This morning, North of Chicago, a 2,000-gallon (8,750 pounds of NH3) nurse tank appears to have suffered a catastrophic failure releasing all 1,700 gallons/8,750 pounds of NH3 onto the road and ditches. The reason I wonder if this was in the realm of a “Worst Case Release Scenario” is that we had Temps in the low 50’s, Night-time (the event occurred at 4:30 am) and we had a wind speed of 5 mph. These are darn close to the weather conditions assigned for our RMP WCS’s. The helicopter footage from Chicago area news station(s) clearly shows the level of concern with this event. The NTSB is traveling to the scene tonight and will begin their investigation in the morning. The Local Fire Chief indicated that the vessels failed in transport and there was no accident that caused the tank(s) to leak… was this another Stress Corrosion Cracking (SCC) failure on a nurse tank? We still do not know if this incident involved just one (1) nurse tank or if somehow both tanks lost their contents, but the post-accident press conferences by the Sherrif and the FC made it sound as if one tank was involved. Here are some pics that may help you understand the layout of the scene so when you’re watching the videos and seeing the news pics you can have some points of reference. Thanks to my friend “J” for his help in helping me understand this layout:
The green circle is the release point. Down and slightly to the right you will see two (2) fields that run parallel to each other (Numbered 1 and 2), separated by a small tree line. These are the openings that contain NH3 gas in the release photo at the bottom of this post. You can see a golf course at the top right of the pic and you can see this in the release photo as well.
I have matched up the numbers to the scene pic from the aerial photo.
