California Air Resources Board

**July 21, 2026**

California Air Resources Board
Industrial Strategies Division

Concerns with Tier 2 Pathway Application B0901, Pathways B090101–B090106

Dear CARB Staff:

I strongly oppose certification of Tier 2 Application B0901 as submitted. Please treat the six sections below as identifying potential factual and methodological errors requiring correction or a detailed applicant response under CARB’s Tier 2 review process.

The proposed pathways concern dairy-manure biogas from JM Larson Barns 3 and 4 in Okeechobee, Florida, upgraded by Chevron Sobek RNG and assigned to California transportation use through pipeline RNG, LNG and L-CNG pathways.

CARB should deny or defer certification unless Chevron provides transparent, project-specific evidence that the claimed reductions are real, additional, accurately measured, fully accounted for and not claimed more than once.

## 1. Baseline and additionality

The application should identify the exact no-project manure-management baseline used to calculate avoided methane, including historical lagoon practices, manure quantities, retention times, herd sizes, temperatures and methane-conversion assumptions.

The calculation may contain a methodological error if it assumes that all covered manure would otherwise remain indefinitely in an uncovered anaerobic lagoon and that all modeled methane would necessarily escape. Liquid lagoon storage is a management practice, not an unavoidable natural condition. Chevron should compare the project with reasonably available lower-methane manure-management alternatives, not only with continued use of the highest-emitting practice.

Additionality is particularly important because public project announcements indicate that construction began in 2020 and that the project began producing RNG in 2023, years before this 2026 pathway review.

Chevron should therefore disclose:

* when the investment decision was made;
* whether anticipated LCFS revenue was included in project financing;
* whether the project would continue operating without LCFS credits;
* whether credits are sought for fuel produced before certification; and
* what new reductions approval of B0901 would cause.

It would be factually and methodologically incorrect to use a counterfactual in which the already-operating digesters do not exist or stop operating unless Chevron provides evidence supporting that assumption.

CARB should not award credits for reductions that were already occurring, already financed or already legally or contractually required.

## 2. Herd size, manure quantities and facility allocation

Chevron should disclose historical and current herd counts, manure production and digester throughput separately for Barns 3 and 4.

The application should also clarify:

* whether herd size increased after project development;
* whether manure is imported from other barns or dairies;
* whether manure or gas is transferred among Larson facilities;
* how gas volumes are assigned to each barn and pathway; and
* how emissions from shared equipment are allocated.

Avoided-methane crediting should be capped at a fixed, verified historical herd and manure baseline. Additional manure resulting from herd expansion, dairy consolidation, imported waste or operational changes intended to increase gas production should not receive additional LCFS credits.

Without such a cap, the methodology creates a perverse incentive: producing more manure generates more modeled baseline methane, which can produce a more negative carbon-intensity score and more credits.

CARB should also require a project diagram and complete mass balance showing manure inputs, biogas production, methane concentration, upgrading losses, pipeline injection and fuel output for each covered facility. Inadequate allocation among barns, digesters or related Larson facilities could lead to incorrect attribution or double counting.

## 3. Lifecycle boundary and measured methane performance

The claimed benefit depends heavily on methane-capture efficiency. Small errors in leakage, digester uptime or digestate emissions could materially alter the pathway’s carbon intensity.

Chevron should disclose which lifecycle emissions are included and excluded, including:

* manure collection and pumping;
* digester heating and electricity;
* equipment downtime and bypass events;
* routine and emergency flaring;
* leakage from digesters, piping and upgrading equipment;
* methane rejected during gas upgrading;
* digestate storage and land application;
* effluent-pond methane;
* compression and pipeline losses;
* refueling losses; and
* end-use methane slip.

In prior dairy-RNG pathway proceedings, environmental organizations have challenged the exclusion or understatement of digestate emissions, lagoon emissions and other portions of the well-to-wheel lifecycle. Following CARB’s calculator does not establish that all material real-world emissions have been captured.

Chevron should provide actual measurements of:

* gross biogas production;
* methane concentration;
* upgraded gas output;
* flare volumes;
* vented gas;
* fugitive leakage;
* downtime; and
* methane remaining in digestate.

CARB should not rely primarily on default leakage or capture assumptions. Certification should require direct monitoring, annual reconciliation of modeled and measured methane performance and downward adjustment of credits when actual performance is worse than assumed.

## 4. LNG and L-CNG accounting

The direct-pipeline, LNG and L-CNG pathways involve materially different processing and transportation chains. They should not receive similar carbon-intensity results unless facility-specific data demonstrate that result.

For B090102 and B090105, Chevron should quantify all emissions associated with liquefaction at the Clean Energy Boron LNG Plant, including:

* electricity and fuel consumption;
* pretreatment and refrigeration;
* methane loss during liquefaction;
* boil-off gas;
* venting and flaring;
* storage and loading losses;
* truck mileage;
* empty return trips; and
* unloading and dispensing losses.

These inputs should reflect current operations at the Boron facility rather than generic LNG assumptions.

For B090103 and B090106, Chevron should separately quantify the additional energy and emissions required to use transported LNG as L-CNG, including pumping, vaporization, recompression, storage and boil-off management.

The application should also identify the vehicle engines and duty cycles assumed and include real-world methane slip, fuel-system leakage and refueling losses.

Omitting or understating any of these stages would create a methodological error. The direct-pipeline route should ordinarily have a lower lifecycle burden than a route requiring liquefaction and trucking, while L-CNG should reflect its additional conversion stage.

## 5. Delivery claims, pathway allocation and double counting

The pathway descriptions state that Florida RNG is “pipelined to CA.” Chevron should clarify whether physical gas is demonstrably delivered through an interconnected pipeline route to California or whether conventional gas is withdrawn in California while the renewable attributes are assigned through book-and-claim accounting.

If the physical methane is not traced to California, describing it simply as “pipelined to CA” may be factually misleading. The calculation should reflect the actual contractual and physical arrangement, including appropriate compression, transmission and leakage assumptions.

Because B0901 proposes six alternative pathways, Chevron must also demonstrate how it prevents the same MMBtu of gas from being credited under more than one pathway. Required controls should include pathway-specific meters, pipeline nominations, LNG loading records, delivery records, dispensing records and an auditable environmental-attribute tracking system.

Chevron should identify all other programs supporting the project, including federal Renewable Fuel Standard credits, tax benefits, utility incentives, grants, voluntary carbon markets and corporate climate claims.

Receiving multiple financial incentives is not automatically double counting. However, the same avoided methane, renewable attribute or lifecycle reduction must not be claimed by multiple parties or programs.

CARB should require a complete chain of environmental-attribute ownership extending from the dairy through Chevron, the pipeline, the LNG plant, fuel distributors and the entity reporting the fuel under the LCFS.

## 6. Transparency and consistency with prior public claims

The public must have enough information to evaluate the calculation meaningfully.

Chevron should publicly disclose, or provide usable ranges for:

* herd counts;
* manure quantities;
* manure fractions;
* baseline lagoon assumptions;
* gas production;
* methane-capture efficiency;
* leakage;
* energy consumption;
* transportation distances;
* digestate management;
* allocation among pathways; and
* requested crediting dates.

Third-party verification is not a substitute for public transparency. A Tier 2 public-comment process is undermined when the inputs necessary to identify factual or methodological errors are withheld.

Chevron should also reconcile B0901 with previous public statements that the Sobek project would produce approximately 171,000 MMBtu annually and avoid more than 57,000 metric tons of greenhouse-gas emissions each year.

CARB should require a table comparing those public estimates with:

* the fuel volume covered by B0901;
* the avoided methane used in the application;
* the number of barns and digesters included;
* total project emissions;
* the resulting pathway carbon intensities; and
* expected LCFS credit generation.

Material inconsistencies should be explained and supported with current operating data.

## Broader opposition and requested action

Even if calculation errors are corrected, I strongly oppose using the LCFS to provide large, long-term subsidies for dairy-manure RNG.

Negative carbon-intensity scores arise primarily from a modeled assumption that methane would otherwise be released. The fuel itself does not remove carbon from the atmosphere when burned. This accounting can reward continued reliance on methane-producing manure lagoons, increase the financial value of manure and encourage larger concentrated dairy operations.

Digesters also do not resolve ammonia, odors, nutrient pollution, groundwater risks, digestate disposal, truck traffic or other environmental and community harms associated with industrial dairies.

California’s transportation policy should prioritize zero-emission vehicles, charging infrastructure, public transportation and reduced petroleum use. Subsidizing pipeline gas, LNG trucking, CNG engines and related combustion infrastructure risks extending dependence on methane-burning vehicles and diverting LCFS value away from genuine transportation electrification.

This application would also use California transportation credits to support manure management at a Florida dairy project that was constructed years ago. California may receive little or none of the associated local air- or water-quality benefits, while the resulting credits can allow fossil-fuel suppliers to continue generating deficits elsewhere.

I therefore **strongly oppose B0901 and pathways B090101 through B090106 as submitted**.

CARB should deny or defer certification unless Chevron corrects the factual and methodological deficiencies identified above, makes sufficient information public for independent review and accepts enforceable conditions concerning historical manure baselines, methane monitoring, pathway allocation and prevention of double counting.

At an absolute minimum, my position is **oppose unless amended**. Even with amendments, CARB should phase out avoided-methane crediting for new dairy-RNG pathways and address agricultural methane through a separate program that directly verifies pollution reductions without subsidizing expanded manure production or methane-combustion transportation.

Sincerely,

**Jeremiah Maller**
Berkeley, California