NC0074772_Permit Modification_20170831

Water Resources
ENVIRONMENTAL QUALITY
August 31, 2017
Thomas J. Roberts, President, COO
AQUA North Carolina, Inc.
202 MacKenan Court
Cary, North Carolina 27511
ROY COOPER
Gwenw
MICHAEL S. REGAN
Secretap,
S. JAY ZIMMERMAN
Direclor
Subject: Correction Change -Pages for Permit
NPDES Permit NCO074772
Diamond Head Subdivision WWTP, Grade WW-2
799 Williamson Road, Mooresville
Iredell County
Dear Mr. Roberts:
The Division of Water Resources (the Division) has recently noted an error in your permit
recently issued July 14, 2017 [see part I, A. (L)]. We note that the units for effluent characteristic
Total Chloride are listed incorrectly as micrograms per liter (ug/L), and should correctly read
milligrams per liter (mg/L).
We have therefore generated change -pages to correct this error. Please insert these change -pages into
your active permit and discard the old pages. We have likewise corrected the Basinwide Information
Management System (BIMS) to mollify any potential compliance issue with submitting Discharge
Monitoring Reports (DMRs or eDMRs).
If you have questions about this correction, or if we can further assist you, please contact Joe R.
Corporon, L.G. at [Joe.corporon ncdenr.gov] or call his direct line [phone]. The Division
regrets any inconvenience this error may have caused your organization.
Re ectfully,
S. Jay Zimmerman
Enclosure: NPDES Permit NCO074772 (correction change -pages)
he: Central Files
NPDES Program Files
ec: MRO/SWPS, Corey Basinger, Supervisor
OCU, Maureen Kinney
ATB, Susan Meadows, Cindy Moore
AQUA, Laurie Ison [[e-mail]]
State ofNonh Camlitta I Envimnmemal Quality I WaterRaom s
1611 Mail service Center I Releigt, Noah Camlina 27699-1611
919 707 9000

Permit NCO074772
Part I
A. (L) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[ 15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of the permit and lasting until expansion above 0.0731
MGD, the Permittee is authorized to discharge from Outfall 001. Such discharges shall be limited, monitored
and reported 1 by the Permittee as specified below:
_ _ ] 1 �+t.. .'?..S ��Y "Y.'F-F"0 ^ .•.ri '. i.•
-. c '11 h..�. Lp5 '6i'-cT'L.
.[-t
'+- 1 !
�- ....r
r ` t .
[� ,�
r
.f,v.Yl.. 1 .''_•
..
-
- �'
A�.
.�-./.��C y ♦
r'7a. _
.;^'•
-Z
,t�,xOCa�IUII-
0.07.3�1hMGD
Flow
50050
0.100 MGD 3
Continuous.
Recording
I or E
Total Residual Chlorine 4
50060
28 µg/L
2/Week
Grab
E
BOD, 5 day (20°C)
C0310
15.0 mg/L
22.5 mg/L
Weekly
Composite
E
Total Suspended Solids
C0530
30.0 mg/L
45.0 mg/L
Weekly
Composite
E
Ammonia (NH3 as N)
C0610
4.0 mg/L
20.0 mg/L
Weekly
Composite
E
Dissolved Oxygen
00300
Daily Average > 5.0 mg/L
Weekly
Grab
E
pH
00400
Not < 6.0 or > 9.0 s. u.
Weekly
Grab
E
Fecal Coliform (geometric mean)
31616
200/100 mL
400/100 mL
Weekly
Grab
E
Temperature (°C)
00010
Weekly
Grab
E
Total Hardness — as [CaCO3 or
00900
Quarterly
Composite
E & U
Ca + M (m
Total Copper
01042
7.88 µg/L
10.47 µg/L
Quarterly
Composite
E
Total Fluoride
00951
1,800 µg/L
1,800 µg/L
Quarterly
Composite
E
Total Chloride
00940
230 mg/L
250 mg/L
Quarterly
Composite
E
Total Zinc
01092
125.7 µg/L
125.7 µg/L
Quarterly
Composite
E
Total Nitrogen (mg/L) 5
C0600
Monitor & Report
Quarterly
Composite
E
(NO2 + NO3 +
Total Phosphorus (mg/L)
C0665
Monitor & Report
Quarterly
Composite
E
Combined radium-226 and
6,7
11503
5 pCi/L (annual average)
Quarterly
Composite
E
radium-228 (pCi/L)
Alpha emitters, excluding radon
and uranium (pCi/L) 6,7
82077
15 pCi/L (annual average)
Quarterly
Composite
E
Beta emitters, excluding potassium-
40 and other naturally occurring
03520
50 pCi/L (annual average)
Quarterly
Composite
E
radionuclides (pCi/L) 6,7
Strontium-90 (pCi/L) 617
13501
30 µg//L (weekly average)
Quarterly
Composite
E
Tritium (pCi/L) 6,7
82126
20,000 pCi/L (annual average)
Quarterly
Composite
E
Uranium (µg/L) 7,8
22708
30 µg//L (weekly average)
Quarterly
Composite
E
Chronic WET Testing 9
TGP3B
-T
Quarterly
Grab
E
See Footnotes, Page 4
Page 3 of 8

Permit NCO074772
Table A. (1.) Footnotes:
1. The Permittee shall submit discharge monitoring reports electronically using the Division's
electronic Discharge Monitoring Report System (eDMR) system [see A. (6)].
2. E = Effluent; I = Influent; U = Upstream
3. Discharge flow limit at 0.100 MGD is not permitted except after applying for, and receiving the
Division's Authorization to Construct (ATC) permit (see page 2 of 8).
4. The Division shall consider compliant all effluent TRC values reported below 50 µg/L. However,
the Permittee shall continue to record and submit all values reported by a North Carolina -
certified test methods (including field certified), even if these values fall below 50 µg/L.
5. For a given wastewater sample, TN = TKN + (NO2 N + NO3 N), where TN is Total Nitrogen
and TKN is Total Kj eldahl Nitrogen, and (NO2 N + NO3 N) is Nitrite/Nitrate Nitrogen.
6. If the quarterly value exceeds 4 times the annual average limit, then (a) the sampling frequency
shall increase to monthly and (b) a written notification shall be sent to the Water Quality
Permitting Section and the Mooresville Regional Office.
7. All quarterly samples shall be taken 72 to 80 hours after the introduction of offsite wastewater
into the equalization tank. If an introduction of offsite wastewater does not occur within a given
quarter, a sample shall be taken of the effluent and noted on the DMR as "No introduction of
offsite wastewater occurred for this quarter."
8. A quarterly value can be determined from one quarterly sample, or from the average of multiple
sample values, not to exceed seven (7) consecutive days, during a given quarter.
9. Chronic Toxicity [TGP3B] (Ceriodaphnia dubia) limited; effluent concentration at 90% during
the months of January, April, July and October [See A. (2.)].
Condition: The Permittee shall discharge no floating solids or foam visible in other than trace amounts.
A. (2.) CHRONIC TOXICITY PERMIT LIMIT (QUARTERLY)
[15A NCAC 02B.0200]
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality to
Ceriodaphnia dubia at an effluent concentration of 90 %.
The permit holder shall perform at a minimum, quarterly monitoring using test procedures outlined in the
"North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure" (revised December 2010 or subsequent
versions), or "North Carolina Phase H Chronic Whole Effluent Toxicity Test Procedure" (revised- December
2010 or subsequent versions). Tests will be performed during the months of January, April, July and
October. These months signify the first month of each three-month toxicity testing quarter assigned to the
facility. Effluent sampling for this testing must be obtained during representative effluent discharge and shall
be performed at the NPDES-permitted final effluent discharge below all treatment processes.
If the test procedure, performed as the first test of any single quarter, results in a failure or ChV below
the permit limit, then multiple -concentration testing shall be performed at a minimum, in each of the two
following months, as described in "North Carolina Phase II Chronic Whole Effluent Toxicity Test
Procedure" (revised -December 2010), or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge
Monitoring Form (MR-1) for the months in which tests were performed, using the parameter code TGP3B for
the pass/fail results and THP3B for the Chronic Value. Additionally, DWR Form AT-3 (original) is to be sent
to the following address:
Page 4 of 8