SW6221001_Response To Comments_20230320

G
GRADIENT
LAND -WATER -INN❑VATION
March 20, 2023
Mr. Jim Farkas
Division of Energy Mineral and Land Resources
North Carolina Department of Environmental Quality
1612 Mail Service Center
512 North Salisbury Street, Office 640E
Raleigh, NC 27699-1612
Re: SW6221001 Macridge 8t Chicken Road Intersection Improvements
Dear Mr. Farkas:
Enclosed is information pertaining to our application for the state Stormwater Management Permit
Application for the above referenced project. In addition to this letter addressing comments,
included as a part of this submittal are the following:
Two folded full-size sets (22x34) of the revised sheets to the project plans, 95% Design for
Regulatory Review, dated 3/20/2023.
Additionally, outlined below, we are responding to your review comments sent to us via email on
March 16, 2023:
Please correct the following:
• Based on the provided revised soils report, there appears to be insufficient separation
between the SHWT and the bottom of SCM 1. The revised SHWT information shows a SHWT
elevation of 257.9' and a bottom elevation of the SCM is shown as 259.7' (259.7' - 257.9' =
1.8' < 2.0' (Per Bioretention MDC 1)). Please revise as needed. NOTE: Per the provided soils
report, the soil permeability is such that, per Bioretention MDC 4, an underdrain and
internal water storage are not required and per Bioretention MDC 5(b)(i), the depth of the
media layer can be reduced to 24" deep.
Response: The SCM design has been revised to raise the bottom elevation of the SCM to
260.2 to provide a minimum separation to the SHWT to be 2.3 feet to accommodate the
requirement of MDC 1. This was achieved by removal of the internal water storage based
upon the provided soils and reduce the soils media depth to 2.0 feet.
NOTE: The other outstanding issues have been addressed.
Response: Noted.
230 Donaldson Street, Suite 500A Fayetteville, NC 26301 1 910.624.7731
1513 Walnut Street, Suite 230 Cary, NC 27511 1 910.824.7731
www.gradientNC.com

All documents listed herein have also been uploaded to the State Stormwater portal at
https://edocs.deg.nc.gov/Forms/SW-Supplemental-Upload as requested (the electronic documents
prefixed with a date of "20230320-").
Should you require any additional information, please do not hesitate to contact us.
Sincerely,
GRADIENT, PLLC
C. Heath Wadsworth, PE