Design Center mobile

209th Avenue Improvement Project

Hillsboro, Oregon

Stormwater Treatment


Washington County, Oregon


HDR – Portland


GoodFellow Construction 


April, 2022

Technical Description:

Stormwater Management StormFilter®

In the spring of 2022, the City of Hillsboro, Oregon, began a massive reconstruction project of 209th Avenue between Alexander Street and Blanton Street.

The project included widening 209th Avenue to five lanes, upgrading crossings at railroad tracks, adding bike lanes, and improving street lighting and sidewalks. It also included a new regional stormwater treatment facility and conveyance system. The total project construction cost was $23 million.

New stormwater management infrastructure was a requirement triggered by the newly added impervious surface area of the road widening portion of the project. Given the existing infrastructure, deep pipe, tight site lines, expanded roadway section, and close-in adjacent buildings, a conventional land-based approach was not feasible, making a buried water quality structure an ideal option.

The Stormwater Management StormFilter was specified based on on-site constraints, Washington County’s preference for Contech cartridge filters, and the design support provided by the local Contech design team on past projects.

The 8’x20’ StormFilter Vault contains 47 cartridges filled with ZPG™ media, a proprietary blend of zeolite, perlite, and GAC to improve the performance of perlite and target organics, soluble metals, and other pollutants.

Contech coordinated with the county maintenance team on access design and selected two 36”x72” hatches over the cartridge bay. The system was approved by the local stormwater regulatory agency, Clean Water Services.

Contech provided design assistance, site-specific system drawings, and custom access design guidance to ensure adequate openings for maintenance crews. The access design required a unique structural design for the top slab, which was coordinated by Contech and completed during the submittal drawing process.

Low power lines required a unique low-profile lowering crane device by Omega Morgan. A Contech Field Consultant was on site to help ensure a quick installation. 

Technical Description:

Stormwater Management StormFilter®


800-338-1122 |
Project #: 686,088


© 2023 Contech Engineered Solutions LLC, a QUIKRETE Company