NC0037508_Permit Modification_20060201

Michael F. Easley
Governor
rWilliam G. Ross, Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E., Director
Division of Water Quality
February 1, 2006
Mr. James D. Frye
Department of Public Works - Moore Co.
1094 Addor Rd.
Aberdeen, North Carolina 28315
Subject: NPDES Permit Modification
Permit No. NCO037508
Moore County WWTP
Moore County
Dear Mr. Frye:
The Division has reviewed your request to modify the mercury requirement in your
NPDES permit. Based on the upstream data collected by Moore County the mercury limit has
been modified. The permit issued on May 13, 2005 contained a mercury limit of 12 ng/L. This
limit was based on the assumption that the stream had reached its assimilative capacity. Moore
County collected data upstream of the discharge for 6 months showing a maximum mercury
concentration of 3.72 ng/1. The mercury limit was recalculated using 3.72 ng/L as the
background concentration. The new mercury limit is 24.1 ng/L. A reasonable potential analysis
was completed using the effluent data provided by Moore County. The results show there is
reasonable potential to exceed the mercury limit; therefore the limit will be implemented in the
permit and the schedule of compliance remains in place.
The effluent limitations and monitoring page with the mercury limit modification is
enclosed, please replace this page in your permit. If you have any questions concerning this
permit modification, please call Teresa Rodriguez at [phone]. extension 553.
Sincerely,,/
V •`` -
Gil Vinzani,FE.
EAST NPDES Unit Supervisor
Cc: NPDES Files 1f
Fayetteville Regional Office - Surface Water Protection
Central Files
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone]
Internet: h2o.encslate.nc.us 512 N. Salisbury St. Raleigh, NC 27604 FAX [phone]
An Equal Opportunity/Affirmative Action Employer -50q Recyded/lO% Post Consumer Paper
N"o�` ,Carolina
Customer Service
1-877-623-6748

Permit NCO037508
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period beginning on February 1, 2006 and lasting until expiration, the Permittee is- authorized to
discharge through Outfall 001. Such discharges shall be limited and monitored by the Permittee as specified
below:
+�P't'_
, - .Z^.^X. C:; i;t�'p�yMY'S
' L ��
...�5 C31�h7,.'}a�
},
:ra•.�w. .-aµf.:,'.,ra1''�.'F�t,...s;Se».._..:..�.:.�
L,1 lWr"s�.,.-:•:v-Tke'r+S2
r 'Wy eeldy ;
4,5:�'{�� �,..: •L-: m
y age
..,. n..- .mar . +
pair]/
- ':.��a'" 1`
� , ,N��y+a�:-
.�"--.-.\-;,a
f re' e`i
tom„
Y e R
.�.
X';
.. Q
Flow
6.7 MGD
Continuous
Recording
Influent or Effluent
BOD, 5 day, 200C
(April 1— October 31 2
22.0 mg/L
33.0 mg/L
Daily
Composite
Influent & Effluent
BOD, 5 day, 200C
November 1— March 31 2
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent & Effluent
Total Suspended Solids SS 2
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent & Effluent
NH3 as N
(April 1— October 31
2.1 mg/L
6.3 mg/L
Daily
Composite
Effluent
NH3 as N
November 1— March 31
6.2 mg/L
18.6 mg/L
Daily
Composite
Effluent
Fecal Coliform(geometric mean
200 / 100 ml
400 / 100 ml
Daily
Grab
Effluent
Total Residual Chlorine C 3
28 µ &
Daily
Grab
Effluent
Dissolved Oxygen
Dail average > 5.0 mg/L
Daily
Grab
Effluent
Temperature °C
Dail
Grab
Effluent
Conductivity
Dail
Grab
Effluent
H
> 6.0
and < 9.0 standard
units
Daily
Grab
Effluent
Total Phosphorus
Monthly
Composite
Effluent
Total Nitrogen
(NO2-N + NO3-N + TKN)
Monthly
Composite
Effluent
Total Copper
2/Month
Composite
Effluent
Total Zinc
2/Month
Composite
Effluent
Total Silver
2/Month
Composite
Effluent
Total Mercury 4
24.1 n L 4
Weekly
Grab
Effluent
Chronic Toxicity 5
Quarterly
Composite
Effluent
Temperature, °C
Variable6
Grab
U, D
Dissolved Oxygen
Variable6
T Grab
U, D
Footnotes
1. U: approximately 100 feet upstream of the outfall. D: Downstream at NCSR 1225.
2. The monthly average effluent BODS and Total Suspended Solids concentrations shall not exceed 15 % of the
respective influent value (i.e., 85% removal is required).
3. Total Residual Chlorine (TRC) shall be monitored only if chlorine is used to disinfect.
4. Mercury -- Compliance to the permit limit shall commence on July 1, 2007, 24 months following the effective date of
this permit (see A. (2.)J. To facilitate the Lumber River's Phase H TMDL process for mercury, the Permittee shall report
mercury using clean -sample collection criteria/test methods established by EPA Method 1631.
5. Chronic Toxicity (Ceriodaphnia) at 41 %; quarterly during March, June, September, December; See A. (3.)
6. Variable: instream samples shall be collected upstream and downstream 3/week during the summer months of June,
July, August, and September; samples shall be collected weekly during the rest of the year.
Units:
mg/L = milligrams per liter µg/L = micrograms per liter m1= milliliter
ng/L = nanograms per liter lbs/Day = pounds per day BOD = biochemical oxygen demand
NH3 as N = ammonia as nitrogen
Effluent shall contain no floating solids or foam visible in other than trace amounts.

REASONABLE POTENTIAL ANALYSIS
Mercury
Date Data
BDL=I2DL
Results
9.57
9.6
Std Dev.
3.0860
9.11
9.1
Mean
7.1031
7.76
7.8
C.V.
0.4345
9.01
9.0
n
26
4.14
4.1
2.58
2,6
Mult Factor =
1.76
3.35
3.4
Max. Value
17.8 ngfL
6.83
6.8
Max. Pred Cw
31.3 ng/L
3.8
3.8
6.2
6.2
4.2
4.2
4.5
4.5
6.0
6.0
72
7.2
8.1
8.1
7.2
7.2
10.5
10.5
7.4
7.4
9.2
9.2
5.7
6.7
6.5
6b
4.6
4.6
9.5
9.5
5.2
5.2
8.7
8.7
17.8
17.8
15.a
C�5
�q•�
MC°OJ
ot,= 4.-1 NbD
60d<Ztouaid (pnca� Cmu� nr.��a fib) 3•�2 n`�/L
5a-aY,6affJ - Q "91L CC -Was
a4, I rijIL-
(Q,ti)(S.3z)
�C- p I<6p
-1_
npdes rpa 200403.4, data
1272006

Mercury 1631 Effluent Test Results
Date
Location
Result
7/7/2005
Effluent
9.57
7/14/2005
Effluent
9.11
7/19/2005
Effluent
7.76
7/28/2005
Effluent
9.01
8/4/2005
Effluent
4.14
8/9/2005
Effluent
2.58
8/18/2005
Effluent
3.35
8/25/2005
Effluent
6.83
8/30/2005
Effluent
3.75
9/8/2005
Effluent
6.16
9/15/2005
Effluent
4.20
9/22/2005
Effluent
4.50
9/27/2005
Effluent
6.04
10/7/2005
Effluent
7.19
10/13/2005
Effluent
8.12
10/18/2005
Effluent
7.21
10/25/2005
Effluent
10.50
11 /3/2005
Effluent
7.41
11 /8/2005
Effluent
9.19
11/17/2005
Effluent
5.72
11 /22/2005
Effluent
6.53
11 /29/2005
Effluent
4.57
12/6/2005
Effluent
9.51
12/13/2005
Effluent
5.22
12/21 /2005
Effluent
8.71
12/29/2005
Effluent
17.8Q

Mercury 1631 Upstream Test Results
Date
Location
Result
7/14/2005
Upstream
3.33
7/26/2005
-Upstream
3.72
8/11 /2005
Upstream
2.85
8/30/2005
Upstream
2.94
9/7/2005
Up stream
1.81
9/20/2005
Upstream
1.43
10/11 /2005
Upstream
1.96
10/20/2005
Upstream
1.62
11 /4/2005
Upstream
1.01
11 /15/2005
Upstream
1.64
12/6/2005
Upstream
3.23
12/20/20051
Upstream I1.53

Permitting for Hg-Impaired Waters.,,
• Water is Hg-impaired and on 303(d) list
• EPA assumes no additional stream assimilation
available
• Perform RPA with NO dilution
• If RPA exists, add limit (WQS at end -of -pipe) and
Compliance Schedule.
• Facility can collect upstream samples to test
assumption.
,' og s l uJarlce 6veifio►1 P. t AIIoW40e-
w6re
(7 Q,u + %) (C.o,) — (7 Q io)(Ce.<o)
—- � QD
70,o = S+re0Y-rMa0
Q6 = de s n hoW
CWQS = wpq-m �,a lr h� siano(c�ci
CaKfin: bacKS,oWhdcotrAho"
STC-P I-Ca/cylq-je inax,wvmPr-eW1cie%EFF/uPai 64Cj 4hon usi�j RP4 Vte4164ee�
STEP Z- 6a/cyle4le #Qow4V(- Effluen) I. -icEo 4l4hI N
EXAM le I-.4sswme (2BKoo= o 061)
70n= 10 M6-D
po= I m6-D
CwJQS= I n6m,
Theyi) Cailowable =
�XAmp�P 2 - AsSyme �'6K6� _
TAen,
1=rld
I
IZrlj11
I
E,carh Ie3_ assume Caxrio = �y/ \
Then, Calhpi-A/e=(Iot1)(Iz) — (Io�(UJ : 9Z Ea
I 16
�P a - add Ltm/I iF regsayloVe pde✓I-u / exl-4j : MoX Pl-edl( ki > Al/ow,. 1e

Department of Public Works
Wastewater Treatment Plant
1094 Addor Road
Aberdeen, NC 28315
10 i
January 12, 2006
Re: Request a Mercury Re -Evaluation
Mr. Alan Klimek
NCDENR/DWQ/NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
Mr. Klimek:
Telephone: [phone]
Facsimile: [phone]
The Moore County Water Pollution Control Plant, NPDES Permit No. NC0037508,
would like to request a mercury re-evaluation. We are currently testing our effluent
weekly using EPA Method 1631 and have a weekly limit of 12 ng/L. The permit states
that if we can provide six months of new data and that there is no reasonable potential for
the effluent concentrations to exceed 12 ng/L or that the upstream concentrations are
below 12 ng/L that we can request a re-evaluation.
I am providing a summary sheet, lab result sheets and a Chain of Custodies for data
collected on Aberdeen Creek which is upstream from our plant at the sampling location
specified in our NPDES Permit. Samples were collected twice a month for six months.
I have also included a summary sheet of the mercury results from our effluent since the
permit went into effect July 1, 2005. I can provide lab result sheets and Chain of
Custodies for these if you desire.
Please consider my request for re-evaluation of mercury. If additional information is
needed, please call me at 910-281-3146.
Sincerely,
l j t2i^"-k
James D. Frye, System Superintendent
JDF/sab
Cc: Ms. Belinda Henson, Fayetteville Regional Office, DEM
Mr. Charles Weaver, NPDES Unit
Mr. Marcus Jones, Moore County Public Works Director