• April 17, 2026

April 17, 2026

Every project leaves an impression, but for Chris Williams, Vice President of Operations, one build stands above the rest. Though his career has spanned many successful endeavors, the New Irvington Tunnel in San Francisco, California remains a defining moment of technical challenge and professional growth. The project was essential to protect the water supply for 2.6 million residents against seismic disruption. Chris noted “the complexity was increased as the tunneling aspect was a new frontier at that time, and the project required navigating the unique dynamics of the union environment.” Ultimately, this project reinforced the importance of bringing a team together for a unified purpose, ensuring that even the most complex infrastructure can be delivered safely and successfully.

A Project of Unmatched Complexity

The New Irvington Tunnel project brought together a wide range of challenging technical elements:

• Excavation of a 3.5-mile tunnel using roadheader and drill-and-blast methods between 30 to 700 feet below ground
• Construction of a 41-foot diameter, 115-foot deep temporary access shaft along Vargas Road
• Installation of a 102-inch welded steel pipe lined with low-density cellular concrete
• Extensive dewatering and reinforcement to manage heavy groundwater inflows reaching 1,200 GPM

Engineering in Extreme Conditions

What made the project truly memorable wasn’t just its scale, but the precision required to build through complex fault zones. In lieu of a traditional tunnel boring machine, the team utilized roadheader and drill-and-blast methods to manage the squeezing ground associated with these fault zones.

The environment demanded constant awareness, particularly when the site was classified as a “gassy tunnel” due to methane pockets. Chris recalls that construction operations had to change radically once the gas was discovered. Specialized equipment with modified ignitions had to be brought in, and airflow monitoring was dramatically increased. The team even had to install safety chambers and utilize specialized electrical cables designed to prevent any possibility of a spark, even while crews were welding in the tunnel.

Rising to the Challenge

Chris is especially proud of how the team navigated these geological obstacles while maintaining a perfect focus on safety. “Working inside, along with the team to solve a dangerous problem, and doing it successfully and safely, was an incredible achievement,” Chris shared. He believes that the pressure of the project provided the perfect environment for development.

Lessons That Last

Working on a build of this magnitude continued to shape Chris’ leadership philosophy, which centers on team unity and operational support. During the project, he was responsible for overseeing daily operations, a role that required a deep understanding of the project’s grand scope. “My skill set is understanding the grand scope of what we’re doing and supporting the men and women that we have on the project,” Chris said. The experience of leading a large group for a unified purpose allowed him to learn lasting lessons on how to bring a team together.