Davis solid-waste update: state rule change will add thousands of tons and lower reported diversion

Jennifer Gilbert, the City of Davis conservation coordinator, told the Climate & Environmental Justice Commission that a change in state reporting will materially affect the city’s recycling metrics and require new procurement and program responses.

"Nothing has changed, just the definition," Gilbert said, describing how material from the wastewater treatment plant that had been counted as reuse will be classified as landfilled waste in 2025 data. She said that change will add "more than 3,000 tons" to Davis’s calculations and is likely to reduce the city’s reported diversion rate from about 62 percent toward the mid-50s — a drop of roughly 5–10 percentage points that could approach the state’s 50 percent threshold.

The shift stems from recent CalRecycle rules and the implementation of the Short-Lived Climate Pollutants law (SB 1383), which also prescribes uniform container colors, contamination monitoring and new procurement accounting for recovered organic waste products. Gilbert said the city began mandatory organics collection in 2016 and is celebrating a 10-year milestone in participation and outreach.

Gilbert highlighted local strengths: Recology Davis conducts route reviews and lid flips; the city’s most recent route-review data for 2025 show about 88 percent of inspected bins were sorted correctly, and a Yolo County compost-facility audit of a single Davis organics load found just 1.3 percent contamination. "That is so unheard of," Gilbert said about the low contamination rate.

But she added procurement poses a significant challenge. Under state rules, jurisdictions must account for purchases or credits for recovered-organic products (compost, mulch, renewable gas credits, etc.). Gilbert described multiple attempts to meet the target — buying compost, seeking mulching credits from city tree-chipping, exploring gas or energy credits — and practical limits: parks departments typically use mulch rather than compost, local compost quality sometimes falls short for some municipal uses, and state rules limit how much of certain local activities can count (for example, Davis may count only 10 percent of tree-chipping toward procurement targets).

Commissioners pressed staff for clarifications. In response to a question about edible-food recovery tiers, Gilbert said the statute defines which grocery stores, restaurants and institutions are subject to mandatory donation and compliance inspections. She also confirmed that certain institutions — including some residential retirement facilities — are exempt by regulation in some cases, but staff and Recology can still perform waste audits and provide outreach to multi-family and community facilities.

Other operational updates: Recology has a carton drop-off bin and the presenter plans to tour a new carton-processing facility in Lodi; the county runs hazardous-waste drop-off and provides free seasonal compost for residents; and the city expects a CalRecycle JACE jurisdictional inspection on SB 1383 implementation and recordkeeping.

Gilbert said staff are coordinating regionally and with the state to seek workable options for biosolids and procurement without causing rate increases. "We're hoping the state was going to help us come up with some solutions," she said. She asked commissioners for continued patience as staff pursue contractual and programmatic options and prepare for the upcoming inspection.

What's next: staff will continue outreach to the county composting operator and to potential local end markets, return with any procurement or contract options, and present 2025-report impacts to the commission when CalRecycle finalizes the numbers.