AWWA Articles

Five new AWWA standards being highlighted at ACE19

An ACE19 presentation, “New AWWA Standards and How to Use Them,” will be held Wednesday, 1:30 - 4:30, in Mile High Ballroom 4C. It will include information about the new C305 standard described below.

Several new and revised standards and a committee report related to the repair and renewal of water infrastructure – specifically pipelines – have recently been published or are under development by the American Water Works Association’s (AWWA) standards committees.
Mohammad Najalfi
“Underground infrastructure systems, and specifically water pipelines, span thousands of miles and are a significant part of the total U.S. infrastructure,” said Mohammad Najafi (pictured at right), chair of AWWA’s Pipe Rehabilitation Standards Committee. “Many are deteriorating and becoming more vulnerable to catastrophic failures, often resulting in costly and disruptive replacements.”

Two new AWWA/ANSI standards were developed and approved by member volunteers from the Pipe Rehabilitation Standards Committee and the Concrete Pressure Pipe Standards Committee:
•    C621-18 Internal Pipe Joint Seal Assemblies for Water Service, published December 2018
•    C305-18 CFRP Renewal and Strengthening of Prestressed Concrete Cylinder Pipe, published December 2018

Another existing AWWA/ANSI standard has been extensively revised:
•    C620-19 Spray-In-Place Polymeric Lining for Potable Water Pipelines 4 In. and Larger, publishing in 2019

While recently developed methods for water pipeline renewal are more cost-effective and less disruptive, “municipalities and government agencies do not have adequate standards and guidelines for these methods,” Najafi added. “AWWA has taken the leadership to develop these new standards.” 

C621-18 Internal Pipe Joint Seal Assemblies for Water Service

This new standard defines minimum requirements for materials and methods used to install flexible, internal joint seals in water transmission mains. Internal joint pipe repair or sealing is a no-dig method to seal joints and prevent leaks in water pipes that are otherwise functioning. It bridges an existing pipe joint with a rubber seal and a corrosion-resistant band to allow continued movement of the pipe joint. 

The selection of materials for these assemblies is critical in locations where there they may be in contact with chlorine or chloramines, to provide long-term usefulness and minimum degradation.

C305-18 CFRP Renewal and Strengthening of Prestressed Concrete Cylinder Pipe

The use of carbon fiber reinforced polymers (CFRPs) began with university testing in the late 1980s and gained acceptance within the engineering and construction industries in the early 1990s to strengthen large-diameter underground PCCP. Advancements in precision inspection methods helped utilities better locate at-risk pipes, increasing the demand for CFRP upgrades and leading to its acceptance as a renewal and strengthening system for PCCP.
Mehdi Zanghamee
“Because CFRP had been in use for a relatively shorter time than traditional construction materials, utilities sought a consensus standard for CFRP renewal and strengthening of their prestressed concrete cylinder pipelines (PCCP),” said Mehdi Zanghamee (pictured left), chair of the C305-18 subcommittee.

“Simultaneously with the formation of AWWA’s C305 committee, the Water Research Foundation, with support from industries and several utilities, sponsored a research program that included both analytical and experimental work and laid the foundation of the requirements of this standard,” Zangahemee added. “The standard will expand the use of the material in degrading infrastructure and prove to be a valuable means for renewal of deteriorating buried water infrastructure.”
Anna Pridmore
Anna Pridmore (pictured right), secretary of the C305-18 subcommittee, noted that pipeline replacement and repair regularly take place in most major water and wastewater agencies. “It is critical that standards exist for methods of repair and rehabilitation so that long-term durability of pipelines and pipeline segments addressed can be predictable and projected with accuracy,” she added. (Zanghamee and Pridmore will present a C305 overview at AWWA’s 2019 Annual Conference and Exposition)

C620-19 Spray-In-Place Polymeric Lining for Potable Water Pipelines 4 In. and Larger

The new edition of C620-19, developed by the Subcommittee for Applied Linings, expands the materials covered and is more widely applicable. 

“The revision covers structural and semi-structural renewal methods using epoxy, polyurethane and polyurea materials for sections of water pipelines that have cracks and holes with certain limits,” Najafi said. “It includes inspection and performance guidelines for these methods to ensure quality installation and delivery.”

Pipe Rehabilitation Standards Committee report: structural classifications

Water pipeline renewal methods can provide structural, semi-structural and/or non-structural solutions, but selecting the correct method can be confusing. The committee is developing a white paper that presents:
•    Selection criteria and recommended testing and acceptance guidance for each renewal method
•    Design equations
•    Sample calculations for application of each method

“This is an important decision-making process for water agencies because conditions of old and leaking water pipes may require different types of solutions, Najafi said. “Selecting the right method will provide long-term benefits with minimum cost.” 
 

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