California’s RNG transition runs on four separate clocks

California’s 2024 LCFS amendments, in effect since 2025, changed four elements of RNG crediting. Avoided-methane crediting now has a finite life, CNG and hydrogen end uses run to different dates, a pipeline physical-flow test arrives in the 2040s, and a 2030 vehicle-count test can pull part of the schedule forward.

Pathway certification date, construction timing, end use and delivery geography together determine a project’s exposure. Most of it turns on a single defined term.

CARB certified pathway record; EPA AgSTAR and LMOP; OAL-approved LCFS regulation order, unofficial electronic version dated 11 August 2025, title 17 CCR; Climate Decode California LCFS fleet model.

Each amendment carries its own schedule, and three of the four apply only to projects that break ground after 31 December 2029.

Five years separate CNG at 2040 from hydrogen and fuel-cell electricity at 2045. A developer choosing offtake in the late 2020s is choosing a crediting horizon at the same time.

Before the amendments, certified dairy and landfill-diversion pathways could keep generating credits against their approved carbon intensities. Section 95488.9(f)(3)(A) now caps that. Pathways certified before 1 July 2025 get three consecutive ten-year crediting periods. Pathways certified from that date through the end of 2029 get two. Each period begins in the quarter after Executive Officer approval, and renewal must be requested through the Annual Fuel Pathway report.

For the older cohort, renewal is mandatory where eligibility continues. The Executive Officer shall renew an eligible pathway.

The drafting leaves one edge case. The maximum crediting period is set by certification date, while the renewal language refers to the date the project broke ground. A pathway certified after 1 July 2025 for a project that broke ground earlier does not fit cleanly within either renewal clause on the face of the text.

Applying the crediting-period rules to CARB’s record of 1,031 certified avoided-methane pathways, with certification years from 2016 to 2026, no pathway reaches the end of its final period before 2046. The first material expiry is 2047, when about a quarter of the pathway base reaches its limit — the 2016 cohort completing a third ten-year period as the 2026 cohort completes a second.

Operating digesters and projects that break ground by 31 December 2029 remain outside all three provisions tied to post-2029 construction. How the regulation defines the term therefore decides which projects are affected at all.

Section 95481 defines break ground by reference to Beginning of Construction for federal investment tax credits, and to IRS Guidance Notice 2022-61, which is incorporated by reference. A developer that has already established a Beginning of Construction date for the investment tax credit has also established the relevant LCFS date, including the applicable safe harbours. Physical earthmoving counts only after required entitlements and permits are approved.

Borrowing the federal test means California’s RNG schedule inherits federal construction-start practice, and the documentation a project assembled for the tax credit does double duty here.

Break ground by 31 December 2029 and three of the four provisions never apply. We model RNG pathway value across LCFS, CFR, Oregon, Washington and the RFS.

Section 95488.8(i)(2)(B)1 requires pipelines along the delivery path to “physically flow from the initial injection point toward the fuel dispensing facility at least 50 percent of the time on an annual basis.” The rule applies to post-2029 projects and begins in 2041 for CNG and 2046 for hydrogen and fuel-cell electricity.

How much that matters depends on how much California-credited RNG is produced outside the state. California credited roughly 224 million diesel-gallon-equivalents of biomethane in 2025. EPA’s AgSTAR database lists 149 livestock anaerobic digesters in California, about 81 M dge of capacity after scaling for incomplete reporting. EPA’s LMOP database lists just three landfill-gas-to-RNG projects in the state, with combined capacity near 6 M dge.

EPA AgSTAR and EPA LMOP databases. Dairy capacity is scaled to allow for incomplete capacity reporting. Diesel-gallon-equivalents.

Taking those capacity estimates as a scale comparison, in-state RNG capacity is equivalent to roughly 39% of the biomethane California credited in 2025. The remaining 61% is consistent with a large share of supply being produced elsewhere, injected into the interstate network and matched to RNG sold in the state through book-and-claim.

For projects relying on distant injection points, the physical-flow rule introduces an eligibility test tied to actual pipeline direction. It begins in 2041, or 2038 if the vehicle-count trigger is met, and it can decide whether a reported volume qualifies at all. Because it applies only to projects breaking ground after 2029, the installed base stays outside its scope. New projects aiming at the California market need to account for it when choosing injection points, pipeline routes and offtake structures.

A shorter delivery clock already applies. The same subsection limits RNG matching to a three-quarter window. Gas injected in the first calendar quarter must be matched to natural gas sold in California as RNG by the end of the third quarter, and unmatched quantities become ineligible for LCFS reporting. That constraint is live now and is a more immediate operational consideration than the long-dated sunsets.

Dairy and landfill RNG use the same pipeline infrastructure and produce very different LCFS credit yields, because avoided-methane treatment changes the pathway carbon intensity.

California dairy pathways cluster around −232 gCO₂e/MJ while landfill gas sits near +51 gCO₂e/MJ. Most of the gap is avoided methane. Capturing gas from a manure lagoon earns credit for methane that would otherwise have been emitted, which pushes the pathway far below zero. Landfill gas pathways generally lack that benefit because gas collection is already part of the baseline.

Against an LCFS benchmark near 80 gCO₂e/MJ, a dairy pathway at −232 earns credits across a spread of more than 300 gCO₂e/MJ. A landfill pathway at +51 earns credits across a spread below 30. Credit yield per unit of energy is roughly an order of magnitude larger for dairy.

That differential explains the project mix. California hosts nearly a third of US dairy digesters and about 2% of landfill RNG projects.

The same economics constrain future credit growth. National landfill RNG capacity is substantial and the development pipeline continues to expand, so additional landfill gas enters the California mix at a much higher carbon intensity than dairy RNG and generates fewer credits per megajoule. Our current modelled blend sits near −187 gCO₂e/MJ. Credit growth from here depends heavily on how much additional low-CI manure supply is available as the overall RNG pool expands.

31 August 2030. CARB must publish the Class 3–8 zero- and near-zero-emission vehicle count by this date. A result above 132,000 at 31 December 2029 moves the CNG physical-flow requirement from 2041 to 2038 and closes new biomass-based-diesel pathway applications from 2031. Under section 95488(d), one published number moves two separate schedules.

Offtake decisions for projects breaking ground after 2029. CNG crediting runs to 2040 and biomethane used for hydrogen production or fuel-cell electricity for EV charging runs to 2045. Five years of crediting is a material difference in long-term offtake value.

New California mandates on manure methane or organic diversion. Section 95488.9(f)(3)(B) ends crediting at the close of the current period for post-2029 projects if a qualifying mandate takes effect. The trigger sits outside the LCFS, so it can change project economics ahead of the scheduled end dates.

The dairy-to-landfill mix in new supply. This determines how quickly additional RNG volume translates into additional LCFS credits, because the two feedstocks generate very different credit yields per unit of energy.

Climate Decode · Advisory

Which clock is your RNG project actually on?

We model California’s LCFS alongside the Canadian Clean Fuel Regulations, British Columbia, Oregon, Washington and the US RFS in one linked system, because the programmes compete for the same molecules.

Method and Sources

Regulatory provisions from the OAL-approved LCFS regulation order, unofficial electronic version dated 11 August 2025, title 17 CCR — sections 95481, 95482(g), 95488(d), 95488.8(i)(2)(B)1 and 95488.9(f)(3), and Table 7-1. Break ground is defined by reference to Beginning of Construction for federal investment tax credits and IRS Guidance Notice 2022-61, incorporated by reference. Certified pathway counts and certification years from CARB’s certified pathway record. Credited biomethane volume from CARB LCFS reporting. Digester and landfill project counts and capacities from EPA AgSTAR and EPA LMOP, with dairy capacity scaled to allow for incomplete capacity reporting. Carbon intensities are certified pathway values. Crediting-period expiry profile, the post-2029 credit reduction and the modelled blend carbon intensity from the Climate Decode California LCFS fleet model.

The in-state share comparison sets nameplate capacity against credited volume and is a scale indicator rather than a measured import figure. Not investment advice.