Attachment A - 15A NCAC 02B .0733 Proposed Revisions

15A NCAC 02B .0733 TAR-PAMLICO NUTRIENT STRATEGY: WASTEWATER DISCHARGE 1
REQUIREMENTS NEW AND EXPANDING WASTEWATER DISCHARGER 2
REQUIREMENTS 3
The following is the National Pollutant Discharge Elimination System (NPDES) wastewater discharge management 4
strategy for new and expanding wastewater dischargers in the Tar-Pamlico River basin: 5
(1) Purpose. The purpose of this Rule is to establish minimum nutrient control requirements for new 6
and expanding point source discharges in the Tar-Pamlico River Basin in order to maintain or restore 7
water quality in the Pamlico Estuary and protect its designated uses. 8
(2) Applicability. This Rule applies to all discharges from wastewater treatment facilities in the Tar-9
Pamlico River Basin that receive nitrogen- or phosphorus-bearing wastewater and are required to 10
obtain individual NPDES permits. This Rule applies to Tar-Pamlico Basin Association member 11
facilities on or after June 1, 2025. This Rule applies to other facilities upon this Rule's effective date. 12
(3) Definitions. The terms used in this Rule, in regard to point source dischargers, treatment facilities, 13
wastewater flows or discharges, or like matters, shall be as defined in Rule .0701 of this Section and 14
as follows: 15
(a) “Active Allocation” means that portion of an allocation that has been applied toward and 16
is expressed as a nutrient limit in an individual NPDES permit. 17
(b) “Association” means the Tar-Pamlico Basin Association, a not-for-profit corporation 18
consisting of NPDES-permitted dischargers in the Tar-Pamlico River Basin; established 19
voluntarily by its members to work cooperatively to meet the aggregate TN and TP 20
allocations originally established in the Tar-Pamlico Nutrient TMDL and subsequently in 21
the group permit. 22
(a)(c) "Existing" means that which obtained an NPDES permit on or before December 8, 1994. 23
(b)(d) "Expanding" means that which increases beyond its permitted flow as defined in in this 24
Item. Item (4) of this Rule. 25
(e) “Limit” means the mass quantity of nitrogen or phosphorus that a discharger or group of 26
dischargers is authorized through an NPDES permit to release into surface waters of the 27
Tar-Pamlico River Basin. 28
(c)(f) “New" means that which had not obtained an NPDES permit on or before December 8, 29
1994. 30
(4) (g) "Permitted flow" means the maximum monthly average flow authorized in a facility's NPDES 31
permit as of December 8, 1994. 32
(h) “Reserve Allocation” means allocation that is held by a permittee or other person but that 33
has not been applied toward and is not expressed as a nutrient limit in an individual NPDES 34
permit. 35
(4) This Item specifies the total combined end of pipe nitrogen and phosphorus discharge allocation for 36
existing Association point source dischargers. 37

(a) Unless revised as provided for in Items (7) through (9) of this Rule, in accordance with the 1
Nitrogen and Phosphorus TMDL for the Tar-Pamlico River Estuary, approved in 1995 by 2
the US Environmental Protection Agency (EPA), the total active nitrogen and phosphorus 3
discharge allocations for Association point source dischargers shall not exceed 891,271 in 4
pounds of nitrogen and 161,070 pounds of phosphorus per calendar year. The nutrient loads 5
discharged annually by these point sources shall not exceed these nitrogen and phosphorus 6
discharge allocations plus any nutrient offset credits obtained in accordance with G.S. 143-7
214.26 and Rule .0703 of this Section. In the event the Association’s allocations are revised 8
as provided for in Items (7) through (9) of this Rule, the NPDES group permit shall be 9
modified to reflect those changes to the active nitrogen and phosphorus discharge mass 10
allocations and limits set forth in this Rule. 11
(b) The Commission shall order future revisions in the Nitrogen and Phosphorus TMDL and 12
nitrogen and phosphorus discharge allocations whenever necessary to ensure that water 13
quality in the estuary meets all applicable standards in 15A NCAC 02B .0200 or to conform 14
with applicable State or federal requirements. 15
(5) This Item specifies the individual nitrogen and phosphorus discharge allocations for existing 16
Association point source dischargers in accordance with the 1995 TMDL. 17
(a) Unless revised as provided for in Items (7) through (9) of this Rule, the following 18
individual discharge mass allocations for total nitrogen and total phosphorus shall apply in 19
conformance with the values in Item (4) of this Rule: 20
21
Mass Allocations (pounds/year)
Facility Name NPDES No. Total Nitrogen Total Phosphorus
Belhaven NC0026492 14,261 2,577
Bunn NC0042269 4,278 773
Enfield NC0025402 14,261 2,577
Franklin County NC0069311 42,784 7,732
Greenville NC0023931 249,576 45,103
Louisburg NC0020231 19,538 3,531
Oxford NC0025054 49,915 9,021
Pinetops NC0020435 4,278 773
Robersonville NC0026042 25,671 4,639
Rocky Mount NC0030317 299,491 54,124
Scotland Neck NC0023337 9,626 1,740
Spring Hope NC0020061 5,705 1,031
Tarboro NC0020605 71,307 12,887

Warrenton NC0020834 28,523 5,155
Washington NC0020648 52,054 9,407
Association Total
Active Allocation

891,271

161,070
Allocation in Reserve 59,798 3,898
1
(b) In the event that the nitrogen and phosphorus TMDL and their discharge allocations for 2
point sources are revised, as provided in Item (4) of this Rule, the Commission shall 3
apportion the revised load among the existing facilities and shall revise discharge 4
allocations as needed. The Commission may consider such factors as: 5
(i) fate and transport of nitrogen and phosphorus in the river basin; 6
(ii) technical feasibility and economic reasonableness of source reduction and 7
treatment methods; 8
(iii) economies of scale; 9
(iv) nitrogen and phosphorus control measures already implemented; 10
(v) probable need for growth and expansion; and 11
(vi) incentives for nutrient management planning, utilities management, resource 12
protection, and cooperative efforts among dischargers. 13
(5)(6) This Item specifies nutrient controls for new facilities. 14
(a) Proposed new wastewater dischargers New facilities proposing to discharge wastewater 15
shall evaluate all practical alternatives to surface water discharge pursuant to 15A NCAC 16
02H .0105(c)(2) prior to submitting an application to discharge. 17
(b) New facilities shall document in their permit application that they have acquired some 18
combination of the following allocations and offsets sufficient to meet the annual limits 19
required elsewhere in this Item for the proposed discharge: 20
(i) nitrogen and phosphorus allocations from existing dischargers; 21
(ii) reserve allocation pursuant to Sub-Item (c) of this Item; and 22
(iii) nitrogen and phosphorus offset credits pursuant to Rule .0703 of this Section. 23
Allocation and offset credits shall be sufficient for no less than 10 subsequent years of 24
discharge at the proposed design flow rate in accordance with 15A NCAC 02H .0112(c). 25
(c) New facilities proposing to use any portion of the reserve allocation described in Sub-Item 26
(5)(a) of this Rule shall submit a written request to the Division for approval of the 27
proposed use. The request shall include concurrence for its use by the Association. 28
(b)(d) New facilities shall meet The technology-based nitrogen and phosphorus discharge limits 29
that shall not exceed the following: for a new facility shall not exceed: 30

(i) For facilities treating municipal or domestic wastewater, the mass load equivalent 1
to a concentration of 3.5 mg/L TN and 0.5 mg/L TP at the monthly average flow 2
limit in the facility's NPDES permit; and 3
(ii) For facilities treating industrial wastewater, the mass load equivalent to the best 4
available technology economically achievable, calculated at the monthly average 5
flow limit in the facility's NPDES permit. 6
(c) Proposed new dischargers submitting an application shall acquire nutrient allocation from 7
existing dischargers or nutrient offset credits pursuant to Rule .0703 of this Section for the 8
mass load dictated by this Item. The allocation and offset credits shall be sufficient for any 9
partial calendar year in which the permit becomes effective plus 10 subsequent years of 10
discharge at the proposed design flow rate in accordance with 15A NCAC 02H .0112(c). 11
(d) The Director shall not issue a permit authorizing discharge from a new facility unless the 12
applicant has satisfied the requirements of Sub-Items (a), (c), and (e) of this Item. If a 13
facility's permit contains tiered flow limits for expansion, the Director shall not authorize 14
an increased discharge unless the applicant has satisfied the requirements of Sub-Items (a), 15
(c), and (e) of this Item. 16
(e) Subsequent applications for permit renewal or, where an existing permit will contain tiered 17
limits, requests to discharge at an increased flow, shall demonstrate that the facility has 18
sufficient nitrogen and phosphorus allocation or offset credits to meet its effluent nutrient 19
limitations for any partial calendar year in which the permit becomes effective plus 10 20
subsequent years of discharge at the proposed an increased design flow rate in accordance 21
with 15A NCAC 02H .0112(c). 22
(f) The Director shall not issue a permit authorizing discharge from a new facility unless the 23
applicant has satisfied the requirements of Sub-Items (a) through (d) of this Item. If a 24
facility's permit contains tiered flow limits for expansion, the Director shall not authorize 25
an increased discharge unless the applicant has satisfied the same requirements of this Item. 26
(f)(g) The Director shall establish more stringent limits for nitrogen or phosphorus upon finding 27
that such limits are necessary to protect water quality standards in localized areas. 28
(6)(7) This Item specifies nutrient controls for expanding facilities. 29
(a) Expanding facilities shall evaluate all practical alternatives to surface water discharge 30
pursuant to 15A NCAC 02H .0105(c)(2) prior to submitting an application to discharge. 31
(b) The nitrogen and phosphorus discharge limits for expanding Non-Association facilities 32
shall be assigned in accordance with the following: 33
(i) Expanding non-Association municipal or domestic wastewater facilities 34
requesting permitted flows greater or equal to 0.1 MGD will be assigned the mass 35
equivalent to a concentration of 3.5 mg/L TN and 0.5 mg/L TP at the monthly 36
average flow limit in the facility’s NPDES permit; and 37

(ii) Expanding non-Association facilities treating industrial wastewater will be 1
assigned the mass load equivalent to the best available technology economically 2
achievable, calculated at the monthly average flow limit in the facility's NPDES 3
permit. 4
(c) An expanding facility that is a member of the Association, as defined in Sub-Item (3)(b) 5
of this Rule, shall not exceed the nitrogen and phosphorus loads equivalent to its active 6
allocations unless they receive Division approval for an increase in their discharge as 7
described elsewhere in this Item. 8
(d) Facilities submitting application for increased discharge or, where an existing permit will 9
contain tiered limits, for authorization to discharge at an increased flow, may acquire 10
nitrogen and phosphorus allocations from existing dischargers or nitrogen and phosphorus 11
offset credits pursuant to Rule .0703 of this Section, or may acquire reserve allocation in 12
compliance with sub-Item (e) of this Item for the proposed discharge. The acquired 13
allocations and offset credits, combined with any preexisting allocations, shall be sufficient 14
to meet its effluent nutrient limits as established elsewhere in this item for any partial 15
calendar year in which the permit becomes effective plus 10 subsequent years of discharge 16
at an increased design flow rate in accordance with 15A NCAC 02H .0112(c). 17
(e) A facility that submits an application to increase its discharge may request approval from 18
the Division to use a portion of the reserve allocation described in Sub-Item (5)(a) of this 19
Rule. Approval will be based on the following criteria: 20
(i) The expanding facility demonstrates that upon expansion their nitrogen and 21
phosphorus discharge would not exceed the mass load equivalent to a 22
concentration of 3.5 mg/L TN and 0.5 mg/L TP, calculated at the monthly average 23
flow limit in the facility's NPDES permit; 24
(ii) The expanding facility requesting use of reserve allocation has received written 25
approval from the Association. 26
(iii) Should the facility cease to discharge, the portion of the reserve allocation that 27
was activated will revert back to reserve allocation; and 28
(f) The Director shall not issue an NPDES permit authorizing increased discharge from an 29
existing facility unless the applicant has satisfied the requirements of Sub-Items (a) through 30
(e) of this Item. If a facility's permit contains tiered flow limits for expansion, the Director 31
shall not authorize discharge at an increased flow unless the applicant has satisfied the 32
same requirements of this Item. 33
(f)(g) The Director shall modify an expanding facility's permit to establish more stringent limits 34
for nitrogen or phosphorus upon finding that such limits are necessary to protect water 35
quality standards in localized areas. 36

(b) The nitrogen and phosphorus discharge limits for an expanding facility shall not exceed 1
the greater of loads equivalent to its active allocation and offset credit, or the following 2
technology-based mass limits: 3
(i) For facilities treating municipal or domestic wastewater, the mass equivalent to a 4
concentration of 3.5 mg/L TN and 0.5 mg/L TP at the monthly average flow limit 5
in the NPDES permit; and 6
(ii) For facilities treating industrial wastewater, the mass load equivalent to the best 7
available technology economically achievable, calculated at the monthly average 8
flow limit in the facility's NPDES permit. 9
(c) Facilities submitting application for increased discharge or, where an existing permit 10
contains tiered flow limits, for authorization to discharge at an increased flow, shall acquire 11
or demonstrate contractual agreement to acquire, prior to authorization to discharge at the 12
increased flow, nutrient allocation from existing dischargers or nutrient offset credits 13
pursuant to Rule .0703 of this Section for the proposed discharge above 0.5 million gallons 14
per day (MGD). The allocation and offset credits shall be sufficient to meet its effluent 15
nutrient limitations for any partial calendar year in which the permit becomes effective plus 16
10 subsequent years of discharge at the proposed design flow rate in accordance with 15A 17
NCAC 02H .0112(c). 18
(d) The Director shall not issue a permit authorizing increased discharge from an existing 19
facility unless the applicant has satisfied the requirements of Sub-Items (a), (c), and (e) of 20
this Item. If a facility's permit contains tiered flow limits for expansion, the Director shall 21
not authorize discharge at an increased flow unless the applicant has satisfied the 22
requirements of Sub-Items (a), (c), and (e) of this Item. 23
(e) Subsequent applications for permit renewal shall demonstrate that the facility has sufficient 24
nitrogen allocation or offset credits to meet its effluent nutrient limitations for any partial 25
calendar year in which the permit becomes effective plus 10 subsequent years of discharge 26
at the proposed design flow rate in accordance with 15A NCAC 02H .0112(c). 27
(g) Existing wastewater dischargers expanding to greater than 0.5 MGD design capacity may 28
petition the Director for an exemption from Sub-Items (a) through (c) and (e) (a), (b), (d), 29
and (e) of this Item upon meeting and maintaining all of the following conditions: 30
(i) The facility has reduced its annual average TN and TP loading by 30 percent from 31
its annual average 1991 TN and TP loading. Industrial facilities may alternatively 32
demonstrate that nitrogen and phosphorus are not part of the waste stream above 33
background levels. 34
(ii) The expansion does not result in annual average TN or TP loading greater than 70 35
percent of the 1991 annual average TN or TP load. Permit limits shall be 36
established to ensure that the 70 percent load is not exceeded. 37

(8) This Item describes the option for dischargers to form a group compliance association or join an 1
existing group compliance association, to collectively meet nitrogen and phosphorus load limits. 2
(a) Any or all facilities within the basin may form a group compliance association or join an 3
existing group compliance association, to meet nitrogen and phosphorus limits collectively. 4
Any such new association formed shall apply for and shall be subject to an NPDES group 5
permit that establishes the effective total nitrogen and phosphorus limits for the association 6
and for its members. More than one group compliance association may be established. No 7
facility may be a co-permittee member of more than one association formed pursuant to 8
this Rule at any given time. 9
(b) An association may modify its membership at any time upon notification to the Division. 10
At such time, the Division shall adjust the nitrogen and phosphorus allocations and limits 11
in the NPDES group permit to reflect the change in membership. 12
(c) No later than 180 days prior to coverage under a new NPDES group permit, or expiration 13
of an existing group permit, the association and its members shall submit an application 14
for an NPDES permit for the discharge of total nitrogen and total phosphorus to the surface 15
waters of the Tar-Pamlico River Basin. The NPDES group permit shall be issued to the 16
association and its members as co-permittees. 17
(d) An association's limit of total nitrogen and total phosphorus shall be the sum of its 18
members' individual allocations and nutrient offset credits plus any other allocation and 19
offset credits obtained by the association or its members pursuant to this strategy. 20
(e) An association and its members may reapportion their individual allocations and nutrient 21
offset credits on an annual basis. The NPDES group permit shall be modified to reflect the 22
revised individual allocations and limits. 23
(f) If an association does not meet its limits in any year, it shall obtain or use existing nutrient 24
offset credits in accordance with G.S. 143-214.26 and Rule .0703 of this Section to offset 25
its mass exceedance no later than July 1 of the following year. 26
(g) An association’s members shall be deemed compliant with the permit limits for total 27
nitrogen and total phosphorus contained in their individually issued NPDES permits while 28
they are members in an association. An association’s members shall be deemed compliant 29
with their individual limits in the NPDES group permit in any year in which the association 30
is in compliance with its limit. If the association exceeds its group limit, the association 31
and any members that exceed their individual limits in the NPDES group permit shall be 32
deemed to be out of compliance with the group permit. 33
(h) Upon the termination of a group compliance association, members of the association shall 34
be subject to the limits and other nutrient requirements of their individual NPDES permits. 35
(9) If an NPDES-permitted discharger or association of dischargers accepts wastewater from another 36
NPDES-permitted treatment facility in the Tar-Pamlico River Basin and that acceptance results in 37

the elimination of the discharge from that other treatment facility, the eliminated facility's total 1
nitrogen and phosphorus allocations shall be transferred into the receiving facility’s NPDES permit 2
and added to its allocations. 3
4
5
History Note: Authority G.S. 143-214.1; 143-215.1; 143-215.3(a)(1); 143-215.8B; 143B-282; 6
Eff. April 1, 1997; 7
Recodified from 15A NCAC 02B .0229 Eff. April 1, 2020; 8
Readopted April 1, 2020. 9
Amended Eff. June 1, 2025. 10