WQ0029945_Additional Information Request #1_20231121

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS,]R.
Director
NORTH CAROLINA
Environmental Quality
November 21, 2023
DAVID M. MOHR, PE — CHIEF OPERATIONS OFFICER
ONSLOW WATER AND SEWER AUTHORITY
228 GEORGETOWN ROAD
JACKSONVILLE, NORTH CAROLINA 28540
Subject: Application No. WQ0029945
Additional Information Request #1
Summerhouse Wastewater
Reclamation WWTP
High -Rate Infiltration System
Onslow County
Dear Mr. Mohr:
Division of Water Resources' Central and Regional staff has reviewed the application package
received on September 7, 2023. However, the Division requires additional information before completing
our review. Please address the items on the attached pages no later than the close of business on December
21, 2023.
Please be aware that the Applicant is responsible for meeting all requirements set forth in North
Carolina rules and regulations. The Applicant is also responsible for any oversights that occur during the
review of the subject application package. The Division may return the application as incomplete pursuant
to 15A NCAC 02T .0107(e)(2) if any omissions are made when responding to the outstanding items in
Sections A through L or the Applicant fails to provide the additional information on or before the above -
requested date.
Please reference the subject application number when providing the requested information. The
Applicant shall sign, seal, and date (where applicable) all revised and/or additional documentation and
submit an electronic response to my attention via the Non -Discharge online portal.
If you have any questions regarding this request, please contact me at [phone] or
[e-mail]. Thank you for your cooperation.
Sincerely,
DocuSigned by:
A4-163-
45A56104B4524E7...
Zachary J. Mega, Engineer III
Division of Water Resources
cc: Wilmington Regional Office, Water Quality Regional Operations Section (Electronic Copy)
Daniel K. Peplinski, PE — McKim & Creed, Inc. (Electronic Copy)
Laserfiche File (Electronic Copy)
E Q - North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 11617 Mail Service Center I Raleigh, North Carolina 27699-1617
oew.M oe F,nmmwni ova` /"� 919.707.9000

Mr. David M. Mohr, PE
November 21, 2023
Page 2 of 5
A. Cover Letter:
1. Please clarify which existing WWTP treatment/storage units will be permanently abandoned and
which will be retained or retrofitted (Phase I and II). Form: HRIS 06-16 and the Engineering Plans
do not provide sufficient detail to make this clear.
B. Application Fee:
1. No comment.
C. Application (Form: HRIS 06-16):
1. Item V.1 — Please provide the estimated influent concentrations for all parameters.
2. Item V.11.b — Please include the information for the four (4) proposed membrane bioreactor (MBR)
units.
3. Item V.1 Lc — Please complete the information below the table for ultraviolet (LTV) disinfection.
4. Item V.1 Le —
a. The listed capacity for the feed -forward pumps of 480 gallons per minute (GPM) and 20 feet
of total dynamic head (TDH) does not match the intersect of the system and pump curves shown
in Section 43 23 13 (Horizontal Solids Handling Pumps) of the Specifications. The worst -case
scenario specified in the Engineering Calculations is 868.1 GPM and 41.98 feet of TDH. Why
was this not used to determine the operating point? Please verify and revise.
b. Six (6) permeate pumps are depicted in the Engineering Plans. Please verify and revise.
5. Item V.1 Lf— Why are two (2) different sets of six (6) blowers listed? Will these blowers be serving
two (2) different processes? The Engineering Plans depict only one (1) set of six (6) blowers on
the repurposed odor control system concrete pad serving the proposed MBR units. Please clarify
and revise the Engineering Plans, if necessary.
6. Item VII.4 — "Yes" was selected for this item, however, no Total Nitrogen (TN) and Total
Phosphorus (TP) concentrations were provided to comply with 15A NCAC 02T .0706(b) or 02T
.0706(c). Please either provide these concentrations or clarify that "Yes" was selected by mistake.
D. Property Ownership Documentation:
1. Per Instruction D of Form: HRIS 06-16 and 15A NCAC 02T .0704(f), please submit property
ownership documentation.

Mr. David M. Mohr, PE
November 21, 2023
Page 3 of 5
E. Engineering Plans:
1. Overall —
a. Please include the electrical design for the proposed MBR units (Phase I and II) and how they
will integrate into the existing WWTP.
b. Please depict and label the feed -forward pumps serving the proposed MBR units on all relevant
sheets in addition to Sheet C00.3.
c. Please label the pipe size and material of all process piping shown for the plan and section
views (not isometric) of the proposed MBR units.
2. Sheet X40.0 — This sheet is unclear as to what is part of the existing headworks. Some call -outs
refer to proposed construction that is not specified in the application package like odor control
modifications for the headcell and coring the equalization (EQ) basin wall to install a new 18"
ductile iron (DI) effluent pipe. There are also references made to sheets not included in the
Engineering Plans. Please revise for clarity and ensure that call -outs only refer to existing facilities
or required demolition.
3. Sheet M05.0 — The flow arrows on the Phase 1 blower piping appear to be reversed. Please verify
and revise.
4. Sheet M 10.0 —Please provide more detail for the piping configuration of the proposed MBR units
and how they will integrate into the existing WWTP (i.e., pipe size, pipe material, valves,
appurtenances, process interconnections, etc.) This sheet provides no insight into how this will be
achieved.
5. Sheet M20.0 — The UV unit section view references a V-notch weir plate detail on the left-hand
side but the call -out is incomplete. Please either remove the reference or provide a detail.
6. Sheet M40.0 — See Comment E.2. Please revise for clarity and ensure that call -outs only refer to
existing facilities or the proposed modifications.
F. Specifications:
1. Overall —
a. Per Instruction J of Form: HRIS 06-16 and 15A NCAC 02T .0704(c)(2), please submit
Specifications that have been signed, sealed, and dated by a North Carolina licensed
Professional Engineer (PE).
b. Please include "Division 1 — General Requirements" when the Specifications are resubmitted.
c. Please submit specifications for the proposed MBR units and mechanically cleaned fine screens
and include all relevant information from the manufacturer.
2. Table of Contents — The footer of Page TOC-I references a facility not part of the subject permit.
Please revise.

Mr. David M. Mohr, PE
November 21, 2023
Page 4 of 5
3. Section 43 23 13 (Horizontal Solids Handling Pumps) —
a. Please include general specifications (i.e., scope of work, QA/QC, submittals, warranty, etc.)
and execution specifications (i.e., installation, field testing, performance testing, operator
training, etc.) in addition to the manufacturer's product information for all pumps. This section
does not follow the same format (Part 1, Part 2, Part 3, etc.) and does not provide the same
information as the other Specifications sections. Alternatively, manufacturer documentation
can be provided similar to what was included in Section 43 25 10 (Regenerative Air Blowers),
which addresses the items above.
b. The section cover page only includes the feed -forward and permeate pumps. Please revise to
include the return activated sludge (RAS) and EQ pumps specified in the proposed design and
ensure all relevant information is included.
c. Feed Forward Pumps — On Page 43 23 13-3, the rated power for the motor is specified as 5.6
kilowatts (kW), which is less than what was shown next to the calculated system curve in the
Engineering Calculations. Please verify and revise.
d. Permeate Pumps — On Page 43 23 13-8, a required flow of 192.9 GPM is specified but 173.6
GPM is specified in the Engineering Calculations. Roughly 27 feet of TDH is also specified
in the Engineering Calculations, however, the plotted operating point on this page does not
match. Please verify and revise.
4. Section 46 21 31 (Side Stream Disc Filter) — Is this section supposed to be the manufacturer's
product information included at the end of the application package? If so, please label it as part of
the Specifications and ensure that all required design, construction, and material specifications are
included. See Comment F.3.a.
G. Engineering Calculations:
1. Overall — Per Instruction K of Form: HRIS 06-16 and 15A NCAC 02T .0704(c)(3). please submit
(for Phase I and II where applicable) (1) blower and MBR sizing calculations, (2) hydraulic and
pollutant loading calculations for each treatment unit (existing and proposed) demonstrating how
the designed effluent concentrations in Item V.1 of Form: HRIS 06-16 were determined, and (3)
flotation calculations for the UV unit since it will be constructed partially or entirely below grade.
2. Permeate Pumps Calculations —
a. Two (2) permeate pumps are shown per phase in the Engineering Plans, three (3) are specified
per phase in Item V.11.e of Form: HRIS 06-16, and up to four (4) are specified in the
Engineering Calculations. Please revise for clarity.
b. How is there a significant difference in piping configurations when determining head loss for
each pumping scenario? All permeate pumps for each phase will be installed on the same
equipment skid. Please clarify and revise, if necessary.
c. How was the operating point of 180 GPM and 27.01 feet of TDH along the system curve
determined? This does not match any of the prior calculations. Please clarify and revise, if
necessary.
RAS Pumps Calculations — The system curve graphs cover up text for both calculations. Please
revise.

Mr. David M. Mohr, PE
November 21, 2023
Page 5 of 5
H. Site Map:
Per Instruction L of Form: HRIS 06-16 and 15A NCAC 02T .0704(d). if Sheets C00.2 and C00.3
of the Engineering Plans will serve as the Site Maps for the modified WWTP (Phase I and 11) please
include (1) topographic contour intervals not exceeding 10 feet or 25 percent of total site relief and
(2) all habitable residences or places of public assembly within 500 feet of all treatment and storage
units.
I. Power Reliabilitv Plan:
1. Per Instructions K and M of Form: HRIS 06-16 and 15A NCAC 02T .0705(k). please demonstrate
in the Engineering Calculations that the specified auxiliary power source is capable of powering all
essential treatment units for the modified WWTP (Phase I and II).
J. Operation & Maintenance Plan:
1. Per Instruction N of Form: HRIS 06-16 and 15A NCAC 02T .0707, please submit an O&M Plan
that has been updated to reflect the modified WWTP (Phase I and II). A final O&M Plan shall be
submitted with the partial and/or final Engineering Certification required under 15A NCAC 02T
.0116, however, a preliminary O&M Plan shall be submitted with each application package.
K. Residuals Management Plan:
Per Instruction O of Form: HRIS 06-16, 15A NCAC 02T .0704(i). and 02T .0708. please submit a
Residuals Management Plan that demonstrates the existing aerobic digesters have sufficient storage
for the residuals generated from the modified WWTP (Phase I and II).
L. Additional Documentation:
➢ Existing Permit:
1. No comment.
➢ Threatened or Endangered Aquatic Species Documentation:
1. Per Instruction P of Form: HRIS 06-16 and 15A NCAC 02T .0105(c)(10), please submit
documentation from the North Carolina Natural Heritage Program demonstrating the presence
or absence of threatened or endangered aquatic species within the boundary of the wastewater
treatment and storage facilities.