NC0020354_Authorization to Construct_20210602

June 2, 2021

Timothy R. Smith
Vice President
105 Weston Estates Way
Cary, North Carolina 27513

SUBJECT: Authorization to Construct
A to C No. 020354A04
Chatham Park Investors LLC
Chatham Park Water Recovery Center
NPDES Permit No. NC0020354

Dear Mr. Smith:

A letter of request for an Authorization to Construct was received November 20, 2020, by
the Division of Water Resources (Division). With additional information received on May 6, 2021
and May 17, 2021, final plans and specifications for the subject project have been reviewed and
found to be satisfactory. Authorization is hereby granted for the activation as a direct discharge
facility and the construction of Phase II modifications to the existing 0.499 MGD Chatham Park
Water Recovery Center, with discharge of treated wastewater into Robeson Creek in the Cape Fear
Basin.

This authorization results in no increase in design or permitted capacity and is awarded for
the construction of the following specific modifications:

Construction of a headworks consisting of two (2) escalator mechanical bar screens each
rated for 1.25 MGD at peak hourly flow, one (1) screw compactor, one (1) screw conveyor
and one (1) odor control dry chemical scrubber, an influent pump station consisting of three
(3) 434 GPM @ 40 ft TDH submersible pumps each with VFD, and a raw wastewater
transfer pump station consisting of two (2) 434 GPM @ 100 ft TDH submersible pumps
with VFDs; construction of two (2) 0.125 MGD 4-stage bioreactor trains each consisting
of one (1) 9,425-gallon anaerobic zone, one (1) 13,500-gallon pre-anoxic zone, one (1)
32,315-gallon aerobic zone with fine bubble diffused aeration, one (1) 8,000-gallon post-
anoxic zone, one (1) 347 GPM @ 0.3 ft TDH recirculation wall pump with VFD, and three
(3) 1.8 HP submersible mixers; construction of one (1) 0.25 MGD 4-stage bioreactor train
consisting of one (1) 21,000-gallon anaerobic zone, one (1) 29,000-gallon pre-anoxic zone,
one (1) 69,000-gallon aerobic zone, one (1) 19,000-gallon post-anoxic zone, one (1) 694
GPM @ 1.2 ft TDH recirculation wall pump with VFD, and three (3) 3.6 HP submersible
mixers; construction of three (3) 303 scfm rotary lobe blowers with VFDs designed to meet

Timothy R. Smith, Vice President
June 2, 2021
Page 2 of 4

air demand of the bioreactor trains; construction of three (3) 695 GPM @ 25 ft TDH
submersible RAS/WAS wetwell pumps with VFDs; construction of one (1) bioreactor odor
control dry chemical scrubber; construction of an intermediate screening system consisting
of one (1) escalator mechanical bar screen rated for 3.25 MGD at peak hourly flow, one
(1) manual bar screen rated for 3.25 MGD at peak hourly flow, one (1) screw
washer/compactor, and one (1) 60 GPM scum skimmer; construction of one (1) scum pump
station consisting of one (1) 60 GPM @ 29 ft TDH submersible scum pump; construction
of one (1) 2,850-gallon permeate holding tank; construction of two (2) 4,170-gallon
membrane bioreactor tanks with membrane modules, two (2) 880 GPM @ 40 ft TDH
reversible rotary lobe permeate pumps with VFDs, and two (2) 924 scfm rotary lobe
membrane blowers with VFDs; construction of a bulk chemical storage area consisting of
one (1) 4,600-gallon NaOH bulk storage tank, two (2) 4.4 GPH @ 45 psig NaOH feed
diaphragm pumps with VFDs, one (1) 2,250-gallon Carbon bulk storage tank, four (4) 3.75
GPH @ 75 psig Carbon feed diaphragm pumps with VFDs, one (1) 4,600-gallon Alum
bulk storage tank, four (4) 2.85 GPH @ 145 psig Alum feed diaphragm pumps with VFDs
for aerobic zone feeding, one (1) 1.4 GPH @ 145 psig Alum feed diaphragm pump with
VFD for WAS holding overflow, one (1) 2,000-gallon NaOCl bulk storage tank, two (2)
203 GPH @ 75 psig NaOCl feed diaphragm pumps, four (4) 50-gallon Citric Acid storage
drums, and one (1) 92 GPH @ 150 psig Citric Acid diaphragm feed pump for cleaning of
membranes; construction of one (1) 130,000-gallon WAS holding tank/aerobic digester,
two (2) 805 scfm helical lobe WAS holding tank blowers with VFDs, one (1) WAS holding
tank odor control dry chemical scrubber, one (1) 250 GPM @ 8 ft TDH reversible rotary
lobe sludge transfer pump with VFD and a truck loading pad; construction of three (3)
parallel ultraviolet light disinfection banks each rated for 0.625 MGD at peak hourly flow;
construction of an effluent pump station consisting of three (3) 434 GPM @ 89 ft TDH
submersible pumps each with VFD; construction of 10,992 feet of 12-inch diameter PVC
force main and 26 feet of 16-inch diameter DIP effluent force main for tie-in with treated
wastewater from the Pittsboro WWTP, and installation of 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.

This ATC is issued in accordance with Part III, Paragraph A of NPDES Permit No.
NC0020354 issued effective June 1, 2021, and shall be subject to revocation unless the wastewater
treatment facilities are constructed in accordance with the conditions and limitations specified in
Permit No. NC0020354.

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.

Timothy R. Smith, Vice President
June 2, 2021
Page 3 of 4

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 Raleigh Regional Office, telephone number 919-791-4200, 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.

The Permittee must also employ a certified back-up operator of the appropriate type and
grade to comply with the conditions of T15A:8G.0202. 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.0202.

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 complying with these Acts.

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

Timothy R. Smith, Vice President
June 2, 2021
Page 4 of 4

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 at
telephone number [phone].

Sincerely,

for S. Daniel Smith
Director, Division of Water Resources

by Min Xiao, PE
NPDES Industrial Permitting Unit

With Engineer’s Certificate attached:
cc: NPDES Files

ecopy: Joshua A Powell, P.E.
McKim & Creed
Email: [e-mail]
DWR Raleigh Regional Office, Water Quality Programs

Without Engineer’s Certificate attached:
cc: Chatham County Health