The April 2018 explosion and fire released an estimated 165 tons of emissions.


An enormous plume of smoke from a second fire at the Husky Energy refinery in Superior billows to the south April 27, 2018. Residents within 10 miles in the direction of the smoke were evacuated. (File / News Tribune)

An enormous plume of smoke from a second fire at the Husky Energy refinery in Superior billows to the south April 27, 2018. Residents within 10 miles in the direction of the smoke were evacuated. (File / News Tribune)


Husky Energy said it would bolster safety at its refinery in Superior and offset the hundreds of tons of pollution released in the April 2018 fire and explosion as part of a settlement in federal court.

In the proposed settlement filed Friday in U.S. District Court in Madison, Husky Energy, which does business at the Superior refinery as Superior Refining Company LLC, said it will add safety measures to the refinery’s use of hydrogen fluoride, establish an appliance change-out program aimed at replacing or retrofitting wood-burning appliances to cleaner appliances in seven nearby counties and install a 440-kilowatt solar array at the University of Wisconsin-Superior.

After a 30-day comment period, a federal judge will consider approving the settlement.

The settlement was first reported by Wisconsin Public Radio.

The settlement stems from a 2010 consent decree between the U.S. Environmental Protection Agency and Murphy Oil, then the refinery’s owner, that required the refinery to lower emissions and meet additional requirements if it were to exceed limits. Murphy Oil sold the refinery to Calumet for $475 million in 2011 and Husky bought the refinery in 2017 for $492 million.

According to court documents, the explosion and fire released an estimated 31.6 tons of particulate matter, between 22.6 tons and 48.3 tons of volatile organic compounds, 6.3 tons of carbon monoxide, 16.8 tons of sulfur dioxide and 400 pounds of nitrogen oxides emissions into the air.

Combined, the appliance-replacement program and solar installation are supposed to reduce emissions by 33.2 tons of particulate matter, 81.9 tons of volatile organic compounds, 187.6 tons of carbon monoxide, 9.2 tons of sulfur dioxide and 6.5 tons nitrogen oxides.

Since the settlement must still be approved by a federal judge, details of the UWS solar project will be determined later, UWS spokesperson Jordan Milan said Tuesday. She said the school “is pleased to be a beneficiary of this settlement.”

Milan did not say what percentage of the college’s energy use the 440-kw solar panels would produce.

Superior Water Light & Power is planning a 250-kilowatt solar garden in Superior that would fill the annual energy requirements for approximately 45 homes based on average residential usage. For comparison, using those figures, 440 kilowatts of solar could supply up to 80 homes.

During the 2018 fire, local officials in Superior ordered an evacuation of much of the city of 27,000 when an explosion and raging fire at the refinery threatened a storage tank containing 15,000 pounds of hydrogen fluoride. While no hydrogen fluoride was released during the incident and the fire never reached the hydrogen fluoride, which was 150 feet away from the location of the explosion, shrapnel was flung 200 feet.

Husky announced in April 2019 it plans to rebuild the refinery and continue to use hydrogen fluoride when it resumes operations.

Husky’s settlement would require it to upgrade its hydrogen fluoride storage by adding a separate tank where the chemical could be dumped in a leak, a laser detection system and additional layers of water curtains, changes Husky already announced last spring.

As part of the settlement, the refinery would also commission studies on its power supplies and any potential additional safety measures, Husky spokesperson Kim Gottormson said Tuesday.

Other ongoing lawsuits

Almost two years after the incident, a number of other lawsuits continue to roll through federal and state courts.

A lawsuit filed by contractors in August 2018 claims workers heard a “strange knocking noise” shortly before the explosion, but were ordered to return to work after they expressed concern. The explosion then occurred within 30-40 minutes of returning work, the lawsuit said. A jury trial is scheduled for August 2020.

A class action complaint filed by several Superior residents in August 2018 argued Husky displayed negligence, nuisance, trespass on land and strict liability — extrahazardous and/or ultrahazardous activity before, during and after the fire and evacuation.

In December 2018, a contractor working at Husky filed a lawsuit against the refinery claiming the April 26 explosion sent him 15 feet into the air, resulting in severe injuries when he hit the floor.

A lawsuit filed in October 2019 claims a man working outside the nearby Enbridge Energy property was “near the explosion and was directly struck by its blast wave, resulting in a traumatic brain injury, permanent partial vision loss, permanent partial hearing loss, and other severe and life-changing injuries.”

*Original article online at

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