches in diameter, will convey groundwater from well fields to be developed in Lincoln and White Pines Counties, Nevada, over 200 miles into Clark County, Nevada. SNWA enlisted the preliminary design services of HDR Engineering to perform system hydraulic analysis and facility definition of the main pipeline. The preliminary design effort included evaluation of various options for pipe procurement. Any procurement option considered would likely result in the pipe being stored for extended periods of time. The duration and harsh climate where the pipe would be stored caused concern that that the integrity of a mortar lining could be compromised. In addition, SNWA experience caused concern that, because of the water chemistry, leaching of alkalinity from the mortar lining could necessitate extensive flushing of the line. Lastly, due to the magnitude of the project, the use of flexible linings had the potential to reduce the tonnage of steel and thus reduce the overall project cost. These factors contributed to convincing the project team that alternate lining materials should be considered. Investigations showed that flexible linings, specifically polyurethane linings, were gaining more acceptance as an alternative to cement mortar linings. However, experience of flexible linings in water pipelines is limited. Epoxy systems were added to the evaluation after considering that recent developments in the formulation of epoxy systems have resulted in quicker set times. Epoxies, as a family of products, have been available longer than polyurethane systems. To help determine the suitability of these flexible lining systems as an alternative to mortar lining, SNWA decided to undertake an extensive testing program to better understand the properties of the flexible lining systems.. The goals of the program were to: (1) Estimate a reasonable life expectancy for flexible lining systems, and (2) Identify properties and quality control parameters critical to obtaining a good application/installation The testing program included five (5) polyurethane and two (2) epoxy shop-applied lining systems. The testing protocol included 16 separate tests developed in conjunction with a technical review panel (TRP) established to provide an independent review of the process, testing protocol, and results. Products were tested in a "blind" environment; that is to say that the name of the product manufacturer for each lining system was kept confidential and an arbitrary letter was assigned to identify each system. This paper presents the development of the testing protocol and results of the testing.

During the cleanup of Lake Washington in the 1950s and 1960s, shorelines of lakeside communities proved to be convenient locations for new sewers. Over 50 years later, many of these facilities are reaching the end of their design life and require complex replacements. Replacement of Reach 3 of the City of Mercer Island's lakeline sewer presented examples of the hard decisions that regional sewerage agencies face in the coming years. Reach 3 consisted of two low-pressure pump stations and about 2 miles of sewer offshore in Lake Washington. The primarily asbestos-cement system had been experiencing physical deterioration, capacity deficiencies and operational problems. After years of evaluating alternatives and coordinating with stakeholders, the City and Tetra Tech implemented an in-lake replacement. The low-pressure system was replaced with a gravity-flow and pumped system that maintains self-cleaning velocities. The project included 20,000 feet of new 6-inch to 16-inch lakeline and a new onshore pump station over 50 feet deep.

Southern Nevada gets nearly 90 percent of its water supply from the Colorado River which is currently facing the worst drought on record. To ensure a more reliable long term water supply for the Las Vegas Valley, the Southern Nevada Water Authority (SNWA, Authority) is planning to develop water resources in east-central Nevada. The Groundwater Development (GWD) Project is proposed to ultimately consist of a pipeline and power conveyance system and well fields. The main pipeline system, made up of welded steel pipe ranging in size from 66-inches to 96-inches in diameter, will transmit groundwater from well fields to be developed in Lincoln and White Pines Counties, Nevada over 200 miles into Clark County, Nevada. SNWA enlisted the preliminary design services of HDR Engineering to perform system hydraulic analysis and facility definition of the main pipeline. The preliminary design effort included evaluation of various options for pipe procurement. Any option considered would likely result in the pipe being stored for extended periods of time. The duration and harsh climate where the pipe would be stored caused concern that that the integrity of a mortar lining could be compromised. In addition, SNWA experience caused concern that, because of the water chemistry, leaching of alkalinity from the mortar lining could necessitate extensive flushing of the line. Lastly, due to the magnitude of the project, the use of flexible linings had the potential to reduce the tonnage of steel and thus reduce the overall project cost. These factors contributed to convincing the project team that alternate lining materials should be considered. Investigations showed that flexible linings, specifically polyurethane linings, were gaining more acceptance as an alternative to cement mortar linings. However, experience with flexible linings in water pipelines is limited. Epoxy systems were added to the evaluation after considering that recent developments in the formulation of epoxy systems have resulted in quicker set times. Epoxies, as a family of products, have been available longer than polyurethane systems. To better understand the properties of polyurethane lining systems, SNWA decided to undertake an extensive testing program. The goal of the program was to: (1) Estimate a reasonable life expectancy for polyurethane lining systems, including potential life cycle costs for periodic maintenance activities; (2) Identify properties critical to obtaining good installation/application, (3) Develop a guide specification for use on future projects, and (4) Define critical quality control parameters for polyurethane lining systems that would allow plant and field inspectors to effectively assess the application and installation. After the initial testing program was developed, epoxy systems were added to the evaluation. Recent developments in the formulation of epoxy has resulted in quicker set times and epoxies, as a family of products, has been available longer than polyurethane systems. The program tested 5 polyurethane systems and 2 epoxy systems, side by side. Products were tested in a "blind" environment; that is to say that the name of the product manufacturer for each lining system was kept confidential and an arbitrary letter was assigned to identify each system. Each of the 7 products was applied to test plates (carbon steel coupons) by a single applicator that was qualified to apply each of the products. The samples were labeled and shipped to KTA Tator's (KTA) laboratories in Pittsburgh, Pennsylvania, where the testing was conducted over the course of approximately nine (9) months. This paper describes the details of the application and testing and discusses the testing data.

This paper is intended to cover some of the challenges associated with designing and overseeing the construction of various antiquated large diameter water mains to meet scheduling deadlines and expectations as set by the client and the DOT. Subjects touched upon include: (1) Overall project scope (2) Conflict identification, (3) Project design/construction phasing, (4) Existing/proposed utility location, (5) DOT coordination, (6) Contractor coordination, (7) Large water main taps on antiquated existing water mains, (8) Reliability of valves in older systems for shut-downs, and (9) Line stops on large water mains, and The design and construction contracts were necessary to make plans to relocate existing water mains to avoid potential identified conflicts with work that was being planned by the DOT for the New Mississippi River Bridge (MRB) project and associated highway improvement projects. The DOT's proposed work included the approach to the new MRB consisting of aerial portions of highway as well as portions to be constructed on compacted fill at elevations up to approx. 20' higher than the existing grade. Proposed work also included the construction of new bridges over an existing highway interchange as well as the reconstruction of the existing interchange. The biggest challenge for the water utility was that there were two (2) existing large water main crossings at the existing interchange that was scheduled to be reconstructed. One crossing consisted of an underground 24-inch lock joint concrete water main and another crossing consisted of dual 30-inch steel water mains that crossed the highway on a steel truss bridge structure approximately 18 feet above the highway across four (4) spans supported by reinforced concrete piers. These crossings would need to be eliminated to allow for the planned DOT construction work, however, these mains served as the primary source of water for many cities and counties downstream of the existing interchange so service could not be easily interrupted. The major challenges included relocating the large water mains across the highway, which required an approximate 350 ft. jack & bore operation on dual 36-inch water mains, and phasing the necessary relocation projects in a way that would meet the DOT's various construction contract schedules.

This paper looks in detail at the specific issues and developments in jointing design and practice in connection with a 1200mm (48") diameter steel drinking water pipeline in the UK. Socket (bell) and spigot jointing systems (lap joints) are common place in low and medium pressure steel pipelines but for potable water systems where an internal epoxy lining is required the external fillet weld invariably damages the internal lining. The "insulating joint" theoretically overcomes this problem as it includes an air pocket that drastically reduces the heat transfer to the internal surface. In practice, despite the simplicity of the design concept, such a joint is far from easy to achieve. This paper documents a series of set backs in achieving the Contractor's dream of avoiding man-entry into the pipe once the pipe has been welded. The trail takes us through detailed design, hydraulic losses, factory production, coating systems, pressure testing and on towards success. An unexpected complication is the behaviour of the air pocket sleeve during pipeline pressure testing. The paper concludes that this is a dream worth following but strongly advises that you don't under-estimate the challenges.

The determination of energy losses caused by the combination and division of flow at tees are important in the design and analysis of piping systems. An accurate estimate of the energy losses across junctions is critical to line sizing and could have a significant impact on hydraulic calculations and in some cases, pump selection. There are many available sources of minor loss coefficients for tees, most of which vary, and provide a single loss coefficient regardless of discharge or junction geometry. Based upon momentum principles, the energy loss should vary with both the discharge in each branch and geometry signifying that the application of a single loss coefficient will provide inaccurate results. A literature review was performed to identify available sources and methodologies of determining/selecting minor loss coefficients in order to determine the corresponding application ranges based upon tee geometry and flow regime in an effort to standardize on the methodology of selecting minor loss coefficients in dividing and combing flow junctions.

When a municipality is surrounded by a larger city, it is inevitable that the two share key utilities or infrastructure. Such is the case with the City of White Settlement, Texas, and the Fort Worth. The City of White Settlement, a 5-square-mile borough nestled within Fort Worth, shares a sewer interceptor with the larger city. This Fort Worth-owned sewer interceptor crosses the City of White Settlement from east to west to connect the west side of Fort Worth (on the upstream) with the east side (downstream); this interceptor serves as the City of White Settlement's main sewer interceptor which shares the same alignment as the Farmer's Branch Creek in the City of White Settlement. For years, the storm-carrying capacity of the creek has caused flooding issues in the City of White Settlement. When the U.S. Army Corp of Engineers (USACE) addressed the flooding issues by widening the creek, the City of White Settlement and the City of Fort Worth, as a consequence, were faced with relocating the sewer interceptor. Although the City White Settlement and Fort Worth have a cost-share agreement for sanitary sewer flows, the City of White Settlement initially assumed full responsibility for planning, designing, and constructing the sewer interceptor relocation since the sewer interceptor is primarily within its city limits. This outdated original cost-share agreement was revised for this project; the updated agreement considered new population, growth rates, and existing and projected flows to provide a more appropriate and equitable cost sharing arrangement for the project construction. This paper addresses the multiple stages of the project, the coordination efforts between all agencies involved, and the challenges the design team faced during project development.

The ground is full of all kinds of pipelines of different sizes, materials, pressures and cathodic protection (CP) systems. Most metallic or concrete pipes installed these days utilize a cathodic protection system of some kind. How do you ensure that the cathodic protection system of your new pipeline will not be compromised by existing cathodic protection systems nearby? Freese and Nichols, Inc. (FNI) recently designed 27,200 feet of 48-inch and 47,400 feet of 42-inch treated water pipeline for the North Texas Municipal Water District in rural North Texas. Paralleling existing utility corridors was favored during pipeline alignment selection to avoid severing properties and reduce overall land acquisition costs, but this also posed challenges during design. The route selected for this pipeline included paralleling an existing natural gas transmission line continuously for approximately 22,000 feet. The existing gas line, configured with an impressed current cathodic protection system, could have significant impacts on corrosion protection systems and life-span of parallel pipelines. Reducing the chance of interference between the two pipelines' cathodic protection systems and ensuring measures were taken to monitor any potential interference in order to extend the life of this asset was a driving factor for the cathodic protection design of this pipeline. This paper discusses the pipe materials considered including bar-wrapped pipe and polyurethane coated steel pipe, as well as the cathodic protection systems considered including impressed current, magnesium ribbon and magnesium groundbeds. Other cathodic protection considerations for a rural pipeline including test station details, rectifier details and placement and pipeline crossing details are discussed in this paper.

Every large pipeline project has its own unique design elements and surprises. Anticipating and knowing how to prepare for these potential issues is critical to the successful design, construction and operation of the pipeline. During Preliminary Engineering for pipeline projects there are a few guiding principles that every team should follow to plan the project effectively. Since a thorough Preliminary Engineering evaluation is fundamental for a project's success, these guiding principles cannot be ignored. This paper provides the planning principles and a detailed checklist for owners and engineering managers to utilize during the planning stages of a major pipeline project. Utilization of these tools will help identify potential surprises encountered on each pipeline project earlier than before. These principles and checklist have been developed through experience of planning and design of over 400 miles of large diameter pipelines in mostly urban environments. Planning for everything may seem too cumbersome to accomplish, but this paper will simplify the process for a majority of the typical challenges and include examples from previous lessons learned.

Cyclic loading of plastic pipe is a known risk factor that can lead to fatigue related failure. While the re-rating of plastic pipe based on cyclic loading is addressed by advisory documents on other continents, there is limited guidance for design engineers in North American practice. Domestic polyvinyl chloride (PVC) and polyethylene (PE) standards include surge allowances above rated working pressure based on limiting values of hoop stress, but only C900 and C905 for PVC pipe include a method for addressing fatigue in design and then only as an informational appendix, not as part of the adopted standard. In this paper, the author uses field measured transient data to develop three classes of cyclic loading that are typical of water and wastewater practice. Various standard design approaches are then applied to the selection of the appropriate pressure class of plastic pipe for each classified transient. Determination of the corresponding dimension ratios allow for the analysis of the transient data in terms of hoop stress. Given sufficient knowledge of the transient conditions in an existing or proposed piping system, the design engineer can not only design for a total number of lifetime cycles, but also reduce risk of fatigue failure by managing the magnitude of repeated stress cycling.

The Sanitation Districts of Los Angeles County (Districts) own, operate and maintain a wastewater treatment and collection system that includes approximately 1,300 miles of sanitary sewers ranging in diameter from 8-inch to 144-inch. This project is the last of a series of projects that provides relief for the District 32 Main Trunk Sewer system, which serves the Santa Clarita Valley. This relief sewer siphon project was successfully constructed by microtunneling a 60-inch steel casing with a 48-inch fiberglass carrier pipe at a depth of 40 feet below the unimproved Santa Clara River at a construction cost of $7.7 million. The 28-foot diameter, 80-foot deep microtunneling shafts were constructed by sinking a concrete caisson without dewatering due to the inability to discharge groundwater into the river because of environmental and permitting restrictions. The project was successfully completed in August 2010.

The Tarrant Regional Water District (TRWD) and City of Dallas have partnered to explore the feasibility of an integrated raw water transmission system to meet future water needs in North Central Texas (TRWD and Dallas service areas). The Integrated Pipeline (IPL) project's ongoing planning and conceptual design phases involve multiple analyses such as operations, capital and life cycle costing, facility siting assessment, permitting and regulatory reviews, and hydraulic evaluation. With an ultimate goal of building a reliable and efficient transmission system, the final system configuration is continuing to evolve. The 134-mile long raw water transmission main pipeline ranges in diameter from 84-inch to 120-inch conveying water from the East Texas to West Texas regions with peak capacity projected at 347 million gallons per day (mgd). Pipe segments converging and diverging from the mainline constitute an additional 18 miles of transmission pipeline. The IPL will be integrated with 72-inch to 108-inch diameter existing transmission pipelines, which currently convey up to 247 mgd of water. A thorough hydraulic evaluation of several potential pipeline corridors was evaluated during the planning phase. Hydraulic evaluations developed and compared pipe sizing for peak flow conditions and capacity/power requirements for pumping stations. This information was fed into a basic decision matrix for various corridor options and combinations to narrow down to a preferred pipeline corridor. Several pumping configurations are being considered for the selected IPL corridor. The pumping facilities consist of three intake stations and two or three booster pump stations depending on the selection of the final system configuration. Various tunnel configurations are being analyzed in order to conserve pumping power and avoid high points and difficult construction areas along the pipeline corridor. The IPL will deliver water to various lakes and water treatment plants served by TRWD and Dallas. Energy optimization is an integral part of this transmission system as it involves pumping water over long distances using large diameter pipelines. Optimization of pipe sizing is being performed by comparing capital investment costs versus energy costs on a present worth/life cycle basis. Potential gravity operation is a possibility over a wide range of low flows using balancing reservoirs at high points and pump station bypass modes at low demand conditions are also being examined. Such potential power savings as well as operational benefit is incorporated in the hydraulic evaluation. Achieving IPL system redundancy, reliability, and operational flexibility in conjunction with the existing transmission system operation is a critical path forward. The hydraulic and operational aspects of achieving these goals will be explored in this paper.

The Clackamas County Sanitary Service District #1 (CCSD#1) serves about 80,000 customers in the City of Milwaukie, Happy Valley, and incorporated county areas located east and south of the City of Portland, Oregon. It owns and operates two treatment plants, the Tri-City and Kellogg Water Pollution Control Plants (WPCP). There is a need for a hydraulic interconnection between those two plants that would divert flows of up to 30 mgd from the Kellogg to the Tri-City WPCP. This diversion is necessary to allow a decrease in flows to Kellogg Creek WPCP during storm events. The effort to connect the two treatment plants required a variety of operational requirements to be met through the diversion. Flows had to be regulated to carefully increase and decrease the diversion between the two plants and not cause rapid flow and load changes to either WPCP. Because flows can change quickly with storms, it was also important to understand how flows respond to storms and what instantaneous changes to pumping flow rate at the diversion pump station would do to downstream and upstream treatment plant operations. In addition to the complexities of operations, the alignment of the new diversion force main resulted in complex hydraulics issues. The pump station had to overcome a local high point in the first 5,000 feet of force main and then accommodate over 20,000 feet of piping with downhill slopes. At low flows, the first 5,000 feet were pressurized and the remaining piping operated as a gravity system. As flows increased, eventually all of the force main converted from gravity to full pressurized flow. This paper will discuss management of the flow variation of incoming flow rate, sizing of the self-cleaning wet well, and selection of pumping equipment. The highly variable conditions result in sections of the system transitioning between gravity and pressure flow. The changing hydraulic conditions result in the potential for siphoning, creation of hydraulic jump(s), and other hydraulic phenomena that increase air movement along the force main, causing temporary flow capacity reductions, transient potentials, and varying pumping head. An emphasis will be given to selection of force main alignment and pumping equipment, dual force mains implementation and air/vacuum valve requirements.

Owners constantly face tough decisions when implementing new large diameter pipeline infrastructure projects. Limited capital project budgets and uncertainties in the current economy create additional pressures for Owners to achieve "Best Value" on these large capital projects. These decisions are often influenced by weighing pipeline design parameters and bid specification options during the design phase that directly impact project cost, constructed project quality, operations and maintenance costs, and long-term service life. A key factor in these decisions involves risk and value judgments of the Engineer and Owner. Contractors are ultimately responsible for the completed project quality in accordance with the plans and specifications. In most cases, Contractors are not given much opportunity to innovate or provide value after bidding, because they are required to complete the project as designed for the cost established by a low bid. Ideas integrating design parameters and bid specifications with construction quality control measures are presented for Owners seeking to create efficiencies and cost savings on large capital projects with constrained budgets. Many of the ideas may appear to be common sense or accepted as common practice; however, this paper explores a framework for decision making and an integrated approach to achieve best value considering risks and trade-offs throughout project implementation. This paper presents ideas related to pipeline conveyance projects, but the process can also be applied to other site-specific water resource projects, such as treatment facilities and pumping stations.

Planning for Colorado's water future includes addressing infrastructure needs associated with meeting future municipal and industrial demands. As part of the Colorado Water Conservation Board's (CWCB) Statewide Water Supply Initiative, CWCB developed reconnaissance-level cost estimates for several pipelines that have been discussed by various entities across the state. The scale of the proposed pipelines is significant, conveying large flows from across the Continental Divide, and even across state lines, to the eastern edge of the Rockies where most of the state's population is concentrated. To compare these major projects, CWCB and CDM developed planning-level cost estimates with considerable detail given the long term of the planning horizon. This comprehensive effort required collaboration between planning engineers and experts in design and construction cost estimation. Many of the unit costs were developed using existing tools intended for design phases. Care was taken to make the methodologies and the tools transferrable to other projects. This unique reconnaissance-level cost estimating project is thus relevant to water supply planners, and anyone interested in the early stages of large pipeline projects or pipeline cost estimation in general.

Hydraulic transients are created during a change in system operation related to flow and pressure. It is typically a temporary unsteady state condition that every system experiences in between initial and final steady state conditions. Typical system operations such as pump starts/stops, valve opening/closing create unsteady state conditions creating pressure waves that propagate through the system. These created pressure waves are the mechanism that hydraulic systems utilize to go from a one hydraulic state to another. The propagating pressure waves create both high- and low- pressure events that can be detrimental to a transmission system. High pressures can create damage to pumps, valves, and other system appurtenances, while low pressures can lead to column separation, cavitation, and subsequent failure of pipelines. Most transients can be controlled by adhering to and implementing operational strategies that are geared towards transient control, such as utilizing procedures for controlled startup and shutdown during normal operation. But events that cannot be controlled by operational strategies, such as power failures or pump failures, need automatic devices that can control the magnitude of and minimize the impact resulting from such transient events. The control of hydraulic transients in very long transmission mains could require several additional considerations in analysis as well as in sizing devices. Even adhering to and implementing established operational strategies may also require several additional considerations and in-depth analyses. This paper will discuss two case studies related to analysis, design and modification of hydraulic transient controls for very long transmission mains with emphasis on operational modifications to existing components.

The proposed Northeast Transmission Main intends to meet subsidence mandates by delivering treated surface water from the City of Houston's Northeast Water Treatment Plant to northwest Houston and several Water Authorities with an approximately 22 mile pipeline. The initial engineering feasibility study (project) entailed the development and analysis of three pipeline alignments, ranging in size from 66 inch to 156 inch, through often dense urban environments. Additionally, to facilitate cost sharing agreements, the feasibility study was put on an accelerated schedule of 90 calendar days. Throughout the feasibility study, project leaders were challenged to simultaneously allow three different teams to update alignment options, analyze large volumes of data, and provide up-to-date exhibits for daily and weekly progress meetings. This was accomplished through good planning and several innovative uses of GIS such as the use of a GIS manager to establish file use protocols, project-wide layer creation, the incorporation of ESRI's free ArcGIS Explorer, and the extensive use of the ArcMap Map Books add-on. Project-wide layer creation served several purposes. The primary benefit of creating and saving file layers was to ensure consistent symbology across all exhibits. By having one user organize, symbolize, label, and filter the necessary GIS data and saving it as a layer file, all other GIS exhibit creators were able to simply load the latest layers into their exhibits and print. Another innovative use of GIS was the incorporation of ArcGIS Explorer (AGE). AGE does not require the purchase or use of any software licenses and can view standard GIS Layers. AGE was used by the project team members that did not need to produce GIS data or exhibits, only analyze the data. The intuitive design of AGE also drastically steepened the learning curve for those team members with no previous GIS experience. Finally, by using the Map Book add-on to ArcMap, the project team was able to quickly provide full exhibit sets detailing each pipeline alignment. The greatest benefit from using a Map Book was that an entire set of exhibits for an alignment could be rapidly produced from only one file. So when a new exhibit set was required for either review or submitting, a project team member would simply open the Map Book file and export the full set, confident that all of the previous changes made to the GIS data were automatically incorporated into the new exhibit set. Through the innovative use of GIS and good management practices, each aspect of this project was improved and expedited. Lead engineers were able to direct updates very rapidly, the design team production staff always had the latest data available without costly delays, and by managing the GIS data, multiple file creation was avoided. All of these factors culminated in a successful alignment design.

Originally constructed in 1929 and 1935, Pipelines No. 2 and 3 convey filtered water from the Sultan River water supply source to the City of Everett. Due to deterioration of the existing pipeline piling support system and pipelines, the City of Everett implemented a plan to replace these pipelines across a relatively inaccessible portion of the Snohomish River Estuary. The Phase 6 project consists of replacing approximately 1,219 meters (4,000 LF) of two parallel 122 cm (48-inch) diameter steel pipes across the western half of Ebey Island just south of and parallel to the State Route 2 highway trestle. The pipeline design needed to address a number of unique design challenges. The project was located within federally regulated wetlands associated with the Snohomish River estuary that fall under the jurisdiction of the United States Army Corps of Engineers. Due to the presence of these Category 1 wetlands, construction access was severely restricted; with access available only from the two ends of the pipe alignment, all construction equipment activities needed to be supported off of a temporary pile supported trestle system or by the new permanent pile bent system that would support the pipeline. Other unique design challenges included: the presence of very soft soil materials, extending to 27 meters (90-feet) and more below the ground surface, the presence of other pile supported structures resulting in a complex web of potential underground conflicts, horizontal angle points resulting in thrust restraint, thermal expansion/contraction of the above ground piping, the need to cross under an existing pedestrian bridge overpass and a buried crossing through an existing dike structure. This paper describes the alternatives investigated and the design solutions developed to address these complex, challenging issues for a major above ground pipeline system while protecting the surrounding wetland resources.

To meet regulatory requirements, as the area's regional provider, the City of Houston undertook the planning of extending the existing surface water system across the northern portion of Houston for approximately 22 miles. Based on initial data review, feasible corridors were investigated and evaluated to facilitate the selection of a preferred alignment. Parameters were established to assess the limiting factors such as available easement width, large diameter pipe constructability issues, familiarity with increased pressure operations, and cost. This paper will focus on the alignment, environmental, traffic control and constructability issues with placing an extra large transmission main in an urban setting.

Recent failures of aging pipeline infrastructure have brought increased attention to the current and future capabilities of critical infrastructure. According to the Department of Energy, natural gas lines alone need $19 billion dollars to maintain current capacities and an estimated $42 billion to keep up with future demands. With over a quarter of the nation's pipelines reaching over 50 years old, it is evident that pipeline projects will continue to increase in scope and cost. Front End Planning (FEP) is a critical process for uncovering project unknowns, while developing adequate scope definition, and a structured approach for the project execution process. FEP assists in identifying and mitigating issues such as right-of-way concerns, utility adjustments, environmental hazards, logistic problems, permitting requirements and so on. This paper will outline a novel and effective risk management tool that has been recently developed by the Construction Industry Institute (CII) called the Project Definition Rating Index (PDRI) for Infrastructure Projects. Input from industry professionals from over 30 companies was used in the tool development which is specifically focused on FEP. Data from more than 90 projects in seven countries representing project input totaling over $8 billion USD in capital investments will be given showing the efficacy of the tool. Critical success factors for FEP of pipelines and other types of infrastructure projects will be shared, including key planning process steps; guidance for administrators and project professionals will be given.

In October 2010, the Provo River Water Users Association, which currently operates the 21-mile-long Provo Reservoir Canal (PRC), also known as the Murdock Canal, and the US Bureau of Reclamation, the owner, broke ground for the Provo Reservoir Canal Enclosure Project, a monumental 3-year, $150 million undertaking that will enclose the PRC into a 126-inch steel pipe with the capacity to carry 400 million gallons of water per day. The enclosure of the canal will save approximately 8,000 acre-feet, or 2.6 billion gallons, of water annually from evaporation and seepage, increase safety along the canal's length in areas that are heavily populated, and offer a number of other benefits. When the project was conceived, several materials for the enclosure conduit were considered, including a precast concrete box culverts with gasket joints, cast-in-place concrete box culverts, non-cylinder reinforced concrete pressure pipe, welded steel pressure pipe, and fiberglass reinforced polymer pipe. A systematic analysis of the suitability of each material for the application was conducted, which included availability in the necessary sizes, history of each material in similar applications, hydraulic and other engineering properties, available joint types and the ability of each material to reduce leakage, economic feasibility, and the constructability of each. This paper provides a detailed discussion of each of these parameters from the unbiased viewpoint of the project owner as well as the design engineer.

Typical joints specified in steel pipe systems include the non-restrained rubber-gasket-type, restrained field-welded-type, flanges, couplings and expansion joints. Since joints are often perceived as the weak-link in a pipeline, it is important for engineers to have a clear understanding of the capabilities of a particular joint design, quality control practices followed during manufacture, and most importantly, a sound track record of its performance over many decades of use. Gasket-joints are the most common non-restrained jointing system specified not only for steel pipes but also for other commonly-used pipe materials. It is therefore important to have a clear understanding of their design and performance. The two main types of gasket joints permitted by the American Water Works Association (AWWA) Manual of Water Supply Practices M11-Steel Water Pipe: A Guide for Design and Installation includes the Rolled Groove type and the Carnegie-type. The former is widely specified for pipe diameters up to 78-inch and 250 psi maximum working pressure, with an allowable maximum transient pressure of 375 psi, though larger diameters and higher pressures can also be accommodated. This paper primarily discusses various aspects of the Rolled Groove joint, but sufficient information is provided on the Carnegie to highlight both similarities and differences.

Linings and coatings have been used for more than 150 years to protect steel water pipe from corrosion. As demonstrated in common field and environmental conditions, some coating and lining systems are better than others at extending the service life of water transmission pipelines with virtually no maintenance. Two systems have been used for over 100 years with a proven history. Some systems, for various reasons, are no longer used. Other systems have been introduced in the last 25 years and have yet to prove long service life in actual installed conditions. The historical performance of lining and coating systems for welded steel water transmission pipelines in the United States under a variety of field and environmental conditions are presented and discussed. These systems are included in internationally-used waterworks standards. This paper presents the results and recommends best practices for the selection of lining and coating systems for welded steel pipe in the water industry.

Water infrastructure engineers commonly evaluate a variety of pipe materials to determine the most appropriate solution for a particular application. Occasionally engineers inappropriately apply identical structural design criteria for both steel and ductile iron pipe (DIP). While similarities do exist, there are substantial differences in the material properties that make their structural designs unique. The applicable AWWA standards and design manuals are evidence of such variances. To demonstrate the distinguishing mechanical properties of steel and ductile iron, large diameter samples were gathered, cut, and subjected to mechanical property testing. A review of the results will validate the existence of distinct material properties and clearly indicate the need for unique design practices that should not be modified or comingled. The mechanical property differences between steel and ductile iron and the implications to applicable AWWA design criteria are discussed.

The population growth in the cities of Tijuana, Rosarito and Tecate, Baja California, Mexico required an expansion of the supply of drinking water. A fifteen year concession was awarded to Administradora de Obras y Concesiones (AOC), a subsidiary of Constructora Makro, to finance 50% of the total construction cost and to design, build, and operate a new pipeline parallel to an existing pipeline. The Acueducto Rio Colorado Tijuana project was commissioned by the state of Baja California, Mexico, in 2007 and was completed in 2010. The project involved building approximately forty miles (64.4 km) of pipeline of 54-inch (1372 mm) and 60-inch (1524 mm) pipe diameters, and increasing the capacity of six existing pumping plants. Welded steel pipe was used with working pressure limits of 50 to 600 psi (3.5 – 42.2 kg/cm²). The project is the first of its kind under a new financial model where the government provides 50% of the cost of the project and the concessioner has to secure financing for the remainder of the project. In exchange, the government will enter into a long term contract to pay the concessioner for the transportation of the water. At the end of the term the concessioner will turn over the pipeline and operations to the government. This paper presents the project design, construction and financing of the new model used in Mexico to build new aqueducts to solve their pressing water needs.

Current pipeline design practice within water pipeline industry is largely based on the American Water Works Association (AWWA) design manuals, which do not address seismic design explicitly. Pipeline designers often use seismic design guidelines published from other sources, such as American Lifelines Alliance (ALA) and American Society of Civil Engineers (ASCE) and building codes such as International Building Code (IBC). The guidance presented in the current ALA and ASCE seismic design guidelines are outdated, as the building codes and seismic hazard maps have been updated few times since the publication of these documents. Although outdated, the concepts and guidance presented in the ALA and ASCE seismic design guidelines, specifically with regard to the establishment of seismic design criteria for a pipeline based on its function and use, are still applicable. The seismic design criteria of a pipeline should be established by considering the performance objectives, such as serviceability, damage control, and collapse prevention. The goal is to ensure life safety performance, while providing an economically feasible design with an acceptable level of functional reliability following a seismic event. To achieve reliable performance of an above ground pipeline segment, the seismic stability of the ground as well as the structural performance of the support should be evaluated by the designer for the intended seismic performance level and criteria. The interdependence of the soil-structure interaction performance during a seismic event should be evaluated and accounted for, with input from both geotechnical and structural engineers. This paper presents a brief summary of the currently used and published seismic criteria in other design practices, presents an approach to determine appropriate seismic hazards for the design of the pipeline and for the evaluation of the ground hazards, and a discussion of seismic design concerns associated with the design of an above ground support.

The City of Portland Bureau of Environmental Services has completed the design of the Balch Consolidation Conduit—the final segment of their West Side Combined Sewer Overflow (CSO) system, part of the City's overall CSO program. This project includes 6,900 feet of 84-inch microtunneling in five drives and 950 feet of 54-inch microtunneling in a single drive. The project was originally envisioned to be a design-bid-build project; however as design progressed, the trenchless risks were identified and considered significant due to areas with extremely soft soils, landfill debris, and cobbles and boulders. As a result, the City chose to use an alternative contracting mechanism for project delivery that included choosing a contractor through a qualifications-based selection process at the 60% design level. From the 60% to 100% design completion level, the contractor participated in final design decisions, made suggestions for modifications to existing design features and provided input to refine cost parameters. This mechanism was previously coined "The Portland Method" on the West and East Side CSO projects. During construction of the third microtunnel segment, a large object (likely a large boulder) was encountered that caused the operator to lose control of the tunnel steering, resulting in major deviations in the tunnel alignment. On a conventional design-bid-build project, this would certainly have been considered a differing site condition that would have resulted in a significant change order and possible claims. However, due to the alternative contracting delivery method that was in place that included a collaborative engineering team, the Contractor, the City, and the Design Engineer were able to work together to mitigate the problems caused by the potential obstruction. Instead of abandoning the microtunnel drive and retrieving the machine in a rescue (or 911) shaft, all parties worked together to develop a compromised solution that could allow continued tunneling at a significant cost savings to the City. This included a number of creative and challenging microtunneling operations to install the pipe beyond the boulder while balancing the hydraulic requirements of the system. This paper will provide the details of the "boulder incident" and show how the Contractor, City and Engineer were able to successfully collaborate to solve a complex problem, demonstrating how alternative contracting delivery can eliminate the risk of claims on microtunneling projects.

The Nacimiento Water Project in San Luis Obispo County, California, was completed in late 2010, and is now capable of delivering 15,750 acre-feet of raw water annually from Lake Nacimiento through 45 miles of pipeline to its service area. The Project includes three pumping stations, three storage tanks, 45 miles of pipeline ranging from 36- to 12- inches in diameter, and a Supervisory Control and Data Acquisition (SCADA) system. The hydraulic aspects of the system dictated careful attention to hydraulic design, with due consideration of normal and transient pressures. The construction contract was modified to add a very intensive hydraulic transient monitoring system. This transient monitoring program was installed during construction, and includes nine TP-1 transient pressure monitoring systems installed at locations most prone to severe hydraulic transients. These systems provide detailed information regarding transient pressures and are integrated into the SCADA system to provide real-time alerts if threshold pressures are exceeded. This paper describes the Nacimiento Water Project, the hydraulic design considerations, the network of transient monitoring systems that is installed, construction considerations, lessons learned, and the results of transient pressure monitoring collected during initial startup and testing. Results will include analysis of actual pipe rupture data that occurred during construction, and validation of hydraulic models.

Horizontal Directional Drilling (HDD) has evolved steadily over the last 20 years and currently is the preferred method for municipal water installations due to its low impact on the surrounding areas. The Bulldog Restraint System (BRS) has added bell-and-spigot to PVC-U and PVC-M piping options for installation by HDD. In North America, BRS is designed for integration into diameters ranging from 3-in. (75-mm) to 16-in. (400-mm). This paper presents the methodology for testing the BRS joints under axial tension, and the corresponding results, for PVC pipes equipped with BRS. In order to compare the BRS capabilities to expected loads for an HDD installation, an Excel spreadsheet was developed to calculate the anticipated pull forces, using ASTM F1962-05 design procedures. In addition, to show the cost effectiveness of the HDD method as applied to the internally restrained PVC pipe, a cost comparison with the traditional open-cut installation is provided.

United Utilities Water plc (UU) supplies potable water to approximately one million homes in North West England. In 2006, work began to plan UU's most significant project of the last five years: a new 1200 mm diameter trunk main which, when completed in 2011, will transfer potable water across one of the most densely populated regions of the UK. Planning consent and an Environmental Impact Assessment (EIA) was required for the new bi-directional trunk main, known as the West East Link Main (WELM). Following extensive route corridor investigations, a 55 km route was selected, which passes through eight separate local planning authorities. Approximately two-thirds of the pipeline route lies within agricultural land and the remaining third is within highly populated areas. The planning and construction of this pipeline presented a range of challenges, not least dealing with the sheer number and variety of stakeholders and constraints encountered on the route. These included other utilities, railways, motorways, roads, rivers, canals, golf courses, landfill sites and hundreds of individual landowners and tenants. Despite the optioneering work carried out to minimise social and environmental impacts of the route within the crowded post-industrial landscape of England's North West, inevitably a number of archaeological sites, protected species, locally important habitats and community groups were affected by construction of the pipeline. Using WELM as a case study, this paper looks at specific and innovative responses of the project team to successfully navigate the approvals process for this recent major construction project in the UK water industry.

In the wake of events in 2010 such as the natural gas explosion in San Bruno, California and the crude oil spill in the Kalamazoo River, Michigan, the U.S. Department of Transportation (USDOT) is considering tougher regulations for pipeline safety. Even prior to these landmark events, pipeline companies have faced many challenges with respect to assuring pipeline integrity, operations and maintenance (O&M), and adhering to pipeline safety rules. Some of these challenges include meeting competing regulatory deadlines. Many federal, state and local authorities regulate pipeline operations and maintenance. USDOT pipeline repair requirements, for example, may conflict with permitting required by the U.S. Army Corps of Engineers or other regulatory authorities. In 2011 and beyond, companies will face obstacles including: (1) maintaining public confidence in their safety and integrity management programs, and (2) maintaining regulator confidence in their abilities to improve their operations and maintenance to reduce future risks of leaks or spills. Companies will need to navigate more regulation at the same time they improve their integrity management programs. In this paper, we discuss the challenges crude oil pipeline companies face in complying with existing regulations and potential approaches for meeting those requirements. We reference case studies comprising approaches (online tools) to managing increasing amounts of integrity management data, improving and streamlining permitting processes, and planning longer term approaches to safety and compliance. We provide examples of methods to coordinate multiple agency permitting requirements at the federal, state, and local levels. We include approaches to improving relationships with regulators. Finally, we include examples of long-term benefits associated with well-coordinated strategies to regulatory compliance and pipeline safety.

Permitting for linear utility projects can be a key driver of schedule, alignment and usually cost. Early and proper management of permit identification and acquisition is a key element of a successful risk management strategy for any project. Permitting for linear pipeline projects presents unique and complicated challenges. This paper will discuss the challenges of permitting, strategies for managing permit acquisition, and perspectives on common permitting issues. Linear pipelines present a unique permitting challenge because they typically extend through multiple jurisdictions and, often, through resources with multiple local, state, and federal permitting agencies. Creating a permit acquisition strategy early in the planning phase can avoid delays in later stages of the project. Four key elements of environmental permitting that a pipeline project manager should understand are discussed in this paper. These are permit triggers, timing, cost and sequence.

Utilities around the world are mapping their water and wastewater infrastructure in GIS, but comprehensive tools for pipeline risk assessment is not yet evident which takes into account the extensive parameters for risk associated with the pipeline failures. Advanced pipeline risk assessment is contingent on accurately locating the buried pipelines, the milieu and also the physical condition of pipelines. This web GIS based state-of-the-art visualization platform provides a robust way to assess the risk associated with the failure of water and wastewater pipelines. This research focuses on the development of a robust model for the quantitative risk assessment for water and wastewater pipelines by taking into account the probability, consequence and the threat due to pipeline failure. Thus, the environmental, traffic, service disruption, time, public health and the financial impact associated with the probability of each pipeline failure are considered along with the threat to the utility operations. These extensive parameters are evaluated heuristically and by real-time data from water and wastewater utilities in US, Canada and Australia, and derived by GIS using advanced geospatial tools. Monte Carlo simulations are used to perform the risk assessments. A Pipeline Infrastructure Database (PID) has been developed which is a web-based integrated service providing the utilities to tweak and run the risk assessment models for each type of pipe and simulate it for extended periods. An exclusive working environment is provided for each utility with access to their respective data to run the risk assessment model and download the results in customized formats as reports, shape files and databases, and thus this serves as a comprehensive tool for sustainable utility risk management. Pilot studies and constructive feedback from major utilities in west coast has shown that this web based risk management tool has important practical value and can be cooperatively expanded.

It has been widely recognized that global climate change will have negative impacts not only on the natural environment but also on the human-built environment. This paper describes the framework developed to assess the potential impacts of climate change and urbanization on drainage systems of Australian urban cities. One of real concerns is how the flooding risk will change over the next 5–25 years under such possible impacts. In this study, the assessment method is explored with regards to two major effects of climate change (i.e. changed pattern of storm event and rising sea level), two effects of urbanization (i.e. increasing impervious area and storm water harvesting) and two effects of hydraulic deterioration (i.e. reduced cross-sectional area and increased internal surface roughness of conduits). The framework is demonstrated on a simulation study at street. The outcomes of this study will provide preliminary understanding on how drainage systems respond to changing climate inputs and also guided steps to implement the framework on real-world problems.

Failure margin analysis of prestressed concrete cylinder pipe (PCCP) evaluates the effect of broken prestressing wires on performance of the pipe and its margin to failure using the risk curves technology. The risk curves technology is based on structural analysis calibrated and verified by hydrostatic pressure testing of pipes with broken wires to failure, nonlinear finite element analysis that simulates the behavior of distressed pipe to failure, and external inspection of pipes with broken wires. This paper compares the observed levels of distress from external inspection of failed or highly distressed pipes to those predicted using the risk curves technology with the observed number of broken wires and expected internal pressure.

This paper describes the bending behavior of ductile iron pipes with rubber gasketed joints. The laboratory tests were performed by a specially designed counterforce frame. The specimens were 150, 200 and 300 mm diameter ductile iron pipes and the bending loads were accompanied with a constant water pressure 0.2 MPa. The bending mechanism is found to be quite different from the axial mechanism. The bending behavior is highly dependent on the lip lengths and clearance fit of the joint. The relationship of the bending moment versus joint bending rotations shows nonlinear behavior and pronounced variability, and the bending rigidity increases gradually with the interlocking bending stresses of the joints. Based on the test results, it has been concluded that rubber gasketed joints are effective in providing a leakproof and flexible connection for jointed buried pipelines.

An approach to evaluate the relative criticality of different pipes in a water distribution system is presented. To quantify the relative criticality of pipelines, a term "Relative Criticality Index (RCI)" has been defined and measured. RCI was developed by summing up the effects of reliability, cost of break repairs and energy required to repair breaks. These three components have been quantified and added appropriately to obtain an overall criticality index of pipelines in water distribution systems. The model is demonstrated by using a 9.4 square mile area of a water distribution system comprising downtown Phoenix, Arizona. The availability of the study area was estimated to be 46.6% and the relative criticality index indicates that galvanized steel pipes followed by regular steel and ductile iron pipes in the system are critical (i.e. vulnerable) for the system considered. The analysis also presents predicted future costs and energy requirements to repair breaks in the water distribution system for a 20 year analysis period. The results indicate that the expenditures to repair pipe breaks in the system for the analysis period is estimated to be $17.1 million. Additionally, the energy required to repair these breaks during the same timeframe would be 2,486 MWH. A Relative Criticality Index (RCI), along with future requirements of critical resources, should aid cities in better planning and managing of their water distribution systems.

The National Institute of Standards and Technology (NIST) and Virginia Tech (VT) hosted a workshop entitled "Measuring Up to Sustainable Water" on September 9 – 10, 2010 in Falls Church, Virginia. The workshop identified opportunities and knowledge gaps relative to critical areas of sustainable water including: Track-1: Infrastructure, Track-2: Membranes and Track-3: Emerging Contaminants. Invited attendees include researchers from academia, industry, and federal institutions. The goal of the workshop was to develop a prioritization for fundamental and applied research at federal institutions and entities funding research in sustainable water. The key question of the workshop, was "What are we concerned about, what do we want to measure, and how?" A prioritized agenda for research, training and education was produced for each of the three identified critical areas. The prioritized agenda was based on invited presentations and structured discussion. This paper presents the workshop outcome related to Track-1: Sustainable Water Infrastructure.

The objective is to inform owners and specifiers how a single fouling release coating system applied to the immersed operating surfaces of water transmission piping would be a solution to combat fouling from indigenous and invasive mussels, as well as, augment water flow efficiency. Step one will be to discuss aquatic bio-fouling, how and why it is a growing problem in North America, the problems being encountered by bio-fouling and the solutions silicone fouling release systems offer. The second step will be to define the silicone fouling release coating system's technology, how it works and how it differs from other coating system options. Industry data, engineering modeling and basic accounting calculations will be employed to provide examples of financial justification of costs, return on investment and the years to payback by investing in the installation of silicone coating systems. Finally, we will focus on the environmentally friendly aspects of the coating system, their installation and use. Case histories will be injected into the presentation to demonstrate and support the technology's use.

King County's Wastewater Treatment Division plans to control all of its 38 combined sewer overflow (CSO) sites to an average of no more than one overflow per year by 2030. Projects are under way to control four CSO sites near Puget Sound beaches—Barton Pump Station, Murray Pump Station, South Magnolia Overflow Weir, and North Beach Pump Station—all in the City of Seattle. In addition to storage and treatment, King County is investigating demand management options to control the Puget Sound beach CSOs. Demand management techniques reduce the amount of stormwater and groundwater in the combined sewer system. Examples include sewer separation, infiltration and inflow reduction, and stormwater diversion/management. Green stormwater infrastructure (GSI) is a cost-effective, sustainable, and environmentally friendly approach to diverting and managing stormwater. The areas (basins) that send stormwater to the four Puget Sound beach CSOs were evaluated to determine whether GSI, either alone or in combination with other methods, can achieve CSO control. This paper describes the methods and results of each step of the evaluation. The first step was to identify the sources of stormwater entering the combined sewer system. To do this, King County conducted a geographic information system (GIS) analysis to calculate the acreages in assessed properties and in the right-of-way in the four Puget Sound beach CSO basins that contribute flow to the combined sewer system. Information from the GIS analysis was used to identify areas that showed potential for GSI applications. Subbasin 416 in the Barton basin emerged as the most promising area for GSI application. The next step was to determine appropriate GSI techniques for this basin and to estimate sizes of facilities and costs for implementing them. Initial analyses were done for areas with less potential.