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Hazel Dell Water Quality Retrofit

Vancouver, Washington

Stormwater Treatment


Clark County 


Clark County Design Engineers 


Clark & Son Excavating 


Winter 2022-2023

Technical Description:

  • Stormwater Management StormFilter® Vault
  • Stormwater Management StormFilter® Catch Basins

In the summer of 2022, Clark County Public Works initiated a project aimed at enhancing the stormwater system along Hazel Dell Avenue, spanning from Northeast 83rd Street to Northeast 86th Street in Vancouver, Washington. This strategic undertaking aligns with the County's commitment to advancing surface water quality, promoting both human and environmental health in the present and safeguarding these benefits for future generations.

The project's focal points include two stormwater treatment basins and a vault designed to improve water quality in Cougar Creek. The necessity to capture and treat stormwater runoff from Hazel Dell Ave underscored the suitability of Contech systems, especially given the challenging landscape with curb-tight sidewalks that rendered a conventional LID treatment approach unfeasible.

The water quality standards of the County required a system with GULD approval through the Washington Department of Ecology for Basic treatment. The County's Clean Water Fund and a WADOE grant provided financial backing for this endeavor, with the total construction cost amounting to $525,000.

The selection of StormFilters was deliberate, guided by their compatibility with site constraints, specifically the curb-tight sidewalks. Clark County's preference for cartridge filters and the design support extended by the local Contech design team further justified this choice. Contech played a pivotal role by offering design assistance, crafting site-specific system drawings, and providing custom access design support, ensuring the precise placement of access castings in the roadway.

Within the 8'x11' StormFilter vault, 26 cartridges filled with ZPG™ media – a proprietary blend of zeolite, perlite, and granular activated carbon – were strategically employed to enhance perlite performance and target organics, soluble metals, and other pollutants. The vault's design incorporated two 36" access castings, in line with the County maintenance department's specifications, and their placement was crucial to prevent conflicts with the curb line.

Despite a delay in the vault installation related to the knockout locations on the top slab, Contech swiftly addressed the issue by constructing a new top slab. This proactive resolution ensured that construction resumed promptly, culminating in the project's completion without any further setbacks.

Technical Description:

  • Stormwater Management StormFilter® Vault
  • Stormwater Management StormFilter® Catch Basins

800-338-1122 |
Project #: 679,523


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