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Millions of miles of aging water, wastewater and natural gas pipelines across the nation are at growing risk of failure, posing significant environmental, safety and financial challenges. Repairing these urban pipelines is often complicated and expensive due to their location beneath buildings and roads, but new repair solutions that significantly cut pipeline repair costs are emerging.

CU Boulder’s Center for Infrastructure, Energy, and Space Testing (CIEST) is at the forefront, pioneering testing procedures for these innovative solutions.

Led by Assistant Research Professor Brad Wham, CIEST played a key role in establishing a new standard for Internal Replacement Pipe (IRP) testing through the American Society for Testing and Materials (ASTM).

The work was made possible through a recently completed $7.8 million Department of Energy (ARPA-e) REPAIR project.

This advancement paves the way for industry approval of cutting-edge pipe repair technologies, such as using robots or other methods to install internal replacement pipes that line aging pipelines, reinforcing their walls and extending their service life.

“Getting an ASTM standard to vote is a big deal,” Wham said. “We designed these methods to serve a variety of industries as well as both current and future pipe replacement solutions. We have also developed unique physical testing capabilities that don’t exist anywhere else in the world.”

CU Boulder led the testing and analysis efforts and served as the primary experimental testing facility for evaluating various pipeline repair methods. CIEST researchers constructed three full-scale testing devices and developed models to predict potential failures in hard-to-reach replacement pipelines. By simulating real-world stresses—such as traffic loads and ground movement—they assessed how well these repair materials would perform over time.

The tests demonstrated that many of the internal replacement pipes effectively sealed holes, cracks and gaps, providing a lasting seal of 50 to 100 years at a cost of less than $1 million per mile—significantly lower than the approximately $10 million per mile it costs to dig up and replace pipes in urban centers.

In addition to a 90 percent drop in cost, the repairs will help reduce methane emissions from natural gas lines, which contribute to climate change, while also decreasing the risk of dangerous explosions from gas leaks. Additionally, they will prevent leaking water lines from wasting significant quantities of treated water and reduce the likelihood of potential contamination from external sources. 

Project collaborators on the grant include Cornell University, the University of Southern Queensland (USQ) and the Gas Technologies Institute (GTI). The USQ team used the data collected by CIEST to develop a publicly available app that can be downloaded and allows users to input material specifications, site information and other details to assess performance and design internal replacement pipe technologies.

“It essentially informs IRP developers what material characteristics and/or geometric properties they would need to survive our testing and extend their pipe service life,” Wham said.

50-year extension

Some municipal water lines stay in service for more than 100 years, so adding another 50 to 100 years through pipe lining technology is a significant advancement, allowing utilities to better manage their replacement schedule for aging infrastructure in a cost-effective way, said Dustin Quandt, an engineering project manager with CIEST.

“Fifty years is an important period of time,” Quandt said. “Because these technologies act as a new pipe with improved performance, utilities can fund these projects through capital improvements rather than maintenance budgets.”

Gaining industry confidence

Natural gas and water utilities have historically been reluctant to adopt new technologies, due to strict regulations and high risks in the event of failure, Wham said. To help address these concerns, the project has included representatives from major gas utilities and global experts to guide the development of testing and analysis techniques.

“By operating as a third-party, unbiased group, we are building confidence in the potential of these technologies to come forward,” he said. “We’re also fostering industry competition, which helps reduce costs.”

The center’s advancements in the natural gas sector have attracted the attention of the water industry, which is now considering adopting their proposed testing methods for pressurized water pipes.

Looking ahead

CIEST is examining pipes with bends and assessing the ability of these repair technologies and robots to navigate these additional geometries and hazards. Other future steps include evaluating these repair techniques under extreme conditions such as earthquakes, landslides, hurricanes and wildfires.

“While we made significant progress in the last few years, there’s a lot more work to be done in this growing industry,” he said.