HomeMy WebLinkAboutNC0021644_Sampling Reduction Request_20160616 1';
TOWN OF LA GRANGE 252-566-31886
203 S.CENTER ST.• PO BOX 368e- 152-566-2.201 (FAX)
LA GRANGE,NC 28551 (/ WWW LAGRAN(ENC COM
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RECEIVEDiNCE' DWR
June 8, 2016 JUN 1 3 2016
Division of Water Resources Permittingg Water Section
WQ Permitting Section
ATTN: Mr. John Hennessy
1617 Mail Ser vice Center
Raleigh, NC 27699-1617
Subject: NPDES Permit Modification Request
Sampling Reduction Request
Town of La Grange
La Grange WWTP
NPDES Permit#NC0021644
Lenoir County
Dear Mr. Hennessy:
The Town of La Grange is requesting a minor permit modification of NPDES Permit NC0021644
for a reduction in sampling. The permit expiration date is January 31, 2018. 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 BODS and NH3-
N removal rates. The date used for this analysis was for the period of May 2013 —April 2016.
Analysis of testing results for the past three years:
- Percent of Monthly Average Limit
Parameter Monthly Limit 3-Year Average % of Limit
(Summer)
BOD5 5.0 mg/1 1.6 mg/1 32 %
TSS 30.0 mg/L 2.5 mg/L 8 %
Fecal Coliform 200/100 ml 4.3 colonies/100 ml 2 %
NH3-N 2.0 mg/1 0.4 mg/1 20%
NC Public Power
Omer/Start Sento
- Number of Samples Over 200% of Monthly Average Limit
Parameter 200% of Monthly Limit Number of Samples Over
BODS 10.0 mg/1 6
TSS 60 mg/L 0
NH3-N 4.0 Summer/8.0 Winter 0 Summer/0 Winter
5 - Fecal Coliform samples exceeded 200%of the weekly average limit
In addition to the exceptional test results, the Town of La Grange WWTP is in compliance with
all other criteria listed in Section B Annroval 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 James Sutton, WWTP Superintendent, at 252/566-3295.
Sincerely,
9terCi
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John Craft, Manager
Town of La Grange
Three Year Data Summary- La Grange NPDES#0021644
2016 BOD Ave BOD Max 155 Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 2.0 5.5 3.4 8.3 4 420 0.4 2.7
February 0.6 4.3 0.2 3.6 2 74 0.8 2.6
March 1.6 9.1 1.9 8.2 3 360 0.8 3.3
April 0.7 5.1 0.0 0.0 2 9 0.2 0.3
2015 BOD Ave BOD Max T55 Ave T55 Max FC Ave FC Max NH3 Ave NH3 Max
January 4.0 9.2 3.3 16.3 5 23 0.2 0.6
February 4.9 10.2 7.8 28.0 39 224 0.2 0.7
March 4.2 9.8 5.9 20.0 16 106 0.3 0.6
April 2.9 11.2 3.4 17.3 7 240 0.2 0.9
May 0.3 3.2 2.5 8.0 4 616 0.2 0.5
June 0.0 0.0 0.0 0.0 2 6 0.3 3.2
July 0.0 0.0 0.0 0.0 4 930 0.1 0.2
August 0.0 0.0 0.0 0.0 3 820 0.1 0.1
September 0.3 3.5 0.2 4.6 2 380 0.1 0.3
October 2.4 6.5 4.5 16.0 2 29 0.2 0.4
November 0.0 0.0 0.0 0.0 2 1180 0.1 0.8
December 1.2 5.6 3.3 32.6 2 17 0.2 0.6
2014 BOD Ave BOD Max TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
January 2.0 5.6 3.3 18.0 2 21 0.9 5.7
February 0.4 3.0 1.9 5.0 7 44 4.4 6.3
March 0.4 5.3 0.0 0.0 8 34 0.2 3.5
April 1.9 5.2 2.9 7.6 8 52 0.4 1.2
May 2.2 6.1 3.3 9.0 5 112 0.3 0.4
June 0.3 3.6 0.0 0.0 2 9 0.4 3.5
July 1.1 6.4 1.6 11.5 4 280 0.2 1.7
August 3.8 9.0 7.6 26.0 12 164 0.4 0.9
September 2.5 11.5 4.5 26.0 10 624 0.2 0.7
October 1.6 9.4 3.1 15.0 5 48 0.2 0.9
November 2.3 12.5 4.5 33.0 6 160 0.4 1.4
December 2.2 7.4 4.8 14.0 8 21 0.2 0.5
2013 BOD Ave BOD Max TSS Ave TSS Max FC Ave FC Max NH3 Ave NH3 Max
May 0.4 3.7 0.0 0.0 3 10 0.1 0.8
June 2.2 7.3 4.0 6.0 10 970 0.3 0.5
July 2.9 8.7 3.9 14.0 25 336 0.3 0.8
August 2.3 6.2 3.3 14.8 6 2100 0.2 0.6
September 0.1 2.7 0.0 0.0 2 12 0.1 0.3
October 0.1 3.2 0.8 12.3 3 86 0.1 0.2
November 3.9 4.9 5.0 10.0 2 7 0.3 0.8
December 0.0 0.0 0.0 0.0 1 12 0.2 0.4
3-Year Arithmetic Average 1.6 r 04
Maximum Daily Result 12.5 33 2100 6.3
3-Year Geometric Mean Average 4.3
Permit Umk 5.0 30.0 200 2.0
% of Limit 32% 8% 2% 20.0%