Safeguarding the Snake River with ProFlex™ Check Valves

Duckbill check valves from Proco Products drive Ontario, Oregon’s upgraded wastewater diffuser system

Snake River, Oregon - Map

Snake River, Oregon – Map

As the Snake River meanders more than 1,000 miles across the U.S. Pacific Northwest, its westward surge that separates Oregon from Idaho passes a crucial milestone: The City of Ontario. Ontario, located in eastern Oregon’s Malheur County, operates a roughly 2-mgd wastewater treatment plant that discharges into the Snake River.

Like many wastewater plants of its size and setting, the Ontario facility operates a lagoon-based system for its effluent discharges. In recent years, as Ontario’s population continues to grow and as environmental regulations become stricter, the treatment facility must more efficiently mix and dilute its effluent due to the amount of ammonia that leaves the facility and enters the Snake River. For that reason, the facility sought to upgrade its existing, single-port outfall with a focus on efficient river mixing to ensure continued compliance with regulatory standards.

Proco Products, Inc., in cooperation with CONSOR Engineers, LLC, and Ballard Marine Construction, answered the call by developing an innovative, multi-port diffuser system for Ontario that capitalizes on Proco’s ProFlex™ Style 710-E Flanged Duckbill Check Valves. The new system began operations on November 1, 2023.

An Improved Mixing Solution for the Snake River

To design an optimal diffuser system for the facility’s specific needs, the project team first had to understand the site’s unique hydrological conditions. MixZon, Inc., an Oregon-based environmental services consultant who specializes in modeling mixing zones, created a state-of-the-art model of the Ontario plant’s effluent discharge point and the resulting interplay with the Snake River to guide the design process.

CONSOR worked alongside MixZon to develop a range of design alternatives according to the model’s insights that would include a series of diffusers to maximize the mixing area within the Snake River without significantly adding to the footprint of the existing outfall. These variations differed in the number of diffusers as well as their size, arrangement, and — importantly — the types of valves affixed on their tips.

The system they ultimately developed features nine diffuser ports evenly arranged along a 31-ft-long stretch of high-density polyethylene pipe running from the treatment plant beneath the surface of the river. With the facility’s previous outfall, treated effluent flowed through a single, 24-inch-wide pipe. The new system instead diffuses effluent through the nine, 8-inch-wide ports at a high velocity, encouraging mixing in the river and thereby minimizing the effects of ammonia.

Snake River wastewater diffuser system, Ontario facility

Snake River wastewater diffuser system, Ontario facility

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