NC0036277_Permit Issuance_20131213

NPDE!i DOCYNENT SCANNINO COVER SHEET
NPDES Permit:
NC0036277
McDowell Creek WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
December 13, 2013
TlziB document is printed on reuise paper -ignore any
content on the resreriae Bide

r
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Resources
Water Quality Programs
Pat McCrory Thomas A. Reeder John E. Skvarla, III
Governor Director Secretary
December 13, 2013
Ms. Jacqueline A. Jarrell, Superintendent
Environmental Management Division
Charlotte -Mecklenburg Utility Department
4222 Westmont Dr.
Charlotte, North Carolina 28217
Subject: NPDES Final Permit NCO036277
McDowell Creek WWTP
Mecklenburg County
Class IV Facility
Dear Ms. Jarrell:
Division personnel have reviewed and approved your application for renewal of the subject
permit. Accordingly, we are forwarding the attached NPDES permit. This permit 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). _
The Division received your comments on the draft permit and provides the following responses:
• The correct zip code for the applicant address will be updated.
• Monitoring for pH, temperature and conductivity will remain as daily. The Division's current
policy for monitoring frequency reduction applies only to BOD, TSS, ammonia and fecal
coliform. Other parameters should be monitored as specified in 15A NCAC 2B .0508.
The final permit contains the following changes from your previous permit:
• References to Charlotte -Mecklenburg Utilities were replaced with Charlotte Mecklenburg Utility
Department to reflect the current name of the Department.
• Following the Mercury Permitting Guidance for the implementation of the Statewide Mercury
TMDL mercury data was reviewed to determine the need for a limit or a Mercury Minimization
Plan (1V W). A mercury limit will not be required for your facility but you have to develop a
Mercury Minimization Plan. See Condition A.(4.) for the 1VIl1/Il' requirements.
+ Monitoring frequencies for zinc and copper were modified to quarterly.
• Monitoring frequencies for CBOD, TSS, ammonia and fecal coliform were modified to 2/week.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St, Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone]
Internet: www.ncwaterauality.ora
Noe Carolina
�tura!!y
An Equal opportunity 1 Affirmative Acton Employer

Charlotte --Mecklenburg Utility Dept. — - -
December 13, 2013
Page 2 of 2
A special condition was added to your permit [See Special Condition A. (5.)] including
requirements for electronic reporting. Proposed federal regulations require electronic submittal of
all discharge monitoring reports (DMRs) and specify that, if a state does not establish a system to
receive such submittals, then permittees must submit DMRs electronically to the Environmental
Protection Agency (EPA). The Division anticipates that these regulations will be adopted and is
beginning implementation. For information on eDMR, registering for eDMR and obtaining an
eDMR user account, please visit the following web page:
http://portal.ncdenr.org/web/wq/admin/bogjipu/edm . For information on EPA's proposed
NPDES Electronic Reporting Rule, please visit the following web site:
If any parts, measurement frequencies or sampling requirements contained in this permit 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.
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 Resources or
permits required by the Division of Land Resources, the Coastal Area Management Act or any other
federal or local governmental permits that may be required.
If you have any questions concerning this permit, please contact Teresa Rodriguez at telephone
number [phone] or at email [e-mail].
Sincerely,
omas A. Reeder
cc: NPDES Files
Central Files
EPA Region 4 (e-copy)
Mooresville Regional Office / Water Quality
Mooresville Regional Office / Public Water Supply (e-copy)
Aquatic Toxicology Unit (e-copy)
Mecklenburg County([e-mail])
F . r

Permit No.-NC0036277
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provision of North Carolina General Statute 143-215.1, other lawful
standards and regulations promulgated and adopted by the North Carolina Environmental
Management Commission, and the Federal Water Pollution Control Act, as amended,
City. of Charlotte
Charlotte -Mecklenburg Utility Department
is hereby authorized to discharge wastewater from a facility located at the
McDowell Creek Wastewater Treatment Plant
4901 Neck Road
Huntersville
Mecklenburg County
to receiving waters designated as McDowell Creek in the Catawba River Basin in accordance with
effluent limitations, monitoring requirements, and other conditions set forth in Parts I, II, III and
IV hereof.
This permit shall become effective January 1, 2014.
This permit and authorization to discharge shall expire at midnight on December 31, 2018.
Signed this day December 13, 2013.
omas A. Reeder, Director
�T
Division of Water Resources
By Authority of the Environmental Management Commission

I , I
- - - -- -- -- Permit No. NC00362?7- r'
SUPPLEMENT TO PERMIT COVER SHEET
The exclusive authority to operate this facility arises under this NPDES permit. The conditions,
requirements, terms and provisions of this NPDES permit governs surface water discharges from
this facility. All previous NPDES Permits issued to this facility bearing this permit number,
whether for operation or discharge, are hereby revoked.
Charlotte -Mecklenburg Utility Department
is hereby authorized to:
1. Continue to operate the existing 12.0 MGD wastewater treatment facility consisting of:
• Two 6 million gallon storm flow equalization tanks
• Mechanical bar screens
• grit removal
0 odor control
• one 1.3 million gallon flow equalization day tank
• five primary clarifiers
• two trains in parallel of activated sludge treatment utilizing three stage Biological
Nutrient Removal (BNR) and two trains in parallel of activated sludge treatment
utilizing five stage Biological Nutrient Removal
• four final clarifiers
• effluent denitrifying filters
• anaerobic sludge digestion
• mechanical sludge thickening and dewatering equipment
• sand drying beds
• UV disinfection
• . Membrane filtration
This facility is located at McDowell Creek Wastewater Treatment Plant, 4901 Neck Road,
near the Town of Huntersville in Mecklenburg County. McDowell WWTP is currently rated
a Class IV facility.
2. Discharge from said treatment works at the location specified on the attached map into
McDowell Creek, which is classified WS-IV water in the Catawba River Basin.

!: .Lo . ---- --- —
Permit No. NCO036277
A. (1.) . EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period beginning on the effective date of the permit and lasting until expiration, the
Permittee is authorized to discharge up to 12 MGD of municipal wastewater from outfall 001.
Such discharges shall be limited and monitored6 by the Permittee as specified below:
EFFLUENT
'CHARACTERIS,TIGS
y
-EFFLUENT LIMITS =
MONITORING"REQUIREMENTS:
-
Monihly;:
Weekly._
:Ayerage1.:
- Daily
Maximum, :
Measurement
Frequency,.
Sample Type ,
Sample=Locations
Flow
12.0 MGD
Continuous
Recording
I or E
CBODs 20°C 2 Summer
4.2 m /L
6.3 m /L
2/Week
Composite
E, I
CBODS 200C 2 [Winter]
8.3 m /L
12.4 m /L
2/Week
Composite
E, I
Total Suspended Solids2
9.0 m /L
13.5 m /L
2/Week
Composite
E, I
% as N
1.0 m /L
3.0 mgfi
2/Week
Composite
E
Dissolved Oxygen3
Daily
Grab
E
Fecal Coliform(geometric mean
100 / 100 ml
200 / 100 ml
2Meek
Grab
E
Total Residual Chlorine4
19 /L
Daily
Grab
E
Temperature' °C
Daily
Grab
E
Total Nitrogen [Summer]
450 lbs/day
Monthly
Composite
E
Total Nitrogen inter
500 lbs/day
Monthly
Composite
E
Total Phosphorus Summer
27 lbs/day
Monthly
Composite
E
Total Phosphorus inter
32 Ibs/da
Monthly
Composite
E
Chronic Toxici 5
Quarter)
Cam osite
E
Conductivity
Daily
Grab
E
Total Copper
Quarterly
Composite
E
Total Zinc
Quartedy
Composite
E
H
Between 6.0 to 9.0 standard
units
Daily
Grab
E
Pollutant Scan
Monitor & Report
See Condition A. 3.
-Effluent
Dissolved Oxygen
Weekly
Grab
U, D
Temperature °C
Weekly
Grab
U, D
Weekly
Grab
U, D
-ConductiVity
Chloro h ll-a Summer
Monthly
Grab
D
Total Phosphorus Summer
Monthly
Grab
D
NH3-N Summer
Monthly
Grab
D
TKN Summer
Monthly
Grab
D
NO2 + NO3 as N Summer
Monthly
Grab
D
Footnotes:
1. Sample Locations: E — Effluent, I — Influent, U — Upstream at Beatties Ford Road, D- Downstream at
Neck Rd.
2. The monthly average effluent CBOD5 and total suspended solids concentrations shall not exceed 15%
of the respective influent value (85% removal).
3. The daily average dissolved oxygen effluent concentrations shall not be less than 5.0 mg/L.
4. Monitoring only if effluent is chlorinated. The Division shall consider all effluent TRC values reported
below 50 µg/L to be in compliance with the permit. However, the Permittee shall continue to record
and submit all values reported by a North Carolina certified laboratory (including field certified), even
if these values fall below 50 µg/ L.
S. Chronic Toxicity (Ceriodaphnia) P/F at 90 % effluent concentration shall be conducted quarterly
(January, April, July and October). Refer to Special Condition A. (2).
6. No later than 90 days from the effective date of this permit, begin submitting discharge monitoring
reports electronically using NC DWR's eDMR application system. See Special Condition A (S).
[Summer] = April 1- October 31 [Winter] = November 1- March 31
Total Nitrogen = NO2 + NOs + TKN Lbs/day= Pounds/Day
There shall be no discharge of floating solids or visible foam in other than trace amounts.

Permit No NCO0362 r7 '
A. (2.) CHRONIC TOXICITY PERMIT LIMIT (QRTRLY)
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 II Chronic Whole Effluent
Toxicity Test Procedure" (Revised- December 2010) or subsequent versions. The 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:
Attention: North Carolina Division of Water Resources
Environmental Sciences Section
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Section no
later than 30 days after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements
and all concentration/response data, and be certified by laboratory supervisor and ORC or
approved designate signature. Total residual chlorine of the effluent toxicity sample must be
measured and reported if chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity
monitoring is required, the permittee will complete the information located at the top of the
aquatic toxicity (AT) test form indicating the facility name, permit number, pipe number, county,
and the month/year of the report with the notation of "No Flow" in the comment area of the form.
The report shall be submitted to the Environmental Sciences Section at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required,
monitoring will be required during the following month. Assessment of toxicity compliance is
based on the toxicity testing quarter, which is the three month time interval that begins on the
first day of the month in which toxicity testing is required by this permit and continues until the
final day of the third month.

Permit No. NC0036277
Should any test data from this monitoring requirement or tests performed by the North Carolina
Division of Water Resources indicate potential impacts to the receiving stream, this permit may
be re -opened and modified to include alternate monitoring requirements or limits.
If the Permittee monitors any pollutant more frequently than required by this permit, the results
of such monitoring shall be included in the calculation & reporting of the data submitted on the
DMR 8. all AT Form submitted.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
um
control organism survival, minimum control organism reproduction, and appropriate
environmental controls, shall constitute an invalid test and will require immediate follow-up
testing to be completed no later than the last day of the month following the month of the initial
monitoring.

Permit No. NCO0362 r7 r`
A. (3) EFFLUENT POLLUTANT SCAN
The Permittee shall perform a total of three (3) Effluent Pollutant Scans for all parameters listed
below. One scan must be performed in each of the following years: 2014, 2015, and 2016.
Analytical methods shall be in accordance with 40 CFR Part 136 and shall be sufficiently sensitive
to determine whether parameters are present in concentrations greater than applicable standards
and criteria. Samples should be collected with one quarterly toxicity test each year, and must
represent seasonal variation [i.e., do not sample in the same quarter every year]. Unless otherwise
indicated, metals shall be analyzed as "total recoverable."
Ammonia (as N)
Chlorine (total residual, TRC)
Dissolved oxygen
Nitrate/ Nitrite
Kjeldahl nitrogen
Oil and grease
Phosphorus
Total dissolved solids
Hardness
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury (EPA Method 1631E)
Nickel
Selenium
Silver
Thallium
Zinc
Cyanide
Total phenolic compounds
Volatile organic compounds:
Acrolein
Acrylonitrile
Benzene
Bromoform
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane
Chloroethane
2-chloroethylvinyl ether
Chloroform
Dichlorobromomethane
1,1-dichloroethane
1,2-dichloroethane
Trans-1,2-dichloroethylene
1,1-dichloroethylene
1,2-dichloropropane
1, 3 -dichloropropylene
Ethylbenzene
Methyl bromide
Methyl chloride
Methylene chloride
1,1,2,2-tetrachloroethane
Tetrachloroethylene
Toluene
1, 1, 1-trichloroethane
1,1,2-trichloroethane
Trichloroethylene
Vinyl chloride
Acid -extractable compounds:
P-chloro-m-cresol
2-chlorophenol
2,4-dichlorophenol
2,4-dimethylphenol
4,6-dinitro-o-cresol
2,4-dinitrophenol
2-nitrophenol
4-nitrophenol
Pentachlorophenol
Phenol
2,4,6-trichlorophenol
Base -neutral compounds:
Acenaphthene
Acenaphthylene
Anthracene
Benzidine
Benzo(a)anthracene
Benzo(a)pyrene
3,4 benzofluoranthene
Benzo(ghi)perylene
Benzo(k)fluoranthene
Bis (2-chloroethoxy)
methane
Bis (2-chloroethyl) ether
Bis (2-chloroisopropyl) ether
Bis (2-ethylhexyl) phthalate
4-bromophenyl phenyl ether
Butyl benzyl phthalate
2-chloronaphthalene
4-chlorophenyl phenyl ether
Chrysene
Di-n-butyl phthalate
Di-n-octyl phthalate
Dibenzo (a,h) anthracene
1,2-dichlorobenzene
1,3-dichlorobenzene
1,4-dichlorobenzene
3, 3-dichlorobenzidine
Diethyl phthalate
Dimethyl phthalate
2,4-dinitrotoluene
2,6-dinitrotoluene
1, 2-diphenylhydrazine
Fluoranthene
Fluorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclo-pentadiene
Hexachloroethane
Indeno(1,2,3-cd)pyrene
Isophorone
Naphthalene
Nitrobenzene
N-nitrosodi-n-propylamine
N-nitrosodimethylamine
N-nitroso diphenylamine
Phenanthrene
Pyrene
1, 2,4-trichlorobenzene
Reporting. Test results shall be reported on DWR Form -A MR-PPA1 (or in a form approved by
the Director) by December 31st of each designated sampling year. The report shall be submitted
to the following address: NC DENR / DWR / Central Files, 1617 Mail Service Center, Raleigh,
North Carolina 27699-1617.

Permit No. NCO036277
A. (4) MERCURY MINIMIZATION PLAN
The permittee will develop and implement a mercury minimization plan during the term of this
permit. The MMP shall be developed 180 days from the effective day of the permit, and shall be
available for inspection on -site. A sample MMP was developed through a stakeholder review
process and has been placed on the Division website for guidance
(http://portal.ncdenr.org/web/wg/swp/ps/npdes, under Mercury Minimization Plan). The MMP
should place emphasis on identification of mercury contributors and goals for reduction. Results
shall be summarized and submitted with the next permit renewal.
A. (5) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
Proposed federal regulations require electronic submittal of all discharge monitoring reports
(DMRs) and specify that, if a state does not establish a system to receive such submittals, then
permittees must submit DMRs electronically to the Environmental Protection Agency (EPA). The
Division anticipates that these regulations will be adopted and is beginning implementation in
late 2013.
NOTE: This special condition supplements or supersedes the following sections within Part II of
this permit (Standard Conditions for NPDES Permits):
• Section B. Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Reporting [Supersedes Section D. (2.) and Section E. (5.) (a)l
Beginning no later than 90 days from the effective date of this permit, the permittee shall
begin reporting discharge monitoring. data electronically using the NC DWR's Electronic
Discharge Monitoring Report (eDMR)--internet-application: - - -
Monitoring results obtained during the previous month(s) shall be summarized for each
month and submitted electronically using eDMR. The eDMR system allows permitted
facilities to enter monitoring data and submit DMRs electronically using the internet. Until
such time that the state's eDMR application is compliant with EPA's Cross -Media Electronic
Reporting Regulation (CROMERR), permittees will be required to submit all discharge
monitoring data to the state electronically using eDMR and will be required to complete the
eDMR submission by printing, signing, and submitting one signed original and a copy of the
computer printed eDMR to the following address:
NC DENR / DWR / Information Processing Unit
ATTENTION: Central Files / eDMR
1617 Mail Service Center
Raleigh, North :Carolina 27699-1617
I'f a permittee is unable to use the eDMR system due to a demonstrated hardship or due to
the facility being physically located in an area where less than 10 percent of the households
have broadband access, then a temporary waiver from the NPDES electronic reporting
requirements may be granted and discharge monitoring data may be submitted on paper
DMR forms (MR 1, 1. 1, 2, 3) or alternative forms approved by the Director. Duplicate signed
copies shall be submitted to the mailing address above.

Permit No. NC0036277 •
Requests for temporary waivers from the NPDES electronic reporting requirements must be
submitted in writing to the Division for written approval at least sixty (60) days prior to the
date the facility would be required under this permit to begin using eDMR. Temporary
waivers shall be valid for twelve (12) months and shall thereupon expire. At such time, DMRs
shall be submitted electronically to the Division unless the permittee re -applies for and is
granted a new temporary waiver by the Division.
Information on eDMR and application for a temporary waiver from the NPDES electronic
reporting requirements is found on the following web page:
http: / /portal.ncdenr.org/web/wg/admin/bog/ipu/edmr
Regardless of the submission method, the first DMR is due on the last day of the month
following the issuance of the permit or in the case of a new facility, on the last day of the
month following the commencement of discharge.
2. minatory Requirements [Supplements Section B. (11.) (b) and supersedes Section B.
(il•) (d)l
All eDMRs submitted to the permit issuing authority shall be signed by a person described in
Part II, Section B. (11.) (a) or by a duly authorized representative of that person as described in
Part II, Section B. (11.) (b) . A person, and not a position, must be delegated signatory
authority for eDMR reporting purposes.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR
user account and login credentials to access the eDMR system. For more information on
North Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account,
please visit the following web page:
http://portal.ncdenr.org/webIMM/adminIbog/i-pu/edmr
Certification. Any person submitting an electronic DMR- using -the state's - eDMR- system- shall
make the following certification [40 CFR 122.22] . NO OTHER STATEMENTS OF
CERTIFICATION WILL BE ACCEPTED:
'7 certify, under penalty of law, that this document and all attachments were prepared under
my direction or supervision in accordance with a system designed to assure that qualified
personnel properly gather and evaluate the information submitted. Based on my inquiry of the
person or persons who manage the system, or those persons directly responsible for gathering
the information, the information submitted is, to the best of my knowledge and belief, true,
accurate, and complete. I am aware that there are significant penalties for submitting false
information, including the possibility of fines and imprisonment for knowing violations. "
3. ]Records Retention [Supplements Section D. (6.)l
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR
submissions. These records or copies shall be maintained for a period of at least 3 years from
the date of the report. This period may be extended by request of the Director at any time [40
CFR 122.41].

Discharge Point
NC00036277 - CMU McDowell Creek WWTP
Latitude:
35°22'54" Sub -Basin: 03-08-33
Lonaitude:
80°5620" County: Mecklenburg
nad H:
F15NW/Lake Norman South
Stream Class:
WS-Iv
Receiving Stream: McDowell Creek
G
Facility
Location
North Charlotte MccklenburNCO036277 Utilities
NC0036277
CMU - McDowell Creek W WTP

North Carolina
Mecklenburg County
The Charlotte Observer Publishing Co.
Charlotte, NC
} ss Affidavit of Publication
}
Charlotte Observer
REFERENCE: 145583 NCDENR/DWQ/POINT SOURCE
0000717666 Public Notice North Carolina Environmental
Management Commission/NPDES Unit 1617
Mail Service Center Raleigh, NC 27699-1617
Before the undersigned, a Notary Public of said County and
State, duly authorized to administer oaths affirmations, etc.,
personally appeared, being duly sworn or affirmed according
to law, doth depose and say that he/she is a representative of
The Charlotte Observer Publishing Company, a corporation
organized and doing business under the laws of the State of
Delaware, and publishing a newspaper known as The
Charlotte Observer in the city of Charlotte, County of
Mecklenburg, and State of North Carolina and that as such
he/she is familiar with the books, records, files, and business
of said Corporation and by reference to the files of said
publication, the attached advertisement was inserted. The
following is correctly copied from the books and files of the
aforesaid Corporation and Publication.
PUBLISHED ON: 10/11/2013
AD SPACE: 44 LINES
FILED ON: 1011112013
723ky,i4
In Testimoniv Whereof I have hereunto
Public Notice
NC 003(o � 7'l
Management
NC 27M-1519
Inlanl to Issue a NPDES Waetaea
TITLE:
DATE:
and affixed my seal, the day and year aforesaid.
fif An _ My commission Expires:
0M 1 1 2013
Fxpir" May 27. 2016

t a •
CHARLOTTE.
November 25th12013
Teresa Rodriquez
NPDES Permitting Unit
NCDENR-DWR
1617 Mail Service Center
Raleigh, NC 27699-1617
IN Lp,0 WC'
DEC 04 2013
DENR-WATER QUALITY
CITY OF CHARLOTTE
CHARLOTTE-MECKLENBURG UTILITIES
Environmental Management
Re: Draft NPDES Permit No. NCO036277 — McDowell Creek WWTP, Mecklenburg County, NC
Dear Ms. Rodriquez,
Charlotte -Mecklenburg Utility Department (CMUD) has received and reviewed draft NPDES Permit No.
NCO036227 issued to McDowell Creek WWTP. Based on our review of the draft permit, we are
submitting the following comments for your review and consideration in the issuance of our final
permit:
1. On the NPDES Fact Sheet for McDowell Creek WWTP the Applicant Address Zip Code should to
CS�L be changed from 28262 to 28217. The Zip Code of 28078 is correct for the Facility Address.
2. We have requested reduced monitoring frequency for conventional pollutants based on
f 1 McDowell Creek WWTP meeting the requirements of an exceptionally performing facility.
However, the field parameters sampling frequency requirement is daily in our draft permit. This
,� r1 ("Lc ' would still require daily site visits by our lab staff to collect and analyze these four field
parameters. Therefore, we are requesting a monitoring frequency of three times a week for the
field parameters of dissolved oxygen, temperature, conductivity, and pH.
We appreciate your consideration of the above comments and requests for revision to our permit. If
you have any questions regarding these comments or need any additional information, please call me at
704/336-4460 or email me at [e-mail]. You may also contact Shannon Sypolt, Water
Quality Program Administrator, at 704/336-4581 or Joseph Lockler, McDowell Creek WWTP ORC, at
704/875-6443. We look forward to hearing back from you soon.
Sincerely,
tic.L,: 0.
Ja ueline A. Jar , P.E.
Superintendent
Environmental Management Division
Charlotte -Mecklenburg Utility Department
4222 Westmont Drive
Charlotte, NC 28217
www.charlottenc.gov 1 4222 Westmont Drive I Charlotte, NC 28217 1 PH: 704.336.4407

DENR/DWR
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NCO036277
Facility
Information
Applicant/Facility Name:
Charlotte Mecklenburg Utility De artment/McDowellCreekWWTP
Applicant Address:
4222 Westmont Dr, Charlotte NC 28262
Facility Address:
4901 Neck Rd., Huntersville, NC 28078
Permitted Flow
12.0 MGD
Type of Waste:
Domestic
Facility/Permit Status:
Class IV, Renewal
County:
Mecklenburg
Miscellaneous
Receiving Stream:
McDowell Creek
Regional Office:
Mooresville
Stream Classification:
WS IV — CA
State Grid / USGS Quad:
F15NW/Lake
Norman
303(d) Listed?
No
Permit Writer:
Teresa Rodriguez
HUC:
0305010114
Date:
10/4/2013
Sub -basin
03-08-33
Lat. 350 22.893' N Long. 800 56.318' W
Drainage Area (mi ):
28.3
Summer 7Q10 (cfs)
1.8
Winter 7Q 10 cfs)
4.2
Average Flow (cfs):
31
IWC (%):
91%
SUMMARY
The Charlotte Mecklenburg Utility Department (CMUD) operates the McDowell Creek WWTP
with a current permitted flow of 12.0 MGD. The treated domestic wastewaters are discharged to
McDowell Creek in the Catawba River Basin. CMUD submitted an application for renewal on
July 5, 2013. The permit expires on December 31, 2013.
The treatment system consists of: mechanical bar screens, grit removal, five primary clarifiers,
two trains activated sludge using three stage biological nutrient removal, two trains activated
sludge using five stage biological nutrient removal, four final clarifiers, denitrifying filter, UV
disinfection, membrane filtration, sludge thickening, and sludge dewatering.
CMUD has a full pretreatment program through the Division of Water Quality's PERCS Unit for
all five municipalities it operates. McDowell Creek W WTP currently has no industrial users.
RECEIVING STREAM
This facility discharges to McDowell Creek in the Catawba River Basin, classified WS-IV CA
waters. The discharge is 0.5 miles upstream of Mountain Island Lake. McDowell Creek and
Mountain Island Lake are not listed in the 2012 NC 303(d) list.
DMR DATA REVIEW AND VEFIFICATION OF EXISTING CONDITIONS
DMR were reviewed for the period of January 2009 to July 2013. Data are summarized in Table
L
Fact Sheet
NPDES NC O036277 Pennit Renewal
Pa<_.e I

Table 1. Data Summary
Parameter
Units
Average
Max
Min
Flow
MGD
4.7
10.6
3.8
CBOD
mg/1
2.2
9
< 2
NH3N
mg/1
0.1
1.5
< 0.1
TSS
mg/1
2.4
8.6
< 2.4
H
SU
7.3
7.8
6.5
Temperature
°C
21.2
27.4
14
TN
lb d
233.4
579.8
121.9
TP
lb d
7.0
68.1
3.4
Fecal Coliform
# 100 ml
2.4
1000
< 1
DO
mg/1
8.4
10.8
7.1
Data for CBOD, TSS, ammonia and fecal coliform was reviewed to determine compliance with
the 2012 Guidance Regarding the Reduction of Monitoring Frequencies. The facility meets all
the criteria specified in the guidance. Monitoring frequency for the above mentioned
parameters will be reduced to 2/week. See attached Reduction in Frequency Evaluation.
Reasonable Potential Analysis
A reasonable potential analysis was performed for copper and zinc. Both present reasonable
potential to exceed the standards. Since these parameters are action level standards no limits
are proposed. Monitoring will be required on a quarterly basis. See attached RPA results.
Mercury Evaluation
A mercury evaluation was conducted in accordance with the Permitting Guidance developed for
the implementation of the statewide Mercury TMDL to determine the need for a limit and
Mercury Minimization Plan (MMP). Based on dilution the water quality based effluent limitation
(WQBEL) for mercury is 13.2 ng/l. The technology based effluent limit (TBEL) is 47 ng/1. The
facility had detections above 1 ng/1 over the past five years, therefore a Mercury Minimization
Plan will be required in the permit but no limit will be implemented. A condition will be added
to the permit describing the requirements for the MMP.
Table 2. Mercury Evaluation
2009
2010
2011
2012
2013
Mercury Annual Average
n 1
1.1
1.1
1.0
1.2
< 1
Mercury Annual Max n L
1 2.3
2.2
1.6
3.9
< 1
LIMITS AND MONITORING REDUIREMENm:
Current conditions, as well as the basis for the limits are summarized in Table 3.
Fact Sheet
NPDES NC0036277 Permit Renewal
Page 2

Table 3. Current Conditions and Proposed Changes
akameters A. ected
s
Pe mit,x emit /Cob �ttnn
Cha�ng�flr�m�re�xQas
,� r tew
asCons range
.;;5....
r K .
F.. .'1..,z" -` ,#�•.
::1 . i..F. i.. G :r. "'
..E...y3xF:%i 7�}3 �' L,+ir-.i e. il
Flow
MA - 12 MGD
No changes
T15A 2B .0505
CBOD5
Summer: 4.2 mg/1 MA
Limits — no change
Limit based on modeling results for
6.3 mg/1 WA
Reduced monitoring to
protection of DO standard.
Winter: 8.3 mg/1 MA
2/week
Reduction in frequency based on
12.5 m WA
exemplary compliance history.
NH3-N
Summer: 1.0 mg/1 MA
Limit — no change
Limit based on modeling results for
3.0 mg/1 WA
Reduced monitoring to
protection of DO standard.
2/week
Reduction in frequency based on
exemplary compliance history.
TSS
9 mg/l MA
Limit — no change
Limits based on holding loads at the
13.5 mg/l WA
Reduced monitoring to
time of the expansion (2003)
2/week
Reduction in frequency based on
exemplary compliance history.
Fecal coliform
200/100 ml MA
Limit — no change
State WQ standards, T15A 2B .0200
400/100 ml WA
Reduced monitoring to
Reduction in frequency based on
2/week
exemplary compliance history.
DO
>5 mg/1
No change
State VVQ standards, T15A 2B .0200
H
6 to 9 SU
No change
State WQ standards, T15A 2B
Total Nitrogen
Summer: 450 lb/d
No change
Limit based on modeling for Mountain
Winter: 500 lb/d
Island Lake to protect for chlorophyll -a
water quality standard.
Total Phosphorus
Summer: 27 lb/d
No change
Limit based on modeling for Mountain
Winter: 32 lb/d
Island Lake to protect the chlorophyll -a
water quality standard.
Total Zinc
Monitor & Report
Reduced monitoring to
Reasonable potential to exceed the
Total Copper
Quarterly
water quality standard. Zinc and copper
are action level standard, no limit will
be implemented.
Total Mercury
Monitor and Report
Eliminate monitoring
See Mercury Evaluation above.
MA — Monthly Average; WA — Weekly Average; DM — Daily Max
INSTREAM MONITORING:
The permit requires instream monitoring upstream and downstream of the discharge. Instream
data shows parameters are within water quality standards.
PRIORITY POLLUTANT ANALYSIS:
The application includes the results of three priority pollutant analyses. No priority pollutants
were detected in the scan.
AQUATIC TOXICITY TESTING:
Permit requires chronic toxicity, ceriodaphnia dubia, 90%. The facility failed one the toxicity
test on January 2012.
SUMMARY OF PROPOSED CHANGES:
1. Charlotte -Mecklenburg Utilities was replaced with Charlotte -Mecklenburg Utility
Department, the current name used by the Department.
2. Reduced monitoring frequency for CBOD, TSS, ammonia and fecal coliform due to
exemplary compliance record.
3. Reduced monitoring frequency for copper and zinc according to NPDES monitoring
frequency guidance for toxicants.
4. Eliminate monitoring requirements for mercury and added condition to require a
Mercury Minimization Plan according to the Statewide Mercury TMDL implementation
guidance.
Fact Sheet
NPDES NC003627 7 Pemiit Renewal
Pk e 3

PROPOSED SCHEDULE FOR PERMIT ISSUANCE
Draft Permit to Public Notice: October 8, 2013
Permit Scheduled to Issue: December 2, 2013
NPDES DIVISION CONTACT
If you have questions regarding any of the above information or on the attached permit, please
contact Teresa Rodriguez at 919-807-6387.
NAME: DATE: 10/
REGIONAL OFFICE COMMENTS
NAME: DATE:
SUPERVISOR: DATE:
Fact Sheet
N1'DES NC00362�7 Pennit Renewal
Pa--e 4

McDowell Creek WWTP REASONABLE POTENTIAL ANALYSIS Outfall 001
NCO036277 Qw = 12 MGD .
Qw (MGD) = 12.00
1 Q l OS (cfs) = 1.51
7Q 1 OS (cfs) = 1.80
7Q 1 OW (cfs) = 4.20
30Q2 (cfs) = NO 30Q2 DATA
Avg. Stream Flow, QA (cfs) = 31.00
Receiving Stream: McDowell Creek
WWTP/WTP Class: Class IV
IWC @ 1Q10S = 92.49%
IWC (Qa 7QIOS = 91.18%
IWC Qa 7Q10W = 81.58%
IWC cQ 30Q2 = NIA
IWC @ QA = 37.60%
Stream Class: WS-IV
CHRONIC TEST CONCENTRATION = DEFAULT %
=90%
PARAMETER
STANDARDS & CRITERIA (2)
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
(1)
-1
a
Z
=
NC WQS / Applied %s FAV /
n # Det. Max Pred Allowable Cw
Chronic Standard Acute
Cw
Acute: 7.9
RP, monitor quarterly.
Copper (AL)
NC
7 FW(7Q10s) 7.3
ug/L
198 108
24
_ __ —_—__ __—
-_---__---_—_—_--- --_
-- —
Chronic: 7.7
—
1 values > Allowable Cw
Acute: 72.4
RP, monitor quarterly
2Jnc(AL)
NC
50 FW(7Q10s} 67
ug/L
20O 200
59.4
_ ---__ __—_
_—_- ____— ---------------
Chronic: 54.8
1 value(s) > Allowable Cw
Acute:
0 0
N/A
-------------------------------------
Chronic:
Acute:
0 0
N/A
----------
— — —
---------------
-
Chronic:
- - —
Acute:
0 0
N/A
-----------------------
Chronic: ---------
Acute:
0 0
N/A
--— --=-
----------
Chronic-
----------- -- ---
RPA.xlsm, rpa
Page 1 of 1 10/2/2013

REASONABLE POTENTIAL ANALYSIS
9
18
Copper (AL)
Zinc (AL)
Date Data
BDL=1/2DL
Results
••
Date Data
BDL=1/2DL
Results
•'
1
6K
2 1
Std Dev.
1.4645
1
37
37
Std Dev.
5.9738
2
!'<.
2 1
Mean
1.8859
2
40
40
Mean
33.3900
3
<
2 1
C.V.
0.7766
3
43
43
C.V.
0.1789
4
<
2 1
n
198
4
40
40
n
200
5
<
2 1
5 ".
36
36
6
3 3
Mult Factor =
1.25
6
44
44
Mult Factor =
1.06
7
<
2 1
Max. Value
19.0 ug/L
7
37
37
Max. Value
56.0 ug/L
8
<
2 1
Max. Pred Cw
23.8 ug/L
8
33
33
Max. Fred Cw
59.4 ug/L
9
<
2 1
9'v.
23
23
10
<
2 1
10
41
41
11
<
2 1
11
27
27
12
<
2 1
12
37
37
13
2 1
13
33
33
14
2 1
14
36
36
15
<
2 1
15
49
49
16
2.5 2.5
16
40
40
17
2.8 2.8
17
38.
38
18
2.2 2.2
18
36
36
19
2.3 2.3
19
47
47
20
2.1 2.1
20
42
42
21
2.2 2.2
21 =.
40.
40
22
2 2
22
39
39
23
2.3 2.3
23
38
38
24
2.9 2.9
24
39
39
25
Z8 2.8
25 :,.
34
34
26
2.8 2.8
26
38
38
27
2A 2.4
27
37
37
28
2 1
28
37
37
29
2.1 2.1
29
44
44
30
2.1 2.1
30
42
42
31
2.7 2.7
31
33
33
32
2.2 2.2
32
27
27
33
3.3 3.3
33
32
32
34
2.3 2.3
34
28
28
35
2.2 2.2
35
29
29
36
2.1 2.1
36
31
31
37
2.4 2.4
37 =
35.
35
38
2.6 2.6
38'
42
42
39
2.1 2.1
39
42
42
40
2.3 2.3
40
37
37
41
_
2.3 2.3
41
31
31
42
Z9 2.9
42;.r
38
38
43
2.7 2.7
43
43
43
44
2.1 2.1
44
25
25
45
2.5 2.5
45
40
40
46
3.2 3.2
46
26
26
47
2 1
47
26
26
48
28 2.8
48
33
33
49
2.3 2.3
49
29
29
60.
2.6 2.6
50
32
32
51
2 1
51
36
36
52
26 2.6
52
34
34
53
2.5 2.5
53
30
30
54
2.7 2.7
54 J'
29
29
55
2.4 2.4
55
32
32
56
2 1
56
35
35
57
2.3 2.3
57
34
34
58
2.8 2.8
58
32
32
59
2.5 2.5
59
33
33
60
2.1 2.1
60
30
30
61
2.1 7#1
61
27
27
62
2.3 2.3
62
26
26
63
2 2
63
25
25
64
2 1
64
33
33
65
2.2 2.2
65
43
43
66
2.1 2.1
66
35
35
67
2 1
67
38
38
68
2 1
68
39
39
69
2 1
69
40
40
RPA.xlsm, data
-1 - 10/2/2013

REASONABLE POTENTIAL ANALYSIS
70
2
1
70
43
71
2
1
71
43
72
2
1
72
37
73
2
1
73
47
74
2
2
74
47
75
2
1
75
36
76
2.2
2.2
76
33
77
2
1
77
33
78
2
1
78
30
79
2.1
2.1
79
27
80
2.2
2.2
80
35
81
2
1
81
27
82
4.5
4.5
82
30
83
2.3
2.3
83
26
84
2.3
2.3
84
27
85
2.2
2.2
85
28
86
2.6
2.6
86
31
87
2.7
2.7
87
29
88
2.8
2.8
88
33
89
2.4
2.4
89
35
90
22
2.2
90
27
91
29
2.9
91
31
92
22
2.2
92
32
93
2.5
2.5
93
30
94
2
1
94 f
35
95
2.6
2.6
95
29
96
2.3
2.3
96
29
97
2,6
2.6
97
32
98
27
2.7
98
31
99
24
2.4
99
32
100
2.3
2.3
100
34
101
3.4
3.4
101
36
102
2.2
2.2
102
33
103
4
4
103
42
104
2
1
104
36
105
2.1
2.1
105
36
106
2
1
106
39
107
2
1
107
36
108
2
2
108
41
109
3.5
3.5
109
34
110
2
1
110
35
111
2
1
111
36
112
2
1
112
40
113
2
1
113
41
114
2
1
114
46
115
2
2
115
39
116
2
1
116
35
117
2
1
117
37
118
q 2
1
118
35
119
2
1
119
37
120
2
1
120
33
121
2
1
121
31
122
2
1
122
34
123
2
1
123
30
124
2
1
124
27
125
2.1
2.1
125
32
126
2.6
2.6
126
56
127
2.5
2.5
127
27
128
2
1
128
29
129
2
1
129
31
130
2
1
130
35
131
2A
2.1
131
35
132
2
1
132
29
133
2
1
133
31
134
<
2
1
134
33
135
'<
2
1
135
36
136
<
2
1
136
41
137
<
2
1
137
31
138
2.5
2.5
138
37
139
2.4
2.4
139
30
140
2.5
2.5
140
35
141
2.8
2.8
141
30
142
2.2
2.2
142
30
143
2.1
2.1
143
28
RPA.xlsm, data
-2- 10/2/2013

REASONABLE POTENTIAL ANALYSIS
2
2.1
2.7
3.7
2.6
2.3
2.2
2.1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2.2
2
4.4
2
2
2
2
2
2
2
2.2
2
2
19
2
2.5
2.5
2.4
2
2.4
2.3
2.4
2.2
2.2
2.3
29
29
31
31
54
54
30
30
37
37
,.:31
31
28
28
26
26
29
29
31
31
26
26
29
29
28
28
31
31
26
26
28
28
28
28
29
29
29
29
26
26
32
32
37
37
29
29
25
25
34
34
29
29
35
35
'. 29
29
'.36
36
36
36
38
38
42
42
35
35
28
29
28
28
29
29
32
32
32
32
21
21
-
23
23
30
30
27
27
26
26
34
34
30
30
32
32
32
32
30
30
19
19
21
21
26
26
35
35
35
35
26
26
27
27
24
24
99
96
-3-
RPA.xlsm, data
1002013

•
,s�ARLOTTE.
June 20, 2013
NPDES Permitting Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
CITY OF CHARLOTTE
CHARLOTTE-MECKLENBURG UTILITIES
Environmental Management
D
E
L 05 2013
DENRwWATER QUALITY
Re: Permit Renewal Application and Reduced Monitoring Frequencies Request
McDowell Creek WWTP — NPDES Permit #NC0036277
Dear NPDES Unit:
Please find the enclosed NPDES permit renewal application for McDowell Creek WWTP. Please note that
Part G of the application, Combined Sewer Systems, is not applicable to McDowell Creek WWTP. The
application includes Attachments #1-9. The following is a summary of the attachments submitted with the
application:
1.
Attachment #1 summarizes the receiving stream total hardness and addresses Part A.10.e.
/OWN 2.
Attachment #2 is a description of the treatment process and addresses Part A.11.a. and Part
13.3.
3.
Attachment #3 addresses Part 13.1. and explains the steps underway to minimize inflow and
infiltration.
4.
Attachment #4 includes the topographical map required in Part 13.2.
5.
Attachment #5 includes the flow schematic required in Part 13.3.
6.
Attachment #6 includes the Priority Pollutants Analysis with organics results that are
summarized in Part D.
7.
Attachment #7 includes copies of the Toxicity reports completed by this facility from October
2008 through March 2013. This information is required in Part E.2.
8.
Attachment #8 is the Significant Industrial User Information required in Part F.3.
9.
Attachment #9 is a summary of our data and DWQ's criteria for reduced monitoring
frequencies as an exceptionally performing facility.
The analytical data summary information reported in Part A.12. — Effluent Testing Information, Part 13.6. -
Effluent Testing Data, and Part D. - Expanded Effluent Testing Data include all the effluent testing results at
McDowell Creek WWTP from January 1, 2010 through March 31, 2013. We have an electronic summary
file of all raw data used in the data summaries. If you would like a copy of the data summary, we can
provide it to you, at your request.
In addition to our permit renewal, we would also like to request a reduction of monitoring frequencies for
CBOD, TSS, NH3, and fecal coliform since McDowell Creek WWTP has met the criteria for an exceptionally
performing facility as outlined in the Division of Water Quality's guidance. Please see Attachment #9 for a
rlo� summary of our data and DWQ's criteria.
www.charlottenc.gov 1 4222 Westmont Drive I Charlotte, NC 28217 1 PH: 704.336.4407

roo
CITY or CHARLOTTE
CHARLOTTE-MECKLENBURG UTILITIES
Environmental Management
Please let us know if you have any questions or if you need any further information. If you do, please call
Shannon Sypolt, Water Quality Program Administrator, at 704/336-4581 or Joseph Lockler, ORC of
McDowell Creek WWTP, at 704/875-6443. You may also contact me at 704/3364460. Thank you for your
assistance with the renewal process.
Respectfully,
4.�$-A��
(Japque e A. Jarrell, P.E.
perintendent, Environmental Management Division
Charlotte -Mecklenburg Utilities
Cc: J. Lockler, S. Sypolt
www.charlottenc.gov 1 4222 Westmont Drive I Charlotte, NC 28217 1 PH: 704.336.4407

McDowell Creek WWWTP - Receiving Stream Hardness Calculation
Date
10/21/2010
11 /2/2010
11 /9/2010
11/16/2010
4/6/2011
5/3/2011
6/6/2011
7/5/2011
8/10/2011
9/14/2011
10/18/2011
11/15/2011
12/6/2011
1/10/2012
2/14/2012
3/20/2012
4/10/2012
5/2/2012
6/6/2012
7/19/2012
8/22/2012
9/20/2012
10124/2012
11 /20/2012
12/20/2012
1/8/2013
2/5/2013
3/4/2013
Average
Count
Upstream - Creek
Above (D-CA)
41
52
50
56
39
58
52
45
38
45
56
57
53
47
60
54
54
60
22
28
42
33
62
55
60
52
56
56
49
28
Downstream - Creek
Below (D-CB)
114
124
115
109
60
98
108
98
96
118
125
123
97
99
96
90
100
120
28
70
106
94
150
140
140
110
120
110
106
28
Receiving Stream Hardness: 78

Charlotte -Mecklenburg Utilities
McDowell Creek WWTP
NPDES # NC0036277
Process Flow Schematics
Attachment #3 — Additional Information
OUTFALL NUMBER: 001
A.1 La Description of Treatment
Treatment consists of coarse and fine mechanical bar screens; grit
removal; odor control in the headworks; five primary clarifiers; two trains
in parallel of activated sludge treatment utilizing three stage biological
nutrient removal and two trains of activated sludge treatment utilizing five
stage biological nutrient removal; four final clarifiers; effluent denitrifying
filters; membrane filtration and reuse distribution; ultraviolet disinfection;
sludge thickening; anaerobic digesters; and sludge dewatering.
(001� A.1 Lb Design Removal Rates
Process Design Percentages of
Removal
Parameter
12.0 mgd
Winter
12.0 mgd
Summer
CBOD (%)
97
98
SS (%)
97
97
P (%}
95
96
N (%)
87
88
B.3. Process Flow Diagram or Schematic
McDowell Creek WWTP is currently designed to treat 12.0 million gallons per day
(mgd) of wastewater. The attached schematics (SC-1, -2, -3) show the process now
through the facility. A full summary of the process flow is included on the following
page.

Charlotte -Mecklenburg Utilities
McDowell. Creek WWTP
NPDES # NCO036277
Process Flow Schematics
12-mgd treatment description
Preliminary treatment:
Wastewater enters the plant through a 36-inch gravity sewer line and splits between
two manholes. Flow then enters the headworks and influent pumping station through two
48-inch gravity sewer lines. Flow entering the head works separates into three screening
channels each sized for 30.0 mgd capacity and passes through mechanical bar screens.
Screenings are compacted and conveyed to a dumpster loading area common with the grit
dumpsters.
Primary treatment:
Following preliminary treatment, the wastewater splits between distribution boxes
(DB), DB-1 and DB-16 and is distributed to the five primary clarifiers (PC-1 through PC-
5). After primary treatment in the clarifiers, a part of the wastewater from PC -I and PC-2
is directed through DB-4. It continues through DB-4a to combine with wastewater from
PC-3, 4 and 5 in DB-4a and further to DB5 where it is combined with Return Activated
Sludge (RAS).
Secondary treatment:
The combined flow from PC -I, 2 and 3 through DB-10 is split equally between
biological treatment trains 1 and 2 where it goes through an anaerobic zone, anoxic/oxic
zone and aeration zone with internal recycle. Flow from PC-4 and PC-5 go through a rate
control structure before entering the newly constructed 5-stage BNR basins (BTB-3 and
4) designed for nitrogen and phosphors removal.
Following the aeration basin, flow from anoxic/oxic basins 1 and 2 is combined in
DB-9 and split to final clarifiers (FC) FC-1 and FC-2. Flow from BTB-3 is sent to FC-3
and from BTB-4 is sent to FC-4.
Tertiary treatment:
Combined secondary effluent from all the final clarifiers is sent to effluent filter
structure (EF) EF-1 and EF-2 for filtration and UV disinfection or 3.0 mgd is sent to
microfiltration units. Filtered effluent from the microfiltration system and the effluent
filter structures will be combined and sent to the cascade aeration structure where
aeration takes place. The cascade aeration structure will discharge through a 48" line into
McDowell Creek.

Inflow and enfi tration (0&0) Reduction Practices
Charlotte -Mecklenburg Utility Department (CMUD) has maintained an established evaluation
and rehabilitation program since the early 1990's. The purpose of this program is to restore
and preserve hydraulic capacity, structural integrity, and to reduce corrective maintenance
costs by addressing issues that cause SSOs. This includes maintaining and implementing an on-
going 1/1 reduction plan.
Multiple construction contracts are continually in place to address these issues. Through
comprehensive SSES efforts, including manhole inspections, smoke testing, CCTV, flow
monitoring, etc., areas are identified for rehabilitation and work orders assigned to a
contractor. The work may include manhole rehabilitation, point repairs, pipe lining and pipe
replacement.
Since July 2003, CMUDs' Rehabilitation Team has inspected 500 manholes, smoke tested
27,000 ft. of pipe, and performed CCTV inspection on 15,000 ft. of pipe, resulting in the
following; 156 manholes rehabbed/repaired, 68 inflow dishes installed and 7,400 ft. of pipe
rehabbed/replaced throughout the collection system. This does not include similar work
--- performed- by-C-MUDs' Field -Operation -Division.--- CMUD also implemente�hemical root
control program in March 2005 and we continue to maintain and expand that program.
CMUD uses flow monitoring extensively to support engineering analyses, to prioritize sewer
improvements, and to evaluate capacity issues and 1/1 loadings in the major trunk lines in the
system. We currently have 52 permanent flow meters installed throughout the service area (3
permanent meters in the McDowell Creek basin) and utilizes temporary flow metering on an as -
needed basis.

E
0
Charlotte-Mecklenb''urg Utilities
Sewer Rehabilitation Program
SSES Summary - McDowell Creek WWTP
Manhole Ins ections
Smoke
Testin
Work
Total
Work
Total
Basin
Performed
Inspections
Performed
Footage
Trunk sewer, major tributaries,
Washam Street
McDowell Creek
and Washam Street pump
493
pump station
27,000
station sub -basin
sub -basin
Total
493
27, 000

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FACILITY NAME AND PERMIT NUMBER:
PERMIT ACTION REQUESTED:
RIVERBASIN:
McDowell Creek WWTP, NCO036277
Renewal
Catawba
SUPPLEMENTAL APPLICATION INFORMATION
PART F.INDUSTRIAL USER DISCHARGES AND RCRAICERCLA WASTES
All treatment works receiving discharges from significant Industrial users or which receive RCRA,CERCLA, or other remedial wastes must
complete part F.
GENERAL INFORMATION:
F.I. Pretreatment program. Does the treatment works have, or is subject ot, an approved pretreatment program? '
X Yes ❑ No
F.2. Number of Significant Industrial Users (SIUs) and Categorical Industrial Users (CIUs). Provide the number of each of the following types of
industrial users that discharge to the treatment works.
a. Number of non -categorical SIUs. 0
b. Number of CIUs. 0
SIGNIFICANT INDUSTRIAL USER INFORMATION:
Supply the following information for each SIU. If more than one SIU discharges to the treatment works, copy questions F.3 through F.8 and
provide the Information requested for each SIU.
F.3. Significant Industrial User Information. Provide the name and address of each SIU discharging to the treatment works. Submit additional pages
as necessary.
Name:
Mailing Address:
FA. Industrial Processes. Describe all the industrial processes that affect or contribute to the SIU's discharge.
F.S. Principal Product(s) and Raw Material(s). Describe all of the principal processes and raw materials that affect or contribute to the SIU's
discharge.
Principal product(s):
Raw malerial(s):
F.6. Flow Rate.
a. Process wastewater flow rate. Indicate the average daily volume of process wastewater discharge into the collection system in gallons per
day (gpd) and whether the discharge is continuous or intermittent.
gpd ( continuous or intermittent)
b. Non -process wastewater flow rate. Indicate the average daily volume of non -process wastewater flow discharged into the collection system
in gallons per day (gpd) and whether the discharge is continuous or intermittent.
gpd ( continuous or intermittent)
F.7. Pretreatment Standards. Indicate whether the SIU is subject to the following:
a. Local limits ❑ Yes ❑ No
b. Categorical pretreatment standards ❑ Yes ❑ No
If subject to categorical pretreatment standards, which category and subcategory?
EPA Form 3510-2A (Rev. 1-99). Replaces EPA forms 7550-6 & 7550-22.
Page 18 of 22

/MN
r1
FACILITY NAME AND PERMIT NUMBER:
PERMIT ACTION REQUESTED:
RIVER BASIN:
' McDowell Creek WIMP, NCO036277
Renewal
Catawba
F.8. Problems at the Treatment Works Attributed to Waste Discharge by the SIU. Has the SIU caused or contributed to any problems (e.g.,
upsets, interference) at the treatment works in the past three years?
❑ Yes ❑ No If yes, describe each episode.
RCRA HAZARDOUS WASTE RECEIVED BY TRUCK, RAIL, OR DEDICATED PIPELINE:
F.9. RCRA Waste. Does the treatment works receive or has it in the past three years received RCRA hazardous waste by truck, rail or dedicated pipe?
❑ Yes ❑ No (go to F.12)
F.10. Waste transport. Method by which RCRA waste is received (check all that apply):
❑ Truck ❑ Rail ❑ Dedicated Pipe
F.11. Waste Description. Give EPA hazardous waste number and amount (volume or mass, specify units).
EPA Hazardous Waste Number Amount Units
CERCLA (SUPERFUND) WASTEWATER, RCRA REMEDIATION/CORRECTIVE ACTION
WASTEWATER, AND OTHER REMEDIAL ACTIVITY WASTEWATER:
F.12. Remediatton Waste. Does the treatment works currently (or has 8 been notified that it will) receive waste from remedial activities?
❑ Yes (complete F.13 through F.15.) ❑ No
F.13. Waste Origin. Describe the site and type of facility at which the CERCLA/RCRA/or other remedial waste originates (or is excepted to origniate in
the next five years).
F.14. Pollutants. List the hazardous constituents that are received (or are expected to be received). Include data on volume and concentration, if
known. (Attach additional sheets if necessary.)
FA 5. Waste Treatment.
a. Is this waste treated (or will be treated) prior to entering the treatment works?
❑ Yes ❑ No
If yes, describe the treatment (provide information about the removal efficiency):
b. Is the discharge (or will the discharge be) continuous or Intermittent?
❑ Continuous ❑ Intermittent If intermittent, describe discharge schedule.
END OF PART F.
REFER TO THE APPLICATION OVERVIEW (PAGE 1) TO DETERMINE WHICH OTHER PARTS
OF FORM 2A YOU MUST COMPLETE
t
EPA Form 3510-2A (Rev. 1-90). Replaces EPA forms 7550-6 & 7550-22.
Page 19 of 22

Data Summary for Reduced NPDES Permit Monitoring Frequency
Data Results and Approval Criteria for McDowell Creek WWTP
Data Set - January 1, 2010 - March 31, 2013
Parameters Monthly Weekly # of 3- Year 50% of # of Results > 200 % # of Results > 200 % Max
Limits Limits Samples Results Monthly monthly average weekly average Daily
Average Limit (CBOD, TSS, NH3) (fecal coliform) Result
CBOD
Winter
8.3
1 12.4
1 374
1 0.36
1 4.15
1 0
N/A
4.9
Summer
1 4.2
1 6.3
1 454
0.78
2.1
0
N/A
6.1
NH3 1.0 3.0 827 1 0.02 0.5 0 N/A 66
TSS 9.0 1 13.5 1 828 0.05 1 4.5 0 N/A 7.5
FecalColiform 1 100 200 1 814 1 7 1 50 1 N/A I 4 1000
Approval Criteria Met:
1) This facility has not received a civil penalty for a permit violation of the target parameters in the last three years
2) Neither the permitee nor any of its employees have been convicted of criminal violation of the CWA with the previous five years
3) This facility is not under an SOC for target parameter effluent limit noncompliance
4) This facility is not on EPA's Quarterly Noncompliance Report for target parameter limit violations
5) McDowell's three year arithmetic mean is less than fifty percent of the monthly average permit limit for CBOD, TSS, and NH3-N
6) McDowell's three year geomean is less than fifty percent of the monthly average permit limit for fecal coliform
7) Less than 15 daily sampling results over the three year review period are in excess of 200% of the monthly average for CBOD, TSS, and NH3
8) Less than 20 daily sampling results over the three year review period are in excess of the 200% of the weekly average for fecal coliform
9) McDowell has not received any non -monthly average limit violations in the past year for the four target parameters