Holocene has been supplying Geotechnical mud rotary drilling services to Skanska USA, Inc. since the beginning of the project. Most of our work has been done at night with rigorous traffic control. The I-405/Brickyard to SR 527 Improvement Project enhances four and a half miles of the corridor, primarily in Bothell, from just south of the State Route 522 interchange and ending at the SR 527 interchange. WSDOT, Sound Transit and design-build contractor Skanska USA Inc.