SUPERIOR, WIS. – The refinery explosion and massive asphalt fire that injured 13 people and caused entire neighborhoods to flee this Lake Superior city lasted less than a day thanks to thousands of gallons of specialized foam, trained firefighters equipped with the right gear and a fire suppression system that showered portions of the refinery in water.
It was a close call, Superior Mayor Jim Paine said at a Friday news conference. Exactly how close is spelled out in a 2011 industry report.
Under the worst-case scenario, up to 180,000 people in the region surrounding this working-class port community of 27,000 residents could have been hurt or killed if the blast had compromised a tank of hydrogen fluoride that sat within 200 feet of Thursday’s fire at the Husky Energy Inc. refinery, according to a report by the Center for Public Integrity, a nonprofit news organization.
“We’re talking about a dense, cold, killing cloud,” said Fred Millar, a Virginia-based environmental consultant and activist on chemical safety. “The serious evacuations in Superior indicate that they were worried about something that could have much more serious consequences than a burning tank of asphalt.”
Nobody was killed in the initial blast or explosions that followed at the refinery south of town.
By Friday morning, the mayor had given residents who evacuated the day before the all-clear to return to their homes, and firefighters had scaled back their emergency response after a harrowing 24 hours.
The U.S. Environmental Protection Agency (EPA) also was on the scene to monitor air quality and to help oversee the beginning of the cleanup.
Hydrogen fluoride is a fast-acting acid that can cause deep, severe burns. Exposure can occur through inhalation and skin contact.
The chemical can permanently damage the eyes, skin, nose, throat, respiratory system and bones, according to a 2013 report issued by the United Steelworkers union, which represents many refinery workers.
Paine acknowledged Friday that the fire had the potential to be “absolutely catastrophic,” but he said the evacuation zone was large enough to contain any release of the chemical, and that the city had adequate medical transport and supplies to treat exposures.
As an added precaution, an industrial sprinkler system was triggered to spray the hydrogen fluoride tank with water, said Superior Fire Chief Steve Panger.
Paine said he was minutes from issuing a public statement Thursday night that spelled out the precautions the city was taking to keep the hydrogen fluoride contained when, at 6:42 p.m., the fire department reported that it had extinguished the blaze.
The initial blast occurred shortly after 10 a.m. Thursday during what a Husky Energy spokesman called a typical day of operations.
Over the next several hours, a series of explosions followed, setting off a raging fire that burned for hours and sent up a plume of noxious, oily smoke that spread for more than 30 miles and prompted the city to order a mandatory evacuation that lasted until 6 a.m. Friday.
The cause of the explosions was still unknown Friday, Husky Energy spokesman Kollin Schade said.
Husky, the U.S. Chemical Safety and Hazard Investigation Board and the Occupational Safety and Health Administration all are conducting investigations.
The refinery’s wastewater treatment plant needs to be brought back online, said David Morrison, the EPA’s on-site coordinator, and firefighting water and foam used to contain the blaze are being recovered. Morrison said the U.S. Coast Guard and oil response contractors have placed booms around the site to keep oily water from entering Hog Island Inlet, which feeds into Lake Superior.
Friday morning, diners at the East End Café, a neighborhood eatery about a mile from the refinery, recalled the moment when the explosion hit.
“I was sitting right here,” said Bill Clark, a cafe regular seated at the counter, “when that thing went ka-boom.” He felt the lunch counter vibrate and pictured a truck slamming into the wall. Outside, he saw smoke rising from the refinery.
About 30 people were in the cafe when the evacuation orders came over the TV, which was tuned to local news.
“They said ‘evacuate, evacuate,’ ” said Susan Mattson, a local librarian and cafe regular. A waitress threw customer’s checks in a drawer and told people they could pay later.
Mattson gathered up her dogs, Molly and Kasey, at home and pointed her car toward Duluth, usually a 10-minute drive. It took two hours. “There were police officers going up and down Ogden Avenue with gas masks on saying ‘You need to evacuate,’ ” said Mattson. She said drivers were honking in intersections as nerves wore thin.
The cafe patrons compared notes Friday morning and questioned the official narrative that the air was safe to breathe.
Mattson and others said they heard from people who went to Poplar, Wis., about 17 miles southeast of the refinery, who said the air smelled like chemicals.
The EPA’s air monitoring program hasn’t turned up anything more than trace amounts of toxic chemicals, the EPA’s Morrison said. “A lot of the chemicals were consumed in the fire,” he said.
Paine said Friday that he’s also heard from people worried about air quality.
“First of all, which way is the plume going? Mostly up,” he said, adding that the air tests were conducted at ground level. “Of course we didn’t want people breathing that black smoke. That’s why we evac’ed them! If you weren’t in that plume, if you weren’t in that smoke, the air was perfectly safe.”
Three petroleum companies — Husky, Enbridge and Plains Midstream — operate in Superior, where several pipelines run by Enbridge bring crude oil from Canada and elsewhere before it’s pumped south and east to serve markets across the nation.
Panger, the Superior fire chief, said firefighters eventually extinguished Thursday’s fire by using a foam-water mixture kept at the fire department that can reach hundreds of feet at 1,500 gallons per minute.
He said the hydrogen fluoride was stored in an area about 150 feet from the fire, and that it was constantly sprayed with water. The asphalt tank that ignited, meanwhile, was the last in a row of tanks, and winds pushed the blaze away from the rest of the refinery.
The refinery, built in 1950, employs about 180 people in the production of gasoline, diesel fuel, motor oils and asphalt, according to the U.S. Energy Information Administration. It was owned for decades by Murphy Oil, which bought it in 1958. Murphy sold it to Calumet Specialty Products in 2011 for $435 million, and Calumet sold it to Calgary-based Husky last year for $492 million.
In 2008, Murphy Oil paid a fine of $179,100 to settle more than 30 federal safety violations, according to the Wisconsin Center for Investigative Journalism.
In 2015, when Calumet was owner, OSHA issued four citations to the refinery, three of them for serious violations involving flammable and combustible liquids, hazardous waste operations and emergency response. Calumet was fined $21,000 but negotiated a settlement for $16,800.
Staff writer Mike Hughlett contributed to this report.