NC0086827_Response to NOV-2020-LV-0675_20201008

AARCADIS Dtesign &Consultancy
ornaturaland
built assets
Mr. Scott Vinson
North Carolina Department of Environmental Quality
Division of Water Resources
3800 Barrett Drive,
Raleigh, North Carolina 27609
Subject:
Response to Notice of Violation, Brenntag Mid -South Facility, 2000 East Pettigrew
Street, Durham, North Carolina
NPDES Permit No. NCO086827
Durham County
Dear Mr. Vinson:
Arcadis G&M of North Carolina, Inc. (Arcadis), on behalf of Brenntag Mid -South,
Inc. (Brenntag) is pleased to submit the following additional information in response
to the Notice of Violation (NOV) dated September 21, 2020. As indicated in the
NOV, the acetone concentration reported for the effluent sample collected on July
28, 2020 was 3.2 parts per million (ppm) which exceeds the permit limit of 2.0 ppm.
The acetone concentration was reported as 3.2 ppm based on the laboratory data
report from Test America Laboratories; however, we are not convinced this result is
actually reflective of the acetone concentration that was being discharged from the
groundwater treatment system.
The 3.2 ppm result is an anomaly in that it represents the highest acetone effluent
concentration reported since operation of the groundwater treatment system began in
2001. In addition, the acetone concentrations detected in the groundwater treatment
system performance samples indicate an increase along the treatment train. The
reported acetone results from the July 28, 2020 sampling event increase from an
influent concentration of 1.2 ppm, followed by a concentration of 1.4 ppm after the
air stripper, with a final effluent concentration of 3.2 ppm, which is located
downstream of the granular activated carbon (GAC) filters. It is highly unlikely that
acetone concentrations would increase after air stripper treatment and GAC filtration.
Additionally, the effluent sample collected on July 28, 2020 passed the chronic
toxicity test, which is a highly sensitive test that measures reproduction of
Ceriodaphnia dubia. If there was truly a high concentration of acetone in the
effluent sample, it would have likely impacted the results of the chronic toxicity test.
Therefore, we believe the most likely explanation for the 3.2 ppm acetone
concentration in the system effluent sample is due to a mix-up with the sample labels
at the laboratory or at the time of sample collection. Arcadis contacted Test America
Laboratories to have them investigate possible sample label issues and/or possible
acetone contamination of the samples as acetone is known to be a common lab
Arcadis G&M of North Carolina,
Inc.
5420 Wade Park Boulevard
Suite 350
Raleigh,
North Carolina 27607
www.arcadis-us.com
ENVIRONMENTAL
Date:
October 8, 2020
Contact:
Dave Twamley
Phone:
919-415-2294
Email:
David.twamley@arcadis.
com
Our ref:
30046885.03

ARCADIS
contaminant. Test America indicated they were unable to find an irregularity with
the quality control sample results.
A subsequent treatment system effluent sample collected on August 25, 2020
contained a significantly lower acetone concentration (0.017 ppm) confirming there
is not currently an issue with elevated acetone concentrations in the effluent. It
should also be noted that Brenntag has a long history of compliance within the
NPDES program, and this appears to be either an erroneous result or an anomaly that
has since been corrected.
If you have any questions regarding the information in this letter, please contact me
at your next convenience.
Sincerely,
Arcadis G&M of North Carolina, Inc.
A-41
David Twamley, L.
Project Scientist
Copies:
David Grenoble (Brenntag)
Rob Walston (Brenntag)
Jeff Best (Brenntag)
Jim Shilliday (Arcadis)
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