Friday, September 2, 2016
US Nitrogen Had Two Excess NO2 Emissions
By Walter F. Roche Jr.
US Nitrogen officials have informed state regulators that there were actually two separate incidents on Aug. 23 in which excess nitric oxide and nitrogen dioxide were emitted from the $200 million ammonium nitrate manufacturing facility.
Notes compiled by an official of the Tennessee Department of Environment and Conservation show that US Nitrogen Plant Manager Andrew Velo acknowledged in an Aug. 25 telephone conversation that some 2,900 pound of nitrous oxide were released during the two events.
The notes provide new details of what caused a huge orange cloud to form above the US Nitrogen site on Aug. 23.
In addition Velo, in a letter to TDEC, reported that the total emissions were likely between 1,000 and 3,000 pounds.
"The release contained nitric oxide and nitrogen dioxide. Both are extremely hazardous substances," Velo's letter states.
"US Nitrogen does not believe that there were any acute or chronic health risks associated with the release," he added.
The notes on the telephone conversation with Velo were compiled by TDEC Manager Michelle Owenby. A copy was provided by TDEC to Park Overall, a local resident.
According to the notes, Velo acknowledged that he probably was in error when he ordered another attempt to restart the nitric acid plant on the afternoon of Aug. 23.
"Andy said in retrospect that he probably shouldn't have attempted the second restart," the TDEC notes state.
During the second restart some 2,400 pounds of nitrous oxide were emitted, while the more visible morning incident resulted in 500 pounds of emissions, the TDEC memo states.
The first incident occurred at 6:15 a.m. when a startup of the plant was initiated and, due to insufficient pressure in the tower led to the emissions and the plant was shutdown after 45 minutes at 7 a.m.
The second startup attempt, the memo states, was initiated at 3:30 p.m.
"The same issues occurred and they kept running the plant in an attempt to identify the source of the leak or failing delivery pressures," the memo continues.
The attempt was not aborted until 6:45 p.m., resulting in the release of the 2,400 pounds of nitrous oxide.
Velo told Owenby that the company then reported the incident to the National Response Center.
Velo, according to Owenby's notes, said the company planned to do testing with argon, an inert gas, to find the source of an apparent leak.
Owenby reported that she questioned Velo about whether adequate and sufficiently trained staff were on duty during the two events. She listed about a half dozen staffers including Velo with experience in running a nitric acid plant.
Velo acknowledged during the conversation that US Nitrogen's environmental manager was not on duty during the two events.
"I asked Andy to be mindful of atmospheric conditions when starting up again," Owenby wrote, adding " I asked him to avoid calm wind and temperature inversion conditions that were unfavorable to atmospheric dispersion."
She stated that Velo "acknowledged the early morning startup may not have been favorable conditions. I also asked Andy to be mindful of the community and the initial impression they were making upon them as they started up."
According to the memo, US Nitrogen will probably be asking for an extension on an upcoming deadline for the completion of required tests.
TDEC spokesman Eric Ward said today that the agency investigation of the emissions was ongoing.