SW5180401_Comment Response_20180518

1401 Aversboro Road, Suite 210  Garner, NC 27529  Office: [phone]  www.rle-pc.com

May 17, 2018

NCDEQ-DEMLR
Stormwater Permitting
1612 Mail Service Center
Raleigh, North Carolina 27699

Re: Concrete Supply Company

Pursuant to the stormwater comments (Dated May 3, 2018) for the Concrete Supply Company,
please find enclosed two (2) copies of the revised plans. Below we have reviewed the
comments and addressed each item on the plans and in written response. To help facilitate your
review of these documents, the review comments are repeated below in BOLD and my
responses are presented in RED. The responses are also categorized by department and
reviewer.

COMMENTS ON SUBMITTAL RECIEVED ON: May 3, 2018

1. As currently designed, the project does not meet the requirement for runoff treatment or
runoff volume match.
Response: Plans have been revised to utilize a wet detention pond. All impervious will
drain to this pond.

2. Please provide pre and post development drainage area maps that delineate the area to
the SCM.
Response: Please see attached drainage area map.

3. Please delineate any wetlands on the map or note that none exist.
Response: There are no wetlands on-site and we have noted this on Sheet C4.

4. Please provide a completed Supplement EZ form.
Response: Please see attached form.

5. Please revise item 8 in the project information of the SWU-101 form and calculate the
percent impervious coverage using the total project area rather than the total property
area.
Response: Please see attached revised application.

6. Please provide a breakdown of BUA as required in item 10 in the projection information
section of the SWU-101 form. Note that this is the total proposed impervious area, not
the total new impervious area.
Response: The Form SWU-101 has been updated.

7. The Storm EZ calculations currently show the entire site draining to the SCM. Please
revise the Storm EZ to show only the actual contributing area to the basin.
Response: Please see attached revised Storm EZ.

1401 Aversboro Road, Suite 210  Garner, NC 27529  Office: [phone]  www.rle-pc.com

8. The Storm EZ calculations should only include the total project area, not the pond area.
Please revise the Storm EZ to only take into account the existing and proposed open
space and impervious surface.
Response: Please see the attached revised Storm EZ.

9. Revise the plans to show a maintenance access and easement that extend to the nearest
right-of way. The maintenance access must be at least 10’ wide and have side slopes no
steeper than 3:1. The easement must contain the entire access and SCM.
Response: An easement has been added to the plans.

10. Based on the proposed grading, a portion of the proposed impervious area on the
northwestern part of the site will not be conveyed to the SCM.
Response: Please see revised plans. We have added 24” curb and gutter to insure all
impervious will be conveyed to the SCM.

11. Please explain how the gravel stockpile area will be used.
Response: This area was mislabeled. It will be a gravel parking area in the permanent
condition. This area will be used for stockpiling soil during construction only.

Thank you for your review comments and assistance. If you have any questions, concerns or
require further information, please feel free to call me at [phone] or email me at
[e-mail]

Regards,

Carlos Bagley, P.E.
Red Line Engineering, P.C.