Petroleum tank farms in Maine would have to continuously monitor emissions and take other steps to reduce off-gassing from aboveground tanks under a bill that received a committee endorsement on Monday.

The bill is a response to concerns in South Portland about noxious odors and air pollution emanating from massive tanks located along the city’s waterfront in close proximity to schools, residential neighborhoods and businesses. Although those concerns date back decades, momentum has built since 2019 to tighten monitoring and reporting of emissions from petroleum tanks amid a high-profile dispute between state and federal regulators over emissions levels.

The proposal, which faces additional votes in the full Legislature, would direct Maine’s Board of Environmental Protection to develop rules requiring the installation of “fenceline” monitoring stations around facilities with aboveground tanks. The low-cost monitors would then track levels of potentially hazardous emissions drifting into local neighborhoods.

The bill also would require use of “floating roofs” – which reduce the accumulation of gases by sitting on the surface of the petroleum – in tanks larger than 39,000 gallons, and insulation in heated, fixed-roof storage tanks to reduce temperature changes that can create additional gases.

The bill also would direct the BEP to mandate the collection of emissions created when loading fuels into empty tanker trucks, and the installation of technology capable of monitoring at least monthly for leaks from storage tanks, piping and fittings.

“I think this makes some really significant progress in strengthening Maine’s regulations and reducing emissions,” said Sen. Anne Carney, D-Cape Elizabeth, who led efforts to craft a bill late in the legislative session.


The Legislature’s Environment and Natural Resources Committee voted 9-2 Monday to endorse the bill, L.D. 163, and send it to the House and Senate for consideration. If approved by the full Legislature – which would require two-thirds majorities as an emergency measure – the bill would require the board and the Maine Department of Environmental Protection to begin rulemaking by year’s end.

South Portland is home to more than 100 petroleum tanks scattered across the city, some located a block or two from schools, daycare centers and homes whose residents have long complained about noxious odors from the facilities. Other petroleum storage tank complexes are located in Searsport and just outside of Bangor.

In 2019, it came to light that one of those major South Portland tank farms, Global Partners LP, had been violating the federal Clean Air Act for more than a decade. But South Portland officials and local residents were never notified about the issue in part because of different ways state and federal regulators regarded the emissions.

A more sweeping bill that was introduced this year by Rep. Victoria Morales, D-South Portland, would overhaul the state’s system for setting emissions limits and require facility operators to test for emissions. Committee members voted Monday to put that bill on the shelf until next year as the BEP develops the new rules.

Morales said that she was “thrilled” with the committee vote on L.D. 163 in part because it will require facilities to monitor pollution levels near their boundaries.

“I think it is a success for our community and other communities that may have these tanks in denser areas because we haven’t had that information,” Morales said. She also pointed out that the bill will require the DEP to report to lawmakers in 2022 on the initial results of monitoring and will require the board to periodically compare Maine’s emissions regulatory system with the “best practices” used by other states and the EPA.


One other provision of those rules would require facilities to collect site-specific emissions data semi-annually during the most active time of year for the tanks.

Roberta Zuckerman, a South Portland resident active with the organizations Protect South Portland and the Tank Emissions Coalition of Maine, said she was particularly pleased with the fenceline monitoring provision. Zuckerman said she hopes that next year the Legislature will revisit the issue of linking emissions licenses to health considerations in the local community.

While the bill wouldn’t contain everything she and other advocates wanted, she described it as “a significant step” that would be meaningful to people in the community concerned about the extent to which hazardous emissions are drifting into neighborhoods.

“This would be a really good step towards addressing people’s concerns and requiring transparency and accountability on the part of the emitters,” Zuckerman said.

Many of the core provisions in L.D. 163 were included in a January 2021 DEP report ordered by the Legislature that examined how to measure and control emissions from aboveground petroleum storage tanks. As a result, the department testified neither for nor against the bill.

One key difference is the requirement that facilities install so-called “fenceline monitoring.”


Carney noted that fenceline monitoring – low-cost systems used to track emissions levels – already is required by the EPA at refineries and other types of facilities. The technology is particularly useful with floating-roof tanks where emissions are more difficult to track.

“So it is really important for us to understand what is being emitted, so fortunately we do have this technology, the fenceline monitoring, that will allow us to do it,” Carney said.

In written testimony submitted to the committee last week, Kathryn Clay with the International Liquid Terminals Association called some of the requirements discussed in L.D. 163 “extremely aggressive and expensive,” and suggested they will only increase the costs Mainers pay for fuel. Clay noted that vehicles are a far larger emissions source of volatile organic compounds, or VOCs, than petroleum tanks.

Clay told lawmakers that “there is not an air quality emergency in Maine or South Portland that would require dramatic and immediate action.”

“ILTA is more than willing to share information demonstrating that liquid terminals should not be the focus of additional regulations when there are so many other sources of air contaminants in Maine and there is no evidence that air quality is significantly affecting public health in South Portland,” Clay wrote.

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