From Bob Klotz's front garden, you can't see any of South Portland's oil tanks — but on certain days, he says, he can smell them. Especially on his morning walks.
"We tend to do the big, wide loop that takes you down to Fore River. So the global tank is right there, and then you walk towards the left, and the other tanks you can see but, and you can see them unloading tankers there."
Klotz, an environmental activist and retired Physician's Assistant, lives nearby two tank farms. He said the odor from the tanks has become all too familiar.
"It's got a density and an edge to it, and it feels dark and icky and dirty," he said. "And so to smell that and know that I'm breathing it in, and to be unsure how it's affecting me is troubling."
South Portland is a fairly densely populated city. The tanks jut up right next to homes, businesses, and schools.
For years, Klotz and other residents of South Portland have been concerned about air quality when it comes to the tanks. That came to a head in 2019 when the federal Environmental Protection Agency sued Sprague and Global, two of the oil terminal companies, for violations to the Clean Air Act.
The Maine Department of Environmental Protection has since installed air monitors around the city. And after additional legislation in 2023, the marine terminal operators have installed fence-line air monitoring; those have been on line for less than a year.
But members of Protect South Portland, a grassroots group, say that, 6 years later, there's still not enough information about how residents living near the tanks are being impacted by emissions. And the city is still waiting on a comprehensive health study from Maine CDC containing air quality data from the DEP and the terminals.
Residents want to definitively know whether, or when they can link what they’re smelling to harmful air pollution.
"The odor is overwhelming at times. But the real question is, what are the tanks emitting? What are residents inhaling, and how is it impacting our health?" said State Senator Anne Carney of South Portland at a recent public hearing.
South Portland Representative Matthew Beck is sponsoring legislation that would require the terminal companies to issue public alerts during loading and offloading times.
"This notice would give members of the public the opportunity to plan their day so they may be able to leave the immediate vicinity during oil transfers, or at least close their windows to minimize their potential exposure to any hazardous vapors that may be released," Beck said.
The hazardous vapors in this case are VOCs, or volatile organic compounds, which can irritate the eyes, nose and throat and cause headaches, respiratory problems and even cancer with prolonged exposure.
Of particular concern to residents are emissions that occur at specific times: when petroleum products are being loaded and unloaded from the storage tanks.
David Carpenter is a professor of environmental health at the University of Albany who has studied air pollution issues.
“A high episodic release is probably as dangerous to maybe even more dangerous than in small, continuous release over long periods of time,” he said.
Carpenter said, when an oil tank is being filled, the existing vapors inside are displaced by the liquid. And during offloading, the liquid itself is being agitated, which can also lead to the release of VOCs.
Carpenter said these emissions can be a blind spot in air quality regulations.
"A release that doesn't last for a whole week, but lasts for maybe 30 minutes at an extremely high level, is extraordinarily dangerous, and that's not captured by most of our federal standards," Carpenter said.
Some residents have called for a study specifically of those emissions, Senator Carney said.
"I do think if there was an intense one year focus, we would really understand what actually is going on, and we could take the appropriate steps again, specifically to protect public health," Carney said.
The terminal operators have so far resisted calls to issue air quality warnings voluntarily, citing security concerns.
At a public hearing on the bill, Tim Winters, VP of Operations at Sprague, said that the strong odors aren't necessarily VOCs.
"We all remember from chemistry that a few molecules of a of a compound open up in chemistry class will create an odor that permeates the room, but there's no harm to us as students," Winters said.
Nick Skally, a Sprague representative, couldn't comment on ongoing discussions with the city when reached directly, but said the companies already report their shipping schedule to the local fire department and other authorities for security reasons.
"There's a lot of reporting that happens currently. I think the concern there was, like, you're going to start scaring your citizens unnecessarily." Skally said. "And it isn't even always correlated to, you know, the concerns that you think you might have."
With South Portland so densely populated, Senator Carney said, residents want to know for certain that their air is safe — especially given how close some of the schools are to tank farms.
"Kaler Elementary school is very close to an oil tank. If you stand on the playground and you're a third grader, you can probably throw a tennis ball and hit or come close to hitting the tank," she said.
If the bill is passed, the operators would be required to begin issuing notices in mid-2026. But for now, the city and the terminal companies are still in talks.
For Bob Klotz, he said the uncertainty affects his day to day life, from morning exercise to time spent in the garden.
"This is a big raspberry bush that our neighbors are allowed to participate in. And the raised bed back over there is really pretty dedicated to garlic, because I think we just have to have garlic all the time," Klotz said.
He said he's quite strict about organic growing practices in his yard.
"But if that toxic stuff is landing on this, how organic is it really? And someone could say, well, everywhere, that would be a risk, but I'm just concerned that it's a greater risk given this community's realities," he said.