Review Article

Organic Waste as a Resource in the United States: Current Practices and Emerging Valorization Pathways

Abstract

Organic waste represents one of the largest yet most underutilized material streams in the United States, simultaneously contributing to landfill methane emissions and offering significant potential for resource recovery within a circular bio economy. This review synthesizes current practices and emerging valorization pathways for organic waste, encompassing food waste, agricultural residues and manure, bio solids, and yard waste. We examine established management approaches, including land filling, composting, anaerobic digestion, and food recovery, alongside emerging bio energy, bio product, biological, and carbon-oriented pathways that aim to deliver higher environmental and economic value. Using a systems-level analytical framework, the review integrates material flow considerations with policy and regulatory drivers, technological readiness, and environmental and socioeconomic outcomes. The analysis highlights substantial variation in climate mitigation potential, resource efficiency, and scalability across pathways, as well as persistent barriers related to infrastructure, market development, and governance fragmentation. We identify priority areas for policy alignment, technological innovation, and data integration that are critical for enabling organic waste to transition from a disposal challenge to a foundational resource. Overall, the review underscores the strategic role of organic waste valorization in advancing U.S. climate goals, resource circularity, and sustainable economic development.