SR 520 Bridge Replacement and HOV Program, Seattle, WA
ATS is a subconsultant for several projects related to the SR 520 Program in Washington State. As part of the Evergreen Floating Bridge and Landings Project ATS is preparing noise and vibration monitoring and mitigation plans that will meet the requirements of the Programmatic Agreement between WSDOT and a number of stakeholders who represent the historic properties and districts in the study area. The plans will include predictions of noise and vibration levels during construction at historic properties and non-historic residences, mitigation measures to minimize the potential impacts during construction and minimize the risk of damage to historic and other properties during construction. The construction of the western approach of the SR 520 replacement bridge and its effects on the National Oceanographic and Atmospheric Administration (NOAA) Northwest Fisheries Science Center (NWFSC) has been studied by ATS senior staff. NOAA’s concerns are: damage risk to NWFSC buildings and fish lab structures during pile driving and bridge demolition; interference with research activities, and human annoyance.