Pipelines 2017: Construction and Rehabilitation

The City of Arlington Water Utilities, Texas (Arlington), maintains over 1,440 mi of water mains in their distribution system, including 588 mi of existing asbestos cement (AC) pipe. In 2015, 72% of the 533 water main breaks were on AC water mains. The emergency costs to repair these water mains was escalating and options for permanent repairs and a programmatic approach was needed. Like most municipalities, the Arlington Water Utilities needed to stretch available capital funds and sought innovative methods for replacing the AC water mains. The Arlington Water Utilities selected pre-chlorinated pipe bursting to install new HDPE in place while reducing customer impacts, minimizing capital spending and reducing operational costs. Murphy Pipelines, who specializes this technology, was awarded the project. To date, work has progressed replacing more than 13,000 linear feet of existing 6-in AC water main with new 8-in HDPE pipe. The majority of the work is in typical residential neighborhoods with a history of frequent water main breaks. Pre-chlorinated pipe bursting has dramatically reduced customer impacts and replaced more AC pipe with less capital funding. Use of pre-chlorinated pipe bursting also dramatically reduced the construction schedule.

This paper presents two field applications of a newly developed pipe that is constructed of fiber reinforced polymer (FRP) products using the sandwich construction technology. The pipe, named StifPipe, received the 2016 ASCE Innovation Award as the world’s first green and sustainable solution for repair and construction of pipelines. Unlike conventional pipes that have a solid wall, the wall of this pipe consists of a lightweight honeycomb core that is covered on the outside and inside with one or more layers of FRP–a technology that has been used for decades in the aerospace industry for construction of fuselages. Segments of this pipe can be easily made by hand and used to repair pipelines following the slip-line technique. The technique allows the use of fewer layers of Carbon FRP and significantly reduces repair costs. In one application, 29 corroded manholes in the Aguirre Power Plant, Puerto Rico, were repaired. The steel manholes were 36 in. in diameter and the design pressure for the system was 400 psi. The 4-ft long sandwich pipe segments had an outside diameter of 35 in. and were lowered into position. The small annular space between the host pipe and the liner was filled with a grout. The rigidity of the pipe can support the lateral loads from the soil and nearby traffic. The premanufactured pipes reduced the repair time significantly. The project was completed in February 2016. The other applications was for repair of a corroded corrugated metal pipe culvert in Australia. A 78-ft long, 72-in. diameter culvert in a remote site more than 1000 mi north of Brisbane had deteriorated and partially collapsed to a diameter of 55 in. The four custom-made pipes manufactured in Australia were twenty feet long each, less than 1 in. thick and had an outside diameter of 51 in. The lightweight pipes could be pushed by hand into the culvert, eliminating the need for jacking equipment on site. The repairs were successfully completed in 4 days in July 2015 with no traffic disruption.

Flanged and mechanical coupled joints are often a necessary component of water transmission pipelines. These joints utilize threaded materials, or fasteners, in the form of bolts, studs and harness rods which must be designed for a number of stresses. Threaded carbon steel is commonly used as a fastening material but in a buried application can be prone to corrosion even with protective coatings. Stainless steel fasteners are sometimes used in lieu of carbon steel with the expectation that stainless steel is inherently less susceptible to corrosion. Nevertheless, stainless steel bolts and tie rods can still corrode under certain conditions. Furthermore, stainless steel fasteners generally have less strength than carbon steel. This can become problematic when specified for applications such as flanges and harness rods because the general design framework of common American Water Works Association (AWWA) standards and design manuals assumes the strength of carbon steel. This paper compares the relative merits of carbon and stainless steel material when used in threaded form for bolts, studs, and harness rods to connect carbon steel water pipe components. Corrosion aspects of both carbon and stainless steel are considered as are strength differences between the two materials and how it relates to design. Examples are provided to illustrate the potential conflicts that can result when stainless steel fasteners are incorporated into an AWWA design framework.

The objective of this paper is to analyze and compare soil hauling operations for tunneling and cut-and-cover pipeline installation in urban and rural areas. This paper is part of a feasibility study for a proposed underground freight transportation (UFT) project between Houston to Dallas. Underground freight transportation is an automated technology to carry individual freight vehicles through pipelines and/or tunnels with minimum impact on the surface. This system can be built on available right-of-way (ROW) and/or under highways. For UFT construction, the two methods of cut-and-cover pipeline installation or tunneling can be selected based on workspace availability and construction operation requirements in rural or urban areas. Factors affecting soil hauling in rural and urban areas, such as, equipment weight and size limits and travel distance are considered. The results of this paper shows that cost of spoil hauling for tunneling construction method is approximately 20% more than cut-and-cover pipeline installation construction method in rural areas. Additionally, the haul cycle time for urban areas is two times and cost is 2.5 times of hauling spoil material in rural areas.

Carbon dioxide (CO₂) is the primary greenhouse gas emitted through human activities. The construction industry is a major producer of such emission due in part to the magnitude of operations and the vast array of equipment. The proposed underground freight transportation (UFT) uses unmanned vehicles to move freight through tunnels and pipelines between terminals. This paper presents a comparison of carbon footprint for conventional open-cut and trenchless technology methods, particularly tunneling in rural area. The paper considers building a freight pipeline in a proposed route from Huntsville to Madisonville, Texas, under existing right-of-way and with a pipe diameter of 8 to 13 ft. The objective of this paper is to quantify carbon emissions produced by construction equipment for hauling excavated soils during pipeline construction. Trenchless technologies with minimum surface and subsurface disruptions offer a viable alternative and result in lesser carbon emissions compared to open-cut method. The findings of this paper will assist the pipeline construction industry in technology selection to minimize environmental impacts.

Many large diameter pipelines in service today were originally lined with coal tar enamel (CTE). In many cases the CTE has reached the end of its usable life and is no longer providing corrosion protection. These pipelines require recoating to protect and extend the service life of these assets. Hartman Walsh completes large diameter pipe coating rehabilitation projects nationwide. Early projects were executed manually. Justification of robotic equipment research and development included: Manual execution of existing lining/scale removal, abrasive blasting, and coating is very labor intensive and hence costly; Manual execution requires long shutdowns; The success and quality of the application is largely dependent upon the skill of the applicators. The outcome and subsequent results of the development and use of the robotic equipment: Substantially increased production capabilities thereby reducing cost and shutdown duration required; Increased level of quality provided, reducing repairs by more than half, thereby increasing the life of the coating, and reducing cost; Reduced use of blasting and coating materials through higher production and better control resulting in a more environmentally friendly process at lower costs; Provided a safer method of execution by reducing and eliminating personnel exposures. This paper reviews the needs, development, and use of this technology over the past 8 years.

This paper presents selection criteria for using cut-and-cover methods for pipeline installation in a proposed underground freight transportation (UFT) system from the Port of Houston to a distribution center in south of Dallas, Texas. UFT uses close-fitting vehicles carrying freight through underground pipelines and tunnels between terminals. For this project, cut-and-cover method is used in rural areas where there are fewer limitations for trench excavation and temporary soil stockpiling. Different trench cross sections are compared to follow Occupational Safety and Health Administration (OSHA) regulations. To decide which trench cross section is more applicable, a comparison is performed for different trench geometry and construction cost based on equipment used for excavation and spoil hauling. In this paper, three trench types were compared in terms of volume of excavation, constructability and cost. It can be concluded that trench Types 2 (combination trench) and 3 (bench cut) have approximately 40% and 50% higher cost than trenches Type 1 (sloped trench) respectively, but trench Type 2 is the best option as it meets the construction space requirements.

Since Hurricane Katrina hit the New Orleans area in 2005, many projects have been built to improve the flood protection in the surrounding communities. One of these projects is the Harahan Pump to the River Project. Under the guidance of the U.S. Army Corps of Engineers, four separate projects bid to connect a new pump station to the Mississippi River. The $105-million program, included a pump station and a triple barrel 84-inch steel pipe line that traversed a levee and discharged into the Mississippi River. The first of the four pipeline projects bid in 2007. This phase consisted of roughly 2,000 ft of 84-in. spiral-welded steel pipe. The next phase was bid in 2012 and consisted of roughly 6,000 feet of pipe including pipe over the levee and a large discharge structure. The third phase bid in 2013 and was roughly 5,100 ft of 84-in. pipe. The fourth and final phase consisted of 13,500 ft of 84-in. spiral-welded steel pipe. The four-project program is scheduled to be completed by the Spring of 2017. This paper will discuss each phase of the project highlighting the unique aspects of each. Some of the challenges include having to work around three sets of high-voltage power lines, needing to build an underground shoring system, holding back the Mississippi River to install a discharge structure, and the rigors of handling and installing triple barrel 84-inch pipe in a single trench. The paper will discuss the design and qualities of spirally welded steel pipe, including the joints, welding, linings, coatings, and the unique joint testing required. It will also discuss how the pipe was assembled and how bedding and backfill were installed.

While traditional cured-in-place pipe (CIPP) for gravity pipeline systems has been around for 40+ years, reinforced CIPP for pressurized force mains and potable water applications is still relatively new. Recently, Insituform Technologies, LLC tackled a difficult project in a very high profile area–The Daytona Speedway. The project consisted of a lift station and pipelines in Daytona Beach, Florida, that presented a variety of challenges. The 30-inch pre-stressed concrete cylinder pipeline (PCCP), originally a raw water transmission system that had been taken out of service decades ago, was being converted to a sanitary sewer force main. After project design and inspection, Insituform was chosen via public bid offering to rehabilitate the pipeline using its fiber-reinforced CIPP rehabilitation system. The system is a reinforced pressure pipe liner and vinyl ester resin system that combines traditional CIPP with specially-needled fiberglass material to provide added tensile strength and adequate internal pressure resistance. The paper will go over not only lining using the reinforced CIPP, but also general contractor responsibilities such as project management and onsite field management for subcontractors performing activities like CCTV, cleaning, jack and bore, installation of new ductile iron pipe and fittings, excavation and concrete repair work. The paper will also highlight the challenges of working along the world’s most famous motor racetrack, such as working around holidays and Speedway events, along with numerous challenges encountered including unforeseen bends, excavation and numerous wet weather events which contributed to area floods and access problems. In addition, the paper will discuss fittings selection, testing and the conclusion of the project.

Miami-Dade Water and Sewer Department (MDWASD) serves over 2.3 million residents. During the next two decades, it will invest $13.5 billion to enhance and upgrade its infrastructure. The 48-inch Interconnect is intended to transfer large flows between the Hialeah/Preston (north) and Alexander Orr (south) water systems, and improve flows and pressures in the Downtown Business Area. The project includes the installation of 8,000 feet of water main from 30 to 48-inch diameter, along with three micro-tunnels under two active Florida East Coast (FEC) railroads and Biscayne Boulevard. This paper describes approaches to installing large diameter pipelines through heavily congested downtown commercial areas with many concurrent construction projects, heavy traffic, dense utility corridors, soil/groundwater contamination, and coordination with many stakeholders. Pursued as design-build, a portion of the project was fast-tracked as design-bid-build, along with material pre-purchases by MDWASD, to avoid conflicts with the grand opening of the “Brightline” Miami Central Railroad Station.

A 17.5 foot diameter prestressed concrete pipe (PCCP) pipe failed in the Navajo Indian Irrigation Project (NIIP), Farmington, New Mexico, on May 2016. This pipe, installed in 1972, featured double-wire wrap with a 16-gauge steel liner. Electromagnetic (EM) inspections showed an increase from 30 wire breaks in 2003 to 60 breaks in 2010 in one section of the pipe. In 2016, the pipe ruptured and blew concrete 100 to 200 ft away, with debris damaging an overhead powerline. Approximately 75,000 acres of irrigated land were without irrigation service, so water was rationed to priority crops. Emergency repairs were a high priority. Reclamation’s Four Corners Construction Office partnered with the Navajo Nation and the Bureau of Indian Affairs for emergency repair and replacement. Emergency actions included shutting down interstate highways to transport 17-foot wide loads on Memorial Day weekend. Service was restored within 30 days. This paper covers failure modes, economic and other losses, coordination, steps needed for emergency repair, and recommended remedial actions.

Sewer blockages are a major cause of sewer flooding. In England and Wales for example, blockages cause more than 4,000 property flooding incidents each year. In North America, such incidents of sewer blockages total several hundred thousand each year. In Australia and New Zealand, these add up to thousands. The practice usually used to clear sewer blockages is by employing 1,500 to 2,000 psi (10.3 to 13.8 MPa) water jetting. The first few units of equipment with 3,000 to 30,000 psi (20.6 to 206 MPa) capability, however, are being trialed to clean drains and remove any blockages and sediments. There has been a long standing concern that high pressure water jets may cause damage to the network of drains and sewers. This conclusion flows from the decades of water cutting of concrete, steel and other high strength materials. Whether damage is caused or not depends on the condition of the sewer main. Contractors just blasting the water jets into a main, typically made of concrete has resulted in failures that required sewer agency’s forces to respond on an emergency basis. Therefore, before one can evaluate the merits of high pressure low volume jetting machines over low pressure high volume type, the intended users have to understand the overall landscape of sewer cleaning and maintenance across America. Given there are 56,000 sewer agencies in America alone, the author embarked on a survey of a large representative sample of these sewer agencies, cleaning companies, engineering firms, and manufacturers. With the help of Great Southern Press, this survey expanded to reaching out globally to over 10,000 of stakeholders. Oildom publishing and Benjamin Media offered additional assistance. The objectives of this paper are to share (a) the results of the responses to the fifteen questions from the survey (b) the lessons learnt (c) the outcome of a preliminary assessment of ultra high pressure jetters versus machines that have been in use for the past few decades and (d) conclusions drawn that would lead toward more effective means and methods.

This paper will discuss managing a major scope change and unforeseen conditions during the performance of a hot tap and plugging operation on a 90 in. concrete cylinder pipe to enable highway improvements without service interruption. In spite of the scope change and unforeseen conditions the work was successfully completed ahead of schedule and within budget. The major scope change was the addition of a 72 in. tap and plug on the same type of pipe and an extension of time caused by unforeseen conditions encountered on adjoining sections of work. The 72 in. tap and plug involved using additional bypass lines and operation of valves not contemplated in the original scope of work.

In the past, City of Grand Junction planners believed that Grand Junction’s water distribution network would expand farther than it has, resulting in several transmission water lines being oversized for present-day water demands. Faced with approximately 4,000 ft of aged 24-in. steel and ductile iron water lines that were prone to failures, the City of Grand Junction’s Water Department analyzed the existing flow characteristics and determined that this particular transmission waterline did not have the water demand necessary to support such a large pipe and the water within the pipe was losing the chlorine disinfection residual because it was not being consumed fast enough. The water line needed to be reduced in size based upon the realistic service area demand. Given the option between traditional open trench installation methods and slip-lining the existing pipe alignment, trenchless methods proved to be more cost effective due to several factors that will be detailed in this paper. The City slip-lined a new 18-in. thermoplastic pipe inside the old metallic pipe. The new waterline was successfully installed in three pulls.

In 2014, the Miami Dade Water and Sewer Department (MDWASD) awarded Nicholson Construction Company a $72.1 million design-build contract to replace an existing 54-in. diameter pre-stressed concrete force main that runs from the Virginia Key Central District Wastewater Treatment Plant (CDWWTP), under the Biscayne Bay Norris Cut, to Fisher Island. The existing force main was previously subjected to a condition assessment which revealed structural deficiencies in the prestressed concrete pipeline. The project connects to a previous phase of work and completes the sewer connection from Miami Beach to the CDWWTP. The project’s main goals are to improve the reliability of a major sewer collection corridor within the MDWASD and to increase the resiliency of MDWASD’s water and sewer system. Design-build procurement was chosen as the preferred delivery method and Nicholson Construction Company was awarded the contract with Arup as their lead designer. Woolpert joined the Arup team as the primary pipeline designer. In order to install the 5,300 ft of 60-in. internal diameter fiberglass reinforced polymer mortar pipe below the bottom of Biscayne Bay at Norris Cut, a tunnel boring machine (TBM) was launched from a 42-foot diameter and 89-foot deep secant pile shaft on Virginia Key and a nine and half foot diameter precast segmentally lined tunnel was constructed as the TBM bored towards a 28-foot diameter and 72-foot deep soil-cement mixed retrieval shaft on Fisher Island. The complex subsurface geotechnical conditions of South Florida made this project a challenging one for the shaft designs, TBM design, final tunnel design and the deep subsurface construction. In order to make the final connection to the treatment plant on Virginia Key, an additional 2,700 ft of prestressed concrete cylinder pipe was installed by open cut methods. The MDWASD required no interruption to service would occur and to minimize the risks of sewer spill at the treatment plant and/or raw sewer discharge to the ocean outfall. Therefore the final connection was made to the treatment plant by means of a 36-in. HDPE force main as temporary bypass, through a direct connection to an existing sewer outlet outside the grit chamber of the CDWWTP. The success of the design-build project was largely a result of an open, trusting relationship between the design-build constructor, design-build designer, and MDWASD’s construction inspection and management team. The design-build approach lead to a cost-effective design, efficient construction, and a finished product that met the needs of the MDWASD.

The Region of Peel (Region) constructed in 2009 a 2,100 mm (84 in.) diameter PCCP C301 feedermain which was found to have a defective joint when a routine connection was made. When further investigations were undertaken on a couple of randomly selected joints, a variety of defects were found, including missing or damaged diapers, and incomplete or missing joint grout. With the prevailing soil conditions being chemically aggressive, there is significant concern that left untreated, the unprotected steel joints will corrode and cause premature failure of the pipeline. The feedermain is situated along a recently widened 4 lane arterial road, so there is a desire not to excavate it in order to complete the repairs. For this reason, a technique to repair the exterior joints from inside the pipeline was developed.

EPCOR Water (USA) Inc. overcame many challenges to replace an aging 3.5 mi, 18″ asbestos-cement sewer force main to better serve its Sun City West Wastewater District in AZ. Challenges included a 1,600′ HDD crossing under the Agua Fria River, coordinating with numerous public and private stakeholders, and completing design and construction within an accelerated 12 month timeframe, all while maintaining operation of the existing 4 MGD wastewater system. EPCOR selected GHD to tackle the project’s design challenges and Achen-Gardner Construction, Inc. (Achen Gardner) as the construction manager at risk (CMAR).

City of Houston needed to renew a critical 30-in. well collection pipeline. The steel cylinder reinforced concrete (SCRC) and prestressed concrete cylinder pipe (PCCP) water main required replacement of approximately 7,600 linear feet, near the Katy Addicks Pump Station along Scenic Ridge Drive. The existing 30-in. diameter transmission main is 37 years old and beginning to show numerous operational problems due to joint leaks. This paper will outline the design phase and selection process as open cut, slip lining, pipe bursting, cured in place pipe and a compressive tight fitting high density polyethylene pipe (Swagelining) were considered. The design criteria required a fully structural Class IV solution capable of 60 psi operating pressure. Overall, the hydraulic cross section needed to be maintained as large as possible requiring an I.D. of liner 28-in. or greater within the 30-in. I.D. host pipe. The optimized design included maintaining various other parameters such as vacuum pressures, live loads and ground water. Among many factors, the compression tight fitting HDPE pipe process was selected because it is trenchless and less disruptive to the residents, required less time for installation, offered a long design life with the new HDPE pipe and was less expensive. Also, the implementation schedule could be accomplished in low water demand season. This paper will also outline the construction phase, including the compression fit process, the pipe installations performed by Murphy Pipelines, and the challenges associated with the installation through an urban residential neighborhood. The utilization of this technology with HDPE pipe allowed the owner to meet all design parameters and increase the flow capacity.

With the aging of old pipelines, maintenance and repair have become important. Operators of pipelines installed under public roads should be prepared to take prompt action in case of reduction of pipe wall thickness due to corrosion or mechanical damage by third-party activities. In particular, in-service repair welding should be possible without stopping the gas flow, which would make it difficult to satisfy gas demand. Due to time constraints, it is also preferable to avoid preheating and post-heating of pipes. Common issues for in-service repair welding methods such as the overlay welding method, spliced plate welding method and sleeve welding method are (1) to avoid burning through the mother pipe during welding, (2) to avoid hardening of the weld, which is a cause of cracking, (3) to realize overmatching of the weld, so that the strength of the weld metal is higher than that of the base material, (4) to ensure the strength of the weld against pipe deformation due to seismic loads and (5) to establish the most suitable inspection method to ensure weld quality. In this paper, solutions to the above-mentioned issues are introduced through a case study of the sleeve welding method for a particular pipeline installed under a public road.

Ho Chi Min City, the largest city and economic hub of Vietnam, has been growing at a rate that, among other things, has created traffic congestion that brings traffic flow in some sectors of the city to a virtual halt during peak demand hours. For this reason the City Council, with the goal of improving environmental and economic conditions, is building a subway system as part of its plan to promote sustainable and safe modes of transport. In order to accomplish this improvement it was necessary to relocate a 48 inch diameter water transmission line in the main financial district of the city to enable subway construction. This paper will discuss meeting the challenges of performing a triple plugging and bypass operation for the relocation of the 48 inch transmission line, while avoiding shutting down the city’s financial district, thereby contributing to the completion of the transportation improvement plan. The challenges, among others, included: organizing, planning and controlling the project; managing and executing operations across a global organization while interfacing with a complex owner organization in order to successfully implement and perform the tapping and plugging procedure.

America depends on a network of more than 2.5 million miles of oil and gas pipelines, 1.2 million miles of water supply mains, and over 1 million miles of wastewater pipelines to move product and keep the country’s infrastructure operational. Aging pipelines need replacement, while new ones are required to meet increasing demand. As pipeline and infrastructure density increases, geometric constraints become a greater struggle during planning and design for pipeline construction. Innovative trench shoring technologies are becoming necessary to adapt to these challenging conditions. In addition, these transfer conduits are often routed through difficult and unstable terrain. Pipeline instabilities (i.e. settlement or landslides) place serious risk on community health and safety; and can sometimes bring commodity transfer to a halt. Stabilizing the ground around the pipelines will be key to keeping the economic engine running. This paper will include several case studies that illustrate innovative solutions to overcome typical challenges in the pipeline industry. Each case study will include the project constraints, options considered, and why the selected alterative was proven to be successful.

This paper provides a case history and lessons learned from Segment 3 of the $180 million rehabilitation of the 12.75-foot diameter Oakland-Macomb Interceptor Drain (OMID) in Oakland and Macomb Counties, Michigan. The over 100-foot deep tunnel extends below 480 KV overhead power lines and several major roads. The sewer is non-redundant, and cannot be diverted. Multiple catastrophic tunnel failures have occurred since the 1970s construction. This project was undertaken to slip-line and structurally replace approximately 26,000 ft of the interceptor, protecting from future failure, without interrupting service to over 830,000 upstream users. This precedent-setting repair was conducted using an in-line flow storage system that involved holding flow behind in-line control gates daily, and slip-lining with centrifugally cast fiberglass reinforced polymer mortar (CCFRPM) pipe over 12 h shifts. All equipment was removed from the pipe daily and flow released during the night. Major innovations and successes included daily control of 100 million gallons of sewage while simultaneously installing 8 to 10-foot diameter slip-line pipe; development of a unique in-tunnel pipe delivery system; construction of shafts with low overhead clearance; and reduction of groundwater infiltration by 90 percent, saving millions in treatment costs each year.

The North Rillito Interceptor (NRI), located in Pima County, Arizona, was installed in the early 1960s and was reaching its end of useful life. This project involved cured-in-place pipe (CIPP) rehabilitation of approximately 53,000 linear feet of 15-in. to 36-in. diameter sanitary sewer interceptor, rehabilitation and replacement of 126 manholes and access structures, and flow management up to 15 million gallons per day (MGD). Manhole and access structure rehabilitation utilized various technologies including epoxy coatings, rigid polyurethane coatings, and structural fiberglass inserts. Manhole and access structures replaced were increased up to 10 feet in diameter with precast polymer concrete. Throughout the interceptor project, residential development, vegetation overgrowth, riparian habitats, private property encroachment, and Pima County Natural Resources, Parks, and Recreation improvements made access and maintenance difficult for Pima County Regional Wastewater Reclamation Department (PCRWRD). Gaining access to the interceptor easements was a significant challenge for contractors during the pipeline rehabilitation. To prevent disruption to the entire 10-mi alignment at one time, the project was divided into six phases. Throughout the project extensive public communication was provided. The project resulted in a fully rehabilitated interceptor with improved hydraulics, reduced odor generation, and a renewed pipeline life of 50+ years. Easements were re-established for PCRWRD to access and maintain the system, while preserving riparian habitats, implementing a plant preservation plan, and minimizing disruption to the Rillito River bike path system. Shared flow management between other PCRWRD projects attributed to substantial project cost savings.

A residential street in NW D.C. reported a sewage backup in addition to a sinkhole and an 8 in. water line break in early January 2010. A hundred year snow event which followed not only hindered the repair work, but also settled the water meter pit by 6″. After rebuilding a 42-ft deep manhole on a 4′×6′ egg shaped sewer, replacing a few segments of 8″ water pipes, point-repair of a 12″ sewer, and backfilling the street around the manhole, the street around the manhole continued to settle until dozens of cubic yards of low mobility grouting (LMG) in the impact zone around the manhole were deployed. During this investigation, DC Water engineers were surprised to find that the rest of the street had a very low blow count below a depth of 8 feet, indicating hidden voids in the soil and thus very poor soil condition. Review of the as-built records indicated that this street appeared to have a 42-ft +/-deep built-up fill in 1892 after constructing a 4′×6′ egg shaped sewer to contain the spring water. Entry inspection by engineers also confirmed clear live flow in the “abandoned” section of the egg shape sewer. Water quality and low pressure issues in this neighborhood qualified the 8″ water line on the list to be replaced with new ductile iron pipes via open-cut, i.e, the conventional rehabilitation method. It came to our engineer’s realization that this dirt fill built-up street is in a delicate equilibrium atop of the hidden voids. The DDOT’s reinforced concrete underlayment slab and a seven feet+/- of soil arch seems to act as a “land bridge” that supports the street. Any conventional open cut approach to slit the street open will likely remove the bridge effect. This presentation will showcase how DC Water engineers perform internal and external benchmarking to assess the risk associated with the conventional open-cut methodology, and how alternative CIPP for water service pipe rehab is confirmed.

Carbon fiber reinforced polymer (CFRP) can be an appropriate alternative to various methods of pipe replacement and repair for structurally deficient pipelines. When traditional pipe replacement, cured-in-place pipe and other types of repair are impractical, external CFRP can be used to reestablish the structural integrity of the pipeline. This paper will focus on four separate case studies where external wrapping using CFRP was used to provide added strength to structurally deficient pipelines. Nickajack Creek Watershed–The Nickajack Creek project consisted of a 24-in. pipe running across the Nickajack Creek in Mapleton, Georgia. The length between supports over the creek (roughly 45 ft) and access issues rendered traditional rehabilitation techniques impractical. CFRP was, therefore, selected to restore the structural integrity of the pipe with no disruption in service. City of Nashville–This project involved a 66-ft section of 60-in. pre-stressed concrete cylindrical pipe (PCCP) that had a working pressure of 150 psi. After wire break analysis was conducted on the pipeline, structural repair was required on four separate areas of the pipeline. Due to the importance of the pipeline, it could not be taken out of service long enough to accommodate traditional repair techniques. Therefore, a specialized repair method was designed with the pipe being excavated, supported, and repaired while still full of water. Accotink Creek–Significant wire breaks on 30-in. and 42-in. PCCP force mains near the Accotink Creek required external CFRP repair. It was determined that external CFRP repair was the most appropriate solution due to internal diameters and the requirement for the pipe to remain in service during repair. City of Portland–The City of Portland project required a specialized repair due to the uniquely deteriorated condition of a 30-in. CCP pipeline running 270 ft underneath a pedestrian bridge. CFRP was installed on the outside while the pipe was still in service, providing additional strength to the host pipe.

The rehabilitation of sewer collection systems is typically performed according to detailed specifications that are the result of video inspections of sewers, service laterals and manholes. These specifications detail the extents and quantities of trenchless rehabilitation, spot replacement of sewers, and manhole rehabilitation actions. This traditional approach ensures that existing conditions, including most defects, connectivity, and locations of critical infrastructure are known prior to construction. However, precious time and money must be expended to perform pre-construction inspections and evaluation prior to design. A new approach to comprehensive rehabilitation has been dubbed the “Find and Fix Method”, in which inspections and evaluations of sewer infrastructure are performed immediately prior to construction. This approach allows municipalities to save time, and potentially money, by eliminating the need to clean and inspect the system, review the CCTV videos, and then create a detailed design package. Instead, specifications are produced showing the general area for planned rehabilitation actions, including bid items to account for unforeseen circumstances which could likely arise during construction. The City of Revere, Massachusetts, has used the “Find and Fix” approach to expedite the rehabilitation of critical sewer infrastructure to show progress to the regulatory agencies in response to a Consent Decree. Each year new unknowns are encountered that help to refine the specifications and produce a quality product for the City. This paper will discuss lessons learned and provide a roadmap by which successful “Find and Fix” specifications can be produced to limit change orders and reduce overall risk.

An existing primary transmission water main on Lamb Boulevard in Las Vegas, NV had developed several leaks, prompting the Las Vegas Valley Water District (LVVWD) to begin design of its rehabilitation in 2011. The existing line consisted of 42-in. and 48-in. steel cylinder concrete pipe (SCCP). The extent of the leaks required rehabilitation from Wyoming Avenue to Vegas Valley Drive, a total length of approximately 5,100 ft. Lamb Boulevard is a heavily trafficked road located in a suburban area within four miles of the Vegas Strip, limiting the possibility of extensive road closures. Due to this restraint, and capacity capabilities through the rest of the system, LVVWD chose to slipline the existing SCCP with 30-in. PVC pipe. The installation included three slipline runs and one 200-foot jack-and-bore under the Flamingo Wash. This paper will review the challenges met in the design and construction leading to a successful rehabilitation of this critical transmission main for LVVWD.

Although trenchless technology in its many forms has been utilized for decades, there are still many engineers that have never incorporated it into their project design. When a situation arises that calls for a trenchless crossing, the best first step for all interested parties is to consult a trenchless contractor with experience in multiple methodologies. An expert with hands-on experience of the limitations of each method, awareness of the constraints of site access, effects of soil conditions and requirements of casing size to accommodate carrier lines can provide invaluable insight at the initial design phase of a trenchless project. This session will utilize multiple case studies of actual trenchless crossings performed by SSC to compare and contrast situations where SSC’s consulting was utilized from conception phase versus projects that were designed without any contractor input. These examples will demonstrate the benefit of including a trenchless technology expert on the design team, and how their involvement can reduce redesign requirements and create a project that can be constructed on time and budget. Participants in this session will gain an insight into the considerations that should be evaluated in the design of any trenchless project. Lived examples will provide context for how each factor, when properly evaluated can impact the success of a trenchless project.

Today, there is an urgent need to upgrade existing drinking water and wastewater treatment facilities and build new ones. Aging infrastructure, population growth, and more stringent environmental regulations have been some of the main drivers. Water industry leaders and decision-makers are looking at innovative technological and project delivery solutions to help ease their financial burden. Water and wastewater treatment plants have traditionally been constructed, retrofitted, and rehabilitated using the design-bid-build (DBB) project delivery. DBB has been used for decades and is adequate for projects where the work is well defined and there is relatively low uncertainty (i.e., projects that are repetitive, with low complexity). However, DBB might not be the best method to use for more complex facilities where integration between the different stakeholders can result in more innovation and improve efficiencies. Several organizations have promoted the use of non-traditional, alternative project delivery methods (APDM) such as design-build (DB) and construction manager at risk (CMAR) touting benefits including lower cost, faster schedules, and higher quality. These alternative methods have been used in the transportation and building sectors, and are starting to be adopted in the water utility sector. This paper overviews published sources that have quantified the impact of delivery systems on project performance in several industries. This overview will be the foundation for a discussion of challenges and opportunities of adopting alternative delivery methods in the water and wastewater industry.

The Santa Clara Valley Water District (District) initiated the Penitencia Delivery Main and Penitencia Force Main Seismic Retrofit Project (Project) to improve the seismic resilience of three critical water supply/deliver pipelines that serve the District’s Penitencia Water Treatment Plant (WTP) in San Jose, California. The most important objective of the project is to retrofit the existing pipelines to protect the life-safety of nearby residents and the Noble Elementary school. The Project planning phase began in 2013 and final design was completed in December 2015. Construction began in April 2016 and is scheduled to be completed in December 2017. The project includes the following key innovations: (1) design for large landslide displacement: the landslide and seismic hazard evaluation estimated the landslide displacement as 7.7 ft (seismic) and 1.7 ft (creep), for a total displacement of 9.4 ft over the 50-year design life; (2) sophisticated finite element modeling: the project team developed the design with a sophisticated 3-D model of the landslide and pipeline interactions; (3) seismic resilience: the project includes several design features to improve the seismic resilience of the pipelines at the landslide toe. The seismic resilience features will provide the ability to shut-down the pipelines during a failure, provide temporary bypass connections to return the facilities to service, monitor pipeline displacement, and monitor seismic events; and (4) constructability challenges: the district, contractor, and project team solved several constructability challenges related to working within the 50-foot easement, sequencing work within the protected bird buffer zone, and installing the ERDIP pipelines to meet the tight construction schedule. This project includes unique challenges of designing for large displacement along the axis of the pipelines which loads the pipelines in compression. This project also has a high visibility within the community because of the risk of failure and proximity of the project within the residential neighborhood.

The North Charleston Sewer District (NCSD) System includes 60 pump stations and approximately 450 miles of gravity and force main piping. The infrastructure serves approximately 31,000 customers and a total population over 100,000. The Felix C Davis Wastewater Treatment Plant (WWTP) is permitted to treat 32 million gallons per day (MGD) and is the only plant utilized by NCSD. Currently, the plant averages approximately 20 MGD from the 59-square mile service area.

Different shaped pipes have been used for centuries to help facilitate low flow velocities in sewer systems for centuries. These non-round sewer pipes were traditionally used in large cities where pipelines were utilized to carry sewer and storm water together. These pipes had the capability to maintain reasonable cleanout velocities for the sewer effluents during times of dry weather, but also had the capacity to carry storm water during significant rain events. These non-round sewer pipes are located all over the globe as part of the city’s infrastructure and the performance of these pipelines are incredibly important to each municipality. More specifically, many of the largest cities in the United States such as New York, Boston, Washington, D.C., and Los Angeles have these types of sewer pipes in their systems. These pipes were traditionally constructed of unreinforced concrete and bricks or clay tiles. The majority of them were hand crafted manually by arguably some of the most skilled masonry laborers to create very specific profiles to achieve the necessary hydraulic conditions for these cities. With many of these sewer lines being constructed in the early 1900s and with continued city expansion and developments, some of these sewers do not follow the public right-of-ways and even cross underneath existing building and residential housing. Because of the corrosive nature of a sanitary sewer environment, these sewers are now approaching the end of their service life and are in need of structural rehabilitation. With the constraints of public disturbance of digging and replacing the pipes, many city engineers are exploring new methods of restructuring with corrosion resistant materials. The difficult challenge that each engineer faces is to come up with a rehabilitation solutions to match the existing profiles as closely as possible, but the solution also has to have the structural integrity needed to hold up long term. This paper will review a recent project installed in Los Angeles. The City of Los Angeles has utilized the slipline method of rehabilitation for their sewers for decades with circular fiberglass pipes. It has only been recently where they have started to utilize profile fiberglass pipes for these non-round sewer rehabilitation projects. This paper will review the physical property requirements required a profile shaped slipline product including the material testing procedures and results. The design approach for the physical properties was an important part of this project which was a driving factor behind the physical pipe properties. In addition, the construction means and methods will be discussed with the focus on the field variables during the installation.

To maintain the integrity of transportation infrastructure, State Departments of Transportation (DOTs) have to continually replace, repair, and renew their culverts. The traditional method of replacing and rehabilitating these culverts is the open-cut construction method. Trenchless technologies offer several advantages over the traditional open-cut method because they are less costly in favorable conditions and also eliminate or minimize many of the risks and social costs of the open-cut construction method. During the value engineering process, a common question is whether the construction work should be performed by a contractor or by the DOT’s own crew (i.e., “in-house”). When done in-house, the DOT may elect to use open cut or an applicable trenchless technology (in this case horizontal auger boring). State DOTs have a scope and dollar limit above which they have to award a project through competitive bidding. For Ohio Department of Transportation (ODOT) to rehabilitate or replace culverts using its own maintenance crew, the force account limit for a single project is $60,420 for the 2016/2017 fiscal year. The purpose of this study is to compare the cost of culverts installed using horizontal auger boring (HAB) to those installed using open cut when the work is done by ODOT’s workforce. Culvert installations completed by ODOT’s own crew using an acquired HAB machine and the open-cut method were observed and data collected. This paper provides a cost analysis that will serve as a platform for other DOTs to determine if it makes economic sense for them to include HAB as an alternative for their in-house operations.

Traditionally, highly deteriorated wastewater pipes are given priority in capital work activities. To this end, when capital budgets are limited, money is first allocated to replacing sewers in WRC Internal Condition Grade 5 (ICG 5), the worst condition based on WRc coding system, and the remaining budget is then used for the next condition groups such as ICG 4. This study investigates the effect of partial allocation of capital budgets between fully-deteriorated (ICG 5) and semi-deteriorated (ICG 4) sewers, using a system dynamic modeling approach over the design life of the asset. The results of analyzing a Canadian wastewater collection network show that a multi-proactive rehabilitation strategy can be more effective in the long-term financial planning of wastewater collection networks. Municipalities and utilities can use the decision-support tool provided herein as an effective asset management plan for wastewater collection networks.

Over the past two decades we have observed the industry development and increased use of carbon fiber reinforced polymers (CFRP) for pipeline rehabilitation. The design of the CFRP rehabilitation was evolving with each project and providing municipalities with better designs and more confidence in the technology. As with any development process, there are many parameters, many tests and various opinions that come together in a dynamic way. The goal, or target, is to develop a design and detailing consensus that is validated by testing and accepted by the engineering community. At the time this paper was submitted, there is still no adopted standard for the most commonly detailed CFRP repairs (AWWA C305 is in the final stage of development). However, these systems have been designed and installed on many pipelines over the last 20-years while the design philosophy and related detailing has been changing. It has been during this time period that the target has truly been moving. A recent forensic study of a 96-in. section of PCCP provided a rare opportunity to look at an older version of the “state of the art” and compare the design and detailing to other methods currently being employed. The forensic analysis was focused on identifying the root cause of a leak, while also investigating all aspects of the CFRP material and the installation. This unique opportunity allowed the team to review the past and current analysis methods and detailing, and the various testing programs and previous work that has been used to develop both the industry and the new AWWA standard for CFRP renewal of PCCP. This paper will review the forensic analysis and the critical findings that led to the remedial measures and a heightened awareness and confidence in the current “state of the art”.

With the arrival of new technologies, rehabilitation of large diameter pressure pipelines has become more cost effective and can often be accomplished without extensive excavation and/or pipe replacement. This paper explores operating pressure and diameter range capabilities of available cured-in-place pipe (CIPP) and other thermoset resin technologies for use in Pressure Pipe applications including sewage force main, NSF 61 certified potable water, and storm water transmission mains. A questionnaire was developed to generate a survey of present-day technologies and availability to prospective end users. We polled several contractors and manufacturers covering a variety of topics including System Type, Diameter and Pressure Range, Constructability, Access Requirements and Closure Methods. Our objective was to discern the current state of CIPP and other thermoset resin based technology allowing for successful installation of 48-inch or greater diameter pressure pipe rehabilitations using little or no excavation.

This paper presents the analysis, findings and recommendations from studies of multiple failures of buried pressure water mains at a large industrial facility in Texas. The authors investigated the origin and nature of the failures and proposed comprehensive trenchless solutions to address corrosive soil issues and pressure management without impacting the operation of critical plant process water supply and fire protection systems. Newer trenchless approaches using strategically-placed pressure sensors, combined with both AWWA Class IV, close-fit HDPE liners, and spray-in-place pipe (SIPP) offered significant cost advantages and rapid return to service. While Class IV liners offered a replacement pipe solution for fully-deteriorated metallic pressure pipes, a pilot program of SIPP is recommended for system-wide adoption. This paper explores the details of the engineering and construction approach and outcomes, as well as, the advantages of using trenchless methods in a congested subsurface environment at a large industrial plant.

The North Texas Municipal Water District (NTMWD) is considering making improvements to the transmission system and pumping scenarios to provide redundancy to their Wylie-Rockwall-Farmersville (WRF) Pump Station, and the planned pumping improvements required an increase in the working pressure rating of an approximately 8,000 ft long portion of the pipeline from 100 psi to 150 psi. The pipeline provides water to two delivery sites, which needed to stay in service throughout the pipeline rehabilitation. Following evaluation of open cut replacement and several trenchless rehabilitation methods, NTMWD selected carbon fiber reinforced polymer (CFRP) liners to strengthen three regions of the pipeline where pipe replacement was not feasible. This paper discusses the project from the feasibility study through construction with particular emphasis on the selection, design, and implementation of CFRP liners.

There is very little guidance in North America Standard Practices for the design of non-circular rehabilitation systems. While the ASCE Pipelines Technical Committee on Design of Liners for Gravity Sewer pipes is currently working on a Manual of Practice (MOP) to develop a unified approach for all host pipe cross sections, there are many unique issues associated with non-circular liners and no current North American or Global consensus on how to address these issues. Aside from finite element analysis (FEA) techniques, there is no universally accepted, simplified model or models to aid in the structural design of non-circular liners. For un-bonded liners, one of the models most commonly used is a modified version of the WRc Sewer Rehabilitation Manual (SRM) design approach commonly referred to as Type II Design. This approach is applicable to products such as cured-in-place pipe (CIPP) and some grouted in place glass reinforced polymer (GRP) structural panels in egg and oval shaped sewer cross sections. The current WRc SRM provides guidance on the design of un-bonded structural sewer rehabilitation systems for egg and oval shaped sewers using beam theory with very little guidance on applied load models other than designing for external hydrostatic stress. North American design practice commonly includes the accommodation of overburden loading in addition to hydrostatic stress. Further, in recent years host pipe considerations have expanded beyond egg and oval sewer cross sections to include the rehabilitation of arches, boxes, and numerous other unique sewer cross sections. The lack of consensus on a standardized approach has led to widely varying practices and a lack of objectivity in comparative assessment of many lining products. Variances in the design of non-circular sections range from the use of unpublished research data and formula derivations to the incorrect use of ASTM F1216, Appendix X1 in non-circular applications. In some cases, through transference of design, this has resulted in inequitable bidding situations with different vendors utilizing radically different design methods even for the same product. There is an over-arching need to develop a coherent design approach for the vast array of non-circular cross sections being rehabilitated with lining technologies in the North American market. While the American Society of Civil Engineers (ASCE) is currently working on a unified MOP that includes non-circular host pipes, this paper highlights the myriad of design approaches that have been employed to date, and their limitations and strengths to assist in rationalizing a conservative, yet effective short term path forward for non-circular liner design. The paper also highlights a number of practical considerations that must be addressed for non-circular liners to be incorporated in a competitive bidding process in a coherent, equitable manner.

The City of Victoria, BC, Canada, has brick sewer infrastructure that was originally constructed in the early 1860s. While they were first used as combined sewers the inventory has long been converted to storm sewer service. It includes over 10 km of largely non-circular cross sections including egg and arch shape cross sections ranging in size from 914 mm × 610 mm (36″ × 24″) to 2100 mm × 2855 mm (84″ × 114″) (H × W). The inventory traverses a wide range of native soils ranging from running cohesionless soils with a high water table to competent cohesive soils and rock cuts all through a mature urban neighborhood. A 15 year upgrading program commenced in 2012 and continued in 2016. This paper reviews the design and rehabilitation in 2016 of a particularly challenging 1585 mm wide by 990 mm high (63″ × 40″) brick arch sewer located under a fully occupied cemetery (Ross Bay Cemetery) with a number of 300–600 mm (12″–24″) high steps in it. After a careful review of alternative rehabilitation methods, it was decided to utilize segmental glass reinforced polymer (GRP) panels to balance design objectives of minimizing construction footprint and the ability to adopt a conservative structural design approach without compromising economics. The design investigated a range of applied loads models and the use of both bonded and un-bonded lining products in an effort to develop an optimum structural section without compromising constructability of a very complex section with even more complex access logistics.

This project involves rehabilitating approximately 36,000 LF of abandoned 36- and 30-inch concrete cylinder pipe (CCP) water transmission main with high density polyethylene (HDPE) plastic pipe slipliner. The project goal is to rehabilitate the abandoned transmission mains to convey approximately 10.0 mgd of additional renewable potable water resources from the Santa Cruz Well Field. The project is located in mixed-use industrial and rural residential areas of southeast Tucson, Arizona. The 36- and 30-in. CCP transmission mains were installed in the 1960s, and were abandoned due to maintenance issues including corrosion and leakage. Slip lining the abandoned transmission mains with HDPE pipe was selected by the City of Tucson Water Department (Tucson Water) as the most cost-effective and least disruptive technology to develop the requisite conveyance facilities.

Value engineering (VE) and peer review (PR) was performed on the Preliminary Design (30% Design) associated with the 16th Avenue Sanitary Trunk Sewer Rehabilitation project located on 16th Avenue (between Minghay Ave and 9th Line) in the City of Markham, York Region. The objective of the VE and PR was to perform an evaluation of the proposed trunk sewer rehabilitation approach based on existing information to identify the “the lowest risk, best technical, and best value solution available” for rehabilitation. The key requirements of the proposed rehabilitation solution were to minimize disruption, reduce construction risks, reduce capital cost, and minimize impact on hydraulic capacity of the sewer. The defects observed in the trunk sewer comprised of groundwater infiltration of varying flow rates located primarily at construction joints, and localized longitudinal cracking and fractures generally parallel to the pipe axis primarily located at or adjacent to pinch points (areas where tunnel section reduced due to difficulties encountered during tunnel construction). The findings of the PR and VE reported “the 16th Avenue sewer to be in adequate structural condition but suffering from high levels of infiltration in certain areas which can lead to structural problems if infiltration is left unattended.” The authors found the proposed preliminary design rehabilitation solution costly; and disruptive to local residents, businesses, and traffic throughout construction. After reviewing the full range of pipe rehabilitation technologies available in the marketplace, using a Multi Criteria Analysis process, it was concluded that a less-costly and lower risk solution to stop groundwater infiltration would be to consider the use of a high-strength spray applied geopolymer mortar to the inner surface of the pipe. A Pilot Study scope of work was developed to demonstrate the suitability of the geopolymer material and installation procedures as an option for system-wide sewer rehabilitation. This paper will discuss the findings of the VE and PR along with the design and results of the Pilot Study.

Canfor, a producer of lumber, pulp and paper needed a solution to replace aging 30-in. (760-mm) fiberglass reinforced pipe. A new PE-RT product now expands PE into industrial applications requiring resistance to high temperatures and having a hydrostatic design basis (HDB) of 800 psi (55 bar) at 180°F (82.2°C). Through chemical processes, Canfor cooks, washes, and extracts pulp fiber from wood that results in both acidic and caustic effluent with temperatures normally in the 50–60°C range or as high as 70–75°C. Traditional fiberglass pipes have experienced repeated joint failures over time, whereas heat-fused HDPE pipe provides solutions reducing unnecessary maintenance and a longer service life. Standard PE4710 high density polyethylene pipes (HDPE) have pressure ratings limited to 140°F (60°C) and are not normally acceptable for such high temperature acidic and caustic effluent. Additionally, the potential for higher oxidation-reduction potential (ORP) from residual chlorine levels and bleaching also justified turning to a different material based on the potential oxidative attack at high temperatures. The new PE-RT resin protects against oxidative attacks at high temperatures and the flexible heat-fused HDPE pipe provides considerable cost savings during installation. Compared to fiberglass, up to eight 40-foot lengths of HDPE pipe can be joined by heat fusion per day, whereas only two 6-m (20-foot) lengths of FRP pipe can be wrapped per day. The presentation will highlight photos during the installation process and report the advantages of using the new pipe material. This project provides reference for expanding HDPE pipe into new applications using PE-RT materials.

This paper describes the replacement of asbestos cement drinking water lines originally installed between 1938 and 1940 within the City of Yuma, Arizona. The project was undertaken in 2016 between February and April and involved the replacement of approximately 5,800 L.F. of existing aging and undersized asbestos cement water lines in the vicinity of the downtown core to reduce maintenance and repairs and improve water service levels. Six line segments of existing 2-inch to 6-inch asbestos cement water lines were replaced by 6-inch diameter PVC pipe. The City of Yuma worked together with Stantec Consulting Services to use this project as a means to conduct a head-to-head analysis of various aspects of traditional open-cut construction compared to horizontal directional drilling (HDD). The project was intentionally separated into HDD (2,000 L.F.) and open-cut (3,800 L.F.) sections. PVC C900 DR14 was installed using open-cut, while Fusible PVC (FPVC) DR 14 was installed by HDD. Onsite data was collected to analyze and compare environmental impacts, traffic impacts, and productivity. HDD was found to be more advantageous in all three areas when compared to traditional open-cut. Airborne emissions generated during the project by each of the two methods were determined using the eCalc program. Water samples were taken for each installation method to compare water quality before and after the installation of the new water lines.

In June 2010, a 72-in. prestressed concrete cylinder pipe (PCCP) force main experienced a catastrophic failure. This failure prompted Miami-Dade Water and Sewer Department (WASD) to conduct an electromagnetic survey on the pipeline. The results of the survey indicated that nearly 25% of the pipeline contained distress. Due to the alarming state of this force main, rehabilitation of this pipeline became an emergency project. WASD chose design-build as the delivery method in an attempt to expedite the project schedule. WASD contracted with a consultant to develop a design criteria package. After advertisement of the project, various issues came to light during the award process. Which, in effect, resulted in the design criteria package to become obsolete. This paper will discuss various unanticipated issues that arose during the duration of the project.

On Friday, May 13th, 2016, the 210-in. diameter Kutz Siphon failed, cutting off the irrigation water to 72,000 acres of farmland. Faced with millions of dollars in crop losses, the Navajo Agricultural Products Industry needed replacement pieces for 40 feet of 210-in. prestressed concrete cylinder pipe (PCCP) quickly. The original PCCP was manufactured onsite in the early 1970s as transporting the pipe would have been a significant challenge. Needing the repair pieces in a timely manner, the manufacturer worked closely with the Bureau of Reclamation to design a solution for which material acquisition, manufacturing, and delivery could be completed in a timely manner. The design solution was to use steel plate and roll up the replacement pieces in short segments that could be hauled as over-width loads, eliminating any over-height issues. Reclamation provided a previously used detail for connection to the existing PCCP. The joints for the repair pieces were designed as buttstraps in lieu of banded bells to facilitate joining of pipe in field. A port was provided for access and ventilation during installation. Paper will cover the steps taken and coordination required to provide the repair pieces in a short time period.

The City of Miami, Florida, is experiencing a resurgence of development following the economic recession of 2008. By 2013, numerous large-scale mixed use high rise complexes within the downtown Brickell area required Miami-Dade County Water and Sewer Department (MDWASD) to implement significant expansion and modernization of both the existing sanitary sewer collection and transmission systems. MDWASD awarded the project to the design-build team of Ric-Man Construction Florida, Miami, and Jacobs Engineering Group, of Miami, as the lead design firm. This paper discusses various aspects of this unique sewer recapitalization design-build project needed to support high density re-development within the downtown and financial districts of Miami, and will include technical trenchless elements, permitting, traffic control, and stakeholder management. Executed in close coordination with a separate design-build project for the receiving Master Pump Station No. 3, this project constructed 4,100 linear feet of 48″ polymer concrete carrier pipe (60″ OD) by four separate Microtunneling drives, the longest of which totaled approximately 1,500 linear feet facilitated by the use of intermediate jacking stations within the pipe string. Successfully completed in January 2016, the project required intense coordination six (6) local and state jurisdictions and stakeholders. Additionally, construction and maintenance of traffic was coordinated with simultaneous ongoing projects for the Miami Avenue Bridge repair, Brickell Avenue improvements, the massive Brickell City Centre development, and numerous other ongoing development projects within the Brickell Downtown District.

This paper discusses the construction of two unique design elements for the City of Bellevue Wilburton Sewer project that were presented at the 2015 ASCE Pipelines conference. The project included 4,300 ft of new 12-in. to 30-in. diameter sewer, with an alignment traversing a peat bog, creek, ten lanes of Interstate 405 (I-405), a Lexus car dealership, a major arterial, and a retaining wall along I-405. These challenging site and soil constraints were navigated by a wide range of design solutions and technologies, including: supporting the pipe on auger cast piles, backfilling the pipe with geofoam, prescribing specialized shoring systems, crossing under the arterial using trenchless technology, CIPP rehabilitation of an existing pipeline, and complex bypass pumping arrangements.

Washington Suburban Sanitary Commission (WSSC)’s condition assessment and repair program on critical transmission mains continued in spring 2016 with a record-breaking project where a total of forty-one 60 in. to 66 in. diameter prestressed concrete cylinder pipe (PCCP) segments were lined with carbon fiber-reinforced polymer (CFRP) in about 30 days. The scope included installation of new CFRP liners in seven pipes according to the current state of the art AWWA C305-CFRP Renewal and Strengthening of PCCP industry standard and proactive upgrade of existing CFRP liners in thirty-five pipes to meet the current strength and watertightness requirements. This is the largest number of proactive upgrades performed by a utility in the same outage to date. This paper discusses the challenges of performing such a large scope of CFRP lining of PCCP in a compressed schedule, with several contractor and quality control/quality assurance teams working simultaneously, without compromising quality.