NC0020338_Speculative Limits_19940513

NPDES DOCIMENT SCANNING COVER SHEET
NC0020338
Yadkinville
NPDES Permit:
WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Speculative Limits
•'f -' �,.-..;"'e'`t.`,,..,.riinn.".+...d:_-._witia:..
Correspondence
Instream Assessment (67B)
Environmental
Assessment (EA)
Permit
History
Document Date:
May 13, 1994
This document is printed on reuse paper - ignore any
content on the reYerse aside

State of North Carolina
Department of Environment,
Health and Natural Resources
Division
f Environmental Management
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
May 13, 1994
The Honorable Donald G. Dunn, Mayor
Town of Yadkinville
Post Office Drawer 816
Yadkinville, North Carolina 27055-0816
SUBJE
NITTIFTA
EDE-iNJ F
Speculative Limits for Town of Yadkinville WWTP Expansion
NPDES Permit No. NC0020338
Yadkin County
Dear May Dunn:
Y ur request for speculative effluent limits for the proposed expansion of the
Yadkin ' e WWTP to 1.15 MGD 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.
pue to the request for an increase in waste flow, the flow estimates at the
discharge ocation were reevaluated using the USGS Report, "Low -Flow Characteristics
of Streams in North Carolina (1991)". The flow estimates are as follows:
(nv , 0,1
-7t,0 3.91 i,c�
iv 7q l u 10. 03 c/H-
3o6(Z : 2,35 c01
Based on available information the tentative limits for conventional constituents are:
Drainage Area = 35.9
Average Flow = 35.9
Summer 7Q10 = 5.77
Winter 7Q10 = 8.73
30Q2 = 12.35
Wasteflow (MGD)
BOD5 (mg/1)
NH3-N (mg/1)
DO (mom)
TSS (mg/1)
Fecal Coliform (#/100m1) 200
pH (SU) 6-9
Chlorine (µg/1) 28
Summer
1.15
30
4
5
30
Winter
1.15
30
10
5
30
200
6-9
28
Ck, tom
It should be noted that the tentative NH3N limits were evaluated and are based on
the protection of North Deep Creek against instream toxicity. North Carolina it 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.
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

P
Letter to
-p
yor Dunn
ge2-
In ' 'tion, under current Division of Environmental Management (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 chlorin in your effluent is 28 µg/1 to ensure protection against acute toxicity. The
process of hlorination/dechlorination or an alternate form of disinfection, such as
ultraviolet ation, should allow the facility to comply with the total residual chlorine
limit.
The instream waste concentration at 1.15 MGD is 24%. A chronic toxicity testing
requirement with quarterly monitoring will remain a condition of the NPDES permit 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. Information
concerning these constituents is not readily available but the Town can assume that effluent
limits and/or monitoring for cadmium, chromium, nickel, lead, cyanide, arsenic, mercury,
aluminum phenols, copper, zinc, selenium and silver should be included.
D
for imple
address
restore w
may be
technolo
M is planning a basinwide water quality management initiative. Our schedule
entation in the Yadkin River Basin is set for 1999. The plan will attempt to
sources of point and nonpoint pollutants where deemed necessary to protect or
quality standards. In addressing interaction of sources, wasteload allocations
ted. Those facilities that already have committed to high levels of treatment
are least likely to be affected.
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].
Sincerely,
Donald L. Safrit, P.E.
Assistant Chief for Technical Support
Water Quality Section
DLS
cc: Wton-Salem Regional Office
Permits and Engineering Unit
Mr. Harry Dail, PE, Municipal Engineering Services Co., PA
Central Files

TOWN OF YADKINVILLE
Post. Office Drawer 816
Yadkinville, North Carolina 27055 — 0816
Telephone [phone]
March 7, 1994
Mr. Donald Safrit, PE
Assistant Chief
Water Quality Section
State of North Carolina
Department of Environment, Health & Natural Resources
Division of Environmental Management
P. O. Box 29536
Raleigh, NC 27626-0535
Re: Speculative Limit Request
Town of Yadkinville, Yadkin County
NPDES Permit No. NC0020338
Dear Mr. Safrit:
q04-,
of
.0
The Town of Yadkinville is considering modifying the flow component of their NPDES
Permit from 1.0 to 1.15 MGD. For the purpose of evaluating the impacts of this
modification, please provide the Town of Yadkinville Speculative NPDES Permit Limits
for their wastewater treatment facility at a new flow of a 1.15 MGD.
The Town of Yadkinville does not intend to make any structural modifications to their
waste treatment facility to accommodate this increase. It is anticipated that the increase
can be accommodated by a re -rating process through their consulting engineer. This
advance planning offered to the Town by DEM and the technical support Branch will be
extremely beneficial to the Town's Consultant in determing the likelihood of a favorable
re -rating review by the Permits and Engineering Section.

We appre•iate your time and consideration in this matter. Should you have any
questions sr comments, please feel free to call our consulting engineer, Mr. Harry Dail,
PE, Muni ipal Engineering Services Co., PA, Garner, NC at 919-772-5393.
Very truly i ours,
Donald G.
Copy: Ms.
Mr
Dunn, Mayor
Coleen Sullins
Hany Dail

Yadkir�ville WWTP NC0020338
N. Deep Creek
Residual) Chlorine
7Q10 (C S)
DESIGN LOW (MGD)
DESIGN LOW (CFS)
STREAM STD (UG/L)
UPS BA KGROUND LEVEL (UG/L)
IWC (%)
Allowable Concentration (ug/I)
Fecal Limit
Ratio of 3.2 :1
Ammonia as NH3
(summer)
5.77 7010 (CFS)
1.15 DESIGN FLOW (MGD)
1.7825 DESIGN FLOW (CFS)
17.0 STREAM STD (MG/L)
0 UPS BACKGROUND LEVEL (MG/L)
23.6 % IWC (%)
72 Allowable Concentration (mg/1)
Ammonia as NH3
(winter)
7010 (CFS)
200/100m1 DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL (MG/L)
IWC (%)
Allowable Concentration (mg/1)
5.77
1.15
1.7825
1.0
0.22
23.6 %
4
8.73
1.15
1.7825
1.8
0.22
17.0 %
10

Discharger
MODEL RESULTS
: YADKINVILLE WWTP
Receiving Stream : NORTH DEEP CREEK
SUMMER
SPECULATIVE 1.0 TO 1.15 MGD
NH3N=4 BOD5=30
The End D.O. is 7.56 mg/l.
The End CBOD is 13.49 mg/l.
The End NBOD is 4.46 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 6.86 0.00 1
Reach 1
Reach 2
Reach 3
Reach 4
co
udklh
60.00 18.00
0.00 0.00
0.00 0.00
0.00 0.00
5.00
0.00
0.00
0.00
titilbh Level 8
mmt(i
1.15000
0.00000
0.00000
0.00000

*** MODEL SUMMARY DATA ***
Discharger YADKINVILLE WWTP Subbasin :.0307
Receiving Stre m : NORTH DEEP CREEK Stream Class: C
Summer 7Q10 : 5.77 Winter 7Q10 : 8.736
Design Temperature: 25.0
'LENGTH' SL0 El VELOCITY I DEPTH' Kd I Kd I Ka 1 Ka 1 KN I KN _1 KNR I KNR I SOD I SOD
I mile I ft/ it fps 1 ft 'design' @20 Idesignl @20 'design' @20 Idesign' @20 'design' @20
Segment 1 1.30 9.10 1.377 0.61 0.87 0.69 125.15 22.56 0.44 0.30 0.44 0.00 0.00 0.00
Reach 1
1 1 1 1 1 1 1 1 I 1 1 1 I I
Segment 1 1 0.851 9.101 0.732 10.86 1 0.48 1 0.38 113.37 111.991 0.44 1 0.30 1 0.44 1 0.00 1 0.00 10.00
Reach 2 1 I I I I I I I I I I I I
1I I 1 1 1 1 1 I I 1 I
Segment 1 1 1.951 30. 01 0.960 10.76 1 0.97 1 0.77 155.75 150.001 0.73 1 0.50 10.73 1 0.00 1 0.00 1 0.00
Reach 3 1 I I I I I I I I I I I I
1 1 I 1 1 I I I 1 1 I I I I
Segment 1 1. 2.001 4.401 0.503 11.06 1 0.34 1 0.27 14.44 I 3.991 0.44 1 0.30 10.44 1 0.00 10.00 1 0.00
Reach 4 1 I I I I 1 I I I I I I I
I Flow 1 CBOD I NBOD I D.O. I
I cfs I mg/1 I mg/1 I mg/1 I
Segment 1 Reach 1
Waste I 1.782 1 60.000 1 18.000 1 5.000
Headwaters) 5.770 1 2.000 I 1.000 I 7.440
Tributary I 0.000 I 2.000 1 1.000 I 7.440
* Runoff I 0.123 1 2.000 I 1.000 I 7.440
Segment 1 Reach 2
W ste 1 0.000 I 0.000 1 0.000 I 0.000
T ibutary 1 0.330 I 2.000 I 1.000 1 7.440
* Runoff 1 0.133 I 2.000 1 1.000 1 7.440
Segment 1 Reach 3
Waste I 0.000 I 0.000 I 0.000 I 0.000
Tributary 1 0.000 1 2.000 I 1.000 I 7.440
* Runoff 1 0.133 I 2.000 1 1:000 I 7.440
Segment 1 Reach 4
Waste I 0.000 I 0.000 1 0.000 I 0.000
Tributary 1 0.000 I' 2.000 I 1.000 1 7.440
* Runoff 1 0.133 I 2.000.1 1.000 I 7.440

•
I 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
1
1
1
I Seg #
I Reach
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4,
4
4
I Reach
SUMMER
SPECULATIVE 1.0 TO 1.15 MGD
NH3-N=4 AND BOD5=30
# I Seg Mi I D.O. I CBOD I NBOD I Flow I
0.00 6.86 15.69 5.01 7.55
0.13 6.97 15.58 4.99 7.57
0.26 7.06 15.48 4.97 7.58
0.39 7.14 15.37 4.95 7.60
0.52 7.21 15.26 4.93 7.62
0.65 7.27 15.16 4.91 7.63
0.78 7.32 15.06 4.89 7.65
0.91 7.37 14.96 4.87 7.66
1.04 7.41 14.85 4.85 7.68
1.17 7.44 14.75 4.83 7.70
1.30 7.47 14.65 4.81 7.71
1.30 7.47 14.13 4.65 8.04
1.38 7.48 14.07 4.63 8.05
1.47 7.49 14.00 4.61 8.07
1.55 7.50 13.94 4.59 8.08
1.64 7.51 13.87 4.57 8.09
1.72 7.52 13.81 4.55 8.10
1.81 7.53 13.75 4.53 8.11
1.89 7.54 13.68 4.51 8.12
1.98 7.54 13.62 4.49 8.13
2.06 7.55 13.56 4.48 8.14
2.15 7.56 13.49 4.46 8.16
2.15 7.56 13.49 4.46 8.16
2.34 7.76 13.30 4.41 8.18
2.54 7.87 13.10 4.36 8.21
2.73 7.92 12.91 4.31 8.23
2.93 7.95 12.73 4.26 8.26
3.12 7.97 12.54 4.21 8.29
3.32 7.98 12.36 4.16 8.31
3.51 7.98 12.18 4.11 8.34
3.71 7.99 12.00 4.06 8.36
3.90 7.99 11.83 4.02 8.39
4.10 8.00 11.66 3.97 8.41
4.10 8.00 11.66 3.97 8.41
4.30 7.89 11.53 3.92 8.44
4.50 7.80 11.41 3.87 8.47
4.70 7.72 11.29 3.82 8.49
4.90 7.65 11.17 3.77 8.52
5.10 7.59 11.05 3.72 8.55
5.30 7.54 10.93 3.67 8.57
5.50 7.49 10.82 3.63 8.60
5.70 7.45 10.70 3.58 8.63
5.90 7.41 10.59 3.53 8.65
6.10 7.38 10.48 3.49 8.68
# I Seg Mi I D.O. I CBOD I NBOD I Flow I

MODEL RESULTS
Discharger : YADKINVILLE WWTP
Receiving Stream : NORTH DEEP CREEK
WINTER
SPECULATIVE 1.0 TO 1.15 MGD
NH3-N=10 BOD5=30
The End D.O. is 9.39 mg/1.
The End CBOD is 8.62 mg/l.
The End NBOD is 6.11 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 8.72 0.00 1
Reach 1
Reach 2
Reach 3
Reach 4
60.00 45.00
0.00 0.00
0.00 0.00
0.00 0.00
6.00
0.00
0.00
0.00
" YA At ii Le ve ( 8 `Yli'i&
1.15000
0.00000
0.00000
0.00000

*** MODEL SUMMARY DATA ***
Discharger
Receiving Stre
Summer 7Q10
Design Tempera
Subbasin : 0307
Stream Class: C
Winter 7Q10 : 8.736
�5.1 V
na"� )0/5
(LENGTH' SLOPE' VELOCITY 1 DEPTH' Kd I Kd I I KN I KN I KNR 1 KNR 1 SOD 1 SOD I
I mile I ft/mil fps 1 ft 'design' @20 'design l @20 'design' @20 'design) @20 (design l @20 I A' AA
: YADKINVILLE WWTP
m : NORTH DEEP CREEK
: 5.77
ure: 14.0
I Ka Ka
1 1 1 1 I I
Segment 1 I 1.351 9.101 0.394 1 1.34 1 0.20 1 0.26 1 4.09 I 4.661 0.19 10.30 1 0.19 1 0.00 1 0.00 10.00
Reach 1 1 I I I I I I I I I I I
I I I 1 1 1 1 I 1 1 1 I I I
Segment 1 I 0.851 9.101 0.403 1 1.37 1 0.20 10.26 14.18 1 4.761 0.19 10.30 10.19 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 1• 1 1 1 1 1 1 1 I 1 I I I
Segment 1 1 1.951 30. 0 I 0.578 1 1.16 1 0.32 1 0.42 120.31 1 23.141 0.32 10.50 10.32 1 0.00 1 0.00 1 0.00
Reach 3 1 1 1 1 1 1 1 I 1 1 1 I I
I I I I I I I I 1 1 1 I I I
Segment 1 I 2.001 4.401 0.332 11.55 10.17 1 0.23 1 1.67 1 1.901 0.19 1 0.30 10.19 10.00 10.00 1 0.00
Reach 4 1 1 1 1 I 1 1 1 1 1 1 1
I Flow 1 CBOD 1 NBOD I D.O. I
I cfs 1 mg/1 1 mg/1 1 mg/1 I
Segment 1 Reach 1
Waste 1 1.782 1 60.000 1 45.000 1 6.000
Hedwatersl 8.730 I 2.000 1 1.000 1 9.280
Tributary 1 0.000 I 2.000 1 1.000 1 9.280
* Runoff 1 0.185 1 2.000 1 1.000 1 9.280
Segment 1 Reach 2
Waste 1 0.000 1 0.000 1 0.000 1 0.000
Tributary 1 0.530 I 2.000 1 1.000 1 9.280
* Runoff I 0.190 1 2.000 1 1.000 1 9.280
Segment 1 Reach 3
Waste I 0.000 I 0.000 1 0.000 1 0.000
Tributary 1 0.000 1 2.000 1 1.000 1 9.280
* Runoff 1 0.190 1 2.000 1 1.000 1 9.280
Se ment 1 Reach 4
Waste 1 0.000 1 0.000 1 0.000 1 0.000
Tributary 1 0.000 I 2.000 1 1.000 1 9.280
* Runoff 1 0.190 1 2.000 1 1.000 1 9.280

WINTER
SPECULATIVE 1.0 TO 1.15 MGD
NH3-N=10 BOD5=30
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 8.72 11.83 8.46 10.51
1 1 0.13 8.77 11.76 8.41 10.54
1 1 0.26 8.82 11.69 8.36 10.56
1 1 0.39 8.86 11.63 8.31 10.58
1 1 0.52 8.90 11.56 8.27 10.61
1 1 0.65 8.94 11.49 8.22 10.63
1 1 0.78 8.98 11.42 8.17 10.66
1 1 0.91 9.01 11.35 8.12 10.68
1 1 1.04 9.04 11.29 8.08 10.70
1 1 1.17 9.07 11.22 8.03 10.73
1 1 1.30 9.09 11.16 7.98 10.75
1 2 1.30 9.10 10.73 7.66 11.28
1 2 1.38 9.12 10.69 7.63 11.30
1 21 1.47 9.14 10.65 7.60 11.32
1 2 1.55 9.16 10.61 7.57 11.33
1 2 1.64 9.17 10.57 7.54 11.35
1 2 1.72 9.19 10.53 7.52 11.36
1 2 1.81 9.20 10.49 7.49 11.38
1 2 1.89 9.22 10.45 7.46 11.40
1 2 1.98 9.23 10.41 7.43 11.41
1 2 2.06 9.24 10.37 7.41 11.43
1 2 2.15 9.26 10.33 7.38 11.44
1 3 2.15 9.26 10.33 7.38 11.44
1 3 2.34 9.52 10.24 7.31 11.48
1 3 2.54 9.70 10.14 7.24 11.52
1 3 2.73 9.81 10.05 7.18. 11.56
1 3 2.93 9.89 9.96 7.11 11.59
1 3 3.12 9.94 9.87 7.05 11.63
1 3 3.32 9.98 9.78 6.98 11.67
1 3 3.51 10.00 9.69 6.92 11.70
1 3 3.71 10.02 9.60 6.85 11.74
1 3 3.90 10.03 9.51 6.79 11.78
1 3 4.10 10.03 9.43 6.73 11.82
1 4 4.10 10.03 9.43 6.73 11.82
1 4 4.30 9.95 9.34 6.66 11.85
1 4 4.50 9.86 9.26 6.60 11.89
1 4 4.70 9.79 9.18 6.54 11.93
1 4 4.90 9.71 9.10 6.47 11.97
1 4 5.10 9.65 9.02 6.41 12.01
1 4 5.30 9.59 8.94 6.35 12.04
1 4 5.50 9.53 8.86 6.29 12.08
1 4 5.70 9.48 8.78 6.23 12.12
1 4 5.90 9.43 8.70 6.17 12.16
1 4 6.10 9.39 8.62 6.11 12.20

V r D�1S( �)
t
35,1
Oisdtar (1
DLD VS 42(
jUd{ I� plropoli -Ho

d e1erm! _ `%t Dr iNtU t./1"U
07(
//r/ Z r-,-1-0m )4,ds) C SR 1710 Sh cZ4Wn ,/✓. • \
M A %ij /' 2- Pe Si / 710 • l ` ! a o %-2 2, "2.€4./
/ ' ? /1? / Z' C HI r4 o ,4 l ✓n,1014
. SAY n// m a ( t!"MO) Gcxc.iC
2-7) t),m ymou-ki, s, eAtat
p/gik7 k5
U Gt , G f) 0 V € D 17/' U [ sc, � v
ZI o ,
�5C o-1 FLOWEST Wark-S t
v s-e d.. W f b - mr7 R= o,' i. 0 s-e Q H- s 7 0 10
{-� } s
VSe d %b 0-tALa crow 0 t cY VYY,d�J
l A Ca l c v tG 3, 1p
f as l✓,bu+
J o ve.e7(A 5 .
/-7,‹ oIS DefCk
urn
(eG Ciis) -1

S L.
3qzo
cel^f‘

USGS weighted low flow estimate procedure
FacilitytYadknville WWTP NPDES # .(NC0020338I
Region
DA LFPR
s7010_LFPR
DA new
MAR
QA eq
[.....±1h10
0
0
;.-.._. 77.4 _.._..I
0.99
76.63
sq mile
cfs
sq mile
cfs/sq mile
cfs
STEP 1 calculate drainage area ratio
Stream=N:Deep Cree
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
ry w v d -c Si # I ;•'
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO < 4, CONTINUE to STEP 2, ELSE too far from gage
#D/0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight Mill weight Iati4
0 1 r
0 _1
#DIV/0! i #DIV/0! I •� #DIV/0!
1 0.25 1 4
weight =
#DIV/0!
STEP 3 calculate 7010_EQ using regional equation
HA3
HA5
HA9
HA10
STEP 4
20.68
1.96
1.96
12.40
cfs
cfs
cfs
cfs
7Q10 EQ = 12.40 cfs
calculate 7010 yield using weighted equation
7Q10yield = [weight_LFPR * 7010 LFPR] + [weight EQ * 70310 EQ]
DA_LFPR DA new
(19t.e.iX
L19LJ
yield = #DIV/01 + #DIV/0! = #DIV/01 cfs/sq mile
STEP 5 calcul to s7010
7010 = 7010yield * DA new
summer 7010 = #DIV/0! cfs

USGS weighted low flow estimate procedure
FacilitylYadkhville WWTP NPDES # [NC0020338 StreamsN. Deep Cree
N_N_..r.._..N .._. »N.Ha.
Region
DA_LFPR
w7Q1O_LFPR
DA new
MAR
QA eq
HA10
0 +sq mile
0 cfs
...�77 4
._N_._.00•..,
0.99
76.63
sq mile
cfs/sq mile
cfs
STEP 1 calculate drainage area ratio
NOTE: procedure applies for regions HA3, HAS,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO 4, CONTINUE to STEP 2, ELSE too far from gage
#D V/0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight ratio weight ratio
0 1 0 1
..NMN_�
f#Dw/0fJ #DIV/0! f#DIV/o!! #DIV/0!
1 0 ,25 1 4
weight =
#DIV/0!
STEP 3 calcul to 7010_EQ using regional equation
HA3
HA5
HA9
HA10
STEP 4
39.53
8.38
8.38
18.49
cfs
cfs
cfs
cfs
7Q10 EQ=
calculate 7010 yield using weighted equation
18.49
cfs/sq mile
7Q10ield = [weight LFPR * 7Q10 LFPR] + [weight_EQ * 7Q10 EQ]
DA LFPR DA new
yield = #DIV/0!
STEP 5 calculate w7Q10
7010 = 7Q10yield * DA_new
winter 7010 = #DIV/01 cfs
+ #DIV/0!
#DIV/0!
cfs/mile

USGS weighted low flow estimate procedure
FacilityLYadkwville WWTP
Region
DA LFPR
3002_LFPR
DA new
MAR
QA eq
STEP 1
NPDES # [NC0020338 J StreamLN. Deep Cree
.N.N_..MN•.._.._ S._N_.N•N_.. N_.N•NM
I. •._,. HA10,_„_
0 sq mile
...� _N ....••._cfs
_N_
� ,N_.•�N_...
0.99�
76.63
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO < 4, CONTINUE to STEP 2, ELSE too far from gage
#DV/0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight Islikl weight r
0 1 0 1
N.N_N_N_.NNN
f#DIWO!1#DIV/0! 1--IFCiiall #DIV/0!
1 0.25 1 4
STEP 3
HA3
HA5
HA9
HA10
weight =
#DIV/0!
calcul to 3002_EQ using regional equation
44.48
11.68
11.68
26.36
cfs
cfs
cfs
cfs 30Q2 EQ = 26.36 cfs/sq mile
STEP 4 calculate 3002 yield using weighted equation
3002yield = [weight LFPR * 3002 LFPR] + [weight EQ * 3002 EQ]
DA_LFPR DA_new
's JDIV/0!N_.
ield = #DIV/0! + #DIV/0! = #DIV/0! cfs/sq mile
STEP 5 calcul to 3002
30Q2 = 3002yield * DA_new
3002 =
#DIV/0!
cfs

MODEL RESULTS
Discharger : YADKINVILLE WWTP
Receiving Stream : NORTH DEEP CREEK
SUMMER
EXTENDED MODEL
ASSUME S. DEEP CK D.O. ARE OK
The End D.O. is 7.20 mg/1.
The End CBOD is 4.42 mg/1.
The End NBOD is 1.32 mg/1.
Segment 1
Reach 1
Reach 2
Reach 3
Reach 4
Reach 5
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flo
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
6.86 0.00 1
to-e_0( ccs
60.00
0.00
0.00
0.00
0.00
18.00
0.00
0.00
0.00
0.00
5.00
0.00
0.00
0.00
0.00
aTh Yci It Lf tif ( //loaf
1.15000
0.00000
0.00000
0.00000
0.00000

*** MODEL SUMMARY DATA ***
Discharger : YADKINVILLE WWTP Subbasin : 0307
Receiving Stream : NORTH DEEP CREEK Stream Class: C
Summer 7Q10 : 5.77 Winter 7Q10 : 8.736
Design Temperature: 25.0
ILENGTHI SL PEI VELOCITY 1 DEPTH' Kd 1 Kd 1 Ka 1 Ka 1 KN 1 KN I KNR 1 KNR 1 SOD 1 SOD
1 mile 1 ft mil fps I ft 'design' @20 Idesign' @20 'design l @20 Idesign' @20 'design l @20
I• I 1 1 1 1 1 1 1 1 1 I I
Segment 1 1 1.301 9.101 0.307 11.29 1 0.32 1 0. 25 1 5.61 I 5.031 0.44 1 0.30 1 0.44 1 0. 00 10.00 10.00
Reach 1 1 1 I I I I I I I I I I I
1
Segment 1 1 0.851 9
Reach 2 1 I
101 0.312 1 1.31 1 0.32 1 0.25 1 5.70 1 5.121 0.44 1 0.30 1 0.44 1 0.00 1 0.00 1 0.00
1 I 1 1 1 1 1 1 1 1 1 1 I I
Segment 1 1 1.951 30 801 0.448 1 1.11 1 0.48 1 0.38 127.69 1 24.841 0.73 1 0.50 1 0.73 10.00 1 0.00 1 0.00
Reach 3 I 1 I I I I I I I I I I I
1
Segment 1 I 2.001 4
Reach 4 1 I
401 0.257 1 1.49 1 0.28 1 0.22 1 2.27 1 2.041 0.44 1 0.30 1 0.44 10.00 10.00 1 0.00
1
Segment 1 1 2.501 3
Reach 5 1 I
601 0.332 1 2.06 1 0.28 1 0.22 1 1.73 1 1.561 0.44 1 0.30 1 0.44 1 0.00 1 0.00 1 0.00
I Flow 1 CBOD 1 NBOD 1 D.O. I
I cfs 1 mg/1 1 mg/1 1 mg/1 I
Segment 1 Reach 1
Waste 1 1.782 1 60.000 118.000 1 5.000
Headwaters) 5.770 I 2.000 1 1.000 I 7.440
Trlibutary I 0.000 I 2.000 1 1.000 1 7.440
* Runoff 1 0.123 1 2.000 1 1.000 1 7.440
Segment 1 Reach 2
Waste 1 0.000 1 0.000 1 0.000 1 0.000
Tributary 1 0.330 1 2.000 1 1.000 I 7.440
* Runoff 1 0.133 1 2.000 1 1.000 1 7.440
Segment 1 Reach 3
Waste 1 0.000 1 0.000 1 0.000 1 0.000
Tributary I 0.000 I 2.000 1 1.000 I 7.440
* unoff 1 0.133 1 2.000 1 1.000 1 7.440
Segment 1 Reach 4
Waste 1 0.000 1 0.000 1 0.000 1 0.000

Tributary 1 0.000 1 2.000 I 1.000 I 7.440
* Runoff 1 0.133 1 2.000 1 1.000 1 7.440
Segment 1 Reach 5
WAste 1 0.000 I 0.000 I 0.000 I 0.000
Tributary 1 12.400 I 2.000 1 1.000 1 7.440
* Runoff I 0.080 I 2.000 1 1.000 1 7.440
Runoff flow is in cfs/mile

SUMMER
EXTENDED MODEL
ASSUME S. DEEP CK D.O. ARE OK
Seg # I Reah # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 6.86 15.69 5.01 7.55
1 1 0.13 6.88 15.53 4.95 7.57
1 1 0.26 6.90 15.38 4.88 7.58
1 1 0.39 6.92 15.22 4.82 7.60
1 1 0.52 6.93 15.07 4.76 7.62
1 4 0.65 6.95 14.92 4.69 7.63
1 1 0.78 6.96 14.77 4.63 7.65
1 0.91 6.98 14.63 4.57 7.66
1 1 1.04 6.99 14.48 4.51 7.68
1 1 1.17 7.01 14.34 4.46 7.70
1 1 1.30 7.02 14.19 4.40 7.71
1 2 1.30 7.04 13.69 4.26 8.04
1 2 1.38 7.05 13.61 4.22 8.05
1 2 1.47 7.06 13.52 4.19 8.07
1 2 1.55 7.08 13.43 4.15 8.08
1 1.64 7.09 13.35 4.12 8.09
1 `1 1.72 7.10 13.26 4.08 8.10
1 2 1.81 7.11 13.17 4.05 8.11
1 2 1.89 7.12 13.09 4.02 8.12
1 2 1.98 7.13 13.01 3.98 8.13
1 2 2.06 7.14 12.92 3.95 8.14
1 2 2.15 7.15 12.84 3.92 8.16
1 3 2.15 7.15 12.84 3.92 8.16
1 3 2.34 7.56 12.64 3.83 8.18
1 3 2.54 7.76 12.45 3.75 8.21
1 3 2.73 7.86 12.26 3.67 8.23
1 3 2.93 7.91 12.07 3.59 8.26
1 3 3.12 7.93 11.89 3.51 8.29
1 3 3.32 7.95 11.71 3.44 8.31
1 3 3.51 7.96 11.53 3.36 8.34
1 3 3.71 7.97 11.35 3.29 8.36
1 3 3.90 7.97 11.18 3.22 8.39
1 3 4.10 7.98 11.01 3.15 8.41
1 4 4.10 7.98 11.01 3.15 8.41
1 4 4.30 7.80 10.84 3.08 8.44
1 4 4.50 7.65 10.66 3.01 8.47
1 4 4.70 7.52 10.50 2.94 8.49
1 4 4.90 7.41 10.33 2.87 8.52
1 4 5.10 7.31 10.17 2.81 8.55
1 4 5.30 7.22 10.01 2.74 8.57
1 4 5.50 7.15 9.85 2.68 8.60
1 4 5.70 7.09 9.69 2.62 8.63
1 4 5.90 7.04 9.54 2.56 8.65
1 4 6.10 6.99 9.39 2.50 8.68
1 5 6.10 7.26 5.04 1.62 21.08
1 5 6.35 7.24 4.98 1.59 21.10
1 5 6.60 7.23 4.91 1.55 21.12
1 5 6.85 7.22 4.85 1.52 21.14
1 5 7.10 7.21 , 4.78 1.49 21.16
1 5 7.35 7.20 4.72 1.46 21.18
1 5 7.60 7.20 4.66 1.43 21.20
1 5 7.85 7.20 4.60 1.40 21.22
1 5 8.10 7.19 4.54 1.37 21.24
1 5 8.35 7.20 4.48 1.35 21.26
1 5 8.60 7.20 4.42 1.32 21.28
Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I

old Flows
Yadkinville WWTP NC0020338
N. Deep Creek
Residual Chlorine
7010 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
UPS BACKGROUND LEVEL (UG/L)
IWC (%)
Allowable Concentration (ug/I)
Fecal Limit
Ratio of 2.2 :1
Ammonia as NH3
(summer)
3.9 7010 (CFS)
1.15 DESIGN FLOW (MGD)
1.7825 DESIGN FLOW (CFS)
17.0 STREAM STD (MG/L)
0 UPS BACKGROUND LEVEL (MG/L)
31.4 % IWC (%)
54 Allowable Concentration (mg/I)
Ammonia as NH3
(winter)
7010 (CFS)
200/l0om1 DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL (MG/L)
IWC (%)
Allowable Concentration (mg/I)
3.9
1.15
1.7825
1.0
0.22
31.4
3
10
1.15
1.7825
1.8
0.22
15.1 clo
11
4/18/94

MODEL RESULTS
Discharger : YADKINVILLE WWTP
Receiving Stream : NORTH DEEP CREEK
o';d F o, 91 /g191,
SUMMER 4 hem f,w
SPECULATIVE 1.0MGD TO 1.15 MGD
NH3N=3 BOD5=30
The End D.O. is 7.15 mg/l.
The End CBOD is 4.80 mg/1.
The End NBOD is 1.13 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 6.51 6.15 4
Reach 1
Reach 2
Reach 3
Reach 4
Reach 5
60.00 13.50
0.00 0.00
0.00 0.00
0.00 0.00
0.00 0.00
5.00
0.00
0.00
0.00
0.00
Sa v-ec as Spd krh an Level )74(1km mono
Wr h tC� s a Vfe a S 4 elki h o n Sa"Pit oir�.
y
1.15000
0.00000
0.00000
0.00000
0.00000

*** MODEL SUMMARY DATA ***
Discharger : YADKINVILLE WWTP Subbasin : 0307
Receiving Stream : NORTH DEEP CREEK Stream Class: C
Summer 7Q10 : 3.9 Winter 7Q10 : 10.0
Design Temperature: 25.0
ILENGTHI SLOPEI VELOCITY 1 DEPTH' Kd I Kd I Ka 1 Ka I KN I KN 1 KNR 1 KNR I SOD 1 SOD
1 mile I fqmil fps 1 ft 'design) @20 'design) @20 'design' @20 Idesign l @20 Idesignl @20
Segment 1 I 1.351 9.101 0.240 1 1.26 1 0.30 1 0.24 14.38 1 3.92) 0.44 1 0.30 10.44 10.00 1 0.00 10.00
Reach 1 1 I I I I I I I I I I I
Segment 1 1 0.851 9.
Reach 2 I I
101 0.243 11.29 1 0.30 1 0.24 14.43 I 3.971 0.44 1 0.30 1 0.44 10.00 1 0.00 1 0.00
I 1 1 1 I I I I 1 1 I I I
Segment 1 1 1.951 30.801 0.349 11.08 10.43 1 0.34 121.60 119.371 0.73 1 0.50 10.73 10.00 10.00 10.00
Reach 3 1 I I 1 1 1 I 1 1 1 1 I I
I I
Segment 1 I 2.001 4.
Reach 4 I I
01 0.202 1 1.44 1 0.28 1 0.22 1 1.78 1 1.601 0.44 1 0.30 1 0.44 1 0.00 1 0.00 1 0.00
I I I I I I I I I I I I I
Segment 1 I 2.501 4.401 0.289 1 1.95 1 0.28 1 0.22 1 1.84 1 1.651 0.44 1 0.30 10.44 1 0.00 10.00 1 0.00
Reach 5 1 I I I I I I I I I I I I
Flow I CBOD 1 NBOD I D.O. I
cfs I mg/1 1 mg/1 I mg/1
Se ent 1 Reach 1
Wate I 1.782 160.000 113.500 1 5.000
Headwaters) 3.900 I 2.000 I 1.000 I 7.440
Tributary I 0.000 I 2.000 I 1.000 1 7.440
* Runoff I 0.070 1 2.000 I 1.000 I 7.440
Segment 1 Reach 2
Waste I 0.000 I 0.000 1 0.000 I 0.000
Tributary I 0.230 I 2.000 I 1.000 I 7.440
* Runoff I 0.080 I 2.000 I 1.000 I 7.440
Se ent 1 Reach 3
Wa to I 0.000 I 0.000 1 0.000 I 0.000
Tributary I 0.000 I 2.000 1 1.000 1 7.440
* Runoff I 0.080 1 2.000 I 1.000 I 7.440
Segment 1 Reach 4
Waste 1 0.000 1 0.000 1 0.000 I 0.000

Tributary I 0.000 I 2.000 I 1.000 I 7.440
* Runoff I 0..080 I 2.000 I 1.000 I 7.440
s
W
T
gment 1 Reach 5
ste I 0.000 I 0.000 I 0.000 I 0.000
ibutary 110.000 I 2.000 I ,1.000 I 7.440
Runoff I 0.080 I 2.000 I 1.000 I 7.440
Runoff flow is in cfs/mile

I Seg # I Reach
1 1
1 1
1 1
1 1
1
1
1 1
1 1
1
1 1
1 1
1 2
1 2
1 2
1 2
1 2
1 2
1 2
1 2
1 2
1 2
1 2
1 3
1 3
1 3
1 3
1 3'1
1 3
1 3
1 3
1 3
1 3
1 3
1 4
1 4
1 4
1 4
1 4
1 4
1 4
1 4
1 4
1 4
1 4
1 5
1 5
1 5
1 5
1 5
1 5
1 5
1 5
1 5
1 5
1 5
I Seg # I Reach
SUMMER
SPECULATIVE 1.0MGD TO 1.15 MGD
NH3N=3 BOD5=30
# I Seg Mi I D.O. I CBOD I NBOD 1 Flow I
0.00 6.67 20.19 4.92 5.68
0.14 6.63 19.95 4.84 5.69
0.27 6.60 19.72 4.76 5.70
0.41 6.58 19.48 4.68 5.71
0.54 6.56 19.25 4.61 5.72
0.68 6.55 19.02 4.53 5.73
0.81 6.55 18.80 4.46 5.74
0.95 6.54 18.58 4.38 5.75
1.08 6.54 18.36 4.31 5.76
1.22 6.55 18.14 4.24 5.77
1.35 6.56 17.92 4.17 5.78
1.35 6.59 17.31 4.05 6.01
1.43 6.60 17.19 4.01 6.01
1.52 6.61 17.06 3.97 6.02
1.60 6.62 16.93 3.93 6.03
1.69 6.63 16.80 3.89 6.03
1.77 6.64 16.68 3.85 6.04
1.86 6.65 16.55 3.81 6.05
1.94 6.66 16.43 3.77 6.05
2.03 6.67 16.31 3.73 6.06
2.11 6.68 16.19 3.69 6.07
2.20 6.69 16.07 3.66 6.08
2.20 6.69 16.07 3.66 6.08
2.39 7.28 15.80 3.56 6.09
2.59 7.57 15.53 3.47 6.11
2.78 7.71 15.27 3.37 6.12
2.98 7.78 15.01 3.28 6.14
3.17 7.82 14.76 3.20 6.15
3.37 7.84 14.51 3.11 6.17
3.56 7.85 14.26 3.03 6.18
3.76 7.86 14.02 2.95 6.20
3.95 7.87 13.79 2.87 6.22
4.15 7.88 13.56 2.80 6.23
4.15 7.88 13.56 2.80 6.23
4.35 7.64 13.30 2.72 6.25
4.55 7.42 13.05 2.64 6.26
4.75 7.24 12.81 2.57 6.28
4.95 7.08 12.57 2.50 6.30
5.15 6.94 12.33 2.43 6.31
5.35 6.82 12.10 2.36 6.33
5.55 6.72 11.88 2.29 6.34
5.75 6.64 11.66 2.23 6.36
5.95 6.57 11.44 2.17 6.38
6.15 6.51 11.23 2.11 6.39
6.15 7.08 5.60 1.43 16.39
6.40 7.08 5.51 1.40 16.41
6.65 7.08 5.43 1.37 16.43
6.90 7.09 5.34 1.33 16.45
7.15 7.09 5.26 1.30 16.47
7.40 7.10 5.18 1.27 16.49
7.65 7.11 5.10 1.24 16.51
7.90 7.12 5.02 1.21 16.53
8.15 7.13 4.95 1.19 16.55
8.40 7.14 4.87 1.16 16.57
8.65 7.15 4.80 1.13 16.59
# I Seg Mi I D.Q. I CBOD I NBOD I Flow I

-r
Ano...lo,n
•
A I. E 'E. Nq ..
cC)9( e Qksc,ttay-
okK
a• ,
2.0
fb.. ,b-
jro
.° .,•,/, f '
1 sluMrnwibr�
LE MEW
4/,/
• i e•4�
HEALTH AND NA1'ut
r al� 1/0s Me='
fr
I
1 ea 1.1/,/,/ soon
1a M /{y) 0 .R
L.
•
�e l
R jr C.,. , 0 N D
/14

oA2\C)0
Tv vacii
aid
Nat" i AL\Uk in moCle
�1t .e.f 4 Or 1 N. Ziy
c((hR) a�e on
a k e o f reo --'Vc
UT ft. ()veel
C�isc1 ar f
iS vT cf (7(f/ti /(f Ui.LS
-Ea 0h &1
oof &uL TP la°0a gels
O0 a_ cde�,� lfzb
r4is e;4,5 w.01 s/W/A//G Z/ 9
/q ��.
G W= o. 0 /e0 >d C /0774eri7L
I'? ZPvo i10k/ .r�rPl[ li1iZ
//,/4 Bo Ps 30
IDD. 6
7Ss 3 0
, /oop sec(
ply G -5
�R dKrn 6dn/rr] ab
7 it46D
30
3d
ao 0
NCb0 giw
/0. 20 cloyyzes G
1,liL19 /002.
2 en) 7 l 0 S yr , /llh y (t G q

aS a
7L'ra rh
(iG h /V - O/e'l /93
k f /f a KeC O /011.-L2Ovt 74r 4 C/#ffi/c 1-1
imtit/ .
. DePrJ e`re� s�4 We'- 1/n a/ 14
/ fJDh /Gt I v-v„, ( p r a d;
S/ a
�r< e oi r c Q' v- 0. l/ J+.I fr/ s���t �r""DO,O' -At
I b /.0 (7 a iS/k /CP e a-14-7 e.f 11/
Sa /i � a
�D�1w/.

DA =35.9
35,1
ST?ko 5, '77
4-73
DA,
10 Los 0,33 Lf
7,910.0. 0,53
30‘12.. _0,93
Dr-) 3
Pf4 No( 1
S7Q10
xv 700 = 717
300 2_
UL nmk 2 tH4/avd,t
CiA u I a 11 -g lo Los ; -147is 'Pork]
ROGt14_.--( --1) /,
2037410 (ri /3 - )‘ 3
R)Vi ( 0+, 7 - t,3 Pigg
d a
Yo hecd___40__1(ecotcvtai-e
-cis _ u_c, s ov_e e
k
beCCLS-Qn2rn QCf1)OUQS IA,
0 CIO WY1 Sikta
tie 4--10 vvs co
•
IV\ ;
k 0 cvn =
Po5960o
ko7(0 !LH — + 4.1 196
1
lWC r-aac
• .5.77+
caft_i, 1-)
ualduL _ _
—124 thirpilemc
D 7- I
/6do 6,7
Coo ,
30(‘ 14 .76
°'/-4
efr. 4
eek
der

4
USGS weighted low flow estimate procedure
Facility LYadknville WWTP NPDES #
Region
DA LFPR
s7Q10 LFPR
DA new
MAR
QA_eq
STEP 1
HA10
H_ _ ...
0 sq mile
.._.._.-. o.NO.._.•••. cfs
.35.9
35.90
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
NC0020338
Stream'N. Deep Cree
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO 4 4, CONTINUE to STEP 2, ELSE too far from gage
#DV/O!
STEP 2 dete
ine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight raft weight ratio
0 _ 1 0 1
#DIV/01 I IiV/0r!#DIV/0!
1 0.25 1 4
STEP 3
HA3
HA5
HA9
HA10
STEP 4 calcu
weight =
#DIV/0!
calculate 7Q10 EQ using regional equation
10.44
1.31
1.31
5.77
cfs
cfs
cfs
cfs
7Q10 EQ=
ate 7Q10 yield using weighted equation
#DIV/0!
5.77
7Q10yield = [weight_LFPR * 7Q10 LFPR] + [weight EQ * 7010_EQ]
cfs
DA LFPR DA new
yield = #DIV/01 + #DIV/0! = #DIV/01 cfs/sq mile
STEP 5 calculate s7Q10
7010 = 7Q10yield * DA new
summer 7010 =
#DIV/0!
cfs

USGS weighted low flow estimate procedure
FacilityLYadknville WWTP NPDES # iNC0020338 StreamIN. Deep Cree
Region
DA LFPR
w7010_LFPR
DA new
MAR
QA eq
HA10
0
0
35.9
1
35.90
sq mile
cfs
sq mile
cfs/sq mite
cfs
STEP 1 calculate drainage area ratio
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO 4, CONTINUE to STEP 2, ELSE too far from gage
#DV/01
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight ratio weight rAIQ
0 1 0 1
I#DIVIO!i #DIV/0! 1 f#Div/oii #DIV/0!
1 0.25 1 4
STEP 3
HA3
HA5
HA9
HA10
STEP 4
eight =
#DIV/0!
calculate 7Q10 EQ using regional equation
19.80
4.57
4.57
8.73
cfs
cfs
cfs
cfs
7Q10 EQ=
calculate 7010 yield using weighted equation
8.73
= L.
cfs/sq mile
7Q10ield = [weight_LFPR * 7010_LFPR] + [weight_EQ * 7010_EQ]
DA LFPR DA_new
STEP 5 calcu
7010
yield = #DIV/01 + #DIV/0! = #DIV/0! cfs/mile
ate w7010
= 7010yield * DA_new
winter 7Q10 = #DIV/0! cfs

USGS weighted low flow estimate procedure
FacilitylYadknville WWTP NPDES # NC0020338J Stream N. Deep Cree
.»N« N)N�»N .MNN_NM.w.wM1N »N_.._.._. .._.
Region
DA LFPR
30Q2 LFPR
DA_new
MAR
QA eq
STEP 1
__._�HA10.
0� sq mile
..� .__. ....._. cfs
._N_
35.90
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO < 4, CONTINUE to STEP 2, ELSE too far from gage
#D V10!
ter ine
STEP 2 de weight of gage (weight_LFPR)
A. RATIO < 1
weight
0
I'
12
EIv7oi
#DIV/0!
1 0.25
STEP 3
HA3
HA5
HA9
HA10
weight =
B. RATIO > 1
weighl tatiQ
_ 0 1
#DIV/0! #DIV/01
1 4
#DIV/0!
calculate 3002_EQ using regional equation
22.11
6.17
6.17
12.35
cfs
cfs
cfs
cfs
3002_EQ =
12.35
cfs/sq mile
STEP 4 calculate 3002 yield using weighted equation
3002yield = [weight LFPR * 3002 LFPR] + [weight EQ * 3002 EQ]
DA LFPR DA new
LiPJ.LQL..J
yield = #DIV/0! + #DIV/0! = #DIV/01 cfs/sq mile
STEP 5 calcul to 3002
30Q = 3002yield * DA new
3002 = #DIV/01 cfs

USGS weighted low flow estimate procedure
FacilitylYadknville WWTP NPDES # NC.0020338_j StreamiN_Deep Cree
Region
DA LFPR
s7Q10_LFPR
DA new
MAR
QA eq
STEP 1
._. HA10
»
I
0 sq mile
._.o_
...._.._.cfs
.._.._.
.._.._. 36.9
36.90
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
T vv»1 d ct(/V )11 u
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO < 4, CONTINUE to STEP 2, ELSE too far from gage
#DIV/0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight weight Lao
_#oiwoi j #orvio! I
weight =
#DIV/0!
#DIV/0! #DI m
1 4
STEP 3 calculate 7Q10 EQ using regional equation
HA3
HA5
HA9
HA10
STEP 4
10.69
1.33
1.33
5.93
cfs
cfs
cfs
cfs
7Q10 EQ=
calculate 7010 yield using weighted equation
5.93
7Q10yield = [weight_LFPR * 7Q10 LFPR] + [weight_EQ * 7010_EQ]
cfs
DA LFPR DA new
yield = #DIV/0! + #DIV/0!
STEP 5 calculate s7Q10
7010 = 7010yield * DA new
summer 7010 =
#DIV/0!
cfs
L.JPIYLQ.L..I
#DIV/0!
cfs/sq mile

USGS weighted low flow estimate procedure
FacilityYadknville WWTP NPDES #
Region
DA LFPR
w7010_LFPR
DA new
MAR
QA eq
STEP 1
HA1 0
0 sq mile
.._o___ ...... cfs
_��
1
36.90
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
s N00020338 l
Stream N. Deep Cree
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO 4, CONTINUE to STEP 2, ELSE too far from gage
#D /0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight weight r to
#DIV/O! #DIV/0! I #DIV/O!
1 0 ,25 1 4
STEP 3
HA3
HA5
HA9
HA10
STEP 4
%Tight =
#DIV/01
calculate 7010_EQ using regional equation
20.30
4.67
4.67
8.97
cfs
cfs
cfs
cfs
7Q10 EQ =
calculate 7010 yield using weighted equation
8.97
cfs/sq mile
7Q10yield = [weight_LFPR * 7010_LFPRJ + [weight EQ * 7010_EQJ
DA LFPR DA new
L1YLQL.J
yield = #DIV/0! + #DIV/0! = #DIV/0! cfs/mile
STEP 5 calcu to w7Q10
7Q10 = 7Q10yield * DA_new
winter 7010 = #DIV/01 cfs

USGS weighted low flow estimate procedure
FacilityLYadknville WWTP NPDES #
Region L.J'19.
NOTE: procedure applies for regions HA3, HAS,
DALFPR � 0 sq mile HA9, and HA10, else see flow SOP
30Q2 LFPR0cfs
_._.._.._..._.._.. ._.
DA new sq mile
MAR cfs/sq mile
QA eq cfs
STEP 1
36.9
36.90
calculate drainage area ratio
NC0020338 l
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO <4, CONTINUE to STEP 2, ELSE too far from gage
#D /0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight faii,Q weight Q
rii5vii
0 1 0 1
#DIV/0! ( 1---i-Ewoy-1#DIV/0.
1 0.25 1 4
weight =
#DIV/0!
STEP 3 calculete 3002_EQ using regional equation
HA3
HA5
HA9
HA10
22.67
6.31
6.31
12.69
cfs
cfs
cfs
cfs
3002_EQ =
STEP 4 calculate 3002 yield using weighted equation
30Q
STEP 5 calculi
3002
StreamiN. Deep Cree
._..#D1V/01.._..]
12.69
cfs/sq mile
ield = [weight LFPR * 30Q2 LFPR] + [weight_EQ * 30Q2_EQ]
DA LFPR DA new
field = #DIV/0! + #DIV/0! = #DIV/0! cfs/sq mile
ate 3002
= 3002yield * DA new
3002 = #DIV/0! cfs

USGS weighted low flow estimate procedure
FacilitylYadknville VIIWTP NPDES #
N _.._N_ _N_.NN_N
Region
DA LFPR
s7Q10_LFPR
DA new
MAR
QA eq
STEP 1
1. HA1 0
NN._NN._NM._.-.
0 sq mile
0 cfs
2.11
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
i NC0020338
Stream l N. Deep Cree
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO < 4, CONTINUE to STEP 2, ELSE too far from gage
#D /0!
STEP 2
determine weight of gage (weight_LFPR)
A. RATIO < 1
weight
_
•
#DIV/01
1
#D;IV/0!
0.25
weight =
#DIV/01
B. RATIO > 1
weight ratiQ
0 1
#DIV/01 #DIV/01
1 4
STEP 3 calcu ate 7010_EQ using regional equation
HA3
HA5
HA9
HA10
STEP 4
0.84
0.29
0.29
0.33
cfs
cfs
cfs
cfs
7Q10 EQ=
calculate 7010 yield using weighted equation
0.33
7Q10yield = [weight LFPR * 7010_LFPR] + [weight_EQ * 7010 EQ]
cfs
DA LFPR DA_new
!..JQIYLQLJ
yield = #DIV/01 + #DIV/01 = #DIV/01 cfs/sq mile
STEP 5 cal late s7010
7Q1 = 7010yield * DA_new
summer 7010 = #DIV/01 cfs

USGS weighted low flow estimate procedure
FacilityLYadknville WWTP NPDES # NC0020338J Stream! N. Deep,Cree
Region
DA LFPR
w7Q10 LFPR
DA new
MAR
QA eq
STEP 1
._,_HA1 0,_.._ NOTE: procedure applies for regions HA3, HA5,
0 sq mile HA9, and HA10, else see flow SOP
0 cfs
2.11
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO 4, CONTINUE to STEP 2, ELSE too far from gage
#DIV/0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight t weight ratio
0 1 0 1
#DIV/0! #DIV/0! #DIV/0! #DIV/0!
1 4
1 0 25
weight =
#DIV/0!
STEP 3 calculate 7010 EQ using regional equation
HA3
HA5
HA9
HA10
1.55
0.49
0.49
0.53
cfs
cfs
cfs
cfs
7Q10 EQ=
STEP 4 calculate 7Q10 yield using weighted equation
0.53
cfs/sq mile
7Q10yield = [weight_LFPR * 7Q10 LFPR] + [weight EQ * 7010 EQ]
DALFPR DAnew
yield = #DIV/0! + #DIV/0! = #DIV/01 cfs/mile
STEP 5 calcul to w7010
7010 7010yield * DA new
winter 7010 = #DIV/0! cfs

USGS weighted low flow estimate procedure
FacilitylYadknviile WWTP NPDES # INC002Eg8.1 StreamN. Deed Cree
Region
DA LFPR
3002_LFPR
DA_new
MAR
QA eq
STEP 1
1. HA10
0
0
2.11
sq mile
cfs
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO 4, CONTINUE to STEP 2, ELSE too far from gage
#D V/O!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight Lati2 weight Q
0 1 0 1
I« #DIV/0! 1 #DIV/0! I [1F1 #DIV/0!
1 0125 1 4
weight =
#DIV/0!
STEP 3 calculate 30Q2 EQ using regional equation
HA3
HA5
HA9
HA10
1.68
0.59
0.59
0.73
cfs
cfs
cfs
cfs 30Q2 EQ = 0.73 cfs/sq mile
STEP 4 calculate 3002 yield using weighted equation
30Q2yield = [weight_LFPR * 3002 LFPR] + [weight_EQ * 3002 EQ]
DALFPR DA_new
i #DIV/O!
yield = #DIV/0! + #DIV/0! = #DIV/0! cfs/sq mile
STEP 5 calcu to 3002
30Q = 3002yield * DA_new
30Q2 =
#DIV/0!
cfs

.
USGS weighted low flow estimate procedure
Facility iYadknville WWTP NPDES #
Region
DA LFPR
s7Q10 LFPR
DA new
MAR
QA eq
STEP 1
HA10
0
0
sq mile
.._.._.�.o.._.._.OW.. cfs
1
42.90
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
i NC0020338 i
StreamlN. Deep Cree
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
d 0I iiki
RATIO = new drainage area
ift
drainage area at gage
IF 0.25 < RATIO < 4, CONTINUE to STEP 2, ELSE too far from gage
#DIV/0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1
weight talk
0 1
• #DIV/O! #DIV/0!
1 d.25
STEP 3
HA3
HA5
HA9
HA10
STEP 4
weight =
#DIV/0!
B. RATIO > 1
wwei ht rata
0 1
#DIV/0! #DIV/0!
1 4
calculate 7010_EQ using regional equation
12.23
1.44
1.44
6.90
cfs
cfs
cfs
cfs
7010_EQ.=
calculate 7010 yield using weighted equation
6.90
7Q10yield = [weight_LFPR * 7Q10 LFPR] + [weight EQ * 7010 EQ]
STEP 5 calcu
yield = #DIV/0!
ate s7Q10
cfs
DA_LFPR DA new
7010 = 7Q10yield * DA new
summer 7Q10 = #DIV/0! cfs
+ #DIV/0! = #DIV/01 cfs/sq mile

USGS weighted low flow estimate procedure
Facility Yadknville WWTP NPDES # NC00203381 Stream IN. DeepCree
Region
DA LFPR
w7Q10_LFPR
DA new
MAR
QAeq
STEP 1
0
sq mile
0 cfs
42.9
42.90
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO <4, CONTINUE to STEP 2, ELSE too far from gage
#DIV/0!
STEP 2 determine weight of gage (weight_LFPR)
A. RATIO < 1 B. RATIO > 1
weight .QMidi latiQ
riis7�T1
0 1 0 1
#DIV/0! I I#DIViO!!
#DIV/01
1 0.25 1 4
STEP 3
HA3
HA5
HA9
HA10
weight =
#DIV/0!
calculate 7010_EQ using regional equation
23.24
5.26
5.26
10.41
STEP 4 calcula
cfs
cfs
cfs
cfs
7010_EQ =
e 7Q10 yield using weighted equation
10.41
cfs/sq mile
7Q10yisfald = [weight_LFPR * 7Q10 LFPR] + [weight EQ * 7010 EQ]
DA LFPR DA new
yield = #DIV/0!
STEP 5 calculat w7Q10
7010 = 7010yield * DA new
winter 7Q10 = #DIV/01 cfs
L..iPiY0L.i
+ #DIV/0! - #DIV/0! cfs/mile

USGS weighted low flow estimate procedure
FacilitylYadkr1vi11e WWTP NPDES #
Region
DA LFPR
30Q2_LFPR
DA new
MAR
QA eq
STEP 1
,_.. HA10,_.._
0 sq mile
.._...._. �__ ...._.... cfs
_
42.90
sq mile
cfs/sq mile
cfs
calculate drainage area ratio
NC0020338
StreamlN. Deep Cree
NOTE: procedure applies for regions HA3, HA5,
HA9, and HA10, else see flow SOP
RATIO = new drainage area
drainage area at gage
IF 0.25 < RATIO < 4, CONTINUE to STEP 2, ELSE too far from gage
#Df 10!
STEP 2 detenr}ine weight of gage (weight_LFPR)
A. RATIO < 1
weight
0
#DIV/0!
1
STEP 3
HA3
HA5
HA9
HA10
1
1 #DIV/O! I
0.25
weight =
#DIV/0!
B. RATIO >
wei ht L3ti4
0 1
#DIV/0! #DIV/0!
1 4
calculate 30Q2 EQ using regional equation
6.00
7.16
7.16
14.76
cfs
cfs
cfs
cfs
3002_EQ =
14.76
cfs/sq mile
STEP 4 calculate 3002 yield using weighted equation
3002yield = [weight_LFPR 30Q2 LFPR] + [weight_EQ 3002 EQ]
DA_LFPR DA new
yield = #DIV/0! + #DIV/0!
STEP 5 calculat 3002
3002 3002yield * DA new
3002 = cfs
#DIV/0!
#DIV/0!
#DIV/01.�.J
cfs/sq mile