The SR 509, I-5 to 24th Avenue S. Expressway Project, part of the SR 509 Completion Project, will extend SR 509 to I-5 in SeaTac, providing a new southern route to Sea-Tac International Airport. This extension will allow drivers to avoid I-5, SR 518, and local streets. This extension will improve airport access and reduce freight traffic on local roads. Along with the SR 99 tunnel improvements, it will create a crucial north-south alternative to I-5 through Seattle and King County.
PACE provides stormwater engineering services, including enhanced runoff treatment, flow control, conveyance, and inspection of existing stormwater systems, as well as managing temporary erosion and sediment control and drainage during construction.
