NC0047384_Permit Issuance(Modification)_20230811

DocuSign Envelope ID: 62FF666E-C1DC-40A2-8E2D-70DEDA19A995
ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHAM E. ROGERS, JR.
Director
Ms. Alicia Goots
\f QCAri Na j
NORTH CAROLINA
Environmental Quality
August 11, 2023
Superintendent of Laboratory and Industrial Pretreatment Services
City of Greensboro Water Resources Department
PO Box 3136
Greensboro, North Carolina 27402
Subject: NPDES Permit Minor Modification
Permit NCO047384
T.Z. Osborne WWTP
Grade IV Biological WPCS
Guilford County
SIC Code 4952
Dear Ms. Goots:
The Division has made the following minor modification based on a request by the City to clarify
monitoring frequencies for CBOD5, TSS, Ammonia and Fecal Coliform at 56.0 MGD effluent
sheet, Page 6 of 19, footnote 13. The provision for reduced monitoring was included in the
originally issued permit.
• The second sentence was modified to allow reduced monitoring at 2/week for TSS and
Fecal Coliform and maintain daily monitoring for CBOD5 and Ammonia.
Please note that if you would like to have reduced monitoring maintained or inserted for the four
above parameters in the permit renewal, a written request with justification per Division guidance
is needed from the Permittee. A copy of the guidance, "DWQ Guidance Regarding the Reduction
of Monitoring Frequencies in NPDESPermits for Exceptionally Performing Facilities" is attached
for your reference.
Accordingly, we hereby forward the minor permit modification on Page 6 of 19 with corrected
text highlighted. Please insert the changed page into your permit.
All other terms and conditions in the original permit remain unchanged and in full effect. This is
a minor technical correction.
Please note that this permit is not transferable except after notice to the Division. The Division
may require modification or revocation and reissuance of the permit. This permit does not affect
the legal requirements to obtain other permits which may be required by the Division of Water
Resources or any other Federal, State, or Local governmental regulations.
North Carolina Department of Environmental Quality I Division of Water Resources
4NORT�HCv 512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
NORTHCAROUNA 919.707.9000
Department ofEnvlronmantal Duali�

DocuSign Envelope ID: 62FF666E-C1DC-40A2-8E2D-70DEDA19A995
If you have any questions concerning this permit, please contact Gary Perlmutter at (919) 707-
3611 or via email at [e-mail].
Sincerely,
CDocuSigned by:khlAhl
dh
C464531431644F.—
for Richard E. Rogers Jr., Director
Division of Water Resources, NCDEQ
Encl. DWQ Guidance Regarding the Reduction of Monitoring Frequencies in NPDES Permits for
Exceptionally Performing Facilities
Hardcopy: NPDES Files
eCopy: US EPA Region 4
DWR/Winston Salem Regional Office/Water Quality/Jenny Graznak
D E Q�� North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
NORTH CAROLINA 919.707.9000
Depanmem of Envlmnmenml Dual

DocuSign Envelope ID: 62FF666E-C1DC-40A2-8E2D-70DEDA19A995
Permit No. NCO047384
Footnotes:
1. No later than March 30, 2015, begin submitting discharge monitoring reports electronically using
NC DWR's eDMR application system. See Special Condition A. (12.).
2. U: Upstream at Old U.S. Highway 70. D1: Downstream at NCSR 2821 (Harvest Road).
D2: Downstream at Huffine Farm Road.
3. The monthly average effluent CBOD5 and TSS concentrations shall not exceed 15% of the
respective influent value (85% removal).
4. These limitations do not become effective until the average plant flow for the calendar year is
greater than or equal to 36 MGD. In the meantime, the ammonia -nitrogen limitations in Section
A. (1.) will remain in effect. When the City of Greensboro reports that the annual average flow is
greater than or equal to 36 MGD with their December DMR, the City shall include a cover letter
with the report stating that the ammonia -nitrogen limits in Section A.(2.) are now effective.
5. The daily effluent dissolved oxygen concentration shall not be less than 6.0 mg/L.
6. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
7. The Division shall consider all effluent TRC values reported below 50 ug/L to be in compliance
with the permit. However, the Permittee shall continue to record and submit all values reported
by a North Carolina certified laboratory (including field certified), even if these values fall below
50 ug/L.
8. TN is Total Nitrogen = TKN + NO3-N + NO2-N, where TKN is Total Kjeldahl Nitrogen, NO3-N
and NO2-N are Nitrate and Nitrite Nitrogen, respectively.
9. TN or TP Load is the mass quantity of Total Nitrogen or Phosphorus discharged in a given period
of time. See Special Condition A.(9.), Calculation and Reporting of Nutrient Loads.
10. Per the Jordan Lake Wastewater Discharge Rule (15A NCAC 02B .0270) as modified by North
Carolina Session Laws 2011-394 (HB119) and 2013-395 (SB515), the annual mass Total Nitrogen
limit shall be effective beginning with calendar year 2019, unless the discharger has received by
December 31, 2019, an authorization -to -construct permit for construction, installation, or alteration
of the treatment works for purposes of complying with this limit, in which case the limit shall be
effective beginning with calendar year 2021. This facility is subject to a TN reduction schedule
outlined in Special Condition A. (4.).
11. Chronic Toxicity (Ceriodaphnia) at 90% with testing in January, April, July and October (see Special
Condition A. (5.)). TOXICITY MONITORING SHALL COINCIDE WITH METALS
MONITORING.
12. Instream monitoring requirements are waived as long as facility retains membership in the
UCFRBA. If membership is cancelled, facility will monitor 3/Week (June -September) and 1/Week
(October -May). Stream sampling may be discontinued at such times as flow conditions in the
receiving waters or extreme weather conditions will result in a substantial risk of injury or death to
persons collecting samples. Upon such discontinuance, stream sampling shall be resumed at the
first opportunity after the risk period has ceased.
13. Upon expansion, the City of Greensboro will sample these parameters daily. Based on review of
effluent data since expansion on July 30, 2021 and finding no violations, monitoring for TSS and
Fecal Coliform is reverted to 2/week as of August 1, 2023. Monitoring for CBOD5 and Ammonia
shall remain at daily.
b. There shall be no discharge of floating solids or visible foam in other than trace amounts.
c. Expansion to a permitted flow of 56 MGD at the T.Z. Osborne WWTP is contingent upon
connection and transfer of all wastewaters received at the North Buffalo Creek WWTP to the
T.Z. Osborne WWTP, cessation of the discharge from the North DocuSigned by:
Buffalo WWTP, and rescission of permit NC0024325. rAkdAAd AKILkUh
PART I, Page 6 of 19 for Richard E. Rogers, Director
Date: August 11, 2023