Perhaps the only good thing to come out of the disaster is
that, if such an accident occurs again, authorities will have better guidelines
for first responders and cleanup crews. These guidelines will be the product of
about two years of testing and research by scientists and engineers at the
Georgia Tech Research Institute (GTRI) and the Georgia Institute of Technology.
GTRI scientists and engineers from Georgia Tech’s National
Electric Energy Testing, Research and Applications Center (NEETRAC) first became
involved in cleanup efforts within a few days after the train wreck that caused
the leak on Jan. 6, 2005, in the small town of Graniteville, S.C. South Carolina
Electric & Gas needed advice, as well as analysis of components from its heavily
damaged power substations that served Graniteville and the large, local textile
facility owned by Avondale Mills. The 70 to 80 tons of chlorine gas that leaked
from the wrecked train corroded equipment in the substations, which eventually
had to be rebuilt.
Because of the magnitude of the disaster, emergency response
activities delayed cleanup crews’ access to the substations and textile mill. It
was 17 days after the accident before clean up began at Avondale, which, by
early February 2005, had contracted with GTRI to do materials testing and
assessment of restoration efforts.
“Basically, you had items sitting in an acid bottle for days,”
says Lisa Detter-Hoskin, a GTRI senior research scientist who led the research.
“Chlorine combined with moisture in the air to form acids that corrosively ate
away at surfaces and moved inward like a cancer in the human body. Much of the
mill’s equipment was beyond repair due to the severity of the chlorine attack.”
Early in the research, it became apparent that the far-reaching
effects of the chlorine accident on Avondale would require a variety of
expertise from GTRI, Georgia Tech and elsewhere. So Avondale’s law firm, King &
Spalding in Atlanta, hired Detter-Hoskin as a consultant to coordinate
environmental and materials-related testing and among them, chemists,
environmental scientists, civil engineers, air.
quality monitoring specialists, metallurgists, water treatment
experts and industrial hygienists. Detter-Hoskin, group leader of the GTRI
Materials Analysis Center, also performed materials analysis and corrosion
testing on behalf of Avondale and provided technical consultation for chemical
cleanup and restoration.
Detter-Hoskin compiled all of the research and recommendations
into a report for Avondale. That report is now the basis for a white paper
Detter-Hoskin – a Ph.D.-level inorganic chemist with almost 20 years of
experience in dealing with materials forensics, including chlorine corrosion –
is writing for the U.S. Department of Homeland Security. She will explain the
relationship between acid concentration, exposure effects and possible degrees
of material damage. She also will document the cleaning protocols most effective
to decontaminate and restore an area affected by a chlorine leak. Detter-Hoskin
believes that paper will ultimately become a handbook for first responders,
disaster cleanup companies and the chemical industry.
“Chlorine and other highly reactive chemicals are of great
concern because they’re shipped daily by rail, barge and truck,” Detter-Hoskin
says. “There have been some leaks in U.S. history, but until Graniteville, they
were mostly small, and little damage was done. So there was very little public
information on how to best serve Avondale Mills in this accident.”
Now, GTRI and Georgia Tech have a unique database of
information resulting from 18 months of testing and assessment of samples from
Avondale’s Graniteville facilities. This information may be able to help in the
event of another accident, or even a terrorist attack, Detter-Hoskin says.
The accident and subsequent cleanup efforts also revealed some
areas of potential future research for GTRI and Georgia Tech, including
technology to improve the safety of shipping chlorine, Detter-Hoskin notes.
Research might also focus on the development of safer chemical alternatives to
chlorine, which is currently used in 27 percent of all U.S. manufacturing
operations, including the sanitization, pharmaceutical and automotive
industries.
In the meantime, Detter-Hoskin is reviewing the details of and
gleaning the lessons learned from the Graniteville disaster. Numerous factors
contributed to the wide-ranging impact of the chlorine leak, she says. For one,
the weather in Graniteville at the time of the accident was warm and humid, and
there was no breeze that might have dispersed the gas.
“The gas had plenty of moisture to react with, in addition to
particulates in the air,” Detter-Hoskin explains. “Chlorine will react with
almost anything to transform it into more reactive chlorine derivatives. So,
dust, lint and dirt in the mill all became chlorinated.”
In addition, process chemicals used in the mill, such as those
for dyeing fabrics, became chlorinated and subsequently super reactive. “So you
weren’t just dealing with chlorine leaking from the rail car. Chlorine was
reacting with everything, including coal, gas and oil fueling the boilers,” she
says.
Another factor negatively affecting cleanup was the delay in
getting initial access to the mill and the ineffective cleanup process that was
implemented, Detter-Hoskin says. “The severe, chlorine-induced corrosion was
prolonged because the damage was not mitigated in a timely manner,” she adds.
Norfolk Southern was in charge of the initial cleanup efforts
at Avondale. According to Detter-Hoskin, their cleaning protocols lacked ongoing
environmental abatement, such as that used in lead paint or asbestos
remediation. This allowed chlorinated dirt and lint to be redistributed onto
cleaned surfaces. Also, limited mechanical or abrasive steps were used to
pre-clean material surfaces, and they did not perform any deep chemical cleaning
with strong acids or bases
The phosphate-based restoration process was selected because
it is environmentally friendly, safer for workers and commonly employed after
chlorine chemical fires,” Detter-Hoskins says. “But these chlorine fires do not
cause the extreme deep-metal pitting damage observed at Avondale Mills. The
phosphate cleaning methods do not aggressively get into metal layers to clean
the chlorine acidic salts deep within pits. The process they used actually
encapsulated a lot of chlorine debris. In the long run, that exacerbated cleanup
attempts.”
Detter-Hoskin recommended implementing two alternative
rigorous cleaning methods approved by the American Society for Testing and
Materials and the Society for Protective Coatings. These processes would have
required skilled workers and costly hazardous acidic waste disposal. But by May
2006, when Avondale Mills settled with its insurance company, damage to
equipment in the mill was beyond repair, Detter-Hoskin says. Two months later
the company went out of business.
Avondale has a federal lawsuit pending against Norfolk
Southern and the three workers who left open the manual switch, leading to the
train wreck. That case will be tried in federal court in Aiken, S.C., but it may
be many years before it’s resolved, Detter-Hoskin says. She will serve as a lead
scientific expert for Avondale in the trial.
“This accident happened in the small community of
Graniteville, South Carolina, and in my estimate, its ultimate economic impact
to the town will likely exceed $1 billion,” Detter-Hoskin says. “Had this
occurred in Atlanta or another large city, you would have had hundreds of
thousands of people hurt and killed within a 10-minute period. The financial
impact would be immense, as well. Metal equipment and electrical wiring would be
destroyed, and computer data would be lost.”
