EPA Reviews Changes To Marine Vessel Loading Emissions

In March, the Environmental Protection Agency presented the results of a “Technology Review” pertaining to marine tank vessel loading operations (MTVLO). The Clean Air Act requires such a review every eight years to evaluate the control of hazardous air pollutants.

Based on that Review, the EPA proposed changes to the MTVLO regulations, part of the federal National Emission Standards for Hazardous Air Pollutants. The MTVLO rules and regulations apply to operations at refineries, bulk terminals, chemical plants and pipeline terminals where liquid commodities (such as crude oil, gasoline and other fuels or chemicals) are pumped from above-ground storage tanks into a marine vessel compartment.

The MTVLO category includes three subcategories: ‘onshore’ terminals, offshore terminals and the Alyeska Pipeline Service Corporation’s Valdez Marine Terminal.

The proposed changes include:

• Clarifying that offshore loading terminals would newly qualify as an MTVLO source. (This is a potential move drawing strong industry opposition.)

• Expanded flare monitoring to align with petroleum refinery requirements.

• New periodic testing for non-flare controls.

• Removing startup, shutdown and malfunction exemptions and requiring that standards always apply.

• Requiring electronic reporting.

The EPA’s proposal opened a public comment period that ended April 20.

To be clear, the EPA’s proposals apply to fixed facilities, not vessels. Pollution control technology for barges is regulated by the Coast Guard (although the EPA sets the air quality standards). The EPA worked with the Coast Guard to develop the rule proposed in March.

The EPA estimates that 190 facilities are likely to be impacted by the regulatory changes. Most are coastal facilities, but many are located in cities on the inland waterways, in Chicago, for example, and Cincinnati and Pittsburgh.

While the EPA’s focus is on fixed facilities, it’s not a big stretch to ask about impacts to vessels and barges, which, after all, are literally attached to a facility’s infrastructure during loading and unloading.

In its text, the EPA’s document does not directly address barges or vessels. It does not change or shift, for example, any facility reporting or monitoring or record-keeping affecting barge operators. It does not reference “ship-to-shore compatibility” or change requirements that facilities equip each terminal with a vapor collection system.

Insights From Industry

The EPA received 22 sets of comments from interested parties, including trade associations, port officials and environmental organizations. Some of those comments reference a number of possible new challenges for vessel and barge operators because of the possible MTVLO changes.

The American Waterways Operators, in a letter from Caitlyn Stewart, vice president of regulatory affairs, suggested that the EPA clarify that monitoring equipment is the responsibility of facility owners and operators and that the EPA provide monitoring guidance. Stewart added that “EPA should also consider how monitoring equipment will be observed and documented without distracting personnel who must remain focused on safe loading operations.”

The American Petroleum Institute (API) teamed up with the American Fuel & Petrochemical Manufacturers and the International Liquid Terminals Association to submit extensive comments referencing a number of problematic issues for vessels and barges that could result from EPA’s proposed changes.

Monitoring And Leak Detection

One topic on which the EPA wanted comments pertains to a specific leak test method (Method 21) and whether that should be a new MTVLO requirement. API cites this as one example of a problematic overlap between facilities and vessels. Method 21, API explains, is implemented during active loading. However, that presents logistical challenges, API explains, because “at marine loading facilities Coast Guard and facility safety requirements restrict access to equipment in the immediate loading zone.” API suggests a different, more distant monitoring protocol.

Repair Requirements

The EPA suggests a 15-day window to complete equipment repairs. Vessels may be part of this repair follow up. However, API points out that a 15-day window could be unworkable because a loaded vessel may not be around in 15 days to allow re-monitoring. API notes that “vessel scheduling is largely beyond the control of the stationary source owner.” API recommends requiring a 15-day deadline to show an initial attempt at repair.

Vapor Recovery Connections

API references vapor recovery during vessel docking prior to loading. It also references past discussion, reported within meeting notes from July 2025, and concerns about vessels venting prior to loading, something that should be addressed, API writes, through a “specific work practice standard.”

API writes further that while venting and purging operations are not universal, Coast Guard regulations often require them in particular circumstances, such as for inerting cargo tanks, preventing overpressure or removing resident vapors if they could damage the MTVLO’s vapor control system. “In any case,” API points out, “these venting and purging operations are under the control of the vessel, not the MTVLO.”

Concerns such as overpressure and inerting were not part of the EPA’s draft proposal. Also, the EPA’s draft included a list of 31 topics on which the agency asked for additional and specific information. The agency is reviewing those comments and suggestions now.

A final rule could be more expansive than the draft implies, which suggests that barge and vessel operators need to keep this on their radar.