NC0043257_Fact Sheet_20211005

DENR/DWQ
EXPEDITED FACT SHEET - NPDES PERMIT DEVELOPMENT
NPDES Permit: NCO043257
2021 Renewal
This form must be completed by Permit Writers for all expedited permits which do not require full Fact Sheets.
Expedited permits are generally simple 100% domestics (e.g., schools, mobile home parks, etc.) that can be
administratively renewed with minor changes, but can include facilities with more complex issues (Special
Conditions, 303(d) listed water, toxicity testing, instream monitoring, compliance concerns).
Facility and Stream Information
Applicant/ Facility Name:
Nature Trail Associates, CLP / Nature Trail MHC WWTP
Applicant Address:
524 Meadow Ave. Loop; Banner Elk, NC 28604
Facility Address:
326 Nature Trail, Chapel Hill, NC 27517
Facility Class Permit Status:
Grade II Biological WPCS Renewal
Permitted Flow (as
built)
0.06 MGD (0.04)
Type of Waste
100% Domestic
Receiving Stream
Cub Creek
Stream Class / ID
ws-iv NSW/ 16-41-2-10-(0.5)
River Basin
Cape Fear
Subbasin
03-06-05
HUC
030300020607
USGS Too
Farrin ton D22SE
7Q10 Sum Win cfs
0.13 0.37
30Q2 cfs
0.7
Avg. Stream Flow cfs
5.6
IWC %) Permitted/Built
42 32
County
Chatham
Regional Office
RRO
Basic Information for
Expedited Permit Renewal
Permit Writer / Date
Bradley Bennett / July 27, 2021
Does permit need daily max NH3 limits?
Yes - Already in permit
Does permit need TRC limits/language?
Yes - Already in permit
Does permit have toxicity testing?
No
Does permit have Special Conditions?
Yes - Nutrient Calcs. and Nutrient Reopener
Does permit have instream monitoring?
Yes - DO and Temp
Stream on 303 d List? For w arameter?
No - Mercury statewide issue only
Any compliance concerns?
Number of Notices and Enforcements; see below
Any modifications since lastpermit?
None noted in application.
New expiration date:
Aril 30, 2026
FACILITY OVERVIEW:
This facility is 100% domestic waste and serves a mobile home park with 200 homes and approximately 800
people. The facility has a permitted flow rate of 0.06 MGD and as -built flow of 0.04 MGD. The treatment system
includes the following wastewater treatment components:
• influent pump station
• equalization basin
• flow splitter box
• aeration basins
• dual clarifiers
• aerobic sludge digesters
• effluent chlorination
• dechlorination
• flow monitoring
Discussions with the Raleigh Regional Office indicate that the facility may not have an influent pump station as
is currently indicated in the components list of the 2016 permit. This issue was relayed to the applicant for
verification. The applicant confirmed (July 26, 2021 email) there is a lift station that pumps influent to the
equalization basins and this component should remain in the permit.

APPLICATION
The application indicates the system is sized for 80% BOD TSS and Nitrogen removal. Average flow noted in the
application is 0.031 MGD which is 77.5% of the as -built flow of 0.04 MGD. This will be pointed out in the cover
letter with the draft permit. The application indicates that the facility is in the Neuse River Basin but the facility
is actually in the Cape Fear Basin.
INSPECTION
The most recent inspection (11/20/2018) did not note any major issues. The inspection summary did note that
the ORC indicated that the influent pump station wasn't part of the WWTP but is listed in the permit
components as noted above. Inspection noted some pin floc in the clarifiers.
MONITORING DATA REVIEW:
Parameter Units
Min
Max
Avg
Permit Limit
Comments
Flow (MGD)
0.011
0.078
0.029
0.04 MA
1 MA > 0.04 and 2 at 0.0399
BOD (mg/L) Summer
0.05
31
4.51
10 MA
15 DM
3 DM exceedances
TSS (mg/L)
1.1
82
6.46
30 MA
45 DM
1 DM exceedance
Temp (C) - Upstream
3.9
23
14.03
-
One large value (955) removed
Temp (C) - Effluent
10.9
26.7
17.21
-
Temp (C) - Downstream
4.1
22.3
13.90
-
NH3-N (mg/L) Summer
< 0.045
7.6
1.27
2 MA 10 M
5 MA exceedances
NH3 N (mg/L) Winter
< 0.045
27
2.45
5 MA
DM
1 DM and 1 MA exceeded at 5/2525
1 DM and 4 MA exceeded at 4 20
DO (mg/L) - Upstream
2
15.9
9.19
-
No limit but 14 < 5
DO (mg/L) - Effluent
6.4
71
7.44
DA >_ 5
No values < 5; 71 value seems high
DO (mg/L) - Downstream
2.1
17.1
9.17
-
No Limit but 22 values < 5
Fecal Coliform (#/ml)
< 1.0
2420
N/A
-
6 DM exceedances
TRC (µg/L)
0.15
38
21.92
28 DM
No values > 38 so within compliance
Total Nitrogen (mg/L)
1.24
33.9
7.5
-
Total Phosphorus (mg/L)
0.19
5.9
1.16
-
pH (su)
6.5
7.6
N/A
>-6 and <-9
MA - Monthly Average WA - Weekly Average DM - Daily Max DA - Daily Average Summer - April through Oct Winter - Nov through March
The data reviewed for the renewal is from August 2016 through April 2021.
REVIEW OF PERMIT LIMITS:
Flow - Over the range of data evaluated for the permit renewal there were 135 daily flow values that
were over the allowed flow limit. While this did not translate to significant monthly average flow
exceedances, it does appear to indicate a potential issue to evaluate. The applicant reported in their
renewal application an average discharge flow for the previous three years that was over 75 % of their
permit limit. The cover letter accompanying the draft permit will note the potential need to begin
evaluating flow needs for the facility.
Ammonia Nitrogen Winter Limits - The current permit requires monitor weekly for NH3-N and has
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 flow tiers. Two issues impact the Ammonia 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
Nature Trail MHC WWTP Fact Sheet
NPDES Renewal 2021 - July 30, 2021
Page 2

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 213.0404(c) requires that winter
waste load allocations for oxygen consuming waste be no less stringent than 2 times the summer
waste load limit. To meet this rule requirement the winter limits for NH3-N are adjusted in the permit.
The draft permit includes proposed changes to the NH3-N limits utilizing the corrected flow numbers
of S7Q10 - 0.13 and W7Q10 - 0.37cfs. The changes also reduce the winter limits to no more than 2
times the summer limit. The table below summarizes the spreadsheet results and the ultimate limits
based on application of the rule.
Limits from WLA (mg/L)
Apply 213.0404(c)
(mg/L)
Flow MGD->
0.04
0.06
0.04
0.06
MA
DM
MA
DM
MA
DM
MA
DM
Summer
2.6
13
2.1
10.5
2.6
13
2.1
10.5
Winter
11.2
35
8.1
35
5.2
26
4.2
21
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 (0.06 MGD) -In the 2016 permit renewal the DO limit for the second flow tier
of 0.06 MGD was changed from 5 mg/L to 6 mg/L. There was no discussion of this change in the 2016
Fact Sheet or cover letter. There is no documented reason for adjusting this limit. It appears that this
was simply a mistake in the last permit renewal. The data reviewed indicates that the effluent DO
levels over the previous permit cycle never fell below 6.4 mg/L. The permit draft is proposing the
return the DO level for the 0.06 MGD effluent limits to 5 mg/L.
COMPLIANCE:
During the permit cycle this facility had one (1) NOD, and sixteen (16) NOVs. The notices were mainly for
violations of limits for BOD, Fecal and NH3-N with a few for TSS and flow. There were also nine (9) enforcement
actions over the permit cycle. The total amount paid in these enforcements was $1,709.63 with $1,350 in
penalties. There is one enforcement action from July 2020 that has not been resolved and remains marked as
unpaid in our system. This is LV-2020-0132 in the total amount of $141.69.
FILE HISTORY REVIEW SUMMARY
• Waste Load Allocations (WLA) for 1978, 1982 and 1988 - Permitted flow of 0.04 MGD. Limits
set for BOD, TSS, NH3-N, DO, Fecal and pH. Monitoring only for settleable matter, TRC and Total
Residue. Upstream/Downstream monitoring for DO, Temperature, Fecal and Conductivity.
7Q10S - 0.075; 7Q10w - 0.2; 30Q2 - 0.4; DA - 2.9 sq.mi.; average stream flow - 3 cfs
• 1996 Permit Renewal - Limits - BOD - 17/25.5; TSS - 30/45; NH3-N - 5; DO > 5; Fecal -
200/400; pH - 6 to 9; Monitoring only for TRC, Temp, Conductivity, TN and TP.
• September 18, 1998 Authorization to Construct (ATC) - ATC to add equalization basin, grinder
pumps and blower, flow splitter box to distribute flow to two trains.
• 2001 Permit Renewal - NH3-N summer limit added at 2 mg/L and conductivity monitoring
removed. Renewal notes high TRC levels that could lead to limit.
• October 31, 2001 Name Change to Nature Trail Associates.
Nature Trail MHC WWTP Fact Sheet
NPDES Renewal 2021 — July 30, 2021
Page 3

• 2004 Permit Modification - The permit modification was to add a tiered flow for expansion of
the WWTP. The initial request was to double the flow to 0.08 MGD but that did not move
forward. It seems that nutrient limits may have impacted this request. The modification was
eventually approved for expansion to 0.06 MGD. The expansion effluent limits were set with
the following changes to the 0.04 MGD discharge.
- BOD limits dropped to 10/15
- TN and TP annual load limits added based on existing load in 1998.
- Daily max limits added for NH3-N added at 10 and 25.
- TRC daily max limit of 28 was added
With this modification a new WLA and Level B model were developed. During this review it
was found that previous WLA/modeling in 1988 had used an inaccurate location of the
discharge point. This resulted in the use of flow data that was not correct. The 2004
model/WLA used the new flow data: 7Q10S - 0.13; 7Q10W - 0.37; 30Q2 - 0.7; DA 5.4 sq mi.
and average stream flow of 5.6 cfs. This information was not updated in BIMS and was not
reflected in future renewals. The permit also incorporated a new special condition to add
Nutrient Control Conditions. BIMS will be updated to reflect the appropriate flow data.
• 2006 Permit Renewal - There was some discrepancy in the permit about the effective date of
the TRC limit. Even though the previous permit modification had made it effective, this permit
renewal set a new timeframe.
• December 12, 2006 Correction Letter - Corrected the issues noted above on the effective date
of the TRC limit.
• January 10, 2008 - ATC issued for the installation of a 10K equalization tank with coarse bubble
diffusers.
• September 25, 2009 - Notification is given of Jordan Lake Nutrient requirements. The facility is
given an allocation as part of the group allocation for dischargers < 100K, but no limit except
where a limit already existed.
• 2011 Permit Renewal - This renewal added the TRC compliance footnote and the Nutrient
Reopener clause. The application notes that the facility has designed a new 0.06 MGD plant, but
are holding off on implementation due to economic issues. The review documents note the
facility is operating better under a new ORC.
• 2016 Permit Renewal - added the electronic permitting requirements and also updated
location of outfall on the map. There is no discussion of why, but this renewal changed the DO
limit in the 0.06 MGD effluent page to 6 mg/L. This appears to have been an oversight and
should not have been changed. This limit will be changed back to 5 mg/L in this permit
renewal.
PROPOSED PERMIT CHANGES:
• Updated eDMR requirements to be consistent with final EPA rule.
• Added regulatory citations throughout permit as needed.
• Modified winter NH3-N limits to stay within the boundaries of rule 213.0404(c) requiring winter
limits to be no less than 2 times as stringent as summer limits.
• Corrected mistaken change of 0.06 MGD DO level to 6 mg/L in the 2016 permit renewal.
• Removed footnoted on TN in the effluent page, language seemed confusing.
• Updated Nutrient Monitoring Re -Opener language.
Nature Trail MHC WWTP Fact Sheet
NPDES Renewal 2021 — July 30, 2021
Page 4

PROPOSED SCHEDULE FOR PERMIT ISSUANCE:
Draft Permit to Public Notice: August 10, 2021
Permit Scheduled Effective Date: October 1, 2021
STATE CONTACT:
If you have questions concerning the above or the attached documents, please contact Bradley Bennett
at [phone] or [e-mail].
Nature Trail MHC WWTP Fact Sheet
NPDES Renewal 2021 — July 30, 2021
Page 5

Public Notice
AFFP
North Carolina Environ-
Public Notice N0043257
mental Management Com-
mission/NPDES Unit
1617 Mail Service Center
Affidavit of Publication
Raleigh, NC 27699-1617
Notice of Intent to Issue a
NPDES Wastewater Permit
NC0O43257 Nature Trails
STATE OF NC } SS
Mobile Home Park WWTP
COUNTY OF } (
The North Carolina
Environmental Manage-
ment Commission pro,
poses tO issue a NPDES
Kimberly Cook, being duly sworn, says:
wastewater discharge per -
mit to the person(s) listed
That she is Billing Clerk of the The Sanford Herald, a daily
below. Written comments
newspaper of general circulation, printed and published in
regarding the proposed
Sanford, County, NC; that the publication, a copy of which
permit will be accepted un-
:_
is attached hereto, was pu��:��hed in the said newspaper
,� 1 30 days a the publish
The Dir-
on the following dates:
date of this notice.
Lie
ector of the NC Division of
August 11, 2021
Water Resources (DWR)
may hold a public hearing
should there be a signific-
ant degree of public in-
terest. Please mail com-
ments and/or information
requests to DWR at the
above address. Interested
That said newspaper was regularly issued and circulated
persons may visit the DWR
on those dates.
at 512 N. Salisbury Street,
SIGNED:
Raleigh, NC 27604 to re-
view information on tile.
Q
Additional information on
NPDES permits and this
Billing Clerk
notice may be found on our
Subscribed to and sworn to me this 11th day of August
website:htta /� � oovtaboutl
2021.
diviSion Slwaier-resources(
water-resourees-
permit iW t water -branch/
2
nodes waGtewateNraubirc-
n i e ,or by calling (919)
Barbara M Daniels, Notary Guilford, County, NC
Trail As -
soc ates CLPture [524 Meadow
Ave. Loop, Banner Elk, NC
My commission expires: February 01, 2022
286041 has requested re-
newal of permit NCOO43257
for its Nature Trail MHP
WWTP in Chatham County.
This permitted facility dis-
70039191 70135749
charges treated domestic
wastewater to Cub Creek in
,,
NA D.
Wren Thedford �J •-. �!!�'°<,.
'y,• '';.
the Cape pear River Basin.
Currently BOD, TSS, am-
Division Of Water Resources S
MAIL SERVICE CENTER mQ; �pI A R Y '`,
monia,1617 form and RC are
RALEIGH, NC 27699-1617 =
fCls
water -quality limited. This
tu-
P U(3��` Q
�,
discharge may affect
ture wastelaad allocations
��FOpp co` .�'
in this portion of Cub
......,,
Creek.

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
S. DANIEL SMITH
Director
NORTH CAROLINA
Environmental Quality
August 10, 2021
MEMORANDUM
To: Shawn Guyer
NC DEQ / DWR / Public Water Supply
Raleigh Regional Office
From: Bradley Bennett BB
Compliance and Expedited Permitting Unit
Subject: Review of Draft NPDES Permit NCO043257
Nature Trail MHC WWTP
Chatham County
Please indicate below your agency's position or viewpoint on the draft permit and
return this form by September 10, 2021. If you have any questions on the draft
permit, please contact me via e-mail [[e-mail]].
RESPONSE: (Check one)
Concur with the issuance of this permit provided the facility is operated and maintained
Fx_1 properly, the stated effluent limits are met prior to discharge, and the discharge does not
contravene the designated water quality standards.
F-1
Concurs with issuance of the above permit, provided the following conditions are met:
F-1
Opposes the issuance of the above permit, based on reasons stated below, or attached:
Si ned� Date:0s/18/2021
g
OIX
D E QJ� North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1617 Mail Service Center I Raleigh, North Carolina 27699-1617
Oepartnental Envirn�me��a�qu0�� /`� 919.707.9000

7/30/2021
Mail - Bennett, Bradley - Outlook
Re: [External] Re: Nature Trail MHC WWTP Permit Renewal - NCO043257
Matthew Raynor <[e-mail]>
Mon 7/26/2021 5:36 PM
To: Bennett, Bradley <[e-mail]>
CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment
to Report Spam.
Absolutely, electronic is fine with me. Matt
Matthew Raynor, Director
REE Va. Inc.
524 Meadow Ave. Loop
Banner Elk, NC 28604
919/270-4831 Cell
828/733-5028 Office
-----Original Message -----
From: Bennett, Bradley <bradley. [e-mail]>
To: Matthew Raynor <[e-mail]>
Sent: Mon, Jul 26, 2021 5:33 pm
Subject: Re: [External] Re: Nature Trail MHC WWTP Permit Renewal - NCO043257
Thanks for the response on this. I certainly may have misunderstood where the info was coming from.
We will keep that component in the permit language.
Not sure if you saw the last part of my email, but could you let me know if you are okay with the Division
transmitting permit documents to you electronically?
Thanks
Bradley Bennett
Compliance and Expedited Permitting
NC Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Phone: [phone]
Email: [e-mail]
Email correspondence to and from this address may be subject to public records laws
From: Matthew Raynor <[e-mail]>
Sent: Monday, July 26, 2021 5:29 PM
To: Bennett, Bradley <brad ley. bennett@ ncden r.gov>
Subject: [External] Re: Nature Trail MHC WWTP Permit Renewal - NCO043257
CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment
to Report Spam.
Mr. Bennett,
There is a lift station located behind the 2 EQ tanks. Been there for 50 years. It pumps influent into the EQ tanks.
don't know who was asked but I assure you it wasn't our ORC, Pete Saulsbury, he's been operating that plant for
10 years.
Matthew Raynor, Director
REE Va. Inc.
https://outlook.office365.com/mail/inbox/id/AAMkADglYjdhZmlxLTMzMGYtNGU3Nil hNGU4LTY3M2E1 ODhmOGQxYgBGAAAAAACylgPJgHeWQptjf... 1/2

7/30/2021
Mail - Bennett, Bradley - Outlook
524 Meadow Ave. Loop
Banner Elk, NC 28604
919/270-4831 Cell
828/733-5028 Office
-----Original Message -----
From: Bennett, Bradley <bradley. [e-mail]>
To: [e-mail] <[e-mail]>
Sent: Mon, Jul 26, 2021 4:56 pm
Subject: Nature Trail MHC WWTP Permit Renewal - NCO043257
Hi Mr. Rayner,
I just wanted to touch base with you about the permit renewal for Nature Trail MHC WWTP
(NC0043257). I am the assigned permit reviewer for this renewal. I have been reviewing the application
submitted for renewal and I am getting close to having a draft ready for public notice. I had one quick
question for you and also I wanted to pass along some information about transmission of permit
documents electronically. These are addressed below.
Question from Document Review:
Looking at the most recent inspection report I noted that there was some question about the treatment
system components list in the current permit. The current permit includes an influent pump station as
part of the system. Our inspector was told by the ORC at the last inspection that there was not an
influent pump station that was part of the system. Could you verify for us if there is a pump station?
Electronic Distribution:
In order to provide more convenience, control, and security to our permittees and assist them in processing their
transactions, The Division of Water Resources is currently transitioning towards electronic correspondence. This
will hopefully provide more efficient service to our permittees and other partners and will allow us to more
effectively process and track documents. We are writing to ask you for your approval of the transmittal of
documents related to your permitting and related activities with the Division in an electronic format. Documents
will be emailed to the appropriate contact person(s) in your organization in a PDF format.
Please respond to me through email with verification that transmittal of your documents in an electronic
manner is acceptable to you. If you have any questions,_please feel free to contact me.
Thanks
Bradley Bennett
Compliance and Expedited Permitting
NC Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Phone: [phone]
Email: [e-mail]
Email correspondence to and from this address may be subject to public records laws
https://outlook.office365.com/mail/inbox/id/AAMkADglYjdhZmlxLTMzMGYtNGU3Nil hNGU4LTY3M2E1 ODhmOGQxYgBGAAAAAACylgPJgHeWQptjf... 2/2

NH3/TRC WLA Calculations
Facility: Nature Trail MHC WWTP
Permit No. NC0043257
Prepared By: Bradley Bennett
Enter Design Flow (MGD): 0.04 0.06 <= Permitted Flow if Different from Design
Enter s7Q10 (cfs): 0.13
Enter w7Q10 (cfs): 0.37
Total Residual Chlorine (TRC)
Daily Maximum Limit (ug/1)
Design Permitted
Ammonia (Summer)
Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
0.13
0.13
s7Q10 (CFS)
DESIGN FLOW (MGD)
0.04
0.06
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
0.062
0.093
DESIGN FLOW (CFS)
STREAM STD (UG/L)
17.0
17
STREAM STD (MG/L)
Upstream Bkgd (ug/1)
0
0
Upstream Bkgd (mg/1)
IWC (%)
32.29
41.70
IWC (%)
Allowable Conc. (ug/1)
53
41
Allowable Conc. (mg/1)
28 cap
28 cap
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Design
Permitted
Fecal Coliform
w7Q10 (CFS)
Monthly Average Limit:
200i100mi
200n00mi
DESIGN FLOW (MGD)
(If DF >331; Monitor)
DESIGN FLOW (CFS)
(If DF<331; Limit)
STREAM STD (MG/L)
Dilution Factor (DF)
3.10
2.40
Upstream Bkgd (mg/1)
IWC (%)
Allowable Conc. (mg/1)
*213 .0404 (c) applies --->
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/l, Monitor Only
2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals)
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis)
If the allowable ammonia concentration is > 35 mg/L, no limit shall be imposed
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)
Design
Permitted
0.13
0.13
0.04
0.06
0.062
0.093
1.0
1.0
0.22
0.22
32.29
41.70
2.6
2.1
Design Permitted
0.37
0.37
0.04
0.06
0.062
0.093
1.8
1.8
0.22
0.22
14.35
20.09
11.2
8.1
5.3
4.2