NC0021326_INSTREAM ASSESSMENT_19931014

NPDES DOCYNENT SCAMMIMS COVER SHEET
NPDES Permit: NCO021326
Dobson WWTP
Document Type: Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Engineering Alternatives Analysis
201 Facilities Plan
Instream Assessment (67B
Correspondence re: Mercury
Permit
History
Document Date: October 14 1993
WIXIM document 10 printed on reuse paper-igiaore anyr
content on the re%rerge fside

1�
DIVISION OF ENVIRONMENTAL MANAGEMENT
Water Quality Section/Rapid Assessment Group
October 14, 1993
MEMORANDUM
TO: Larry Coble
THROUGH: Ruth Swanek��
Carla Sanderson
FROM: `Dave Goodrich' -�
SUBJECT: Instream Assessment for the Town of Dobson WWTP
NPDES No. NCO021326
Surry County
030702
Summary and Recommendations
An instream assessment for the Town of Dobson has been completed by Technical
Support. George Smith from the Winston-Salem Regional Office has requested an SOC
for Dobson since the plant has inflow/infiltration problems and is unable to consistently
meet limits for flow and ammonia. Dobson has requested an additonal flow of 0.027 MGD
(domestic waste) to add to their current wasteflow (0.1474 MGD). Smith further requests
that an allowance for inflowfinfiltration of 0.0756 MGD be given to equal an SOC flow of
0.25 MGD. This additional flow will exceed the permitted flow of 0.16 MGD.
Technical Support has no objections to the relaxation of the limits for ammonia or
flow. During analyses for the increased BOD5 limit, it was apparent that the additonal flow
of 102,600 gpd will not substantially affect the instream DO. The EMC 67(b)criteria(the
D.O. minimum shall not decrease by more than 0.5 mg/l and/or the distance the D.O. is
less than 5.0 mg/l shall not increase by more than 0.5 mile) were maintained with the
additional flow.
It should be noted, however, that based on the current criteria for instream ammonia
(1.0 mg/l in the summer and 1.8 mg/I in the winter) the effluent from this facility may cause
toxicity in the stream. It is therefore recommended that the period of this SOC be limited
especially in terms of the length of time the relaxed ammonia limit is allowed. Also,please
note that the model predicts Cody Creek to be sensitive to effluent dissolved oxygen levels
at the mix point during the winter. It is important that the facility keep effluent dissolved
oxygen concentrations above 5.0 mg/l. In fact, as a measure of safety, it would be good to
tell the permittee to try to keep D.O. in the effluent at or above 6.0 mg/1 in the winter.
Background
The Town of Dobson WWTP discharges to Cody Creek which is classified C in the
Yadkin River basin. The 7Q10 (summer) at the point of discharge is estimated to be 0.16

i
cfs, with a 7Q10 (winter) of 0.26 cfs, a 30Q2 of 0.36 cfs, and an average flow of 1.0 cfs.
Instream data do not show any violations of the water quality standard for dissolved
oxygen in the past 12 months. Self-monitoring data indicate this facility is having difficulty
meeting the monthly average limitations for flow and ammonia.
Analysis and Discussion
Headwater conditions (flows and water quality characteristics) were identical in
both pre-SOC and post-SOC modeling analyses. Carbonaceous BOD values for the
models were input as the monthly average limit of BODS (30 mg/1) multiplied by 1.5.
Nitrogenous BOD was assumed to be at the requested concentration of NH3 (4.0 mg/1 in
the summer and 6.0 mg/l in the winter) multiplied by 4.5.
An instream assessment was performed using the Level B framework. A
comparison was made using the average monthly flow for the past year(0.1474 MGD) and
the average monthly flow for the past year plus the requested increase in flow (0.25 MGD).
Some change in instream DO was noted between the two flows. However, the difference
in minimum DO between the two models run under summer conditions was<0.5 mg/l.
Further, there was no DO sag below 5.0 mg/l, so criteria specified in 67(b) were not
violated.
cc: Steve Mauney
Jeff Bouchelle
Central Files

TABLE 1. Instream Assessment Summary for the Town of Dobson
Wasteflow Assumptions
Design Capacity 0.1600 MGD
Pre-SOC (12/90- 11/91) 0.1474 MGD
SOC Flow Requested 0.1026 MGD
Domestic/Commercial Flow 0.0270 MGD
Inflow/Infiltration Flow 0.0756 MGD
Pre-SOC + SOC Flow 0.2500 MGD
Model Input Summary
Headwater conditions:
S7Q10 0.16 cfs
W7Q10 0.26 cfs
Qavg 1.04 cfs
Design Temperature (Summer) 25.0°C
Design Temperature (Winter) 14.0°C
CBOD 2.0 mg/1
NBOD 1.0 m8/1
DO (90% saturation) 7.44 mg/l
Wastewater Inputs:
Pre-SOC Wasteflow 0.1474 MGD
Post-SOC Wasteflow 0.2500 MGD
CBOD (1.5*assumed max. BOD5) 45.0 mg/l
Summer]\BOD (4.5*requested NH3) 18.0 mg/]
Winter NBOD (4.5*requested NH3) 27.0 mg/1
Model Output Summary*
Qw DO Net Distance D.O. Net
(MGD) Min. Change <5.0 mg/1 Change
(mg/1) (mg/1) (mi) (mi)
Pre-SOC 0.1474 6.00 NA 0.0 NA
Post-SOC 0.2500 5.71 .29 0.0 0.0
*Summary results for summer conditions only. Results under winter conditions resulted in
no predicted violations of the D.O. standard. Net change in the predicted D.O. minimum
under winter conditions were near 0.5 mg/l. The model shows D.O. in Cody Creek to be
very sensitive to effluent D.O.

\o)_ 'V
Request Form for In—stream Assessment for 67D
NAME OF FACILITY 1 Cl.ti' ! C I_� —_—_ SUBBASIN _— � J-�•L
COUNTY REGION 1t'CRi DESIGN FLOW
1
RECEIVING STREAM E _
BACKGROUND DATA s
A. Why is SOC needed? (Facility is out of compliance with which
effluent limits?) � L
FLOW' uc.uf - T aLT �-� �.:��
e. Bistory of SOC requests:
1. Monthly Average waste flow �, ' U mqd
prior to any SOC I
Time period averaged thru
2 . Previously approved SOC's:
Dates flow: mgd
Date: flow: ____mgd
total of previously approved SOC flow:________mgd
3. Flows lost from plant flowz______mgd
( facilities that have gone
off line)
4 , Current SOC request flow:, p_O 7__mgd
S. Total plant flow post-SOC
(sum of original flow and ,rr � �77 uu
SOC flow minus losses) flow: SL_j_LlJ_mgd
6. I.s this an accurate flow balance for/ plant? why/why not?

C. please attach DMR summary for past year for all permitted parame-
ters. If possible, include reports from previous years if
facility has been under SOC for more than a year.
CURRENT - SOC REQUEST : -
R. Request is for domestic or industrial waste? If it is a combin-
ation, please specify percentages.
( c- 6 c,
Z7, G' bv
D. What type of industry? Please attach any pertinent data.
C. The region proposes the following SOC limits:
SODS O. mg/1
(RPRr .T SM'tt'-PJAR
NB3
DO .5_ C mg/1
TSS_ 30- o mg/1
fecal coliform_ /_ C)C?.
C) 4/100m1
PH--- Q SO
other pa rameters_��Old!
D. what is the basis for these limits?
b1-10• 53 e�l.00
C-_) . 13

SUMMER
DOBSON PRE-SOC (LBDATA41)
QW = 0 . 1474 & NBOD = 18 MG/L
---------- MODEL RESULTS ----------
Discharger : DOBSON WWTP
Receiving Stream : CODY CREEK
----------------------------------------------------------------------
The End D .O. is 8 . 11 mg/l .
The End CBOD is 3 . 57 mg/l .
The End NBOD is 1 . 21 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 . 00 0 . 00 1
Reach 1 45 . 00 18 . 00 5 . 00 0 . 14740
Reach 2 0 . 00 0 . 00 0 . 00 0 . 00000
Reach 3 0 . 00 0 . 00 0 . 00 0 . 00000
Reach 4 0 . 00 0 . 00 0 . 00 0 . 00000

SUMMER
DOBSON PRE-SOC (LBDATA41)
QW = 0 . 1474 & NBOD = 18 MG/L
I Seg # I Reach # Seg Mi I D .O . I CBOD I NBOD I Flow I
1 1 0 . 00 6 . 00 27 . 29 11 . 00 0 . 39
1 1 0 . 01 6 . 21 27 . 11 10 . 93 0 . 39
1 1 0 . 02 6 . 40 26 . 93 10 . 86 0 . 39
1 1 0 . 03 6 . 56 26 . 76 10 . 80 0 . 39
1 1 0 . 04 6 . 70 26 . 59 10 . 73 0 . 40
1 1 0 . 05 6 . 82 26 . 42 10 . 67 0 . 40
1 1 0 . 06 6 . 93 26 . 25 10 . 61 0 . 40
1 1 0 . 07 7 . 03 26 . 08 10 . 54 0 . 40
1 1 0 . 08 7 . 11 25 . 91 10 . 48 0 . 40
1 1 0 . 09 7 . 18 25 . 75 10 . 42 0 . 41
1 1 0 . 10 7 . 25 25 . 58 10 . 36 0 . 41
1 2 0 . 10 7 . 25 25 . 58 10 . 36 0 . 41
1 2 0 . 16 7 . 28 24 . 62 9 . 95 0 . 42
1 2 0 .22 7 . 32 23 .72 9 . 58 0 . 43
1 2 0 .29 7 . 35 22 . 86 9 . 22 0 . 44
1 2 0 . 35 7 . 38 22 . 06 8 . 88 0 . 45
1 2 0 . 41 7 . 41 21 .29 8 .56 0 . 47
1 2 0 . 47 7 . 44 20 .57 8 .26 0 . 48
1 2 0 .53 7 . 47 19 . 88 7 . 97 0 . 49
1 2 0 . 60 7 . 49 19 .23 7 . 70 0 .50
1 2 0 . 66 7 .52 18 . 61 7 . 45 0 .51
1 2 0 . 72 7 . 54 18 . 02 7 . 20 0 . 53
1 3 0 . 72 7 . 47 6 . 85 2 . 88 1 .74
1 3 0 . 82 7 . 64 6 . 72 2 . 80 1 .75
1 3 0 . 92 7 . 75 6 .59 2 .73 1 .77
1 3 1 . 02 7 . 83 6 . 47 2 . 67 1 . 79
1 3 1 . 12 7 . 88 6 . 35 2 . 60 1 . 81
1 3 1 . 22 7 . 91 6 . 23 2 .54 1 . 83
1 3 1 . 32 7 . 93 6 . 11 2 . 48 1 . 85
1 3 1 . 42 7 . 95 6 . 00 2 . 42 1 . 87
1 3 1 . 52 7 . 96 5 . 89 2 . 36 1 . 89
1 3 1 . 62 7 . 97 5 . 79 2 . 30 1 . 91
1 3 1 . 72 7 . 98 5 . 68 2 .25 1 . 93
1 4 1 . 72 7 . 98 5 . 68 2 .25 1 . 93
1 4 2 . 02 8 . 02 5 . 40 2 . 10 1 . 98
1 4 2 . 32 8 . 03 5 . 14 1 . 97 2 . 03
1 4 2 . 62 8 . 05 4 . 90 1 . 84 2 . 09
1 4 2 . 92 8 . 06 4 . 67 1 . 73 2 . 14
1 4 3 . 22 8 . 07 4 . 46 1 . 63 2 . 20
1 4 3 . 52 8 . 08 4 . 26 1 .53 2 . 25
1 4 3 . 82 8 . 09 4 . 07 1 . 44 2 .30
1 4 4 . 12 8 . 10 3 . 89 1 . 36 2 .36
1 4 4 . 42 8 . 10 3 . 73 1 . 28 2 .41
1 4 4 . 72 8 . 11 3 . 57 1 . 21 2 . 47
Seg # I Reach # Seg Mi I D .O. I CBOD I NBOD Flow I

*** MODEL SUMMARY DATA ***
Discharger : DOBSON WWTP Subbasin 0307
Receiving Stream : CODY CREEK Stream Class : C
Summer 7Q10 : 0 . 16 Winter 7Q10 : 0 .26
Design Temperature : 25 . 0
ILENGTHI SLOPEI VELOCITY I DEPTHI Kd I Kd I Ka I Ka I KN I KN I KNR I KNR I SOD I SOD 1
1 mile I It/mil fps I ft Idesignl @20 Idesignl @20 Idesignl @20 Idesignl @20 Idesignl @20 I
-------------------------------------------------------------------------------------------------------------------
1 I I I 1 I 1 I I 1 I I I 1 1
Segment 1 1 0.101167.001 0.265 1 0.32 1 0.89 10.70 155.75 150.001 0.73 1 0.50 10.73 1 0.00 10.00 1 0.00 1
Reach 1 1 I I 1 1 I I I I 1 I I I
-------------------------------------------------------------------------------------------------------------------
I I I I I I I I I I I I I I I
Segment 1 I 0.621 62.00I 0.201 1 0.39 1 0.64 10.51 124.96 122.391 0.13 1 0.50 1 0.73 1 0.00 10.00 10.00 1
Reach 2 I I I I 1 I I I I I 1 1 I
-------------------------------------------------------------------------------------------------------------------
I I I I I I I I I I I I I I I
Segment 1 I 1.00I 35.001 0.244 1 0.71 10.46 10.37 117.14 115.371 0.73 10.50 10.73 1 0.00 10.00 1 0.00 1
Reach 3 I I I 1 I I I I I I I 1 1
-------------------------------------------------------------------------------------------------------------------
I I I I I I I I I I I I I I I
Segment 1 I 3.00I 35.00I 0.260 10.75 10.46 1 0.37 118.29 116.411 0.73 1 0.50 10.73 1 0.00 1 0.00 1 0.00 1
Reach 4 I I I I I 1 I I I I I I I
-----------------------------------------------------------------------------------------------------
I Flow I CBOD I NBOD I D .O. I
I cfs I mg/l I mg/l I mg/1 I
Segment 1 Reach 1
Waste 1 0 . 228 145 . 000 1 18 . 000 I 5 . 000
Headwatersl 0 . 160 1 2 . 000 1 1 . 000 I 7 . 440
Tributary 1 0 . 000 I 2 . 000 1 1 . 000 I 7 . 440
* Runoff 1 0 . 190 I 2 . 000 1 1 . 000 I 7 . 440
Segment 1 Reach 2
Waste 1 0 . 000 I 0 . 000 1 0 . 000 I 0 . 000
Tributary 1 0 . 000 1 2 . 000 1 1 . 000 I 7 . 440
* Runoff I 0 . 190 1 2 . 000 1 1 . 000 I 7 . 440
Segment 1 Reach 3
Waste 1 0 . 000 I 0 . 000 1 0 . 000 I 0 . 000
Tributary I 1 . 210 I 2 . 000 1 1 . 000 1 7 . 440
* Runoff 1 0 . 190 1 2 . 000 1 1 . 000 1 7 . 440
Segment 1 Reach 4
Waste I 0 . 000 1 0 . 000 I 0 . 000 I 0 . 000
Tributary I 0 . 000 1 2 . 000 1 1 . 000 1 0 . 000
* Runoff 1 0 . 180 1 2 . 000 1 1 . 000 1 7 . 440

SUMMER
DOBSON POST-SOC (LBDATA41)
QW = 0 . 25 & NBOD = 18 MG/L
---------- MODEL RESULTS ----------
Discharger : DOBSON WWTP
Receiving Stream : CODY CREEK
----------------------------------------------------------------------
The End D.O. is 8 . 06 mg/l .
The End CBOD is 5 . 00 mg/l .
The End NBOD is 1 . 70 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 . 71 0 . 00 1
Reach 1 45 . 00 18 . 00 5 . 00 0 .25000
Reach 2 0 . 00 0 . 00 0 . 00 0 . 00000
Reach 3 0 . 00 0 . 00 0 . 00 0 . 00000
Reach 4 0 . 00 0 . 00 0 . 00 0 . 00000

SUMMER
DOBSON POST-SOC (LBDATA41)
QW = 0 .25 & NBOD = 18 MG/L
Seg # Reach # I Seg Mi I D .O . I CBOD I NBOD I Flow I
1 1 0 . 00 5 . 71 32 . 43 13 . 03 0 . 55
1 1 0 . 01 5 . 89 32 .27 12 . 97 0 . 55
1 1 0 . 02 6 . 04 32 . 11 12 . 92 0 . 55
1 1 0 . 03 6 . 19 31 . 94 12 . 86 0 .55
1 1 0 . 04 6 . 32 31 .78 12 . 80 0 .56
1 1 0 . 05 6 . 43 31 . 62 12 . 74 0 .56
1 1 0 . 06 6 .54 31 . 46 12 . 69 0 .56
1 1 0 . 07 6 . 63 31 . 30 12 . 63 0 . 56
1 1 0 . 08 6 . 72 31 . 15 12 . 57 0 .56
1 1 0 . 09 6 . 80 30 . 99 12 . 52 0 . 56
1 1 0 . 10 6 . 87 30 . 84 12 . 46 0 . 57
1 2 0 . 10 6 . 87 30 . 84 12 . 46 0 . 57
1 2 0 . 16 7 . 03 29 . 93 12 . 09 0 . 58
1 2 0 . 22 7 . 14 29 . 05 11 . 74 0 .59
1 2 0 . 29 7 . 22 28 . 22 11 . 40 0 . 60
1 2 0 . 35 7 . 28 27 . 41 11 . 08 0 . 61
1 2 0 . 41 7 . 32 26 . 65 10 . 77 0 . 63
1 2 0 . 47 7 . 36 25 . 91 10 . 47 0 . 64
1 2 0 . 53 7 . 39 25 .20 10 . 19 0 . 65
1 2 0 . 60 7 . 42 24 . 52 9 . 91 0 . 66
1 2 0 . 66 7 . 44 23 . 87 9 . 65 0 . 67
1 2 0 . 72 7 . 46 23 .24 9 . 39 0 . 68
1 3 0 . 72 7 . 45 9 . 67 4 . 03 1 . 89
1 3 0 . 82 7 .59 9 . 49 3 . 93 1 . 91
1 3 0 . 92 7 . 68 9 . 31 3 . 84 1 . 93
1 3 1 . 02 7 . 75 9 . 14 3 . 74 1 . 95
1 3 1 . 12 7 . 79 8 . 97 3 . 65 1 . 97
1 3 1 . 22 7 . 82 8 . 80 3 .57 1 . 99
1 3 1 . 32 7 . 84 8. 64 3 . 48 2 . 01
1 3 1 . 42 7 . 86 8 . 48 3 . 40 2 . 03
1 3 1 . 52 7 . 88 8 . 33 3 . 32 2 . 05
1 3 1 . 62 7 . 89 8 . 18 3 .24 2 . 07
1 3 1 . 72 7 . 90 8 . 04 3 . 17 2 . 08
1 4 1 . 72 7 . 90 8 . 04 3 : 17 2 . 08
1 4 2 . 02 7 . 94 7 . 64 2 . 96 2 . 14
1 4 2 . 32 7 . 96 7 . 27 2 . 77 2 . 19
1 4 2 . 62 7 . 98 6 . 92 2 . 60 2 .25
1 4 2 . 92 7 . 99 6 . 59 2 . 44 2 . 30
1 4 3 .22 8 . 00 6 . 28 2 .29 2 . 35
1 4 3 . 52 8 . 02 5 . 99 2 . 15 2 . 41
1 4 3 . 82 8 . 03 5 . 72 2 . 03 2 . 46
1 4 4 . 12 8 . 04 5 . 47 1 . 91 2 . 52
1 4 4 . 42 8 . 05 5 . 23 1 . 80 2 .57
1 4 4 . 72 8 . 06 5 . 00 1 . 70 2 . 62
Seg # I Reach # I Seg Mi I D .O. I CBOD NBOD I Flow I

*** MODEL SUMMARY DATA ***
Discharger : DOBSON WWTP Subbasin 0307
Receiving Stream : CODY CREEK Stream Class : C
Summer 7Q10 : 0 . 16 Winter 7Q10 : 0 . 26
Design Temperature : 25 . 0
ILENGTHI SLOPEI VELOCITY I DEPTHI Kd I Kd I Ka I Ka I KN I KN I KNR I KNR I SOD I SOD I
I mile I ft/mil fps I It Idesignl @20 Idesignl @20 Idesignl @20 Idesignl @20 Idesignl @20 1
-------------------------------------------------------------------------------------------------------------------
I I I 1 1 1 1 I 1 I 1 1 I I 1
Segment 1 1 0.101167.001 0.341 1 0.33 1 1.03 1 0.82 155.75 150.001 0.73 10.50 1 0.73 1 0.00 10:00 10.00 1
Reach 1 I I I I I I I I I I I I I
------------------------------------------------------- -----------------------------------------------------------
I I I 1 I I 1 1 I I 1 1 I I 1
Segment 1 1 0.621 62.001 0.250 1 0.41 1 0.71 1 0.57 131.11 1 27.901 0.73 10.50 10.73 1 0.00 1 0.00 10.00 1
Reach 2 1 I 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 I
Segment 1 1 1.00I 35.001 0.260 10.71 1 0.47 1 0.38 118.24 1 16.361 0.73 10.50 1 0.73 1 0.00 10.00 1 0.00 1
Reach 3 1 I I I 1 I 1 1 I I 1 1 I
-------------------------------------------------------------------------------------------------------------------
I I I I I I I I I I 1 1 I I I
Segment 1 ( 3.001 35.001 0.274 1 0.76 10.47 1 0.38 119.28 117.291 0.73 10.50 1 0.73 1 0.00 10.00 10.00 I
Reach 4 1 I I 1 I 1 1 I I I 1 1 I
-----------------------------------------------------------------------------------------------------
I Flow I CBOD I NBOD I D .O. I
I cfs I mg/l I mg/1 I mg/l . I
Segment 1 Reach 1
Waste I 0 . 388 145 . 000 118 . 000 I 5 . 000
Headwatersl 0 . 160 I 2 . 000 1 1 . 000 1 7 . 440
Tributary I 0 . 000 I 2 . 000 1 1 . 000 I 7 . 440
* Runoff I 0 . 190 I 2 . 000 1 1 . 000 I 7 . 440
Segment 1 Reach 2
Waste I 0 . 000 I 0 . 000 1 0 . 000 I 0 . 000
Tributary 0 . 000 2 . 000 I 1 . 000 I 7 . 440
* Runoff 0 . 190 2 . 000 I 1 . 000 I 7 . 440
Segment 1 Reach 3
Waste I 0 . 000 0 . 000 I 0 . 000 1 0 . 000
Tributary 1 1 . 210 2 . 000 I 1 . 000 1 7 . 440
* Runoff 1 0 . 190 2 . 000 I 1 . 000 1 7 . 440
Segment 1 Reach 4
Waste I 0 . 000 I 0 . 000 I 0 . 000 I 0 . 000
Tributary 1 0 . 000 I 2 . 000 1 1 . 000 1 0 . 000
* Runoff 1 0 . 180 1 2 . 000 1 1 . 000 I 7 . 440

f
WINTER
DOBSON PRE-SOC (LBDATA41)
QW = 0 . 1474 & NBOD = 27 MG/L
---------- MODEL RESULTS ----------
Discharger : DOBSON WWTP
Receiving Stream : CODY CREEK
----------------------------------------------------------------------
The End D .O . is 10 .20 mg/l .
The End CBOD is 3 . 61 mg/l .
The End NBOD is 2 . 04 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 7 .28 0 . 00 1
Reach 1 45 . 00 27 . 00 5 . 00 0 . 14740
Reach 2 0 . 00 0 . 00 0 . 00 0 . 00000
Reach 3 0 . 00 0 . 00 0 . 00 0 . 00000
Reach 4 0 . 00 0 . 00 0 . 00 0 . 00000

WINTER
DOBSON PRE-SOC (LBDATA41)
QW = 0 . 1474 & NBOD = 27 MG/L
Seg # I Reach # I Seg Mi I D .O . I CBOD I NBOD I Flow I
1 1 0 . 00 7 .28 22 . 11 13 . 16 0 . 49
1 1 0 . 01 7 .50 21 . 98 13 . 09 0 . 49
1 1 0 . 02 7 . 71 21 . 84 13 . 01 0 .49
1 1 0 . 03 7 . 90 21 .71 12 . 94 0 .50
1 1 0 . 04 8 . 07 21 .58 12 . 87 0 .50
1 1 0 . 05 8 . 23 21 . 45 12 . 79 0 .50
1 1 0 . 06 8 . 37 21 . 32 12 . 72 0 .50
1 1 0 . 07 8 .50 21 . 19 12 . 65 0 . 51
1 1 0 . 08 8 . 62 21 . 07 12 . 58 0 . 51
1 1 0 . 09 8 . 73 20 . 94 12 . 52 0 .51
1 1 0 . 10 8 . 83 20 . 82 12 . 45 0 .52
1 2 0 . 10 8 . 83 20 . 82 12 . 45 0 .52.
1 2 0 . 16 9 . 14 20 . 09 12 . 03 0 .53
1 2 0 .22 9 . 35 19 . 41 11 . 63 0 .55
1 2 0 . 29 9 .50 18 . 77 11 . 26 0 .57
1 2 0 . 35 9 . 60 18 . 17 10 . 92 0 .58
1 2 0 . 41 9 . 67 17 . 60 10 . 59 0 . 60
1 2 0 . 47 9 . 72 17 . 06 10 . 27 0 . 62
1 2 0 . 53 9 . 76 16 .55 9 . 98 0 . 63
1 2 0 . 60 9 . 80 16 . 07 9 . 70 0 . 65
1 2 0 . 66 9 . 82 15 . 62 9 . 44 0 . 67
1 2 0 . 72 9 . 84 15 . 18 9 . 18 0 . 68
1 3 0 . 72 9 . 43 5 .51 3 . 18 2 . 56
1 3 0 . 82 9 . 64 5 . 44 3 . 14 2 .59
1 3 0 . 92 9 . 79 5 . 38 3 . 10 2 . 62
1 3 1 . 02 9 . 89 5 . 31 3 . 06 2 . 64
1 3 1 . 12 9 . 96 5 .25 3 . 02 2 . 67
1 3 1 . 22 10 . 02 5 . 18 2 . 98 2 . 70
1 3 1 . 32 10 . 06 5 . 12 2 . 95 2 . 72
1 3 1 . 42 10 . 08 5 . 06 2 . 91 2 . 75
1 3 1 . 52 10 . 10 5 . 00 2 . 87 2 . 78
1 3 1 . 62 10 . 12 4 . 94 2 . 84 2 . 81
1 3 1 . 72 10 . 13 4 . 89 2 . 80 2 . 83
1 4 1 . 72 10 . 13 4 . 89 2 . 80. 2 . 83
1 4 2 . 02 10 . 16 4 . 72 2 . 71 2 . 92
1 4 2 . 32 10 . 17 4 . 57 2 . 62 3 . 00
1 4 2 . 62 10 . 18 4 . 43 2 . 53 3 . 08
1 4 2 . 92 10 . 18 4 .29 2 . 45 3 . 17
1 4 3 . 22 10 . 19 4 . 16 2 . 37 3 .25
1 4 3 . 52 10 . 19 4 . 04 2 . 30 3 . 34
1 4 3 . 82 10 . 19 3 . 93 2 .23 3 . 42
1 4 4 . 12 10 . 20 3 . 82 2 . 16 3 .50
1 4 4 . 42 10 . 20 3 . 71 2 . 10 3 .59
1 4 4 . 72 10 . 20 3 . 61 2 . 04 3 . 67
I Seg # I Reach # I Seg Mi D .O. I CBOD I NBOD I Flow I

*** MODEL SUMMARY DATA ***
Discharger : DOBSON WWTP Subbasin 0307
Receiving Stream : CODY CREEK Stream Class : C
Summer 7Q10 : 0 . 16 Winter 7Q10 0 . 26
Design Temperature : 14 . 0
ILENGTHI SLOPEI VELOCITY I DEPTHI Kd I Kd I Ka I Ka I KN I KN I KNR I KNR I SOD I SOD 1
1 mile I ft/mil fps I ft Idesignl @20 Idesignl @20 Idesign) @20 Idesignl @20 Idesignl @20 1
-------------------------------------------------------------------------------------------------------------------
I I 1 I I I I I I I I I I
Segment 1 I 0.101167.001 0.316 1 0.33 1 0.59 1 0.78 143.88 1 50.001 0.32 1 0.50 1 0.32 1 0.00 1 0.00 1 0.00 1
Reach 1 1 I I I I I I I I I I I I
-------------------------------------------------------------------------------------------------------------------
I I 1 1 1 1 1 1 1 1 1 1 1 1 1
Segment 1 I 0.621 62.001 0.242 1 0.41 1 0.42 1 0.56 123.71 1 27.021 0.32 1 0.50 1 0.32 10.00 1 0.00 1 0.00 1
Reach 2 1 1 1 1 1 1 1 1 1 1 1 I 1
-------------------------------------------------------------------------------------------------------------------
I I I I I I I I I I I I I
Segment 1 I 1.001 35.001 0.326 1 0.74 1 0.31 1 0.41 118.04 1 20.561 0.32 1 0.50 1 0.32 1 0.00 1 0.00 1 0.00 1
Reach 3 1 1 1 1 1 1 1 1 1 1 1 1 1
-------------------------------------------------------------------------------------------------------------------
I I I I I I I I 1 1 1 1 1 1 1
Segment 1 1 3.001 35.001 0.350 1 0.79 1 0.32 1 0.42 119.34 1 22.031 0.32 10.50 1 0.32 1 0.00 1 0.00 1 0.00 1
Reach 4 1 1 1 1 1 1 1 1 1 1 1 1 1
-----------------------------------------------------------------------------------------------------
I Flow I CBOD I NBOD I D .O. I
I cfs I mg/l I mg/l I mg/1 I
Segment 1 Reach 1
Waste 1 0 .228 1 45 . 000 1 27 . 000 1 5 . 000
Headwatersl 0 .260 1 2 . 000 1 1 . 000 1 9 . 280
Tributary 1 0 . 000 1 2 . 000 1 1 . 000 1 9 . 280
* Runoff 1 0 .270 I 2 . 000 1 1 . 000 1 9 . 280
Segment 1 Reach 2
Waste 1 0 . 000 I 0 . 000 1 0 . 000 1 0 . 000
Tributary 1 0 . 000 I 2 . 000 I 1 . 000 I 9 . 280
* Runoff 1 0 .270 I 2 . 000 I 1 . 000 I 9 . 280
Segment 1 Reach 3
Waste 1 0 . 000 1 0 . 000 1 0 . 000 1 0 . 000
Tributary 1 1 . 880 1 2 . 000 1 1 . 000 1 9 . 280
* Runoff 1 0 . 270 1 2 . 000 I 1 . 000 1 9 . 280
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 9 .280
* Runoff 1 0 .280 1 2 . 000 I 1 . 000 I 9 .280

WINTER
DOBSON POST-SOC (LBDATA41)
QW = 0 .25 & NBOD = 27 MG/L
---------- MODEL RESULTS ----------
Discharger : DOBSON WWTP
Receiving Stream : CODY CREEK
----------------------------------------------------------------------
The End D .O. is 10 . 17 mg/l .
The End CBOD is 4 . 89 mg/l .
The End NBOD is 2 . 85 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 . 72 0 . 00 1
Reach 1 45 . 00 27 . 00 5 . 00 0 .25000
Reach 2 0 . 00 0 . 00 0 . 00 0 . 00000
Reach 3 0 . 00 0 . 00 0 . 00 0 . 00000
Reach 4 0 . 00 0 . 00 0 . 00 0 . 00000

WINTER
DOBSON POST-SOC (LBDATA41)
QW = 0 .25 & NBOD = 27 MG/L
I Seg # I Reach # I Seg Mi D .O. I CBOD I NBOD I Flow I
1 1 0 . 00 6 . 72 27 . 73 16 . 56 0 . 65
1 1 0 . 01 6 . 93 27 . 60 16 . 49 0 . 65
1 1 0 . 02 .7 . 13 27 . 46 16 . 41 0 . 65
1 1 0 . 03 7 . 31 27 . 33 16 . 34 0 . 66
1 1 0 . 04 7 . 49 27 .20 16 .27 0 . 66
1 1 0 . 05 7 . 65 27 . 06 16 . 20 0 . 66
1 1 0 . 06 7 . 79 26 . 93 16 . 13 0 . 66
1 1 0 . 07 7 . 93 26 . 80 16 . 06 0 . 67
1 1 0 . 08 8 . 06 26 . 67 15 . 99 0 . 67
1 1 0 .109 8 . 18 26 . 55 15 . 93 0 . 67
1 1 0 . 10 8 . 29 26 . 42 15 . 86 0 . 67
1 2 0 . 10 8 . 29 26 . 42 15 . 86 0 . 67
1 2 0 . 16 8 . 75 25 . 67 15 . 43 0 . 69
1 2 0 . 22 9 . 06 24 . 96 15 . 03 0 . 71
1 2 0 .29 9 . 28 24 . 28 14 . 65 0 . 72
1 2 0 . 35 9 . 43 23 . 63 14 . 28 0 . 74
1 2 0 . 41 9 . 53 . 23 . 01 13 . 93 0 . 76
1 2 0 . 47 9 . 61 22 . 42 13 . 59 0 . 77
1 2 0 . 53 9 . 66 21 . 86 13 . 27 0 . 79
1 2 0 . 60 9 .70 21 . 31 12 . 96 0 . 81
1 2 0 . 66 9 . 74 20 . 79 12 . 67 0 . 83
1 2 0 . 72 9 . 76 20 . 30 12 . 39 0 . 84
1 3 0 . 72 9 . 43 7 . 66 4 . 52 2 . 72
1 3 0 . 82 9 . 62 7 . 56 4 . 46 2 . 75
1 3 0 . 92 9 . 76 7 . 46 4 . 40 2 . 78
1 3 1 . 02 9 . 86 7 . 37 4 . 35 2 . 80
1 3 1 . 12 9 . 93 7 . 28 4 .29 2 . 83
1 3 1 . 22 9 . 98 7 . 18 4 .23 2 . 86
1 3 1 . 32 10 . 01 7 . 09 4 . 18 2 . 88
1 3 1 . 42 10 . 04 7 . 01 4 . 13 2 . 91
1 3 1 . 52 10 . 06 6 . 92 4 . 08 2 . 94
1 3 1 . 62 10 . 07 6 . 84 4 . 02 2 . 96
1 3 1 . 72 10 . 08 6 .75 3 . 97 2 . 99
1 4 1 . 72 10 . 08 6 . 75 3 . 97 2 . 99
1 4 2 . 02 10 . 11 6 . 52 3 . 83 3 . 08
1 4 2 . 32 10 . 13 6 . 30 3 . 70 3 . 16
1 4 2 . 62 10 . 14 6 . 09 3 . 57 3 . 24
1 4 2 . 92 10 . 14 5 . 89 3 . 45 3 . 33
1 4 3 . 22 10 . 15 5 . 70 3 . 34 3 . 41
1 4 3 . 52 10 . 16 5 .52 3 . 23 3 .50
1 4 3 . 82 10 . 16 5 . 35 3 . 13 3 .58
1 4 4 . 12 10 . 16 5 . 19 3 . 03 3 . 66
1 4 4 . 42 10 . 17 5 . 03 2 . 94 3 . 75
1 4 4 . 72 10 . 17 4 . 89 2 . 85 3 . 83
1 Seg # I Reach # I Seg Mi I D .O. I CBOD I NBOD I Flow I

*** MODEL SUMMARY DATA ***
Discharger : DOBSON WWTP Subbasin 0307
Receiving Stream : CODY CREEK Stream Class : C
Summer 7Q10 : 0 . 16 Winter 7Q10 0 . 26
Design Temperature : 14 . 0
ILENGTHI SLOPEI VELOCITY I DEPTHI Kd I Kd I Ka I Ka I KN I KN I KNR I KNR I SOD I SOD 1
1 mile I ft/mil fps I It Idesignl @20 Idesignl @20 Idesignl @20 Idesignl @20 Idesignl @20 1
-------------------------------------------------------------------------------------------------------------------
I I I I I I I I I I I I I I I
Segment 1 1 0.101167.001 0.388 10.34 10.68 1 0.89 143.88 150.001 0.32 10.50 10.32 1 0.00 1 0.00 1 0.00 1
Reach 1 I I I I I I I I I I I I I
-------------------------------------------------------------------------------------------------------------------
I I I I I I I I I I I I I I I
Segment 1 1 0.621 62.001 0.289 10.42 1 0.47 1 0.61 128.29 1 32.241 0.32 1 0.50 1 0.32 1 0.00 1 0.00 1 0.00 1
Reach 2 1 I 1 I 1 1 1 1 I 1 I I 1
------------------------------------------------------------------------ ------------------------------------------
I I I I I I I I I I I I I I
Segment 1 I 1.001 35.001 0.341 1 0.75 1 0.32 10.42 118.84 1 21.461 0.32 10.50 1 0.32 10.00 1 0.00 1 0.00 1
Reach 3 1 1 1 1 1 1 I 1 1 1 1 1 1
-------------------------------------------------------------------------------------------------------------------
I I I 1 1. 1 I 1 I 1 1 1 1 1 1
Segment 1 I 3.001 35.00I 0.362 10.79 1 0.32 1 0.42 120.04 122.841 0.32 1 0.50 1 0.32 1 0.00 1 0.00 1 0.00 1
Reach 4 1 I 1 1 1 1 1 I I 1 1 1 1
-----------------------------------------------------------------------------------------------------
I Flow I CBOD I NBOD I D .O. I
I cfs I mg/l I mg/l l mg/l I
Segment 1 Reach 1
Waste I 0 . 388 1 45 . 000 1 27 . 000 1 5 . 000
Headwatersl 0 . 260 1 2 . 000 1 1 . 000 1 9 . 280
Tributary 1 0 . 000 1 2 . 000 1 1 . 000 1 9 .280
* Runoff 1 0 . 270 1 2 . 000 1 1 . 000 1 9 .280
Segment 1 Reach 2
Waste 1 0 . 000 I 0 . 000 1 0 . 000 I 0 . 000
Tributary 1 0 . 000 2 . 000 1 1 . 000 I 9 .280
* Runoff 1 0 . 270 2 . 000 1 1 . 000 I 9 .280
Segment 1 Reach 3
Waste 1 0 . 000 0 . 000 1 0 . 000 I 0 . 000
Tributary 1 1 . 880 1 2 . 000 1 1 . 000 1 9 .280
* Runoff 1 0 . 270 1 2 . 000 I 1 . 000 I 9 .280
Segment 1 Reach 4
Waste 1 0 . 000 I 0 . 000 I 0 . 000 I 0 . 000
Tributary 1 0 . 000 I 2 . 000 I 1 . 000 I 9 .280
* Runoff 1 0 . 280 I 2 . 000 I 1 . 000 I 9 .280