WQ0045586_Correspondence_20240719 (8)

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J. Phillip Norris, P.E. N O R R I S& BLAND
[e-mail]
910-287-5900 -CONSULTING ENGINEERS, P.C. -
1429 Ash -Little River Road NW, Ash, NC 28420
www.nbengr.com
June 28, 2024
H. Dale Crisp, PE
Environmental Engineer II
NC DEQ / DWR
Water Quality Section — PERCS UNIT
512 N. Salisbury St.,
Archdale Bldg. 9th Floor Suite 925
Raleigh, NC 28604
Joseph K. Bland, P.E.
[e-mail]
910-287-5900
Re: Alternative Sewer Extension Application Review Response
The Tides at Ocean Isle Beach - LPSS extension permit application WQ0045586
N&B Project No. NT21159-1
Dear Mr. Crisp,
We are responding to the emailed review comments dated July 12, 2024, as follows:
1.The ASEA indicates a proposed sewer flow rate on page 2 of 5, line #8 of 10,500 GPD based
on 50 lots at 210 GPD per residence for 3 bedroom homes as indicated. This equates to a
proposed flowrate of 70 GPD per bedroom per home. Line #7 of the same page indicates a
reduced sewer flowrate has been approved by the Division for this permittee facility, but no copy
of the approval letter from the Division appears to be included. Please provide a copy of the
approval letter, as required, or a revised application. The requested Flow Reduction Letter was
provided via email on 07-12-24 by the Director of Brunswick County Engineering, William Pinnix.
2.The ASEA indicates 360 gallons of emergency storage is provided on page 3 of 5, line #4 in
each simplex pump station wetwell, but no calculations are included in the supporting documents
confirming this amount of storage. Please provide. A copy of the approved Brunswick County
Barnes Grinder Pump Station submittal has been provided for your use. On page 3 under Tank,
the second sentence confirms a reserve storage of 360 Gallons. Additionally, the reserve
storage elevation and 360 gallons is identified on the pump station cut sheet.
3.The project narrative and the overall engineering site plans included in the project submittal
reference a downstream sewer pump station, but the FTSE does not include an evaluation of
the pump station and if there is sufficient capacity to serve the 50 lots served by the LPSS.
Please provide a revised FTSE that includes the evaluation of this pump station. The pump
station gravity system that the low pressure system discharges to is currently being permitted as
NCBELS License C-5102

H. Dale Crisp, PE
July 18, 2024
The Tides at Ocean Isle Beach - LPSS extension permit application WQ0045586
N&B Project No. NT21159-1
Page 2
part of the subdivision design. The pump stations calculations account for all flows in the system
both low pressure and gravity.
4.The project engineering plan and profile sheets submitted include some proposed 8-inch
gravity sewer, as well as the proposed LPSS wastewater collection system. How is the gravity
sewer portion of this project being permitted? The gravity portion of this system as well as pump
stations are currently being permitted through the FTA program via the NCDEQ Wilmington
Regional Office.
5.Sheets C4.27 and C4.3 of the engineering plan and profile sheet appear to indicate fire hydrant
assemblies and the pressure sewer blow -off assemblies that are located adjacent to each other
in the two (2) cul-de-sacs of Street "M". Please verify and label that a minimum horizontal
separation of 10 feet will be provided between these utilities. The label has been added as
requested. Copies of the revised plan sheets have been provided for your use.
6.The engineering plans on sheet C6.8 in the simplex pump station detail have a reference to
anti -flotation requirements of Brunswick County, but no specifics provisions and no calculations
are provided, as required in ASEA instructions. Please provide anti -flotation calculations for the
proposed simplex pump stations. The approved Brunswick County Barnes grinder pump station
submittal. Page 6 provides Basin Ballast Requirements. See circled Basin Ballast
Requirements. Additionally, see Buoyancy Calcs.
Sincerely,
NORRIS & BLAND
CONSULTING ENGINEERS, P.C.
J Je�h. Bland, P.E.
J KB/ttw
cc: Brian Ketchem
NCBELS License C-5102