Case Study from Pasco, Washington, USA: Process Water Reuse Facility Industrial Symbiosis

The City of Pasco, WA, embarked on an ambitious project to modernize and expand its Process Water Reuse Facility, demonstrating an innovative approach to industrial symbiosis. This initiative aimed to tackle challenges posed by aging infrastructure, system inefficiencies, and the increasing demands of the food processing industry. With a total investment of $137 million, the project set out to treat 2 billion gallons per year of industrial wastewater from seven major food processors, transforming waste into valuable resources while supporting economic growth and sustainability.

Start and Expansion: In 2023, Pasco initiated a significant modernization and expansion of its wastewater treatment facility. The project was designed to address the facility's incapacity to handle projected increases in nitrogen loads resulting from the growth of the food processing industry. Recognizing the limitations of traditional solutions, Pasco Public Works innovated a symbiotic network of solutions to extract value from waste, reduce fossil fuel reliance, and facilitate the creation of hundreds of jobs.

Sustainable Practices: The Pasco Process Water Reuse Facility incorporates several key practices of industrial symbiosis:

• Methane Capture for Renewable Natural Gas: By introducing Low Rate Anaerobic Digesters, the facility captures methane gas from food processing wastewater. This gas is then converted into renewable natural gas, providing a sustainable energy source.

• Irrigation with Pre-Treated Water: Close to 1.5 billion gallons per year of pre-treated water, containing some nitrogen, is utilized for crop irrigation. This practice reduces the need for synthetic fertilizers, benefiting farmers and the environment alike.

• Algae-Based Nitrogen Removal and Fertilizer Production: A biological, low-energy nitrogen removal system employs algae, which not only cleans the water but also results in the production of an algae-based fertilizer. This marketable product offers an innovative solution to nutrient management.

Interesting Fact: The project has led to the creation of over 300 full-time jobs due to the facility's year-round capacity for food processing, in addition to construction jobs. This significant job creation underscores the project's role in bolstering the local economy while advancing sustainable practices.

Continuous Management: The management of the Pasco Process Water Reuse Facility involves ongoing efforts to enhance efficiency, reduce energy demand, and explore new avenues for waste-to-value conversion. The city's commitment to data analysis, collaborative innovation, and attracting funding showcases a proactive approach to managing and expanding the project's sustainability impacts.

The Pasco Process Water Reuse Facility stands as a beacon of industrial symbiosis, demonstrating how waste streams can be transformed into valuable resources. Through methane capture, nutrient recycling, and algae-based solutions, Pasco not only addresses environmental challenges but also fosters economic growth and sustainability.

SOURCES:

Roth, R., M.P. Wolcott, G.G. Yorgey, J.L. Male, T. Sturdevant, D. Camenzind, F. Pierobon, J. Padowski, C.E. Kruger, A. Whittemore, T. Carroll, K. Jensen, S. Moddemeyer, and A. Ybarra. 2023. Increasing the Economic Value and Sustainability of Washington’s Agricultural Sector through Industrial Symbiosis: A report to the Washington Legislature. WSU Center for Sustaining Agriculture and Natural Resources, WSU Institute for Northwest Energy Futures, Richland, WA.

[87] Nature Energy. (n.d.). About us. Retrieved April 23, 2024, from https://nature-energy.com/about-us/nature-energy