Pipelines 2009: Infrastructure's Hidden Assets

The 4^th largest City in the US has established a Condition Assessment program for its large diameter transmission mains. This program begins with prioritizing the existing water infrastructure based on record information, planning ahead for shut downs, performing inspections, making immediate repairs and planning for secondary repairs if needed, and establishing a schedule for future re-inspections and monitoring. As part of the ongoing effort, the need to establish a dynamic monitoring protocol for prestressed concrete cylinder pipelines (PCCP) became evident. Based on the inspection results and other factors, certain pipelines are recommended for short term (less than 6 months) or long-term (greater than 6 months or permanent) dynamic monitoring using acoustic technology. This paper will discuss the process the City of Houston went through to evaluate the choices for assessment and long-term monitoring. Additionally, the paper will present the issues with implementing such a program utilizing city personnel vs. outside consultants

The City of Aurora, Colorado provides high quality water to over 300,000 people. The Prairie Waters Project is a key element of Aurora's plan for a future water supply. When completed in 2010, this project will collect water from the South Platte River and deliver to a new treatment facility. The conveyance portion of this project is comprised of over 34 miles of 60-inch diameter welded steel pipe and three pumping stations, which will deliver over 50 million gallons of water per day to the treatment facility. The pipeline has been divided into 3 bid packages, with construction which started in early 2008 on the first 9-mile segment. The remaining sections of the pipeline started construction in mid 2008, with completion scheduled for mid 2010. As part of Aurora Water's Asset Management program, emphasis has been placed on collecting correct and comprehensive as-built data to be incorporated into the Geographical Information System (GIS). To ease data collection efforts, Aurora Water uses handheld GPS units requiring pipeline inspectors to collect data as the pipeline is being constructed. This paper presents data collection, quality assurance, equipment and methods used to deliver accurate GIS information to the Aurora Water Asset Management System. Data collectors with sub-meter GPS capability are used to input data and locate physical features during pipeline installation. GIS Dynamic Segmentation is used to model the pipe segments and data assigned using a core ESRI APDM data model. As-built variations in the design drawings will be adjusted in the GIS and noted in the project report.

The San Diego County Water Authority (Water Authority) has over 400 kilometers (km) of large diameter pipelines that provide up to 95 percent of the water to San Diego County's 3 million people. In this 400 km is 133 km of prestressed concrete cylinder pipe (PCCP) manufactured between 1958 and 1982 ranging in diameters of 168 cm to 244 cm. In order to provide a safe and reliable supply of water to San Diego County, the Water Authority implemented the Aqueduct Protection Program (APP) in 1992 which includes the condition assessment of the Water Authority's PCCP. Part of the program consists of developing and researching new non-invasive/non-destructive inspection procedures to determine the condition of existing PCCP. Between March 2006 and February 2009, the Water Authority has installed 79 km of acoustic fiber optic (AFO) cable to monitor wire break activity and to provide critical information on the remaining service life of the pipeline. This paper will focus on how the Water Authority is incorporating real time monitoring into their APP, the accuracy of the wire break results based on excavations, and how this technology is changing the remaining service life of the pipeline.

The Rampart Raw Water Pipelines deliver water from Aurora's Rampart Reservoir to the Griswold and Wemlinger Water Treatment Plants for treatment and distribution to the City of Aurora's customers. The Rampart Raw Water Pipeline Phase III (Sta. 617+81 to Sta. 841+50) consists primarily of 54-inch-diameter Prestressed Concrete Cylinder Pipe (PCCP) manufactured by the Concrete Pipe Division of United States Pipe and Foundry Company in 1980. In addition, Aurora jointly owns (with the City of Colorado Springs) the Homestake Pipeline, a 66-inch Prestressed Concrete Non-Cylinder pipeline, which is an intermountain water supply that is the primary source for the water transported through the Rampart Pipeline. Simpson Gumpertz & Heger (SGH) prepared a Preliminary Failure Risk Analysis and Repair Priorities report (dated February 13, 2008), which presents the results of the company's risk analysis and repair priorities for the distressed PCCP between Sta. 762+11 and Sta. 815+29. Based on review of available data and risk analysis, SGH evaluated the pipe sections with a high distress rate in the area indicated above. PPIC had identified 80 pipe sections with broken wires in 2006, compared to 38 pipes in the 2002 inspection. The number of pipes with broken wires more than doubled over a 3-year period, which equates to an increase of 28% per year. Because of the apparently high increase in wire breaks or wire break activity, SGH recommended performing wire continuity measurements on 8 pipes identified by PPIC in 2006 as having more than 50 wire breaks to develop a relationship between the REF/TC-predicted and the number of broken wires indicated by the continuity test. Additionally, Pure Technologies performed electromagnetic testing (P-wave) in 2002, and PPIC performed RFEC/TC testing in 2002 and 2006 on portions of the Homestake Pipeline. One pipe, Pipe 352, was identified with 5 to 20 wire breaks in 2002 by Pure; with 25 in 2002; and with 50 in 2006 by PPIC. This pipe was selected as a candidate for continuity testing and, ultimately, dissection, to verify the actual number and location of broken wires. Two separate continuity-testing programs were performed on Pipe 352. The pipe was then removed, dissected, and documented. This paper presents the results of the continuity tests performed on certain pipe sections of the Rampart and Homestake Pipelines to develop a relationship between the REF/TC-predicted number of broken wires and the number of broken wires indicated by the continuity test.

Acoustic monitoring of PCCP is not new. Research on acoustic monitoring began in the late 1980's and early 1990's by the Bureau of Reclamation. Results up to this point have focused on "listening" for large distinctive acoustic anomalies using sensors placed at some distance from the anomalies, with suitable equipment for relatively short periods of time, typically a few months to one year. When wire break activity was detected, in most cases, only a few acoustic events were recorded. Improvements in technology have lead to longer monitoring times and the recording of literally thousands of wire break acoustic events with very high fidelity from pipes with a wide variety of conditions. This relatively new plethora of high quality data provides the opportunity to "mine" more useful information from acoustic data. This work presents analysis of acoustic emission data in the time domain and other transformed domains for a pipeline from the onset of installation of a permanent fiber- optic acoustic monitoring system through rupture of the pipe. The overall characteristics of the acoustic events are discussed along with progression and changes in the events as the pipe approaches rupture. Once the overall characteristics are understood, the details of the each acoustic event are mathematically investigated and characterized as the pipe approaches rupture. The goal is to develop analytical methods which allow condition assessment from condition monitoring data.

The Great Man-Made River pipeline is the one of the largest water projects in the world, with more than 4000km (2485 miles) of mainly four metre (158-inch) diameter prestressed concrete cylinder pipe (PCCP) in operation. After experiencing failures on their pipeline between 1999 and 2001, the Great Man-Made River Authority (GMRA) conducted an aggressive rehabilitation program and implemented technologies to assess the condition of remaining pipe sections. GMRA first installed acoustic monitoring equipment when the pipeline was put back into operation following the rehabilitation stage. The original monitoring configuration employed by GMRA consisted of hydrophone assemblies installed in three consecutive manhole or air valve structures 600 meters (1968 feet) apart, allowing for 1.2km (4000 feet) of monitoring from one data acquisition system. Initially able to monitor approximately 40km (25 miles), the system has been expanded since 2000 and now covers almost 100km (62 miles) of pipeline. In its continuing effort to effectively manage its critical asset, GMRA recently embarked on a massive expansion of this already impressive acoustic monitoring program. More than 650km (404 miles) of Acoustic Fiber Optic (AFO) cable is being installed to track deterioration and to detect pipes in advanced states of distress. This paper will focus on a comparison case study used to verify the new technology, and discuss how the technology is employed as part of GMRA's asset management strategy.

Condition assessment of prestressed concrete pipe (PCP) often includes an inspection using Remote Field Transformer Coupling (RFTC). The RFTC technique involves collecting data with a tool that travels through the pipeline, and then analyzing the collected data to identify broken wires within individual pipes. In the past, RFTC inspections relied on manned entry so that field technicians could move the RFTC tool through the pipeline. Pipes that were smaller than 36-inch were too small for this procedure so to facilitate the inspection of these smaller diameter pipelines, a remote controlled RFTC tool called PipeCrawler was developed. PipeCrawler also had the additional benefit where unlike manned inspections in which the entire portion to be inspected needs to be dewatered, only the entry points required dewatering so that the tool can be assembled inside the pipe. This decreased the dewatered costs and as well as decreased the safety concerns with manned entry. Although the original purpose of the unmanned tool was to facilitate inspections of smaller diameter pipe, the benefits of reduced dewatering requirements and the increased safety made it an attractive option for larger diameter pipes as well. In order to utilize PipeCrawler on larger diameters the tool needed to be modified. This paper describes this development as well as a case study where a large diameter pipeline was successfully inspected using PipeCrawler.

The Rampart Raw Water Pipeline Phase III consists primarily of 54-inch-diameter Prestressed Concrete Cylinder Pipe (PCCP) manufactured by the Concrete Pipe Division of United States Pipe and Foundry Company in 1980. Inspection efforts have focused on 4.25 miles of 54-inch PCCP and have included Remote Field Eddy Current/Transformer Coupling (RFTC) internal pipe inspections by the Pressure Pipe Inspection Company (PPIC) in 2000, 2002, and 2006 and P-Wave electromagnetic inspection by Pure Technologies, Inc. (Pure) in 2008. This paper presents a comparison of the RFTC and P-Wave inspections, including similarities, differences, and an explanation of why the results vary, depending on the testing method.

A PCCP Reliability Management program was developed for the Washington Suburban Sanitary Commission (WSSC) to address deterioration of the 96" Potomac Transmission Main. The reliability program consisted of developing repair and monitoring recommendations that created the best value while maintaining a safe and reliable water delivery system. Reliability recommendations were based on both state-of-the-art forensics and performance analysis, including evaluation of the feeder's consequence-of-failure and delivery-redundancies. Together, these data allowed the development of an unprecedented large scale PCCP reliability program. The program enhanced investment while addressing both life and property safety through technologies not previously used for this purpose. Pipeline Reliability was directly influenced by the level and quality of assessment data obtained. An understanding of the pipeline's condition was at a level not previously seen in the industry. Assessment methods used consisted of nondestructive technologies (NDT) both common and un-common to PCCP evaluations. The technologies include: visual, magnetic, Sonic-Ultrasonic (SU), and Acoustic assessments, including Performance-Analysis based on the NDT data. The uncommon technologies used were the Sonic Ultrasonic and Performance-Analysis. The Sonic Ultrasonic NDT allowed the identification of both early and advanced stages of pipe deterioration. Degradation measured, from on-set to advanced, are: 1) de-lamination at the pre-stress wire, 2) micro-cracking at the outer core, 3) de-lamination at the embedded cylinder, and 4) micro-cracking at the inner core. These data complement both the magnetic and acoustic assessments by identifying the stages of deterioration leading to pipe failure. Performance Analysis uses the data produced from the NDT (magnetic, SU, acoustic, and visual) to predict pipe performance with loss of pre-stress. The advantage here is pipe performance is measured by structural Safety Factors. This allows easy prioritization of the myriad of suspect pipe (low safety-factor pipe are more vulnerable than pipe with high safety-factors). Further, this approach has been refined for cost efficiency. For WSSC, 15 select suspect spools were used to develop 15 Performance Curves. From these 15 curves all suspect pipe were evaluated and safety factors developed, 90 spools in all. This technology allowed every suspect pipe to be individually evaluated and performance to be understood relative to each other. This reliability approach allowed resources to be used where and when needed, resulting in the best return on investment while offering the continued safe and reliable operation of the 96" Potomac Transmission Main.

Weaknesses in the core concrete and/or delamination of the core layers and the mortar coating provide data to determine the current condition, instillation and use history of PCCP pipes. A combination of measured wave velocity and thickness resonate frequency values are used to identify and categorize weak areas in PCCP pipe concrete. The velocity/speed that sonic/ultrasonic waves propagate through the core concrete is used to determine the elastic moduli and strength characteristics of PCCP core concrete. These velocity values are primarily affected by the severity and density of cracking and the compressive force exerted by the wire wrap. Resonate frequency data, obtained simultaneously with velocity data, are used to assess for delamination/ loss of bonding between core layers and the mortar protective coating. The combination of the velocity and resonant frequency data and specific location where anomalous readings occur are indicators of pipe conditions such as overloading, broken wires, pipes manufactured with low or no prestressing, loss of mortar coating etc.This paper will discuss the sonic/ultrasonic testing method and comparison of results with excavated pipe conditions and reported pipe operation incidences.

Toho Water Authority operates a 36-inch effluent main that is a critical asset for the agency. It is the sole source of conveyance for treated wastewater to be transmitted out of their largest wastewater treatment plant. Further, it supplies cooling water to two power generation facilities and parallels/crosses a CSX rail line at several locations. The pipeline has not experienced any significant problems, but as a proactive measure a comprehensive condition assessment program was implemented. The 13 mile long pipeline consists of a 36-inch diameter prestressed (AWWA C301), lined cylinder pipe that presented several challenges when performing the condition assessment. This paper describes the condition assessment challenges and how a condition assessment program was structured and implemented while the pipeline remained in service. The project was implemented in phases to allow for the collection of data along the full length of pipe in a cost effective manner.

The City of Coronado's (City) Original Transbay Sewer Force Main (original force main) was in continuous service from its construction in 1974 until mid-2007. The original force main was the City's only option for conveying wastewater across San Diego Bay to wastewater treatment facilities in the San Diego. When a new parallel force main was completed in May 2007, the City wanted to inspect the original force main and determine options for its reuse or abandonment. Because of its relatively young, high value, and potential for redundancy of wastewater conveyance, the original force main had the potential to be a valuable asset if an inspection could confirm its condition. The original force main is approximately 3,600 linear feet of 24-inch ductile iron pipe buried below the bottom of San Diego Bay with both termination points in busy shopping areas. Any inspection program needed with great care to avoid risk to public health, the environment and locally important shopping and tourist facilities. The City hired Winzler & Kelly, who teamed with Pipe Eye International and was supported by Affordable Drain Service, to provide visual and sonar inspection. This paper provides a summary of the risk management plan prepared in order to identify and resolve potential issues that might occur, the original force main inspection results, and an outline of the City's next steps for pipeline rehabilitation.

A condition assessment was initiated for the Bay Division Pipeline 4 (BDPL4) with the goal of improving reliability of the pipeline and extending useful service life in a cost effective manner. Electromagnetic and internal sounding inspections were the primary approaches used to evaluate the prestressed concrete cylinder pipe (PCCP) condition. A structural risk analysis identified and prioritized critical pipe segments in need of additional investigation measures or immediate repair. A seismic risk analysis was performed to detect lengths of the pipeline that are susceptible to joint pullout due to ground shaking, and liquefaction and landslide failure following an earthquake. A present value worth analysis found that extending the life expectancy of the BDPL4 was the most cost effective approach to execute into the asset management plan. As a result, contemporary PCCP rehabilitation and monitoring methods were researched and post tensioning of the critical PCCP segments via tendon straps was selected as the preferred repair method and electromagnetic and internal sounding inspection procedures will continue while also introducing acoustic monitoring for monitoring. A Geographic Information Systems (GIS) geo-database provides the means to track changes to the pipeline over time to support a long-term asset management program over the remaining lifetime of the PCCP.

Water plays a critical role in every aspect of civilization: agriculture, industry, economy, environment, recreation, transportation, culture, and health. The earliest civilizations grew out of Africa's great river basins; America's development followed our tributaries and coasts. Long before Louis Pasteur established the connection between clean water and human health, sanitation was considered essential to any advanced society. While clean water and sanitary conditions remain an elusive luxury in many parts of the world, we, as Americans, take them for granted. We expect delivery and disposal systems to work, if we think about them at all. As with our highways that stretch from coast to coast or the electricity that powers our 24-7 society, we consider water and sewer infrastructures an American given. And why shouldn't we? The same era of Public Works efforts that produced such visible symbols of human ingenuity as the Golden Gate Bridge, Hoover Dam, the Panama Canal, and the Interstate Highway system resulted in equally impressive infrastructure projects, including the hundreds of thousands of miles of underground water and sewer systems that serve communities nationwide. The Liquid Assets documentary tells the story of our nation's clean water infrastructure and was made available for national broadcast in fall 2008. Liquid Assets is a public education and awareness initiative on U.S. drinking water, wastewater. and storm water infrastructure produced by Penn State Public Broadcasting (PSPB). Liquid Assets includes a 90-minute documentary, for national public broadcasting distribution, combined with an outreach toolkit to facilitate local engagement. The initiative also includes an outreach grant program that provides public television stations resources to produce a local issues program in concert with the national documentary. Produced in partnership with ASCE by Penn State Public Broadcasting, the documentary is the centerpiece of an outreach effort to make the public more aware of the threats to our drinking water and processing of wastewater by our reliance on infrastructure that in some places is more than a century old. This paper presents a TV documentary and educational toolkit for utilities, elected officials, associations, and public titled "Liquid Assets: The Story of Our Water Infrastructure System".

As part of a continued focus on operational efficiencies and reliable customer service the City of Houston established a Condition Assessment Program (CA) as a means to initiate a proactive approach for extending the useful life and enhancing the functionality of its water system infrastructure. Since 2001, both catastrophic failures and corrosion-related leaks have significantly impacted the City's water transmission system. These failures and leaks required these major transmission lines to be taken out of service for extended periods of time. These failures occurred unexpectedly and without prior warning. In response to these previous failures and leaks the CA program utilized a systematic process to prioritize its existing large diameter lines for future assessment. On the basis of the following criteria a 60-inch PCCP transmission line (the South 60), was identified as the highest criticality and priority for assessment. The South 60 water transmission line conveys approximately 35 MGD of surface water from the City's East Water Purification Plant (EWPP) to areas south and west of downtown Houston. The South 60 service area includes the Texas Medical Center. The South 60 consists of approximately 30,700 LF of steel pipe (from the EWPP to approximately 1,500 LF and 29,000 LF of PCCP. Condition assessment of the South 60 was performed in conjunction with a planned project to replace air release valves (ARV) along the same line. Improvements to the ARVs along the South 60 were recommended as part of a previous study to support the City's effort to achieve compliance with Texas Commission on Environmental Quality (TCEQ) regulatory requirements. Because of the nature of work required, the ARV project also included contractor support services for condition assessment of the South 60. By combining the ARV improvements with condition assessment of the South 60, the City optimized the work activities to isolate and shut down the pipeline.

This paper describes the case history of the field investigations, modeling, condition assessments, identification and evaluation of alternatives, design, bidding, and construction of a major sewer project in Cedar Rapids, Iowa. Cedar Rapids is a vibrant community in central east Iowa with a population of 140,000. The robust industrial development creates wastewater discharges equivalent to a population of 1,300,000. Corrosion observed at the treatment plant generated concerns about the conditions of the upstream sewers. The three most critical trunk sewers in the city were selected for inspection and evaluation. This work was performed in two phases. The first phase included liquid sampling, limited internal inspections, airspace monitoring, sewer air flow and sulfide modeling, recommendations for second phase inspections, sewer rehabilitation, and sulfide and odor control. The second phase focused on detailed inspection and evaluation of the 96-inch diameter Main Interceptor Sewer, which was prioritized due to concerns with its condition and the consequences associated with its failure. Information gathered from the second phase inspections was used to identify and evaluate multiple alternatives for replacement or rehabilitation of 4,400 feet of the lowermost 96" diameter Main Interceptor Sewer.

The Puerto Rico Aqueduct and Sewer Authority (PRASA) has approximately 20,000 lineal feet of trunk sewer system that conveys combined wastewater and storm water flows from the western portion of San Juan to the Puerto Nuevo WWTP. The trunk sewer ranges in diameter from 36" to 84" in diameter, is primarily constructed with reinforced concrete pipe (RCP), and the age ranges from 40 to 45 years old. The system also has three siphons that convey flows under channels that discharge into the ocean. The system comprises of three sections of trunk sewer: 1) San Juan Trunk Sewer 2) Baldorioty Trunk Sewer 3) Miramar Trunk Sewer (Upper and Lower sections) Much of the system has been in service in excess of 50 years, is corroding, and filling with sediment. Throughout the life of the trunk system, major cleaning has not been performed. Part of the system, the Old San Juan sewer, was constructed of brick conduits collecting both sewer and storm waster. Six shallow sea discharge pipes were diverted in the 1970's to a collection system which pumps all wastewater and storm water to the gravity trunk main, which is the object of our study. During wet weather events, when all lift stations are operating at their maximum capacity, it was common for the trunk system to back up and cause manhole lids to float and be carried down streets. An overall map of the system is presented in Figure 1.

A number of case studies are discussed in which pipeline failures have been the direct result of inadequate inspection or quality control at some point in the process from manufacture to installation. The resulting fixes in these cases ranged from a low of $300,000 to in excess of $12,000,000. The authors have been retained to evaluate the pipe failure causes, assist in subsequent legal actions as experts, and to design the rehabilitation, repair or replacement projects. The failures discussed include asbestos cement pipe (ACP), welded steel pipe (WSP), prestressed concrete cylinder pipe (PCCP), ductile iron pipe (DIP), plastic pipe (PVC and HDPE), conventional reinforced concrete pipe (RCP), and vitrified clay pipe (VCP). Some of the failures occurred after ten or fifteen years of service, others after as little as one or two years of service, and some occurred during installation. No pipe material is "bullet proof". No pipe material is exempt from failure in the absence of proper design followed by adequate inspection. A poorly informed inspector, or one who has not been properly trained in the manufacture, inspection, handling, installation, and testing of the type of pipe he or she is hired to inspect is often worse than no inspection at all.

Eight breaks have occurred on a 16-inch diameter recycled water transmission pipeline, most recently in October 2008. After a break in September 2006, because the pipeline is only about 12 years old, an investigation was structured to determine if there is a systematic problem. Two of the most recent breaks occurred less than 100 feet apart, in Kanan Road, near its intersection with Hawthorne Drive, in the Oak Park area of Ventura County, California. The five most recent failures—in 1999, 2003, 2006, 2007, and 2008—necessitated round-the-clock emergency repairs with the associated impacts to traffic and the public. The pipeline was constructed of PVC that was specified as conforming to AWWA Standard C905. Pipe manufactured to that standard has a nominal design safety factor of 2.0 at 100,000 hours (11.4 years) of service at its rated pressure. This particular pipe is DR-25, which is rated for 165 pounds per square inch (psi) (without surge), and the static pressure is approximately 140 psi at the most recent point of failure. This paper describes the investigation into the possible causes of failure, including conducting laboratory tests, surge analyses, and design replication. The risk to continued operation of the pipeline (expecting to have further breaks) was addressed along with repair and replacement as means of addressing the continued longevity of the pipeline.

The Riverdale Outlet Sewer Replacement included approximately two-miles of gravity sewer line replacement. The majority of the existing pipe was 24-in diameter concrete to be replaced with 36-in diameter concrete pipe. Design constraints included high groundwater, close proximity to a major river, a major highway embankment crossing, two separate railroad crossings, a railyard crossing, and a soil profile that was largely sandy gravel with cobbles. The majority of the project was installed using typical open trench techniques, but did warrant trenchless installations in four locations: a highway crossing, a rail yard crossing, and two rail line crossings. The trenchless crossings varied in length from 100 feet to 550 feet and all had existing 24-in sewerlines. Because the purpose of the project was to increase pipe capacity to a 36-in diameter concrete hydraulic equivalent most lining technologies were eliminated and several trenchless methods for installing a new corridor were considered. The trenchless solutions most seriously considered were auger boring, pipe jacking, microtunneling, pipe bursting, and cured-in-place pipe. The presentation will illustrate the project conditions that should be considered when choosing among trenchless methods. Ultimately, auger boring was selected for two crossings and cured-in-place pipe was selected for the other two crossings. Auger boring required significant dewatering. The cured-in-place pipe installation required removal of an existing carrier pipe, an uncertain proposition requiring preliminary field work. During a time of high inflation in the cost of steel casing the cost savings resulting from the selection of these trenchless technologies was almost $1 million.

The Metropolitan Water District of Salt Lake and Sandy (MWDSLS) is the owner of an existing 1753 millimeter (inside diameter) water transmission pipeline that begins in Wasatch County, Utah traverses through Utah County and ends at the terminal reservoirs in Salt Lake City. The approximate length of the water transmission pipeline is 67.6 kilometers. The pipeline was approved for design and construction by the President of the United States on October 24, 1938, built by the Bureau of Reclamation (BOR) in the 1940's and turned over to MWDSLS in 1951. (Ref. 1) The Salt Lake Aqueduct (SLA) supplies water to Salt Lake City and Sandy City municipalities. This paper will discuss existing facilities, condition assessment of interior and exterior linings, hydraulic assessment, capacity evaluation, and multi-hazard risk assessments for Level 1 and Level II seismic events as required to develop prioritized replacement projects.

This paper focuses on developing a rapid and cost effective evaluation methodology for the condition assessment of culverts to estimate their remaining service life. Nondestructive inspection methods are selected based on their reliability and effectiveness. A synthesis of current and emerging non-destructive technologies (NDT) for culverts assessment management is presented. The information presented intends to serve as a database for a generalized algorithm for selecting a NDT scheme for condition assessment of culverts and their embedment.

The City of La Mesa (City) owns over 156 miles of sewer assets, which consists of pipelines ranging in diameter from 6-inch to 24-inch, serving an area over nine square miles. From 2001 to 2007, PBS&J completed approximately 536,000 linear feet of sewer main cleaning, inspection and assessment. Working closely with the City staff, PBS&J developed inspection criteria and a severity ranking methodology to quickly and consistently assess the condition of every foot of inspected pipeline and manholes. As part of the sewer assessment program, PBS&J reviewed the CCTV video and screen captures to verify severity of pipe problems and accuracy of data codes entered. We also established cost estimates for the identified pipes needing rehabilitation, and developed a list of priority projects for the Inflow and Infiltration Reduction Program. This presentation will discuss the key elements in developing and successfully completing the CCTV inspection and assessment program within a limited budget. These elements include having a clear understanding of the City's CCTV history; knowing the pipe conditions based on extensive interviews with City's public works staff; developing detailed assessment criteria; integrating CCTV data with GIS using cutting-edge software; developing a selection criteria based on assessment ratings; and prioritizing projects based on location and pipe ratings.

This paper provides a brief summary of the inspection technologies available for wastewater force mains, and describes acoustic technologies in more detail. The scope and goals of the HRSD pilot program will be defined and the results of the pilot testing discussed. The emphasis of the paper will be on a discussion of the results of the field testing and the lessons learned during the program. The goal of the paper is to suggest adaptations to improve reliability and durability of the acoustic technology for use in wastewater force mains.

A comprehensive study on the available water supply and distribution system; along with the pipeline repair data due to 12 November, 1999 Duzce Earthquake (Mw=7.2) has been carried out. Correlations of the observed damage patterns with the system, ground motion parameters and geotechnical characteristics have been evaluated. Generic soil profiles were used in conducting 1-D equivalent linear site response analyses; which served as a basis for the estimation of liquefaction triggering potential and liquefaction induced ground deformations. A maximum likelihood based model for the probabilistic assessment of seismically induced buried pipeline performance was developed. The proposed model uses liquefaction induced ground settlements, peak ground acceleration and soft layer thickness as descriptive variables. The current model yields an unbiased estimate of observed damage rate throughout Duzce; and is valid for consequences of permanent ground settlements due to liquefaction, rather than tectonically or landslide induced damage to pipelines. Providing an improved fragility model that also accounts for the ground response related effects is believed to establish a greater level of reliability during risk planning against future hazards.

Water utilities know too well that they face major costs in maintaining and replacing their transmission and distribution pipe networks. And as more and more networks decline each year, these costs are increasing and will peak when water pipes installed during the post-war boom begin to reach the end of their service lives. Gaining access to these pipes to inspect them can be difficult and disruptive-until now. Researchers in IRC's Urban Infrastructure Rehabilitation Program and Echologics Engineering have developed and patented a new non-destructive test method for water utilities to use in evaluating pipe wall thickness The new 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 thickness. This paper will outline the background Physics of the method, and provide results from a number of case studies from Hamilton ON, Las Vegas NV, Mapleridge BC, and Bristol in the UK.

Asbestos cement (AC) pipe was first introduced in North America in the late 1920s and became a common choice for potable water main construction from the 1940s to the 1970s. The use of AC pipe was largely discontinued in North America in the early 1980s but AC pipe is still a significant portion of the water distribution systems in many North American cities. As the pipes deteriorate and fail to meet service requirements, appropriate rehabilitation/replacement methods need to be determined. This paper summarizes survey data on the rehabilitation/replacement methods for AC pipes provided by 19 water utilities in the United States and Canada. The paper also reviews current available rehabilitation/replacement methods to provide some background of the current practices used by the utilities. The survey indicates that trenching is the main method used to repair, rehabilitate, and replace AC pipes. Cost was cited as the main reason for utilities to choose a particular repair/rehabilitation/replacement method. Although most of the rehabilitation/replacement methods have potential social and environmental effects because of possible release of asbestos fibers, the effects were generally not given high priority when selecting methods for renewing AC pipes.

Sewers are an important part of our society. They serve to promote public health, protect the environment, and support economic growth within our communities. They also happen to provide a unique view into everyday life, and thus the connection between sewers and sociology. This paper provides a tour of the City of San Diego and its surrounding metropolitan area through the eyes of a sewer, as revealed through hydrographs of sewer flow data. An overview of sewer use patterns is provided for normal weekday and weekend periods. Variations are then discussed based on land use differences. Other events that depart from normal diurnal patterns are also presented - including holidays, shopping, conventions, wildfire evacuations, and even a Madonna concert. This paper is not a typical technical paper, but rather a collection of interesting observations of human behavior documented by flow monitors located throughout the San Diego area. Practical applications include sewer design, infiltration and inflow evaluation, hydraulic modeling, and real-time alarming.

The intent of force main (FM) design is for the pipe to flow full all the time so that conditions conducive to internal corrosion do not exist. Unfortunately, pipelines in teh constructed environment can develop air pockets at high points in the line which leads to corrosion in and around the air pocket. Typically, waiting for the pipeline to fail is the only mode of monitoring available. Air pockets in ductile iron pipe (DIP) force mains (FM) can be problematic if internal linings are compromised. Formation of sulfuric acid in the humid air space at the crown of the pipe can cause rapid corrosion of the iron leading to uncontrolled discharges. Orange County Sanitation District experienced discharges from DIP FM near the Bitter Point pump station in November 2001. Flow modeling identified eleven other locations with the system which could sustain air pockets and lead to similar failures. Two locations were identified for futher inspection and testing in an effort to assess, understand and monitor the accumulation of corrosion damage in the system as a function of time. This paper discusses the use and results of portable and permanent ultrasonic testing over approximately 5 years. In this paper, we describe a program that utilized flow modelling to locate potential high points and air pockes followed by ultrasonic inspection and testing to monitor internal corrosion of polyurethane and mortar lined DIP. Periodic excavation to conduct periodic ultrasonic testing required extensive planning, traffic control as well as increasing data reproducibility. Evenutally, permanent high Resolution ultrasonic instrumentation was identified and installed which allowed monitoring of the air pocket corrosion and management of assets in a highly populated area. Simple test stations which require minimal traffic control permit rapid and frequent access to data. The increased resolution of the instrumentation increased measurement sensitivity to +/– 0.3 mils per year. The resulting information and savings from this approach means that capital expenditures can be planned and designs can proceed at non-accelerated rates.

The Puerto Rico Aqueduct and Sewer Authority (PRASA), owns and operates the Puerto Nuevo and Bayamón Wastewater Treatment Plants which serve37 % of the sewer service in the island). Primary treated effluent is discharged to the Atlantic Ocean through an effluent pipeline that is shared between the Puerto Nuevo and Bayamón WWTP and the Bacardi Corporation WWTP which extends approximately 10 kilometers to an ocean outfall. The effluent pipeline is deemed to be a critical asset, whereby service cannot be interrupted. Discharge of any effluent from the pipeline would be in violation of EPA regulations. Much of the pipeline is located in environmentally sensitive areas where the pipeline runs adjacent to natural waterways and traverses wetlands The effluent pipeline was constructed in the 1970's and 1980's using prestressed concrete cylinder pipe (PCCP) manufactured in accordance with AWWA Standard C301. The pipeline ranges in size from 72-inches to 120-inches in diameter. Although there have been no failures on the effluent pipeline, PCCP used in the construction of PRASA's nearby Super Aqueduct pipeline have failed in the past. Usually, these pipes last a long time without service problems; however, there are variables that if not addressed properly during the design, installation and maintenance, can lead to corrosion of the prestressing wire. Under certain conditions, hydrogen sulfide gas may accumulate in air pockets that form at high points in wastewater force mains. The gas can oxidize into sulfuric acid and damage the top of the pipe wall. Conversion of the gas to sulfuric acid requires an aerobic or oxygen-supplied condition - such as that provided by an air pocket. To better understand the condition of the effluent pipeline and to minimize the risk of future failure, CH Caribe Engineers/PSC (CH-Caribe) and Openaka (a division of Pure Technologies) performed a preliminary investigation of the pipeline. The investigation focused on selected pipe sections that were readily accessible, where the scope of work included visual inspection, sounding, continuity testing of prestressing wire, sampling and analysis of prestressing wire and cement mortar coating, sampling and analysis of surrounding soil and groundwater, ultrasonic testing to measure wall thickness, etc. This paper addresses the procedures of the investigation, testing protocols, inspection and laboratory results, findings and recommendations.

This paper presents the challenges faced in protecting existing buried piping and new piping added as a part of the expansion of the Trinity River Pump Station. ExxonMobil installed an impressed current cathodic protection system to protect their pipelines near the Trinity River Pump Station. The piping installed by the Coastal Water Authority (CWA) was tied into the ExxonMobil cathodic protection system to mitigate stray current corrosion on the CWA piping. The location of the cathodic protection system anode beds on the far side of the CWA property made the CWA piping susceptible to the stray current. During construction, a portion of the pump station structure shifted causing contact between the sheet piling and the buried piping. After field testing for current requirements, the design was modified to protect all buried metallic structures at the existing pump station and in the section. This paper presents the steps taken to incorporate the present cathodic protection system into a complex piping and structure configuration.

This paper summarizes major findings of a long-term study of hydrogen sulfide gas (H₂S) adsorption and oxidation on concrete and plastic sewer pipe surfaces. The processes have been studied using a pilot-scale setup designed to replicate conditions in a gravity sewer located downstream of a force main. H₂S related concrete corrosion and odor is often observed at such locations. The experiments showed that the rate of H₂S oxidation was significantly faster on concrete pipe surfaces than on plastic pipe surfaces. Steady state calculations based on the kinetic data demonstrated that the gas phase H₂S concentration in concrete sewers would typically amount to a few percent of the equilibrium concentration calculated from Henrys law. In plastic pipe sewers, significantly higher concentrations were predicted because of the slower adsorption and oxidation kinetics on these surfaces. Finally, the paper demonstrates how the kinetic data can be used for prediction of concrete corrosion in real sewer systems based on H₂S measurements from a conventional gas detector.

The Southern Nevada Water Authority (SNWA), Las Vegas, Nevada, experienced a corrosion failure on the Las Vegas Valley Lateral in 2007 and retained the services of HDR Engineering, Inc. (HDR) to provide a critical condition assessment of this large-diameter potable water pipeline in Las Vegas, Nevada. Consisting of approximately 58,000 linear feet (17,678.4m) of predominantly 66-, 72-, and 90-inch-diameter (1676.4, 1828.8, and 2286 mm) cement-mortar-lined-and-coated (CML&C) steel pipe and some 96-inch-diameter (2438.4 mm) pre-stressed concrete cylinder pipe (PCCP), the Las Vegas Valley Lateral (LVVL) and the North Las Vegas Lateral (NLVL) pipelines were constructed during the late 1960s with no cathodic protection and only a few corrosion test stations installed. The project team included various specialized subconsultants (Schiff Associates, Kleinfelder, TRC Solutions, Rafael Civil, and the RockSolid Group) for corrosion testing and evaluation, geotechnical investigation, surveying, test station installation and excavations, and broadband electromagnetic testing. Buried pipelines often operate in a state of anonymity with respect to internal or external corrosion until the deterioration is severe enough to cause failure. Corrosion is the deterioration of a substance or its properties because of a reaction with its environment. External environments (around the outside surface of the pipe) more commonly promote water pipe corrosion. Condition assessment of the pipeline provides useful information to determine the current pipe condition to make recommendations for repair, renewal, or monitoring. The focus of this paper is the application of specialized inspection technologies for water pipeline condition assessment and the development of the strategic phases of field work to deploy these technologies only when needed. The progression to the next phase of work required an evaluation of the data and results obtained from the previous phase.

Proper life cycle cost consideration of corrosion control options for water and wastewater transmission pipelines is key to any asset management strategy. This paper will examine the economic costs and benefits for six options of corrosion control methodologies that are implemented for ferrous based pipeline materials in corrosive soil environments.

Evaluating the condition state of infrastructure assets is one of the most integral pieces of information to the asset manager. Water infrastructure poses specific challenges compared to sewer infrastructure where techniques like CCTV are now being consistently used to assess condition. The number of water main breaks is commonly used as a proxy for water main condition. Statistical water main performance models rely on using past breakage patterns and rates to predict future performance of the water main network. Performance models can be broadly classified into two groups. Rate-of-failure models attempt to extrapolate the breakage rate for a particular cohort of pipes and do not differentiate between the times between successive failures. Examples of statistical modeling approaches for these models include the Non-Homogeneous Poisson Process and the Multi-Variant Exponential (MVE) model. On the other hand, Transition-State (TS) models attempt to model the time between successive failures for pipes. Examples of these models include the Proportional Hazards Model and the Transition State - Life Regression Model. This paper presents a comparison and analysis of rate-of-failure models and transition-state models using a single data set for cast and ductile iron pipes in the City of Hamilton, Canada. The paper makes comparisons between the models' ability to support breakage forecasting, long-term strategic planning and short-term tactical planning. The paper also analyzes the data needs of each model and the impact of data inaccuracies (that are common in water main databases) on the predictive accuracy of each model.

Subsurface Utility Engineering (SUE) is increasing in use and becoming a standard process during the planning and pre-engineering stages of a project. Studies performed show a savings benefit on projects that employ either designating or locating activities vs. the traditional one-call approach. Most of the technologies associated with these activities are used throughout the world routinely; however, the choice on which technology is appropriate for a single project is difficult. Currently, the decision is made almost entirely on a person's prior experiences and not so much as a standard process based on facts and data. Research has been done to quantify which ASCE Quality Level is most closely associated with a project based on the level of risk as determined by the amount of known and unknown information (such as utility type, depth, and material). But, after a quality level is determined there is a lack of direction on which technology or method is best suitable for locating utilities for a given project. The research presented in this paper is aimed at producing a decision support tool that will aid persons such as state department of transportation officials, consultants, and whoever else is responsible for utilities on a project. The tool developed consists of two evaluations designed to collect information about how a locating technology operates, its' limitations, data produced, and associated costs. The Performance Evaluation and the Economic Evaluation are filled out for various pieces of equipment and then, in conjunction with the project information sheet, compared to determine the most suitable method for finding buried assets on the project site. The performance evaluation takes into account factors such as soil type, environmental conditions, proximity and type of nearby structures, amount of training required to perform the testing, and material properties of the utility. Field demonstrations are on-going with consultants, municipalities, and State DOTs to further evaluate the tool's effectiveness and refine how the information is presented to the user. The final goal of the research is to take the data gathered and combine it into an interactive tool that can be used to determine a suitable technology to use to locate buried assets while minimizing cost and keeping the quality of data at the desired level. The process can also be used as a training tool for field and office personnel to familiarize themselves with the available technology and its' limitations.

The County Sanitation Districts of Los Angeles County (LACSD) operate the Palmdale Water Reclamation Plant, which is currently undergoing an expansion that will ultimately result in tertiary treatment for approximately 22 million gallons per day (mgd) of flow in the Antelope Valley. The plant effluent is utilized for agricultural irrigation, however during the winter months when plant flow exceeds the agronomic demand of the agricultural reuse sites, the effluent will be stored in lined reservoirs located 12 miles from the plant. A 12-mile long plant effluent force main was constructed to convey plant effluent to the reservoirs during the winter. The 48-inch high-density polyethylene (HDPE) pipeline also serves to return the effluent to agricultural sites adjacent to the treatment plant during the summer when irrigation demands exceed plant flow. This paper provides a case study of the planning, design, and construction of this "two-way" pipeline. Initial project planning included route selection, geotechnical investigation, and aerial survey. The design team investigated pipe material options and, in conjunction with the system hydraulics, determined HDPE to be the most feasible material for the application. The Contractor utilized a state of the art trenching machine that significantly reduced construction time by simultaneously excavating the 6-foot wide trench and laying the fusion welded pipe. Twelve miles of pipeline was installed in 26 working days with the most productive day exceeding 5,000 feet.

Over the past decade, water pipeline operators have seen new inspection technologies and failure analysis techniques that enable them to determine the condition of their pipeline assets, the pipeline deterioration rate and probability of failure. Routine inspection and analysis of a pipeline system and related aboveground features creates the numerous datasets necessary to accurately and efficiently plan capital improvement projects to maintain the pipelines and associated assets in a sustainable manner. The quantity and diversity of this data can be a challenge to manage especially if one uses differing electronic file systems and standard paper files. Complexity increases further when engineers discover that the "real-world" conditions surrounding their pipelines have changed from that shown on their original "as-built" plans of construction. By deciding upon a GIS-enabled database, pipeline engineers can work towards an intuitive and dynamic system that provides users with timely information and analysis tools. Using GIS technologies effectively for a water pipeline requires a detailed data structure to address the jointing aspects specific to water pipelines. The data model needs to track individual pipe segments, from bell to spigot, with inspection and integrity information. Enabling this database for view through common software packages such as Microsoft Word, delivers GIS technology with a high value data set that is very accurate at representing existing water pipeline infrastructure but without expensive licensing fees and long learning curves. Using case studies, the paper illustrates how GIS technologies can leverage off a well designed pipeline data model and pipeline operators can fully realize the advantages of maintaining their pipeline assets in a spatial database including 1) increased data availability; 2) identification of urgent repair needs; and 3) improved maintenance and capital planning.

The City of La Mesa's Sewer Atlas was formerly only in a hard copy format that contained a combination of GIS and CAD files. Attribute information of the sewer system is maintained in an asset management system called CarteGraph, as well as through manual edits to the hard copy maps. The City desired to create a centralized database to store information and perform edits. They also needed an automated tool to update their sewer map books.

Availability of data in an organized way is required for accurate prediction of wastewater and water pipe structural or functional deterioration. The key is to develop a standard data model which helps in developing indices for a prediction model. Sharing and integrating useful Municipal Infrastructure Asset Management Information is the initial step in creating a standard data model. GIS allows viewing, understanding, question, interpreting, and visualizing data of geographically referenced information in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts. The primary objective of this research is therefore to develop a standard GIS data model that can be used to develop protocols and methods for predicting the remaining life of water and wastewater assets. The main objective is to set up a one-stop shop for a center of Excellence to address, facilitate, promote and show case successful Municipal Infrastructure Asset Management Programs. Geospatial water and wastewater infrastructure data and associated metadata are collected from a minimum of 17 cities. The source data is the utility data and other downloadable data available for the public like in USGS, SSURGO etc. Field mapping files are generated from source files and the standard data model. These are then programmed to the common XML file developed as a base which is then converted to the data model where the final form of utility data is stored. The data taken from the utilities is cleansed and analyzed to match with the standard data model. It is then uploaded to the standard data model through the common XML and stored in the data warehouse as a geospatial database. The geospatial database is an aggregated water and wastewater infrastructure data consisting of the utility data in standard data model format. The data warehouse is developed for utilities to store their data at a centralized server i.e. San Diego Super Computing center or otherwise. In the future, web applications shall demonstrate how the aggregated data in the geodatabase can be published, queried and visualized in a map-based browser application. This aggregation of data will help in providing timely access to Asset Management (AM) information and resources that will lead to more efficient programs. This also helps in providing the public with a convenient tool to learn about municipal water and wastewater infrastructure systems.

This paper presents the challenges faced and the results from the condition assessment of the approximate 4.1 miles of pipeline carried out in August 2008 on the 24" and 36" steel pipe in the canyon above Ogden, Utah. The 24" was constructed in about 1920 and the 36" was constructed in about 1937. These two pipelines deliver the majority of the water to Ogden City customers. The challenges were significant because our approach was to determine the actual condition of the pipe based on physical testing of the pipe. These inspections consisted of ultrasonic evaluations to determine pipe wall thickness, coupon analyses to determine condition and strength of the steel, and leak detection using a patented, sensitive technology named Sahara. The results of the inspection are divided into two portions. The first portion was the ultrasonic inspection and coupon testing of the pipe wall to determine if there was loss of pipe wall thickness and remaining structural strength. The second inspection was the leak detection along accessible portions of the pipeline. The ultrasonic inspections clearly showed that the segments of the 36" pipe that were inspected are in good condition. The sections of the 36" pipe that were exposed had a shotcrete coating. The 24" pipe did not appear to have any coating or lining. The condition of the 24" pipe varies from good to poor condition, with isolated and generalized wall loss at all five locations inspected. Leakage inspection covered 10,632 linear feet of the 24" transmission main as measured by PPIC, or just over 50% of the total length of the pipe. Due to the anticipated better condition of the 36" transmission main, only 3,739 feet or less than 20% of the 36" pipe was inspected. There were no leaks found on the 36" pipe. On the 24" pipe 15 leaks were detected, there are twelve leaks classified as large, two as medium and one as small. Based on the leaks detected, there is a high probability of additional leaks on the pipeline in the area not inspected above Fairmont. The quantity of water loss from the leaks can not be estimated until they are exposed for repair.

The Providence Water Supply Board (PWSB) Supplemental Tunnel and Aqueduct is about 9 mile long and made with 78 in. and 102 in. diameter prestressed concrete cylinder pipe (PCCP). The pipeline was built between 1966 and 1968 as a part of the Providence water supply system, providing drinking water for Providence, Cranston, Warwick, and other surrounding towns. The pipes are embedded cylinder type (ECP) without shorting straps and are manufactured by Interpace. The 78 in. diameter pipeline has not experienced any failures to date, and the 102 in. diameter pipe failed in 1996. PWSB requested a pipeline condition assessment as a proactive approach to identify and repair high-risk pipes in order to maintain acceptable reliability of the aqueduct. This paper presents the method of approach that included pipeline preparation for internal inspection, internal visual and sounding and electromagnetic inspection, pipe failure risk analysis, external inspection and repairs by post-tensioning and encasement. The results of electromagnetic inspection indicated that about 5% of 102 in. diameter and 7.3% of 78 in. diameter pipes had broken wires, slightly more than in other similar pipelines. Pipe distress was predominantly in the form of corroded and broken prestressing wires and partially dissolved mortar coating, likely as a result of acidic ground water and soil. Failure risk analysis and external inspection identified seven pipes at a high risk of failure that needed to be repaired. The pipes were repaired externally, using post-tensioning or encasement, depending on the internal water pressure and external earth load. At least one pipe was in imminent danger of failure and would have ruptured by now had it not been repaired.

Dallas Water Utilities (DWU) has established itself as a pioneer in the use of advanced leak detection technologies. In a pilot study in 2004, DWU determined that tethered inline leak location was the most effective technology for locating leaks on its large diameter transmission mains. Since then, DWU has applied the tethered inline technology to 40 miles (64 km) of water main and thereby reduced water loss by 4 MGD (15MLD). Given the tremendous success of this program, DWU elected to run a pilot project using the tethered inline leak location technology on its pressurized wastewater forcemain. The intent of the program is to use the tethered inline technology to locate both leaks and pockets of trapped gas, which can have a detrimental effect on pipeline condition. This paper presents a case study on this pilot project.

South Africa is a "water stressed" country and therefore optimal use of the water resources is of the utmost importance. This inevitably implies that unaccounted for water (water lost in pipelines) and water lost through illegal connections must be eliminated. The rapidly growing water demands throughout South Africa are not sustainable and, as a result water conservation has become a top priority. Government recently instituted legislation to ensure more efficient water use and penalties for inefficient use. Although it is possible to determine whether sections of pipelines are leaking or not, it is virtually impossible to locate the leaks especially on larger diameter and non-metallic bulk water pipelines. A new technology was recently introduced in South Africa to accurately detect and locate leaks in bulk water pipelines of all material types. The system is being used with great success in North America and in the United Kingdom where it was developed. This paper describes the technology and presents case studies from recent inspections and field verification conducted on Rand Water's bulk water pipelines in South Africa. Rand Water is the largest supplier of bulk water in Africa providing bulk potable water to more than 11 million people. Its pipeline network includes over 3000 km of large diameter pipelines providing, on average, 3 550 million liters of water daily to local authorities, large industries and mines. The paper further describes the innovative use of Dynamic Probe Super Heavy (DPSH) soil penetration testing in areas of identified leaks next to the pipelines. The purposes of the DPSH testing were to determine the presence of possible voids in the backfill soil near the pipeline due to water action (i.e., migration of fines) and to assess the general side fill support conditions next to the pipeline before it is excavated.

The Sewerage & Water Board of New Orleans (S&WB) is charged with providing drinking water, wastewater, and drainage services to the City of New Orleans. The events of August 29, 2005 - Hurricane Katrina - significantly increased the challenges facing the S&WB. Before the August 29, 2005 storm, New Orleans' residents used about 120 mgd, with about 30 percent of that considered non-revenue. That means that 84 mgd was used by the residents and industries prior to Katrina, while the rest was used to fight fires or for other public uses - or was lost through faulty pipes in the distribution system. Immediately after Katrina, these statistics were reversed - whereby close to 85 mgd of treated water was now unaccounted for and probably leaking out of the system. Although the S&WB has made great strides in addressing the unaccounted for water loss, they have yet to reach pre-Katrina levels. Not only do the leaks represent added cost to the S&WB with no revenue offset, but pressure is extremely difficult and costly to maintain. This has interfered with the operation of some businesses and compromises fire protection. To address water loss attributed to leaking pipelines, S&WB has undertaken a strategic water loss control program including flow monitoring and a leak detection program to accurately and reliably identify water leaks. Using this information, the S&WB can prioritize pipeline leaks and pro-actively identify and repair leaking pipes. In addition to savings from the reduction in lost water, such an approach offers significant cost savings when compared to emergency repairs. Two technologies are currently being utilized by the S&WB to identify leaks in the water pipeline systems: noise loggers and digital correlators to identify and locate leaks on the small diameter mains and a free-swimming acoustic tool to identify leaks on large diameter pipelines. This paper focuses on the recovery efforts of the Sewerage and Water Board of New Orleans, as it relates to water loss control in the drinking water distribution system.

Initially developed in the UK and North America, advanced tools for leak location in large diameter water transmission mains have begun to spread across the globe. Recognizing the tremendous opportunity presented by these technologies to reduce losses of potable water in an economical manner, Empresa Portuguesa das Aguas Livres S.A. (EPAL) and WRc Plc (WRC) have worked together to pioneer these technologies in Portugal. The technologies have now been successfully applied to over 47 km of cast iron, concrete, and PCCP water transmission mains in Lisbon, ranging from 30 inches (750 mm) to 72 inches (1800 mm) in diameter. A total of 62 leaks have been located, ranging from tiny leaks that were barely detectable to very large leaks losing massive amounts of water. These successful projects have shown that advanced leak detection technology can be effectively applied in typical European pipelines, and that the leakage rates in these pipelines do indeed make it an economical practice.

Bay County, Florida Utility Services Department initiated a project in Spring 2008 to evaluate several large diameter force mains for the purpose of locating potential air pockets and leaks within the pipelines. This was achieved by releasing an Un-tethered Acoustic Air Pocket and Leak Detection device directly into the pipeline's flow. Four (4) pipes were involved in the leak and air pocket detection survey, the pipes ranged in diameter of 36-inch to 54-inch. Two of the pipes were subaqueous waste force mains, the remaining two were raw water mains. Three of the pipes were prestressed concrete cylinder (PCCP) material and the fourth pipe was high density polyethylene (HDPE). The un-tethered acoustic air pocket and leak detection device was recently introduced to identify and locate air pockets and leaks in large diameter force main pipelines. The device is inserted into a fully operational pipeline and is released into the flow stream to monitor several miles of pipeline during a single deployment. A 4-inch diameter access was required for both insertion and retrieval of the device. Because the device traveled in the flow and passed directly adjacent to the air pocket or leak, it identified the noise signature created by the air pocket and leak. The position of the device was continuously tracked and recorded by a proprietary GPS synchronized acoustic receiver that identified a high frequency timed pulse from an ultrasonic transmitter located inside the device. This recorded data was analyzed to identify locations of air pockets or leaks.

Acoustic devices are the most common type of equipment used to locate leaks in municipal water pipes. These include simple listening devices such as ground microphones and listening sticks. Acoustic devices also include leak noise correlators, which were first developed more than two decades ago and have significantly improved the accuracy of locating leaks. It is generally accepted that the effectiveness of existing correlators is limited on plastic pipe and larger diameter trunk mains. This paper will go over the physics of leak noise in plastic and larger diameter trunk mains, sound. The frequency and wavelength of the sound waves will be reviewed in relation to the field procedures required to measure the physical acoustic waves of leaks on plastic pipe and trunk mains. Case studies will then be provided to illustrate best practices for conducting leak detection on plastic pipe and trunk mains. Leak studies of actual leaks on both plastic pipes and trunk mains will be reviewed to demonstrate the field methods that were successfully implemented, as well as the leak noise frequencies of the successful detects.

In March of 2008 the City of Calgary Water Services Department contacted Pure Technologies for assistance in finding a leak in a water pipeline under a busy 4 lane road. Pure Technologies agreed to survey the line utilizing the SmartBall technology, an innovative leak detection technology for larger diameter water and waste water pipelines. The length of the survey was 2040 feet. The pipeline was a concrete pressure line 48 inches in diameter. The pipeline was installed in 1974. Within hours after the inspection the City of Calgary was notified of the location of the 34 gal/min leak. The location and approximate size of the leak was verified by City crews before repairs were made. The free-swimming acoustic leak detection tool demonstrated an ability to successfully identify and locate leaks in larger diameter transmission pipelines. The device was inserted into a fully operational pipeline. A 4 inch diameter access port was required for both insertion and retrieval of the device. Because the device traveled in the pressurized water column and passed directly adjacent to the leak, it clearly and distinctly identified the noise signature created by each leak. The position of the inspection tool was tracked by receivers from the surface - the position and location of the device known at all time. The recorded data allowed for correlation of any identified leak with the position of the device in the pipeline. This paper will summarize the field performance of the free swimming acoustic device utilized by the City of Calgary for the leak detection survey.

The City of Allentown, Pennsylvania initiated a project in the summer 2008 to perform leak detection of a 5-mile, cast iron raw water main pipe, Schantz's Spring Pipeline. A majority of the 30-inch cast iron line was installed and has been in service over 100 years. The large diameter, low pressure pipe did not allow for conventional leak detection tools. As a result, the project utilized an internal free-swimming acoustic leak detection tool applicable for medium and large diameter transmission pipelines. The device typically requires a 4-inch tap at the insertion and extraction locations. However, to minimize pipeline modifications, the device was inserted into the pipeline through the open end of the pipe inside a storage tank at the upstream end of the line. From this location the device traversed the line to a location near the treatment plant at the downstream end of the line. A 4-inch tap was installed in the pipe at the downstream end to allow for the extraction process. At the extraction location, the device was captured in a net that was inserted through the tap. Prior to removing the device from the pipe, several simulated leaks of varying magnitude were created and a calibration equation was developed to estimate the magnitude of leaks identified within the survey. This paper addresses the results of the survey. It shows data from the leaks detected and the estimated magnitude of leaks. To date, one excavation to confirm the leaks has been performed. It also describes how the City of Allentown plans to manage the pipeline as a result of the survey.

A comprehensive solution for in-line and real-time monitoring of long distance pipeline using distributed fiber optic sensors is presented in this paper. The technique is based on Brillouin scattering and is capable of measuring strain and temperature over distances larger than 150 km with meter resolution using a single instrument. The solution includes ground movement, leakage and third party intrusion detection. The solution presentation is supported by experimental results and practical cases of implementation.

This paper presents the results of a condition assessment effort which saved the Coastal Water Authority (CWA) thousands of dollars in future repair costs. Internal observations were made of three existing 250-foot long sections of 54-inch and 78-inch coal tar-lined steel intake pipe at the Trinity River Pump Station. Six physical condition items were observed and measured during the condition assessment: deflection/settlement, roundness/ovality, interior pipe coating condition, interior pipe exposed steel condition, pipe wall thickness and additional anomalies. A confined space entry crew conducted field tests in order measure the six physical conditions of each of the three sections of pipe to be evaluated. A report that included field measurement results, as well as conclusions and recommendations, was provided to the CWA. It was found that all three pipes had measurable deflections and measured out of round. It was recommended that a structural engineer evaluate the pipes. Coating failure was also found on two of the pipes. A coating rehabilitation plan was presented to the CWA. Once the condition assessment was completed, the client was able to secure a contractor to finish the recommended coating and piping repairs in record time. The means and methods used during this project are presented in this paper.

A methodology for software based pipeline leak monitoring using feature extraction and classification is presented here. For feature extraction, time domain features of the measured flow, pressure and temperature of the pipe at its inlet and outlet are used. The time domain features are calculated for every time window. Information in the time domain signals is converted to matrix of features. The leak and no-leak signals are classified using k nearest neighbor and Bayesian classifiers. This approach is tested on a real multiphase pipeline with various leak positions and sizes. Also the ability of the classifiers for distinguishing operational changes from leakages is evaluated. Results shows that feature extraction and classification can be applied successfully to the problem of pipeline leak detection.

The 144-inch-diameter composite-steel-and-concrete tunnel liner for the Arrowhead tunnels below the San Bernardino mountain range in Southern California (the cover over the crown of the tunnel is as much as 1590 feet), 9 miles long, was designed for external heads up to 1200 feet (520 psi) and maximum internal pressure of 80 psi. The steel cylinders resist the internal pressure and a portion of the external pressure while the concrete cores resist the major portion of the external pressure. The special liner design required high concrete compressive strength with high modulus of elasticity and low creep properties to ensure that there would be no overstress in the steel cylinder for the long term conditions. The composite-wall tunnel liner also required concrete core reinforcement designs to withstand all pipe handling and installation forces. Structural analyses of the pipe, with a few preliminary reinforcement schemes including embedded studs, were conducted assuming a line-bearing support with 50% impact. The analysis included calculations for maximum pipe deflections and maximum stresses due to moment and thrust at the pipe invert and springline. Shear and radial tension was also checked. Two test pipe sections were manufactured (based on the final proposed reinforcement scheme) and were subjected to load-deflection tests to verify the pipe design. In this paper, the overall design concept, the summary of the structural analyses results, creep and modulus qualification tests, pipe-deflection test results, and the steel cylinder fabrication testing requirement will be presented. The advantages of this unique concept tunnel-liner design for high external heads will be discussed.

In early 2008 the California Department of Transportation (Caltrans) was scheduled to commence widening of Interstate 15 over the San Diego County Water Authority's Second Aqueduct crossing as part of the I–15 Managed Lanes Projects. As a result, Pipelines 3, 4, and 4A would be impacted by both the work performed by Caltrans and the resulting load caused by the road widening. To ensure protection of the pipelines was completed without impact to Caltrans' schedule a Design Build Request for Proposals was advertised in the summer of 2007. On November 20, 2007 the San Diego County Water Authority, in partnership with the Design Build team of L. H. Woods & Sons, Inc. and Tetra Tech, commenced the relining of three 72-inch Pre-stressed Concrete Cylinder Pipelines directly beneath Interstate 15 utilizing a combination of 1-inch thick steel liners and high strength grout. Early on it was clear that a list of challenges would present themselves due to the proximity of the project to existing residential structures, work preformed during California gnatcatcher breeding season, and two scheduled aqueduct shutdowns in a relatively short timeframe. Despite these challenges the project was completed ahead of schedule and under budget while providing multiple lessons learned for the project team in the following areas: environmental, public affairs, and communication. In order to expedite the commencement of relining ahead of the proposed Caltrans work, the Water Authority filed a categorical exemption to comply with the California Environmental Quality Act (CEQA). The categorical exemption coupled with the dissemination of many suitable habitats by the wildfires of 2007 magnified a potential problem that a breeding pair of gnatcatchers could have in halting construction of the project until the end of the gnatcatcher breeding season. Prior to construction, the project team had already anticipated some of the challenges associated with the project's close proximity to surrounding residences. One projectsite / access point was located in the middle of a common area in a condominium complex, twenty feet from the nearest residence while another site was in the middle of an owner's "extended" backyard. This proximity resulted in close scrutiny by the surrounding public who paid particular attention to the aesthetics of the site, something that had not been considered on prior projects. Ultimately, many of the complaints and questions received were mitigated with an effective approach to communicating the project information. However, the most critical element to the success of the project was clear, rapid, and efficient lines of communication. Never was it more evident than around the two scheduled aqueduct shutdowns requiring coordination not only among the project team, the contractor, and sub consultants but, including the multiple departments within the Water Authority. The experiences and lessons from this project continue to benefit not only the Water Authority's projects, but the public as a whole.

Since its formation in 1951, the North Texas Municipal Water District has been charged with developing a reliable water supply source for its 13 member cities and 57 other customers (some direct and some indirect), serving more than 1.6 million people in portions of north Texas. The District's service area covers portions of Collin, Dallas, Denton, Fannin, Hunt, Kaufman, Rains, and Rockwall Counties. Long-range water supply planning efforts identified significant increases in water demands that must be met through a corresponding increase in available raw water supply. Compounding the need for raw water is the fact that the north Texas region experienced serious drought conditions within the last few years with the District's primary water supply reservoir, Lake Lavon, falling some 17 feet in water surface elevation from May 2005 to October 2006. Additional raw water supply was needed to prevent extensive water restrictions during this drought and provide for continued growth of the service area. In an effort to supplement available supplies, the District contracted for 50,000 acre-feet of water per year from the Sabine River Authority in Lake Tawakoni, located approximately 45 miles east of Dallas in October 2005. The infrastructure needed to transfer this water from Lake Tawakoni was designed and constructed within an accelerated schedule from January 2006 to July 2008. The infrastructure includes approximately 30 miles of 54 and 60-inch-diameter transmission pipeline and two pump stations, each with a raw water pumping capacity of 75 MGD at a total project cost of nearly $100 million. Construction management and coordination of the multiple project components was critical. The focus of this paper will be a discussion of the major project components, construction management, and lessons learned during construction of the multi-million dollar project on an accelerated schedule. Unique project issues included coordination of 5 construction contracts, equipment preselection and delivery, implementing pipeline corrosion control, technology based management and paperless submittal process, conflict resolution, and specific items of interest related to engineers as resident representatives. Some of the construction issues to be discussed include addressing failures of pipeline joint bonds and construction of a 14-foot diameter shaft on the shore of Lake Tawakoni.

The Systems Conveyance and Operations Program (SCOP) is owned and managed by the Clean Water Coalition (CWC), which consists of four member agencies; the City of North Las Vegas (CNLV), the City of Las Vegas (CLV), Clark County Water Reclamation District (CCWRD), and the City of Henderson (COH). Created to address future water quality concerns in the Las Vegas Wash and Lake Mead, CWC has spent the past seven years developing SCOP as the best alternative to meet the future needs of the Las Vegas Valley. Major elements of SCOP include four points of connection, effluent interceptors, a power generating station, and a submerged, diffused outfall. Designed to meet the projected flows in 2050, SCOP is sized to handle an average day flow of 400 mgd with a peak hourly flow of 600 million gallons per day (mgd). The operational date is targeted for 2013. SCOP will be built utilizing a traditional design-bid-build delivery method. The program has been divided into ten separate projects. Each project consists of one or more design and construction packages. A list of these projects, with associated elements is described later in further detail.

Easily accessible new water sources are diminishing, with the logical result of water purveyors looking at water importation projects to meet future demands. Since water importation typically involves transporting water from remote rural areas, this presents a unique set of planning, design, and construction challenges as compared to the typical project implemented in metropolitan areas. Construction challenges must be considered in the planning and design phases of an importation project to improve the chances of successful implementation. Vidler Water Company developed the Fish Springs Water Supply Project as a public/private partnership with Washoe County to import water into Reno, Nevada from a water-rich valley approximately 30 miles north of the Reno-Sparks metropolitan area. The project consisted of approximately 29 miles of 30-inch diameter cement-mortar lined and coated welded steel pipe, 14 miles of ductile iron pipe, four water storage tanks, five well houses, and a high-pressure booster pump station. Additionally, work on the Fish Springs project was performed under many local, state, and federal permits. This paper discusses the planning, design, and construction issues that relate to the remoteness of the Fish Springs Water Supply Project, such as limited availability of supporting infrastructure in a rural area, steep mountain terrain, limited access routes, archaeological finds, and coordination of multiple contractors.

Even with the best of technology not all projects are as successful as we anticipate. In order to minimize the possibility delays and overruns it is necessary to have a clear understanding of the scope of the project, a good design plan, employ proven pre-construction practices such as S.U.E., and have the wisdom and experience to "expect the unexpected." October 2008, a private development firm contracted with Kimley-Horn and Associates, Inc (KHA) to design the on-site and off-site infrastructure associated with a 270 acre mixed use development in north Phoenix. The site was located north of the 101 Freeway between 56^th and 64^th streets. Stipulations related to the land purchase demanded the private developer install a portion of a regional sewer line along the southern boundary of the property and connect to an existing 36" line downstream to the west of the project. The existing 36" line was located within 56^th street right-of-way, passing though both City of Phoenix and Arizona Department of Transportation right-of-way, along the whole alignment. As as-built and preliminary field inspections were completed, complex existing utility conflicts became evident. The most significant, a 42" high pressure water line that made a conventional connection to the existing 36" stub impossible. Through close collaboration with the City of Phoenix Water Services Department, Arizona Department of Transportation (ADOT) and Specialized Services Company (SSC), hired to pothole and consult on conflict resolutions, KHA designed an atypical but highly effective solution that split the 36" sewer line into three 18" lines at the point of conflict to allow for the transfer of flow below the 42" & 24" waterlines (with only 4-inches of separation). Two custom junction structures were also designed complete with internal diversion benches and air jumper.

Louisiana Energy Services LLC ("LES") is currently constructing an enrichment plant (the National Enrichment Facility) in Eunice, New Mexico which is expected to become operational in 2009. The National Enrichment Facility (NEF) project is a uranium enrichment plant that, when construction is complete, will operate using centrifuge technology to provide safe, cost effective, and reliable uranium enrichment services for the civil power generation industry. A Controlled Low Strength Material (CLSM) Test Pad was installed at the NEF site during construction in December 2007 to conduct plate load tests on a 100-psi (at 7-days) CLSM mixture, evaluate the results, and provide recommendations for the use of CLSM, in lieu of compacted soil backfill, in QA Level 1 and QA Level 3 structural fill applications,

In the late 1990's, Denver Water began a plan to acquire and convert gravel pits into water storage facilities. The main purpose of the facilities was to capture reusable wastewater effluent and store it for downstream water rights exchanges. Two facilities, the Cat and Miller gravel pits, were acquired on opposite sides of the South Platte River in Adams County, Colorado. A 42-inch steel pipeline was needed to connect both facilities. Both open cut and tunneling methods were examined to install the pipeline. Obstacles for the open cut design involved not only crossing the South Platte River, but also an excavation over 25 feet deep in clean sands through an Xcel Energy power line corridor. Beneath a 115 kVA line in the power corridor was also a 42-inch steel wastewater force main. Installation of the pipeline by tunneling also presented problems. The river alluvium and the high groundwater table presented risks for tunneling. The geotechnical trenchless recommendation was to microtunnel in the claystone deposit under the alluvium. This design would put the pipeline below both reservoir floors and cause major modifications to the Miller outlet tower, already in final design. These issues, coupled with a relatively short length of microtunnel, led Denver Water to bid the construction as an open cut contract. This paper will discuss the design problems, the final approach and the construction that resulted in a successful project.

The language in pipe installation standards and specifications should be as clear, concise, and consistent as possible. Accordingly, there should be uniformity in all the soil groupings for buried pipe installation. In the ASTM and AWWA standards for different pipe types, the exact same soil is variously described as "Class II", "SC2", "Category I", "Type 4 laying condition", "Coarse-grained soils with little or no fines", and "Suitable bedding material," etc. Why should a pipe designer wade through all the different soil descriptions to select the best soil type for the different types of pipes that could be included in the specifications? Confusion can lead to either over-designed or under-designed pipe. Uniform soil groups will help contractors better understand the type of soil they have to provide and make more accurate bids (are five different soils needed or does one soil fit all requirements?). Pipeline inspectors should not have to refer to many different installation standards to determine whether or not the right soil is being used. Unnecessary complexity and confusion leads to poor installation and future pipe failures and leaks. The specifications and project manuals can be simplified by using consistent language in the installation standards. A uniform soil grouping is proposed that can apply to all types of pipe. These soil groups have already been incorporated into some standards. The committees responsible for the other pipe standards and manuals are encouraged to adopt these soil groups.

FEATURES of plastic utility piping for performance, and the resulting BENEFITS upon which decisions are made to fund and implement projects, will be addressed. Both of these are equally important within a changing marketplace and your plastic pipe municipal systems. If you were to look just at the "surface" of the ever increasing demands on our municipal infrastructure; you might think roads, lighting and other above ground networks were the only major components to address. However, looking "below the surface" you will discover a much greater depth to our infrastructure needs. Water mains, sanitary sewers, storm water systems, force mains and transmission lines serve as the veins and arteries that support all that is essential for our economic and personal well being. This paper will focus primarily on water mains and discuss how these systems have a dynamic nature, always in motion being pushed, pulled, pressurized and abused. Communities continue to place more demands and stresses on these utilities and want more dependable service at the same time. The HDPE (High Density Polyethylene) Plastic Pipe Industry listens to customer needs and is driven to emerge as the best pipe product for this changing dynamic marketplace. HDPE plastic pipe material will provide exceptional strength with the flexibility and ductility that is so vital in satisfying the ever changing forces within a municipal water system. The features of HDPE plastic will be presented, but more importantly the benefits produced will be explored to show improved performance within a utility system in motion.

The benefits of diverting flow from an active watermain to a bypass pipe without interruption of service are presented. The project was complex due to the type, size and location. The project purpose was to relocate a 5,000 foot, 90 plus inch pre-stressed concrete cylinder transmission main operating at 145 psi to enable construction of a new runway at Chicago's O'Hare airport. The owner of the main required no loss of service or operating pressure and O'Hare required no air service interruptions. Conventional construction methods were estimated to cost $80 million. An alternate proprietary STOPPLE® process was selected at an estimated cost of $6 million but required installation of bulkheads in two locations. These bulkheads would incur an estimated 1.5 million pounds of force as the flow was diverted into a 60-inch temporary by pass pipe. With challenges involving the site, service and weather constraints, two massive thrust restraint systems were successfully designed and built on schedule within the expected cost parameters.

Helix Water District's 48-inch Flume project consists of replacing an existing concrete cylinder pipeline (CCP) with a steel pipeline, in order to meet new higher pressure requirements. The project is part of the East County Regional Treated Water Improvement Program (ECRTWIP), partnered with the San Diego County Water Authority (CWA). The ECRTWIP included the Los Coches Pump Station Upgrade, which increases the hydraulic gradeline in the Flume pipeline. A 3,300 foot, 42-inch diameter CCP segment of the existing flume pipeline had insufficient pressure capacity for the increased hydraulic gradeline. The pump station upgrade and improvements to the Flume pipeline will enable Helix Water District to allocate an additional 10 mgd from the District's R.M. Levy Water Treatment Plant for delivery to neighboring Otay Water District and Padre Dam Municipal Water District facilities. Design and construction of the 48-inch Flume Pipeline needed to be completed concurrently with the Los Coches Pump Station Project. The design phase included an alignment study, preliminary and final design completed within an aggressive schedule. Shutdown sequencing and scheduling was particularly important since the existing pipeline is critical to the distribution of potable water to the region. The longest the pipeline could be taken out of service was 30 hours during periods of cool weather. The Contractor worked closely with the construction management and design team to develop a construction schedule that met the completion date criterion. Several shutdowns were conducted, which enabled a shorter duration for the final shutdown and connection. Construction of the pipeline along a new alignment would require blasting or more expensive rock breaking techniques for the hard granite rock in the area. To avoid blasting in close proximity to high pressure gas pipelines located in close proximity to the available alignment options, the new pipeline was placed in the original trench occupied by the existing pipeline. Since loss of use of the pipeline for more than 30 hours would result in severe operational difficulties and supply shortages for the region, a 32-inch diameter HDPE pipeline was designed to handle flow during construction. Challenges for the above-ground HDPE pipeline included control of movement due to internal pressure changes and thermal expansion and contraction.

In October 2006 the City of Phoenix (City) had a catastrophic failure of the 60-inch Prestressed Concrete Cylinder Pipe (PCCP) Superior Waterline that supplies as much as 50-million gallons per day (MGD) to south Phoenix. After extensive assessment and emergency repairs in the two months following the failure, the City elected to install 11,600-feet of Acoustic Fiber Optic (AFO) into the pipeline to monitor wire breaks. To meet summer demands, the City placed the pipeline back into service in February 2007. Over the first three months of operation, the AFO system recorded over 200 wire breaks in the Superior Waterline. Due to this excessive number of wire breaks, the City contracted Brown and Caldwell (BC) to design an emergency rehabilitation for this pipeline with Kiewit Western Co. Western Corporation on board as the Construction Manager at Risk (CM@R). The rehabilitation method chosen for this project was steel can slip lining based on the successful implementation of slip lining on prior City waterline rehabilitation projects. However, as opposed to prior split can slip lining projects, the lining method designed for this project was solid can slip lining. This method was utilized because of its accelerated manufacturing schedule, reduced construction schedule, and lower construction cost. The accelerated schedule was critical since the City's operations could only remove this pipeline for three months in the low demand months. While both methods utilize steel pipe as the rehabilitation material, there were many modifications in design and construction that had to be considered. Some of these modifications included: 1) Reduction in capacity 2) Pipe joint length and fit-up 3) Connection to existing services 4) Hydrant connections 5) Distance between portals 6) Grout plugs vs. centering screws 7) Welding methods.

Cured-in-place piping is a commonly used rehabilitation method for aging gravity sewer systems. In general, there is limited guidance on when external (open trench) point repairs are required in preparation for cured-in-place piping. The decision to make point repairs prior to installing cured-in-place piping is typically left to the engineer of record or other party reviewing the closed-circuit television (CCTV). This paper will examine the issues of determining when external point repairs may be appropriate prior to cured-in-place piping installation, and the potential impact of certain defects on long-term liner performance for small diameter (less than 24" gravity sewer) rehabilitation. Typical defects including holes, broken pipe, collapsed pipes, sags, and void spaces will be discussed. The use of external point repairs prior to installing a cured-in-place pipe is a balance between the severity of the defect, surrounding conditions, rehabilitation objectives, risks during installation, aesthetics of the final product, future maintenance and long-term performance.

The City of Fort Lauderdale is a fully developed, coastal city in southeast Florida and highly dependent on the success of the tourism industry as the primary engine driving growth and redevelopment. The older portions of the City's existing sanitary sewage collection system, constructed primarily of vitrified clay and concrete pipe contributes to high levels of inflow and both rainfall induced (RDII) and groundwater (GWI) infiltration (I&I), pipeline failures and conveyance disruptions. A value engineering study concluded that the most cost effective means of providing needed additional wastewater treatment plant capacity was to remove I&I from both the base and peak flows to the wastewater treatment plant. The specific goal of the sewer rehabilitation program is to cost effectively reduce GWI based I&I base flows to the treatment plant currently averaging approximately 20 MGD and RDII influenced peak flows in excess of 85 MGD, to accommodate growth and redevelopment activities while not requiring additional WWTP capacity. As part of the WaterWorks 2011 infrastructure program, the City initiated a comprehensive sewer rehabilitation program using only trenchless technologies to repair the existing collection system. This paper will discuss the implementation of the sewer rehabilitation portion of the WaterWorks 2011 program and discuss the results, experiences and lessons learned. This paper provides details of the system evaluation and prioritization, the development of specific projects, experiences with projects constructed to date and the implications of system flow data obtained as projects have been completed. Evaluation of flow data indicates sharply reduced levels of RDII as evidenced by dramatic reductions in peak flows at the WWTP observed during rainfall events and reduced levels of GWI as evidenced by continually decreasing ADF at the WWTP despite the continuing addition of thousands of new service connections being added to the system as part of the Waterworks program.

Lining of a pipe with a polymeric liner is a viable trenchless technology for rehabilitating sewer pipelines. Polymeric liners are typically installed within the deteriorated segments of a sewer line, from one access hole to the next; to essentially create a new pipe within the old pipe without the need for excavation and removal. However, some concerns exist regarding the need to grout or seal the joints where the new liner connects with access holes and laterals. This study attempts to quantify the amount of flow within the annular space that could exist between a polymeric liner and a deteriorated host pipe. Results of full-scale field tests on twelve pipelines lined with four different deformed/reformed or fold-and-form (DR/FF) and cured-in-place-pipe (CIPP) liner products indicated that gaps of different sizes existed in all of the tested pipelines. These gaps resulted in variable annular flow between the liner and host pipe. Based on the results of the full-scale tests, a mathematical relationship was established between the annular flow in a lined pipeline and the annular space. The relationship between the annular flow rate and the average annular gap size depends on the difference in head between the entry and exit points along the pipeline. In turn, the average annular gap size depends on many factors including tolerances and imperfections in the host pipe and liner, conditions of the host pipe and the quality of liner installation. The results of the numerical analysis indicate similar flow rates for annular gap sizes greater than 1.3 mm (50 mils), which suggest tight installations of a liner into the host pipe to eliminate annular flow.

As the water distribution infrastructure continues to deteriorate across North America, there is a continued need to develop pipeline rehabilitation methods that are cost effective and minimally disruptive on one hand, while minimizing the time a pipe must be taken out of service on the other hand. Spray-on linings that satisfy the requirements of NSF 61 are one such emerging class of rehabilitation methods for pipes and conduits subjected to internal pressure. Unfortunately, there appears to be a lack of design guidelines regarding the needed thickness of such lining applications to ensure a particular pressure rating at a given factor of safety. The paper provides an overview of spray-on lining methods in general, and chemically hardened lining products in particular. Thereafter, the findings of an extensive study aimed at evaluating the internal pressure resistance rating of a spray-on rigid polyurethane lining system are reported. The experimental program consisted of testing polyurethane panels in a specially designed pressure cell with a circular opening to simulate a deteriorated host pipe. The experimental setup was designed to determine the burst pressure of the panels. The thickness of the panels ranged between 0.14 and 0.42 inches and the size of the opening was 3 or 4.5 inches. Using these controlled variables, along with the measured burst pressure values, a linear regression equation was derived for calculating the pressure rating for a known lining thickness, maximum gap diameter in the host pipe, and a safety factor value. The researchers are currently working on expanding the testing program to other types of spray-on linings in an attempt of developing a generalized equation that incorporate key mechanical properties of the lining material.

This paper describes a structured framework for the design and construction of horizontal directional drilling (HDD) projects. This framework is implemented in a new HDD software design program BoreAid. The framework consists of five interlinked modules: 1) bore planner; 2) load/deflection calculator; 3) drill planner; 4) bore pressure estimator; and 5) equipment/tooling selection. Each module is discussed in detail and a case study example is presented to demonstrate how this new framework methodology can be used as a HDD project quality assurance and quality control tool and to increase the probability that the project will be completed on time and within budget by ensuring industry good practices are followed.

High density polyethylene (HDPE) pipeline systems have been growing in use since its birth in the early 1950's. This confidence has increased in the decades of the 70's, 80's, and 90's; such that newer and more extensive uses of HDPE in trenchless applications is now common for vital underground utilities. With AWWA approvals and standards providing still more confidence in polyethylene plastic usage, we now observe this industry working with trenchless methods and moving into other areas of utility reconstruction needs. Included in these newer and innovative uses, are trenchless installations of HDPE water mains; resulting in significant advantages over traditional pipe materials and excavation installations. This is the story of one project in a busy Midwest community. It will illustrate not only the physical features that improved construction; but also to tell the "benefits story" of the neighborhood residents and the city's bottom line political and financial gains. Taking the time to do it right can potentially match a newer technology (trenchless HDPE) with old fashion common sense and unexpected benefits. If you were asked the question....Would you want to repair a failing water main using a technology and material that will significantly save in local disruption, decrease construction time, not decrease capacity and potentially increase the utility's performance, and do this at a lower price? Your answer would most likely be YES after knowing this is an established method already being used in municipal water systems nationwide. Please come and listen to the impressive results and share how HDPE trenchless water main reconstruction might help in one of your own problem situations.

Within 12 years after it was installed, a 16-inch PVC recycled water transmission pipeline failed in seven locations near the intersection of Kanan Road and Hawthorne Drive, in the Oak Park area of Ventura County. After an investigation determined that the breaks were most likely due to defective PVC material, a strategy for rehabilitating the pipeline was needed that met hydraulic requirements and minimized impacts on traffic and the surrounding community. As such, a variety of trenchless methods were evaluated, and pipe splitting with 18-inch HDPE pipe, supplemented by open-trench construction, was ultimately selected. The two main goals of the project were to minimize lane closures and detours along Kanan Road, a busy four lane street, and limit service outages to any customer to no more than one week. This paper describes how these challenges were addressed during the design phase through a combination of careful selection of pit locations and pipe laydown areas, a detailed construction scheduling plan, temporary connections to potable water sources, and phased traffic control plans. The resulting design allowed the rehabilitation to proceed with no planned closures along Kanan Road and less than one week service interruptions. Other design considerations included locating trenchless access pits at appurtenances to be reconnected to minimize excavations and restraining the new HDPE pipe at connections to the existing PVC pipeline to address thermal contraction and Poisson's Effect in the flexible HDPE pipe. Construction of the rehabilitated pipeline is constrained to low demand winter months and will be completed in May 2009.

Engineers and contractors are continually challenged with evaluating alternative pipe material and construction options for best meeting their project needs. Traditional open-cut construction methods have proven design and installation specifications; however, the increase in utilization of trenchless construction methods has facilitated the development of pipe materials suited for such installation methods. Today, technologies such as Horizontal Directional Drilling (HDD) have increased significantly as an alternative installation method in the municipal sector. Installation of potable water, force mains, reclaimed water, and gravity projects employing directional drilling have grown as demand for installations in difficult areas, like under rivers or major highways, or highly urbanized and congested utility corridors has increased. The nature of the HDD process necessitates the use of continuously joined pipe products capable of being pulled in, as opposed to pushed in by segmental installations. Fusible PVC pipe is one such material for installation of water and wastewater, pressure and non-pressure infrastructure using HDD. While maximum safe pull load criteria have been developed for this material, the present pull load predictive tools for the HDD process are highly variable and, in some cases, overly conservative in evaluating safe pull loads. This paper describes the field validation of a predictive model for HDD installations using Fusible PVC from data captured during commercial installations using an in-line measuring device attached between the backreamer and the product pipe. The results of eight projects are presented in this paper to demonstrate the model validity.

The City of Laredo has seen remarkable growth over the last several decades. As a result, the need to make significant improvement to the storm sewer infrastructure has increased. Adjacent development and, at some locations, encroachments to storm sewer easements have complicated the situation. This paper will discuss the problems, the evaluation and the solution recommended for rehabilitation of a 114-inch corrugated metal pipe (CMP) storm sewer trunk line through a highly urbanized portion of Laredo. The 114-inch CMP storm sewer trunk line was constructed over 30 years ago and serves an extensive drainage system through an older section of the City of Laredo near the Gateway to Americas International Bridge which is one of the city's five international bridges to Mexico. The project addresses many utility and environmental issues among which is crossing a former landfill area. Here the existing storm sewer has a depth of cover of more than twenty feet below the surface along certain sections of the project. The existing storm sewer line also transverses densely compacted residential and commercial areas including the Rio Grande Plaza Hotel, a Laredo landmark, before the line outfalls into the Rio Grande. Additionally, numerous public facilities would be impacted by any open cut construction. Based on a preliminary analysis, it was determined that the most cost effective solution would be to rehabilitate the existing storm sewer trunkline instead of removing and replacing the old line. This paper will review the issues involved in the recommendation to rehabiliate the line. Additionally, it will present the challenges of installing a structural liner in the existing line and the use of multiple trenchless construction methods for rehabilitation which include sliplining fiberglass reinforced plastic (FRP) and spiral wound renewal pipe system (SWPR).

This paper describes the collapse and subsequent renovation and reconstruction of an 8ft diameter brick barrel sewer. The size and depth of the sewer, typically 10.0m to invert, together with unusual ground conditions, presented a number of challenges which were resolved by creative thinking and innovative solutions. A temporary pumping station, approximately 12m deep with a capacity of 4.5m³/sec was constructed and fully operational within three weeks. Downstream of the collapse, pipejacking techniques were used to renovate 63m of sewer utilising GRP pipes. Upstream of the failure, the sewer was at risk of imminent collapse and was replaced with 2.4m diameter reinforced concrete pipes laid in a special reinforced concrete cradle. A further 1.0km of the sewer was surveyed and the "LightLine" technique was used to measure the deformations and determine the maximum size of liner that could be inserted.

Tarrant Regional Water District (TRWD) supplies raw water to over thirty wholesale customers (approximately 1.6 million people) in ten Texas counties. TRWD's existing raw water supply system includes two major reservoirs in East Texas, pipelines and pump stations to deliver water from East Texas to Tarrant County, the West Fork reservoirs, two terminal storage lakes in Tarrant County, and the Benbrook Connection, which delivers East Texas water to the southwest side of Fort Worth. TRWD has recently completed construction of the $140 million Eagle Mountain Connection Project that allows TRWD to pump water from their East Texas Reservoirs to Eagle Mountain Lake. The project includes 20 miles of 96-inch and 84-inch pipeline, the 430 MGD Rolling Hills Pump Station (expandable to 630 MGD), the 230 MGD Benbrook Booster Pump Station (expandable to 350 MGD), a 120-million-gallon balancing reservoir, and a number of other required facilities. The 96/84-inch Eagle Mountain Pipeline runs from Benbrook Lake to Eagle Mountain Lake. The pipeline contractor was faced with several challenges during construction of the project. The paper will describe in detail two such challenges, one planned and one surprise, and the innovative techniques used by the engineer and contractor to overcome these challenges. The first challenge was the installation of 700 feet of subaqueous pipe and an outlet structure in Eagle Mountain Lake. The pipe was installed in an underwater trench and backfilled with coarse gravel. The Contractor used an innovative cable system to install the pipe. The outlet structure consisted of a prefabricated steel box with an S-shape pipe that was set on H-piles and given concrete ballast for thrust restraint. The second challenge was an unforeseen site condition consisting of a large underground marsh consisting of highly saturated, extremely loose silty sands and clayey sands found in an old river valley during pipe laying operations. To provide bottom and side support, the pipe was installed on prefabricated concrete planks supported by h-piles and then encased in concrete. Sheet piles were also used to stabilize the trench walls.

With the rapid increase of new installations, replacement and repairs of pipe utilities, the demand for trenchless excavation methods with minimum disruption to the public such as horizontal directional drilling (HDD) has increased. Canadian National Research Council reports that rehabilitation of municipal water systems would cost $28 billion from year 1997 to 2012 (NRC 2004). Contractors, engineers, and decision makers are always facing a challenge of how to estimate the cost of new pipe installation using the HDD due to the presence of subjective factors. The HDD process involves a large number of factors to be considered for productivity prediction and cost estimation. Therefore, an emergent need for developing a dedicated HDD productivity model is currently undertaken to meet industrial needs. The presented research aims at identifying the main factors that affect productivity of HDD operations and designing a productivity model. A neurofuzzy approach is utilized to design the HDD productivity prediction model for underground pipe installations in clay soil. The neurofuzzy system is developed based on actual project data that are collected through interviews, phone calls and questionnaire surveys. Results show that crew and operator skills and pipe diameter greatly affect the HDD productivity and the project as a whole.

Horizontal Directional Drilling (HDD) has been widely accepted and used for installing gas and water lines, telecommunication cables, etc. However, one area where HDD has been used with only limited success is in the installation of gravity flow sewer lines. One primary reason is the difficulty with maintaining critical grades essential for gravity-flow sewer systems when using conventional HDD tracking methods. Recently, advancements made in tracking systems, electronics, and operational techniques have made HDD technology a technically feasible and an economically attractive method for installing on-grade underground pipes in many situations. The newly developed technology illustrated in U.S. Patent 7510029 is one of representative techniques for accurate identification and tracking of the vertical location of the drilling head. This paper evaluates technical capabilities and the economic feasibilities of this new on-grade HDD technology using actual project data. The accuracy of the installed pipe placement is shown, along with a comparison of project costs compared to a theoretical open-cut installation in the given soil type for the sample project.

The City of Phoenix, Ariz., recently elected to perform two large pipe bursting projects; one of these projects utilized vitrified clay jacking pipe as the replacement pipe material. The notice to proceed for the project was given May 12, 2008. The Guaranteed Maximum Price (GMP) for the project is $5,323,524.05. This project represents a first in both (1) the most significant upsize and (2) maximum drive length in the United States using the static pull bursting method with replacement segmental pipe. This project also demonstrates a commendable level of cooperation between equipment manufacturer, product pipe manufacturer, contractor, engineering firm and municipality. One of the first sections replaced included bursting and replacing 3,938 linear feet of existing 12-inch VCP with 18-inch VCP. The existing sewer line's capacity had been exceeded due to growth of the contributory service area. The utility corridor encompassing the existing line was congested with other utilities making open cut construction challenging. Trenchless pipe bursting was ultimately chosen because of the adjacent utilities and concern of traffic disruption. Soil conditions in the area proved to be one of the biggest challenges. The original pipe to be burst was bedded in a soft dry silty sand material and installed in a trench width ranging from 3 to 5 ft depending on depth. Existing trench depths range from 10 to 20 feet deep. This first segment was successfully completed on June 10, 2008.

Culverts are considered nowadays by DOT's as assets; however their value may not be apparent until repair or replacement costs appear. Rehabilitation of culverts can be accomplished using several methods; nonetheless, replacement of culverts can only be achieved by just a few such as: open-cut, pipe bursting and pipe eating or microtunneling. Even though they provide culvert upsizing, neither is economical nor has been widely studied. This ongoing research investigates the current need on replacing obsolete culverts, explains the current trends and methods used to provide culvert renewal and a suggests new conceptual model on how to replace culverts via trenchless using modifications and advantages of other well established trenchless construction methods. The main focus of the new model is to enable culvert upsizing by either ramming or jacking a new and bigger cross sectional pipe over the external surface of the host culvert. Once the encasing culvert gets to the other end of the embankment, the host culvert is either pushed or pulled. In this manner the culvert gets upsized as well as renewed. The process is finalized by cleaning the new surface to detach any soil particles. For this paper the authors provide a method description, a suggested installation procedure and materials to use depending on whether jacking or ramming the new culvert pipe.

Trenchless contractor KRG Utility, Inc., Lenoir, N.C., recently completed an emergency project for the city of Wilmington, N.C. The project included bursting and replacing a ductile iron force sewer main. The city of Wilmington was under a Special Order of Consent (SOC) mandate from the state of North Carolina that prevented the city from starting any new construction development until the force sewer main was replaced or repaired. The main had been lined three times, however, due to the pressure requirements of the main, the liner systems failed under pressure testing. KRG Utility was called in to facilitate a solution to the problem. KRG decided to burst and replace the existing main with High Density Polyethylene pipe (HDPE) utilizing the static bursting method with the most powerful static pipe bursting unit available in the world.

Highly treated effluent from the regional wastewater treatment plants in the Las Vegas basin currently discharges into the Las Vegas Wash and is conveyed to the Las Vegas Bay of Lake Mead. The Systems Conveyance and Operations Program's (SCOP) goal is to collect the majority of the region's highly treated effluent and convey the reclaimed water directly to a deep basin of Lake Mead, bypassing the Las Vegas Wash and Bay, thereby preserving the water quality of the bay. A conveyance system of gravity and pump pressurized pipelines and tunnels are being designed to deliver the reclaimed water directly to Lake Mead. This paper addresses the design methods for the pressurized steel liner of the Reach 3 Tunnel drop shaft which connects the in-trench pipeline and tunnel segments of the project. The vertical drop between the 10-foot diameter steel pipeline and 10-foot diameter steel lined pressure tunnel is approximately 99 feet. The conveyance system is designed to transport a maximum flow of 617 million gallons per day (mgd), the peak hour flow in the year 2050. The tunnel portion of the project is required to convey the water under the Las Vegas Wash and through the River Mountains with minimal impact to the surface above. The drop shaft changes the flow from the horizontal direction of the pipeline to the vertical direction of the shaft and then back to the horizontal orientation of the tunnel thereby creating large unbalanced hydraulic thrusts which must be resisted by the design. The directional and elevation changes of the drop shaft must be achieved with minimal head loss to preserve pressure head at the terminus of the tunnel which feeds two 8 megawatt hydroelectric turbines. Access to the shaft and tunnel must also be provided. The drop shaft serves as a high point to vent air when filling or draining and as an air trap for pressurized air release during normal operation.

A Buried Duct/Pipeline Network (BDN) is presently under development representing an integrated system to facilitate future upgrades of buried communications (telephony, CATV) and power lines. The new pipe network, being developed with the support and encouragement of the U.S. Department of Transportation (US DOT), provides improved, cost-effective hardware and practices relative to current buried construction procedures, which do not otherwise allow for future upgrades or replacement of initially installed utility cables. The BDN supports and encourages present trends for placing utilities belowground, and minimizes future problems with such installations. The shortcomings of conventional direct-buried construction methods can lead to road damage or public safety hazards, including risk of gas or power line hits during reconstruction activities, possibly inhibiting continuation of desired trends toward universal belowground facilities. Previous information on this project was reported at Pipelines 2008. The present paper describes recent progress, including the results of recent field applications as well as information on the development of the related ASCE Manual of Practice for Belowground Pipeline Networks for Utility Cables.

This paper critically assesses the design approach presented in the American Water Works Association M51 manual of practice, entitled "Air-Release, Air/Vacuum, & Combination Air Valves." The design approach presented in this manual of practice is widely used in potable water system pipeline design for both sizing and locating air valves. The recommended design approach has been evaluated and an alternative approach is proposed. The current M51 recommended design approach introduces a very broad range of design criteria in regards to sizing and locating air valves in a pipeline system. This approach does consider different loading conditions, but does not consider that during the life of the pipeline all these different loading conditions may be experienced. Therefore, the author proposes that a more careful and more rigorous method be used to size and locate air valves. The proposed method considers the air valve's primary modes of operation, the air valve's performance under dynamic loading conditions, and the use of a fully dynamic hydraulic model to assess the air valve sizing and location. The paper introduces a hypothetical case where the M51 design approach is utilized and the results of M51 design are compared to the design approach utilizing the more rigorous method. In summary, to meet all the established criteria, the sizing of the air valve(s) for air release and surge control is decreased but to accommodate the uncontrolled drainage mode of operation an additional air valve was required.

Civil engineers have been analyzing buried flexible pipe structures using traditional theories such as the horizontal deflection formula (modified Iowa formula) and the prism load theory. The design based on these traditional theories may not correspond to the actual field pipe performance, due to the assumptions involved in the underlining methods. Within the last 10 years, new theories (vertical deflection formula, soil arching load theory, and others) were developed for the soil-pipe interaction problems. With these new theories available, a more realistic design/analysis is now possible for the flexible pipe structures. This paper first reviews the traditional design approach and points out their deficiencies. It then introduces the readers to the recent theoretical developments made in this area. The paper concludes its contents by going through a design example that incorporates the improved design approach.

The Cachuma Operation and Maintenance Board (COMB) operates the South Coast Conduit (SCC) from the Lake Cachuma north portal to the Carpinteria Reservoir. This pipeline is the primary source of water for the Santa Barbara, Goleta, Montecito, and Carpinteria Valley areas on the central coast of California. No redundant pipeline exists for conveyance of water supply to these communities when the pipeline needs to be taken out of service for repair or maintenance. In addition to any time needed to effect repairs on the pipeline, dewatering and rewatering this section of the SCC is a lengthy process. Due to the age and the material from which it is constructed, the pipe is difficult to repair or modify. Since 2004, three isolation valves have been installed utilizing the line stopping method. Line stopping is a process where a "hot tap" is performed on the pipe and a temporary plug is installed through the tap to stop the flow. Two line stops are required to isolate a pipeline section for removal and replacement with a section that includes a line valve. Temporary bypass piping is also required to allow flow to continue around the removed section of the main pipeline. The pipe on either side of the isolated section remains under full line pressure. This paper presents some of the design, construction, and operational issues attendant with the line stopping and lessons learned for application to the next three in-line valve installations planned.

Flanged connections have been used on steel water pipe for approximately 100 years and were required for the installation of flanged appurtenances, such as valves, into the piping system. These rolled angle or plate flanges were not manufactured to any official standard and were riveted to the pipe barrel. As the use of steel pipe for waterworks service increased, the need for standardization of flanges increased in importance. Prior to 1950, steel flanges were designed to ASME standards. Flanges complying with these ASME standards were manufactured to dimensions that had a minimum pressure rating of 275 psi, which is in excess of pressure requirements needed for most drinking water supply purposes. In 1945, the ASME and the AWWA established a committee to develop a standard for steel flanges for use in the waterworks industry that were compatible with the pressures, temperatures and dimensions normally encountered in water supply piping systems. Ultimately the report findings, issued by the joint committee in the early 1950's were published as AWWA C207-52T, Tentative Standard Specification for Steel Pipe Flanges. This standard was revised in 1955, 1978, 1986, 2001 and 2007, which represents the current edition of the AWWA flange standard. In addition, a companion AWWA Standard C228 for Stainless Steel Flanges was approved in 2008. Each of these standards includes tables listing various sizes and pressure ratings of both ring and blind flanges along with dimensional information. Embedded in each standard is information related to the design approach used to determine the flange dimensions for the rated pressure conditions and the associated allowable stresses. During the latest revision to AWWA C207, and during the development of AWWA Standard C228, questions were presented relative to the design basis for AWWA steel ring flanges. The discussions presented during this revision period focused on dimensional, primarily flange thickness, differences between AWWA and ASME steel ring flanges. Members of both the Steel and Stainless Steel Pipe Committees convened a special task force to evaluate the concerns expressed during the revision process and to retrieve/evaluate the original design data from the late 1940's and early 1950's. The evaluation revealed two important technical findings, the flange dimensions as published in the two AWWA flange standards were confirmed, and the pipe wall thickness is a critical component relative to flange stresses.

The use of horizontal directional drilling has become commonplace in the underground construction industry. It is widely accepted as a time saver and problem solver on many construction projects. Unfortunately, all too often the use of this highly innovative and effective tool has proven to be baffling to many when the time comes to calculate operating costs and determine profitability. While the operation of these highly-complex systems has been mastered by many, a good number of individuals do not fully understand what criteria must be met in order to maximize profits. The net result is that many companies are accepting jobs at pricing that simply will not support profitability.

The Modulus of Soil Reaction (E') represents the stiffness of the embedment soil placed on the sides of buried flexible pipe. E' is used to estimate the deflection of the pipe due to dead and live loads over the pipe. E' varies with the type of embedment soil and with the degree of compaction. The resulting support for the pipe also depends on the width of the embedment soil and the stiffness of the insitu trench walls. This resulting support can be represented by a composite E' that combines the stiffness of the embedment soil and the trench wall soil. The composite E' is the E' of the embedment soil modified by a Soil Support Combining Factor. The Soil Support Combining Factors are given in a table that uses the ratio of the trench width to the pipe diameter and the ratio of the E' values of the embedment and the trench walls. The history and development of the composite E' is discussed. A new proposed table of presumptive E' values of the insitu trench walls is presented.

The practice of thrust restraint design within the water/wastewater pipeline industry has continuously evolved over the years, benefiting from both theoretical and experimental research. Many of these research activities have primarily been originated by the pipe manufacturing industry, thus the research and the resulting practice changes have essentially been reflected in the design practice of these pipe materials. Widely varying material properties and joint configurations have made it difficult to have coordinated practice changes, which have resulted in a lack of consensus on a common design approach amongst different pipe materials. This results in not only significantly different guidance from AWWA design manuals for different pipe materials and agency requirements, but also widely varying design practices and company specific best practice approaches amongst the consulting engineering community. Recognizing the need to develop consensus amongst practicing engineers, the members of the ASCE Technical Committee on Pipeline Installation and Location have formed a special task committee "Thrust Restraint Design of Buried Pipelines" to prepare a white paper on the subject. The objective of this task committee in preparing this white paper is: 1) To document current design practices of thrust restraint systems for various pipe materials; and compare current practices with theory. 2) To document the historical evolutions of the different design approaches, collect and compile field tests completed for different pipe materials. 3) To explore improvements to current practice, develop consensus, and propose recommendations for the development of a manual of practice. Preliminary findings of this white paper are presented in a series of three companion papers: Part 1, Current Practice; Part 2, Historical Development; and Part 3, Roadmap for Unified Approach. This is the first paper presenting current practice. This paper documents the various methods currently used to calculate and mitigate thrust for common pipeline materials including concrete, ductile iron, fiberglass, polyvinyl chloride (PVC), polyethylene (PE), and Steel. Also, this paper utilizes the current design approaches to quantitatively summarize the similarities and differences in the thrust calculations for each material and provide tabular and graphical comparisons of each design approach.

The practice of thrust restraint design within the water/wastewater pipeline industry has continuously evolved over the years, benefiting from both theoretical and experimental research. Many of these research activities have primarily originated within the pipe manufacturing industry, thus the research and the resulting practice changes have essentially been reflected in the design practice of the pipe material. Widely varying material properties and joint configurations have made it difficult to have coordinated practice changes, which have resulted in a lack of consensus on a common design approach amongst different pipe materials. This resulted in not only significantly different guidance from AWWA design manuals for different pipe materials and agency requirements, but also widely varying design practices and company specific best practice approaches amongst the consulting engineering community. Recognizing the need to develop consensus amongst practicing engineers, the members of the ASCE Technical Committee on Pipeline Installation and Location have formed a special task committee "Thrust Restraint Design of Buried Pipelines" to prepare a white paper on the subject. The objective of this task committee in preparing this white paper is: 1) To document current design practices of thrust restraint systems for various pipe materials; and compare current practices with theory. 2) To document the historical evolutions of the different design approaches, collect and compile field tests completed for different pipe materials. 3) To explore improvements to current practice, develop consensus, and propose recommendations for the development of a manual of practice. Preliminary findings of this white paper are presented in a series of three companion papers: Part 1, Current Practice; Part 2, Historical Development; and Part 3, Roadmap for Unified Approach. This is the second paper presenting the historical development of the current design approaches. This paper presents historical evolutions of the different design approaches, compilation of the field tests completed and the results reported for different pipe materials. It is the objective of this paper to fully utilize the historical research as a foundation to better understand and compare the differences and similarities amongst the various approaches.

The practice of thrust restraint design within the water/wastewater pipeline industry has continuously evolved over the years, benefiting from both theoretical and experimental research. Many of these research activities have primarily originated within the pipe manufacturing industry, thus the research and the resulting practice changes have essentially been reflected in the design practice of the pipe material. Widely varying material properties and joint configurations have made it difficult to have coordinated practice changes, which have resulted in a lack of consensus on a common design approach amongst different pipe materials. This results in not only significantly different guidance from AWWA design manuals for different pipe materials and agency requirements, but also widely varying design practices and company specific best practice approaches amongst the consulting engineering community. Recognizing the need to develop consensus amongst practicing engineers, the members of the ASCE Technical Committee on Pipeline Installation and Location have formed a special task committee "Thrust Restraint Design of Buried Pipelines" to prepare a white paper on the subject. The objective of this task committee in preparing this white paper is: 1) To document current design practices of thrust restraint systems for various pipe materials; and compare current practices with theory. 2) To document the historical evolutions of the different design approaches, collect and compile field tests completed for different pipe materials. 3) To explore improvements to current practice, develop consensus, and propose recommendations for the development of a manual of practice. Preliminary findings of this white paper are presented in a series of three companion papers: Part 1, Current Practice; Part 2, Historical Development; and Part 3, Roadmap for Unified Approach. This is the third paper presenting the road map for unified approach. This paper presents a preliminary approach and recommendations to improve current design practice. It is the objective of this paper to determine if a more unified approach would benefit the pipeline manufacturing and design community and improve the integrity of pipeline design in general. The final recommendations from the white paper will form a basis for the development of a Manual of Practice on the subject.

The Carmel Valley Trunk Sewer is located in McGonigle Canyon in the northern coastal area of the City of San Diego (City), as shown in Figure 1. The original trunk sewer was constructed in the early 1970's utilizing fiberglass reinforced plastic mortar pipe (RPM) as manufactured by Techite. This pipe material suffers from de-lamination and rapid failure, which can result in significant sewer spills. The City's Metropolitan Wastewater Department had replaced a majority of the sewer over the years, excluding approximately 14,000 feet of pipe in this environmentally sensitive canyon and creek. The $10 million Carmel Valley Pipeline Project was developed to replace the last critical sections of the RPM pipeline to prevent damaging sewer spills, and upsize the pipeline in time to support rapidly growing communities in northern San Diego.

Local scour below pipelines commonly occurs due to the erosive action of currents and waves. Such scour may cause pipeline suspension and ultimately leads to pipeline failure. Over the last three decades, both physical and numerical modeling of pipeline scouring in steady currents and waves has been developed for better understanding of local scour. In this paper, a review on scour modeling below pipelines is presented from both physical and numerical modeling aspects. Advantages and limitations of both scour modeling methods will be provided. Future development of scour modeling below pipelines will also be discussed.

The Weber River Outfall is a one-mile, 108-inch effluent pipeline with a unique cross section. The project is part of a wastewater treatment plant expansion for the Central Weber Sewer Improvement District. The expansion increases peak capacity in the outfall from 60 mgd to 180 mgd. Calculations showed flotation would occur due to the combination of high groundwater and periodic low water surface elevations in the pipe. Weak insitu soils further limited design options. The final bid package allowed three options for different concrete pipe cross sections: a prebed pipe, a pipe wall over two inches thicker than standard pipe, or standard pipe with a concrete cap. Prebed pipe has a circular interior cross section and a flat exterior bottom; the haunches are cast with the pipe. Concerns about haunch compaction are eliminated allowing the prebed pipe to have a lower class. All three options have very similar costs. Because the outfall is an expansion of the existing plant, the upstream hydraulic grade line is a design constraint. Between that upstream constraint and the downstream constraint of a 100-year floodplain, a tradeoff was established between different outfall diameters affecting headloss through the outfall. The preferred option became a larger, more expensive outfall yielding lower costs from a smaller influent pump station and better site grading. The project also had two open channel crossings that would normally have required siphons. With headloss concerns, two parallel 4' by 12' box culverts were used instead.

The Golden State Water Company (GSWC) serves more than 1 in 20 Californians with drinking water, which is a total of over 1.5 million customers. They serve a diverse number of water systems located all over the state, including Southern California. The Central District includes the cities of Bell and Bell Gardens. The two cities have diverse sources of supply including surface supplies and some groundwater. In order to improve the water supply reliability of both systems, GSWC decided to construct a 12-inch main connecting the two distribution systems. The distance between the systems is about 1,400 feet (ft); however, it includes several daunting obstacles. A long bridge across the Los Angeles River and another bridge across the 710 freeway are between the two water systems, along with a multitude of utilities including gas, petroleum, communication ducts, water mains, and storm and sanitary sewers. Permits must be obtained from the California Department of Transportation (Caltrans), the statewide transportation agency, both cities, and several utilities with prior rights-of-way.

This paper chronicles the relocation of a twin existing 48-inch force main across New Haven Harbor in advance of construction of the new signature I-95 Pearl Harbor Memorial Bridge in New Haven, CT. The pipeline relocation alignment was severely congested with the I-95 bridge foundations, the adjacent historic Yale Boathouse, fuel pipelines, tank farms, an active concrete plant, pile supported electrical transmission towers and the existing active twin force mains.

In 2006, Chesapeake Energy and the Dallas-Fort Worth International Airport teamed together to produce natural gas from the Barnett Shale. What resulted was an $80 million fast tracked gas gathering and produced water pipeline project. The project includes 80 miles of gas and waterlines around the perimeter of the airport. One of the more intriguing aspects of the project was the design and construction of 15 miles of pipe installed by Horizontal Directional Drilling (HDD). The 15 miles of HDD pipelines presented many unique and challenging design and installation methods such as: 1) boring between two buildings less than 7 feet apart, 2) a 2,600 linear foot HDD on a 1,600 foot radius while paralleling multiple utilities less than 25 feet apart, 3) challenges of boring across a major state highway and a developed area without impacting either constraint, 4) design and construction of 5 major state highway bores, 5) a 2,400 linear foot bore underneath a major airport office building parking lot, and crossing under a taxiway bridge The purpose of this paper is to present the many different fast tracked HDD design and installation case studies, their constraints and challenges, lessons learned, and the practical design principles used on this project that can be applied to other HDD projects.

Properly functioning isolation valves are the backbone to any transmission system. Due to a variety of reasons, the City of Houston (City) has historically relied on butterfly valves to isolate the transmission mains. Although they have a lower initial cost than gate valves, butterfly valves can have operational issues that may render the valve inoperable. These operational issues are easily addressed with a proper specification and awareness of the valve's limitations during its service life. The City of Houston has standardized on the use of large diameter butterfly valves for its water transmission main system. Recently, a rash of valve failures prompted Houston to revisit the design, actuator requirements and field operation procedures in an effort to improve reliability. This paper presents the issues encountered, analyzes the problems with the valves and some specification modifications adopted to enhance the long-term performance of these critical isolation valves. In addition, the paper offers suggested improvements to the field operations to avoid damaging various components of the valve. Also presented is the City's recently implemented valve exercise program intended to address some of the problems encountered. As part of this recently adopted exercise program, the results and benefits of the contract will be summarized.

For more than 30 years, pipeliners have been extensively utilized to extend the performance life of our aging pipe systems. As pipe rehabilitation projects are planned and implemented within the scope of maturing asset management strategy, those same asset management principles must become an integral part of the definition of the success or failure of a pipe rehabilitation project. Our experiences with the asset management of aging pipes should be leveraged to guide the asset management planning for our rehabilitated pipes. The following aspects are closely examined: 1) Similarities and differences between direct burial pipes and trenchless rehabilitation pipeliners; 2) The influences of such similarities and differences on the long-term asset management of rehabilitated systems; 3) Foreseeable asset management difficulties that will be encountered with aging rehabilitated systems, as demonstrated by existing applications and research; 4) Design phase controls to overcome such difficulties and improve the long-term asset manageability of rehabilitated pipes. The authors provide additional pipeliner design considerations, quality assurance requirements, and improved performance life and maintenance prediction methods uniquely applicable to pipeliners which will assist in achieving successful and sustainable asset management through pipe rehabilitation. The authors encourage adoption of such practices in the technology selection and design phases of pipe rehabilitation projects so as to permit feasible long-term asset management of rehabilitated systems. For a pipe rehabilitation project to be defined as a success, mere specification of a minimum design-life requirement is insufficient; the long-term asset management needs of the owner also need to be planned for and achieved.

The Board of Supervisors of the San Luis Obispo County Flood Control and Water Conservation District (District) adopted the Final Environmental Impact Report (EIR) for the Nacimiento Water Project (Project) in January 2004, thus providing direction to District staff to begin the design of the raw water conveyance for 15,750 acre-feet per year from Lake Nacimiento located in San Luis Obispo County, California. The District had secured this water right in 1959, and over four decades thereafter, feasibility studies indicated the economical source of water supply for communities within the County was from groundwater; however, the time came when the next economical supply of supplemental water was the surface waters stored behind Nacimiento Dam, and the Project born. The Project consists of 45-miles of pipeline ranging from 36- to 12-inches, three pump stations, and three water storage tanks. The Project's Participants (customers) currently include Paso Robles, Templeton, Atascadero, and San Luis Obispo (Initial Participants) and later were joined by San Luis Obispo County Service Area 10- Zone A. The design phase of the Project began in 2004, and continued through the successful bidding of the Project in the fall of 2007. An "army of consultants" was hired by the District to perform several professional services including design engineering, environmental permitting, right-of-way, and financing. This paper describes the hydraulic design of the Project and related engineering elements of the Project design.

Eastern Municipal Water District (EMWD) encompasses an area of approximately 555 square miles in the western portion of Riverside County as is shown in Figure 1. The water system has 64 pressure zones with five main service areas. CH2M HILL prepared a Water Facilities Master Plan using tools that were custom developed for EMWD, to identify needed improvements from their existing system through ultimate conditions. A hydraulic computer model was validated against SCADA information and field tests. The next step was to identify system deficiencies for supply, storage, and pumping under various demand scenarios. The custom tools were invaluable in completing the analysis as EMWD is a complex system.

Surge modeling is a tool used by engineers and utility owners in determining the surge pressures or transients that may result from routine pump and valve operations. Recent surge modeling work has focused on low and/or negative pressures within water distribution systems and how those occurrences could lead to intrusions. Effective surge modeling is needed in order to determine if the intrusion potential exists and what mitigation is needed to prevent intrusions. This work focuses on the generally unexplored area of using surge models to predict the location and duration of transient induced low and/or negative pressures within complex water distribution systems. The studied system serves 350,000 people in the southeast United States, has 65 MGD of pumping capacity at two treatment plants, over 1500 miles of main and 12 storage tanks. This work focuses on the correlation between field data and the surge model using the author's operational knowledge of the system, access to realtime SCADA data, and different celerity (or `wave speed') values. This work traces the steps taken by the author to locate areas within the system that experienced transient induced low and/or negative pressure. Additional work was done to estimate the experimental error in field measurements of celerity using commercially available equipment, and to examine methods for reducing this error.

This paper describes the challenges faced when constructing 600m of strategic pipeline on the Isle of Wight through an area of active landslip. The project comprised a new 150mm diameter, 3km pipeline through fields and public highway connecting to the existing distribution network and a new booster pumping station. The geology of the island is quite complex, with many known areas of landslipping on the south coast. The available route for the pipeline was such that there was no alternative but to construct the pipeline for part of its length through an area of landslips. The slip planes are approximately 3m below ground surface, with a predicted movement of approximately 10mm per year. The final solution was to hang a welded pipeline down the slope, and embed it in expanded polystyrene balls. This was done to ensure that any future slippages didn't place high loads onto the pipeline.

Many cities in the Former Soviet Union have made extensive use of steel pipe for water, sewer and district heating services. During the Soviet era bare steel pipe was often delivered to construction sites, despite engineering designs and Soviet standards that called for lined and coated pipe. Local utilities had two choices - reject the pipe and do without needed replacements and additions, or use the pipe and accept the inevitable short service lives. In one of those cities - Atyrau, Kazakhstan - the average life of water distribution pipe was five years. Water losses were 50 percent. The average lives of raw water supply lines, steel sewer lines, and district heating lines were also on the order of 6 to 10 years. Piping systems were failing throughout the city. Customers either could not or would not pay for service. (Official unemployment exceeded 30 percent.) There was no money to replace the failing pipes. And, at the rate pipes were failing, the water and sewerage utilities were in a death spiral. Working with USAID, USTDA, the World Bank, and the Government of Kazakhstan, the author introduced HDPE pipe to Kazakhstan, helped obtain funding, introduced local government officials to international funding mechanisms, competitive bidding and transparency requirements, and led an American-Kazakhstani engineering team in the design of 27,540 meters (90,360 feet) of HDPE water and sewer lines ranging from 80 millimeters (3.15 inches) to 800 millimeters (31.5 inches) in diameter. The project led to the successful establishment of an HDPE pipe manufacturing facility in Atyrau and acceptance of HDPE pipe as a viable material in Kazakhstan.

The Transient Analysis Task Committee has been formed to create a manual of practice for the application of hydraulic transient modeling in the design of transmission pipelines. At present, there is no stand alone manual of practice in the civil engineering profession that advises the Owner and Engineer on the basics of transient analysis, the control of transients in transmission pipelines, and the management of transient modeling tasks during design. The core content of the proposed manual will be an update of the surge control section of Pressure Pipe Design for Water and Wastewater published by ASCE in 1992. New sections will be added to address planning level activities for locating control facilities and selecting profiles that are more conducive to surge control. Advances in control strategy will also be included. The committee will develop guidelines to use for the qualification of modelers, career mentoring, and quality control. The experience of Owner's engineers with various approaches to transient control will be gathered and the results will be published in the manual of practice as case histories. The work of the committee began in July 2008, with the goal of having a full draft for review by August 2009.

Described is LADAR-based system for measuring Ovality and Deflection. The system is unique in that it employs a three dimensional scanning technique that is robust to imaging geometry. More specifically, the system is able to produce accurate cross-sectional analysis even where there is a large divergence of the imaging axis with the central pipe axis. This capability becomes increasingly critical as the diameter of the host pipe increases. In large diameter pipe, even small divergence angles can result in significant diametric measurement errors. Results from inspection of nearly 25,000 linear feet of newly constructed 30, 36, and 42 inch Centrifugally Cast - Glass Fiber Pipe (CC-GFP) by the aforementioned system are presented. True cross-sections extracted from the 3-D point cloud data identified five segments that exceeded the 5% deflection limitation for CC-GFP pipe 30 days after installation. Measurements were verified by direct manual and laser line measurement and found to be accurate to within 1/16 of an inch. More importantly, the ability of the Laser Radar (LADAR) system to quantify the deformations was an important aspect in the repair strategy and ultimately led to design changes that will improve the operational life of the installed pipeline.

Calleguas Municipal Water District is the major wholesaler of potable water in Ventura County, California. Calleguas annually supplies about 120,000 acre-feet of imported State Project Water to its purveyors through Calleguas' 150 miles of transmission pipelines, which range in size from 24 inches to 78 inches in diameter. The bulk of Calleguas' conveyance system is cement mortar lined and coated (CML&C) welded steel pipe (AWWA C200), bar-wrapped steel cylinder concrete pressure pipe (AWWA C303), and prestressed concrete cylinder pipe (PCCP, AWWA C304). Much of the PCCP has been repaired or relined due to failures of the prestressing wires. Calleguas has never used any large diameter plastic pipe in its potable water system, although it has used 12- to 16-inch PVC (AWWA C905) in recycled water systems. In 2002, Calleguas began construction of a Salinity Management Pipeline ("SMP"; then called a Brine Line) for the transport of salty and brackish water from groundwater treatment plants, wastewater treatment plants, and other sources to a future outfall in the Pacific Ocean. Because of the high levels of chlorides and sulfates in the water, Calleguas and its engineers were concerned about using their preferred pipe material—CML&C welded steel pipe—due to the possibility that high chlorides would leach through and degrade the cement mortar lining and lead to corrosion of the steel pipe. As such, Calleguas considered plastic pipe for the initial stages of the project: 54-inch high-density polyethylene pipe (HDPE, AWWA C906) for about 21,000 feet, and then 48-inch PVC (AWWA C905) for the next 12,600 feet of pipe. During construction of those initial phases, Calleguas experienced ongoing problems with the large-diameter plastic pipe, ranging from construction issues to manufacturing and fabrication issues. These problems were exacerbated by a lack of clarity in some of the industry standards. This paper describes Calleguas' specific experiences with using large-diameter plastic pipe. It discusses the reasons why Calleguas decided to pursue plastic pipe for the SMP, particularly given Calleguas' historically good experiences using steel pipe. It discusses the specific problems that Calleguas encountered, and the ongoing concerns Calleguas has with plastic pipe. Finally, it will discuss the direction Calleguas will take for the remainder of the SMP project, and why Calleguas is returning to CML&C steel pipe.

This paper will address that the mathematics of helix, including the calculus derivation of a curve length in space to determine the length of a helix in one revolution; this derivation demonstrates the length of spiral seam per unit length of pipe, and provides the basis for other geometric relationships that include the pipe diameter, coil width, coil splice and helix or spiral seam angle. The paper will also present pressure vessel derivations for principal hoop and longitudinal stress including the Barlow and PA (pressure-area) formulas. From engineering mechanics of materials, knowing the stresses on a solid body under rotation, stresses on spiral weld seams and coil splices can be calculated. The results of this investigation provide for an interesting discussion because they indicate that spiral weld seam stress is typically very low compared with the hoop stress of a pipeline.

There have been numerous papers involving failures of welded lap joints on steel pipe. The most common lap joint failures referenced include Denver Water's Conduit No. 27 and the City of Atlanta's 72-inch diameter pipeline. There were numerous problems with both pipelines. The authors will list the items that were common in both the Atlanta problem and Denver Water's failures. It is the authors' opinion that not one of the problems led to the failures but a combination of conditions led to the failures. This paper will look at the changes in steel making and how these process changes alleviate some of the problems involved with lap joint pipe. This paper will also go through the steps taken in AWWA Standards to prevent, with proper safeguards, the occurrence of future failures of the type and magnitude of the reported failures. These safeguards include engineering procedures, manufacturing restrictions, and installation STET procedures. Finally the paper will make recommendations on how to write a specification to help prevent failures of this type.

Low density cellular concrete grout (LDCCG) has been used as a filler material in the annulus space between the steel final liner and the initial tunnel support. LDCCG is a mix of cement, fly ash grout, and a foaming agent and was investigated to characterize corrosion behavior of embedded steel by determining the permeability of four different cellular grout mixes, and compared to a standard grout, to chloride penetration. Four mixes of cellular grout (Mix 3, Mix 10, Mix 10+Inhibitor and Mix 11)and one standard grout were tested using two experiments: pressurized with representation chlorides to service conditions (Pressurized Test) and ambient pressure with elevated chlorides (Ambient Test). The Pressurized Test was conducted at a pressure of 50 psig with 3,000 mg/kg (ppm) chloride solution. The Ambient Test was conducted at ambient pressure with 50,000 ppm chloride solution. The Pressurized Test results indicate that higher water-cement ratio LDCCG Mix-10, Mix-10+Inhibitor, and Mix- 11 are more prone to chloride penetration due largely to permeation while lower water-cement ratio grouts such as Mix-3 and Standard Grout are more resistant to chloride penetration due to permeation. The Ambient Test indicated chloride transport, largely due to diffusion, was greatest in LDCCG Mix-10, Mix-10+Inhibitor, and Mix-11 followed by Mix-3 and Standard Grout. The electrochemical corrosion potential (ECP) measurements for the embedded steel electrical resistance (ER) probes exposed in the Ambient Test indicated that Mix-10, Mix-10+Inhibitor, and Mix-3 were below the ASTM C876 potential of-350 mV v. CSE, indicating active corrosion. Mix-11 and Standard Grout initially follows the same trend, but recovers (repassivates) after approximately 45 days of exposure. The electrical resistance (ER) readings did not provide statistically significant and measurable corrosion since general corrosion rates were low. The linear polarization resistance (LPR) measurements indicate low corrosion damage accumulations. Based on the electrochemical measurements, Standard grout provided the most corrosion protection followed by LDCCG Mix-11, Mix-10+Inhibitor, Mix- 10, and Mix-3.

This paper summarizes the performance of water and gas piping systems during the six past earthquakes in four different countries: US (1906 San Francisco; 1989 Loma Prieta; 1994 Northridge), Japan (1995 Great Hanshin-Awaji (Kobe)), Thailand (2005) and Columbia (1999). Also, the paper will present data from the UK and Sweden about the performance of pipes in non-earthquake environments. The paper will assist design engineers and owners in selecting pipe materials based on past performance and recommendations from AWWA and ASCE.

Linear projects confront unique permitting challenges due to the need for concurrent approvals across jurisdictions with differing requirements. Regulatory requirements present scheduling and design constraints that can create project risk and require design changes and construction delays that can ultimately jeopardize on-time project delivery. The City of Aurora's Prairie Waters Project, designed to deliver up to 10,000 acrefeet of raw water for water purification annually by 2010, requires multi-jurisdictional coordination and many approvals. The Project case study provides insight to key elements critical for successful regulatory coordination and approvals and gives essential steps necessary for avoiding pitfalls associated with regulatory constraints. By integrating reliable planning strategies into initial design process and throughout design and construction, project owners can reduce risk and avoid unexpected costs, re-work and delays. Identification of land use and regulatory constraints, costs, and schedules during the preliminary design phase is fundamental. Subsequent communication and relationship building with regulatory staff is vital during final design. The permitting process for large linear projects often falls outside of agencies' standard review processes. Applicants should be prepared to collaborate with regulatory agencies to effectively provide relevant information to assist in agency review of the project. Applicants face a shifting landscape of requirements given agency staff turnover, updates to ordinances, and organizational changes. Applicants can expect differing levels of sophistication, divergent requirements, and varied approaches not only from each agency having jurisdiction, but within separate departments of the same agency. Even minor changes in project design or alignment can impact regulatory approvals. This paper summarizes the challenges of streamlining regulatory review processes and the techniques used to enable the Prairie Waters Project to meet an aggressive schedule.

Risk is commonly defined as the product of the likelihood of an event and the consequences should that event occur. The economic risk that must be weighed by electric utilities in evaluating repair and replacement options for circulating water system piping is significantly different from other industries. Energy generation facilities depend on circulating water as a critical component of plant operations. Circulating water piping systems for existing generation facilities were generally constructed without redundancy, so evaluation or repair of the pipelines likely requires a costly generation outage. Additionally, the failure of a pipe section may result in an unplanned generation outage. Although the likelihood of a system failure is low for generation facilities, the consequences of disrupting plant operations are substantial. This paper describes the unique factors that affect the circulating water pipe repair/replacement decision process for the energy generation industry, with an emphasis on the evaluation of economic risk. A case history of Great River Energy's (GRE) decision to replace a portion of a 96-inch- to 120-inch-diameter prestressed concrete cylinder pipe (PCCP) circulating water pipeline at Coal Creek Station is also presented.

The number of water utilities implementing asset management systems and spatial databases is growing, and vast amounts of data are accumulating at these utilities. One of the challenges faced within this community is developing a methodology to evaluate and manage risks to heterogeneous pipeline systems in the face of aging infrastructure and limited budgets. Predicted budget shortfalls for the United States for water utilities over the next twenty years exceed $500 billion. Allocating resources to increase infrastructure stability under these challenging conditions highlights the importance of increasing the return on investment of any expenditure. A spatial risk analysis methodology, derived from the oil and gas pipeline industry integrity management programs, can be used to evaluate risks to the integrity of water pipeline systems, increasing the return on investment for asset management and GIS data collection. The risk methodology can incorporate diverse data sources to provide a quantitative analysis of the probability and consequences of a failure. The method uses dynamic segmentation to incorporate information from linear events, such as pipe attributes, and geospatial data, such as soils data, into a customizable risk algorithm. In addition to evaluating the risk of water line breaks with regard to the assets of the water utility, the methodology can also incorporate the impact of failures on the surrounding community, whether that be due to overland flow resulting in damages, loss of service, or other consequences. This risk methodology can be used to provide a quantitative guide for investment in future inspections, pipe replacement or repair, changes in security measures, and other mitigation activities to reduce the risks to the utility and community of water line failures. A case study will be presented, demonstrating the use of this methodology to evaluate the condition of a water utility pipeline.

The East Bay Municipal Utility District (EBMUD) relies on three (3) large aqueducts, known as the Mokelumne Aqueducts, crossing the Sacramento-San Joaquin Delta (the Delta) to convey over 90% of its water supply from its source in the foothills of the Sierra Nevada Mountains to its 1,300,000 water users on the east side of San Francisco Bay. EBMUD has interconnections with the San Francisco Public Utilities Commission and the Contra Costa Water District, making the aqueducts a linchpin in an increasingly integrated regional water system. The Delta is a large area of interconnected waterways surrounding numerous "islands" that are all below sea level. These "islands" are protected by fragile levees up to 100 years old, many constructed without the benefit of current engineering practices. EBMUD decided to evaluate its levees due to: 1) increased vulnerability to island flooding due to sea level rise; 2) increased flows in adjacent rivers and sloughs resulting from climate changes, 3) island consolidation due to oxidation of the underlying peat soils, and; 4) recently recognized seismicity from newly documented faults. This evaluation was made to better understand the reliability of its aqueducts through the Delta and to develop possible long-term mitigation strategies for the risks identified. The evaluation was done in response to, and concurrently with, the State of California's Delta Vision and Delta Risk Management process (DRMS). The recommendations of the Delta Vision and DRMS process will have a significant part in determining the future of the Delta as a whole and may or may not have a positive effect on the security of EBMUD's water conveyance system.

The prediction of the remaining lifetime of existing pipelines is a critical aspect of any long-term asset management program and the programming as well as prioritization of the maintenance and repair activities. The Pipe Risk Management System (PRMS) is method developed for lifetime prediction for the Great Manmade River Authority, in Libya. The Tucson Water Department, in Arizona implemented a revised version of the PRMS. The method utilizes several inputs for the purposes of predicting the remaining lifetime including: structural modeling, finite element analysis, operating environment and conditions, chemical analysis, and corrosion algorithms. The model also utilizes visual inspection information, NDT verification from Electromagnetic Inspections and Structural Health Monitoring via an acoustic monitoring of PCCP for Wire breaks to measure the accuracy and uncertainty of the empirical methods. The system has now been in use for multiple years and substantial feedback has been received from the users. This paper will present the lessons learned and the improvements made to the application such as: the GIS representation, calculation model refinement, and the link to additional systems. Finally the expansion of the system to new pipe types such as Steel, DIP, and CIP will be discussed.

East Bay Municipal Utility District (EBMUD) is a water utility providing water to 1.3 million people in the Oakland Bay Area. EBMUD's main source of water is the Mokelumne River watershed in the Sierra foothills, located about 90 miles northeast of the San Francisco East Bay Area. The aqueduct system that transports water to the service area consists of three large diameter steel pipelines of 65", 67", and 87", built in 1929, 1949, and 1963, respectively. These pipelines are a critical component of EBMUD's water system and the State of California's (State) overall water infrastructure. Approximately 15 miles of the aqueduct runs across the fragile Sacramento-San Joaquin Delta (Delta) area through 5 islands that are approximately 5 to 15 feet below mean sea level. This Delta crossing consists of approximately 4.5 miles of buried pipeline, 10 miles of elevated pipeline, and 3 major river crossings with about 0.5 miles of submerged pipeline. The Delta has approximately 1,100 miles of levees, many of significant height (up to 25 feet), which continuously impound sloughs and river waters and protect agriculture and urban areas within islands and tracts. The islands' floor in the central and western Delta is below sea level by up to 20 feet as a result of subsidence from farming of organic and peaty soils. There have been 166 levee failures leading to island inundations since 1900. The State is conducting studies on the Delta region as part of their Delta Risk Management Strategy (DRMS) project. As a part of the State's studies, all potential hazards from flooding and seismicity were identified and quantified and potential impacts and risks to the Delta levees were evaluated and quantified. Both flooding and seismicity fragility curves were developed for the Delta region on a Delta reach-by-reach basis. Geographic Information Systems were used to identify the hazard by levee reach.

Of the many pipeline accident causes that occur to oil and gas pipelines, approximately 80% of all the accidents are caused by impacts (mechanical damage) to the pipeline from a digging or excavation activity. The pipeline industry indicates that clearly half of the accidents are caused due to incursion of excavating activities into the buried pipeline right of way and the excavator did not notify the pipeline company or the One Call System of the intent to conduct the excavation activity. In addition, the potential for mechanical damage to be inflicted to pipelines located in or near urban expansion areas has become a major concern for the pipeline owner/operators and government regulators charged with the safety of the community. Recent technical advances have resulted in the development of the General Electric ThreatScan system, which relies on acoustic waves traveling through the natural gas medium pipelines. However, installation and maintenance of such systems are expensive. Other security surveillance technologies also lack some critical advantages for this application, namely, cost effectiveness and sufficiently long working life. Indeed, most existing technologies such as aerial surveillance using automated drones, video cameras and infrared detectors cannot work continuously on battery for more than a few days/weeks. Therefore, low cost, long-life, self monitoring sensors are desirable for localized installation and monitoring of pipeline right-of-way.

Drinking water is the most essential basic need for humans. Many aid agencies practice drinking water interventions to try to improve the aviailability of clean drinking water. Yet the provision of drinking water alone does not necessarily empower community development unless it is partnered with appropriate health and hygiene education programs wherein the participants are taught to maintain the purity of the water through appropriate handwashing and other water use practices. Further, sanitation facilities where drinking water is separated from human and animal waste are necessary to optimize the benefits resulting in the provision and use of clean drinking water. Sustainability is another critical part of a successful intervention. Building a truly self-sustaining drinking water source requires an intervention strategy, a financial support and management structure, a local support/back-up system that includes a local private sector that functions to provide spare parts, a local government that can resolve conflicts, and a local Non-Governmental Organization (NGO) that can retrain communities once interventions have ended. Finally, sustainability includes a pre-planned exit strategy wherein the aid organization steps back from the intervention and no longer needs to take an active role in the operation, maintenance and repair of the facility. Without sustainability, drinking water interventions are not sufficiently long term to effect the behavioral changes required for community empowerment.

This paper describes in detail the challenges faced by the project team during the inspection and refurbishment of the Thirlmere Aqueduct. This raw water aqueduct is a prime example of Victorian engineering at its best and supplies up to 250 million litres of raw water per day to United Utilities' Lostock Water Treatment Works for treatment and the provision of potable water to over 1 million people in Manchester. For the first time in over 50 years the entire length of the Thirlmere Aqueduct has been drained for inspection and essential maintenance.

The recent trend to privatization coupled with a new requirement to report tangible capital assets on annual government statements has focused the need for an understanding of the impact of valuation method and performance prediction models on network asset valuation. Asset valuation holds great promise as a readily understood performance measure and, as an asset management integration mechanism for trade-off analysis between competing components (water, wastewater etc.). However, there is no framework available to guide engineers in the selection of which valuation method to use for which asset category. To comply with Government Accounting Standards Board's Statement-34 (GASB 34) requirements, governments must report the value of their infrastructures' assets by using a depreciation method or a modified approach method. However, including these two methods, most existing valuation approaches do not properly account for the change of assets' conditions and time-value of money. This may lead to absurd asset value especially for infrastructures that have significantly longer service life than other capital assets. This paper presents an asset valuation model, combined with Markov chain-based, condition prediction and regression-based, price index prediction to capture the change of asset condition and time value of money. The model will not only assist in predicting the future value of the asset but also play an important role in constructing the optimal R&R policies and the timing of their application.

President-Elect Barak Obama pledged public works on a vast scale as reported by the press on December 6, 2008. While this is most welcome by all of us in the pipeline industry, there would never be enough public funds to meet all of our pipelines needs. Therefore, what can we do to attract more private funds into our industry? As engineers dealing with pipelines, we need to understand that about 75% of the budget of designing, constructing and managing either a water or wastewater utility is in the pipe networks. Mere 25% is in treatment plants, yet many investors feel that most advances in technology have been on the treatment side of the business. Investors also feel that the network side of the business has remained impervious to change: they work in much the same way as they did when they were first laid out 200 years ago. The author disagrees to a certain degree. This paper provides an overview on how far we have come in networks, in what way we will be forced to change even more in the way we design, build, renovate, and manage networks, how private equity entering the water and wastewater sector when combined with the right new technology will enhance our ability to do far more with less, and how the best is yet to unfold. The author also provides valuable insights into where the growth opportunities are in the water and wastewater sector. This paper provides many news ideas on how we can make matches between the owners of utilities with over $ 1 trillion needing to renovate aging pipe networks and private equity funds formed of the pension investments from the baby boomers, in the amount of $ 1 trillion looking for worthy projects to fund.

The San Diego County Water Authority (SDCWA) Water Resources Department has undertaken a number of planning studies involving the SDCWA system pipelines and facilities to further define priority projects for their Capital Improvement Program. The objective of the studies is to assure that specific project goals can be fulfilled by evaluating alternatives in a comprehensive manner at the feasibility level. The planning effort entails creating realistic conceptual level layouts, cost estimates, and schedules for development within the next phases of the project. Internal stakeholders are included in the process in order to address the interests of various SDCWA departments. The first planning study that utilized the comprehensive alternatives approach was the Lake Murray Control Valve (LMCV) study, a project that determined the preferred location and configuration for a new flow control facility. Using the comprehensive approach, it was found that environmental and permitting schedule impacts, coupled with operational hydraulic transient issues, controlled the selection of a recommended alternative.

As the world's pipeline infrastructure continues to age and the demand for product delivery continues to grow, every utility has been required to make decisions about the condition and adequacy of their existing pipeline systems. When utilities find that the existing systems do not have adequate capacity or have become too costly or risky to operate to meet future needs, many times replacement is the only solution. As systems are being replaced, everyone is looking to reduce up-front capital, operational, and maintenance cost through detailed design. However, there are unconsidered environmental costs associated with these financial savings. This paper uses a Life Cycle Cost (LCC) approach to address the pros and cons of using Polyvinyl Chloride (PVC) or Ductile Iron (DI) pipeline material in design. The study considers the project life cycle and how each life cycle phase is impacted by standardized design approaches. For each pipeline material, the following life cycle phases have been evaluated: material production and pipeline fabrication, material transport, life cycle usage, and end of life. Each phase has been evaluated for both economic and environmental impacts. The results of this particular case study are directly impacted by the applicable design standards for the each pipeline materials. In this design example, the PVC pipeline internal diameter was significantly less than the DI pipeline internal diameter. This design consideration made the DI pipeline material hydraulically more efficient, which over the life cycle, made the DI pipeline the most fiscally and ecologically attractive alternative. This study demonstrates that specific design standards and specific system design characteristics (flow rate, pressure requirements) influence the LCC and total CO₂ emissions. The conclusion of this study demonstrates that a complete pipeline design should be considered in the LCC approach before a decision is made on what material is used in design.

North Cornwall Township (North Cornwall) is a growing municipality in central Pennsylvania. North Cornwall is responsible for the operation and maintenance of the Dairy Road Pumping Station (PS) which conveys wastewater flows originating from four separate municipalities to the City of Lebanon wastewater treatment plant (WWTP). Wastewater flow is conveyed from the Dairy Road PS via a combined force main which serves both the Dairy Road PS and the nearby Cleona Boulevard PS. Although the Cleona Boulevard PS is operated by a neighboring municipality, North Cornwall is responsible for the maintenance of the combined section of the force main as a stipulation of an intermunicipal agreement. The combined section of the force main consists of approximately 2,000 feet of 14-inch diameter ductile iron pipe. Since July 2004, the pipe has sustained five (5) breaks within the combined section. As the result of two breaks in March 2007, North Cornwall initiated design to replace the force main. Testing completed on excavated pieces of the force main indicated that the pipe was deteriorating from both the inside and the outside due to the corrosive composition of the local soils. During the preliminary stages of the design, numerous technical and political issues were encountered. Three significant issues encountered were sizing the force main, choosing the preferred replacement alternative, and cost sharing. Developing flow projections for the new force main involved multiple meetings between the four municipalities and involved legal interpretation of the numerous intermunicipal agreements. Two primary alternatives were established; replacement of the force main with a similar alignment, and separate the stations utilizing two parallel force mains. Two municipalities preferred the separation alternative to; however, this alternative had significantly higher costs. The other two municipalities preferred the less expensive alternative of a new combined force main. Value engineering, to reduce the estimated cost of the parallel force main alternative, included evaluation, of trenchless lining of the existing pipe to serve as one of the parallel lines.

The City of Baton Rouge, Parish of East Baton Rouge (C-P) entered into a Consent Decree with the United States Environmental Protection Agency (EPA) and the State of Louisiana in 2001 to take remedial actions in their collection system to reduce sanitary sewer overflows (SSOs) by 31 December 2014. In response to the Consent Decree the C-P developed the Baton Rouge Sanitary Sewer Overflow (BTRSSO) Program. The purpose of the BTRSSO Program is to reduce SSOs while planning for future flows. In 2006, the C-P contracted with CH2M HILL to manage the BTRSSO Program. Planning was necessary to meet the goals of the Consent Decree and the 2014 deadline. CH2M HILL developed the Program Project Delivery Plan (PDP). The PDP provides a summary of the SSO and Wastewater Facilities Program. The three parts of the program are: comprehensive rehabilitation projects; capacity improvement projects; wastewater treatment and storage improvements.

In the City of Houston (City), a proposed light rail transit system coincides with an existing drinking water transmission pipeline in one of the City's most densely populated areas. The density of the area makes it attractive for transit and this transmission main serves as a 66-inch surface water refill line to a major regional re-pump station. In many cases, the proposed alignment for the light rail, or supports for the overhead catenary system, is (are) directly atop the 66-inch waterline, in some cases, less than five feet above the waterline. The City and the transit entity want to assess the condition of the existing waterline prior to light rail construction. Right-of-way, maintenance, and other agreements between stakeholders encourage the installation of an acoustic monitoring system as well. The monitoring should detect and provide early warning for any potential construction or operational impacts of the light rail. In order to perform the condition assessment and prepare the pipe for monitoring, the 66-inch waterline would have to be shut down. Approximately half the City would be affected by catastrophic failure of the 66-inch line. Creative solutions are needed to maintain water service for complete and constructional shut downs of the 66-inch water line. Hydraulic modeling is done to find and evaluate other alternatives to supply the southwestern region of the water system. With accelerated construction schedules, hydraulic modeling is critical to formulate feasible solutions. Options examined include existing groundwater plants, modifying groundwater plants to work as surface water re-pump stations, adding system grid extensions and interconnects, and reversing flow in other, large transmission mains.

The goal of this project was to determine the value of the system currently serving the Little Rock Wastewater service area (including wastewater treatment facilities, pump stations and the collection system) to demonstrate asset stewardship. Financial planning efforts include, among other things, assessing appropriate fees and charges while strategic planning efforts include, among other things, communication with the community with respect to the value of water. The initial review of LRW asset types included review of data to produce an inventory of LRW's asset base. RFC/MWH defined what assets are being valued and identified the appropriate methodologies to be used. Methodologies relevant for calculating value include Original Cost Less Depreciation (OCLD), Depreciated Reproduction Cost (DRproC), Depreciated Replacement Cost (DRplaC), and Optimized Depreciated Replacement Cost (ODRC). The methodology selected for LRW was the DRplaC approach, which relies primarily on replacement cost and depreciation or the Modified Asset Approach, where: Total Replacement Cost – Depreciation = Replacement Cost New Less Depreciation (RCNLD) The project also included a comprehensive review of best asset management practices; this included a collection of case studies, and capabilities assessment for LRW to determine how well they are positioned to meet their asset management goals and objectives. This was a good complement to the valuation study as the data that was available ties in well with many of the activities that LRW is considering for example, risk-based renewal forecasting.

Balance is necessary to make pipeline projects successful while addressing important sustainability issues. Equipoise among economic, social, and environmental needs must be achieved to realize optimal Triple Bottom Line benefits. Even with effective efficiency and conservation efforts in place, communities' requirements for sustainable and high quality water supplies continue to grow in response to population growth, climate change, etc. This demand has led to a growing need for conveyance projects. These important projects help to satisfy economic, social, and environmental needs in the communities they serve and to harden their water supplies against drought, climate change, etc. However, these projects must carefully satisfy these needs in the face of other competing interests. This balance is possible through careful and pertinent planning, design, and communication that address resource utilization, conservation, and efficiency; environmental impacts; economic considerations; and social needs while meeting expectations of the vast stakeholder interests that are invested in the areas where pipelines pass and from where they draw their resources. Structured decision-making approaches and tools can optimize these efforts.

PressureCast Steel Pipe utilizes a new (patent pending) manufacturing and design process that allows higher design stress levels in mortar- or concrete-lined steel cylinders while providing a pipe that is much more rugged and less expensive to install when compared to ordinary steel pipe. This paper presents the laboratory and full-scale material and manufacturing testing accomplished to verify the design performance of PressureCast^TM Steel Pipe.

Ideally, long range financial plans should be completed approximately every five years. It is difficult to accurately predict factors such as inflation, customer base, exact capital needs and general economic conditions more than five years out. Therefore, even if long range planning efforts span over 10 years, the long range plan is often obsolete after a few years. Long range financial planning is a process which involves several steps as shown in Figure 1. First, a facility master plan is required to ascertain the extent of facilities required for expansion, upgrade and rehabilitation of a utility. Usually master plans extend over a 20 or 30-year period and contain much more than the near term (5 or so years) capital facilities needed.

Characterizing the condition of buried infrastructure for wastewater system is an important aspect for our environment. This paper presents a better methodology to predict the condition of buried infrastructure and subsequently plan for the necessary repairs to rehabilitate the city's sanitary system. This research compares existing condition assessment grading systems used by the industry. The proposed approach will benefit municipalities by identifying critical reaches of buried infrastructure, therefore reducing the number of inspections, and as a result, reducing emergency repair and rehabilitation by planning expenditures in advance.

The City of Los Angeles (The City), as part of its $4.5 billion, 10-year Wastewater Capital Improvement Program, is executing rehabilitation of one of its largest and oldest sewers, namely Central Outfall Sewer (COS). The City's Bureau of Engineering (BOE) in the Department of Public Works (DPW) is the group within the City responsible for planning, designing and construction of its wastewater collection system projects. The COS is a non-circular (60 inch x 73 inch oval) brick sewer that was constructed in 1908. After more than century of service, recent condition assessments indicated that COS has experienced severe corrosion and in some locations, moderate to severe brick loss.

The Orange Water and Sewer Authority (OWASA), located in Carrboro, NC and serving the Towns of Chapel Hill and Carrboro, and the University of North Carolina at Chapel Hill, maintains a proactive program for rehabilitating and/or replacing water lines in the service area. The water system contains approximately 340 miles of pipe ranging in size from 2-inch to 24-inch, with varying age, material, soil conditions, land use, and customer types. Previously, in a given year, as much as 5% of the system has been targeted for replacement. Staff had used performance (recent breaks and leaks) and pipe material (e.g., a goal to replace asbestos cement pipe) as the primary criteria for selecting and developing rehabilitation and replacement projects. OWASA wanted to improve upon the traditional approach to the selection of water line rehabilitation and replacement, by prioritizing projects in the service area and more efficiently planning the Capital Improvements Budget (CIB). OWASA retained the professional services of AECOM to develop a dynamic model in Microsoft Access that prioritizes water lines needing replacement. The model input consists of physical data on the distribution system, and service level criteria based on industry and local standards. To insure the highest quality input possible, OWASA and AECOM worked together to: 1) develop an accurate system wide inventory. 2) establish service levels and performance criteria for individual water mains. 3) ensure "buy-in" by stakeholders on the water main prioritization criteria. Through these efforts, an "OWASA specific" dynamic water main prioritization model was created, and has been consistently used for planning the fiscal year CIB, since 2004.

The Trinity River Authority of Texas (TRA) provides water supply and wastewater collection and treatment in 17 counties along the 18,000-square mile Trinity River basin. TRA's operations are divided into the Northern Region and the Southern Region. TRA is a political subdivision charged by legislative mandate with three functions. These include maintenance of a Master Plan for basin-wide development, serving as the local sponsor for federal water projects and providing services authorized by the Texas Legislature within TRA's defined territory. Public services currently provided by TRA include wastewater treatment, water treatment, and recreation and reservoir facilities. TRA also serves as a conduit for tax-exempt financing for municipal water and wastewater facilities and industrial air and water pollution control facilities.

In light of the subsidence issues and mandates in Harris County, the City of Houston (City) has been converting its single pressure plane distributed groundwater system to a surface water system. The City's primary sources of surface water are located on the eastern side of the City. In addition to new re-pressurization facilities to send the water westward, some significant groundwater pump stations are being converted to surface water repump stations. The Bellaire Braes pump station is one such facility currently pumping approximately 14 MGD of groundwater to customers in a roughly 70 square mile area on the City's western limits—nearly 9 miles from another re-pressurization facility and over 24 miles from the surface water purification plant. In addition to existing customers, the City will begin providing an additional 19.5 MGD to a regional water authority. To identify impacts and system modifications needed to convert the Bellaire Braes pump station to a surface water re-pump station, hydraulic modeling was performed. The modeling was performed to analyze the infrastructure modifications required to bring the required flow to Bellaire Braes plant and sustaining adequate local system pressures. Modeling these scenarios was also required to review construction options for improvements to minimize disruption to the system. To re-construct a facility in this way involved significant flow reversal with original transmission mains becoming surface water refill lines and changing existing connections to the system, along with capacity improvements upstream. This paper will present the hydraulic modeling efforts, the challenges and solutions identified as well as proposed system improvements.

Determination and quantification of levels of service in municipal context assist in performing quality-cost trade-off analysis for its services. This trade-off depends on the willingness of a community to pay for municipal services as well as on the condition of municipal assets. This paper presents a simple and generic methodology to develop a level of service model for water distribution networks. In order to develop this Analytical Hierarchy based model, in all nine operational level performance measures are identified. These account for reliability, capacity, and health and safety concerns related to a water network. A hypothetical case study is designed to exemplify the proposed method. Output of the model is in terms of service percentile which is an integrated representation of asset performance to meet user's requirements. This model can assist asset managers in quantifying the improvements required in asset performance and in making more informed decision towards sustainable asset management.

Camp, Dresser, and McKee (CDM) and the San Diego County Water Authority (Water Authority), in collaboration with a number of south San Diego County agencies, investigated the feasibility of a regional concentrate conveyance facility in southern San Diego County to transport brines to ocean discharge. Construction of a regional concentrate conveyance facility could facilitate the development of additional groundwater resources and potentially reduce or eliminate impacts and discharges from current concentrate management practices. This Feasibility Study identified various potential municipal, industrial, and institutional system users and determined their expected contribution to the proposed conveyance system. Preliminary conveyance system alternatives were identified, including pipeline sizes, alignments, and system configuration. Three of the alternatives were evaluated in more detail including development of hydraulic models and cost estimates. For this Feasibility Study, eight decision criteria were identified. The agencies participated in a weighting exercise known as "forced pair comparison" to determine the relative weights of the decision criteria. This comparison was performed for all the possible pairs of criteria, and the results were aggregated using simple algorithms to determine the overall relative importance of every criterion. Institutional issues were also addressed regarding ownership, payment terms, permitting, rate setting, and operation enforcement of a regional concentrate conveyance pipeline.

Management of a project's construction budget cannot be limited to managing the content of its design; consideration must be given to the project's bidding process. Taking a strategic approach to a project's bidding process can significantly increase the success of the management of the project's construction budget. Case history of the bidding of the Nacimiento Water Project proves this point. The Nacimiento Water Project (Project) consists of a sloping multi-port intake facility and pump station, two intermediate pump stations, three storage tanks, control center, and approximately 45 miles of transmission pipeline ranging in diameter from 36-inches to 12-inches, with the goal of delivering 15,750 acre-feet of raw water to communities spread across the County of San Luis Obispo, California. The Project is owned and managed by the San Luis Obispo County Flood Control and Water Conservation District (District) and began its design phase in 2004. In 2007, the engineer's estimate predicted a construction value of $140.5-million; however, bids for the Project, opened in the fall of 2007, resulted in a construction value of $123.8-million. To date, the Project's construction is within budget. This paper discusses the District's bidding of the Project. Specifically, the paper addresses how the District's implementation of bidding strategies such as division of project into contracts, bid timing, contractor outreach, contractor pre-qualification, bid packaging, and bid advertising improved the management of the Project's construction budget and positioned the Project to obtain favorable bids, quality contractors, and a stable budget throughout construction.

In a time when construction costs are out-pacing funding, the predictability of project costs is essential when agencies develop their Capital Improvement Program budgets. This paper will present a systematic plan developed to dissect the components that make up the overall cost of a pipeline project. Various guides will be discussed to improve the accuracy of preliminary estimates while accounting for unique project requirements. Also, this paper will present recommended categories for estimating pipeline projects and typical percentages based on recent bid tabulations.

The City of Garland, Texas, approached Freese and Nichols, Inc. (FNI), about a design for a new sanitary sewer trunk line in the City's ROWL-1 Sub-basin. The existing line is at its capacity and needs to be upsized, or paralleled to meet the growing demands of the area. The ROWL-1 Sub-basin includes a large, undeveloped area along a recently completed portion of the George Bush Turnpike, a major highway running through northern Dallas and Collin Counties. A new sewer line is vital to any development occurring in this area. Even though the surrounding areas of this sanitary sewer line were not developed, the project was not going to be easily planned from a design or construction perspective. Unfortunately, the existing trunk main was constructed in Spring Creek, along the flow of the channel. This, along with the existing line being concrete encased, prevented the possibility of an adjacent parallel line, or the use of pipe bursting methods to increase the capacity of the existing trunk line. After further analysis, it was determined to parallel the existing line north of Spring Creek, where the growth and development along the George Bush Turnpike would be more easily accessed. The new line was proposed to be out of the channel, on the north bank and in the flood plain to minimize disruption to developable areas along Spring Creek. This plan produced an entire separate group of issues when it came time to lay out proposed alignments.

PressureCast Steel Pipe utilizes a new (patent pending) manufacturing and design process that allows higher design stress levels in mortar- or concrete-lined steel cylinders while providing a pipe that is much more rugged and less expensive to install when compared to ordinary steel pipe. This paper presents the basic manufacturing concepts and applicability of this pipe to either a flexible or rigid pipe design scenario, such that PressureCast^TM Steel Pipe could be installed in soils with either good soil support or near-fluid soil conditions. Designing PressureCast^TM Steel Pipe to resist corrosive installation conditions is also presented.

The Orlando Utilities Commission (OUC) is a potable water and electric utility that serves the residents of the City of Orlando and unincorporated Orange County in Florida. OUC's primary source for potable water is groundwater. In central Florida, groundwater withdrawals require Consumptive Use Permits (CUP), which are regulated by the St. John's River Water Management District (SJRWMD). The OUC Project RENEW is a regional reuse program that was created to comply with the CUP issued by the SJRWMD in May 2004. The CUP requires OUC to deliver an annual average flow of 8.55 mgd from City of Orlando's CONSERV II Water Reclamation Facility to City of Apopka's Water Reclamation Facility for use by the Cities of Apopka, Winter Garden and possibly Ocoee. In order to deliver this flow, approximately 14 miles of 24-inch diameter reclaimed water transmission main and a new pumping station are required. To comply with the CUP, this new reclaimed water delivery system must be operational by October 8, 2011.

The Trenchless Technology Center, in collaboration with industry associations, has developed comprehensive, yet easy to use interactive software for the evaluation of alternative construction methods that can be employed in the installation and rehabilitation of buried pipes (gravity driven and pressurized) and manhole structures utilized in municipal applications. The decision support software was implemented in an on-line format, so it can be accessed simultaneously by multiple users over the internet via a web-portal named TTWorld. A Social Cost calculator was added to the web-portal to assist users in estimating the social costs associated with the various construction methods. The software is updated regularly to include emerging and evolving technologies and materials, and is available in both, English and Spanish. Future developments will focus on enabling the software to accept input data directly from relational databases associated with commonly used GIS software packages.

The Ingenio Community is located on PR State Road 867 in the municipality of Toa Baja, about 15 miles west of San Juan, Puerto Rico. This community does not have a sanitary sewer collection system and relies on septic tanks which frequently overflow due to the high water table. These overflows pose a hazard to public health and the environment. A new project to construct a sanitary sewer collection system is under design by CH Caribe (CH2M HILL's San Juan, Puerto Rico, office). The Ingenio Sanitary Sewer System project was originally planned to be a gravity system that collected and conveyed sanitary wastewater to a new pump station.