NC0027103_Instream Assessment_19920327

DIVISION OF ENVIRONMENTAL MANAGEMENT
March 27, 1992
MEMORANDUM
TO M. J. Noland
THROUGH: J. Trevor Clements
Ruth Swanek I�
Carla Sanderson
FROM: Susan A. Wilso
SUBJECT: Instream Assessment for the Town of Pembroke WWTP
NPDES No. NC0027103
Robeson County
Summary and Recommendations:
The Technical Support Branch has completed the instream assessment in response
to the SOC request for the Town of Pembroke. The Town requests an increase in domestic
flow of 52,060 GPD. The facility has had inflow and infiltration (I/I) problems which
created an exceedance of their permitted flow of 0.82 MGD.
The Fayetteville Regional Office plans to implement a schedule for compliance to
correct the treatment plant and its I/I problems within the SOC. The I/I problems have not
caused the facility to exceed its monthly average flow limit of 0.82 MGD. However, this
flow limit has been exceeded on certain days after rainfall events.
The results of the Level B analyses indicated that the predicted dissolved oxygen
(DO) concentrations were not significantly effected by the increase in domestic flow of
0.05206 MGD. The EMC 67 (b) criteria (not causing a DO sag of greater than 0.5 mg/1
and not extending the DO sag length greater than 0.5 miles) was maintained with the
additional flow.
Analysis and Discussion:
Pembroke WWTP discharges to the Lumber River. This portion of the Lumber
River is classified as "C-Sw, HQW". The 7Q10 (summer) at the point of discharge is
estimated to be 114 cfs, with a drainage area of 427 square miles and an average flow of
590 cfs.
An instream assessment was performed using the Level B framework. A
comparison was made using the monthly average flow for the past year (0.4826 MGD) and
the monthly average flow for the past year plus the requested increase in domestic flow
(0.5347 MGD). No predicted change in instream DO was noted between the two flows.
The DO was at its lowest at the point of discharge point, so the DO sag criteria specified in
67 (b) was not violated.

Although the 67 (b) criteria was met, the DO for the existing flow and the additional
flow was below 5 mg/1 based on the addition of wasteflow and the background conditions
of 4.3 mg/1 DO (taken from instream monitoring data). The DO recovered rapidly as
indicated in ambient station data, approximately 3.5 miles downstream, which showed no
DO values less than 5 mg/1 for the past five years. Due to the low DO conditions and the
classification of HQW for this portion of the Lumber River, upon Pembroke WWTP's
expansion above 0.82 MGD the facility will receive more stringent limitations.
cc: Kent Wiggins
Central Files

TABLE 1. Instream Assessment Summary for the Town of Pembroke.
Wasteflow Assumptions
Design Capacity
Pre-SOC (1/'91 - 12/'91)
SOC Flow Requested
Pre-SOC + SOC Flow
Model Input Summary
Headwater conditions:
0.8200 MGD
0.4826 MGD
0.05206 MGD
0.5347 MGD
7Q10 114.0 cfs
Qavg 590.0 cfs
Design Temperature 27.0 °C
CBOD 2.0 mg/1
NBOD 1.0 mg/1
DO (54% saturation) 4.3 mg/1
Wastewater Inputs:
1st Wasteflow
2nd Wasteflow
CBOD (1.5*BOD5)
NBOD (4.5*NH3-N)
Model Output Summary
0.4826 MGD
0.5347 MGD
45.0 mg/1
90.0 mg/1
Qw DO Net Distance Net
(MGD) Min. Change <5.0 mg/1 Change
(mgil) (mom) (mi) (mi)
0.4826 4.27 NA 1.85 NA
0.5347 4.27 0.0 1.85 0.0

NC(2)Z7r0'
P _1,010
L uni (L
9. = o, sZ
Wpd
CV/AM' Lt /4 t T 5 45: = 30/30
3(4
SAKI.
o 3o7(
G� uv 3 . asa. figN rern /003
7� li,frus=ltTp N)
A(0c- Z/r (Voe s, Fu --or! L''ro2ATD2(can\ aN ?i9!
UnT, (-j Soc-
C / 9(00 c'Pv o,"- 1jpp/ roN lr/C g-c----wAT6LeANip6
!A,P2oW75 /N 0Pc eM-04 _eF{IC/CNG/E5)
ids ,Nt,i,5 A = 4 • S
- eivs 7r J14pp - fog SPEC. u44( - 5 FoX- _6KRiAli/O/V L lAko_ (s 1):// STa
f1V .1“_ Roo Wiz/ ADPP ,.FioW• __._W —L- cis -_SAM, 14EADfr,OY(2-
�A _t 52 obJ ctFv) = 0. 53+7

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,Eitlogcyz€ 1MW7/
Gu M*IL Q.-
� f 0,02 "o
-_ apa gltow• D'Fr VC '.LtW AJ 4.1_8 44D_ I.
0. 53170AA4,) Are5T p,0 s u D T if-/� r�/Sc�l�@/ c �oi4/
(/7e/ n/ 4: _ SMk. , __LP. = 2 7 n •2
WrGt F�So._._� �n� /?0� w 7i _f (,lLL_f.WWr, /ko�lT/ L� VftL-(lE.
c2lN -ref P�15r _Y i2 (0_.73 M4�) SZ060 4.P_
- 0 , 7®2- f ./ FP
ul j-1F! irks ii
(A d•02_ ,1c/1Aic-
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�No .S/O /FI 7 p 2 . 6 D5.w A) T/e-C- i(u_ of 72I SCF/,92rj �

SUMMER
QEFF=0.4826 MGD, BOD5=30 MG/L
MODEL RESULTS
Discharger : PEMBROKE WWTP
Receiving Stream : LUMBER RIVER
The End D.O. is 5.45 mg/l.
The End CBOD is 2.04 mg/l.
The End NBOD is 1.30 mg/l.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flow
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 4.27 0.00 1
Reach 1 45.00 90.00 0.00 0.48260
SAVLAs' jlEitt3Tzov
LBDArA4J

SUMMER
QEFF=0.4826 MGD, BOD5=30 MG/L
I
I
Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 4.27 2.28 1.58 114.75
1 1 0.37 4.42 2.25 1.55 114.75
1 1 0.74 4.56 2.23 1.52 114.75
1 1 1.11 4.69 2.20 1.49 114.75
1 1 1.48 4.81 2.18 1.46 114.75
1 1 1.85 4.93 2.16 1.43 114.75
1 1 2.22 5.05 2.13 1.41 114.75
1 1 2.59 5.16 2.11 1.38 114.75
1 1 2.96 5.26 2.08 1.35 114.75
1 1 3.33 5.36 2.06 1.33 114.75
1 1 3.70 5.45 2.04 1.30 114.75
Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I

*** MODEL SUMMARY DATA ***
Discharger : PEMBROKE WWTP Subbasin : 030751
Receiving Stream : LUMBER RIVER Stream Class: C-SW, HQW
Summer 7Q10 : 114.0 Winter 7Q10 : 155.0
Design Temperature: 27.0
'LENGTH' SLOPE' VELOCITY 1 DEPTH! Kd I Kd I Ka I Ka 1 KN 1
1 mile 1 ft/mil fps 1 ft 'design' @20 'design' @20'•z 'design]
I I I 1 I 1 I I I I
Segment 1 1 3.701 2.401 0.600 1 3.57 1 0.30 10.22 11.48 I 1.271 0.51 I
Reach 1 I I I 1 I I I I I I
1 Flow 1 CBOD 1 NBOD 1 D.O. 1
I cfs I mg/1 1 mg/1 1 mg/1 1
Segment 1 Reach 1
Waste I 0.748 1 45.000 1 90.000 1 0.000
Headwaters1114.000 1 2.000 1 1.000 1 4.300
Tributary I 0.000 1 2.000 1 1.000 1 7.170
* Runoff 1 0.000 I 2.000 1 1.000 1 7.170
* Runoff flow is in cfs/mile

SUMMER
QEFF=0.5347 MGD, B0D5=30 MG/L
Discharger
Receiving Stream
MODEL RESULTS
: PEMBROKE WWTP
: LUMBER RIVER
The End D.O. is 5.44 mg/l.
The End CBOD is 2.06 mg/l.
The End NBOD is 1.35 mg/1.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flow
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 4.27 0.00 1
Reach 1 45.00 90.00 0.00 0.53470

*** MODEL SUMMARY DATA ***
Discharger : PEMBROKE WWTP Subbasin : 030751
Receiving Stream : LUMBER RIVER Stream Class: C-SW,
Summer 7Q10 : 114.0 Winter 7Q10 : 155.0
Design Temperature: 27.0
ILENGTHI SLOPEI VELOCITY 1 DEPTH' Kd 1 Kd I Ka I Ka I KN I
I mile I ft/mil fps 1 ft 'design! @201, !design! @203i Idesignl
I 1 I 1 1 I I I I I
Segment 1 1 3.701 2.401 0.600 1 3.57 1 0.30 10.22 1 1.48 1 1.271 0.51 I
Reach 1 1 1 1 1 I I I I I I
1 Flow 1 CBOD I NBOD 1 D.O. I
1 cfs 1 mg/1 1 mg/1 1 mg/1 I
Segment 1 Reach 1
Waste 1 0.829 1 45.000 1 90.000 1 0.000
Headwaters1114.000 1 2.000 1 1.000 1 4.300
Tributary 1 0.000 1 2.000 1 1.000 1 7.170
* Runoff 1 0.000 1 2.000 1 1.000 1 7.170
* Runoff flow is in cfs/mile

SUMMER
QEFF=0.5347 MGD, BOD5=30 MG/L
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 4.27 2.31 1.64 114.83
1 1 0.37 4.41 2.28 1.61 114.83
1 1 0.74 4.55 2.26 1.58 114.83
1 1 1.11 4.68 2.23 1.55 114.83
1 1 1.48 4.81 2.21 1.52 114.83
1 1 1.85 4.93 2.18 1.49 114.83
1 1 2.22 5.04 2.16 1.46 114.83
1 1 2.59 5.15 2.14 1.43 114.83
1 1 2.96 5.25 2.11 1.41 114.83
1 1 3.33 5.35 2.09 1.38 114.83
1 1 3.70 5.44 2.06 1.35 114.83
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I

SUMMER
QEFF=0.7821 MGD, BOD5=30 MG/L
MODEL RESULTS
Discharger : PEMBROKE WWTP
Receiving Stream : LUMBER RIVER
The End D.O. is 5.38 mg/l.
The End CBOD is 2.19 mg/l.
The End NBOD is 1.60 mg/1.
WLA WLA WLA
DO Min CBOD NBOD DO Waste Flow
(mg/1) Milepoint Reach # (mg/1) (mg/1) (mg/1) (mgd)
Segment 1 4.25 0.00 1
Reach 1 45.00 90.00 0.00 0.78210

*** MODEL SUMMARY DATA ***
Discharger : PEMBROKE WWTP Subbasin : 030751
Receiving Stream : LUMBER RIVER Stream Class: C-SW,
Summer 7Q10 : 114.0 Winter 7Q10 : 155.0
Design Temperature: 27.0
ILENGTHI SLOPE' VELOCITY 1 DEPTH' Kd I Kd 1 Ka I Ka I KN I
I mile I ft/mil fps 1 ft 'design' @20], 'design' @201h 'design'
I 1 1 I I 1 1 1 I 1
Segment 1 I 3.701 2.401 0.602 1 3.57 10.30 10.22 1 1.48 1 1.271 0.51 I
Reach 1 I I I I I 1 1 1 I I
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 1.212 1 45.000 1 90.000 1 0.000
Headwaters1114.000 1 2.000 1 1.000 1 4.300
Tributary 1 0.000 1 2.000 1 1.000 1 7.170
* Runoff I 0.000 1 2.000 1 1.000 1 7.170
* Runoff flow is in cfs/mile

SUMMER
QEFF=0.7821 MGD, BOD5=30 MG/L
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD I Flow I
1 1 0.00 4.25 2.45 1.94 115.21
1 1 0.37 4.39 2.43 1.90 115.21
1 1 0.74 4.52 2.40 1.86 115.21
1 1 1.11 4.65 2.37 1.83 115.21
1 1 1.48 4.77 2.34 1.79 115.21
1 1 1.85 4.88 2.32 1.76 115.21
1 1 2.22 4.99 2.29 1.72 115.21
1 1 2.59 5.10 2.27 1.69 115.21
1 1 2.96 5.20 2.24 1.66 115.21
1 1 3.33 5.29 2.22 1.63 115.21
1 1 3.70 5.38 2.19 1.60 115.21
I Seg # I Reach # I Seg Mi I D.O. I CBOD I NBOD 1 Flow I

DIVISION OF ENVIRONMENTAL MANAGEMENT
Memorandum
To: Boyd Devane
From: Carla Sanderson
Through: Ruth Swanek
Subject:
March 13, 1992
rA'
Pembroke WWTP
NPDES Permit No. NC0027103
Facilities Amendment Plan
Robeson County
I have reviewed the Amendment Plan (January, 1992) for the Town of Pembroke
WWTP. The proposed permit limits listed in Table 1 are the limits recommended
by Technical Support and comply with the current regulations for High Quality
Waters.
The plan also mentioned the need for additional treatment capacity for
unspecified industries in the future. In light of this, the facility should be
aware that a chronic toxicity test at 3.6% effluent and an acute toxicity test
at 90% effluent will be required when or if industrial sources tie into the Town
of Pembroke WWTP. Limits for specific toxics and metals may also be required if
industrial sources are added.
Thanks for the opportunity to review the Plan. Let me know if you have any
questions concerning the above.
cc: Central Files

DIVISION OF ENVIRONMENTAL MANAGEMENT
February 28, 1992
MEMORANDUM
": i;c' t 31992
TO: Trevor Clements, Supervisor
Water Quality Section
FROM: M. J. Noland, Regional Supervise
Fayetteville Regional Office
SUBJECT: In -Stream Assessment for 67b SOC
Town of Pembroke Wastewater Treatment Plant
NPDES Permit No. NC0027103
Robeson County
The Fayetteville Regional Office placed the Town on sewer connection
moratorium on June 12, 1991 because our office learned that the wastewater
treatment plant does on occasion experience a bypass due to excessive I/I. In
reviewing the monthly DMR data, the plant appears to be in compliance,
however, the dry weather flow usually brings the monthly average flow within
compliance with the permitted flow of 0.82 MGD.
In order to get a better handle on treatment plant by-passing, the Town
installed a high water telephone alarm system at the influent pump station and
established a procedure to chlorinate the bypass and collect samples during
the bypass event. Based on records at the wastewater treatment plant, the
facility has not experienced a bypass since July 1991.
It is our opinion that the appropriate means to address this problem was
to get the Town under an SOC with a compliance schedule. So far, this has
been successful and the Town has agreed to an SOC with a schedule for
correcting both treatment plant and I/I problems. The Town currently has an
approved loan through the State Revolving Loan Program and has met the first
three (3) SOC compliance dates.
The Town has requested the addition of 52,060 gpd of additional domestic
wastewater during the period of the SOC (date of issuance - 12-31-94). This
is not the usual SOC 67b scenario, however, we would appreciate your review
and comments on this matter.
MJN/KTS/mla

Request Form for In -stream Assessment for 67B
NAME OF FACILITY -TOWYN- OCy \ �p�rO'4 SUBBASIN \---uw�Wcv
\ ,v
COUNTY 2\o �D t_Soh REGION o�c��cv:\�� DESIGN FLOW Q.
RECEIVING STREAM LvstcY R:v&-C C -S�r e Q
BACKGROUND DATA :
A. Why is SOC needed? (Facility is out of compliance with which
effluent limits?)
S
B. History of SOC requests:
1. Monthly Average waste flow
prior to any SOC
0•1-t82(0 mgd
Time period averaged 1‘cA\ thru \2`44\
2. Previously approved SOC's: fv)%
Date: flow:
Date: flow:
mgd
mgd
total of previously approved SOC flow: mgd
3. Flows lost from plant
(facilities that have gone
off line)
4. Current SOC request
5. Total plant flow post-SOC
(sum of original flow and
SOC flow minus losses)
flow: II J f mgd
mgd
flow: mgd
flow:
6. Is this an accurate flow balance for plant? Why/why not?
C� 1+� ��-e 4�t•n..l�. �! ( Y c t e Vv c t `*., d N"•-'1.4rcr`a� 'T\c.,., Y a\e �1•�•
ekces s
! �\-► �tvw:. c.� c\ OW 6 \eV Y O.\ S Cvev>>! L NV O w tv cv C�v\r'•v.,%
(1or v.v:o�, `.:L �r.ot tio,. N.tit u\\c\"..., a. v\g:Na10. lr..vr.X\\y
avc�rr►`c Civ\ ow i a Qt V c1\\N \h G. ��:�, ecAt. wv..A
`roue \e•trot 41/4,1‘. air. So6o aVYd \S 4\\1\4
UYAev

w Cv-
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 11E2UEST :
A. Request is for domestic or industrial waste? If it is a combin-
ation, please specify percentages.
w o.S %cw&NtC
B. What type of industry? Please attach any pertinent data.
NII.
C. The region proposes the following SOC limits:
BOD5 30 mg/1
NH3 No ��r.:� mg/1
DO mg/1
TSS O mg/1
fecal coliform #/100m1
pH (1)_ q SU
other parameters
D. What is the basis for these limits?
U P S c , CV st 1r it.""•?1' r\VV. — .v-A1' div CNN-- •••?1-
elk .` C� \°l°L\ -�o
t-c5r; : s..,�c . Y c\�c.,,�,�! • C\0.ti NC%-;'
'l►d e :v

saw.pembroke.data
date
time
bod5
90/03/21
1430
0.9
90/06/13
1230
1.1
90/09/17
1400
1.3
90/12/06
1315
1.3
91/06/24
1115
3.1
91/09/12
1200
0.9
91/12/16
1000
0.6
temp
90/03/21
1430
16
90/06/13
1230
21
90/09/17
1400
22
90/12/06
1315
10
91/06/24
1115
23
91/09/12
1200
24
91/12/16
1000
9
do
87/03/23
1445
10
87/06/11
1420
6.1
87/06/30
1430
6.4
87/07/20
1300
6.3
87/07/29
1130
6.2
87/08/19
1300
5.5
87/09/21
1241
6.2
87/10/14
1030
8.7
87/12/29
1235
8.3
88/03/28
1300
8.4
88/06/09
1420
6.7
88/09/13
1210
6.8
88/12/01
1530
8.6
89/03/13
1515
9.2
89/06/08
1230
6.4
89/09/27
1730
5.9
89/12/13
1430
9.8
90/03/21
1430
9
90/06/13
1230
7.2
90/09/17
1400
6.8
90/12/06
1315
9
91/06/24
1115
5.8
91/09/12
1200
6.3
91/12/16
1000
9.5
Page 1

•
STREAM DATA
INSTREAM SELF -MONITORING DATA
MONTHLY AVERAGES
Discharger: 'oakb(Zgc-wiAriP
Receiving Stream: L uIY1Q.a (2
Upstream Location:
DATE
Dec-91
Nov-91
Oct-91
Sep-91
Aug-91
Jul-91
Jun-91
May-91
Apr-91
Mar-91
Feb-91
Jan-91
Dec-90
Nov-90
Oct-90
Sep-90
Aug-90
Jul-90
Jun-90
May-90
Apr-90
Mar-90
Feb-90
Jan-90
Dec-89
Nov-89
Oct-89
Sep-89
Aug-89
Jul-89
Jun-89
May-89
Apr-89
Mar-89
Feb-0
Jan -
TEMP
D.O.
COND.
FECAL COLI.
9,4(►G)
Loi.to/'5,
411.
11.66
6.2(6,4)
rk5(I bv'
? 1, (Iq
4.414. 6
ls6(7)10)
Z3(2]
4-3(3,5)
io4.5*
25-(z6)
Z(a (1)
lJ (3.�)6,000)
5. I (4,S)
,5 (ram
4-(z4-1
4, 6(410)
97 (- 0c,
211(z4"
4i7(4-.
70134)
141(
4.s C4.0
rl (55)
►3(Ia)
6.40 5,5)
5-7(4
1, z (i0)
(a,4(4,0)
&s (Go)
8.5 tin
1 (lo.
So NO
SA(12)
6.5 6.05
$2(too)
Permit No. )4(100Z-1103
Sub -basin:
Downstream Location: y2 MIS- �7WN$� vl a/lJ
33Q 004;14 om 51.I344
D.O. COND. FECAL CO
TEMP
1. i (l 5)
6.?(5.9;
, •
it (14)
(0.1 (- q
i(,%650\
(7, c
4-611-.1)13,9N
<
23 (2
41(4o)
4, (14r�
24(25
3, s (3,7)
cost-, oo`
2- (27)
4.4(".Ii
g6, (l s)
z4(z4-
4.4(3.4'
et Clop
Cz)
43l3,S
71 (S4.5
1 (2f)
¢.¢( ,o)
50(54)
I2-.2(it
G, 4-(_.3\
S4-(S6)
8.5 no)
4 (1-,o
rim (G6)
8. 2_t_ 1 z.)
Cb4i
14 (10
8,4-01-)
&.(,(b.o\
84 600
Page 1

MEMO
TO:
PewItyutt
DATE.
SUBJECT:
a0L amenciatuJ Loco do& in
Pi
C sue- r,�; Con, 6vakt/
STATE o'.
Mtn
OUNA
From.
North Carolina Department of Environment,
Health, and Natural Resources ©
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