EPA Urges USN Permit Changes

By Walter F. Roche Jr.

Citing the need for additional monitoring, reporting and record-keeping, federal environmental regulators are recommending a series of changes in a controversial Tennessee permit for a major Greene County chemical manufacturer.
The permit, known as conditional major, sets environmental requirements for US Nitrogen, the Greene County manufacturer of ammonium nitrate. It was sent in draft form for comment nearly two months ago to the U.S.Environmental Protection Agency.
In a detailed response to the Tennessee Department of Environment and Conservation, EPA's Atlanta regional office recommended about a half dozen changes covering everything from visible emissions to setting annual limits on natural gas consumption.
In a cover letter EPA officials said they looked forward "to working with you to address any questions you have regarding our comments regarding the monitoring, record-keeping and reporting requirements."
"We consider our comments to be recommendations to ensure compliance with Title V of the Clean Air Act," the Nov. 6 letter states.
The EPA recommended that the permit be amended to set reporting and record-keeping mandates for monitoring visible emissions at the nitric acid plant. EPA noted that as written the permit does not include a compliance method for meeting opacity standards.
In addition EPA noted that the draft permit does not include any record keeping requirement.
While Tennessee officials had stated that provisions of a state law allow for excess emissions when they are "necessary and unavoidable," EPA recommended "that the permit require monitoring of opacity as appropriate" along with additional record-keeping.
At US Nitrogen's steam generating plant EPA urged the addition of a requirement for the company to record the amount of natural gas used and to limit natural gas consumption to 990 million standard cubic feet per year "and to keep a record of 12 month rolling average of the natural gas combustion."
For the company's anhydrous ammonia plant EPA recommended that US Nitrogen be required to keep a log of heat input on a monthly basis. In addition the permit should require the company to record the amount of natural and purge gas used, according to the EPA.
For the flares used at various points in the manufacturing process, the EPA is urging that there be a five minute limit on the use of flares at the steam generating boiler. Noting that TDEC had stated that weekly monitoring would be inappropriate, EPA said it was unclear from the permit how or when the company would monitor the flares.
EPA recommended that the permit be amended to require "a monitoring frequency appropriate for the source" which could include monitoring the flare only during startup and shutdown.
At the nitric acid plant EPA recommended that the permit require US Nitrogen to maintain electronic records that show the ammonia concentrations.
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