WQ0029945_More Information (Requested)_20200625

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
NORTH CAROLINA
Environmental Quality
June 25, 2020
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
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 April 13, 2020. However, additional information is required before the review may be completed.
Please address the items on the attached pages no later than the close of business on July 27, 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,
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), and submitted
electronically.
If you have any questions regarding this request, please do not hesitate to contact me at (919) 707-
3660 or [e-mail]. Thank you for your cooperation.
Sincerely,
%wv -t A,"
Tessa Monday, Environmental Engineer
Division of Water Resources
cc: Wilmington Regional Office, Water Quality Regional Operations Section (Electronic Copy)
Miles Galloway, PE — The Wooten Company (Electronic Copy)
Permit Application File
DEQ �� 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
NORTH CAftOLINA
DepanmamofEnWoomentalMari /� 919.707.9000

Mr. David M. Mohr, PE
June 25, 2020
Page 2 of 2
A. Hydrogeologic Report (15A NCAC 02T .0704(e)):
Comments from Poonam Giri (Central Office Hydrogeologist), Morella Sanchez -King (Wilmington Regional
Office Supervisor), and Bryan Lievre (Wilmington Regional Office Engineer).
Provide additional information on the design of the groundwater lowering system, including a map which
identifies the extent of the system.
2. The proposal indicates that three to four piezometers would be installed between the pond and one of the
existing drains. Information provided indicates that at least three piezometers were installed, however no
information was provided on the location of the existing drain. Please update the site sketch to show the
location of the existing drains.
3. Provide information on the installation of the constructed piezometers (materials, methods, drilling log,
etc.).
4. Please show the following (within 500 feet of the facility area):
a. All wells and piezometers, including usage and construction details;
b. Ephemeral, intermittent, and perennial streams;
c. Springs, lakes, ponds, and other surface drainage features; and
d. Review and compliance boundaries.
5. Provide a description of the site hydrogeology, including groundwater discharge features, drainage
features, existing and abandoned wells, and other features that may affect the movement of the
treated wastewater, including the groundwater lowering system.
6. Provide a discussion of the current groundwater flow regime of the site and the post modification
groundwater flow regime, focusing on the relationship of the system and basin to groundwater
receptors, groundwater discharge features, and groundwater flow media.
7. Provide modeling results of the mounding analysis to predict the level of the seasonal high water
table after increased wastewater application.
8. Identify the source of the rainfall data provided in the application.
9. Indicate what equipment was utilized to obtain water elevation data.
10. Indicate the depth of Basin #2 relative to mean sea level, or another datum at the site (if known).
11. Address if additional measurements were obtained after January 10, 2020 to observe the
Groundwater Pump Station Data to equalize.
12. Provide the MODFLOW modeling results of the increased loading rate during the pilot study.
13. As indicated in the approved pilot study proposal, provide a comparison of the pilot test results to
the original MODFLOW modeling results for the basin.