NC0089630_Application (ATC)_20211129

Hazen Hazen and Sawyer
9101 Southern Pine Boulevard,Suite 250 RECEIVED Charlotte,NC 28273•704 357.3150
NOV 292021
November 22, 2021 NCDEQ/DWR/NPDES
Ms. Min Xiao
North Carolina Division of Water Resources
512 North Salisbury Street
9th Floor—Archdale Building
Raleigh,NC,27604
Re: Charlotte Water
Stowe Regional Water Resource Recovery Facility-Stage 1
NPDES No. NC0089630
Request for Authorization to Construct
Dear Ms. Xiao:
The enclosed Application for Authorization to Construct Permit(Form ATC-12-14)is for the project
"Stowe Regional Water Resource Recovery Facility Project—Stage 1". On behalf of Charlotte Water,
Hazen and Sawyer submits this letter and enclosures to request Authorization to Construct this project.
This project proposes to construct a new regional wastewater treatment facility with the initial capacity
of 15 million gallons of wastewater per day with provisions to upgrade that capacity to 25 mgd in the
future. The facility,located in western Mecklenburg County,will treat Charlotte Water customers in the
surrounding area as well as the Cities of Mt. Holly and,ultimately,Belmont in Gaston County.
Construction for is scheduled to begin in late March 2022, and final completion of the entire facility is
anticipated by August 2026.
The construction is planned to be executed in 3 stages. This application is for Stage 1 construction
only. The subsequent stages(Stage 2 and Stage 3)will be submitted for approval separately,but progress-
level plans for these stages are enclosed to help provide context for the overall project. It is anticipated
that Authorization to Construct for Stages 2 and 3 will be applied for in mid-January 2022 and mid-
August 2022,respectively. The scope of Stage 1 construction work includes:
• Three(3)new final clarifiers
• Civil site work related to site grading,erosion control,and stormwater runoff collection
In accordance with the ATC Application,the following documents are included within the submittal
package:
• Application for Authorization to Construct Permit(Form ATC-12-14)
• Engineering plans including civil,mechanical, and structural.
• Engineering specifications including civil,process mechanical, and structural.
• NPDES Permit(NC0089630)
hazenandsawyer.com

I

Hazen
• Engineering Calculations.
• USB with digital PDFs of the above items.
A construction sequence plan is not included with this submittal because the proposed Stowe Facility
is entirely new and therefore has no existing operations around which to plan.
Thank you for your consideration of this application. If you have any questions or need any additional
information to complete your review,please do not hesitate to contact me at 980-833-8521 or via email at
[e-mail].
Very truly yours,
itivg"Ag
Michael J. Benchich, PE
Senior Associate
Cc: Nicole Bartlett(Charlotte Water)
Page 2 of 2
hazenandsawyer.com

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC-12-14)
SECTION 1: INSTRUCTIONS AND INFORMATION
A. The Division of Water Resources will accept this application package for review only if all of the items are provided and the
application is complete.Failure to submit all of the required items will result in the application package being returned as incomplete
per 15A NCAC 02T.0105(b).
B. Plans and specifications must be prepared in accordance with 15 NCAC 02H.0100, 15A NCAC 02T, North Carolina General Statute
133-3, North Carolina General Statute 143-215.1, and Division of Water Resources Minimum Design Criteria for NPDES
Wastewater Treatment Facilities.
C. The plans and specifications submitted must represent a completed final design that is ready to advertise for bid.
D. Any content changes made to this Form ATC-12-14 shall result in the application package being returned.
E. The Applicant shall submit ONE ORIGINAL and ONE DIGITAL COPY (CD) of the application, all supporting documentation and
attachments. All information must be submitted bound or in a 3-ring binder, with a Section tab for each Section, except the
Engineering Plans.
F. Check the boxes below to indicate that the information is provided and the requirements are met.
11 G. If attachments are necessary for clarity or due to space limitations, such attachments are considered part of the application
package and must be numbered to correspond to the item referenced.
H. For any project that requires review under the State Environmental Policy Act (SEPA), an Authorization to Construct cannot be
issued prior to the completion of a State Clearinghouse advertisement period for a FONSI, EIS, etc. unless the project qualifies for
a Determination of Minor Construction Activity.
I. For more information,visit the Division of Water Resources web site at:https://deq.nc.gov/about/divisions/water-resources/water-
resources-permits/wastewater-branch/npdes-wastewater/authorization-to-construct.
J. In addition to this Authorization to Construct,the Applicant should be aware that other permits may be required from other Sections
of the Division of Water Resources(for example: reclaimed water facilities permits; Class A or B biosolids residuals permit).
SECTION 2: APPLICANT INFORMATION AND PROJECT DESCRIPTION
A. APPLICANT
Applicant's name Charlotte Water
Signature authority's name per 15A NCAC 02T.0106(b) Joseph C. Wilson
Signature authority's title Chief Engineer
Complete mailing address 5100 Brookshire Blvd,Charlotte, NC 28216
Telephone number 704-995-7516
Email address [e-mail]
B. PROFESSIONAL ENGINEER
Professional Engineer's name Michael J. Benchich
Professional Engineer's title Senior Associate
North Carolina Professional Engineer's License No. 32685
Firm name Hazen and Sawyer
Firm License number C-0381
Complete mailing address 9101 Southern Pine Blvd,Suite 250, Charlotte, NC 28273
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 1

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT(FORM ATC-12-14)
Telephone number 704-941-6058
Email address [e-mail]
C. NPDES PERMIT
NPDES Permit number NC0089630
Current Permitted flow(MGD)—include permit
flow phases if applicable Phase I: 15 MGD,Phase II:25 MGD
D. PROJECT DESCRIPTION
Provide a brief description of the project:The project consists of construction of a new wastewater treatment facility with an
initial capacity of 15 mgd,expandable to 25 mgd in the future.The facility is located in western Mecklenburg County along the
Catawba River upstream of the confluence with Long Creek.The project is being constructed in 3 stages.Stage 1 includes the
construction of three final clarifiers,site grading,and erosion control.
SECTION 3:APPLICATION ITEMS REQUIRED FOR SUBMITTAL FOR ALL PROJECTS
A. Cover Letter
® The letter must include a request for the Authorization to Construct;the facility NPDES Number; a brief project description
that indicates whether the project is a new facility,facility modification,treatment process modification,or facility expansion;
the construction timeline;and a list of all items and attachments included in the application package.
❑ If any of the requirements of 15 NCAC 02H. 0100, 15A NCAC 02T, North Carolina General Statute 133-3, North Carolina
General Statute 143-215.1, and Division of Water Resources Minimum Design Criteria for NPDES Wastewater Treatment
Facilities are not met by the proposed design,the letter must include an itemized list of the requirements that are not met.
B. NPDES Permit
® Submit Part I of the Final NPDES permit for this facility that includes Part A(Effluent Limitations and Monitoring Requirements)
for the monthly average flow limit that corresponds to the work that is requested for this project.
C. Special Order by Consent
❑ If the facility is subject to any Special Orders by Consent(SOC),submit the applicable SOC.
® Not Applicable.
D. Finding of No Significant Impact or Record of Decision
® Submit a copy of the Finding of No Significant Impact or Record of Decision for this project.
❑ Provide a brief description of any of the mitigating factors or activities included in the approved Environmental Document
that impact any aspect of design of this project,if not specified in the Finding of No Significant Impact or Record of Decision.
❑ Not Applicable.
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 2

State of North Carolina
• Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT(FORM ATC-12-14)
E. Engineering Plans
® Per 15A NCAC 02T.0504(c)(1),submit one set of detailed plans that have been signed,sealed and dated by a North Carolina
Licensed Professional Engineer.
® Per 21 NCAC 56.1103(a)(6),the name, address and License number of the Licensee's firm shall be included on each sheet of
the engineering drawings.
® Plans must be labeled as follows: FINAL DRAWING—FOR REVIEW PURPOSES ONLY—NOT RELEASED FOR CONSTRUCTION.
® 15A NCAC 02H .0124 requires multiple (dual at a minimum) components such as pumps, chemical feed systems, aeration
equipment and disinfection equipment. Is this requirement met by the design? ❑ Yes or ❑ No. If no, provide an
explanation:
Plans shall include:
® Plans for all applicable disciplines needed for bidding and construction of the proposed project(check as appropriate):
• Civil ❑ Not Applicable
® Process Mechanical ❑ Not Applicable
® Structural ❑ Not Applicable
❑ Electrical ® Not Applicable
❑ Instrumentation/Controls ® Not Applicable
❑ Architectural ® Not Applicable
❑ Building Mechanical ® Not Applicable
❑ Building Plumbing ® Not Applicable
® Plan and profile views and associated details of all modified treatment units including piping,valves,and equipment(pumps,
blowers, mixers,diffusers,etc.)
® Are any modifications proposed that impact the hydraulic profile of the treatment facility?❑ Yes or❑ No. If yes, provide
a hydraulic profile drawing on one sheet that includes all impacted upstream and downstream units. The profile shall include
the top of wall elevations of each impacted treatment unit and the water surface elevations within each impacted treatment
unit for two flow conditions: (1) the NPDES permitted flow with all trains in service and (2)the peak hourly flow with one
treatment train removed from service.
® Are any modifications proposed that impact the process flow diagram or process flow schematic of the treatment facility?
❑Yes or❑No. If yes,provide the process flow diagram or process flow schematic showing all modified flow paths including
aeration, recycle/return,wasting,and chemical feed,with the location of all monitoring and control instruments noted.
F. ® Engineering Specifications
® Per 15A NCAC 02T.0504(c)(2),submit one set of specifications that have been signed,sealed and dated by a North Carolina
Licensed Professional Engineer.
® Specifications must be labeled as follows: FINAL SPECIFICATIONS — FOR REVIEW PURPOSES ONLY — NOT RELEASED FOR
CONSTRUCTION.
Specifications shall include:
® Specifications for all applicable disciplines needed for bidding and construction of the proposed project (check as
appropriate):
® Civil El Not Applicable
® Process Mechanical El Not Applicable
® Structural ❑ Not Applicable
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 3

hilij: State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL DUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC-12-14)
E Electrical ® Not Applicable
❑ Instrumentation/Controls ® Not Applicable
❑ Architectural ® Not Applicable
❑ Building Mechanical ® Not Applicable
❑ Building Plumbing ® Not Applicable
® Detailed specifications for all treatment units and processes including piping, valves, equipment (pumps, blowers, mixers,
diffusers,etc.), and instrumentation.
® Means of ensuring quality and integrity of the finished product including leakage testing requirements for structures and
pipelines, and performance testing requirements for equipment.
❑ Bid Form for publicly bid projects.
G. Construction Sequence Plan
❑ Construction Sequence Plan such that construction activities will not result in overflows or bypasses to waters of the State.
The Plan must not imply that the Contractor is responsible for operation of treatment facilities. List the location of the
Construction Sequence Plan as in the Engineering Plans or in the Engineering Specifications or in both:
H. Engineering Calculations
❑ Per 15A NCAC 02T.0504(c)(3),submit one set of engineering calculations that have been signed,sealed and dated by a North
Carolina Licensed Professional Engineer;the seal,signature and date shall be placed on the cover sheet of the calculations.
For new or expanding facilities and for treatment process modifications that are included in Section 4.C,the calculations shall
include at a minimum:
• Demonstration of how peak hour design flow was determined with a justification of the selected peaking factor.
• Influent pollutant loading demonstrating how the design influent characteristics in Section 4.B.2 of this form were
determined.
• Pollutant loading for each treatment unit demonstrating how the design effluent concentrations in Section 4.B.2 of this form
were determined.
❑ Hydraulic loading for each treatment unit.
Li Sizing criteria for each treatment unit and associated equipment(blowers, mixers, pumps, etc.)
❑ Total dynamic head(TDH)calculations and system curve analysis for each pump specified that is included in Section 4.C.6.
• Buoyancy calculations for all below grade structures.
❑ Supporting documentation that the specified auxiliary power source is capable of powering all essential treatment units.
I. Permits
• Provide the following information for each permit and/or certification required for this project:
Permit/ If Not Issued Provide
Not Date Date Certification Status and Expected
Permit/Certification Applicable Submitted Approved Number Issuance Date
Dam Safety x - - - -
Soil Erosion and Sediment Control - Oct. 2021 - - -
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 4

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC-12-14)
USCOE /Section 404 Permit - May 2020 SAW 2019
01988
Revised USCOE /Section 404 March 2022
Permit
DWR#20-
Water Quality Certification (4011 - May 2020 0405
Revised Water Quality Certification
(401) March 2022
SAW-2019-
USCOE/Section 10 May 2020 01988
Revised USCOE/Section 10 - - - - March 2022
Stormwater Management Plan - - - - -
CAMA x - - - -
NCDOT Encroachment Agreement x - - - -
Railroad Encroachment Agreement x - - - -
Other: Duke Energy Line Crossing
Permit Nov 2021 Feb. 2022
Other: Floodplain Development - Oct. 2021 - - -
DWR#20-
Catawba River Buffer Authorization - May 2020 0405
Revised Catawba River Buffer
March 2022
Authorization
•
Mecklenburg County Building
Nov. 2021
Permit
J. Residuals Management Plan
For all new facilities, expanding facilities, or modifications that result in a change to sludge production and/or sludge
processes, provide a Residuals Management Plan meeting the requirements of 15A NCAC 02T .0504(() and 15A NCAC 02T
.0508;the Plan must include:
A detailed explanation as to how the generated residuals(including trash, sediment and grit)will be collected, handled,
processed, stored,treated,and disposed.
❑ An evaluation of the treatment facility's residuals storage requirements based upon the maximum anticipated residuals
production rate and ability to remove residuals.
❑ A permit for residuals utilization or a written commitment to the Applicant from a Permittee of a Department approved
residuals disposal/utilization program that has adequate permitted capacity to accept the residuals or has submitted a
residuals/utilization program application.
❑ If oil,grease,grit or screenings removal and collection is a designated unit process, a detailed explanation as to how the
oil/grease will be collected, handled, processed,stored and disposed.
❑ Not Applicable.
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 5

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT(FORM ATC-12-14)
SECTION 4: PROJECT INFORMATION
A. WASTEWATER TREATMENT PLANT FLOW INFORMATION—COMPLETE FOR NEW OR EXPANDING FACILITIES
1. Provide the following flow information:
Plant Flows
Existing Plant Design N/A
Current NPDES Permit Limit 15 MGD
Current Annual Average N/A
(past 12 months)
For Past 12 Months: For Past 24 Months:
Start Date: Start Date:
End Date: End Date:
Maximum Month N/A N/A
Maximum Day N/A N/A
Peak Hour N/A N/A
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 6

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT(FORM ATC-12-14)
B. WASTEWATER TREATMENT FACILITY DESIGN INFORMATION—COMPLETE FOR NEW OR EXPANDING FACILITIES AND
FOR TREATMENT PROCESS MODIFICATIONS
1. Have all of the requirements of 15 NCAC 02H. 0100, 15A NCAC 02T, North Carolina General Statute 133-3, North Carolina
General Statute 143-215.1,and Division of Water Resources Minimum Design Criteria for NPDES Wastewater Treatment
Facilities been met by the proposed design and specifications?❑ Yes or❑ No. If no, provide justification as to why the
requirements are not met, consistent with 15A NCAC 02T.0105(n):
2. Provide the design influent and effluent characteristics that are used as the basis for the project design,and the NPDES
permit limits for the following parameters:
Project Basis of Design
Design Influent Design Influent
Influent Concentration Load
Concentration- (Must be (Must be
Current Annual supported by supported by
Average(past Engineering Engineering Design Effluent
12 months)if Calculations Calculations Concentration and/or NPDES Permit Limits
Parameter Available [Section 3.H]) [Section 3.H]) Load (monthly average)
Ammonia Nitrogen 1 mg/L Summer 1 mg/L Summer
N/A 29.7 mg/L 3,690 lb/day
(NH3 N) 1 mg/L Winter 1 mg/L Winter
Biochemical 4.2 mg/L Summer 4.2 mg/L Summer
Oxygen Demand N/A 334 mg/L 41,400 lb/day
(BOD5) 8.3 mg/L Winter 8.3 mg/L Winter
Fecal Coliform 200 per 100 mL 200 per 100 mL
Nitrate+Nitrite
Nitrogen (NO3-N+ 4.5 mg/L Not Permitted
NO2-N)
Total Kjeldahl N/A
Nitrogen
5 mg/L summer 6 mg/L summer
10 mg/L winter 12 mg/L winter
Total Nitrogen
133,857 lb/year summer 160,628 lb/year summer
188,901 lb/year winter 226,681 lb/year winter
1 mg/L 1 mg/L
Total Phosphorus N/A 6.6 mg/L 820 lb/day 45,662 lb/year 45,662 lb/year
Total Suspended N/A 311 mg/L 38,600 lb/day 30 mg/L 30 mg/L
Solids(TSS)
3. Based on the"Project Basis of Design"parameters listed above,will the proposed design allow the treatment facility to
meet the NPDES Permit Limits listed above?E Yes or❑ No. If no, describe how and why the Permit Limits will not be
met:
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 7

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC-12-14)
4. Per 15A NCAC 02T.0505(j), by-pass and overflow lines are prohibited. Is this condition met by the design?0 Yes or❑ No
If no,describe the treatment units bypassed,why this is necessary, and where the bypass discharges:
5. Per 15A NCAC 02T.0505(k), multiple pumps shall be provided wherever pumps are used. Is this condition met by the
design? E Yes or❑ No. If no, provide an explanation:
6. Per 15A NCAC 02T.0505(I), power reliability shall be provided consisting of automatically activated standby power supply
onsite capable of powering all essential treatment units under design conditions,or dual power supply shall be provided
per 15A NCAC 02H.0124(2)(a). Is this condition met by the design? E Yes or❑ No. If no, provide (as an attachment
to this Application)written approval from the Director that the facility:
> Has a private water supply that automatically shuts off during power failures and does not contain elevated water
storage tanks,and
> Has sufficient storage capacity that no potential for overflow exists, and
V Can tolerate septic wastewater due to prolonged detention.
7. Per 15A NCAC 02T.0505(o), a minimum of 30 days of residual storage shall be provided. Is this condition met by the
design? ❑ Yes or❑ No. If no, explain the alternative design criteria proposed for this project in accordance 15A NCAC
02T.105(n): Residual storage and handling is being designed and constructed by others and will be permitted separately.
8. Per 15A NCAC 02T.0505(q),the public shall be prohibited from access to the wastewater treatment facilities. Explain how
the design complies with this requirement: Stowe RWRRF includes a fence around the permitter of the plant with restricted
entry gates at each entrance.
9. Is the treatment facility located within the 100-year flood plain? ❑Yes or❑ No. If yes,describe how the facility is
protected from the 100-year flood:
C. WASTEWATER TREATMENT UNIT AND MECHANICAL EQUIPMENT INFORMATION-COMPLETE FOR NEW OR
EXPANDING FACILITIES AND FOR MODIFIED TREATMENT UNITS
1. PRELIMINARY AND PRIMARY TREATMENT(i.e., physical removal operations and flow equalization):
No.of Plan Sheet Specification Calculations
Treatment Unit Provided?
Units Type Size per Unit Reference Reference
(Yes or No)
Manual Bar Screen N/A
Mechanical Bar N/A
Screen
Grit Removal N/A
Flow Equalization N/A
Primary Clarifier N/A
Primary Clarifier N/A
Other N/A
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 8

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT(FORM ATC-12-14)
2. SECONDARY TREATMENT(BIOLOGICAL REACTORS AND CLARIFIERS) (i.e., biological and chemical processes to remove
organics and nutrients)
No.of Plan Sheet Specification Calculations
Treatment Unit Type Size per Unit Provided?
Units Reference Reference (Yes or No)
Aerobic Zones/ N/A
Tanks
Anoxic Zones/ N/A
Tanks
Anaerobic N/A
Zones/Tanks
Sequencing Batch N/A
Reactor(SBR)
Membrane N/A
Bioreactor(MBR)
160 ft diameter; 16 ft side M300 to Yes
Secondary Clarifier 3 Circular water depth M308
Secondary Clarifier N/A Rectangular
Other N/A
3. TERTIARY TREATMENT
No.of Plan Sheet Specification Calculations
Treatment Unit Type Size per Unit Provided?
Units Reference Reference
(Yes or No)
Tertiary Clarifier N/A Circular
Tertiary Clarifier N/A Rectangular
Tertiary Filter N/A
Tertiary Membrane N/A
Filtration
Post-Treatment N/A
Flow Equalization
Post-Aeration N/A
Other N/A
4. DISINFECTION
No.of Plan Sheet Specification Calculations
Treatment Unit Type Size per Unit Provided?
Units Reference Reference
(Yes or No)
Ultraviolet Light N/A
Chlorination N/A
Dechlorination N/A
5. RESIDUALS TREATMENT
4 Page9
Application for Authorization to Construct Permit(FORM ATC 12 1 )

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT(FORM ATC-12-14)
No.of Plan Sheet Specification
Calculations
Treatment Unit Type Size per Unit Provided?
Units Reference Reference
(Yes or No)
Gravity Thickening N/A
Tank
Mechanical
Thickening/ N/A
Dewatering
Aerobic Digestion N/A
Anaerobic N/A
Digestion
Composting N/A
Drying N/A
Other N/A
6. PUMP SYSTEMS(include influent, intermediate,effluent, major recycles,waste sludge,thickened waste sludge and plant
drain pumps)
Capacity of
Location No.of Purpose Type each pump Plan Sheet Specification
Pumps GPM TDH Reference Reference
N/A
7. MIXERS
No.of Power of Plan Sheet Specification
Location Purpose Type each Mixer
Mixers (HP) Reference Reference
N/A
8. BLOWERS
No.of Capacity of Plan Sheet Specification
Location Blowers Purpose Type eac(CBlower Reference Reference
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 10

State of North Carolina
Department of Environmental Quality
IhrZ
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC-12-14)
1
N/A
•
9. ODOR CONTROL
No.of Plan Sheet Specification
Location Units Purpose Type Reference Reference
N/A
D. SETBACKS—COMPLETE FOR NEW WASTEWATER TREATMENT STRUCTURES
1. The minimum distance for each setback parameter to the wastewater treatment/storage units per 15A NCAC 02T.0506(b)
are as follows:
Is Minimum Distance
Minimum Distance Requirement met by the
Setback Parameter Required from Nearest Design? If"No", identify
Treatment/Storage
Unit Setback Waivers in Item D.2
Below
Any habitable residence or place of assembly under separate 100 ft ❑ Yes ❑ No
ownership or not to be maintained as part of the project site
Any private or public water supply source 100 ft ❑Yes ❑ No
Surface waters(streams—intermittent and perennial, perennial 50 ft ®Yes ❑ No
waterbodies, and wetlands)
Any well with exception of monitoring wells 100 ft ❑Yes ❑ No
Any property line 50 ft ❑Yes ❑ No
2. Have any setback waivers been obtained per 15A NCAC 02T .0506(d)? ❑ Yes or ❑ No. If yes, have these waivers been
written, notarized and signed by all parties involved and recorded with the County Register of Deeds? ❑ Yes or ❑ No. If
no, provide an explanation:
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 11

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL°UAL.ry APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT(FORM ATC-12-14)
SECTION 5: APPLICATION CERTIFICATION BY PROFESSIONAL ENGINEER
Professional Engineer's Certification per 15A NCAC 02T.0105:
I, Michael Benchich, attest that this application package for an Authorization to Construct
(Typed Name of Professional Engineer)
for the Stowe Regional Water Resource Recovery Facility
(Facility and Project Name)
was prepared under my direct supervisory control and to the best of my knowledge is accurate, complete and consistent
with the information supplied in the engineering plans, specifications, calculations, and all other supporting
documentation for this project. I further attest that to the best of my knowledge the proposed design has been
prepared in accordance with all applicable regulations and statutes, 15 NCAC 02H.0100, 1SA NCAC 02T, North Carolina
General Statute 133-3, North Carolina ueneral Statute 143-215.1, and Division of Water Resources Min mum Design
Criteria for NPDES Wastewater Treatmen: Facilities,and this Authorization to Construct Permit Application,except as
provided for and explained in Section 4.B.1 of this Application. I understand that the Division of Water Resources'
issuance of the Authorization to Construct Permit may be based solely upon this Certification and that the Division may
waive the technical review of the plans, specifications,calculations and other supporting documentation provided in this
=pplication package. I further understand that the application package may be subject to a future audit by the Division.
,Ithough certain portions of this submittal package may have been prepared, signed and sealed by other professionals
licensed in North Carolina, inclusion of these materials under my signature and seal signifies that I have reviewed the
materials and have determined that the materials are consistent with the project design.
I understand that in accordance with General Statutes 143-215.6A and 143-215.6B, any person who knowingly makes
any false statement, representation, or certification in any application package shall be guilty of a Class 2 misdemeanor,
which may include a fine not to exceed $10,000, as well as civil penalties up to $25,000 per violation.
North Carolina Professional Engineer's seal with written signature placed over or adjacent to the seal and dated:
401
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Application for Authorization to Construct Permit(FORM ATC-12-14) Page 12

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT(FORM ATC-12-14)
SECTION 6:APPLICATION CERTIFICATION BY APPLICANT
Applicant's Certification per 15A NCAC 02T.0106(b):
I, C. I`x.i l L. r r L_n ,44 r'c' ,attest that this application package for an Authorization to Construct
(Typed Name of Signature Authority and Title)
for the Stowe Regional Water Resource Recovery Facility
(Facility and Project Name)
has been reviewed by me and is accurate and complete to the best of my knowledge. I also understand that if all
required parts of this application package are not completed and that if all required supporting information and
attachments are not included,this application package will be returned to me as incomplete. I further certify that in
accordance with 15A NCAC 02T.0120(b),the Applicant or any affiliate has not been convicted of environmental crimes,
has not abandoned a wastewater facility without proper closure,does not have an outstanding civil penalty where all
appeals have been abandoned or exhausted,are compliant with any active compliance schedule, and does not have any
overdue annual fees.
I understand that the Division of Water Resources' issuance of the Authorization to Construct Permit may be based
solely upon acceptance of the Licensed Professional Engineer's Certification contained in Section 5, and that the Division
may waive the technical review of the plans,specifications, calculations and other supporting documentation provided
in this application package. I further understand that the application package may be subject to a future audit.
I understand that in accordance with General Statutes 143-215.6A and 143-215.6B any person who knowingly makes
any false statement, representation, or certification in any application package shall be guilty of a Class 2 misdemeanor,
which may inclyd 1 fine not to exceed$10,000, as well as civil penalties up to$25,000 per violation.
Signature: Date: Ji/j2/2 '/
THE COMPLETED APPLICATION AND SUPPORTING INFORMATION SHALL BE SUBMITTED TO:
NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER RESOURCES/NPDES
By U.S. Postal Service By Courier/Special Delivery:
1617 MAIL SERVICE CENTER 512 N. SALISBURY STREET, 9TH FLOOR
RALEIGH, NORTH CAROLINA 27699-1617 RALEIGH, NORTH CAROLINA 27604
TELEPHONE NUMBER: [phone]
Application for Authorization to Construct Permit(FORM ATC-12-14) Page 13

ATTACHMENT 3B
NPDES PERMIT

ADDENDUM NO. 2-EXHIBIT 1 Permit NC0089630
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provisions 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,
Charlotte Water
is hereby authorized to discharge wastewater from a facility located at the
Joe C. Stowe,Jr. Regional Water Resources Reclamation Facility
800 Hawfield Road,Charlotte
(Long Creek Pump Station Access)
Mecklenburg County
to receiving waters designated as the Catawba River 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 December 1,2019.
This permit and authorization to discharge shall expire at midnight on November 30,2024.
Signed this day November 4,2019.
Original signed by Julie A. Grzyb for
Linda Culpepper,Director
Division of Water Resources
By Authority of the Environmental Management Commission

Permit NC0089630
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility,whether for operation or discharge are hereby revoked.As of this
permit issuance, any previously issued permit bearing this number is no longer effective. Therefore, the exclusive
authority to operate and discharge from this facility arises under the permit conditions, requirements, terms,and
provisions included herein.
Charlotte Water
is hereby authorized to:
1. Upon receipt of an Authorization to Construct from the Division of Water Resources,construct and
operate Phase 1 of the Joe C.Stowe,Jr. Regional Water Resources Reclamation Facility,a 15.0 MGD
wastewater treatment facility to be located at 800 Hawfield Road,Charlotte,in Mecklenburg County;
and
2. Upon receipt of an Authorization to Construct from the Division of Water Resources,construct and
operate the Phase 2 expansion of the facility with a design flow of 25.0 MGD;and
3. Upon receipt of Authorizations to Operate from the Division of Water Resources as specified herein,
discharge treated wastewaters from said treatment works into the Catawba River,a Class WS IV,CA
water in the Catawba River Basin,at the location specified on the attached map.
ii

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•rh
Charlotte Water—Joe C. Stowe, Jr. RWRRF
x
N NC0089630
County: Mecklenburg
SCALE t
Receiving Stream: Catawba River
USGS Quad #: Stream Classification: WS-IV,CA
E17NW(Mount Holly), 1:24,000 River Basin: Catawba
(1"=20000
E17NE(Mountain Island Lake) Sub-Basin/8-Digit HUC#: 03-08-33/03050101
iii

Permit NC0089630
CONTENTS
PERMIT i
PART I-MONITORING,CONTROLS,AND LIMITATIONS FOR PERMI F1"ED DISCHARGES 1
A.(1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS-15 MGD 1
A.(2.)EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS-25 MGD 2
A.(3.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS 3
A.(4.) INSTREAM MONITORING REQUIREMENTS 4
A.(5.) CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT 5
A.(6.) EFFLUENT POLLUTANT SCAN AND SECOND-SPECIES TOXICITY TESTING 6
A.(7.)TOTAL NITROGEN AND TOTAL PHOSPHORUS LIMITS 7
A.(8.)NUTRIENT ALLOCATIONS 8
A.(9.) CALCULATION AND REPORTING OF TOTAL NITROGEN AND TOTAL PHOSPHORUS
LOADS 10
A.(10.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS 11
PART II-STANDARD CONDITIONS FOR NPDES PERMITS
PART III-OTHER REQUIREMENTS
PART IV-SPECIAL CONDITIONS FOR MUNICIPAL FACILITIES
iv

Permit NC0089630
PART I-MONITORING,CONTROLS,AND LIMITATIONS FOR PERMITTED DISCHARGES
A.(1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS-15 MGD
[15A NCAC 02B.0400 et seq.,02B .0500 et seq.] Grade IV Biological WPCS[15A NCAC 08G .0302]
(a.) During the period beginning on the effective date of this permit and conditioned upon submittal of
the engineer's certification of construction of the 15.0 MGD facility and receipt of an Authorization to
Operate per Condition A.(3.) of this permit,and lasting until expansion to 25.0 MGD capacity or until
permit expiration,whichever is sooner,the Permittee is authorized to discharge treated wastewaters
from Outfall 001.Such discharges shall be limited and monitored by the Permittee as specified in this
condition and in Condition A.(3.):
PARAMETER EFFLUENT LIMITATIONS MONITORING REQUIREMENTS
Monthly Weekly Daily Measurement Sample Sample
Parameter Code Average Average Maximum Frequency Type Location 1
Flow sooso 15.0 MGD Continuous Recording I or E
Total Monthly Flow(MG) 82220 Monitor and Report Monthly Recorded or I or E
Calculated
CBOD5 (Summer)2'3 80082 4.2 mg/L 6.3 mg/L Daily Composite I,E
CBOD5 (Winter)2.3 80082 8.3 mg/L 12.5 mg/L Daily Composite I,E
Total Suspended Solids 2 C0530 30 mg/L 45 mg/L Daily Composite I,E
NH3-N co610 1.0 mg/L 3.0 mg/L Daily Composite E
Dissolved Oxygen 00300 Daily average>- 6.0 mg/L Daily Grab E
Fecal Coliform(geometric mean) 31616 200/100 mL 400/100 mL Daily Grab E
Total Residual Chlorine 4 50060 28 pg/L Daily Grab E
pH 5 00900 >_ 6.0 and <_ 9.0 standard units Daily Grab E
Temperature(°C) 0010o Daily Grab E
TKN(mg/L) 00625 Monitor and Report Weekly Composite E
NO3-N + NO2-N(mg/L) 00630 Monitor and Report Weekly Composite E
Total Nitrogen(mg/L)6 co600 Monitor and Report Weekly Composite E
TN Load' QM600 Monitor and Report(lb/mo) Monthly Calculated E
Total Phosphorus(mg/L)6 C0665 Monitor and Report Weekly Composite E
TP Load' QM665 Monitor and Report(Ib/mo) Monthly Calculated E
Total Hardness(mg/L as CaCO3)8 00900 Quarterly Composite E
Chronic Toxicity 9,10 TGP3B P/F at 19.7% Quarterly Composite E
Effluent Pollutant Scan NCol Monitor and Report Footnote 10 Footnote 10 E
Footnotes:
1. Sample locations:E=Effluent,I=Influent.
2. The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15%of the
respective influent value(i.e.,85%removal is required).
3. Summer is defined as April 1 -October 31.Winter is defined as November 1 -March 31.
4. TRC limits and monitoring requirements apply only if chlorine or chlorine derivatives are used for
disinfection. The Permittee shall report all effluent TRC values reported by a NC-certified laboratory
[including field-certified]. Effluent values below 50 µg/L will be treated as zero for compliance purposes.
5. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
6. Total Nitrogen(TN)is defined as NO3-N+NO2-N+TKN,where NO3-N is nitrate nitrogen,NO2-N is nitrite
nitrogen,and TKN is total Kjeldahl nitrogen.TP is Total Phosphorus.
7. See Condition A.(9.)regarding calculation and reporting of seasonal and annual mass loads.
8. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent metals
(cadmium,copper,lead,nickel,silver,and zinc).
9. See condition A.(5.),Chronic Toxicity;tests performed during March,June,September,and December.
10. See Special Condition A.(6.) Effluent Pollutant Scan and Second-Species Toxicity Testing.
(b.) There shall be no discharge of floating solids or visible foam in other than trace amounts.
Part I,Page 1 of 12

Permit NC0089630
A.(2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS -25 MGD
[15A NCAC 02B .0400 et seq.,02B .0500 et seq.] Grade IV Biological WPCS [15A NCAC 08G .0302]
(a.) Beginning upon expansion to 25.0 MGD capacity and conditioned upon submittal of the engineer's
certification of construction of the 25 MGD facility and receipt of an Authorization to Operate per
Condition A.(3.) of this permit,and lasting until permit expiration,the Permittee is authorized to
discharge treated wastewaters from Outfall 001.Such discharges shall be limited and monitored by
the Permittee as specified in this condition and in Condition A.(3.):
PARAMETER EFFLUENT LIMITATIONS MONITORING REQUIREMENTS
Parameter Code Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location 1
Flow soo5o 25.0 MGD Continuous Recording I or E
Total Monthly Flow(MG) 82220 Monitor and Report Monthly Recorded or I or E
Ca
lculated
CBOD5 (Summer)2'3 80082 4.2 mg/L 6.3 mg/L Daily Composite I,E
CBOD5 (Winter)2'3 80082 8.3 mg/L 12.5 mg/L Daily Composite I,E
Total Suspended Solids 2 C0530 30 mg/L 45 mg/L Daily Composite I,E
NH3-N C0610 1.0 mg/L 3.0 mg/L Daily Composite E
Dissolved Oxygen 00300 Daily average>- 7.0 mg/L 4 Daily Grab E
Fecal Coliform(geometric mean) 31616 200/100 mL 400/100 mL Daily Grab E
Total Residual Chlorine 5 50060 28 pg/L Daily Grab E
pH 6 00400 >- 6.0 and 5. 9.0 standard units Daily Grab E
Temperature(°C) moo Daily Grab E
TKN(mg/L) 00625 Monitor and Report Weekly Composite E
NO3-N + NO2-N(mg/L) 00630 Monitor and Report Weekly Composite E
Total Nitrogen(mg/L)' C0600 Monitor and Report Weekly Composite E
TN Load 8 QM600 Monitor and Report(lb/mo) Monthly Calculated E
Total Phosphorus(mg/L)' C0665 Monitor and Report Weekly Composite E
TP Load 8 QM665 Monitor and Report(lb/mo) Monthly Calculated E
Total Hardness(mg/L as CaCO3)9 00900 Quarterly Composite E
10 110
Chronic Toxicity - TGP3B at 29.0/o QuarterlyComposite E
P/F Po
Effluent Pollutant Scan NC01 Monitor and Report Footnote 11 Footnote 11 E
Footnotes:
1. Sample locations:E=Effluent,I=Influent.
2. The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent value(i.e.,85%removal is required).
3. Summer is defined as April 1-October 31.Winter is defined as November 1-March 31.
4. The Division may lower the Dissolved Oxygen limit to as low as 6.0 mg/L without modification of this permit
provided that the Permittee further evaluates the potential impact of its Phase 2 discharge and demonstrates to
the Division's satisfaction that,at the full permitted flow and the lower D.O.limit concentration,the discharge
would not cause a violation of the D.O.surface water quality standard.
5. TRC limits and monitoring requirements apply only if chlorine or chlorine derivatives are used for
disinfection. The Permittee shall report all effluent TRC values reported by a NC-certified laboratory
[including field-certified]. Effluent values below 50 µg/L will be treated as zero for compliance purposes.
6. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
7. Total Nitrogen(TN)is defined as NO3-N+NO2-N+TKN,where NO3-N is nitrate nitrogen,NO2-N is nitrite
nitrogen,and TKN is total Kjeldahl nitrogen.TP is Total Phosphorus.
8. See Condition A.(9.)regarding calculation and reporting of seasonal and annual mass loads.
9. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent metals
(cadmium,copper,lead,nickel,silver,and zinc).
10. See condition A.(5.),Chronic Toxicity;tests performed during March,June,September,and December.
11. See Special Condition A.(6.) Effluent Pollutant Scan and Second-Species Toxicity Testing.
Part I,Page 2 of 12

Permit NC0089630
(b.) There shall be no discharge of floating solids or visible foam in other than trace amounts.
A.(3.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq.,02B.0500 et seq.] Grade IV Biological WPCS [15A NCAC 08G.0302]
(a.) During the period beginning on the effective date of this permit and lasting until receipt of an
Authorization to Operate in accordance with paragraph(c.), (d.),or(e.)of this Condition or until
permit expiration,whichever is sooner,the Permittee shall not discharge wastes to surface waters of
the state.
(b.) The Permittee shall notify the Division in writing of the intended date of connection of the City of
Belmont wastewater collection system and the intended date of connection of the City of Mount Holly
wastewater collection system to the Joe Stowe,Jr.Regional WRRF no later in each case than 60 days
prior to the intended date of connection.
(c.) Mount Holly connection.During the period beginning upon connection of Mount Holly and receipt of
an Authorization to Operate and lasting until connection of Belmont or permit expiration,whichever
is sooner,the Permittee is authorized to discharge treated wastewaters from Outfa11 001.Such
discharges shall be limited and monitored by the Permittee as specified below and in Condition A.(1.)
[15.0 MGD] or A.(2.) [25.0 MGD] of this permit,whichever is effective:
PARAMETER EFFLUENT LIMITATIONS MONITORING REQUIREMENTS
Parameter Code Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location 1
TN Load 2,3 Q5600 111,973 lb/summer Seasonally Calculated E
Q5600 124,345 lb/winter Seasonally Calculated
TP Load 3 QY665 31,405 lb/yr Annually Calculated E
Footnotes:
1. Sample locations:E=Effluent,I=Influent.
2. Summer is defined as April 1 -October 31.Winter is defined as November 1-March 31.
3. See Condition A.(9.)regarding calculation and reporting of seasonal and annual mass loads.
(d.) Belmont connection.During the period beginning upon connection of Belmont and receipt of an
Authorization to Operate and lasting until connection of Mount Holly or permit expiration,whichever
is sooner,the Permittee is authorized to discharge treated wastewaters from Outfall 001.Such
discharges shall be limited and monitored by the Permittee as specified below and in Condition A.(1.)
[15.0 MGD] or A.(2.) [25.0 MGD] of this permit,whichever is effective:
PARAMETER EFFLUENT LIMITATIONS MONITORING REQUIREMENTS
Parameter Code Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location 1
TN Load 2.3 Q5600 88,656 lb/summer Seasonally Calculated E
Q5600 115,449 lb/winter Seasonally Calculated
TP Load 3 QY665 21,309 lb/yr Annually Calculated E
Footnotes:
1. Sample locations:E=Effluent,I=Influent.
2. Summer is defined as April 1 -October 31.Winter is defined as November 1 -March 31.
3. See Condition A.(9.)regarding calculation and reporting of seasonal and annual mass loads.
(e.) Mount Holly and Belmont connections-15.0 MGD.During the period beginning upon connection of
both Mount Holly and Belmont and receipt of an Authorization to Operate and lasting until permit
expiration or expansion to 25.0 MGD capacity,whichever is sooner,the Permittee is authorized to
discharge treated wastewaters from Outfall 001 in accordance with the terms and conditions in this
Part I,Page 3 of 12

Permit NC0089630
paragraph and in Condition A.(1.)of this permit:
PARAMETER EFFLUENT LIMITATIONS MONITORING REQUIREMENTS
Parameter Code Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location 1
TN Load 2,3 Qs600 160,628 lb/summer Seasonally Calculated E
Q5600 226,681 lb/winter Seasonally Calculated
TP Load 3 QY665 45,662 lb/yr Annually Calculated E
Footnotes:
1. Sample locations:E=Effluent,I=Influent.
2. Summer is defined 910.)regarding calculation and reporting of seasonal and annual mass loads.
(f.) Mount Holly and Belmont connections-25.0 MGD.During the period beginning upon expansion to
25.0 MGD capacity,connection of both Mount Holly and Belmont,and receipt of an Authorization to
Operate and lasting until permit expiration, the Permittee is authorized to discharge treated
wastewaters from Outfall 001 in accordance with the terms and conditions in this paragraph and in
Condition A.(2.) of this permit::
PARAMETER EFFLUENT LIMITATIONS MONITORING REQUIREMENTS
Parameter Code Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location 1
TN Load 2,3 Q5600 200,629 lb/summer Seasonally Calculated E
Q5600 239,794 lb/winter Seasonally Calculated
TP Load 3 QY665 52,713 lb/yr Annually Calculated E
Footnotes:
1. Sample locations:E=Effluent,I=Influent.
2. Summer is defined as April 1 -October 31.Winter is defined as November 1-March 31.
3. See Condition A.(9.)regarding calculation and reporting of seasonal and annual mass loads.
A.(4.) INSTREAM MONITORING REQUIREMENTS
[15A NCAC 02B .0500 et seq.]
During the period beginning on submittal of the engineer's certification of construction of the 15.0 MGD
facility and lasting until expiration,the Permittee shall conduct instream monitoring as specified below:
PARAMETER FREQUENCY SAMPLE SAMPLING
TYPE LOCATIONI
Dissolved Oxygen (mg/L) Footnote 2 Grab U&D
Temperature(°C) Footnote 2 Grab U&D
Conductivity(pmho/cm) Footnote 2 Grab U&D
pH (S.U.) Footnote 2 Grab U&D
Total Nitrogen(mg/L) Footnote 2 Grab U&D
Total Phosphorus(mg/L) Footnote 2 Grab U&D
Hardness(mg/L as CaCO3) Quarterly Grab U
Footnote:
1. U=upstream at NC Highway 27 bridge. D=downstream at I-85.Upon written request and justification by the
Permittee,the Division may,without further review,modify this permit to move these sampling locations to
other representative locations.
2. Instream samples shall be grab samples taken 3/week(June-September)and 1/week(October-May).
Part I,Page 4 of 12

Permit NC0089630
A.(5.) CHRONIC TOXICITY PERMIT LIMIT
NC
AC A AC 02B .0200]5 C
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality
to Ceriodaphnia dubia at an effluent concentration of 19.7%(15.0 MGD) or 29.0% (25.0 MGD).
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 March,June,September,
and December.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
permitmultiple-concentrationtesting performed limit,then shall be 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:
North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1621 Mail Service Center
Raleigh,NC 27699-1621
Or,results can be sent to the email,[e-mail].
Completed Aquatic Toxicity Test Forms shall be filed with the Water 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 Water
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.
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.
NOTE: Failure to achieve test conditions as specified in the cited document,such as minimum 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.
Part I,Page 5 of 12

Permit NC0089630
A.(6.) EFFLUENT POLLUTANT SCAN AND SECOND-SPECIES TOXICITY TESTING
[G.S. 143-215.1(b)]
(a.) Effluent Scans.In each of the first three years of discharge from this facility,the Permittee shall
perform an Effluent Pollutant Scan for all parameters listed below.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.,not
collected in the same quarter every year). Unless otherwise indicated,metals shall be analyzed as
"total recoverable."
Ammonia(as N) Trans-1,2-dichloroethylene Bis(2-chloroethyl)ether
Chlorine(total residual,TRC) 1,1-dichloroethylene Bis(2-chloroisopropyl)ether
Dissolved oxygen 1,2-dichloropropane Bis(2-ethylhexyl)phthalate
Nitrate/Nitrite 1,3-dichloropropylene 4-bromophenyl phenyl ether
Kjeldahl nitrogen Ethylbenzene Butyl benzyl phthalate
Oil and grease Methyl bromide 2-chloronaphthalene
Phosphorus Methyl chloride 4-chlorophenyl phenyl ether
Total dissolved solids Methylene chloride Chrysene
Hardness 1,1,2,2-tetrachloroethane Di-n-butyl phthalate
Antimony Tetrachloroethylene Di-n-octyl phthalate
Arsenic Toluene Dibenzo(a,h)anthracene
Beryllium 1,1,1-trichloroethane 1,2-dichlorobenzene
Cadmium 1,1,2-trichloroethane 1,3-dichlorobenzene
Chromium Trichloroethylene 1,4-dichlorobenzene
Copper Vinyl chloride 3,3-dichlorobenzidine
Lead Acid-extractable compounds: Diethyl phthalate
Mercury(EPA Method 1631E) P-chloro-m-cresol Dimethyl phthalate
Nickel 2-chlorophenol 2,4-dinitrotoluene
Selenium 2,4-dichlorophenol 2,6-dinitrotoluene
Silver 2,4-dimethylphenol 1,2-diphenyihydrazine
Thallium 4,6-dinitro-o-cresol Fluoranthene
Zinc 2,4-dinitrophenol Fluorene
Cyanide 2-nitrophenol Hexachlorobenzene
Total phenolic compounds 4-nitrophenol Hexachlorobutadiene
Volatile organic compounds: Pentachlorophenol Hexachlorocyclo-pentadiene
Acrolein Phenol Hexachloroethane
Acrylonitrile 2,4,6-trichlorophenol Indeno(1,2,3-cd)pyrene
Benzene Base-neutral compounds: Isophorone
Bromoform Acenaphthene Naphthalene
Carbon tetrachloride Acenaphthylene Nitrobenzene
Chlorobenzene Anthracene N-nitrosodi-n-propylamine
Chlorodibromomethane Benzidine N-nitrosodimethylamine
Chloroethane Benzo(a)anthracene N-nitrosodiphenylamine
2-chloroethylvinyl ether Benzo(a)pyrene Phenanthrene
Chloroform 3,4 benzofluoranthene Pyrene
Dichiorobromomethane Benzo(ghi)perylene 1,2,4-trichlorobenzene
1,1-dich loroethane Benzo(k)fluoranthene
1,2-dichloroethane Bis(2-chloroethoxy)methane
(b.) Reporting of Scan Results. No later than December 31st of each designated sampling year,the
Permittee shall report the year's test results on its electronic Discharge Monitoring Report for the
sampling date,on DWR Form-A MR-PPA1,or in a form approved by the Director.Printed reports,if
used,shall be submitted to the following address:
NC DEQ/ DWR/ Water Quality Permitting Section
Attn: Central Files
1617 Mail Service Center
Raleigh,North Carolina 27699-1617
Part I,Page 6 of 12

Permit NC0089630
(c.) Second-Species Toxicity Testing.
(i.) In the four-and-one-half year period prior to application for permit renewal,the Permittee shall
conduct four (4)whole effluent toxicity tests for a second species of test organism in addition to
the tests and species specified in the Chronic Toxicity condition of this permit.
(ii.) The second-species tests shall be conducted either quarterly for a 12-month period or annually
and shall be performed as specified in the Chronic Toxicity condition of this permit.
(d.) Reporting of Toxicity Test Results.
(i.) The multiple species toxicity test results shall be filed with the Aquatic Toxicology Branch at the
following address:
NC DEQ/ DWR/ Water Sciences Section
Aquatic Toxicology Branch
1621 Mail Service Center
Raleigh,North Carolina 27699-1621
NOTE: The Aquatic Toxicology Branch (919-743-8401)can provide guidance on conducting the
additional toxicity tests and reporting requirements.
(ii.) Results shall also be summarized in Part E (Toxicity Testing Data) of Application Form 2A when
applying for renewal of this NPDES permit.
A.(7.) TOTAL NITROGEN AND TOTAL PHOSPHORUS LIMITS
[G.S. 143-215.1(b)]
(a.) Total Nitrogen(TN) allocations and load limits for NPDES dischargers in the Lake Wylie watershed
are seasonal (summer and winter)values.Summer is defined as April 1 through October 31,and
winter is defined as November 1 through March 31.Total Phosphorus (IV)allocations and load limits
are annual values and apply on a calendar year basis,January 1 through December 31.
(b.) The TN(or TP)Load limit in this Permit may be modified as the result of allowable changes in the
Permittee's allocation.
(i.) Allowable changes include those transfers resulting from the purchase,sale,trade,or lease of
allocation between the Permittee and other dischargers assigned allocation under the 1995 Lake
Wylie TMDL;regionalization(if both facilities were assigned allocation); and other transactions
approved by the Division.
(ii.) The Permittee may request a modification of the TN(or TP)Load limit in this Permit to reflect
allowable changes in its allocation.
(A) The request must include an analysis demonstrating that change in allocations and limits
does not have a reasonable potential to cause localized water quality impacts.
(B) Upon receipt of timely and proper application,the Division will propose to modify the
permit as appropriate and in accordance with state and federal program requirements.
(C) Changes in TN or TP limits become effective on the first January 1 (annual limit),the first
April 1 (summer limit),or the first November 1 (winter limit)following permit
modification.The Division must receive application no later than 180 days prior to the
requested effective date for any limit change.
(iii.) Any requests for modification should be sent to:
NCDEQ/ DWR/ NPDES Programs
Attn:Nutrient Coordinator
1617 Mail Service Center
Raleigh,NC 27699-1617
Part I,Page 7 of 12

Permit NC0089630
A.(8.) NUTRIENT ALLOCATIONS
[G.S. 143-215.1(B)]
(a.) The following tables list the Total Nitrogen(TN)and Total Phosphorus(TP)allocations acquired by or
transferred to the Permittee in accordance with the 1995 Lake Wylie TMDL and nutrient management
strategy and the status of each as of permit issuance.The allocations in this table are not enforceable
limits nor do they supersede any TN limit(s)established elsewhere in this permit.
(b.) The tables in this paragraph list the allocations held by the Permittee and show their status at permit
issuance.These tables apply until the Permittee is authorized to discharge per Condition A.(3.)(c.),
(d.), or(e.).Summer is defined as April 1 -October 31,winter is defined as November 1 -March 31,
and Annual means on a calendar year basis,January 1 -December 31.
Total Nitrogen Allocation at Permit Issuance
ALLOCATION ALLOCATION ALLOCATION
TYPE SOURCE DATE SUMMER WINTER STATUS
(LB/SEASON) (LB/SEASON)
Supplemental Purchase from Clariant Corp. 12/12/2012 61,418 43,337 —
(NC0004375)
Decremental Transfer by agreement to 5/3/2018 -47,722 -33,673 Deducted
Mount Holly(NC0021156)
Decremental Transfer by agreement to 5/3/2018 -13,696 -9,664 Deducted
Belmont(NC0021181)
Total Allocation 0 0 —
Total Phosphorus Allocation at Permit Issuance
ALLOCATION ALLOCATION
TYPE SOURCE DATE ANNUAL STATUS
(LB/YEAR)
Supplemental Purchase from Clariant 12/12/2012 13,140 —
Corp. (N00004375)
Decremental Transfer by agreement to 5/3/2018 -13,140 Deducted
Mount Holly(NC0021156)
Total Allocation 0 —
(c.) Mount Holly connection.The tables in this paragraph list the allocations to be held by the Permittee
upon connection of the City of Mount Holly collection system to the Joe Stowe,Jr.Regional WRRF and
apply while the Permittee's discharge is subject to Condition A.(3.)(c.) of this permit.
Total Nitrogen Allocation-Mount Holly Connection
ALLOCATION ALLOCATION ALLOCATION
TYPE SOURCE DATE SUMMER WINTER STATUS
(LB/SEASON) (LB/SEASON)
Supplemental Return transfer by agreement 12/12/2012 47,722 33,673 Active
from Mount Holly(NC0021156)
Supplemental Transfer by agreement from 5/3/2018 64,251 90,672 Active
Mount Holly(NC0021156)
Total Allocation 111,973 124,345 Active
Part I,Page 8 of 12

Permit NC0089630
Total Phosphorus Allocation-Mount Holly Connection
ALLOCATION ALLOCATION
TYPE SOURCE DATE ANNUAL STATUS
(LB/YEAR)
Return transfer by agreement
Supplemental from Mount Holly(NC0021156) 12/12/2012 13,140 Active
Supplemental Transfer by agreement from 5/3/2018 18,265 Active
Mount Holly(NC0021156)
Total Allocation 31,405 Active
(d.) Belmont connection.The tables in this paragraph list the allocations to be held by the Permittee upon
connection of the City of Belmont collection system to the Joe Stowe,Jr.Regional WRRF and apply
while the Permittee's discharge is subject to Condition A.(3.)(d.) of this permit.
Total Nitrogen Allocation-Belmont Connection
ALLOCATION ALLOCATION ALLOCATION
TYPE SOURCE DATE SUMMER WINTER STATUS
(LB/SEASON) (LB/SEASON)
Return transfer by
Supplemental agreement from Belmont 12/12/2012 13,696 9,664 Active
(NC0021181)
Supplemental Transfer by agreement from 5/3/2018 74,960 105,785 Active
Belmont(NC0021181)
Total Allocation 88,656 115,449 Active
Total Phosphorus Allocation-Belmont Connection
ALLOCATION ALLOCATION
TYPE SOURCE DATE ANNUAL STATUS
(LB/YEAR)
Supplemental Transfer by agreement from 5/3/2018 21,309 Active
Belmont(NC0021181)
Total Allocation 21,309 Active
(e.) Mount Holly and Belmont connections-15.0 MGD and 25.0 MGD.The tables in this paragraph list
the allocations to be held by the Permittee upon connection of both the City of Belmont and the City of
Mount Holly collection systems to the Joe Stowe,Jr.Regional WRRF and apply while the Permittee's
discharge is subject to Conditions A.(1.) (15.0 MGD)and A.(3.)(e.)or to Conditions A.(2.) (25.0 MGD)
and A.(3.)(f.) of this permit.
Total Nitrogen Allocation-Mount Holly and Belmont Connections
ALLOCATION ALLOCATION ALLOCATION
TYPE SOURCE DATE SUMMER WINTER STATUS
(LB/SEASON) (LB/SEASON)
Return transfer by agreement
Supplemental from Mount Holly 12/12/2012 47,722 33,673 Active
(NC0021156)
Supplemental Return transfer by agreement 12/12/2012 13,696 9,664 Active
from Belmont(NC0021181)
Supplemental Transfer by agreement from 5/3/2018 64,251 90,672 Active
Mount Holly(NC0021156)
Part I,Page 9 of 12

Permit NC0089630
ALLOCATION ALLOCATION ALLOCATION
TYPE SOURCE DATE SUMMER WINTER STATUS
(LB/SEASON) (LB/SEASON)
Supplemental Transfer by agreement from 5/3/2018 74,960 105,785 Active
Belmont(NC0021181)
Total Allocation at 25 MGD(Condition A.(1.)) 200,629 239,794 Active
Total Allocation at 15 MGD(Condition A.(2.)) 160,628 226,681 Active
Reserve Allocation at 15 MGD 1 40,001 13,113 Reserve
1. Active allocations are capped at 6.0 mg/L summer and 12.0 mg/L winter;remainder is held in reserve.
Total Phosphorus Allocation-Mount Holly and Belmont Connections
ALLOCATION ALLOCATION
TYPE SOURCE DATE ANNUAL STATUS
(LB/YEAR)
Supplemental Transfer by agreement from 5/3/2018 21,309 Active
Belmont(NC0021181)
Supplemental Return transfer by agreement 12/12/2012 13,140 Active
from Mount Holly(NC0021156)
Supplemental Transfer by agreement to 5/3/2018 18,265 Active
Mount Holly(NC0021156)
Total Allocation at 25 MGD(Condition A.(1.)) 52,7131 Active
Total Allocation at 15 MGD(Condition A.(2.)) 45,662 Active
Reserve Allocation at 15 MGD 2 7,052 Reserve
1. The sum differs from the expected value due to rounding of the individual values.
2. Active allocation is capped at 1.0 mg/L;remainder is held in reserve.
(f.) Any addition,deletion,or modification of the listed allocation(s) (other than to correct typographical
errors) or any change in status of arty of the listed allocations shall be considered a major modification
of this permit and shall be subject to the public review process afforded such modifications under
state and federal rules.
A.(9.) CALCULATION AND REPORTING OF TOTAL NITROGEN AND TOTAL PHOSPHORUS
LOADS [G.S. 143-215.1(b)]
(a.) The Permittee shall calculate monthly,seasonal,and annual mass loads for TN and TP as follows:
(i.) Monthly TN (or TP)Load (lb/mo) =TN (or TP) x TMF x 8.34
where:
TN or TP the average Total Nitrogen or Total Phosphorus concentration
(mg/L)of the composite samples collected during the month
TMF the Total Monthly Flow of wastewater discharged during the
month(MG/mo);that is,the sum of daily flows in the month
8.34 conversion factor,from (mg/L x MG) to pounds
(ii.) Summer TN Load (lb/season) =Sum of the Monthly TN Loads for April-October.
(iii.) Winter TN Load (lb/season) =Sum of the Monthly TN Loads for November-March.
(iv.) Annual TP Load (lb/year) =Sum of the 12 Monthly TP Loads for the calendar year.
(b.) The Permittee shall report monthly Total Nitrogen and Total Phosphorus results(mg/L and lb/mo)in
the appropriate discharge monitoring report for each month;the summer TN results with the October
DMR;the winter TN results with the March DMR;and each calendar year's results with the December
report for that year.
(c.) Any addition,deletion,or modification of the listed allocation(s) (other than to correct typographical
errors) or any change in status of any of the listed allocations shall be considered a major modification
Part I,Page 10 of 12

Permit NC0089630
of this permit and shall be subject to the public review process afforded such modifications under
state and federal rules.
A.(10.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[G.S.143-215.1(b)]
Federal regulations require electronic submittal of all discharge monitoring reports(DMRs)and program
reports.The final NPDES Electronic Reporting Rule became effective on December 21,2015.
NOTE: This special condition supplements or supersedes the following sections within Part II of this permit
(Standard Conditions for NPDES Permits):
• Section B. (11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Reporting Requirements[Supersedes Part II,Section D. (2.)and Section E.(5.)(a)1
The permittee shall report 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 DEQ/ Division of Water Resources/Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh,North Carolina 27699-1617
If 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. See
"How to Request a Waiver from Electronic Reporting"section below.
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.
Starting on December 21,2020,the permittee must electronically report the following compliance
monitoring data and reports,when applicable:
• Sewer Overflow/Bypass Event Reports;
• Pretreatment Program Annual Reports;and
• Clean Water Act(CWA)Section 316(b)Annual Reports.
The permittee may seek an electronic reporting waiver from the Division(see"How to Request a Waiver
from Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.41(1)(9),the permittee must identify the initial recipient at the time of
each electronic submission. The permittee should use the EPA's website resources to identify the initial
recipient for the electronic submission.
Part I,Page 11 of 12

Permit NC0089630
A.(10.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS (cont.)
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity (EPA
or the state authorized by EPA to implement the NPDES program) that is the designated entity for
receiving electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for each
type of electronic submission and for each state. Instructions on how to access and use the appropriate
electronic reporting tool will be available as well. Information on EPA's NPDES Electronic Reporting
Rule is found at:https://www.federalregister.gov/documents/2015/10/22/2015-24954/national-
pollutant-discharge-elimination-system-npdes-electronic-reporting-rule
Electronic submissions must start by the dates listed in the"Reporting Requirements" section above.
3. How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an
electronic reporting waiver,a permittee must first submit an electronic reporting waiver request to the
Division. Requests for temporary electronic reporting waivers 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 submitting monitoring data and reports. The duration of a temporary waiver
shall not exceed 5 years and shall thereupon expire. At such time,monitoring data and reports shall be
submitted electronically to the Division unless the permittee re-applies for and is granted a new
temporary electronic reporting waiver by the Division. Approved electronic reporting waivers are not
transferrable. Only permittees with an approved reporting waiver request may submit monitoring data
and reports on paper to the Division for the period that the approved reporting waiver request is
effective.
Information on eDMR and the application for a temporary electronic reporting waiver are found on the
following web page: http://deq.nc.gov/about/divisions/water-resources/edmr
4. Signatory Requirements[Supplements Part II,Section B. (11.)(b)and Supersedes Section B. (11.)(d)1
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://deq.nc.gov/about/divisions/water-resources/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:
"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 fines and imprisonment for knowing violations."
5. Records Retention [Supplements Part II,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].
Part I,Page 12 of 12

ATTACHMENT 3D
RECORD OF DECISION

REVISED
RECORD OF DECISION
STOWE REGIONAL WATER RESOURCE RECOVERY FACILITY
(formerly known as the Long Creek Regional Wastewater Treatment Plant)
CHARLOTTE WATER/CITY OF MOUNT HOLLY/CITY OF BELMONT
MECKLENBURG AND GASTON COUNTIES,NORTH CAROLINA
DEQ#1603;DENR#1597
PREPARED BY:
NORTH CAROLINA DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
January 2, 2020
(Replaces the approved March 18,2015 version)
CONTACT PERSON:
David Wainwright
NCDEQ, Division of Water Resources
Mail Service Center 1611
Raleigh, NC 27699-16I 1
[phone]
[e-mail]

REVISED-Record of Decision—Charlotte-Mecklenburg Utilities/City of Mount Holly Regional Wastewater Treatment
REVISION NOTE
Prior to construction of the proposed project, the applicant contacted the DWR regarding a few minor
changes to the project. Changes include the location of an equalization basin and new access and
construction roads.The preferred alternative has not changed and remains alternative 2.The applicant has
submitted documentation to the Division dated December 20, 2019, with the subject line of "Charlotte-
Mecklenburg Utilities/City of Mount Holly/City of Belmont Regional Wastewater Treatment Final
Environmental Impact Statement Revision Letter" which outlines proposed changes to the project and are
addressed in this revised ROD.
Proposed revisions are only to occur at the current Long Creek Pump Station site.Proposed project revisions
will include additional impacts to wetlands, prime and unique farmlands, and floodplains; but all will be
minor or negligible impacts. Bridges over Long Creek will result in minor impacts to wetlands (less than
0.1 acre) and potentially minor or negligible impacts to floodways. Clearing of land will increase
(approximately 4.5 acres for temporary construction access,approximately 8.5 acres for a permanent access
road,and approximately 20 acres for the equalization basin).Much of these lands are considered prime and
unique farmlands or farmland of statewide importance.However,these areas are forested and not currently
being farmed,are zoned either industrial or single family residential,and are owned by the City of Charlotte.
Due to these conditions, impacts to prime and unique farmlands is considered minimal. Due to the
additional clearing, impacts to land cover will occur. Wildlife may be impacted by the additional clearing,
but much of the surrounding area will still be forested and it is therefore expected that wildlife will relocate
to those areas.
The proposed changes will impact the Thread Trail (used for walking, hiking, and mountain biking).
Impacted portions of the will be relocated within the remaining 85-acre forested track, thereby mitigating
additional impacts to public lands, scenic,and recreational areas.
No additional impacts to areas of archeological or historical value; rare or protected species; air quality;
noise; water resources, shellfish, and their habitats; water quality; soils; ground water; water supply; or
impacts from toxic substances are anticipated.
SUMMARY
An EIS has been prepared for the Charlotte-Mecklenburg Utilities Department (CMUD) and the planned
wastewater treatment expansion for the existing service area as well as surrounding service areas. The
proposal considers wastewater treatment at a regional level and includes the City of Mount Holly,the City
of Belmont, Clariant Corporation (Clariant), and CMUD's western Mecklenburg County wastewater
service area.A feasibility study was performed in 2006 for CMUD and the City of Mount Holly to identify
potential alternatives to meet the needs of the projected growth in the service areas. Study results
recommended a regional approach, and that is what is being pursued by CMUD and the City of Mount
Holly.As discussed in the EIS,there has been extensive stakeholder involvement with the public and private
sector as well as government officials throughout project development.
The preferred alternative would include constructing a new Wastewater Treatment Plant(WWTP)facility
on the Mecklenburg County side of the Catawba River on land near the existing Long Creek pump station.
from both CMUDand the Cityof Mount Holly. Flows from new facility would treat wastewatero t y the
City of Mount Holly and the City of Belmont would be pumped under the Catawba River to the new facility.
1

REVISED-Record of Decision—Charlotte-Mecklenburg Utilities/City of Mount Holly Regional Wastewater Treatment
A new force main would be constructed from the City of Belmont WWTP to the Paw Creek lift station.
The existing Long Creek pump station would be modified to serve as the influent pumping station for the
new facility.
PURPOSE AND NEED
The purpose of the proposed project is to address future wastewater demands in northwestern Mecklenburg
and eastern Gaston Counties. Populations in these areas are expected to grow considerably by 2030.
Population growth in the CMUD service area, which includes the Long Creek Basin, Paw Creek Basin,
Catawba Creek Basin,Gar Creek Basin,and the Lower Mountain Island Lake Basin,is expected to increase
from 43,371 in 2010 to 115,580 in 2030.Consequently,wastewater flows in the service area is expected to
increase from 6.44 million gallons per day(mgd) in 2010 to 14.74 mgd in 2030. In order to meet the needs
of these growing areas, without hindering growth, the wastewater capacity of the region will need to be
increased.
ALTERNATIVES ANALYSIS
Several alternatives were identified during the planning process. A total of seven alternatives were carried
forward and considered in the EIS;the EIS provides a full discussion of these alternatives. A brief statement
on each is below:
I. No Action: The No Action Alternative does not include construction of a new wastewater treatment
plant or other associated infrastructure. However, based on a NCDENR requirement, this alternative
would include upgrading the existing City of Mount Holly WWTP (Mount Holly WWTP)and City of
Belmont WWTP (Belmont WWTP)_ Wastewater from the Long Creek hasin would continue to he
piped over 20 miles to the McAlpine Creek Wastewater Management Facility (WWMF). The Mount
Holly WWTP is approaching its maximum design capacity. Without expansion, areas not currently
serviced would likely have to utilize onsite septic systems.
2. Operate jointly at New Regional WWTP in Mount Holly(Alternative 1):This alternative consists
of constructing a new WWTP facility on land adjacent to the existing Mount Holly WWTP site. This
new plant would serve the City of Mount Holly as well as CMUD. The Belmont WWTP would be
decommissioned and replaced with a new pump station. A new force main would be constructed from
the Belmont WWTP to the Paw Creek lift station. Wastewater from Long Creek would be pumped
across the Catawba River to the new facility. A portion of the wastewater may be treated for reuse or
reclaimed purposes such as landscape irrigation and industrial purposes.
3. Operate Jointly at New Regional WWTP in Mecklenburg County near Long Creek(Alternative
2—Preferred Alternative): Under this alternative,a new WWTP facility would be constructed on the
Mecklenburg County side of the Catawba River on land near the existing Long Creek Pump Station.
The new facility would treat wastewater from both CMUD and the City of Mount Holly. Flows from
the City of Mount Holly and/or City of Belmont would be pumped under the Catawba River to the new
facility.A new force main would be constructed from the Belmont WWTP to the Paw Creek lift station.
The existing Long Creek pump station would be modified to serve as the influent pumping station for
the new facility. A portion of the wastewater may be treated for reuse or reclaimed purposes such as
landscape irrigation and industrial purposes.
2

REVISED-Record of Decision—Charlotte-Mecklenburg Utilities/City of Mount Holly Regional Wastewater Treatment
4. Non-Discharge/Land Application Alternative: State law requires land application to be considered
for any WWTP. This option was found to be technically and economically infeasible due to the large
amount of land that would be required. Based on calculations, necessary land requirements would he
between 37 and 230 acres for non-discharge ponds and storage and between 1,000 acres and 13,000
acres for land application.In an urban setting these land requirements would be difficult to achieve and
the cost to purchase suitable land would be prohibitive.
PREFERED ALTERNATIVE
Alternative 2, operate jointly at a new regional WWTP on the Mecklenburg County side of the Catawba
River near Long Creek,was chosen as the preferred alternative.This alternative was selected over the others
because it meets the developing region's need for additional wastewater treatment capacity and results in a
combination of fewer negative environmental consequences. These include comparatively fewer natural
resource and environmental impacts at the building site; fewer construction and operational constraints;
greater public recreation and open space benefits; reduced energy use; increased water volume in Lake
Wylie for local uses such as power generation, cooling water, low flow supplementation, and drinking
water; and concurrence with the planning goals of the affected local governments.
Additionally, the placement of a single WWTP is preferable to other alternatives in terms of compatibility
with existing and future land uses,protection of riparian buffers,and reduced impacts to critical areas such
as streams and wetlands. Advanced treatment at a new facility would produce high quality effluent with
low nutrient concentrations and provide additional water into Lake Wylie for many beneficial uses. The
Preferred Alternative also provides regional wastewater treatment with a single discharge that promotes
efficient planning,design, and permitting; minimizes shoreline and wetland impacts; and cost-effectively
achieves project goals.It also has the potential to eliminate three existing discharges and reduce the risk of
overflows by reducing wastewater pumping distance.
ENVIRONMENTAL IMPACTS
All means of avoiding or minimizing environmental and cultural impacts outlined in the EIS will he
incorporated into the project. Moreover, the project will be designed and constructed to avoid adverse
impacts to existing environmental features as much as practicable.A summary of impacts to environmental
features and mitigative actions for the preferred alternative is described below:
Topography and soils: There will not be significant long-term impacts as a result of the project. Impacts
include those associated with leveling,excavation, and grading from construction of the project.Much of
the preferred alternative would occur on land that has been previously disturbed.Impacts to soils and soil
loss would be controlled through the use of appropriate Best Management Practices(BMPS).
Land Cover and Land Use: The new facility constructed under the preferred alternative would be located
on land currently zoned industrial and the Belmont pump station and force main would be constructed on
previously disturbed land. With the preferred alternative, there would be approximately 85-acres of
undisturbed forested lands adjacent to the National Whitewater Center that could be used for public uses
such as greenways or other recreational activities. Impacts to the Thread Trail would be mitigated by
relocating affected trail portions within the remaining forested tract adjacent to the project.
3

REVISED-Record of Decision—Charlotte-Mecklenburg Utilities/City of Mount holly Regional Wastewater Treatment
Wetlands and Floodpl_ains: Force mains would cross the Catawba River,Paw Creek,and Long Creek.These
crossings would be within the floodplain and associated wetland areas. Force mains and outfall structure
would be directionally bored, eliminating direct impacts to wetlands. The outfall would be constructed
within the Catawba River floodplain but will not result in an increase in the 100-year flood base flood
elevation. impacts from access road bridges over Long Creek will minimize impacts to wetlands and
floodplains but will still result in unavoidable but minimal impacts to wetlands and floodplains.
Water Quality: Impacts to surface waters include those from stormwater runoff, riparian buffer impacts,
and wastewater effluent. Increases in stormwater runoff may affect aquatic resources. The project will
require a Sturrnwater Pollution Prevention Plan(SWPPP);the included guidelines will minimize and reduce
the number and amount of pollutants leaving the site through BMPs. Riparian buffer areas may be affected
by force main and outfall crossings.Impacts to these areas will be minimized through the use of directional
boring under streams and associated riparian areas. Additionally,proposed facilities will be located outside
of riparian buffer areas. Wastewater discharge to Lake Wylie will increase. Compliance with all NPDES
permit limits will be required.
Ground Water: No direct impacts to groundwater are expected.
Water Supply: The proposed project will increase the amount of wastewater beingdischarged into Lake
P p g
Wylie. NPDES permit limits will protect the quality of water which will not exceed drinking water
standards.
Wildlife and Aquatic Resource Habitats: Impacts to terrestrial species is expected to be limited to those
areas that will be cleared;impacted wildlife may move to adjacent forested areas.Impacts to aquatic species
are expected to be minimal due to stormwater controls and stringent NPDES discharge limits.
Rare and Protected Species:The preferred alternative will not impact any rare or protected species.
Public, Scenic, and Recreational Areas: A portion of the proposed project is in close proximity to the
National Whitewater Center. The proposed alternative would preserve an approximately 85-acre tract
adjacent to the National Whitewater Center which could be used to provide additional hiking and biking
trails as well as a new canoe launch on Long Creek.Potential adverse impacts include odors and wastewater
spills,which could result in disruption of recreational activities.New facilities would be designed to prevent
storm-flow bypasses and sanitary sewer overflows.Odor control technology would be incorporated into the
project as well. Impacts to the Thread Trail would be mitigated by relocating affected trail portions within
the remaining forested tract adjacent to the project.
Energy Resources: Energy consumption would increase as the new facility comes online,but usage would
partially be offset by not having to pump wastewater from Long Creek pumping station to McAlpine Creek
WWTP.Additional water volume in Lake Wylie could potentially be used for additional power generation,
and it may be possible to use onsite generated methane to partially power the facility and reduce the
consumption of natural gas.
Archeological or Historical Resources:There are no properties registered on the National Sate Register of
Historic Places. State Historic Preservation Office correspondence states that they will not require any
archeological surveys.
Prime Agricultural Lands:Construction of the equalization basin,access roads,and temporary construction
access roads will result in impacts to prime agricultural lands. However, the affected lands are currently
forested and not being used for agriculture, arc zoned industrial and single residence,and are owned by the
4

REVISED-Record of Decision—Charlotte-Mecklenburg Utlllties/City of Mount Holly Regional Wastewater Treatment
City of Charlotte. Since the City of Charlotte has no intent to sell or farm the land, and based on current
zoning, impacts are deemed minimal.
Air Quality: Direct impacts to air quality will be temporary and minor. During construction, dust control
measures will he employed to limit dust exposure in the project area.Operation of the plant will not produce
any regulated air quality contaminants. Nearby residences and businesses would be buffered by forested
areas surrounding the facility. An air quality permit would be required for the operation of the back-up
generators and methane gas produced onsite would likely be used to generate power for the facility.
Nuisance Conditions: Temporary noise and dust will be generated as result of construction. Odor control
measures would be used at the plant and pumping station. Most equipment would be housed in buildings
which will also help reduce noise and odors. A forested buffer around the facility will also help alleviate
potential noise and odor concerns.
Toxic Substances: Toxic substances will not be introduced during construction. All chemical storage and
feed areas at the plant would be provided with secondary containment. Onsite diesel fuel tanks for
generators will have secondary containment and leak detection systems.
SECONDARY AND CUMULATIVE IMPACTS
The secondary and cumulative impacts associated with the preferred alternative would generally be related
to continued urban growth and land use changes associated with population increases in the service area.It
is expected that population increases and associated secondary and cumulative impacts would occur
regardless of whether or not the proposed project is constructed.
The Gar and Catawba Sub-basins and portions of the Mountain Island Lake Sub-basin currently utilize
onsite septic tanks. The preferred alternative may allow these areas to be serviced with the wastewater
facility which would help eliminate the effects of failing septic sewer systems. If these areas were to be
serviced by the new facility,it would allow higher density development than what currently exists in these
areas.This may allow these areas to have more development due to higher density than would be seen if
the area remained on individual septic systems. Growth would continue in other areas of the service areas
as well. Several local and State regulations are in place throughout the project service area that will
minimize secondary and cumulative impacts and include various zoning restrictions, Water Supply
Watershed Protection areas, stormwater BMPS and regulations, riparian buffer niles, NPDF.S permitting,
floodplain protection ordnances, and municipal separate storm sewer systems (MS4). Public sewer
extension projects would he required to apply for and obtain the necessary permits and evaluate,avoid,and
minimize environmental impacts. Water supply watershed protection rules, which limit land use densities
and apply other development restrictions to protect water quality, apply to a large portion of the project
service area in both Gaston and Mecklenburg Counties. Additionally, a number of local policies and
ordinances are in place that would further limit secondary and cumulative impacts.
Beneficial impacts of the proposed project may also occur. By relocating the discharge point from Long
Creek to Lake Wylie, energy currently being used to pump wastewater 20 miles will be saved. The
additional discharge into Lake Wylie could be used to produce additional electricity. While some of the
treated effluent would be used onsitc as reclaimed water,there exists the possibility that the reclaimed water
5

REVISED-Record of Decision—Charlotte-Mecklenburg Utilitles/City of Mount Holly Regional Wastewater Treatment
program could be expanded to include industrial and/or landscape applications,which could, in turn,reduce
the demand for treated drinking water during peak and drought conditions.
NECESSARY ACTIONS
It is anticipated that the project will require the following actions:
•NPDES Permit
•FERC Permit
•Air Quality Permit
•Dam Permit(for Equalization Basin embankment)
•401 Water Quality Certification
•404 Clean Water Act Permit
•Erosion Control Permit
•Mecklenburg County Building Permit
•Authorization to Construct
EIS REVIEW AND COMMENT
The EIS has been properly advertised and reviewed by State and Federal agencies. Extensive public input
has been made into the planning process. Comments from agencies and citizens have been incorporated
into the proposed project. A copy of this Revised Record of Decision will be sent to the Clearinghouse,all
review agencies,and a notice of its availability will be published in the Environmental Bulletin.
/s//5/24 O
L da Culpepper (Date)
Director,Division of Water Resources
6

ATTACHMENT 3E
ENGINEERING PLANS

ATTACHMENT 3F
ENGINEERING SPECIFICATIONS

APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT
SECTION 3.F ENGINEERING SPECIFICATIONS
See separate bounded engineering specifications.
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.F
NPDES No. NC0089630

ATTACHMENT 3G
CONSTRUCTION SEQUENCE PLAN
1

APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT
SECTION 3.G CONSTRUCTION SEQUENCE PLAN
The proposed work is part of a larger project to construct an entirely new wastewater treatment facility
in a location where none exists. Since there are no existing operations that could overflow or be
bypassed, no Construction Sequence Plan has been prepared.
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.G
NPDES No. NC0089630

ATTACHMENT 3H
ENGINEERING CALCULATIONS

CHARLOTTE WATER
CHARLOTTE
W TER
Stowe Regional Water Resource Recovery Facility
Stage 1
DESIGN CALCULATIONS
Hazen
NOVEMBER 2021

CHARLOTTE WATER
CHARLOTTE
Ws ,TER
Stowe Regional Water Resource Recovery Facility
Stage 1
DESIGN CALCULATIONS
04,Id of
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( Q
.a SEAL r'
32685 11/22/z1
0y' bG NE '��G��
6- v• • ,zy,G'
Hazen
NOVEMBER 2021

STOWE RWRRF - STAGE 1
DESIGN CALCULATIONS
INDEX
HYDRAULIC PROFILE
HYDRAULIC CALCULATIONS
FINAL CLARIFIERS CALCULATIONS
BUOYANCY CALCULATIONS
DESIGN INFLUENT CONCENTRATIONS
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.H
NPDES No.NC0089630

HYDRAULIC PROFILE
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.H
NPDES No.NC0089630

U
6 STARE MR FROCEw PLOW PUMNTrCWUFlMw INRaanew, rbH MR BASINS
NOTES: o
PRIMARY TNHl9 ARE BASED ON THE NORTH
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103161.100 OIRII UNIT OOE) mm EtWAt - u R P u a - _--
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—PWEf.P010700.11 UNIT 0061 MIMW Ofm6a. 07.70 aW W. NOM E1916 01E67 SR SIRED MW Ra MUT Z
RETURN ACTIVATED SLUDGE•1006 OF
-INFLUENT FLOW AT THE WI%MOMH ROW T 1 ` NITRIFlED RECYQE=600%OF PART INFLUENT
ea --_- —_____.___- . 61p FLOW ET THE IM%MpITH FLOW p
MAEO.SEE NINE WEE
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ACCOUNT OF PIPE AND CHANNELS.ARE
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a9°f°° �L HYDRAULIC PROFILE-UNITS IN SERVICE
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y 6m _._ ________-. ___ _. ._ .____—__.___._-- W000L s.m SR
8 _._._. FEE... EpTOMS1160 TOMS EOr um TOTALS
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•
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CHANNELS
R XITUEOAEYSnEGEL DATE. NOVEMBER2021
E � �� W6TER Stowe Regional
M.MCIAlAB IPaH NW 31460001
I 1! _DESIIMED wAwxR.er C.ALLENn Garney� i CHARLOTTE,NORTH CAROLINA PROCESS MGENEECHANICAL DOHTRAaTNO.. 1
CIEwMO n. C_JGFd90N _
Ho. HYDRAULIC PROFILE NI°MiaEWeR`
MARLO„E NORTH wOLINAMO - STOWS REGIONAL WATER
03 MAME r°MR eI CRAM. : i NOT 0 VI ' RESOURCE RECOVERY FACILITY
f4 — =AM FOR 660E 6‘, ■NOT TONu2.00 CROW�ER Mt

HYDRAULIC CALCULATIONS
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.H
NPDES No.NC0089630

',JY=. h",--I',., '-f1r.ri.i,1 .-.''46 7.1i; xlsrn
22:'2f.1 3 1 k AM
City of Chart-
CHARLOTTE STOWS Regi•` - - }e Rec• Sry Facility - _ -
W`TER Hydraulic Profile-Secondary Clarifiers
•
•
All Treatment Largest Treatment
Units in Service Unit Out of Service
Phase 1 Phase 1 Phase 1 Phase 1 Please 2 Phase 2 Phase 1 Phase 1 Phase 2 Phase 1
Low Diurnal Dully Avg Max Month Peak Hour Max Month Peak Hour Max Month Peak Hour Max Month Peak Hour
Flow Description Units Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow
Plant Influent Flow mgd 5.0 8.0 15.0 30.0 25.0 50.0 15.0 30.0 25.0 50.0
Return Activated Sludge(RAS)Flow mgd 5.0 8.0 15.0 15.0 25.0 25.0 15.0 15.0 25.0 25-0
HGL from Filters= 608.60 608.64 608.72 608.84 608.80 608.98 608.72 608.84 608.80 608.98
START-SECONDARY CLARIFIERS
Secondary Clarifier Diameter(ft)= 160
Secondary Clarifier Perimeter(ft)=502.7
Number of Secondary ClarMers In Service 2 2 3 3 4 4 2 2 3 3
•
300.01 Filter Influent Pipe
Module PIP1 Piping by Hazen-W#liams Equation
#of clarifiers Contributing Flow= 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0
Diameter= 42 in a(mgd)= 5.00 8.00 10.00 20.00 12.50 25.00 15.00 30.00 16.67 33.33
Length= 118 ft V(fps). 0.80 1.29 1.61 3.22 2.01 4.02 2.41 4.83 2.68 5.36
Hazen&Will.C= 120 Hv(ft)= 0.01 0.03 0.04 0.18 0.06 0.25 0.09 0.36 0.11 0.45
Minor Loss K's: Exit 1.0 Hf(ft)= 0.01 0.02 0.03 0.10 0.04 0.15 0.06 0.22 0.07 0.26
90 Bends 0.3 Hm(ft)= 0.02 0.04 0.06 0.26 0.10 0.40 0.14 0.58 0.18 0.71
Through WYE 0.3 HL(ft)= 0.02 0.06 0.09 0.36 0.14 0.56 0.20 0.79 0.25 0.98
Sum K= 1.6
EGL a HGL 608.63 608.70 608.81 609.20 60815 609.54 608.92 609.64 609.06 609.96
300.02 Filter Influent Pipe
Module PIPE Piping by Hazen-Williams Equation
#of clarifiers Contributing Flow= 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Diameter= 38 in D(mgd)= 2.50 4.00 5.00 10.00 6.25 12.50 7.50 15.00 8.33 16.87
Length= 260.0 ft V(fps)= 0.55 0.88 1.09 2.19 1.37 2.74 1.84 3.28 1.82 3.85
Hazen&Will.C= 120 He(ft)= 0.00 0.01 0.02 0.07 0.03 0.12 0.04 0.17 0.05 0.21
Minor Loss K's Entrance 0.5 Hf(ft)= 0.01 0.02 0.04 0.13 0.06 0.20 0.08 0.28 0.09 0.34
22.5 Bends 0.1 Hm(ft)=. 0.00 0.01 0.02 0.06 0.02 0.10 0.04 0.14 0.04 0.18
45 Bends 0.15 HL(ft)= 0.01 0.03 0.05 0.20 008 0.30 0.11 0.42 0.14 0.51
Red 0.1
Sum K= 0.85
EGL•NIX 606.64 608.74 608.86 609.40 609.03 609.64 609.03 810.06 609.19 610.47
300.03 Secondary Clarifier Effluent Box
Module CCR Rectangular Closed Conduct by Mannings Equation
Widen= 8 ft a(mgd)= 2.5 4.0 6.0 10.0 6.3 12.5 7.5 15.0 8.3 16.7
Height= 5 ft V(fps). 0.13 0.21 0.26 0.52 0.32 0.64 0.39 0.77 0.43 0.86
Length= 11.26 ft He(ft)= 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.00 0.01
Manning n= 0.015 Hf(ft)= 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
SumK= 0.5 Hm(ft)- 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01
HL(ft)= 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.01
EGL a HGL 608.64 608.74 608.86 609.40 609.03 609.64 609.03 610.06 609.19 610 48
300.04 Clarlfer Effluent Launder
Module OCLI Rectangular Lateral Inflow Channel
Invert El= 807.75 ft 0(mgd)= 1.3 2.0 2.5 5.0 3.1 6.3 3.a 7.5 4.2 8.3
Width= 3 ft Backwater(ft). 0.89 0.99 1.11 1.65 1.28 2.09 1.28 2.31 1.44 2.73
Length= 247.7 ft Yc(ft)= 0.23 0.32 0.37 0.59 0.43 0.69 0.49 0.77 0.52 0.83
Slope= 0.0000 ft/ft Actual Depth(ft). 0.89 0.99 1.11 1.135 1.28 2.09 1.28 2.31 1.44 2.73
Manning n= 0.015 V-end(fps). 0.72 1.05 1.16 1.56 1.26 1.54 1.51 1.67 1.49 1.57
Hf(ft)- 0.01 0.02 0.02 0.03 0.02 0.02 0.03 0.03 0.03 0.02
Yu(ft)= 0.92 1.04 1.17 1.75 1.35 2.19 1.38 2.43 1.54 2.63
HGL 608.67 608.79 608.92 609.50 609.10 609.94 609.13 610.18 609.29 610.58
SC Effluent Weir Freeboard= 2.33 2.21 2.08 1.50 1.90 1.06 1.87 0.82 1.71 0.42
300.05 Secondary Clarifier Effluent V-Notch Weir
Module WV V-Notch Weir
Weir El= 811.00tt 0(mgd)= 26 4.0 5.0 10.0 6.3 12.5 7.5 16.0 8.3 16.7
Length of Weir= 461.7 DMatch(mgd)= 0.003 0.004 0.005 0.010 0.006 0.013 0.008 0.016 0.009 0.017
#Notches= 963 He(ft)= 0.08 0.09 0.10 0.13 0.11 0.15 0.12 0.16 0.12 0.16
Depth of Notch= 3 in Weir Submergence(ft). 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Length between Notches= 6 in Weir Submerged? No No No No No No No No No No
Notch Overtopped? No No No No No No No No No No
EGL•HGL 811.08 611.09 611.10 611.13 611.11 811.15 811.12 611.16 811.12 811.16
1 of 2

•
STOWE W W TP-Proposed Hydraulic Profile(31480-000).xlem
11/22/2021 9:18 AM
City of Charlotte,North Carolina
CHARLOTTE STOWE Regional Water Resource Recovery Facility ...
•
W(,�TER Y' Hydraulic Profile-Secondary Clarifiers
All Treatment Largest Treatment
Units in Service Unit Out of Service
•
Phase 1 Phase 1 Phase 1 Phase 1 Phase 2 Phase 2 Phase 1 Phase 1 Phase 2 Phase 2
Low Diurnal Daily Avg Max Month Peak Hour Max Month Peak Hour Max Month Peak Hour Max Month Peak Hour
Flow Description Units Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow
Plant Influent Flow mgd 5.0 8.0 15.0 30.0 25.0 50.0 15.0 30.0 25.0 50.0
Return Activated Sludge(RAS)Flow _mgd 5.0 8.0 15.0 15.0 25.0 25.0 15.0 15.0 25.0 25.0
300.06 SC Energy Dissipating Inlet(Exit)
Module MFR Manufacturer Head Loss Info
Manufacturer Reference Headloss= 0.09 0.21 0.11 0.25
Reference Cl= 25.00 mgd 0(mgd)= 5.0 8.0 10.0 15.0 12.5 18.8 15.0 22.5 16.7 25.0
Reference HL= 0.25 ft HL(ft)= 0.01 0.03 0.04 0.09 0.06 0.14 0.09 0.21 0.11 0.25
HGL Upstream of Energy Dissipating Inlet= 811.09 611.12 611.14 611.22 611.17 811.29 811.21 611.36 811.24 611.42
300.07 Center Column
Module PIPE Piping by Hazen-Williams Equation
Diameter= 42 in O(mgd)= 5.0 8.0 10.0 15.0 12.5 18.8 15.0 22.5 16.7 25.0
Length= 27.5 ft V(fps). 0.80 1.29 1.61 2.41 2.01 3.02 2.41 3.62 2.68 4.02
Hazen&Will.C= 120 Hv(ft)= 0.01 0.03 0.04 0.09 0.06 0.14 0.09 0.20 0.11 0.25
•
• Minor Loss K's. Entrance at Bottom 0.5 Hf(ft)= 0.00 0.00 0.01 0.01 0.01 0.02 0.01 0.03 0.02 0.04
Hm(ft). 0.01 0.01 0.02 0.05 0.03 0.07 0.05 0.10 0.06 0.13
HL(ft)= 0.01 0.02 0.03 0.06 0.04 0.09 0.06 0.13 0.07 0.16
Sum K= 0.5
EGL.HSL 611.09 611.14 611.17 611.28 611.21 611.38 611.27 611.49 611.31 611.58
END-SECONDARY CLARIFIERS
2rst2

FINAL CLARIFIERS CALCULATIONS
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.H
NPDES No.NC0089630

Stowe Regional Water Resource Recovery Facility
Final Clarifier Design Calculations
Phase I - 15.0 MGD
Clarifier Diameter 160 ft
Clarifier Area 20,106 sq. ft.
Number = 3
Total Area = 60,319 sq. ft.
Total Areaone Unit Out of Service= 40,212 sq. ft.
Design Secondary Effluent Flow = 14.9 mgd
Peak Secondary Effluent Flow = 30 mgd
RAS Flow (% MMADF) = 100%
RAS Flow = 14.9 mgd
Operational MLSS = 3500 mg/I
Parameter 10 States Stnd All Units in Service One Unit Out of Service
Design Peak Design Peak
Solids Loading Rate (Ib/d/ft2) = 35 14.42 21.73 21.63 32.59
Solids Loading Rate (Ib/hr/ft2) = 1.46 0.60 0.91 0.90 1.36
Surface Overflow Rate (gpd/ft2) = 900 247 497 371 746
Weir Loading Rate (gpd/ft) = 30,000 9,881 19,894 14,821 29,842
Ten State Standards are Based on The Following:
Solids Loading Rate - Maximum Day Solids Loading for Nitrification
Surface Overflow Rate - Maximum SOR at Design Peak Hour Flow - Systems with Chemical Addition to Remove Phosphorus
Weir Loading Rate - Maximum Loading Rate at Design Peak Hour Flow

Stowe Regional Water Resource Recovery Facility
Final Clarifier Design Calculations
Phase II - 25.0 MGD
Clarifier Diameter 160 ft
Clarifier Area 20,106 sq. ft.
Number= 4
Total Area = 80,425 sq. ft.
Total Area One Unit Out of Service= 60,319 sq. ft.
Design Secondary Effluent Flow = 24.9 mgd
Peak Secondary Effluent Flow = 50 mgd
RAS Flow (% MMADF) = 100%
RAS Flow = 24.9 mgd
Operational MLSS = 5500 mg/I
Parameter 10 States Stnd All Units in Service One Unit Out of Service
Design Peak Design Peak
Solids Loading Rate (Ib/d/ft2) = 35 28.40 42.72 37.87 56.96
Solids Loading Rate (Ib/hr/ft2) = 1.46 1.18 1.78 1.58 2.37
Surface Overflow Rate (gpd/ft2) = 900 310 622 413 829
Weir Loading Rate (gpd/ft) = 30,000 12,384 24,868 16,512 33,157
Ten State Standards are Based on The Following:
Solids Loading Rate - Maximum Day Solids Loading for Nitrification
Surface Overflow Rate - Maximum SOR at Design Peak Hour Flow - Systems with Chemical Addition to Remove Phosphorus
Weir Loading Rate - Maximum Loading Rate at Design Peak Hour Flow

BUOYANCY CALCULATIONS
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.H
NPDES No.NC0089630

Haz en Project Job Ref.
Stowe WRRF 31460-001
Subject Sheet no./rev.
Hazen and Sawyer
9101 Southern Pine Boulevard S300 Series—Final Clarifier Flotation Calculations 1
Suite 250 Calc.by Date Chk'd by Date App'd by Date
Charlotte,NC 28273 CSW 11/18/2021 JPB 8/9/2021
S300 SERIES - FINAL CLARIFIER FLOTATION DESIGN CRITERIA
Structure designed according to the 2018 North Carolina Building Code which has the following referenced standard:
• ASCE 24-14-Flood Design
Flood Design
Design Flood =Structure designed for the 100-Year flood elevation (Base Flood Elevation)of 579.50 and for the Future 100-
year Flood Elevation of 580.75 Based Upon the Base Flood Elevation in Long Creek
500 Year Flood elevation =581.00
DESIGN SUMMARY
The structural design outlined in the calculation package covers the design of threee, mostly identical, circular clarifiers set at
the same elevations on the site—identified as Final Clarifier No. 1, Final Clarifier No. 2 and Final Clarifier No. 3 and located at
the proposed Stowe Water Resource Recovery Facility.
CONFIGURATION
The tank has the following preliminary geometric parameters:
• 160 ft internal tank diameter
• 18'—2"wall height
• Inboard effluent trough consisting of cantilevered concrete and a 154 ft diamter to the weir wall process face(3.0 ft
fixed effluent flow area)
GROUNDWATER
The lowest bearing slab of the final clarifiers are planned for elevation 577.33 (at lower centerwell slab elevation),which is just
below the design flood elevation. No flood design for the main clarifier basin is required according to ASCE 24-14 (elevation at
585.83). The Geotechnical Engineering Report has the following language regarding design of subgrade elements considering
groundwater level (page 24, last paragraph):
"The recommended equivalent fluid pressures assume that constantly functioning drainage systems are installed between walls
and soil backfill to prevent the accidental buildup of hydrostatic pressure and lateral stresses in excess of those stated. In the
event that a functioning drainage system is not installed, the lateral earth pressures should be determined using the buoyant
weight of the soil and the appropriate above provided coefficient of earth pressure. Hydrostatic pressures calculated with the
unit weight to water should then be added to these earth pressures to obtain the total stress for design."
Given this recommendation and following discussions with the Owner and Design-Builder as well as following preliminary
calculations, Hazen will incorporate hydrostatic pressure relief wall valves into the bottom portion of the clarifier walls. These
wall valves will serve the function of draining the majority of the tank walls when the clarifier is empty and exterior groundwater
is elevated. We do not anticipate continuous or significant groundwater flow through these valves will occur and the tanks

Hazen Project Job Ref.
Stowe WRRF 31460-001
Subject Sheet no./rev.
Hazen and Sawyer
S300 Series—Final Clarifier Flotation Calculations 2
9101 Southern Pine Boulevard
Suite 250 Calc.by Date Chk'd by Date App'd by Date
Charlotte,NC 28273 CSW 11/18/2021 JPB 8/9/2021
should be able to be completely drained as required for preventative maintenance and any future work. The use of these
valves enable a significant reduction in clarifier structure required to resist hydrostatic forces above their instalaltion level.
BUOYANCY CHECK
Pup = {[((163.33ft)2*3.14159/4)*4.5ft]+ 1/3* (6.5ft*((163.33ft)2*3.14159/4)}*63pcf
=(94283 ft3+45396 ft3)*63 pcf=8800 kips uplift
Pdown = 3223.77 CY Concrete (From Revit Model)*27 CF/CY* 150 PCF= 13056 Kips
FS against uplift= 13056 kips/8800 kips= 1.5
Soil over toe not considered—ok by inspection. Buoyancy OK(and conservatively based on perched/high groundwater and not
flood elevation). Design meets and exceeds requirement of the code.

DESIGN INFLUENT CONCENTRATIONS
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.H
NPDES No.NC0089630

CHARLOTTE
WVER Stowe Regional
Technical Memorandum
Ga ne) Hazen
June 2020
To: Charlotte Water
From: Stowe Regional WRRF DB Team
Project No.: 31460-001
Stowe Regional WRRF Flow / Load Memorandum
Purpose and Scope
The purpose of this Technical Memorandum is to document the proposed design flows and loads for the
Stowe Regional WRRF and compare them to the flows and loads presented in the 2018 Preliminary
Engineering Report (2018 PER) developed by Black&Veatch. Influent loads were calculated for both the
initial 15-mgd maximum month average daily flow(MMADF)design and the future 25-mgd MMADF
design. Conclusions are as follows:
1. The aggregate influent loads to the Stowe Regional WRRF based on data through 2019 are
similar to those proposed in the 2018 PER and will be used to design the Stowe Regional WRRF.
2. The duration of sustained,equalized,wet weather flows is based upon previous work presented
by Black&Veatch in October 2018.A 24-hr duration for peak flows from the Mt. Holly and
Belmont WWTPs and a 14-hr duration for peak flows from the Long Creek and Paw Creek Pump
Stations will be used.An equalized peak flow factor of 2.0 times the MMADF is assumed.
3. Data from five Charlotte Water WWTPs indicated a minimum effluent temperature between
14°C and 15°C.A minimum week wastewater temperature of 13°C was proposed during the
Secondary Alternatives Workshop. The Process Selection Facility Plan (PSFP)evaluations will
assume a minimum wastewater temperature of 12°C based on feedback Charlotte Water
provided during the workshop.
1. Historical Influent Flows and Loads
1.1 Long Creek Pump Station
Table 1-1 summarizes daily Long Creek Pump Station flow data from January 2016 through December
2019. Flows have steadily increased over the past several years.
1

CHARLOTTEStowe Re ional
W(,rTER g:..�.,a,.a�__, June 2020
Table 1-1: Long Creek PS Flow Data (mgd)
Min Day Annual Max Max Max Max Day
Average Month 30-Day 7-Day
2016 3.23 3.91 5.10 5.13 6.96 7.34
2017 3.33 4.02 4.52 4.77 5.91 7.24
2018 1.86 4.20 5.82 5.87 7.01 7.49
2019 3.19 4.72 5.52 6.33 6.70 7.63
Average 2.90 4.21 5.24 5.52 6.64 7.43
Typ. Peaking Factor 0.69 - 1.25 1.31 1.58 1.77
Table 1-2 compares the average Long Creek PS wastewater characteristics to the values in the 2018 PER.
Average Long Creek PS characteristics are based on 43 samples collected between March 2010 and
February 2019. The average characteristics are similar to the values in the 2018 PER with the exception
of COD, which is 11%lower than the 2018 PER.
Table 1-2: Long Creek PS Wastewater Characteristics Comparison
Long Creek PS 2018 PER
cBODs, mg/L 291 300
BOD5, mg/L 342 353
COD, mg/L 584 655
TSS, mg/L 304 334
TKN, mg/L 48 48
NH3-N, mg/L 30.7 29.6
TP, mg/L 6.2 6.4
Alkalinity, mg/L1 175 177
'as CaCO3
1.2 Paw Creek Pump Station
Table 1-3 summarizes daily Paw Creek PS flow data from January 2016 through December 2019. Flows
have steadily increased over the past several years.
Table 1-3: Paw Creek PS Flow Data (mgd)
Min Day Annual Max Max Max Max Day
Average Month 30-Day 7-Day
2016 2.95 4.57 5.87 5.89 7.59 8.82
2017 3.70 4.69 5.41 5.79 7.35 10.00
2018 3.02 5.19 7.27 7.32 8.83 10.00
2019 4.21 5.87 6.85 8.17 9.43 12.11
Average 3.47 5.08 6.35 6.79 8.30 10.23
Typ. Peaking Factor 0.68 - 1.25 1.33 1.63 2.01
2

CHARLOTTE StoweRe Tonal
WLTER 9Ha<.,�-.� .4�. , June 2020
Table 1-4 compares the average Paw Creek PS wastewater characteristics to the values in the 2018 PER.
Average Paw Creek PS characteristics are based on 44 samples collected between March 2010 and
February 2019. The average characteristics are similar to the values in the 2018 PER.
Table 1-4: Paw Creek PS Wastewater Characteristics Comparison
Long Creek PS 2018 PER
cBODs, mg/L 270 273
BOD5,mg/L 318 321
COD, mg/L 620 656
TSS, mg/L 299 302
TKN, mg/L 46 48
NH3-N, mg/L 28.2 28.0
TP, mg/L 6.1 6.2
Alkalinity,mg/L1 178 183
'as CaCO3
1.3 Mount Holly WWTP Influent
Table 1-5 summarizes daily Mount Holly WWTP effluent flow data from January 2017 through
December 2019. Effluent flow data was used for flow and load evaluation since the influent flow was
identified as being unreliable at high flows. Average daily flows increased by 15%between 2017 and
2019.
Table 1-5: Mount Holly WWTP Effluent Flows (mgd)
M Max Max
Min Day Average Month 30-Day 7-Day Max Day
2017 0.84 2.00 2.23 2.28 2.91 4.16
2018 0.72 2.04 2.41 2.46 3.19 5.79
2019 1.08 2.30 2.77 3.02 4.06 7.53
Average 0.88 2.11 2.47 2.59 3.39 5.83
Typ. Peaking Factor 0.41 - 1.17 1.22 1.60 2.73
Tables 1-6 and 1-7 summarize historical influent wastewater concentrations and loads(based on effluent
flow). Influent BOD5 and TSS loads have been constant over the past three years but influent nitrogen
and phosphorus concentrations and loadings increased in 2019.
Table 1-6: Mount Holly WWTP Average Influent Concentrations (mg/L)
BODs TSS TKN NH3-N TP
2017 167 188 30.5 19.7 3.8
-
2018 157 177 29.9 19.2 4.0
2019 151 161 32.9 18.8 4.6
3

CHARLOTTE Stowe Regional
W(�TER 9h,«.-...,.-,..,,..-,, June 2020
2017-2019 Average I 158 I 175 I 30.8 I 19.2 I 4.2
Table 1-7: Mount Holly WWTP Average Influent Loads (lb/day)
BODs TSS TKN NH3-N TP
2017 2,790 3,130 510 329 64
2018 2,660 3,000 507 326 68
2019 2,880 3,090 614 360 88
2017-2019 Average 2,780 3,080 540 339 74
Table 1-8 compares the minimum day,30-day,7-day,and maximum day load peaking factors. Load
peaking factors are typical of municipal WWTPs similar in capacity to the Mount Holly WWTP. There is
insufficient data to calculate 7-day average TKN and TP loads, and these are indicated by"ND".
Table 1-8: Mount Holly WWTP Load Peaking Factors-2017-2019 Average
BODs TSS TKN NH3-N TP
Minimum Day 0.34 0.36 0.55 0.45 0.49
Maximum 30-Day 1.37 1.43 1.30 1.15 1.41
Maximum 7-Day 1.76 1.99 ND 1.31 ND
Maximum Day 2.56 3.13 1.71 1.80 1.73
Table 1-9 compares the Mount Holly WWTP influent characteristics to the values in the 2018 PER. The
influent characteristics are similar to the values in the 2018 PER except that the TSS decreased and TP
increased compared to the 2018 PER.
Table 1-9: Mount Holly WWTP Influent Wastewater Comparison
2018 PER 2018 PER
Annual Average Max 30-Day' Annual Average Max Month
Flow, mgd 2.11 2.59 2.12 2.59
Loads, lbs/day
BODs 2,780 3,800 3,044 4,048
TSS 3,080 4,400 4,271 6,353
TKN 543 705 554 759
NH3-N 339 392 338 463
TP 74 100 66 83
Concentration,mg/L
BOD5 158 176 172 188
TSS 175 204 242 294
TKN 30.8 32.6 31.3 35.2
NH3-N 19.2 18.1 19.1 21.4
TP 4.2 4.6 3.7 3.8
'Maximum 30-day concentrations based on maximum 30-day load at maximum 30-day flow
4

CHARLOTTE
TEStowe Regional W TER g . x,ry June 2020
1.4 Belmont WWTP Influent
Table 1-10 summarizes daily Belmont WWTP effluent flow data from January 2015 through December
2019. Annual average flows increased by 24%between 2015 and 2019.
Table 1-10: Belmont WWTP Effluent Flows (mgd)
Max Max Max
Min Day Average Month 30-Day 7-Day Max Day
2015 0.83 1.51 2.03 2.03 2.69 5.55
2016 0.97 1.64 2.00 2.02 2.41 4.13
2017 0.85 1.80 2.44 2.45 2.80 3.67
2018 0.93 1.88 3.02 3.03 3.71 4.82
2019 1.19 1.87 2.07 2.95 3.03 3.95
Average 0.96 1.74 2.31 2.50 2.93 4.42
Typ. Peaking Factor 0.55 - 1.33 1.43 1.68 2.58
Tables 1-11 and 1-12 summarize historical influent wastewater concentrations and loads (based on
effluent flow). Influent concentrations have remained relatively constant over the past five years, and
loads have increased proportionally to effluent flow.
Table 1-11: Belmont WWTP Average Influent Concentrations (mg/L)
BOD5 TSS TKN NH3-N TP
2015 174 158 28.9 13.5 4.0
2016 161 181 27.1 15.1 4.6
2017 163 179 30.3 16.2 4.1
2018 170 168 27.6 17.0 3.8
2019 165 166 35.8 19.2 4.5
2015-2019 Average 167 171 30.1 16.3 4.2
Table 1-12: Belmont WWTP Average Influent Loads (lb/day)
BOD5 TSS TKN NH3-N TP
2015 2,180 1,990 363 169 50
2016 2,210 2,480 372 207 63
2017 2,440 2,680 454 242 61
2018 2,660 2,630 432 266 59
2019 2,580 2,590 558 300 70
2015-2019 Average 2,420 2,480 435 236 62
Table 1-13 compares the minimum day, 30-day, 7-day, and maximum day load peaking factors. The
calculated BOD5 and TSS load peaking factors exhibit greater variability than typically observed at
municipal WWTPs. There is insufficient data to calculate 7-day average TKN,NH3-N, and TP loads, and
these are indicated by"ND".
5

CHARLOTTE
W6TER Stowe Regional June 2020
Table 1-13: Belmont WWTP Load Peaking Factors-2015-2019 Average
BOD5 TSS TKN I NH3-N TP
Minimum Day 0.21 0.16 0.48 0.17 0.51
Maximum 30-Day 1.47 1.73 1.17 1.47 1.44
Maximum 7-Day 2.04 2.29 ND ND ND
Maximum Day 3.75 4.76 1.90 1.89 1.83
Table 1-14 compares the Belmont WWTP influent characteristics to the values in the 2018 PER. The
influent concentrations are substantially lower than those presented in the 2018 PER. The 2018 PER
noted that the influent wastewater concentrations were trending downward. Current maximum 30-day
loads are similar to those developed in the 2018 PER.
Table 1-14: Belmont WWTP Influent Wastewater Comparison
Annual Average Max 30-Day' 2018 PER 2018 PER
Annual Average Max Month
Flow, mgd 1.74 2.50 1.36 1.59
Loads,Ibs/day
BOD5 2,420 3,560 2,839 3,529
TSS 2,480 4,300 2,941 4,643
TKN 436 498 460 601
NH3-N 236 346 280 366
TP 61 94 63 92
Concentration, mg/L
BOD5 167 171 250 267
TSS 171 206 259 351
TKN 30.1 23.9 40.5 45.4
NH3-N 16.3 16.6 24.7 27.7
TP 4.2 4.5 5.6 7.0
'Maximum 30-day concentrations based on maximum 30-day load at maximum 30-day flow
2. Design Influent Flows and Loads
2.1 Assumptions 1
Design flows and loads were developed for the Stowe Regional WRRF start-up conditions (2024),the15-
mgd MMADF design flow,and the future 25-mgd MMADF design flow. Design influent concentrations
and loads are based on a composite of the various influent sources to the facility, assuming the wastewater
characteristics presented in the previous section and the following assumptions:
• Design annual average and maximum month flows are based on the 2018 PER.
6

CHARLOTTE
Stowe Re Tonal
W6TETER g... ....;<..e,,...,,,„,, June 2020
• Load peaking factors for Long Creek PS and Paw Creek PS flows are similar to Mount Holly
WWTP loads.
• Maximum day-to-annual average aeration load peaking factors of 2.5 for COD/BOD5 and 2.0 for
NH3-N/TKN.
• An additional flow of 0.20 mgd from Clariant,with wastewater characteristics similar to the
Belmont WWTP influent to be consistent with the 2018 PER.
• Table 2-1 summarizes design maximum month load peaking factors.
Table 2-1: Design Maximum Month Load Peaking Factors
Flow COD/BOD5 TSS NH3-N/TKN TP
Long Creek PS 1.19 1.4 1.4 1.3 1.4
Paw Creek PS 1.20 1.4 1.4 1.3 1.4
Mount Holly WWTP 1.13 1.4 1.4 1.3 1.4
Belmont WWTP 1.20 1.5 1.7 1.4 1.6
2.2 Start-Up (2024)
The Stowe Regional WRRF is anticipated to commence operation in 2024. Only flows from the Long
Creek PS,Mount Holly WWTP, and Clariant are anticipated to be sent to the Stowe Regional WRRF at
start-up. Table 2-2 summarizes estimated start-up flows and loads.
Table 2-2: Stowe Regional WRRF Start-up Loads and Concentrations (2024)
Annual Average Max 30-Day
Flow, mgd 7.8 9.0
Loads, lbs/day
BOD5 17,200 24,100
TSS 16,200 22,800
TKN 2,650 3,450
NH3-N 1,680 2,180
TP 350 490
Concentration, mg/L
BOD5 264 322
TSS 249 304
TKN 40.7 46.1
NH3-N 25.8 29.2
TP 5.4 6.5
7

CHARLOTTE
W6TER Stowe Regional June 2020
2.3 15-mgd Design (2038)
The 15-mgd design flows and loads, summarized in Table 2-3, are based on projected 2038 flows from
the Long Creek PS,Mount Holly WWTP,and Clariant. The Paw Creek PS and Belmont WWTP will
continue to be diverted to either the McAlpine Creek WMMF or the Irwin Creek WWTP until expansion
to 25 mgd. Figures 2-1 and 2-2 compare 15-mgd design loads to those in the 2018 PER.
Table 2-3: Stowe Regional WRRF 15-mgd (Phase 1) Design Loads and Concentrations (2038)
Annual Average Max 30-Day
Flow, mgd 12.8 14.9
Loads,lbs/day
BOD5 29,600 41,400
TSS 27,600 38,600
TKN 4,470 5,810
NH3-N 2,840 3,690
TP 590 820
Concentration,mg/L
BOD5 278 334
TSS 259 311
TKN 42.0 46.8
NH3-N 26.7 29.7
TP 5.5 6.6
15-mgd Annual Average Loads
35.000
30.000
25,000
20,000
v
c 15,000
10,000
5,000 111
nem
BOD5 TSS TKN NH3-N TP
■Hazen ■2018 PER
Figure 2-1: Stowe Regional WRRF 15-mgd Annual Average Design Loads Comparison
8

CHARLOTTE
TER 9
W(�TE Stowe Regional
�oa.pso,aw� , June 2020
15-mgd Maximum Month Loads
45,000
40,000
35,000
✓ 30,000
v
e• 25,000
v
0
• 20.000
3
15,000
10,000
5.000 H
.I
BOD5 T55 TKN
■Hazen •2018 PER
Figure 2-2: Stowe Regional WRRF 15-mgd Maximum Month Design Loads Comparison
2.4 25-mgd Design (Phase 2)
The 25-mgd design flows and loads, summarized in Table 2-4, are based on projected 2044 flows from
the Long Creek PS, Paw Creek PS, Mount Holly WWTP, Belmont WWTP, and Clariant. Figures 2-3 and
2-4 compare 25-mgd design loads to those in the 2018 PER.
Table 2-4: Stowe Regional WRRF 25-mgd (Phase 2) Design Loads and Concentrations (2044)
Annual Average Max 30-Day
Flow, mgd 21.1 24.9
Loads, lbs/day
BOD5 47,700 66,700
TSS 44,800 62,700
TKN 7,250 9,420
NH3-N 4,510 5,860
TP 960 1,340
Concentration, mg/L
BOD5 271 321
TSS 254 302
TKN 41.1 45.4
NH3-N 25.6 28.2
TP 5.4 6.5
9

CHARLOTTE
( Stowe Regional June 2020
W(rTER TE
25-mgd Annual Average Loads
60.000
50,000
— 40 00O
vo 30.000
= _20,000
10,000
11 .1.
BOD5 T55 TKN NH3 P;
■-1 ,P, 2olfi PEP
Figure 2-3: Stowe Regional WRRF 25-mgd Annual Average Design Loads Comparison
25-mgd Maximum Month Loads
80.000
70.000
60,000
50,000
n
es
a0.0OO
c
30,000
20,000
1O,0O0
ii ■Ilk
BODE
•Hazen ■2018 PER
Figure 2-4: Stowe Regional WRRF 25-mgd Maximum Month Design Loads Comparison
10

CHARLOTTE
WLTER Stowe Regional June 2020
3. Diurnal Flow Analysis
April 2018 dry weather diurnal flow data for the Long Creek PS and Paw Creek PS were used to develop
representative hourly diurnal flow peaking factors(Figure 3-1). These diurnal flow patterns will be used
for dynamic process modeling during secondary alternatives evaluation. The diurnal flow pattern for the
Mt. Holly and Belmont WWTPs will utilize the average diurnal curve shown in Figure 3-1. Impacts of
planned dry-weather diurnal equalization will also be considered.
16
1.4
1.2
u 1.0
u_
Y 08
a,
a.
° 0.6
73
0.2
0.0
0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 0:00
Time of Day
—LC PS PC PS —Average
Figure 3-1: Long Creek PS and Paw Creek PS Dry Weather Hourly Flow Pattern (unequalized)
Wet-weather and daily dry-weather equalization will be constructed as part of the Long Creek Influent
Pump Station project. Peak flows to the Stowe Regional WRRF will be limited to 30 mgd and 50 mgd at
the 15-mgd and 25-mgd design flows,respectively,resulting in a peak flow factor of 2.0. Attenuated wet
weather storm flow hydrographs were presented to Charlotte Water by Black&Veatch in October 2018.
The hydrographs illustrate a 24-hr attenuated peak flow for the Mount Holly and Belmont WWTPs,and
an approximate 14-hr peak flow for the Long Creek and Paw Creek PSs(Figures 3-2 and 3-3). The
PSFP will assume these peak flow durations to develop secondary capacity requirements.
11
1

CHARLOTTE
TER r a,
W(,TE Stowe Regional
•a,�a ������ June 2020
Peak Wet Weather Flow
Mount Holly & Belmont
To EQ Storage
Pumping Capacity
> ToWWTP
Figure 3-2: Peak Flow Hydrograph— Mount Holly and Belmont WWTPs (Black &Veatch 10/4/2018
Presentation)
Peak Wet Weather Flow
Long Creek & Paw Creek
P�mpuig Rate
D
Figure 3-3: Peak Flow Hydrograph— Long Creek and Paw Creek PSs (Black &Veatch 10/4/2018
Presentation)
12

CHARLOTTE
W(rTER Stowe Regional • June 2020
4. Wastewater Temperature Analysis
The proposed basis of design for the Stowe Regional WRRF is to treat maximum month loads under
the minimum 7-day temperature. Figure 4-1 presents reported effluent wastewater temperatures for
Charlotte Water's five WWTPs. Minimum reported temperatures for each plant were above 15°C,
except for the Irwin Creek WWTP,where minimum day temperatures dropped to 14°C.
A minimum week wastewater temperature of 13°C was proposed during the Secondary Alternatives
Workshop. The PSFP evaluations will assume a minimum wastewater temperature of 12°C based on
feedback Charlotte Water provided during the workshop.Minimum design wastewater temperatures
will be confirmed with Charlotte Water prior to detailed design.
30
28 l':,
4
111)\1'En
m 26 .1 •
24 .
otit
I
22 20 18 4 16
LU
W
14
12
lac 1, 13 c .o Sao lac �.. 0eQ ‘i5, §s lac 1 �� coo 4)4 eC‘ fat
—Irwin —Mallard McAlpine —McDowell —Sugar
Figure 4-1: Charlotte Water WWTPs Reported Daily Effluent Temperatures
13

ATTACHMENT 3J
RESIDUALS MANAGEMENT PLAN

APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT
SECTION 3.J RESIDUALS MANAGEMENT PLAN
The Stowe Regional Water Resource Recovery Facility will produce primary sludge and waste activated
sludge. Table 1 below presents the design sludge production rates.
Table 1—Design Sludge Production Rates at Monthly Maximum Average Design Flow(15 MGD)
Type e T e Sludge Production Rate(lb/day)
Primary Sludge 24,000
Waste Activated Sludge 15,500
All sludge produced at the Stowe RWWRF will be collected and stored onsite in two sludge holding tanks
and then pumped offsite to Charlotte Water's McAlpine Creek Wastewater Management Facility from a
transfer pump station located on the Stowe RWWRF property. The sludge holding tanks and transfer
pump station are being designed and constructed by others.
This application for ATC pertains to the final clarifiers. All other unit processes will be part of future
applications for ATC. Solids produced in the final clarifiers will be conveyed to the RAS Pump Station.
Charlotte Water FORM ATC-12-14
Stowe Regional Water Resource Recovery Facility Attachment for Section 3.J
NPDES No. NC0089630