WQ0007569_Amended Additional Information Letter_20200717

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
NORTH CAROLINA
Environmental Quality
July 17, 2020
J. BRYCE MENDENHALL — VICE PRESIDENT OF OPERATIONS
CAROLINA WATER SERVICE, INC. OF NORTH CAROLINA
4944 PARKWAY PLAZA BOULEVARD, SUITE 325
CHARLOTTE, NORTH CAROLINA
Subject: Application No. WQ0007569
Additional Information Request
Amendment
Brandywine Bay WWTF
High Rate Infiltration System
Carteret County
Dear Mr. Mendenhall:
Division of Water Resources' Central and Regional staff has reviewed the proposal to change the
discharge point for the groundwater lowering system to the ditch that flows northward from the wastewater
treatment plant received May 15, 2020 by Linwood Stroud. However, additional information is required
before the review may be completed. This letter is an amendment to the additional information request letter
dated April 6, 2020 for this application signed by Ashley Kabat. Please address the items on the attached
pages, as well as the items from the April 6 request, no later than the close of business on August 17, 2020.
Please be aware that you are responsible for meeting all requirements set forth in North Carolina
rules and regulations. Any oversights that occurred in the review of the subject application package are
still the Applicant's responsibility. In addition, any omissions made in responding to the outstanding items
in Sections A through D of this request and the items of the additional information letter issued April 6,
2020, or failure to provide the additional information on or before the above requested date may result in
your application being returned as incomplete.
Please reference the subject application number when providing the requested information. All
revised and/or additional documentation shall be signed, sealed and dated (where needed), with two paper
copies and one electronic copy submitted to my attention at the address below.
If you have any questions regarding this request, please do not hesitate to contact me at (919) 707-
3659 or [e-mail]. Thank you for your cooperation.
Sincerely,
�2� �azw
Erick Saunders, Engineer
Division of Water Resources
cc: Wilmington Regional Office, Water Quality Regional Operations Section (Electronic Copy)
Linwood E. Stroud, PE — Stroud Engineering, PA (Electronic Copy)
Permit Application File WQ0007569
D E Q�� North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1617 Mail Service Center I Raleigh, North Carolina 27699-1617
NoarH c oaouNa �
oePxnmem i enmmomenwi auaiN /� 919.707.9000

Mr. J. Bryce Mendenhall
July 17, 2020
Page 2 of 3
A. Easement:
The proposal received May 15, 2020 to discharge the groundwater lowering water into the ditch on
the north side of the site provides an easement dated December 2, 1976 to the utility company to
install, alter, repair maintain and operate storm drains. However, the extent of this easement is
unknown, as the referenced "Exhibit 1" was also not attached. Lot 57, the adjacent property from
the discharge point, and other properties in the subdivision to the north are listed as part of the
Hammock Place subdivision. Please provide verification that the easement covers the Hammock
Place Subdivision.
B. Water Ouality:
1. The proposal does not discuss the chemistry of the water that will be discharged into the ditch, or
the potential impacts of the water chemistry on receiving water bodies. This proposal shall include
estimated effluent concentrations for parameters that describe the quality of the groundwater
discharge water, and provide a discussion of the effects of these parameters on receiving water
bodies. The discussed parameters shall include at a minimum:
a. Nutrients, including a discussion or model on how nutrients will affect downstream
surface water quality of Hull Swamp.
b. Iron, which is common to shallow groundwater, which may cause an issue with iron
bacteria blooms in receiving waters and impact the performance and aesthetic of
receiving stormwater systems;
c. pH;
d. BOD; and
e. Turbidity
C. Application:
1. The proposal provides calculations that the first 24" culvert and a point upstream of this culvert
would not flood at the proposed flows during a 10-year storm event. Please provide an explanation
as to why a 10-year storm event was chosen for the calculations.
2. The figure sent May 22, 2020 named "DITCH TO 70" contains a culvert labeled "`24" INV.
11.25", which then appears to daylight and flow northeast over Sleepy Court into a swale that
flows from the back of the cul-de-sac into the main drainage ditch leading out of the subdivision.
However, from review of stormwater permits in the area, it is instead suspected that this culvert
actually runs northwest underneath Sleepy Court and into the main drainage ditch via the culvert
labeled as `24" RCP INV. 10.70". This flow path is shown as the yellow highlighted path in the
attached map. Please verify the flow path of the groundwater lowering discharge and make any
necessary changes to the application based on any changes in this flow path.
The proposal includes discharging water into an existing ditch which ties into existing stormwater
swale for the Hammock Place subdivision. This stormwater system was not designed with the
additional flow coming from this groundwater lowering system in mind, both in terms of quality
and quantity of water. Please provide documentation from the North Carolina Division of Energy,
Mineral and Land Resources (NCDEMLR) Stormwater Program that verifies that the proposed
additional flow won't adversely impact the downstream stormwater systems serving the entire flow
path between this ditch and Hull Swamp.

Mr. J. Bryce Mendenhall
July 17, 2020
Page 3 of 3
4. The additional flow coming from this groundwater lowering system also crosses Highway 70.
Please provide documentation from the North Carolina Department of Transportation (NCDOT)
stating that the additional water is not a concern for the culvert or the road.
D. Recommendations: (Response not required)
1. The language of the easement is vague and does not cover the surface discharge of mechanically
lowered groundwater into the stormwater system and the applicability of this easement is
questionable for the proposed activity. A stronger easement would be recommended

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