Engineering Out Legionella: Foundations and Design Responsibility
Thursday, May 28, 2026
12:00 - 1:00pm CDT
Technical Content Level: Intermediate
Legionella risk is strongly influenced by plumbing system design decisions made early in a project, often before construction or operation is considered. This session serves as the first in a three‑part series focused on how engineers can proactively engineer out Legionella risk during the design phase.
Christoph Lohr, P.E. will introduce core design concepts drawn from the ASPE Legionella Design Guide and current industry guidance, with an emphasis on system volume, temperature control, flow, and circulation strategies. The session will also include live audience survey questions to better understand current design practices and challenges. Results from these surveys will help shape the focus and depth of the subsequent sessions in the series.
→ Describe the engineer’s professional responsibility for controlling Legionella risk at the design stage, recognizing how early plumbing system decisions shape long‑term public health outcomes and project liability.
→ Evaluate advanced plumbing design strategies for Legionella risk reduction—including system volume minimization, temperature control, flow regimes, and circulation design—using principles drawn from the ASPE Legionella Design Guide and current industry guidance, rather than introductory microbiology concepts.
→ Critically analyze common plumbing design practices through a risk‑based lens, identifying where seemingly standard engineering choices may unintentionally increase Legionella risk due to incomplete application of water systems guidance.
→ Examine the professional and legal risk to engineering firms associated with undervaluing plumbing system design.
Christoph Lohr, P.E. is the IAPMO Vice President of Technical Services and Research. As part of his duties he provides industry leadership through participation in strategic industry initiatives, and provides technical support to all IAPMO’s business units as needed. Christoph has over a decade of experience in designing plumbing systems and has a reputation as a results-oriented expert, particularly in the realm of balancing waterborne pathogen prevention and water sustainability. He is a distinguished graduate from the Virginia Military Institute, with a Bachelor of Science in Mechanical Engineering.
