SW3201202_Responce to Comments_20210302

CDM
S ith
4600 Park Rd, Suite 240
Charlotte, North Carolina 27209
tel: [phone]
March 1, 2021
Mr. Jim Farkas
Environmental Engineer
North Carolina Department of Environmental Quality
Division of Energy, Mineral & Land Resources Stormwater Program
512 N. Salisbury Street
Raleigh, NC 27699-1612
Subject: Union County Public Works - Yadkin Regional Water Treatment Plant
Post -Construction Stormwater Permit Application
State Project Number SW3201202
Dear Mr. Farkas
We received your letter dated January 28, 2021 with comments related to the subject permit
submittal for Union County Public Works (UCPW) and the new Yadkin Regional Water Treatment
Plant (WTP). Please find below a summary of your comments and our responses:
1. Please include the name of the county in which the project is located (Section I, 2 of the
Application).
Response: The County name has been added to the Application.
2. There appears to bean error in the summation of the impervious areas listed in the table in
Section IV, 10 of the Application. If the numbers shown are added up the total amount of
impervious area is 313,820 sf (313,819 sf is shown). This is probably just a rounding error, but it
should be corrected.
Response: The table in Section IV, 10 of the application has been corrected to address the
rounding error. The total has changed per Comment 3 (do not include off -site impervious
area for a low -density project). We also updated the Existing BUA in the table to account for
the portion of New Salem Road that is included in the project area (the property lines extend
to the centerline of the road).
3. Since this project is low -density, the off -site impervious area determination (Section IV, 11) is
not needed.
Response: Acknowledged, we have updated the off -site area row in the table in Section IV,10
and in Section IV,11.

CDM . . . . .
S ith
Mr. Jim Farkas
March 1, 2021
Page 2
4. Please complete and provide a Supplement-EZ Form and 0&MAgreementForm for the project
as these items are required for all projects. These forms can be found at the following link:
htt s:,I de .nc. ov,0about divisions/eneray-mineral-land-resourcesfenergv-mineral-land-
permit-quidancefstormwater-bmp-manual (Section V & Section VI, 3).
NOTE: The proposed pond is not needed to meet State post -construction
stormwater requirements and does not need to be included in these forms.
Response: The requested Supplement-EZ Form and 0&M Agreement are completed and
attached.
5. Please dimension the property boundary with bearings and distances (Section VI, 8i).
Response: Property boundaries have been labeled with bearings and distances on Sheet C-2.
6. Please show the drainage areas to the proposed vegetated conveyances in the main set of plans
(Section VI, 80).
Response: Sheet C-27 has been added to the drawing set to depict the drainage areas and
summarizes the areas to the vegetated conveyances.
7. There does not appear to be any way for captured runoff to leave the proposed pond (aside from
overtopping the service road). Please include any riser structure, outlet pipe, emergency
spillway, etc ...for this pond on the plans.
Response: Sheet C-9 has been revised to depict the pond outlet structure and detail reference.
8. Please include a swale detail in the main set of plans showing, at a minimum, the side slopes,
bottom width, and type ofgrass to be used.
Response: A detail for the swales has been added as Detail F/CD-1.
9. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, and 1 hardcopy of other
documents.
Response: Cover letter, revised PDF of drawings, revised calculations, supplemental EZ form
and 0&M form and revised application file have been uploaded to the website.
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WTP - Stormwater Comments Response Cover Letter

CDM . . . . .
S ith
Mr. Jim Farkas
March 1, 2021
Page 3
If you have any questions or require anything further, please do not hesitate to contact me at (704)
342-4546 or at [e-mail].
Sincerely,
J nathan S. Lapsley, E., MP
Vice President
CDM Smith Inc.
cc (email): John Shutak, UCPW Tracy Randazzo, HDR
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WTP - Stormwater Comments Response Cover Letter