NC0089630_Authorization to Construct_20231228

North Carolina Department of Environmental Quality | Division of Water Resources
512 North Salisbury Street | 1611 Mail Service Center | Raleigh, North Carolina 27699-1611
919.707.9000

December 28, 2023
Mr. Derek Dixon
Engineering Project Manager
Charlotte Water
5100 Brookshire Blvd.
Charlotte, North Carolina 28216
SUBJECT: Authorization to Construct
A to C No. 089630A05
Charlotte Water
Stowe Regional WRRF
NPDES Permit No. NC0089630
Dear Dixon:

A letter of request for an Authorization to Construct was received June 27, 2023, by the
Division of Water Resources (Division). With additional information received on December 4,
2023 and December 22, 2023, final plans and specifications for the subject project have been
reviewed and found to be satisfactory. Authorization is hereby granted for the construction of the
new 15 MGD Stowe Regional Water Resources Reclamation Facility, with discharge of treated
wastewater into the Catawba River in the Catawba River Basin.

This authorization is for a new permitted discharge of 15 MGD, and is awarded for the
following specific construction:

Construction of one (1) chemical building consisting of three (3) peristaltic hose Alkalinity
metering pumps, two (2) duty and one (1) standby, each rated for 2.2 GPM @ 55 PSI with
VFDs, two (2) 10 HP vertical mixers, and two (2) 18,700-gallon carbon steel Alkalinity
Storage Tanks with secondary containment; construction of one (1) chemical building
consisting of three (3) peristaltic hose Metal Salt metering pumps, two (2) duty and one (1)
standby, each rated for 0.6 GPM @ 60 PSI with VFDs, three (3) peristaltic hose Metal Salt
metering pumps, two (2) duty and one (1) standby, each rated for 1.2 GPM @ 100 PSI with
VFDs, three (3) peristaltic hose Supplemental Carbon metering pumps, two (2) duty and
one (1) standby, each rated for 0.33 GPM @ 70 PSI with VFDs, three (3) peristaltic hose
Supplemental Carbon metering pumps, two (2) duty and one (1) standby, each rated for
0.33 GPM @ 100 PSI with VFDs, one (1) 15,450-gallon fiberglass reinforced plastic Metal
Salt Storage Tanks with secondary containment, and one (1) 13,500-gallon stainless steel
Supplemental Carbon Storage Tanks with secondary containment; construction of one (1)
chemical building consisting of two (2) peristaltic tube Sodium Hypochlorite metering
pumps, one (1) duty and one (1) standby, each rated for 0.16 GPM @ 25 PSI with VFDs,
and one (1) 7,000-gallon fiberglass reinforced plastic Sodium Hypochlorite Storage Tank
with secondary containment; construction of one (1) tertiary filtration building consisting
of four (4) 684 square-foot deep bed filters; construction of one (1) aeration blower
building consisting of two (2) 250 HP turbo blowers each rated for 4,100 cfm and two (2)
400 HP turbo blowers each rated for 5,900 cfm; construction of one (1) UV disinfection
facility consisting of three (3) parallel low-pressure UV channels each consisting of four
(4) banks, three (3) duty and one (1) standby, with each bank containing twenty-four (24)
DocuSign Envelope ID: C9811761-13D7-460F-82A2-9B0AB2597AC4

Mr. Derek Dixon, Engineering Project Manager
December 28, 2023
Page 2 of 3

lamps and rated for 10 MGD at peak hourly flow, two (2) backwash water supply vertical
turbine pumps each rated for 4,104 GPM @ 47 TDH, and five (5) non-potable water
vertical turbine pumps each rated for 595 GPM @ 350 TDH; construction of one (1) final
clarifier scum pump station consisting of two (2) submersible centrifugal chopper pumps
each rated for 150 GPM @ 73 TDH; construction of one (1) cascade post-aeration structure
and all necessary piping and controls; in conformity with the project plans, specifications,
and other supporting documentation comprising the ATC Permit Application package
submitted to the Department of Environmental Quality.

[NOTE: This 15 MGD Stowe Regional WRRF project consists of three contracts including
headworks, liquid train (excluding headworks), and biosolids holding and transfer facilities.
Each contract contains one or more stages. The Authorization to Construct permits are being
issued, once for each stage. All the final Engineer’s Certification shall be submitted to the
Division before the Stowe Regional WRRF may be operated.]

This ATC is issued in accordance with Part III, Paragraph A of NPDES Permit No.
NC0089630 issued effective December 1, 2019, and shall be subject to revocation unless the
wastewater treatment facilities are constructed in accordance with the conditions and limitations
specified in Permit No. NC0089630.

It is the Owner’s responsibility to ensure that the as-constructed project meets the
requirements of all applicable regulations and statutes, the ATC Permit Application package, and
all of the requirements contained herein. Failure to comply may result in penalties in accordance
with North Carolina General Statute §143-215.6A through §143-215.6C.

The sludge generated from these treatment facilities must be disposed of in accordance
with G.S. 143-215.1 and in a manner approved by the Division.

In the event that the facilities fail to perform satisfactorily, including the creation of
nuisance conditions, the Permittee shall take immediate corrective action, including those as may
be required by the Division, such as the construction of additional or replacement wastewater
treatment or disposal facilities.

The Mooresville Regional Office, telephone number 704-663-1699, shall be notified at
least forty-eight (48) hours in advance of operation of the installed facilities so that an on-site
inspection can be made. Such notification to the regional supervisor shall be made during the
normal office hours from 8:00 a.m. until 5:00 p.m. on Monday through Friday, excluding State
Holidays.

Upon completion of construction and prior to operation of this permitted facility, a
certification must be received from a Professional Engineer certifying that the permitted facility
has been installed in accordance with the NPDES Permit and the ATC Permit Application package.
Mail the Certification to: Division of Water Resources, WQ Permitting – NPDES, 1617 Mail
Service Center, Raleigh, NC 27699-1617.

Upon classification of the facility by the Certification Commission, the Permittee shall
employ a certified wastewater treatment plant operator to be in responsible charge (ORC) of the
wastewater treatment facilities. The operator must hold a certificate of the type and grade at least
equivalent to or greater than the classification assigned to the wastewater treatment facilities by
the Certification Commission.

DocuSign Envelope ID: C9811761-13D7-460F-82A2-9B0AB2597AC4

Mr. Derek Dixon, Engineering Project Manager
December 28, 2023
Page 3 of 3

The Permittee must also employ a certified back-up operator of the appropriate type and
grade to comply with the conditions of T15A:8G.0201. The ORC of the facility must visit each
Class I facility at least weekly and each Class II, III and IV facility at least daily, excluding
weekends and holidays, must properly manage the facility, must document daily operation and
maintenance of the facility, and must comply with all other conditions of T15A:8G.0204.

A copy of the project plans and specifications shall be maintained on file by the
Permittee for the life of the facility.

During the construction of the proposed additions/modifications, the Permittee shall
continue to properly maintain and operate the existing wastewater treatment facilities at all times,
and in such a manner, as necessary to comply with the effluent limits specified in the NPDES
Permit.
You are reminded that it is mandatory for the project to be constructed in accordance with
the North Carolina Sedimentation Pollution Control Act, and when applicable, the North Carolina
Dam Safety Act. In addition, the specifications must clearly state what the contractor’s
responsibilities shall be in compliance with these Acts.

Prior to entering into any contract(s) for construction, the recipient must have obtained all
applicable permits from the State.

The issuance of this ATC does not preclude the Permittee from complying with any and
all statutes, rules, regulations, or ordinances which may be imposed by other government agencies
(local, state, and federal) which have jurisdiction.

If you have any questions or need additional information, please contact Nick Coco, PE at
telephone number [phone] or by email at [e-mail].

Sincerely,

Douglas Dowden
Supervisor, NPDES Industrial Permitting Unit

Attachments: Engineer’s Certification

cc: NPDES Files
ecopy: Michael Benchich, PE
Hazen and Sawyer
Email: [e-mail]
DWR Mooresville Regional Office, Water Quality Programs

Without Engineer’s Certificate attached:
cc: Mecklenburg County Health
DocuSign Envelope ID: C9811761-13D7-460F-82A2-9B0AB2597AC4

Charlotte Water
Stowe Regional WRRF
Authorization to Construct No. 089630A05
Issued December 28, 2023
NPDES Permit No. NC0089630

Engineer's Certification

I, , as a duly registered Professional Engineer in
the State of North Carolina, having been authorized to observe (periodically/weekly/full time)
the construction of the modifications and improvements to the Stowe Regional Water Resources
Reclamation Facility, located in Mecklenburg County, hereby state that, to the best of my
abilities, due care and diligence was used in the observation of the following construction:

Construction of one (1) chemical building consisting of three (3) peristaltic hose
Alkalinity metering pumps, two (2) duty and one (1) standby, each rated for 2.2
GPM @ 55 PSI with VFDs, two (2) 10 HP vertical mixers, and two (2) 18,700 -
gallon carbon steel Alkalinity Storage Tanks with secondary containment;
construction of one (1) chemical building consisting of three (3) peristaltic hose
Metal Salt metering pumps, two (2) duty and one (1) standby, each rated for 0.6
GPM @ 60 PSI with VFDs, three (3) peristaltic hose Metal Salt metering pumps,
two (2) duty and one (1) standby, each rated for 1.2 GPM @ 100 PSI with VFDs,
three (3) peristaltic hose Supplemental Carbon metering pumps, two (2) duty and
one (1) standby, each rated for 0.33 GPM @ 70 PSI with VFDs, three (3)
peristaltic hose Supplemental Carbon metering pumps, two (2) duty and one (1)
standby, each rated for 0.33 GPM @ 100 PSI with VFDs, one (1) 15,450-gallon
fiberglass reinforced plastic Metal Salt Storage Tanks with secondary
containment, and one (1) 13,500-gallon stainless steel Supplemental Carbon
Storage Tanks with secondary containment; construction of one (1) chemical
building consisting of two (2) peristaltic tube Sodium Hypochlorite metering
pumps, one (1) duty and one (1) standby, each rated for 0.16 GPM @ 25 PSI with
VFDs, and one (1) 7,000-gallon fiberglass reinforced plastic Sodium
Hypochlorite Storage Tank with secondary containment; construction of one (1)
tertiary filtration building consisting of four (4) 684 square-foot deep bed filters;
construction of one (1) aeration blower building consisting of two (2) 250 HP
turbo blowers each rated for 4,100 cfm and two (2) 400 HP turbo blowers each
rated for 5,900 cfm; construction of one (1) UV disinfection facility consisting of
three (3) parallel low-pressure UV channels each consisting of four (4) banks,
three (3) duty and one (1) standby, with each bank containing twenty-four (24)
lamps and rated for 10 MGD at peak hourly flow, two (2) backwash water supply
vertical turbine pumps each rated for 4,104 GPM @ 47 TDH, and five (5) non-
potable water vertical turbine pumps each rated for 595 GPM @ 350 TDH;
construction of one (1) final clarifier scum pump station consisting of two (2)
submersible centrifugal chopper pumps each rated for 150 GPM @ 73 TDH;
construction of one (1) cascade post-aeration structure and all necessary piping
and controls; in conformity with the project plans, specifications, and other
supporting documentation comprising the ATC Permit Application package
submitted to the Department of Environmental Quality.
DocuSign Envelope ID: C9811761-13D7-460F-82A2-9B0AB2597AC4

I certify that the construction of the above referenced project was observed to be built within
substantial compliance, intent and in conformity with all applicable regulations and statutes and
the project plans, specifications, and other supporting documentation comprising the
Authorization to Construct Permit Application package.

[NOTE: This 15 MGD Stowe Regional WRRF project consists of three contracts including
headworks, liquid train (excluding headworks), and biosolids holding and transfer
facilities. Each contract contains one or more stages. The Authorization to Construct
permits are being issued, once for each stage. All the final Engineer’s Certification shall be
submitted to the Division before the Stowe Regional WRRF may be operated.]

Signature Registration No.____________________

Date__________________

Mail this Certification to: Attn: Ori Tuvia
NPDES Industrial Permitting Unit
DEQ/DWR/Water Quality Programs
1617 Mail Service Center
Raleigh, NC 27699-1617

DocuSign Envelope ID: C9811761-13D7-460F-82A2-9B0AB2597AC4