Saturday, October 28, 2017

US Nitrogen Clears Key Test


By Walter F. Roche Jr.

With a last minute adjustment suggested by Tennessee officials, US Nitrogen has cleared a critical test on its sometimes troubled nitric acid manufacturing plant in Greene County.
Approval of the performance test and the accompanying data was disclosed in a Sept. 12 letter from Jeryl W. Stewart of the Tennessee Department of Environment and Conservation to Andrew Velo, US Nitrogen's plant manager.
The Midway company was required to submit data for 30 days of operation. TDEC said that after reviewing the revised data "the division considers the report to be technically correct and acceptable for compliance demonstration."
TDEC records show the approval came after the company submitted data for an additional day of testing. Velo wrote in an Aug. 24 letter to TDEC that the company had originally omitted the data for the day in question because it was a startup day and included only two hours of operation.
In the letter to Velo, Stewart noted that data was omitted for May 31 "due to the fact that the monitoring system was undergoing preventative maintenance during that time period."
Stewart said TDEC also reviewed acid production data from US Nitrogen and "the division agrees "the emission rate demonstrated compliance" with a rate of emissions of 3.7 pounds per hour.
"The division agrees that US Nitrogen has demonstrated compliance with the nitrogen oxide limits as set above," the letter states.
He added that US Nitrogen has also completed the performance test requirements.
US Nitrogen missed the original deadline for completing the performance test requirements.
The efforts to start up the acid plant have been marked by missteps including the emission of nitric acid vapors into the atmosphere.
The acid plant is but one part of the process of producing ammonium nitrate. US Nitrogen is shipping that chemical to Austin Powder, its corporate parent, for use in the production of explosives.
Contact: wfrochejr999@gmail.com



Monday, October 16, 2017

US Nitrogen Files River Report


By Walter F. Roche Jr.

US Nitrogen has reported that it withdrew another 19.475 million gallons of water from the Nolichucky River for use at its Midway chemical manufacturing facility in September.
In a one-page report filed with the Tennessee Department of Environment and Conservation, the company reported withdrawing over 900,000 gallons from the Nolichucky on two days with less than 900,000 reported on all other days.
On two days, Sept. 25 and Sept. 28 the company drew no water from the river.
Water discharged back into the river in September totaled more than seven million gallons. On nine days during the month no water was discharged back to the river, That includes from Sept. 1 through Sept. 5.
The reports are required under the terms of one of US Nitrogen's state permits.
The company had reported drawing nearly exactly the same amount from the river in August. The report for July showed 14 million gallons were withdrawn.

Monday, October 9, 2017

TDEC Says No Damage from US Nitrogen Incident


By Walter F. Roche Jr.

Tennessee environmental officials have concluded that there was no damage from the April 19 release of nitric acid vapor from the US Nitrogen's Midway plant and any harm to residents was unlikely.
In a nine-page report, the Tennessee Department of Environment and Conservation also said that under state and federal regulations US Nitrogen was not even required to report the incident because the amount of nitric acid released was well below the threshold triggering a reporting requirement.
The agency did say that it was referring one complaint from a local resident to the state Health Department.
In a letter to US Nitrogen accompanying the report, TDEC division director Michelle W. Owenby, said the agency was closing its investigation.
According to the report, about 424 pounds of nitric acid was released over a four minute period in the April incident caused by the rupture of a heat exchanger. However, it states the level that triggers a reporting requirement is 15,000 pounds.
"In the case of the April 19, 2017 incident, the amount released is below the reportable thresholds and USN reported the release incident even though it fell below the reporting levels as identified," the report states.
In addition the reporting requirement only applies to releases with a concentration of 80 per cent or more, but the nitric acid in use at US Nitrogen had a concentration of only 59 per cent, TDEC found.
"For reasons noted above, the division concludes that section 112(r) of the Clean Air Act is not applicable to the event on April 19, that involved nitric acid of 59 per cent concentration," the report continues.
Citing the fact that much of the land around the US Nitrogen plant is owned by the company or the Industrial Development Authority, TDEC concluded that "no serious environmental or health impacts likely occurred."
The report states that the closest school, West Greene High School is 1.9 miles away and the Mosheim Elementary School is 2.7 miles east of the plant. The closest business is about a quarter mile away.
The population density is very low in the area and the closest residences are nearly a half mile away, the report states.  In addition the release occurred at 6 p.m. when "local schools would not be in session and most local businesses would have already closed for the day."
TDEC did note that a "vehicle reconnaissance" of the area showed evidence of old homes or residences located on the properties owned by US Nitrogen and the IDB.
As for the weather, TDEC said that the presence of rain showers at the time of the release "likely helped to mitigate the transport of any nitric acid emissions associated with the event."
TDEC did say that it received one complaint of "alleged health-related impacts associated with the event." The agency also received one anonymous call complaining of health related effects, but that caller chose not to file a formal complaint.
The one formal complaint is being referred to the state Health Department.
"Finally, the division does not believe any environmental damage occurred as a result of the April 19 incident," the report concludes.

Sunday, October 1, 2017

August US Nitrogen Incident Reported


By Walter F. Roche Jr.

Officials of US Nitrogen have filed a report with the state disclosing that an early August incident forced a shutdown of its Green County ammonia plant.
Calling it a "process upset," US Nitrogen's manager Andrew Velo wrote that the incident resulted in three abnormal flare events "which led to an operating shutdown."
In a letter to Michelle Owenby, the manager of air pollution programs at the Tennessee Department of Environment and Conservation, Velo said that the incident triggered an internal investigation to determine the root cause.
According to the letter, as a result of the investigation some equipment had to be replaced and extensive staff training was implemented. Still further training may yet be required.
The incident is the latest in a series of start up misfires that have triggered concern among some area residents.
Velo wrote that the internal investigation found that liquid carryover from an ammonia liquid let-down vessel led to the incident when the ammonia combined with water to form excess levels of aqua-ammonia, triggering the flare events.
"This level resulted in heavy flare events during plant pressure variations. The investigation team  determined that uncertainty in interpreting the fault state of the level indication on D-7 and the subsequent operational response due to this uncertainty were the main root causes of this incident," Velo's letter states.
The plant manager said the investigative team determined that some changes including the replacement of some equipment had to be completed before the plant could be restarted.
He listed a series of actions, including retesting of all let-down vessels "to verify functionality and reliability, and replacement of a pressure valve.
Velo said all recommended steps were taken before start up  and that the plant has operated without incident since the re-start. He did not disclose the date of the start up.
"Several long term actions related to training and operating procedures have been identified and will be completed in the coming months," the letter concludes.
Contact: wfrochejr999@gmail.com