Pipelines 2006: Service to the Owner

The design of hydraulic structures for large water supply systems is crucial to the operations of large diameter pipeline projects. The hydraulic structures are used to control flow rate and surge pressures and in some instances to create pressure drops. The hydraulic design should consider operating conditions, valve flow control capability, potential noise vibrations and cavitation, cost, and reliability. The Eagle Mountain Connection Project for the Tarrant Regional Water District is a 350 MGD water supply system that features several unique hydraulic applications which are essential to the delivery of raw water to TRWD's larger customers. The hydraulic applications to be discussed in this paper are listed as follows, 1) 120 MGD River Outlet Structure with Flow Control Valve, 2) 118 Million Gallon Balancing Reservoir and Bypass Standpipe, and 3) 280 MGD Lake Outlet with Flow Control Valves and Subaqueous Discharge Pipe. The goal is to provide TRWD and their customers with the most flexible, reliable, and cost effective design which will produce the desired objectives. As a result, each structure in this project serves more than one of the following purposes: water storage, outlet structure, surge protection, flow control, and maintenance bypass. This paper covers each application and hydraulic requirements, options evaluated, advantages and disadvantages of each option, and final selection. Lessons learned while investigating and designing each particular application are also discussed. The Eagle Mountain Connection Project is scheduled to be in operation by the end of January 2008. It is anticipated that approximately 18 months years will be needed to mobilize, construct, start up and test the project. The design of the hydraulic structures for the $130-million project is crucial to serving future infrastructure needs of a rapidly growing community.

Damage to pressure pipelines is often attributed to the occurrence of pressure transients and water hammer events, however the corroborating evidence is usually missing due to the impracticality of testing and detecting the occurrence of these events, particularly the water hammer events that accompany cavitations in the pipeline. Water hammer events are difficult to detect because they may occur without warning and have durations of less than 1/20^th of a second. Recent innovations in digital technology have facilitated the development of a system capable of monitoring pipeline pressures in such a way that these most unexpected, short-duration events can be detected and accurately recorded. The paper discusses results of installations of this technology on water transmission lines, liquid petroleum pipeline booster stations, a reverse osmosis plant, water distribution lines, a wastewater treatment plant and a fire suppression sprinkler system.

With the power of Geographic Information Systems (GIS) and the wealth of GIS data available, creating and updating a City's water system model can become a less daunting process. In today's hydraulic modeling software market, several hydraulic modeling packages integrated with GIS currently exist; however, these packages can come with a hefty price tag. With the right resources and a little ingenuity, a City's existing hydraulic model, previously developed using the U.S. Environmental Protection Agency's EPANET, was updated utilizing existing GIS data and ESRI's ArcGIS software. The City of Houston's Geographic Information & Management System (GIMS) daily maintains the City's utility GIS datasets including information on its water infrastructure. Working with a subsection of the water system, LAN pioneered a method to update the existing EPANET model based on the latest GIMS water system data. Part of the project entailed skeletonization of the water system to reduce the dataset to all water lines six inches and larger and development of GIS Geodatabases to manage the various datasets. The project also involved allocation of water demands through use of Thiessen Polygons in GIS.

This paper presents the results of a pressure surge analysis for a 30 km (19 mile) long sewage pipeline in Sacramento, California. Several surge control strategies (e.g., spring-loaded sewage vacuum relief valves, pressurized surge tanks, flywheels, and open surge towers) were developed to eliminate the possibility of vapor pressure conditions within the sewage pipeline following a loss of power to the pump stations. Each surge control strategy was compared on the basis of constructability and cost. The installation of spring-loaded sewage vacuum relief valves on the pipeline were selected as the preferred surge control strategy. In addition to their ease of installation, sewage vacuum relief valves saved approximately $22 million when compared to the costs associated with installing and operating pressurized surge tanks at the pump stations, which was the second most preferred surge control strategy for the sewage pipeline.

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 46 other customers (some direct and some indirect), including more than 1.3 million people in portions of Collin, Dallas, Denton, and Kaufman Counties and all of Rockwall County. Historically, municipal water supplies have been obtained from surface water. However, recent long-range water supply planning efforts have identified significant increases in water demands that must be met through conservation, water treatment plant expansions, and improvements to both the raw water and potable water transmission systems. The District has elected to pursue augmentation of current water supply reservoirs with recycled water by the use of wetlands in which river water is treated and recycled. The East Fork Raw Water Supply Project is designed to transfer water from the East Fork of the Trinity River near Combine in Kaufman County, Texas, to the north end of Lake Lavon near Farmersville in Collin County. This system uses a river intake and diversion pump station to transfer water out of the East Fork and into a constructed wetland. It also uses a conveyance pump station and a 44-mile conveyance pipeline to transfer the water from the wetland to an outfall that discharges into Lake Lavon. The conveyance pipeline's nominal diameter was set at 84 inches to convey flows ranging from 36 to 250 MGD. The focus of this paper is to discuss options considered to optimize the hydraulic performance of the last 5,000 linear feet of the proposed conveyance pipeline while considering impacts to the overall project cost. Constraining factors on the design included variable flow ranges, existing topography (creeks and ridge lines), outfall elevations at Lake Lavon and steep grades upstream of the outfall, long gravity flow sections with high flow velocities, deep trench excavations to minimize partial pipe flow velocity, full-pipe flow for flow metering facilities, impacts to life-cycle costs of adjusting the system high point, and overall construction costs. Options considered to address the many design constraints included lowering the pipeline, weir/drop structures, throttling valves, orifice plates, cast-in-place box culverts, multiple pipe systems, baffle chutes, and various combinations of these options.

The North Harris County Regional Water Authority (Authority) accepted wholesale customer requests to build portions of its 2010 Groundwater Reduction Plan transmission system in 2005. The transmission system will convey groundwater from districts with excess supplies (seller districts) to districts with water quality issues or immediate water supply needs, (buyer districts). The Authority established the Groundwater Transfer Program (GTP) in 2004 and designed and constructed three GTP transmission systems, i.e. the North, South and West Systems, in 2005 and early 2006. This paper discusses how the Authority successfully implemented the GTP. Flow monitoring test data was analyzed and the hourly multipliers for certain districts were combined into either composite residential or mixed land use diurnal curves. The University of Kentucky PIPE2000 computer program was used to run static and extended period simulation models of minimum and maximum GTP operating pressures. Control valve stations equalized the daily and seasonal fluctuations occurring outside the GTP transmission system, i.e., within the district's water systems. Fire hydrant tests indicated that seller districts could meet their contract capacities. For buyer districts' water plants, the opening and closing of solenoid valves at the same time resulted in only minor pressure changes in the GTP transmission system, and the system appears to be robust enough to allow almost instantaneous response to flow changes. Water age may be an issue during periods of low demand. The Authority anticipates its operators will conduct routine tests of potable water quality including the chlorine residual content for disinfection. In addition, the Authority may consider requiring that a buyer district's control switches be set to allow the Authority to provide the prime (or base) water supply to each district with the district groundwater wells serving as a secondary supply.

In early 2005, Santa Clara Valley Water District (District) staff discovered low pressure (∼5 psi, or 35 kPa) groundwater leaking into a RCCP section of 66 in. (168 cm) high pressure pipeline under a major freeway embankment in downtown San Jose. The leak was discovered during an internal eddy current inspection on adjacent PCCP sections of the pipe. Although it had not been detected externally or deemed obvious from modest changes in system flows, leakage from the pipeline during normal operation was a big concern as the pipe operates at 177 psi (1220 kPa). If the leak worsened, it could have undermined the Highway 87 freeway embankment and impacted use of the freeway, caused a major outage in the District water supply system, and posed a major threat to public safety. Investigation showed that the leak occurred in an area under a surcharge embankment, at a joint located between a horizontal and vertical thrust block, where consolidation had been expected and factored into the design. The situation was complicated by construction changes which impacted joint performance; these changes were not adequately recorded on the as-built drawings. Localized deflection/rotation exceeded the design tolerances, leading to a leak at a gasketed joint. External geotechnical investigations showed modest void-space below but not next to the pipeline in this area; it's not clear if these voids were caused solely by consolidation and local pipe movement or by the leakage from the pipe, or a combination of factors. Settlement records strongly suggested that primary settlement due to embankment construction had stabilized. With a basic understanding of the mechanism involved in this failure, staff was able to confidently complete the repairs and put the pipe back into service. Repairs included: installation of flexible Weko-Seals at the two joints of concern; welding of patches on the holes drilled in the 66 in. (168 cm) pipe to investigate the voids; grouting of the voids below the pipe; patching of cement-mortar lining; and installation of a new precast vault for improved access. This experience produced a number of major "lessons learned" which will help District staff and others in the future.

The 37^th Street Water Treatment Plant is one of two water treatment plants owned and operated by the City of Norfolk, Virginia. It was constructed originally in 1920, and serves the citizens in the western half of the city, as well as U.S. Naval Station Norfolk. The treatment plant is served by two 36-inch raw water mains, each approximately 16 to 20 miles long. These mains originate from the City of Norfolk's Western Branch Pumping Station, located in Suffolk, Virginia, and traverse through the cities of Chesapeake, Portsmouth, and into Norfolk. One main, installed originally in the 1920s, includes some of the original reinforced concrete bar-cylinder pipe with lead joints. The other main was installed originally in 1943, and contains large portions of 1940s vintage reinforced concrete (steel) cylinder pipe. Both of these mains have undergone varying degrees of upgrades and repairs during the past 30 to 40 years, including several emergency repairs in recent years. Based on the age(s) of these mains, fear of other future catastrophic failures, and because the two mains are the only sources of water supply to the 37^th Street plant, the City of Norfolk determined it was necessary to conduct a condition assessment of the two pipelines. Since these water mains are located in several cities, and lie within limited right-of-way/easement corridors, it was more prudent and cost effective to conduct a condition assessment of the mains up front, rather than opt for wholesale replacement. The condition assessment helped determine the structural integrity, pressure capacities, and overall condition of the existing water mains, as well as the capability to rehabilitate and/or need to replace these pipelines. It included analysis of the existing conditions of the raw water mains, evaluation of the frequencies of repairs and causes of failure, as well as thorough investigation and inspection of representative segments of each pipeline. This paper will present the components involved in the condition assessment program, including: records research and compilation of data, site selection for field investigations, coordination with neighboring jurisdictions, evaluation and prioritization of pipeline deficiencies, and public outreach, and recommendations for rehabilitation or replacement of the water mains, plus a few of the repair projects currently under design. It will summarize the existing conditions of pipe joints, associated appurtenances, aerial crossings, special structures and other facilities along each pipeline, along with environmental conditions and other factors that will impact the usefulness of these water mains. In addition, this paper will describe the development of a data/document management file system utilizing digital aerial photography, which was used to organize existing as-built record drawings, property and deed information, and other important documents, into a single environment.

Prestressed concrete cylinder pipe (PCCP) often plays an important role in the transmission systems for medium to large utilities. Although PCCP has been a very durable product, a number of sudden catastrophic PCCP failures have occurred throughout the U.S., most of which have stemmed from corrosion and subsequent failure of "Class IV" prestressing wire. Baltimore County, Maryland has implemented a state-of-the-art assessment and management program for a 48-inch PCCP transmission main which feeds water from a major pumping station to a large finished water reservoir. The program consisted of two phases — electromagnetic testing simultaneously with visual inspections for Phase 1 and acoustic monitoring for Phase 2. As a result of the Phase 1 inspections, four pipe sections were identified as requiring immediate replacement before the main could be returned to service. Subsequently, the four pipe sections were dissected as a part of forensic analysis. The actual number of wires broken were compared with those previously predicted using the electromagnetic inspection techniques. The Phase 2 assessment program was modified to incorporate new technology which used "fiber optics" in addition to the planned "acoustic" technology to monitor on-going wire breakage over a 90-day period.

Acoustic monitoring of prestressed concrete cylinder pipe (PCCP) has been used on a number of mains through the United States and overseas as an important asset management and/or condition assessment tool. To date, acoustic monitoring has relied on the application of hydrophones or piezoelectric sensors to continuously monitor the acoustic activity in a pipeline to identify the acoustic event associated with a breaking prestressing wire. Hydrophones and piezoelectric sensors have certain limitations that sometimes make it difficult to implement practical monitoring solutions. Recently, a significant advance was made in acoustic monitoring technology for pipelines through the application of fiber optic sensors and optical data acquisition systems. Fiber optic sensors are long continuous glass fiber sensors that are able to transmit light. To manufacture a fiber optic sensor, the glass fiber is run parallel to another fiber that provides strength to resist tension. Both the fiber optic sensor and the strength member are encased in a protective coating to form the fiber optic sensor. The sensor is run through the pipe and one end is attached to an optical data acquisition with a laser that projects a beam of light through the fiber. Acoustic waves in the water column impart pressure waves on the fiber, which in turn, imparts stress waves on the fiber. When the beam of light encounters a changing stress field in the fiber the light is dynamically reflected. This dynamic reflection of light is returned to and analyzed by the data acquisition system to acoustically monitor the pipeline. Since the data acquisition system is using the entire length of fiber as a channel to transmit light, the entire length of fiber is being used as an acoustic sensor. This has many advantages, including the fact that the sensor will, at most, be one pipe diameter away from the acoustic event of interest (i.e., a wire break). This paper will describe the application of acoustic monitoring of PCCP with fiber optic sensors and detail the capabilities and limitations of this monitoring approach. Further, it will describe the application of the fiber optic monitoring system on a 48 in. pipeline where it was run in parallel with an acoustic monitoring system relying on standard hydrophone technology. A comparison of both techniques will be made based on the results of this project.

Wastewater utilities in Pennsylvania are required to submit an annual Wasteload Management - Chapter 94 Report. The report addresses performance issues related to wastewater treatment plants, pumping stations and sewer collection systems. Metrics utilized in the process include hydraulic wastewater flow quantities treated, organic loadings, industrial waste contributions, pump runtimes, and projected future growth on a five-year basis. Historical five-year wastewater flows and organic loadings are reported. This information is utilized to provide baseline characteristics and performance measures of the system. Baseline metrics are then adjusted using the factors calculated for the five-year projection period. The estimated hydraulic wastewater flows and organic loadings for the future fifth year are ultimately compared to the permitted capacities of the systems. Hydraulic and organic overloads identified during the projection period must be addressed through capital improvement plans, and infiltration and inflow (I/I) reduction programs. Many communities are utilizing asset management and condition assessment to assist in the overall utility management process. The NASSCO Pipeline Assessment and Certification Program (PACP) is a standardized format to evaluate internal television inspections of sewerline assets. Visual defects are identified utilizing key structural and O&M parameters. Standard defect coding is a key component of the program. Collection system assessment through PACP, or other similar methods, can then be recorded and evaluated during the projection period. This paper will compare and contrast the data contained in the annual reporting of various municipal entities in the central Pennsylvania region. Key data contained in the Chapter 94 Reports will be utilized to identify benchmarking opportunities and comparisons between the systems. Typical data that will be evaluated will include collection system cleaning, internal closed-circuit television inspections, hydraulic and organic loadings, equivalent dwelling units (EDUs), pump station runtimes, annual precipitation amounts, collection system extensions and repairs, and flow per EDU calculations.

In December 2004, the Pressure Pipe Inspection Company (PPIC) conducted a nondestructive evaluation of the Prestressed Concrete Cylinder Pipe (PCCP) portion of the Bay Division Pipeline No. 4 for the San Francisco Public Utilities Commission (SFPUC) using its patented Remote Field Eddy Current/Transformer Coupling (RFEC/TC) Technology. The RFEC/TC inspection was conducted over an overall distance of approximately 8.2 miles (13.12 km) and spanned a total of 2,167 inspected pipes. Several sections of the pipeline had a large number of reported wire breaks. After consulting Simpson Gumpertz & Heger Inc. (SGH) regarding the probability of pipe failure, SFPUC proceeded to conduct a simple verification of four pipe sections before making any decisions regarding repairs or replacement. The field verification exercise grew in magnitude as a series of successively more invasive tests failed to verify PPIC's results. Two new test procedures; X-Ray and turn-to-turn resistance measurements were attempted with mixed results. After these tests were complete, SFPUC, on the advice of SGH proceeded to put the pipeline back into service with no repairs. The details surrounding the unusual and unexpected results of the SFPUC verification using accepted practices and two new technologies are of interest to owners and operators of PCCP pipelines as well as their consulting engineers since they threaten to undermine confidence in the RFEC/TC in general.

This paper presents strategies for the control of external corrosion on municipal transmission pipelines as part of a comprehensive Asset Management Program. Several Asset Management strategies are available to municipal utility managers including run to failure; run until failure and repair as required; and operate and maintain using preventative maintenance to provide an indefinite life. Examples of these strategies would include operating a water pump to failure, operating a pipeline until a failure occurs and then making repairs as required, and operating and maintaining a facility such that the facility has an indefinite life. Several asset management strategies are currently being used in the municipal transmission pipeline arena. This paper discusses the short term and long term impacts of these strategies.

Building on the success of the Sahara Leak Location system in potable water mains, a new service is now being finalized for use in rising mains and other pressurized wastewater pipelines to pinpoint exfiltration. Failure of wastewater forcemains cause an environmental hazard as well as extreme operational difficulties while the forcemain is being repaired. Previous research has shown that pipes at greatest risk of failure have often been leaking for some time, but unfortunately, to date there has been no technology available to undertake an effective force main inspection in a live operating condition without excavation. As with the water main leak detection system, the intention is for surveys to be carried out with the pipe remaining in service and provide real time information on the exact location of leaks of any size of plastic, fiberglass, iron, concrete, steel, ductile iron, cast iron or clay pipes. It has become apparent that water utilities would prefer any device put inside their live pipelines to be tethered so that the device can be controlled and removed. This preference is echoed with wastewater system operators who realize the serious potential problems associated with lost equipment in an operating pressurized system. This paper discusses some of the important operational issues to consider when using an intrusive tethered survey tool in wastewater pipelines and some of the challenges overcome during the development and adaptation of the Sahara system. Field trials conducted by WRc that have shown that the Sahara leak location system can be successfully deployed and operated in wastewater piping systems are presented.

A computational tool for leakage detection in a real water distribution system was developed by the Water Distribution and Sewer Systems Research Center at the Universidad de los Andes in Bogotá - Colombia, supported by the Colombian Institute for Science and Technology Development "Francisco José de Caldas" - COLCIENCIAS. This methodology is based on a recent approach known as inverse transient analysis with genetic algorithms and uses observed pressure data, collected during the occurrence of transient events in a real network, to find the optimal location of the leak with genetic algorithms. This optimal location must minimize the difference between calculated and observed data. The methodology was tested and verified with experimental data collected in a real network located in the township of Chía, near Colombian District Capital Bogotá. The Chía network was selected because of its relatively small size and homogeneity of pipe material (PVC).

The scattergraph is a graphical tool used to evaluate flow monitoring data from sewer systems. The scattergraph depicts a relationship between flow depth and velocity and provides insight into the hydraulic conditions within a sewer. The addition of iso-Q lines brings a new dimension - flow rate - to the scattergraph and illustrates the impact that existing hydraulic conditions have on the operational capacity of a sewer. Simply put, an iso-Q is a line of constant quantity and is analogous to a contour line on a topographic map. The concept of the iso-Q is presented and developed in this paper. Practical examples from flow monitoring locations throughout the United States are also provided, demonstrating the use of iso-Qs to evaluate the operational capacity of existing sewers under a variety of conditions.

Engineers are aware of the instability associated with critical flow conditions and are generally advised to avoid them during sewer design. However, such conditions are often encountered in existing sewers and can impact the accuracy and reliability of flow monitoring data. The Froude number (Fr) is a dimensionless number used to describe flow conditions within a sewer. These conditions can be illustrated on a scattergraph using iso-Froude lines. Certain flow conditions such as hydraulic jumps, sewer bores, and undular jumps are readily identified by evaluating flow monitoring data with respect to iso-Froude lines. The concept of the iso-Froude is presented and developed in this paper. Practical examples from flow monitoring locations throughout the United States are also provided, demonstrating the scattergraph signatures of various transcritical and near-critical flow phenomena. Flow monitors can operate well in sewers under subcritical or supercritical conditions, but accuracy may deteriorate near the transition. Such conditions should be avoided when possible in flow monitoring applications.

The use of condition assessment tools to help prioritize pipeline rehabilitation needs has continued to grow. New tools and techniques that provide uniform, consistent results are needed to address the overwhelming backlog of pipelines that are nearing their useful service life. Sewer electro-scan is one technology that provides some promise in meeting these needs. This paper presents insights into the use of sewer electro-scan for large, gravity sewer applications.

Pipeline suspension bridge structures normally consist of an intricate cable/rope system. Accurate estimation of forces in the cables is essential for calibration of analytical models and evaluation of the structural integrity and assessment of the stresses in the pipeline and other structural elements. Stress in the main suspension cables and the pipe can be evaluated based on forces in the cable systems. Recently, a laser-based non-contacting force measurement technique has been used successfully for measurement of cable forces in some suspension pipeline bridges. The new vibration technique replaces the cumbersome and approximate cable stiffness measurement method for such structural elements. The laser technique allows measurement of cable forces from a distance away from the bridge, e.g., on river banks, adding to the efficiency and speed of inspections. This paper describes the technique for measurement of cable forces and reviews the procedure employed for two bridges along the Trans Alaskan Pipeline.

This paper addresses three empirical methods used to determine degree of Base Infiltration (BI) in 45 isolated sewer basins throughout the Orange County Sanitation District (OCSD) collection system. These include a common estimation method called night-time "Wastewater Production", a second method called "Minimum flow Factor", and a third empirical method called the "Stevens/ Schutzbach" equation. These empirical methods were tested against a chemical parameter verification method that involves regressing hourly parameter concentrations (Chemical Oxygen Demand - COD, etc.) with sewage flow rates. Results to date indicate that the "Minimum flow Factor" method and a slightly modified version of the "Wastewater Production" method provide more accurate estimates of BI in basins yielding flows comprised of more than 25% BI. Alternatively, the "Stevens/Schutzbach" empirical method provides good estimations of BI in basins yielding BI flows less than 25% and is also far more stable in such basins (i.e., less sensitive to errors in minimum night-time flow measurements).

Concrete Cylinder Pipe (CPP) has been manufactured in North America since 1942 and forms the backbone of its water supply infrastructure. By all accounts, CPP is a skillfully engineered composite that exploits concrete in compression and steel in tension to create an economical, efficient, and long lasting product. Consequently, nearly every major water utility in North America uses CPP for the transmission and distribution of raw and potable water. Remote Field Eddy Current / Transformer Coupling (RFEC/TC) is commonly utilized by pipeline operators to identify and quantify the number of broken wires in individual CPP pipes. Results show that 3.7% of the pipes inspected using RFEC/TC contain broken prestressing wires and that although there is some correlation between certain pipeline properties (eg: whether or not the pipes contain shorting straps), condition assessment should still be performed to assess which 3.7% should be targeted for rehabilitation and/or replacement. This paper examines this assertion by studying data taken from approximately 175,000 pipes that have been examined in North America using Remote Field Eddy Current / Transformer Coupling (RFEC/TC) and comparing the occurrence of distress found in these pipes to determine if any trends exist.

The recent development and application of technologies to inspect and monitor prestressed concrete cylinder pipe (PCCP) has provided new opportunities to manage deterioration in these large-diameter water and wastewater pipelines. Previously, little information was available about the extent and rate of deterioration of the prestressing wires in this type of pipe. Engineers had to rely on visual inspection and corrosion surveys to try to identify pipes approaching a critical structural condition, which could then only be confirmed through excavation and forensic examination. Now, however, electromagnetic inspection can provide a good approximation of the number of wires that have failed in a given pipe, and continuous acoustic monitoring can identify and locate wire breaks as they occur during the monitoring period. This information has been used to identify and replace severely distressed pipe and to assist in the development of repair or replacement programs. However, with few exceptions, this high-quality data is currently used only as part of a static approach, that is, information is collected from periodic electromagnetic inspection surveys or short term monitoring programs and decisions are made on the basis of an analytical or subjective assessment of risk of failure at that particular point in time. This can lead to the adoption of inadequate or over-conservative mitigation strategies. The combination of electromagnetic inspection, long-term acoustic monitoring and comprehensive dynamic risk management modeling provides an assessment of remaining time to failure for each pipe while protecting against spontaneous rupture. The integration of this information into a comprehensive database with an intuitive interface allows agencies to optimize PCCP management and offers a far more sophisticated and cost-effective solution to assuring pipeline integrity than current practice. This paper describes how such a strategy can be implemented and presents a case study on how one North American water agency is adopting this approach to manage its PCCP inventory.

In 1999, NDT Corporation conducted sonic/ultrasonic nondestructive testing measurements to determine the integrity and condition of 1062 pipes in the New Jersey Water Supply's Round Valley 108-inch PCCP Force Main. NDT repeated the measurements in 2002 to evaluate the deterioration rate. The information was used to develop a long-term management plan to minimize risk and optimize expenditures. Sonic/ultrasonic results are used to assess the condition of each pipe by determining the strength of the core concrete, and to determine whether the pipe is acting as a composite structure. Delamination of the mortar from the wire can also be detected. Repeating sonic/ultrasonic measurements at a later date provides two data sets in time to determine the deterioration rate (if any) of each pipe section.

Thames Water Utilities Limited is the largest water and wastewater services company in the United Kingdom. It serves 13 million customers in London and across the Thames Valley, from Kent and Essex in the east to the edges of Gloucestershire in the west. The utility business treats and supplies an average of approximately 2,700 million liters (713 million US gallons) of water per day. In London as a whole, over a third of mains are more than 150 years old. Over half are more than 100 years old. Thames Water initiated trunk main leakage reduction programs concentrating on unaccounted for water losses in its transmission mains before the distribution network. A range of new and traditional leak detection methods was compared. Parameters included cost of operation, sensitivity of detection and accuracy of location. Thames concluded that the Sahara Leak Location system was the most accurate and cost effective way of detecting and locating trunk main leaks. Consequently, Sahara was used exclusively for subsequent phases. To date, over 960 surveys have been completed and over 960 leaks have been located with Thames Water reporting that, recently, the average leak repaired is approximately 0.15Ml/day (25 US gallons/day) arising mainly from deteriorated lead run joints on cast iron mains and corrosion through the wall of steel mains. In excavating at the identified locations, Thames Water quoted a near 100% accuracy record. This paper discusses the financial benefits to Thames Water from the annual volume of leaks identified within their water transmission system in the eight years from 1998 to 2005, including the cumulative leakage found as well as the approximate leak volume per distance inspected each year.

Acoustic leak detection systems have proven to be an effective means for identifying leaks in water pipelines. Currently, there are three predominant acoustic leak detection systems utilized. These include acoustic listening devices, leak noise correlators and tethered hydrophone systems. Although each system has merit, each is also limited in its ability to cost effectively survey long reaches of larger diameter water transmission pipelines. Recent technological advances have resulted in the development of a free-swimming acoustic leak detection device capable of surveying more than twelve miles of pipeline with a single deployment into a fully operational pipeline. The system can identify and locate small leaks in large (>10 in. diameter) water pipelines constructed of any pipe material. The device can also pass through in-line valves and negotiate bends in the pipeline. These benefits provide a cost effective and timely approach to identifying and locating leaks in water transmission pipelines.

The Greater Lawrence Sanitary District (GLSD) learned in 2002 that pipe supplied to GLSD in 1974 was similar to pipelines experiencing a high rate of catastrophic failures throughout the United States. The District began a assessment program to assess the structural condition of one of its pipelines. Through this evaluation one pipe section was found to be in a state of imminent failure and required emergency repairs to advert a catastrophic failure that would have significant financial and environmental implications. This paper discusses GLSD's implement of an asset management program to prepare for a possible catastrophic pipe failure, the techniques used for assessing the pipeline, successful repair of the pipe section subject to imminent failure and the cost effective management of this asset.

One of the greatest challenges facing municipal engineers is the condition assessment of buried infrastructure assets. It is a mandatory process to establish and employ management strategies for these assets. Condition assessment of water mains is challenging compared to other infrastructure assets because they are typically underground, operated under pressure, and mostly they are inaccessible. To assess the condition of water mains, current research considers physical, environmental, and operational factors and their effect on different types of water mains. A condition assessment model, using the analytic hierarchy process (AHP), is developed in order to set up rehabilitation priority for water mains. Various factors are incorporated in the developed model, such as physical (pipe type, size, age, breakage rate), environmental (Cathodic protection, ground water level, soil type, surface type, and road type), and operational (Hazen-Williams factor, operational pressure). Data, which are collected from municipal engineers who are experts in water system, include pair-wise comparison matrices among factors and their sub-factors. The AHP procedure is applied to these pair-wise comparison matrices in order to generate the relative weights of each factor on a scale out of 1.0. A model is developed to determine the condition of water main based on the AHP results. Each factor weight represents the relative importance of this factor among other factors that affect water main condition. Results show that pipe age has the highest relative contribution factor among others (20.95%); then pipe material (17.49%); however, the third factor is the breakage rate (13.13%). On the other hand, the least factor is type of service (2.85%). The developed model will assist municipal expertise to prioritise pipe inspection and rehabilitation planning for their existing water mains.

To augment existing water supplies, ease financial burdens, and allow for collaboration with other water providers, the East Cherry Creek Valley Water & Sanitation District's (District) is constructing the Northern Water Supply Facilities. This drinking water transmission system will consist of a Reverse Osmosis (RO) membrane water treatment facility, 31 miles of transmission pipeline, and two pumping stations, with Phase I facilities designed to handle flows up to 14.5 million gallons a day (MGD) under normal operations, including a 1-MGD winter maintenance flow. Phase II will increase the total system capacity to 40-MGD via water treatment plant and pumping station expansion. The Northern Water Supply Project represents a major step in conversion from finite deep groundwater supplies to completely renewable water sources. Hydraulic modeling was used to optimize the phased approach to design and construction of the transmission pipeline. Further hydraulic analyses guided the selection of pumping equipment for multiple phases of construction; emphasizing efficiency, minimizing the quantity of pumping units, and maximizing the pumping range. Transient modeling was also conducted to determine design features necessary to protect all system components against transient pressures and vacuum conditions. Project construction of the 31 mile/48 inch high pressure transmission pipeline and two booster pump stations has required extensive coordination and permitting from multiple jurisdictional agencies. The District has pre-purchased pipe and pumps as well as other long lead items to expedite construction schedule. Construction of the dual pumping stations is occurring simultaneously and multiple pipe installation and tunneling crews are working on at least four separate headings with the goal to complete Phase I project facilities by the summer load season of 2006. The District's Northern Water Supply Facilities are the next step in development of a north metro Denver transmission and water supply network, addressing the long-term water supply needs of the growing communities in Colorado's northern and eastern plains.

Constructing a full scale common duct network (CDN) requires considerable budget support. In reality, a CDN is constructed in distinct phases rather than in a single phase because of budgetary limitations and other related factors. How to prioritize the route construction of a CDN is thus a crucial issue for the authorities. This study derives the critical variables for determining the construction priorities of routes in a CDN using expert interviews and questionnaire surveys. Statistical analysis is also performed to check the validation and verification of the survey results. Moreover, factor analysis is used to derive 24 priority determinant variables and classify them into five groups, including utility agency, traffic condition, local government, infrastructure project, and site condition. An evaluation model is developed herein to rank the construction priority of the routes in a CDN. The pairwise comparison method is then used for weighting the five groups. The site condition is found to be less important than other factors in determining route construction priorities for a CDN. Finally, a six-route CDN located in northern Taiwan is analyzed using the proposed model, and the analytical results are objective because of the consideration of multiple viewpoints.

For the last fifteen years, the Las Vegas Valley Water District (District) has performed all aspects of construction management with the resources of its own staff. This, however, has not been an easy accomplishment. Las Vegas has been one of the fastest growing metropolitan areas in the United States for the last fifteen years. The District has continued to engineer and construct water distribution facilities to meet the community's evolving water demands. The District's customer base includes the typical residential, commercial and industrial users as well as serving the 35 million plus visitors and tourists that visit our city each year. Approximately 6,000 new residents are connected each month. The City's population grew approximately 71.3 percent from 1993 to 2003. The District has had to face the challenge and adapt to provide the necessary infrastructure to meet the continually changing water demands. In this regard, the District developed an in-house construction management organization that represents the District's commitment to self-assessment, continuous improvement, and comprehensive planning. This organization has evolved and developed itself into a self-contained, start-to-finish construction management services. The overall management approach will be presented. This includes how planning, design, inspection, and construction management are integrated to provide a horizontal integration of these disciplines. The strategy of assembling a cohesive project team will be presented. The project team is the key ingredient to establish the construction ground rules, monitor the work, and document the construction phase. This presentation will also discuss and display the tools that help the project team accomplish their work. These tools include in-house developed software for construction management as well as off-the-shelf software that are readily available for any construction management organization. This paper will discuss the overall District management approach and focus on the tools utilized, the benefits realized and the lessons learned from self-performing construction management activities at a large water utility district.

In the summer of 2005, Texas Sterling Construction L.P., under contract to the City of Houston, finished the installation of a 30 in. Fiberglass Collector line. The Fiberglass pipe was provided by Ameron FCPD and was selected by Lockwood, Andrews & Newnam due to its non-metallic nature, rendering it immune to corrosion. The line failed a series of hydrostatic pressure tests when it was subjected to test pressure. This suggested the presence of high pressure leakage. Attempts were made to locate the leaks utilizing a variety of methods including excavation at ponding areas and other experimental technologies. None of these methods proved universally effective. In a further attempt to locate the leaks, in August 2005 Texas Sterling Construction L.P. contracted with the Pressure Pipe Inspection Company (PPIC) to inspect this line using the Sahara leak location system. The Sahara system was inserted into the pipeline at two separate locations. Because the pipeline had not been placed in service and there was no water flow in it, pulltape was used to pull the inspection equipment through the testing area. The overall inspected distance was 5,083 feet, and was conducted over a 2-day period. Analysis of the data obtained during this inspection revealed two leaks within the areas tested. Texas Sterling Construction, L.P. verified the results through excavation and repaired the affected joints. Consequently, this line passed its pressure test and was handed over to the City of Houston.

The Libyan Great Man-Made River Project (GMRP) is a US$20B, 4000 kilometre prestressed concrete cylinder pipeline project incorporating well fields, pump stations, water treatment facilities and storage reservoirs designed to deliver over 6.5 million tonnes (1.7 billion US gallons) of water daily to the agricultural, industrial and municipal areas of Libya. Although briefly described below, it is not the purpose of this paper to dwell on the details of the project's conception, design and implementation nor on the awesome statistics of its size and cost since these have been extensively, though by no means exhaustively, reported elsewhere. This paper looks at the broad strategic decisions underpinning the management framework intended to deliver the completed Project in a planned and orderly manner. Reference is also made to some of the unforeseen events that challenged the planned order and describes how management was able to meet and deal with them. It is the Owner who will live with and depend on the project for generations to come. This paper therefore examines the project management system seen from the Owner's perspective and its ability to meet his needs and objectives. The absolute importance of an effective management system to the success of a project is recognised as are the constraints and limitations of any system. The authors identify the key management processes and their adaptation to the GMR Project while recognising that there is no uniquely appropriate management system for any given project, nor one that performs independently of the people involved in it.

In operation since 1953, Erie County Water Authority (ECWA) is located in western New York state. ECWA operates as a self-sustaining business enterprise and pays for all operating expenses out of revenues generated from the sale of safe, clean water to a population of nearly 550,000. The Engineering Department is vital to ECWA's ability to provide high quality water and efficient service to this ever-expanding customer base with the least amount of disruption to their customers. One of the many responsibilities of Engineering is to oversee the study, design, construction and evaluation of conventional and potential alternative means for capital improvements to their transmission and distribution systems. A veteran staff has chosen Trenchless Technology Methods as part of their forward thinking and innovative five year capital improvement program. Contract No. EA-06, Water System Improvements in the Town of Amherst, New York, was designed as a 36-in (914mm) water transmission main approximately 11,000-feet (3.3km) long. A particularly challenging crossing of Ellicott Creek and the Corps of Engineers flood control channel at I-990 is the primary focus of this paper. ECWA and their engineer, Erdman-Anthony, chose to use flexible restrained joint ductile iron pipe in a horizontal directional drill (HDD) installation. The 785-feet (239m) 36-in (914mm) HDD installation was ECWA's first experience with HDD of any size. The 36-in (914mm) pipe was installed using the assembled-line method in two separate stages of approximately 400-feet (121m) each. Both stages were pulled through the pre-reamed borepath in a total time of approximately 72 minutes. This paper will discuss the successful installation of 36-in (914mm) flexible restrained joint ductile iron pipe using HDD and the importance of project management and coordination between ECWA, consulting engineer, general contractor, HDD sub contractor, and the pipe supplier.

Beginning in 2000, as part of the City of Houston's efforts to reduce groundwater usage and convert to surface water, a total of 45 projects have been designed and constructed under a fast track approach. These projects have involved diameters ranging between 84-inches to 30-inches and have totaled over 70 miles of pipeline in an urban setting at a cost of over $220 million. To achieve the necessary groundwater conversion, the project schedules for both design and construction have been compressed as much 50% of the normal allowed times. As a result, project control execution and compliance was essential to completing the projects on time and within budget. Complicating the project control aspect of these projects was the need to utilize specialty sub-consultants, such as SUE contractors and right-of-way acquisition teams. These issues, plus other critical factors, required the innovative approach of monitoring activities normally considered routine, utilized specialty software programs for document management, and developed unique tracking forms for total permitting and approval requirements. This paper presents some of the project controls "checks and balances" successfully implemented to meet the project schedule and budget constraints. Additionally, this paper will discuss areas where adequate project controls was not able to overcome some of the obstacles such as poor contractor performance and failure of timely delivery of key materials and equipment. This paper will also evaluate the successes and shortcomings of various incentives used to expedite construction activities.

A new 108 inch sewer outfall pipeline was completed in two years at a cost of $21,000,000. The sewer line is owned by the Northeast Ohio Regional Sewer District and extends from the Westerly Waste Water Treatment Facility next to Cleveland's Edgewater Park out into Lake Erie some 4,800 feet. This new line was installed to replace an existing smaller outfall line. The purpose of this new line is to minimize pollution entering Lake Erie and the inner harbor area of Cleveland, Ohio. Due to the location - near a marina and park, in one of the Great Lakes, in a northern climate, through existing breakwaters, and near fish spawning areas - this 4,800' line and associated structures presented many scheduling and construction challenges, such as: temporary and permanent sheet piling work, new drop structure, diffuser section, breakwater demolition and reconstruction, seasonal shutdowns for fish spawning, keeping navigation passage to marina open, Lake Erie weather, special handling and disposal of contaminated trench spoils, permanent demolition of outdated structures, safety, and "closing" between near-shore and off-shore sections under 50 ft. of water.

This paper will explain the details of an ISO 9001:2000 registered Corporation. It will also go into the merits of specifying this requirement for pipeline projects. The system offers the Manufacturing Corporation and specifying agency multiple leading-edge advantages. The internationally organized Quality Management System in place motivates staff by defining their key roles and responsibilities. Cost savings are realized through improved efficiency and productivity, as product and service deficiencies are highlighted. A strong focus on continual improvement results in less waste and fewer complaints. Customers will notice the consistency, timeliness and attention to specifications. The ISO standard requires increased involvement of top management in the Quality Management System. This starts with the setting of the Quality Policy and Quality Goals and Objectives. It continues with Management Review Meetings that focus on the data from the system, and taking corrective action if necessary to make sure the quality goals are met, new goals are set, and continual improvement is achieved. Internal operational efficiency is achieved through the consistency of outputs by well-defined and documented procedures. Efficient, reliable processes require documented procedures and performance reports and must be audited on a regular schedule by qualified individuals. Internal controls enhance process control and flow that is regularly reviewed and improved. The documentation and awareness of processes identifies current best practices, strengthens employee quality knowledge, and demonstrates effective management throughout the Corporation. This paper will also go into how to evaluate the effectiveness of a supplier's ISO registration to meet the needs of the specifying agency for specific projects.

This paper describes the events that led to the formation of high surges in a newly constructed major pipeline during the commissioning process, the resulting ruptures, the investigation that was performed to determine the extent of the resulting damages to the line, and the remediation measures adopted. It presents a summary of the valuable lessons learned. The paper discusses the need for an improved integrated system of quality control and assurance that would eliminate the chance of major surges and damage to the line. The paper presents the procedure used to identify the structural effects of the surge events, inspection and testing used to evaluate the effects of the surges on the future performance of the surged pipe, and the rehabilitation procedure adopted.

Contra Costa Water District has 4,170,000 feet of pipe in the treated water distribution system and 440,000 feet of pipe in the raw water piping system. The District has had a comprehensive Pipeline Renewal and Replacement Program to renew or replace aged, corroded, and undersized pipes since 1996. Typically, the District is able to replace over 10,000 linear feet (almost 2 miles) of water mains per fiscal year. The District uses a combination of contract delivery methods for pipeline replacement, depending on the type of the contract used and the timeframe for delivery and installation. This paper address the following key issues: conflicts with other utilities - methods of identifying utility conflicts ahead of bid time and how to deal with unexpected utilities encountered in the field during construction, pipeline pricing - unit pricing per foot installed or the lump sum method, pros and cons of each, and when to use each method to your best advantage, pavement thickness and type - what to do with pavement variances encountered in the field, how to address it in the bid, and methods of restoration scenarios, traffic control and flow - how to deal with rush hour traffic, residential and business access and impacts as well as how to coordinate work with other agencies, change order and claim negotiation — steps for successful change order negotiation on pipeline contracts and proper documentation for pricing, community outreach and coordination - how to deal with customer outages, how to handle customer complaints, and how to maintain customer satisfaction, and value engineering in the field - flexibility and how to deal with changes - how to keep the work going, and how to control pricing and schedule. Careful consideration of these issues has resulted in an informed approach to the administration of pipeline construction contracts. This has in turn resulted in a reduction in administrative costs associated with pipeline replacement that has been successfully benchmarked through collection of annual data.

This paper discusses the thrust restraint behavior of mechanically harnessed pipelines subjected to internal pressure. Mechanically harnessed joints, with either a C-clamp or Snap Ring, are highly nonlinear. The mechanically harnessed joints are quite flexible initially and the stiffness increases rapidly until they behave as welded joints after some level of extension or rotation. The initial flexibility can be considered as slack. This slack can significantly alter the thrust restraint behavior and magnitude of forces and moments of a pipeline with mechanically harnessed joints relative to one with welded joints. This paper presents a discussion on the behavior of pipelines with mechanically harnessed joints at bends. The effects of variation of deflection angles at bends, soil types, and the magnitude of slack are discussed. The application of the procedure to the design of thrust restraint systems with a mix of different pipe types, mix of mechanically harnessed and welded joints, and elbow extensions are discussed. Comparisons are made with thrust restraint of pipe with welded joints.

The Metropolitan Water District of Southern California (MWD) has developed Carbon Fiber Liner standard specifications for retrofitting wire-deteriorating Pre-Stressed-Concrete Cylinder-Pipelines (PCCP). The standard consists of installation details, written specifications, material and contractor qualification requirements, and a design approach consistent with methodologies used by modern pipeline design Engineers. The standard was substantiated through MWD's full scale testing program. The effort was a joint venture between MWD, related industry, and academia. Upon completion of the repair standard, MWD awarded several successful PCCP repair contracts resulting in cost savings over conventional repair methods. Completed contracts include a broad range of PCCP-classifications. Repaired pipe ranged between 69 and 192 inches in diameter, with earth covers between 1 to 3 diameters. The number of carbon fiber layers applied per repair ranged between 2 and 24, for pressures up to 250 psi.

The ozone contactor for the high pressure Cheney Ozone Facility, owned and operated by the City of Wichita, Kansas (City), was constructed with prestressed concrete cylinder pipe (PCCP) modified for ozone resistance. The ozone facility, part of the City's drinking water treatment process, treats up to 80 mgd (12,600 m³/h) raw water from the Cheney Reservoir with a maximum dissolved ozone dose of 5 mg/L to eliminate taste and odor caused by algae. Water from the Cheney Reservoir is pumped uphill for about 7 mi (11 km), then flows another 18 mi (29 km) by gravity to the City's water treatment plant through a 60-inch (1,500 mm) diameter PCCP pipeline constructed in the early 1960's. The ozone facility, procured as a design-build project and completed in June 2005, is located on the discharge side of the raw water pump station, where pressures range from 56 to 95 psi (4.0 – 6.5 bar) depending on the pumping rate. Ozone treatment of drinking water consists of generating ozone gas on-site from oxygen, dissolving the gas into water, and providing a contact time for the chemical reactions to occur. Ozone is a strong oxidant, and few materials can resist degradation or destruction over a twenty-year design life of the structure. Conventional ozone contactors are typically baffled concrete or stainless steel tanks with a free water surface and maximum pressures of 4 to 13 psi (0.3 – 0.9) from the depth of the contained water. Due to the pressures at the Cheney Ozone Facility, conventional tanks were not feasible; pipe provided the most efficient structure. Several pipe materials were evaluated, including 316L stainless steel (SS), polyvinylidene fluoride (PVDF)-lined fiberglass-reinforced plastic (FRP), and PCCP. Standard PCCP has several deficiencies in terms of ozone resistance. During the design-build process, a leading manufacturer of PCCP proposed a special design with ozone resistant materials for all wetted surfaces. The design uses a heavy wall embedded cylinder pipe (ECP), stainless steel end rings, and full-circumferential field welds to join adjacent lengths. The modified PCCP met all project requirements, including cost, delivery, constructability, pressure- and ozone-resistance. The modified PCCP ozone contactor is both an innovative application and economical solution resulting from the collaborative effort of the manufacturer, engineer, and contractor during the design-build process.

Steel water pipe in the municipal industry has typically been designed with either restrained or non-restrained joints, (typically rubber gaskets). Restrained joints are required where thrust at elbows, tees, laterals, wyes, reducers, valves, and dead ends. These joints are restrained by welding, harnessing and blocking. Most typical are the welded slip joint, because of its flexibility, ease in forming and laying, watertight quality and its ability to make small angle changes at each joint. The efficiency of the welded slip joints and rubber gasket joints has been tested by numerous manufactures for internal pressure. The pipe barrel will usually fail by exceeding the elastic limit of the steel prior to leaking or failure of the joint. This is due to the increased section modulus of the joint configuration and stress orientation. The ASME, recommends applying joint efficiencies of 0.45 and 0.55, respectfully for single and double-fillet lap welds and 0.9 for butt-welded pipe. The full-scale tests done by Thompson Pipe and Steel Company (1984) showed efficiencies in the 0.83 to 0.76 range for lap welded pipe. The unpublished tests at Consolidated Western Steel (1958) revealed efficiencies at nearly 1.0 for lap welded joints. Joint efficiency values are sometimes used to calculate shell thickness for buried pipelines. The question arises, what do these efficiencies mean, and how should they used in design of welded joints?

Joint leakage is very common in underground pipelines that are made of Reinforced Concrete (RC) sections. Leakage would cause soil erosion in the vicinity of the pipeline and the subsidence of the road surface. The usual practice of rehabilitation by road authorities is to patch the pavement surface. However, the repeated patching of pavement due to continuous loss of soil from leakage-induced exfiltration or infiltration worsens the problem since compaction loads contribute to creating additional stresses on the already damaged pipe section or joints. Existing onsite repair techniques by trenchless methods using either Cured-In-Place Pipes (CIPP) lining or joint sealing can not restore the original structural integrity of the joints. Replacing entire sections of the pipes has been proven uneconomical. This paper describes the development of a local repair technique for RC pipeline with leaking joints using Carbon Fiber-Reinforced Polymer (CFRP) composite wraps. The technique is designed to be rapid and only requires local excavation at the leaking joints. Two prototype specimens were built and tested in the laboratory according to the ASTM C497-03a Standard for Concrete Pipes. The test results were satisfactory.

Tampa Bay Water is Florida's largest wholesale supplier of drinking water. In 1998 the West Coast Regional Water Supply Authority was restructured to become Tampa Bay Water. In that same year the agency began design on a series of new water supply projects which had been recommended in the agency's Master Water Plan. Completion of construction of these projects in 2005 transformed Tampa Bay Water from a single source (groundwater) to a multiple source (groundwater, surface water, desalinated seawater) supplier of water. These new projects included a 66 mgd surface water plant, a 15 billion gallon capacity above ground reservoir, a 25 mgd reverse osmosis seawater desalination plant, and over 60 miles of new interconnecting pipelines (36-inch to 84-inch diameter). Tampa Bay Water's current pipeline network now consists of almost 200 miles of pipe, 130 miles of which is large diameter (36 in. – 84 in.). This paper discusses the history of the regional pipeline system, the development of alternative pipeline material specifications and designs, the configuration and composition of the current system i.e. use of various pipeline materials, system pressures, operational flexibility, and corrosion control and monitoring systems. Switching to a blended water supply has resulted in improved water quality. However, various blends have different effects on member customers' distribution system pipe materials. The results and recommendations from a recent research study on various pipe materials are presented.

It is common practice to weld joints in water pipe. The practice is more recent than welded joints in pressure vessels. Therefore, it is inevitable that welding standards for pipe welds would have been influenced by the older pressure vessel codes. There are significant differences between high-pressure tanks and pipes for transmission and distribution of water. Successful lap welded pipelines and test programs on welded lap joints provide information on the performance and performance limits of welded lap joints in pipes. Single welded lap joints are adequate for most welded steel water pipe. Double welded lap joints are roughly ten percent stronger (than single). Single welded lap joints can resist longitudinal stresses when valves are closed, i.e., zero flow, (highest pressure and worst case pressure analysis). Longitudinal stress caused by change in temperature must be included if the pipe length is fixed. Design is based on safety factors, which should be ratio of longitudinal weld strength and maximum longitudinal stress. Longitudinal weld strength should be determined by full pipe sections - not coupons cut from a joint. Maximum longitudinal stress is generally less than the hoop stress. Hoop stress is the primary design consideration.

The design service life of corrugated high density polyethylene (HDPE) drainage pipe has been a subject of considerable debate and research over the past several years. While significant long-term performance data is available for smooth-walled polyethylene pipe, the data for corrugated drainage pipes is somewhat limited. This paper presents a method for determination of long-term service life of corrugated HDPE pipe by utilizing some of the current widely-accepted methods employed by the plastic pipe industry, while modifying them somewhat to take into account the unique geometry and installation conditions of buried corrugated pipe. The process for long-term service life prediction is two-fold: First, the anticipated service conditions of the drainage pipe must be assessed, including such factors as environmental conditions, soil and traffic loads, and the resulting long-term stresses and strains evident in the pipe. Second, the capacity of the material and the manufactured pipe product must be assessed. The service conditions of the pipe will vary by geographic location, based on temperature and soil and traffic loads. While deep installations may result in large compressive stresses on the pipe, shallow installation are more subject to bending and tensile stresses. Although these stress levels are typically lower in magnitude than the compressive stresses associated with deep burial conditions, they are considered a limiting condition as the material is more prone to failure in tension rather than compression. Recent research performed by Dr. Timothy McGrath for the Florida Department of Transportation on the limiting stress conditions of buried corrugated pipe is presented in this paper. The capacity of the material to resist failure is the second factor that must be addressed. Based on its wide use as a piping material (i.e. gas, water, industrial, oil field, etc...) polyethylene is a highly scrutinized material and its mechanisms of failure are well known. For corrugated drainage pipe, the primary mechanisms of material failure are slow crack growth and oxidation or chemical failure. Some recently proposed methods by Dr. Grace Hsuan for the Florida Department of Transportation to ensure long-term material resistance to these failure modes are presented in this paper.

The Great Man Made River Authority (GMRA) is in charge to build and operate a major water supply system in Libya. This system includes pumping stations located at the well fields, conveyor pipes and reservoirs. Six phases are scheduled. To date, three phases are in service representing around 4 000 km of pipes. Most of the pipes are 4.20m internal diameter, made of prestressed concrete, prefabricated in 7,5m long elements. In 1999, GMRA has faced some pipe bursts due to a high corrosive environment. GMRA started immediately pipe inspections and asked Freyssinet to proceed with repair of critical pipes with additional external post tensioning. The first emergency repairs have been carried out using available materials. Since this first repair, GMRA and Freyssinet have cooperated to develop a special technology which gives a long term service and makes the repair as a final solution.

This paper will go through the history of the steel making process and how these changes have affected the quality of steel. The process has changed dramatically from early processes to methods used today. Development of these methods resulted in more cost effective manufacturing. One of the methods developed was to use chemistry to enhance the steel. The chemistry of micro alloyed steels will be explained in detail and the benefits and drawbacks of specifying these types of steel for pipeline projects will be discussed. The elements that make up the steel composition, such as Carbon, Manganese, Sulfur, Columbium, and Vanadium, will be discussed and the effect on the steel will be explained. Actual steel making data will be presented and discussed. Pressure vessel quality steel and what the term means will be evaluated. Controlled rolling practices will be explained and how they can be used to affect the steel properties. The paper will take the information about steel and discuss how these changes should or could be used in the design and specifications for pipelines. Finally the cost benefit of these steels will be discussed.

A new steel liner installed in a prestressed concrete cylinder pipeline failed due to eccentric welds and high pressures in the line. The failure was in the form of tears trough the eccentric welds and the backing bar along the longitudinal joint at the intersection of the longitudinal and the circumferential joints. The failed liners were repaired and critical areas were reinforced using cover plates applied over the longitudinal and circumferential welds. This paper details the nonlinear finite element analyses used to predict the failure of the steel liners before and after weld repair and to determine the effect of additional reinforcement on the safety of the liner in form of local cover plates and butt-and-strap steel repair bands. 2D and 3D finite element analyses accounting for large deflection and plasticity were performed. The failure was governed by the ductile failure criterion, expressed in terms of plastic strain reaching the ultimate strain capacity of steel and the brittle failure criterion expressed in terms of triaxiality criterion. Triaxiality failure criterion is expressed in terms of a relationship between effective stress and maximum principal stress. The resulting stresses and strains were compared to the capacities of the steel in triaxial stress state to determine liner safety against brittle failure and in total plastic strain in ductile failure modes.

Widespread flooding of a dense urban area is a rare event in North America. Thus, little information is available regarding the impact of such natural disasters on buried infrastructure systems. In August of 1992, Hurricane Andrew struck southern Florida, leaving over $100M in damage to potable water systems alone. In the aftermath of the 1997 Red River flood, which resulted in the flooding of the town of Grand Forks (ND) and portions of the city of Winnipeg, Canada, it was suggested that the effect of surcharge on the internal pressure loading in vitrified clay gravity pipes resulted in extensive cracking. When the water receded, loss of bedding support also was suspected to occur. Hurricane Katrina brought the most severe flooding in modern US history, including the submergence of the city of New Orleans, a one million strong major metropolitan area. At present, there are no proven tools for assessing the damage sustained by buried infrastructure networks by hurricane or flood struck areas. The paper describes the preliminary findings of a comprehensive investigation into the impact of Hurricanes and other flooding mechanisms on buried infrastructure systems. A summary of damages and the difficulties encountered during the recovery process in the aftermath of Hurricane Andrew and the 1997 Red River flood are presented. Thereafter, preliminary findings from an on-going study investigating the damages inflicted by Hurricanes Katrina and Rita on municipal buried infrastructure systems (i.e., water, sewer and gas) along the Gulf Coast coastline are presented. Specifically, observations made in Slidell, LA and Lake Charles, LA are presented.

Use of a thermoplastic liner to rehabilitate degraded concrete pipe is an attractive alternative to excavation and replacement of the pipe. The design of such liners is generally based upon a design assumption that the liner is placed inside the host pipe, which can be RCP or PCCP, and that the host pipe degrades and fully deteriorates over time, thereby leaving the liner to carry the external loads. This approach fails to capture the true behavior of the liner-plus-host pipe system. As the host pipe degrades, it does not lose strength uniformly around its perimeter, and the deformed shape is not elliptical, but it develops cracking at the invert, crown and springline and deforms to a shape with high curvature at these points. At this stage of degradation, the pipe looses its stiffness and deforms under the external load. The deformation of the host pipe causes localized areas of high curvature and thus high stress in the liner; thereby reducing the resistance of the liner to inward buckling due to external hydrostatic pressure, as would be present in a non-pressure pipeline located below the ground water table.

This paper presents case histories where polyethylene encasement and cathodic protection have been used together to effectively control external corrosion of ductile iron pipelines in very corrosive soils. This practical and cost effective strategy capitalizes on the synergistic effects of these two established corrosion control techniques. Pipeline designs dating back to at least the 1970s for over 300 miles of construction have included this corrosion control methodology. The case histories include both impressed current and galvanic current protection. Non-invasive surface electrical potential measurements and record reviews were used to determine locations for excavations to inspect the condition of the pipe and polyethylene encasement.

This project included the replacement of 1,300 ft. of 35 in. and 1,300 ft. of 36 in. 145 year old cast iron water main with a single 54 in. Prestressed Concrete Cylinder Pipe (PCCP) line. This, in itself, is not a huge project, but it was complicated as both the 35 in. and 36 in. mains were located within a Civil War era brick tunnel. The brick tunnel runs from the existing Eden Park Pump Station (Approximately 60 ft. deep) to the Elsinor Tower (Eden Park Castle) which is a local historic landmark built by the Greater Cincinnati Water Works (GCWW) as a valve house. The valve, no longer exist within the tunnel; however, the Eden Park Castle is still a local architectural landmark to the area. The only access into the tunnel is a door within the Eden Park Castle and a standard manhole located near the stage of the Seasongood Pavilion, an outdoor amphitheatre in surrounding Eden Park. This project became further complicated because of the re-development of the property abutting the Eden Park Castle site. The GCWW worked with the site developer's engineer to prepare plans that would meet the schedule and site concerns of the developer. Plan specifications were developed and a contract was let for construction of the new 54 in. main. Bowen Engineering of Indianapolis was contracted to excavate a 60+ foot deep access shaft next to the Eden Park Pump Station, demolish and remove the old cast iron water mains, install a 54 in. PCCP water main within the tunnel and connect to the existing system. This project was completed on time without any adverse effects to the WCPO-TV development. Some of the interesting issues involved with the project, were the significant amounts of groundwater, the existing manhole abandonment, as well as the rail system installation all within the confines of an aged, deep tunnel.

The Ayr Storm Outfall is a single 2400mm diameter pipeline that extends 2.1km from the new pumping station at Newton Shore into the Firth of Clyde. The outfall was constructed in the summer of 2000 by Ham Dredging Ltd, part of the HBG group, at a contract value of £7.8 million. The outfall is the first use in the UK of the Price Brothers pre-stressed concrete cylinder pipe units that were installed using a unique hydraulic jointing method called Hydropull. The project has been delivered on time and the success has been attributed to both the working relationship between Ham and Halcrow, their designers, and the innovative approach to pipe installation.

The City of Houston, the 4^th largest city in America, is facing the same dilemma as other metropolitan areas across the country - how to do more with less funding. A recent study performed on behalf of the City of Houston by Lockwood, Andrews, & Newnam, Inc. identified a priority of projects requiring replacement and rehabilitation. In the past several years, the City has been experiencing problems with existing 24, 30, and 36-inch cast iron water lines concentrated in the vicinity of the City's Museum District and the Galleria Mall retail and business area. These two areas experience very high traffic volumes and are considered some of the City's most recognized places. The 24, 30, and 36-inch water lines were constructed over 50 years ago and consist of cast iron material with caulked joints. Coupons cut from the existing line indicate the existing pipeline is structurally sound. However, the leak history of these lines indicates that a disproportionate amount of effort is required by City forces to maintain these lines, making them a maintenance burden for the City. Based on a preliminary analysis, it was determined most cost effective to rehabilitate the line was by installing interior joint seals. This paper will review the issues involved in the recommendation to rehabilitate the line. Additionally, it will present the challenges to take the existing line temporarily out of service during installation of the internal joint seals. Complicating the project design efforts, the project required extensive coordination with TxDOT and carefully planned traffic control measures. Special provisions were incorporated into the project to address concerns and minimize impacts to the local residents, retail facilities and businesses. Finally, the paper will summarize some of the lessons learned by undertaking a project with these types of constraints.

In 2003, the City of Phoenix initiated a program to investigate and identify the condition of their large diameter water mains. With over 150 miles of large diameter pipeline, the City's initial investigation began with the high profile Val Vista Water Transmission Main. This 30-year-old pipeline supplies one-third of all water delivered to the City of Phoenix. The 15-mile long, prestressed concrete cylinder pipeline is jointly owned by Cities of Phoenix and Mesa. The pipeline ranges in diameter from 72 to 108 inches with no redundancy. The pipeline alignment once traversed largely undeveloped land. However, growth in the Phoenix Metro area in the past 30 years has brought residential and commercial development immediately adjacent to, and sometimes above, the alignment. A failure of this pipeline would be catastrophic. Three years of investigation have been conducted to date using both destructive and non-destructive testing. State-of-the-art investigations conducted to provide a complete understanding of the pipeline condition included, 1) Electromagnetic surveys to identify broken prestressing wires 2) Sounding and visual inspection to reveal damaged pipeline segments 3) Metallurgical analyses of the prestressing wire 4) Petrographic sampling to identify carbonation of the concrete coating, and 5) Extensive soils analysis along the alignment. The results of the investigation have identified several pipe sections with wire breaks and delamination of the concrete mortar. To date, 26 pipe sections have been identified that were in need of immediate repair. These pipe sections were repaired using internally-applied carbon fiber to withstand internal operating pressures and external loads. This paper focuses on the long-term rehabilitation of the Val Vista Water Transmission Main. The City of Phoenix initiated a multi-year rehabilitation program to slipline all but one mile of the pipeline using steel pipe. The program begins with sliplining 6,300-foot of 72-inch diameter pipeline in Fall 2005. Sliplining the remaining portion of the pipeline is planned for completion over the next five years. Design, system shut-down and start-up, scheduling, and construction techniques for the Fall 2005 program are discussed.

Air Release Valves (ARVs) are critical to the performance of water transmission lines. They provide a means for trapped air to be released and they serve to dissipate transient (surge) events caused by rapid closure of valves or the start up or shut down of pumps. Changes in the Texas Commission on Environmental Quality (TCEQ) rules for Public Water Systems Chapter 290 raised concerns that the air release vent piping in question may not be up to standards. The City of Houston (City) also expressed concerns about the long-term serviceability of the pipeline due to the age and the pipe material. An inventory of the existing air valve data was performed, which included review of record drawings, pipe lay schedules, and the City's Geographic Information and Mapping System (GIMS) data to determine the location of existing air valves and appurtenances Direct consultation with City maintenance personnel also assisted in the location effort. The air valves were identified, their operation was tested and their physical condition was evaluated. Transient modeling was also performed by inputting the recorded profile and valve locations along with past, current and future projected plant operation scenarios in The Liquid Transient (LIQT) software. A design package was then prepared to remove and replace the deficient air valves, including the isolation gate valves. After test-cuts were performed to determine the functionality of isolation valves and determine the shut down sections of pipe. Existing ARVs were replaced in accordance with City and TCEQ standards, and distressed pipe sections replaced or reinforced, the line was able to be fully returned in service.

This paper discusses the design for structural rehabilitation of man-entry size cast-in-place semi elliptical concrete sewers. Many such sewers were built in the early 1900's and are still in service, notably in Chicago, Los Angeles and Seattle. Even though some were lined with clay tiles even these are now in need of repair due to severe hydrogen sulfide induced corrosion above normal flow lines of these concrete structures. As these structures were design as arches, the principal load is compression in the wall section and no reinforcing steel is required. The inverts of these sewers are most always very flat (very large radius of curvature). This paper discusses design approaches that address the repair of the plain concrete structure to restore (or increase) its wall section properties, i.e., load capacity. The rehabilitation materials considered are strain compatible with and bond to the concrete structure walls. Thus, composite material design is appropriate using classical transform-section analysis. Also discussed is the often-overlooked (ignored) process of determining the current state of stress of the structure before rehabilitation. This consideration is shown to be important in rehabilitation design and points out the need to accurately determine (as possible and practical) the actual total load on the structure. A design example from a past project is given.

The failure behavior of an epoxy resin (EPON 826) was investigated by a series of tests on thin-walled tubular specimens and the results are presented in this paper. The tests were designed such that a constant octahedral shear strain rate was applied along different loading paths. The rate effect was also studied by changing the octahedral shear strain rate. The experimental investigation showed that a change in stress state influences the failure strengths and failure modes. The different failure strengths and failure modes are attributed to the influence of the hydrostatic component of stress. Changing the strain rate influenced the failure stress, but not the failure characteristics.

In the USA, about 90% of drinking water home plumbing systems use copper pipes. Pinhole leaks in copper plumbing pipes have significantly increased recently. For majority of homeowners, their home is the most valuable asset. The possibility of falling home value and health concerns have caused considerable anxiety among the affected homeowners. A decision support tool to determine whether to repair or to replace the whole system and which material to use is needed. Plastic pipes such as PEX (Cross-linked polyethylene) and CPVC (Chlorinated Polyvinyl Chloride) are used along with the copper. Stainless steel is being considered but does not have a significant market share. The material selection process is formalized within the frame work of the Analytic Hierarchy Process (AHP). Multiple attributes including price, corrosion resistance, fire retardance, health effects, longevity, re-sale value of home, and taste and odor are considered. This methodology is implemented for a focus group. Participant's overall preferences are analyzed and reported in this paper.

Accurate location, measurement, and characterization of all pipe defects that are potential sources of water leaks in a sewer line are essential inputs for the cost-effective design of infiltration/exfiltration mitigation projects. Electro-scan, joint pressure testing (JPT) and closed circuit television inspection (CCTV) were compared to evaluate their relative effectiveness of detecting pipe defects that were potential sources of leaks. These test methods were applied to 2,230 ft of mainline gravity sanitary sewer pipe. The joint condition assessment comparison showed that; the number of defective joints detected by JPT were within 4% of those detected by electro-scan, and both the JPT and electro-scan independently detected more than three times the number of defective joints than those detected by CCTV. The joint by joint comparison between the joint condition assessment provided by the CCTV and JPT combined and electro-scan showed that the ratio of coincident test results to the total number of tests varied between 100% (perfect coincidence) to 72% with an average of 87%. The comparison between faulty service connections reported by CCTV and electro-scan showed that electro-scan detected four times more defective service connections than CCTV. The electro-scan also suggested that these defects were generally considerably larger than those at the pipe joints. Comparison of costs showed that JPT is 4 to 5 times more than electro-scan or CCTV and the all-up cost of electro-scan is significantly less than CCTV. The study showed that: electro-scan is as reliable as JPT and CCTV combined at 20% to 25% of the cost of JPT; and electro-scan is at least three times more effective at finding pipe defects than CCTV at significantly lower all-up cost than CCTV.

The Calleguas Municipal Water District (Calleguas) is a water wholesaling agency that provides water to over 500,000 customers in Ventura County, California. Calleguas owns and operates approximately 209 km (130 miles) of pipelines ranging from 0.61 meter (24 inches) to 1.98 meter (78 inches) in diameter. Approximately 40 km (25 miles) of these pipelines, including the only two pipelines that convey imported water to Ventura County, are pre-stressed concrete cylinder pipe (PCCP). The District's primary PCCP, the 1.98 meter (78 inch) Calleguas Conduit North Branch (CCNB), was constructed in 1977. Eddy current inspection identified several locations with multiple prestressing wire breaks and collapsible steel liners with a longitudinal seam were installed in these areas in 2000. In subsequent years, Calleguas installed steel liners of similar design throughout the system for a total length of 1,000 linear meters (3,300 linear feet). In March 2005, the CCNB failed, resulting in a leak visible at the street surface. The steel liner had failed along the longitudinal seam for approximately 42.7 linear meters (140 linear feet). Calleguas immediately undertook emergency pipe liner repairs to restore water delivery. Once service was restored, Calleguas began a more detailed evaluation of the causes of the failure in order to develop an approach for reinforcement of other steel liner segments throughout the system. The reinforcement program is being implemented in winter 2005–2006. This paper describes the following, 1) Background of the failed pipeline, including original pipeline construction, eddy current inspection, liner installation, and subsequent visual inspection, 2) Mode of failure for the steel liners, 3) Emergency repair approach, 4) Results of the finite element analysis for the original constructed condition, repair, and potential reinforcement approaches, and 5) Reinforcement method for all steel liners to be implemented in liners throughout the system.

The ability to regularly deliver safe drinking water is a constant challenge to municipalities. According to the Canadian National Research Council reports, the renewal and rehabilitation of infrastructure across Canada is estimated to be at least $15 billion. Therefore, selecting the best repair and/or rehabilitation scenarios is essential to optimize the quality of the existing water mains and to minimize rehabilitation cost losses. Current research identifies several rehabilitation methods for water mains, which are classified into three main categories: (1) repair (e.g. Open trench, sleeves); (2) renovation (e.g. slip lining, cement lining, epoxy lining, CIPP); and (3) replacement (e.g. pipe bursting, micro-tunneling, directional drilling, auger boring, open cut). Stochastic life cycle cost (SLCC), using Monte Carlo simulation approach, is utilized to compare the developed scenarios so that the optimal scenario can be accommodated for different types of water main pipes (e.g. Cast Iron, Ductile Iron, Concrete, and PVC). Data, related to the cash flow of each scenario, are collected from contractors and municipalities in Canada. Current research framework will assist municipality engineers to select the optimum rehabilitation scenario for each type of water main. In addition, it will assist them to properly manage their assets, which guarantee better quality of life for the society.

The City of Chicago's water system supplies water to 2.9 million city consumers and 2.5 million suburban consumers for a total of 5.4 million people, which is 44% of the population of the State of Illinois. Lake Michigan is the source of the city's drinking water. The city operates two filtration plants and 12 pumping stations. The city's water distribution system has over 4200 miles of water main. The city schedules 40 to 50 miles of water main replacement projects every year. This figure is based on a water main having 100 years of useful life. Most of the city's water mains are under paved streets. Replacing old water mains by the traditional open cut method means that costly street restoration is required after a new main is installed. This paper presents the design and construction aspects of three projects. They are (1) Wabansia Avenue Transmission Main Cleaning and Lining Project, (2) Wentworth Avenue Transmission Main Cleaning and Lining Project, and (3) Harlem Avenue Transmission Main Cleaning and Lining Project. The City of Chicago has found that the lining method of pipeline rehabilitation is very satisfactory to mains meeting certain parameters.

The City of Myrtle Beach, South Carolina has evolved over the past three (3) decades as one of the most popular beach resorts on the East Coast of the United States with more than 14 million visitors annually. Stormwater management for the City has consisted of some seventy-nine (79) outfall pipes leading to the beach, coupled with natural swashes which collect stormwater from inland areas. The beach outfalls are unsightly and cause erosion of the natural beach. In addition, the stormwater transmits bacteria to the beach during and immediately after a rainfall event. In spite of these problems the City had taken no action to find alternatives to eliminate these pipes due to the significant expense and because no citizen or visitor had ever become ill due to contact with the stormwater from these pipes. The City was forced to reexamine their position in 1997. The Clean Water Act of 1972 effectively strengthened existing laws and regulations to prevent, reduce or control water pollution. This paper will present the thought process, political issues, regulatory/environmental obstacles and the results of this large scale stormwater management replacement and revitalization Project.

Technical design considerations for an offshore outfall at Myrtle Beach for discharge of stormwater carrying undesirable bacteria are described, together with dispersion characteristics of the discharge. Hydrodynamic forces associated with a 50yr design wave are considered to determine the required burial depths for the pipes and for providing rubble protection at the outfall nozzle. Dispersion studies included laboratory experiments and mathematical models to determine the rate of dilution of the discharge water through mechanical dispersion and bacteria die-off associated with the field environment.

In 1998 it was determined the population growth rate in the service area of the North Texas Municipal Water District's (NTMWD) North System would eclipse the population and demand projections. It was decided an additional parallel transmission line was needed to serve the increased demands of the region. The first parallel line needed was a 72-inch transmission line approximately seven miles in length through mostly developed subdivisions and crossing under two major highways, State Highway 121 and US-75. State Highway 121 is currently being widened to a six-lane highway with frontage roads and US-75 is currently a six-lane highway with frontage roads. Multiple routes were considered for the construction of the Allen/Plano/Frisco/McKinney 72-inch Pipeline. The route chosen had the most impacts to existing roadways, highways, utilities and subdivisions. Even with the number of impacts, it was chosen because it was the shortest and most economical route. The route is along the median of Exchange Parkway in the City of Allen which currently is a four-lane divided roadway with a future six-lane section at build out. The pipeline was constructed under the two major highways within a 90-inch tunnel totaling 1250 feet. The SH 121 crossing was especially challenging because it crossed under five, six foot by nine foot multiple box culverts and was located under a 16 foot high retaining wall at a bridge approach for the main lanes of State Highway 121. The pipeline was split in two bid packages, Phase I and Phase II. The first phase was bid in the fall of 2004 and was awarded at $13,197,000 and the second phase was bid in the fall of 2005 at a cost of $8,813,000. This paper discusses the methodology used in the pipeline route selection process and the design and construction issues associated with construction of a large diameter pipeline in a highly urban setting.

Selecting an optimum route for a water transmission main is a challenging process that requires an in-depth analysis of many factors. These factors include political, financial, environmental, technical, regulatory, schedule, and many others. A developer approached Aqua Illinois (water utility) with a new development in the Village of Hawthorn Woods (Lake County, Illinois) that will require water to its future 600 homes. In order to serve the new development, Aqua would have to design and build a new transmission main that takes water from its Hawthorn Woods Water Treatment Plant (WTP) to the new development, Hawthorn Woods Country Club (HWCC). Since the developer was planning to sell homes by October 2004, water had to be in the pipeline by then, giving Aqua less than six months to complete the job. A detailed review of available routes was completed that included survey and field reconnaissance, discussions with regulatory agencies, hydraulic modeling, discussions with local agencies, cost estimates, constructability review, schedule impact review, environmental review, utility conflict review and others. This detailed analysis provided the utility (Aqua) with an optimal water transmission main route that had the least impact on cost and schedule and was most favorable when factoring all conditions. This resulted in a 16-inch ductile iron pipe water transmission main over one mile in length. This project was successfully completed on time under a tight schedule. This was accomplished using innovative approaches during the route selection and design of the project. This paper discusses the challenges and solutions faced during route selection and detailed project design.

The City of Columbus has historically been experiencing numerous stormwater drainage problems in the 2,800-acre, built-out watershed contributory to the Bliss Run trunk sewer. Development in the area resulted in additional connections and extensions to the Bliss Run trunk sewer causing frequent surcharging of the storm sewer and severe flooding problems in the watershed. CDM has been assisting the city in planning, designing and construction of flood mitigation improvements, including a two- mile long parallel relief trunk sewer (ranging from 84 in. diameter pipe to 12 ft. x 8 ft. box). CDM has been involved with the Bliss Run Watershed and flooding mitigation project since 1993. The third phase of this relief trunk sewer is the final piece of construction (scheduled to begin in the spring of 2006) that will bring eleven years and over $35 million of planning, design, and construction to a successful conclusion. This paper presents numerous aspects of this monumental project and describes some of the valuable lessons learned that can be applied to other pipeline projects.

Designing new yard piping at existing waterworks plants can be very challenging, especially at already congested sites. There are always several issues associated with existing piping, including the actual location of all old utility lines, which can be helped by the use of Subsurface Utility Engineering that uses nondestructive geophysical investigation techniques. Connecting to and constructing very near existing lines can also be a challenge. Multiple pipeline crossings can result in several conditions that must be given attention, but a detailed sequence of construction can help minimize disruptions and plant shutdowns. Alignment issues include proper separation between water and wastewater lines, designing for future repairs and expansions, keeping utilities in defined corridors, and minimizing the number of fittings. Piping systems must be designed with the appropriate linings, coatings, pipe materials, pressure classes, beddings, joints, corrosion protection, and testing requirements. Designers must stay abreast of the new materials in the market in order to properly analyze alternate systems. Depth of cover plays a very large part in design, as does seismic considerations, and the need for thrust restraint and flexibility at connections to buildings. A critical step in the design is specifying the proper pressure testing procedures, for which a few alternatives are discussed. Good record drawings are a must, as is a design that is cost-effective, since yard piping is so much more expensive per unit of length than equivalent linear pipelines.

The route selection phase of a water transmission pipeline is critical to obtaining an efficient, cost-effective project. By taking the correct approach to the route selection phase, an Owner can, 1) Lower construction costs, 2) Reduce power costs over the life of the project, 3) Lower the easement acquisition costs, 4) Lessen the environmental impact and permitting requirements, 5) Lessen impact on landowners, 6) Shorten the design, permitting, and easement acquisition schedule, and 7) Improve the operation and maintenance of the system. This paper will discuss the steps used in the route selection phase on several recent large diameter pipeline projects. Some of the key concepts include the following, 1) Cost estimating techniques, 2) Estimating real estate costs, 3) Hydraulic analysis of routes, 4) Using GIS effectively to increase efficiency, 5) Evaluation criteria for alternate routes, and 6) Transitioning to the Survey and Easement Acquisition Phase. The paper will incorporate examples and lessons learned from recent projects to provide a guide to the route selection process for both Owners and Engineers.

Orange County Water District (OCWD) and Orange County Sanitation District (OCSD) have embarked on a joint Ground Water Replenishment (GWR) System. One of the projects included in the GWR System is the construction of a new Advanced Water Purification Facility (AWPF) at Water Factory 21, adjacent to OCSD's Treatment Plant No. 1. The AWPF is a 70 mgd (upgradeable to 130 mgd) reverse osmosis (RO) facility, with microfiltration (MF) pre-treatment and ultraviolet (UV) disinfection. Due to the large size of the required facilities and limited space available at the existing Water Factory 21 site, special considerations were needed to route the site piping, which included steel pipelines up to 96-inches in diameter. Additional constraints included corrosive RO brine concentrate, highly aggressive RO product water, soft and highly corrosive alluvial soils with pockets of organic peat, high groundwater, highly variable potential settlements due to seismic-induced liquefaction, and the requirement to keep Water Factory 21 and Treatment Plant No. 1 operational during construction of the new AWPF. These challenges required the use of several special analysis, design, and construction methods, including: installation of buried pipe on piles, special coating systems, large diameter stainless steel pipe, soil-cement slurry backfill, a large, buried, multi-layered pipe gallery backfilled with run-able granular material, and detailed, continuous, pipe-as-beam bending analyses to deal with the widely varying potential liquefaction settlements. This paper provides an overview of the project, followed by a review of the demanding site conditions and constraints. Specific analysis techniques and design approaches will be reviewed, along with some unusual techniques employed during construction of the project.

Although seismic events rarely cause structural damages to buried pipelines, they can nevertheless result in a significant loss of functionality. While the dynamic response of a pipe is obviously dependent on the characteristics of the seismic event and the type of pipe in question, a careful assessment of the stresses induced by the earthquake cannot neglect the interaction between the pipeline and the surrounding soil. In the present paper a numerical model is developed in order to evaluate the dynamic stresses acting on buried pipes under the hypothesis that the soil is a Winkler elastic medium and the pipe can be held to be continuous thanks to the welded joints employed. The model allows to evaluate the influence of the pipe length and the type of constraining conditions at the ends of the pipe into the assessment of earthquake effects. In particular, it was decided to refer to the conditions both of the end-free pipe and the end-constrained pipe, so as to better highlight the influence that the end constraints have on pipe displacements. The model makes it possible to evaluate, with reference to specific boundary conditions and at a generic abscissa, the trend over time of the pipe's axial and transverse displacements. These can then be used to define the corresponding trends over time of the deformations and, hence, the stresses acting on the pipe. In this note the pipe-soil interaction model is discussed. Then, with reference to steel and HDPE pipes with welded joints, a numerical analysis is conducted, showing from a technical standpoint that once the characteristics of the seismic wave, of the soil and of the pipe have been assigned; the pipe's dynamic response is also strongly affected by pipe length and the type of constraints.

Protecting water infrastructure systems from intentional attacks and developing strategies to make the water networks robust, resilient, and more immune to intentional attacks have been one of the top priorities in water industry since the September 11, 2001 terrorist events. The water distribution system typically consists of multiple subsystems in grid or network patterns. An intentional attack on a well-selected set of physical components can result in catastrophic disruption of water service. This paper presents a mitigation model which can reduce or minimize adverse consequences when a water network suffers from significant water shortage due to functional failures of critical facilities due to intentional physical attacks. The model developed in this study can be also applicable to water supply shortage situations due to non-intentional incidents such as major pump failures or main breaks. The proposed model optimizes a water supply plan for water customers utilizing the information regarding the priority of water customers in emergency situation, their functional sensitivity to water supply, and dynamic nature of water demand patterns. The solutions generated from the model are water rationing plans which can guarantee at least a short-term water supply to every water customer in 24-hour period. A Genetic Algorithm based program linked with a hydraulic solver (EPANET 2.0) is developed to find optimal rationing plans. A test of the developed program using an example water network in EPANET 2.0 manual indicates that the proposed model can successfully generate water rationing plans to reduce the consequences while meeting hydraulic constraints in water networks. The findings of this paper will provide a practical approach that can be used by managers of water networks in preparing emergency operations of their water networks.

Using advanced numerical tools, which account for the cold-expansion manufacturing process, the axial capacity of welded slip pipeline joints under compressive loading is investigated. The numerical results are in good agreement with available experimental data, and show the effects of several geometric parameters. Internal pressure effects are also examined, and an assessment of previously reported simplified design equations is conducted.

This paper presents the results of analysis and evaluation of the seismic soil strains resulting from wave propagation or permanent ground deformation on sweeping bends in buried pipelines with bell and spigot joints. A finite element analysis of the sweeping bend with pipe-soil interaction is used to compute conservative axial forces and bending moments in the pipeline. The bell and spigot joint have limited capability to transmit moments resulting from compression waves. Stability of the joint exists when eccentricity caused by the moment is less than the outer radius of the pipe and the compressive stresses are not high enough to cause crushing of concrete. This instability of the pipe joints and the crushing of the concrete at the pipe joints are check by evaluating the combined effects of the axial force and bending moment at critical sections of the pipeline. This method can also be used to analyze the effects of soil strains resulting from transient ground motion or permanent ground deformation occurring simultaneously with internal pressure and temperature load.

This study presents two full-scale test results of shear behavior of 1.22 m x 1.22 m x 1.22 m (4 ft x 4 ft x 4 ft) precast reinforced concrete box culverts. One single and one double box jointed together without grouting were tested. A monotonically increasing load was applied through a 254 mm x 508 mm (10 in x 20 in) load plate in order to simulate the HS20 truckload per AASHTO LRFD bridge design specifications. Instrumentation included strain gauges, high-resolution laser deflection sensor, and automated data acquisition. Laser sensor data and dial gauge readings were recorded to measure the deflection profile of the box culvert. Strain gauges were placed on the steel reinforcement to measure axial strain at the locations of maximum positive and negative bending moments. The test results include reporting the loads at which each crack initiated and propagated. The displacement profile of the top slab from the laser instrumentation output is also reported.

Field buried pipe tests were conducted using steel pipes with 3500mm-diameter and 26mm-thickness as a part of Irrigation Pipeline Project. In current design for irrigation pipeline in Japan, there are no design criteria for pipeline with diameter larger than 3000 mm. In the field tests, two cases of backfilling methods were employed. In Case 1, soil-cement was used as backfill material to a height of half the diameter measured from the bottom of the pipe. In Case 2, soil-cement was used as backfill to a height of quarter diameter measured from the bottom of the pipe. The mixed rock, which was recycled crushed concrete and crushed gravel, was backfilled above soil-cement to the top of the pipe. The pipe was buried under a depth of approximately 3.0 m in both cases. Displacement transducers were installed in the pipes and strain gauges were attached to the inner of the pipe. Earth pressure transducers and pore water pressure transducers were installed in the backfill materials around the pipes. The deformations in each of the backfilling stage were measured. It is found that the behavior of the buried pipe was strongly influenced by backfilling methods and external force.

The ring stiffness of flexible pipe specimen is usually measured in the laboratory according to the parallel-plate load test (ASTM D-2412) method. When the laboratory test equipment is not available, a theoretical solution based on the elastic curved beam theory is often used to estimate the ring stiffness of the flexible pipe. Laboratory test data accumulated by the author indicated that the classical solution has a tendency to overestimate the actual ring stiffness of thermoplastic pipe significantly. In this paper, the parallel-plate load test method is examined closely to identify the area where the classical curved beam solution deviates from the actual test conditions. Based on the finding the classical theory is modified to obtain a more realistic solution for the ring stiffness of the flexible pipe measured under the parallel-plate load test condition. The revised solution expresses the ring stiffness as a function of the pipe radius, flexural rigidity of the wall section, and the extent of the flattened region appearing at the pipe's crown and invert regions. The revised pipe stiffness formula is evaluated using the laboratory test cases presented earlier. The outcome shows that it reduces the degree of overestimation made by the classical solution.

This research investigates the soil-pipeline interaction in sand subjected to lateral ground displacements with emphasis on the peak forces exerted to a bended elbow-pipe. The purposes of this study are to reveal the behaviour of the buried elbow-pipe, where larger soil restraints are likely to occur on the elbow-region under sudden ground movements, and to improve the structural modelling. A series of three-dimensional (3-D) finite element (FE) analyses were performed to develop a design guideline of a buried elbow pipeline subjected to lateral ground loading. The investigations were conducted in both opening and closing modes of the elbow section for different initial pipe bending angles. Considerations were also given to the effects of pipe embedment depth, sand density and pipe-surface roughness. The pipeline was modelled by isotropic 3-D shell elements and the sand was modelled by 3-D solid continuum elements. To model the mechanical behavior of sands, Nor-Sand soil model was adopted. Results show that the opening mode exhibited higher ultimate forces and greater localised deformations when compared to the closing mode. Higher peak force values were computed when the pipe is deeper and the soil is denser. A non-dimensional chart that accounts for pipeline locations, bending angles and soil densities is developed. The observed soil failure mechanisms are also presented.

The very weak peat soil stretches over Sorachi District in Hokkaido which is an extremely important agricultural area. There are many agricultural facilities that encounter geotechnical problem, such as long-term settlement. The settlement of the bedding of pipeline has been a serious problem. In this study, two types of field tests were conducted using the Fiber-reinforced plastic mortar pipe and polyvinyl chloride pipe having diameters 700mm and 350mm, respectively. By changing the bedding materials using sand and peat, comparison experiments were carried out on the deflection of pipe and circumferential strains, and pipe settlements. Contrary to existing design specifications that require sand as bedding material, the test result showed that the deflection of pipe using the peat as bedding material was smaller than that of sand.

Soil-structure interaction analysis of culverts is typically conducted within two-dimensions, assuming the culvert and surrounding soil are in a plane strain condition. This is adequate for analysis of deeply buried pipes, but is a poor compromise for investigating the performance of pipes with a shallow cover subjected to live loads, where three-dimensional attenuation of the live load takes place both through the soil and the structure. In most cases evaluating live load effects in two dimensions leads to conservative designs, as the longitudinal distribution of load is underestimated. Recent advances in computational technology now allow full three-dimensional analysis of this problem, but there are many questions to be addressed in determining suitable soil models and other aspects of the problem. This paper reports on research into modeling of full scale live load tests on culverts. Important aspects of soil models suitable for three-dimensional analysis of culverts subjected to live loads are discussed. Shear failure and stiffness variation with depth are found to be important in modeling live loads.

Current design standards do not take account of soil variability along buried sewer pipes ignoring the longitudinal bending. However, considering the current installation practice it appears obvious that the bedding or loading conditions are not uniform. In order to quantify the amount of disorders that originate from the longitudinal pipe behavior a statistical analysis of CCTV inspections outcome gathered in the Greater Lyon, France is used. It appears indeed that the major part of the observed defects might be related to the longitudinal behavior. An explanation of this result may be given both by a statistical and numerical approach. A statistical model developed from the database helps to identify some factors that may contribute to the failure occurrence within buried pipes by longitudinal bending. The performed numerical 3D simulations analyze the effect of both the pipe joint and the most common bedding heterogeneities.

A bend in the pipeline with internal pressure will generate thrust externally. For a buried pipe, this thrust is supported by the passive earth pressure through the backfill at the bend, which is typically supported by the concrete block. The magnitude and the shape of distribution of the earth pressure are not readily known. In this paper, pit tests were conducted using a pipe model having 260 mm diameter and that was equipped with 20 bi-axial load cells on the surface. Similar tests were conducted using a plate for direct comparison. The earth pressure distributions acting on the pipe surface were observed. In addition, numerical analyses by distinct element method were conducted to clarify the mechanism of the behavior of the laterally loaded pipe. The test and the numerical analyses results indicated that the passive soil pressure distribution for a plate was uniform. However, in case of a pipe bend, the lateral earth pressure distribution was not uniform and it was affected by friction between the pipe surface and soil.

Gravity sewer installations require a level of accuracy tolerance of 25 mm (1 inch) on line and grade. Gravity sewers [smaller in diameter than 914 mm (36 inch)] can be installed using open cut and trenchless techniques such as pilot tube guided boring, microtunneling, and auger boring. Each of these techniques has advantages and disadvantages, and each can be the best option under certain circumstances. Open cut is a costly alternative if the sewer is deep, is below the ground water table, or includes costly reinstatement. Similarly, the above-cited trenchless methods are costly. Therefore, the owners of gravity lines need more economical alternative technique than these methods. The ability of conventional horizontal directional drilling, to install pipelines with the required accuracy for sewer installations, is questionable. However, the ArrowBore technique promises the ability to install gravity sewers using horizontal directional drilling as a cost-effective alternative. This paper presents a case history of the installation of 122 m (400 ft) of 300mm (12 inch) diameter gravity sewer in Berea, Ohio that was installed using the ArrowBore method. This sewer line was 12 m (40 ft) deep in gray clay with shale fragments. The sewer was installed successfully, except at a certain location where an unforeseen rock formation was encountered. This paper presents the design and construction aspects of this sewer, along with a discussion of the lessons learned.

A two pass tunneling system has been traditionally used for installation of water transmission crossings due to concerns of damaging the carrier pipe or its joints during the installation process. The improvements of the micro-tunneling techniques and the availability of rugged, rigid pipe and joints such as reinforced concrete cylinder pipe (RCCP) have allowed the use of single pass micro-tunneling systems in a growing number of recent projects. RCCP with individually testable joints as the pipe is being installed has been specified to insure that proper installation methods have been utilized. RCCP's continuous steel cylinder and steel joint rings welded to the cylinder ends allows for field welding to provide thrust restraint when required. Five such recent projects, which vary from 36 in. (914 mm) to 66 in. (1676 mm) in diameter and design pressures between 49 psi (340 KPa) and 350 psi (2413 KPa), are presented. The main components and features, pipe design and manufacturing procedures, and performance record of RCCP used in jacking or micro-tunneling are described. The cost advantages of a single pass micro-tunneling system over the two pass system are discussed and shown. Conclusions based on the results of these projects are given.

Models available for estimating the rheological response of high density polyethylene (HDPE) are reviewed. A constitutive model combining elastic, viscoelastic, and viscoplastic components is proposed to calculate strain recovery and long term stress conditions in HDPE pipes pulled into place using trenchless construction methods. The ability of the new model to capture HDPE creep, relaxation, strain reversal, and strain accumulation and recovery during cyclic loading is examined by comparing simulations with experimental data. The new model is better able to provide response involving unloading and strain reversal. Temperature effects on the mechanical behaviour of HDPE are not considered in this paper.

With an increase in horizontal directional drilling being employed for the installation of buried utilities in urban areas, unmarked sewer service laterals present a risk of accidental and unknowing cross-bores with these distribution lines. While the physical damage to underground facilities is always unwanted, a major concern facing utility contractors are catastrophic losses resulting from utility lines that are exempt from locating laws. Even the most professional HDD contractors are being held liable for hitting these unmarked, unknown lines. The insurance industry is rapidly becoming aware of this exposure and is subsequently making it difficult and costly for contractors to secure insurance for trenchless utility projects. State legislation mandates the marking and locating of underground infrastructure; however, the question of who assumes responsibility for marking and locating sewer service laterals is a contentious one. System owners/operators generally place the responsibility of locating and marking in the hands of unsuspecting property owners claiming that the laterals are on private property. In reality, property owners lack the expertise and equipment to mark and locate these service laterals. This paper discusses the issue of current legislation pertaining to unmarked sewer service laterals and examines ways for minimizing exposure to public risk from cross-bores.

New EPA and State of California drinking water regulations mandate the filtration and disinfection of potable water supplies subject to surface water runoff. In response to these regulations, the City of Los Angeles Department of Water and Power (DWP) embarked on the $70 million Stone Canyon Water Quality Improvement Project, modifying facilities originally constructed in the 1920s and subsequently changed in the 1950s. Because of restricted access to the project site, sensitive nearby residential communities, and the scenic environs, design of a new 8,000-ft long bypass pipeline and appurtenant facilities was based on trenchless construction methods, and includes two tunnels and a reservoir bottom pipeline. The new Bypass Line No. 2 interfaces with the existing Bypass Line No. 1 and includes a new diversion structure, several large valves and metering vaults, a microfiltration plant and pump station, and a chlorination facility.

In the summer of 2005, two (2) HDD shore approaches (2200 feet & 2300 feet long) were constructed to the Port of Miami from the Marine Sanctuary in Biscayne Bay and under the main shipping channel. 24-inch diameter steel casings, pre-installed with two (2) 8-inch diameter steel ducts, were installed at each crossing to house 138 kV and 69kV power line circuits. Two horizontal rigs were utilized and worked in unison to drill the shore approaches. An 880,000-pound rig was setup on land inside the Miami container port and a 70,000-pound rig was setup on a barge staged in the Biscayne Bay. Several challenges were faced in view of having to work within one of the busiest ports in the US along a congested shipping channel with strict regulations imposed by the Department of Environmental Protection (DEP) and the Department of Environmental Resource Management (DERM) for operating in this highly environmentally sensitive area. DEP and DERM were involved in all activities occurring in these "clear & pristine waters of Florida." The regulations were very demanding and included no movement of equipment at night, trained on site observers for manatees (large, herbivorous, marine mammals) with a complete marine project shutdown in the event of any manatee sightings, and a restricted work zone in the marine sanctuary to allow containment of any drilling fluid returns or fractures while minimizing the extent of sea grass damage. This paper describes the operational procedures that were designed to enable construction within the confines of the permitted activities and used to deliver the successful completion of the HDD shore approaches.

In the past two decades, the Hillsborough County Water Resource Service Department (HCWRS) has been actively expanding its reclaimed water system in the south-central service area, both as an effluent disposal method and as a potable water saving mechanism. Currently the HCWRS reclaimed water customer base is comprised of golf course users, industrial users, commercial and residential customers. To meet increasing demands in the south-central service area and pressure requirements during the peak hours, HCWRS has identified the need for additional Reclaimed Water Transmission Main (RWTM) capacity along Lithia Pinecrest Road and Bloomingdale Avenue. To serve high demands of the fast growing communities in Hillsborough County, Florida, HCWRS is challenged with designing new transmission mains within highly congested and restricted right-of-way. For each project the Water Department designers must be conscious of the impact of surface disruption and the associated socio-economic costs to the general public, as well as the projects' overall cost. The design for the 24 in. (610mm) transmission main in Lithia-Pinecrest Road, a two-lane thoroughfare, was no different. This project was complicated by the volume of traffic in combination with portions of the alignment transitioning through a very congested right of way. The line begins at the intersection of Lithia Pinecrest Road and Bloomingdale Avenue, an east-west arterial highway and proceeds in a southeasterly direction for approximately 12,500 ft. (3.6 km) on an alignment that takes it past schools, businesses, and residential areas, and terminates at the entrance to River Hills Country Club. After a thorough analysis of the route studies and cost of open-cut construction versus horizontal directional drilling (HDD) methods, HCWRS project management chose to install the line using both open-cut and HDD construction methods. The 6,000 ft. (1.8 km) of water line installed by HDD construction would be a series of seven separate pulls using 24 in. (610 mm) flexible restrained joint ductile iron pipe manufactured by American Ductile Iron Pipe in 20 ft. (6.1 m) joint lengths. This paper will discuss in detail the comparison of the costs of the different routes and the two (2) methods of construction. It will then detail that portion of the line installed using HDD technology and address the flexible restrained joint ductile iron pipe and how using the cartridge method minimized disruption to the general public.

Early in the conceptual design stages of a water transmission main design project for the Wareham Fire District, Wareham, MA, it was learned that a second, independent municipal entity was planning to provide sewer service to the same area. In order to reduce design and construction costs, it was decided to have both the water and sewer lines designed by a single firm. This would eliminate or reduce costs involved by having two parties design similar crossings. Also, by including the construction of both lines in one bid package, mobilization and construction costs were reduced. The two installations consisted of 488 meters (1,600 linear feet) of 300 mm (12-inch) diameter High Density Polyethylene (HDPE) water main and a 488 meter (1,600 linear feet), 250 mm (10-inch) diameter HDPE casing sleeve in which a 150 mm (6-inch) force main was to be installed. Both lines were constructed under the Weweantic River, a tidal water body, by means of Horizontal Directional Drilling (HDD). The paper will present design, coordination and permitting issues for the project. It will cover the construction activities which included encountering boulders along the drill path. It will also present the drilling contractor's working closely with neighbors and residents who live adjacent to the work site.

This paper presents the case history of a wastewater main infrastructure rehabilitation project with a challenging set of location parameters to overcome. The challenge presented by this project is how to rehabilitate an existing 50-year old clay wastewater main located in a utility easement traversing established, residential backyards. The location of this main is adjacent and along the shore of the domestic water supply lake where access to all the manholes is restricted from vehicle access. The condition assessment for the approximately 14,600 linear feet of a 33-inch, 30-inch and 24-inch trunk wastewater main indicated serious infiltration ground water leakage into the manholes and clay pipe joints - including root intrusion in certain sections of the main. This infiltration increased in direct response to operating water levels of the domestic water supply lake. Thirty-six residential service laterals were also directly connected to the main which were leaking and also had severe root intrusion. The project contained a total of 40 manholes which were located in developed residential backyards with landscaped amenities including swimming pools, landscaped beds, tennis courts, fencing, boathouses and ramps adjacent to a domestic water supply reservoir with no vehicular access. The Trenchless Cured in Place Pipe ("CIPP") Technology process is performed from access provided by existing manholes along the sewer alignment. The location of the manholes range from actually submersed in the domestic water supply lake to the high bank making the location of the existing manholes problematic for the application of CIPP trenchless technology due to weight and size of the vehicle required to transport the rehabilitation material to the manhole access. The transportation weight of CIPP is in excess of a fully loaded 8 cubic yard cement mixer vehicle. There were many challenges faced during this rehabilitation project. In addition to the location and access issues, the City of Arlington Mayor lived across the street from the first insertion site on the project which added to the difficult location issues. Thirty-six residential laterals needed to be excavated and disconnected before beginning the rehabilitation; then reconnected after rehabilitation. The issues associated with the routing and operation of the wastewater by-pass pumps and pipelines in private backyards adjacent to high bank of the potable domestic water supply were also addressed in this project. The project also addressed the need for by-pass pumping of fifteen wastewater mains in utility easements that were connected to this existing wastewater main in need of rehabilitation. Rehabilitation of the wastewater main was required to reduce the infiltration and restore original flow capacity. This paper will present innovative design solutions on how these rehabilitation issues were solved, details on how the City of Arlington addressed the concerns of residents, and how this project was managed - including the use of innovative A+B bidding - resulting in the completion of this project ahead of schedule and within budget.

Traditional methods of underground pipeline installation and replacement generally employ conventional open cut methods. These trenching methods in most urbanized settings typically create road closures, traffic delays, unnecessary detours, loss of access to homes and businesses, unsightliness, noise, and general disruption for everyone. Faced with population growth and an aging underground utility system, China has looked to emerging technologies to provide sustainable solutions to addressing this situation. Many challenges are present when promoting trenchless technologies in China including minimal local engineering knowledge, lack of trained contractors, lack of specifications, and system impact concerns raised by government owners. This paper provides a discussion of experiences in adopting trenchless technologies in China with recommendations obtained from lessons learned for individuals looking to initiate such future projects.

Two dimensional finite element analyses can successfully estimate ground movements and stresses associated with static pipe bursting in the plane perpendicular to the pipe axis. However, they provide no information about the ground movements parallel to the pipe axis or the magnitude of pulling force needed to advance the burst head. Axisymmetric finite element analysis has therefore been developed to explore the axial progression of the burst head, the ground resistance to that advance, the magnitude of axial ground movements, and the effect of soil characteristics on the response of the burst head and the surrounding ground. Calculated response is compared to laboratory measurements of ground movement and pulling force to evaluate the effectiveness of the finite element modeling.

Manholes are a crucial part of the collection system. They serve as entryways to an extensive underground pipeline infrastructure. Today, the big picture is really the same as yesterdays and that is achieving the most cost effective and time saving methods for eliminating as much infiltration/inflow as possible. By addressing and implementing renewal techniques for one of the most critical and obvious portions of the collection system, "the manhole chimney" the big picture becomes more obtainable. Manhole chimneys were typically constructed poorly with shims and small pieces of brick and mortar. This area is subject to freeze/thaw conditions in many geographical areas. Poor construction practices and freeze/thaw conditions are direct causes of faulty chimneys and have been identified as a crucial source of inflow. Technology for renewing the vast network of pipelines and manholes is advancing with faster, more efficient, and more cost effective techniques. This paper will discuss new technologies for renewing and sealing the manhole chimney/ frame area using a (cured in-place manhole chimney liner). This paper will explain the simplicity of a one-size liner used to fit a host of various sized and configured manholes with minimal labor requirements. Most importantly, this paper explains the stringent protocol carried out by a third party engineering/testing laboratory to extrapolate longevity of a renewed chimney that has been subjected to severe freeze/thaw cycles.

As part of the San Diego County Water Authority's (SDCWA) $939 million Emergency Storage Project, the Lake Hodges to Olivenhain Pipeline Tunnel (LHOP) will connect Lake Hodges to Olivenhain Reservoir to provide an uninterrupted source of water to San Diego County if a catastrophe, such as a major earthquake, were to cut off the water supply from north. The pipeline will allow the SDCWA to move water from one reservoir to another and will also be used for pumped storage, generating electricity at peak times. Seeking to expedite project completion, the project was advertised as Design-Build, a first for the SDCWA. Awarded to Kiewit Pacific with Parsons as designer, it was decided to construct the tunnel using a conventional drill and blast technique, incorporating a final steel liner with grades as steep as 20%. Anticipating difficult ground conditions, the mining method was well suited to deal with the shear zones, faults, and the potentially high groundwater table anticipated along the alignment. In addition, the high alignment provides long term operational benefits to the SDCWA. At the apex of the alignment, a 200 ft. high, 11 ft.'–6 in. diameter unreinforced raised-bore shaft will be constructed with a surge chamber to protect against pump malfunction. Due to pressures exceeding 450 psi, the inherent strength of the rock was utilized through load sharing to reduce the wall thickness of the steel liner, balancing economy and strength. With stringent requirements for steel strength and toughness, ASTM A841 steel was identified as an ideal material. Created using the Thermo-Mechanical Control Process technique (TMCP), the steel has excellent mechanical and toughness properties, with an extremely fine grain structure. The steel was purchased and sent from Voest-Alpine in Linz, Austria. Scheduled to come on-line by January 1, 2008, the Lake Hodges to Olivenhain Pipeline 40 megawatt pumped storage project is valued at $108 million, delivering a reliable source of water in emergency situations and electricity-generating capability to meet the demands of the growing San Diego region.