NC0025879_Speculative Limits_20080729

NPDES DOCUMENT SCANNING COVER SHEET
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NC0025879
Robbinsville WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Report
Speculative Limits
Instream Assessment
(67b)
Environmental Assessment (EA)
Permit
History
Document Date:
July 29, 2008
As% This document is printed on reuse paper - ignore any
content on the reverse side

Michael F. Easley, Governor
State of North Carolina
William G. Ross, Jr., Secretary
Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
July 29, 2008
The Honorable Bobby Cagle, Mayor
Town of Robbinsville
P.O. Box 126
Robbinsville, North Carolina
Subject: Speculative Limits for Robbinsville WWTP
NPDES Permit No. NC0025879
Graham County
Dear Mayor Cagle:
This letter is in response to the request for speculative effluent limits for relocation and an
expansion of the Robbinsville WWTP from 0.63 MGD to 1.0 MGD. Mr. David L. Honeycutt of
McGill Associates submitted this request to our office on your behalf.
Receiving Stream. The speculative request was for a relocation of Robbinsville's discharge to
the Cheoah River and to cease discharge into Long Creek. Cheoah River is classified as a C
Trout waterbody in the Little Tennessee River Basin. The best usage of these waters includes
aquatic life propagation and maintenance of biological integrity, wildlife, secondary recreation,
and agriculture. The Trout designation is for those waters which have conditions that shall
sustain and allow for trout propagation and survival of stocked trout on a year-round basis.
The proposed Robbinsville WWTP discharge point in the Cheoah River has a drainage area of
55.3 square miles, with an estimated average flow of 160 cfs; a summer 7Q10 flow of 26 cfs and a
winter 7Q10 flow' of 38 cfs.
Speculative Limits. Based on current available information, speculative effluent limits for the
discharge of the current permitted flow of 0.63 MGD to the Cheoah River are presented in
Table 1. Speculative limits for an expansion flow of 1.0 MGD to Cheoah River are presented in
Table 2. These limits are recommended by Best Professional Judgment for protection of the
receiving waters based on the proposed discharge into the headwater arm of Santeetlah Lake.
Although this segment of the Cheoah River is not impaired, the Division has applied tertiary
limits to this proposed discharge to protect the river for its best usage. Current resources within
the Division do not allow for conducting a lake model to determine if less stringent limits may
be a viable option. If the Town of Robbinsville does not concur with these limits, you may
contract an outside resource to model this segment of the Cheoah River for determination of
effluent limits at the relocation site. The Division will evaluate the model and limits upon its
completion.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Telephone [phone] FAX [phone]
512 N. Salisbury Street, Raleigh, North Carolina 27604 On the Internet at http://h2o.enr.state.nc.us/
An Equal Opportunity/Affirmative Action Employer
one
Nsor Carolina
Naturally

Letter to Mayor Cagle
page 2
At this time the Division does not believe nutrients (phosphorus and nitrogen) are a concern, so
no effluent nutrient limits will be imposed at this time. However, instream monitoring will be
required.
A complete evaluation of these limits and monitoring frequencies, in addition to monitoring
requirements for metals and other toxicants, will be addressed upon receipt of a formal NPDES
permit request. The recommended limits for ammonia (NH3-N) are calculated to protect
against ammonia toxicity instream.
The following procedure has been recently implemented by the Division of Water Quality
(DWQ): Total residual chlorine (TRC) compliance level changed to 50 ug/1. Effective March 1,
2008, the Division received EPA approval to allow a 50 ug/1 TRC compliance level. This change
is due to analytical difficulties with TRC measurements. Facilities will still be required to report
actual results on their monthly discharge monitoring report (DMR) submittals, but for
compliance purposes, all TRC values reported below 50 ug/1 will be considered to be in
compliance with the permit. 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/1.
TABLE 1. Speculative Limits for Robbinsville WWTP, 0.63 MGD, relocation to
Cheoah River
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly Average
Daily Maximum
Flow
0.630 MGD
BOD5 (summer)
5 mg/L
7.5 mg/L
BOD5 (winter)
10 mg/1
15 mg/1
NH3 as N (summer)
2 mg/L
6 mg/L
NH3 as N (winter)
4 mg/L
12 mg/L
TSS
30 mg/L
45 mg/L
Dissolved Oxygen
Daily average not
<6.0mg/L
Total Residual Chlorine
28 ug/L
pH
6.0 - 9.0 S.U.
Fecal coliform (geometric
mean)
200/100 mL
400/100 mL
2

4
Letter to Mayor Cagle
page 3
TABLE 2. Speculative Limits for Robbinsville WWTP, 1.0 MGD, relocation to
Cheoah River
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly Average
Daily Maximum
Flow
1.0 MGD
BOD5 (summer)
5 mg/L
7.5 mg/L
BOD5 (winter)
10 mg/L
15 mg/L
NH3 as N (summer)
1 mg/L
3 mg/L
NH3 as N (winter)
2 mg/L
6 mg/L
TSS
30 mg/L
45 mg/L
_
Dissolved Oxygen
Daily average not
<6.0mg/L
Total Residual Chlorine
28 ug/L
pH
6.0 — 9.0 S.U.
Fecal coliform (geometric
mean)
200 / 100 mL
400 / 100 mL
Chronic Toxicity
• 5.7%*
* Toxicity test will be conducted quarterly.
Engineering Alternatives Analysis (EAA). Please note that the Division cannot guarantee that
an NPDES permit modification for the relocation or the expansion to 1.0 MGD 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 Town's proposed expansion. In accordance with
the North Carolina General Statutes, the practicable wastewater treatment and disposal
alternative with the least adverse impact on the environment is required to be implemented.
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.
Alternatives to a surface water discharge, such as spray/drip irrigation, wastewater reuse, or
inflow/infiltration reduction, are considered to be environmentally preferable. A copy of the
EAA guidance document is attached to this letter. Permit. applications for new or expanding
flow will be returned as incomplete if all EAA requirements are not adequately addressed. If
you have any questions regarding these requirements, please contact the DWQ NPDES
Program at 919-807-6300.
3

Letter to Mayor Cagle
page 4
The fee schedule for NPDES permits has changed as of September 1, 2007. Application fees for
this major modification will be $260 should the Town pursue this relocation at the existing flow
or $1030 for the relocation and expansion to 1.0 MGD. If you have any questions about these
speculative limits or NPDES permitting requirements, please feel free to contact Jackie Nowell
at [phone].
Respectfully,
Slzsan A. Wilson, P.E.
Supervisor, Western NPDES Program
Attachment: EAA Guidance Document
cc: (without Attachment)
U.S. Fish and Wildlife Service, Ecological Services, PO Box 33726, Raleigh, NC 27636-
3726 Attn: Sara Myers
David Honeycutt, E.I./McGill Associates, P.O. Box 2259 Asheville, NC 28802
Asheville Regional Office/Surface Water Protection Supervisor
Dan Blaisdell/ Construction Grants and Loans
Central Files
NPDES Permit File
4

SUMMER
MODEL RESULTS
Discharger : ROBBINSVILLE
Receiving Stream : CHEOAH RIVER
The End D.O. is 7.81 mg/l.
The End CBOD is 1.86 mg/1.
The End NBOD is 1.01 mg/1.
Segment 1
Reach 1
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flow
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
7.66 0.00 1
7.50 9.00 6.00 0.63000

SUMMER
MODEL RESULTS
Discharger : ROBBINSVILLE
Receiving Stream : CHEOAH RIVER
Q /.0
AGO
The End D.O. is 7.76 mg/1.
The End CBOD is 1.96 mg/l.
The End NBOD is 1.14 mg/1.
Segment
Reach
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flow
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mad)
7.62 0.00 1
7.50 9.00 6.00 1.00000

*** MODEL SUMMARY DATA ***
Discharger
Receiving Stream :
Summer 7Q10
Design Temperature:
ROBBINSVILLE
CHEOAH RIVER
25.7
23.0
Subbasin : 040404
Stream Class: C TROU
Winter 7Q10 : 38.1
LENGTH SLOPE VELOCITY I DEPTH Kd I Kd I Ka Ka KN
mile ft/mi fps ft design @20° design @20° design
Segment 1
Reach 1
4.00
4.001
0.374 12.20
0.26 1 0.22 1 1.41
1.321 0.38
Flow
cfs
Segment 1 Reach 1
Waste 1.550
Headwaters 25.700
Tributary 0.000
* Runoff 0.000
�D�D�/lI
7.500 9.000 6.000
2.000 1.000 7.720
2.000 1.000 7.720
2.000 1.000 7.720
* Runoff flow is in cfs/mile

SUMMER
Seg #
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Seg #
Reach # I Seg Mi I D.O.
1 0.00 7.62
1 0.10 7.63
1 0.20 7.63
1 0.30 7.63
1 0.40 7.64
1 0.50 7.64
1 0.60 7.64
1 0.70 7.65
1 0.80 7.65
1 0.90 7.65
1 1.00 7.66
1 1.10 7.66
1 1.20 7.66
1 1.30 7.67
1 1.40 7.67
1 1.50 7.67
1 1.60 7.68
1 1.70 7.68
1 1.80 7.68
1 1.90 7.69
1 2.00 7.69
1 2.10 7.70
1 2.20 7.70
1 2.30 7.70
1 2.40 7.71
1 2.50 7.71
1 2.60 7.71
1 2.70 7.72
1 2.80 7.72
1 2.90 7.72
1 3.00 7.73
1 3.10 7.73
1 3.20 7.74
1 3.30 7.74
1 3.40 7.74
1 3.50 7.75
1 3.60 7.75
1 3.70 7.75
1 3.80 7.76
1 3.90 7.76
1 4.00 7.76
Reach # I Seg Mi I D.O.
CBOD I NBOD 1 Flow I
2.31 1.46 27.25
2.30 1.45 27.25
2.29 1.44 27.25
2.28 1.43 27.25
2.27 1.42 27.25
2.27 1.41 27.25
2.26 1.40 27.25
2.25 1.39 27.25
2.24 1.38 27.25
2.23 1.38 27.25
2.22 1.37 27.25
2.21 1.36 27.25
2.20 1.35 27.25
2.19 1.34 27.25
2.18 1.33 27.25
2.17 1.33 27.25
2.16 1.32 27.25
2.15 1.31 27.25
2.15 1.30 27.25
2.14 1.29 27.25
2.13 1.29 27.25
2.12 1.28 27.25
2.11 1.27 27.25
2.10 1.26 27.25
2.09 1.25 27.25
2.08 1.25 27.25
2.08 1.24 27.25
2.07 1.23 27.25
2.06 1.22 27.25
2.05 1.22 27.25
2.04 1.21 27.25
2.03 1.20 27.25
2.02 1.19 27.25
2.02 1.19 27.25
2.01 1.18 27.25
2.00 1.17 27.25
1.99 1.17 27.25
1.98 1.16 27.25
1.97 1.15 27.25
1.97 1.14 27.25
1.96 1.14 27.25
CBOD I NBOD I Flow I

NC0025879
Town of Robbinsville WWTP Speculative limits
Long Creek C Trout F3SE
LTN04 (040404)
jmn
The Robbinsville facility is requesting spec limits at 0.63 MGD and 1 MGD with a
relocation of the discharge point from Long Creek directly into the Cheoah River.
The existing permit is for 0.63 MGD w/ limits are as follows:
BOD5=30 mg/1
TSS = 30mg/1
Summer NH3 = 4.2 mg/1 (mo. avg.); 12.6 mg/1 (weekly avg.)
Winter NH3 = 11.5 mg/1 (mo. avg.); 34.5 mg/1 (weekly avg.)
Fecal = 200/100m1
TRC=28 ug/1
Draft 2008 303d lists a segment of the Cheoah River as impaired for the use support
category of Aquatic Life. The impaired segment is from Santeelah Dam to Rock Creek,
downstream of the relocated discharge. Biological criteria is exceeded. The parameter of
interest is the ecological/biological integrity of benthos.
Model results
A Level B model was run to determine if DO would be protected in the Cheoah River
with the relocated discharge. A DO standard of 6 mg/1 for trout designation must be
protected instream.
The Cheoah River flows into the Santeelah Lake. On the other side of the lake, from the
Santeelah Dam to Rock Creek, the Cheoah River is impaired.
Model results
The DO standard is protected however the DO minimum of 7.1 mg/1 occurs at the end of
the model. The end CBOD=3.76 mg/1 and the end NBOD= 3.51 mg/1, nearly back to
background of CBOD = 2 mg/1 and NBOD = 1 mg/1.
31 Gi if V / %ice tj c- .
n 641,i lv .� ✓El ' 'r
�,lll Z72' 1 w zays r�
w 2ov 9 w

Michael F. Easley, Govemor
State of North Carolina
G William G. Ross, Jr., Secretary
Department of Environment and Natural Resources
,C Coleen H. Sullins, Director
Division of Water Quality
The Honorable Bobby Cagle, Mayor
Town of Robbinsville
P.O. Box 126
Robbinsville, North Carolina
Dear Mayor Cagle:
June, 2008
2-1
Subject: Speculative Limits for Robbinsville WWTP
NPDES Permit No. NC0025879
Graham County
This letter is in response to the request for speculative effluent limits for an expansion of the
Robbinsville WWTP from 0.63 MGD to 1.0 MGD. Mr. David L. Honeycutt of McGill Associates
submitted this request to our office on your behalf.
Receiving Stream. The speculative request was for a relocation of Robbinsville's discharge to
the Cheoah River and to cease discharge into Long Creek. Cheoah River is classified as a C
Trout waterbody in the Little Tennessee River Basin. The best usage of these waters includes
aquatic life propagation and maintenance of biological integrity, wildlife, secondary recreation,
and agriculture. The trout designation is for those waters that have conditions that shall sustain
and allow for trout propagation and survival of stocked trout on a year-round basis.
The proposed Robbinsville WWTP discharge point has a drainage area of 55.3 square miles,
with an estimated average flow of 160 cfs; a summer 7Q10 flow of 26 cfs and a winter 7Q10 flow
of 38 cfs.
Speculative Limits. Based on current available information, speculative effluent limits for the
discharge of the current permitted flow of 0.63 MGD to the Cheoah River is presented in Table
1. Speculative limits for an expansion flow of 1.0 MGD to Cheoah River are presented in Table
2. A complete evaluation of these limits and monitoring frequencies, in addition to monitoring
requirements for metals and other toxicants, will be addressed upon receipt of a formal NPDES
permit request. The recommended limits for ammonia (NH3-N) are calculated to protect
against ammonia toxicity instream.
The following procedure has been recently implemented by DWQ: Total residual chlorine (TRC)
compliance level changed to 50 ug/1 Effective March 1, 2008, the Division received EPA approval
to allow a 50ug/1 TRC compliance level. This change is due to analytical difficulties with TRC
measurements. Facilities will still be required to report actual results on their monthly discharge
monitoring report (DMR) submittals, but for compliance purposes, all TRC values below 50 ug/1
will be treated as zero.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Telephone [phone] FAX [phone]
512 N. Salisbury Street, Raleigh, North Carolina 27604 On the Internet at http://h2o.enr.state.nc.us/
An Equal Opportunity/Affirmative Action Employer
1V_One Carolina
Naturally

Letter to Mayor Cagle
page 2
TABLE 1. Speculative Limits for Robbinsville WWTP, 0.63 MGD, relocation to
Cheoah River
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly Average
Daily Maximum
Flow
0.63 MGD
BOD5
30 mg/L
45 mg/L
NH3 as N, Summer
21 mg/L
35 mg/L
NH3 as N, Winter
monitor only
TSS
30 mg/L
• 45 mg/L
Dissolved Oxygen
Daily average not
<5.0mg/L
Total Residual Chlorine
28 ug/L
pH
6.0 - 9.0 S.U.
Fecal coliform (geometric
mean)
200/100 mL
400/100 mL
TABLE 2. Speculative Limits for Robbinsville WWTP, expansion to 1.0 MGD,
relocation to Cheoah River
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly Average
Daily Maximum
Flow
1.0 MGD
BOD5
30 mg/L
45 mg/L
NH3 as N, Summer
13 mg/L
35 mg/L
NH3 as N, Winter
monitor only
TSS
30 mg/L
45 mg/L
Dissolved Oxygen
.
Daily average not
<5.0mg/L
28 ug/L
Total Residual Chlorine
pH
6.0 - 9.0 S.U.
Fecal coliform (geometric
mean)
200/100 mL
400/100 mL
Chronic Toxicity
5.7%
Engineering Alternatives Analysis (EAA). Please note that the Division cannot guarantee that
an NPDES permit modification for expansion to 1.0 MGD 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 Town's proposed expansion. In accordance with the North Carolina
General Statutes, the practicable wastewater treatment and disposal alternative with the least
adverse impact on the environment is required to be implemented. 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
2

SUMMER
MODEL RESULTS
Discharger : ROBBINSVILLE
Receiving Stream : CHEOAH RIVER
The End D.O. is 7.59 mg/1.
The End CBOD is 2.66 mg/1.
The End NBOD is 1.54 mg/1.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flow
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 7.55 1.30 1
Reach 1 22.00 18.00 5.00 1.00000
16 410 -

SUMMER
Seg # I Reach #
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
I Seg # I Reach #
1
Seg Mi 1 D.O. I CBOD 1 NBOD I Flow I
0.00 7.57 3.14 1.97 27.25
0.10 7.56 3.12 1.95 27.25
0.20 7.56 3.11 1.94 27.25
0.30 7.56 3.10 1.93 27.25
0.40 7.56 3.09 1.92 27.25
0.50 7.56 3.07 1.91 27.25
0.60 7.56 3.06 1.90 27.25
0.70 7.56 3.05 1.88 27.25
0.80 7.56 3.03 1.87 27.25
0.90 7.55 3.02 1.86 27.25
1.00 7.55 3.01 1.85 27.25
1.10 7.55 3.00 1.84 27.25
1.20 7.55 2.98 1.83 27.25
1.30 7.55 2.97 1.82 27.25
1.40 7.55 2.96 1.80 27.25
1.50 7.55 2.95 1.79 27.25
1.60 7.55 2.94 1.78 27.25
1.70 7.55 2.92 1.77 27.25
1.80 7.55 2.91 1.76 27.25
1.90 7.56 2.90 1.75 27.25
2.00 7.56 2.89 1.74 27.25
2.10 7.56 2.87 1.73 27.25
2.20 7.56 2.86 1.72 27.25
2.30 7.56 2.85 1.71 27.25
2.40 7.56 2.84 1.70 27.25
2.50 7.56 2.83 1.69 27.25
2.60 7.56 2.82 1.68 27.25
2.70 7.56 2.80 1.67 27.25
2.80 7.56 2.79 1.65 27.25
2.90 7.57 2.78 1.64 27.25
3.00 7.57 2.77 1.63 27.25
3.10 7.57 2.76 1.62 27.25
3.20 7.57 2.75 1.61 27.25
3.30 7.57 2.73 1.60 27.25
3.40 7.57 2.72 1.59 27.25
3.50 7.58 2.71 1.58 27.25
3.60 7.58 2.70 1.58 27.25
3.70 7.58 2.69 1.57 27.25
3.80 7.58 2.68 1.56 27.25
3.90 7.59 2.67 1.55 27.25
4.00 7.59 2.66 1.54 27.25
Seg Mi I D.O. I CBOD I NBOD I Flow f

SUMMER
MODEL RESULTS
Discharger : ROBBINSVILLE
Receiving Stream : CHEOAH RIVER
The End D.O. is 7.10 mg/l.
The End CBOD is 3.76 mg/1.
The End NBOD is 3.51 mg/l.
Segment 1
Reach 1
WLA WLA WLA
DO. Min CBOD NBOD DO Waste Flow
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
7.10 4.00 1
45.00 62.50 5.00 1.00000

SUMMER
Seg #
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
• 1
Seg #
Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 0.00 7.57 4.45 4.50 27.25
1 0.10 7.54 4.43 4.47 27.25
1 0.20 7.52 4.41 4.44 27.25
1 0.30 7.50 4.39 4.42 27.25
1 0.40 7.48 4.37 4.39 27.25
1 0.50 7.46 4.35 4.36 27.25
1 0.60 7.44 4.34 4.33 27.25
1 0.70 7.42 4.32 4.31 27.25
1 0.80 7.40 4.30 4.28 27.25
1 0.90 7.39 4.28 4.26 27.25
1 1.00 7.37 4.26 4.23 27.25
1 1.10 7.36 4.25 4.20 27.25
1 1.20 7.34 4.23 4.18 27.25
1 1.30 7.33 4.21 4.15 27.25
1 1.40 7.31 4.19 4.13 27.25
1 1.50 7.30 4.18 4.10 27.25
1 1.60 7.28 4.16 4.08 27.25
1 1.70 7.27 4.14 4.05 27.25
1 1.80 7.26 4.12 4.03 27.25
1 1.90 7.25 4.11 4.00 27.25
1 2.00 7.24 4.09 3.98 27.25
1 2.10 7.23 4.07 3.95 27.25
1 2.20 7.22 4.06 3.93 27.25
1 2.30 7.21 4.04 3.90 27.25
1 2.40 7.20 4.02 3.88 27.25
1 2.50 7.19 4.01 3.86 27.25
1 2.60 7.18 3.99 3.83 27.25
1 2.70 7.17 3.97 3.81 27.25
1 2.80 7.17 3.96 3.78 27.25
1 2.90 7.16 3.94 3.76 27.25
1 3.00 7.15 3.92 3.74 27.25
1 3.10 7.15 3.91 3.71 27.25
1 3.20 7.14 3.89 3.69 27.25
1 3.30 7.13 3.87 3.67 27.25
1 3.40 7.13 3.86 3.65 27.25
1 3.50 7.12 3.84 3.62 27.25
1 3.60 7.12 3.83 3.60 27.25
1 3.70 7.11 3.81 3.58 27.25
1 3.80 7.11 3.79 3.56 27.25
1 3.90 7.11 3.78 3.54 27.25
1 4.00 7.10 3.76 3.51 27.25
Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I

*** MODEL SUMMARY DATA ***
Discharger
Receiving Stream :
Summer 7Q10
Design Temperature:
ROBBINSVILLE
CHEOAH RIVER
25.7
23.0
Subbasin : 040404
Stream Class: C TROU
Winter 7Q10 : 38.1
LENGTH SLOPE VELOCITY I DEPTH Kd I Kd 1 Ka I Ka I KN
mile ft/mi fps ft design @20° design @20° design
Segment 1
Reach 1
4.00
4.00
0.374 12.20 10.26 10.22 11.41 I 1.321 0.38
Flow CBOD NBOD
cfs mg/I mg/I
Segment 1 Reach 1
Waste 1.550 45.000 62.500
Headwaters 25.700 2.000 1.000
Tributary 0.000 2.000 1.000
* Runoff 0.000 2.000 1.000
* Runoff flow is in cfs/mile
D.O.
mg/1
5.000
7.720
7.720
7.720

SUMMER
MODEL RESULTS
Discharger : ROBBINSVILLE
Receiving Stream : CHEOAH RIVER
The End D.O. is 7.24 mg/l.
The End CBOD is 4.09 mg/l.
The End NBOD is 3.98 mg/l.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flow
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 7.24 2.00 1
Reach 1 45.00 62.50 5.00 1.00000

*** MODEL SUMMARY DATA ***
Discharger
Receiving Stream .
Summer 7Q10
Design Temperature:
ROBBINSVILLE
CHEOAH RIVER
25.7
23.0
LENGTH SLOPE VELOCITY
mile ft/mi fps
DEPTH
ft
Winter 7Q10
Subbasin : 040404
Stream Class: C TROU
38.1
Kd Kd I Ka
design @20° design
Ka KN
@20° design
Segment 1
Reach 1
2.00
4.00
0.374
2.20
0.26
0.22
1.41
1.32
0.38
Flow
cfs
Segment 1 Reach 1
Waste 1.550
Headwaters 25.700
Tributary 0.000
* Runoff 0.000
CBOD NBOD D.O.
mg/1 mg/1 mg/1
45.000 62.500 5.000
2.000 1.000 7.720
2.000 1.000 7.720
2.000 1.000 7.720
* Runoff flow is in cfs/mile

SUMMER
Seg #
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Seg #
Reach #
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Reach #
Seg Mi
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
1.80
1.90
2.00
Seg Mi
D.O.
7.57
7.54
7.52
7.50
7.48
7.46
7.44
7.42
7.40
7.39
7.37
7.36
7.34
7.33
7.31
7.30
7.28
7.27
7.26
7.25
7.24
D.O.
CBOD
4.45
4.43
4.41
4.39
4.37
4.35
4.34
4.32
4.30
4.28
4.26
4.25
4.23
4.21
4.19
4.18
4.16
4.14
4.12
4.11
4.09
CBOD
NBOD
4.50
4.47
4.44
4.42
4.39
4.36
4.33
4.31
4.28
4.26
4.23
4.20
4.18
4.15
4.13
4.10
4.08
4.05
4.03
4.00
3.98
NBOD
Flow I
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
27.25
Flow I

Sub/Waterbody
Caney Fk
Moses Cr
Cuilowhee Cr
Savannah Cr
Tuckasegee R
Scott Cr
Conley Cr
Bradley Fk
Oconalufee R
Deep Cr
Deep Cr
Noland Cr
Forney Cr
Panther Cr
Stecoah Cr
Hazel Cr
Twenty Mile Cr
040403
Nantahala R
Nantahala R
Dicks Cr
Whiteoak Cr
Whiteoak Cr
040404
Tulula Cr
Cheoah R
Snowbird Cr
L Santeetlah Cr
Cheoah R
Cheoah R
Location
SR 1740
SR 1739
SR 1001
SR 1367
off SR 1378
SR 1556
off SR 1177
off US 441
SR 1359
AB Campground
SR 1340
near mouth
near mouth
SR 1233
SR 1237
near mouth
NC 28
FSR 437
US 19/74
off SR 1401
SR 1397
off SR 1310
SR 1275
off SR 1138
SR 1120
Ab Footbridge
SR 1147
At gauge
County Index No. Date
Jackson 2-79-28-(2.5)
Jackson 2-79-28-8
Jackson 2-79-31
Jackson 2-79-38
Jackson 2-79-(38)
Jackson 2-79-39 •
Swain 2-79-39
Swain 2-79-55-12-(11)
Swain 2-79-55-(16.5)
Swain 2-79-63-(16)
Swain 2-79-63-(21)
Swain 2 90
Swain 2 97
Graham 2115
Graham 2130
Swain 2-146-(19)
Swain 2-178-(4)
Macon 2-57-(0.5)
Swain 2-57-(22.5)
Macon 2-57-42
Macon 2-57-45
Macon
Graham 2-190-2-(0.5)
Graham 2-190-(3.5)
Graham 2-190-9-(15.5)
Graham
Graham
Graham
2-190-19-7
2-190 (22)
2-190-(22)
8/2/2004
7/20/1999
8/2/2004
7/20/1999
8/4/2004
7/20/1999
8/4/2004
7/21/1999
8/4/2004
7/21/1999
8/4/2004
7/21/1999
8/3/2004
7/21/1999
8/3/2004
7/22/1999
8/5/2004
7/22/1999
8/2/2004
8/9/1999
8/2/2004
8/9/1999
8/3/2004
8/11/1999
8/3l2004
8/11/1999
8/4/2004
8/10/1999
8/4/2004
8/11/1999
8/3/2004
8/11/1999
8/4/2004
7/21/2004
8/24/1999
7/20/2004
8/23/1999
7/21/2004
8/13/1999
7/212004
7/20/2004
8/13/1999
7/19/2004
7/19/2004
8/12/1 999
7/20/2004
8/12/1999
7/20/2004
7/4/2005
08/04/2004
ST
107
97
46
37
43
91
53
84
75
74
70
34
79
67
106
104
78
81
96
106
92
100
83
63
78
61
84
89
59
54
EPT BI EPTBI BioClass
54 3.63 2.68 Excellent
53 3.68 3.03 Excellent
46 1.71 1.71 Excellent
37 1.91 1.91 Excellent
47 - 2.61 Excellent
43 2.96 2.96 Excellent
40 4.15 3.11 Good
32 3.80 3.48 Good
44 4.27 3.44 Excellent
40 4.39 3.82 Good
35
36
34
44
47
39
51
53
43
47
38
45
35
40
44
46
35
39
30
39
46
56
29
49
49
35
35
27
34
26
34
31
31
38
48
48
52
32
19
42
4.07
4.14
2.82
2.59
2.67
3.96
3.93
2.58
2.66
3.26
2.95
3.2
3.4
4.2
4.3
3.5
4.0
4.0
3.5
2.9
5.7
323
3.22
2.82
3.17
2.02
1.87
2.97
3.20
2.13
2.67
2.18
2.95
1.92
1.98
1.80
1.68
2.07
2.24
2.94
3.02
2.17
1.97
2.15
1.93
2.45
2.26
2.29
1.59
1.93
2.33
1.68
2.14
3.24
3.14
2.84
2.06
2.56
1.65
3.92
3.00
Good
Good
Good
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Good
Excellent
Excellent
Excellent
Good
Excellent
Good
Excellent
Excellent
Excellent
Good
Excellent
Excellent
Good
Good
Good -Fair
Good
Good -Fair
Excellent
Good
Good
Good
Excellent
Excellent
Excellent
Good
Fair
Excellent
NCDENR, Division of Water Quality
Basinwide Assessment Report - Little Tennessee River Basin - April 2005
56

Little Tennessee River Basin Lower Little Tennessee River 8-Digit Subbasin 06010204
Assessment Unit Number Name Use Use
Description Support Support Reason for Parameter of Collection Listing IR
Classification DWQ Subbasin Miles/Acres Watershed (s) Category Rating Rating Interest Year Year Category
2-190-(22)a Cheoah River
From Santeetlah Dam to Rock Creek
C;Tr 04-04-04
3.4 FW Miles
060102040109 Aquatic Life Impaired Biological Criteria Ecological/biological Integrity 2004 2008 5
Exceeded Benthos
Neuse River Basin
Pamlico Sound 8-Digit Subbasin 03020105
27-149-4-1 Great Pond
From source to Cedar Island Bay
SA;ORW,NSW 03-04-14
3.0 S Acres
030201050401 Shellfish Impaired Standard Violation Fecal Coliform (shellfish) 2006 2008 5
Harvesting
Neuse River Basin
Upper Neuse River 8-Digit Subbasin 03020201
27-(1) NEUSE RIVER (Falls Lake below 030202010105 Aquatic Life Impaired Standard Violation Turbidity
normal pool elevation) 030202010404 Aquatic Life Impaired Standard Violation Chlorophyll a .
From source (confluence of Eno River Arm of Falls Lake and 030202010305
Flat River Arm of Falls Lake) to I-85 bridge 030202010403
WS-IV;NSW,CA 03-04-01 2,703.6 FW Acres 030202010402
2006 2008 5
2006 2008 5
27-(38.5) NEUSE RIVER 030202011105 Aquatic Life Impaired Standard Violation Turbidity 2006 2008 5
From a point 0.2 mile downstream of Johnston County SR 030202011104
1700 to point 1.4 mile downstream of Johnston County SR
1908
WS-IV;NSW 03-04-02 9.7 FW Miles
27-(41.7) NEUSE RIVER
From City of Smithfield water supply intake to a point 1.7
miles upstream of Bawdy Creek
WS-V;NSW 03-04-02 26.2 FW Miles
030202011702 Aquatic Life Impaired Standard Violation Turbidity 2006 2008 5
030202011107
030202011007
B. Draft 2008 303(d) List -Integrated Report Category 5 Version-20080107 Page 38 of 96

r
Legend
Monitoring Stations
Ambient Monitoring Station
a; Benthic Community
® Fish Community
* Lake Monitoring Station
® Recreation Locations
NPDES Discharges
Q Major
A Minor
tic Life Use Support Rating
Impaired
d'N/ No Data
^/ Not Rated
Supporting
'zr4ation Use Support Rating
/ Impaired
Primary Roads
OCounty Boundary
O Municipality
Gihhnein tnrinry
Figure 9 Little Tennessee Subbasin 04-04-04
anteetlah
Lake
Miles
Planning Section
Basinwide Planning Unit
May 22, 2006

SPECULATIVE LIMITS REQUEST
TOWN OF ROBBINSVILLE
GRAHAM COUNTY, NORTH CAROLINA
Mc
ASSOCIATES
ENGINEERING•PLANNING•FINANCE
55 BROAD STREET ASHEVILI-E. NC PH. [phone]

H rT b U1 7\ 1
StreQw :
l'I04RStem v DfanCli
Stapt C41cu t&tuan S
cliLyq
0 • g;14;
r 4j
a
•
eity
turn
dist
0
4.1
d i st
Sfopt

Facility: robbinsviiie spec
NPDES#: NC0025879
Receiving Stream: Cheoah River
Comment(s):
Low Flow Record Station Number
Hydrologic Area Number.
Drainage Area Low Flow Record Station:
Qave Low Flow Record Station:
s7Q10 Low Flow Record Station:
w7Q10 Low Flow Record Station:
30Q2 Low Flow Record Station:
Drainage Area New Site:
MAR New Site:
Qave per Report Equation:
s7Q10 per Report Equation:
w7Q10 per Report Equation:
30Q2 per Report Equation:
03.5170.0000
HA10
177
513.30 cfs
68.00 cfs
111.00 cfs
154.00 cfs
must be < 400 sq. miles
55.30 sq. miles
2.9
Drainage Area Ratio:
[ new DA/Daatgage
Weighted Ratio:
Over -ride Inappropriate Site (y ):
160 cfs
26.15 cfs
38.41 cfs
55.17 cfs
Continue
0.31 :1
Continue
0.08 :1
Drainage Area New Site:
MAR New Site:
Weighted Qave per Report Equation:
Weighted s7Q10 per Report Equation:
Weighted w7Q10 per Report Equation:
Weighted 30Q2 per Report Equation:
11
55.30 miles squared
2.9
160 cfs
25.74 cfs
38.10 cfs
54.58 cfs

Robbinsville WWTP at 0.63 MGD, relocate to Cheoah River
Residual Chlorine
7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
UPS BACKGROUND LEVEL (I
IWC (%)
Allowable Concentration (ugi
Fecal Limit
Ratio of 26.3 :1
25.7
0.63
0.9765
17.0
0
3.66
464.41
Ammonia as NH3
(summer)
7010 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL
IWC (%)
Allowable Concentration (m
Ammonia as NH3
(winter)
7Q10 (CFS)
200/100m1 DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL
IWC (%)
Allowable Concentration (m
25.7
0.63
0.9765
1.0
0.22
3.66
21.53
38.1
0.63
0.9765
1.8
0.22
2.50
63.45
6/4/2008

Robbinsvilte WWTP w/ 1.0 MGD expansion
Residual Chlorine
7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
UPS BACKGROUND LEVEL (I
IWC (%)
Allowable Concentration (ugi
Fecal Limit
Ratio of 16.6 :1
25.7
1
1.55
17.0
0
5.69
298.87
Ammonia as NH3
(summer)
7010 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL
IWC (%)
Allowable Concentration (m
Ammonia as NH3
(winter)
7Q10 (CFS)
200/100m1 DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL
IWC (%)
Allowable Concentration (m
25.7
1
1.55
1.0
0.22
5.69
13.93
38.1
1
1.55
1.8
0.22
3.91
40.64
2/5/2008

C
A S S o C 1 A "1' [i S
January 18, 2008
Ms. Susan Wilson
Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, North Carolina 27699 - 1617
RE: WWTP Expansion/Relocation
Robbinsville, North Carolina
Ms. Wilson:
The Town of Robbinsville is considering the expansion of their WWTP at a new
location. 1 have attached a quad sheet marking the proposed location. The coordinates are 35° 19'
56"N, 83° 48' 33"W. We have not completed a full flow projection at this time but would like to
receive speculative limits for 0.63 mgd, 0.75 mgd, 0.90 and 1.0 mgd at the location shown. Note
that this will be a relocation and therefore the existing discharge, (NPDES No. NC0025879)
which is in this basin, should be considered removed for these limits.
Thank you in advance for your assistance on this project. if you have any questions or
need additional information please don't hesitate to contact me or Harry Buckner, P.E. at 828-
252-0575.
Sincerely,
McG1LL ASSOCIATES, P.A.
DAVID L. HONEYCUTT E.I.
Engineering Associate
Enclosure
cc: Bobby Cagle, Mayor
Jeff Bishop, P.E.
Harry Buckner, P.E.
Engineering • Planning • Finance
P:120061065fjotitt m\wilzo ,¢roc P.O. Box 2259, Asheville, NC 28802 • 55 Broad Sireei, Asheville, NC 28801
828-252-0575 • Fax: [phone]

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