A five mile radius kill zone that never happened

Saw this Letter to the Editor in the Dallas Morning News last week:

Source

What caught my eye was the statement "killed every living thing within a five-mile radius."

Just that afternoon in my DOT Hazmat Employee class I was teaching in Mesquite we were discussing "poison inhalation hazard materials and how the Emergency Response Guidebook's (ERG) Table of Initial Isolation looks at the hazard of the poison based on its toxicity and how that relates to DOT's use of the "hazard zone A, B, C, and D."

Source

You will notice that the compound "hydrogen sulfide" has a downwind night time protection distance of 3.9 miles.  In other words, the ERG considers a large release of hydrogen sulfide to not present a health hazard to the public 3.9 miles from the source.

Ellen Childress, the letter writer, claims:

A blowout of a pipeline carrying natural gas from wells to plant in Van Zandt County some years ago killed every living thing within a five-mile radius.

What, I thought to myself, would have been transported in a pipeline that could kill "every living thing within a five-mile radius."

Ms. Childress believes that the culprit was hydrogen sulfide:

Not a word was said in the article about the extreme danger of transporting hydrogen sulfide gas, a component of the "natural" gas when it comes out of the ground, through neighborhoods to a processing plant.

Understanding the concept of dose, dispersion, and the concentration of hydrogen gas sent in pipelines, I was curious as to what happened in " Van Zandt County some years ago."  Was there a blowout that killed "every living thing within a five-mile radius?"

Why would Ms Childress make this claim if it were not true?  And, more importantly, if it wasn't true, it was now in the newspaper for all to see and believe it to be true.  How does one make an informed decision on risk if the risk is under or over inflated?

It was easy for me to discount the "five mile radius" claim as impossible.  It was therefore easy for me to believe that whatever happened in Van Zandt County did not kill every living thing in that area.

So what, if anything, did happen "some years ago?"

In Texas the Railroad Commission (RRC) is in charge of oil & gas drilling and production.  The one thing the Railroad Commission does not have jurisdiction over is railroads - but that's for another blog post I suppose.

The Texas RRC logs "Blowouts and Well Control Problems" and posts them on their web site.  So I searched for blowouts in Van Zandt County and this RRC website for Region 5 came up.

Based on this data, there was a fire in 1972 and a hydrogen sulfide (H2S) release in 1978.  The RRC does not report any deaths or injuries for any of the five reported issues in Van Zandt County.

I did a search for a newspaper account of the release.  Here is what I found:

Source

Searching for "Van Zandt County" and "hydrogen" provided no other hits.

So, what's the lesson here?  Don't put anything in print that has not been confirmed.  Why five miles?  Why not 10 or three?

So when she asks: "What kind of protections do homeowners and others have today against that kind of disaster?"

"That kind of disaster" never happened.

There are real risks and real protections.  Focus on those in order to make your decision.


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