Pipelines 2010: Climbing New Peaks to Infrastructure Reliability: Renew, Rehab, and Reinvest

Some known phenomena which cause a buried steel pipeline to fail are large ground motion and landside. Thus, many researchers have studied pipelines behavior against those phenomena with simplified assumptions in which effects of interaction between soil and pipe are not considered as well. In this study, the behavior of a pipe through Normal and Strike slip faults and contact between them are simulated close to reality with the powerful software of ABAQUS. The results from a parametric analysis on effects of those faults on buried steel pipelines show that increasing the angle between the pipe axis and fault plane (up to 90°), as well as the pipe thickness, and decreasing the burial depth diminish the probability of pipe failure crossing active faults. Change in pipe diameter also affects the pipe strength to a lesser degree.

The Ojai Valley Sanitary District (OVSD) experienced failures on two old asbestos cement force mains due to hydrogen sulfide caused corrosion. The failures were worrisome, because the failures had occurred next to a stream crossing, not far from the Ventura River, and the pipe structures were found to have very poor integrity. The pipeline was also exposed at the stream crossing and thus was vulnerable to high-flow events. Moreover, concrete encasement of the pipeline had become an impediment to fish passage. The Ventura River and many of its side streams are considered critical habitat for the Southern Steelhead Trout, and other endangered species. As part of an environmentally concerned community, OVSD continuously strives to mitigate its impact on the environment. Instead of taking a band-aid approach to the force main problem, the District looked at how the failing pipeline fit into the system as a whole. Currently, two 40-year old lift stations operate in series, which results in septic conditions and severe H₂S corrosion at both the second lift station and at high points within the pipeline. Both lift stations are in need of repair and refurbishment, and fall short of modern standards in terms of working space, safety, and reliability. Proposed development in the area created opportunities that did not exist earlier, and certainly would not exist later, once the developments were constructed. After studying several alternatives, the District determined that a single, high-head lift station should be used, along with a new gravity flow pipeline. Eliminating the second lift station would result in reduced operations and maintenance expenses. A completely new force main would be constructed along a new alignment, delivering wastewater directly to the treatment plant, about 2 miles away. Much of the project expense involved the construction of two parallel pipelines, a force main and gravity main, within a common trench. This paper looks at specific details of the project design and construction, including provisions to minimize H₂S generation. Large portions of the pipelines were constructed using trenchless methods (horizontal directional drilling, pipe ramming, and bore and jacking) because of conflicts with existing utilities, archeological sites, and other site conditions. Passing both a petroleum refinery and water treatment plant, portions of the pipeline alignments were dense with active and abandoned pipelines. Ground penetrating radar was used in an extensive effort of utility mapping. Challenging and variable geologic conditions exist, with high groundwater, running sand, cobbles, and concealed boulders found interspersed with more favorable materials. Both HDPE and PVC were used for different portions of the pipelines. The design includes a new lift station "shoe horned" into the existing lift station site, using caisson construction methods for the deep wet well.

The CSO Conveyances Project consists of approximately 4,500 feet of new gravity conveyance pipe ranging in size from 12 to 96 inches in diameter. The installation of the new conveyance system consisted primarily of cut and cover method up to cover depths of 23 feet. Railroad, water crossings and those sections of the alignment at depths greater than 23 feet were constructed using trenchless methods, such as jacking, pipe ramming and microtunneling. The purpose of this paper is to summarize the pipe selection process and to present the results of the pipe design analysis for a number of pipe materials. For the cut and cover method, two flexible pipe materials were evaluated - fiberglass reinforced plastic (FRP) and high density polyethylene (HDPE) pipe. For the section constructed using trenchless technology, FRP and Polycrete pipe were considered. In total, the characteristics of pipe produced by five different pipe manufacturers were evaluated for the cut and over sections of the alignment. Pipe produced by two different manufacturers were evaluated for the jacked pipe alignment. To be able to manage the enormous volume of calculations, excel spreadsheets were developed and tested using hand calculations of typical sections.

Horizontal directional drilling (HDD) has played a major role in allowing construction of a raw water delivery system project for the Standing Rock Sioux Tribe in South and North Dakota. A record setting 1,463 m (4,800 LF) bore under a dam-retained section of the Grand River, Oahe Lake, of 600 mm (24-inch) Fusible C- 905® pipe has defined an early success on the 110 million dollar project. King Contracting, Inc. (King) completed the bore which represents the longest bore ever done using 600 mm (24-inch) Fusible PVC^TM pipe (FPVCP) to date. This crossing represents a little less than 1.5 km of the ∼100 km (62 miles) raw and treated water transmission pipeline delivery system, which when completed, will provide water to the Standing Rock Reservation.

The City of North Bay Village (City) needed to construct a new 16-inch Sanitary Sewer Forcemain from the City's Main Pump Station along the 79^th Street Causeway west through the City of Miami and connecting directly to a Miami-Dade Water and Sewer Department (MDWASD) 24-inch forcemain. The proposed 16-inch forcemain (FM) will serve as a replacement pipeline to the existing 12- inch forcemain that transports wastewater from the City of North Bay Village to Miami Beach's wastewater system which is the re-pumped to MDWASD's Central District Wastewater Treatment Plant (CDWWTP). The existing 12,000 feet of cast iron forcemain poses environmental, health and safety risks due to its age and condition. In addition, the existing forcemain could be rehabilitated in the future providing the City with a redundant forcemain to transport sewage should the proposed line fail or be required to be shut off. The Design-Build Proposal presents the findings of the City's Feasibility Study and our team's due diligence, technical and construction experience to deliver the best solution to meet or exceed the City's goals for schedule, budget, innovation, operability and public impact.

The Val Vista Water Transmission Main (Val Vista) carries approximately 1/3 - up to 220MG - of the City of Phoenix's (City) potable water from the largest of five water treatment plants within the City's water distribution system. The pipeline consists of a single 15-mile pipeline that includes 72-, 84-, 90-, 96-, and 108-inch Prestressed Concrete Cylinder Pipe (PCCP), installed in the mid 1970's in five separate phases. The pipeline is operated by gravity from the water treatment plant's finished water reservoir, which results in pressures ranging from 10 to 80psi.The pipe was manufactured with many different design parameters, but for the most part it was rated for 150psi with class III wire and 16-gauge steel cans. When the pipeline was originally constructed, much of the easement was undeveloped land though the Cities of Tempe and Mesa. However, through the years the areas surrounding the alignment have grown significantly with high volume roads, retail, residential, and industrial development. With this development, the pipeline has encountered some realignment projects that resulted in the original pipeline being removed and replaced. Once such realignment took place in 1999 at the lower portion of the pipeline on approximately l,000LF of 72-inch pipe. During the removal and replacement project, the pipe was discovered to have significant signs of corrosion. This discovery resulted in the Phoenix Water Services Department to initiate a long term program to investigate the condition of the entire pipeline. This included numerous electromagnetic & visual/sounding inspections, live monitoring, and removal and dissection to determine the level of condition on this critical artery of distribution system. Due to the results of these investigations there were multiple sections of internal carbon fiber installed, and two pilot rehabilitation projects completed between 2003 and 2006. After successfully completing split steel can rehabilitation of 10,000LF of 72-inch on the Val Vista pipeline in 2005 and 2006, the City decided to initiate a program to design the rehabilitation of the remaining 68,000LF so that it could be constructed as funds were available over the next ten years. The design was completed in August 2007 allowing the first phase of construction to be completed in the 2008/2009 shutdown period. Consisting of 18,500LF of 72-, 90-, and 96-inch pipe (Figure 1), this project resulted in the largest split steel can rehabilitation project of PCCP to date in the United States of America.

The on-set and propagation of tensile cracks are the limiting factors in designing grout-in-place liners which utilize cementitious grouts. To improve the strength of the grout and postponed the on-set and delay the propagation of tensile cracking, micro-fibers were added to a low viscosity commercial grout. Four fiber types were utilized in this experimental study (polypropylene, poly-vinyl alcohol, glass fiber and carbon fiber) to determine the best performing fiber that maximizes the tensile and flexural strengths of the grout with little or no reduction in flowability. Micro-fibers were added at predetermined weight percentage fraction with respect to the cementitious material. The addition fiber percentage was controlled by the need to maintain the viscosity of the grout within a fixed range. The effect of fiber addition on the grout strength was studied by performing standard tensile and bending tests (ASTM C 307 and ASTM C 580) on the fiber reinforced grout specimens. Results from the tensile and flexural tests suggest that the addition of micro-fibers could significantly enhance the tensile strength of low viscosity cementitious grouts without hindering their flowability.

The City of Fort Lauderdale is a fully developed, coastal city in southeast Florida. However, even in this densely populated area, almost 40% of the City was still served by onsite sewage disposal systems. One of the primary goals of the City's $700 Mil Waterworks 2011 infrastructure program was to provide sanitary sewer service to the remainder of the City. Faced with the need to construct over 560,000 LF of new gravity sewers in 19 sewer basins in a relatively short period of time, alternative construction project delivery methods were considered. Due to the nature of underground sewer construction in urban areas, there was the desire to control issues which can negatively impact the progress of a project including: change orders and delays due to unforeseen conditions, contractor performance, site maintenance, relationships with the affected community and the ability to get projects under construction in a timely manner. The basic concept of general services contracting (GSC) is to reduce what would be a potentially unmanageable number of construction contracts to a lesser number of potentially longer term contracts. Over $150 Mil in sanitary sewer and water distribution main work was separated into two general services contracts. The contracts were developed by establishing and bidding generalized work quantities based on 4–6 contractors being selected for work under each contract. Contractors were selected based on lowest bids to the generalized quantities. Once the contractors were selected and under contract, individual work orders were issued for the specific projects. While maintaining compliance with public bidding requirements, the City went through only 2 bidding processes in 5 years while completing 63 separate projects. This not only reduces time and costs for the City, it allows contractors to plan and schedule work instead of relying on the uncertainties of bidding. The use of general services contracting provides efficiency with respect to managing the competitive bidding process, while maintaining an appropriate level of control over the contractor's activities. In addition to reduced administrative costs, the use of GSC allowed the City to continually evaluate the performance of each contractor with respect to safety, change orders, public outreach and quality of work and to decide if future work would be issued under the contract. Another benefit was the development of positive relationships between the City and its contractors, leading to improved cooperation in all aspects of the construction process. The use of GSC contracts created the ability to break large project areas up into smaller construction packages, thus reducing neighborhood impacts and schedules while maintaining the economies of scale usually only seen with larger projects. The use of GSC was a win-win situation for the City and the contractors that performed the work. Without the use of this tool, the City would not have completed the Waterworks 2011 sewer construction program within the planned schedule.

The Calleguas Municipal Water District is constructing a new ocean outfall, the Hueneme Outfall, near Port Hueneme, California. The outfall will serve as the termination point for the Calleguas Salinity Management Pipeline (SMP), which will collect salty water generated by groundwater desalting facilities and excess recycled water and convey that water for reuse. When there is insufficient demand for the recycled water, unused flows will be discharged to the ocean through the Hueneme Outfall. The Hueneme Outfall will consist of 2,300 feet of horizontal directionally drilled (HDD) 36-inch outside diameter (OD) high density polyethylene (HDPE) pipe connecting to 2,700 feet of 30-inch inside diameter (ID) steel pipe laid on the seafloor and terminating in a 30-inch ID steel pipe multi-port diffuser with duckbill valves. The HDD segment exits in about 30 feet of water and involved reaming, pipe layout, and pipe pullback using the assistance of divers, barges and marine support vessels. The seafloor segment, including the diffuser, will be laid on the ocean floor using marine vessels and divers.

Calleguas Municipal Water District (Calleguas) is a member agency of the Metropolitan Water District of Southern California (MWD). One-hundred percent of Calleguas' potable water supply comes from MWD, through the California State Water Project; the water enters Calleguas' service area in Ventura County through a single pipeline at the eastern end of its service area. Until recently, there was no redundancy or alternate supply of water, other than a 10,000-acre-foot reservoir (Calleguas' annual demand is approximately 120,000 acre-feet). Calleguas' entire water supply could be shut off in the event of an emergency such as an earthquake. In the late 1980s, Calleguas began planning a means of supplementing the supply from MWD. They executed a conjunctive use agreement with MWD, whereby Calleguas would construct aquifer storage and recovery facilities to allow Calleguas to take excess water from MWD during periods of low demand (i.e., the wet periods) to store in an underground aquifer, and then pump the stored water from the aquifer into the transmission system during periods of high demand (summer months or droughts) or in the event of an emergency or outage from MWD. Calleguas' service area encompasses an aquifer about 18 miles long and 4.5 miles wide, with about 300,000 acre feet of available storage space. Calleguas began a multi-year effort to plan, design, and construct the aquifer storage and recovery (ASR) facilities necessary to implement a conjunctive use project using the Las Posas Basin Aquifer. The facilities included a wellfield with 18 ASR wells with a total capacity of 70 cfs, five miles of large-diameter pipelines ranging in size from 60- to 72-inches in diameter and located in a major thoroughfare, a five million gallon reservoir, chloramination facilities to disinfect the water when it is pumped from the aquifer, and a new pump station and pressure regulating station. The wellfield and pipeline facilities were completed in 2006, and have operated to store about 70,000 acre-feet of water in the aquifer to date. The pump station was completed in 2009, and was put into immediate use due to cutbacks in the supply from MWD; it has operated nearly continuously since it was completed. This paper discusses the need for the project, the agreement with MWD for conjunctive use, and the process of planning, designing, and constructing the ASR facilities. It presents some of the many challenges encountered during planning, design, and construction of the facilities, particularly during the construction of the large-diameter pipelines and associated tunnels.

The City of Aurora is one of the fastest growing communities in Colorado, and currently the state's third-largest city with a 2007 estimated population of 312,000. With this growing population, the capacity of several key segments of the wastewater collection system must be increased. The Tollgate Creek Interceptor conveys wastewater collected from the Tollgate Creek drainage basin to the Sand Creek Interceptor, which then conveys the wastewater to treatment at the City's Sand Creek Water Reuse Facility and the Metro Wastewater Reclamation District's Robert W. Hite (formerly "Central") Wastewater Treatment Plant. A portion of the Tollgate Interceptor between East 2^nd and East 11^th Avenues was paralleled in the early 1990s. More recently, interceptor capacity needs have been addressed via paralleling portions of the interceptor upstream (south) of East Alameda Parkway. The remaining portions of the interceptor (identified herein as the South and North projects) require parallel pipelines. In 2007, a collection system hydraulics model was developed to determine system needs. Based upon the results and predicted flows, the parallel pipes were sized at 36-inch diameter and 42-inch diameter. To allow for rehabilitation of the existing interceptor, the City has requested that the new interceptor be designed to transport all flow for ten years after completion of construction. The City of Aurora retained CDM to complete the route analysis and design for the interceptor parallel.

Plastic pressure pipes have been in use in North America for at least 40 years. Thermosetting plastics and thermoplastics commonly utilized in municipal pressure applications include fiberglass reinforced plastic pipes (FRP), polyvinyl chloride (PVC), high density polyethylene (HDPE), and more recently, fusible polyvinyl chloride (FPVC). Typically, these materials undergo hydrostatic pressure testing first in the manufacturing facility, then a second time in the field following installation. For field hydrostatic leakage testing, most pipe materials have an associated "allowable makeup water" or "allowable leakage" to accommodate the unique characteristics of the material as well as other irregularities during testing such as air in the line, temperature variations, and even instrument inaccuracies. Test methods and formulas for calculating makeup water usually vary based on the pipe material-specific standards. The wide discrepancies that exist for makeup water between different pipe materials do not place them on a level playing field for a given application. This paper is a review of both in-plant and in-field hydrostatic pressure testing and the topic of makeup water as outlined in AWWA standards for plastic materials. Quality control and qualification tests for joints of each pipe material standard are also reviewed. Recommendations are made for consideration by the Specification Engineering community for future revisions of standards pertaining to the field testing of plastic pipelines.

The City and its Engineer bid, during the summer of 2005, about 3,200 ft of 36 inch HDPE pipe for a lake crossing to be installed via Horizontal Directional Drilling (HDD) in order that this water transmission line could be put in service by May 1, 2006. On July 14, 2005 when bids were tabulated, Company X became the lowest bidder at $1,740,000. The second and third lowest bidders were at $ 2,004,053. and $ 2,289,400, respectively. The contract completion date was agreed upon as November 1, 2005 at the pre-construction meeting held on August 16, 2005. The entire, final design and alignment selection were based on only 4 soil borings and no appropriate geotechnical baseline report was ever done or used by the Engineer or their HDD consultant. The driller had so many problems that could have been anticipated even if one of the parties involved in this project spent a few more minutes studying the implications of the 4 soil borings. The author was retained on November 14, 2007, by the law firm representing the driller, to conduct an independent investigation as to the causes that led to the delay and cost overruns on this project after the driller had been at the site for longer than 1,000 days and had spent over $6 million by their estimate. Loss of drilling fluids, caving of roads, settlement of houses, buildings, and other calamities were the outcome that the driller, the engineers and the city faced. The lives of local residents were disrupted for many months. There were many lessons learnt and the author shares many of them with the attendees of this conference in the hope similar problems can be avoided in the future.

Twenty-first Century pipeline projects are faced with challenging constraints, increased regulatory requirements, escalating costs, greater demand for service, and a high expectation for the newest improvements. The City of Aurora, CO retained third-party construction management services to represent their interest during the construction for the Prairie Waters Project (PWP). This project includes a north campus with an alluvial well field, an aquifer recharge and recovery basin. It also included a conveyance system of over 37 miles of 60" diameter steel pipe, twenty- one trenchless crossing, three 50 MGD raw water pump stations and a water purification facility. The project had major environmental constraints and mitigation. It was designed and constructed in a manner to prevent a federal permitting process. As the City's 3^rd party construction manager for the north plant and conveyance part of these elements, the author provides insight to the following project specific challenges during construction: (1) Stringent environmental controls for a project which avoided the EIS process (2) Owner Controlled Insurance Program (OCIP) (3) Hand held GPS survey measurements for each joint and appurtenance (4) Paperless Document Control Administration via the City's SharePoint "Prairie Net" (5) Multijurisdictional installations (6) Coordination with the City's Program Manager, Public Involvement Program, Environmental Consultant, Land Acquisition Agent and Permitting Consultants (7) Contract Administration on concurrent construction contracts The PWP is a critical part of Aurora's plan to improve the level of service of its water supply system under drier conditions, to meet growing demands, and provide additional supply reliability by accessing a new water source that is less weather-sensitive than the traditional mountain and trans-basin sources which are being used for current supplies. This paper discusses how using third-party construction management (CM) effectively controls costs for owners throughout the project life cycle. The author begins by defining third-party construction management and describing instances when an owner should consider this delivery management system. The paper describes completion of work despite the challenges listed above from the role of third-party construction management during the construction stage of the project life cycle. The value delivered to owners from employing this delivery management approach is shared from the author's first-hand experience with pipeline inspection during construction.

Since its first uses and patents in the mid-nineties, the application of carbon fiber reinforced polymer (CFRP) strengthening (fiber wrap) in pipelines has grown to become a widely used and recognized repair and strengthening system for aging prestressed concrete cylinder pipes (PCCPs) with broken prestressing strands. The ability of FRP repair techniques to allow the host PCCP sections to resist high internal pressures and as well as external loadings without requiring excavation of the pipe provide advantages for the fiber wrap technology over existing techniques. Advantages of FRP repair of PCCP is specially highlighted when considering the time and cost savings provided by a trenchless approach in congested areas or the political cost of open cut repair methods. Improvements in materials, design, workmanship and safety are now opening the door for new applications beyond the traditional fiber wrap strengthening application of PCCP lines which have broken prestressing strands. Applications of FRP strengthening to sewers, tie-offs between old and new pipelines, strengthening of manhole section (existing or to come) and uses on other pipeline materials such as RCP or steel are becoming more and more common. This paper will discuss a new application for fiber wrap strengthening of pipelines in which a new steel pipe, used as part of an emergency repair, was strengthened using FRP in order to achieve the desired capacity.

The Alameda County Water District recently completed the construction of over 2,750 meters (9,100 feet) of 400- and 560-millimeter (16- and 22-inch) diameter water pipeline through residential neighborhoods and commercial/industrial areas of the cities of Fremont and Newark, California. Along its alignment, the project pipeline crossed under the Hetch-Hetchy Aqueduct (a major water supply transmission pipeline for the City of San Francisco and surrounding communities), several major arterial roadways, two flood control channels and Interstate 880. The majority of the project pipeline was constructed by open-cut trenching; however, site specific geotechnical and operational concerns (e.g., existing utilities, space constraints, etc.) at critical project undercrossings warranted the evaluation and eventual selection and use of four different trenchless construction methods. Trenchless construction methods that were evaluated and utilized include microtunneling, horizontal directional drilling, auger bore and jack tunneling and pilot tube guided boring. The paper will present case histories for four of the project undercrossings, discussing: why specific trenchless construction methods were selected for the individual crossings; the design measures that were implemented to account for specific subsurface conditions (e.g., high groundwater table, flowing ground, contamination, etc.); issues that arose during construction; and how construction- related issues were resolved.

The City of Cocoa, Florida, is a regional water supplier to approximately one third of Brevard County, Florida, which includes Cape Canaveral and the Kennedy Space Center. This paper will describe the South Mainland Water Transmission Main project which serves the new development in the southwest portion of their service area with a projected total demand of 7.8 mgd. The ductile iron pipeline will also provide increased reliability to existing customers, strengthen system pressures, and improve fire protection along the route. The selected 36,000-linear foot alignment of ductile iron pipe includes segments through City and County right-of-way, three micro-tunnel undercrossings of Interstate-95 (FDOT right-of-way), five canal crossings (one ductile iron aerial using a unique combination of flanged and restrained joint to span over 53'-1" and four sub-aqueous), as well as a 7,700-linear foot segment through a seasonally flooded wetlands. Another unique feature of the pipeline included eight 42-inch gate valves with ends that mated to the adjoining push-on flexible restrained joint pipe, temporary pig launching and receiving facilities. The $17.3M construction project began in April 2008, and is scheduled to be completed by October 2009, within the 18-month contract time. The only major change to date has been a 32-day schedule impact attributed to Tropical Storm Fey in the fall of 2008. Portions of the ductile iron pipeline installed by open-cut methods included a segment through a congested residential corridor necessitating extensive public involvement, and requiring removal and replacement of subdivision entrance features and school, church, and business signage, as well as various utility relocations. The lighter weight of ductile iron pipe proved beneficial in maneuvering the restricted right of way. A segment in the County right-of-way paralleled an existing 26-inch gas transmission main as close as 10-feet, and was placed underneath the northbound travel lane of the asphalt road. A third open cut segment was placed through seasonally flooded wetlands which required segregation and replacement of the native muck surface, as well as trench dewatering and enhanced restoration efforts. This paper will discuss in greater depth the detail of the installation described above from the perspective of the engineer, owner, contractor and pipe manufacturer.

The ability of a municipal pressure pipeline to prevent leakage at joints is an indicator of the efficiency of that piping system. Cement-based and metallic pipe materials used in pressurized municipal water distribution and transmission systems include high head concrete pressure pipe (CCP), gasket-sealed-joint and welded-joint welded steel pipe (WSP), and ductile iron pipe (DIP). For these materials, hydrostatic pressure testing is typically performed twice, once at the pipe manufacturing plant to confirm structural integrity and proper manufacture, and again after the pipeline has been installed and backfilled to confirm that the pipe, joints, and thrust restraint systems have been properly constructed. For field hydrostatic leakage testing, most pipe materials have an associated "allowable makeup water" or "allowable leakage" to accommodate the unique characteristics of the material as well as other irregularities during testing such as air in the line, temperature variations, and even instrument inaccuracies. Test methods and formulas for calculating makeup water usually vary based on the pipe material-specific standards. The wide discrepancies that exist for makeup water between different pipe materials do not place them on a level playing field for a given application. This paper is a review of both in-plant and in-field hydrostatic pressure testing and the topic of makeup water as outlined in AWWA and ASTM standards for the above-named pipe materials. Quality control and qualification tests for joints of each pipe material standard are also reviewed. Recommendations are made for consideration by the Specification Engineering community for future revisions of standards pertaining to the field testing of pipelines.

The Aurora Prairie Waters Project (PWP) provides a new water supply for the City of Aurora, Colorado. At a total cost of $750 million, the project included 10 separate bid packages for construction of a 50-MGD treatment plant, 34 miles of 60-inch pipe, three pump stations with tank fore-bays, and a collection well field and aquifer recharge and recovery facility. This paper summarizes the physical construct of PrairieNet, a project management information system, for the PWP, and describes how specific information needs were satisfied. It also details how a well-structured information technology database can streamline delivery of major transmission pipeline projects, improve collaboration and information sharing, and reduce risks and delivery costs.

As more land areas are urbanized, the need for Tarrant Regional Water District (TRWD) to protect or maintain their pipelines and for construction contractors and utility companies to cross existing pipelines will increase. The contractors performing the work will often request to cross or work over pipelines with heavy equipment; these crossings should be evaluated to determine if the pipe will withstand the additional loading. This paper presents a process for reviewing crossing requests and how to analyze transient loads through the soil and how to use the Unified Design Procedure (UDP) software to determine the pipe's allowable dead and transient load capacity. In addition, this paper presents a discussion on the crossing construction and the crossing reliability based upon the loading frequency. Freese and Nichols, Inc. (FNI) recently investigated construction loads over prestressed concrete cylinder pipe (PCCP) for a paralleled construction project. The preferred construction sequence required operating and staging large construction equipment and materials over the existing pipeline. Therefore, the loads generated by the construction equipment were analyzed and compared to the capacity of the pipeline, which was determined by the UDP software. The pipe was found to be adequate if the equipment is treated as a transient load, but inadequate if the equipment is treated as a dead load. Since parked equipment and staged materials were assumed to cause dead loads on the pipe, no equipment or materials were allowed to be operated or staged over the pipeline. The results of this study led to subsequent pipeline crossing studies for a concrete- aggregate mining operation and a new business development center. The crossing for the mining operation required a slab bridge to protect the PCCP by spanning across the pipe. The crossing for the business development required the installation of Geofoam to offset the additional weight of four feet of fill over the pipeline. A later project was undertaken to standardize a crossing design procedure and standardize crossing details to speed up the application and approval process for third parties' permit requests to cross TRWD's 90-inch and 72-inch PCCP pipelines.

Carbon Fiber Reinforced Polymer (CFRP) has been utilized in strengthening structural elements for over 20 years. More recently, CFRP has been introduced as a repair alternative for failing pipe sections and joints as well as other emergency applications that afford a shortened construction schedule, minimal curing time and immediate return to service conditions and pressures. Studies have recently been performed at a university testing laboratory to determine the effectiveness of CFRP when used for emergency repairs. Column samples have been tested to failure without yielding the steel. The failed samples have then been repaired by patching the damaged concrete, injecting epoxy into the cracks and applying CFRP to strengthen the column. The repaired columns were then tested within 48 hours of the CFRP application to determine the effectiveness of the concrete patch, epoxy injection and CFRP repair under a shortened allowable cure schedule. The shortened schedule is intended to simulate an immediate recurrence of a large scale seismic event or other loading condition that would test the capacity of the element to determine if it is feasible to take an unserviceable element (column) and immediately return it to serviceability. In all cases, the CFRP repaired columns have performed as well or better than the original un-strengthened test specimen. This paper will use a recent emergency pipe repair to illustrate the benefits of utilizing the CFRP repair method in an effort to obtain a sound and timely emergency pipe repair.

The Regional Optimization Master Plan (ROMP) is the largest capital improvements program in the history of Pima County Regional Wastewater Reclamation Department (PCRWRD), Arizona, valued at over $720 million in construction, project management and inspection services. One phase of this major undertaking, the ROMP Plant Interconnect Project, consisted of a 5-mile pipeline, with two wash crossings, connecting two metropolitan treatment facilities. Two parallel siphon structures across two wash crossings had to meet more stringent regulatory requirements than the gravity sewer itself. During the Value Engineering stage, welded steel pipe (WSP) was identified as an acceptable material substitution to ductile iron pipe (DIP) for the two siphons. The use of WSP enabled the Owner to meet and/or exceed the performance requirements for strength and corrosion protection of the Arizona State Rule governing the design of sanitary sewers. After reviewing the rigorous testing performed on polyurethane as a dielectric barrier against corrosion, the PCRWRD approved the use of WSP, lined and coated with polyurethane, for the project siphon crossing application. The two parallel steel pipelines were buried at depths of 30 feet, and the use of lap-welded joints provided a fully restrained piping system. A portion of the funding for this project came from the stimulus package provided as part of the American Recovery and Reinvestment Act (ARRA). This paper presents project details, and descriptions of the processes for adopting an alternate pipe material, the justification for selecting WSP over DIP, qualification of the dielectric coating and lining system, and challenges in the design and construction of the deep parallel siphons.

The 120-inch-diameter steel liner of the tunnel, which connects the Olivenhain Reservoir and Lake Hodges in San Diego County, CA, was part of a 40- megawatt pumped storage project. The liner was designed for a maximum internal pressure in excess of 450 psi, and required high-strength steel and improved fracture toughness due to cyclic high transient pressures resulting from frequent start ups of the generator and pumps. Steel material and fabrication procedures had to conform to the requirements of ASME Section VIII Division 2 and ASCE Manuals and Reports on Engineering Practice No.79, Steel Penstocks. The project's first challenge occurred when heat-treated steel plate (normalized or quenched and tempered steel) considered at bid time was not available at the start of the project in early 2005 since the US military requisitioned most of the available heat-treated steel for use in armor plates. Alternative types of steel with physical properties, similar to that of the physical requirements for the heat treated steel plate were investigated; the selected ASTM steel had to be listed in ASME Section IX groupings unless a special case number was assigned by ASME. Welding procedure qualifications for the steel and weldment were conducted before selecting the steel. The steel selection, qualification and approval process, which led to selection of steel plate produced by the Thermo-Mechanical Control Process (TMCP), will be discussed and presented. The project's second challenge occurred during the steel liner fabrication using the straight seam process. Forming the high-strength steel liner, with thicknesses up to 1–1/8 in., was very difficult due to the required minimum yield and tensile strength of 60,000 psi and 80,000 psi, respectively. The fabrication procedure was modified to be able to form the pipe and also comply with the Pressure Vessel Code requirements for flat spots and peaks. Although no preheating before welding was required per the code, low temperature preheating was applied. No post-weld heat treatment was applied since the measured residual stresses were low and there was a concern that heat application may reduce the steel physical properties in the heat affected zone of the TMCP steel. Residual stresses in the weldment were measured by the X-ray diffraction method. Observations and recommendations will be presented.

The A-Line Interceptor is a 96-inch inside diameter gravity relief interceptor sewer that allows the City of Concord to eliminate a major city pump station that currently pumps an average dry weather flow of 10 mgd. The new pipeline was constructed through a variety of site conditions including a municipal golf course, busy city streets in a fully- developed commercial neighborhood and under the earthen Walnut Creek flood control channel. The interceptor sewer and tie-in pipelines were installed by three different methods including pipe jacking by earth pressure balance machine (EPBM) tunneling (3,050 feet of 96-inch ID pipe), microtunnel boring machine (MTBM) tunneling (870 feet of 72-inch ID pipe) and conventional open-cut trenching (540 feet of twin 48-inch ID pipes) across the Walnut Creek flood control channel. The A-Line Relief Interceptor Project has several key accomplishments that make it unique. These are: EPBM Installation: The design and construction pushed the limits for installation lengths for the EPBM construction method. Limited amount of pipe cover meant that control of the radial overcut was crucial to success of the project. Due to the limited cover subsurface and surface monitoring points were installed to monitor settlement along the alignment. Intermediate jacking stations (US), and jacking pits were designed and constructed to allow for the high jacking forces.

Twenty-one foot diameter buried steel pipe were constructed on the Central Arizona Project by the US Bureau of Reclamation and the Central Arizona Water Conservation District. The project conveys water from the Colorado River through Phoenix to Tucson, Arizona. The 336 mile long project included open canals, tunnels, pumping plants, pipelines, and inverted siphons. The first section of the project included seven 21-foot inside diameter siphons. Six of the siphons were constructed of precast prestressed concrete pipe. These siphons were fabricated and installed in 1975 through 1978. Investigations in the early 1990's revealed distress to the mortar coating and prestressing wire. Two of the siphons were replaced by new parallel 21-foot diameter steel pipe. The installations were the largest buried steel pipe ever designed by Reclamation. The size of the pipe and the depth of burial presented unique construction challenges and several modifications were made during construction. Pipe wall thickness, interior bracing, the Arizona heat, dewatering, and backfilling all presented challenges during installation. Subsequent interior inspections found no structural distress but found problems with the interior lining that required remedial work. Details of the design of the pipe and installation are discussed in a companion paper.

Twenty-one foot diameter buried steel pipe was installed on the Central Arizona Project by the US Bureau of Reclamation and the Central Arizona Water Conservation District. The project conveys water from the Colorado River through Phoenix to Tucson, Arizona. The 336 mile long project includes open canals, tunnels, pumping plants, and seven 21-foot inside diameter inverted siphons. Some of the siphons were constructed of precast prestressed concrete pipe. These siphons were built in 1975 through 1978. Investigations begun in 1990 revealed distress to the mortar coating and prestressing wire. Two of the siphons were replaced by new parallel steel pipelines. The Salt River Siphon replacement is about 8025 feet of new pipe and the Aqua Fria River Siphon replacement is about 9875 feet of new pipe. The maximum soil cover over the pipe is 45 feet and the maximum internal pressure head is 275 feet. Unique design issues for pipe of this size included selection of pipe type options, coatings and linings, soil stiffness selection, dewatering plans, flotation, and depth of cover. Two of the pipe options were steel pipe and cast-in-place monolithic reinforced concrete pipe. Steel pipe was selected for both replacement siphons and they were constructed in 1993 through 1997. Details of the construction are discussed in a companion paper.

The Central Utah Water Conservancy District (CUWCD) operates numerous aqueduct pipelines throughout northern Utah. Most of these pipelines convey a Wasatch Front surface water supply that induces both calcite and brown slime growth on aqueduct mortar linings. These resulting in 15 to 35 percent capacity losses after years of operation. Building on the experience of other aqueduct owners, CUWCD is designing their Diamond Fork and Utah Lake systems with upsized pipes and pigging facilities to address the anticipated capacity losses associated with this water supply.

Assigning depth or elevation values to existing utility mapping is becoming more pervasive as we move from a 2-D CAD design platform to 3-D platforms, whether they be CAD or GIS based, or used for more than just design issues. 3D data depiction allows for a robust visualization of mapping elements that can benefit virtually all aspects of a project's development. That benefit is only realized when the collected data are accurate, reliable, and comprehensive, or else we fall into the "garbage in, garbage out" syndrome. Achieving utility data depiction that fits these criteria of accurate, reliable, and comprehensive is not trivial. Accurate data can only be assured through direct measurements, and most of our utility infrastructure is buried and unable to be directly measured except at surface appurtenances and excavation spots. Reliable data are only achieved when the means and methods of collecting and depicting data follow strict protocols. Comprehensive data may in some cases not be achievable, due to budget or technologic constraints. Many times we are forced to make judgments or assumptions on the presence or location of a utility, since these utilities are not exposed and therefore able to be directly observed and measured. We use a variety of sources for these judgments; utility records, historical project data, visual cues, indirect surface geophysical sensing methods, our past experiences, reliance upon someone else's past experiences, and government or private GIS systems are examples of these sources. Sometimes the source data is incorrect. We are forced to interpret the data from these sources, because positional references are usually vague, out-of-date, non-existent, or non-recoverable or source data may be illegible to the user. All of these problems could have historically been addressed if only we had good protocols regarding recording utility data, referencing that data to recoverable survey control, and providing secure and accessible certified record drawings. But we didn't, and so we are in the dilemma of having an estimated 20 million miles of underground utilities in this country for which data is not accurate, reliable, and/or comprehensive. Planners, engineers, and constructors must build this risk of poor data into their decisions, thus increasing project costs and time or ratepayer costs. CI/ASCE 38-02, "Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data, uses a system of Utility Quality Levels that addresses primarily the horizontal component of a utility's location. Adding the z component to utility mapping data is not trivial. We use a variety of sources for these judgments. It is important to document the sources for these judgments. This paper discusses source information and documentation issues.

Current restrained joint design theories for different pipe materials depend on two primary forms of resistance mechanisms to resist the unbalanced thrust forces that arise at a horizontal bend, valve, tee or other similar sources of thrust in a buried pressure pipeline. The first and most commonly recognized form of resistance is from friction and adhesion resistance at the pipe-soil interface; and the second form is from passive and/or bearing resistance of the pipe against the soil surrounding the pipe. Considering these resistance mechanisms, the various American Water Works Association (AWWA) design manuals appear to have been based on certain simplifying assumptions in arriving at different, yet similar, simple (M11, M23, and M41) as well as somewhat complex (M9 2008) design formulae. These simplifying assumptions have not been adequately documented from basic principles. For friction and adhesion resistance, simplifying assumptions have been made with regard to direction of pipe movement along the pipe legs; direction of the resultant friction (and/or adhesion) force generated; coefficient of friction at the pipe soil-interface; and most importantly a simplified approach to estimate frictional resistance without explicitly considering the normal pressure distribution at the pipe-soil interface. Questions regarding the validity of these assumptions have been raised from time to time, quoting the inconsistencies amongst the various design formulae and the appearance of non- compliance or violation of simple Coulomb frictional analysis principles. It is not clear how the frictional resistance estimated by this simplified approach compares to an estimate using the normal pressure distribution and the frictional characteristics of the pipe-soil interface. This paper critically examines the simplifying assumptions utilized in the current design equations to estimate friction (and adhesion) contribution to thrust restraint design problems and the validity of these assumptions. A similar examination for passive and/or bearing resistance contribution to thrust restraint design problems is planned to be undertaken by the task committee in a subsequent paper.

In current water/wastewater pressure pipeline design practice, bolted flange joints (BFJs) for most commonly encountered design problems are intended to be designed and specified per various American Water Works Association (AWWA) standards such as, C207-07 for steel flanges, C228-08 for stainless steel flanges, and C115-05 for ductile iron flanges. These standards provide simple prescriptive solutions for the selection and specification of all three BFJ components, flange, gasket, and nuts and bolts. This practice has resulted in numerous successfully completed projects, as the design solutions presented within these standards provide solutions for most commonly encountered situations. However, from time to time, designers are faced with design situations where deviations from the AWWA standard is either required or requested. AWWA standards do not provide a mechanism to evaluate such requests for changes, substitutions, or less common design situations. Despite the lack of guidance, the evaluator still must recognize the interdependence of the three components (flange, gasket, and nuts and bolts) to achieve successful design and performance of a BFJ. The AWWA approach to the design of BFJ was first introduced to water/wastewater practice in early 1950s. Prior to that, the practice was primarily based on ASME codes, which produced conservative flange thicknesses for traditional water/wastewater system design pressures. It is still permissible and acceptable practice to follow ASME codes to evaluate a non-standard AWWA design situation, as this would result in conservative results. The dilemma, however, is that the designer is now faced with an overstressed AWWA flange, when evaluating an almost AWWA compliant BFJ, per the ASME code. This paper presents an overview of the current BFJ practices based on AWWA and ASME standards and an approach to evaluate and design steel and ductile iron BFJs for water/wastewater pressure pipelines meeting the intent of the AWWA standards.

The proposed Lake Powell Pipeline will convey up to 100,000 acre-ft per year from Lake Powell to the Sand Hollow Reservoir near Saint George, Utah. The pipeline covers a distance of 133 miles and has been defined as three separate subsystems; the Intake System, the Water Conveyance System and the Hydro System. The proposed intake system location is just upstream of Glen Canyon Dam on Lake Powell near Page, Arizona. The intake will include two vertical intake shafts, six horizontal intake tunnels and a pump station. The proposed Water Conveyance System includes four pump stations, two regulating tanks, one hydro station and a 69-inch diameter pipeline which will convey water from the Intake System to Regulating Tank-2 located approximately 50 miles northwest of Page, Arizona. The four pump stations will lift the water approximately 2,100 feet. The proposed Hydro System includes six hydropower stations and a 69-inch diameter penstock which will convey water from the High Point Regulating Tank-2 to Sand Hollow Reservoir located approximately 13 miles northwest of Saint George, Utah. Four of the hydro stations are twin jet impulse (Pelton) hydropower stations and are located along the penstock at strategic locations. The fifth hydro station is a 4 jet impulse (Pelton) station located at the base of the Hurricane Cliffs. The sixth hydro station is a twin jet impulse (Turgo) station, the Sand Hollow Hydro Station, and is located adjacent to the Sand Hollow Reservoir. The pipeline profile is divided into distinct hydraulic segments to limit the pumping lift and to limit the length of pipeline subjected to hydraulic transients caused by loss of power at a single pump station. A forebay tank is provided at each pump station as a free water surface to divide the pipeline into distinct hydraulic segments. Pumping station discharge pressures are limited to 300 psi to minimize equipment and piping cost. Pumped and most gravity portions of the pipeline are sized for maximum velocities of 5.6 ft per second to limit hydraulic losses and to minimize the potential for high hydraulic transients. Pumping stations are located to prevent pipeline profile high points from exceeding the drop in HGL during the worst case hydraulic transient event thereby avoiding negative pressure zones, vapor cavities and high pressure spikes from vapor cavity collapse. Hydropneumatic tanks are provided at each pump station as the primary hydraulic transient mitigation devices. Gravity segments are outlet controlled by an energy dissipating flow control valve or by a hydroelectric turbine. Flow control valves will be operated slowly to prevent large hydraulic transients. The hydroelectric turbines in the Hydro System will be the impulse type with deflectors at the spear valve nozzles. The deflectors will be used during load rejection to prevent turbine runaway while allowing the spear valves to be closed slowly to prevent large hydraulic transients in the pipeline.

The City of Santa Monica embarked on this project to expand the capacity of its sewer system. The project is located in downtown Santa Monica within 1/4 mile of City Hall, the City Mall, and the Santa Monica Pier. An existing 33-inch sewer is an integral part of the City's sewer system, as it collects and conveys 2/3 of the City's sewer flows. The existing sewer, with a peak capacity of 29.7 cfs (840 L/s), is in need of an upgrade due to damage from an earthquake and being undersized for anticipated future flows. This new Colorado Ocean Relief Sewer will accommodate existing and future wastewater flows, provide operational flexibility, and address the City's desire for a redundant system for future emergencies. The design involved a triple barrel inverted siphon that runs beneath a major highway. This paper will describe design constraints, considerations, and construction challenges associated with the new pipeline.

ASTM F1962, "Use of Maxi-Horizontal Directional Drilling for Placement of Polyethylene Pipe or Conduit Under Obstacles, Including River Crossings", was first published a decade ago. The standard and its appendices cover most of the critical design aspects of directional drilling installation of polyethylene pipe. It is more than a standard; it is a design guide. Since initial publication, there has been marked growth in the use of polyethylene pipe for directional drilling applications, particularly for municipal applications. F1962 has proven to be a reliable guide helping design engineers better understand the nuances of directional drilling with polyethylene pipe. When a design engineer considers a directionally drilled crossing, F1962 is an important standard to review. It guides the design engineer through the evaluation of the soil friction forces applied to the pipe during pullback installation and their affect upon the pipe. More importantly it gives equations for the sometimes neglected procedure of long term design. Directionally drilled pipes are not surrounded by a carefully placed embedment envelop but are initially in a fluid which over time may regain some of the fabric of the surrounding soil. What loads reach the pipe? How does the pipe react to these loads? Neglect of these considerations can result in unsatisfactory results. These considerations are explained in the paper and an interpretation of F1962 is given so that the reader understands their critical nature. Examples are drawn from projects and unique applications—deep crossings, large diameter pipe, long pulls, etc. This paper also shows how the principles in the standard, such as those governing pullback force calculation and post installed loads have with only minor exceptions stood the test of time. Several papers published since 2000 have discussed aspects of F1962. These ideas will be explained and incorporated into the overall design framework. The hope is that an engineer using this paper and F1962 will be able to develop a rational and cost effective design, monitor installation, and build a safe and reliable pipeline crossing.

Denver Water is upgrading an existing 24-inch storm drain to a new 42-inch diameter storm drain to improve drainage from their West Side Complex to the South Platte River. The 1,665 foot pipe includes two tunnel crossings under a railroad and Interstate 25 as well as through fill soil potentially contaminated with radium. Historical research revealed that in the late 19th century, a portion of the proposed alignment was a tailrace channel for a pump house on the shore of historic Lake Archer. During the subsurface exploration, we discovered that the now buried abutments of a railroad bridge that used to cross the tailrace still exist and create a very tight usable corridor for the alignment of the pipeline through the existing railroad right-of-way. Other challenges to design of the tunneled and open cut sections of the pipeline related to the long history of development in the area include radioactive and hydrocarbon contamination, shallow bedrock and groundwater, loose sands, and historic construction debris in the fill. Pipe ramming was finally recommended as the preferred tunnel construction method to provide the best chance of success for placement of the pipeline under the existing railroad tracks.

The major aspects of pipeline design associated with large scale water conveyance projects generally consist of the pipe material selection, layout and design, air release and vacuum design, isolation design, and blowoff design. Often blowoff design is neglected compared to the other major aspects of pipeline design. Blowoffs play a critical role as they provide the option to completely drain the pipeline for emergencies, inspections, repairs, and general maintenance which could increase the life expectancy of a pipeline and prevent catastrophic breaks. Attention to blowoff design is critical for blowoff sizing, configuration, and drain times. This paper focuses on the benefits and importance of blowoffs associated with large scale water conveyance projects along with key design considerations such as; location, operational sequence, hydrologic analysis, and design criteria.

As part of a 10-year sewer improvement program known as Partners Acting for a Cleaner Environment, the Knoxville Utilities Board (KUB) committed to replacing their largest inverted siphon. The project schedule was accelerated because of a partial blockage in the existing system, the age of the existing system, and its limited capacity. In this paper, the authors present an alternative analysis and an accelerated design and construction process of a new dual inverted siphon system. A condition assessment initiated the process, which was followed by an evaluation of construction alternatives. A contractor was procured for early involvement to aid the selection of a final construction method and to provide assistance during the preliminary design. Upon completion of the preliminary design and a comprehensive geotechnical evaluation, the project team entered into the concurrent design and construction phase. The new system provides a dual pipe, 450 mm (18 in) and 600 mm (24 in), inverted siphon installed using conventional open-cut method.

Utilities construction in areas where known groundwater and soil contamination is present requires up front planning and attention to constraints imposed by the owner, as well as local, state and federal regulatory agencies to mitigate cost and time risks. This paper presents the concept of a Materials Handling Plan (MHP) to mitigate these risks and was developed concurrent with design to incorporate areas known contamination and design data into the quantification and materials handling protocols for differing excavated materials that the Constructor might encounter during construction. After identifying the likely contamination and material handling protocols, the A/E, using GIS tools, historical maps, and known areas of soil and groundwater contamination to quantify each type of contaminated material the Constructor was likely to encounter. This approach was used at a former WWII munitions plant with antiquated infrastructure that is now occupied with government agencies. This facility requires replacement and rehabilitation of all or portions of water, sanitary sewer, storm water and electrical systems and has known volatile organic compounds (VOCs), metals, polyaromatic hydrocarbons (PAHs) and asbestos contamination in the soil and VOCs contamination in the groundwater.

Welded Steel Pipe (WSP) is arguably the most widely utilized pipe material for the transmission of water throughout the United States. Spiral WSP is manufactured by placing steel coils, supplied by steel mills to the pipe manufacturer, into a pipe mill that levels the coils and helically rolls and welds the steel sheet into pipe. During the pipe manufacturing process, the steel undergoes various permanent changes in shape. These changes require the steel to yield, which may result in alterations to the mechanical properties of the original steel coil. The pipe ends may also be expanded past yield point or swaged to shape a bell, while spigot ends may be rolled to accommodate gaskets. All of this processing can have varying effects on the steel's mechanical properties. While various factors of safety incorporated into the design of steel pipe systems amply address any potential mechanical property changes that may take place during fabrication of the pipe, the topic has never been fully understood by the design engineering community at large. In order to address this issue, testing was done to measure the changes in steel mechanical properties during the pipe manufacturing process. This paper outlines the testing and the subsequent variations found in the mechanical properties of the steel used through the manufacturing process. Based on the testing, the paper will provide conclusions and design considerations for pipe with both restrained (welded) and non-restrained joints.

Pipe materials used in underground infrastructure are manufactured according to published national standards such as AWWA and ASTM. The pipe bedding, backfill and shoring systems, however, vary regionally across the country. This is due to variations in native soil conditions, availability of pipe zone materials, and local pipeline contractor preferences. The varying regional practices often limit an engineer's ability to specify trench and shoring conditions without adequate knowledge of local practices. Recognizing the need to document the varying regional practices as a resource to owners, practicing engineers and prospective contractors, the members of the ASCE Pipeline Installation and Location Technical Committee formed a special task committee in August 2009, titled "Pipe Bedding, Backfill and Trench Shoring Systems" to prepare a white paper on the subject with an eventual objective of producing a Manual of Practice (MOP). As part of this effort, a national survey will be conducted in 2010 to collect and document the regional practices in trench bedding, backfill and shoring systems. Through this national survey, the task committee is planning to collect data on existing specifications, standard details, design criteria, and material specific concerns, with an aim to document regional variations of specifying and construction practices and constructability issues associated with local native ground conditions, including interaction between native ground and bedding and backfills placed and compacted, testing requirements, use of waste or recyclable materials, and construction methods such as use of varying types of trench boxes, sheeting and shoring systems. The survey will target the Department of Transportation (DOT) from a number of states or similar local jurisdictions, large municipalities, water or wastewater agencies, national engineering firms, national pipe suppliers, contractors, and pipe vendors. This paper will present a summary of the preliminary findings from this national survey, with the primary objective of soliciting feedback and collecting additional input from those attending the technical sessions in Pipelines 2010 conference to be held in Keystone, CO.

Dune sands cover vast areas in Oman and create major problems for construction of infrastructures. Also suitable backfill soils for construction of buried pipes are not available in these areas. Plastic buried pipes are in use for decades but their performances are not well understood. This paper investigates the performance of thermoplastic pipes installed in dune sand. It simulates the problem as a two dimensional plane strain finite element model by using AQUS/CAE, Version 6.1. The proposed model considers only one half of the system because of symmetry of the problem. The mesh extends horizontally 3-D (where D is the pipe diameter) from pipe center, 1.5-D below the invert and 2-m above the crown. Complete fixity was enforced at the lower edge of the mesh. Roller support was used at both vertical sides of the mesh. A hypoelastic constitutive model was used for soil. Full bonded or contact or slip elements were employed at pipe-soil interface. The pipe soil system response includes percentage change in vertical diameter, thrust, bending moment and shear stresses around the pipe. The study considers different factors that affect the pipe-performance such as relative density (dense, medium dense and loose dune sand soil), pipe material (i.e. HDPE, PVC) and soil cover on the performance of plastic pipes installed in dune sand. The study shows that these parameters have a large influential effect on the performance of thermoplastic pipes. For example, all the pipe responses (e.g. change in vertical diameter, thrust and bending moment) increase with the increase in relative density of soil and the increase in soil cover. The effect of pipe material is not as significant. There is a slight difference in percentage in vertical diameter for PVC and HDPE pipes, although the modulus of elasticity of PVC is larger than that of HDPE. However, the thrust and bending moment induced in PVC are larger than those induced in HDPE. However, the opposite is true for the bending moment. The main conclusion of this study is that medium-dense to dense-dune sand can be used as a backfill material for thermoplastic plastic pipes. The predicted changes in vertical diameter using these backfills are much less than the typical specified value of 5%.

In August 2008, three breaks occurred in a two mile, 36-inch diameter section of the Capital Circle Force Main during and immediately after Tropical Storm Fay. This section of force main is constructed of Hobas pipe and lies beneath Capital Circle Roadway, a Florida Department of Transportation (FDOT) roadway that is one of the most heavily trafficked roadways within Tallahassee. Pipe bursting was selected as the trenchless repair method to expedite construction, minimize disruption to the existing roadway, and maximize the internal diameter of the repaired pipe. Since Hobas pipe had not previously been burst and to alleviate upheaval concerns from FDOT, a pilot was proposed to verify the viability of bursting Hobas pipe. A pilot length of 280 linear feet was successfully completed in 90 minutes at an average production rate of 3 feet per minute (fpm) with no upheaval. The lessons learned from the pilot were utilized to complete the design and construction of the pipe bursting repair of the remaining length of pipe.

Bedding and backfill materials play a critical role in the long-term structural integrity of buried municipal pipelines. Soil strength is resistance to soil slip, and is a function of soil friction angle and any cohesion in the soil. It determines the stability of the soil. Soil stiffness is the modulus of soil elasticity, E', and is a function of soil type and the applied level of compaction. E' is also affected by depth of burial which increases confining pressure. E' determines the ring deflection of flexible rings. The Modified Iowa equation is used to predict ring deflection of buried flexible pipes. Common types of backfill material can range from native soils (which usually have fines, silt and clay) to imported crushed rock, to soil-cement slurry (or flowable fill/CLSM). Whenever backfill material other than native soils is specified on a project, the reason for doing so must be justified. This paper reviews and recommends best practices for the selection of common bedding and backfill materials for flexible pipes and conducts an economic analysis of the various options utilized. Theoretical aspects of pipe-soil interaction as it relates to ring deflection of pipe for various soil types are discussed.

This paper will discuss a process to evaluate appurtenance alternatives for a pipeline project in order to simplify operation and maintenance and save costs. It presents an approach taken to obtain owner acceptance of simplification measures to proceed with in developing final designs. The appurtenances considered included combination air release valve vaults (CARV), blow off structures (BOS), access manways, and isolation valve vaults (IVs). The first step taken to simplify the pipeline appurtenances alternatives was to complete a survey of appurtenances of projects over the past ten years. The survey included collecting detail drawings, construction dates and locations, and construction cost information. The alternative appurtenances were diverse in many ways and this paper will discuss some of the advantages and disadvantages of each. The second step taken was to evaluate the detail drawings from the survey and determine if the appurtenances included simplification measures that could be implemented in the project design. Cost information, if available, was also brought to current dollars using current Engineering News Record Construction Cost Index. The third step taken was to present the survey information at a workshop. Attendees included client project management and operations and maintenance staff and consultant design staff. The workshop provided a forum for obtaining feedback from the client on the alternatives presented. Lastly, the paper will discuss how owner acceptance of the appurtenance design was obtained. It will include a description of a technical memorandum documenting the feedback obtained from the client at the workshop. This paper will benefit the professional community by showing: (1) Alternatives to typical appurtenances designs exist and that they provide the same operational flexibility/function (2) Simplification measures for appurtenances that will decrease costs (3) Methods to provide clients with information and their acceptance

Recent research studies and surveys have shown that air pockets in wastewater transmission systems cause extensive damage and hindrance. Air pockets decrease flow capacity, they induce significant head losses and energy losses, they prompt serious corrosion, and they can trigger and/or enhance pressure surges. In the advent of concern for energy conservation, more and more research is invested in studying the effect of air pockets on flow efficiency and energy consumption. Conclusions are that air pockets have a very significant impact on these, especially in wastewater force mains. Much has been written in the past about Hydrogen Sulfide corrosion in wastewater pipelines. The EPA published a number of papers, pamphlets, and reports to Congress on this subject. More and more papers and studies today, attribute Hydrogen Sulfide corrosion to air pockets, including a number of papers presented at the ASCE Pipelines 2009 Conference in San Diego. Most of these papers refer to detection, monitoring, evaluation, assessment and management of corrosion, but not of prevention. They point out the contribution of air pockets to Hydrogen Sulfide corrosion, but they do not discuss the means and ways of preventing air pocket accumulation. Though, for many years, it was commonly accepted by surge experts that air pockets dampen surges, it was determined in recent research studies that air pockets of certain sizes and in certain locations along a pipeline, can induce and/or enhance surges. These surges, especially in force mains weakened by corrosion, can cause intensive and severe damage to pipelines, resulting in soil and water source polluting leakage, and health endangering pathogen and contaminant intrusion to drinking water transmission systems. Even though there is a great mistrust of air valves for wastewater applications, modern, innovative air valves are reliable and efficient, and are an extremely cost efficient and readily available device for preventing the accumulation of air pockets and for averting the above-mentioned damages and hindrances.

Ring girders are a key support component of elevated welded steel pipe. The technology for ring girder is traceable to advances in stress analysis of the 1930s and 1940s where supporting of large diameter welded steel penstocks was first pioneered. A notable contribution toward stress analysis of ring girders is included in Penstock Analysis and Stiffener Ring Design, Bulletin 5, Part 5, Technical Investigation Boulder Canyon Project, Final Design Reports published by US Bureau of Reclamation, 1944. Historically, seismic design of ring girders received only slight attention until the advent of the Northridge Earthquake where significant damage occurred to many structures. Seismic design has become a focus for piping and support design and stress analysis. Today engineers must consider strength and serviceabilty of designs to comply with current seismic provisions of IBC-2009 (International Building Code) and ASCE 7-05, Minimum Design Loads for Buildings and Other Structures This paper will address that historical development of ring girder design and focus on recent seismic provisions contained in current codes. An example problem is included in the Part 2 companion paper, illustrating application of seismic forces in context of ring girder design. Figure 1 illustrates construction of the ring girder supported segment of the 120 inch diameter Olmstead Flow Line, near Provo, Utah

This paper presents a design example to illustrate application of seismic forces in context of ring girder design. A companion paper, Part 1 discusses historical development of ring girder design and focuses on recent seismic provisions contained in current codes.

When Monks Hollow Reservoir, was eliminated by environmental conflicts, Central Utah Water Conservancy District's (CUWCD) had to redesign their Diamond Fork System without its central operating storage. Finding a hidden asset in their commitment to augment Diamond Fork Creek flows to enhance its fishery, they designed two large pressure reducing stations to constantly "trickle flows" to the creek. This created a simple hydraulic system with its daily and hourly operating storage 2000-feet above the main aqueduct gradient. The new, more efficient, system has all the benefits of major storage at aqueduct gradient, but eliminates its liabilities: water losses to evaporation, reservoir O&M, and canyon environmental impacts.

The nature of transient hydraulics in a pipeline system is often very difficult to identify and fully quantify. As a result, surge control strategy is often a compromise on providing the greatest benefit for the lowest cost while also considering the full range of alternatives and operational constraints. This may be difficult to do, especially with staged facility expansion that must address near and long term flow projections. Design often relies on a maximum flow rate that is identified as a "worst case" scenario surge control based on this assumption. However, these simplifications, when considered in a system with near and long-term projected flow rates, may be incorrectly defining the best surge control strategy, particularly if the highest projected flow rate is never realized. This paper will use case studies to compare two different approaches with regard to surge control protection while considering near and long term flow rates and the associated flexibility or lack thereof that is related to the surge control. Pros and cons will be discussed for each approach and discussion will be developed for reader consideration.

Theory and practice of thrust restraint design of restrained-joint buried pipelines are dependent on the pipe-soil interaction at the pipe-soil interface, which can be quite complex. It is generally recognized that a buried pipe has to move against soil in order to develop aggregate friction, adhesion and passive resistance forces. In combination, these forces resist the unbalanced thrust forces in a bend. Design equations currently in use in the water/wastewater industry are often based on simplifying assumptions that do not necessarily address the interfacial behavior clearly. These pipe movements potentially cause additional pipe stresses (bending and shear) on the pipe at or near the unbalanced forces. However, these additional stresses are typically not considered in the designs of water/wastewater pipelines using most of the current AWWA pipe design manuals. Pipe movements in a pipe-soil interaction system should be considered in the design and selection of pipe and its associated joints. There exist numerous joint configurations, some with substantial axial and rotational slack (deflection flexibility) and others that are instead rigidly harnessed or welded. While most manufacturers have information on joint configuration that could be used to estimate available axial and rotational slack at the joints, the impact of the slack and/or pipe bend movements on the design of the pipe itself is less understood. The ASCE task committee plans to gather information to document the current understanding of allowable pipe bend movements in the design of pipelines at the unbalanced thrust sources. Having understanding of these differing movements, and being able to quantify basic levels of movements available for each pipe material and joint configuration will form a key component of efforts towards future practice improvements on the subject. This paper presents information gathered to date on the subject in terms of available data on thrust-induced movement of commonly used pipe materials (e.g., concrete, ductile iron, fiberglass, polyinyl chloride (PVC), polyethylene (PE), and steel) and joint configurations to form the basis of the respective thrust calculations for these materials.

The Prairie Waters Project (PWP) will increase the City of Aurora's water supply by 20 percent; delivering up to 10 thousand acre-feet (about 3.3 billion gallons) of water per year. One key element of the PWP is the conveyance system comprised of approximately 33 miles of 60-inch diameter underground raw water transmission piping, 15 trenchless crossings (including the South Platte River) and three pumping stations which lift water over 900 vertical feet from near the South Platte River in Adams County to the new Peter Binney Water Purification Facility located in the City of Aurora. Trenchless methods were used to construct the pipeline beneath waterways, wetlands, highways, arterial streets, and railroads. One of the most significant and challenging trenchless crossings of the project is the South Platte River crossing. Subsurface conditions at the South Platte River crossing are characterized by alluvial deposits containing fine to coarse grained sands and gravels with interbedded cohesive floodplain deposits, and occasional cobbles and boulders, overlying claystone bedrock. The alluvial deposits are 25-30 feet thick and generally have high permeability and high storage capacity, while the claystone has low permeability. The tunnel is approximately 260-feet long and positioned in the claystone layer at a maximum depth of 48 feet and features a 78-inch in diameter steel casing, 60-inch diameter steel pipeline and a fiber optic cable/conduit to support system supervisory control and data acquisition (SCADA) communications. This paper describes the management of risk associated with South Platte River Crossing. Additionally, the paper discusses the unique design and construction challenges associated with constructing the project without impact to federally regulated Waters of the United States and wetlands that fall under the jurisdiction of the United States Army Corps of Engineers.

For pipeline projects in wastewater collection systems, standard specifications are frequently cited in the project design and pipe manufacturing process, e.g. ASTM standard specifications. Different pipes have different standard specifications, and many pipes have more than one standard specification. In most cases standard specifications outline the minimum requirements in the pipeline industry, and they are often more than sufficient to meet the project application requirements. However, it is prudent to understand the specific requirements and the applicable conditions, especially for large pipeline projects with unique features. This paper will review the current pipeline standard specifications for four types of pipe that are commonly used in wastewater collection systems: Vitrified Clay Pipe (VCP), Reinforced Concrete Pipe (RCP), Polymer Concrete Pipe (PCP), and Fiberglass Reinforced Pipe (FRP). Differences among pipe standard specifications will be reviewed and their impact to pipe applications evaluated. Several heuristic models related to pipe applications will be discussed.

As the standard technology for condition assessment of gravity sewers, closed-circuit television has a long history of success and acceptance. Conventional CCTV technology requires access available through manholes, and non-surcharged operation, making it extremely difficult to apply to water transmission mains. For the past five years, inline CCTV inspections have been available for water transmission mains using a tethered inspection system that allows these inspections to take place while the mains remain in operation. This paper details the innovation and application of this technology for the past 5 years. It describes the mechanism used to pass a sensor through an in-service water main, as well as the evolution of the video technology to allow for longer surveys and better resolution. Specifications for the system, as well as case studies describing various applications of the technology, are presented.

Prestressed Concrete Cylinder Pipe (PCCP), as any other pipe material, decays over time. The rate of decay is influenced by the quality of materials and workmanship used during manufacturing, construction methods, operational parameters and environmental conditions. PCCP pipe does not go from a perfect condition to failure instantly, but rather it is a deterioration/aging process that can be measured and tracked with sonic/ultrasonic nondestructive testing. Often the mortar coating is carbonated due to environmental conditions. The reduction in coating thickness can reduce the structural capacity of the pipe and compromises the passivation of the prestressing wire. The coating thickness can be precisely determined by sonic/ultrasonic method. The concrete core can experience cracking due to low wire prestressing, inadequate bedding, earth overload, over pressurization, or aging. Depending on the level of core cracking, the cracking can extend to the mortar coating and allow prestressing wire corrosion. Sonic/ultrasonic testing can detect the level of core cracking and the longitudinal extent. A subsequent sonic/ultrasonic survey provides the data needed to develop a pipe decay curve vs. time.

In the early morning hours of December 25, 2008, a 48-inch prestressed concrete cylinder pipe (PCCP) water transmission line failed under a major state highway in the southern part of Houston, Texas. The failure flooded the nearby area with water depths up to four feet and closure of Almeda Road. Service was maintained in the area due to multiple groundwater wells operating for the concurrent planned shutdown of the Southwest Pump Station refill line. Lockwood, Andrews, & Newnam, Inc. (LAN) and a local utility contractor were contacted by the City of Houston (City) Utility Maintenance crews to assess the extent of damage and restore the water line and roadway to service. Condition Assessment of the PCCP portions of the W. Bellfort 48-inch included visual observations of pipe interior, limited observations of pipe exterior, electromagnetic survey and materials testing. The failed PCCP pipe section was removed along with three adjacent pipe sections and replaced with approximately 64 LF of a 48-inch steel pipe. This paper will present the findings and conclusions of the Assessment as well as discuss measures taken to restore the roadway and water line to service quickly over the weeks between Christmas and New Years.

Two failures within a two year timeframe on a 36-inch ductile iron sewage force main installed in 1983 has raised serious questions on the expected life and risks associated with this underground asset. With proper design and installation a life expectancy of at least 60 years should have been expected for this pipeline. The cost for the repair of each break was between $50,000 and $75,000. In addition, a sanitary sewer overflow (SSO) resulted from each of these failures, which is a violation of the operating permit with the State of Wisconsin. To help determine the condition of the pipe, Pure Technologies was hired to perform a leak survey using their proprietary SmartBall® (Pure Technologies). The results of this survey are one of the tools being used to determine the current condition of the asset, in line with a defined asset management approach. This paper will outline the asset management approach being taken to assess the condition of the 36-inch ductile iron force main and the repair, rehabilitation and replacement strategies being considered for the pipeline asset.

This paper discusses case histories of condition assessments that have been performed in Sydney, Australia, Hong Kong, China and Singapore. The paper discusses the methodologies and contractual arrangements to perform these condition assessments, as well as a cost-benefit analysis of the work. The paper briefly explains the techniques involved and the advantages and disadvantages of each. In most cases condition assessment has been shown to be extremely cost effective targeting specific sections or mains for selective replacement. In the case of 150km of sewer rising mains in Singapore, for instance, less than 5km was targeted for short term rehabilitation and replacement. The paper finally discusses the concept of CapEx Programming, whereby a water authorities capital expenditure budget can be generated from a combination of condition assessment outputs, cost of replacement, and risk that the city or authority is prepared to accept. This approach is seen as the approach that most regulators will introduce and enforce in the next ten or so years.

All conveyance system owners develop, evaluate, and select performance measures to measure and track the cause-and-effect relationships between activities and the outcomes of interest in their utility. For instance, conveyance system department managers will monitor reports that track activities from crew productivity to financial status. Regardless of what the performance measure pertains to in the organization it is important to understand the relevance of the measure and whether it properly supports the organizational mission and goals or provides the best measure of the activity. This paper presents the considerations for developing and selecting conveyance system performance measures in three steps. One step involves inventorying what data is readily available and determining the quality of the data. Examples are provided that show the quality differences in data that represent direct measurement and indirect measure of the parameter of interest; e.g. I/I in pipelines is more directly measured when linked to the characteristics of the pipeline such as length or inch-diameter-mile versus the indirect measure of service area in acres. Another illustrated example is the sensitivity of the performance measure parameters selected and incorporated into the numerator and denominator of a metric measuring the relationship between rainfall and rainfall derived infiltration/inflow in the collection system. Another step determines what organization or process changes might be needed to collect the performance measure parameter. An example is provided that shows how a performance measure that tracks the productivity of a CCTV inspection crew is sensitive to the inclusion of multiple parameters such as number of defects encountered and the number of CCTV hours worked by the crew per day. This helps management decide the importance of modifying data collection procedures if the data is not currently recorded or retrievable. The paper benefits conveyance system managers and engineers at all levels of an organization since each organizational level not only develops performance measures for its work but also for the objectives of the management level above or below it. Regulators will better understand that selection of a performance measure is not an arbitrary process.

Dallas Water Utilities (DWU) provides water services to approximately 2 million people in Dallas and nearby communities. Large diameter pre-stressed concrete cylinder pipelines (PCCP) convey water from seven different resources to three treatment plants. The transmission mains are critical supply lines, and maintenance of these infrastructures is challenging. After one of the pipes in the White Rock pipeline failed in 2001, DWU initiated a proactive condition assessment program. Thereafter, DWU utilized RFTC technologies to quantify and locate broken, pre-stressed wires in each pipe segment of their pipelines. Performing condition assessment of these pipelines with RFTC typically requires the utility to completely de-water the pipeline for internal inspection. In early 2009, DWU experienced a failure on their 84" Tawakoni pipeline. The contractor quickly mobilized an emergency RFTC inspection with a robotic inspection vehicle, successfully inspecting 8,000lf of the pipeline while requiring only one access point to be de-watered. Right after the emergency inspection DWU immediately requested that the remaining 13 miles to be inspected. The 72" Simpson Stuart Supply Main is a critical pipeline, providing treated water to the southern part of Dallas. Raw water is pumped from the Lake June Pump Station and is treated at the East Side Treatment Plant. Treated water is then conveyed through the pipeline under the Trinity River, to the South Cliff Pump Station. The ability to perform condition assessments under river crossings is critical for Water Utilities to maintain the integrity of their pipelines. This paper, presented jointly by DWU and the contractor, presents the experience of the project and identifies what the city learned about this essential asset.

When the electromagnetic condition assessment technology known as Remote Field Transformer Coupling (RFTC) was developed for prestressed concrete cylinder pipe (PCCP) water mains, one of the main design considerations was that it works from the inside of the pipe, as most pipelines are buried. Recently, it was discovered that the technology worked from the outside of the pipe as well. While internal electromagnetic inspections are still more practical for standard condition assessment projects, external scanning has several useful applications. External scanning is clearly an asset for un-buried pipe, as it eliminates the need to dewater, and it is strategically useful in rehabilitation work for pipes that have been identified as distressed with conventional internal scanning. Scanning an excavated pipe and reviewing the data for locations of break regions, will confirm that the right pipe was located prior to executing rehabilitation. Scanning an excavated pipe can also provide more detailed information on wire break regions of pipes that are difficult to analyze, as the signal is clearer because it does not need to penetrate the steel cylinder. This information can help determine if rehabilitation is actually required. This paper presents the design, capabilities and applications of external electromagnetic inspections, including case study where an exposed pipeline was successfully inspected.

Recent negative publicity for the nation's aging water infrastructure has lead many communities to recognize the need to systematically manage their existing water systems. A key component of water infrastructure asset management is assessing the condition of existing water mains to allow rehabilitation before failures occur. As a result of this growing trend, water main assessment and rehabilitation technologies continue to advance, leaving system owners with difficult and complex choices to make about which assessment methods to use. To help owners and agencies navigate these decisions, this paper provides a review of common pipeline failure factors and various available means for performing pipeline condition assessment. This review forms the basis of a systematic matrix that was developed to evaluate various condition assessment methods. The evaluation matrix serves as a tool for agencies to measure the appropriateness of their available assessment options while recognizing the limitations many of these technologies and methods have.

Evaluating the seismic functionality of water distribution networks is of great importance for making decision on either upgrading the vulnerable components of the network, or emergency actions for more critical parts of the city in the aftermath of large earthquakes. In this paper a method is proposed for seismic evaluation of water distribution networks based on nonlinear seismic analysis of piping systems. In the proposed method at first the nonlinear behavior of connections is assessed numerically by finite element analysis (FEA). Then, pipe segments are modeled as beam elements, and the connections by nonlinear springs, whose specification has been assessed by FEA. In the next step, the modeled piping is analyzed subjected to a set of selected accelerograms, to find out which ones of connecting parts fails. In the last step, the amount of water leakage from each crack and the resulting pressure drop in the main pipe and its branches are calculated, to realize the critical components and critical parts of the city network for making decision on the required activities both before and after the earthquake. The proposed method has been applied to a selected part of Tehran metropolis water distribution network to show its efficiency.

Staff from the Metropolitan Water District (MWD) visually inspected 5.3 miles of the 144 inch diameter Etiwanda Pipeline to evaluate the condition of the internal mortar lining. The inspection showed that large portions of the lining are either failing or have failed. Approximately 35% of the total length of the pipeline has either missing or delaminated mortar. MWD conducted an exhaustive literature search to see if other utilities have experienced this type of failure. MWD also reviewed the construction history, soil conditions, backfill and design criteria in order to determine the cause of the failure. After the investigation the significant factors that contributed to the failure are believed to be: 1. The pipe was designed for a higher stress than historically recommended by AWWA standards or traditionally used by MWD. The higher allowable stresses will cause the liner to crack more and have larger cracks than on typical mortar lined steel pipelines. 2. The fact Etiwanda Pipeline is a 12 foot diameter pipe also results in increased crack size in the mortar lining. The large diameter also results in increased length of the arch and this makes the mortar more likely to fail. 3. The Etiwanda Pipeline functions as a penstock for the Etiwanda Power Plant. Pressure fluctuations caused by the Etiwanda Power Plant are preventing the cracks from autogenous healing. The inability of the lining to heal is causing the lining to delaminate from the steel pipe wall. This eventually causes the lining to fail due to the effects of gravity. 4. It is possible that a differential pressure may develop between the water inside the pipe and the water behind the lining In view of this failure it is suggested that tests be performed to determine the stress limitation as the pipe diameter changes. Until those tests are completed the stresses in mortar lined pipe should be limited to 18 ksi. In addition, if a pipeline is to be subjected to fluctuating levels of stress the pipe lining must be chosen carefully. The best choice for the lining would be a flexible lining. Mortar lining without reinforcing should not be used and mortar lining with welded wire fabric should not be used without additional testing verifying its viability.

Since 2006, a number of peer reviewed studies have linked earlier observed polyethylene oxidation research to field failures of HDPE pipes in water transport environments. Of particular interest have been reports of premature polyethylene pipe failure in the presence of common water disinfectants such as chlorine (hypochlorite), chlorine dioxide and chloramines. Studies in France by major water utilities (i.e. Suez Environnement and Veolia Environnement) have linked factors such as type of disinfectant, average service temperature, disinfectant concentration and pressure to HDPE pipe oxidation and failure. With a growing number of European studies documenting oxidative aging of HDPE of all types, this study undertook to 1) review published work on the subject including laboratory testing and evaluation of exhumed HDPE pipe studies both in Europe and the United States and 2) conduct a forensic analysis of HDPE pipe from U.S. water utilities. This paper will summarize the results of both parts of the study.

The U.S. Environment Protection Agency released a study in 2002 that highlighted the funding gap between actual and needed investment in water and wastewater infrastructure (U.S. EPA, 2002a), estimated at $122 billion for wastewater and $102 billion for drinking water under current revenue scenarios. The projected funding gap is a result of aging infrastructure and increasing population and quality demands on water systems. Closing the gap will likely require both increases in funding and efficient management of water and wastewater assets, e.g., through application of Strategic Asset Management approaches.

Energy Benchmarking metrics are applied to water utilities after the 2007 publication of a benchmarking method for water and wastewater utilities based on the EPA's energy star rating system for buildings. This paper explores the application of such benchmarking methods to drinking water utilities in their production stage, and an additional indicator called thermodynamic score is proposed to provide complementary information on the utility's energy efficiency. The thermodynamic score is obtained from a mechanistic approach, in contrast with the applied benchmarking method which comes from an empirical approach. Both metrics were applied to a set of randomly selected utilities in Virginia. Some of the benchmarking scores were found to be skewed. The thermodynamic score proved to be an effective tool for measuring energy efficiency in most cases. The energy analysis of water utilities can be used as an asset management tool by water utilities to proactively manage their infrastructure systems.

The Metropolitan Water District of Southern California (Metropolitan) has 163 miles of prestressed concrete cylinder pipe (PCCP) within its distribution system. Metropolitan's PCCP pipelines were installed between 1962 and 1985, vary from 42 to 201-inches in diameter and operate at pressures up to 300 psi. Eighty percent ofMetropolitan's PCCP is 78-inch diameter or larger. In 1996, Metropolitan initiated a PCCP condition assessment program. The early internal inspections included visual, sounding, and limited Impact Echo. Corrosion and electrolysis test records were compared to inspection findings. Corrosion mitigation systems were installed and repairs were conducted as needed. In 2000, Metropolitan added Remote Field Transformer Coupling (RFTC) to its PCCP condition assessment tools. As of June 2009, Metropolitan completed RFTC inspections in 99 percent of Metropolitan's PCCP, second RFTC inspections in 70 percent, and third inspections in 11 percent. Metropolitan has repaired approximately 130 PCCP pipe sections as a result of the RFTC testing. In 2004, Metropolitan used P-Wave in the Rialto Pipeline; three months after RFTC testing identified several pipe sections with excessive wire breaks. The P-Wave inspection was conducted prior to repairs triggered by RFTC wire break predictions. The P-Wave inspection was conducted to determine if it provided results similar to RFTC. Metropolitan verified actual wire breaks in one pipe section during the repairs. In 2009, Metropolitan scheduled side-by-side RFTC and P-Wave inspections in four PCCP pipelines, totaling 3 miles. Two pipelines were scheduled to have several PCCP pipe sections removed shortly after the inspection for a treatment plant upgrade. The removal of pipe sections for the plant upgrade presented an opportunity to conduct a blind test of RFTC and P-Wave. One pipeline contained a pipe section with wire breaks detected by RFTC in 2002 that Metropolitan verified in 2003. One pipeline included a reach that was previously inspected using both methods in 2004, providing an opportunity to compare second inspection results. This paper provides an overview of Metropolitan's PCCP condition assessment program, a comparison of RFTC and P-Wave wire break predictions from the side by side inspections in four pipelines, and the results of the blind tests.

Current design methods for structural rehabilitation of rigid pipes by flexible liners (ASTM F1216) are incorrect. Further, structural design methods for rigid liners (GIPL) are not yet codified as design standards by ASTM. This paper will document how and why the flexible liner design is incorrect and propose new design methods. Also, the paper will propose a design method for rigid liners, such as grouted-in-place-liners (GIPL), and give design examples. The proposed design methods are based on fundamental engineering mechanics and the theory of composite materials. The assumed failure states are based on well - known and documented characteristics of buried rigid pipes.

With the advent of continuous acoustic fiber optic (AFO) monitoring systems, evaluating and managing the condition of prestressed concrete cylinder pipelines (PCCP) has improved over the last few years. In the past, methods for evaluating PCCP were limited to internal visual inspection and sounding, and possibly external excavation and visual inspection. In the 1990's electromagnetic testing (EMT) technologies provided a tool to identify broken wires in the PCCP. Although useful, internal inspection techniques and EMT typically require that the pipeline be empty of water — resulting in a full de-pressurization and re-pressurization cycle of the pipeline. Based on real time monitoring provided by the AFO monitoring systems during such pressurization cycles, we are discovering that the practice of de-watering to provide access may be causing more damage to the pipeline than previously thought. This paper will examine the causal relationship between pressurization cycles and wire break occurrences by evaluating data collected using acoustic monitoring. The data will be used to assess the change in rate of wire break occurrences during pressurizing cycles. Locations of wire breaks occurring during pressurization cycles will be compared to those occurring during normal operation of the pipeline. This will help determine whether cycles simply concentrate wire break activity in time by accelerating the stress on wires already deteriorated or if the cycle might actually be producing damage that might not otherwise occur. Several PCCP failures have also been documented during filling and re-pressurization of PCCP start-up, when the pressurization causes reverse deformation to occur. Acoustic monitoring during the filling and re-pressurization has documented significant wire break activity. This paper will examine four case studies where more than a normal amount of wire breaks were recorded during the pressure cycles during a shutdown where the pipe is dewatered and refilled.

Assessing pipe wall condition in pipelines is essential to reduce product loss, operational cost and damage to the environment and the general public. Thinning in the pipe wall can lead to leaks and have the potential to cause catastrophic failures. As such, utilities owner need a method of assessing the pipe wall thickness of the pipelines to properly manage and maintain their infrastructure. Pure Technologies' SmartBall^TM Pipe Wall Assessment (PWA) is a new approach that takes advantage of the SmartBall^TM leak detection capability to simultaneously assess the physical condition of the pipe. The tool is a spherical device that rolls on the bottom of the pipe and is capable of navigating obstacles that would be impossible for a tethered system or a traditional pig. The patent pending method measures the velocity of a low frequency pulse as it propagates along the pipe. Variation in the propagation velocity of the pulses indicates changes in pipe wall thickness. This paper describes the theoretical background of the technology and presents field work completed to date.

This paper presents the results of case histories of some of the oldest installations where gray cast and/or ductile iron pipelines were installed using polyethylene encasement as a means of corrosion control. Investigative procedures included soil testing, excavation and physical inspection of exposed pipe sections, and laboratory testing of the polyethylene material. Included are testing results and the location sites of each investigation. The investigations demonstrate the effectiveness of polyethylene encasement as an external corrosion protection method for gray cast and/or ductile iron pipe.

Prestressed Concrete Cylinder Pipes (PCCP) are complex composite pipes which are generally used in large diameter water pipelines throughout the United States to convey large volumes of water. Therefore, prediction and prevention of failure of these pipelines is complex and requires a thorough understanding of the pipe system (structure, surrounding soil, pressure, load, etc.). This paper presents the development of a Predictability Index for PCCP as a tool to help utilities identify the pipes prone to risk and indicate the level of risk associated with each pipe. This Index is developed by understanding the various failure modes and mechanism of PCCP pipes (manufacturing, installation, operation, others). In addition, the paper also presents development of a Preventability Index providing the utilities with a guideline on the technologies and/or methodologies they could employ to identify the distress indicators their pipelines are prone to. This Index is developed by evaluating the various state- of-the-art technologies and considering the emerging technologies. The proposed Predictability (Pred) and Preventability (Prev) Indices (P&P) are evaluated and validated with the data and information collected from the Washington Suburban Sanitary Commission (WSSC), Laurel, Maryland. The proposed indices will help utilities predict and prevent PCCP pipe failures in a sophisticated manner. In the future, Predictability and Preventability Indices can be developed for other pipe materials.

To effectively manage sanitary sewer system assets, utilities should collect condition data, analyze the data, and make decisions on what to do with each asset based on this information. Infrastructure owners should know the condition of their systems and have processes that support their program activities. Without condition and performance knowledge, appropriate preventative measures cannot be properly planned and implemented. In addition, regulators are expanding their push for better condition assessment practices through programs such as Capacity, Management, Operations, and Maintenance (CMOM) and in enforcement actions at both the state and federal levels. This paper describes analysis of manhole and sewer pipeline data to develop estimates of infiltration and inflow (I/I) and to prioritize each asset using a risk-based approach for prioritizing improvement needs. Defect I/I rates are necessary for conducting a full cost-effectiveness analysis. Specifically this paper will address the following: (1) Risk-based approach to condition data analysis. (2) Guidelines for assignment of defect I/I rates.

Water and wastewater utilities are faced with a mounting need to inspect and assess the condition of their pressure pipelines. This urgency is the result of increasing focus by regulatory authorities as well as a growing realization of the need on the part of the utilities themselves. The increased attention on pressure mains has highlighted the difficulties in accessing and inspecting pressure mains and the need for better inspection methods and technologies. This paper will review current available inspection technologies and discuss the strengths and weaknesses of each. The discussion will review ease of use, pipeline operational status during inspection, and the reliability and usefulness of the resulting data. This will not be a simple literature review rather, the review and comments will be based on the authors' personal experiences with input from the literature where pertinent. The text will include a discussion of new and developing technologies both in the United States and abroad and will discuss research and development needs in a number of areas, specifically: (1) Inspection technologies. Improvements are needed in the range and accuracy of technologies for measuring wall thickness in ferrous pipes for instance. (2) Conveyance technologies. Better methods for transporting inspection devices within pressure pipelines over longer distances, more reliably. This discussion will look at wheeled and tracked vehicles, their stability and their reliability; at flotation devices their stability; and other transport methods. (3) Insertion and retrieval devices and methods. This includes flexibility of inspection and conveyance technologies themselves in terms of ease of insertion and retrieval and the fittings installed on pipelines for insertion and retrieval of inspection equipment. (4) Data management including data storage, data analysis and most importantly data reporting formats. The feasibility of combining data from a variety of inspection devices in a unified standard format.

Aging infrastructure is a major problem facing the USA. ASCE's Infrastructure Report Card graded the nation's water distribution systems with a D-, and indicated an annual shortfall of $11 billion to renovate the aging drinking water infrastructure needs over the next 20 years. Consequences of failure in a water distribution pipeline may be severe, including water quality degradation, hydraulic capacity loss, structural failure, and water losses due to leakage. Recent technological advances in trenchless methods are being considered by more water authorities across the country because they minimize the need for excavation and can save from 20 to 60 percent in overall costs. The objective of this study was to provide an overview of trenchless water main rehabilitation and analyze the effect of trenchless pipeline rehabilitation on the hydraulic capacity. Data from experimental work on a full-scale testing setup (for relined and slightly deteriorated unlined pipe) and computational flow analysis (for pipe in poor condition) showed that rehabilitation will significantly increase flow capacity (that is more flow at the same pumping power) of a severely deteriorated pipe. Whereas, flow capacity might be decreased by as high as 20 percent for the slightly deteriorated cast iron water main in comparison with relined pipe.

The lack of technical resources and limited experience in developing new and emerging underground technologies has created needs for research, development and outreach throughout the world. An important element in addressing the underground infrastructure challenges is international collaboration among industries and researchers, specifically from the developing countries and world powers, where the problems and possible solutions may be addressed. Funded by a grant by the U.S. National Science Foundation (Grant No. 0741764), an international workshop on Trenchless Technology and Critical Underground Infrastructure Issues was held in October 2007, in Wuhan, China. This workshop was co-sponsored by The University of Texas at Arlington and China University of Geosciences. As result of this workshop, the China-U.S. Joint Center for Trenchless Research & Development, at the College of Engineering, China University of Geosciences (Wuhan) was established. In October 2009, the ASCE Pipeline Division sponsored a follow-up International Conference on Pipelines and Trenchless Technology (ICPTT 2009) in Shanghai. Between 2007 and 2009, several site visits by Chinese and U.S. industries and researchers were arranged. This paper provides an overview of these activities, future activities planned, and recommendations for future research, outreach, and development between the U.S. and China.

Corrosion is an electrochemical process and, therefore, related to the electrical properties and configuration of the pipeline. Since electrical access to pipelines can be limited and excavation to attach test facilities expensive, owners and engineers must use a variety of techniques to assist in the assessment process. This paper will review the use of soil chemical corrosivity assessment, surface potential mapping techniques, longitudinal electrical continuity verification, and stray current mapping. These techniques along with engineering judgment and understanding of pipeline configuration and construction allowed the project team to successfully assess approximately 20 miles of raw and potable water pipe ranging in diameter from 27 to 108 inches. Piping material ranged from asbestos-cement pressure pipe; prestressed concrete cylinder pipe, steel-cylinder type; concrete pressure, bar-wrapped, steel cylinder type; reinforced concrete pressure pipe; and steel water pipe with a cement-mortar coating. The results of this assessment along with data from other condition assessment methods will be used to develop a remediation and rehabilitation program for critical pipelines.

Performing structural evaluations of aged civil engineering structures has traditionally been performed on a static basis. The condition of the structure is tested either destructively or non-destructively to determine its present day condition and the strength is evaluated to determine if the structure can safely withstand anticipated loads. One of the problems with managing structures in this fashion is that structures do not behave in a static fashion. This is especially true for large diameter PCCP (Prestressed concrete cylinder pipeline) mains that have wire break damage resulting from corrosion or cracking from hydrogen embrittlement. Given the variability in rate of deterioration in a PCCP main the risk associated with a pipe section changes with time. Pipe sections where risk is deemed to be acceptable may change to a point where risk is not acceptable in a relatively short duration of time. This phenomenon has been observed on multiple pipe sections. This paper examines the rate of deterioration of PCCP mains to evaluate how risk changes or does not change with time and how this information can be used to determine when a pipeline should be repaired.

The Southern Nevada Water Authority (SNWA) initiated a program to assess water transmission laterals that were constructed prior to 2000 and retained the services of HDR Engineering, Inc. (HDR) to provide condition assessment of approximately 108 miles in Las Vegas, Nevada. Echologics Engineering Inc. (Echologics) was retained by HDR to perform acoustic testing of the asbestos cement pressure pipe (ACPP) laterals to determine the presence of any leaks, as well as the overall average structural thickness of the pipe wall. The Echologics acoustic technology to determine pipe wall thickness uses the velocity of acoustic waves within the pipe to determine the structural thickness of pressurized water pipes. This technology is particularly effective on asbestos cement pipes. The method relies on the measurement of the acoustic velocity using easy-to-access measurement locations such as fire hydrants and control valves. In the case of the SNWA project, potholes were vacuum excavated to allow a direct connection to the pipe. Changes to the signal-specific changes to transmission or propagation velocity, can be related to changes in the pipe wall thickness. For the SNWA project four laterals were assessed using the acoustic technology, the North, Robinson, Foothills and Boulder City Laterals. The results of the pipe wall assessment were then related directly to the original specifications of the asbestos cement pipe. Working with HDR, an overall structural assessment of the pipe was conducted based on the results of the acoustic testing. This paper will outline the results of the SNWA study, as well as other studies that have verified the accuracy of the acoustic technology. It will also cover various criteria for establishing the residual life of the AC pipe.

Many types of large diameter pipelines tend to degrade gradually, with the pipe walls losing thickness over time before complete failure. It is well established in the literature that as pipe walls lose thickness and strength, they also lose stiffness. This stiffness loss in turn has an impact on the speed at which sound propagates through a pipeline. An understanding of the relationships between wall thickness and the speed of sound, combined with a method of measuring the speed of sound over intervals of a pipeline, make it possible to estimate the remaining wall thickness of stretches of pipeline without the need to de-water or even take the line out of service. This paper outlines the principles and application of acoustic wall thickness measurement in large diameter pipelines. The approach discussed employs multiple sensors, some at fixed locations, and one traveling in a controlled manner through the pipeline, in order to take wall thickness measurements at fairly tight intervals along a large diameter pipeline. Several implementations of this technique are discussed: using correlators to measure the speed of sound over set intervals, using a mobile in-pipe hydrophone, and using a combination of the two techniques, correlating signals from a mobile in-pipe hydrophone and a fixed location sensor.

Many utilities and other pipeline owners are understandably concerned about the condition of their wastewater force mains. By their very nature, force mains are difficult to repair, and spillage from a force main can cause significant environmental, regulatory, and public relations difficulties. Like all pipelines, force mains deteriorate as they age from various corrosion processes. Force mains also can break or pull apart due to various ground movements or other external forces that can accumulate over time. Under optimal conditions, force mains may last 100 years or more. However, failures after a mere 20 years are also common. The ramifications of spillage from a wastewater force main are certainly more acute than for other water pipelines, and become greater every year. As part its defense when a problem arises, a utility will want to demonstrate that a proactive infrastructure management program was in place, including the use of state-of-the-art condition assessment—but what is the state of the art? This paper examines various alternatives for assessing the condition of small diameter force mains. Several evaluation methods are briefly described, along with their applications to ductile iron, steel, and asbestos cement force mains. Two case studies are presented, where condition assessments were performed on small diameter ductile iron pipelines, after only about 20 years of service. Both pipelines had experience failures. In the first case study, the pipeline was well engineered, but localized failures occurred possibly due to undetected construction defects. After investigating the probable cause of the failure (microbial induced corrosion) and determining the extent of deterioration (limited), the owner used pipe bursting to replace a portion of the pipeline believed to be in poor condition (about 10 percent of the overall pipeline). The remainder of the pipeline was then tested using controlled destructive examination. In the second case, the pipeline was not well engineered. It had been installed as a "temporary" facility, but had remained in service for two decades. Extensive corrosion was occurring both externally and internally, but the cost of replacing the pipeline was high. The owner selected an in-pipe nondestructive evaluation technique that detected corrosion losses over the entire length of the pipeline. In both cases, testing allowed the owner to keep most portions of the pipeline in service indefinitely, with relatively good assurance that problems on these portions would not recur for several more years.

This paper presents a framework for application of modelling tools in an integrated approach to deal with the probabilistic manner of deterioration processes. The framework will assist industry towards implementation of integrated asset management approaches by addressing research and practical challenges such as (1) which assets should be inspected with high priority? and (2) how decision support models can be used to provide important information for various levels of asset management. The framework is applied to a case study relating to asset management of sewers and manholes. A preliminary result of statistical analysis on sewer data of the case study is also presented.

Stormwater pipe networks are an important part of the water infrastructure that removes stormwater runoff from urban cities of Australia. This paper presents the attempts made to improve the classification or prediction of structural condition for individual stormwater pipes. Such predictive information can be used to prioritize pipes for inspection and subsequent maintenance actions and thus support water utilities implementing their proactive management strategies. In this paper, a support vector machine (SVM) was developed, tested and compared against the back-propagation neural network (BPNN) model which has been used in a previous study. The developed model was applied to a case study using a sample of CCTV inspected pipes and corresponding pipe factors. The results showed that with regards to correctly predicting structural condition of individual stormwater pipes, the SVM model outperformed the BPNN significantly in the train dataset and marginally in the test dataset. Several advantages of the SVM model were also found compared to the BPNN model.

Asbestos cement (AC) pipe was first introduced in North America in 1929 and became a common choice for potable water main construction from the 1940s to the 1970s. To understand the condition of AC pipe in North America, a survey was conducted that obtained information about AC pipe inventory, pipe conditions, working environments, rehabilitation/replacement methods, and safety and health-related management practices. This paper summarizes the AC condition assessment techniques used by the surveyed utilities. It also reviews other available condition assessment methods for AC pipes.

The Southern Nevada Water Authority (SNWA) initiated a program to assess water transmission laterals that were constructed prior to 2000 and retained the services of HDR Engineering, Inc. (HDR) to provide condition assessment of approximately 108 miles of pipe in Las Vegas, Nevada, summarized in Table 1. The project team included specialized subconsultants (Schiff Associates, Pressure Pipe Inspection Company, Echologics, Kleinfelder, TRC Solutions, Rafael Civil, Rock Solid Group, and Cardno TBE) for corrosion testing and evaluation, internal inspection of PCCP, acoustic testing, geotechnical investigation, surveying, test station installation and excavations, broadband electromagnetic testing, and potholing.

Like other urban centers in the United States, aging infrastructure in the Dallas / Fort Worth (DFW) area is a fast-growing problem. Critical pipeline assets are reaching their service life, and pipeline condition assessments are becoming critical in order to gain additional years. Dallas County / Parks Cities Municipal Utilities District (MUD) has a 36-inch pre-stressed concrete cylinder pipe (PCCP) that has been in service since 1950 with no recent condition assessment. The PCCP is a critical asset for Park Cities MUD since it is currently the only water supply transmission line for the Highland Park and University Park communities. As a result, the pipeline can only be taken out of service for short periods of time. Camp Dresser & McKee (CDM) was asked by Park Cities MUD to determine the condition of the 36-inch PCCP. The Pressure Pipe Inspection Company's (PPIC) PipeDiver tool was used to determine the condition of the PCCP while it remained in service. This paper will describe the pipe diver inspection; the process used by CDM to determine the condition of the line, and will give an update in regards to the design of the pipeline modifications.

Most of North America's oldest water mains are constructed of ferrous material, in particular cast iron, ductile iron, and steel. Budgetary realities often make it impossible for utilities to replace these pipelines at the end of their design life. Utilities are increasingly looking to asset management programs to help direct scarce resources to where they are most needed, and these programs depend on reliable condition assessment information. There is an obvious need for condition assessment tools that will allow utilities to implement selective repair and replacement strategies based on the actual condition of their pipelines. In order to keep the overall project cost and effort manageable, and to maintain customer service levels, these technologies need to be able to address pipelines while they are in service. This paper outlines two approaches that are now available for condition assessment of metallic mains while they remain in service. The first is a tethered inline inspection system which can detect discontinuities in the pipe wall, internal corrosion, damage to or loss of the liner, and has now been adapted to provide indications of average wall thickness over set intervals. The second is a new free-swimming "smart pig" allowing for Remote Field Eddy Current (RFEC) testing of metallic pipelines, which provides detailed readings of metal loss, even through a pipe liner. Technology specifications and case studies are presented for both approaches. An approach to using this information to estimate remain life of pipelines is also discussed.

Damages and defects in prestressed concrete pipes (PCCP), such as prestressing wire breaks and cracks, reduce the stiffness and natural frequencies of the pipe. In this study, A finite element method (FEM) was used to evaluate the natural frequencies and mode shapes of PCCP. Structural health monitoring (SHM) of PCCP was performed by considering the variation of natural frequencies due to wire breaks. For damage identification, vibration responses of undamaged and damaged PCCP were compared. The severity of damage was presented by increasing the number of broken prestressing wires. The proposed model was applied to obtain the effects of wire breaks on resonance response of PCCP. Based upon the obtained results, suggestions for future work were presented and discussed.

Sonic/ultrasonic nondestructive impact echo testing results of a 48 inch diameter PCCP Force Main identified pipes with wall thicknesses 1/4 to 1/2 inches thinner than design specifications and delaminations at the boundary between the outer core and mortar coating. Excavation and visual inspection of pipes confirmed corroded thinning mortar coating. Sonic/ultrasonic impact echo results also identified pipes with wall thickness indicating a delaminating at the boundary between the outer core and the mortar coating (at the wire wrap). A section of core concrete with mortar coating recovered from a failed pipe had cracking and partial delamination below and between the wires.

As the fourth largest City in the U.S. and a regional water provider, the City of Houston operates and maintains a water system that contains over 550 miles of transmission mains and pumped at rates over 450 MGD during the summer of 2009. Like most utility agencies extending the useful life and enhancing the function of existing infrastructure through proper asset management is a necessity. The City of Houston has established a formal condition assessment and dynamic monitoring program. Key to the program is the development of a proactive process to assess and rehabilitate critical water transmission lines rather than rely on a reactive response to failures and urgent conditions, and to develop an effective action plan in the event of an unexpected shut down of some of the most critical lines in the system. The City, with the support of their consultant, Lockwood, Andrews and Newnam, Inc. (LAN) have developed an Emergency Action Plan which identifies the appropriate actions, notifications and coordination required for various potential emergency events. These events range from detecting minor wire breaks to leaks or in extreme cases pipe failure. This paper will discuss the process the City of Houston went through to evaluate the methods it uses to monitor and assess risk and the issues in establishing a written document for responding to emergencies. The paper will present the issues of establishing such a program including setting up monitoring technology, defining responsibilities, frequency of action plan updates, protocol for notifications, and hierarchy for communication. Included in the discussion will be a case study detailing how the action plan affected the implementation of the City's dynamic monitoring system on an existing 84-inch and 66-inch water transmission main.

In 2008 Denver Water deployed the Sahara® (The Pressure Pipe Inspection Company) and SmartBall (Pure Technologies) leak detection systems into an 11.7 mile, 60 and 66-inch diameter potable water transmission main. Leaks unknown to the contractors were simulated by the owner during the testing. This paper compares the preparation required, implementation, and inspection results for each system as experienced by Denver Water.

CDM has been implementing sewer inspection, assessment and I/I studies for numerous national and international sewer collection system owners. CDM has developed several unique tools and procedures for assessment and rehabilitation of sanitary sewer systems. The goal of these programs are to identify locations and causes of sewer system hydraulic deficiencies, public and private sources of I/I, structural pipe defects, operation and maintenance (O&M) defects, and to provide conceptual designs to reduce I/I, improve the sewer system performance, and minimize basement flooding. The first tool is a unique custom-built GIS application that links CCTV inspection data in a PACP© database to a GIS pipes shapefile by way of a customizable interactive tree-like interface. This interface applies series of user-defined filtering queries to the data to classify pipes based on inspection results and other criteria. Outputs include prioritized recommendations for every pipe in the study areas. Each recommendation is also prioritized based upon the consequence of failure or blockage. The GIS tool efficiently processes digital CCTV video, sewer inspection data, hydraulic modeling data, resident complaint data, surface feature data, and costing data to produce prioritized structural and O&M sewer recommendations in a GIS mapping environment. The tool has been successfully applied to several national programs that are collecting large amounts of sewer inspection data in PACP© format. The development of the tool, the types of data that can be incorporated as well as examples of its use will be shown and discussed. The other GIS tool was developed and applied to all of the field investigation data to identify all the potential sources, locations and quantities of stormwater getting into the sanitary sewer known as inflow and infiltration. The GIS application organizes, queries and maps all of this data including flow monitoring data, dye testing results, hydraulic modeling data, residential complaint records, and surface feature data to determine areas that are highly susceptible to I/I to develop cost effective I/I reduction recommendations.

The objective of this study was to investigate the mechanisms of corrosion and corrosion control for ductile iron pipe (DIP) encased in polyethylene as specified in AWWA Standard C105. The current study is the second phase of a multiphase project funded by the Ductile Iron Pipe Research Association (DIPRA). In-situ measurements of corrosion rate were made for three types of probes placed in the narrow gap or annulus (∼2 mm) between a polyethylene encasing surface and the exterior surface of an asphalt coated DIP. The probes were comprised of carbon steel, DIP with an annealing oxide and DIP without an annealing oxide (Bare DIP). The electrolyte solution in the annulus space was slowly circulated through a reservoir with and without an external supply of oxygen. The electrolyte solution was made from soil water extracts so that actual soil chemistry and conditions could be accurately simulated. The pH and dissolved oxygen concentrations of the electrolyte solution were periodically measured in the reservoir. In-situ Electrical Resistance (ER) and Linear Polarization Resistance (LPR) measurements were made over the course of three months. Corrosion rate measurements are possible in the annulus space formed by polyethylene encasement of ductile iron pipe. The corrosion rate in the case of polyethylene encased carbon steel and ductile iron pipe is strongly influenced by the amount of oxygen available in the corrosive fluid. The corrosion rate decreases to near zero when the oxygen level of the electrolyte in the annular space drops to zero. Since the polyethylene encasement deprives the system of oxygen, corrosion is slowed or even stopped. This supports the effectiveness of corrosion control provided by polyethylene encasement. The long term corrosion mechanism occurring for ductile iron pipe is dominated by general uniform corrosion at the surface. This is especially true when oxygen is absent. Steady state corrosion rates for ductile iron pipe as manufactured with annealing oxide under conditions where soil pore water is saturated with air are low (less than 1 mil per year). The oxide surface of annealed ductile iron pipe protects the pipe from the electrolyte solution and buffers the pH thus mitigating corrosion. Ductile iron pipe without annealing oxide (bare DIP) experiences a high initial corrosion rate. The long term steady state corrosion rate under aerated conditions as determined by LPR (4 mils per year) and ER (1.2 to 0.6 mils per year) did not agree well. This may have been an artifact of the bead blasting of the sensor surface to remove the annealing oxide. The corrosion of carbon steel is dominated by localized corrosion or pitting. The long term steady state corrosion rate for carbon steel under aerated conditions may be as high as 4 mils per year.

Large diameter sewers are often the backbone of a municipal wastewater conveyance system. Trunk sewers, interceptors, and transfer sewers form the network by which sewage from the customers is collected and transported to the appropriate treatment facility. This method of centralized collection has been the standard for centuries. In the United States, many of these large diameter sewers are constructed of reinforced concrete pipe (RCP) and have been in service well past their design life. As a result, headlines of sinkholes, pipe collapses, and overflows when these sewers fail have become more frequent. Such failures have discharged up to 10 billion gallons of raw sewage into natural waters, cost cities up to $35 million in fines, and have attracted the attention of major public media (USA Today, 5/8/2008). To prevent similar problems from occurring in their systems, many municipalities are implementing condition assessment programs to inspect their large diameter sewers, with the intent of addressing problem areas before they become worse. Condition assessments of very large transfer sewers involves higher flows, elevated levels of H₂S, wider easement requirements, and a sensitivity to the elevated system dependence on these large sewers. Conventional methods of condition assessment that utilize primarily CCTV inspections can be overly expensive and inefficient. A multi-faceted and tiered approach that includes both conventional and higher-level technologies can be more cost-effective and thorough. This progressive approach will also reserve the most detailed, thorough, and expensive inspection methods for the segments that need it most, thus avoiding unnecessary inspection and evaluation costs. This paper will present a explanation of the goals, methods, and results of the progressive approach and is based on experience from several progressive large-diameter RCP assessment programs representing more than 35,000 feet, ranging in size from 36-inch to 84-inch diameters.

The Washington Suburban Sanitary Commission (WSSC) is the 8th largest water and wastewater utility in the United States, serving approximately 1.8 million residents in Montgomery and Prince George's County Maryland (suburban Washington D.C.). The over 1,000 square mile service area contains nearly 5,500 miles of water pipelines and over 5,300 miles of sewer pipelines all operated and maintained by WSSC. Of the nearly 5,500 miles of water pipelines, approximately 145 miles (2.7%) are comprised of large diameter (greater than 36-inches in diameter) prestressed concrete cylinder pipe (PCCP). These PCCP pipelines are the backbone of WSSC's large diameter water transmission system therefore placing a high criticality and consequence of failure on these pipelines. This paper will discuss WSSC's comprehensive approach to their PCCP Management Program, which is recognized as an industry-leading program. Various condition assessment techniques (including their benefits and limitations), condition/criticality analysis approaches, and acoustic monitoring/web-based management tools will also be described in detail.

Since 2003, the Goleta West Sanitary District (GWSD) has been rehabilitating their collection system in phases. Each phase involved rehabilitation of portions of their collection system using different techniques based on bid results. The District is currently moving forward with construction of Phase V which involves several changes based on the experiences obtained from the first four phases and their performance. Since roots are the major problem for with the GWSD system, Phase V improves the reliability and long term performance of pipe rehabilitation.

Remote Field Transformer Coupling (RFTC) inspection has become the industry standard in condition assessment of Prestressed Concrete Cylinder Pipe (PCCP) since its commercial introduction in 1997. While the technique works for almost all types of PCCP, it is a huge challenge to actually conduct RFEC/TC inspections for many PCCP lines, especially since most of these can not be taken out of the service and fully dewatered. In 2007, a free-swimming tool was developed and successfully used in the field for small diameter PCCP (24" – 48"). It is capable of conducting RFTC inspection in a live PCCP line. This innovative tool can be launched into an in-service pipeline through a small hot-tap, travel along the pipeline with the water flow while collecting RFTC data and then be retrieved from another small hot-tap at the downstream end. Currently, this free-swimming tool is being scaled up for large diameter application (60" and larger). This paper will describe its technical capabilities and operational requirements for live inspection of large diameter PCCP. The field test results will also be presented.

Monitoring and condition assessments methods have struggled with discerning the differences between various degradation activities on Prestressed Concrete Cylinder Pipe (PCCP). The accumulated damage due to wire breaks can be estimated and assessed using electromagnetic methods. Wire break activity can be monitored using acoustic methods. Previous work with acoustic methods indicates that it may be possible to determine post wire break, slips and mortar delaminations from acoustic dataⁱ. Recent workⁱ indicates that it may be possible to harvest condition assessment information from acoustic data. In this work, above grade sections of PCCP are instrumented and wires systematically cut while acoustic and mechanical distortion data were collected. Instantaneous changes along with relatively long term relaxation of the pipe were monitored. Advance acoustic data process were applied and results correlated with mechanical measurements and observations including, wire breaks (WB), apparent wire slips (WS) and delaminations (DLAM) of the mortar coating. Results of the testing on an instrumented aboveground 48-inch lined cylinder PCCP show that WBs can be distinguished from other mechanical/structural degradation activity including WSs and DLAMs based on the amplitude, time domain characteristics and frequency spectra. The conclusion is therefore that by using acoustic monitoring detections of the early, intermediate and advanced stages of PCCP degradation leading up to failure can be measured, discriminated and acted upon.

Over the last several years, a 36-inch diameter section of the Papillion Creek Interceptor sanitary sewer in Omaha, Nebraska, has experienced chronic maintenance and capacity issues. The pipeline was originally constructed in the late 1960's and recent extensions of the interceptor to the north and west have increased the original service area substantially. The interceptor generally parallels the west bank of Big Papillion Creek and the original 36-inch segment was constructed with extremely flat slopes. The most maintenance prone section of the sewer is a 4,300-foot long reach running beneath a privately owned golf course where maintenance access is limited and cleaning equipment causes damage and disruption to the property. Prolonged accumulation of grit and debris in the golf course restricted flow, and along with increasing flows from new development, has caused upstream surcharging, odor problems during dry weather flows, and created a potential for significant SSO's during rain events. Alignment alternatives and a detailed hydraulic model were developed for both replacement and parallel pipelines to solve these issues. Alternatives were evaluated based on cost, constructability, ease of maintenance, easement acquisition, disruption to the public and property owners, and utility interferences. The results showed that the best alternative for the City was to construct a replacement 60-inch interceptor along the east bank of Big Papillion Creek with inverted siphons connecting to the existing interceptor at the upstream and downstream ends. The existing 36-inch section is to be abandoned through the golf course.

This paper presents two cases studies that utilized Three Dimensional Subsurface Imaging (3DSI) to map the vertical and horizontal positions of underground pipelines. The first case involved mapping the horizontal position and depth of three large, 9+ foot diameter water supply lines so that a new 16-inch service line could be installed in the right-of-way without conflict. The second case involved mapping the elevation of a force main that had experienced reduced capacity because of entrained air. The goal of that survey was to identify the location of any highpoints in the line. Multi-channel Ground Penetrating Radar (GPR) and multi-sensor Time Domain Electromagnetic Induction (TDEMI) deployment carts coupled to a high-precision GPS and robotic total station were used to provide the advanced three dimensional mapping results.

Asbestos cement (AC) water mains, generally considered as non-friable asbestos-containing materials (ACMs), are not believed to represent a significant hazard to public health in normal use. However, repair, rehabilitation and removal of AC pipes involve cutting, polishing, and demolition can release asbestos fibers into the air, posing risks to public health. Many water utilities in North America currently have significant portions of their water mains composed of AC pipes. A comprehensive survey was conducted with 20 water utilities in the United States of America and Canada to understand the existing conditions of AC water mains in North America and to determine current management practices related to AC pipe repair, rehabilitation, and replacement. The survey was conducted through questionnaires that covered various areas: pipe inventory; environmental working conditions; current practices in pipe repair, rehabilitation and replacement; and safety/health protection practices used in working with, and disposing of AC pipe. This paper focuses on the survey results related to safety and disposal issues, including existing regulations related to testing and concentrations of asbestos fibers in drinking water, AC pipe project management, worker protection measures, and existing disposal practices for broken AC pipes. Results indicate that some utilities do not have well-established procedures to provide suitable protection for workers and the general public during AC pipe projects. Some current practices can also lead to potential problems for future site development. For example, less than half of the utilities reported having a formal procedure specifically for dealing with AC pipe in water distribution systems. When replacing broken AC pipes, more than half of the utilities had abandoned broken pipes and buried them in place as their primary method of disposal. Standardized procedures, which can be critical for the safety of workers, the public and future site development, are needed by water utilities for handling AC pipes during the repair, rehabilitation, and replacement of AC water mains.

This paper presents a risk-based inspection approach for large diameter sewers in a UK water company. The approach uses structural engineering principles for buried pipelines to estimate Factors of Safety (FOS) as surrogate measures of failure likelihood. To ensure coverage of the large set of sewers, engineering judgement and rules of thumb were used to provide sufficient information to calculate FOS-values. for those sewers with calculated FOS-values less than 1, failure was considered imminent. Future inspection of these sewers was then prioritised based on the perceived consequences of collapse. Consequence assessment was based on the size of collapse hole that would be produced at the surface from sewer failure and the number of roads that would be affected. The client used the method to prioritise sewers for future CCTV and walk-through inspection

The rapid deterioration and aging of infrastructure elements require transportation agencies to make quick and reliable decisions. While comprehensive infrastructure management strategies have been developed for the visible components of the highway system (e.g. bridges and pavement), culverts and drainage structures are often neglected. In a previous study, the authors investigated the current culvert asset management practices of transportation agencies and also developed the inventory and inspection protocols necessary for establishing an effective culvert asset management program (Najafi et al. 2008). This study builds upon the findings of the previous research project and focuses on the application of trenchless technologies for inspection, construction, repair and renewal of culverts. First, a review of the relevant literature was conducted. Second, in order to identify and characterize trenchless technology methods used for buried pipes, departments of transportation and technology providers were asked to complete a written survey. The limitations of trenchless technologies in terms of applicability to culverts are investigated. A decision support tool is generated in order to help decision makers to identify the most preferred repair/renewal procedures given the condition of the culvert.

Regarding the nonlinear behavior of soil and pipes in strong earthquakes, in this study the possible damages in straight continuous steel buried pipelines subjected to strong surface transverse waves has been investigated, and a relationship between the maximum compressive strain and the pipe reduced hollow-section area has been presented. For this purpose at first the concept of "minimum acceptable length" has introduced, which if is used for the pipe segment in pipeline modeling, the seismic response of the pipe around the middle of the segment length will not be affected by the end-conditions. Then the pipeline segment, modeled by beam elements, has been analyzed subjected to transverse waves, assuming different values for the pipe's diameter and thicknesses, and also various kinds of surrounding soil (clay and sand), and the maximum lateral displacement in the pipe segment middle point has been calculated. In the next step, regarding that by using the beam elements the reduced hollow-section area of the pipe is not directly obtainable, the relationship between the maximum compressive strain and the reduced pipe section has been obtained by using shell elements in a series of finite element analyses of a limited part of the pipeline, in which the influence of internal gas pressure has been taken into consideration as well. By this kind of analysis the corresponding strain to the local buckling in the pipe, and also the relation between the reduced hollow-section area in shell element model and the compressive strain in beam element model have been obtained.

Since its inception, application of carbon fiber liners for the retrofit of degrading Prestress Concrete Cylinder Pipe (PCCP), have evolved in both design and application. Carbon Fiber Liners have roots in bridge design. This is where the California Department of Transportation (Cal Trans) studied the use of Carbon Composite materials to retrofit bridge columns for improved performance during seismic events. The Department's study proved successful through the efforts of a couple of small innovative Southern California based companies. Upon completion of the composite bridge study these companies were positioned with advanced materials and application methods. Coincidentally, the development of advanced Fiber Reinforced Composite materials for the Civil industry occurred at the time when PCCP failures were happening at an alarming rate in North America. PCCP water-main failures were more than an inconvenience to the managing public agencies. Failures proved to be very costly in both repair and loss water sales. PCCP failures threatened public safety, property, as well as stimulating political unrest aimed at the managing public agencies. Pipeline professionals recognized the advantages offered by carbon composites for the retrofit of degrading PCCP over existing repair methods. Existing repair methods include: Remove and Replace, Slip Lining, and Relocation. The benefits offered by Carbon Liners over these conventional repair methods come from the fact that installation of FRP liners do not require exaction or extended planning and repair schedules common to conventional repair methods. This is very important property of FRP liners because it allows feeders to be repaired during the same pipeline shutdown where the distress was uncovered, allowing the pipeline to be brought back in to service in a very short window fully retrofitted. Prior to the development of the FRP liner technology agencies faced bringing a defective feeder back into service while planning its future repair with convention methods. Bringing a defective feeder back in to service without first repairing it is what I term the "cross your fingers approach to public safety". Needless to say, the cross your fingers method of repair is not recommended. During the infancy of FRP liners Pipe Owners did not know how to design or specify the product. Early liners were designed through a combination of lessons learned through the Cal-trans study, conventional analysis used by Civil Engineers, with the application of limited laboratory test data performed on PCCP lined with carbon composites. The emerging design models offered the foundation for Carbon Fiber Reinforced Polymer (CFRP) liners used today. Since the first installation in the mid 1990's the design and installation of CFRP liners has evolved through the cooperative efforts of both pipe owners and the private sector. A discussion of this evolution follows.

Recent digital maps from both new mapping and digitized old maps, can be used for new interactive GIS applications and web based access. Digital data can be combined for geohazard evaluations giving rapid low cost preliminary risk evaluations over large areas. for pipeline applications, this is useful in planning, design and maintenance data archival with web access between field offices and the corporate office. Three examples are provided in this paper, including: (1) Seismic slope hazard mapping using USGS/FEMA simplified methodologies. (2) Multi-hazard analysis of a pipeline alignment, covering over a dozen geologic and climatic hazards in an interactive Google Earth based format. (3) GIS based master database using a web based interactive platform to access multiple software platforms across a regional distribution network. Engineering judgment is needed to obtain rational user friendly results. These three examples reflect progressive tiers of detail: (1) single hazard evaluations, (2) multi-hazard comparisons and (3) condition assessments / system inventories. They can guide detailed risk assessments of pipeline systems and other critical infrastructure, as provided in the National Infrastructure Protection Plan (NIPP) (DHS, 2009), including hazard mitigations and system monitoring over time (ASCE, 2009).

Rail continues to be a major mode of transport in the 21^st century. According to the Association of American Railroads, there were nearly 1.4 million freight cars in service in the United States in 2009, operating on around 140,000 miles of track. As such, it is important to continue to evaluate the different drainage materials that are used underneath railroads. Small diameter corrugated high density polyethylene (HDPE) pipe has been used beneath railroads for decades. Currently, corrugated pipe is manufactured in sizes up to 60 inches in diameter. The Plastics Pipe Institute (PPI) funded a study to assess the performance of large diameter corrugated HDPE pipe beneath railroads under relatively shallow fills. Transportation Technology Center, Inc. (TTCI) conducted the test of 48-inch corrugated high-density polyethylene pipes at the Facility for Accelerated Service Testing (FAST). FAST operates as a test bed for railroad track and components, and for rail vehicles and components. The Federal Railroad Administration, the Association of American Railroads, and individual railroads and railroad suppliers (through in-kind contributions) have cooperatively funded the operations at FAST and its test programs. Typically, the train consist at FAST is four GP-40 locomotives and 80 315,000-pound gross rail load (GRL) cars. Approximately 120 million gross tons (MGT) of heavy axle load (HAL) traffic accumulate each year at FAST. Testing at FAST allows for safe, controlled testing of components without incurring the risk of in-service evaluations. The pipes were instrumented to allow data collection during train operations. Transducers were installed at various locations on the pipes to measure pipe wall strains and lateral, vertical, diagonal, and circumferential deflections. Strains and deflections were measured when the pipes were in place before the trenches were backfilled, after backfill, during normal operations at FAST after accumulating 1 MGT of HAL traffic, and after accumulating 96 MGT of HAL traffic. Also, the pipes were monitored visually and with a video camera. The pipes performed excellently, with negligible deflections, stresses, and strains resulting from the heavy railroad loading.

As the installation of oil and gas pipeline increases rapidly, more and more Horizontal Directional Drilling (HDD) machines are utilized in China. The main function of slips in a HDD rig is to loosen the screw of two drill rods which are screwed up in the drilling or reaming process. The more tightly the drill rods are screwed, the larger the force acting on the drill rod, which can cause notches on drill rod. However, if the force is not big enough, there would be insufficient friction force to loosen the screw. The damage modes of the drill rod surface caused by slips indicate that the interaction mechanism between integrated slips and the drill rod is elastic, while the sharp teeth of combined slips can embed into the surface of drill rod. This assumption is proven by two calculation examples. ABAQUS is used to simulate the interaction mechanism between slip and drill rod, and the result is approximately coincided with the calculated results. The friction coefficient between slips and drill rod are calculated and then compared to the experiential results. Finally, some advice is given to solve the problem.

Long term durability of carbon fiber reinforced polymer (CFRP) systems used to strengthen prestressed concrete cylinder pipes (PCCP) and other water transmission structures has been a topic of significant interest since the CFRP systems were initially implemented for structural repair of pipelines in 1997. Although there is a substantial amount of durability studies available on some CFRP systems for strengthening of structural elements, there is significantly less information on long term durability studies of the CFRP when submerged in water. The Metropolitan Water District of Southern California (MWD) and two CFRP manufacturers submitted CFRP samples to be submerged in water tanks at the MWD laboratory and tested as part of MWD's ongoing CFRP liner research program. Some of the samples that were submerged in 2000 were recently tested by MWD and an independent laboratory to provide long term durability data. In conjunction with the laboratory experiments, inspection results. The results from the recent inspection and the laboratory experiments showed negligible change in the performance of the materials thereby supporting previous data on the capability of CFRP materials as a long term durable solution for pipeline rehabilitation. The experimental data and pipeline inspection results were analyzed and reported through a cooperative research study between MWD and the CFRP manufacturer in order to provide the PCCP user industry specific durability effects to CFRP material properties submerged in water for extended periods. This study will assist engineers and pipeline users in establishing the applicability of a CFRP system as a long term repair. This paper should prove to be a useful document in the ongoing study of CFRP as a viable repair solution by addressing the materials long term durability performance.

Pressure pipe systems are an important part of infrastructure, used to convey commodities such as drinking water, petroleum, chemicals, and heating and cooling fluid. These pipelines are often our population centers' only means of receiving goods which are vital to day-to-day existence. Pipelines face similar challenges to other structural elements in that the integrity of pressure pipes is subject to aging, corrosion, earthquake damage as well as additional stresses due to variable loading conditions from internal and external pressures. Over time, these demands cause strength loss, structural deficiencies, leaks, and even failures. Replacement of deficient pressure pipe systems can not only be costly, but time consuming as well. In many instances pressure pipes in need of immediate repairs can ill-afford to be shut down for extended periods of time. Through the widespread use of pipeline monitoring and assessment, pipeline systems are now often able to be repaired or replaced prior to catastrophic failure. One pipe repair method is the application of Carbon Fiber Reinforced Polymer (CFRP) to the inside or outside of a pipe in order to provide a structural repair to the pipeline. Despite much advancement in structural and durability testing of CFRPs over the past 50 years with specific application to civil infrastructure for nearly 25 years, the design and application of fiber wrap in pressure pipelines is and will continue to be on a case-by-case basis with so many variables determining exact design. As these pipelines are the "backbone" of so many communities, the importance of the proper design and implementation of any structural repair for pipelines is paramount. This paper will present general guidelines for the proper design and installation of fiber wrap systems for pressure pipelines. Discussion will center upon case histories and best practices for designing the retrofit, and how to best implement the proper installation of these systems. The case studies will be explored in detail to evaluate the performance of past and present designs, both for municipal and industrial clients. Also to be discussed will be adaptation of a standard within the Industry and the impact this will have on the future of fiber wrap repairs of buried pressure pipelines.

This paper describes the emergency repair of a newly constructed cast in place reinforced concrete penstock located at "El Encanto" Hydroelectric Power Plant near San Jose, Costa Rica. The 7 foot (2.1 meter) diameter and 5742 feet (1750 meter) long penstock conveys river water from an upstream reservoir, along mountainous terrain, to a turbine complex building. While the water flows by gravity, the flow is also pressurized due to the difference in elevation between the reservoir and the building. In the spring of 2009, when plant construction was completed, the penstock was subjected to a pressurized flow test and extensive leaking was observed from surface cracks though out its length. As a first repair measure, the penstock was dewatered and all visible cracks were sealed with typical leak repair products; however, when the penstock was re-pressurized, the cracks reopened and leaking continued. As much as 20% of the flow was lost and as a result, the volume of water reaching the turbine complex was insufficient to efficiently generate electricity. The repair alternative that was successfully implemented considered the installation of a Glass Fiber Reinforced Polymer (GFRP) fabrics on the entire inner surface of the penstock; nearly 150,000 ft² (14,000 m²) of GFRP lining was installed, making this the world's largest FRP pipeline repair project on record performed in a single phase. Among the challenges of the repair project were the significant variations in the vertical and horizontal layout of the penstock due to the mountainous terrain, the limited access to the inside of the penstock through four service access points and the use of a local labor force with no prior experience in FRP installation projects. To minimize the plant shutdown time, the fabric and epoxy manufacturing plants were placed in accelerated production runs and all materials were shipped while the engineering design phase was finalized. Two engineers and four field supervisors were sent to run the installation phase and train the installation crews integrated by 40 local laborers. The installation of the GFRP liner and a protective epoxy top coat was completed in a record 15 day period and the penstock was successfully re-pressurized in July of 2009.

Soil friction is an important design factor for restrained buried pipes with internal pressure. Utilizing the bedding soil for thrust restraint eliminates the need for thrust blocks and makes pipe installation simpler. A full scale experimental investigation of soil-pipe friction coefficients was performed for an innovative, direct buried, restrained, PVC pipe under controlled laboratory conditions. The experimental work covered a wide range of soil types, over burden pressures and moisture contents. Measurements included force needed to overcome friction between pipe and its surrounding bedding, total pipe movement along its longitudinal axis, rigid body movement, and elongation of pipe under applied axial force. Based on the experimental data, three approaches are proposed for calculating the friction force of a buried restrained PVC pipe installed using the cut-and-cover method. The values reported in this paper are considered conservative and higher friction coefficient values can be anticipated over time due to consolidation and aging of the bedding soil around the pipe.

This paper describes an experimental research on ductile iron pipes with rubber gasketed joints. The laboratory tests on the pull-out of rubber gasketed joints for 150, 200 and 300 mm diameter ductile iron pipes have been performed. The experimental data indicate that the axial force-displacement relationship of the joint shows nonlinear behavior and pronounced variability. Based on the test results, rubber gasketed joints are effective in providing a leak proof and flexible connection for jointed buried pipelines.

The U.S. Environmental Protection Agency (EPA) sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,500-ft long, cement-lined, 24-in. cast-iron water main in Louisville, KY from July through September 2009. Six inspection companies demonstrated a total of 12 technologies that were at various stages of development and provided different types and levels of structural condition data. This paper presents the results of six pipe wall integrity assessment technologies, including both inline inspection of the entire pipeline length (i.e., Sahara Video®, PPIC PipeDiver® RFEC, and Russell NDE Systems See Snake® RFEC) and external inspection at selected excavation points (i.e., AESL ECAT, RSG HSK, and RSG CAP). These inspection technologies can acquire pipe condition data, such as wall thickness, metal loss, and/or cracks. For each technology, inspection results will be compared to the dimensions and locations of induced defects and naturally-occurring defects found after excavation; however, this portion of the project had not yet been completed at the time this paper was written.

The U.S. Environmental Protection Agency (EPA) sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,000-ft long, cement-lined, 24-in. cast iron water main in Louisville, KY from July through September 2009. Six inspection companies demonstrated a total of 12 technologies that were at various stages of development and provided different types and levels of structural condition data. For the study purposes, simulated leaks with various leak rates and machined defects with various sizes were pre-installed on the pipeline. Natural leaks identified by the technologies were excavated at selected locations to confirm the presence/absence of leaks. Approximately 200 ft of pipe segments were exhumed and examined in laboratories for comparison with the results from field inspections. This paper presents the results of three leak detection/location technologies (i.e., Sahara®, SmartBall®, and LeakfinderRT) in conjunction with pipe wall thickness testing deployed on the same inspection platforms.

Pipeline projects are being installed, how do you keep track of assets associated with them? This is a question for every municipality of any size. for the installation of its Prairie Waters System, the City of Aurora, Colorado was proactive in the use of GPS for GIS data collection. The City of Aurora, Colorado retained third-party construction management services for the Prairie Waters Project. This includes an alluvial well field over 37 miles of 60 inch diameter steel pipe, three 50 MGD raw water pump stations, one 100 MGD water pump station and a water purification facility. This required coordination between the City of Aurora, Construction Managers and Contractors. This paper will discuss how this was achieved and provide some back ground on the existing city system for integration of this data, including: (1) Equipment used (2) Software used (3) Type of data collected (4) Training of inspectors (5) Safety issues and challenges (6) Processing of data (7) Lessons learned about the process This paper will discuss how forethought and planning will keep your utility assets located and up to date. The use of GPS for GIS data collection during installations will increase accuracy and efficiency when making critical time sensitive decisions. This type of information collection improves the ability to accurately locate specific areas during repairs. With the use of the GIS system Aurora has been able to map the entire pipeline knowing that in the future, designers will be able to know what's in place and determine where additional structures may be accommodated or if an alternative route will be required.

April 23, 2009 saw the successful completion of a new ductile iron pipe (DIP) water supply by horizontal directional drilling in Austin, Texas. This project required an engineered prediction of pull loads that could be applied to the pipe for this installation as the pipe was longer than previous DIP installations. The requirements of the owner were very specific, the District wanted DIP with a low profile, flexible restrained joint for HDD. The issue was that construction required a large drill rig to make the bore though the tough rock therefore; the rig pull capacity significantly exceeded the strength of the pipe. The owner was concerned about damaging the product pipe during the pull. Though the risk was on the contractor, the owner required engineering calculations to assess the possibility of exceeding the allowable pulling load for the pipe. This paper describes the project, DIP characteristics, the new DIP pull load calculation method developed specifically for this project, and includes an assessment of the new calculation method against available data.

One constant in the world is change- change in personnel, politics, economy, weather. In the engineering world it is important to anticipate changes that can occur in areas that can affect designs-such changes as shifts in population, modification of use, effects of age, and natural disasters. The design of pipelines is not immune to this need to anticipate change. Events as dramatic as earthquakes or as mundane as temperature changes can have detrimental effects on pipeline performance. However, attempts to alleviate the effects of these events can have consequences of their own. In 1989 a flexible expansion joint (FEJ) product, the EBAA Iron, Inc Flex-Tend® joint, comprised of two ball joints joined by an expansion joint, was introduced to the US market. For the first time one product was available to protect pipelines and pipeline connections from differential movement resulting from seismic activity and soil expansion/contraction in areas of poor soil support, frost heave, and transitions from stable to unstable areas. This product has provided years of pipeline protection with some of the most dramatic examples being in areas that have been subjected to earthquakes. while the total amount of expansion and contraction is controlled through physical stops, one of the primary design considerations for the implementation of the product into a pipeline is the accommodation of the hydraulic thrust force that develops when the unit is pressurized. Structural restraints must be used when the unit is installed above ground at changes in direction, in long pipe runs where buckling can occur, or connections to weak structures. At the same time the structural restraints must not restrict the ability of the FEJ to protect the pipeline from the damaging movement it was intended to accommodate. This can be a tricky tradeoff. The new and improved design, a force balanced flexible expansion joint (FBFEJ), incorporates a secondary hydraulic cylinder that counteracts the thrust force that develops at the pressurized, primary cylinder. This dual cylinder design neutralizes that force while, at the same time, enabling the ability of the FBFEJ to expand or contract without restriction.

This paper will discuss the innovative application of leak detection technology to evaluate the effectiveness of identifying leaks on a combined gravity sewer system that is surcharged. Metropolitan St. Louis Sewer District (MSD) is a public agency and is responsible for the interception, collection and treatment of wastewater, as well as stormwater management. The District's current boundaries cover 525 square miles and encompass all of the City of St. Louis and approximately 80% of St. Louis County serving a population of approximately 1.4 million with approximately 519,000 single-family residential, multi-family residential and commercial/industrial accounts. MSD currently operates seven wastewater treatment facilities, treating a combined average of 330 million gallons of sewage per day and operates and maintains 9,649 miles of sewers. The Foul Water Interceptors (FWI) are part of the River Des Peres system and were inspected in 2005 during low flow conditions with CCTV equipment and several potential sources of inflow have been identified. However, unacceptably high flows in the system during high river stages continue to inundate the sewers and require a significant increase in pumping from the Lemay Pump Station No. 1. The MSD staff attended a presentation that discussed the use of a technology named Sahara® that uses an acoustic sensor to detect and locate leaks in force mains. Since the FWI are surcharged during the high river stages they should exhibit similar characteristics as a force main, and the District wanted to evaluate the use of this technology. The technology has been used by the Pressure Pipe Inspection Company (PPIC) to detect leaks in pipelines beneath rivers, so the assumption is that it can detect leakage entering the pipe as well as exiting. The work was completed as a trial aspect of the application of the technology. The advantage to this technology is that it allows for the inspection of the FWI during the high river level conditions. MSD requested a trial of the leak detection technology to possibly identify large sources of inflow.

For large diameter conventional steel pipe, standard trench requirements normally call for the use of granular materials to provide side support to limit final deflection and to prevent over deflection of the pipe during mechanical compaction of the pipe zone material. The use of the much stiffer PressureCast^TM Steel Pipe (PCSP) permits many native materials excavated from the trench to be used in the pipe zone. In this case a fine to medium sandy clay (CL) material for pipe installation and mechanical compaction methods for the pipe zone material were used. To understand and verify the design performance and behavior during installation and initial loading of large diameter PressureCast^TM Steel Pipe, 120-in PCSP test sections were subjected to 120-degree sand-bearing loading and a full-burial test in a lower quality bedding with a large surcharge loading. This paper presents the pipe test results, installation details and procedure, and the engineering criteria that were utilized for the successful placement and backfilling of the pipe.

A method for thrust restraint using liquefied stabilized soil (LSS) is proposed in this paper. LSS has been used as backfill material of pipelines recently, but it is not readily known how the bends of pipelines behave when backfilled with the LSS. We expect that the LSS is an effective backfill material against a thrust force. Model pit experiments using a model pipe having a diameter of 260 mm were carried out in order to examine the effectiveness of the LSS for the thrust restraint of a buried bend. The LSS was applied to the passive area of the model pipe and dry silica sand was used as backfill material. The model pipe was laterally loaded at a speed of 1 mm/min after backfilling to simulate the thrust force. The lateral resistance and the horizontal displacement of the model pipe were both measured. The earth pressure distributions of the passive ground were observed. In addition, numerical analyses using the distinct element methods (DEM) were carried out to simulate the model tests. The results of the model experiments showed that the lateral resistance of the bend in using the LSS was increased. It was verified that the LSS is an effective backfill material to some extent for thrust restraint. Moreover, the numerical analyses clarified the resistance mechanism of the proposed method.

The Metropolitan St. Louis Sewer District (STLMSD) faced a problem familiar to many big city wastewater departments managing underground assets. A large (72-inch) sanitary sewer needed to be replaced with an even larger line to handle wet weather flows without experiencing sanitary sewer overflows (SSOs). In the years since initial installation, the above-ground area had become heavily developed making excavation a difficult choice. Additionally, concrete pipe would be subjected to microbiologically induced corrosion (MIC) requiring consideration of long-term protection against future corrosion. The problem was overcome by tunneling 5,000 linear feet of 96-inch reinforced concrete pipe fortified with an antimicrobial additive at depths 25 feet below the roads, parks and buildings located above it.

The flow pattern around a submerged pipeline is studied by applying a full dynamic two dimensional vertical (2DV) numerical model which solves the governing Navier-Stokes Equations (NSE). The equations are solved using Finite Volume (F.V.) method in a Sigma coordinate like system of gridding. Turbulence is also considered by implementing (k-ε) model. The procedure for implementing dry elements within the computational domain is described. A circular pipe section which is comprised of a set of dry elements is considered as an example and the results of the simulations are validated against measured laboratory data.

This paper describes a new and innovative approach to the internal rehabilitation of aging and degraded, high pressure liquid and gas pipelines by the use of pipe made of layered thermoplastic composite materials. The several significant advantages of the methodology include its ability to: (1) be installed in congested and other locations where the time and cost of uncovering the host pipe is prohibitive, (2) significantly increase the pressure rating of the host pipe, (3) preclude any further strength loss due to corrosion, and (4) continually monitor the pipeline to detect external damage and leaks. Two installation methods are possible. One is best suited to long continuous installations in a tight fit manner, the other to short lengths and large diameters (e.g., as in cased crossings) as a loose fit. Following a brief introduction to the need for this new technology, this paper will describe two manufacturing/installation methods available for this class of pipe, and will address the concern for loss of flow area for internal reinforcement. The unique combination of computer simulation and testing work that along with a self-monitoring system ensures both the safety and the economy of one specific pipe system — the Smart Pipe® — that embraces this methodology will also be described.

There has been a growing interest in the use of Fiber Reinforced Polymer (FRP) for repair and strengthening of pipelines in recent years. This paper focuses on the development of a new generation of FRP products called SuperLaminate. These sheets are produced in the plant per design specifications to meet the strength and stiffness requirements of the particular project. The products are stronger than conventional FRP and are installed in significantly less time. Among the applications are strengthening of pressurized pipes, repair of corrugated metal pipe culverts and joints in water and sewer pipes.

The design of horizontal directional drilled (HDD) pipeline installations often requires an evaluation of the potential for hydraulic fracture of the soil layers through which a drilled crossing passes. This potential can be an important design factor if the crossing passes beneath a critical structure such as a regulated levee. If hydraulic fracture of the underlying soils causes the drilling fluid to migrate to the ground surface, the resulting inadvertent return may create preferential pathways for water seepage or cause damage to foundation soils. As a result, some regulating agencies require a very detailed evaluation of the hydraulic fracture and inadvertent return potential for HDD crossings. In developing a hydraulic fracture model for an HDD crossing, one of the important contributing factors to the factor of safety against hydraulic fracture and inadvertent returns is the shear strength of the soils. If an HDD crossing targets a zone of higher shear strength soils, the potential for hydraulic fracture will often be reduced. This study compares the results of the hydraulic fracture models for two HDD crossings. The subsurface soil conditions of the first crossing consist of soft to medium stiff clay for the full depth of the HDD crossing. The subsurface conditions of the second crossing consist of medium stiff clay overlying a significant layer of medium dense to very dense sand. By targeting the dense sand, the results of the hydraulic fracture and inadvertent returns models indicate significantly higher factors of safety.

The American Society of Civil Engineers (ASCE) report card for the year 2009 has graded the nation's infrastructure with a grade of "D." Pipelines deteriorating conditions and lack of proper asset management programs have increased the total cost of repair, renewal, and replacement by 38% from $1.6 trillion in 2005 to $2.2 trillion in 2009 (ASCE, 2009). With the current federal program funding addressing only a small portion of the nation's requirements, municipalities and utility owners will have to find more ways to address the renewal of their old and deteriorated pipelines. The causes of pipeline problems are due to a several reasons such as corrosion, soil movements, traffic loads, and operational factors, such as excessive pressures. For potable water pipes, a lining that can resist internal and external pressures as well as address water quality issues will be ideal. The new trenchless technology product, Spray-in-Place Pipe (SIPP) using a polyurea material has been developed to address just that. Additionally, the new polyurea is capable of addressing abrasion and chemical problems. This paper presents an overview of SIPP polyurea lining along with its properties, current testing, design and installation guides, benefits and range of applications. It describes some of the current developments on the long-term tests conducted on several variations of polyurea materials manufactured by 3M Water Infrastructure, such as SIPP 169, SIPP 169HB and SIPP 269. The paper further describes additional tests conducted according to AWWA guidelines. Additionally, an overview of ASTM, AWWA and ASCE standard developments currently underway is presented.

A newly developed technology enables reinforced thin walled HDPE pipe to be inserted into aged/degraded high pressure host pipe to restore its safe pressure carrying capacity. This technology is particularly economical in urbanized areas and in other difficult to access locations, and in cased crossings and other applications where corrosion is difficult to control. This paper describes in detail the first actual rehabilitation project of this kind; a project carried out to restore the integrity of a 300 ft. long, 24 inch diameter aging steel pipe that passes under a complex of railroad tracks in an extremely congested and highly sensitive location. This successful installation opens the door to a wide range of pipeline restoration projects of possible interest to the civil engineering community.

The Nacimiento Water Project under construction in San Luis Obispo County, California, will deliver 15,750 acre-feet of raw water annually from Lake Nacimiento through 45 miles of pipeline to its service area. The Project includes three pumping stations, three storage tanks, 45 miles of pipeline ranging from 36- to 12- inches in diameter, and a SCADA system. The hydraulic aspects of the system dictated careful attention to hydraulic design, with due consideration of normal and transient pressures. As a follow-up to the hydraulic design, the project will include a very rigorous transient monitoring program, possibly the most intensive on any pipeline in the USA to-date. This transient monitoring program scheduled for installation in March 2010 includes nine TP-1 transient monitoring systems installed at locations most prone to severe hydraulic transients. These systems provide detailed information regarding transient pressures and are integrated into the SCADA system to provide real-time alerts if threshold pressures are exceeded. This paper describes the Nacimiento Water Project, the hydraulic design considerations, the network of transient monitoring systems that is installed, and the results of transient pressure monitoring collected to-date.

Sanitary sewer collection systems are among the largest infrastructure investments made by communities. As such, it is imperative that they are managed, operated, and maintained in a manner that maximizes their serviceable life. In addition to preserving the value of public infrastructure, it is critical that sanitary sewer agencies minimize overflows from these systems. Overflows of domestic and industrial wastes can pose a substantial risk to public health and the environment. Agencies throughout the nation vary widely in their success at achieving these objectives. National and State regulatory and enforcement attention toward sanitary sewer overflows (SSOs) has been increasing in recent years. In 2000, Colorado Springs Utilities (Utilities) began the Sanitary Sewer Evaluation Program (SSEP) as a means of assessing the condition of selected wastewater collection system infrastructure components. This program was created to provide comprehensive and systematic evaluation of the sanitary sewer collection system for lift stations, pipe segments greater than 10-inches in diameter, and all stream crossings (including segments less than 10-inches in diameter). The intent of the Program was to develop a comprehensive framework for analyzing the structural integrity and capacity constraints of the sanitary sewer collection system assets and for refining Utilities' preventative maintenance programs. One of the primary goals of the Program was the protection of public health through repair and upgrading of the City's aging wastewater collection system. As the Program began to evolve, identification of the severity and locations of system defects created the need to expand the scope of the Program. In 2002, Utilities expanded the Program and re-named it the Sanitary Sewer Evaluation and Rehabilitation Program (SSERP); this program would assure areas requiring immediate repair would be scheduled and repaired based upon prioritized condition assessments. Annual budgets were established to rehabilitate the most severe defects on a priority basis. Results from the condition and capacity evaluations were used to recommend and implement repair, rehabilitation, monitoring and maintenance programs to minimize risk of future sanitary sewer overflows (SSOs).

Major water supply projects along the Colorado Front Range are facing a significant timing hurdle: National Environmental Policy Act (NEPA) compliance and completion of environmental impact statements. How can a major water supply project be designed, constructed, and have water flowing in 6 years when the EIS process is taking 6 or more years for most major water supply projects? The City of Aurora (City) faced this challenge in 2004 when it was determined that the City needed an additional water supply of 10,000 acre-feet online by 2010. The Prairie Waters Project (PWP), scheduled for completion in December 2010, was designed and implemented to comply with all federal and state environmental regulations and still meet the aggressive schedule to have water flowing to the City by 2010. This case study looks at the strategy and steps the City successfully implemented from the initial planning process, gaining concurrence from the environmental regulatory agencies, on through construction and contractor cooperation, and the lessons learned.

It is known that chilled gas pipelines buried at a boundary between permafrost and non-permafrost are subject to severe bending deformation since they are held tightly in the permafrost whereas the growth of frost bulbs in the non-permafrost region causes frost heave of the pipes. However, the flexural rigidity and the behavior of the pipe and the surrounding frost bulb have not yet been studied as a composite structure which resists against the deformation together, although they are important factors in evaluating structural safety and stability. The purpose of this study is to experimentally determine the interactions between a chilled gas pipeline and a frost bulb under the simplified condition of axial symmetry, and also to evaluate the adfreeze strength and behavior of the frost bulb in order to expect their composite flexural rigidity.

The pressure pipe restraint joint system was originally designed for providing thrust restraint in open-trench construction for pressure pipeline applications. The advantages of using polyvinyl chloride (PVC) restraint joint are ease of use and quick assembly of pipe compared with other pipe joint systems. Applicability of restraint joint in horizontal directional drilling (HDD) was studied through Finite Elements Analysis (FEA) and laboratory tests of assembled PVC restraint joint pipes. The pipes were tested under axial tensile loads, and expected to be evaluated under combined tensile and bending loads to simulate loads that the pipe is subjected during horizontal directional drilling operations. This paper presents methodologies and results of the tensile testing, and it presents the methodology proposed for analyzing the combined effects of tension and bending. Based on these analytical investigations and laboratory tests, the tensile strength of the Bulldog Restraint System^TM (BRS) is well inside the range with other thermoplastic products used in this application. Thus, further investigation into its performance characteristics is justified.

The City of Baton Rouge, Parish of East Baton Rouge (C-P) entered into a Consent Decree with the United States Environmental Protection Agency (EPA) and the State of Louisiana in 2001 to take remedial actions in their collection system to reduce sanitary sewer overflows (SSOs) by 31 December 2014. In response to the Consent Decree, the City-Parish developed the Baton Rouge Sanitary Sewer Overflow (BTRSSO) Program. The purpose of the BTR SSO Program is to reduce SSOs while planning for future flows. This paper will provide an understanding of aspects of program planning related to conveyance, specifically documents such as design requirements that address dry and wet weather design flows, gravity and forcemain hydraulics and pipe sizing, pipe design pressures, velocities, thrust restraint, air release and air/vacuum valve sizing and locations, bedding and backfill material, paved and non-paved surface restoration, manhole spacing and diameters, manhole to pipe connections, servitudes, utility crossings, locating of existing utilities, the evaluation of pipe materials for gravity sanitary sewers and forcemains, sewer service laterals, and the evaluation of fusible pipe materials. The requirements also address alternative construction methods such as microtunneling, hand tunneling, horizontal directional drilling (HDD) for both gravity sanitary sewers and forcemains, jack and bore, auger boring, sliplining, and pipe bursting.

The City of Modesto realized the existing sewer line running along the east bank of Dry Creek was at "High Risk" for pipe failure due to creek erosion that could result in uncontrolled discharges, subsequent fines, and cleanup costs. The existing 6-inch line is more than 50 years old and was subject to constant erosion due to the frequent flooding in Dry Creek. The existing line was constructed through a riparian corridor with limited and/or no access for maintenance making it difficult to perform even routine monitoring of the pipe and bank condition. This paper will review the pre-design assumptions and the post construction lessons learned.

This paper presents current issues faced by utilities in the rehabilitation of water distribution infrastructure. It views system rehabilitation of buried infrastructure from the eyes of a renewal engineer. System Rehabilitation is the application of infrastructure repair, renewal and replacement technologies in an effort to return functionality to the water distribution system. The water industry has an environment that is very different from the wastewater industry when it comes to the amount of rehabilitation undertaken or even completed. Practiced renewal programs are based partly on theoretical and mathematical models and fair engineering judgment. Common renewal engineering issues like corrosion, bypass pumping, service lines, disinfection and continuous health monitoring are sometimes overlooked in project feasibility and execution of water main rehabilitation. An assessment of approximately thirty-five commercial technologies with relevant information on design, cost and industry application was done. Water main rehabilitation cannot be addressed on a reactive basis. Installing a rehabilitation product is one part of the water main renewal program. Identifying the optimal rehabilitation product requires knowledge and relationships between key decision-making factors. Large utilities integrate macro-scale factors like lifecycle costing, inspection and monitoring data, condition assessment, prioritization factors, watershed modeling, life-cycle economics and project delivery options. A Decision-Support System (DSS) framework encompassing these factors in a dynamic environment is required to address Water Main Rehabilitation. The author suggests a framework of this Decision Support System (DSS) keeping the applicability, performance, benefits and costs of the water main rehabilitation technology in mind.

The Lake Fork Pipeline is a new raw water transmission line that connects Lake Fork with a yield of 106 mgd to the City of Dallas water supply system. The Lake Fork Pipeline is a 44.3 km (27.5 mile) long 2.74 m (108-inch) diameter AWWA C 301 embedded cylinder prestressed concrete cylinder pipeline. The raw water pipeline begins on the western shore of Lake Fork at a raw water pump station and terminates at an Interconnection Structure. The Interconnection is the junction between two existing raw water transmission lines, one 1.83 m (72-inches) in diameter, the other 2.13m (84-inches) in diameter and the Lake Fork Pipeline. The pipeline was constructed in five contracts with a total dollar value of $148.5 million. The first contract was started in 2001 and the last contract was completed in 2009. The project included right-of-way acquisition, surveying, cultural resources investigations, hydraulic modeling, corrosion protection, pipeline design, surge analysis and control, construction management and inspection, and start up. Additionally, the project included the design of a 96.6 km (60 mile) microwave communications system that includes towers and microwave radios at five locations. Two additional locations are serviced by spread spectrum radios. The Interconnection is the junction for a total of six existing or planned pipelines with an ultimate planned capacity of 35 m³/s (800 mgd). The Interconnection consists of a 4.27 m (168-inch) diameter spine, two 4.27 m (168-inch) butterfly valves, four 3.66 m (144-inch) butterfly valves, and two 2.74 m (108inch) butterfly valves. The Interconnection was designed around the ASME Pressure Vessel Code, which eliminated the use of crotch plates, simplifying fabrication, transportation, and construction. The Interconnection was awarded the 2008 Pipe Fabrication of the Year Award by the Steel Plate Fabricators Association. The Lake Fork Pipeline was awarded a Silver Medal by the Texas Council of Engineering Companies in 2009.

Ute Reservoir, located in northeastern New Mexico on the Canadian River, is the source of up to 16,450 acre-feet per year (ac-ft/yr) of water intended for use by New Mexico communities located in the Eastern New Mexico Rural Water Authority (ENMRWA) area. As `owner' of the water, the New Mexico Interstate Stream Commission has worked with U.S. Bureau of Reclamation (USBR) to develop a project to use the allocation to relieve the critical municipal water shortage situation in eastern New Mexico. The shortage is caused by the steady declines in water levels in the Ogallala (or High Plains) aquifer, which is currently the sole source of supply for much of eastern New Mexico for both municipal and agricultural water. The Eastern New Mexico Rural Water Supply Project was established to provide a surface water supply to Ute Reservoir water for ENMRWA members. The majority of the supply will be used to meet demands in the population centers of Clovis and Portales, but supplies will be conveyed through approximately 150 miles of pipelines as far as 120 miles south of the reservoir to the Town of Elida. Because significant pipelines are required to convey this surface supply, small changes in pipeline design can result in significant changes in capital and O&M costs. CH2M HILL developed and employed a dynamic simulation optimization model of the pipeline, pumps, and system storage to aid in developing an efficient (e.g. least cost) design. The primary objective of the evaluation was to test the hydraulic simulation-optimization approach, evaluate trade offs between pipe sizing, storage requirements, pump capacity, control valving, and overall costs as measured by estimated capital and operating costs. The model was developed using CH2M HILL's Replica^TM Model resulting in nearly a 6 percent overall cost savings at more than $18 Million from the conceptual design report (CDR). This paper will discuss an overview of the project and project status, the design basis established for system demands, model components, model configuration, results, and project cost savings. This paper will benefit the professional community by showing how optimization models can potentially reduce costs for large transmission pipeline projects.

With the aging infrastructure and water agencies having to "do more with less", the need has never been greater for the consideration of water main rehab technologies. In the past, water main rehab technologies have not been as advanced as those within the wastewater arena. However, there has been a significant focus by both the industry and agencies to advance the technologies. As a result, rehab technologies such as slip lining and other lining systems are now used for various water main applications. Additional advancements in these technologies have allowed for rehabilitation of larger diameter water transmission mains that were once ineligible for this process due to their size. This paper will present a review of commonly used technologies for large diameter (i.e., greater than 24-inches) transmission mains. The advantages and limitations of these technologies will be discussed and used to form the basis of a systematic evaluation matrix. The goal of this matrix is to evaluate the water main rehab technologies and provide a tool for owners to select the best available rehabilitation option.

In 2007, ICON Engineering, Inc. began a project with Aurora Water to investigate and evaluate a large diameter corrugated metal pipe (CMP) outfall system in the City of Aurora, Colorado. Initial phases of the project focused on comparing the existing hydraulic capacity with the expected discharges from the urbanized watershed and evaluating the structural integrity of the pipe. Subsequent phases included the design and construction of a relining system. In order to accomplish the project tasks and goals, a variety of methods were utilized including: dynamic SWMM analysis of the storm sewer; robotic and hands-on pipe inspection; and final design where relining was completed within the existing CMP system. The City Center outfall system was constructed in 1974 and ranges in size from 84-inches to 120-inches. The overall length of the system is approximately 4,350-feet. This pipe system serves as the outfall for a large drainage basin within a very prominent area of the City of Aurora, including the Town Center at Aurora and the Aurora Municipal Center. Given the high imperviousness of the development basin, the discharges upstream of the outfall system have the potential to exceed the system capacity. This, in combination with complicated flow splits and detention characteristics necessitated the need for a dynamic storm sewer model utilizing the EPA SWMM 5 program. Three phases of inspection, sampling, and testing were completed on the existing outfall pipe system. These phases will be discussed in detail in the final paper. This past year Aurora Water elected to pursue relining of 3,060-feet of pipeline within the existing 120-inch CMP. As expected, many obstacles were encountered in the final design phase, with the most prominent being limitations regarding pipe insertion and surface access. Construction for the relining project is anticipated to begin in December 2009. In summary, the final paper will cover the 120-inch CMP from the initial inspection to determine its present condition (extensive corrosion) through the construction of the relining in the winter of 2009/2010.

Wrapping iron pipe in polyethylene encasement has been used successfully for over 50 years to combat against external corrosion. This proactive corrosion control approach represents an incidental cost when included in the construction of ductile iron pipe and can extend the pipe service life for many years. This paper presents utility case histories where polyethylene encasement is used in highly corrosive soils as a standard corrosion control practice. Also included are the results of an industry poll on this matter distributed to utility operators throughout the United States and Canada. Success stories and lessons learned are provided.

The North Central Texas Metroplex, which includes the cities of Dallas and Fort Worth, has seen record growth during the past 10 years and landscape irrigation needs are a big part of the regional water demand. Fort Worth Village Creek Wastewater Treatment Plant provides a high quality source of effluent that is currently discharged to the Trinity River. In 2007, the Fort Worth Water Department completed a "Reclaimed Water Priority and Implementation Plan" to evaluate potential reuse projects that have a high probability of being implemented. The Eastern Reclaimed Water System had the most viable customer base and lowest capital cost of all alternatives evaluated in this plan. The system includes a 10-mile pipeline and was envisioned as a regional project primarily serving wholesale customers, including the City of Arlington, City of Euless and Dallas-Fort Worth International Airport (DFWIA). The ultimate capacity of the pump station is 18 million gallons per day (mgd). The pipeline has a reducing capacity at various take points. The pipeline sizes are 36-inch (steel), 30-inch (ductile iron), 24-inch (ductile iron and PVC), 20-inch (PVC), and 16-inch (PVC) (Reference Figure 1). Implementation of the project required collaboration between Fort Worth and each of the wholesale customers. In order to facilitate initial discussions about the project, the City prepared preliminary estimates of potential rates and identified key issues requiring consensus in order to proceed with subsequent discussions. Initial meetings with the customers were positive and the framework for a wholesale contract was laid out. Development of an equitable rate structure that could be agreed upon by all parties was a key component of contract negotiations. Key contractual issues for Fort Worth were a minimum payment (i.e., "take or pay") provision to ensure a minimum level of cash flow to the utility, and a commitment to a systemwide rate from all customers. While the City was willing to subsidize the system in the initial years, it was committed to a goal of operating a system that would ultimately be self-sufficient with rates based on cost-of-service principles. In order to accommodate customer concerns, the City agreed to limit the percentage increase of the rate in any given year and provide an upper limit on the rate equal to its wholesale water rate for potable water.

Recognizing the importance of a sustainable and reliable water supply, the city of Wichita, Kansas Water Utilities Department (WWU) is in the process of implementing a comprehensive aquifer storage and recovery (ASR) project. The ASR project will ultimately recharge up to 100 million gallons per day (mgd) of water into the Equus Beds aquifer. During drier periods, the system can be switched into production mode, with up to 146 mgd of groundwater being pumped south to the city's main water treatment plant (WTP). The current phase of the ASR project includes construction of approximately 22 miles of raw water transmission pipelines ranging up to 66 inches in diameter. These new pipelines will be integrated with approximately 31 miles of 42- to 66-inch diameter concrete transmission pipelines, which currently carry water from existing production wells south to the city WTP. Given the history of occasional widespread power outages and pipe breakages within the existing raw water pipeline network, a more robust power distribution system and improved hydraulic transient control are considered critical elements of overall project success. The transient modeling for the ASR system predicted that without surge mitigation there would be widespread low-pressure conditions that could lead to water column separation and cavitation, resulting in localized pressure rise in the various operational scenarios. This was considered unacceptable for both the existing and proposed pipelines and appurtenances. Recommended mitigation includes a surge anticipator valve and vacuum breaker/air release (VB/AR) valves at the main recharge pump station, as well as regularly spaced VB/AR valves along the new transmission lines. The production scenarios are complicated by the fact that the ASR well field is located at an elevation approximately 100 feet above the city's water treatment plant. During a system-wide power failure, the system could drain in a relatively short period of time allowing large amounts of air into the system through the VB valves. To ameliorate this situation, two standpipes were located and designed in the well field. Transient modeling was used to optimize the size and configuration of these tanks. By taking a proactive approach to transient modeling and mitigation, WWU is taking the necessary steps to significantly reduce the probability of a damaging surge event, thus ensuring the reliability of a critical water supply system and protecting a significant capital investment.

The Dallas Water Utilities has completed all five phases of their Lake Fork Pipeline. Included in Phase Five was a interconnect structure that would allow for connections for future pipelines from the Iron Bridge Pump Station to the Tawakoni Balancing Reservoir. Inside this vault structure was a 168" diameter steel header, 168" and 144" diameter butterfly valves and many other large diameter fittings. As typical AWWA design standards only incorporate pipe sizes up to 144", innovative design processes were developed. This paper will investigate the design procedure that was ultimately followed and address differences between this new innovative procedure and classic AWWA design methods.

Integration planning of Infrastructure systems reveals a changeling decisions facing Canadian municipalities for planning repair/renewal of road network, water distribution network, wastewater distribution network. Decision-making for these networks requires the incorporation of a massive amount of data collection, building business processes, identifying decision variables and optimization. The objective of this research is to establish a methodology to facilitate decision making process that ensures reliable and optimum decision regarding corridor rehabilitation for road, water and wastewater network. This proposed framework employs the following tasks: (1) analyze risk; (2) conduct performance evaluation; (3) assess the current physical condition of the pipe and road segment; (4) collecting data and performing data gap analysis; (5) document a conceptual business process diagrams; (6) develop decision analysis trees; and (7) implementing optimization of repair/renewal cost and defining the best replacement interval via genetic algorism (GA). In order to demonstrate the model features, a case study has been utilized from the City of Guelph, ON, Canada. The model is developed via genetic algorism (GA) using GIS platform. The results assist in setting priorities for integrated corridor rehabilitation and anticipated to generate a capital planning program for the city's infrastructure. In conclusion, this framework helps Canadian municipalities evaluate and select feasible optimal assets for integrated corridor rehabilitation.

The Milwaukee Metropolitan Sewerage District (MMSD), located in Milwaukee, Wisconsin, pioneered the beneficial conversion of wastewater sludge, or biosolids, into a soil amendment marketed as a product named Milorganite®. As is common in most wastewater treatment facilities, the biosolids are wasted from the treatment process in liquid form followed by a thickening process. The thickened sludge is then dried further and stabilized using heat. MMSD currently uses natural gas to provide the heat to dry the biosolids and produce the Milorganite® product. Natural gas is used to drive turbine generators for power production at the plant. The waste heat from the turbines is also used in the Milorganite® process. In 2008, natural gas prices hit record highs, and MMSD and their contract operator, Veolia Water Milwaukee (VWM), realized that alternative sources of energy were needed to reduce the dependence on natural gas and the vulnerability to huge increases in operating costs. A viable source of alternative fuel was identified at the Emerald Park Landfill. MMSD estimates that the use of landfill gas (LFG) will save the ratepayers $148 million over 20 years. LFG is the byproduct of the decomposition of municipal solid waste in anaerobic conditions in capped landfills. Although LFG is used in many locations for either power generation or heat production, the majority of LFG is burned, or flared, at the landfill. When LFG is used beneficially, however, it is usually on site or piped to a facility located a short distance away. Unfortunately, in this case, the Emerald Park Landfill is located over 17 miles away from the Jones Island Water Reclamation Facility (JIWRF) where the Milorganite® is produced. This paper will review the challenges presented by the project, including planning, designing, and constructing a pipeline from the landfill to the WRF; meeting the regulatory and permitting requirements; and satisfying the contract requirement to have gas flowing by January 1, 2011 (18 months from Design Notice to Proceed). Specifics include maximizing the use of available data in terms of GIS mapping; coordination with several concurrent road improvement projects in multiple jurisdictions; avoidance of historic, cultural, and environmental resources, including threatened and endangered species habitats; and establishing design and operational parameters to qualify for low pressure transmission status in the gas pipeline regulatory environment. Other potential time and cost savings measures are also described. These include bidding strategies and advance procurement of pipe materials, as well as evaluation of the use of an existing, mothballed, steel petroleum pipeline. This existing pipeline would reduce the length of new construction by 25 percent and eliminate impacts to the most heavily developed residential area along the route. Condition assessment of the existing pipeline and gas quality parameters are discussed in terms of using the steel pipeline as is or whether it must be sliplined.

This paper will discuss the importance of monitoring pipeline material costs in managing project budget expectations for major water transmission pipeline projects. The combined pipeline material and manufacturing cost is the single largest capital cost component for large diameter steel pipeline projects. The communication and sharing of information between engineers, owners, and pipeline manufacturers are keys in establishing and updating accurate budgets for projects developed and constructed over multiple years. Using general construction industry standard cost indexes to predict changes in pipeline material and manufacturing costs may not provide accurate changes for these components due to the volatility and fluctuations in raw material costs associated with the production of steel pipe. This paper will provide an example of a major pipeline project and present historical steel pipe costs and their relationship to the cost of steel, the importance of monitoring these costs, and the differences between actual pipe costs and projections based on cost indexes, thereby establishing the value of monitoring pipeline material costs.

The City of Anaheim, with a current population of almost 350,000 and centrally located within Southern California, is the regional hub for economic activity in Orange County and is fast becoming a world-class business center. The City is known worldwide as a center for entertainment, tourism, and convention activities, with more than 18 million visitors annually. This translates into a prestigious, high-profile international address that balances business and residential growth. For example, the City is the home of two professional sports teams, the Los Angeles Angels of Anaheim (baseball) and the Anaheim Ducks (hockey). Anaheim is known to most Americans for the Walt Disney Resort, commonly referred to as Disneyland. Disneyland has, in recent years, expanded to include an adjacent theme park, California Adventure, and has spawned other civic improvements such as Gardenwalk, a large retail development, and upgrades to the premier Anaheim Convention Center. Last year California voters approved an $11 billion bond issue to begin building a high-speed rail system from Sacramento and San Francisco to San Diego. Anaheim is already preparing preliminary documents for a major transit hub called ARTIC (Anaheim Regional Transportation Intermodal Center) located on the high-speed rail route. Refer to Figure 1.

The Central Utah Water Conservancy District (District) is a political subdivision of the State of Utah originally charged with managing and operating the Central Utah Project, a federally funded water project. The District covers 10 counties of Utah and provides culinary and secondary water to a wide range of communities and water districts within these counties. They are primarily a water wholesaler and provide water to communities and other water districts. They operate several dams, reservoirs, canals, pipelines, tunnels, and water treatment plants. In 2005, the District opted to purchase about 42,000 acre-feet of groundwater rights, 23 existing wells, pipelines, a pump station and other associated assets made available from the bankruptcy liquidation of the former Geneva Steel Plant which was located in Vineyard, Utah on the shore of Utah Lake. This purchase provided an opportunity to convert groundwater sources that had previously been used for industrial purposes into a municipal/industrial system by the District. The District then embarked on a study to determine the best way to use this resource. MWH Americas, Inc. was hired to assist the District in planning and implementing a program to use this water and other rights the District has accumulated over the years. After examining several options the District decided to develop their first non-federally funded system to develop and distribute this water to their customer's agencies. In an analysis of needs, it was determined that the majority of the communities that needed and wanted additional water for current and future growth were located north and west of Utah Lake in northern Utah County and Salt Lake County located to the north of Utah County. A system was developed to pump, store, and convey the water to potential end users. Figure 1 shows the basic concepts developed for the project. The project was named the Central Utah Water Conservancy District Water Development Project and given the short title of CWP.

The City of Aurora has over 2.5 million feet of sanitary sewer in need of rehabilitation. The pipes are vitrified clay pipe (VCP) that is over fifty years old and has exceeded its original design life. Aurora Water plans to spend $5 million annually to rehabilitate the sanitary sewer pipe ranging in size from 8 to 27 inches in diameter. The following critical items of the CIPP process will be discussed: liner thickness required; wet out calculations and resin strength; long-term creep testing for different resins as it relates to a 50-year design life; construction inspection; software used; tap activation; extended tap trimming; data storage; and public involvement. This paper will serve as a practical guide to municipal owners desiring to use trenchless technology (CIPP) to rehabilitate their sanitary sewer systems, and as instruction on how to be sure that they are getting a system that will maximally extend the life of their asset.

With the aged infrastructure in many U.S. cities and the devastation caused by large diameter (i.e., greater than 24-inches) transmission main failures, the need for many cities and water utilities to perform an assessment of their system has intensified. The challenge in assessing these large transmission mains includes budgeting and manpower constraints. Even with the latest technology, assessment requires a delicate balance to physically shutdown critical mains while still supplying system demands and with as little public disruption as possible. The answer involves in planning, communicating, planning, testing, and planning some more. With limited time and other facility shutdowns required for construction or rehabilitation work, creative solutions are needed to formulate feasible shutdown solutions. This paper will discuss the preparation efforts and considerations taken by the City of Houston (City) in performing condition assessment of several of their large diameter water mains ranging in size from 48- to 84-inches.

Wastewater utilities are constantly working to preserve and improve their wastewater collection system and reassure capacity. In order to do so it is essential to develop a systematic approach to operating, maintaining and rehabilitating the wastewater collection system. Effective inspection, cleaning, and rehabilitation are key processes for optimizing the proper functioning of a collection system. This paper provides a case study of a systematic manhole inspection program. The study area consists of three basins. Manholes were inspected for both structural defects and inflow and infiltration (I/I) defects. This paper also provides an in-depth look into what to do with the data and how to prioritize rehabilitation of the manholes, thus maintaining the integrity of the collection system. The guidance to conduct a comprehensive manhole inspection program was obtained from ASCE's Manhole Inspection and Rehabilitation Manual No. 92⁽¹⁾. Inspection includes data recording for asset management and evaluating the structure for structural condition, flow condition and maintenance conditions. From the defect rating, the ASCE MOP 92 was used as a guide to develop flow rates resulting from these defects. The defects were prioritized and ranked to understand the overall system integrity. These rankings were used to prioritize manholes for rehabilitation. Cost effective analysis was performed to compare the cost of rehabilitation to the cost of transporting and treating the I/I contributed by the defects. This paper also provides guidance on how to translate the manhole defect schedule into a manhole rehabilitation schedule.