AQ_F_0900009_20200310_ST_RvwMemo

Division of Air Quality
March 10, 2020
MEMORANDUM
To: Heather Carter, Fayetteville Regional Supervisor
From: Gary L.Saunders, Stationary Source Compliance Branch
Subject: The Chemours Company—Fayetteville Works
Fayetteville, Bladen County, North Carolina
Facility ID. No.0900009, Permit No.03735T47
Performance Testing for HFPO Dimer Acid on February 26—March 1, 2019 at Vinyl
Ethers North (VEN) Carbon Bed, Division Waste Gas Stack and Blower Intake by Weston
Solutions, Inc.
Tracking No. 2019-070ST
Summary of HFPO Dimer Acid Test Program
Sources Tested
During 2018, Chemours had upgraded controls to improve control efficiency and reduce emissions of
HFPO Dimer Acid. In addition to the installation of the carbon bed system to control fugitive emissions
from room air, Chemours had installed a secondary scrubber to provided additional scrubbing and had
added the capability to route the gases from the secondary scrubber to the inlet of the carbon bed
adsorber for final control prior to being discharged to the Division Waste Gas stack. This configuration
of controls could be used during the production of PPVE.
It was initially believed that this configuration could substantially reduce the overall emissions of HFPO
Dimer Acid from the VEN process area during the production of PPVE. However, a previous test
indicated results that indicated performance that was not to the level expected. The cause could not be
determined from the previous testing. Since there are a number of batch process steps/operations that
occur during normal operations, a series of test runs were conducted to determine if these cycles
adversely affected scrubber and carbon bed performance.
During the testing conducted between February 26 and March 1,2019, a series of eight individual 90-
minute test runs were conducted at the carbon bed inlet,the carbon bed outlet(to determine the
removal efficiency of HFPO Dimer Acid during the run for the particular operational cycle), and the
Division Waste Gas Stack. In addition, the air intake for the VEN room air was sampled to determine the
level of HFPO Dimer Acid in the air entering the VEN building.
Sampling Method
Testing was conducted using a modified EPA Method 0010 found in the SW-846 compendium of Test
Methods for Evaluating Solid Waste: Physical/Chemical Methods. This sampling train is a variation of the
EPA Reference Method 5 found in 40 CFR 60, Appendix A. The Method 0010 train extracts a sample

isokinetically from the gas stream, passes the sample through a temperature-controlled filter,through a
temperature-controlled condenser and into a series of XAD-2 resin "traps" and impingers to capture and
collect the materials that passed through the filter. The test method is designed to capture certain
particulate and condensable materials for later recovery and analysis.
After sample recovery,the samples were sent to Chemours' contractor,Test America's laboratory in
Denver, Colorado. GenX was extracted from the resin traps. The DAQ required split samples after
extraction to be submitted for independent analysis. This summary of results only addresses the results
provided by Test America for Chemours. Laboratory analysis and quantification was performed using a
liquid chromatography column and a dual mass spectrometer(LC/MS/MS).
Test Results
The reported HFPO test results reflect corrected emission rates accounting for dilution and spike
recovery values. Since each run represents a specific operational condition,this review only provides an
overview of the overall test program. The test report should be consulted to see the individual run
characteristics.
During each test run,the concentration of HFPO Dimer Acid at the Division Waste Gas Stack was two to
three orders of magnitude greater than measured at the fan inlet. Based upon this data,the ambient air
surrounding the VEN area was not considered to be a significant source of additional HFPO being
"added"to the process emissions.
With the exception of a single run (Run 4), the carbon bed had an average removal efficiency of 99.0%
or greater. During Run 4,the removal efficiency was measured at 80.0%. The cause for this decrease in
removal efficiency could not be determined from the available data. The inclusion of this one run in the
total data gave an average removal efficiency of 97.3%with an HFPO Dimer Acid emission rate of 1.56E-
03 lb/hr.
The emissions from the Division Waste Gas Stack were also measured during each test run to compare
to the outlet of the carbon bae adsorber. In each run during the test program,the emission rate from
the stack was between one to four orders of magnitude higher than the outlet of the carbon bed
adsorber, including Run 4 where the carbon bed removal efficiency was measured to be 80%. The
average emission rate of HFPO Dimer Acid was 7.42E-02 lb/hr.
Summary and Conclusions
The test results indicated that the carbon bed appeared to be performing normally. The apparent loss
of performance during Run 4 may be related to a sampling issue,given the consistency of performance
observed during other runs. However,the observation that the stack emissions are much higher than
the outlet of the carbon bed indicates that there is another unidentified source of HFPO Dimer Acid
entering the gas stream/stack after the carbon bed adsorber because the emission rate is significantly
higher than the outlet of the carbon bed adsorber.
NC DAQ staff members were on site during each day that source testing occurred. DAQ staff observed
the source test teams,the sample recovery and the process operations. Based upon the onsite
observation of the testing and review of the test report, NC DAQ concludes that the testing was
conducted in accordance to the modified testing protocol submitted by Chemours and that the

analytical results appear representative of the stack conditions and process operations during the
testing.
Cc: Central Files—Bladen County
[BEAM Documents-0900009