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SR 520 – Montlake Project – Noise and vibrations

Noise and vibrations

WSDOT and Graham recognize that people living, working or traveling through a complex project are those most affected by the work. While some inconvenience from SR 520 construction is unavoidable, we strive to minimize effects on neighbors as much as possible.

Nighttime construction

Graham will perform nighttime work under a City of Seattle-approved Major Public Project Construction Noise Variance. The variance sets limits for nighttime construction noise for the duration of construction.

How are nighttime noise restrictions monitored and enforced?

  • Electronic noise meters record noise levels 24 hours per day.
  • Weekly and annual noise monitoring reports are provided to the Seattle Department of Construction and Inspections and are available to the public.
  • A WSDOT-assigned independent noise inspector is on site during all nighttime work to report any violations or neighborhood complaints to the Seattle Department of Construction and Inspections. Residents can report noise complaints to the 24-hour hotline: 206-775-8885.

How will crews reduce noise?

  • Strict noise restrictions on jackhammers and other impact equipment between 5 p.m. and 8 a.m.
  • Not allowing trucks to idle longer than a few minutes or to use unmuffled compression brakes.
  • Prohibiting pure-tone backup warning devices after 10 p.m.
  • Requiring the use of radios for long-range communications.
  • Designating haul routes that can reduce noise impacts caused by trucks.
  • Controlling noise at the source by using less noisy equipment and/or muffling the equipment.

Nighttime hours when variance is applicable:

Weekdays: 10 p.m. to 7 a.m.

Weekends and holidays: 10 p.m. to 9 a.m.

Construction vibration

Some residents in the Montlake and Madison Park neighborhoods may notice vibrations when crews perform certain work during Montlake Project construction.

Vibration monitoring

  • Graham has installed vibration monitors around Montlake and Madison Park. The vibration monitors provide Graham and WSDOT with data to track and monitor vibration levels.
  • WSDOT may provide home inspections to homeowners depending on location and nearby construction activities.

Vibration-producing equipment and activities

  • Vibratory and impact hammers used for pile installation and drilling shafts.
  • Hoe-rams and munchers used for structure removal.
  • Excavators used for digging and trenching.
  • Vibratory rollers used for paving.
  • Concrete and flatbed trucks.