NC0026441_Permit (Modification)_20150504

NCDENR
North Carolina Department of Environment and Natural Resources
Pat McCrory Donald R.van der Vaart
Governor Secretary
May 4, 2015
Mr. Bryan Thompson, Town Manager
Town of Siler City
P. O. Box 769
Siler City, North Carolina 27344-0769
Subject: NPDES Permit Modification
Permit Number NCO026441
Siler City WWTP
Chatham County
Dear Mr. Thompson:
Division personnel have reviewed and approved your application for minor modification of the subject
permit. Accordingly we are forwarding the attached modified permit page. Please remove the existing
"Effluent Limitations and Monitoring Requirements"page and replace it with the one attached to this
letter.
This modification reduces the effluent monitoring frequencies for Biochemical Oxygen Demand
(BOD5),Total Suspended Solids (TSS) and Fecal Coliform from daily to 2/week monitoring. The
modification was based upon an evaluation of three years of facility effluent monitoring data. The
facility's performance satisfies the criteria established in the "DWQ Guidance Regarding the Reduction
of Monitoring Frequencies in NPDES Permits for Exceptionally Performing Facilities" as approved by
the Director of the Division of Water Resources on October 22, 2012, and justifies reduced monitoring
for these parameters. The modified monitoring frequencies will become effective on June 1, 2015.
Ammonia Nitrogen (NH3-N) did not meet the guidance standard that no more than 15 daily sampling
results over the 3-year(36 months) review period(March 2012 to February 2015) can be over 200% of
the monthly average limit for NH3-N. For parameters with summer and winter limits, an annual
arithmetic mean of the seasonal limits was used in the calculation which was 1.42 mg/L [seven(7)
months with 1.0 mg/L and five (5)months with 2.0 mg/L]. Sixteen(16) daily samples were greater than
200% of this arithmetic mean which is 2.83 mg/L. Monitoring frequency for Ammonia Nitrogen
(NH3-N) is daily.
This modification is issued pursuant to the requirements of North Carolina General Statute 143-215.1
and the Memorandum of Agreement between North Carolina and the U.S. Environmental Protection
Agency dated October 15,2007 (or as subsequently amended).
1617 Mail Service Center,Raleigh,North Carolina 27699-1617
Phone:[phone] Internet:www.ncwaterquality.org
An Equal Opportunity 1 Affirmative Action Employer

Mr. Thompson
NC0026441 Monitoring Frequency Reduction 2015 ,
Page 2 of 2
Please note that this permit is not transferable except after notice to the Division. The Division may
require modification or revocation and reissuance of the permit. This permit does not affect the legal
requirements to obtain other permits which may be required by the Division of Water Resources or any
other Federal, State, or Local governmental permits that may be required.
If you have any questions concerning this permit,please contact Derek Denard at telephone number
[phone] or via e-mail at [e-mail].
Si
7,
.�'
Jay Zimmerman, Director
Division of Water Resources,NCDENR
attachment
cc: Central Files
DWR/Raleigh Regional Office—Danny Smith
NPDES Permit File
ec: EPA Region 4 [[e-mail]]

Permit NCO026441
Part I
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
a. During the period beginning with the effective date and lasting until expiration,the Permittee is authorized to discharge
treated wastewater through Outfall 001. Such discharges shall be limited and monitored'by the Permittee as specified below:
EFFLUENT LIMITS MONITORING REQUIREMENTS
PARAMETERS Monthly Weekly Daily Measurement Sample Sample T
Average Average Maximum Fre uency e Location2
Flow 4.0 MGD Continuous Recording Influent or
Effluent
October
(April 1 thru October 31) p
BOD,5 day, 5.0 mg/L 7.5 mg/L 2/Week10 Composite Influent and
Effluent
BOD,5 day,20°C 3 10.0 mg/L 15
(November 1 thru March 31) .0 mg/L 2/Week10 Composite In fl d Effluent
Total Suspended Solids3 30.0 mg/L 45.0 mg/I, 2/Week10 Composite Influent and
NH3 as N Effluent
(April 1 thru October 31) 1.0 mg/L 3.0 mg/L Daily Composite Effluent
NH3 as N
(November 1 thru March 31) 2.0 mg/L 6.0 mg/L Daily Composite Effluent
Fecal Coliform 200/100 ml 400/100 ml 2/Week10 Grab Effluent
(geometric mean)
Total Residual Chlorine(TRC)4 17 µg/L Daily Grab Effluent
Temperature(°C) Daily Grab Effluent
Dissolved Oxygen Daily average>6.0 mg/L Daily Grab Effluent
pH >6.0 and<9.0 standard units Daily Grab Effluent
Total Nitrogen
(NO2+NO3 +TKN) Weekly Calculated Effluent
NO3-N+NO2-N(mg/L) Weekly Composite Effluent
TKN(mg/L) Weekly Composite Effluent
Total Phosphorus 0.5 mg/L(quarterly average) Weekly Composite Effluent
(April 1 thru September 30)
Total Phosphorus ;2.0 mg/L(quarterly average) Weekly Composite Effluent
.(October 1 through March 31)Total Cadmium 6 2. L 15.5 µg/L Monthly Composite Effluent
Total Copper Quarterly Composite Effluent
Total Zinc Quarterly Composite Effluent
Chloride Quarterly Composite Effluent
Chronic Toxicity$ Quarterly Composite Effluent
Effluent Pollutant Scan Monitor and Report Footnote 9 Footnote 9 Effluent
Footnotes:
1. No later than March 1,2015,begin submitting discharge monitoring reports electronically using NC DWR's eDMR
application system. See Condition A.(7).
2. Instream monitoring shall be performed in accordance with Condition A.(2).
3. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15 %of the respective
influent value(i.e., 85%removal is required).
4. TRC limits and monitoring requirements apply only if chlorine or chlorine derivatives are used for disinfection. The
Permittee shall report all effluent TRC values reported by a NC-certified laboratory[including field-certified]. Effluent
values below 50 µg/L will be treated as zero for compliance purposes.
5. Compliance with the Total Phosphorus limits shall be based on a calendar-quarter average of weekly samples.
6. Total Cadmium limits become effective December 1,2015. Monitoring shall begin on the effective date. See
Condition A.(6).
Page 3 of 10

Permit NCO026441
Footnotes A.(1)Continued:
7. Sample Quarterly in conjunction with Chronic Toxicity Test. '
8. Chronic Toxicity(Ceriodaphnia)at 90%;quarterly during March,June, September,December[see Condition A.(8)].
9. The permittee shall perform three Effluent Pollutant Scans during the term of this permit[see Condition A.(9)].
10. Sampling must occur on any two non-consecutive days during the calendar week(Sunday through Saturday).
b. Effluent shall contain no floating solids or foam visible in other than trace amounts.
A. (2) INSTREAM MONITORING REQUIREMENTS
Parameter Sample Type Location 1 Measurement Frequency 2
Dissolved Oxygen Grab LCU,LCD,RRU,RRD 3/Week(June—September),
1/Week(October-May)
Temperature Grab LCU,LCD,RRU,RRD 3/Week(June—September),
1/Week(October-May)
Total Phosphorus Grab LCU,LCD,RRU,RRD Monthly
TKN Grab LCU,LCD,RRU,RRD Monthly
NO3-N+NO2-N Grab LCU,LCD,RRU,RRD Monthly
Footnotes:
1. LCU-Loves Creek,upstream of the discharge;LCD-Loves Creek,downstream of the discharge and above the
confluence with the Rocky River;RRU—Rocky River,upstream of the confluence with Loves Creek;RFD—Rocky
River,downstream of the confluence with Loves Creek.
2. All monitoring is required to be performed at the above-mentioned monitoring locations. Instream Monitoring
may be performed by the Upper Cape Fear River Basin Association as outlined in the Memorandum of Agreement
(MOA)between the association and the permittee. If so,the data is to be collected and submitted to DWR in
accordance to the terms of the MOA. Should membership in this association terminate for any reason,the permittee
shall immediately notify the Division's NPDES Unit in writing and resume responsibility to monitor and report the
above parameters as specified in this permit.
A.�(3) NUTRIENT REOPENER
In the event that Permittee proposes to accept future industrial process wastewater that is expected to contain
concentrations of Total Nitrogen(TN)and/or Total Phosphorus(TP)greater than typical domestic wastewater
concentration(i.e. greater than 40.0 mg/L TN or greater than 5.0 mg/L TP),the Permittee shall notify the NPDES
Complex Permitting Unit of the Division at 1617 Mail Service Center,Raleigh,NC 27699 and the Raleigh
Regional Office at 3800 Barrett Drive,Raleigh,NC 27609 within 30 days of knowledge that the town is
considering accepting new industrial process wastewater containing excess nutrients. The notification shall contain
information regarding the proposed discharge flow,composition and treatability in the Siler City WWTP. Changes
in effluent characteristics may require a permit modification, so notification should be at least 180 days prior to the
start of the proposed discharge.
Based on information provided by the Town regarding a potential new industrial process wastewater with high
nutrient concentration,and pursuant to N.C. General Statute Section 143-215.1 and the implementing rules found in
Title 15A of the North Carolina Administrative Code, Subchapter 2H, specifically, 15A NCAC 2H.0112(b)(1)and
2H.0114(a),and Part 11, Sections B-12 and B-13 of this permit,the Director of DWR may then reopen this permit
to require supplemental nutrient limits for Total Nitrogen and/or Total Phosphorus in accordance with the current
Basin Plan for the Cape Fear River Basin.
Page 4 of 10

DATE
Facility Name X l e v, C J y n
NPDES Permit# V G 0(7 Z 6�L�
Have any Civil Penalties assessed against the facility during the past 3 years? Yes /
Data Review Z •.7 Fe 13
Period of Review Fe L I y
(POR) ��� �
From: 12 To:
BOD G031p
4�2 Number of permit limit violations for BOD that occurred during the previous year
5 . I;,ID
Permit Monthly Average Limit mg/L
3 Year Effluent Data Average Z• mg/L
5 Highest Daily Values During POR
2 $. Date: 7 j�
(S • 6 Date: I t
Date: ( 2A� �3
Date: C 3
• Date: -3/-V 3
TSS C v �3 v
_ 6�7 Number of permit limit violations for TSS that occurred during the previous year
Permit Monthly Average Limit 7 mg/L
3 Year Effluent Data Average Z mg/L
5 Highest Daily Values During POR
LIV Date: )Ito/
U�] Date: 7 I/
Date: q Z d 12
3 Date: 1( zj- 1`1
(0, 3 Date: ( ? IT

NH3-N G-O
y Number of.permit limit violations for NH3-N that occurred(during the previous year
Permit Monthly Average Limit ` ' O mg/L `' `• /
3 Year Effluent Data Average O •6 mg/L
5 Highest Daily Values During POR
P. 3 Date: Voq
7- 3 Date: 11dy
Date: � f g 1
�. Date: 1 /y
e Date: 1 2 /�
Fecal Coliform/Enterococci ZE& w 1 b
'22 Number of permit limit violations for Fecal Coliform/Enterococci that occurred during the
previous year
Permit Monthly Average Limit 2 C9-O /100m1
3 Year Effluent Data Geometric Mean S.78 /100ml
5 Highest Daily Values During POR
NOD Date: 1 V $, / �
-7� b Date: �y
S J S� Date: ! I y
(47,0 Date: 1
1 Date:
Daily data must be depicted graphically on attached sheets for each parameter.
I certify that the information provided on this permit modification request sheet is accurate and
complete to the best of my knowledge.
Signature/Title

n
Data Review Summary
Monitoring Frequency Reduction Evaluation
Facility Name _ ��(14
NPDES Permit ,✓C 0 o Zb 9 N
Receiving Stream L bU s Basin: !� dG �+�f Y
303(d) listed? No
Data Period of Review �i`/,��
Reviewed by feet k c -,4
Date 1 p [ �{c
a'z7 e f Gi k
Permit Limits: Summer Winter
Monthly Avg. Weekly Avg. Monthly Ate. Weekly Avg.
T�a mg/L 7.Y mg/L 10.0 mg/L /J, o mg/L
IN �� �2.be
3 Year Average �J �mg/L (target=
# Daily Values> mg/L
Meets the review guidance standards for this parameter?
TSS
Permit Limits: All Months �---
Monthly Av . Weekly Avg.
?—a—mg/L q-r, mg/L
3 Year Average Z -q 2 mg/L (target= IS— )
#Daily Values> 60 mg/L O
Meets the review guidance standards for this parameter?
NH3-
Permit Limits: Summer Winter
Monthly Avg. Weekly Avg. Monthly Avg. Weekly Avg.
�. D mg/L 3, o mg/L ,"a mg/L Z) mg/L
3 Year Average � O.bq mg/L (target=yf-?I �� x ?, �Z ryj
Z �
#Daily Values> mg/L *� /
Meets the review guidance standards for this parameter? /2 l y1�w
cal Colif /Enterococci
its: All Months �2
Monthly Avg. Weekly Avg_ Zvi►!.,
? o p /100 ml Oo /100 ml
3 Year Geometric Mean �' (target= 100 )
#Daily Values> 10 b 1?
Meets the review guidance standards for this parameter? ,
Attach Violation and Enforcement Reports

DATE 05/01/2015
Facility Name Siler Citv WWTP
NPDES Permit# NCO026441
Have any Civil Penalties assessed against the facility during the past 3 years? No: Not since 2003.
See attached Permit Enforcement History by Permit.
Data Review
Period of Review(POR)
From: March 2012 To: February 2015
BOD
0 Number of permit limit violations for BOD that occurred during the previous year: See attached
Monitoring Report(MR) Violations 03-2013 to 02-2015. No action, best professional judgment
was taken for a 02/28/2015 missing BOD. Unsafe to sample due to winter storm.
Permit Monthly Average Limit: 5.0/ 10.0 m /L Summer/Winter 7.08 m /L annual arithmetic
mean of seasonal limitsl
3 Year Effluent Data Average: 2.60 mg/L: See attached C0310 -BOD data.
5 Highest Daily Values During POR
25.5 Date: 03/10/2014
15.6 Date: 03/11/2014
15.1 Date: 12/19/2013
8.9 Date: 03/06/2013
8.9 Date: 03/07/2013
TSS
0 Number of permit limit violations for TSS that occurred during the previous year: See attached
Monitoring Report(MR) Violations 03-2013 to 02-2015. No action, best professional judgment
was taken for a 02/28/2015 missing TSS. Unsafe to sample due to winter storm.
Permit Monthly Average Limit 30 mg/L
3 Year Effluent Data Average 2.92 mg/L: See attached C0530 -BOD data.
5 Highest Daily Values During POR
44 Date: 03/10/2014
27 Date: 03/11/2014
<25 Date: 09/21/2012
13 Date: 11/25/2014
10.3 Date: 01/12/2015

NH3-N
0 Number of permit limit violations for NH3-N that occurred during the previous year: See attached
Monitoring Report(MR) Violations 03-2013 to 02-2015. No action, best professional judgment
was taken for a 02/28/2015 missing NH3-N. Unsafe to sample due to winter storm.
Permit Monthly Average Limit 1.0/2.0 mg/L�ummer/winter) 11.42 mg/L annual arithmetic
mean of seasonal limits)
3 Year Effluent Data Average 0.64 mg/L See attached C0610 -N113-N data.
5 Highest Daily Values During POR
8.3 Date: 03/10/2014
8.3 Date: 03/11/2014
6.2 Date: 02/28/2014
5.8 Date: 02/18/2014
5.4 Date: 07/12/2013
Fecal Coliform/Enterococci
0 Number of permit limit violations for Fecal Coliform/Enterococci that occurred during the previous
year: See attached Monitoring Report(MR) Violations 03-2013 to 02-2015. No action, best
professional judgment was taken for a 02/28/2015 missing Fecal Coliform. Unsafe to sample due
to winter storm.
Permit Monthly Average Limit 200/100m1
3 Year Effluent Data Geometric Mean 5.78/100ml: See attached 31616—Fecal Coliform data.
5 Highest Daily Values During POR
1900 Date: 11/15/2013
760 Date: 05/16/2014
535 Date: 01/02/2014
420 Date: 08/13/2014
381 Date: 11/21/2014

Data Review Summary
Monitoring Frequency Reduction Evaluation
Facility Name Siler City WWTP
NPDES Permit NCO026441
Receiving Stream Loves Creek 117-43-101 Basin: Cape Fear
303(d) listed? Yes: Listed for DO, Benthos Fair, and Fish Tissue Hiz (see_ attached
2012 North Carolina 303(d) List-Category 5
Data Period of Review _March 2012-February_ 2015
Reviewed by Derek Denard
Date May 1, 2015
BODs
Permit Limits: Summer (7 months) Winter(5 months)
Monthly Avg. Weekly Avg. Monthly Avg. Weekly Avg.
5.0 mg/L 7.5 mg/L 10.0 mg/L. 15.0 mg/L
used 7.08 mg/L annual arithmetic mean of seasonal limitsl
3 Year Average 2.60 mg/L (target=3.54)
#Daily Values> 14.6 mg/L 3
Meets the review guidance standards for this parameter? Yes
TSS
Permit Limits: All Months
Monthly Avg. Weekly Avg.
30 mg/L 45 mg/L
3 Year Average 2.92 mg/L (target= 15)
#Daily Values> 60 mg/L 0
Meets the review guidance standards for this parameter? Yes
NEb-N
Permit Limits: Summer Winter
Monthly Avg. Weekly Avg. Monthly Avg. Weekly Avg.
1.0 mg/L , 3_0 mg/L 2_0 mg/L 6_0 mg/L
fused 7.08 mWL annual arithmetic mean of seasonal limits]
3 Year Average 0.64 mg/L (target= 0.71)
#Daily Values>2.83 mg/L 16
Meets the review guidance standards for this parameter? NO: more than 15 daily_(16) sampling
results in the review period over the 200% of monthly averalze limit
Fecal Coliform/Enterococci
Permit Limits: All Months
Monthly . Weekly Avg.
200/100 ml 400/100 ml
3 Year Geometric Mean 5.78 (target=110)
#Daily Values>800 1
Meets the review guidance standards for this parameter? Yes
Attach Violation and Enforcement Reports

DWQ Guidance Regarding the Reduction of Monitoring Frequencies in
NPDES Permits for Exceptionally Performing Facilities
October 22, 2012
A. Purpose
In its efforts to reduce the regulatory burden upon permittees while maintaining adequate compliance
oversight over point source discharges, DWQ has developed the following guidance for the reduction
of monitoring frequencies in NPDES permits for specific target parameters., Standard minimum
NPDES monitoring frequencies are established in 15A NCAC 213 .0508 for discharges from facilities
with specific Standard Industrial Classification (SIC) categories. However, 2B .0508(b)(1) states: "If it
is demonstrated to the satisfaction of the Director that any of the tests and measurements, sampling
points, or frequency of sampling requirements, as required in this Rule for a particular SIC group, are
not applicable to the discharge of a particular water pollution control facility, or if it can be
demonstrated that the objectives of this Section can be achieved by other acceptable means then
such requirements may be waived or modified to the extent that the Director determines to be
appropriate." This document identifies criteria to be used by DWQ that satisfies the regulatory
standard for the allowance of reduced monitoring frequencies for facilities included in SIC 4952.
This guidance applies to facilities with outstanding NPDES program compliance histories, exhibiting
effluent discharges that are excellent in both quality and consistency. Such performance will
demonstrate that compliance for particular parameters can be adequately evaluated with less
monitoring. Facilities demonstrating consistent, long-term treatment performance at levels far below
effluent limitations (<50%) may be considered for a reduction in monitoring from existing permit
frequencies to a 2/week minimum frequency for the parameters BODSi CBOD5 TSS, NH3-N and fecal
coliformlenterococci (the "target parameters").
B. Approval Criteria
Individual NPDES facilities shall submit a written request to modify their NPDES permit specifying
which parameters are to be considered for reduced monitoring . Permit holders must include with
their requests sufficient data, statistical analyses, and other information to support the justification for
reduced monitoring. NPDES permit staff shall review the application and supporting information.
Approval of reduced monitoring frequency shall be granted if all the criteria below are met:
• The facility has no more than one civil penalty assessment for permit limit violations for each
target parameter during the previous three years.
• Neither the permittee nor any of its employees have been convicted of criminal violations of the
Clean Water Act within the previous five years.
• The facility is not currently under an SOC for target parameter effluent limit noncompliance.
• The facility is not on EPA's Quarterly Noncompliance Report for target parameter limit violations.
• For BOD5i CBOD5, TSS, NH3-N and TSS, the three year arithmetic mean of effluent data must be
less than fifty percent of the monthly average permit limit. For fecal coliform or enterococci, the

three year geometric mean must be less than 50 percent of the monthly average permit limit. For
parameters with summer and winter limits, an annual arithmetic mean of the seasonal limits may
be used in the calculation.
• With the exception of fecal coliform or enterococci, no more than 15 daily sampling results over
the 3-year review period can be over 200% of the monthly average limit for BOD5i CBODS, TSS,
or NH3-N . Values associated with documented impacts of extreme weather or events beyond the
control of the permittee will not be included.
• For fecal coliform or enterococci, no more than 20 daily sampling results may be over 200% of the
weekly average limit. Values associated with documented impacts of extreme weather or events
beyond the control of the permittee will not be included.
• For the four target parameters, sampling results shall not show more than two non-monthly
average limit violations during the previous year.
• Reduced effluent monitoring must not impair assessment of sensitive downstream uses, such as
endangered species.
C. Implementation
After DWQ review and approval, the facility's NPDES permit will be reissued with reduced monitoring
frequencies for qualified parameters. Additional NPDES permit requirements will include:
• Eligible facilities may be granted a reduction from existing permit monitoring frequencies to a
2/week minimum frequency for the four target parameters. Reductions will be made for both
effluent and influent sampling.
• Where monitoring is reduced to twice per week, it must occur on any two non-consecutive days
during the calendar week (Sunday through Saturday).
• Required monitoring frequency reductions establish new permit minimums for monitoring. As
always, facilities may monitor more often than required in the permit.
• If a reportable event, as defined by the permit[e.g., Part 11 (E) (6 & 9)] occurs, any facility granted
reduced monitoring frequencies will be encouraged to monitor on a daily basis until the episode is
resolved.
Monitoring frequency reduction from the minimum frequencies reductions established by the rules are
based upon consistent, exceptional performance. DWQ may revoke on a case-by-case basis these
reductions if the facility begins to perform in noncompliance with permit limits. If a facility's monitoring
reduction for a specific parameter is removed through permit modification, reconsideration of
monitoring frequency reduction will only occur three years following the revocation/permit modification
action, or at the next permit renewal.

Tobin of wirer City
SILER CITY,NORTH CAROLINA 27344-0769
all
PO BOX 769 `e' e4 r PHONE[phone]
311 N SECOND AVENUE i FAX[phone]
�aw
March 25, 2015
RECEIVED/DENROWR
NC Department of Environment and Natural Resources APR — 2 2015
Division of Water Quality/NPDES Unit Water Quality
ATTN:Mr.John Hennessy Permitting Section
1617 Mail Service Center
Raleigh,NC 27699-1617
Subject: NPDES Permit Modification Request
Sampling Reduction Request
Town of Siler City
NPDES Permit#NC0026441
Chatham County
Dear Mr. Hennessy:
The Town of Siler City is requesting a minor permit modification of NPDES Permit NCO026441 for a
reduction in sampling. We request that monitoring for BODS, TSS, Ammonia Nitrogen and Fecal
Coliform be reduced under the "exceptionally performing facilities" criteria to two times per week. The
attached data (summarized in the following table) indicates that the WWTP effluent has exceeded the
minimum criteria for reduced monitoring. The most restrictive summer limit was used for calculating all
BODS and Ammonia Nitrogen removal rates. In addition to the test results, the Siler City WWTP is in
compliance with all other criteria listed in Section 8 Approval Criteria-of the-October-22, 2012 guidance
document regarding reduction of monitoring frequencies. The date used for this analysis was for the
period of January 2012—February 2015.
Analysis of testine results for the past three years:
Percent of Monthly Average Limit
Parameter Monthly Limit 3-Year Average %of Limit
BOD5 S.0 mg/I 1.5 mg/I 30%
TSS 30.0 mg/L 0.7 mg/L 2S%
NH3 1.0 mg/I 0.21 mg/I 21%

Fecal Coliform 200/100 ml 5.5 colonies/100 ml 3 0
Number of Samples Over 200%of Monthly Average Limit
Parameter 200%of Monthly Limit Number of Samples Over
BOD5 10 mg/l 2
TSS 60 mg/L 0
NH3 2 mg/l 4
One(1)Fecal Coliform sample exceeded 200"/o of the weekly average limit
The Town appreciates the Division's effort to reduce the regulatory and monetary burden on
systems that strive consistently to provide exceptional wastewater treatment. We thank you for
your consideration in these matters. If you have any additional questions or comments, please
call Chris McCorquodale at 919/742-4581
Sincerel ,
Bryan Thompson, Town Manager
Town of Siler City

Three Year Data Summary - Siier City NPDES #0026441
2012 BOD Ave 30D Ma TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 1.0 6.3 0.0 <2.5 1 2 1.2 3.5
February 0.0 2.0 0.0 <2.5 1 1 0.0 <0.5
March 0.0 2.0 0.0 <2.5 1 1 0.0 <0.5
April 1.7 4.2 0.0 <2.5 1 3 0.0 <0.5
May 2.5 4.1 0.0 <2.5 2 295 0.0 <0.5
June 2.4 3.8 0.0 <2.5 3 9 0.0 <05
July 4.1 5.7 0.0 <2.5 5 57 0.1 0.8
August 2.1 4.2 0.1 <2.5 4 16 0.0 <0.5
September 1.3 4.1 0.1 <2.5 10 32 0.0 <0.5
October 0.8 2.9 0.0 <2.5 4 14 0.0 <0.5
November 0.8 3.9 0.0 <2.5 2 6 0.0 <0.5
December 0.5 2.3 0 <2.5 1 1 0.1 <0.5
2013 BOD Ave 300 Ma: TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 1.4 5.5 0.3 3.3 1.2 4 0.5 3.0
February 2.0 4.4 2.1 7.3 1 2 0.4 3.7
March 2.9 8.9 3.6 7.5 1 1 1.0 4.0
April 1.5 3.6 0.0 <2.5 2 11 0.0 <0.5
May 21 4.1 0.3 1.0 14 200 0.0 <0.5
June 1.4 4.0 0.1 <2.5 18 45 0.1 2.0
July 1.9 8.6 0.3 3.6 39 265 0.5 5.4
August 0.9 4.6 0.0 <2.5 40 133 0.0 <0.5
September 1.1 5.0 0.0 <2.5 29 56 0.0 <0.5
October 0.6 4.4 0.0 <2.5 20 43 0.1 <0.5
November 1.4 7.1 0.0 <2.5 22 1900 0.1 <0.5
December 2.1 15.1 0.0 <2.5 2 11 0.0 <0.5
2014 SOD Ave 30D Ma; TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 0.6 4.6 0.2 4.2 2 535 0.1 2.3
February 1.3 3.9 0.5 3.9 1 4 1.3 6.2
March 4.1 25.5 3.8 44.0 2 3 1.3 8.3
April 2.7 3.9 0.0 <2.5 4 16 0.0 <0.5
May 2.8 6.7 0.9 8.9 44 760 0.1 0.9
June 1.3 4.0 0.0 <2.5 43 230 0.0 <0.5
July 1.6 5.6 0.2 <2.5 26 59 0.1 0.8
August 0.7 4.8 0.4 4.7 23 420 0.5 S.2
September 0.6 4.0 0.0 <2.5 38 57 0.0 <0.5
October 0.7 3.6 0.0 <IS 27 48 0.0 <0.5
November 1.3 3.5 4.5 13.0 30 381 0.0 <0.5
December 1.1 3.1 3.4 10.2 6 23 0.0 <0.5
2015 BOD Ave 30D Ma: TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 2.3 5.2 3.7 10.3 4 240 0.0 0.5
February 1.1 5.7 2.2 7.3 2 14 0.1 1.4
3-Year Arithmetic Average 1.5 0.7 �� 0.21
3-Year Geometric Mean Average 5.5
Permit Limit 5.0 30.0 200 1.0
% of Limit 30% 2.5% 3% 21%