NC0043532_Speculative Limits_19940728

NPDES DOCUMENT :;CANNING COVER SHEET
NPDES Permit:
NC0043532
West Stanly / Oakboro WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
-
Speculative Limitsy -
Environmental Assessment (EA)
Document Date:
July 28, 1994
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State cf North Carolina
Department of Environment,
Health and Natural Resources
Division of Environmental Management
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
July 28, 1994
The Honorable Fetzer E. Hartsell, Mayor
Town of Oakboro
Post Office Box 610
Oakboro, North Carolina 28129
1 r i 7 - : 9 4 FA
_lir
I:3EHNR
SUBJECT: Speculative Limits for Town of Oakboro Wastewater Treatment Plant
NPDES Permit No. NC0043532
Stanly County
Dear Mayor Hartsell:
A speculative analysis for the proposed expansion of the Oakboro Wastewater
Treatment Plant to 0.9 MGD at the existing location on Long Creek and the proposed
relocation of the discharge to the Rocky River has been completed by the Technical Support
Branch. In order to receive final permit limits, a formal application will have to be
submitted to the Division's Permits and Engineering Unit.
In 1993 the Division of Environmental Management (DEM) conducted a study
(excerpts attached) on the Rocky River Watershed to determine the level of treatment which
will protect the dissolved oxygen standard as well as prevent any one discharge from using
up 100 percent of the available assimilative capacity of the river. Results from this study
indicate that any new or expanding discharge in the lower watersheds of the Rocky River
should receive a total Biochemical Oxygen Demand ultimate (BODu = CBOD + NBOD) of
32 mg/1 or less.
Based on available information the tentative limits for conventional constituents are:
Long Creek Rocky River
Summer Winter Summer Winter
Wasteflow (MGD) 0.9 0.9 0.9 0.9
BODS (mg/1)* 9 18 9 18
NH3-N (mg/1)* 3 6 3 6
DO (mg/1) 5 5 5 5
TSS (mg/1) 30 30 30 30
Fecal Coliform (#/100m1) 200 200 200 200
pH (SU) 6-9 6-9 6-9 6-9
Chlorine (µg/1) 28 28 28 28
* See attached graph for potential effluent limit combinations.
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post -consumer paper

•
-Page 2-
Letter to Mayor Hartsell
It should be noted that the tentative NH3N limits were evaluated and are based on
the protection of Long Creek against instream ammonia toxicity. North Carolina is
currently evaluating all NPDES dischargers for ammonia toxicity and following EPA
guidance to protect the waters for an instream criteria of 1 mg/1 in the summer and 1.8 mg/1
in the winter, under 7Q10 flow conditions. The tentative NH3N and BOD5 limits for the
Rocky River discharge location are based on a BODu of 32 mg/1 or less. To convert
NH3N to NBOD a multiplier of 4.5 is used. Current Division procedure and the
percentage of industrial waste in the effluent yield a CBOD/BOD5 ratio of 2:1. See
attached graph for possible alternative NH3N and BOD5 limits for the Rocky River
discharge location. The Rocky River discharge summer limits for NH3N and BOD5 can
range from NH3N maximum of 4 with a corresponding BOD5 limit of 7 mg/1 to an NH3N
minimum limit of 2 mg/1 with a corresponding BOD5 maximum of 11 mg/1.
In addition, under current DEM procedure, dechlorination and chlorine limits are
now recommended for all new or expanding dischargers proposing the use of chlorine for
disinfection. An acceptable level of chlorine in your effluent is 28 µg/1 to ensure protection
against acute toxicity. The process of chlorination/dechlorination or an alternate form of
disinfection, such as ultraviolet radiation, should allow the facility to comply with the total
residual chlorine limit.
The instream waste concentration (IWC) at the Long Creek location is 30% at 0.90
MGD; the IWC at the Rocky River location is 5% at 0.90 MGD. A chronic toxicity testing
requirement with quarterly monitoring will remain a condition of the NPDES permit for
both discharge locations. The effluent concentration at which there may be no observable
inhibition of reproduction or significant mortality will be based on the IWC at both
discharge locations. A complete evaluation of limits and monitoring requirements for
metals and other toxicants will have to be addressed at the time of formal NPDES
application. Due to the IWC, the effluent limits for the parameters of concern will most
likely be less stringent at the proposed relocation site on the Rocky River then at the
existing location on Long Creek. Information concerning these constituents is not readily
available but the Town can assume that effluent limits and/or monitoring for chromium,
nickel, lead, cyanide, mercury, copper, zinc, fluoride, sulfide, aluminum, arsenic, iron,
manganese, selenium, tin, oil and grease, MBAS, and silver should be included.
DEM has implemented a statewide basin water quality management initiative. Our
schedule for implementation in the Yadkin River Basin is set for 1998. The plan will
attempt to address all sources of point and nonpoint pollutants where deemed necessary to
protect or restore water quality standards. In addressing interaction of sources, wasteload
allocations may be affected. Those facilities that already have committed to high levels of
treatment technology are least likely to be affected.

-Page 3-
Letter to Mayor Hartsell
This information should provide some assistance in your planning endeavors. As
previously mentioned, final NPDES effluent limitations will be determined after a formal
permit application has been submitted to the Division. If there are any additional questions
concerning this matter, please feel free to contact Ruth Swanek or Michelle Wilson of my
staff at [phone].
erely,
nald L. Saffit,
Assistant Chief for Tec icupport
Water Quality Section
DLS/MMW
cc: Municipal Engineering Services Co., P.A.; David Dickenson, P.E.
Mooresville Regional Office
Permits and Engineering Unit
Central Files

A QUAL2E-UNCAS APPLICATION TO THE
ROCKY RIVER AND MALLARD CREEK.
CABARRUS, IREDELL, AND MECKLENBURG COUNTIES
NORTH CAROLINA.
NORTH CAROLINA DEPARTMENT OF ENVIRONMENT, HEALTH
AND NATURAL RESOURCES
This report has been approved for relea
Steve W. Tedder, Chief
Water Quality Section
N.C. Division of Environmental Management
Date 1/1/13//V

5
EXECUTIVE SUMMARY
Water quality models for three sections of the Rocky River and its tributaries were
joined to produce one calibrated model for 47.6 stream miles in the Yadkin River basin.
This model was used to predict dissolved oxygen and biochemical oxygen demand
concentrations at low flow conditions for both permitted and summer average discharge
conditions.
The general objective of this project was to provide a tool to assist with
management of wastewater discharge issues in the upper watershed of the Rocky River.
A more specific objective of the project was to provide a model that could be used to
determine the appropriate waste load allocation for the Charlotte -Mecklenburg Utility
Department (CMUD) Mallard Creek WWTP. CMUD has applied for an expansion of the
Mallard Creek WWTP from 3 to 6 MGD.
Results from this model indicate that water quality in the upper watershed of the
Rocky River is not adequately protected by the current NPDES permit effluent limits.
Under current operating conditions, that are well below permitted loads, the DO standard
is not predicted to be violated in the Rocky River study area. However, three DO sags are
predicted to drop to or near the stream standard, indicating that little assimilative capacity
remains for oxygen consuming wastes. It is recommended that no new or expanded
discharges be permitted in the study area unless an evaluation of engineering alternatives
shows that it is the most environmentally sound alternative. If new or expanding
discharges are permitted, they should receive best available technology limits in the
watersheds above the confluence of Mallard Creek and the Rocky River, due to severely
limited assimilative capacity. Any new or expanding discharge in the lower watersheds of
the Rocky River should receive a total BODu limit of 32 mg/1 or less, equivalent to 10
mg/1 BOD5 and 4 mg/1 NH3 for typical domestic discharges. This level of treatment will
protect the DO standard as well as preventing any one discharge from using up 100
percent of the available assimilative capacity of the river.
In addition, it is recommended that Mooresville WVVTP, Mallard Creek WWTP,
and Concord WWTP be encouraged to continue to meet advanced treatment levels. Upon
expansion or modification, Mooresville WWTP and Concord WWTP should receive more
advanced treatment requirements that will protect water quality in the Rocky River. This
will mean advanced tertiary treatment at the Mooresville WWTP and limits at least as
stringent as 10 mg/1 BOD5 (5.7 mg/1 CBODS) and 4 mg/I NH3 at the Concord WWTP.

11 .
2
Oakboro Wastewater Treatment Plant
Expansion to 0.90 MGD
Possible Limits for BODu = 32 mg/1
LONG CREEK LOCATION
NH3-N (mg/I)
Potential effluent limit combinations:
BODS NH3-N
11 2
9 3

8
7
Oakboro Wastewater Treatment Plant
Expansion and Relocation 0.90 MGD
Possible Limits for BODu = 32mg/1
ROCKY RIVER LOCATION
■
2.00
1
3.00
NH3-N (mg/I)
Potential effluent limit combinations:
BOD5 NH3-N
11 2
9 3
7 4
4.00

OPERATION/CONSTRUCTION MANAGERS
P.O. Box 97, Garner, North Carolina 27529 [phone]
May 26, 1994
Mr. Donald Safrit
N.C.D.E.M. - Water Quality Planning
P.O. Box 29535
Raleigh, North Carolina 27626-0535
CIVIL/SANITARY ENGINEERS
Engineering.
Company, P.A.
Box 349, Boone, North Caroline704)262 1767\—
RE: Town of Oakboro Wastewater Treatment Plant Expansion
MESCO Project No. G94026
Dear Mr. Safrit:
.14
1
We would like to formally request that speculative limits be provided to us for the
proposed expansion to the Oakboro wastewater treatment plant. The design for this
expansion is scheduled to be completed by October of this year, and we are proposing to
provide additional wastewater treatment facilities that will increase the treatment capacity
of the plant from 0.5 MGD to 0.9 MGD. The design of these facilities will be based in
large part on the speculative limits provided to us, since the treatment processes within the
plant will be targeted toward the effluent limits. The Town of Oakboro currently serves
one large industry, and the effluent characteristics for this plant are attached. The flow
from this plant is currently approximately 350,000 gallons per day. Population growth
within the Oakboro area and potential plant expansions will require that an expansion to
their treatment capacity be made in the near future.
The Town of Oakboro currently utilizes one discharge point on Long Creek for their
wastewater treatment plant. They also have a proposed discharge point on Rocky River.
We would like the speculative limits to include both discharge points rated for the total 0.9
MGD flow at both points. In the future, the Town is planning to shift their discharge point
from Long Creek to Rocky River, but it is not known at this time whether this change will
be made before or after the completion of the expansion of the wastewater treatment
plant. The schedule for the change may be affected by the speculative limits provided to us
if the limits are significantly different at the two discharge points. A map showing the
location of the proposed and existing discharge points is attached.

Mr. Donald Safrit May 26, 1994 Page 2
If you would like any additional information about this project, please do not hesitate to
call. We are anxious to resolve this matter, and we will do everything we can to assist in
your review. We look forward to hearing from you.
Sincerely,
MUNICIPAL ENGINEERING SERVICES. CO., P.A.
David Dickenson, P.E.

17'30"
:
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Smith
1
7
458
a
565
i 1969.4
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oft,-
‘
OAKBORO QUADRANGLE
NORTH CAROLINA Pc„.
7.5 MINUTE SERIES (TOPOGRAPHIC) 'P`'0
566 1.1 620000 FEET 567 568 80 ° 15'
0••1•
•
W)
•
562 (OLIVE BRA NCH) se
4J54 I1! $$
SCALE 1:24000
0
s64
1000 0 1000 2000 3000 4000 5000
6000 7000 FEET
1 .5 0
1 KILOMETER
CONTOUR INTFRvAL to 1 T
ARGFI
35.3 p.
1 MILE =�
35°15'
3900
38gg
540 000
FEET
3898
itt
w
J
0
0
12'30"
3896
FIGURE "B"
OAKBORO, N. C.
N3507.5—W8015/:.E
1971

•
•
STANDARD FORM A —MUNICIPAL
SECTION 8 INDUSTRIAL WASTE CONTRIBUTION TO MUNICIPAL SYSTEM
Submit a description of each major Industrial facility discharging to the municipal system, using a se
parates Section IV tion. Indicate the 4 digit Standard Industrial Classification (SIC) Code for the industry, the ma or product or raw material,
t the
n ino`p.
Mu. -
sand gallons per day). and the characteristics of the wastewater discharged from the Industrial faculty Into the municipal system. Consult :MO
I11 for standard measures of products or raw materials. (see Instructions) .
1• Major Contributing Faculty
(see Instructions)
Name
Number& Street
City
County
State
Zip Code
2. Primary Standard Industrial
Classification Code (see
instructions)
3. Prindpal Product or Raw
Material (see instructions)
Product
Raw Material
4. Flow Indicate the volume of water
discharged into the municipal sys.
tem In thousand gallons per day
and whether this discharge Is Inter.
mlttent or continuous.
S. Pretreatment Provided Indicate It
pretreatment Is provided prior to
entering the municipal system
S. Characteristics of Wastewater
(see instructions)
4003.
0 Ia
4 46
Parameter
Name
Parameter
Number
Value
401a
401b
401c
401d
4010
401 f
402
403a
403b
404a
404b
405
Stanly Knitting Mills, Inc.
FOR AGENCY USE
IiItIftm]
Main St.. PO Box 479
0akboro
Stanly
North Carolina
2R129
2252
Textilg Products
350
thousand gallons per day
Intermittent (int) MContinuous(con)
'Pi D N0
said.
Guantl
BOD(5) COD pH TKN Cu Tcn
00310 00340 00625 01042
108 479 9.6 19.8 0.116 .008
IV•1
Units (See
Table III)
GPO 863.706
This section contains 1 page.

DISCHARGE SERIAL NUMBER
001
Parameter and Code
214
Flow
Million gallons per day
50050
pH
Units
00400
Temperature (winter)
°F
74028
Temperature (summer)
°F
74027
Fecal Streptococci Bacteria
Number/100 ml
74054
(Provide if available)
Fecal Coliform Bacteria
Number/100 ml
74055
(Provide if available)
Total Coliform Bacteria
Number/100 ml
74056
(Provide if available)
BOD 5-day
mg/1
00310
Chemical Oxygen Demand (COD)
mg/l
00340
(Provide if available)
OR
total Organic Carbon (TOC)
mg/1
00680
(Provide if available)
(Either analysis is acceptable)
Chlorine —Total Residual
mg/I
50060
14. ascription of Influent and Effluent (see Instructions)
Influent
(1)
NA
0'. 373
F4PA
Al\ AL.
NA
77
(3)
Effluent •
<
(4)
0.323
0.493
7.3
51
8.3
64
72
82
0
<
(5)
FOR AGENCY USE
1111111'=
0
A
Z<
(6)
F
A
w
tIf
(7)
Cont
3/7
1/7
1/7
NA
1/7
"NA
NA
156
52
NA i
52 G
NA
52
NA
NA
NA
1111111111111111111111
NA
NA
NA
NA
I
II-S
NA
NA
NA
0.20
NA
NA
NA
NA
NA
NA
NA
0.35
2/7
104 G

Parameter and Code
wita
Total Solids
mg/1
00500
Total Dissolved Solids
mg/I
70300
Total Suspended Solids
mg/1
00530
Settleable Matter (Residue)
m1/I
00545
DISCHARGE SERIAL NUMBER
FOR AGENCY USE
001
14. Description of Influent and Effluent (see Instructions) (Continued)
Influent
Effluent
NA
NA
102
NA
• t
(2)
NA
NA
5.7
NA
NA
NA
NA NA
3.1 10
NA NA
NA
NA
•1/7
Ammonia (as N)
mg/I
00610
(Provide if available)
NA
1.30
0.50 4.0
NA
1/7
NA
52
NA
52
NA
NA
NA
i jeldahl Nitrogen
mg/1
00625
(Provide if available)
Nitrate (as N)
mg/1
00620
(Provide if available)
NA
5.1
4.5 6.0
1/90
4
Nitrite (as N)
mg/I
00615
T. (Provide if available)
Phosphorus Total (as P)
mg/1
-00665
(Provide if available)
Dissolved Oxygen (DO)
mg/1
00300
NA
NA
NA
x
8.1
0.356
1.32
3.4 15.7
0.040 0.848
0.86 2.08
1/90 •
1
1/90
1/90
•
7.3
6.4 8.2
1/7
4
4 C
52 G

.� .
DISCHARGE SERIAL NUMBER
001
[FOR AGENCY USE
IS. Additional Wastewater Characteristics
Chock the box next to each parameter If It Is present In the affluent. tie instrsCtlons)
Parameter
(215)
Bromide
71870
2
Cobalt
01037
Parameter
(215)
Chloride
00940
Chromium
01034
2
/r
Thallium
01059
Parameter
(215)
Titanium
01152
Cyanide
00720
Copper
01042
Tin
01102
Fluoride
00951
Iron
01045
X
Zinc
01092
Sulfide
00745
Lead
01051
Algicides•
74051
Aluminum
01105
Manganese
01055
Chlorinated organic compounds*
74052
Antimony
01097
Mercury
71900
Oil,and grease
00550
Arsenic
01002
Molybdenum
01062
Pesticides*
74053
Beryllium
01012
Nickel
01067
Phenols
32730 •
Barium
01007
Boron
01f22
cadmium
n1027
Selenium
01147
Surfactants
38260.
Silver •
01077
Radioactivity•
74050
•S.
*Provide spec compound and/or element in Item 17, if known:
Pesticides (Insecticides, fungicides, and rodenticides) must be reported in terms of the acceptable common names specified in Acceptable Com-
mon Names and OOemical Names for the Ingredient Statement on Pesticide Labels. 2nd Edition, Environmental Protection Agency, Washington,
D.C. 20250, June 1972, as required by Subsection 162.7(b) of the Regulations for the Enforcement of the Federal Insecticide, Fungicide, and
Rodenticide Act.
II-7

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Sear Wallow Valley Mobile Home Paris- -.
Town of Oakboro WWTP
Rocky River N(; LC4 3 j j L,
Residual Chlorine
7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
UPS BACKGROUND LEVEL (UG/L)
IWC (%)
Allowable Concentration (ugl )
Fecal Limit
Ratio of 20.8 :1
1 c4 dYi
Ammonia as NH3
(summer)
29 7Q10 (CFS)
0.9 DESIGN FLOW (MGD)
1.395 DESIGN FLOW (CFS)
17.0 STREAM STD (MG/L)
0 UPS BACKGROUND LEVEL (MG/L)
4.6 % IWC (%)
370 Allowable Concentration (mg/I)
Ammonia as NH3
(winter)
7Q10 (CFS)
200/100m1 DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL (MG/L)
IWC (%)
Allowable Concentration (mg/1)
29
0.9
1.395
1.0
0.22
4.6 %
17
51
0.9
1.395
1.8
0.22
2.7
60
7/13/94

MODEL RESULTS
Discharger : TOWN OF OAKBORO WWTP
Receiving Stream : ROCKY RIVER
SUMMER
BODU=32 BOD5=7 NH3N=4
NO DO LIMIT ROCKY RIVER
The End D.O. is 7.40 mg/l.
The End CBOD is 2.18 mg/1.
The End NBOD is 1.37 mg/l.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 6.96 0.00 1
Reach 1 14.00 18.00 0.00 0.90000
Reach 2 0.00 0.00 0.00 0.00000
GoD5 `f /(
N N = ,,48,1C
ib 0 id Sa. Jo S Oct it too rb r o) i Ydk1 t1 Le lief i3 m i71 I, 0
13 4
iWo 141J iljs 1910 WL1l
3
77,
v

v
SUMMER
BODU=32 BOD5=7 NH3N=4
NO DO LIMIT ROCKY RIVER
I Seg # 1 Reach # I Seg Mi I D.O. I CBOD I NBOD 1 Flow I
1 1 0.00 6.96 2.55 1.78 30.39
1 1 0.17 6.97 2.52 1.74 30.39
1 1 0.34 6.97 2.49 1.71 30.39
1 1 0.51 6.98 2.46 1.68 30.39
1 1 0.68 6.98 2.43 1.64 30.39
1 1 0.85 6.99 2.40 1.61 30.39
1 1 1.02 6.99 2.37 1.58 30.39
1 1 1.19 7.00 2.35 1.55 30.39
1 1 1.36 7.01 2.32 1.51 30.39
1 1 1.53 7.02 2.29 1.48 30.39
1 1 1.70 7.03 2.26 1.45 30.39
1 2 1.70 7.03 2.26 1.45 30.46
1 2 1.76 7.07 2.25 1.45 30.46
1 2 1.83 7.12 2.25 1.44 30.46
1 2 1.89 7.16 2.24 1.43 30.46
1 2 1.96 7.20 2.23 1.42 30.46
1 2 2.02 7.24 2.22 1.41 30.46
1 2 2.09 7.28 2.21 1.40 30.46
1 2 2.15 7.31 2.20 1.40 30.46
1 2 2.22 7.34 2.19 1.39 30.46
1 2 2.28 7.37 2.19 1.38 30.46
1 2 2.35 7.40 2.18 1.37 30.46
I Seg # I Reach # I Seg Mi I D.O. I CBOD 1 NBOD I Flow I

*** MODEL SUMMARY DATA ***
Discharger : TOWN OF OAKBORO WWTP Subbasin : 030713
Receiving Stream : ROCKY RIVER Stream Class: C
Summer 7Q10 : 29.0 Winter 7Q10 : 51.0
Design Temperature: 26.0
ILENGTHI SLOPEI VELOCITY 1 DEPTH' Kd I Kd I Ka 1 Ka I KN I KN I KNR 1 KNR I SOD I SOD
I mile I ft/mil fps I ft ldesignl @20 'design l @20 'design) @20 ldesignl @20 'design' @20
1 I 1 1 1 1 1 1 1 1 I 1 I I
Segment 1 1 1.701 5.781 0.245 1 2.88 1 0.28 1 0.21 1 1.42 1 1.25) 0.48 1 0.30 10.48 1 0.00 10.00 10.00
Reach 1 1 I I I I I I I I I I I I
1 1 1 1 1 I 1 1 1 1 1 1 I I
Segment 1 I 0.65) 15.381 0.325 12.50 10.31 1 0.24 15.01 I 4.401 0.48 10.30 10.48 10.00 10.00 10.00
Reach 2 1 I I I I I I I I I I I I
I Flow 1 CBOD 1 NBOD 1 D.O. I
I cfs 1 mg/1 1 mg/1 I mg/1 I
Segment 1 Reach 1
Waste 1 1.395 1 14.000 1 18.000 I 0.000
Headwaters) 29.000 1 2.000 I 1.000 I 7.300
Tributary 1 0.000 1 2.000 1 1.000 I 7.300
* Runoff 1 0.000 1 2.000 1 1.000 I 7.300
Segment 1 Reach 2
Waste I 0.000 1 0.000 1 0.000 1 0.000
Tributary 1 0.070 1 2.000 1 1.000 I 7.300
* Runoff I 0.000 I 2.000 1 1.000 1 7.300
* Runoff flow is in cfs/mile

MODEL RESULTS
Discharger : TOWN OF OAKBORO WWTP
Receiving Stream : ROCKY RIVER
SUMMER
NH3N ALLOWABLE + BOD5=30
EXISTING DO LIMIT ROCKY RIVER
The End D.O. is 7.04 mg/1.
The End CBOD is 3.98 mg/1.
The End NBOD is 3.44 mg/1.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 6.63 1.70 1
Reach 1 60.00 76.50 6.00 0.90000
Reach 2 0.00 0.00 0.00 0.00000

*** MODEL SUMMARY DATA ***
Discharger : TOWN OF OAKBORO WWTP Subbasin : 030713
Receiving Stream : ROCKY RIVER Stream Class: C
Summer 7Q10 : 29.0 Winter 7Q10 : 51.0
Design Temperature: 26.0
'LENGTH' SLOPE' VELOCITY I DEPTH' Kd I Kd I Ka I Ka 1 KN 1 KN I KNR I KNR I SOD I SOD
I mile I ft/mil fps 1 ft 'design' @20 Idesign' @20 'design l @20 Idesignl @20 'design l @20
I I I I I I I I I I I I I
Segment 1 I 1.701 5.781 0.245 1 2.88 1 0.28 1 0.21 1 1.42 1 1.25) 0.48 1 0.30 1 0.48 1 0.00 1 0,00 1 0.00
Reach 1 1 I 1 1 1 1 1 I 1 1 1 1 I
I I I I I I I I I I I I I
Segment 1 1 0.651 15.381 0.325 12.50 1 0.31 1 0.24 1 5.01 I 4.40 10.48 10.30 1 0.48 10.00 10.00 10.00
Reach 2 1 I I I I I I I I I I I I
Flow I CBOD 1 NBOD 1 D.O. I
cfs I mg/1 I mg/1 1 mg/1 I
Segment 1 Reach 1
Waste 1 1.395 160.000 176.500 I 6.000
Headwaters) 29.000 I 2.000 I 1.000 1 7.300
Tributary 1 0.000 1 2.000 1 1.000 I 7.300
* Runoff 1 0.000 1 2.000 1 1.000 1 7.300
Segment 1 Reach 2
Waste I 0.000 I 0.000 I 0.000 I 0.000
Tributary 1 0.070 I 2.000 1 1.000 I 7.300
* Runoff 1 0.000 1 2.000 1 1.000 1 7.300
* Runoff flow is in cfs/mile

SUMMER
NH3N ALLOWABLE + BOD5=30
EXISTING DO LIMIT ROCKY RIVER
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 7.24 4.66 4.47 30.39
1 1 0.17 7.15 4.61 4.38 30.39
1 1 0.34 7.07 4.55 4.29 30.39
1 1 0.51 6.99 4.50 4.20 30.39
1 1 0.68 6.93 4.44 4.12 30.39
1 1 0.85 6.86 4.39 4.04 30.39
1 1 1.02 6.81 4.34 3.96 30.39
1 1 1.19 6.76 4.29 3.88 30.39
1 1 1.36 6.71 4.24 3.80 30.39
1 1 1.53 6.67 4.19 3.72 30.39
1 1 1.70 6.63 4.14 3.65 30.39
1 2 1.70 6.64 4.13 3.64 30.46
1 2 1.76 6.69 4.12 3.62 30.46
1 2 1.83 6.74 4.10 3.60 30.46
1 2 1.89 6.78 4.08 3.58 30.46
1 2 1.96 6.83 4.07 3.56 30.46
1 2 2.02 6.87 4.05 3.54 30.46
1 2 2.09 6.91 4.04 3.52 30.46
1 2 2.15 6.94 4.02 3.50 30.46
1 2 2.22 6.98 4.01 3.48 30.46
1 2 2.28 7.01 3.99 3.46 30.46
1 2 2.35 7.04 3.98 3.44 30.46
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I

EXECUTIVE SUMMARY
Water quality models for three sections of the Rocky River and its tributaries were
joined to produce one calibrated model for 47.6 stream miles in the Yadkin River basin.
This model was used to predict dissolved oxygen and biochemical oxygen demand
concentrations at low flow conditions for both permitted and summer average discharge
conditions.
The general objective of this project was to provide a tool to assist with
management of wastewater discharge issues in the upper watershed of the Rocky River.
A more specific objective of the project was to provide a model that could be used to
determine the appropriate waste load allocation for the Charlotte -Mecklenburg Utility
Department (CMUD) Mallard Creek WWTP. CMUD has applied for an expansion of the
Mallard Creek WWTP from 3 to 6 MGD.
Results from this model indicate that water quality in the upper watershed of the
Rocky River is not adequately protected by the current NPDES permit effluent limits.
Under current operating conditions, that are well below permitted loads, the DO standard
is not predicted to be violated in the Rocky River study area. However, three DO sags are
predicted to drop to or near the stream standard, indicating that little assimilative capacity
remains for oxygen consuming wastes. It is recommended that no new or expanded
discharges be permitted in the study area unless an evaluation of engineering alternatives
shows that it is the most environmentally sound alternative. If new or expanding
discharges are permitted, they should receive best available technology limits in the
watersheds above the confluence of Mallard Creek and the Rocky River, due to severely
limited assimilative capacity. Any new or expanding discharge in the lower watersheds of
the Rocky River should receive a total BODu limit of 32 mg/1 or less, equivalent to 10
mg/1 BOD5 and 4 mg/1 NH3 for typical domestic discharges. This level of treatment will
protect the DO standard as well as preventing any one discharge from using up 100
percent of the available assimilative capacity of the river.
In addition, it is recommended that Mooresville WWTP, Mallard Creek WWTP,
and Concord WWTP be encouraged to continue to meet advanced treatment levels. Upon
expansion or modification, Mooresville WWTP and Concord WWTP should receive more
advanced treatment requirements that will protect water quality in the Rocky River. This
will mean advanced tertiary treatment at the Mooresville WWTP and limits at least as
stringent as 10 mg/1 BOD5 (5.7 mg/1 CBOD5) and 4 mg/1 NH3 at the Concord WWTP.
ll

SUMMER
EXISTING LIMITS WITH EXPANSION
MODEL RESULTS
Discharger : TOWN OF OAKBORO WWTP
Receiving Stream : LONG CREEK
The End D.O. is 5.52 mg/l.
The End CBOD is 13.00 mg/l.
The End NBOD is 15.82 mg/l.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 2.21 0.65 1
Reach 1 60.00 90.00 0.00 0.90000
Reach 2 0.00 0.00 0.00 0.00000

MMORIo'il'e'Park NC0076082
Town of Oakboro WWTP
Long Creek �,f (; OU 3 5 2-, 005 l7 I Clh 01
Residual Chlorine
7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
UPS BACKGROUND LEVEL (UG/L)
IWC (%)
Allowable Concentration (ug/1)
Fecal Limit
Ratio of 2.4 :1
Ammonia as NH3
(summer)
3.3 7Q10 (CFS)
0.9 DESIGN FLOW (MGD)
1.395 DESIGN FLOW (CFS)
17.0 STREAM STD (MG/L)
0 UPS BACKGROUND LEVEL (MG/L)
29.7 % IWC (%)
57 Allowable Concentration (mg/1)
Ammonia as NH3
(winter)
7Q10 (CFS)
200/looml DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL (MG/L)
IWC (%)
Allowable Concentration (mg/1)
J
I
3.3
0.9
1.395
1.0
0.22
29.7 %
3
5.8
0.9
1.395
1.8
0.22
19.4 %
8
7/13/94

MODEL RESULTS
Discharger : TOWN OF OAKBORO WWTP
Receiving Stream : LONG CREEK
SUMMER
NH3N ALLOWABLE WITH BOD5U=32
EXISTING DO LIMIT AND NEW QW
The End D.O. is 7.44 mg/l.
The End CBOD is 4.86 mg/l.
The End NBOD is 2.84 mg/l.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 6.49 0.65 1 ()(�
Reach 1 18.50 13.50 /6(.00 0.90000
Reach 2 0.00 0.00 0.00 0.00000
OloW
&U9S_
bon o� �dirt/ Leve/4116 A / 3
�aU� aS u � v��
M� v
flA0/
Ouv)C 4rcvir\ 18"`I uses
i\AP.\\\J\-s xYDlh Vici0 WUA-

SUMMER
NH3N ALLOWABLE WITH BOD5U=32
EXISTING DO LIMIT AND NEW QW
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 6.91 6.90 4.71 4.70
1 1 0.07 6.85 6.83 4.63 4.70
1 1 0.13 6.79 6.76 4.56 4.70
1 1 0.20 6.74 6.69 4.48 4.71
1 1 0.26 6.69 6.62 4.40 4.71
1 1 0.33 6.64 6.55 4.33 4.72
1 1 0.39 6.60 6.49 4.25 4.72
1 1 0.46 6.57 6.42 4.18 4.73
1 1 0.52 6.54 6.35 4.11 4.73
1 1 0.58 6.51 6.29 4.04 4.74
1 1 0.65 6.49 6.22 3.97 4.74
1 2 0.65 6.50 6.16 3.93 4.81
1 2 0.76 6.70 6.01 3.80 4.89
1 2 0.88 6.87 5.86 3.67 4.97
1 2 0.99 7.00 5.72 3.55 5.05
1 2 1.11 7.10 5.58 3.44 5.13
1 2 1.22 7.19 5.45 3.32 5.21
1 2 1.34 7.26 5.32 3.22 5.29
1 2 1.45 7.31 5.20 3.12 5.37
1 2 1.57 7.36 5.08 3.02 5.45
1 2 1.68 7.40 4.97 2.93 5.53
1 2 1.80 7.44 4.86 2.84 5.62
I Seg # I Reach # I Seg Mi I D.O. 1 CBOD I NBOD I Flow I
1'

*** MODEL SUMMARY DATA ***
Discharger : TOWN OF OAKBORO WWTP Subbasin : 030713
Receiving Stream : LONG CREEK Stream Class: C
Summer 7Q10 : 3.3 Winter 7Q10 : 5.8
Design Temperature: 26.0
'LENGTH' SLOPE' VELOCITY 1 DEPTH' Kd 1 Kd 1 Ka I Ka 1 KN 1 KN I KNR 1 KNR I SOD 1 SOD
I mile I ft/mil fps 1 ft 'design l @20 Idesign' @20 'design l @20 'design' @20 Idesignl @20
I I I I I I I I I I I I I I
Segment 1 I 0.651 7.70 I 0.116 1 1.65 1 0.28 1 0.21 1 1.83 1 1.601 0.48 1 0.30 10.48 10.00 10.00 10.00
Reach 1 1 I I 1 I 1 1 1 1 1 1 1
I I I I I I I I I I I I I
Segment 1 1 1.151 16.701 0.154 11.50 1 0.31 1 0.23 1 5.27 1 4.621 0.48 1 0.30 1 0.48 1 0.00 10.00 10.00
Reach 2 1 I I 1 1 I I 1 I 1 I 1 I
1 Flow 1 CBOD 1 NBOD 1 D.O. I
I cfs I mg/1 1 mg/1 1 mg/1 I
Segment 1 Reach 1
Waste 1 1.395 118.500 113.500 1 6.000
Headwaters) 3.300 1 2.000 1 1.000 1 7.300
Tributary 1 0.000 I 2.000 1 1.000 1 7.300
* Runoff 1 0.070 I 2.000 1 1.000 1 7.300
Segment 1 Reach 2
Waste 1 0.000 I 0.000 1 0.000 1 0.000
Tributary 1 0.070 1 2.000 I 1.000 1 7.300
* Runoff 1 0.700 1 2.000 1 1.000 1 7.300
* Runoff flow is in cfs/mile

MODEL RESULTS
Discharger : TOWN OF OAKBORO WWTP
Receiving Stream : LONG CREEK
SUMMER
NH3N ALLOWABLE WITH EXISTING
BOD5 AND DO LIMIT NEW QW
The End D.O. is 6.92 mg/1.
The End CBOD is 13.00 mg/l.
The End NBOD is 2.84 mg/1.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 5.65 0.65 1
Reach 1 60.00 13.50 6.00 0.90000
Reach 2 0.00 0.00 0.00 0.00000

*** MODEL SUMMARY DATA ***
Discharger : TOWN OF OAKBORO WWTP Subbasin : 030713
Receiving Stream : LONG CREEK Stream Class: C
Summer 7Q10 : 3.3 Winter 7Q10 : 5.8
Design Temperature: 26.0
(LENGTH' SLOPEI VELOCITY I DEPTHI Kd I Kd I Ka I Ka I KN I KN I KNR I KNR I SOD 1 SOD
I mile I ft/mil fps 1 ft 'design' @20 Idesign' @20 Idesignl @20 'design' @20 'design l @20
I I I I I I I I I I I I I
Segment 1 I 0.651 7.701 0.116 1 1.65 1 0.28 1 0.21 1 1.83 1 1.601 0.48 10.30 1 0.48 1 0.00 10.00 10.00
Reach 1 1 I I I I 1 I 1 1 1 1 I I
I I I I I I I I I I I I I
Segment 1 1 1.151 16.701 0.154 1 1.50 1 0.31 10.23 15.27 1 4.621 0.48 1 0.30 1 0.48 1 0.00 1 0.00 1 0.00
Reach 2 1 I I I I I I I I I I I I
I Flow I CBOD 1 NBOD 1 D.O. I
cfs I mg/1 1 mg/1 1 mg/1 I
Segment 1 Reach 1
Waste 1 1.395 1 60.000 113.500 1 6.000
Headwaters' 3.300 I 2.000 1 1.000 1 7.300
Tributary I 0.000 1 2.000 1 1.000 I 7.300
* Runoff 1 0.070 1 2.000 1 1.000 1 7.300
Segment 1 Reach 2
Waste I 0.000 I 0.000 1 0.000 I 0.000
Tributary 1 0.070 1 2.000 1 1.000 1 7.300
* Runoff 1 0.700 1 2.000 1 1.000 1 7.300
* Runoff flow is in cfs/mile

SUMMER
NH3N ALLOWABLE WITH EXISTING
BOD5 AND DO LIMIT NEW QW
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 6.91 19.23 4.71 4.70
1 1 0.07 6.73 19.03 4.63 4.70
1 1 0.13 6.57 18.83 4.56 4.70
1 1 0.20 6.41 18.63 4.48 4.71
1 1 0.26 6.27 18.44 4.40 4.71
1 1 0.33 6.15 18.25 4.33 4.72
1 1 0.39 6.03 18.05 4.25 4.72
1 1 0.46 5.92 17.87 4.18 4.73
1 1 0.52 5.82 17.68 4.11 4.73
1 1 0.58 5.73 17.49 4.04 4.74
1 1 0.65 5.65 17.31 3.97 4.74
1 2 0.65 5.68 17.09 3.93 4.81
1 2 0.76 5.94 16.61 3.80 4.89
1 2 0.88 6.15 16.14 3.67 4.97
1 2 0.99 6.32 15.70 3.55 5.05
1 2 1.11 6.45 15.27 3.44 5.13
1 2 1.22 6.57 14.85 3.32 5.21
1 2 1.34 6.66 14.45 3.22 5.29
1 2 1.45 6.74 14.07 3.12 5.37
1 2 1.57 6.81 13.70 3.02 5.45
1 2 1.68 6.87 13.34 2.93 5.53
1 2 1.80 6.92 13.00 2.84 5.62
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I

MODEL RESULTS
Discharger : TOWN OF OAKBORO WWTP
Receiving Stream : LONG CREEK
SUMMER
NH3N ALLOWABLE WITH BOD5U=32
NO DO LIMIT AND NEW QW
The End D.O. is 7.36 mg/l.
The End CBOD is 4.86 mg/l.
The End NBOD is 2.84 mg/l.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 5.13 0.00 1
Reach 1 18.50 13.50 0.00 0.90000
Reach 2 0.00 0.00 0.00 0.00000

SUMMER
NH3N ALLOWABLE WITH BOD5U=32
NO DO LIMIT AND NEW QW
I Seg # I Reach # 1 Seg Mi 1 D.O. I CBOD I NBOD I Flow I
1 1 0.00 5.13 6.90 4.71 4.70
1 1 0.07 5.18 6.83 4.63 4.70
1 1 0.13 5.22 6.76 4.56 4.70
1 1 0.20 5.26 6.69 4.48 4.71
1 1 0.26 5.30 6.62 4.40 4.71
1 1 0.33 5.35 6.55 4.33 4.72
1 1 0.39 5.39 6.49 4.25 4.72
1 1 0.46 5.43 6.42 4.18 4.73
1 1 0.52 5.47 6.35 4.11 4.73
1 1 0.58 5.50 6.29 4.04 4.74
1 1 0.65 5.54 6.22 3.97 4.74
1 2 0.65 5.57 6.16 3.93 4.81
1 2 0.76 5.99 6.01 3.80 4.89
1 2 0.88 6.31 5.86 3.67 4.97
1 2 0.99 6.57 5.72 3.55 5.05
1 2 1.11 6.77 5.58 3.44 5.13
1 2 1.22 6.93 5.45 3.32 5.21
1 2 1.34 7.06 5.32 3.22 5.29
1 2 1.45 7.16 5.20 3.12 5.37
1 2 1.57 7.24 5.08 3.02 5.45
1 2 1.68 7.31 4.97 2.93 5.53
1 2 1.80 7.36 4.86 2.84 5.62
I Seg # I Reach # I Seg Mi 1 D.O. I CBOD 1 NBOD I Flow I

*** MODEL SUMMARY DATA ***
Discharger : TOWN OF OAKBORO WWTP Subbasin : 030713
Receiving Stream : LONG CREEK Stream Class: C
Summer 7Q10 : 3.3 Winter 7Q10 : 5.8
Design Temperature: 26.0
!LENGTH' SLOPE) VELOCITY) DEPTH' Kd 1 Kd I Ka I Ka I KN I KN I KNR I KNR I SOD I SOD
I mile I ft/mil fps I ft Idesignl @20 'design l @20 'design' @20 Idesignl @20 'design' @20
1 1 I 1 1 1 1 1 1 1 1 1 I I
Segment 1 1 0.651 7.701 0.116 1 1.65 1 0.28 10.21 11.83 I 1.601 0.48 1 0.30 1 0.48 10.00 10.00 10.00
Reach 1 1 I I I I I I I I I I I I
1 1 I 1 I I 1 1 1 I I I I I
Segment 1 1 1.151 16.701 0.154 1 1.50 1 0.31 1 0.23 1 5.27 1 4.621 0.48 1 0.30 1 0.48 1 0.00 1 0.00 10.00
Reach 2 1 I I I I I I I I I I I I
Flow I CBOD I NBOD ) D.O. I
I cfs 1 mg/1 I mg/1 1 mg/1. I
Segment 1 Reach 1
Waste 1 1.395 118.500 113.500 I 0.000
Headwaters) 3.300 I 2.000 1 1.000 1 7.300
Tributary 1 0.000 I 2.000 1 1.000 I 7.300
* Runoff 1 0.070 1 2.000 1 1.000 1 7.300
Segment 1 Reach 2
Waste I 0.000 1 0.000 1 0.000 I 0.000
Tributary 1 0.070 1 2.000 I 1.000 I 7.300
* Runoff 1 0.700 1 2.000 I 1.000 I 7.300
* Runoff flow is in cfs/mile

MODEL RESULTS
Discharger : TOWN OF OAKBORO WWTP
Receiving Stream : LONG CREEK
WINTER
NH3N ALLOWABLE + BOD5=13.5
EXISTING DO LIMIT AND NEW QW
The End D.O. is 9.68 mg/1.
The End CBOD is 6.01 mg/l.
The End NBOD is 6.73 mg/l.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 8.64 0.00 1
Reach 1 27.00 36.00 6.00 0.90000
Reach 2 0.00 0.00 0.00 0.00000

<< f 0
WINTER
NH3N ALLOWABLE + BOD5=13.5
EXISTING DO LIMIT AND NEW QW
I Seg # I Reach # I Seg Mi 1 D.O. I CBOD I NBOD I Flow I
1 1 0.00 8.64 6.85 7.79 7.20
1 1 0.07 8.66 6.81 7.74 7.20
1 1 0.13 8.68 6.78 7.70 7.21
1 1 0.20 8.69 6.75 7.66 7.22
1 1 0.26 8.71 6.72 7.61 7.22
1 1 0.33 8.72 6.68 7.57 7.23
1 1 0.39 8.73 6.65 7.53 7.24
1 1 0.46 8.75 6.62 7.49 7.25
1 1 0.52 8.76 6.59 7.45 7.25
1 1 0.58 8.77 6.56 7.40 7.26
1 1 0.65 8.79 6.52 7.36 7.27
1 2 0.65 8.79 6.48 7.30 7.34
1 2 0.76 8.97 6.43 7.24 7.35
1 2 0.88 9.11 6.38 7.19 7.36
1 2 0.99 9.24 6.34 7.13 7.37
1 2 1.11 9.34 6.29 7.07 7.39
1 2 1.22 9.42 6.24 7.01 7.40
1 2 1.34 9.49 6.19 6.96 7.41
1 2 1.45 9.55 6.15 6.90 7.43
1 2 1.57 9.60 6.10 6.84 7.44
1 2 1.68 9.65 6.06 6.79 7.45
1 2 1.80 9.68 6.01 6.73 7.46
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow 1

*** MODEL SUMMARY DATA ***
Discharger : TOWN OF OAKBORO WWTP Subbasin 030713
Receiving Stream : LONG CREEK Stream Class: C
Summer 7Q10 : 3.3 Winter 7Q10 : 5.8
Design Temperature: 14.0
(LENGTH' SLOPE' VELOCITY I DEPTH' Kd I Kd I Ka 1 Ka I KN I KN I KNR I KNR I SOD I SOD
I mile 1 ft/mil fps 1 ft Idesign' @20 'design l @20 'design' @20 'design' @20 'design' @20
I I I I I I I 1 I I I I I 1
Segment 1 1 0.651 7.701 0.159 1 1.74 1 0.17 1 0.22 1 1.94 1 2.211 0.19 1 0.30 1 0.19 1 0.00 1 0.00 10.00
Reach 1 1 I I I I I I I I I I
1 1 1 1 1 1 1 1 1 1 1 1 I
Segment 1 1 1.151 16.701 0.200 1 1.57 1 0.18 1 0.24 1 5.28 1 6.011 0.19 1 0.30 1.0.19 1 0.00 1 0.00 10.00
Reach 2 I 1 1 I 1 1 1 1 I I 1 1 I
I Flow 1 CBOD I NBOD 1 D.O. I
I cfs 1 mg/1 I mg/1 1 mg/1 I
Segment 1 Reach 1
Waste I 1.395 127.000 1 36.000 1 6.000
Headwaters) 5.800 I 2.000 1 1.000 I 9.280
Tributary I 0.000 1 2.000 1 1.000 1 9.280
* Runoff I 0.110 I 2.000 I 1.000 1 9.280
Segment 1 Reach 2
Waste I 0.000 1 0.000 1 0.000 I 0.000
Tributary I 0.070 I 2.000 1 1.000 I 9.280
* Runoff I 0.110 1 2.000 I 1.000 I 9.280
* Runoff flow is in cfs/mile

MODEL RESULTS
Discharger : TOWN OF OAKBORO WWTP
Receiving Stream : LONG CREEK
WINTER
NH3N ALLOWABLE + BOD5=13.5
NO DO LIMIT AND NEW QW
The End D.O. is 9.57 mg/l.
The End CBOD is 6.01 mg/l.
The End NBOD is 6.73 mg/1.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 7.48 0.00 1
Reach 1 27.00 36.00 0.00 0.90000
Reach 2 0.00 0.00 0.00 0.00000

*** MODEL SUMMARY DATA ***
Discharger : TOWN OF OAKBORO WWTP Subbasin : 030713
Receiving Stream : LONG CREEK Stream Class: C
Summer 7Q10 : 3.3 Winter 7Q10 : 5.8
Design Temperature: 14.0
ILENGTHI SLOPEI VELOCITY I DEPTHI Kd I Kd I Ka I Ka I KN 1 KN I KNR I KNR I SOD I SOD
mile I ft/mil fps 1 ft 'design l @Z0 'design' @20 Idesignl @20 'design' @20 'design l @20
1 1 I I 1 1 1 I I I 1 I I
Segment 1 1 0.651 7.701 0.159 11.74 1 0.17 10.22 11.94 1 2.211 0.19 10.30 10.19 1 0.00 10.00 10.00
Reach 1 1 1 I I 1 1 I 1 1 1 1 1
1 I 1 1 1 1 1 1 1 1 1 I I
Segment 1 1 1.151 16.701 0.200 1 1.57 10.18 1 0.24 1 5.28 1 6.011 0.19 1 0.30 1 0.19 10.00 1 0.00 10.00
Reach 2 1 1 1 1 I I 1 1 I 1 1 1 I
I Flow I CBOD I NBOD I D.O. I
I cfs I mg/1 1 mg/1 1 mg/1 I
Segment 1 Reach 1
Waste I 1.395 127.000 136.000 1 0.000
Headwaters) 5.800 I 2.000 1 1.000 I 9.280
Tributary I 0.000 1 2.000 1 1.000 I 9.280
* Runoff I 0.110 1 2.000 1 1.000 1 9.280
Segment 1 Reach 2
Waste I 0.000 I 0.000 1 0.000 I 0.000
Tributary I 0.070 I 2.000 1 1.000 I 9.280
* Runoff I 0.110 1 2.000 1 1.000 I 9.280
* Runoff flow is in cfs/mile

WINTER
NH3N ALLOWABLE + BOD5=13.5
NO DO LIMIT AND NEW QW
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 7.48 6.85 7.79 7.20
1 1 0.07 7.55 6.81 7.74 7.20
1 1 0.13 7.62 6.78 7.70 7.21
1 1 0.20 7.69 6.75 7.66 7.22
1 1 0.26 7.75 6.72 7.61 7.22
1 1 0.33 7.81 6.68 7.57 7.23
1 1 0.39 7.87 6.65 7.53 7.24
1 1 0.46 7.92 6.62 7.49 7.25
1 1 0.52 7.98 6.59 7.45 7.25
1 1 0.58 8.03 6.56 7.40 7.26
1 1 0.65 8.08 6.52 7.36 7.27
1 2 0.65 8.09 6.48 7.30 7.34
1 2 0.76 8.38 6.43 7.24 7.35
1 2 0.88 8.63 6.38 7.19 7.36
1 2 0.99 8.83 6.34 7.13 7.37
1 2 1.11 9.00 6.29 7.07 7.39
1 2 1.22 9.15 6.24 7.01 7.40
1 2 1.34 9.27 6.19 6.96 7.41
1 2 1.45 9.36 6.15 6.90 7.43
1 2 1.57 9.45 6.10 6.84 7.44
1 2 1.68 9.52 6.06 6.79 7.45
1 2 1.80 9.57 6.01 6.73 7.46
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I

DIVISION OF ENVIRONMENTAL MANAGEMENT
May 19, 1993
MEMORANDUM
TO: Monica Swihart
FROM: Susan A. Wilson,
THROUGH: Ruth Swanek
Carla Sanderso
SUBJECT: Town of Oakboro WWTP (NC0043532), EA
Relocation to Rocky River (030713), Yadkin River Basin
Stanly County
The Technical Support Branch (TSB) has reviewed the Town of Oakboro's
Environmental Assessment with regard to the relocation from Long Creek to the Rocky
River.
Oakboro's current permit indicates the limits the facility will be required to meet at
the relocation point on the Rocky River. No application has been received for the Town to
expand to 1 MGD. The limits for 1 MGD may be more stringent than those estimated in
the February 5, 1991 correspondence from the NPDES Permit Group; this is due to the
conclusion of the Rocky River report and to the potential interaction with Carolina Solite.
The facility should submit a request for speculative limits or a formal NPDES request for
expansion to 1 MGD in order for the TSB to adequately assess the impact of the expanded
discharge.
cc: Rex Gleason, MRO