NC0031836_Permit (Modification)_20120724

NPDES DOCUMENT SCANNING; COVER SHEET
NC0031836
Fourth Creek WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modificatio
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
July 24, 2012
This document la priYtted cork reuse paper - more any
content on the reYerse side

ATA
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Charles Wakild, P. E. Dee Freeman
Governor Director Secretary
July 24, 2012
Mr. Jerry Byerly
Assistant Director, Water Resources Dept.
City of Statesville
P.O. Box 1111
Statesville, North Carolina 28687
Subject: Permit Monitoring Revision for Fourth Creek WWTP
NPDES Permit NC0031836
Iredell County
Dear Mr. Byerly:
Division personnel have reviewed your request to reduce the mercury monitoring
requirements in the Fourth Creek WWTP permit. The Division is providing this monitoring
frequency reduction for consistency with our monitoring frequency guidance for toxicants,
dated July 15, 2010. The Division is able to make a minor modification in accordance 15A
NCAC 2H.0114 which reduces the mercury sampling frequency from weekly to monthly.
We are forwarding you the new pages for Sections A. (1.) and A. (2.), Effluent Limitations
and Monitoring Requirements, which reflect the reduction in mercury monitoring. You should
replace your existing Effluent Limitations and Monitoring Requirements sheets with these revised
pages. This minor 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).
If any parts, measurement frequencies or sampling requirements contained in this permit
correction are unacceptable to you, you have the right to an adjudicatory hearing upon written
request within thirty (30) days following receipt of this letter. This request must be in the form of a
written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with
the Office of Administrative Hearings (6714 Mail Service Center, Raleigh, North Carolina 27699-
6714). Unless such demand is made, this decision shall be final and binding.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone]
Internet: www.ncwateraualitv.org
No1e Carolina
�tllCRllI,J
An Equal Opportunity 1 Affirmative Action Employer

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
Quality or permits required by the Division of Land Resources, the Coastal Area Management Act or
any other Federal or Local governmental permit that may be required.
If you have any questions concerning this permit, please contact Julie Grzyb at telephone number
[phone].
for Charles Wakild, P.E., Director
Enclosure NPDES Permit NC0031836 (Modified Permit)
cc: NPDES Files
Central Files
Mooresville Regional Office / Surface Water Protection
e-copy:
EPA Region 4

Permit NC0031836
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (4.0 MGD)
During the period beginning on the effective date of the permit and lasting until the monthly average flow
discharged exceeds 3.6 MGD, the Permittee is authorized to discharge from outfall 001. Such discharges shall be
limited and monitored by the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample Location1
Flow
4.0 MGD
Continuous
Recording
Influent or Effluent
BOD, 5 day, 20 °C
(April 1 to October 31)2
17.0 mg/L
25.5 mg/L
Daily
Composite
Influent & Effluent
BOD, 5 day, 20 °C
(November 1 to March 31)2
27.0 mg/L
40.5 mg/L
Daily
Composite
Influent & Effluent
Total Suspended Solids2
30.0 mg/L
45.0 mg1L
Daily
Composite
Influent & Effluent
NH3 -N
(April 1 to October 31)
12.0 mg/L
35.0 mg/L
Daily
Composite
Effluent
_
NH3 -N
(November 1 to March 31)
18.0 mg/L
35.0 mg/L
Daily
Composite
Effluent
Dissolved 0xygen3
Daily ' -
Grab
Effluent
Dissolved Oxygen
3/Week
Grab
. Upstream & Downstream
Fecal Coliform
(geometric mean)
200 / 100 mL
400 / 100 mL
Daily
Grab
Effluent
Total Residual Chlorine
28 µg/L
Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
Temperature
3/Week
Grab
Upstream & Downstream
Conducfivity
Daily
Grab
Effluent
Total Nitrogen
(NO2 + NO3 + TKN)
Weekly
Composite
Effluent
Total Phosphorus
Weekly
Composite
Effluent
pH4
Daily
Grab
Effluent
Total Mercury5
27 ng/L
27 ng/L
Monthly
Grab
Effluent
Chronic Toxicity6
Quarterly
Composite
Effluent
Effluent Pollutant Scan
See A. (5.)
Annual
Grab
Effluent
Notes:
1. Upstream = at NCSR 2316. Downstream = approximately 0.5 miles downstream from the outfall. Upstream
and downstream samples shall be grab samples collected 3/week during June, July, August and September then
once per week during the rest of the year: (As a participant in the Yadkin Pee -Dee Diver Basin Association, the subject
facility is not responsible for conducting the instream monitoring requirements as stated above. Shouldyour membership in the
agreement be terminated, you shall notify the Division immediately and the instream monitoring requirements specified inyour permit
will be automatically reinstated)
2. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent value (85% removal).
3. The daily average dissolved oxygen effluent concentration shall not be less than 5.0 mg/L.
4. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
5. The facility may request a permit modification to reflect the requirements of the mercury TMDL once it
is adopted by the state.
6. Chronic Toxicity (Cerzodaphnia) at 45%: January, April, July & October (see special condition A. (3.)).
There shall be no discharge of floating solids or visible foam in other than trace amounts.

Permit NC0031836
A. (2.)
During the period beginning when the monthly average flow discharged exceeds 3.6 MGD and lasting until
expiration, the Permittee is authorized to discharge from outfall 001. Such discharges shall be limited and monitored
by the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample Locationl
Flow •
6.0 MGD
Continuous
Recording
influent or Effluent
BOD, 5 day, 20 °C
(April 1 to October 31)2
17.0 mglL
25.5 mglL
Daily
Composite
Influent & Effluent
BOD, 5 day, 20 °C
(November 1 to March 31)2
27.0 mg/L
40.5 mg/L
Daily
Composite
Influent & Effluent
Total Suspended Solids2
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent & Effluent
NH3 -N
(April 1 to October 31)
2.0 mg/L
6.0 mg/L
Daily
Composite
• Effluent
NH3 -N
(November 1 to March 31)
4.0 mg/L
12.0 mglL
Daily
Composite
Effluent
Dissolved 0xygen3
Daily
Grab
Effluent
Dissolved Oxygen
3/Week
Grab
Upstream & Downstream
Fecal Coliform
(geometric mean)
200 /100 mL
4001100 mL
Daily
Grab
Effluent
Total Residual Chlorine
28 µglL
Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
Temperature
3/Week
Grab
Upstream & Downstream
Conductivity
Daily
Grab
Effluent
Total Nitrogen
(NO2 + NO3 + TKN)
Weekly
Composite
Effluent
Total Phosphorus
Weekly
Composite
Effluent
pH4
Daily
Grab
Effluent
Total Mercury5
22 ng/L
22 nglL
Monthy
Grab
Effluent
Total Phenols6
816 uglL
816 uglL
Weekly
Grab
Effluent
Chronic Toxicity?
Quarterly
Composite
Effluent
Effluent Pollutant Scan
See A. (5.)
Annual
Grab
Effluent
Notes:
1. Upstream = at NCSR 2316. Downstream = approximately 0.5 miles downstream from the outfall. Upstream
and downstream samples shall be grab samples collected 3/week during June, July, August and September then
once per week during the rest of the year. (As a participant in the Yadkin Pee -Dee River Basin Association, the subject
facility is not responsible for conducting the instream monitoring requirements as stated above. Shouldyour membership in the
agreement be terminates you shall notify the Division immediately and the instream monitoring requirements specified inyour permit
will be automatically reinstated)
2. The monthly average effluent BODS and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent value (85% removal).
3. The daily average dissolved oxygen effluent concentration shall not be less than 5.0 mg/L.
4. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
5. The facility may request a permit modification to reflect the requirements of the mercury TMDL once it is
adopted by the state.
6. The facility is allowed 18 months from the time it becomes subject to the 6 MGD Effluent Limitations and
Monitoring Requirements before the total phenols limitation takes effect After 24 data points are collected, the
facility may request DWQ to determine if there is still reasonable potential to exceed the EPA criteria. If no
reasonable potential exists, the Division may remove the limit and/or reduce the monitoring frequency.
Statesville may submit this request in conjunction with the review of its mercury data or wait until the facility
becomes subject to the 6 MGD Effluent Limitations and Monitoring Requirements before submitting a request
for the review of the phenols data.
7. Chronic Toxicity (Ceriodaphnia) at 55%: January, April, July & October (see special condition A. (4.)).
There shall be no discharge of floating solids or visible foam in other than trace amounts.

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Ili. a Nux 1111 • 'tutesuille. Nurtli Carolina aBiiB7
18 June, 2011
Tom Belnick
DWQ
Surface Water Section
Complex Permitting Unit
Central Office
1617 Mail Service Center
Raleigh, NC, 27699-1617
Dear Mr. Belnick:
The cover letter dated 7 July, 2010 that accompanied the City of Statesville Fourth
Creek plant permit, #NC0031836 allowed the City to request a change in
Mercury monitoring if the City could demonstrate the lack of reasonable
potential for mercury in our effluent. I am attaching monitoring results for 89
samples. As you can see by the results there were no instances of mercury
reaching the permit limits. On days when mercury was a little higher than our
normal we can trace that to maintenance activities in the plant or a rainfall event.
Based on the data the City requests that the mercury limit be removed from our
permit.
If we can provide any further information, please feel free to contact me at 704-
878-3438.
Sincerely,
(l/
erry W. Byerly
Assistant Director, Water Resources Department
Ft. (s.7--3 R{F812
ith.„;
- ._{UALLTY

WEEKLY MERCURY SAMPLING
4TH CREEK WWTP
NUMBER
DATE
RESULT (ng/I)
PERMIT LIMIT
(DAILY/MONTHLY)
1
8/4/10
2.21 ng/I
27 ng/I
2
8/23/10
2.36 ng/I
27 ng/I
3
9/2/10
2.51 ng/I
27 ng/I
4
9/15/10
2.15 ng/I
27 ng/I
5
9/29/10
2.81 ng/I
27 ng/I
6
10/6/10
1.4 ng/I
27 ng/I
7
10/20/10
3.5 ng/I
27 ng/I
8
11/3/10
2.2 ng/I
27 ng/I
****9
11/10/10
17.0 ng/I
27 ng/I
10
11/17/10
3.3 ng/I
27 ng/I
11
11/24/10
<1.0 ng/I
27 ng/I
12
12/3/10
2.5 ng/I
27 ng/I
13
12/8/10
2.0 ng/I
27 ng/I
14
12/15/10
2.3 ng/I
27 ng/I
15
12/22/10
3.5 ng/I
27 ng/I
16
12/29/10
3.0 ng/I
27 ng/I
17
1/5/11
3.6 ng/I
27 ng/I
18
1/12/11
3.0 ng/I
27 ng/I
19
1/19/11
2.1 ng/I
27 ng/I
20
1/25/11
3.7 ng/I
27 ng/I
21
1/31/11
6.1 ng/I
27 ng/I
22
2/8/11
2.2 ng/I
27 ng/I
23
2/16/11
1.7 ng/I
27 ng/I
24
2/23/11
2.3 ng/I
27 ng/I
25
3/2/11
1.4 ng/I
27 ng/I
26
3/8/11
2.7 ng/I
27 ng/I
27
3/16/11
3.1 ng/I
27 ng/I
28
3/23/11
2.4 ng/I
27 ng/I
29
3/29/11
2.2 ng/I
27 ng/I

WEEKLY MERCURY SAMPLING
4TH CREEK WWTP
NUMBER
DATE
RESULT (ng/I)
PERMIT LIMIT
(DAILY/MONTHLY)
30
4/6/11
2.4 ng/I
27 ng/I
31
4/12/11
2.1 ng/I
27 ng/I
32
4/20/11
2.2 ng/I
27 ng/I
33
4/26/11
1.6 ng/I
27 ng/I
34
5/3/11
1.2 ng/I
27 ng/I
35
5/10/11
1.1 ng/I
27 ng/I
36
5/18/11
1.2 ng/I
27 ng/I
37
5/23/11
1.2 ng/I
27 ng/I
38
5/31/11
1.2 ng/I
27 ng/I
39
6/7/11
1.1 ng/I
27 ng/I
40
6/15/11
1.9 ng/I
27 ng/I
41
6/22/11
1.6 ng/I
27 ng/I
42
6/28/11
2.2 ng/I
27 ng/I
43
7/6/11
1.6 ng/I
27 ng/I
44
7/13/11
<1.0 ng/I
27 ng/I
45
7/20/11
1.7 ng/I
27 ng/I
46
7/27/11
1.1 ng/I
27 ng/I
47
8/3/11
1.1 ng/I
27 ng/I
48
8/10/11
<1.0 ng/I
27 ng/I
49
8/17/11
1.5 ng/I
27 ng/I
50
8/24/11
2.6 ng/I
27 ng/I
51
8/31/11
1.6 ng/I
27 ng/I
52
9/7/11
1.4 ng/I
27 ng/I
*** 53
9/14/11
9.6 ng/I
27 ng/I
54
9/22/11
2.0 ng/I
27 ng/I
55
9/28/11
2.0 ng/I
27 ng/I

WEEKLY MERCURY SAMPLING
4TH CREEK WWTP
NUMBER
DATE
RESULT (ng/I)
PERMIT LIMIT
(DAILY/MONTHLY)
56
10/5/11
2.8 ng/I
27 ng/I
***57
10/12/11
20.0 ng/I
27 ng/I
58
10/18/11
4.1 ng/I
27 ng/I
59
10/25/11
4.5 ng/I
27 ng/I
60
11/2/11
4.6 ng/I
27 ng/I
61
11/9/11
2.6 ng/I
27 ng/I
62
11/15/11
2.4 ng/I
27 ng/I
63
11/21/11
2.6 ng/I
27 ng/I
64
11/28/11
1.7 ng/I
27 ng/I
65
12/6/11
1.5 ng/I
27 ng/I
66
12/14/11
1.8 ng/I
27 ng/I
67
12/19/11
1.6 ng/I
27 ng/I
68
12/28/11
3.0 ng/I
27 ng/I
69
1/3/12
2.2 ng/I
27 ng/I
70
1/10/12
1.6 ng/I
27 ng/I
71
1/18/12
1.9 ng/I
27 ng/I
72
1/25/12
1.5 ng/I
27 ng/I
73
2/1/12
4.9 ng/I
27 ng/I
74
2/8/12
2.4 ng/I
27 ng/I
75
2/15/12
3.6 ng/I
27 ng/I
76
2/22/12
4.1 ng/I
27 ng/I
77
3/1/12
1.8 ng/I
27 ng/I
78
3/7/12
1.5 ng/I
27 ng/I
79
3/14/12
1.3 ng/I
27 ng/I
80
3/21/12
2.8 ng/I
27 ng/I
81
3/28/12
1.6 ng/I
27 ng/I
82
4/4/12
1.1 ng/I
27 ng/I

WEEKLY MERCURY SAMPLING
4TH CREEK WWTP
NUMBER
DATE
RESULT (ng/I)
PERMIT LIMIT
(DAILY/MONTHLY)
83
4/11/12
1.5 ng/I
27 ng/I
84
4/17/12
1.8 ng/I
27 ng/I
85
4/25/12
1.4 ng/I
27 ng/I
86
5/2/12
1.4 ng/I
27 ng/I
87
5/7/12
2.3 ng/I
27 ng/I
88
5/16/12
2.3 ng/I
27 ng/I
89
5/24/12
1.5 ng/I
27 ng/I
90
5/30/12
91
6/7/12
****I questioned Prisim Lab about this high Mercury result and it was retested
which resulted in an 11.0 ng/I.
***9/14/11 and 10/12/11 Painting
1 ng/I = .000001 mg/I