NC0005258_RESP_NOVNOI2023OC0002_20230123

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JAN 13 2013 -�
4C 1� Stephen Richards
sg l carbon 82ep9e5-05 charardsDirect Water Quality Regional Operations
Stephen. Richards@SGLCarbbVi:Cc7'Y& Regional Office
January 19, 2023
Via E Mail and Certified Mail
Mr. Daniel Boss, Assistant Regional Supervisor
Water Quality Regional Operations Section
Asheville Regional Office
Division of Water Resources, NCDEQ
RE: Notice of Violation & Notice of Intent to Enforce
NOV-2023-OC-002 (Incident #202201877)
Unlawful Discharge of Petroleum Products
NPDES Permit No. NC0005258
Burke County
Dear Mr. Boss:
As Environmental Health and Safety Manager for SGL Carbon, LLC ("SGL"), we respectfully
submit this letter in response to the Notice of Violation & Notice of Intent to Enforce ("NOV") issued by
North Carolina Department of Environmental Quality ("NCDEQ") dated January 11, 2023.
As described herein, the NOV relates to an equipment malfunction upset incident that took
place in December 2022 at SGL's Morganton, NC facility. This response describes, based on a review of
the events in question, how and why the incident occurred, the estimated amount of material released,
and SGL's response and actions to the upset event.
Description of Release Incident and Amount and Duration of Release
On December 31, 2022, SGL was notified by NCDEQ of release of material from SGL's permitted
outfall for NPDES Permit No. NC0005258. Upon notification SGL activated the Spill Prevention, Control
and Countermeasure Plan ("SPCC"). On January 1, 2023, an environmental response team responded
to an equipment malfunction upset incident. On January 4, 2023, SGL located and isolated a
malfunctioning heat exchanger.
Based on visual observation and a review of the facts a total of 525 gallons of hydraulic fluid was
released into SGL's stormwater system, 450 gallons of hydraulic fluid was collected by the
environmental response team, and 75 gallons of hydraulic fluid is unaccounted.
Due to the nature of this event, SGL initiated a systematic evaluation of all hydraulic fluid
containing components onsite (90-acre facility). Through an elimination process SGL was able to isolate
a portion of the site by tracking the hydraulic fluid through our stormwater water system, this process
involved opening each storm drain (180 in total) and following the hydraulic fluid upstream to the
source; a hard piped discharge located in a secured high voltage electrical area.
DCO public - (RICHARDSST)

Cause of Release Incident
At the time the release occurred, Morganton NC experienced unseasonably prolonged cold
weather conditions and during this event SGL experienced upsetting conditions. Due to the design of
the heat exchanger SGL was not aware the internal components of the heat exchanger failed during this
upset condition allowing hydraulic fluid to contact single pass cooling water (uncontaminated potable
water). Under NPDES Permit No. NC0005258 non-stormwater discharge is authorized for discharge of
uncontaminated potable water, allowing the single pass cooling water (uncontaminated potable water)
to enter the stormwater system.
Corrective Action
SGL is committed to prevent or abate the emissions of harmful pollutants from company
operations. As noted above, unseasonable prolong weather conditions contributed to the release
event. SGL has taken corrective measures to prevent incidents like the one that occurred on December
31, 2022, from reoccurring. The heat exchanger related to this event has been removed from service
and replaced with a heat exchanger that does not discharge single pass cooling water to SGL's
stormwater system. Furthermore, SGL has included the heat exchanger in SGL's cold weather plan, by
insulating the heat exchanger and providing heat freeze protection to the heat exchanger. SGL has
reviewed all other uncontaminated potable water discharges for similar designs.
If you have any questions or request additional information, please contact me.
Sincerely,
Stephen Richards
DCO public - (RICHARDSST)