Frequently Asked Questions about the Superior Refinery incident

General Questions - May 5, 2018

1. What did burning asphalt release into the air? Is it harmful?

Based on air quality monitoring, the levels of emissions do not appear to have been harmful.

The refinery produces three different grades of asphalt, which generally have similar properties. Asphalt is a thick liquid refined from crude oil. Its most common use is to construct roads. It contains heavy petroleum compounds, sulfur, and trace metals such as iron, nickel, and vanadium.

The black smoke during the fire was caused by the asphalt burning and was a mixture of particulate and gases.

2. What else was released into the air during the fire? Is it harmful?

Based on air quality monitoring, the levels of emissions do not appear to have been harmful. In addition to asphalt, the refinery produces gasoline and diesel. When gasoline and diesel burn, they produce carbon dioxide and water vapor, similar to when fuel combusts in a vehicle.

3. What is in the foam used to put out the fire? Is it harmful?

Firefighting foam is very important, in part because it can remove oxygen from the fire and prevent the release of vapors. As with many chemicals, the foam is potentially harmful if ingested. The firefighting foam is being collected by booms in Newton Creek and vacuum trucks are removing it from the collection points. We are sampling Newton Creek at several locations between the refinery and the mouth of the creek to determine whether additional steps need to be taken. See page four for more information.

4. What if I inhaled smoke during the incident?

If you have an immediate health concern, please contact your health provider.

5. Was Hydrogen Fluoride released?

No. The first layer of protection in place, the fire suppression system, worked as it was designed to.

The tank was not compromised in the fire.

The HF storage tank is designed with multiple protection levels including a dedicated deluge system that douses the tank with a water curtain to keep it cooled and mitigate potential releases.

The HF tank also has a pressure safety valve. In the event pressure builds in the tank, the safety valve opens and the HF gases flow to a scrubber where they are neutralized and sent on to the flare system for destruction. The remaining liquid HF would be drained to the acid neutralization pit and rendered safe.

6. If it’s safe, why are you still monitoring the air?

As a precaution, we continue to monitor air quality, including potential fugitive emissions. Air monitoring results have consistently been within safe levels. Our focus is on the safety of the community.

7. Who is doing the air and water monitoring?

Husky is monitoring air quality, as is the Environmental Protection Agency. The results of the air quality testing conducted by Husky and the EPA are being posted on the Douglas County website. Husky and the Wisconsin Department of Natural Resources are testing water quality.

8. Are there harmful substances inside my home?

Particles in smoke are not easily transported inside buildings. The gases that may have been produced by the fire dissipate naturally and would not remain inside a home.

9. I am concerned about my immediate health, what should I do?

Please contact your medical provider if you have any immediate concerns about your health.

10. What about soot?

If you have questions with respect to soot, you should contact the Douglas County Department of Health and Human Services.

Read the Douglas County Department of Health and Human Services fact sheet here.

11. Do I need to clean inside my home or in my ducts?

It is unlikely that particles or gases made it into homes.

12. Is it safe to play outside?

Smoke from the fire has cleared from the air and has likely been removed from play surfaces by natural processes, such as rain or snow.

13. What about soil and gardening?

Read the Douglas County Department of Health and Human Services fact sheet here.


Air Quality Monitoring

Husky, the Environmental Protection Agency and other agencies have been monitoring the air and are sharing data with each other every 12 hours. The air monitoring data will be posted on the Douglas County website.

Fixed monitors are located within, and around the perimeter of, the refinery. Mobile monitoring is being conducted over a wide area throughout the City of Superior.

Air Quality Monitoring

Protecting Fish and Water Bodies

The water used to fight the fire is being contained on site and is being sampled and tested. Treatment strategies are currently being evaluated, and we will be working with the relevant agencies to process this water. Booms are being used to help contain any potential runoff and prevent it from flowing out of the mouth of Newton Creek.

Husky, working closely with the Wisconsin Department of Natural Resources (DNR), is testing water quality at several locations downstream of the refinery. We are testing for gasoline, diesel, oil, metals, sulfate, volatile and semi-volatile organic compounds, and per- and polyfluoroalkyl substances (PFAS). PFAS are a component found in many things, including firefighting foam. It may have been present in some of the foam used to extinguish the fire. Once samples are collected they are sent to an independent third-party laboratory for analysis. Husky will share any necessary remediation plans with the community.