Friday, February 1, 2008

Chlorine – A special case

Two recent news stories point out the special problem that DHS has when trying to regulate security for Chlorine as a Release Chemical of Interest. On January 21st twenty-one people were transported to the hospital from a Holiday Inn. There had been a chlorine leak at a water park at the hotel. On January 30th a janitor at a high school was transported to the hospital and students were required to shelter in place for 90 minutes because of a chlorine leak at the pool.


If these accidents had actually been intentional they would have been classified as release incidents not as theft incidents. Chlorine has two separate STQs, one for release and one for theft. The release STQ is 2,500 lbs and the theft/diversion STQ is 500 lbs. For a typical chemical facility, a manufacturing facility, distributors warehouse or water treatment plant, it would take 2,500 lbs to have a significant off site effect.


A small water park or a large swimming pool would have no need of having 2,500 lbs of chlorine on site. They would probably use 100-lb cylinders to feed chlorine into their water system. One or two would be attached to the system and there would be one or two on hand as replacements. Two to four hundred pounds of chlorine on site would mean that the facility would be under the STQ for Theft/Diversion and the facility would not come to the attention of DHS.


An attack on the chlorine cylinders at an indoor water recreational facility or pool would not have to wait for a gas plume to drift off site to have an effect on untrained civilians. It might have to drift only ten to twenty feet in a relatively confined space to reach children and untrained adults. The panic in such a situation would probably do as much harm as the chemical itself.


Would such an attack, if properly carried out, be a successful terrorist attack? Well, it would not be as successful as the Twin Towers or the Oklahoma Federal Building, but with proper news coverage it would bring terrorism home to more people than either of those attacks. And the cost in planning and trained personnel to conduct such an attack would not be anywhere near as high.


The other side of the question is what would it cost to regulate the chemical security at every public pool and water park? With the limited number of personnel that DHS has working on the chemical security issue there is no way that DHS could expend any manpower on checking the security at such facilities. Furthermore, those facilities have relatively limited budgets in the first place and would probably not have the ability to conduct a vulnerability assessment or implement an adequate site security plan.


An alternative would be for the pool supply and chlorine industries to get together and develop a simple set of standards that would help reduce the effects of a successful attack. Such things might include:


  • Flow rate limiters on chlorine cylinders that would limit how fast a cylinder could discharge.
  • Require that indoor facilities have a positive ventilation flow from the public areas to where the chlorine cylinders are stored with venting to outside of the building.
  • Require the use of chlorine detectors with audible alarms in the areas where chlorine cylinders are stored or used.

Others would suggest that the government require that alternative forms of disinfection be used in such facilities. This would eliminate the danger of chlorine release. Unfortunately, the alternatives also have their disadvantages. Ozonation and UV light treatments are a lot more complex to implement and maintain so their costsare probably higher. The use of hypochlorite (bleach) as an alternative source of chlorine would eliminate some of the release issues, but there are already a large number of chemical accidents associated with the handling of this material.


Of course, if there is a successful terrorist attack against such a facility, DHS will be racked over the coals by the commissions with perfect hind site. The news people will crucify Col. Stephans or his successors for not regulating the use of such dangerous chemicals. DHS just cannot win.

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