Project Description

BNSF Railway, Seattle, WA

BNSF Railway operates their South Seattle Hub, a large truck/rail trans-loading facility, in Seattle. The South Seattle Hub site has three drainage subbasins, two of which required stormwater treatment for total suspended solids (TSS), copper, zinc and turbidity. BNSF Railway contacted StormwateRx for treatment support at this facility following a successful installation of a StormwateRx treatment system at another BNSF intermodal facility in Tacoma, Washington.

TARGETED POLLUTANT: copper, zinc, TSS and turbidity


zinc b gone stormwater treatment


IEA Engineering, Science & Technology designed a stormwater treatment retrofit system that included conveyance modifications, bypass pump stations, and Aquip enhanced stormwater filters.  Each of the two 10-acre subbasins requiring industrial stormwater treatment will be managed by a simple pump station and an Aquip 400SBE enhanced stormwater filtration system.

Project Design Parameters

  • Industrial Process: Container handling with top loaders, for loading/unloading containers from rail cars and trucks. Facility includes a maintenance shop and administrative offices.
  • Drainage Characteristics: Each of the two drainage subbasins requiring industrial stormwater treatment is 10-acres. The facility is 100% impervious with the exception of office track ballast areas and administrative landscaping.
  • Treatment Characteristics: Treatment sizing meets the Western Washington Hydrology Model stormwater sizing method that diverts approximately 91% of the annual average runoff volume through treatment.


100% compliance to date following completion of construction activities.