Principal Engineering, Inc.

08/19/2026

Principal Engineering, Inc. is a SDVOSB – What does that mean?

SDVOSB stands for Service-Disabled Veteran Owned Small Business. It is an SBA federal designation for small businesses that are majority owned and controlled by one or more service-disabled veterans.

Principal Engineering is an SBA Certified SDVOSB, a firm led by two military veterans. Our President, Henry DiFranco, PE and our Vice-President, Andre Monnot, PE both served our country as military engineers.

And it puts Principal in an exclusive group: less than 10% of engineering firms nationwide are SDVOSBs.

For Principal Engineering, the designation represents more than contracting eligibility. The values behind military service, including leadership, accountability, discipline, and commitment to the mission, are values we bring to every project.

08/17/2026

Please join us in welcoming two new team members to Principal Engineering!

We’re excited to welcome Sutton and Lacie to the Principal team as we continue to grow and strengthen our engineering capabilities.

Sutton is a 2024 graduate of LSU, where she earned her Bachelor of Science in Civil Engineering (BSCE).

Lacie is a 2018 graduate of Louisiana Tech University, where she earned her Bachelor of Science in Engineering. We’re also proud to congratulate Lacie on recently earning her Engineer Intern (EI) certification, an important milestone in her engineering career!

Principal Engineering President Henry DiFranco and our entire team are thrilled to have both Sutton and Lacie on board and look forward to the talent, energy, and experience they’ll bring to Principal Engineering.

Welcome to the team, Sutton and Lacie!

08/13/2026

Principal Engineering, Inc. wants to thank our student summer interns for their work this summer: Michael O'Conner, an Engineering student at LSU New Orleans (LSUNO), and Samuel Arnold, an Engineering student at the University of Louisiana at Lafayette (UL Lafayette).

Michael and Samuel worked alongside our team of professional engineers on the design of a new surface water treatment plant and a parish-wide master drainage plan where they assisted in the development of the Hydrologic and Hydraulic (H&H) model to analyze the existing conditions.

"Michael and Samuel put in real work this summer and it showed," said Henry DiFranco, Jr., PE, Retired Air Force Lt Colonel and President of Principal Engineering, and Andre Monnot, PE, Vice President. "We appreciate everything they brought to the team, and we wish them good luck in their studies in the upcoming semester.”

Michael, Samuel, thank you for your efforts over the past two months.

07/05/2026

Happy 250th Independence Day from Principal Engineering!

05/25/2026

This Memorial Day, we pause to honor the brave men and women who made the ultimate sacrifice for our country and our freedom.

Today, we remember them — and thank those who gave all. 🇺🇸

05/18/2026

Principal Engineering, Inc. is proud to have provided professional engineering and architectural services for the new St. Bernard Parish Sheriff’s Office Warehouse and Office project in Chalmette.

This new facility gives the Sheriff’s Office expanded operational space to better support its staff, equipment, and day-to-day public safety needs. Our team was honored to help bring the project from design through completion, working alongside the St. Bernard Parish Sheriff’s Office to deliver a functional, durable facility built to serve the parish for years to come.

01/01/2026

12/02/2025

Project Spotlight: Causeway/Central Sewer Upgrades - Mandeville

For years, the Causeway/Central intersection in Mandeville was known for one thing: the smell.

The issue came from the former sewer pump station at that location, which received flow from multiple upstream force mains across the city.

Principal Engineering worked with the City of Mandeville to eliminate the pump station entirely and replace it with a manifold system. We developed a detailed pressure-pipe model to determine how to upgrade several upstream pump stations so that flow could bypass the old site and go directly to the Mandeville Wastewater Treatment Plant.

With the aged sewer no longer collecting at this intersection, the long-standing odor problem was resolved.

We appreciate the City of Mandeville for trusting us with this important improvement for their residents and visitors.