NC0020214_WASTELOAD ALLOCATION_19851119

NPDES DOCUMENT SCAMMINC COVER SHEET
NPDES Permit: NC0020214
TWSA Plant #2 / Sylva WWTP
Document Type: Permit Issuance
Wasteload Allocation
J
Authorization to Construct (AtC)
Permit Moauication
Staff Report
201 Facilities Plan
Instream Assessment (67B)
Environmental Assessment (EA)
Permit
History
Document Date: November 19, 1985
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DIVISION OF ENVIRONMENTAL MANAGEMENT
November 19, 1985
M E M 0 R1A N D U M
TO: Forrest Westall
FROM: Randy Dodd 4D .
THRU: Meg Kerr (, -
SUBJECT: Town of Sylva
ByPass to Scotts Creek
A Level B model has been run per your office 's request to assess
the impact of the discharge of untreated wastewater to Scotts Creek
(C-Tr) . I understand that a bypass for roughly three days may be
necessary in the near future for maintenance purposes .
Plant influent data from the past year and winter 7Q10 conditions
were used as design data. A temperature of 180C was chosen as the
design temperature. Major model inputs are listed in Table 1 .
Assuming background D.O. = 90% saturation (9.2 mg/1 ) , the predicted
D.O. minimum is 9.05 mg/l . Therefore, the discharge should not signif-
icantly impact the stream's oxygen resources .
Assuming fecal coliform levels typical of domestic wastewater (2 x
105P OO ml ) , the predicted instream fecal level is 3000/100 ml . There-
fore, the discharge could cause a violation in the fecal standard.
Please advise if you have any questions.
RCD:mIt
Attachment

Table 1
Model Inputs
Qw (mgd) 0.31
BODS (mg/1) 180.0
NH3-N (mg/1 ) 14.4
CBOD (mg/1 ) 360.0
NBOD (mg/1 ) 65.0
IBOD (mg/1 ) 425.0
Streamflow (cfs) 29.7 **
Design Temperature (°C) 18.0
fecal coliform (#/100 ml ) r 2 x 105
* 90th percentile from past years' monitoring data
** Winter MO

Soo
I
j 3
27 O q
. 27 r �

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3-

DISCHARGER SYLVA + -
RECEIVING STREAM : SCOTT S CREEK
WASTEFLOW ,31
1 SE=G NO I REACH I SEG MI I Ito I CBOD I NBOD 1 FLOW I
! 1 I 1 1 0 . 001 9 . 051 8 , 731 0 . 001 30 , 181
I 1 I 1 1 0 . 101 9 . 08 ! 8 . 701 0 . 001 30 . 181
I 1 i 1 1 0 .201 9 . 111 8 . 671 0 . 001 30 . 181
I 1 I 1 1 0 .301 9 . .4 1 8 , ,J I 0 . 001 30 . 19 1
! 1 ! 1 I 0 . 401 9 . 16E 8 .601 0 .001 30 . 181
! 1 1 1 1 0 , 501 9 . 191 8 . 561 0 . 001 30 . 18E
i 1 I 1 I 0 .601 9 . 211 8 . 531 0 . 001 30 . 181
! 1 1 1 I 0 .701 9 . 231 8 . 501 0 . 001 30 , 181
1 1 1 1 1 04801 9 . 251 8 . 461 0 . 001 30 . 181
1 1 1 1 1 0 .901 9 . 271 8 . 431 0 . 001 30 . 181
I 1 I 1 11001 9. 291 8 . 391 0 . 001 30 . 181

##fit MOREL SUMMARY DATA ***
DISCHARGER ; SYL..VA SUBBASIN ; 040402
RECEIVING STREAM ; SCOTTS CREEK STREAM CLASS : C-TR
7010 ; 29 . 7 CFS WINTER 7010 : CFS
DESIGN TEMPERATURE ; 18 DEGREES C . WASTEFL.OW ; . 31 MGD
1LENGTHISLOPE I VELOCITY IDEPTH I KI I K1 I K2 I K2 E Kn I
I MILES I FT/Ml: I FPS I FT I /DAY 1 020 I /DAY 1 020 I /DAY I
I I 1 I I I I I E 1
SEGMENT 1 1 1 . 001 11 . 001 0 . 604 1 1 .E32 1 0 . 39 1 0 . 43 1 5 . 601 5 . 851 0 . 001
REACH 1. 1 1 1 1 1 1 E 1 1 1
FOR BYPASS ANALYSIS
w INPUT DATA SUMMARY
l FLOW I C1;':�OD I NBOD I D .O . I
I CFS I MG/L I MG/L I MG/L I
I I 1 I I
SEGMENT 1 REACH I I I I 1 !
WASTE 1 0 . 451 1425 . 000 E 0 , 000 l 0 . 000 1
HEADWATERSI 29 , 700 1 2 . 000 1 0 . 000 1 9 . 200 1
TRIBUTARY 1 0 , 000 1 0 . 000 1 0 . 000 1 0 , 000 1
RUNOFF # I 0 .000 1 0 . 000 E 0 . 000 1 0 . 000 1
A RUNOFF FLOW IS IN CFS/MILE

DISCHARGER SYLVA
RECEIVING STREAM 1 SCOTTS CREEK
WASTEFLOW I . 31
I SEG NO I REACH I SEG M l: 1 DO 4 CBOD I ORGY! I NH3N I NO2 I FLOW I CS I
1 1 1 1 1 0 . 001 0 . 01 0 . 01 0 . 01 0 . 01 0 . 01 30 . 21 3283 . 1
1 1 1 1 1 1 . 001 4 . 11 0 . 01 0 . 01 0 . 01 0 . 01 30. 21 2965. 1
li

'r ;< MODEL SUMMARY DATA
DISCHARGER t SYLYA SUBBASIN 04040'
RECEIVING STREAM f SCOTTS CREEK STREAM CLASS ! C—TR
7010 29 . 7 CFS WINTER 7010 CFS
DESIGN TEMPERATURE 18 . 0 DEGREES C , WASTEFLOW . 31 MOD
I LENGTH I SLOPE I VELOCITY I DEPTH I K1 1 Kr I Kra I Knr I K2 !
IMILES IFT/MI I FPS 1 FT I /LAY I /LAY I /DAY I /DAY I /DAY I
I I 1 1 1 3 1 I I 1
SEGMENT 1 1 1 . 001 11 . 001 0 . 60 1 1 .83 1 0 . 39 1 0 .00 1 0 . 00 1 0 .00 1 4 . 99 1
REACH 1 I I I I I I I I I I

. K MODEL SUMMARY CONTINUED
I SOD lKonsetI Konhydro I Knh I Kdn I VSS Kset l NET F/R I
IMG/M2DI /DAY I /DAY IMG/M2/DAYIMC/M2/IkAYI /DAY IMG/M2/DAY I
I 1 i l l i I 1
SEGMENT 1 1 0 . 01 0 . 001 0 . 00 1 0 .0 1 0 . 0 1 1100 . 1 0 . 00 1
REACH 1 1 1 I 1 1 1 1 1
ALL RATES ARE AT 18 ,0 DEGREES C .
FOR BYPASS ANALYSIS

�C INPUT DATA 6"UMMA.RY *�k
I FLOW 1 ORGN 1 NH3N I 1403N I CBOD I D .O . I C . S . I
I C F S' 1 MG/L I MG/L I MG/L I MG/L I MI?;1._ I MG:1... I
1 I I I i I I I
SEGMENT 1 REACH 1 1 1 1 I I I I I
W.")STE 1 0 , 481 0 . 001 0 . 001 0 . 001 0 , 001 0 . 001 HEADWATER
I
'TRIBUTARY 1 0 . 001 0 . 001 0. 001 0 . 001 0 . 001 0 . 001 0 . 001
RUNOFF 1 0 , 001 0 . 001 0 . 001 0 . 001 0 ,001 0 +001 0 . 001
p^
RUNOFF c' v iv .a�. �TM CF- S/MTLE