NC0021211_Speculative Limits_20200127 (2)

ROY COOPER
Governor
MICHAELS.REGAN
Secretary
LINDA CULPEPPER
Dtrecmr
Tonya Mann
Utilities Director
City of Graham
PO Box 357
Graham, North Carolina 27523
Dear Ms. Mann:
NORTH CAROLINA
Environmental Quality
January 27, 2020
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4V,4::)
Subject: Speculative Effluent Limits
Graham WWTP
Permit No. NCO021211
Alamance County
Cape Fear River Basin
This letter provides speculative effluent limits for 5 MGD and 6.2 MGD at the Graham WWTP. The
Division received the speculative limits request in a letter dated June 6, 2019 from Mary Sadler, P.E., of
Hazen and Sawyer. On October 20, 2019, Mary Sadler requested seasonal (winter) limits for the facility.
This letter provides seasonal limits and corrects the nutrient limits that had been mistakenly transposed in
the October 1, 2019 speculative limits letter. Please recognize that speculative limits may change based on
future water quality initiatives, and it is highly recommended that the applicant verify the speculative limits
with the Division's NPDES Unit prior to any engineering design work.
Receivine Stream. The Haw River is located within the Cape Fear River Basin. The Haw River has a
stream classification of WS-V, NSW, and waters with this classification have a best usage for the
protection of downstream drinking water supplies. The NSW supplementary classification designates
the waterbody as a nutrient sensitive water subject to 15A NCAC 02B .0270 for wastewater discharges
to the B. Everett Jordan Reservoir. The Haw River has a summer 7Q10 flow of 34 cfs, a winter 7Q10
flow of 85 cfs, a 30Q2 flow of 114 cfs, and an annual average flow of 553 cfs.
Based upon a review of information available from the North Carolina Natural Heritage Program
Online Map Viewer, there are not any Federally Listed threatened or endangered aquatic species
identified within a 5 mile radius of the proposed discharge location. If there are any identified
threatened/endangered species, it is recommended that the applicant discuss the proposed project with
the US Fish and Wildlife Service to determine whether the proposed discharge location might impact
such species.
SSveculative Effluent Limits. Based on Division review of receiving stream conditions and water quality
modeling results, speculative limits for the proposed expansion to 5 MGD and 6.2 MGD are presented
in Tables 1 and 2, respectively. A complete evaluation of these limits and monitoring requirements for
metals and other toxicants, as well as potential instream monitoring requirements, will be addressed
upon receipt of a formal NPDES permit application. Some features of the speculative limit
development include the following:
D_EQ�� North Carolina Department ofEnvironmental Quality IDivision ofWater Resources
512 North Salisbury Street 11617 Mall Service Center I Raleigh. North Carolina 27699-1617
'��r� /'� 919.707.9000

BOD/NH3 Limits. These speculative limits are based on freezing current permitted BOD
ultimate loading (i.e., facility will not be allowed to discharge oxygen -consuming waste above
what is currently permitted). The resultant limits at expanded flows are considered
technologically -feasible.
Nutrient Limits. Annual mass limits for total nitrogen (TN) and total phosphorus (TP) are
allocated by rule 15A NCAC 02B .0270. These annual limits will be carried over unless
additional TN or TP allocation credits are acquired. The permittee will be required to
demonstrate that their design will be capable of achieving these limits upon application for
expansion.
TABLE 1. Speculative Limits for City of Graham WWTP (Proposed Expansion to 5 MGD)
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly
Average
Daily Maximum
Flow
5.0 MGD
BODs (April -October)
8.4 mg/L
12.6 mg/L
BODs(November-March)
16.8 m
25.2 mgIL
NH3 as N (April -October)
2.8 m
8.4 m
NH3 as N(November-March)
5.6 m
16.8 mgIL
Dissolved Oxygen minimum
5.0 m
TSS
30 mgIL
45 m
TRC
28 u
Fecal coliform (geometric
mean
200/100 ml
400/100 ml
Total Nitrogen
56,3151bs/ ear annual load
Total Phosphorus
7,079 lbs/ ear annual load
Chronic Toxicity PassTail
(Quarterly test
19%
Note: At 5 MGD, nutrient load limits are approximately TP = 0.46 mg/L, and TN = 3.7 mg/L.
TABLE 2. Speculative Limits for City of Graham WWTP (Proposed Expansion to 6.2 MGD)
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly
Average
Daily Maximum
Flow
6.2 MGD
BODs (April -October)
6.7 m
10.0 m
BODs ovember-March
13.4 m
20.1 mgfL
Nf13 as N (April -October)
2.2 m
6.6 m
NH3 as N(November-March)
4.4 m
13.2 m
Dissolved Oxygen (minimum)
5.0 m
TSS
30 m
45 m
TRC
28 ugIL
Fecal coliform (geometric
mean
200/100 ml
400/100 ml
Total Nitrogen
56,315 lbs/ ear annual load
Total Phosphorus
7,0791bs/ ear annual load
Page 2 of

Chronic Toxicity Pass/Fail
22%
(Quarterly test
Note: At 6.2 MGD, nutrient load limits are approximately TP = 0.37'mg/L and TN = 3.0 mg/L.
Engineering Alternatives Analysis(EAA). Please note that the Division cannot guarantee that an
NPDES permit for a new or expanding discharge will be issued with these speculative limits. Final
decisions can only be made after the Division receives and evaluates a formal permit application for
the new/expanded discharge. In accordance with North Carolina Administrative Code 15A NCAC
2H.0105( c), the most environmentally sound alternative should be selected from all reasonably cost
effective options. Therefore, as a component of all NPDES permit applications for new or expanding
flow, a detailed engineering alternatives analysis (EAA) must be prepared. The EAA must justify
requested flows and provide an analysis of potential wastewater treatment alternatives. A copy of the
Division guidance for preparing EAA documents is attached.
State Environmental Policy Act (SEPA) EA/EIS Requirements. A SEPA EVEIS document may be
required for projects that: 1) involve $10 Million or more of state funds; or 2) will significantly and
permanently impact 10 or more acres of public lands. Please check with the DWR SEPA coordinator
(David Wainwright, 919-707-9045) as to whether your project requires SEPA review. For projects that
are subject to SEPA, the EAA requirements discussed above will need to be folded into the SEPA
document. Additionally, if subject to SEPA, the NPDES Unit will not accept an NPDES permit
application for a new/expanding discharge until the Division has approved the SEPA document and
sent a Finding of No Significant Impact (FONSI) to the State Clearinghouse for review and comment.
Should you have any questions about these speculative limits or NPDES permitting requirements,
please feel free to contact David Hill at [phone] or Julie Grzyb at [phone].
Respectfully,
Grzyb
pervisor, NPDES Complex Permitting Unit
Hardcopy:
Central Files
NPDES Permit File
Electronic Copy:
DWR/Water Quality Regional Operations/Winston-Salem Regional Office
DWR/Basinwide Planning, Ian McMillan
DWR/NPDES Server>Specs
Hazen and Sawyer, Mary Sadler [e-mail]
Page 3 of 3

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ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Director
October 1, 2019
Tonya Mann
Utilities Director
City of Graham
PO Box 357
Graham, North Carolina 27523
Subject: Speculative Effluent Limits
Graham WWTP
Permit No. NCO021211
Alamance County
Cape Fear River Basin
Dear Ms. Mann:
This letter provides speculative effluent limits for 5 MGD and 6.2 MGD at the Graham WWTP. The
Division received the speculative limits request in a letter dated June 6, 2019 from Mary Sadler, P.E., of
Hazen and Sawyer. Please recognize that speculative limits may change based on future water quality
initiatives, and it is highly recommended that the applicant verify the speculative limits with the Division's
NPDES Unit prior to any engineering design work.
Receiving Stream. The Haw River is located within the Cape Fear River Basin. The Haw River has a
stream classification of WS-V, NSW, and waters with this classification have a best usage for the
protection of downstream drinking water supplies. The NSW supplementary classification designates
the waterbody as a nutrient sensitive water subject to I SA NCAC 02B .0270 for wastewater discharges
to the B. Everett Jordan Reservoir. The Haw River has a summer 7Q10 flow of 34 cfs, a winter 7Q10
flow of 85 cfs, a 30Q2 flow of 114 cfs, and an annual average flow of 553 cfs.
Based upon a review of information available from the North Carolina Natural Heritage Program
Online Map Viewer, there are not any Federally Listed threatened or endangered aquatic species
identified within a 5 mile radius of the proposed discharge location. If there are any identified
threatened/endangered species, it is recommended that the applicant discuss the proposed project with
the US Fish and Wildlife Service to determine whether the proposed discharge location might impact
such species.
Sl2eculative Effluent Limits. Based on Division review of receiving stream conditions and waterquality
modeling results, speculative limits for the proposed expansion to 5 MGD and 6.2 MGD are presented
in Tables 1 and 2, respectively. A complete evaluation of these limits and monitoring requirements for
metals and other toxicants, as well as potential instream monitoring requirements, will be addressed
upon receipt of a formal NPDES permit application. Some features of the speculative limit
development include the following:
• BOD/NHa Limits. These speculative limits are based on freezing current permitted BOD
ultimate loading (i.e., facility will not be allowed to discharge oxygen -consuming waste above'
D Nonh Carolina Department of EnWrorlmemal Quality! Division of Water Resnm'ces
i 512 Norl h Salisbur y Street i Ibli Mall Service Center 1 Raleigh, North Carolina 276991617
919.707.9000

what is currently permitted). The resultant limits at expanded flows are considered
technologically -feasible.
Nutrient Limits. Annual mass limits for total nitrogen (TN) and total phosphorus UP) are
allocated by rule 15A NCAC 02B .0270. These annual limits will be carried over unless
additional TN or TP allocation credits are acquired. The permittee will be required to
demonstrate that their design will be capable of achieving these limits upon application for
expansion.
TABLE 1. Speculative Limits for City of Graham WWTP (Proposed Expansion to 5 MGD)
vera a
:D it
Flow
5.0 MGD
BODs
5.0 m
7.5 m
NH3 asN
1.0m L
3.0m L
Dissolved Oxygen minimum
5.0 m L
TSS
30 m L
45 mg/L
TRC
28 u L
Fecal coliform (geometric
mean
200/100 in
400/100 ml
Total Phos horus
56,315
lbs/ ear annual load
Total Nitrogen
7 079 lbs/ ear annual load
Chronic Toxicity Pass/Fail
uarterl test
19%
Wrote: At.) MGD, nutrient load limits are approximately TP = 0.46 mg/L, and TN = 3.7 mg/L.
TABLE 2. Speculative Limits for City of Graham WWTP (Proposed Expansion to 6.2 MGD)
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Flow
6.2 MGD
BOD5
5.0 mg/L
7.5 mp&
NHa as N
1.0 mg/L
3.0 mg/L
Dissolved Oxygen minimum
5.0 mgIL
TSS
30 m L
45 m L
TRC
28 u L
Fecal coliform (geometric
mean
200/100 ml
400/100 in
Total Phosphorus
56,315
lbs/ ear annual load
Total Nitrogen
7,079 lbs/ ear annual load
Chronic Toxicity Pass/Fail
(Quarterly test
22%
!Vote: At 0.2 MUD, nutrient load limits are approximately TP = 0.37 mg/L and TN = 3.0 mg/L.
Enei�, ineering_ Alternatives Analysis (AA). Please note that the Division cannot guarantee that an
NPDES permit for a new or expanding discharge will be issued with these speculative limits. Final
decisions can only be made after the Division receives and evaluates a formal permit application for
Page 2 of 3

the new/expanded discharge. In accordance with North Carolina Administrative Code 15A NCAC
2H.0105( c), the most environmentally sound alternative should be selected from all reasonably cost
effective options. Therefore, as a component of all NPDES permit applications for new or expanding
flow, a detailed engineering alternatives analysis (EAA) must be prepared. The EAA must justify
requested flows and provide an analysis of potential wastewater treatment alternatives. A copy of the
Division guidance for preparing EAA documents is attached.
State Environmental Policy Act SEPA EA/EIS Requirements. A SEPA EA/EIS document may be
required for projects that: ]) involve $10 Million or more of state funds; or 2) will significantly and
permanently impact 10 or more acres of public lands. Please check with the DWR SEPA coordinator
(David Wainwright, 919-707-9045) as to whether your project requires SEPA review. For projects that
are subject to SEPA, the EAA requirements discussed above will need to be folded into the SEPA
document. Additionally, if subject to SEPA, the NPDES Unit will not accept an NPDES permit
application for a new/expanding discharge until the Division has approved the SEPA document and
sent a Finding of No Significant Impact (FONS1) to the State Clearinghouse for review and comment.
Should you have any questions about these speculative limits or NPDES permitting requirements,
please feel free to contact David Hill at [phone] or Julie Grzyb at [phone].
Respectfully,
J ie Grzyb
upervisor, NPDES Complex Permitting Unit
Attachment: EAA Guidance Document
Hardcopy:
Central Files
NPDES Permit File
Electronic Copy:
NC WRC, Inland Fisheries, [e-mail]
US Fish and Wildlife Service, [e-mail]
DWR/Water Quality Regional Operations/Winston-Salem Regional Office
DWR/Basinwide Planning, Ian McMillan
DWR/NPDES Server>Specs
Hazen and Sawyer, Mary Sadler [e-mail]
Page 3 of 3

Hazen
June 6, 2019
Hazen and Sawyer
4011 West Chase Blvd., Suite 500
Raleigh, NC 27607 • 919.833,7152
Ms. Julie Grzyb
Supervisor, NPDES Unit
North Carolina Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Re: Request for Speculative Limits
Graham Wastewater Treatment Plant, NPDES Permit No. NCO021211
City of Graham
Dear Ms. Grzyb:
The City of Graham has retained Hazen and Sawyer to assist in an initial planning and permitting phase
for the City's Wastewater Treatment Plant (WWTP) expansion. The City is currently permitted to
discharge 3.5 million gallons per day (mgd) per National Pollutant Discharge Elimination System
(NPDES) permit NCO021211. The City's proposed capacity expansion will require an increase in the
permitted capacity of the NPDES discharge to the Haw River.
As part of our planning efforts, we respectfully request an opinion from the Division of Water Resources
(DWR) NPDES Unit regarding effluent limits for the capacity expansion. We request that DWR provide
tiered speculative flow limits for a discharge of 5 mgd and a discharge of 6.2 mgd. Per a scoping meeting
on May 10, 2019, we understand that additional Qual2K water quality modeling will not be required. The
City acknowledges that an Engineering Alternatives Analysis (EAA) will be necessary to support the
proposed capacity expansion.
We recognize that the proposed effluent limits developed by DWR will be speculative in nature. We
appreciate the time and consideration of DWR regarding this request. Please don't hesitate to contact me
at 919-755-8650 or [e-mail] if you should have any questions or need more
information.
`Sincerely,
Mary E. Sadler, PE
Senior Associate
cc: Tanya Mann, City of Graham Shelby Smith, City of Graham
Cris Routh, City of Graham Alan Stone, Hazen and Sawyer
Shannon Dorsey, Hazen and Sawyer

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