Northeast 120th Street Surface Water Quality Treatment

Submissions closed on January 01, 0001, 12:00 AM

  • Project typeSurface Water
  • Project value800,000
  • Project scheduleJune 2021-February 2022
  • Contractor nameAccord Contractors

Map of the NE 120th Street Water Quality Project between slater and 132nd Ave NE

Six locations on the hill by Lake Washington Technical Institute will be replaced, cleaning surface water before it gets to Totem Lake, Juanita Creek, and Lake Washington.

Council Goals 

This project supports Council Goal #8: Financial Stability, Council Goal #9: Sustainable Environment, and Council Goal #11: Dependable Infrastructure.

Project Intent 

Treating nearly 4 acres of residential and commercial properties ( or 1.87 acres of pollution collecting impervious surface), and ranking fourth of twenty-two priority projects to improve the quality of storm water runoff in this area, the Northeast 120th Street Water Quality Treatment project gets underway shortly.

Six drains on the shoulder of the roadway will be replaced with basic engineering structures that provide enhanced reduction of sediment prior to discharge into Totem Lake.

Project Impact

The project is expected to begin in late July, with 45 days contracted for project completion.  Work will occur on weekdays, and no night work is expected. The bike lane will be impacted during construction on this steep hill but no lane closures are expected.

 Technical Description

The Project includes the installation of six water quality structures to provide water quality treatment for approximately four acres of previously untreated basin area. Runoff treatment and volume reductions from the proposed water quality treatment will improve dissolved oxygen levels; remove total suspended solids and metals (such as copper and zinc); and help reduce damaging peak flow conditions and durations from small storm events that contribute to erosion, sedimentation, and impacts to salmonids and other aquatic organisms.  This is particularly beneficial to Juanita Creek because it is on the Washington State Department of Ecology’s (DOE’s) list to improve dissolved oxygen and bacteria impairments.  These Project improvements will increase Benthic Index of Biotic Integrity (B-IBI) scores in Juanita Creek and improve creek health.



13000 120th lane,  98034  View Map

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