AEG staff provided professional design services for Chicago Department of Aviation’s O’Hare Modernization Program and Northwest Suburban Municipal Joint Action Water Agency (NSMJAWA). A final design package for the OMP’s Site Preparation / 90-inch Water Transmission Main Relocation was prepared to avoid the new Runway 9L-27R project without interruption of customer service (the existing watermain served seven communities with a population of 315,000 people). The existing 90-inch water transmission main operated by NSMJAWA ran directly beneath Runway 18L/36R and conflicted with proposed airport improvements. The existing line accommodated up to 90 million gal per day at 165 psi. The conceptual design of the project included the construction of approximately 11,000 linear feet of 90-inch water main at a cost of $16.3 million. Key responsibilities as Water Transmission Main Designer, included managing design plans and specifications, preparation and determined hot tap locations as part of the $40 million project, relocating approximately 9,000 feet of the NSMJAWA 90-inch water main. Additional project tasks included designing 48-inch temporary bypass lines 3,500 feet and 1,600 feet in length to reduce the amount of new 90-inch water main installation by approximately 50 percent, and initiating revisions to the master schedule for airport expansion. Based on creative design solutions the construction cost of the 90-inch water main relocation project from $29.2 million to $16.3 million for a savings of $12.9 million.