Dangerous incidents involving pipelines are rare, but September has been a bad month.
'Pipelines are imposed on us'
Pennsylvania is in the midst of a pipeline-building boom, and the Mariner East 2 natural gas liquids line is supposed to come online soon. It's created a lot of controversy -- and fear.
"You're aware it's there. You just go about your day, like all the other things that could befall a person: a car accident, a lightning strike, a terrorist attack," said Phil Stober, an organic farmer living next to the pipeline in Lebanon County. "It's just one more element to think about."
He said he laughed out loud when the company building it sent him a mailer with its safety instructions. While he may not be able to see or smell a leak, Sunoco Pipeline warned he must avoid creating any kind of spark -- even by ringing a doorbell -- and head upwind, away from a cloud of highly flammable things like ethane, propane, and butane.
"The information you get from Sunoco is don't start your car, don't use your cell phone. Just run away," Stober said.
Many things play into how people perceive risk, according to David Ropeik, who has studied some of the biggest fear factors. Pipelines hit on a lot of them. For one thing, he says, people rarely get to choose whether a pipeline will run through their property.
Companies like Energy Transfer Partners (the parent company of Sunoco) are often granted eminent domain.
"Pipelines are imposed on us," Ropeik said. "We don't volunteer to have one built under our house, or near our house. If we did, we wouldn't be as afraid."
The Mariner East project is part of a set of export pipelines -- so a lot of Pennsylvanians are being asked to live next door to something that may not bring them benefits, but carries a risk.
Energy Transfer Partners would not discuss the issue for this story. However, spokeswoman Lisa Dillinger emailed information about how the company works to train first responders and wrote that "pipelines, with their proximity to civilization, have a very good track safety record."
The dread factor
But if something goes wrong, it could be devastating.
"We over-fear low probability risks, if they cause us to die in really nasty ways," Ropeik said. "We freak out about shark attacks. They're not likely to happen."
Researchers call this the dread factor. On average, sharks kill about six people globally each year. Although rare, it does happen: a 26-year-old man was killed this month while boogie boarding off Cape Cod, Massachusetts. In the U.S., pipelines have killed average of 17 people per year, and injured 65 per year, over the past two decades, according to federal data.
"It's not the odds of dying," Ropeik explained. "It's the nature of how you get dead. Being blown up or burning to death carries the awfulness factor."
As a former journalist turned author and consultant, Ropeik has advised groups including the U.N.'s Intergovernmental Panel on Climate Change and pipeline companies about how humans perceive risk. He says it also matters if we trust the other people involved.
"If a risk comes from somebody we trust it won't bother us as much, as if it comes from somebody we don't trust," he said. "And the fossil fuel industry has been painted as super, uber bad guys."
A sense of control
Situations can also seem scarier if we don't feel in control, according to Stephen Broomell, an associate professor of social and decision sciences at Carnegie Mellon University. He gives the example of flying in an airplane (which is, statistically, a very safe thing to do) versus driving in a car. Fatal crashes kill tens of thousands of people on U.S. roadways every year.
"When you're driving a car you have the wheel in your hands, you may feel like you're such a great driver that you can remove yourself from dangerous situations," he said.
But even the best driver can't control the behavior of other people on the road.
"And it's that feeling of control that's the key," Broomell said. "It's not about whether you're actually in control "
It also matters whether a risk feels familiar or unfamiliar. The less people know about something, the scarier it can seem. But "riskiness" often means more to people than simply looking at the probability of fatalities. No matter what the statistics are, Broomell says people need to be heard.
"The perceptions people have should be treated as valid," he said. "What we need to understand is why they feel that way, before we can figure out if it's right or wrong to feel that way."
Despite the risks, there are many clear benefits to pipelines. The products they carry heat homes, powers factories, and generate electricity.
On his Lebanon County farm, Stober is not happy about the Mariner East pipeline, and he joined a local group fighting it. But he said he doesn't lay awake at night over the possibility of it hurting him personally. He's more worried about the bigger global threat of burning fossil fuels: climate change.
"That's what really troubles me," he said. "It's cooking the planet right now."
This story is part of the series "Mariner East 2: At what risk?"
Read more from our partners, StateImpact Pennsylvania.