SOUTH PORTLAND—It’s one of Maine’s most desirable locations—home to a vibrant and diverse community, nearby beaches, and close proximity to Portland’s downtown. But for years, residents in South Portland have wondered: With 120 massive petroleum storage tanks dotting the shore and knitted into some neighborhoods here, is the air safe to breathe?

Now the first answers are in, thanks to a year of emissions monitoring along the fencelines of the city’s tank farms. At two of those locations, in particular, the results showed levels of benzene—a known carcinogen—well above the state’s limit.

“We’re about 300 feet from those tanks,” said Ted Reiner, whose home is surrounded by three of the city’s tank farms. It’s where he and his wife raised their two daughters, now 38 and 28. Around Christmas, Reiner had surgery for bladder cancer. Now he’s undergoing immunotherapy, and he can’t help but wonder whether his environment is contributing to his health woes.

“You just don’t know what the cumulative effect is,” he said. “I think about it a lot.”

Reiner lives closest to the Citgo South Portland Terminal, in a part of South Portland known as Turner Island. The tanks there primarily hold gasoline, while others in the city contain an array of petroleum products, including heating oil and asphalt. He and his family are among the more than 12,600 people who live within a mile of the tank farm, according to EPA data.

According to data collected by Maine’s Department of Environmental Protection, the CITGO terminal is one of two tank farms in the city where emissions exceed the state limit. Average benzene levels were measured at 2.18 micrograms per cubic meter, well above Maine’s allowed limit of 1.28 micrograms.

The highest levels in the city—3.05 micrograms—were measured at South Portland Terminal LLC owned by Buckeye Partners, which, unlike Citgo’s tanks, does not have people living nearby. A tank farm owned by Sunoco, meanwhile, had measurements just below the state guideline.

Long-term inhalation of benzene can damage bone marrow and blood-forming cells, suppress the immune system, and increase the risk of leukemia. According to the World Health Organization, there is “no safe level of exposure.”

Each reported number from the state is the average of a two-week continuous sample. Citgo’s final number for the year is the average of all those two-week samples. When examining a year’s worth of data, higher emissions levels get masked. But levels spike: For one two-week period in particular, the average benzene level recorded near the Citgo facility was 11.8 micrograms per cubic meter, nearly 10 times the state limit.

Those shorter-lived “burst emissions” can be dangerous in their own right.

One to 14 days of exposure to higher levels of benzene can cause headaches and breathing issues for sensitive individuals, such as children, older adults, or people with preexisting health conditions. The risk level for short-term exposure for benzene is 30 micrograms per cubic meter. What’s not clear in the state’s data is whether benzene levels get high enough to trigger those responses.

Rich Johnson, a spokesman for Citgo, said the company takes the concerns of South Portland residents seriously and is continuing to work with state regulators. “We believe it is important that any study of air monitoring results support accurate, representative conclusions about community-level air quality,” Johnson said.

Buckeye Partners did not respond to multiple emails requesting comment.

Petroleum companies and oil terminal owners use various technologies to eliminate emissions, but they still happen. Most often, chemicals escape from tank vents, equipment leaks and loading rack operations.

Anna O’Sullivan, a 42-year-old artist and therapist, thinks about all of this. She worries when her 7-year-old son, Henry, plays in the yard. “Is he just, like, absorbing what’s in the air?” she wonders.

She’s hesitant to eat anything grown in the soil there. She’s concerned that staying put means poisoning them both.

But she’s also stuck. O’Sullivan bought her three-bedroom cape, built in 1904, with a big backyard for $190,000 in 2017—a charming and impossible find in the market today.

“I can see the tanks from my house,” she said. The feeling is: “I need to move. I can’t raise my kids in an area where it’s just, like, poisonous air.”

But also: “I like my house. … It’s hard to move, it’s hard to buy a house.”

The science supports these emotions.

The readings are high enough “to merit serious attention,” said Drew Michanowicz, a senior scientist at Physicians, Scientists, and Engineers for Healthy Energy, an independent scientific research institute that brings science to energy policy.

Across South Portland, most people don’t live immediately next to the tanks, which lessens their exposure because emissions are quickly dispersed. But especially around the Citgo facility, some live quite close.

Until last fall, when she had to move following a house fire, Jacky Gerry was living near the Citgo tanks. “Did I ever think we were safe? Probably not,” she said. “But did a lot of people have a choice as to where you live? No.”

People in South Portland first became concerned about the tanks in 2019, after the EPA announced consent decrees, a resolution of a dispute without an admission of guilt, with two companies with tanks here—Global Partners LLC and Sprague Energy. In both cases, heated petroleum storage tanks containing asphalt and a thick fuel oil were emitting what are known as volatile organic compounds—chemicals that include benzene—in violation of their state permits. That issue was specific to tanks containing asphalt and number 6 fuel oil, which were previously thought to have no emissions, and is not the situation with the Citgo tanks.

As a result of the consent decrees, the operators installed systems to capture emissions that appear to have worked. In the most recent testing, emissions levels around both tank farms were below Maine’s threshold.

The consent decrees also helped put the tanks on the radar of lawmakers. In 2021, a newly passed law mandated that all petroleum tank farms in the state begin fenceline monitoring for chemicals including benzene. That monitoring began in August 2024, and the first results were released late last year.

Residents here have long taken the fight against industrial emissions into their own hands, including in a high-profile—and successful—fight to keep oil from Canadian tar sands from being piped into the city in 2018.

It was in that spirit that South Portland resident Tom Mikulka, a retired chemist with a Ph.D. in biochemistry from Cornell, opted to analyze the state results so residents would be able to start understanding the implications.

“I wouldn’t want to go to sleep knowing there’s high benzene levels that close to my home,” said Mikulka, referring to the houses that stand just feet from a fenceline monitor mounted along the Citgo property. “While there is diffusion, I can’t imagine the data is much different just a few feet away.”

The state findings validate the concerns he’s had all along. Mikulka first began testing emissions in the neighborhood back in 2020, when he used COVID relief checks to purchase air monitoring equipment. He hung one of the monitors on Reiner’s property, near the swing his grandkids like to play on.

Now, six years later, with official data in hand, Mikulka hopes the findings will be harder for regulators to dismiss.

That’s Jacky Gerry’s hope, too.

“Now that we have these answers, who’s stepping up to the plate to say, ‘Let’s try to fix that?’” she said. “Is it a city problem? An oil company problem? Where does it fall?”