The Central Terminal Expansion added approximately 115,000 square feet to the airport terminal. Terracon's Redmond office (formerly AMEC) provided both on-call and resident inspection and testing services for the expansion of the Sea-Tac International Airport. Staffing required two full-time resident inspectors with up to six support inspectors assigned periodically as needed on an on-call basis. Terracon's scope of work included all of the typical Special Inspections and testing for items such as foundation installations, concrete, masonry, structural steel fabrication, erection, welding and bolting, fireproofing, and shotcrete. Work on this project required security clearances and special safety training due to ongoing airport operations, confined spaces, and difficult access work areas. Additionally, construction often occurred 24 hours a day and required staffing during "swing" and "night" shifts.