WQCS00031_NOV-2024-DV-0086_20240318 (2)

Orange Water and Sewer Authority
Our community's trusted partner for clean water and environmental
protection.
March 14, 2024
Mr. Michael Hall, Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources, North Carolina Division of Environmental Quality
3800 Barrett Drive
Raleigh NC 27609
SUBJECT: Response to Notice of Violation (NOV-2024-DV-0086)
Sanitary Sewer Overflow — January 2024
Collection System Permit No. WQCS00031
Incident Number (202400073) — 01/09/2024
Dear Mr. Hall:
As requested in your letter dated February 13, 2024, received on February 26, 2024, we are
writing to provide you information about the Sanitary Sewer Overflow (SSO) cited in the above
referenced letter (Attachment 1). The incident occurred on January 9, 2024, at 10:30 PM, at 132
Creekview Circle, Carrboro, NC.
Background
Orange Water and Sewer Authority (OWASA) provides water and sewer services to the
southern portions of Orange County, NC including the Town of Carrboro and the Town of
Chapel Hill. Our wastewater collection system includes approximately 350 miles of gravity
sewer mains, 21 lift stations, and 14 miles of pressurized sewer force mains.
Initial Response
On Tuesday, January 9, 2024, during a period of heavy rain from a severe thunderstorm moving
through our service area, OWASA's after-hours emergency line received a call from a citizen
regarding a manhole overflowing. The operator immediately dispatched our collection system
on -call technician to investigate. OWASA's technician. arrived at the location and quickly located
a manhole (manhole 2899) that was overflowing near a heavily flooded area adjacent to Bolin
Creek. Our technician dispatched additional resources to investigate and address the source of
the overflow. Upstream manholes 2918 and 2979 were checked and were surcharging, but not
overflowing. Manhole 2884, immediately downstream was located, but was found to be flooded
along with all other downstream manholes. Crews monitored the SSO, began photographing the
area, and preparing for the surcharge to recede to begin cleaning the area. (Attachment 2)
Investigation
The National Weather Service (NWS) in Raleigh issued a severe thunderstorm warning for
Southern Orange County on Tuesday January 9, 2024. At 5:17 PM, severe thunderstorms were
located along a line extending from 8 miles north of Pittsboro and 7 miles east of Goldston to 8
A400 Jones Ferry Road, Carrboro, NC 27510 0 919-968-4421 (D [e-mail] 0 @OWASA_NC 0 www.owasa.org

Response to Notice of Violation (NOV-2024-DV-0086)
March 14, 2024
Page 2
miles south of Sanford moving 60 miles per hour, which directly affected this portion of our
service area. The NWS (Attachment 3) and the NOAA Online Weather (NOW) Data -
Climatological Records (Attachment 4) show that our service area received severe weather
resulting in 3.07 inches of rain during this storm event that evening.
OWASA's Collection System Operator in Responsible Charge (ORC) Nick Rogers was called
and arrived on the scene at 6:30 AM on January 10, 2024 to inspect the area of the SSO. The
heavy rain event and subsequent inflow and infiltration due to the excessive flooding contributed
to the surcharge of manhole 2899 which discharged approximately 1,500 gallons of untreated
wastewater. (Attachment 5)
Remediation
OWASA technicians monitored manhole 2899 at Creekview Circle during the heavy rain event.
Once flood waters receded and the site was safe, OWASA's crew began cleaning, removing all
debris from the surcharged site, and covering site area with lime and deodorizer.
Root Cause of the Overflow
We have no previous records of overflows due to surcharging or any other issues in this area.
The sanitary sewer overflow that we experienced was due to heavy rainfall (more than 3 inches)
within a short span of time and subsequent flooding. We worked with our collection system
modeling consultant to understand the severity of this storm. The consultant determined that
this event was classified as a 15 to 25-year storm. It resulted in significant flooding that was
higher than the manhole rims in this low-lying area of our collection system, which made this
infrastructure inaccessible due to high water.
Our collection system and Mason Farm Wastewater Treatment Plant (WWTP) were impacted
by the severe storm. Our records for January 9, 2024, show the Rogerson Drive pump station,
which is downstream of this area, reached a maximum instantaneous flow of 18.420 million
gallons per day (MGD) with a total of 10.279 million gallons pumped within a 24-hour period.
Our WWTP experienced a maximum instantaneous flow of 37.686 MGD with 16.893 million
gallons treated in 24 hours. The average daily flow is 4.5 MGD at this pump station and 7.5
MGD at our WWTP. During this event, our system experienced more than double our average
daily flow.
Efforts to Imorove
OWASA's maintenance crews are continuously working on preventative and corrective
maintenance of our collection system. Our maintenance crews have recently completed a
system -wide smoke testing initiative to locate and address inflow and infiltration issues. We
have increased our cleaning and CCTV efforts by adding offroad camera equipment to access
and inspect our infrastructure in-house. We have inspected 10 miles of offroad assets since
acquiring this equipment in the last year. This information feeds our Gravity Sewer
Rehabilitation Program within our Capital Improvements Program (CIP) to continuously address
issues within our gravity sewer system and improve the condition of our infrastructure. Our 5-
year CIP includes more than $9.7 million for gravity sewer rehabilitation projects.
OWASA's Engineering and Planning department reviewed the flow characteristics through the
hydraulic model to highlight any issues in the area or manholes that should be adjusted to
higher elevations to assist with capacity issues in the low-lying area. We found an area for

Response to Notice of Violation (NOV-2024-DV-0086)
March 14, 2024
Page 3
improvement within our manhole covers and created work orders to install new bolt -down
covers for 6 manholes in this low-lying area to help prevent future discharges.
Commitment to the highest level of environmental stewardship has been and continues to be
one of the fundamental principles of OWASA. We believe that OWASA's actions before, during,
and after the event reflect this commitment. OWASA requests that you consider these key
factors in any subsequent action the Division of Water Resources might take:
• We addressed the issue immediately to minimize impact to the environment.
• We continue to inspect critical manholes and sewer lines before and after storms.
• We have an ongoing gravity sewer program to clean, inspect, repair, rehabilitate, and
replace sewer lines.
• We met all reporting requirements.
We hope that the information provided is sufficient to understand the details of the event. Please
let us know if you have any questions or need additional information.
Sincerely,
Todd Taylor, P.E.
Executive Director
cc: Mary Darr, P.E., General Manager of Operations
Jesse DuClau, Distribution and Collection Systems Manager
Nicholas Rogers, Assistant Distribution and Collection Systems Manager and Collection
System ORC
Attachments:
1. Notice of Violation (NOV-2024-DV-0086)
2. Collection System Map with Flood Zone Information
3. National Weather Service Storm Briefing
4. Climatological Records for January 2024
5. Collection System Sanitary Sewer Overflow Reporting Form CS-SSO

Attachment 1
DowSlgn Envelope ID: E6A8573C-37B64778-8346•FFEEEFFDIFEC
ROY COOPER
ELIZABETH S. BISER
N.Tlen
RICHARD E. ROGERS. JR.
awhx'
Certified Mail # 7016 3560 0000 4428 6161
Return Receipt Requested
Todd Taylor
Orange Water and Sewer Authority
400 Jones Ferry Rd
Carrboro, NC 27510-2001
N; %'I i, CARuI.iNA
fnvir onmenrol Quafiiy
February 13, 2024
SUBJECT: NOTICE OF VIOLATION
Tracking Number: NOV-2024-DV-0086
Sanitary Sewer Overflows - January 2024
Collection System Permit No. WQCS00031
OWASA Collection System
Orange County
Dear Mr. Taylor:
iEl 2 6 2024
The self -reported Sanitary Sewer Overflow (SSO) 5-Day Report submitted by Orange Water and Sewer Authority
indicates violations of permit conditions stipulated in the subject permit and North Carolina G.S. 143-215.1.
Violations include failing to effectively manage, maintain, and operate the subject Collection system so that there is
no SSO to the land or surface waters and making an outlet to waters of the State for purposes of G.S.
143-215.1(a)(1), for which a permit is required.
Specific incident(s) cited in the subject report include the following:
Total Vol
Total
Surface
Incident Start Duration
Vol
Water
Number Date (Mina) Location
Cause
(Gals)
(Gals) DWR Action
202400073 1/9/2024 30 132 CREEKVIEW
Inflow and Infiltration,
1,500
1,500 Notice of Violation
CIRCLE, CARRBORO,
Severe Natural
27510
Condition

DowSign Enelape ID: ESM573C-37BB4778-8348-FFEEEFFDIFEC
Remedial actions, if not already implemented, should be taken to correct the above noncompliance. Please submit
a written response to this Notice of Violation. Your response is to be received by the regional office within 15
business days following receipt of this violation. Please include any additional documentation about this incident(s)
in the response. The submittal will be considered in determining whether the Division will assess a civil penalty for
the cited violations.
If you have any questions, please do not hesitate to contact Kevin Fowler with the Water Quality Section in the
Raleigh Regional Office at 919-791-4200 or via email at [e-mail].
Cc Laserfiche
Sincerely,
[U
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Michael Hall, Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources, NCDEQ
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Attachment 2
Creekview Cir Spill Map - Incident #202400073

Attachment 3
t NATIONAL WEATHER SERVICE As of 1/8/2024 2 50 PM
~f...1O
An Impactful Storm Expected Tonight Through Tuesday Night
New With This Update:
1. A Flood Watch has been issued for the Piedmont and
western 5andhills of central NC, including the Triad
and Triangle regions.
Event Highlights:
✓ A strong storm system will bring widespread heavy
rain, gusty winds, and a threat for damaging winds
and a few tornadoes.
✓ Storm total rainfall through Tuesday night will range
from 1.5 to 3 inches, highest in the western Piedmont.
Locally higher amounts are possible.
✓ Isolated moderate to heavy rainfall may lead to minor
to moderate river flooding, with isolatediscattered
flash flooding also possible.
Confidence
(j Website: www.weather.gov/raleigh Facebook: @NWSRaleigh Twitter/X: @NWSRaleigh 14

weather.gov/rah
�yNAT10NAL WEATHER SERVICE

NATIONAL WEATHER SERVICE As of 1/8/2024 2:50 PM
A Wind Advisory remains in effect for all of central NC, from 10 AM Tuesday to 10 PM Tuesday
Sustained winds of 20 to 30 mph are likely Tuesday into Tuesday night. Frequent gusts of 35 to 45 mph will be possible,
with the strongest gusts expected in the southern Piedmont, Sandhills, and southern Coastal Plain.

( -46 NATIONAL WEATHER SERVICE
F
Rainfall totals are expected to range from 1.5 to
3 inches.
As of 1/8/2024 2:50 PM
Website: www.weather.gov/raleigh Facebook: @NWSRaleigh Twitter/X: @NWSRaleigh

*► NATIONAL WEATHER SERVICE VUM
,»
Contact and Next Briefing Information
When: By600AMon 11912024
Method: E-mail
Briefing Webpage:
httpJAw weathergov/media/rah/briefina/NWSRaleighLatestBriefinaodf
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Phone (public):
(9191326-1052E-mail:
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[e-mail]
Disclaimer. The information contained within this briefing
Is time -sensitive. Do not use after 600 AM, Monday, January 91", 2024.
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Attachment 5
State of North Carolina
QWR
Department of Environment and Natural Resources
Division of Water Resources
Collection System Sanitary Sewer Overflow Reporting Form
Division of Water Resources Form CS-SSO
PART I:
This form shall be submitted to the appropriate DWQ Regional Office within five business days of the first knowledge of the
sanitary sewer overflow (SSO).
Permit Number: WQCS00031 (WQCS# if active, otherwise use WQCSD#)
Facility: OWASA Collection System Incident #: 202400073
Owner: Orange Water and Sewer Authority
City: Carrboro
County: Orange Region: Raleigh
Source of SSO (check applicable): 0 Sanitary Sewer ❑ Pump Station / Lift Station
SPECIFIC location of the SSO (be consistent in description from past reports or documentation - i.e. Pump Station 6,
Manhole at Westall & Bragg Street, etc): 132 CREEKVIEW CIRCLE, CARRBORO, , 27510
Manhole #: 2699
Latitude (Decimal Degrees):
Longitude (Decimal Degrees):
Incident Started Dt: 01/09/2024 Time: 10:30 pm
(mm-dd-yyyy) (hh:mmAM/PM)
Estimated Volume of the SSO: 1,500
Incident End Dt: 01/09/2024 Time: 11:00 pm
(mm-dd-yyyy) (hh:mm AM/PM)
gallons Estimated Duration (Round to nearest hour): 0:30 hours
Describe how the volume was determined: A visual overflow chart was used to help determine the volume.
Weather conditions during the SSO event: Severe thunderstorms with heavy rain fall and hazardous wind gust's..
Did SSO reach surface waters? 0 Yes ❑ No ❑ Unknown Volume reaching surface waters (gals): 1500
Surface water name: Bolin Creek (Hogan Lake)
Did the SSO result in a fish kill? ❑ Yes ❑ No 0 Unknown If Yes, what is the estimated number of fish killed?
SPECIFIC cause(s) of the SSO:
0 Severe Natural Con( 0 Inflow and Infiltration
24 hour verbal notification (name of person contacted ): Zachary Thomas
0 DWR ❑ Emergency Mgmt Date (mm-dd-yyy): 01/10/2024 Time (hh:mm AM/PM): 09:00:00 am
If an SSO is ongoing, please notify the appropriate Regional Office on a daily basis until SSO can be stopped.
Per G.S. 143-215.1 C(b), the responsible party of a discharge of 1,000 or more of untreated wastewater to surface waters
shall issue a press release within 24-hours of first knowledge to all print and electronic news media providing general
coverage in the county where the discharge occurred. When 15,000 gallons or more of untreated wastewater enters surface
waters, a public notice shall be published within 10 days and proof of publication shall be provided to the Division within 30
days. Refer to the reference statute for further detail.
The Director. Division of Water Resources, may take enforcement action for SSOs that are required to be reported to
Division unless it is demonstrated that:
1) the discharge was cause by sever natural conditions and there were no feasible alternative to the discharge; or
2) the discharge was exceptional, unintentional, temporary and caused by factors beyond the reasonable control of the
Permittee and/or owner, and the discharge could not have been prevented by the exercise of reasonable control.
Part II must be completed to provide a justification claim for either of the above situations. This information will be the basis
WHETHER OR NOT PART III IS COMPLETED, A SIGNATURE IS REQUIRED AT THE END OF THIS FORM
CS-SSO Form Page: 1

PART If:
ANSWER THE FOLLOWING QUESTIONS FOR EACH RELATED CAUSE CHECKED IN PART 1 OF THIS FORM AND
INCLUDE THE APPROPRIATE DOCUMENTATION AS REQUIRED OR DESIRED
COMPLETE ONLY THOSE SECTONS PERTAINING TO THE CAUSE OF THE SSO AS CHECKED IN PART I
(In the check boxes below, NA = Not Applicable and NE = Not Evaluated)
A HARDCOPY OF THIS FORM SHOULD BE SUBMITTED TO THE APPROPRIATE DWR REGIONAL OFFICE UNLESS IS
Severe Natural Condition
Describe the "severe natural condition" in detail?
service area has experienced heavier than normal rain fall within the last week. On 01/09/24 we received 3.07" of rain in
short period. This rain combined with I&I contributed to the overflow of manhole 2899 which discharged 1,500 gal from
1030pm-11 om into Bolin Creek.
How much advance warning did you have and what actions were taken in preparatio
for the event?
We had advance warning via news forecast 48 hrs. prior Creek crossing inspection & debris removal were completed 48
before storm.
Comments:
N/A
Inflow and Infiltration
Are you under an SOC (Special Order by Consent) or do you have a schedule in any Yes W No E NA ❑ NE
permit that addresses UP
Explain if Yes:
What corrective actions have been taken to reduce or eliminate I & I related overflow
at this spill location within the last year?
Easement maintenance and manhole inspections along with cleaning of the sewer main in the last year.
Has there been any flow studies to determine 1/1 problems in the collection system at ❑ Yes W No ❑ NA DNE
the SSO location?
If Yes, when was the study completed and what actions did it recommend?
Has the line been smoke tested or videoed within the past year?
If Yes, when and indicate what actions are necessary and the status of such actions:
Last smoke test was on 3/22/22
Are there 1/1 related projects in your Capital Improvement Plan?
If Yes, explain:
Downstream trunk main is planned for capacity improvements in the future.
Yes [Z No
W Yes No
NA ❑ NE
❑ NA ❑ NE
CS-SSO Form Page: 2

Have there been any grant or loan applications for 1/1 reduction projects? ❑ Yes W No DNA EINE
If Yes, explain:
Do you suspect any major sources of inflow or cross connections with storm sewers., ❑ Yes W No NA ❑ NE
If Yes, explain:
Have all lines contacting surface waters in the SSO location and upstream been 0 Yes ❑ No ❑ NA D NE
inspected recently?
If Yes, explain:
Lines were inspected on 7/12/2023 and again on 01/10/2024
What other corrective actions are planned to prevent future 1/1 related SSOs at this
location?
More frequent inspections before and after storms and a possible elevation change to the manhole as long as it does not
impact our customers.
Comments:
System Visitation
ORC Yes
Backup ❑ Yes
Name:
Nicholas Rogers
Cert#
998691
Date visited:
01 /10/2024
Time visited:
06:30 AM
How was the SSO remediated (i.e. Stopped and cleaned up)?
Supervisor monitored the manhole at the location during the heavy rain events when the waters receded, and the site we!
safe. A crew came out and clean up all debris and put out lime, deodorant and straw. Manholes upstream and downstreai
were reinspected and lines will be CCNed inspected.
CS-SSO Form Page: 3

As a representative for the responsible party, I certify that the information contained in this report is true and accurate to the
best of my knowledge.
Person submitting claim: Nicholas F Rogers Date: 01/10/24 11:00 am
Signature:
Telephone Number:
Title:
Any addition information desired to be submitted should be sent to the appropriate Division Regional Office within five days of i
knowledge of the SSO with reference to the incident number (the incident number is only generated when electronic entry of th
form is completed, if used).
CS-SSO Form Page: 4