NC0004375_Wasteload Allocation_19800725

NPDES DOCUHENT SCANNIN` COVER :SHEET
NPDES Permit:
NC0004375
Clariant Corporation
Document Type:
Permit Issuance
Waste oad Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Additional Information Received
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
July 25, 1980
This document is printed on reuse paper - ignore any -
content on the rezzerse side

SUMMARY REPORT
SODYECO-CATAWBA RIVER WASTELOAD ALLOCATION STUDY
DEPARTMENT OF NATURAL RESOURCES AND COMMUNITY DEVELOPMENT
DIVISION OF ENVIRONMENTAL MANAGEMENT
TECHNICAL SERVICES BRANCH
July 25, 1980

Conclusions
A non -steady state model, RECEIV-II, was used to develop a wasteload
allocation for the Catawba River below Mt. Holly and Sodyeco. The limits
are listed below:
Design Flow (MGD) BOD5 NH3-N (mg/1) D.O.
Mt. Holly 4.0 30 20
Sodyeco 3.9 33 20
The flow of the river was modeled in a time -variable manner
the 24-hour average was equal to 329 cfs. Decay rates of
5
5
such that
oxygen -demanding
substances were 0.3 per day, base e at 20°C (CBOD) and 0.05 per day, base
e at 20°C (NH3-N). Reaeration rates were equal to 2 : depth for each of the
four reaches modeled.
The effluent limits appear to be valid for most critical flow situations.
During extended periods of minimal power plant operation, however, the validity
of these limits becomes questionable.

I. Introduction
Sodyeco, a Division of Martin Marietta Corporation, discharges its
treated effluent into the Catawba River 4.1 miles below Mountain Island
Dam. The discharge canal is located approximately one mile below NC
27 on the river's east bank, almost directly across from the City of
Mt. Holly's discharge. The design flow of the Sodyeco wastewater
treatment plant is 3.9 MGD, while that of the Mt. Holly facility is
4.0 MGD.
The discharge of the river is controlled by Duke Power's hydro-
electric -generating facility located at Mt. Island Dam. This station
is designed to meet peak power needs of Duke's customers and thus the
discharge from the dam is erratic. A letter from Mr. L. P. Julian,
Vice President, of Duke Power to then Director W. E. Knight of the
Division of Environmental Management guarantees that 314 cfs will be
the minimum daily average flow from the dam until July 1, 1985.*
Very often however, instantaneous flows approach 10,000 cfs during
turbine operation, and drop to 80 cfs when no power is being generated.
After discussion with the interested parties (Sodyeco; Main Engineering,
Sodyeco's consultant; Raytheon Corp., the developers of RECEIV-II; and
DEM staff) it was decided that a non -steady state model such as RECEIV-II
would be best suited for modeling this type of situation in the intersts
of obtaining a wasteload allocation. RECEIV-II is a time -varying model
developed for EPA,capable,,of simulating many different situations in
water quality modeling.
*Except in cases of emergency shut downs.

II. Intensive Surveys, Data Summary
Intensive surveys were performed on April 22, 1977 and October 17, 1979.
The area of study included the Catawba River from the Sodyeco discharge
downstream about 4.6 miles to the power lines which cross the river after
it becomes Lake Wylie. The scope of the surveys included dye studies,
cross-section measurements and water quality sampling. During the first
intensive study, the dye cloud was lost due to the start of an unexpected
period of operation of the hydroelectric plant at Mt. Island Dam. However,
the 1979 dye study was successful and times -of -travel were obtained for
the flows observed on the river (see Table I).
Other physical data required for analysis was obtained from various
sources. Duke Power supplied hourly flow data describing releases from
the dam for the October 17-19 period (Appendix A). Duke also provided
cross -sections at full pond for several locations on the river above and
below Sodyeco's discharge. DEM staff, in addition, determined cross -sections
for some other locations in the same area.
The above data was reduced to a form acceptable for model inputs to
RECEIV-II. These inputs are summarized in Table II.
Water quality data also was collected during both intensive surveys.
However, the data collected during the October 1979 survey is more complete
with respect to number and location of stations and parameters sampled.
Therefore, these data were used in calibration efforts, and are summarized
in Table III.
Note that BOD and ammonia -nitrogen data from the river samples show
no real trends. In fact, NH3-N was undetected in virtually all of these
samples. This certainly adversely affects any effort in calibrating the
water quality portion of the model (i.e. determining decay rates). The
procedure for selecting rates (Kd, KNH3-N) is discussed below in the
section describing the allocation model.

IvlT. I5Lfiit v Li
E
MT HOLLY
srr, ---�
/./5to;
0.85rn
0 1 ki;
1
►. 3srm
0
C 5-
"7
31
1
1P
SOD'ECC)
Er Li) IJ1-
se-m ca►v r 5 rP --�
(5-voe)
WoX 3
(1400'
NOOc
0‘00 /)
NODE 5
145.

TABLE I. Calibration Inputs -Flow and Velocity
A. Flows From Dam During October 17-18, 1979 Intensive Survey.
Hour
Flow
(cfs)
Real Time/
Date
0.0
24.0
42.0
48.0
64.0
80
9193*
80
9130*
80
*Represents average of hourly flows
B. Time -of -Travel During Intensive Survey.
Location
Sodyeco Disc.
I-85 Bridge
US 29-74
Bridge
S. RR Trestle
Power Lines
Peak Time/
Date
0230/10.18
0905/10-18
0954/10/18
1045/10/18
1310/10-18
T.O.T.
Dye Dump
6HR35MIN
(1HR35MIN)
49 MIN
41 MIN
2HR25MIN
0730/10-17
0130/10-18
0730/10-18
2330/10-18
during period of operation
**
Dist. Between Flow-Thru Adjusted
Stations, Ft. Vel. FPS. Vel., FPS
9300
4600
3600
7000
0.39
1.65
1.46
0.80
1.63
1.56
1.46
0.80
**Velocity after subtracting time period in which flow from dam ceases
(approx. 6 hrs)

Node
Sta.
1
(Sodyeco)
2
(10,11) 3400
3
(1-85) 5900
4
(US 74&29) 4600
5
(SRR) 3600
TABLE II. Physical Characteristics of Catawba River at Full Pond
(569.4 feet above MSL)
Length of Width of Length of
Upstream Upstream Downstream
Channel Channel Channel
(ft) (ft) (ft)
671
760
838
1267
3400
5900
4600
3600
Width of
Downstream
Channel
(ft)
671
760
838
1267
Surface Area
of Downstream
Channel
(ft2)
2282170
4484000
3854800
4561200
Surface Area
of Downstream
Channel
(sq. ft.)
2282170
4484000
3854800
4561200
Surface Area
of Node
(sq. ft.)
1,141,085
3,383,085
4,160,400
4,208,000
2,280,600

TABLE III. Water Quality Data Summarization Table
(31-Day) D. 0. Temperature
BOD5 BOD TKN NH3-N (mg/1) (°C)
Station (mg/1) (mg/1) (mg/1) (mg/1) Top Bottom Top Bottom
CR-Upstream 1.3 2.8 0.2 <0.05 7.65 6.65 18.5 18.5
Sodyeco Efflu. 8.87 43.05 - - 7.7 17.0
CR-0 1.38 3.55 0.25 <0.05 7.93 7.43 17.8 17.8
CR-5 1.36 3.05 0.15 <0.05 7.55 7.5 17.9 18.0
CR-7 1.83 4.1 0.2 <0.05 7.5 7.55 17.9 18.0
CR-9 1.59 3.75 0.2 <0.05 7.65 7.55 17.9 17.95
CR-12 1.14 3.7 0.2 <0.05 7.65 7.4 17.6 17.9
CR-14 1.7 4.1 0.2 <0.05 7.65 7.35 17.6 17.9
CR-I85 1.9 5.4 0.2 <0.05 7.5 7.4 17.55 17.9
US 74 1.23 4.3
SRR Bridge 1.9 4.8
See Figure I for Station Locations

III. Calibration - Quantity Model
In the true sense of the word, a calibration was not obtained with
the data available. Although time -of -travel and flow data was available
from the intensive survey and Duke Power Co. (see appendices) this data
was not of the form needed for a hydrodynamic (quantity) calibration of
RECEIV-II. In order to calibrate the flow model, one needs "instantaneous"
flows and velocities at distance intervals along the river. As flows
from the dam change with respect to time, flows and velocities change
downstream of the release with respect to time also. There are also
"backwater" effects (waves) which must be considered using stage height
recorders. The effort required to collect such data was beyond the
financial and manpower resources of DEM. From the data that was
collected, however, a reasonable approximation of the observed flow
and velocity pattern was obtained using a Manning coefficient of 0.02
(English Units).
The "calibration" model was set up for the river by dividing some
physical parameters in half (flows, cross -sections) so that the effects
of the island located below the discharge were eliminated. This proved
effective in "calibration". For allocation purposes, the island was
neglected altogether, but the river was "returned" to its true dimensions.

IV. Allocation Model - April 1 to October 31
The intial step in developing a wasteload allocation for the
section of the Catawba River under consideration was to choose an
appropriate flow regime. This regime must be equivalent in volume of
flow released from the dam per day to the guaranteed minimum daily average
release, 314 cfs, plus the 7Q10 tributary inflow between the dam and the
location of the dischargers, 15 cfs. The pattern chosen for each day
simulated was 12 hours at the minimum instantaneous release (0000 to 1200)
6 hours at 1016 + 15 = 1031 cfs (1200 to 1800) and 6 more hours at
minimum instantaneous release (1800 to 2400). The net result of this
regime is 18 hours "off", 6 hours "on", and the daily average flow
becomes 329 cfs. •
Stream decayrates of 0.3 da -1 20°C base e)for ammonia nitrogen
/ Y ( g
were used. The value representing Kd was chosen based on DEM's past
experience on rivers similar to the Catawba. This rate was selected
also in conjunction with a background CBOD concentration of 0.5 mg/l.
Running the model with no point source loadings, at 0.3 day-1 Kd and
0.5 mg/1 upstream CBOD, no appreciable D.O. sag occurred in the river
at any point downstream. Lower rates and higher background CBOD values
did produce "artificial" sags downstream and thus these combinations were
rejected. The value chosen for the ammonia -nitrogen decay rate was also
based on past experiences on rivers similar to the Catawba (e.g. the
Cape Fear River). For reaeration rates, O'Connor's formula (2 : depth
as lower limit) was used in the present effort.
At design conditions (temperature = 26°C, flow = time variable -
(329 cfs average), wasteflow = 4.0 MGD for Mt. Holly, 3.9 MGD for
Sodyeco), allocations were obtained for Mt. Holly and Sodyeco. The
appropriate effluent limitations are listed in the table below:
Effluent Limitations (mg/1)
Flow CBOD BOD5 NH3-N DOeff
Sodyeco 3.9 MGD 99 33 30 5
Mt. Holly 4.0 MGD 45 30 20 5

Note that a CBOD/BOD5 ratio of 3.0 was used to assign a BOD5 limitation
to Sodyeco's discharge. This value is typically used by DEM for chemical
plant wastes. Effluent samples analyzed by DEM during the intensive
surveys showed ultimate BOD/BOD5 ratios in the range of 3.9 to 5.4. For
Mt. Holly, a CBOD/BOD5 ratio of 1.5 was used since its treatment plant
receives domestic (and some textile) waste primarily. This is the ratio
that DEM uses for most of its "Level C" type analyses.
The procedure in developing the above effluent limitations is as
follows. Mt. Holly was assigned "secondary" limits. These are the
minimum treatment requirements for a municipal facility as mandated by
EPA. Sodyeco was then allowed the maximum CBOD and NH3-N that the
Catawba River could assimilate based on the variable flow pattern
described above.
As a confirmation of the validity of the effluent limits listed
above, different flow patterns were input to the model to determine
any change in the allocation. The Manning coefficient was not changed.
If the river was assumed to be regulated such that a constant flow of
329 cfs was maintained at all times, the same allocation was obtained.
If a time variable flow regime such as the one used to obtain the
allocation was input, but that the "flow" period was assumed to occur
at different times of the day, the average downstream D.O. minimum
changed. In the "worst" condition, when the "off" period was 36 hrs.
(days 5 to 6), the D.O. minimum averaged 4.9 mg/1 on day 8. The most
severe flow pattern tested had a one -hour "on" period where the river
flow was 5711 cfs, and a 23-hour "off" period (river flow = 95 cfs).
The D.O. minimum dropped to 2.8 mg/1 under these conditions. Therefore,
the effluent limits suggested appear to be valid, except under the most
severe flow situations. These situations would include extended periods
of shutdown of the power plant (see next paragraph), or extended periods
whereby the plant was operated only one or two hours per day.

The model, in addition, was run for 8 days at a time -constant
flow of 95 cfs to simulate a "shut -down" situation. The effluent limits
obtained were 10 mg/1 BOD5, 3 mg/1 NH3-N and 5 mg/1 D.O. for both
Mt. Holly and Sodyeco.

V. Allocation Model - November 1 Thru March 31
According to Regulation 15 NCAC 2B .0404 (C), a discharger may
request a seasonal variation in its effluent limitations as they relate
to oxygen -consuming materials. To be eligible, a request must be
submitted to the Director along with a rationale as to the need for
such limitations. The winter oxygen -consuming wasteload allocation
shall in no case be less stringent than two times the summer oxygen
consuming wasteload limitations nor shall it be less restrictive than
minimum treatment requirements.
The model for April 1 to October 31 was modified with respect to
design temperature only. The minimum daily average flow was assumed
to be 329 cfs for the "winter" period also. The effluent limitations
for the "winter" period would be allowed to be twice the summer limitations
(BOD5 = 66 mg/1, NH3-N = 40 mg/1, for Sodyeco, secondary for Mt. Holly .
A similar allocation for Sodyeco would be 96 mg/1 BOD5, 20 mg/1 NH3-N).
These limitations are based on modeling analysis. They do not consider
any potential BPT or minimum treatment guidelines, to which Sodyeco's
winter discharge could be limited if some were to be adopted.

2' /.nx__alnrUt
CaryG►w. e•�.a.• /
-- -H—_ ... _ ----
iev rd4k,4f
:. /Ys 4/F1 Ko.�
+
/1Noo Z
6G7r.../te
O. 2.4-7o _/51.r eti.P,o.�s
. ( Le
aryo„ ie. s /• Y0
dovA s lt.6.4. 4. 10
,Saw , 4.1
tar P
%0)1g.5re
a.o6
ii,nsX D,30
Tres lore
/744
2 , .5- A 46 L)

3,G 3o /f5 /dam
coo
, 14 0 k,
0,o4/ MGD
/.1/v Ad
6.0c. MGO
`/o (r i2 y S s. (i<3 if. 7) (G/b )
6,,,te/.#rj x /<g /��y
r
.433 .47. /S1/47
6,aA
O, 00 6 S 0.036 /<y /eLy
f, H
2).. 6,j��.� • /J7es
6-?
%/t/. 7
q/, b 3 0"/5/57)
d6 a 6.-•,ye /i: (i X gottks G/ar.> (/ 'y , c >>
/3 0 /;3-
7.5 S
3oa
/4,4,./s
dat e.a.` G.)4 J /fie !ak K
Bo/Dr
ss
p 7a
O. 060 A116A

r.
H„4,.., Yf -- -1 0ridsl!.c,.:_ d.-C"/ Mya.. 4 /• 5/ MG1J_
.Cod_._ 3 3---_. '17 Al //.)07
/30P — sg 11 q . .. 663.._.. kl_ / 4). 7
r55. _ 361. 914. /<, I./.),.
or, i,rit,
diusii►!,
PH
..1 ,lea/_.. - - —
..e Pia. k./_ Pig..) l a h / M G. 4>
MG 0_ 3. 7g
r �t
f
a� •._ /21
3. 71r
$

Form ##001
WASTE LOAD ALLOCATION APPROVAL FORM
Facility Name: SY►�i- -
County: t4 z ' (e4i •
Regional Office:
LA(g Mo2r&sui)
Type of Wastewater: Industrial /OD
a
Sub -basin:
Requestor:
QQ 3l0V --
14 / A9; /l s
Domestic
If industrial, specify type(s) of industry: aitevnizai dyetedlles
Receiving stream: / MUM( , Class:
Other stream(s) affected: Class:
7Q10 flow at point of discharge: (Kirov iek d - P k04 6-rdo
30Q2 flow at point of discharge:
Natural stream drainage area at discharge point:
Recommended Effluent Limitations
-f Ji -co ihit04,91 st,1,' a p p/3 -1AVIG0 -fie- daily avt1 D a d: scj a e. 1 o
Mt iThicmci 1704, > 3/ cf 5.
suw�m�✓ �9�or htiaa1610*
�37i/- lb/dC
*so . slb/t
zfria.3.3145/
650.S165/ O
/1 fiv
V
sVl - / s-ii.
o. rq gies o.r4u Ibs/a/j
Ar eased spry (Tr) rot -Fs -rvoyvtdcy4) s- c4c f r, Ptdrii Crp e j/
earamdev-
,6096-
N
p.o,
?hef101s;
This allocation is:
Recommended and reviewed by:
for a proposed facility
for a new (existing) facility
a revision of existing limitations
a confirmation of existing limitations
Head, Techncial Services Branch
Reviewed by:
Regional Supervisor
Permits Manager
Approved by:
Division Director
Date:
Date:
Date:
Date:
Date:
3)

Form 9FUU1 '
Facility Name: S,
County: Alec le
Regional Office:
Type of Wastewater:
WASTE LOAD ALLOCATION APPROVAL FORM
/146r-/1/1 rCvie /JJ/
Sub -basin:
Requestor: / l3, /l/]/S
Industrial
Domestic
/OD
If industrial, specify type(s) of industry:
Receiving stream: GafacJ/A Class:
Other stream(s) affected: Class:'
APL3t,/6 f -se, hp kit)
7Q1O flow at point of discharge:
3OQ2 flow at point of discharge:
Natural stream drainage area at discharge point:
l Recommended Effluent Limitations
744 k,llew/l+-�C! /rhoii apply whem - Ce ti%, overa dlsckrqe,
- rom Jv7 -Tsk a/ PAM rs hods
Pa ra rn_i7C�
o, s1N l65/�1
Wes►- (Nov,_
/203S 45/
3 lizieby
to-`f 5,u•
o,54/465/d
This allocation is:
Recommended and
//
/ /
reviewed by:
for a proposed facility
for a new (existing) facility
a revision of existing limitations
a confirmation of existing limitations
AG)
Head, Techncial Services Branch
Reviewed by:
Regional Supervisor
Permits Manager
Approved by:
Division Director
Date:
Date:
Date:
Date:
Date:
r3l