INTRODUCTION
The purpose of this contract is to provide engineering and related services to King County
Department of Natural Resources and Parks, Solid Waste Division ("County") to develop design
documents, start the permit application, and provide engineering services during construction
for the Shoreline Recycling and Transfer Station (SRTS) Dust Collection Project.
The contract is anticipated to be phased as follows, as detailed below in the Scope of Work:
Phase 1: Planning and Predesign - anticipated duration 4 months
Phase 2: Final Design, Implementation, and Closeout - anticipated duration 16 months
This Scope of Work reflects the County's current understanding of the work; however, it may be
updated during negotiations.
PROJECT BACKGROUND
The Shoreline Recycling and Transfer Station (SRTS) is at 2300 North 165th Street in
Shoreline, WA. Available records indicate the original facility was constructed in 2009.
Supplemental changes including the addition of a dust capture hood above the west compactor
chute were done in 2011.
Previous work on this project involved the issuance of a Final Report dated October 25, 2019,
which proposed various solutions. The County has determined that the proposed solutions were
not feasible; therefore, the basis for this project will be to develop a new solution.
The dust collection systems consist of two cartridge type dust collection systems (AAF OptiFlo(R)
RC) with pulse jet cleaning rated at about 15,000 cubic feet per minute (CFM). Each collector is
coupled with a utility set type centrifugal fan that discharges the exhaust air through the roof. A
misting system also exists to promote the settling of the dust downward to reduce air-borne
dust. Dust is collected in 55-gallon drums below each dust collector (two drums per dust
collector, four drums total).
The original design of the dust collection system does not adequately capture fine airborne
dusts. The proximity of the misting nozzles below the dust collector air intake openings is too
close and the mist spray "short circuits" into the air intakes thus reducing the effectiveness of
the mist spray. The air intake openings have been blanked off at the east and west compactor
chutes, and the misting nozzles have been de-activated at the east compactor chute. A sheet
metal dust capture hood has been installed above the west compactor chute. However,
significant dust is by-passing the hood and settling on the mezzanine deck, the dust collection
equipment on the mezzanine, and the structural members and catwalks at the upper parts at the
south end of the facility. The east dust collection system has been deactivated so system is not
currently contributing to the dust control of the facility.
The existing dust collection system was designed to be operated from remote locations by
County staff using two dust collection systems on the mezzanine at the south end of the
receiving area. Operation of the system has been limited:
The dust collection intake opening above the east compactor chute has been blanked off thus
rendering the east dust collection system inoperable.
The 55-gallon drums located below each of the two dust collection systems are difficult and
unsafe to be emptied safely due to their locations on the mezzanine. So, the collection drums
are not being emptied regularly. This is limiting the operation of the west dust collection system.
.webp)
