NC0024945_Renewal (Application)_20211201

ROY COOPER-
Governor 4 .
ELIZABETH S.BISER \,.N ,0`„-
Secretary •- •
S.DANIEL SMITH NORTH CAROLINA
Director Environmental Quality
• December 03, 2021
Charlotte Water
Attn: Jackie A. Jarrell, Deputy Dir.
5100 Brookshire Blvd
Charlotte, NC 28216-3371
Subject: Permit Renewal
Application No. NC0024945
Irwin Creek WWTP
Mecklenburg County
Dear Applicant:
The Water Quality Permitting Section acknowledges the December 1, 2021 receipt of your permit renewal application
and supporting documentation. Your application will be assigned to a permit writer within the Section's NPDES WW
permitting branch. Per G.S. 150B-3 your current permit does not expire until permit decision on the application is made.
Continuation of the current permit is contingent on timely and sufficient application for renewal of the current permit.The
permit writer will contact you if additional information is required to complete your permit renewal. Please respond in a
timely manner to requests for additional information necessary to allow a complete review of the application and renewal
of the permit.
Information regarding the status of your renewal application can be found online using the Department of Environmental
Quality's Environmental Application Tracker at:
https://deq.nc.gov/permits-regu lations/permit-guidance/environmental-application-tracker
If you have any additional questions about the permit, please contact the primary reviewer of the application using the
links available within the Application Tracker.
Si erely
�n
Wren Thedford
Administrative Assistant
Water Quality Permitting Section
ec: WQPS Laserfiche File w/application
North Carolina Department of Environmental Quality I Division of Water Resources
_E Mooresville Regional Office I610 East Center Avenur,Suite 301 I Mooresville,North Carolina 28115
ra m�o� 704.663.1699

CHARLOTTE
WTER
November 22, 2021
ATTN: Mr. Michael Montebello
Division of Water Resources
Water Quality Permitting Section
Municipal NPDES Permitting Unit RECEIVED
161
7 Mail Service Center
Raleigh, NC 27699-1617 DEC 0
g r Z021
Re: Permit Renewal Application - Irwin Creek WWTP NCDEQ/pw�NPDt$
NPDES Permit#NC0024945; Charlotte Water
Mr. Montebello:
Please find the enclosed NPDES permit renewal application for Irwin Creek WWTP. Outlined below are
some important details regarding our submission:
• Attachment#1 is a narrative description of Irwin's treatment process.
• Attachment#2 provides additional information requested in Section 1.6. Inadequate space was
available to record 'Other' environmental permits.
• In Section 1.10,the Design Flow Rate is reported as 15.0 MGD (as currently allowed in our NPDES
permit). The Irwin Creek WWTP was originally constructed in 1927 and significant capacity
expansion has not occurred in more than 25 years. There have been many reliability/improvement
projects over the years, but we are not currently aware of any existing design flow rates.
• Attachment#3 summarizes the Contractor Information requested in Section 1.25.
• Attachment#4 addresses Section 2.2. and explains the ongoing work that CLTWater does to
minimize inflow and infiltration.
• Attachment#5 includes the map required in Section 2.3.
• Attachment#6 includes the plant flow schematic required in Section 2.4.
• Attachment#7 provides the scheduled improvements as requested in Sections 2.5 and 2.6.
• In Section 3.8 there are no Design Removal Rates reported. As previously mentioned, due to the
age of the facility, these are not available. The facility operates well above the Secondary Treatment
Standards for POTWs (CBOD &TSS). Currently Irwin operates under the shared 'bubble limit'for
phosphorus. This limit includes the McAlpine Creek and Sugar Creek facilities. There is no total
nitrogen limit for Irwin at this time.
• The data in Table A is summarized for the time period of 10/01/2019—09/30/2021. Most of the
construction work related to plant performance was completed earlier in 2019, so this best
represents current treatment capabilities.
• For Table B most parameters are again summarized from 10/01/2019—09/30/2021. However,TRC,
Oil and grease, and TDS were summarized for the past 4.5 years (04/01/2017—09/30/2021), in
order to provide a larger data set.
• For Table C, parameters that are sampled infrequently (only during the annual Effluent Pollutant
Scan) are provided for the past 4.5 years (04/01/2017—09/30/2021). These are easily recognizable
Charlotte Water 5100 Brookshire Blvd,Charlotte,NC 28216 charlottewater.org
6 Operated by the City of Charlotte

since most of them are represented by 5 data points. All of the other parameters are sampled more
frequently, so we chose again to use the time period from 10/01/2019—09/30/2021.
• Attachment#8 includes a list of current components to be included on the Supplement to the Permit
Cover Sheet.
Please note that some of the parameters for which data has been submitted in this application have two
method detection limits. This is due to a change in the sensitivity of the analytical method or a change
in the requirement to use a different analytical method and/or report to a lower detection limit.
Please let us know if you have any questions or if you need any further information. If you do, please
contact Shannon Sypolt,Water Quality Program Administrator, at 704/634-6984. You may also call me
at 704/634-5430. Thank you for your assistance with this renewal.
Respectfully, ,A
�"--'�--�
a gt1line A.Jarrellt .
puty Director, Charlotte Water
Cc: Jacob Bolick
Joseph Lockler
Shannon Sypolt
Charlotte Water 5100 Brookshire Blvd,Charlotte,NC 28216 charlottewater.org
Operated by the City of Charlotte

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
Form U.S.Environmental Protection Agency
2A aEPA Application for NPDES Permit to Discharge Wastewater
NPDES NEW AND EXISTING PUBLICLY OWNED TREATMENT WORKS
SECTION 1.BASIC APPLICATION INFORMATION FOR ALL APPLICANTS(40 CFR 122.21(j)(1)and(9))
1.1 Facility name
Irwin Creek Wastewater Treatment Plant
Mailing address(street or P.O.box)
4000 Westmont Drive
City or town State ZIP code
o Charlotte NC 28217
Contact name(first and last) Title Phone number Email address
Jacob Bolick Plant Supervisor [phone] [e-mail]
Location address(street, route number,or other specific identifier) ❑ Same as mailing address
4000 Westmont Drive
LL
City or town State ZIP code
Charlotte NC 28217
1.2 Is this application for a facility that has yet to commence discharge?
❑ Yes 4 See instructions on data submission ✓❑ No
requirements for new dischargers.
1.3 Is applicant different from entity listed under Item 1.1 above?
❑✓ Yes ❑ No 4 SKIP to Item 1.4.
Applicant name
Charlotte Water
Applicant address(street or P.O. box)
5100 Brookshire Blvd.
City or town State ZIP code
c Charlotte NC 28216
Contact name(first and last) Title Phone number Email address
a Jacqueline A.Jarrell Deputy Director II [phone] [e-mail]
1.4 Is the applicant the facility's owner,operator,or both?(Check only one response.)
❑ Owner ❑ Operator ✓❑ Both
1.5 To which entity should the NPDES permitting authority send correspondence?(Check only one response.)
Facility and applicant
❑ Facility ❑✓ Applicant ❑ (they are one and the same)
1.6 Indicate below any existing environmental permits.(Check all that apply and print or type the corresponding permit
r number for each.)
Existing Environmental Permits
a NPDES(discharges to surface ❑ RCRA(hazardous waste) ❑ UIC(underground injection
cwater) control)
E NC0024945
2 ❑ PSD(air emissions) ❑ Nonattainment program(CM) ❑ NESHAPs(CM)
a�
N ❑ Ocean dumping(MPRSA) ❑ Dredge or fill(CWA Section ❑✓ Other(specify)
w 404)
See Attachment#2
EPA Form 3510-2A(Revised 3-19) Page 1

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
1.7 Provide the collection system information requested below for the treatment works.
Municipality Population Collection System Type Ownership Status
Served Served (indicate percentage)
100 %separate sanitary sewer 0 Own 0 Maintain
Charlotte,NC 110,992 %combined storm and sanitary sewer ❑ Own ❑ Maintain
cc) ❑ Unknown ❑ Own ❑ Maintain
o %separate sanitary sewer ❑ Own ❑ Maintain
.15
%combined storm and sanitary sewer ❑ Own ❑ Maintain
a ❑ Unknown CIOwn ❑ Maintain
a %separate sanitary sewer ❑ Own 0 Maintain
-a %combined storm and sanitary sewer ❑ Own ❑ Maintain
c
di ❑ Unknown ❑ Own ❑ Maintain
41 %separate sanitary sewer ❑ Own ❑ Maintain
%combined storm and sanitary sewer ❑ Own 0 Maintain
cn
o ❑ Unknown ❑ Own ❑ Maintain
Total
41 Population 110,992
c i Served
Separate Sanitary Sewer System Combined Storm and
Sanitary Sewer
Total percentage of each type of ° °
sewer line(in miles) 100 %0 /0
L' 1.8 Is the treatment works located in Indian Country?
c
co 0 Yes 0No
c 1.9 Does the facility discharge to a receiving water that flows through Indian Country?
cc
c ❑ Yes ❑✓ No
1.10 Provide design and actual flow rates in the designated spaces. Design Flow Rate
15.0 mgd
o
r Annual Average Flow Rates(Actual)
TOTwo Years Ago Last Year This Year
1 MI
p 10.24 mgd 10.89 mgd 11.31 mgd
`L Maximum Daily Flow Rates(Actual)
Two Years Ago Last Year This Year
17.4 mgd 18.8 mgd 18.7 mgd
r 1.11 Provide the total number of effluent discharge points to waters of the United States by type.
o Total Number of Effluent Discharge Points by Type
a Q Constructed
4) Combined Sewer
F- Treated Effluent Untreated Effluent Overflows Bypasses Emergency
co Overflows
to
in 1
EPA Form 3510-2A(Revised 3-19) Page 2

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
Outfalls Other Than to Waters of the United States
1.12 Does the POTW discharge wastewater to basins,ponds,or other surface impoundments that do not have outlets for
discharge to waters of the United States?
❑ Yes ❑✓ No 4 SKIP to Item 1.14.
1.13 Provide the location of each surface impoundment and associated discharge information in the table below.
Surface Impoundment Location and Discharge Data
Average Daily Volume Continuous or Intermittent
Location Discharged to Surface (check one)
Impoundment
❑ Continuous
gpd 0 Intermittent
O Continuous
gpd ❑ Intermittent
❑ Continuous
gpd ❑ Intermittent
w 1.14 Is wastewater applied to land?
❑ Yes ❑✓ No 4 SKIP to Item 1.16.
0 1.15 Provide the land application site and discharge data requested below.
Land Application Site and Discharge Data
Continuous or
Location Size Average Daily Volume Intermittent
Applied (check one)
acresgpd ❑ Continuous
El Intermittent
acresgpd El Continuous
0 Intermittent
0
❑ Continuous
acres gpd ❑ Intermittent
7, 1.16 Is effluent transported to another facility for treatment prior to discharge?
o ❑ Yes ❑ No 4 SKIP to Item 1.21.
1.17 Describe the means by which the effluent is transported(e.g.,tank truck,pipe).
1.18 Is the effluent transported by a party other than the applicant?
❑ Yes ❑ No 4 SKIP to Item 1.20.
1.19 Provide information on the transporter below.
Transporter Data
Entity name Mailing address(street or P.O.box)
City or town State ZIP code
Contact name(first and last) Title
Phone number Email address
EPA Form 3510-2A(Revised 3-19) Page 3

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
1.20 In the table below, indicate the name,address,contact information, NPDES number,and average daily flow rate of the
receiving facility.
Receiving Facility Data
Facility name Mailing address(street or P.O. box)
City or town State ZIP code
0
v
Contact name(first and last) Title
0
Phone number Email address
QNPDES number of receiving facility(if any) ❑ None Average daily flow rate mgd
N
1.21 Is the wastewater disposed of in a manner other than those already mentioned in Items 1.14 through 1.21 that do not
have outlets to waters of the United States(e.g.,underground percolation,underground injection)?
❑ Yes ❑✓ No 4 SKIP to Item 1.23.
0 1.22 Provide information in the table below on these other disposal methods.
Information on Other Disposal Methods
o Disposal Location of Size of Annual Average Continuous or Intermittent
Method Disposal Site Disposal Site Daily Discharge (check one)
to
Description Volume
❑ Continuous
acres gpd ❑ Intermittent
❑ Continuous
acres gpd ❑ Intermittent
❑ Continuous
acres gpd ❑ Intermittent
1.23 Do you intend to request or renew one or more of the variances authorized at 40 CFR 122.21(n)?(Check all that apply.
• h Consult with your NPDES permitting authority to determine what information needs to be submitted and when.)
• tjj ❑ Discharges into marine waters(CWA ❑ Water quality related effluent limitation(CWA Section
Section 301(h)) 302(b)(2))
❑✓ Not applicable
1.24 Are any operational or maintenance aspects(related to wastewater treatment and effluent quality)of the treatment works
the responsibility of a contractor?
❑✓ Yes ❑ No+SKIP to Section 2.
1.25 Provide location and contact information for each contractor in addition to a description of the contractor's operational
and maintenance responsibilities.
Contractor Information
Contractor 1 Contractor 2 Contractor 3
Contractor name
(company name) See Attachment#3 See Attachment#3 See Attachment#3
o Mailing address
(street or P.O.box)
City,state,and ZIP
code
O Contact name(first and
c last)
Phone number
Email address
Operational and
maintenance
responsibilities of
contractor
EPA Form 3510-2A(Revised 3-19) Page 4

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
SECTION 2.ADDITIONAL INFORMATION(40 CFR 122.21(j)(1)and(2))
o Outfalls to Waters of the United States
= 2.1 Does the treatment works have a design flow greater than or equal to 0.1 mgd?
D Yes 0 No 4 SKIP to Section 3.
0 2.2 Provide the treatment works'current average daily volume of inflow Average Daily Volume of Inflow and Infiltration
and infiltration. 1,346,000 gpd
LT-
Indicate the steps the facility is taking to minimize inflow and infiltration.
Please see the information provided in Attachment#4.
0
0
2.3 Have you attached a topographic map to this application that contains all the required information?(See instructions for
R 0 specific requirements.)
0
F ❑✓ Yes ❑ No
E 2.4 Have you attached a process flow diagram or schematic to this application that contains all the required information?
o R (See instructions for specific requirements.)
" o ❑✓ Yes 0 No
2.5 Are improvements to the facility scheduled?
❑✓ Yes 0 No SKIP to Section 3.
Briefly list and describe the scheduled improvements.
0
1. Please see the information provided in Attachment#7.
m
E
2.
E
0
3.
a
a�
U)
4.
ca 2.6 Provide scheduled or actual dates of completion for improvements.
Scheduled or Actual Dates of Completion for Improvements
Affected Attainment of
d Scheduled Begin End Begin
o Outfalls Operational
Improvement Construction Construction Discharge
EL (from above) (list outfall (MM/DD/YYYY) (MM/DD/YYYY) (MM/DD/YYYY) Level
number) (MM/DD/YYYY)
1. See Attach.#7
a)
a>
2.
3.
4.
2.7 Have appropriate permits/clearances concerning other federal/state requirements been obtained?Briefly explain your
response.
❑✓ Yes 0 No 0 None required or applicable
Explanation:
Permits are applied for and obtained as required by each project.
EPA Form 3510-2A(Revised 3-19) Page 5

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
SECTION 3.INFORMATION ON EFFLUENT DISCHARGES(40 CFR 122.21(j)(3)to(5))
3.1 Provide the following information for each outfall. (Attach additional sheets if you have more than three outfalls.)
Outfall Number 001 Outfall Number Outfall Number
State North Carolina
County Mecklenburg
o City or town Charlotte
o Distance from shore 0 ft. ft. ft.
.Q
v Depth below surface 0 ft. ft. ft.
Average daily flow rate 11.1 mgd mgd mgd
Latitude 35° 11' 42.4" N 11 1 11
0
Longitude 80° 54' 29.8" W
3.2 Do any of the outfalls described under Item 3.1 have seasonal or periodic discharges?
❑ Yes ✓❑ No 4 SKIP to Item 3.4.
6 3.3 If so,provide the following information for each applicable outfall.
Outfall Number Outfall Number Outfall Number
a Number of times per year
0 discharge occurs
a Average duration of each
`o discharge(specify units)
a Average flow of each
0 discharge mgd mgd mgd
cn Months in which discharge
occurs
3.4 Are any of the outfalls listed under Item 3.1 equipped with a diffuser?
❑ Yes ❑✓ No 4 SKIP to Item 3.6.
3.5 Briefly describe the diffuser t pe at each applicable outfall.
0
Outfall Number Outfall Number Outfall Number
U)
o 6. 3.6 Does the treatment works discharge or plan to discharge wastewater to waters of the United States from one or more
discharge points?
(3 w ❑✓ Yes ❑ No 4SKIP to Section 6.
EPA Form 3510-2A(Revised 3-19) Page 6

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
3.7 Provide the receiving water and related information(if known)for each outfall.
Outfall Number 001 Outfall Number Outfall Number
Receiving water name Irwin Creek
Name of watershed,river,
0 or stream system Sugar Creek
U.S.Soil Conservation
•L
N Service 14-digit watershed
o code
°, Name of state
management/river basin Catawba
rn
.- U.S.Geological Survey
5 8-digit hydrologic 03050103
o
ce cataloging unit code
Critical low flow(acute) 4.09 cfs cfs cfs
Critical low flow(chronic) 4.9 cfs cfs cfs
Total hardness at critical mg/L of mg/L of mg/L of
low flow unknown CaCO3 CaCO3 CaCO3
3.8 Provide the following information describing the treatment provided for discharges from each outfall.
Outfall Number ool Outfall Number Outfall Number
Highest Level of ❑ Primary ❑ Primary 0 Primary
Treatment(check all that 0 Equivalent to ❑ Equivalent to 0 Equivalent to
apply per outfall) secondary secondary secondary
❑ Secondary 0 Secondary ❑ Secondary
O Advanced ❑ Advanced ❑ Advanced
❑ Other(specify) ❑ Other(specify) 0 Other(specify)
c
- Design Removal Rates by
.5 Outfall
d
in
BODs or CBODs %a % 0/0
c
d
E
m TSS % % %
I-
❑Not applicable ❑ Not applicable ❑Not applicable
Phosphorus
❑ Not applicable ❑ Not applicable ❑ Not applicable
Nitrogen % 0/0 o
/o
Other(specify) ❑Not applicable ❑Not applicable ❑ Not applicable
%
EPA Form 3510-2A(Revised 3-19) Page 7

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
3.9 Describe the type of disinfection used for the effluent from each outfall in the table below. If disinfection varies by
season,describe below.
-a
d
.0
0
0
Outfall Number 001 Outfall Number Outfall Number
- Disinfection type
Ultraviolet light
d
Seasons used
All
is
Dechlorination used? ❑✓ Not applicable ❑ Not applicable ❑ Not applicable
❑ Yes ❑ Yes ❑ Yes
❑ No ❑ No ❑ No
3.10 Have you completed monitoring for all Table A parameters and attached the results to the application package?
❑✓ Yes ❑ No
3.11 Have you conducted any WET tests during the 4.5 years prior to the date of the application on any of the facility's
discharges or on any receiving water near the discharge points?
❑✓ Yes ❑ No 4 SKIP to Item 3.13.
3.12 Indicate the number of acute and chronic WET tests conducted since the last permit reissuance of the facility's
discharges by outfall number or of the receiving water near the discharge points.
Outfall Number 001 Outfall Number Outfall Number
Acute Chronic Acute Chronic Acute Chronic
Number of tests of discharge
water 0 16
Number of tests of receiving 0 0
water
3.13 Does the treatment works have a design flow greater than or equal to 0.1 mgd?
❑✓ Yes ❑ No 4 SKIP to Item 3.16.
3.14 Does the POTW use chlorine for disinfection,use chlorine elsewhere in the treatment process,or otherwise have
reasonable potential to discharge chlorine in its effluent?
47.
❑ Yes 4 Complete Table B,including chlorine. ✓❑ No 4 Complete Table B,omitting chlorine.
3.15 Have you completed monitoring for all applicable Table B pollutants and attached the results to this application
package?
❑✓ Yes ❑ No
3.16 Does one or more of the following conditions apply?
• The facility has a design flow greater than or equal to 1 mgd.
• The POTW has an approved pretreatment program or is required to develop such a program.
• The NPDES permitting authority has informed the POTW that it must sample for the parameters in Table C,must
sample other additional parameters(Table D),or submit the results of WET tests for acute or chronic toxicity for
each of its discharge outfalls(Table E).
Yes 4 Complete Tables C, D,and E as
❑ applicable. IDNo 4 SKIP to Section 4.
3.17 Have you completed monitoring for all applicable Table C pollutants and attached the results to this application
package?
❑✓ Yes ❑ No
3.18 Have you completed monitoring for all applicable Table D pollutants required by your NPDES permitting authority and
attached the results to this application package?
❑ Yes ❑ No additional sampling required by NPDES
permitting authority.
EPA Form 3510-2A(Revised 3-19) Page 8

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
3.19 Has the POTW conducted either(1)minimum of four quarterly WET tests for one year preceding this permit application
or(2)at least four annual WET tests in the past 4.5 years?
❑✓ Yes ❑ No+ Complete tests and Table E and SKIP to
Item 3.26.
3.20 Have you previously submitted the results of the above tests to your NPDES permitting authority?
No 4 Provide results in Table E and SKIP to
❑✓ Yes ❑ Item 3.26.
3.21 Indicate the dates the data were submitted to your NPDES permitting authority and provide a summary of the results.
Date(s)Submitted Summary of Results
(MM/DD/YYYY)
All WET tests passed during this permitting cycle. WET tests were
completed on the following dates: 10/03/17,01/09/18,04/24/18,
07/17/18,10/09/18,01/15/19,04/04/19,07/16/19,10/08/19,01/14/20,
�_— 04/14/20,07/07/20,10/13/20,10/27/20,01/05/21,04/13/21,07/13/21
o 3.22 Regardless of how you provided your WET testing data to the NPDES permitting authority,did any of the tests result in
toxicity?
0 Yes ❑✓ No 4 SKIP to Item 3.26.
3.23 Describe the cause(s)of the toxicity:
ai
L.
3.24 Has the treatment works conducted a toxicity reduction evaluation?
0 Yes ❑ No 4 SKIP to Item 3.26.
3.25 Provide details of any toxicity reduction evaluations conducted.
3.26 Have you completed Table E for all applicable outfalls and attached the results to the application package?
❑ Yes ❑✓ Not applicable because previously submitted
information to the NPDES sermittin. authorit
SECTION 4.INDUSTRIAL DISCHARGES AND HAZARDOUS WASTES(40 CFR 122.21(j)(6)and(7))
4.1 Does the POTW receive discharges from Sills or NSCIUs?
❑✓ Yes ❑ No 4 SKIP to Item 4.7.
d 4.2 Indicate the number of SlUs and NSCIUs that discharge to the POTW.
Number of SIUs Number of NSCIUs
20 0
2 4.3 Does the POTW have an approved pretreatment program?
1.1
❑✓ Yes 0 No
g 4.4 Have you submitted either of the following to the NPDES permitting authority that contains information substantially
identical to that required in Table F:(1)a pretreatment program annual report submitted within one year of the
application or(2)a pretreatment program?
s
❑✓ Yes ❑ No 4 SKIP to Item 4.6.
To 4.5 Identify the title and date of the annual report or pretreatment program referenced in Item 4.4.SKIP to Item 4.7.
11)
Pretreatment Annual Report 02/26/2021
-o
4.6 Have you completed and attached Table F to this application package?
0 Yes ❑ No
EPA Form 3510-2A(Revised 3-19) Page 9

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
4.7 Does the POTW receive,or has it been notified that it will receive, by truck, rail,or dedicated pipe,any wastes that are
regulated as RCRA hazardous wastes pursuant to 40 CFR 261?
❑ Yes ❑✓ No 4 SKIP to Item 4.9.
4.8 If yes,provide the following information:
Annual
Hazardous Waste Waste Transport Method Amount of Units
Number (check all that apply) Waste
Received
❑ Truck El Rail
❑ Dedicated pipe ❑ Other(specify)
0
d ❑ Truck ❑ Rail
❑ Dedicated pipe ❑ Other(specify)
O
❑ Truck ❑ Rail
_ ❑a Dedicated pipe ❑ Other(specify)
so
s4.9 Does the POTW receive,or has it been notified that it will receive,wastewaters that originate from remedial activities,
including those undertaken pursuant to CERCLA and Sections 3004(7)or 3008(h)of RCRA?
❑ Yes ❑✓ No 4 SKIP to Section 5.
3 4.10 Does the POTW receive(or expect to receive)less than 15 kilograms per month of non-acute hazardous wastes as
specified in 40 CFR 261.30(d)and 261.33(e)?
❑ Yes 4 SKIP to Section 5. ❑ No
4.11 Have you reported the following information in an attachment to this application:identification and description of the
site(s)or facility(ies)at which the wastewater originates;the identities of the wastewater's hazardous constituents;and
the extent of treatment, if any,the wastewater receives or will receive before entering the POTW?
❑ Yes ❑ No
SECTION 5.COMBINED SEWER OVERFLOWS(40 CFR 122.21(j)(8))
5.1 Does the treatment works have a combined sewer system?
o� ❑ Yes ❑✓ No-*SKIP to Section 6.
a 5.2 Have you attached a CSO system map to this application?(See instructions for map requirements.)
❑ Yes
c ❑ No
5.3 Have you attached a CSO system diagram to this application?(See instructions for diagram requirements.)
U ❑ Yes ❑ No
EPA Form 3510-2A(Revised 3-19) Page 10

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
5.4 For each CSO outfall,provide the following information.(Attach additional sheets as necessary.)
CSO Outfall Number CSO Outfall Number CSO Outfall Number
City or town
0
.Q State and ZIP code
0
to
0 County
ms
Latitude
0
Longitude °
U
Distance from shore ft. ft. ft.
Depth below surface ft. ft. ft.
5.5 Did the POTW monitor any of the following items in the past year for its CSO outfalls?
CSO Outfall Number CSO Outfall Number CSO Outfall Number
Rainfall ❑ Yes D No ❑ Yes ❑ No ❑ Yes ❑ No
co
o CSO flow volume ❑ Yes ❑ No ❑ Yes ❑ No ❑ Yes ❑ No
CSO pollutant ❑ Yes ❑ No ❑ Yes ❑ No ❑ Yes ❑ No
0 concentrations
co
c� Receiving water quality ❑ Yes ❑ No ❑ Yes ❑ No ❑ Yes 0 No
CSO frequency 0 Yes ❑ No ❑ Yes 0 No 0 Yes ❑ No
Number of storm events 0 Yes ❑ No ❑ Yes ❑ No 0 Yes ❑ No
5.6 Provide the following information for each of your CSO outfalls.
CSO Outfall Number CSO Outfall Number CSO Outfall Number
03
>- Number of CSO events in events events events
N the past year
cAverage duration per hours hours hours
c event 0 Actual or❑ Estimated ❑Actual or❑Estimated ❑Actual or❑Estimated
w million gallons million gallons million gallons
o Average volume per event
0 ❑Actual or❑ Estimated 0 Actual or❑ Estimated 0 Actual or 0 Estimated
Minimum rainfall causing inches of rainfall inches of rainfall inches of rainfall
a CSO event in last year 0 Actual or❑ Estimated 0 Actual or 0 Estimated ❑Actual or 0 Estimated
EPA Form 3510-2A(Revised 3-19) Page 11

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
5.7 Provide the information in the table below for each of your CSO outfalls.
CSO Outfall Number CSO Outfall Number CSO Outfall Number
Receiving water name
Name of watershed/
stream system
U.S.Soil Conservation 0 Unknown ❑ Unknown ❑ Unknown
Service 14-digit
watershed code
(if known)
Name of state
management/river basin
U.S.Geological Survey 0 Unknown ❑ Unknown ❑ Unknown
8-Digit Hydrologic Unit
Code(if known)
Description of known
water quality impacts on
receiving stream by CSO
(see instructions for
exam.les
SECTION 6.CHECKLIST AND CERTIFICATION STATEMENT(40 CFR 122.22(a)and(d))
6.1 In Column 1 below,mark the sections of Form 2A that you have completed and are submitting with your application. For
each section,specify in Column 2 any attachments that you are enclosing to alert the permitting authority. Note that not
all applicants are required to provide attachments.
Column 1 Column 2
Section 1: Basic Application
Information for All Applicants ❑ w/variance request(s) ❑✓ w/additional attachments
✓❑ Section 2:Additional ✓❑ w/topographic map ❑✓ w/process flow diagram
Information ✓❑ w/additional attachments
✓❑ w/Table A ❑ w/Table D
❑ Section 3: Information on ✓❑ w/Table B ❑ w/Table E
Effluent Discharges
❑✓ wl Table C ❑ wl additional attachments
Section 4: Industrial ❑ w/SIU and NSCIU attachments ❑ w/Table F
❑✓ Discharges and Hazardous
Wastes ❑ w/additional attachments
Section 5:Combined Sewer ❑ w/CSO map ❑ wl additional attachments
❑ Overflows
❑ wl CSO system diagram
❑ Section 6: Checklist and ❑ w/attachments
Certification Statement
N
Y 6.2 Certification Statement
C)
a)
I 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 fine
and imprisonment for knowing violations.
Name(print or type first and last name) Official title
Signature Date signed
— 3 � ' Z
EPA Form 3510-2A(Revised 3-19) Page 12

EPA Identification Number NPDES Permit Number Facilitiy Name Outfall Number Form Annrnved 03/05/19
1000541922 NC0024945 I reek WWTP 001 < o.2040-0004
TABLE A. EFFLUENT PARAMETERS FOR ALL POTWS
Maximum Daily Discharge Average Daily Discharge 1
Analytical ML or MDL
Pollutant Number of Method(1) (include units)
Value Units Value Units Samples
Biochemical oxygen demand X ML
CBOD5 3.5 mg/L 0.1 mg/L 416 SM5210B-11 2.0 mg/L MDL
Fecal Coliform 78 CFU/100 ml 2 CFU/100 ml 500 SM9222D-11 1 CFU/100 mll X ML
MDL
Design flow rate 18.8 MGD 11.1 MGD 731
pH (minimum) 6.3 SU
pH (maximum) 7.7 SU
Temperature(winter) 23.3 Deg C 17.5 Deg C 202
Temperature(summer) 26.7 Deg C 23.3 Deg C 299
Total suspended solids(TSS) 5.5 mg/L 0.0 mg/L 416 SM2540D-11 2.5 mg/L X ML
MDL
(1)Sampling shall be conducted according to sufficiently sensitive test procedures(i.e.methods)approved under 40 CFR 136 for the analysis of pollutants or pollutant parameters or
required under 40 CFR chapter I,subchapter N or O.See instructions and 40 CFR 122.21(e)(3).
EPA Form 3510-2A(Revised 3/19) Page 13

This page intentionally left blank.

r.nnventionals PPA
Start Date 10/1/2019 4/1/2017
End Date: 9/30/2021 9/30/2021
EPA Identification Number NPDES Permit Number Facilitiy Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WVVTP 001 OMB No.2040-0004
TABLE B. EFFLUENT PARAMETERS FOR ALL POTWS WITH A FLOW EQUAL TO OR GREATER THAN 0.1 MGD
Maximum Daily Discharge Average Daily Discharge
Pollutant Analytical ML or MDL
Value Units Value Units Number of Method(1) (include units)
Samples
Ammonia(as N) 1.8 mg/L 0.01 mg/L 416 SM 4500-NH3-H-11 0.1 mg/L X ML
MDL
Chlorine(total residual, TRC)(2) 15 pg/L 3 pg/L 5 Hach 10014ULR 15 X ML
pg/L MDL
Dissolved Oxygen 10.2 mg/L 8.9 mg/L 501 ASTM D888-09C 1.0 mg/L X ML
MDL
X ML
Nitrate/nitrite 23 mg/L 17.6 mg/L 416 EPA 353.2-93 0.05 mg/L MDL
Kjeldahl nitrogen 2.3 mg/L 0.77 mg/L 416 EPA 351.2-93 0.25 mg/L X ML
MDL
X ML I
Oil and grease 0.0 mg/L 0.0 mg/L 5 EPA 1664E 5.0 mg/L MDL
Phosphorus 7.0 mg/L 0.83 mg/L 416 SM 4500P-H-11 0.1 mg/L X ML
MDL
Total dissolved solids 380 mg/L 324 mg/L 5 SM 2540C-11 25 mg/L X ML
MDL
(1)Sampling shall be conducted according to sufficiently sensitive test procedures(i.e.methods)approved under 40 CFR 136 for the analysis of pollutants or pollutant parameters or
required under 40 CFR chapter I,subchapter N or O.See instructions and 40 CFR 122.21(e)(3).
(2)Facilities that do not use chlorine for disinfection,do not use chlorine elsewhere in the treatment process,and have no reasonable potential to discharge chlorine in their effluent are not
required to report data for chlorine.
EPA Form 3510-2A(Revised 3/19) Page 15

Conventionals PPA
Start Date: /2019 4/1/2017
End Date: /2021 9/30/2021
EPA Identification Number NPDES Permit Number Facilitiy Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP 001 OMB No.2040-0004
TABLE C.EFFLUENT PARAMETERS FOR SELECTED POTWS
ge ML or MDL
Pollutant Value Units Value Units _.__ SamplesNumber of Analytical ML
)
Maximum Daily Discharge Average Daily Discharge
Method 1 (include units
Metals,Cyanide and Total Phenols
7 ML
Hardness(as CaCo3) 170 mg/L 129 mg/L 26 EPA 200.7 1.0 mg/L X MDL
Antimony,total recoverable 0.0 pg/L 0.0 pg/L 5 EPA 200.8 5.0 pg/L X ML
EPA 200.7 MDL
EPA 200.8 X ML
Arsenic,total recoverable 0.0 pg/L 0.0 µg/L 26 EPA 200.7 5.0 pg/L MDL
Beryllium,total recoverable 0.0 pg/L 0.0 pg/L 5 EPA 200.8 5.0/2.0 pg/L X ML
EPA 200.7 MDL
Cadmium,total recoverable 0.0 pg/L 0.0 pg/L 26 EPA 200.8 1.0/0.5 pg/L X ML
EPA 200.7 MDL
EPA 200.8 X ML
Chromium,total recoverable 0.0 pg/L 0.0 pg/L 26 EPA 200.7 5.0 pg/L MDL
EPA 200.8 X ML
Copper,total recoverable 7.6 pg/L 2.3 µg/L 26 EPA 200.7 2.0 pg/L MDL
Lead,total recoverable 0.0 pg/L 0.0 pg/L 26 EPA 200.8 5.0 pg/L X ML
EPA 200.7 MDL
Mercury,total recoverable 1.08 ng/L 0.65 ng/L 26 EPA 1631E 0.50 ng/L X ML
MDL
Nickel,total recoverable 9.7 pg/L 3.3 pg/L 26 EPA 200.8 2.0 p /Lg X ML
EPA 200.7 MDL
Selenium,total recoverable 0.0 pg/L 0.0 pg/L 26 EPA 200.8 5.0 pg/L X ML
EPA 200.7 MDL
Silver,total recoverable 0.0 pg/L 0.0 µg/L 26 EPA200.8 1.0 pg/L X ML
EPA 200.7 MDL
Thallium,total recoverable 0.0 pg/L 0.0 pg/L 5 EPA 200.8 5.0/1.0 pg/L X ML
EPA 200.7 MDL
Zinc,total recoverable 57 pg/L 44.1 pg/L 26 EPA 200.8 10 pg/L X ML
EPA 200.7 MDL
Cyanide 0 mg/L 0.0 µg/L 26 10-204-00-1-X 10 pg/L X ML
MDL
Total phenolic compounds 0.000 mg/L 0.000 mg/L 14 EPS 420.2 0.050 mg/L X ML
MDL
,Volatile Organic Compounds
'X ML
Acrolein 0.0 pg/L 0.0 µg/L 5 EPA 624.1 100/25 pg/L MDL
Acrylonitrile 0.0 pg/L 0.0 pg/L 5 EPA 624.1 100/2.0 pg/L X ML
MDL
Benzene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
Bromoform 0.0 pg/L 0.0 µg/L 5 EPA 624.1 5.0/2.0 pg/L
X ML
MDL
EPA Form 3510-2A(Revised 3/19) Page 17

Start Date: 4/1/2017
End Date: 9/30/2021
EPA Identification Number NPDES Permit Number Facilitiy Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP 001 OMB No.2040-0004
TABLE C.EFFLUENT PARAMETERS FOR SELECTED POTWS
i Maximum Daily Discharge Average Daily Discharge _ { Analytical ML or MDL
Pollutant (1) units)
Value Units Value Units Number of Method (include I
Samples
Carbon tetrachloride 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 µg/L X ML
MDL
Chlorobenzene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
Chlorodibromomethane 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
Chloroethane 0.0 pg/L 0.0 pg/L 5 EPA 624.1 10/5.0 pg/L X ML
MDL
2-chloroethylvinyl ether 0.0 pg/L 0.0 pg/L 5 EPA 624.1 10/2.0 pg/L X ML
MDL
X ML
Chloroform 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L MDL
Dichlorobromomethane 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
1,1-dichloroethane 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
1,2-dichloroethane 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
trans-1,2-dichloroethylene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
1,1-dichloroethylene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
1,2-dichloropropane 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
1,3-dichloropropylene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
Ethylbenzene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
Methyl bromide 0.0 pg/L 0.0 pg/L 5 EPA 624.1 10/5.0 pg/L X ML
MDL
Methyl chloride 0.0 pg/L 0.0 pg/L 5 EPA 624.1 10/5.0 pg/L X ML
MDL
Methylene chloride 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
1,1,2,2-tetrachloroethane 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
Tetrachloroethylene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
Toluene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
1,1,1-trichloroethane 0.0 pg/L 0.0 pg/L 5 EPA624.1 5.0/2.0 pg/L X ML
MDL
1,1,2-trichloroethane 0.0 L 0.0 X ML
µg/ pg/L 5 EPA 624.1 5.0/2.0 µ9/L MDL
EPA Form 3510--,..�tised 3/19) Page 18

Start Date: 17
End Date: 321
EPA Identification Number NPDES Permit Number Facilitiy Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP 001 OMB No.2040-0004
TABLE C.EFFLUENT PARAMETERS FOR SELECTED POTWS
Maximum Daily Discharge Average Daily Discharge ML or MDL
Pollutant _. -_ Analytical
Value Units Value Units Number of Method(1) (include units)
Samples
Trichloroethylene 0.0 pg/L 0.0 pg/L 5 EPA 624.1 5.0/2.0 pg/L X ML
MDL
Vinyl chloride 0.0 µg/L 0.0 pg/L 5 EPA 624.1 10/5.0 pg/L X ML
MDL
Acid-Extractable Compounds
p-chloro-m-cresol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X MDL
X ML
2-chlorophenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
2,4-dichlorophenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
2,4-dimethylphenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
4,6-dinitro-o-cresol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 20/5.0 pg/L MDL
2,4-dinitrophenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 50/20 pg/L X ML
MDL
2-nitrophenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
X ML
4-nitrophenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
Pentachlorophenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 20/10 pg/L MDL
Phenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
X ML
2,4,6-trichlorophenol 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
Base-Neutral Compounds
I1 X ML
Acenaphthene j 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
Acenapthylene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
Anthracene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
Benzidine 0.0 pg/L 0.0 pg/L 5 EPA 625.1 50/5.0 pg/L X ML
MDL
X ML
Benzo(a)anthracene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
Benzo(a)pyrene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
3,4-benzofluoranthene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
EPA Form 3510-2A(Revised 3/19) Page 19

Start Date: 4/1/2017
End Date: 9/30/2021
EPA Identification Number NPDES Permit Number Facilitiy Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP 001 OMB No.2040-0004
TABLE C.EFFLUENT PARAMETERS FOR SELECTED POTWS
Maximum Daily Discharge Average Daily Discharge Analytical ML or MDL I
Pollutant
Value Units Value Units Number of Method(1) (include units)
J____ Samples
X ML
Benzo(ghi)perylene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 µg/L MDL
Benzo(k)fluoranthene 0.0 pg/L 0.0 µg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
X ML
Bis(2-chloroethoxy)methane 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
Bis(2-chloroethyl)ether 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
ML
Bis(2-chloroisopropyl)ether 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X MDL
X ML
Bis(2-ethylhexyl)phthalate 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
4-bromophenyl phenyl ether 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
Butyl benzyl phthalate 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
X ML
2-chloronaphthalene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
4-chloro hen I phenyl ether 0.0pg/L 0.0X ML
p y p y pg/L 5 EPA 625.1 10/5.0 µ9/L MDL
Chrysene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
X ML
di-n-butyl phthalate 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L
MDL
di-n-octyl phthalate 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
Dibenzo(a,h)anthracene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
1,2-diclorobenzene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
1,3-dichlorobenzene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
1,4-dichlorobenzene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
3,3-dichlorobenzidine 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
Diethylphthalate 0.0pg/L 0.0 X ML
Y µ9/L 5 EPA 625.1 10/5.0 µ9/L MDL
Dimethyl phthalate 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 X ML
µg/L MDL
2,4-dinitrotoluene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
2,6-dinitrotoluene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L
X ML
MDL
EPA Form 3510 „prised 3/19) Page 20

Start Date: 117
End Date: '021
EPA Identification Number NPDES Permit Number Facilitiy Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP 001 OMB No.2040-0004
TABLE C.EFFLUENT PARAMETERS FOR SELECTED POTWS
Pollutant alue Maximum Daily Units Value Average DailyDischarge AnalyticaNumber of Method(11) (inLc ude units)
Discharge
its Samples
X ML
1,2-diphenylhydrazine , 0.0 µg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
Fluoranthene 0.0 pg/L 0.0 pg/L 5 EPA625.1 10/5.0 pg/L MDL
X ML
Fluorene 0.0 pg/L 0.0 µg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
Hexachlorobenzene 0.0 µg/L 0.0 µg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
Hexachlorobutadiene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
Hexachlorocyclo-pentadiene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
Hexachloroethane 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
Indeo(1,2,3-cd)pyrene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
Isophorone 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
Naphthalene 0.0 µg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L X ML
MDL
X ML
Nitrobenzene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
N-nitrosodi-n-propylamine 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
N-nitrosodimethylamine 0.0 µg/L 0.0 µg/L 5 EPA 625.1 10/5.0 µg/L MDL
X ML
N-nitrosodiphenylamine 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
Phenanthrene , 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
Pyrene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
X ML
1,2,4-trichlorobenzene 0.0 pg/L 0.0 pg/L 5 EPA 625.1 10/5.0 pg/L MDL
I
(1)Sampling shall be conducted according to sufficiently sensitive test procedures(i.e.methods)approved under 40 CFR 136 for the analysis of pollutants or pollutant parameters or
required under 40 CFR chapter I,subchapter N or O.See instructions and 40 CFR 122.21(e)(3).
EPA Form 3510-2A(Revised 3/19) Page 21

This page intentionally left blank.

EPA Identification Number NPDES Permit Number Facility Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
TABLE D.ADDITIONAL POLLUTANTS AS REQUIRED BY NPDES PERMITTING AUTHORITY
Maximum Daily Discharge Average Daily Dischar e
Pollutant Analytical ML or MDL
(list) Value Units Value Units Number of Method' (include units)
Samples
ErNo additional sampling is required by NPDES permitting authority.
o ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
❑ML
❑MDL
1 Sampling shall be conducted according to sufficiently sensitive test procedures(i.e.,methods)approved under 40 CFR 136 for the analysis of pollutants or pollutant parameters or required
under 40 CFR chapter I,subchapter N or 0.See instructions and 40 CFR 122.21(e)(3).
EPA Form 3510-2A(Revised 3-19) Page 23

This page intentionally left blank.

EPA Identification Number NPDES Permit Number Facility Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
TABLE E.EFFLUENT MONITORING FOR WHOLE EFFLUENT TOXICITY
The table provides response space for one whole effluent toxicity sample.Copy the table to report additional test results.
Test Information
Test Number Test Number Test Number
Test species
Age at initiation of test
Outfall number
Date sample collected
Date test started
Duration
Toxicity Test Methods
Test method number
Manual title
Edition number and year of publication
Page number(s)
Sample Type
Check one: ❑ Grab ❑ Grab ❑ Grab
❑ 24-hour composite 0 24-hour composite ❑ 24-hour composite
Sample Location
Check one: ❑ Before Disinfection ❑ Before Disinfection ❑ Before disinfection
El After Disinfection ❑ After Disinfection ❑ After disinfection
❑ After Dechlorination ❑ After Dechlorination ❑ After dechlorination
Point in Treatment Process
Describe the point in the treatment process
at which the sample was collected for each
test.
Toxicity Type
Indicate for each test whether the test was ❑Acute ❑Acute El Acute
performed to asses acute or chronic toxicity,
or both.(Check one response.) ❑ Chronic CI Chronic El Chronic
❑ Both ❑ Both ❑ Both
EPA Form 3510-2A(Revised 3-19) Page 25

EPA Identification Number NPDES Permit Number Facility Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
TABLE E.EFFLUENT MONITORING FOR WHOLE EFFLUENT TOXICITY
The table provides response space for one whole effluent toxicity sample.Copy the table to report additional test results.
Test Number Test Number Test Number
Test Type
Indicate the type of test performed.(check one ❑ Static ❑ Static ❑ Static
response.)
❑ Static-renewal ❑ Static-renewal ❑ Static-renewal
❑ Flow-through ❑ Flow-through ❑ Flow-through
Source of Dilution Water
Indicate the source of dilution water.(check ❑ Laboratory water ❑ Laboratory water 0 Laboratory water
one response.)
❑ Receiving water ❑ Receiving water ❑ Receiving water
If laboratory water,specify type.
If receiving water,specify source.
Type of Dilution Water
Indicate the type of dilution water.If salt ❑ Fresh water ❑ Fresh water ❑ Fresh water
water,specify"natural"or type of artificial
sea salts or brine used. ❑ Salt water(specify) ❑ Salt water(specify) ❑ Salt water(specify)
Percentage Effluent Used
Specify the percentage effluent used for all
concentrations in the test series.
Parameters Tested
Check the parameters tested. 0 pH ❑ Ammonia ❑ pH ❑ Ammonia ❑ pH ❑ Ammonia
❑ Salinity ❑ Dissolved oxygen ❑ Salinity ❑ Dissolved oxygen ❑ Salinity ❑ Dissolved oxygen
❑ Temperature ❑ Temperature ❑ Temperature
Acute Test Results
Percent survival in 100%effluent
LC50
95%confidence interval
Control percent survival 0/0
EPA Form 3510-2A(Revised 3-19) Page 26

EPA Identification Number NPDES Permit Number Facility Name Outfall Number Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
TABLE E.EFFLUENT MONITORING FOR WHOLE EFFLUENT TOXICITY
The table provides response space for one whole effluent toxicity sample.Copy the table to report additional test results.
Test Number Test Number Test Number
Acute Test Results Continued
Other(describe)
Chronic Test Results
NOEC 0/0
IC25
Control percent survival
Other(describe)
Quality Control/Quality Assurance
Is reference toxicant data available? ❑ Yes ❑ No ❑ Yes ❑ No ❑ Yes ❑ No
Was reference toxicant test within
acceptable bounds? ❑ Yes ❑ No ElYes ❑ No ❑ Yes ❑ No
What date was reference toxicant test run
(MM/DD/YYYY)?
Other(describe)
EPA Form 3510-2A(Revised 3-19) Page 27

This page intentionally left blank.

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
TABLE F.INDUSTRIAL DISCHARGE INFORMATION
Response space is provided for three SIUs.Copy the table to report information for additional Sills.
SIU SIU SIU
Name of SIU
Mailing address(street or P.O.box)
City,state,and ZIP code
Description of all industrial processes that affect
or contribute to the discharge.
List the principal products and raw materials that
affect or contribute to the SIU's discharge.
Indicate the average daily volume of wastewater
discharged by the SIU. gpd gpd gpd
How much of the average daily volume is
attributable to process flow? gpd gpd gpd
How much of the average daily volume is
attributable to non-process flow? gpd gpd gpd
Is the SIU subject to local limits?
❑ Yes ❑ No ❑ Yes ❑ No ❑ Yes ❑ No
Is the SIU subject to categorical standards?
❑ Yes ❑ No ❑ Yes ❑ No ❑ Yes 0 No
EPA Form 3510-2A(Revised 3-19) Page 29

EPA Identification Number NPDES Permit Number Facility Name Form Approved 03/05/19
110000541922 NC0024945 Irwin Creek WWTP OMB No.2040-0004
TABLE F.INDUSTRIAL DISCHARGE INFORMATION
Response space is provided for three SIUs.Copy the table to report information for additional SIUs.
SIU SIU SIU
Under what categories and subcategories is the
SIU subject?
Has the POTW experienced problems(e.g.,
upsets, pass-through interferences)in the past 4.5 ❑ Yes ❑ No ❑ Yes ❑ No ❑ Yes ❑ No
years that are attributable to the SIU?
If yes,describe.
EPA Form 3510-2A(Revised 3-19) Page 30

Attachment #1
Irwin Creek WWTP Narrative of Treatment Processes
Liquid Processes
h Irwin Creek Wastewater Treatment Plant through the Influent Pumping Influent flow enters the C eeg p g
Station where it is screened via two %" multi rake bar screens. It is then pumped to the grit removal
building via four influent pumps. It flows by gravity through the grit chambers where grit settles out
and is removed. Both screenings and grit are dewatered, captured in dumpsters, and taken to the
landfill for disposal. After grit removal, influent flow mixes with BFP filtrate flow from the Filtrate
tank (a solids processing side stream high in ammonia and phosphorous)that is metered in by
gravity. There is also an option here to meter in Aluminum Sulfate (Alum)to chemically bind
phosphorous. Flow is then diverted to primary clarification utilizing one of three 125-ft diameter
primary clarifiers. Liquid then flows by gravity over V-notch weirs to the primary clarifier effluent
structure (PCES) where it mixes with Return Activated Sludge (RAS), Sand Filter Backwash Water,
Gravity Belt Filtrate, and Magnesium Hydroxide for alkalinity adjustment. Flow is then evenly
distributed via an aeration basin distribution structure (ATDS)to seven (7) aeration basins that are
currently running in an anoxic-oxic configuration. This activated sludge process is designed to aid in
biological phosphorous treatment by promoting a phosphorous release in the anoxic zones then
luxury uptake in the oxic zone. Dissolved oxygen is provided by four(4) high speed turbo blowers
running through a fine bubble diffuser grid. As the flow leaves the aeration basins there is an option
for Alum addition to chemically bind phosphorous into the solids to aid in the phosphorous
treatment process. Mixed liquor from the aeration basins flows by gravity to Secondary Clarification
where it is introduced to three of four 125-ft secondary clarifiers. RAS is then pumped from the
clarifiers via 3 out of the 5 RAS pumps back to the PCES (where it is mixed with fresh wastewater).
Clarified water then flows by gravity to the Filter Pump station, then to UV disinfection, and out to
Irwin Creek over a cascade aerator.
Flow equalization is also provided for emergencies, wet weather events, or for plant shutdowns due
to construction projects. During these periods the additional flow in the system travels by gravity
over a weir gate to the flow equalization (EQ) control structure. Wastewater then flows through
two 3/8" climbing screens where rags are removed, dewatered, and disposed of in a landfill. Four
20 MGD EQ pumps transfer the flow from a wet well to the flow equalization basins. Total
equalization volume is 30 million gallons. This is comprised of a 10 million gallon basin and a 20
million gallon basin. At this structure,flow can be routed to the 54" relief sewer line to McAlpine
Creek WWTF, having never entered the Irwin treatment train.
EQ flows can be metered and drained back into the plant pre grit removal, drained into the Taggart
Creek sewer line where it is mixed in with the main plant influent (repumped and screened before
entering the plant), or as a third option it can be drained to the 54" relief sewer line to be treated at
McAlpine Creek WWTF.

Tertiary filtration and disinfection system.
Secondary clarifier effluent is pumped from the filter pump station to ten 250-square foot sand
filters. Filtered effluent flow is then disinfected with UV lamps. Irwin maintains two UV channels
with three banks of lamps totaling 672. Under normal operating circumstances one channel with
two banks are required to maintain adequate disinfection. After disinfection, effluent flow is
metered and sent by gravity over a cascade aerator for dissolved oxygen addition then into Irwin
Creek.
Solids Processes
Primary Sludge (PS)from the primary clarifiers is pumped to the anaerobic digesters using three air
operated diaphragm pumps.
Waste activated sludge (WAS) is thickened using two gravity belt thickeners (GBT(s)). The WAS is
thickened to approximately 5-percent solids using polymer to bind to the solids. GBT filtrate is
returned to the plant by gravity into the PCES.The thickened WAS (TWAS) is mixed with primary
sludge from the primary clarifiers before entering the anaerobic digesters.
The TWAS and PS are combined and mixed in 4 anaerobic digesters. The digesters provide a volume
of approximately 2.7million gallons. Once digested,the solids flow by gravity in two 600,000 gallon
holding tanks prior to dewatering. Two Belt Filter Presses are available for dewatering of the
biosolids. The dewatered cake is thickened to approximately 15-percent solids. Dewatering filtrate
then flows to the filtrate EQ basin where it is aerated via fine bubble diffusers, and eventually
metered back into the plant at 100 gpm.
Biosolids residuals are permitted, managed, and disposed of under a contract with Synagro. Land
application and land filling are the means for ultimate use of the residuals.
Auxiliary Processes
Duke energy maintains a dedicated power substation onsite for Irwin's utility power.As a backup
there are two 3000kw Caterpillar generators onsite that are used for backup power.
There are two 16,000 gallon magnesium hydroxide tanks and two 10,000 gallon aluminum sulfate
tanks maintained on site for chemical feeds. Currently one of each are in service and are maintained
full.

Attachment #2
Existing Environmental Permits
NC General Stormwater Permit: NCG110008
Land Application of Residuals: NC WQ000057
SC ND0080900
Wastewater Collection System Permit: WQCS00001
Dams on NC DEMLR Inventory: MECKL-083, NID ID NC03450
MECKL-174, NID ID NC05344

Attachment #3
The Contractors at Irwin Creek WWTP are listed below. The addresses and telephone numbers
for the contractors are included.
CITI LLC Address: 4030 Yancey Rd.
Charlotte, NC 28217
Telephone#: [phone]
Contract Emphasis: Instrumentation
Maintenance/Calibration and
PLC/System Integrator.
Carolina Caterpillar Address: 9000 Statesville Road
Charlotte, NC 28269
Telephone#: [phone]
Contract Emphasis: Service provider for PM and repair
maintenance for the WWTP's two
3000KW diesel generators.
Kemp Construction Address: 2217 Lynmore Drive
Sherrill's Ford, NC 28675
Telephone#: [phone]
Contract Emphasis: General Contractor for O&M of the
WWTP repairs for plant equipment and
processes.
BW Service Solutions LLC Address: 138 Pine DR
Lowell, NC 28098
Telephone#: [phone]
Contract Emphasis: General Contractor for O&M of the
WWTP repairs for plant equipment and
processes.
Gilbert Engineering Company
General Contractor Address: 638 S. Meeting St.
Statesville, NC, 28677
Telephone#: [phone]
Contract Emphasis: General Contractor for the Irwin Creek
Rehab Improvement Project at Irwin
Creek WWTP.

Environmental Services of Charlotte
Address: 2101 South Tryon Street
Charlotte, NC, 28203
Telephone#: [phone]
Contract Emphasis: HVAC maintenance and repair
contractor for Irwin Creek VVVVfP.
Hach Company Address: PO Box 389
Loveland, CO, 80539
Telephone#: [phone]
Contract Emphasis: Hach Brand Plant Instrumentation
maintenance and repair for Irwin Creek
VWVfP.

Attachment #4
Inflow and Infiltration (1&I) Reduction Practices
Charlotte Water(CLTWater) 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 I/I 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 are assigned to a contractor. The work may include manhole
rehabilitation, point repairs, pipe lining, and pipe replacement.
From August 2010 to September 2021, CLTWater's Rehabilitation Team has:
• inspected 69,962 manholes
• smoke tested 9,163,110 ft. of pipe
• CCTV inspection of 1,680,963 ft. of pipe
These SSES efforts resulted in the following:
• 3,511 manholes rehabbed/repaired
• 661 inflow dishes installed
• 696,874 ft. of pipe rehabbed/replaced
• 1,406 clean-outs replaced
• 2,999 service laterals replaced
This does not include similar work performed by CLTWater's Field Operation Division or other sections
within CLTWater. CLTWater also implemented a chemical root control program in March 2005 and we
continue to maintain and expand that program. We have treated approximately 10,906,207 ft of line in the
McAlpine basin since this program was initiated.
CLTWater uses flow monitoring extensively to support engineering analyses, to prioritize sewer
improvements, and to evaluate capacity issues and I/I loadings in the major trunk lines in the system.
CLTWater currently has 60 permanent flow meters installed throughout the service area and utilizes
temporary flow metering on an as-needed basis.

Rehab Totals as of 10/26/2021
Pipelines MHs Smoke MH Inflow Cleanouts Laterals
CCTV(LF) Rehab/Replace (LF) Inspected (EA) Testing (LF) Rehab/Replace (EA) Dishes (EA) Repair/Replace (EA) Replaced (EA)
FY11 133,097 59,414 9,480 1,352,912 674 231 229 252
FY12 93,774 57,533 7,686 1,313,994 446 160 217 149
FY13 73,688 46,892 3,347 492,078 403 88 197 306
FY14 161,980 41,345 3,991 484,092 173 37 128 236
FY15 74,950 58,508 914 360,092 365 33 144 451
FY16 3,148 50,094 2,143 398,500 183 21 45 228
FY17 425,310 48,318 1,202 270,060 201 47 76 299
FY18 217,997 64,528 8,626 244,561 298 38 125 415
FY19 230,190 102,773 7,141 1,432,459 288 0 76 235
FY20 170,862 69,751 14,109 750,234 264 6 104 223
FY21 71,162 60,598 8,875 1,528,548 189 0 58 189
FY22 YTD 24,805 37,120 2,448 535,580 27 0 7 16
Total 1,680,963 696,874 69,962 9,163,110 3,511 661 1,406 2,999
Average
Per Year
Excluding
FY22 150,560 59,978 6,138 784,321 317 60 127 271

Charlotte Water
Sewer Rehabilitation Program
Overall SSES Summary Through September 30, 2021
Basin/ Manhole Inspections Smoke Testing
Area Work Total Work Total
Performed/Anticipated Inspections Performed/Anticipated Footage
Andover Road
Entire sub-basin 182 Entire sub-basin 50,000
area
Briar Creek Entire basin 5,953 Entire basin 1,986,699
Primarily Huntersville; Primarily Huntersville;
Clarke Creek started Highland Creek 2,143 started Highland Creek 278,936
area February 09 area February 09
Trunk sewer and major McCullough Branch sub-
Coffee Creek 2,697 174,677
tributaries basin
H2S Investigation (limited
Four Mile Creek 249 None 34,778
scope)
Trunk sewer and major Trunk sewer and major
tributaries complete; tributaries complete;
Irwin Creek 14,342 1,584,293
began remainder of basin began remainder of basin
September 2012 September 2012
Trunk sewer and Gum Trunk sewer and Gum
Branch sub-basin Branch sub-basin
Long Creek complete; began 16,948 complete; began 3,018,684
remainder of basin remainder of basin
October 2008 November 2008
Trunk sewer complete;
Mallard Creek remainder of basin 5,119 Basin partially complete 137,914
partially complete
Trunk sewer and major
tributaries complete;
McAlpine Creek 18,729 Entire basin 3,079,493
began remainder of basin
October 2010
Trunk sewer, major
tributaries, and Washam Washam Street pump
McDowell Creek 6,958 38,569
Street pump station sub- station sub-basin
basin
Old ADS smoke leaks
McMullen Creek Trunk sewer 8,656 initially; began basin work 202,912
for B&C April 2017
Paw Creek Entire basin 2,274 Entire basin 560,000
Entire Plott Road pump Entire Plott Road pump
Reedy Creek 797 214,000
station sub-basin station sub-basin

Griffith Street and Included in Griffith Street and
Davidson College pump McDowell Davidson College pump 45,000
Rocky River stations sub-basins Creek stations sub-basins
Davidson and Huntersville 1,112 Davidson and Huntersville 235,000
Trunk sewer and major
Six-Mile Creek tributaries and Pasofino 304 None 29,267
pump station sub-basin
Trunk sewer and major
Steele Creek 209 Carowinds 15,452
tributaries; also Carowinds
Lower Little Sugar
Entire basin 2,999 Entire basin 378,774
Creek _
Trunk sewer and major McCullough Branch sub-
Upper Little Sugar tributaries complete; basin complete; began
10,753 1,548,913
Creek began remainder of basin remainder of basin
September 2008 September 2008
Miscellaneous Various small areas 190 None 28,674
Total 100,614 ;, 13,642,035

Irwin Creek Wastewater Treatment Plant
Flow Schematic-Calendar Year 2021
'Optional chemical addition points
Magnesium Aluminum
Aluminum Hydroxide Sulfate'
Sulfate* 0 I I-ATE I-FCE
I-INF n I I-PCE
Activated Sludge i at,t I-EFF
Influent Influent Grit PCE Structure Aeration Basins Final Clarifiers Sand Filters
Primary Clarifiers UV
Diversion Pump Removal i ;
Structure Bar screens Station tBrr 4 •= ••410: ► Disinfection Cascade
�\\\\ ► A 40 of�► � Effluent Filter
y,r rrr" Aerator
Influent
Pump Station ''''�° `"- Ill
To Landfill . I-RAW I Return Sludge(RAS)
To Landfill
Sand Filter BackwashActivated
III Auxiliary Irvin
Bar screens Backwash Basin Creek
—+\\\\\\ Equalization
EQ Pump Basins I I-FILT I
* Station
To Landfill Filtrate Storage
V 1 I-GBTFT I I-WAS
Bypass to
McAlpine WWMF I I-BFPFILT > Polymer y 1
Biosolids �, Y®
Storage Pad I ® Waste Activated I_
Slud a WAS
To Land i I I-TWAS Gravity Belt WAS Storage g ( )
Application/ 4 ,,,,,
Landfill Thickeners II
Polymer
I-CAKE Belt Press
Dewatering
I-FEED Ferric Storage Anaerobic Digesters
Chloride*
I-DIG
Legend Flow Meters Sampling Locations
- Wastewater Location(#) Variable Name(s)in WIMS Tag Description
At influent composite sampler I-INF Flow[Note:Meter of Record] I-INF Influent[Note:Permitted sampling location]
.— Treated Water Pumped flow to sand filters Sand Filter Influent Flow I-PCE Primary Clarifier Effluent
Solids At effluent composite sampler I-EFF Flow I-ATE Aeration Tank Effluent
Sludge from primary clarifiers Raw Sludge Flow I-FCE Final Clarifier Effluent
7 Pump RAS pumped to PCE structure RAS Flow I-EFF Effluent[Note:Permitted sampling location]
MO Flow Meter WAS pumped to WAS storage WAS Flow I-RAW Raw Primary Sludge
� WAS feed flow to gravity belt thickeners WAS Average Feed Flow I-WAS Waste Activated Sludge
`
` Sampling Location TWAS pumped to digesters TWAS Flow I-TWAS Thickened Waste Activated sludge
Total Raw and TWAS to digesters Sludge Flow to Digesters I-GBTFT Gravity Belt Thickener Filtrate
* Optional chemical addition point Digested sludge to dewatering storage Sludge Flow to Dewatering I-DIG Digested Sludge from Digester(s)
Total sludge flow to belt filter presses Belt Sludge Flow I-FEED Dewatering Feed
From filtrate storage to primary clarifiers Dewatering Filtrate Flow to Plant I-CAKE Dewatered Cake
I-BFPFILT Belt Press Thickener Filtrate(Pre-storage tank)
I-FILT Belt Press Thickener Filtrate

Irwin Creek Wastew, r Treatment Plant
One Mile Radius
Wastewater Mains 0 Well Drinking Water L'ImIrwin Creek WWTP Parcel Biosolids Storage
ForceMain ,'" " li
is
Wastewater Lift Stations _ Irwin Creek WWTP One Mile Radius
issim Gravity
- Streams
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Irwin Creek Wastewater
Treatment Plant Technology Services - GIS Group for generalCharlotteWater informationgeographic purposesdata only.and Whileother Charlotterecordsare Waterprovided
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released data.

Attachment #7
Project Name Project Summary Dates & Other Details
UV Disinfection System Improvement Project Project provides for replacement of existing UV Consultant: HDR
disinfection system that has been in service for Anticipated Construction Start Date: July 2025
over 15 years and is nearing the end of its Anticipated Construction Completion: July 2027
useful life. Project includes demolition of
existing UV equipment and replacement with
new UV equipment and associated electrical
equipment, furnishing and installing a temporary
disinfection system during construction,
modifications to existing UV equipment
channels, new UV level control finger weirs,
new non-potable water pumps, check valves,
butterfly valves, and an air release valve, new
non potable pump control panels to include
VFDs, and installation of a new magnetic flow
meter on the effluent filter backwash piping.
IRWIN FILTER PUMP STATION Perform assessment of the Filter pump station Consultant: Brown & Caldwell
ASSESSMENT Anticipated Start Date of Assessment: November 2021
IRWIN SLUDGE DRYING BEDS Consultant will report on the current condition of Consultant: CDM Smith
ASSESSMEMT the beds along with recommended repairs and Anticipated Assessment Completion Date: 1st Quarter
SOP usages and recommendations for the 2022
beds
IRWIN DIGESTED SLUDGE TANK AND Bid documents are currently being prepared to Consultant: Hazen & Sawyer
DIGESTER CLEANING clean out the digested sludge storage tank and Anticipated Start Date: Spring 2022
6 digesters at the plant
IRWIN REHAB AND IMPROVEMENTS Rehabilitation of multiple processes and/or Currently underway with completion anticipated in the 4th
PROJECT systems at Irwin WWTP: Quarter of 2022
Influent Pump Station Design Improvements
Effluent Flowmeter Design Improvements
Chemscan Process Analyzer Design
Administration & Old Chlorine Storage Building
Roof Replacement
Equalization (EQ) Basin Design Improvements
Addition of 3rd Bar Screen Design
Final Clarifier Stress Testing

Attachment #8 — Irwin Creek WWTP Component List for Supplement to Permit
Cover Sheet
Below is the current list of components:
• Mechanical bar screen
• Influent pump station
• Grit removal
• Flow equalization
• Influent flow measurement
• Three primary clarifiers
• pH adjustment
• Aeration basins (diffused air)
• Four secondary clarifiers
• Ten tertiary filters
• Effluent flow measurement
• Ultraviolet disinfection
• Cascade aeration
• Four anaerobic digesters
• Two unmixed secondary digester tanks
• 300,000 gallon sludge storage for WAS
• Two gravity belt thickeners with polymer feed
• 1.8 MG digested sludge storage tank
• 2 Backup generators