Propane Revisited

It has been a while, but let’s look at a recent chemical incident as very briefly reported at KHQ.com. A propane explosion caused a reported $1 million dollars in property damage at a construction site in Mukilteo, WA when a valve was knocked off a tank when it was being moved.

How much propane did it take to produce a ‘300-foot blast zone’? It only took about 300 gallons or about 2,000 lbs. It doesn’t take much flammable gas to provide a really significant explosion when the conditions are right. That is why DHS set the screening threshold quantity (STQ) for flammable gasses at 10,000 lbs; about five times as much as was involved in this explosion.

OOPS. I should have said all flammable gasses except propane. At the urging of the propane industry, and more importantly the agriculture industry, DHS set the STQ for propane at 60,000 lbs. This means that all but the largest commercial propane tanks and the wholesale tanks at distributors are presumed to not be a threat to homeland security if successfully attacked by terrorists.

While politics certainly had a part to play in the DHS decision on the listing of propane, one must also assume that in a twisted sense reality also had a great deal to play in that decision. I have not seen reliable figures on how many tanks holding 10,000 lbs or more exist in the United States, but I would surely bet that it was more than the 40,000+ number of facilities that did submit Top Screens to the CFATS program.

That means that we could have had more than 80,000 Top Screens submitted with a similar doubling of the about 4,000 facilities going into the site security planning process. And you think that DHS has had problems processing site security plans now? OMG!

Of course the tank at this facility could have been designed to hold 60,000 lbs of propane, the article doesn’t say. One would like to think that you pretty much empty a propane tank when you move it, just to prevent this type of accident. You also reduce the cost of the crane that has to lift it if you lighten the load. So it is possible that this sight could actually have been covered by CFATS.

OOPS. Wrong again. You see it was a water treatment facility. So, even if it did have a 60,000 lb propane tank on site, it would not have been covered by CFATS. Nor would it have been covered by the much weaker EPA regulations that don’t require security plans. The EPA is concerned with protecting the purity of the drinking water (a very important concern to be sure) not with protecting the public from terrorist attacks on the chemicals on site.

Oh well. I guess the good people of Mukilteo, WA will just have to hope that their water facility management can provide adequate anti-terrorism security without federal oversight.