Top Photo: Courtesy of City of Modesto

In many California communities, certified compostable packaging is absent from the list of materials accepted in municipal organics programs. Cities have opted not to allow these products, often pointing to uncertainty around regulatory alignment and their potential impact on compost end markets. A key concern is how compost containing compostable packaging aligns with the USDA National Organic Program (NOP) standards for materials applied to land certified for organic agriculture. Because California produces more organic crops than any other state, protecting access to organic agriculture markets remains a central consideration for many compost manufacturers, who also receive a premium for compost approved for use in organic agriculture. Organic agriculture approval has become a proxy for quality compost in California, rather than using performance-based tests like US Composting Council’s Seal of Testing Assurance (STA).

At the same time, policy discussions are evolving. Recent developments tied to California’s AB 1201 labeling law and ongoing national standards discussions are pushing California regulators and industry groups to clarify how certified compostable packaging can be integrated into composting systems without compromising compost markets.

Against that backdrop, the City of Modesto is pursuing a different approach. Rather than excluding certified compostable packaging from its organics stream, the city continues to invest in education and infrastructure that allow those materials to be included alongside food scraps and yard trimmings. The effort is made possible through support from the Closed Loop Center for the Circular Economy’s Composting Consortium grant program, led in partnership with the Biodegradable Products Institute (BPI) and with technical guidance from the US Composting Council. The City’s approach reflects a preemptive approach to align local organics processing with California’s broader shift toward recyclable or compostable packaging under SB 54, the state’s Extended Producer Responsibility (EPR) law.

A key element of the project is the redesign of organics cart labels across the city’s residential and commercial collection system. City staff partnered with the Closed Loop Center’s Composting Consortium and BPI to design new labels that feature clear visual icons that show food scraps, yard trimmings, and certified compostable packaging together as accepted materials. The artwork on the labels is intended to make the program immediately understandable at the curb, written in both English and Spanish to support the diversity of languages spoken in Modesto, reinforcing correct behavior each time residents approach the bin.

“Our grant partnership with the City of Modesto reflects what’s possible when municipalities see certified compostable packaging not as a standalone solution, but as one tool to help capture more food scraps and expand diversion,” says Caroline Barry, project lead for the Closed Loop Center’s Composting Consortium. “We’re proud to support a city that understands the value of building local circular systems that strengthen organics recovery and demonstrate what’s possible for other California communities.”

A System in Transition

Located in California’s Central Valley, Modesto is both a major agricultural community and a growing city of more than 200,000 residents. Agriculture surrounds the city, and the region depends heavily on soil health and nutrient cycling to support crop production.

Modesto’s waste management system has evolved significantly over the past decade. The region was among the last in California to retire a municipal waste incinerator, closing the facility as the state accelerated its initiative to increase diversion from landfill and organics recovery.

Today, Modesto operates a municipal composting program that processes yard trimmings, paper, and food scraps generated throughout the community. It is one of the few California jurisdictions that both owns and operates its composting facility. The facility, which spans 65 acres with approximately 30 acres currently permitted for active use, utilizes a windrow system to process roughly 50,000 tons annually, with capacity allowances up to 130,000 tons. Green cart materials suitable for composting are first delivered to a transfer station for sorting before being transported to the composting facility, while the City’s Forestry Division Green Waste Team delivers separately collected green waste such as tree trimmings and leaves directly to the site. Material typically remains on site for 9 to 12 months before being screened into finished compost products.

The site has accepted both yard waste and food scraps since at least 2018, reflecting an earlier transition from green waste only operations. Since then, the City has been working to fit its programs to the community’s needs and material streams. When early pilots that moved organics collection to a biweekly schedule generated resident complaints about odors, pests, and limited cart space from food scraps sitting in green waste bins for two weeks, the City Council restored weekly organics collection in July 2023.

Leslie Rodgers (BPI), Jody Strait (City of Modesto), John Chavez (City of Modesto), and Caroline Barry (Closed Loop Center) walk through Modesto’s 65-acre site.

As the City continues to advance its organics program, its leaders see compostable packaging as part of the broader circular system that composting makes possible. “By allowing certified compostable packaging in the organics stream, our goal is to offer convenience to residents while supporting the city’s broader waste diversion goals,” says Jody Strait, Solid Waste Specialist for the City of Modesto.

Clarifying What Goes in the Bin

The City of Modesto’s updated commercial cart labels indicate that compostable packaging as accepted materials in its program.

One of the most visible components of Modesto’s grant-funded project is a systemwide relabeling initiative across its organics collection program. Working with the Closed Loop Center’s Composting Consortium and BPI, the City redesigned labels for residential carts and commercial containers to provide clear, consistent guidance that certified compostable packaging is accepted in the program, something previous stickers did not indicate. The updated artwork shows examples of certified compostable packaging, along with existing guidance on food scraps, paper, and yard trimmings, each paired with recognizable icons and certification indicators to help residents distinguish compostable products from non-compostable plastics. By showing recognizable products and certification marks directly on the cart label, the city aims to remove uncertainty at the curb and help residents sort materials correctly.

The labels are being rolled out across nearly 20,000 residential units – and more than 4,000 commercial and multifamily accounts. Modesto’s goal is to create an environment where residents and businesses encounter the same clear instructions wherever they interact with the city’s organics collection program.

Turning Waste Into a Local Product

Once organics are collected by the City, the materials are transported to the city’s composting facility. “We’re taking the community’s food scraps and yard trimmings and turning it into a product that goes right back into local soils,” says Delio Costa, Compost Facility Crew Lead. “A lot of it ends up supporting nearby farms and landscaping businesses, so it really does stay in the region.” In addition to agricultural and commercial uses, finished compost is also applied in community spaces such as Cesar Chavez Park, supporting local landscapes and advancing the City’s broader sustainability goals.

For a region where agriculture plays such a central role in the economy, the significant local demand from these end markets helps sustain the composting system.

Costa notes that maintaining high compost quality is essential to sustaining those markets. Facility staff are trained to recognize certified compostable packaging and differentiate it from lookalike plastics so that acceptable materials remain in the composting process while contaminants are removed. The facility further safeguards quality through regular testing, conducting STA testing within the first five days of each month, pathogen testing around mid-month, and metals testing on a monthly basis.

Modesto’s finished compost is used by local agriculture, landscapers, and other businesses.

Lessons for Municipal Programs

Modesto continues to demonstrate that successfully integrating compostable packaging in organics collection and processing depends on coordination across the entire program. Clear guidance for residents, consistent labeling, operational awareness at compost facilities, and alignment with haulers all help ensure compostable packaging functions as intended within the organics stream – helping bring more food scraps into composting facilities and away from landfills.

At a time when end market considerations and compost use definitions continue to shape organics recovery in California, Modesto stands out as an important example. While some municipalities remain cautious about integrating certified compostable packaging into their programs, Modesto is experimenting with a model that emphasizes clear communication, infrastructure alignment, and community participation around compostable packaging recovery. The grant-supported education and labeling effort is only one part of that broader strategy, offering useful lessons on how compostable packaging can fit within a municipal composting system that produces compost for beneficial uses such as landscaping and agriculture.

This article was produced as sponsored content in partnership with Closed Loop Center’s Composting Consortium and the City of Modesto’s staff and operations team, and tailored for BioCycle’s audience.