A fire was reported at the Patrick Cudahy meat packing facility in Cudahy, WI at approximately 2130 on July 5, 2009. It has been reported that the fire was caused by a signal flare that landed on the roof top of the facility. This claim is being investigated. The fire quickly spread throughout the wood-structured facility engulfing large sections of the older parts of the facility. As the fire spread, refrigeration units were compromised by the fire and at approximately 0500 on July 6 an anhydrous ammonia release was reported to the National Response Center. It is estimated by Patrick Cudahy representatives that 2,000 - 5,000 pounds of anhydrous ammonia were released to the atmosphere. Actions were taken by the facility to capture and isolate the remaining anhydrous ammonia to prevent further release of the material. As a precaution, residents were evacuated within a one-mile radius of the facility.
U.S. EPA was requested to perform air monitoring for the evacuation area.
At the request of the Wisconsin Department of Natural Resources (WDNR) and Incident Command, U.S. EPA conducted air monitoring of the evacuation area. U.S EPA arrived to the scene at approximately 0830 hours on July 6. U.S. EPA subsequently tasked the Superfund Technical Assessment and Response Team (START) contractor to conduct air monitoring at the site. Monitoring parameters included ammonia, volatile organic compounds, carbon monoxide, hydrogen sulfide, lower explosive limit, oxygen, and radiation. No concentrations above background were detected within the evacuation area with the exception of particulates. A peak concentration of 8.16 milligrams per meter cubed (mg/m3) was measured during a brief flare up within the evacuation zone. No sustained readings were recorded for any of the parameters monitored for during the event outside of the evacuation area.
The evacuation was lifted for residents by fire officials at approximately 7 PM on July 6.
