NC0021601_Action Plan_20220401

Town of Tryon
Wastewater Treatment Plant
301 N.Trade St.
Tryon, N.C. 28782
[phone]
March 28, 2022
NCDEQ/DWR RECEIVED
NPDES Permitting Branch
1617 Mail Service Center APR 01 2022
Raleigh, NC 27699-1617
Attn: Michael Montebello NCDEQIDWRINPDES
RE: Town of Tryon
NPDES Permit No.NC 0021601
NPDES/Action Plan
Dear Mr. Montebello:
The Town of Tryon is sending this letter in response to the requirements in Section A.4. (1 & 2), schedule
of compliance for total copper and chloride limitations of the current NPDES permit. The following
letter includes the actions taken, results, and preliminary conclusions and recommendations. Please
review the included data and let us know if you need additional information or have any questions.
Sincerely,
Deborah Bradley, ORC
Tryon WWTP
CC:
Mikal Willmer—NCDEQ/DWR
Zach 011is—Town Manager
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A. Summary of Actions Taken:
The Town of Tryon in response to the requirements in Section A.4.(1 &2) of the current NPDES
permit dated August 1, 2020 has been monitoring the copper and chloride concentrations of the
WWTP effluent and from the wastewater discharge from our (SIU) Tryon Finishing Corporation.
Tryon Finishing Corporation has been identified by the Town staff as contributors of copper and
chloride based on known characteristics of the processes they employ. These results were
tracked and analyzed to evaluate NPDES compliance.
• In January 2018 the Town modified the IUP to lower copper limits from 0.27 mg/L to
0.24 mg/L.
• In June 2021 our SIU (Carolina Yarn Processors) changed ownership to Tryon Finishing
Corporation.
• The Town will implement a Compliance Schedule for the SIU if they have chronic
exceedances of copper in the next 24 months and/or if Tryon's effluent numbers
increase and/or biosolids levels increase significantly.
B. Monitoring Results:
The copper and chloride results are in the table below. The copper and chloride were taken
quarterly from March 2020 to December 2020 and January 2021 to December 2021. The NPDES
limits for copper are 22.2 ug/L (0.0222 mg/L) and chloride 625.7 mg/L. The permitted flow for
the plant is 1.5 MGD, which results in a mass balance of 0.275 lbs/day for copper and 7827
lbs/day for chloride. The minimum reporting level for copper is 0.002 mg/L and chloride is 4
mg/L.
Table 1.1-Tryon WWTP
Tryon Tryon
Effluent Effluent
Tryon Flow Copper Chloride
Date MGD mg/L lbs/day mg/L lbs/day
3/10/2020 0.352 0.015 0.044 30 88
6/9/2020 0.325 0.005 0.0135 30 81
9/8/2020 0.243 0.008 0.0162 38 77
12/1/2020 0.255 0.005 0.0106 19 40
1/14/2021 0.255 0.05 0.1063 36 76
2/2/2021 0.248 0.011 0.023 31 64
3/9/2021 0.262 <0.01 ND 38 83
4/6/2021 0.365 <0.01 ND 23 70
5/4/2021 0.509 <0.01 ND 25 106
6/8/2021 0.265 0.005 0.011 36 79
7/6/2021 0.176 <0.01 ND 74 108
8/3/2021 0.261 0.007 0.0152 51 111
9/7/2021 0.289 0.009 0.0217 46 110
10/5/2021 0.322 0.011 0.0295 59 158
11/2/2021 0.228 0.012 0.0228 38 72
12/14/2021 0.181 0.011 0.0166 52 78
Page 2 of 3

Total copper and chloride did not exceed effluent limitations for the years 2020
and 2021.
The current SIU (Tryon Finishing Corporation) contribute copper and chloride concentrations
with limits of 0.24 mg/L for copper and no limits for chloride. TFC quarterly and annually testing
for copper and chloride are shown in the table 1.2, below.
Table 1.2—Tryon Finishing Corporation
Tryon Finishing Corp. Tryon Finishing Corp.
TFC Flow Copper Chloride
Date MGD mg/L lbs/day mg/L lbs/day
1/5/2021 0.006 0.045 0.00225
3/9/2021 0.012 450 45
4/6/2021 0.017 <0.01 ND
7/13/2021 0.023 0.131 0.0251
10/12/2021 0.022 0.38 0.0697
11/29/2021 0.031 0.227 0.0587
The samples seem relatively consistent except for the October 2021 result.
C. Preliminary Conclusions:
The analysis of the results yields the following conclusions:
• The WWTP is compliant with the copper and chloride NPDES limits.
• One of the copper samples from our IU exceeded the IUP limits.
• The SIU initially identified by the Town are the primary contributors of
copper and chloride contaminants.
D. Recommendations:
The Town would put forward the following recommendations:
• The Town will continue to monitor and track the WWTP effluent concentrations for a
minimum of 24 months.
• The Town will also continue SIU monitoring and sampling over the same period.
• The Town will meet with Tryon Finishing Corporation to understand the process that
releases copper and chloride and evaluate options that could reduce the concentrations
of these constituents.
Page 3 of 3