Wilsonville Wastewater Treatment Plant

The Wilsonville Wastewater Treatment Plant improvement project replaced old equipment and structures, incorporated new technology, and addressed odor issues. The upgrade met current and future capacity needs while ensuring compliance with current & future regulatory requirements. The wastewater plant was also converted from a liquid bio-solids by-product to a more easily managed solid biosolid by-product.

The City of Wilsonville entered into a long-term contract with CH2M Hill to design, build and operate the wastewater treatment plant for a 15-year period. Design of the improvements were completed in the Spring of 2012. Construction was completed two years later in February 2014.

Wastewater Treatment Odor

In the treatment of wastewater, odor control was a key project goal. Approximately $1.4 million of construction cost is specific to odor control. The contract has an “odor guarantee” with specific penalties for violations.

After the upgrades the capacity will be approximately 4 MGDm which should be adequate to serve the city wastewater needs until approximately 2025, depending on flows. Additional features are being incorporated into the design to allow future expansion to 7 MGD – the projected “build out” capacity needed in year 2035.

The WWTP project received a 2014 National Award of Merit from Design-Build Institute of America in the field of water & wastewater.