NC0021181_Speculative Limits_19930602

NPDES DOCUMENT SCANNIN& COVER SHEET
NPDES Permit:
NC0021181
Belmont WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Engineering Alternatives Analysis
201 Facilities Plan
Instream Assessment (67B)
Speculative Limits`
Permit
History
Document Date:
June 2, 1993
This documeazt is printed on reure paper -ignore any
content on the reverse ride

State of 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., RE., Director
June 2, 1993
Gerald E. Hatton, P.E.
G. Hatton Associates, P.C.
6715 Fairview Rd, Suite D
Charlotte, NC 28210
Subject: Belmont Speculative
NPDES Nos. NCO021181
Gaston County
Dear Mr. Hatton:
ALTX.XA
IT7
1:3EHNR
My staff has completed an evaluation for speculative effluent limits for the City of
Belmont. On the basis of projected growth, the City has requested discharge limits at 10
MGD (an increase of 5 MGD). Since the proposed expansion is greater than 0.5 MGD,
an Environmental Assessment including justification of the need for the additional
wasteflow will be necessary. You should contact Boyd DeVane or Monica Swihart of the
Water Quality Planning Branch at [phone] for more information.
On the basis of the information available, tentative limits for conventional
constituents are as follows:
BOD5
NH3-N
TSS
Fecal Coliform
pH
Total Phosphorus
Total Nitrogen
5 mg/1
2 mg/1
30 mg/1
200/100 nil
6-9 su
0.5 mg/1
4 mg/1 (summer)
8 mg/1 (winter)
These limits are based on low instream dissolved oxygen levels due to wastewater
inputs and the operation of the dam upstream at Mountain Island Lake. Modeling shows
there is very little mixing due to low ambient velocities and the existing outfall design. In
addition, the long-term BOD data show the waste is slow to decay so a factor of 8 is
needed to convert BOD5 to CBOD.
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

.L
2
G
Nutrient limits are required for the expanded Belmont facility as a result of
recommendations from the report, "Water Quality Investigation of Lake Wylie, April
1989- September 1990". Lake Wylie is threatened by eutrophic conditions and to prevent
further nutrient enrichment, it is recommended that upon expansion or major modification,
existing point source discharges be required to apply state -of -art nutrient removal
technology. Current technology means meeting the recommended TP and TN limits listed
above.
Due to the large industrial constituency of Belmont's discharge, effluent limits were
developed for metals and other toxicants using available pretreatment information and
instream dilution based on plume modeling (3 :1) of the existing submerged outfall. The
recommended daily maximum limits are:
Cadmium
6 ug/1
Chromium
150 ug/1
Nickel
264 ug/1
Lead
75 ug/1
Cyanide
15 ug/1
Mercury
0.036 ug/l
The effluent limits for chromium, nickel, and lead are high and Belmont should be
aware that the Division may set caps for chemical specific toxicants in the future. Belmont
should make_ the effort to keep the concentrations as low as possible. Monthly effluent
monitoring requirements should also be included for copper, zinc, and silver. The
instream waste concentration (IWC) at 10 MGD is 3 3 % and a chronic toxicity testing
requirement, with sampling in the months of February, May, August, and November, will
remain a condition of the NPDES permit.
Under a relatively new Division procedure, dechlorination and chlorine limits are
now recommended for all new or expanding discharges proposing the use of chlorine for
disinfection. An acceptable level of chlorine in Belmont's effluent is 28 ug/1 for protection
against acute toxicity. The process of chlorination/dechlorination could be required
treatment that should allow the facility to comply with the total residual chlorine limit.
The Division is initiating a basinwide water quality management strategy for the
state's surface waters. All NPDES permits within a given basin will be renewed in the
same year, allowing the Division to examine interaction among all point and non -point
sources of pollutants for that basin. The basin plan for the Catawba Basin will be finalized
in 1995 and a draft version will be available for public comment sometime in 1994. In
addressing interaction of sources, wasteload allocations may be affected. Those facilities
that already have high levels of treatment technology are least likely to be affected. The
City of Belmont may want to consider implementation of this basinwide strategy in
planning their expansion.

Basin management plans are likely to develop strategies to address documented
water quality problems. Our records indicate that color problems exist -at the Belmont
WWTP at this time. The City should note that DEM is evaluating the state color standard
and is considering potential management actions. Belmont may want to begin building a
database of influent and effluent color (we recommend monitoring in units of ADMI).
The above limits are speculative and are for use in an engineering review of
discharge alternatives. Final limits will be provided upon receipt of an application for
permit expansion. Changes in the design of the outfall, i.e., installation of a diffuser to
increase instantaneous nixing may be a mitigating factor in the development of discharge
lints. If you have any questions concerning the above issues, please contacmlWy
Johnson or Jackie Nowell of my staff at [phone].
ion
Donald L. Safri
Asst. Chief for
Water Quality Section
cc: Boyd DeVane
Mooresville Regional Office
City of Belmont
Central Files

DIVISION OF ENVIRONMENTAL MANAGEMENT
May 19,1993
MEMORANDUM
TO: Coleen Sullins
FROM: Betsy Johnson
THROUGH: Ruth SwanekkC:
Mike Scoville Mp;
Subject: Belmont Speculative
NPDES Nos. NC0021181
Gaston County
An evaluation for speculative effluent limits for the Town of Belmont has been completed by the Technical
Support Branch. On the basis of projected growth, the Town has requested discharge limits at 10 MGD. Since the
proposed expansion(s) are greater than 0.5 MGD, an Environmental Assessment will be necessary. The applicant
should contact Boyd DeVane of the Water Quality Planning Branch at [phone] for more information.
On the basis of the information available, tentative limits for conventional constituents are as follows:
BOD,i
NHq-N
TSS
Fecal Coliform
pH
Total Phosphorus
Total Nitrogen
5 mg/I
2 mg/1
30 mg/l
200/100 ml
6-9 su
0.5 mg/I
4 mg/I (summer)
8 mg/I (winter)
These limits are based on low instream DOs due to wastewater inputs and the operation of the dam at
Mountain Island Lake. Modeling shows there is very little mixing due to low ambient velocities or the existing
outfall design. In addition, the long-term BOD data shows the waste is slow to decay so a factor of 8 is needed to
convert BODS to CBOD.
Nutrient limits are required for the expanded Belmont facility as a result of recommendations from the
report, "Water Quality Investigation of Lake Wylie, April 1989- September 1990". Lake Wylie is threatened by
eutrophic conditions and to prevent further nutrient enrichment, it is recommended that upon expansion or major
modification, existing point source discharges be required to apply state -of -art nutrient removal technology.
Current technology means meeting the recommended TP and TN limits.
Due to the large industrial constituency of Belmont's discharge, effluent limits were developed for metals
and other toxicants using available pretreatment information and instream dilution based on plume modeling (3:1)
of the existing submerged outfall. The recommended daily maximum limits are:
Cadmium
6 ug/I
Chromium
150 ug/I
Nickel
264 ug/l
Lead
75 ug/I
Cyanide
15 ug/I
Mercury
0.036 ug/I

i t 0 1
Although the effluent limits for chromium, nickel, and lead are high, the Division may set caps for
chemical specific toxicants in the future`. Belmont should make the effort to keep the concentrations as low as
possible. Monthly effluent monitoring requirements should also be included for copper, zinc, and silver. The
instream waste concentration (IWQ at 10 MGD is 33% and a chronic toxicity testing requirement, with sampling in
the months of February, May, August, and November, will remain a condition of the NPDES permit.
Under a relatively new Division procedure, dechlorination and chlorine limits are now recommended for
all new or expanding discharges proposing the use of chlorine for disinfection. An acceptable level of chlorine in
Belmont's effluent is 28 ug/1 for protection against acute toxicity. The process of chlorination/dechlorination could
be required treatment that should allow the facility to comply with the total residual chlorine limit.
The Division is initiating a basinwide water quality management strategy for the state's surface waters. All
NPDES permits within a given basin will be renewed in the same year, allowing the Division to examine interaction
among all point and non -point sources of pollutants for that basin. The basin plan for the Catawba Basin will be
promulgated by 1994 and a draft version will be available for public comment sometime in 1995. In addressing
interaction of sources, wasteload allocations may be affected. Those facilities that already have high levels of
treatment technology are least likely to be affected. The Town of Belmont may want to consider implementation of
this basinwide strategy in planning their expansion.
Basin management plans are likely to develop strategies to address documented water quality problems.
Our records indicate that color problems exist at the Belmont WWTP at this time. The Town should note that DEM
is evaluating the state color standard and is considering potential management actions. Belmont may want to begin
building a database of influent and effluent color (we recommend monitoring in units of ADMI).
The above limits are speculative and are for use in an engineering review of discharge alternatives. Final
limits will be provided upon receipt of an application for permit expansion. Changes in the design of the outfall,
i.e., installation of a diffuser to increase instantaneous mixing may be a mitigating factor in the development of
discharge limits. If you have any questions concerning the above issues, please contact me.
cc: Boyd DeVane
Mooresville Regional Office
Central Files

-s /! Y/93
'Jay CIO^Ce.i
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05/11/93
Facility:
NPDES Permit No.:
Status (E, P, or M):
Permitted Flow:
Actual Average Flow:
Subbasin:
Receiving Stream:
Stream Classification:
7010:
IWC:
Stn'd / Bkg
Pollutant AL Cone.
(ug/1) (ug/1)
Cadmium
S
2.0
Chromium
S
50.0
Copper
AL
7.0
Nickel
S
88.0
Lead
S
25.0
Zinc
AL
50.0
Cyanide
S
5.0
Mercury
S
0.012
Silver
AL
0.06
Selenium
S
5.00
Arsenic
S
50.00
Phenols
S
NA
NH3-N
C
T.R.Chlor.AL
17.0
Pollutant
-Cadmium S
Chromium S
Copper AL
Nickel S
-Lead S
Zinc AL
-Cyanide S
_Mercury S
Silver AL
Selenium S
Arsenic S
Phenols S
NH3-N C
T.R.Chlor.AL
Allowable
Load
(#/d)
4.95
41.25
7.70
25.62
26.05
43.04
2.41
0.02
0.20
0.99
16.50
T 0% I C
S R E V
I E W - "S, ne,
CITY OF BELMONT
JJ
N00021181
6o11'f `7Nr
7&0 = ��✓�!" a`
-
��
E
/ \)
3
10.0
mgd
=/,B
3.7
mgd
'030834
CATAWBA (LAKE WYLIE)I
--------- PRETREATMENT DATA --------------
1----EFLLUENT
DATA---- I
WSIII&B
ACTUAL-
PERMITTEDI
I
31.0
of$
I
Intl. +
Intl. +
FREQUENCY 1
33.33
8
Domestic
PERMITTED
Domestic I
OBSERVED
of Chronicl
Removal
Domestic
ACt.Ind.
Total
Industrial
Total I
Eflluent
Criteria I
Eff.
Load
Load
Load
Load
Load I
Cone.
Vlolationsl
#
(#/d)
(#/d)
(#/d)
(#/d)
(#/d) I
(ug/1)
(#vio/#Sam)I
--------
92%
--------
0.0
--------
0.1
--------
0.15
---------
0.1
-------- I
0.090 1
--------
2.0
1
76%
0.2
1.1
1.27
15.1
15.280 1
0.0
1 I
82%
0.2
3.8
4.06
1.0
1.250 1
200.0
1 N
32%
0.1
0.9
0.97
0.9
0.930 1
60.0
1 P
81%
0.2
0.8
0.95
2.0
2.230 1
30.0
1 U
77%
0.7
2.4
3.03
6.1
6.790 1
100.0
1 T
59%
0.2
0.9
1.04
1.9
2.080 1
0.0
1
86%
0.0
0.0
0.02
0.0
0.021 1
0.0
1 S
94%
0.0
0.5
0.55
0.1
0.160 I
0.0
1 E
0%
1 C
40%
0.0
0.0
0.01
0.0
0.010 1
1 T
0e
I L
OS
I 0
06
I
I N
I
ALLOWABLE
PRDCT'D
PRDCT'D
PRDCT'D
I
I
--------- MONITOR/LIMIT ---------
I
I
1--ADTN'L RECMMDTN'S-- I
Effluent
Effluent
Effluent
Instream
I Recomm'd I
Cone.
using
using
Cone.
Based on
Based on
Based on
I FREQUENCY INSTREAM I
CHRONIC
ACTUAL
PEP141T
using
ACTUAL
PERMITTED
OBSERVED
I Eff. Mon. Monitor. I
Criteria
Influent
Influent
OBSERVED
Influent
Influent
Effluent
I based on Recomm'd 2 I
(ug/1)
(ug/1)
(ug/1)
(ug/1)
Loading
Loading
Data
I OBSERVED (YES/NO) I
--------
6.000
---------
0.389
--------
0.233
------
0.67
--------
Monitor
--------
Monitor
---------I
Limit
--------- -------- I
I NCAC NO I
A
150.000.
9.872
118.770
0.00
Monitor
Limit
I NCAC NO I
N
21.000
23.668
7.287
66.67
Monitor
Monitor
Monitor
I Weekly YES I
A
264.000
21.363
20.482
20.00
Monitor
Monitor
Limit
I NCAC NO I
L
75.000
5.846
13.722
10.00
Monitor
Limit
Limit
I NCAC NO I
Y
150.000
22.571
50.579
33.33
Monitor
Monitor
Monitor
I Monthly NO I
S
15.000
13,810
27.620
0.00
Limit
Limit
I NCAC NO
I
0.036
0.096
0.096
0.00
Limit
Limit
I NCAC NO
I S
,0.180
1.069
0.311
0.00
Monitor
Monitor
I Monthly NO
I
15.000
0.000
0.000
0.00
1
1 R
150.000
0.194
0.194
0.00
1
1 E
0.000
0.000
0.000
0.00
1 S
0.000
0.00
I
1 U
51.000
0.00
I
L
T
I
S

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CORMIX SESSION REPORT:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
CL MONE EXPERT
ORNELIXIN8 Z
SYSTEM
Parent system:
CORMIX v.2.00
July 1992
SITE NAME/LABEL:
Catawba River
DESIGN CASE:
Belmont WWTP expansion
FILE NAME:
Belmont
Using subsystem CORMIX1:
Submerged Single
Port Discharges
(Version: CMX1 v.2.10
July 1992)
Start of session:
05/07/93--16:17:21
*****************************************************************************
SUMMARY OF INPUT DATA.-.
AMBIENT PARAMETERS:
Cross-section
= bounded
Width
EIS =
425
in
Ambient flowrate
QA =
2.69
m^3/s
Average depth
HA =
5
m
Depth at discharge
HD =
3.6
m
Ambient velocity
UA =
0.0012
m/s
Darcy-Weisbach friction factor
F =
0.0286
Calculated from Manning"s n
=
.025
Wind velocity
UW =
2
m/s
Stratification Type
STRCND = U
Surface temperature
=
27
degC
Bottom temperature
=
27
degC
Calculated FRESH -WATER DENSITY
values:
Surface density
RHOAS =
996.51
kg/m-***-3
Bottom density
RHOAB =
996.51
kg/(-iv`-3
DISCHARGE PARAMETERS:
Submerged Single
Port
Discharge
Nearest bank
= right
Distance to bank
DISTB =
90
in
Port diameter
D0 =
.76
in
Port cross -sectional area
A0 =
0.4536
m^2
Discharge velocity
U0 =
0.48
m/s
°'--�---- �,-._-�-
r1j"i
-7)!3
0'-

'^"=Ck"=
, Dis�harge"portnheight
H0 =
.38
m
^Vertical d'Ischai-ge angle
THETA =
0
deg
. Horizontal discharge angle
SIGMA =
90
deg
Discharge temperature (freshwater>
=
29
degC
' Corresponding density
RHO0 =
995.94
kg/m^3
Density difference
DRHO =
0.57
kg/m^3
Buoyant acceleration
81:10 =
.0056
m/s^2
Discharge concentration
C0 =
100 percent
Surface heat exchange coeff.
KS� =
0
m/s
Coefficient of decay
KD =
0.000002
/s
DISCHARBE/ENVIRONMENT LENGTH SCALES:
LQ = 0.67 m Lai
= 257.96
in
Lb = 608008.36 m
LM = 5.81 m Lm'
= 99999.9
m
Lb' = 99999.9 m
NON--DIPIENSIONAL PARAMETERS:
Port densimetric Froude number FRO = 7.42
Velocity ratio R = 383.01
MIXING ZONE / TOXIC DILUTION ZONE / AREA OF INTEREST PARAMETERS:
Toxic discharge = no
Water quality standard specified = no
Regulatory mixing zone = no
Region of interest = 5000.00 in downstream
**************************************************************++**************
HYDRODYNAMIC CLASSIFICATION:
( FLOW CLASS = H4-90A4 |
This flow configuration applies to a layer corresponding to the full water
depth at the discharge site.
Applicable layer depth = water depth = 3.6 m
*****************************************************************************
MIXING ZONE EVALUATION (hydrodynamic and regulatory sum(Tiary):
X-Y-Z Coordinate system:
Origin is located at the bottom below the port center:
90 m from the right bank/shore.
NEAR -FIELD REGION (NFR) CONDITIONS :
Note: The NFR is the zone of strong initial mixing. It has no legal
implication. However, this informat10n may be useful for the discharge
designer because the mixing in the NFu R is usually sensitive to the
-
discharge design conditions.
Pollutant concentration at
edge of NFR =
.0000 percent
Dilution at edge of NFR
=
4383.5
NFR Location:
x =
16291.55
m
(centerline coordinates)
y =
11.79
in
z =
3.60
m
NFR plume dimensions:
half -width =
32579.45
m
thickness =
11.69
m
Benthic attachment:
For the present combination of discharge and ambient conditions, the
discharge plume becomes attached to the channel bottom within the NFR
immediately following the efflux. High benthic concentrations may
occur.
The REGION OF INTEREST (ROI) specification occurs before the near -field
mixing (NFR) regime has been completed. Specification of ROI is highly
restrictive.
Interaction of the discharge plume with both banks occurs within
the bounded channel and within the initial NFR.
This leads to the formation of an upstream intruding SURFACE (or pycnocline>
DENSITY WEDGE.
Wedge length = 2084562.00 m

VV="y= ^^p
' Thicknes� at'ediffuser location (NFR) 3.23 m
' <W�dge thickness gradually decreases to zero at wedge tip.)
UPSTREAM INTRUSION SUMMARY:
PIume exhibits upstream intrusion due to low ambient velocity or strong
discharge buoyancy.
Intrusion length = 2855.35 m
Intrusion stagnation point = -2853.52 m
Intrusion thickness = 1.25 m
Intrusion half width at impingement = 32579.45 m
Intrusion half thickness at impingement = 11.69 m
In this case, the UPSTREAM INTRUSION IS VERY LARGE, exceeding ten (10)
times the local water depth.
This may be caused by the small ambient velocity, perhaps in combination
with the strong buoyancy of the effluent, or alternatively, a strong
ambient stratification.
If the ambient conditions are quite unsteady (e.g,, tidal), then the
CORMIX steady-state predictions of the upstream intrusion are probably
unrea1istic. The plume predictions in the immediate near -field!; prior
to the intrusion layer formation, are acceptable, however.
************************ TOXIC DILUTION ZONE SUMMARY ************************
No TDZ was specified for this simulation.
********************** REGULATORY MIXING ZONE SUMMARY ***********************
No RMZ and no ambient water quality standard have been specified.
*****************************************************************************
DESIGN CASE: Belmont WWTP expansion
FILE NAME: Belmont
8ubsystem CORMIX1: Submerged Single Port Discharges
(Version: C11X1 v.2.10 July 1992)
END OF SESSION/ITERATION: 05/07/93--16:35x15
XXXXXXXXXXXXX�XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

�ORMIX PREDICTION FILE:
1111111111111111111111111111111111111111111111111111111111111111111111111111111
CORNELL 11IXI1q8 ZONE EXPERT SYSTEM
Subsystem CORMIX1: Subsystem version:
Submerged Single Port Discharges CMX1 v.2.10 July 1992
______________________________________________________
CASE DESCRIPTION
Site name/label: Catawba^River
Design case: Bel mont^WWTP^expansion
�l|.E NAME: cormix\sim\Belmont .cx1
Time of Fortran run: 05/07/93--16:20:52
ENVIRONMENT PARAMETERS (metric units)
Bounded
section
BG =
425.00
AS =
2125.00
QA =
2.69
HA =
5.00
HD =
3.60
UA =
.001
F =
.029
USTAR =
.7600E-04
UW =
2.000
UWSTAR=
.2198E-02
Uniform
density environment
^
8TRCND=
U
RHOAM =
996.51
DISCHARGE
PARAMETERS (metric
units)
BANK =
RIGHT
DI8TB =
90.00
D0 =
.760
A0 =
.454
H0 =
.38
THETA =
.00
SIGMA =
90.00
U0 =
.485
Q0 =
.220
=
.2200E+00
1:;"1-400 =
995.94
DRHO0 =
.57
8P0 =
.5609E-02
CO =
.1000E+08
CUNITS=
percent
IPOLL =
2
K8 =
.0000E+00
KD =
.2000E-05
FLUX VARIABLES (metric units)
Q0
= .2200E+00
M0 = .1067E+00 J0
= .1234E-02 SIGNJ0=
1.0
Associated
length
scales
(meters)
LQ
= .67
LM
= 5.31 Lm
= 257.96 Lb =
608008.40
Lmp
= 99999.90 Lbp =
99999.90
NON -DIMENSIONAL
PARAMETERS
FRO
= 7.42
R
= 388.01
`
FLOW CLASSIFICATION
111111111111111111111111111111111111111111
1 Flow class (COFUylIX1) = H4-90A41
1 Applicable layer depth HS = 8.60 1
111111111111111111111111111111111111111111
MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS
C0 = .1000E+08 CUNIT8= percent
1\18T1) = 0 CSTD = .1000E+07
REGMZ = 0 RE8SPC= 0 REGVAL= 99999.90
XREG = .00 WREG = .00 AREG = .00
XINT = 5000.00 XMAX = 5000.00
X-Y_Z COORDINATE SYSTEM:
ORIGIN is located at the bottom and below the center of the port:
-90.00 m from the RIGHT bank/shore.
X-axis points downstream, Y-axits points to left, Z-axis points upward.
NGTEP = 10 display intervals per module
F3EGIN MODIOI: DISCHARGE MODULE

(,-IU NDA ATT40-111EI�,,1- immediately following the discharge..
x Y 9 C B
END OF MOD i 01 : D ! SCFSAk(33E. MODULE
BEGIN MOD112: WEAKLY DEFLECTED WALL JET 11\1 CF:OSSFLOW
CROSSR .. OWING WALL JET
Profile defini. tion=,-
B _ Gaussian 11e ( 7%) half -width, normal to trajectory
H .%lf walll, jet., attached to t3ottc:imn
w = hydro--fd y} namic center l ine dilution
C _ Centerline concentration (includes reaction effects,, if any)
x
Y
z
S
C
B
r. 0 0
r Cio
.. (Rio
I . k2i
. I 00E-+.-0 3
.:.: 3
n 0
.54
.. ffjf{{;.%(jf
1. J.
n
.64
((S:%
1.00
n L�S•.r
u;.+0
1.2
t��'�%f(�']SjjE,,��:~+~0
n B6CE+0 -
n 6 7
01.
1. R47
Of-li
1.2 S
837. E ! 2
7f.;j
., iSr�f:I
1.34
.. �'�/}0
:1 .3
�. 3 7Q�E+02
n -: 3
7).
I7 �.•[)1
1 N 6 1.
7�:.
i7 0
1.3
n 767E+02
.76
.7 0 :1
:1 .. Si S
., 2:ijtr�ii
1.4
,. '73SE-t-02
n ` 0,
n 3:.{{+ 1
1•••� n 1 4
a �i.I.j J..j
n `i•
1.4
n S 1 E• r k�.{j 2
n C7S•�•J
..{11..• 2
2.41
.00
1.5
�1 1�
n l� Gi �I.I E +,0{i�...
.85
r. 7�y2
2. ��}9
{i{i
n }..+3«+
1.5
, 66�7 E+L--r2
.88
Cumulative
travel time
__
5. s;set--
END OF IYICD 112 u WEA LY DEFLECTED WALL JET IN CROSSFLCW
BEGIN I (31)1',C . LIFT OFF/FALL DOWN
Profile de•f-'i.nitic=ns
1� G'ausma'sian I/e (;: 7%) ha.1f•.••widthn 3'1(: v-flial to 'trajec-tory
S hydrodynamic centerline dilution
C = centerline concentration (includes re�-tction effects,) if any)
x Y
t
n {{ Y � 1.... SJ e. :-1 n 00
Y
.1 n ° jir 2 n �:UClumt-d'--ttive travel time
S C El
END OF MOD-152.- LIFT OF+'1/FALL DOWN
BEGIN MOD .l 2 :1 : WEAk--** ... Y DEFLECTED LE4.....}..ED PLUI'IE 1 1\1 CROSwSF LOW
i='rof i 1.e definitions:
B _- Gaussian i 1 e ( 7% ) h �-t i f •--t j J. d t h :F t r- a ,j e c t c-., r- y
__ }•iyt•'rod►,tna-tmic: r.-enterl ine dilution
C = ce-n-ber":line coi'tcentration (includes reaction eft"ect:s;7 if any)
I n 118
3.
2
.. 3ED
f... 6
b 62�.-'.E+02
.89
11.78
4
.. 7;`73
.. 59
1
58 JL+t-i2
.93

1.79
-
, 6�66
1.18
1.9
.524E+02
.99
,1.80
~ 7.57
1.48
2.0
.496E+02
1.02
` 1.81
8.47
1.77
2.1
.471E+02
1.06
' 1.81
9.33
2.07
2.2
.448E+-02
1.09
^ 1.82
10.17
2.36
2.3
.426+
E02
1.12
1.82
10.99
2.66
2.5
.407E+.CJ2
1.15
1.83
11.79
2.96
2.6
.388E+02
1.19
Cumulative
travel
time
=
1396.
sec
END OF 1110D121: WEAKLY DEFLECTED PLUME IN CROSGFLOW
BEGIN 1110D132: LAYER BOUNDARY IMPINGEMENT/UPSTREAM SPREADING
Vertical angle of layer/boundary impingement = 88.85 deg
Horizontal angle of layer/boundary impingement = 89.57 deg
Upstream intrusion length =
2855.35 m
X-position of
upstream stagnation point =
-2853.52 in
Thickness in
intrusion region =
1.25 in
Half -width at
downstream end =
32579.45 m
Thickness at
downstream end =
11.69 m
In this case, the upstream INTRUSION IS VERY LARGE., exceeding 10 times
the local water depth.
This may be caused by a very small ambient velocity, perhaps in
combination with large discharge buoyancy.
If the ambient conditions are strongly transient (e.g. tidal), then the
CORMIX steady-state predictions of upstream intrusion are probably
unrealistic.
The plume predictions prior to boundary impingement will be
acceptable, however.
Plume width as a function of position:
X: -2853.52 -118.51 2616.50 5351.51 8086.52 10821.53 13556.54 16291.55
BH: .00 12313.87 17414.45 21828.25 24627.75 27534.66 30162.71 32579.45
Profile definitions:
BV = top -hat thickness, measured vertically
BH = top -hat half -width, measured horizontally in Y-direction
ZU upper plume boundary (Z-coordinate>
ZL = lower plume boundary (Z-coordinate)
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
Control volume inflow:
X Y Z S C B
1.83 11.79 2.96 2.6 .388E+02 1.19
Control volume outflow:
X Y Z S C BV BH ZU ZL
16291.55 11.79 3.60 4383.5 .152E-12 11.69 32579.45 3.60 .00
Cumulative travel time = 12868480. sec
END OF MOD132: LAYER BOUNDARY IMPINGEMENT/UPSTREAM SPREADING
** End of NEAR -FIELD REGION (NFR) **
The LIMITIN8 DILUTION (given by ambient flow/discharge ratio) is: 13.2
This value is below the computed dilution of 4383.5 at the end
of the NFR.
Mixing for this discharge configuration is constrained by LOW AMBIENT FLOW!
The previous module predictions are unreliable since the limiting dilution
�`��~4- k r--% 1-1 A en A 4"~� + k ; c- �---% I I~� ����� A ; v-- r- k =, v- 1-9 m r-"�-F ; ri,,�= + ;"vi

^ .^
~ Subseque-nt mod[xle 1%MOD181 ) wi 11 predict the properties of the
. cr-ross-sectiona1ly fully mixed plume with limiting dilution and will
compute a POSSIBLE UPSTREAM WEDGE INTRUSION.
BEGIN MOD181: MIXED PLUME/BOUNDED CHANNEL/POSSIBLE UPSTREAM WEDGE INTRUSION
The DOWNSTREAM flow field for this unstable shallow water discharge is
VERTICALLY FULLY MIXED.
The mixing is controlled by the limiting dilution = 13.2
Channel DENSIMETRIC FROUDE NUMBER (FCHAN) for this mixed flow = .03
An UPSTREAM INTRUDING) WE1:8E is formed along the surface/pycnooline.
UPSTREAM WEDGE INTRUSION PROPERTIES in bounded channel (laterally uniform):
Wedge length = 2084562.00 m
X-Position of wedge tip = ********** m
Thickness at discharge (end of NFR) = 8.23 m
(Wedge thickness gradually decreases to zero at wedge tip. "I
`
In this case, the upstream INTRUSION IS VERY LARGE, exceeding 10 times
the local water depth.
This may be caused by a very small ambient velocity, perhaps in combi'nation
with large discharge buoyancy.
If the ambient conditions are strongly transient (e.g. tidal)!, then the
[%]RMIX steady-state predictions of upstream intrusion are probably
unrealistic.
The plume predictions prior to boundary impingement and wedge formation
will be acceptable-4 however.
X Y Z S C BV BH ZU ZL
16291.55 '-90.00 3.60 13.2 .502E-10 3.60 425.00 3.60 .00
Cumulative travel time = 12868480. sec
Vertically and laterally fully mixed over layer depth: END OF SIMULATION!
END OF MOD181: MIXED PLUME/BOUNDED CHANNEL/POSSIBLE UPSTREAM WEDGE INTRUSION
CORMIX1: Gubmergvad Single Port Discharges End of Prediction File
1111111111111111111111111111111111111111111111111111111111111111111111111111111

*****************************************************************************
DESIGN CASE,-. Belmont 10 M8D
FILE NAME: Belmont2
Subeystem CORMIX1: Submerged Single Port Discharges
(Version: CMX1 v.2.10 July 1992)
END OF SE88ION/ITERATION: 05/10/93--12:47:07
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
COR11IX PREDICTION FILE:
1111111111111111111111111111111111111111111111111111111111111111111111111111111
CORNELL MIXING ZONE EXPERT SY8TEM
Subsystem COR11IX1: Subsystem version:
Submerged Single Port Discharges CMX1 v.2.10 July 1992
CASE DESCRIPTION
Site name/label: Catawba -`River
Design casex Belmont^10^MGD
FILE NAME -.-
Time of Fortran run: (05/10/93--11:25:44
ENVIRONMENT PARAMETERS (metric units)
_ _
Bounded section
BS = 425.00 AS =
HA = 5.00 HD =
UA = .001 F =
UW = 2.000 UWGTAR=
Uniform density environment
STRCND= U RHOAM =
2125.00 QA =
3.60
.029 USTAR =
.2198E-02
996.23
DISCHARGE
PARAMETERS
(metric
units)
BANK =
RIGHT
DISTB =
90.00
D0 =
.760
A0 =
.454
H0
THETA =
.00
CS) IGMA =
90.00
U0 =
.970
Q0 =
.440
RHO0 =
995.00
DR1-AO0 =
1.23
GPO
co =
.1000E+03
CUNITS=
percent
IPOLL =
1
KS =
.0000E+00
KD
FLUX VARIABLES (metric units)
Q0 = .4400E+00 M0 = .4267E+00
Associated length scales (meters)
LQ = .67 LM = 7.23
2.69
= .38
= .4400E+00
= .1211E-01
J0 = .5327E-02 8IGNJ0= 1.0
Lm = 515.98 Lb =2625254.00
Lmp = 99999.90 Lbp = 99999.90
NON_DIMENGIONAL PARAMETERS
FR0 = 10.11 R = 766.11
Ff..-OW CLASSIFICATION

^^^^^^`^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1 Flow class (�QORMIX1) = H4-90A41
t Applicable layer depth HG = 3.60 1
_ 111111111111111111111111111111111111111111
C0 =
.1000E+03
CUNIT8=
percent
NSTD =
0
CSTD =
.1000E+07
REGMZ =
0
REGGPC=
0 RE8VAL= 99999.90
XREG =
.00
WRE8 =
.00 AREG
XINT =
4500.00
XMAX =
4500.00
X-Y-Z COORDINATE SYSTEM:
ORIGIN is located at the bottom and below the center of the port:
-90.00 in from the RIGHT bank/shore.
X-axis points downstream, Y-axis points to left, Z-axis points upward.
N8TEP = 5 display intervals per module
BEGIN MOD101: DISCHARGE MODULE
COANDA ATTACHMENT immediately following the discharge.
X Y Z S C B
.00 .00 .00 1.0 .100E+03 .54
END OF MOD101: DISCHARGE MODULE
BEGIN MOD112: WEAKLY DEFLECTED WALL JET IN CROS8FLOW
CROS8FLOWIN8 WALL JET
Profile definitions:
B = Gaussian 1/e (37%> half -width, normal to trajectory
Half wall jet, attached to bottom.
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X
Y
Z
S
C
B
.00
.00
.00
1.0
.100E+03
.58
.00
1.11
.00
1.2
.826E+02
.70
.01
2.22
.00
1.4
.704E+02
.83
.01
3,34
.00
1.6
.613E+02
.95
.02
4.45
.00
1.8
.543E+02
1.07
.02
5.56
.00
2.1
.488E+02
1.19
Cumulative
travel time
=
7. sec
END OF 1"O0112: WEAKLY DEFLECTED WALL JET IN CROSSFLOW
BEGIN MOD152: LIFT OFF/FALL DOWN
Profile definitions.-
-8 = Gaussian 1/e (37%) half -width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effe(-_-ts, if any)
Control volume inflow:
X Y Z
' .02 5.56 .00
8 C B
2.1 .488E+02 1.19
Control volume outflow:
X Y Z
2.41 5.56 .00
Cumulative travel time =
S C B
2.1 .488E+02 .84
1892. sec

END OF MOD1512: L'IFT OFF/FALL D[�N
Profile definitions:
B = Gaussian 1/e (37%) half-widthv normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X
Y
Z
2.41
5.56
.00
2.42
7.77
.59
2.43
9.88
1.18
2.43
11.89
1.77
2.44
13.82
2.36
2.45
15.68
2.96
Cumulative
travel
time
=
S
C
B
2.1
.488E+02
1.17
2.2
.446E+02
1.24
2.4
.409E+02
1.30
2.7
.377E+02
1.37
2.9
.349E+02
1.43
3.1 .824E+-0V2 1.50
1896. sec
END OF MOD121: WEAKLY DEFLE[3ED PLUME IN
_..... ...
___
BEGIN MOD132: LAYER BOUNDARY IMPINGEMENT/UPSTREAM SPREADING
Vertical angle of layer/boundary impingement = 89.24 deg
Horizontal angle of layer/boundary impingement = 89.76 deg
UPSTREAM INTRUSION PROPERTIES
Upstream intrusion length = 5825.31 m
X-position of upstream stagnation point = -5822.86 m
Thickness in intrusion region = .70 m
Half -width at downstream end = 68624.09 at
Thickness at downstream end = 13.32 m
In this case, the upstream INTRUSION IG VERY LAR8E, exceeding 10 times
the local water depth.
This may be caused by a very sma1l ambient velocity, perhaps in
combination with large discharge buoyancy.
If the ambient conditions are strongly transient (e.g. tidal), then the
CORMIX steady-state predictions of upstream intrusion are probably
unrealistic.
The plume predictions prior to boundary impingement will be
accept,abl.e,. however.
Plume width as a function of positiono
X: -5822.86 -88.95 5644.96 11878.86 17112.77 22846.68 28580.59 34314.49
BH: .00 25987.47 36681.12 44925.01 51874.93 57997.94 63533.56 68624.09
Profile definitions:
BV = top -hat thickness, measured vertically
BH = top -hat half -width, measured horizontally in Y-direction
ZU = upper plume boundary (Z-coordinate)
ZL = lower plume boundary (Z-coordinate)
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
Control volume in�low:
X Y Z S C B
2.45 15.68 2.96 3.1 .324E+02 1.50
Control volume outfIow:
X Y Z S C BV BH ZU ZL
34814.49 15.68 3.60 5260.1 .190E-01 13.32 68624.09 3.60 .00
Cumu1ative travel time = 27104620. sec
,-^= ",- """.,""r, = "==""=" ,b.4=,^.==M r.:' ^n-//oM M r-'-^n`u,1%

L-.°" .. ..^.'^.L.... U.--.-., ~~~.,~..`.
** End of NEAR-FMLD REGION (NFR) **
'
'The LIMITING DILUTION (given by ambient flow/discharge ratio) is: 7.1
� This value is below the computed dilution of 5260.1 at the end
of the NFR.
Mixing for this discharge configuration is constrained by LOW AMBIENT FLOW!
The previous module predictions are unreliable since the limiting dilution
cannot be exceeded for this shallow water discharge configuration.
A subsequent module (MOD181) will predict the properties of the
cross -sectionally fully mixed plume with limiting dilution and will
compute a POSSIBLE UPSTREAM WEDGE INTRU8ION.
BEGIN M0D181: MIXED PLUME/BOUNDED CHANNEL/POSSIBLE UP8TREA1*11 WEDGE INTRUSION
The DOWNSTREAM flow field for this unstable shallow water discharge is
VERTICALLY FULLY MIXED.
The mixing is controlled by the limiting dilution = 7.1
Channel DBNSIMETRIC FROUDE NUMBER (FCHAN) for this mixed flow = .02
An UPSTREAM INTRUDING" WEDGE is formed along the surface/pycnooline.
UPSTREAM WEDGE INTRUSION PROPERTIES in bounded channel ( lateral III uniform):
Wedge length = 7957390.00 m
X-Position of wedge tip = ********** m
Thickness at discharge (end of NFR) = 3.37 m
(Wedge thickness gradually decreases to zero at wedge tip.)
In this case, the upstream INTRUSION IS VERY LARGE.. exceeding 10 times
the local water depth.
This may be caused by a very small ambient velocity, perhaps in combination
with large discharge buoyancy.
If the ambient conditions are strongly transient (e.g. tidal), then the
CORMIX steady-state predictions of upstream intrusion are probably
unrealistic.
The plume predictions prior to boundary impingement and wedge formation
will be acceptable, however.
X Y Z S C BV BH ZU ZL
34314.49 -90.00 3.60 7.1 .141E+02 3.60 425.00 3.60 .00
Cumulative travel time = 27104620. sec
Vertically and laterally fully mixed over layer depth: END OF SIMULATION!
END OF MOD181: MIXED PLUME/BOUNDED OHAN1\E1/17-'O8SIBLE UPSTREAM WEDGE INTRUSION
C0R11,1IX1: Submerged Single Port Discharges End of Prediction File
11111111111111�11111111111111111111111111111111111111111111111111111111111111111

CORMIX SESSION REPORT:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
CORNELL MIXING ZONE EXPERT SYSTEM
Parent system: CORMIX v.2.00 July 1992
SITE NAME/LABEL: Catawba River
DESIGN CAGE: Belmont 10 MGD
FILE NAME,: Be1mont2
Using subsystem CORMIX1: Submerged Single Port Discharges
(Version: CMX1 v.2.10 JuIy 1992)
Start of session: 05/10/93--11:23:17
*****************************************************************************
SUMMARY OF INPUT DATA:
AMBIENT PARAMETERS
CrosS-section
bounded

MIXING ZONE / TO IC DILUTION ZONE / AREA OF INTE1--,E8T PARAMETERS:
,Toxic disc``_rg~'. = no
Water quality standard specified = no
` R ^ulatory mixing zone = no
_Region of interest = 4500.00 m downstream
*****************************************************************************
HYDRODYNAMIC CLASS IFICATION
:
( FLOW CLASS = H4-90A4 |
This flow configuration applies to a layer corresponding to the full water
depth at the discharge site.
Applicable layer depth = water depth = 3.6 m
*****************************************************************************
MIXING, ZONE EVALUATION (hydrodynamic and regulatory summary)x
X-Y_Z Coordinate system. -
Origin is located at the bottom below the port center:
90 m from the right bank/shore.
1',IEAR----F*IEI...D REGION iNFR) CONDITIONS
Note: The NFR is the zone of strong initial mixing. It has no legal
implication. However, this information may be useful for the discharge
designer because the mixing in the NFR is usually sensitive to the
discharge design conditions.
Pollutant concentration at edge of NFR = .0190 percent
Dilution at edge of NFR = 5260.0
NFR Location: x = 34314.49 m
(centerline coordinates) y = 15.67 m
z = 3.60 m
NFR plume dimensions: half -width = 68624.09 m
thickness = 13.32 m
Benthic attachment:
For the present combination of discharge and ambient conditions, the
discharge plume becomes attached to the channel bottom within the NFR
immediately following the efflux. High benthic concentrations may
occur.
The REGION OF I1\1TERE8T (ROD specification occurs before the near -field
mixing (NFR) regime has been completed. Specification of ROI is highly
restrictive.
Interaction of the discharge plume with both banks occurs within '
the bounded channel and within the initial NFR.
This leads to the formation of an upstream intruding SURFACE- ((.-tr pycnocline)
DENSITY WEDGE.
Wedge length = 7957390.00 m
Position of wedge tip = -7928076.00 m
Thickness at diffuser location (NFR) = 3.36 m
(Wedge thickness gradually decreases to zero at wedge tip.)
UPSTREAM INTRUSION SUMMARY:
Plume exhibits upstream intrusion due to low ambient velocity or strong
discharge buoyancy.
Intrusion length = 5825.30 m
Intrusion stagnation point = -5822.85 m
Intrusion thickness = .69 (1-1
Intrusion half width at impingement = 68624.09 m
Intrusion half thickness at impingement = 13.32 m
In this case, the UP8TREA1%,11 INTRUSION IS VB�Y LARGE!, exceeding ten (10)
times the local water depth.
This may be caused by the small ambient velocity, perhaps in combination
with the strong buoyancy of the effluent, or alternatively, a strong
ambient stratification.
If the ambient conditions are quite unsteady (e.g. tidal), then the
CORMIX steady-state predictions of the upstream intrusion are probably

Ll-hrea1istic. 'lhe plume preclzctzons zn ttie zmmedzate near-TIC1u, przor
to the VnArt-tAion layer formation, are acceptable, however.
TOXIC DILUTION ZONE SUMMARY ************************
Wo Tl9Z was specified for this simulation.
********************** REGULATORY MIXI1M8 ZONE SUMMARY ***********************
N� RMZ and no ambient water quality standard have been specified.

n
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�Up G. HATTON ASSOCIATES, PC
Consulting Engineers
6715 Fairview Road, Suite D
Charlotte, NC 28210
[phone]
FAX [phone]
May 5, 1993
Ms. Betsy Johnson
Water Quality Section
Division of Environmental Management
ter'
P.O. Box 27535
Raleigh, NC 27626-0535 MAY Q 71t
TWIiioUL &urrufcl trZ dCH
Re: City of Belmont f;Y
WWTP Improvements # j
SRF No. CS 370702-04 dJj
Dear Ms. Johnson:
Per your request, we are submitting plans for the construction of
the effluent outfall to the City's treatment plant as placed in
operation in November 1991. Should you require additional
information, please feel free to call us directly.
Best regards,
G. HATTON ASSOCIATES, PC
Gerald E. Hatton, P.E.
cc: Mitchell B. Moore
10-016-016
diSGI.O.i'giE pp�J'4 �S o�n Y�O'0�1" V,.,
l Z �d-
e1[tn.,ds,
30'f
Ltl A�i— 'li inr4.0„
...:h n� _ °l5 �S
A,g ; Zal 4-

03/25/93
Facility:
NPDES Permit No.:
Status (E, P, or M):
Permitted Flow:
Actual Average Flow:
Subbasin:
Receiving Stream:
Stream Classification:
7Q10:
IWC:
Stn'd / Bkq
Pollutant AL Cone.
(ug/1) (ug/1)
--------- -- --------
Cadmium S 2.0
Chromium S 50.0
Copper AL 7.0
Nickel S 88.0
Lead S 25.0
Zinc AL 50.0
Cyanide S 5.0
Mercury S 0.012
Silver AL 0.06
Selenium S 5.00
Arsenic S 50.00
Phenols S NA
NH3-N C
T.R.Chlor.AL 17.0
Pollutant
Cadmium S
chromium S
Copper AL
Nickel S
Lead S
Zinc AL
Cyanide S
Mercury S
Silver AL
Selenium S
Arsenic S
Phenols S
NH3-N C
T.R.Chlor.AL
Allowable
Load
(#/d)
13.58
113.16
21.12
70.29
71.47
118.08
6.62
0.05
0.54
2.72
45.26
T 0 X I C
S R E V
I E W _ Lr. Sin
J
CITY OF BEIMONT
NCO021181
E
10.0
mgd
3.7
mgd
'030834
CATAWBA (LAKE WYLIE)I
--------- PRETREATMENT DATA --------------
I ---- EFLLUENT
DATA---- I
WSIII&B
ACTUAL
PERMITTEDI
1
95.0
CIS
Ind. +
Ind. + I
FREQUENCY 1
14.03
%
Domestic
PERMITTED
Domestic I
OBSERVED
of Chronicl
Removal
Domestic
Act.Ind.
Total
Industrial
Total I
Eflluent
Criteria I
Eff.
Load
Load
Load
Load
Load I
Cone.
Violationsl
i
(4/d)
(4/d)
(4/d)
(i/d)
(i/d) I
(ug/1)
(ivio/tsam)l
--------
925
--------
0.0
--------
0.1
--------
0.15
---------
0.1
-------- I
0.090 I
--------
2.0
--------- 1
I
76%
0.2
1.1
1.27
15.1
15.280 I
0.0
I I
82%
0.2
3.8
4.06
1.0
1.250 I
200.0
I N
32%
0.1
0.9
0.97
0.9
0.930
60.0
P
81%
0.2
0.8
0.95
2.0
2.230
30.0
U
77%
0.7
2.4
3.03
6.1
6.790
100.0
1 T
59%
0.2
0.9
1.04
1.9
2.080 I
0.0
1
86%
0.0
0.0
0.02
0.0
0.021
0.0
I S
94%
0.0
0.5
0.55
0.1
0.160
0.0
1 E
0%
C
40%
0.0
0.0
0.01
0.0
0.010 I
I T
0%
I
I 1
0►
I 0
06
I
N
I
ALLOWABLE
PRDCT'D
PRDCT'D
PRDCT'D
I
--------- MONITOR/LIMIT ----- ---
I
1--ADTN'L RECWMDTN'S-- 1
Effluent
Effluent
Effluent
Instream
I Recomm'd I
Cone.
using
using
Cone.
Based on
Based on
Based on
I FREQUENCY INSTREAM
CHRONIC
ACTUAL
PERMIT
using
ACTUAL
PERMITTED
OBSERVED
I Eff.Mon. Monitor.
Criteria
Influent
Influent
OBSERVED
Influent
Influent
Effluent
I based on Recomm'd ?
(uq/1)
(ug/1)
(ug/1)
(ug/1)
Loading
Loading
Data
I OBSERVED (YES/M
--------
14.258
---------
0.387
--------
0.232
--------
0.28
--------
Monitor
------
Monitor
-I
Limit
----------------- 1
NCAC NO 1 A
356.452
9.819
118.131
0.00
Monitor
Limit
NCAC NO I N
49.903
23.541
7.248
28.05
Monitor
Monitor
Monitor
I Weekly YES I A
627.355
21.248
20.371
8.42
Monitor
Monitor
Monitor
I NCAC NO I L
178.226
5.814
13.649
4.21
Monitor
Monitor
Limit
I NCAC NO I Y
356.452
22.449
50.307
14.03
Monitor
Monitor
Monitor
I Monthly NO I S
35.645
13.736
27.471
0.00
Limit
Limit
I NCAC NO 1 1
0.086
0.095
0.095
0.00
Limit
Limit
I NCAC NO I S
0.428
1.063
0.309
0.00
Monitor
Monitor
I Monthly NO 1
35.645
0.000
0.000
0.00
I R
356.452
0.193
0.193
0.00
E
0.000
0.000
0.000
0.00
I I S
0.000
0.00
I I U
121.194
0.00
I 1 L
T
S

BELMONT W WTP/ EXPANSION
BELMONT WWTP
Residual Chlorine
Ammonia as NIi3
(summer)
7010(CFS)
95
7Q10(CFS)
95
DESIGN FLOW (MGD)
10
DESIGN FLOW (MGD)
10
DESIGN FLOW (CFS)
15.5
DESIGN FLOW (CFS)
15.5
STREAM STD (UG/L)
17.0
STREAM STD (MG/L)
1.0
UPS BACKGROUND LEVEL (UG/L)
0
UPS BACKGROUND LEVEL (MG/L)
0.22
IWC (%)
14.03
IWC (%)
14.03
Allowable Concentration (ug/1)
121.19
Allowable Concentration (mg/1)
5.78
sl
a.s(-
Fecal Limit
(based on 331 : 1)
Ammonia as NFt3
(winter)
7Q10(CFS) 95
200 /100ml DESIGN FLOW (MGD) 10
DESIGN FLOW (CFS) 15.5
STREAM STD (MG/L) 1.8
UPS BACKGROUND LEVEL (MG/L) 0.22
IWC (%) 14.03
Allowable Concentration (mg/I) 11.48
V.94
NC0021181 3/25/93

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?. 7 _ ,2. 9> W- 9l s7 e
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L� /fin, �p o s crc c� AP7 a a �h�2J . ✓ca 6 y ws
a0
... (il/i/'(( �i/D� rJl� 1G7� S hM/ �{-�pG✓ . � �� GSi pZ v� % �tl /a /�✓S 7Sj// � S.�WQ�
/64

,
r
J ttj�' ���, North Carolina Division of Environmental Management
�-{�.� Water Quality Section / Intensive Survey Group
,a �
MEMORANDUM
To: Ruth Swanek
Through: Jay Sauber
From: Howard Bryant
Subject: Long-term BOD Analysis for Belmont WWTP
SAY
BM
0
5
1.54
8
2.70
15
4.72
20
5.75
25
6.55
30
7.25
35
7.78
40
8.01
50
8.95
60
9.75
70
11.16
80
12.16
90
13.18
100
13.93
110
14.37
132
15.52
176
16.64
Date Collected:
July 28, 1987
1115
NBOD: 3.60
County: Gaston
NPDES # NCO021181
Receiving Stream: Catawba River
Sub -basin: 030834
NH3-N
TKN-N
NOX-N TN-N
0.39
2.9
2.90 5.8
0.24
1.5
3.00 4.5
0.03
1.2
3.20 4.4
0.02
2.6
3.40 6.0
0.03
0.9
3.40
4.3
0.02
1.3
3.20
4.5
0.02 1.1 3.70 4.8
cc: Central Files
Regional Water Quality Supervisor
Collected by: Haynes
pH: 7.2
CBOD: 13.00
Test evaluation:
Seeded: unseeded
CBOD/BOD-5:

Jl
Facility {3�(�w W Wastefl& (MGD)
Summer/Hinter (circle one)
11
rn
ER
v1
0
0
m
/d
s
. r 1
Q / z 3 y S
a3 3 N (mg/1)
Potential effluent limit combinations: 4f)( C&O _ ¢3'JX
8005 NH3-N 30 Mb
/S (30) Z ✓C9,o)

city of belmont
CHLORINE ANALYSIS
7Q10: 95.0000 cfs
C12 Effl. Conc: 0.0000 mg/l
AL (17/19 ug/1) : 17.0000 ug/l
Upstream CL2 Conc.: 0.0000 ug/l
Design Flow: 5.0000 MGD
Predicted CL2 Downstream: 0.00 ug/l
0 mg/l
CL2 Limit: 225.3870 ug/l
0.225387 mg/1

SUMMER
MODEL RESULTS
Discharger
:
TOWN OF BELMONT
Receiving Stream :
UT CATAWBA RIVER
w--
r- w w w w - w
w r w w w w w- w w w w--
The End D.O.
w w w w- w w
is 6.15
w- 1 w w w w w w w w i r w r1 w w- w w-
mg/l.
w w W w w w w w w
w w w- w w 4 w
The End CBOD
is 1.06
mg/l.
The End NBOD
w w w w- w w w w w A w-
is 0.16
A w - w w- w-
mg/l.
w w- wwww - w w w w-- w w w w- w
w- - ----- w
w w w- w w---- r-
M w w r w w w
WLA
WLA
WLA
DO Min
CBOD
NBOD
DO Waste Flow
(mg/l)
-- w- w
Milepoint Reach #
w- w wwww w w w w w w-- w
(mg/1)
w- Y w
(mg/1)
-- w r
(mg/1) (iagd)
w w ----------
Segment 1
5.02
1.60 1
4-
Reach 1
24.00
13.50
5.00 10.00000
4c- Sla /(o

*** MODEL SUMMARY DATA ***
Discharger : TOWN OF BELMONT Subbasin : 030834
Receiving Stream : UT CATAWBA RIVER Stream Class: WSIII
& B
Summer 7Q10 : 95.0 winter 7Q10 : 95.0
Design Temperature: 26.0
JUNGTHI SLOPEI VELOCITY I DEPTHI Kd I Kid I Ka I Ka I KN I KN I KNR I KIR I
I mile I ft/mil fps I ft i design 10200 I design 1 920, des i gn i 0201 I design I@ 201 1
-----------------------------------------------------------------------------------------------------
1
Seq enc 1 1 4,001 5,001 0,041 129.50 1 0,26 1 0,20 1 0,38 1 0,331 0,48 1 0,30 1 0.48 1 0,00
Reach 1
.....................................................................................................
I
Flow I
CBOD I
NBOD I
I
cfs (
mg/1 (
mg/1 I
Segment 1 Reach 1
Waste 1
15.500 (
24.000 (
13.500 I
Headwatersj
95.000 1
2.000 1
1.000 1
Tributary 1
0.000 (
2.000 I
1.000
* Runoff I
0.000 (
2.000 1
1.000 j
* Runoff flow is in cfs/mile
D.O.
mg/1 I
5.000
7.300
7.300
7.300

w: 1
SUMMER
( Seg
( Reach
( Seg Mi {
D.O. {
CBOD
NBOD {
Flow
1
1
0.00
6.98
5.09
2.75
110.50
1
1
0.10
6.67
4.89
2.56
110.50
1
1
0.20
6.39
4.70
2.39
110.50
1
1
0.30
6.15
4.52
2.23
110.50
1
1
0.40
5.94
4.35
2.07
110.50
1
1
0.50
5.76
4.18
1.93
110.50
1
1
0.60
5.60
4.02
1.80
110.50
1
1
0.70
5.46
3.86
1.68
110.50
1
1
0.80
5.35
3.71
1.56
110.50
1
1
0.90
5.26
3.57
1.45
110.50
1
1
1.00
5.18
3.43
1.35
110.50
1
1
1.10
5.13
3.30
1.26
110.50
1
1
1.20
5.08
3.17
1.18
110.50
1
1
1.30
5.05
3.05
1.09
110.50
1
1
1.40
5.03
2.93
1.02
110.50
1
1
1.50
5.02
2.82
0.95
110.50
1
1
1.60
5.02
2.71
0.88
110.50
1
1
1.70
5.03
2.61
0.82
110.50
1
1
1.80
5.04
2.51
0.77
110.50
1
1
1.90
5.06
2.41
0.72
110.50
1
1
2.00
5.09
2.32
0.67
110.50
1
1
2.10
5.12
2.23
0.62
110.50
1
1
2.20
5.16
2.14
0.58
110.50
1
1
2.30
5.20
2.06
0.54
110.50
1
1
2.40
5.25
1.98
0.50
110.50
1
1
2.50
5.30
1.90
0.47
110.50
1
1
2.60
5.35
1.83
0.44
110.50
1
1
2.70
5.40
1.76
0.41
110.50
1
1
2.80
5.46
1.69
0.38
110.50
1
1
2.90
5.51
1.63
0.35
110.50
1
1
3.00
5.57
1.56
0.33
110.50
1
1
3.10
5.63
1.50
0.31
110.50
1
1
3.20
5.69
1.45
0.28
110.50
1
1
3.30
5.75
1.39
0.26
110.50
1
1
3.40
5.80
1.34
0.25
110.50
1
1
3.50
5.86
1.28
0.23
110.50
1
1
3.60
5.92
1.24
0.21
110.50
1
1
3.70
5.98
1.19
0.20
110.50
1
1
3.80
6.04
1.14
0.19
110.50
1
1
3.90
6.10
1.10
0.17
110.50
1
1
4.00
6.15
1.06
0.16
110.50
( Seg (
Reach (
Seg Mi (
D.O. (
CBOD (
NBOD (
Flow

Lq,vq 6 /i4wA , U)= 15 t jyr
SaiOO'L em /01
7/s )l4=
T��9
4.0

7
I �. 3 m,' �a 7�14yf = O. 6 7 ) 00
y �(Ho0
0. 0 �l I

� � � S.r�Gro
- _ _ _ _ _ - _._ Zo _..- -- -- —
- -�- --
lG N1 Grp � j,�-- - - /�
wwT�o (S..u-�.2� ft�-�
--- --�
-�

l
wx-� <- /%�d' � f •w.Q.� :cam � ,�U n-�.._ q � 2 ^�/,P �'`�,.�'_�` S��`
S � �� ��u� �/ f/�ic ,�+�, �f o�2.. •�"1��--dam �`�`
o.Oo z /PJ
L;
7a

,6t7 % �� Jam-

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711fo Dv,.9 P�y.��
�0 2/ Y Fo F h�,, z 7
0

at�
.J VE" D
MAR 121993
fEUh iGAL SUHURT 6RANG;H
TJ. Permits and Engineering Unit
Water.Quality Section
Attention: Charles Alvarez
SOC PRIORITY PROJECT: Yes/No
If Yes, SOC No. N/A
Date: March 10, 1993
NPDES STAFF REPORT AND RECOMMENDATIONS
County: Gaston
NPDES Permit No.: NCO021181
MRO No.: 93-35
PART I - GENERAL INFORMATION
1. Facility and Address: City of Belmont WWTP
Post Office Box 431
Belmont, N.C. 28012
2. Date of Investigation: March 2, 1993
3. Report Prepared By: Michael L. Parker, Environ. Engr. II
4. Person Contacted and Telephone Number: Carol Standafer,
[phone] (WWTP)
5. Directions to Site: From the intersection of Hwy. 273 and
Catawba Street in the City of Belmont, travel east on
Catawba Street 0.25 mile and turn right on loth street.
Travel 0.25 mile and turn left onto Stowe Thread Street. The
WWTP is located at the end of Stowe Thread Street.
6. Discharge Point(s), List for all discharge Points: -
Latitude: 350 13' 33"
Longitude: 810 00' 53"
Attach a USGS Map Extract and indicate treatment plant site
and discharge point on map.
USGS Quad No.: G 14 NE
7. Site size and expansion area consistent with application:
Yes. If No, explain.
8. Topography (relationship to flood plain included): Gently
sloping towards the receiving stream at a rate of 2-4%. The
site is located above the 100 year flood plain elevation of
the receiving stream.
9. Location of Nearest Dwelling: None within 500 feet of the
site.

Page Two
10. Receiving Stream or Affected Surface Waters: Catawba River
(Lake Wylie).
a. Classification: WS-IV, B
b. River Basin and Subbasin No.: Catawba 030833
C. Describe receiving stream features and pertinent
downstream uses: Lake Wylie is used for primary and
secondary recreation and receives frequent bodily
contact. Although there are no water intakes for
several miles below the point of discharge, there are
other dischargers downstream of this facility.
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
a. Volume of Wastewater: 5.0 MGD (Design Capacity)
b. What is the current permitted capacity: 5.0 MGD
C. Actual treatment capacity of current facility (current
design capacity): The WWTP is preparing for a
construction project that will modify the existing
facility by providing greater solids handling
capability and enhancing other facets of the treatment
process. In preparation for this proposed activity, an
existing aeration basin has been taken out of service,
temporarily reducing hydraulic capacity (actual
capacity unknown). Construction is anticipated to take
approximately one (1) year. Construction will not
include expansion of the existing facility (see item F
below).
d. Date(s) and construction activities allowed by previous
ATCs issued in the previous two years: ATC for the
activity discussed in item C was issued in July, 1992.
e. Description of existing or substantially constructed
WWT facilities: The existing WWT facilities consist of
dual influent bar screens, caustic addition, flow
recorder with parshall flume, grit chamber, dual
aeration basins with mechanical aeration, dual
secondary clarifiers, chlorine disinfection, effluent
parshall flume, effluent flow measurement with recorder
and sludge drying beds.
Description of proposed WWT facilities: The permittee
proposes to modify an existing aeration basin into two
(2) aerated sludge holding basins. One-third of the
aeration basin will be retained to allow for future
expansion. Additional WWT units include a mechanical
bar screen, mechanical grit removal, replacement of
existing fixed aerators with floating aerators, an
aerobic digester and a standby generator.

Page Three
g. Possible toxic impacts to surface -waters: This
facility passed all four (4) toxicity test undertaken
in 1992. No results are yet available for 1993.
h. Pretreatment Program (POTWs only): Approved
2. Residual handling and utilization/disposal scheme:
a. If residuals are being land applied specify DEM Permit
No. WQ0003281.
Residuals Contractor: EWR, Inc.
Telephone No. [phone]
b. Residuals stabilization: PSRP
C. Landfill: N/A
d. Other disposal/utilization scheme (specify): N/A
3. Treatment Plant Classification: Less than 5 points; no
rating (include rating sheet). Class III based on existing
treatment units. Facility will be a Class IV facility upon
completion of the proposed construction activities.
4. SIC Code(s): 2262, 2261, 4952
Wastewater Code(s):
Primary: 01
Secondary: 55
5. MTU Code(s): 02003
PART III - OTHER PERTINENT INFORMATION
1. Is this facility being constructed with Construction Grant
Funds or are any public monies involved (municipals only)?
Yes, public monies will help finance proposed modifications.
2. Special monitoring or limitations (including toxicity)
requests: None at this time.
3. Important SOC/JOC or Compliance Schedule dates: N/A
4. Alternative Analysis Evaluation: N/A
PART IV - EVALUATION AND RECOMMENDATIONS
The City of Belmont requests renewal of the subject Permit.
Upon completion of the proposed WWTP modifications, the WWTP
classification will change from a Class III to a Class IV
facility. The renewed Permit should contain effluent monitoring
frequencies that reflect both Class III and Class IV criteria.

Page Four
A rather lackadaisical approach to the implementing and
enforcement of the City's Industrial Pretreatment Program
continues to jeopardize compliance at this facility from month to
month. Inadequately treated wastewater and/or surge flows from
industries cause frequent operational problems that will be
exacerbated during the construction period while existing units
are out of service. Stricter enforcement of the City's Sewer Use
Ordinance appears necessary to insure that influent wastewater_
concentrations and volumes remain consistent. The WWTP
superintendent has been made aware that compliance problems can
not be tolerated. An SOC application has been forwarded to the
City for their use should compliance problems occur as a result
of the construction activities.
Flow data also suggests problems with I/I in the City's
collection system. -According to Ms. Standafer, some progress has
been made in this area; however, based on flow readings, much
work is still needed.
This facility has a significant amount of color in it's
effluent and, therefore, should be included in any proposed color
monitoring program implemented by the Division.
Pending receipt and approval of the WLA, it is recommended
that the NPDES Permit be renewed.
Si ature df Oport Preparer Date
Water Quality R onal Supervisor Da e

O
G. HATTON ASSOCIATES, PC
Consulting Engineers
6715 Fairview Road, Suite D
Charlotte, NC 28210
[phone]
Fax [phone]
February 11, 1993
Mr. Donald Safrit, PE
Supervisor
Permits and Engineering Unit
Division of Environmental Management
P.O. Box 29535 =;:?
Raleigh, NC 27626-0535
..a
Re: City of Belmont POTW
NPDES Permit No. NCO021181
Gaston County
Dear Mr Safrit:
We have been retained by the City of Belmont, to study
current and future wastewater treatment needs for the
community and its sewer service area. The evaluation of the
proposed treatment requirements is being undertaken in
accordance with 15A NCAC 2H.0223. Our analysis of potential
flow rates is now complete.
The existing POTW is permitted at 5.0 MGD average monthly
flow. From the enclosed Water Production & Wastewater
Treatment exhibit, you will note that monthly average flows
to the POTW have grown progressively over the three years
preceding 1992. In the last year, the monthly average has
exceeded 3.8 MGD eight times. This dramatic change has
occurred through increased SIU utilization of permitted
pretreatment flow allocations. The progressive rise over the
previous three year period reflects the expansion of the
sewer service area and population.
Several of the SIU's have requested increases in their flow
limits to take advantage of current market demands. The
consideration of these requests is vital to Belmont's
economic stability. In addition, ongoing pressure for the
development of vast vacant property holdings within the city
limits, has necessitated the need for an expansion of the
POTW.
Our analysis of the projected 20-year wastewater treatment
flow indicates the need to expand the existing plant by 5.0
MGD to a total capacity of 10.0 MGD.

O
On behalf of the City, we request a determination of
speculative discharge limits for a 10.0 MGD monthly average
flow rate at the current discharge point in the Catawba
River. With this information, we can formulate an expansion
program with the processes required to achieve the limits.
Any assistance that you can provide would be appreciated.
Best regards,
G. HATTON ASSOCIATES, PC
q-a� i, w447'.,
Gerald E. Hatton, P.E.
cc: Mitchell B. Moore
Psi
10-016-016

WATER PRODUCTION & WASTEWATER TREATMENT
FLOW CHARACTERISTICS
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WASTEWAIEA ,i
'89MAR Y JULY S PT NOV '9D MAR MW DULY SEPT NOVJAN'St MAY J LY S PT NOV '82 MAH MAY JU Y S PT NOV
FEB APR JUNE AUG OC1 DEC FEB APH JUNE AUG OCT DEC FEB APR JUNE AUG OCT DEC FEB APR JUNE AUG OCT DEC
MONTHLY AVERAGE AND MAXIMUM DAY
- AVERAGE WASTEWATER ------ AVERAGE WATER - INDUSTRIAL LIMITS
MAX. DAY WASTEWATER •••••. MAX. DAY WATER - WWTP CAPACITY