Case study: From waste to water — reclaiming COW water through a Romtec pumping system

In 2021, a farmer-owned dairy invested $1 billion to construct a state-of-the-art dairy processing plant in Pasco, Washington. The project included multiple sustainability goals, including reusing water byproduct from dairy processing — specifically condensate of whey (COW) water.

Romtec Utilities played a critical role by designing and supplying a reclaimed water pump system that supports the recovery and reuse of this valuable resource. The new pump system will be part of the City of Pasco’s Process Water Reuse Facility (PWRF).

Challenge: Managing and reusing agricultural process water

Because milk is 90% water, dairy processing creates a significant amount of wastewater.

The dairy processing facility in Pasco is designed to process up to 8 million pounds of milk per day, presenting both a significant water management challenge and a major sustainability opportunity.

COW water can be reused for non-potable purposes if treated properly. A dairy plant that produces 50,000 pounds of cheese requires 500,000 pounds of raw milk and generates over 50,000 gallons of COW water a day.

Solution: Engineered pumping system for COW water reuse

Romtec Utilities engineered and supplied a packaged lift station for PWRF which is critical in transporting COW and other process water for advanced treatment and eventual reuse. The system transports reclaimed process water from two on-site storage ponds to hydrants where it will be used for cleaning.

The system features:

1. Pressure-based operation: Pumps are operating according to incoming flow rates to maintain system efficiency.
2. Capacity: The system is designed to pump up to 600 gallons per minute.
3. Controls: A pressure transmitter sends signals to variable frequency drives, adjusting pump speeds to maintain desired pressure.
4. Pumps: Two Goulds L Series Model 320L, 11-stage, 40 horsepower explosion-proof submersible pumps.
5. Redundancy and safety: All level settings and alarms are set below the lift station’s invert-in elevation for added protection.

The PWRF owns and operates the new lift station. The facility is dedicated to the treatment of process water collected from local fruit, vegetable and dairy processors. PWRF is a pretreatment and storage facility, as well as a land treatment system, and operates under a discharge permit from the Washington Department of Ecology.

Partners: Tapani and RH2 Engineering

Tapani, a family-owned civil and utility infrastructure contractor in the Pacific Northwest, completed the installation of the lift station. Tapani has worked with Rotmec Utilities on several past projects and appreciates the clear communication and efficiency of the packaged system.

“I’m an avid communicator, and there was communication throughout the process which makes it easier,” said Benji Tapani, who began as project manager and later served as general superintendent on the project. “One minute of pre-planning saves six minutes in the field.”

The installation required unusually deep placement to accommodate piping that travel underground to the ponds and the reuse facility. Thanks to detailed pre-construction planning and Romtec’s coordinated design process, installation was seamless.

“The (Romtec Utilities) design team talked about the parts we were going to receive pre-construction,” Tapani said. “When the parts showed up it all made sense.”

RH2 Engineering designed and provided the controls for the lift station. The engineering firm had also previously collaborated with Romtec on projects.

Sustainability and impact

The reuse of COW water reduces the facility’s freshwater demand and minimizes the volume of wastewater sent to treatment. This aligns with the dairy’s broader sustainability goals, which include:

1. A partnership with the City of Pasco to expand its PWRF, including an anaerobic digester, allowing responsible treatment and reuse of agricultural wastewater.
2. Low-emission burner technology in milk dryers to significantly reduce nitrogen oxide emissions.
3. Reduce transportation emissions by choosing a strategic location within the Port of Pasco and close to member farms, creating transportation efficiencies and reducing logistics-related emissions.

The new plant opened June 3, 2025. The Pasco, Washington, plant would process up to 8 million pounds of milk per day from more than 100 regional farms. It is expected to employ nearly 200 people directly and provide 1,000 jobs in total to the area in transportation, warehousing, and farming.

Conclusion

With the help of the custom-designed pumping system, the City of Pasco and the dairy processing facility are able to take a big step toward sustainable dairy processing by converting a once-overlooked byproduct into a valuable water source. This project highlights how public infrastructure investment can power economic development and environmental responsibility.