Portland, Maine Weighs First-in-State Ban on Cruise Ship Scrubbers

Portland, Maine's City Council votes Monday, November 16, on a measure that would make it the first port in the state to ban cruise ship scrubbers at berth — a rule with real cost implications for lines calling at one of New England's busiest cruise stops.

The resolution would prohibit ships from running scrubbers or discharging scrubber wash water while docked at city-owned piers. It targets open-loop systems specifically, the kind that wash exhaust with seawater and pump the used water overboard.

Why does this matter for cruise sellers?

Portland is a staple on New England and Canada itineraries, and its peak season is substantial. The port just closed out September and October, its busiest months; November's traffic thinned to a single call by the 3,560-passenger Majestic Princess.

The forward schedule shows how much is at stake. September 2027 alone has 41 cruise calls booked. If lines decide compliance costs at Portland outweigh the stop's value, itineraries could shift — though supporters insist that's not the intent.

The push comes from local group Portland Cruise Control, which has campaigned for the ban for two years.

What's actually being restricted?

Scrubbers let ships burn cheaper heavy fuel oil while still meeting international sulfur limits on exhaust. The alternative is pricier low-sulfur fuel such as marine gas oil. Not all systems work the same way:

• Open-loop systems use seawater to strip sulfur and pollutants from exhaust, then discharge the wash water — the target of Portland's proposal.
• Closed-loop systems recirculate treated water and hold it for later removal ashore.
• Hybrid systems switch between the two modes.

The wash water can be acidic and carry polycyclic aromatic hydrocarbons (PAHs), heavy metals, particulates and other contaminants. Environmental advocates argue scrubbers simply relocate air pollution into the water.

JoAnn Locktov of Portland Cruise Control estimated the ban would keep roughly 32 million gallons of scrubber wash water out of Casco Bay per season. That's the volume of about 48 Olympic swimming pools dumped annually, at present traffic levels.

"Cruise ships shouldn't be allowed to turn their air pollution into our water pollution," Locktov said. "This is about protecting the bay, not reducing cruise visits."

That framing is a claim worth watching. Compliance costs land on the lines, and whether call volumes hold depends on how they weigh fuel-switching expenses against Portland's itinerary value.

Is there a precedent?

Yes, and it's instructive. Through a terminal tariff, the Port of Seattle already bans open-loop scrubbing at berth, alongside agreements encouraging cleaner dockside operations.

Seattle's results suggest traffic doesn't necessarily suffer. The port just finished one of its best seasons ever, with nearly 2 million passengers across 330 ship calls — while the restriction was in force.

Other jurisdictions limiting scrubber discharge include ports in California, Connecticut, Vancouver, Canada, and a lengthening list of international ports.

What would ships actually do?

If the measure passes, calling lines have a few workable paths:

• Switch to compliant low-sulfur marine gas oil or similar fuel while at berth, removing the need for open-loop scrubbing.
• Run closed-loop or hybrid scrubbers in a mode that holds wash water in tanks rather than discharging at the dock.

Shore power would let engines shut down entirely, but Portland currently has no shore power infrastructure — so that escape route doesn't exist yet.

What happens Monday?

If approved, the city would revise its tariff rules, and cruise lines would have to adjust their exhaust handling at Portland's piers. Portland would become Maine's first port with such restrictions, and other East Coast ports could follow — a scenario that would multiply compliance decisions for lines up and down the seaboard.

For now, backers promise the bay gets cleaner and the ships keep coming; the first test of that promise will be whether Portland's call counts hold once lines start paying for cleaner operations.