NC0043257_Draft Permit_20210810

ROY COOPER
Governor
ELIZABETH S. BIER
secretary
5, DANIEL SMITH
orevior
Matthew E. Raynor
Nature Trails Associates
Nature Trails MHC WWTP
524 Meadow Ave. Loop
Banner Elk, NC 28604
Dear Mr. Raynor:
NORTH CAROUNA
'nvlrvhmentai Quality
August 10, 2021
Subject: Draft NPDES Permit NC0043257
Nature Trails MHC WWTP
Grade II Biological WPCS
Chatham County
Attached with this letter is a copy of the Draft NPDES permit renewal for your facility. Please review
this draft carefully to ensure thorough understanding of the requirements and conditions it contains. We
understand from your renewal application that there have been no significant changes to the treatment
system. There are a few changes in the draft from the existing permit. These changes are summarized
below.
• Regulatory Citations - Language has been added where necessary in the permit to provide regulatory
citations for permit requirements.
• Electronic Reporting - Permit language has been modified to be consistent with the finalization of
federal requirements for electronic reporting.
• Ammonia Nitrogen (NH3-N) Monitoring — In the current permit you monitor weekly for NH3-N and
have and have summer effluent limits of 2 mg/L (monthly average) and 10 mg/L (daily max) and
winter limits of 5 mg/L and 25 mg/L for both effluent tiers. Two issues impact the NH3-N limits in
this permit renewal. In a 2004 permit modification (see discussion below in the File Review
Summary) corrected stream flow data was determined for the discharge point to Cub Creek. It
appears that this data adjustment may not have been applied to the ammonia limits. This is corrected
in this permit renewal. In addition, recent review by Division staff has noted that 15A NCAC 2B
.0404(c) requires that winter waste load allocations for oxygen consuming waste be no less stringent
than 2 times the summer waste load limit.
N. JOIWAn°
North Cnrr lir.n Department of Enwlranmentak Quality t DIYIKlan of %ler 0.rwuUrcem
S12 North 5alvihui y Slrril 11417 Mali SerIcr Crnler I Raleigh, Nail Combing bina 2 N01t 1417
1C9.7O7.9O00

Matthew E. Raynor
Nature Trails Associates
Page 2
The draft permit includes proposed changes to NH3-N limits. These changes will impact both
effluent tiers in the permit with the 0.04 MGD limits increasing and the 0.06 MGD limits decreasing.
The proposed limits are summarized in the table below.
Proposed NH3-N Effluent Limits
0.04 MGD
0.06 MGD
MA
DM
MA
DM
2.6
13
2.1
10.5
5.2
26
4.2
21
MA — Monthly Average DM — Daily Max
While there could be some impacts with this change, based on the data reviewed from the previous
permit cycle it appears that the proposed change in limits can be regularly attained with the existing
system. This is obviously an area of change that should be reviewed closely especially if the system
expands to 0.06 MGD and the limits are reduced.
• Dissolved Oxygen Limit — In the 2016 permit renewal there appears to have been a mistaken change
to the DO levels in the 0.06 Effluent Limits page. The limit was changed to 6 mg/L. There is no
documentation of the reason for this change and it does not appear to be appropriate given the
discharge and receiving stream. The draft permit proposes to return the DO limit to 5 mg/L as it was
prior to the 2016 permit renewal.
• Permitted Flow Levels - 15A NCAC 02T .0118, "Demonstration of Future Wastewater Treatment
Capacities," was adopted by the Environmental Management Commission to ensure that wastewater
treatment systems do not exceed their hydraulic treatment capacities. This Rule specifies that
publicly -owned facilities exceeding 80% of their hydraulic treatment capacity must conduct
evaluations of future wastewater treatment needs.
While this rule does not apply to your facility, we have noted a few months where your monthly
average flow has been at your flow limit of 0.04 MGD. There have also been over 130 daily flow
values above the 0.04 MGD level. In your renewal application you indicated an average flow for the
previous 3 years over 75% of your facility's design capacity. This poses a risk that your facility will
become noncompliant with its effluent limitations. We urge you to evaluate the cause[s] for these
high flows and take the necessary steps to keep your facility in compliance. We encourage you to
contact staff in our Raleigh Regional Office concerning your efforts to address potential flow issues.
• Enforcement Case Remains Open — Our records indicate that a penalty assessed to your facility in
July of 2020 has not yet been resolved. This case (LV-2020-0132) assessed penalties and
enforcement costs of $142.69. If you have paid this penalty please provide us with documentation of
the payment and we will update our records.
The NPDES standard conditions (Parts II, III, and IV) that are a part of the permit are not included in this
draft document (cover, map, and Part I). The conditions are the same as in your current permit. The latest
version of the standard conditions is available at https://bit.ly/3k5NFaL and can be viewed online or
downloaded as a PDF file.
Concurrent with this notification the Division is publishing a notice in a newspaper having general
circulation in the Chatham County area soliciting public comments on this draft permit. Please provide
any written comments you may have to me no later than 30 days after receipt of this draft permit

Matthew E. Raynor
Nature Trails Associates
Page 3
Following the 30-day public comment period, the Division will review all pertinent comments and take
appropriate action prior to issuing a final permit. If you have questions concerning this draft permit,
please call me at [phone] or contact me by email at [e-mail]. At this time,
contact by email is the most effective method. If we need to set up a call to discuss any issues we can set
that up through email.
Sincerely,
?4 ?,24-41'
Bradley Bennett
Compliance and Expedited Permitting Unit
cc: NPDES Files - electronic
Raleigh Regional Office / Water Quality — electronic
Operator Certification Program/Maureen Kinney — electronic

Draft NPDES Permit NC0043257
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
NPDES
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards
and regulations promulgated and adopted by the North Carolina Environmental Management
Commission, and the Federal Water Pollution Control Act, as amended,
Nature Trail Associates CLP
is hereby authorized to discharge wastewater from a facility located at the
Nature Trail MHC WWTP
326 Nature Trail, Chapel Hill 27517
Chatham County
to receiving waters designated as Cub Creek in the Cape Fear River Basin, in accordance with effluent
limitations, monitoring requirements, and other conditions set forth in Parts I, II, III and IV hereof.
This permit shall become effective
This permit and authorization to discharge shall expire at midnight on April 30, 2026.
If the permittee intends to continue discharging at the facility beyond the term of this permit, a renewal
application must be submitted no later than October 2, 2025 (180 days before the expiration of this permit)
Signed this day
S. Daniel Smith, Director
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 9

Draft NPDES Permit NC0043257
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby
revoked, and as of this issuance, any previously issued permit bearing this number is no longer
effective. Therefore, the exclusive authority to operate and discharge from this facility arises under the
permit conditions, requirements, terms, and provisions included herein.
Nature Trail Associates CLP
is hereby authorized to:
1. continue to operate an existing 0.04 MGD wastewater treatment facility with the following
components;
• influent pump station
• equalization basin
• flow splitter box
• aeration basins
• dual clarifiers
• aerobic sludge digesters
• effluent chlorination
• dechlorination
• flow monitoring
The facility is located at the Nature Trail MHC WWTP, 326 Nature Trail, Chapel Hill, NC,
Chatham County,
2. upon receiving an Authorization to Construct from the Division, construct and (after submitting an
engineer's certification form) operate facilities for a design capacity of 0.060 MGD, and
3. discharge from said treatment works via Outfall 001, at the location specified on the attached map
into Cub Creek [16-41-2-10-(0.5)], a waterbody currently classified WS-IV; NSW waters located
within Subbasin 03-06-05 [HUC: 030300020607] of the Cape Fear River Basin.
Page 2 of 9

Draft NPDES Permit NC0043257
PART I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Grade II Biological Water Pollution Control System [15A NCAC 08G.0302]
During the period beginning on the effective date of this permit and lasting until expansion above 0.04
MGD or expiration, the Permittee is authorized to discharge from outfall 001. Such discharges shall be
limited, monitored and reported' by the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
[eDMR Code]
LIMITS
MONITORING REQUIREMENTS'
Monthly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample2
Location
Flow (MGD)
50050
0.04 MGD
Continuous
Recording
I or E
BOD, 5-day (20°C) (mg/L)
C0310
17.0 mg/L
25.5 mg/L
Weekly
Composite
E
Total Suspended Solids (mg/L)
C0530
30.0 mg/L
45.0 mg/L
Weekly
Composite
E
NH3 as N (mg/L)
(April 1— October 31)
C0610
2.6 mg/L
13.0 mg/L
Weekly
Composite
E
NH3 as N (mg/L)
(November 1 — March 31)
C0610
5.2 mg/L
26.0 mg/L
Weekly
Composite
E
Dissolved Oxygen (DO)
00300
Daily averagnng�Lless than 5.0
Weekly
Grab
E
Dissolved Oxygen (DO)
00300
Monitor & Report
Weekly
Grab
U & D
Fecal Coliform 3 (#/100ml)
31616
200 / 100 ml
400 / 100 ml
Weekly
Grab
E
Total Residual Chlorine (TRC) 4
(µg/L)
50060
28 µg/L4
2/Week
Grab
E
Temperature (°C)
00010
Monitor & Report
Daily
Grab
E
Temperature (°C)
00010
Monitor & Report
Weekly
Grab
U & D
Total Nitrogen (TN) (mg/L)
C0600
Monitor & Report
Quarterly
Composite
E
Total Phosphorus (TP) (mg/L)
C0665
Monitor & Report
Quarterly
Composite
E
pH (su)
00400
> 6.0 & < 9.0 standard units
Weekly
Grab
E
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the NC DWR's eDMR system
[see A. (5)].
2. Upstream at least 50 feet upstream from the outfall. Downstream — at least 1.2 miles downstream from the
outfall.
3. Fecal Coliform shall be calculated using the geometric mean, according to the procedure detailed in Part II.
Section A.
4. The Division shall consider all effluent TRC values reported below 50 µg/L to be in compliance with the
permit. However, the Permittee shall continue to record and submit all values reported by North Carolina
certified test methods (including field certified), even if these values fall below 50 µg/L.
Conditions:
• There shall be no discharge of floating solids or foam visible in other than trace amounts.
Page 3 of 9

Draft NPDES Permit NC0043257
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (0.06 MGD)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Grade II Biological Water Pollution Control System [15A NCAC 08G.0302]
Beginning upon expansion above 0.04 MGD and lasting until expiration, the Permittee is authorized to
discharge treated wastewater from outfall 001. Such discharges shall be limited, monitored and
reported' by the Permittee as specified below:
EFFLUENT CHARACTERISTICS
[Parameter Code]
LIMITS
MONITORING
REQUIREMENTS1
Monthly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample 2
Location
Flow (MGD)
50050
0.06 MGD
Continuous
Recording
I or E
BOD, 5-day (20°C) (mg/L)
C0310
10.0 mg/L
15.0 mg/L
Weekly
Composite
E
Total Suspended Solids (mg/L)
C0530
30.0 mg/L
45.0 mg/L
Weekly
Composite
E
NH3 as N (mg/L)
(April 1— October 31)
C0610
2.1 mg/L
10.5 mg/L
Weekly
Composite
E
NH3 as N (mg/L)
(November 1 — March 31)
C0610
4.2 mg/L
21.0 mg/L
Weekly
Composite
E
Dissolved Oxygen (DO)
00300
Daily average not less than 6.0 mg/L
Weekly
Grab
E
Dissolved Oxygen (DO)
00300
Monitor & Report
Weekly
Grab
U & D
Fecal Coliform 3 (#/100ml)
31616
200 / 100 ml
400 / 100 ml
Weekly
Grab
E
Total Residual Chlorine (TRC) 4 (µg/L)
50060
28 µg/L4
2/Week
Grab
E
Temperature (°C)
00010
Monitor & Report
Daily
Grab
E
Temperature (°C)
00010
Monitor & Report
Weekly
Grab
U & D
Total Nitrogen (TN) 5 (mg/L)
C0600
669 lbs/yr
Quarterly
Composite
E I
Total Phosphorus (TP) 5 (mg/L)
C0665
243 lbs/yr
Quarterly
Composite
E
pH (su)
00400
> 6.0 & < 9.0 standard units
Weekly
Grab
E
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the NC DWR's eDMR system
[see A. (5)]
2. Upstream — at least 50 feet upstream from the outfall. Downstream — at least 1.2 miles downstream from the
outfall.
3. Fecal Coliform shall be calculated using the geometric mean, according to the procedure detailed in Part II.
Section A.
4. The Division shall consider all effluent TRC values reported below 50 µg/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 test methods (including field certified), even if these values fall below 50 µg/L.
5. See Condition A. (3.).
Conditions:
• There shall be no discharge of floating solids or foam visible in other than trace amounts.
Page 4 of 9

Draft NPDES Permit NC0043257
A. (3.) CALCULATION OF TOTAL NITROGEN AND TOTAL PHOSPHORUS LOADS
[G.S. 143-215.1(b)]
a. The Permittee shall calculate monthly and annual TN and TP Loads as follows:
i. Monthly TN (or TP) Load (lb/mo) = TN (or TP) x TMF x 8.34
where:
TN (or TP) = the average Total Nitrogen or Total Phosphorous concentration
(mg/L) of the composite samples collected during the month
TMF = the Total Monthly Flow of wastewater discharge during the
month (MG/mo)
8.34 = conversion factor, from (mg/L x MG) to pounds
ii. Annual TN (or TP) Load (lb/yr) = Sum of the 12 Monthly TN (or TP) Loads for the
calendar year
b. The Permittee shall report monthly Total Nitrogen or Total Phosphorus results (mg/L and lb/mo)
in the discharge monitoring report for that month and shall report each year's annual results
(lb/yr) in the December report for that year.
A. (4.) PERMIT RE -OPENER: SUPPLEMENTARY NUTRIENT MONITORING
[G.S. 143-215.1(b)]
(a) Pursuant to N.C. General Statues Section 143-215.1 and implementing rules found in Title 15A of
North Carolina Administrative Code, Subchapter 02H, specifically, 15A NCAC 02H.0112(b)(1)
and 02H.0114(a), and Part II, Sections B.12 and B.13. of this Permit, the Director of DWR may
reopen this permit to require supplemental nutrient monitoring of the discharge. The additional
monitoring will be to support water quality modeling efforts within the Cape Fear River Basin, and
shall be consistent with a monitoring plan developed jointly by the Division and affected
stakeholders. In addition, the results of water quality modelling may require that limits for total
nitrogen and total phosphorous be imposed on this permit upon renewal.
(b) The Division may, upon written notification to the permittee, re -open this permit in order to
incorporate or modify effluent limits, monitoring and reporting requirements, and other permit
conditions when it deems such action is necessary to implement TMDL(s) approved by the
USEPA.
Page 5 of 9

Draft NPDES Permit NC0043257
A. (5.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[G.S. 143-215.1(b)]
Federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and
program reports. The final NPDES Electronic Reporting Rule was adopted and became effective on
December 21, 2015.
NOTE: This special condition supplements or supersedes the following sections within Part II of this
permit (Standard Conditions for NPDES Permits):
• Section B. (11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Reporting Requirements [Supersedes Section D. (2.) and Section E. (5.) (a)1
The permittee shall report discharge monitoring data electronically using the NC DWR's
Electronic Discharge Monitoring Report (eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet. The eDMR system may be
accessed at: https://deq.nc.gov/about/divisions/water-resources/edmr.
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the
facility being physically located in an area where less than 10 percent of the households have
broadband access, then a temporary waiver from the NPDES electronic reporting requirements
may be granted and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1.1,
2, 3) or alternative forms approved by the Director. Duplicate signed copies shall be submitted to
the following address:
NC DEQ / Division of Water Resources / Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
See "How to Request a Waiver from Electronic Reporting" section below.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
reported via the eDMR system no later than the last calendar day of the month following the
completed reporting period. Regardless of the submission method, the first DMR is due on the last
day of the month following the issuance of the permit or in the case of a new facility, on the last
day of the month following the commencement of discharge.
Page 6 of 9

Draft NPDES Permit NC0043257
Starting on December 21, 2025 the permittee must electronically report the following compliance
monitoring data and reports, when applicable:
• Sewer Overflow/Bypass Event Reports;
• Pretreatment Program Annual Reports; and
• Clean Water Act (CWA) Section 316(b) Annual Reports.
The permittee may seek an electronic reporting waiver from the Division (see "How to Request a
Waiver from Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.41(1)(9), the permittee must identify the initial recipient at the time
of each electronic submission. The permittee should use the EPA's website resources to identify
the initial recipient for the electronic submission.
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the
entity (EPA or the state authorized by EPA to implement the NPDES program) that is the
designated entity for receiving electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for
each type of electronic submission and for each state. Instructions on how to access and use the
appropriate electronic reporting tool will be available as well. Information on EPA's NPDES
Electronic Reporting Rule is found at:
https://www.federalregister.gov/documents/2015/10/22/2015 -24954/national-pollutant-discharge-
elimination-system-npdes-electronic-reporting-rule
Electronic submissions must start by the dates listed in the "Reporting Requirements" section
above.
3. How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an
electronic reporting waiver, a permittee must first submit an electronic reporting waiver request to
the Division. Requests for temporary electronic reporting waivers must be submitted in writing to
the Division for written approval at least sixty (60) days prior to the date the facility would be
required under this permit to begin submitting monitoring data and reports. The duration of a
temporary waiver shall not exceed 5 years and shall thereupon expire. At such time, monitoring
data and reports shall be submitted electronically to the Division unless the permittee re -applies for
and is granted a new temporary electronic reporting waiver by the Division. Approved electronic
reporting waivers are not transferrable. Only permittees with an approved reporting waiver request
may submit monitoring data and reports on paper to the Division for the period that the approved
reporting waiver request is effective.
Information on eDMR and the application for a temporary electronic reporting waiver are found on
the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr
Page 7 of 9

Draft NPDES Permit NC0043257
4. Signatory Requirements [Supplements Section B. (11.) (b) and Supersedes Section B. (11.) (d)]
All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part
II, Section B. (11.)(a) or by a duly authorized representative of that person as described in Part II,
Section B. (11.)(b). A person, and not a position, must be delegated signatory authority for eDMR
reporting purposes.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user
account and login credentials to access the eDMR system. For more information on North
Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account, please visit
the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall
make the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF
CERTIFICATION WILL BE ACCEPTED:
"I certify, under penalty of law, that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief true, accurate,
and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations."
5. Records Retention [Supplements Section D. (6.)]
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR
submissions. These records or copies shall be maintained for a period of at least 3 years from the
date of the report. This period may be extended by request of the Director at any time [40 CFR
122.41].
Page 8 of 9

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Nature Trail Associates, CLP
Nature Trail WWTP
Receiving Stream:
River Basin:
Latitude:
Stream Segment
Grid/Quad:
Cub Creek Stream Class: WS-IV; NSW
Cape Fear Sub -Basin: 03-06-05
35° 51' 30" Longitude: 79° 01' 50"
16-41-2-10-(0.5) HUC#: 030300020607
D22SE / Farrington Coun : Chatham
NORTH
Facility
Location
(not to scale)
•
NPDES Permit NC0043257
Page 9 of 9