I ran across an
interesting
editorial about a recent anhydrous ammonia pipeline leak. The focus of the
editorial was on the problem of aging pipelines, but it briefly addressed an
issue that I have touched upon on several occasions; the problem of anhydrous
ammonia leaks near major roadways.
The Incidents
The most recent incident was on October 18
th near
Tekamah, NE (see news reports
here,
here,
here
and
here).
There was a major leak on an above ground portion of an 8” diameter pipeline
carrying liquefied anhydrous ammonia. The resulting vapor cloud crossed US 75.
A motorist drove through the cloud and died. The accident is being investigated
by the National Transportation Safety Board (NTSB).
The other incident that
I
have reported on was in August of 2009 in South Carolina where there was a
hose rupture during a tankwagon unloading incident. Again, the resulting vapor
cloud crossed a major highway (US 321). A mother of two drove into the cloud
and died.
In both cases the facility owners properly notified
authorities of the incidents, but the response was not quick enough (or perhaps
not well planned enough) to have stopped the victims from driving into the
cloud.
PHMSA and Leak Detection
Back in 2010 while
reporting
on an advanced notice of proposed rulemaking (ANPRM) from the DOT’s
Pipeline and Hazardous Material Safety Administration on hazardous liquid
pipelines I did a
special
post of the comments that I submitted on that rulemaking. In those comments
I noted that pipelines carrying poisonous inhalation hazard (PIH) chemicals
(like anhydrous ammonia) pose a special hazard in the case of leaks. I
suggested that:
“Any time that a PIH pipeline
traverses an area near major thorough fare the PHMSA regulations should provide
treatment similar to the HCA provisions even if the roadway is in an otherwise
rural area. Once again, any above ground portions of the PIH pipeline in these
areas will have an even larger potential affect.”
I also noted that:
“Once again, I would like to
suggest that any place where a PIH pipeline is above ground externally based
leak detection sensors are the only technology that would provide adequate
warnings of the relatively small leaks of PIH materials that could affect
unprotected civilians.”
In its notice of proposed rulemaking (NPRM) on the hazardous
material pipeline revisions PHMSA responded to my comments (and similar
comments by others) about HCA provisions for pipeline segments near roadways
by saying:
“PHMSA is not proposing to
designate major road and railway crossings as HCAs, but will consider whether
the pipeline IM requirements should be applied to these areas when completing
the study that Congress mandated under section 5 of the Pipeline Safety Act of
2011. PHMSA notes that the pipelines at such crossings would be afforded
additional protections under the other proposals made in this proceeding,
including the requirements for the performance of periodic internal inspections
and the use of leak detection systems.”
On the external leak detection issues, PHMSA
responded:
“PHMSA commissioned Kiefner and
Associates, Inc., to perform a study on leak detection systems used by
hazardous liquid operators. That study, titled “Leak Detection Study,” [4] was
completed on December 10, 2012, and was submitted to Congress on December 27, 2012.
PHMSA is considering, in a different rulemaking activity, whether to adopt
additional or more stringent requirements for sensitive areas in response to
this study.”
It should be noted that in the recent incident, it appears
that the pipeline operator did have flow-based leak detection active on the
affected pipeline section. One
news
report stated that: “the company’s remote sensing system detected a
pressure drop on the portion of the pipeline that runs through Burt County. A
pressure drop means a release may have occurred, he said.” Automated valves
were then closed and authorities notified, just not soon enough to stop the one
victim from driving into the ammonia cloud.
Emergency Notification
In both of these incidents the facility owner made all of
the appropriate notification when the leak was discovered and there is no
indication that the emergency response was not prompt. Still, in both cases an
innocent third-party, with no connection to the facility, died as a consequence
of the leak. In both cases they drove into a vapor cloud that looked no
different than innocent bank of fog. Once in the cloud the auto’s motor stopped
(for lack of oxygen) and the people died either from ammonia exposure or lack
of oxygen.
While it is easy to say that better something would have
prevented the leak (and the NTSB investigation will tell us that), it is even
easier to say that if the person driving the car had been warned not to drive
into the cloud, they would not have been killed. We have to expand our
definition of emergency notification.
For local residents, notifications can be made by a reverse
911 notification system. In the most recent incident that would have saved the
victim; he was a local who apparently was in search of the source of the ‘pungent
odor’ of ammonia that he had smelled. If he had been notified by a reverse 911
system, he may never have left the house, and almost certainly would not have
driven into the cloud if the message had been properly crafted.
For out of area personnel traversing highways near such
incidents, the reverse 911 system is much more problematic. More advanced
systems use phone location for notifications not sign-up addresses. But, then
again, safety people are trying very hard to stop people from answering phone
calls while driving. Something else is needed.
I proposed in an earlier blog post that signs could be
posted on major roadways near fixed facilities and pipelines that handle PIH
chemicals. These would be digital signs that would flash a warning not to
proceed when a local PIH chemical detector detected a chemical cloud near the
roadway. When not warning of a PIH leak, the signs could display other safety
messages.
Moving Forward
The editorial that peaked my interest in this incident
concludes by saying:
“Nebraska’s congressional
delegation needs to work together to ensure the agency [PHMSA] is giving
Nebraska proper attention, particularly in the case of anhydrous ammonia, to
avoid a repeat of the tragedy caused by the leak in Burt County.”
The Nebraska congressional delegation does have some
influence. Rep. Fortenberry (R,NE) is on the House Appropriations Committee
(but not the Transportation Subcommittee). Sen. Fischer (R,NE) is an
influential member of the Senate Commerce, Science and Transportation Committee
and Chair of the Surface Transportation and Merchant Marine Infrastructure,
Safety and Security Subcommittee (at least until December 31st).
The most immediate thing that will influence any legislative
or regulatory action on the pipeline safety issues involved in this incident
will be the outcome of the NTSB investigation. The preliminary investigation by
NTSB has not yet resulted in the incident being added to the list of current
investigations. This means that there may not be a formal NTSB investigations.
If, the NTSB does not take up this investigation then the effects of this
accident on future legislative or regulatory actions will be very limited.