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Chehalis Wastewater Treatment Plant

W. H. Reilly & Co. assists in development of new Chehalis wastewater treatment plant

Gibbs & Olson, Inc., a Washington-based civil engineering firm, relied on Wm. H. Reilly & Company to supply equipment and provide ongoing support for the design and construction of a new wastewater treatment plant for the city of Chehalis.

Reilly supplied the primary biological process systems and many of the major treatment plant components, including:

  • A Siemens/Jet Tech three-tank sequencing batch reactor (SBR) system, which was selected over technologies that utilized fine-bubble diffusers and floating mixers.
  • A Parkson/Dynasand tertiary filter system, an innovative upflow continuous backwashing sand-filter, with a strong, proven track record.
  • An RDP EnVessel pasteurization system, in which dewatered sludge is blended with lime and heated, creating an end product that meets Class A biosolids standards. These biosolids are virtually pathogen free and may be applied to land in the same way as commercial fertilizer.

Reilly also supplied a Siemens/RJ Environmental odor control system, Swaby lobe pumps, and a Siemens/Stranco polymer system.

A careful, thorough selection process

The wastewater treatment plant equipment was selected after thorough present-worth analyses that took into account capital costs, low long-term operating costs, and durability. Plant operators also played a significant role in selecting the appropriate equipment.

The new plant is capable of treating up to 3.5 mgd of wastewater to Class A reclaimed water for irrigation and groundwater augmentation and up to 13 mgd to secondary treatment standards for discharge to the Chehalis River.

Initial planning for the plant began more than a decade ago; Reilly was brought onto the project in 2002. The facility was completed in October 2007 and has performed admirably. The plant was constructed above the Chehalis River floodplain and remained fully operational during floods in December 2007 and January 2009.

Reilly rated a 9 on a 10-point scale

Patrick Wiltzius, wastewater superintendent for the city of Chehalis, says, “Reilly is far better than a lot of other equipment suppliers we deal with. If I have to go to anyone, I trust Reilly.

Tom Gower, Gibbs & Olson project engineer, says, “We’ve established a relationship with Reilly over the years on a number of projects, and having that relationship makes it nice. We call them, they know us, and they’re able to pick right up on things. They assisted us throughout the project start-up phase. They also worked with us during the design phase.

“Their follow-up and responsiveness is very good.”

“On a scale of 1 to 10, I’d rate Reilly a 9,” says Mike Marshall, Gibbs & Olson project manager. “We can always call on them whenever we have issues. When we’re facing a problem, they have many products and technologies to help us with.”

Gibbs & Olson earns statewide award

Gibbs & Olson maintains offices in Longview and Olympia, and provides clients in western Washington and northern Oregon with civil engineering, land surveying, and planning services. The company was honored with an award–best in state for exceeding client expectations—for its work on the Chehalis wastewater treatment plant.

Gibbs & Olson was established in 1950 and has a long history of improving quality of life and promoting economic development through the planning and provision of essential infrastructure.

Pond and mini-waterfall grace front entrance gate.

Aerial view of plant from the west; I-5 is in background.

Sequencing batch reactor (SBR) basin #3 with aeration blowers operating.

RDP EnVessel pasteurization system in development, prior to wall construction.

Upper left: Conveyor belt of RDP EnVessel pasteurization system.

RV building, chemical feed building, and sludge holding tank under construction.

Sequencing batch reactor (SBR) basin wall under construction.

Sequencing batch reactor (SBR) basin under construction.

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