SWA000058_Stormwater Submittal Cover Letter_10/23/2019

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Civil & Environmental Consultants, Inc.
October 22, 2019
North Carolina Department of Environmental Quality
Division of Energy, Mineral and Land Resources
512 North Salisbury Street
Raleigh, NC 279699-1612
Mr. Farkas:
Subject: Stormwater Permit 9SWA000058
Project Cure
CEC Project 185-984
In response to your letter of disapproval dated October 18, 2019 for the subject project, the following
are responses to your comments in italic:
1. Comment: Please fill out Section D4 of the application since the applicant is not the
property owner.
Response: Attached is updated Section D4 of the application.
2. Comment: The forebay is larger than 20% of the main pool. Based on the provided stage
storage tables, it appears that the surface area of the forebay at elevation 883.40 is 7,719 sf
which yields a volume of about 20, 000 cf.
Response: The grading of the eastern side of the forebay area has been revised to reduce the
surface area to 5,904 sf at an elevation of 883.50. This will provide a total volume of 18,325
cf for the forebay area which is 19% of the total volume of the main bay. Attached you find
the revised wet pond calculation worksheet and Sheet C-407.
3. Comment: There is a small section of B UA at the intersection of Lutetium Circle and
proposed Trivium Parkway that does not drain to the SCM.
Response: A berm and diversion ditch will be constructed on the eastern edge of Trivium
Parkway leading to the SCM.
4. Comment: The side slopes on the embankments of the SCMare too steep. Please provide
calculations showing that the soil and vegetation will remain stable.
Response: Per Figure 3 of Section C-3 of the stormwater manual, the recommended side
slope is 3: 1. Due to the site constraints we have developed the design utilizing 2 1/2:1 side
slopes. These slopes will be highly compacted, tested and matted with erosion control
matting for protection during the growth of the vegetation. Attached you will find a
calculation supporting the stability of the 2 '/z:1 side slopes.
5. Comment: Provide pdf of all revisions, two hardcopies of revised plans and one hardcopy of
other documents.
Response: Two hardcopies of the revised plans (Sheets C-400, Sheet C-407), one hardcopy
of the updated calculations and Section D4 of the application are attached.
3701 Arco Corporate Drive, Suite 400' Charlotte. NC 28273 1 p: 980-237-0373 f: 980-237-0372' www.cecinc.com

Jim Farkas - NCDEQ
CEC Project 185-984
Page 2
October 22, 2019
Should you have any questions or require any additional information in support of this application,
please do not hesitate to contact me at 980-237-0373.
Sincerely,
CIVIL & ENVIRONMENTAL CONSULTANTS, INC.
Matthew Johnson Shad W. Walters, PE
Project Consultant Principal
Civil & Environmental Consultants, Inc.