Utility Master Plan/Franklin Heating Station Updates

The Franklin Heating Station — the power behind the Mayo Clinic’s reliable daily operations — was due for an upgrade to continue delivering the optimal utility service it’s known for.

Detailed permits and a phased construction schedule for new boilers and a centralized control room are paving the way for efficient project execution while maintaining full hospital operations and, in turn, world-class care.

Looking to modernize its operations, the Mayo Clinic in Rochester, Minnesota, hired our team to draw up a robust utility master plan that included an upgrade to its Franklin Heating Station (FHS). Originally built in 1928, FHS has long been providing steam, chilled water and electricity to the downtown Rochester campus. Currently, the FHS is equipped with four 50-year-old steam boilers that range in size from 70,000 to 120,000 pounds per hour (PPH) of capacity with pressure/temperature conditions of 400 psi/750°F and 850 psi/900°F. But for the plant to remain reliable, Mayo Clinic officials opted for the replacement of all boilers and centralization of the facility’s control rooms, merging the two into one.

Our team led the clinic through the entire permitting process to obtain the required Prevention of Significant Deterioration (PSD) minor amendment permit, issued by the Minnesota Pollution Control Agency (MPCA). The permit needed to state that Mayo Clinic could provide maximum operating flexibility while also maintaining continuous reliable power throughout construction. To put that language into practice, we performed a PSD netting analysis for each boiler replacement, which examined multiple upgrade options and identified permit requirements for each unit. Our team determined that three 120,000 PPH boilers at 850 psi/900°F steam conditions — one field erected, two packaged — would fit within the existing space, replaced seamlessly using a phasing construction plan. Clinic officials agreed.


Mayo Clinic


Rochester, Minnesota




Campus Energy

Distributed Energy Resources


Commercial, Retail & Institutional




PPH boilers



steam conditions




To maximize the plant’s operational flexibility while still adhering to regulatory requirements, we also incorporated language about a predictive emission monitoring system (PEMS) within the permit. A software-based solution, PEMS provides reliable and accurate real-time emission estimations. Studies show it’s also less costly and less time-consuming than a continuous emission monitoring system (CEMS), which requires additional staff and consistent management.

With a solid master plan in the works and approved permits in hand, our team performed a schematic design to confirm the maximum steam capacity, define the sequence and phasing of the boiler replacements, and develop a project scope to determine overall costs. Including equipment shutdown and startup timing in the permit highlighted the plant’s capability to properly maintain day-to-day functions and operations during construction — a necessity for Mayo Clinic staff.

Next steps on the project.

Following the design of the boiler replacement, Mayo Clinic retained our team to design the replacement of two existing emergency diesel-fueled generators with three.