Public Works
REUSING WASTE BYPRODUCTS: Tons of biosolids beneficially used
Current Value
12,496
Definition
The City of Portland produces approximately 15,000 dry tons (≈ 75,000 wet tons) of biosolids per year at the Columbia Boulevard Wastewater Treatment Plant (CBWTP). Biosolids are the nutrient-rich by-product of municipal wastewater treatment. The City of Portland treats raw sewage solids (often called sludge) to meet stringent U.S. Environmental Protection Agency (EPA) standards for pathogen reduction, vector attraction reduction, and pollutant levels before they can be classified as biosolids and used beneficially. Further, the biosolids must meet additional Oregon Department of Environmental Quality (DEQ) regulatory requirements, which are included in the City’s Biosolids Management Plan and National Pollutant Discharge Elimination System permit.
Why Is This Important?
Biosolids are the nutrient-rich by-product of municipal wastewater treatment. The City works with farmers and ranchers in Eastern Oregon to apply the them as a soil amendment to grain fields and pastures, providing environmental and economic benefits. Biosolids production and land application are strictly regulated by the Environmental Protection Agency and the Oregon Department of Environmental Quality (DEQ). To make sure Portland's biosolids can be beneficially used, the city tests it on a daily schedule and monitors the treatment process to detect any problems.
The beneficial reuse of biosolids frees up finite landfill space and replenishes the soil with valuable nutrients and organic matter, improving soil fertility. Land application of biosolids is an important component of a circular economy where society aims at a continual use of resources and eliminating waste.
What Do The Numbers Show?
Biosolids recycling via land application at the City’s DEQ-authorized sites will continue to be the major focus of the City’s biosolids management program in 2025. The authorization of additional land application sites in 2025 to allow for future capacity and program resiliency is also anticipated.
How Did We Arrive at These Numbers?
Figures are derived based on scale weight of biosolids hauling trucks.
Where Can I Find More Information?
You can find more information on the City’s resource recovery efforts at the Biosolids webpage.
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