NC0020231_Modification Request_20160425

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Office of the Mayor
110 W. Nash St.
Louisburg, N.C. 27549 °UNOEDo�� tale
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[phone] 111
[phone] FAX
April 19, 2016
RECEIVED/NCDE61/DWR
Division of Water Resources APR G 5 X016
WQ Permitting Section
ATTN: Mr. John Hennessy Water Quality
Permitting Section
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: NPDES Permit Modification Request
Sampling Reduction Request
Town of Louisburg
Tar River Water Reclamation Facility
NPDES Permit #NC0020231
Franklin County
Dear Mr. Hennessy:
The Town of Louisburg is requesting a minor permit modification of NPDES Permit NC0020231
for a reduction in sampling. The permit expiration date is September 30, 2019. We request that
monitoring for BOD5, TSS, NH3-N 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 greatly exceeded the minimum criteria for
reduced monitoring. The most restrictive summer limits was used for calculating BOD5 and
NH3-N removal rates. The date used for this analysis was for the period of January 2013 —
December 2015.
Analysis of testing results for the past three years:
- Percent of Monthly Average Limit
Parameter Monthly Limit 3-Year Average % of Limit
BOD5 8.0 mg/1 0.7 mg/1 9 %
TSS 30.0 mg/L 6.4 mg/L 21 %
Fecal Coliform 200/100 ml 29.2 colonies/100 ml 15 %
NH3-N 3.0 mg/1 0.2 mg/1 6.7%

- Number of Samples Over 200% of Monthly Average Limit
Parameter 200% of Monthly Limit Number of Samples Over
BODS 16.0 mg/I 0
TSS 60 mg/L 0
NH3-N 6.0 0
No Fecal Coliform sample exceeded 200%of the weekly average limit
In addition to the exceptional test results, the Tar River Water Reclamation Facility is in
compliance with all other criteria listed in Section B Approval Criteria of the October 22, 2012
guidance document regarding reduction of monitoring frequencies.
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 Jimmy Ellington, WRF Superintendent, at 919/496-2677.
Sincerely,
Karl Pernell, Mayor
Town of Louisburg

Three Year Data Summary- Louisburg NPDES #0020231
2015 BOD Ave BOD Max TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 0.0 0.0 9.4 15.0 11 60 0.4 0.9
February 0.8 3.5 11.0 17.8 8.9 300 0.4 1.3
March 0.4 2.4 12.4 18.8 48.3 330 0.3 0.8
April 1.0 4.2 8.9 15.2 59.6 250 0.2 0.3
May 0.9 6.3 7.4 10.4 15.9 120 0.3 0.4
June 1.4 7.8 5.1 8.7 11.3 180 0.2 0.3
0.6 0.6 3.5 3.6 5.3 28.7 330 0.2 0.2
August 0.6 7.5 4.0 5.8 21.1 340 0.2 0.2
September 0.2 3.3 3.4 4.3 79 320 0.1 0.2
October 0.6 3.0 3.8 7.8 24 250 0.2 0.3
November 0.2 2.9 5.7 9.9 23.1 260 0.2 0.3
December 0.4 5 5 9.7 38.3 230 0.2 0.5
2014 BOD Ave BOD Max TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 0.9 5.3 10.6 17.8 5.7 100 0.9 4.1
February 1.1 3.7 5.1 7.0 1 1 0.2 0.5
March 1.5 7.9 12.4 18.3 1.5 7 0.2 0.3
April 1.2 6.5 7.3 15.4 23.8 340 0.3 1.0
May 0.0 0.0 7.0 12.7 27.9 320 0.2 0.3
June 0.6 8.3 3.5 5.7 30.1 360 0.2 0.3
July 1.7 6.0 3.3 5.8 19.4 280 0.2 0.3
August 0.2 2.0 5.1 11.5 51 330 0.2 0.2
September 0.5 2.7 8.2 15.2 16.8 350 0.2 0.3
October 0.0 0.0 8.6 13.9 20 290 0.2 0.2
November 0.2 2.1 9.4 14.0 15.6 250 0.2 0.5
December 0.6 2.9 6.6 12.7 14.6 120 0.3 1.2
2013 BOD Ave BOD Max TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 0.6 4.6 3.6 8.3 21.7 70 0.3 0.6
February 0.5 2.4 3.1 5.9 52 350 0.2 0.4
March 2.8 6.4 10.9 16.4 76.6 200 0.3 0.4
April 0.9 3.6 4.0 8.4 29.6 280 0.2 0.3
May 0.4 2.4 3.7 6.8 21 70 0.2 0.5
June 0.0 0.0 4.1 5.2 18.5 150 0.2 0.3
July 0.3 2.2 6.0 8.2 71.1 330 0.2 0.4
August 0.9 8.2 3.5 5.4 58.8 320 0.2 0.4
September 0.4 3.0 5.4 13.7 100 350 0.2 0.3
October 1.4 6.8 6.8 13.7 1.2 4 0.2 0.3
November 0.2 2.4 7.6 12.9 1 0 0.2 0.3
December 0.4 2.7 8.9 12.8 1.8 44 0.2 0.3
3-Year Arithmetic Average 0.7 6.4 0.2
Maximum Daily Result 8.3 18.8 360 1.3
3-Year Geometric Mean Average 29.2
Permit Limit 8.0 30.0 200 3
of Limit 9% 21% 15% 6.7%