NC0031038_Correspondence_20240227

From: Hughes, Maribeth
To: Bell, Wes
Cc: Wyatt, John M.; Carpenter, Stanley
Subject: [External] NPDES NCO031038
Date: Wednesday, February 21, 2024 1:02:11 PM
Attachments: January 2024.Ddf
Affirmative Defense January 2024 DMR.pdf
CAUTION: External email. Do not click links or open attachments unless verified. Report suspicious emails with the
Report Message button located on your Outlook menu bar on the Home tab.
Wes —
Colonial submitted the Discharge Monitoring Report (DMR) covering January 2024 today (see
attached). This DMR illustrates an exceedance of the benzene limit contained within the subject
permit. Colonial is including the attached letter as an affirmative defense towards any potential
enforcement actions.
If you have any questions or concerns, please call me to discuss at your convenience.
Maribeth
Maribeth Hughes, PE, CSP
Environmental Specialist
Colonial Pipeline Company
m.704-458-3993 1 mhu hes col i e.com
0
Colonial Pipeline Notice - This e-mail message (including any attachment) contains information that may
be confidential, be protected by attorney -client or other privilege, or constitute non-public information. If
you are not the intended recipient, please notify the sender by electronic mail or telephone and delete the
original message without making any copies. Use, dissemination, distribution, or reproduction of this
message by unintended recipients is not authorized and may be unlawful.

CDColonial Pipeline Company
Maribeth D. Hughes, PE, CSP
Environmental Specialist
February 20, 2024
Mr. Wes Bell
Division of Water Resources
NCDEQ - Water Quality Regional Operations
610 East Center Avenue
Suite 301
Mooresville, North Carolina 28115
RE: NPDES Permit NCO031038 Exceedance
Colonial Pipeline Company, Charlotte Delivery
Mr. Bell:
Phone: [phone]
e-mail: [e-mail]
Colonial Pipeline Company (CPC) owns and operates the facility (Facility) located
at 7524 Kenstead Circle in Charlotte, North Carolina. The Facility operates under
the above -referenced National Pollutant Discharge Elimination System permit
number (NPDES Permit).
On January 9, 2024, severe storms passed through North Carlina resulting in
Governor Cooper issuing an Executive Order declaring a State of Emergency. As
measured by the National Weather Service, over 2.5 inches of rain fell in the
Charlotte area on this date. This was after 1.08 inches of rain fell on January 6,
2024. The record -breaking rain events caused unprecedented runoff from
neighboring residential properties (Photo 1) and neighboring petroleum -impacted
industrial sites (Photo 2) over several hours. This runoff flowed directly onto the
CPC property in a non -preventable manner three days prior to collection of the
monthly NPDES samples on January 12, 2024.
The excessive rain amount and subsequent heavy runoff rates caused the oil/water
separator (OWS) at CPC's Facility to receive an overwhelming volume of influent
that was high in solids and potential petroleum impacts (Photo 3). The runoff from
7524 Kenstead Circle Charlotte, North Carolina 282081 w .colpipe.com

CDColonial Pipeline Company
the neighboring properties, as well as portions of Colonial's facility, drains to the
facility manifold area which, in turn, drains to the facility oil -water separator
(OWS). Outfall 010 is the downstream discharge point from the OWS (Photo 4),
which was inundated during the storm. Figure 1 shows photograph locations.
The rate in which the influent entered the OWS was greater than the normal OWS
operating design rate. This likely resulted in the OWS not providing the retention
time that is required to operate as designed. In conjunction with the offsite flow,
these conditions likely contributed to the permit -required limit for benzene (1.19
part per billion, ppb) being exceeded in the sample collected at Outfall 010 on
January 12, 2024 (4.2 ppb).
Following the early -January rain events, CPC cleaned the OWS, and it is now
operating as expected during normal flow conditions. CPC collected a second
Outfall 010 sample on January 31, 2024. This second sample exhibited a non -
detectable concentration of benzene.
To provide you with context surrounding the early -January rain events and the
flooding of CPC's Charlotte Delivery facility, photos are provided below.
Furthermore, additional photographic and video evidence of the impacts are
available from CPC upon request.
7524 Kenstead Circle Charlotte, North Carolina 282081 w .colpipe.com

iw '4 �� e'
r'pfA+1Yq
'�
fiy
1
.� '^C � 3�
�. � •iv'
� 4C .y�y��.

aColonial Pipeline Company
Photo 3: View to north showing combined runoff from residential and industrial properties (1/9/241:25 pm)
17
Photo 4: View of inundated Outfall 010 at bottom of stairs (1/9/24 1:42 pm)
7524 Kenstead Circle Charlotte. North Carolina 282081 www.colpipe.com

�p Colonial Pipeline Company
Photo 4
Photo 3
Photo 1
Photo 2
Figure 1: Photo location map
7524 Kenstead Circle Charlotte, North Carolina 282081 w .colpipe.com

aColonial Pipeline Company
If you have any questions or require any additional information, please contact me
at704-458-3993.
Sincerely,
/1; ( I atdc-e-w q'L3- /(-A
Maribeth Hughes, PE, CSP
Environmental Specialist
cc: John Wyatt, Colonial Pipeline Company
7524 Kenstead Circle Charlotte. North Carolina 282081 w .colpipe.com