TD&H provided civil and structural engineering services for expansions as part of the Mobile Source Air Toxins Project at the Montana Refining Company’s Petrochemical Facility. Structural steel framing was designed for new pipe racks and equipment, as well as large foundation systems for process towers, heater units, pressure vessels, elevated fin-fans, and other systems. The project was fast paced and required working closely with the owner and contractor to address conflicts with existing equipment and structures that were discovered both during the design and construction phases. Major aspects of the project included stormwater control systems, fire suppression systems, concrete containment systems, and foundation design for 2 108’ tall process towers, 2 60’ vertical heaters, several pump and exchanger units, structural steel pipe rack and equipment platforms, and elevated vertical pressure vessels. The project included structural steel design for 250 lineal feet of multi-level pipe rack design, including a 44’ pipe bridge to span over existing equipment, a multi-level equipment platform with a fin-fan unit supported approximately 22’ above grade, and the expansion of an elevated fin-fan platform to support an additional fin-fan and an exchanger unit.