Overview:
- Southwest Detroiters say they’re frustrated with recurring odor issues that seem to occur in the middle of the night
- Michigan regulators say a Canadian facility caused recent odor issues, but a spike in pollution at the Marathon refinery has also raised concerns.
- A state official said the pollution at Marathon likely came from elsewhere, but an air quality expert has voiced skepticism.
In the middle of the night, Hubbard Farms resident Elizabeth Luther woke up to a foul odor that smelled like “extremely concentrated natural gas.” Once morning came, she took to the neighborhood’s listserv to see if anyone else smelled the “terrible odor” on the morning of July 19 around 2:45 am.
“If it’s in the middle of the night, my first inclination is that someone is doing something they shouldn’t be,” Luther said. “And they’re trying to do it when no one is paying attention.”
This latest round of odors highlights an everyday problem in Southwest Detroit, where pollution from vehicles and industrial sources on both sides of the river takes a toll on residents’ health and quality of life. Meanwhile, regulators struggle to find the source of specific odor complaints, with dozens of major industrial facilities emitting pollution in the area.
A 2016 study warns these ongoing issues could pose a risk for children in Southwest Detroit, who make up a more significant portion of the population than in other areas of the city.
With still-developing bodies, younger residents are “particularly vulnerable to adverse health effects associated with exposure to air pollutants than other areas of the city,” according to the study.
Southwest odor pollution likely came from Canada, regulators say
Following a survey of the area, a state investigator found that the odor on the night of July 19 likely originated in Windsor, Ontario where the Plains Midstream Canada facility reported a leak of mercaptan. This smelly compound is added to odorless fuels like natural gas to ensure that leaks don’t go undetected.
The Canadian Broadcasting Corporation reported the substance had been added to propane, but no propane was released.
“What was remarkable about this particular odor, in my opinion, is how persistently strong it lasted during its travel north,” Jeff Korniski, a supervisor at the Michigan Department of Environment, Great Lakes and Energy’s Air Quality Division, wrote in an email to a resident. He said that on the night of July 19, the odor was powerful along the riverfront and in the Hubbard Farms neighborhood, based on his observations in the field.
Luther reported the smell to EGLE’s emergency hotline twice the following evening, around 7:45 p.m. and 12:40 a.m. On Sunday, July 21, around 10 p.m., Hubbard Farms resident Robert Anderson smelled a “very localized” odor just east of the Gordie Howe Bridge.
While Hubbard Farms is roughly two miles from the Plains Midstream’s Windsor storage facility, Stuart Batterman, an environmental health researcher at the University of Michigan, said it’s relatively easy for this pollution to move across the wide Detroit River without dispersing the way it would move over land, reaching Detroit at almost the same concentration it was in Canada.
Pollution spike at Marathon raises questions
Around 5 a.m. on July 22, a private air pollution monitor at the Marathon refinery detected a spike in pollution near the intersection of Fort and Pleasant streets. The monitor showed an hourly average for levels of total reduced sulfur (or TRS) at nearly 30 parts per billion.
Batterman said the most likely cause of the high TRS readings was hydrogen sulfide (or H2S), a pollutant with a 2-minute limit of 5 ppb.
Although the monitor provides hourly readings and not data by the minute, Batterman said the spike in pollution could suggest “multiple violations” of Michigan Rule 406, which sets limits on hydrogen sulfide emissions.
The monitor’s readings stopped until 8 a.m. when levels had returned to normal. This data lapse often occurs in the early mornings on Marathon’s air monitoring site.
Korniski wrote in his email that Marathon monitors cut out for a few hours most mornings, and the reporting gap on July 22 didn’t appear “to be a deliberate reaction to the high measurement registered.”
Hydrogen sulfide is removed from oil during the refining process and has a rotten egg smell like mercaptan. At high levels, it can cause convulsions and death, while at lower concentrations, it’s linked to neurological effects and ear, eye, and nose irritation as well as quality of life issues on account of the strong smell.
Southwest Detroit community activist Theresa Landrum lives near the refinery. She said the smells happen “everyday all day,” adding that many residents have central air to avoid opening their windows. Rotten egg, sulfur, you name it, Landrum has smelled it.
“They use the palatable word ‘odor.’ No. What chemicals are causing the odors?” Landrum said.
Regulators doubt Marathon was the cause of pollution spike
It’s unclear if the Canadian facility was emitting more pollution before Marathon registered the high TRS levels, although one resident reported odor issues the evening prior. The Plains Midstream facility reported another release was likely on July 22, but not until much later in the afternoon. Batterman said mercaptan released in Canada could have affected TRS readings, but there was reason for skepticism.
“If you do have a plume drifting over to Canada and it hits the eastern monitor at Marathon, how come it didn’t hit the other monitors?” he said.
There are many other pollution sources in the area, but Batterman said past monitoring suggests the Marathon refinery emits significant amounts of TRS.
He also noted that the winds were low when the reading was taken.
Yet, considering that winds were coming from the north to northeast at the time of the spike, Korniski concluded that Marathon was likely not the cause of the high TRS readings, but that its monitor was detecting pollution from elsewhere.
He told Planet Detroit that to enforce a Rule 406 violation against Marathon, “we first would need to establish, unequivocally, that Marathon is the cause of an odor.” Only after the agency traced the odor back to the refinery would EGLE look at TRS readings to prove a violation.
Neither Marathon Petroleum nor Plains Midstream Canada responded to Planet Detroit’s request for comment for this article.
‘Residents are tired’
On July 23, the “sewage-like” odor hit Hubbard Farms again. Resident Martha Potere took her dog out at 2:30 am and reported the smell to Michigan’s 24-hour Pollution Emergency Alerting System hotline. Luther and other residents reported being awakened by the “pungent” odor. She said it’s frustrating to have no resolution.
“I don’t know anything about mercaptan, and I don’t have the time and energy to research it,” Luther said. “Do we know what parts per billion floating through our neighborhood at 2 am were safe?”
The U.S. Centers for Disease Control and Prevention says mercaptan can cause eye, ear, nose and throat irritation as well as shortness of breath. At higher exposures it can cause nausea, vomiting, dizziness and lack of coordination.
Potere said the recurring issue has led to an erosion of trust.
“It’s always at night, which gives me the heebie-jeebies…it makes me feel like there’s something that they’re trying to do while not everyone’s paying attention,” Potere said.
As a lifelong Southwest resident and community activist, Landrum said people get tired of calling because it’s an everyday thing. But, she added that residents need to keep reporting.
Residents can submit an air quality concern here, addressed Monday through Friday from 8 a.m. to 5 p.m. For after-hours concerns or emergencies, call the Pollution Emergency Alerting System (PEAS) at 1-800-292-4706.
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