Cleaning Up California’s Ports: The At-Berth Regulation, Tanker Terminal Compliance, and the Fuel Supply Risks Nobody Is Talking About

The California Air Resources Board (CARB) has set an ambitious goal of reducing the pollution that blankets port communities. The CARB At-Berth Regulation, which covers large, moored vessels (including petroleum tankers) requires terminal operators to deploy emissions capture-and-control (C&C) systems that capture and treat exhaust from docked ships or switch those ships to shore power. Port communities have lived with disproportionate air quality burdens for decades, and cleaning up at-berth vessel emissions is a meaningful step toward addressing that.

The problem is that California has set a compliance deadline for a technology that does not yet exist in a form that can safely operate on petroleum tankers. When the compliance deadline arrives, CARB will face a choice it has not publicly acknowledged: enforce the regulation and risk constraining the fuel supply, or back down and undermine the regulation’s credibility. Neither outcome serves the port communities the rule was designed to protect.

In this article, we review the terminal and port compliance plans submitted to CARB through April 2026 – including independent engineering feasibility studies commissioned by several Bay Area operators – and examine what they reveal about the state of compliance and the downstream implications for California’s fuel supply.

Why Petroleum Tankers Are Different – And Why Geography Matters

The CARB At-Berth Regulation requires vessels to connect to an approved emissions control strategy while docked – either shore power or a barge-based C&C system. For container ships, this has been workable, but petroleum tankers present different challenges. Tankers are sourced opportunistically rather than on fixed routes, vary widely in stack height and mooring geometry, must be capable of getting underway within 30 minutes of an emergency (potentially incompatible with barge C&C systems whose spuds take 30 to 60 minutes to stow) and require any dockside equipment to be certified safe within classified hazardous zones.

The 2020 regulation is also the first time petroleum tankers have ever faced at-berth emissions requirements in California. Container and cruise vessels had a 16-year head start under a 2007 regulation, an established international shore power standard (IEC/IEEE 80005-1), and requirements to meet the San Pedro Bay Clean Air Action Plan in Southern California.

Southern California petroleum tanker terminals are late on the 2025 deadline but moving, because the Port of Los Angeles (POLA) and Port of Long Beach (POLB) are purpose-built harbors with calm water and predictable currents. The Bay Area terminals are mostly located in the Carquinez Strait, a tidal river channel with strong, variable currents. The geotechnical conditions also differ: soft bay mud, underwater utilities, and dock structures not designed for spud barge[1] loads. A barge designed for LA harbor cannot reliably hold station in the Strait.

In early 2026, Bay Area terminal operators filed updated compliance plans that collectively constitute a formal, engineering-backed declaration that no commercially available C&C technology can safely operate at their facilities. Valero Benicia stated flatly that “no commercially available system exists that has been demonstrated safe for interfacing with all tankers.” Phillips 66 Rodeo will contract with a vendor only after CARB certifies two or more vendors for Bay Area conditions – effectively putting the ball back in CARB’s court. Marathon’s Avon Wharf lists a target date of January 1, 2032. Kinder Morgan’s two Richmond terminals submitted plans with no vendor contract and no completion date. Chevron relies on “Innovative Concepts” – equivalent emissions reductions from other sources rather than any physical control system at the berth.

The table below summarizes compliance status across all regulated California tanker terminals.

Source: Stillwater analysis of CARB data. We note that Chevron El Segundo’s Off-Shore Wharf is out of scope for the At-Berth regulation.

The Supply Disruption Problem

Even where barge C&C is eventually deployed, it narrows the acceptable vessel pool, caps throughput at barge availability, and adds vetting friction to spot-market terminals that already receive vessels they have never seen before. Stockton reported only 15 percent of vessels returned more than once between 2023 and 2025. In a supply disruption, the terminals least able to accept whatever vessel is available are precisely the ones the state will need most.

California has a well-documented history of fuel supply disruptions where the ability to bring in emergency tanker deliveries quickly (from whatever vessel was closest) was central to managing the crisis. The At-Berth regulation would significantly complicate that response. When a terminal needs to accept an emergency import on short notice, its options are to burn through its annual Terminal Incident Event (TIE) allocation, apply to the remediation fund, or accept the noncompliant vessel and face enforcement action. No fuel supply emergency exemption currently exists. The regulation’s safety and emergency exception covers utility outages and severe weather, but it fails to account for the possibility of an unforeseen refinery outage (e.g., a refinery fire) that drives emergency product demand. In that case, the terminal would be physically operational, but the emergency would be in the fuel market, and the regulation has no mechanism to distinguish between those situations.

Only two of the five historical Bay Area refineries are currently operating in petroleum service: Chevron Richmond and PBF Martinez. Two of the others have converted to renewable fuels / petroleum terminals, and the last has shut down with its future unclear.[2] What this means is that a single unplanned outage at either of the operating petroleum refineries would cut refining capacity in half – in a market where not one of the large terminals has an approved technology solution.

The product import terminals at POLA and POLB are not insulated from this problem simply because their plans are marked “complete” by CARB. “Complete” means CARB found the plan adequate, not that the technology works or that every vessel that calls can be serviced. Shell Mormon Island, Vopak POLA, and Phillips 66 POLA all explicitly acknowledge that some vessel calls will be uncontrolled, relying on Innovative Concepts credit banking or TIEs to cover those gaps.

In the end, CARB will probably not enforce its way into a fuel supply shortage. The agency has walked back implementation timelines before when economic and supply stakes got high enough. The political economy of penalizing a terminal for accepting an emergency gasoline delivery during a supply crunch is not one CARB wants to navigate publicly. But “CARB will probably blink” is not a fuel supply policy; it is an informal assumption that exists nowhere in writing, cannot be planned around, and could change with a new state administration or CARB executive officer.

Conclusions

No matter how noble, good intentions do not conjure technology into existence, and the State must develop mechanisms to manage product supply emergencies under this regulation.

The State needs answers to three problems that will not resolve themselves regardless of how CARB chooses to act when the deadline arrives:

The technology does not yet exist. Bay Area terminal operators, supported by independent engineering studies, have formally documented that no commercially available capture-and-control system can safely operate at their facilities. This is not a vendor selection problem or a procurement delay. It is a technology readiness gap that cannot be resolved by regulatory pressure alone.
The operational implications are real. When barge C&C systems are eventually deployed, they will narrow the pool of acceptable vessels, impose capacity constraints tied to barge availability, and add operational friction to terminals that already run on tight schedules and tidal windows. These are manageable challenges, but they exist.
The supply disruption scenario has no regulatory solution. The regulation has no emergency exemption mechanism for fuel supply shortfalls. TIEs and the remediation fund are not substitutes. California has built a robust framework for responding to fuel supply emergencies on the fuel-specifications side but has built nothing equivalent on the emissions-control side. That gap will not matter until it does; and when it does, it will matter a great deal.

These are supply security questions dressed in regulatory clothes. They require answers that take both the environmental goals and the fuel supply implications seriously.

Sources: Terminal and port plan submissions filed with the California Air Resources Board under CCR Title 17, Section 93130.14(a)(3), reviewed through April 2026. CARB At-Berth Regulation FAQs (TTD21-272, November 2021). Martinez Refining Company At-Berth Feasibility Risk Assessment (Simpson Gumpertz & Heger, April 14, 2023). CARB 2024 Shore Power Enforcement Data Portal. California Code of Regulations, Title 17, Sections 93130–93130.22; Title 2, Section 2340.