NC0000892_Response to NOV-2024-LV-0448_20240806

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Performance Applied
August 5, 2024
CERTIFIED MAIL #9589071052700489982658
RETURN RECEIPT REQUESTED
NCDEQ Raleigh Regional Office — Water Quality Section
Attn: Vanessa Manuel, Assistant Regional Supervisor
3800 Barrett Drive
Raleigh, NC 27609
RE: Response to revised Notice of Violation — Intent to Assess Civil Penalty
NOV-2024-LV-0448
Arclin USA, LLC
NPDES Permit Number NC0000892
Chatham County
Dear Ms. Manuel:
The following is in response to the above referenced revised Notice of Violation/Intent to Issue
Civil Penalty (NOV) letter received at site via e-mail on July 24, 2024, originally received at site
on June 6, 2024, with Arclin response on June 14, 2024. The following is an update on site
waste water treatment plant (WWTP) performance in response to upset condition reported to
Kevin Fowler at NC DEQ on March 7, 2024.
Arclin's continuing investigation, monitoring and response actions due to the upset were
presented to NC DEQ during site visit on April 1011, and in follow-up communication on May 16'h
2024. As discussed with DEQ, unusually low ambient temperatures during that period cause an
upset in the WWTP that significantly reduced biological activity, resulting in elevated BOD
results.
Arclin took immediate action upon discovery of the upset condition and continues to invest labor
and economic resources to address return to normal operations, such as:
- Addition of municipal mixed liquor;
- Contracting waste water treatment consultant to aid in initial remedial measures and
operational adjustments;
- Development of robust control plans, expanding monitoring parameters for enhanced
process control and system adjustments;
- Evaluating WWTP to identify feasible improvement opportunities; and
- Comprehensive evaluation of site waste water streams composition and process control
and/or reuse potential

Page 2 of 3
Ardin USA LLC
Our monitoring data demonstrates a correlation between water temperature and BOD results as
illustrated by the graph in Attachment 1. As temperature dropped in January and February of
2024, BOD results began to fluctuate, peaking in March and subsiding only when ambient
temperatures began increasing in April. The results have since stabilized, demonstrating the
causal relationship between ambient temperature and BOD levels.
Though our results indicate the BOD results have stabilized, we will continue more frequent
monitoring of indicator parameters in the event additional controls are required, and to account
for any fluctuations that may be observed in the future due to the system's long hydraulic
residence times (50 days) and even longer mean cell residence times.
Given the trend obtained as part of our investigation, we believe the BOD results were the
outcome of the exceptional and unforeseen circumstances that arose from extreme cold
weather that reduced biological activity and caused system upset condition,
We request DBQ consider the effect of the upset condition, as per 40 CFR 122.41(n), as well as
Arclin's notification; proper operation at the time of discovering the upset; investigation and
findings; assignment of resources and remedial measures into account, and eliminate the intent
to assess civil penalty.
If you have any additional questions, please contact me at [phone]
Daniel Cox
Deputy Director of Manufacturing

Page 3 of 3
Arcfin USA LLC
Attachment 1 — Temperature vs. BOD Trend
Temperature Vs BOD
35
30
25
u
20
15
10
300.00
250.00
200.00
150.00
100.00
50.00
5 -r - - _ ..— — - # -alb - I-
12/30/2301/19/2402/08/2402/28/2403/19/2404/08/2404/28/2405/18/2405/07/240E/27/2407/17/24
♦ Temperature BOD