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City Soil Farm is a really unique project. It’s on the wastewater treatment plant’s facility. It uses renewable resources. It’s a community space where people can come and learn about how their food is grown, and taste the food, and take some food home.

City Soil Farm is a 1.5 acre demonstration farm located at the King County Wastewater Treatment Plant in Renton. It was once an unused area of the treatment plant’s grounds. It has been transformed into a teaching farm and native tree nursery that showcases sustainable farming and accessible, local food. The farm is managed in partnership between King County Wastewater Treatment Division, King Conservation District, DIRTCorps, and White Center Food Bank.


Our vision of the future is one where education leads to increased public-private partnerships, community participation and innovation, and ecologically and socially sustainable food systems.


CitySoil Farm is an urban space devoted to environmental education and resource recycling to promote community food systems with imagination. Our mission is to help people make informed decisions and develop innovative solutions for food challenges. We view ourselves as partners with our community and environment, providing a platform for shared knowledge, non-traditional land-use, and the art of salvage.

We practice more than just urban agriculture at CitySoil

We are taking on the challenge of restoring and rebuilding soil to produce food and educate people on an industrial site in an urban area. Our farm space is part of a sprawling 90-acre industrial utility that was built in the 1960's. In the last sixty years, the City of Renton has transitioned from a more rural-agricultural to a dense industrial suburban and partially urban area. Our shared land-use contract has enabled us to farm and give new life to a neglected soil's ecosystem.

At CitySoil, we can take advantage of resources recycled from our waste system with recycled water and compost made from Loop® biosolids.

King County cleans 175 million gallons of wastewater every day, in a process that mimics nature's biological processes. But King County does not just clean the water, it also recovers valuable, sustainable resources: Loop biosolids, biogas, and recycled water. By proximity, CitySoil has a great opportunity to use both compost made with Loop and recycled water. We promote conversations and awareness of both recycled water and biosolids products, encouraging people to ask hard questions and think about how we should manage our nutrient and waste streams.

Beyond water resources, we also acquire and salvage building and art materials from second hand stores, online advertising sites, and community members. We invest in sustainable resources and recycling so our demonstrations and workshops can be more easily replicated. Our collaboration with the community helps to share the value of these practices.

As it has for the past 40 years, King County cleans the water and produces Loop, a natural fertilizer and soil builder. Using Loop recycles the nutrients in our food back to the land, the same way nature does. Grounded in decades of research and rigorously tested, Loop is produced according to precise standards.

In addition to composting our own materials on-site at CitySoil, we have proudly used compost made with Loop for years. Rich in organic matter and slow release nutrients, compost made with Loop is a renewable alternative to chemical fertilizers that boosts plant growth and replenishes our soil. Compost made with Loop is local and recycled, and it even helps our soil sequester carbon, helping us become carbon neutral.

The King County Recycled Water Program produces a reliable and sustainable supply of crystal-clear and odor-free water. It's called "the right water for the right use" because it is the perfect water for landscape and crop irrigation, industrial processes and wetland enhancement. It is engineered for safety and reliability, making its quality more predictable than many existing surface and groundwater sources.

With the nutrients that occur naturally in recycled water, we are both enriching our soil and protecting our waterways, providing benefits to people and the environment.

We provide venues for environmental education and demonstration, increasing public familiarity with garden and agricultural uses of recycled water and biosolids. We also support university curriculum, student internships, and are developing relationships with high school and technical programs in South Seattle, Tukwila, Skyway, and Renton. A huge benefit of ecology and sustainable resource education is making science accessible and relatable. When students and volunteers get the big picture of whole systems, this reinforces awareness of local waste streams and basic decomposition processes,especially at a youth level.

We call our monthly volunteer events, 'Work & Learn' days for a good reason. Although we, of course, benefit from communal labor, our focus is on the quality of experience and human connection. We believe when we are fully engaged, connect with each other and leave room for lots of laughter, creativity and collaboration will excel.

We are working to cultivate food gardeners and to increase outreach and services for our neighboring communities. The food grown at City Soil is accessible to everyone: volunteers and students can harvest the food as they learn or tend to the farm, but most of the food is donated to the White Center Food bank for those in need. As CitySoil grows, increased food production will help us expand donations to other organizations in need.
King County Wastewater Treatment Division is proud to partner with King Conservation District , the White Center Food Bank, and DIRT Corps . This partnership transformed an area of the treatment plant into a sustainable farm and native tree nursery, and has allowed all the organizations to share this unique educational and agricultural space. The partnership fosters community involvement and open participation at CitySoil Farm, increases accessibility, and brings in a constant flow of exciting new ideas.

Contact us

For questions about CitySoil Farm education programs and volunteering opportunities contact Charity Villines at


Learn more

Learn more about the wastewater process and the resources that get recycled everyday by visiting the websites below:

CitySoil Farm partners