As part of the 17th Avenue Rebuild-Millikin Tunnel Repair project, it was critical to secure and repair the structural integrity of the Millikin utility tunnel. Support racks for various piping systems, including steam, condensate, and other water/utility lines, were to be repaired or replaced as part of the project scope. Abatement of asbestos containing pipe insulation on steam lines and abandoned piping, as well as decontamination of asbestos debris throughout the tunnel, was required. L&A, as the hazardous materials consultant for the project, reviewed historical documentation, visually assessed suspect asbestos-containing and other hazardous materials, procured bulk samples for laboratory analysis and prepared technical reports detailing types, quantities, locations, and cost estimates for abatement. Subsequently, asbestos abatement drawings, specification and bid documents were prepared. Challenges encountered during the design phase of the project included designing asbestos abatement of pipe insulation from active steam lines in a high temperature work environment. L&A worked closely with OSU EH&S to create an effective, yet safe, abatement design within the tunnel. Unique engineering controls, emergency evacuation procedures, heat stress monitoring procedures, and construction sequencing were developed to meet these challenges. L&A provided project oversight during all abatement activities to ensure contractor compliance with all applicable federal, state, and local regulations, as well as the OSU Building Design Standards and project specifications.