I just had an interesting conversation with a television news person who contacted me about some research he was doing about the explosion the day before yesterday at the West Fertilizer Company facility in West, TX. He had apparently talked to someone at ISCD earlier who told him that (so this is now third hand information that I have not verified) that the facility had not filed a top screen reporting the anhydrous ammonia stored in two storage tanks on site. The facility has (according to rtknet.org) had filed Risk Management Plan (RMP) reports with the EPA documenting 54,000 lbs of anhydrous ammonia on site.
I was asked if I thought that it would be unusual for a facility of this type not to have filed a Top Screen. My reply was essentially yes and no. I mentioned that ISCD had done considerable outreach to chemical facilities in the years since the introduction of the program in 2007. I know that agricultural supplier organizations were one of their target audiences in the early days; so one would like to think that the word had gotten down to facilities like West Fertilizer.
But the CFATS program is the Chemical Facility Anti-Terrorism Standards and I would bet that many owners of facilities like this ignored the information pushed their way because they knew that they weren’t ‘chemical companies’; they were agricultural supply retailers. That plus the fact that no terrorist worthy of the name would waste their time in an attack on a rural facility like the one in West, TX would tend to reinforce the view in the minds of many owners of this type of facility that the CFATS program couldn’t possibly apply to them.
Anhydrous Ammonia Explosion?
I was also asked if I though an anhydrous ammonia bleve (Boiling Liquid Expanding Vapor Explosion) could have been responsible for the catastrophic explosion at the facility. Now I am hardly an expert on bleves, but I do know that they are typically preceded by a hot fire outside of the tank (and videos and news reports certainly show a fire before the explosion) and can produce spectacular explosions. Now anhydrous ammonia is hardly a flammable chemical, but a fire hot enough to cause the combination of tank softening and increased pressure necessary for a bleve would certainly be hot enough to ignite an anhydrous ammonia cloud. So you certainly have a potential for a fuel-air explosion.
There are other possible explosion sources at a fertilizer company. An Ag retail facility like this could typically be expected to store/sell ammonium nitrate and urea fertilizers. Both of these types of fertilizers can also produce spectacular explosions. So why the immediate focus on the anhydrous ammonia? It is the only chemical that a news organization can readily confirm was located at the site by searching an on-line source like rtknet.org; neither ammonium nitrate nor urea are required to be reported to the EPA under the RMP program.
Google Map® Investigation
This conversation peaked my interest enough that I did a map investigation of the facility using Google Maps®. If you look at the facility from the satellite view you will see four good size tanks; three to the north of the two main buildings and one to the south. None of these tanks would be holding anhydrous ammonia; they are not pressure tanks.
I can’t tell what is actually in them, but the large diameter piping going to the smaller three of these tanks would be typical of a solids handling system similar to the type used to handle ammonium nitrate or urea.
Again, I can’t see any tank markings in these satellite images, but I think that we’ll find that the two anhydrous ammonia tanks are among the four horizontal tanks south of the larger building along the railroad siding. These horizontal tanks are commonly used for storing anhydrous ammonia.
Now there are a number of smaller vertical tanks between the building and the horizontal tanks. If these tanks contained some sort of flammable or combustible liquid and they released their contents to the ground you could get the type of fire that could cause a partially filled anhydrous ammonia tank to bleve. Of course this is also the type fire that we would expect a responding fire crew to be flooding with water and that would effectively prevent a bleve.
No, I think that we will find that one or more of the three intermediate size tanks held ammonium nitrate and that was what caused the devastatingly catastrophic explosion.
Chemical Safety Board Starting Investigation
The Chemical Safety Board investigators started arriving on site yesterday. They are deploying a large contingent because of the number of deaths and the amount of property damage that certainly places this chemical accident among the most deadly in recent memory. There is no telling how long it will take for them to complete their investigation, but we should start to hear some definitive information being provided by the CSB to the national media.