California Air Resources Board

**July 21, 2026**

California Air Resources Board
Industrial Strategies Division

**Re: Concerns with Tier 2 Applications B0897, Pathways B089701–B089706 Methodological and Factual Errors**

Dear CARB Staff:

I strongly oppose certification of Tier 2 Applications B0897 and 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.

CARB states that comments identifying potential factual or methodological errors are forwarded to the applicant, which must correct the application or provide a detailed explanation of why revision is unnecessary.

The application concern dairy-manure biogas from:

* Larson Dairy Barns 5 and 8, under B0897; and

Each application proposes pipeline RNG, LNG and L-CNG pathways assigned to California transportation use. Taken together, Chevron seeks approval for 12 pathways involving four digesters, two related facilities, shared project infrastructure and three fuel-delivery configurations.

CARB should deny or defer certification unless Chevron demonstrates through 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 applications should identify the exact no-project manure-management baseline used for each of the four barns, including historical lagoon practices, manure quantities, retention times, temperatures, herd sizes and methane-conversion assumptions.

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

Additionality is particularly important because the Sobek project was publicly announced and construction began in 2020. Chevron and Brightmark announced delivery of the project’s first RNG in August 2023, years before these 2026 pathway reviews. The project was described as consisting of four lagoon anaerobic digesters at Larson family farms.

Chevron should therefore disclose:

* when the investment decisions were made;
* whether anticipated LCFS revenue was included in project financing;
* whether the digesters would continue operating without these credits;
* the requested crediting start dates;
* whether credits are sought for fuel produced before certification; and
* what additional emission reductions approval would cause.

It would be incorrect to calculate credits using a counterfactual in which these existing digesters do not operate unless Chevron provides evidence supporting that assumption.

## 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, 4, 5 and 8.

The applications should clarify:

* whether herd sizes increased following project development;
* whether manure is imported from other barns or dairies;
* whether manure or gas moves between the two facilities;
* whether the four digesters share gathering, upgrading or pipeline equipment;
* how gas and emissions are allocated among the four barns; and
* how shared equipment emissions are divided between B0897 and B0901.

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

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

Public permitting information indicates that the RNG operations at Larson Dairy are located at Barns 5 and 8, with a digester and flare at each barn and the biogas-upgrading unit located at Barn 5. Chevron should disclose whether that upgrading unit also processes gas associated with JM Larson Barns 3 and 4 and, if so, how its energy use, methane losses and output are allocated.

CARB should require a combined project diagram and mass balance covering all four digesters. Reviewing B0897 and B0901 as if they were isolated projects could conceal incorrect allocation or duplicate attribution.

## 3. Lifecycle boundary and measured methane performance

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

Chevron should disclose whether each calculation includes:

* 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 upgrading;
* digestate and effluent-storage emissions;
* digestate land application;
* compression and pipeline losses;
* LNG processing and transportation;
* refueling losses; and
* end-use methane slip.

Following a CARB calculator does not itself establish that all material real-world emissions have been captured.

Chevron should provide measured data for gross biogas production, methane concentration, upgraded gas output, flaring, venting, fugitive leakage, downtime and methane remaining in digestate.

CARB should require direct monitoring, annual reconciliation of modeled and measured performance, and downward adjustment of credits when actual methane capture is worse than assumed. Measurements should be reported separately for the four digesters wherever feasible so that poor performance at one barn is not obscured by aggregated project data.

## 4. LNG and L-CNG accounting

Eight of the 12 proposed pathways require additional processing beyond pipeline delivery: four LNG pathways and four L-CNG pathways.

For B089702, B089705, B090102 and B090105, Chevron should quantify all emissions from liquefaction at the Clean Energy Boron LNG Plant, including:

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

The inputs should reflect current, facility-specific operation of the Boron plant rather than generic LNG assumptions.

For B089703, B089706, B090103 and B090106, Chevron should separately quantify the additional energy and emissions required to use LNG as L-CNG, including pumping, vaporization or conditioning, recompression, storage and boil-off management.

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

The direct-pipeline, LNG and L-CNG routes should have distinct calculations. Omitting or understating these additional stages would materially understate the pathways’ carbon intensities.

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

All 12 pathway descriptions state that Florida RNG is “pipelined to CA.” Chevron should clarify whether physical gas is demonstrably transported through an interconnected pipeline route to California or whether renewable attributes are assigned to California through book-and-claim accounting.

Public descriptions state that the project’s gas enters the Peoples Gas pipeline system in Florida. If physical methane is not traced to California, describing it simply as “pipelined to CA” may be factually misleading. The calculations should reflect the actual physical and contractual arrangement.

Chevron must also demonstrate how the same gas cannot be credited under multiple applications or pathways. Required controls should include:

* meters at each digester and upgrading facility;
* a combined monthly mass-and-energy balance;
* pipeline nominations;
* LNG production and loading records;
* fuel-delivery and dispensing records;
* pathway-specific environmental-attribute tracking; and
* procedures for reconciling discrepancies.

This is especially important because B0897 and B0901 divide one publicly described four-digester project into two applications and 12 alternative pathways.

Chevron should also identify federal Renewable Fuel Standard credits, tax benefits, grants, utility incentives, voluntary carbon credits and corporate claims associated with the project. Multiple financial incentives are not automatically double counting, but the same avoided methane, renewable attribute or lifecycle reduction must not be claimed more than once.

## 6. Transparency and consistency with public claims

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

Chevron should disclose, or provide useful ranges for:

* herd counts and manure quantities;
* baseline lagoon assumptions;
* gas production by barn;
* methane-capture efficiency;
* leakage and flare activity;
* upgrading energy and losses;
* transportation distances;
* digestate management;
* allocation between B0897 and B0901;
* allocation among the 12 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 errors are withheld.

Chevron should also reconcile the two applications with previous public statements that the combined Sobek project would produce approximately 171,000 MMBtu annually and avoid approximately 57,400 metric tons of greenhouse-gas emissions each year.

CARB should require a combined table showing:

* total project gas production;
* production attributed to each barn;
* fuel volumes attributed to B0897 and B0901;
* avoided methane;
* lifecycle project emissions;
* carbon intensity for each pathway; and
* expected LCFS credit generation.

The totals across both applications should reconcile with measured project production and should not exceed the project’s physical output.

## Broader opposition and requested action

Even if individual 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. Burning the RNG does not itself remove carbon from the atmosphere. This accounting can reward continued use of methane-producing 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 harms associated with industrial dairies.

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

These applications would use California transportation credits to support manure management at an existing Florida project that began producing gas years before pathway certification. California may receive little or none of the local air- and water-quality benefits, while the credits can allow fossil-fuel suppliers to comply without equivalent reductions in California transportation emissions.

I therefore **strongly oppose Applications B0897 and B0901 and pathways B089701–B089706 and B090101–B090106 as submitted**.

CARB should evaluate these applications together and deny or defer certification unless Chevron corrects the deficiencies identified above, provides enough information for independent review and accepts enforceable conditions addressing historical manure baselines, measured methane performance, allocation across all four digesters 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 verifies pollution reductions without subsidizing expanded manure production or methane-combustion transportation.

Sincerely,

**Jeremiah Maller**
Berkeley, California