Long-term night work to begin this spring at U District Station
Sound Transit's excavation and tunneling contractor expects to begin long-term nighttime work at the U District Station construction site as early as June 2015.
The nighttime work will be performed under the City of Seattle Department of Planning and Development's (DPD) Major Public Project Construction Variance (MPPCV) for the U District Station construction site. DPD approved the U District Station MPPCV on December 17, 2012 (DPD project number 3013261). The MPPCV for U District Station is approved for 30 months which will begin when the variance is formally activated by DPD.
City of Seattle's Noise Control Code typically limits work to daytime hours, defined as 7 a.m. to 10 p.m. on weekdays and 9 a.m. to 10 p.m. on weekends and holidays. The MPPCV allows the contractor to work during nighttime hours between 10 p.m. and 7 a.m. on weekdays and between 10 p.m. and 9 a.m. on weekends and holidays. The Noise Control Code limits high impact noise activities (such as jackhammering) to the hours between 8 a.m. and 5 p.m. on weekdays and 9 a.m. and 5 p.m. on weekends and holidays.
Activities and Equipment
The contractor will be performing construction activities to support building the underground light rail twin-bored tunnels between the future U District Station and the University of Washington Station. The extended work hours enable the contractor to perform work in a safe and efficient manner. Work may include, but not be limited to, these types of activities:
- Truck deliveries of concrete tunnel segments and other construction materialsHandling, hoisting, and hauling of dirt and materials
- Digging and excavating the future U District light rail station
- Tunneling activities, including boring the underground tunnels and installing tunnel infrastructure
- Operations of onsite equipment (e.g., generators, tunnel ventilation fans)
The majority of nighttime work will occur onsite within the project construction walls or underground within the tunnels.
Example equipment includes cranes, trucks, loaders, generators, concrete grout plant, and concrete trucks.
Minimizing Noise During Construction
Sound Transit works to minimize and mitigate noise during construction. This includes the use of a construction wall around the site, shrouding equipment to muffle noise, using broadband back-up alarms on construction vehicles, limiting idling of construction vehicles, monitoring noise equipment, and keeping noise-generating equipment in good working condition.