Loud 'Jet Engine Sound' From Construction Expected Near Downtown Bellevue Thursday Afternoon

A loud noise described as rushing air or a jet engine noise might be heard throughout downtown Bellevue between 1 and 2 p.m. today (Feb. 3) as construction crews work on a natural gas line, according to the Bellevue Fire Department.

Pilchuck Contractors will be conducting natural gas line work in the area of NE 12th St and 112th Ave NE on Feb. 3, according to the fire department.  The actual work is expected to take place between 1 p.m. and 2 p.m., but could start as early as noon or end as late as 3 p.m., the fire department reported.

The contractors will test, purge and then place the in-service of a newly installed natural gas main.

The purging process is the loudest for people who happen to be in the area at the time, according to the memo from the fire department. Compressed air that is testing the strength of the new main will be released, and the contractor expects a lot of noise from the process. It can best be described as loud, rushing air, or jet-engine sound.

The air is not natural gas; simply compressed air, the fire department reported. So, it is neither dangerous nor flammable.

The gas line will then be filled with inert nitrogen gas, then filled with natural gas and placed in service. Some of the nitrogen gas may be purged as well. There may be some natural gas smell, but it will not be flammable nor dangerous.

This work is being done in association with the Interstate 405/State Route 520 braid project and the replacement of the NE 12th overpass.

--- Information from the Bellevue Fire Department