NC0020664_Compliance Schedule Report for Cu and Ag limits_20220629

June 29, 2022
NCDEQIDWR
NPDES Permitting Branch
1617 Mail Service Center
Raleigh, NC 27699-1617
Attn: Gary Perlmutter
Re: Town of Spindale
NPDES No. NC0020664
NPDES Monitoring Report
Dear Mr. Perlmutter,
The Town of Spindale is submitting this letter in response to the requirements in Section A.4.
Schedule of compliance for total copper and total silver limitations of the current NPDES permit.
The following information includes the actions taken, results, and conclusions and
recommendations. Please review the included data and let us know if you need additional
information or have any questions. Thanks again for working with us on the NPDES permit.
Very Truly Yours,
Scott Webber
Town Manager
CC
Mikal Willmer — NCDEQ-DWR
Guy O'Connor - Town of Spindale
Kurt Wright, PE — SDG Engineering
Joseph Rodriguez, El — SDG Engineering

A. Summary of Actions Taken
The Town of Spindale (Town) in response to the requirements in Section A.4.1 of the current NPDES
permit dated July 1, 2020 has been monitoring the copper and silver concentrations of the WWTP
effluent and influent and from the wastewater discharge from three significant industry users (SIU).
These SIUs had been identified by the Town staff as likely contributors of copper and silver based on
known characteristics of the processes they employ. These results were tracked and analyzed to
evaluate NPDES compliance.
B. Monitoring Results
The copper and silver results are in the table below. The copper and silver tests were taken monthly
from April 2020 to June 2022 which included results from the WWTP and the SIUs. The copper and
silver test date range for the WWTP specifically, was June 2020 to May 2022. The NPDES limits for
copper and silver are 45.7 µg and 0.3 µg respectively. The permitted ADF for the plant is 3MGD,
which results in a mass balance of 1.14 lbs./day and 0.0075 lbs./day of copper and silver respectively.
The minimum reporting level from the available test for silver is 0.50 µg, therefore <0.50 jig in the
tables below represents a non -detectible (ND) level of silver. During this period, there were two
samples that exceeded the copper concentration limits. The September 2020 copper sample was well
outside the other samples and could be an anomaly and the December 2021 was just slightly over the
limit, additional test data will be needed to confirm this. Consideration should be given to split sampling
to confirm the analytical results.
Table 1.1 - Spindale WWTP
DATE
SPINDALE
FLOW MGD
SPINDALE EFFLUENT COPPER
SPINDALE EFFLUENT SILVER
MGD
µg/L
lbs./day
µg/L1
lbs./day
7/14/2020
0.43
17.1
0.06132
<0.50
ND
8/3/2020
0.66
22
0.12110
<0.50
ND
9/15/2020
0.64
109
0.58180
<0.50
ND
10/16/2020
0.54
12.4
0.05584
<0.50
ND
11/2/2020
0.63
20.8
0.10929
<0.50
ND
12/3/2020
0.64
23.4
0.12490
<0.50
ND
1/4/2021
0.48
18.3
0.07326
<0.50
ND
2/1/2021
0.65
23.4
0.12685
<0.50
ND
7/6/2021
0.46
39.4
0.15115
<0.50
ND
11/1/2021
0.52
24.1
0.10452
<0.50
ND
12/6/2021
0.51
n - 5
0.20204
<0.50
ND
1/3/2022
2.48
21.3
0.44055
<0.50
ND
2/1/2022
0.5
25
0.10425
<0.50
ND
5/3/2022
0.59
21.1
0.10382
<0.50
ND
Mean
0.695
30.3
0.16862
<0.50
ND
1Minimum detectible limit of silver is <0.50p.g/L.
21Page
Town of Spindale
NPDES Monitory Report

The samples seem consistent except for the September 2020 result. Although the December 2021 result
exceeds the copper limits, it is still relatively consistent with the higher copper values that did not
exceed copper limits. The mean and standard deviation with the September data is 30.3 µg and 22.65
µg respectively and without the September data is 24.29 µg and 8.92 µg respectively. Chart 1.1 shows
the effluent copper concentration and mass balance over time. As can be seen, the September 2020
sample is significantly higher than the other samples, which were within the NPDES limits It should be
noted that the effluent copper concentration for December 2021 was also higher than the monthly limit
but not as significant as the September 2020 result. Also, the mass balance for January 2022 was higher
than the monthly mass balance limit, but this is most likely the result of the high flows that the WWTP
experienced that day.
Concentration (pg/L)
120
100
80
60
40
20
0
12/1/2019
Chart 1.1 - WWTP Effluent Copper
0.70
6/18/2020 1/4/2021 7/23/2021 2/8/2022
0.60
0.50
0.40
0.30
0.20
- 0.10
0.00
8/27/2022
Mass Balance (Ibs/day)
f Effluent
Copper
— 0—Monthly Limit
(conc.)
Average
Concentration
--Daily Limit
Mass Balance
31Page
Town of Spindale
NPDES Monitory Report

Chart 1.2 shows the samples without the September 2020 results and indicates the general consistency of
the samples. As mentioned previously, the December 2021 result was slightly above the monthly
copper limit, but the result is still consistent with the higher copper values that were collected during this
time period. Additional testing including split sampling techniques will be conducted should there be a
change in the consistency of the copper concentrations over time.
60
50
J
co 40
0
30
n3
a)
0
a 20
U
10
0
12/ 1 /2019 6/18/2020 1/4/2021 7/23/2021 2/8/2022 8/27/2022
Chart 1.2 - WWTP Adjusted Effluent Copper
•
Effluent
Copper
f Monthly Limit
(conc.)
Average
Concentration
Daily Limit
The silver concentration in the WWTP effluent was <0.50 ng or non -detect for the sampling period.
There were some detectible silver limits from one of the SIUs. The current SIUs, which contribute
copper and silver concentrations, are Ultimate Textiles, Timken, and Spindale Mills. The Ultimate
Textiles monthly testing for both copper and silver are shown in Table 1.2 below. Ultimate Textiles is
the largest contributor in terms of flow, copper, and silver of the SIUs. Table 1.3 and 1.4 contain the
monthly results for Timken and Spindale Mills respectively. The Mass Balance of the WWTP and SIUs
are shown in Chart 1.3 and demonstrate that Ultimate textiles is a major contributor, with Spindale Mills
as a moderate contributor, and Timken as a minor contributor.
41Page
Town of Spindale
NPDES Monitory Report

Table 1.2 - Ultimate Textiles (SIU1)
DATE
ULTIMATE
TEXTILE FLOW
ULTIMATE TEXTILE COPPEFR
ULTIMATE TEXTILES SILVER
MGD
µg/L
lbs./day
µg/L1
lbs./day
4/22/2020
0.029
24.3
0.005877
3.1
7.50E-04
5/22/2020
0.06
300
0.15012
0.144
7.21E-05
6/22/2020
0.06
24.2
0.01211
<0.50
ND
7/23/2020
0.075
108
0.067554
<0.50
ND
8/12/2020
0.051
952
0.404924
<0.50
ND
9/16/2020
0.054
589
0.265262
2.5
1.13E-03
10/23/2020
0.058
2150
1.039998
<0.50
ND
11/13/2020
0.069
80.7
0.04644
<0.50
ND
12/10/2020
0.064
396
0.211369
<0.50
ND
1/22/2021
0.067
46
0.025704
<0.50
ND
2/19/2021
0.052
105
0.045536
<0.50
ND
3/29/2021
0.083
167
0.115601
<0.50
ND
4/22/2021
0.089
93.7
0.06955
<0.50
ND
5/28/2021
0.076451
170
0.108392
<0.50
ND
6/14/2021
0.076
25.8
0.016353
<0.50
ND
7/16/2021
0.0685
88.3
0.050445
<0.50
ND
8/23/2021
0.0687
106
0.060734
<0.50
ND
9/23/2021
0.0318
3650
0.968024
<0.50
ND
10/11/2021
0.056
1240
0.57913
<0.50
ND
11/18/2021
0.053
128
0.056579
<0.50
ND
12/20/2021
0.043
44
0.015779
<0.50
ND
1/26/2022
0.033
46.3
0.012743
<0.50
ND
2/25/2022
0.038
2450
0.776454
<0.50
ND
4/14/2022
0.051
123
0.052317
0.52
<0.0002
5/6/2022
0.048
495
0.198158
<0.50
ND
6/16/2022
0.042
269
0.094225
2.00
<0.0007
Mean
0.057556
533.5115
0.20959
0.722
3.46E-04
1Minimum detectible limit of silver is <0.50µg/L.
5 Page
Town of Spindale
NPDES Monitory Report

Table 1.3 - Timken (SIU2)
DATE
TIMKEN FLOW
TIMKEN COPPER
TIMKEN SILVER
MGD
µg/L
lbs./day
µg/L1
lbs./day
6/3/2020
0.0086
78.5
0.00563
<0.50
ND
7/8/2020
0.0015
52
0.00065
<0.50
ND
8/26/2020
0.00135
36
0.00041
<0.50
ND
9/16/2020
0.0095
28.6
0.00227
<0.50
ND
10/28/2020
0.00432
40.2
0.00145
<0.50
ND
12/2/2020
0.001
26.2
0.00022
<0.50
ND
1/22/2021
0.072
7.6
0.00456
<0.50
ND
3/17/2021
0.0005
106
0.00044
<0.50
ND
7/30/2021
0.00105
20.2
0.00018
<0.50
ND
8/20/2021
0.0081
24
0.00162
<0.50
ND
9/22/2021
0.00153
71
0.00091
<0.50
ND
2/16/2022
0.0063
2
0.00011
<0.50
ND
3/23/2022
0.0027
21.9
0.00049
<0.50
ND
Mean
0.0091
39.6
0.00146
<0.50
ND
'Minimum detectible limit of silver is <0.50µg/L.
Table 1.4 - Spindale Mills (SIU3)
DATE
SPINDALE MILLS
FLOW
SPINDALE MILLS COPPER
SPINDALE MILLS SILVER
MGD
µg/L
lbs./day
µg/L1
lbs./day
4/3/2020
0.035
14
0.00409
<0.50
ND
5/22/2020
0.05
23
0.00959
<0.50
ND
7/30/2020
0.064
12
0.00641
<0.50
ND
8/11/2020
0.088
84.3
0.06187
<0.50
ND
9/16/2020
0.064
12.4
0.00662
<0.50
ND
11/10/2020
0.061
130
0.06614
<0.50
ND
12/11/2020
0.154
30.9
0.03969
<0.50
ND
2/16/2021
0.144
13
0.01561
<0.50
ND
3/29/2021
0.11
430
0.39448
<0.50
ND
4/14/2021
0.142
63.5
0.07520
<0.50
ND
5/13/2021
0.0626
199
0.10389
<0.50
ND
61Page
Town of Spindale
NPDES Monitory Report

Table 1.4 - Spindale Mills (SIU3) cont.
DATE
SPINDALE MILLS
FLOW
SPINDALE
MILLS COPPER
SPINDALE
MILLS SILVER
DATE
SPINDALE
MILLS FLOW
MGD
µg/L
lbs./day
µg/L'
lbs./day
6/10/2021
0.09
123
0.09232
<0.50
ND
7/20/2021
0.0649
19.9
0.01077
<0.50
ND
8/18/2021
0.102
38.6
0.03284
<0.50
ND
9/2/2021
0.052
14.7
0.00638
<0.50
ND
10/21/2021
0.008
172
0.01148
<0.50
ND
11/16/2021
0.02
68.8
0.01148
<0.50
ND
12/14/2021
0.114
0.012
0.00001
<0.50
ND
1/21/2022
0.095
161
0.12756
<0.50
ND
2/10/2022
0.101
196
0.16510
<0.50
ND
4/13/2022
0.081
16.5
0.01115
<0.50
ND
5/11/2022
0.05
31.9
0.01330
<0.50
ND
Mean
0.0797
84.296
0.05754
<0.50
ND
'Minimum detectible limit of silver is <0.50µg/L.
1.40000
1.20000
• 1.00000
• 0.80000
a)
U
TO 0.60000
m
vci 0.40000
0.20000
0.00000
12/1/2019
Chart 1.3 - Copper Mass Balance
6/18/2020
Town of Spindale
NPDES Monitory Report
1/4/2021
2/8/2022
- e-WWTP Mass
Balance
f Ultimate
Textiles
- Timken
Spindale Mills
f Headworks
Mass Balance
8/27/2022
71Page

The SIU silver and copper contributions were combined in Table 1.5 in a head works analysis. The
combined influent characteristics from the SIUs account for 4.88% of the permitted flow, 23.49% of the
copper mass balance, and 4.62% of the silver mass balance.
Table 1.5 - Combined SIU
Significant Industry User
Flow
Avg. Influent Copper
Avg. Influent Silver
MGD
µg/L
lbs./day
µg/L
lbs./day
Table 1.2 - Ultimate Textiles
(SIU1)
0.0576
533.51
0.2096
0.721692308
3.46E-04
Table 1.3 -Timken (SIU2)
0.0091
39.55
0.0015
<0.50
ND
Table 1.4 - Spindale Mills
(SIU3)
0.0797
84.30
0.0575
<0.50
ND
Subtotal
0.14633
0.2686
0.000346423
of NPDES Limits
4.88%
23.49%
4.62%
C. Conclusions
The analysis of the results yields the following conclusions:
• The WWTP is predominantly compliant with the copper and silver NPDES limits.
• Two of the copper samples exceeded the NPDES limits (one appears to be an anomaly).
• The silver concentrations are undetectable.
• The SIUs initially identified by the Town are the primary contributors of silver and copper
contaminants.
D. Recommendations
The Town would put forward the following recommendations:
• The Town will continue to monitor and track the WWTP effluent concentrations for the
remainder of the permit.
o The Town will submit a summary of actions taken towards achieving compliance to the
Division per Section A.4.3 on July 1, 2023.
o The Town shall achieve compliance by July 1, 2024 per Section A.4.4.
o This data then can be used by DEQ for the next RPA (Reasonable Potential Analysis) at
permit renewal time.
• The Town will also continue SIU monitoring and sampling over the same period.
• The Town will continue to meet with Ultimate Textiles to understand the process that releases
copper and silver and will evaluate options that could reduce the concentrations of these
constituents.
81Page
Town of Spindale
NPDES Monitory Report