SW5230802_Response To Comments_20231222

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ENGINEERING & ENVIRONMENTAL SCIENCE COMPANY
3008 ANDERSON DRIVE,SUITE 102
RALEIGH,NC 27609
[phone]
LETTER OF TRANSM I[T'i[ AIL
Date: December 20, 2023
To: Mr. Jim Farkas
NCDEQ-DEMLR, Raleigh Regional Office
3800 Barrett Drive
Raleigh,NC 27609
From: Robert W. Brantly, P.E.
Engineering and Environmental Science Company (E2S)
3008 Anderson Dr., Suite 102
Raleigh,NC 27609
[e-mail]
Subject: Chatham Habitat for Humanity Townhouse Development
Stormwater Permit No. SW5230802
TBD Craft Lane
Siler City,NC 27344
Chatham County
The following are submitted for the above referenced project:
-Two (2) original copies of the revised Stormwater Management Application Form
indicating that the project will be permitted as 'High Density'
-Two (2) hard copies of the signed/notarized High Density Deed Restrictions and
Protective Convenances document.
-Two (2) sets of revised 24"x36"plans and specifications
-Revised O&M Agreement and Supplemental Forms
-Stormwater Evaluation and Calculations
The following are responses to the review comments received in a letter from NCDEQ-
DEMLR dated November 2, 2023.
1. As designed, the proposed project will not meet all of the requirements for a low-
density project upon completion.
It is understood that the project does not meet all of the requirements for Low
Density, because of the proposed Dry Detention Basin SCM. The project has <24%
BUA, but the proposed SCM is required based on the local municipality's (Siler
City) storm water ordinances, that requires peak flow and runoff volume treatment
for any site with >7% BUA. The application and forms have been revised to indicate
that the project will be permitted as a 'High Density' project.

2. Please provide official documentation showing that the Applicant is in good standing
with the North Carolina Secretary of State and showing the title and position of the
signing official (Harvey Harman) as required per 15A NCAC 02H .1042(2)(b). If Mr.
Harman does not meet the signing official requirements outlined in 15A NCAC 02H
.1040(1),you will either need to change the signing official to someone who is or provide
authorization for Mr. Harman to sign on behalf of the applicant form someone who is.
The signing official has been changed to Ms. Anna Tuell, Finance and Development
Director. Paperwork has been submitted to the NC Secretary of State to update
Chatham Habitat for Humanity's information to have Ms. Anna Tuell listed as the
present "Registered Agent".
3. Please correct the following issues with the plans:
a. Please show the drainage areas to the proposed swales. This item is required per 15A
NCAC 02H .1042(2)(g)(iv) and Section VI,8o of the Application.
Drainage areas for the proposed swales are delineated and provided as an
attachment in the Stormwater Evaluation.
b. Please provide a cross-section detail for the proposed swales and specify the type of
lining that will be used for the proposed swales. This item is required per 15A NCAC
02H .1042(3)(b) and Section VI,81 of the Application. Please note that the calculations
for the swales should reflect the swales in their permanent design configuration (if
temporary E&SC matting is used, it should not be reflected in the permanent design
calculations).
A cross-section detail for the swales is provided on Sheet 10 of the plan drawings.
4. Please correct the following issues with the calculations:
a. Please use NOAA Atlas 14 rainfall data(https://hdsc.nws.noaa.gov/pfds/?bkmrk—nc)
for determining the 10-year storm flowrates for the proposed swales.
The rainfall data for the swale design has been revised to reflect the NOAA Atlas 14
rainfall data.
b. Please provide calculations showing that the stormwater outlets are stable in
accordance with 15A NCAC 02H .1003(5).
Figure 8.06.3. from the 1vCDEQ Erosion Control Manual is provided in the
Stormwater Evaluation and Calculations.
c. When determining the percent BUA for a site with existing BUA,the following
method is used: [Net Increase in BUA]/([Total Project Area] —[Existing BUA]). If
the existing BUA for the site is 3,280 sf,the net increase in BUA is 25,303 sf, and the
project area is 135,907 sf,this would result in a percent BUA of about 19% (25,303 sf
/(135,907 sf—3,280 sf) = 19.1%). Please revise as needed.
The percent BUA has been revised in the application.
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5. Please correct the following issues with the Application Form:
a. Section IV, 10—Please only list one column per permitted drainage area. This project
only has one permitted drainage area,the low-density area.
This Section has been revised as requested.
b. Section IV, 10, Onsite Buildings/Lots—For a subdivision project like this one,this
value corresponds to the BUA allocated to the individual lots(not just the buildings
on the lots).Please revise as needed. The information in this column should
correspond to the low-density column of the Supplement-EZ Form.
The Application and Supplement-EZ Form have been revised.
c. Section IV, 11 —This section is only required if there are off-site portions to the
permitted drainage area.
There are off-site portions within the drainage area for the Dry Detention Basin.
d. Section IX—Since the property owner is also the applicant, Section IX should not be
filled out. With your permission,I can cross out the original signature on the provided
hard copy,however,you should revise the electronic copy of the form.
The revised application does not have Section IX filled out.
6. Please correct the following issues with the Deed Restriction Document:
a. The project name listed on this form,"Hadley Hills Townhomes"does not match the
project name as shown on the other submittal documents, "Chatham Habitat for
Humanity Townhouse Development". Please revise as needed. A new original Deed
Restriction Document will be needed if the information on this form is changed.
The Deed Restriction Document has been revised to High Density, and the Project
Name is not on this form.
7. Please correct the following issues with the Supplement-EZ Form:
The Supplement-EZ Form has been revised as requested.
8. Please correct the following issues with the O&M Agreement Form:
a. Please specify the type of low-density that is being proposed for this project("Type:"
field on the right side of the"Low Density"line).
The O&M Agreement Form has been revised to 'High Density'.
b. Please click on the"CLICK TO UPDATE MANUAL"link on the cover page. This
form uses Macros to generate the correct pages (listing the O&M procedures that are
being agreed to be performed)of this form based on the information entered on the
cover page. A complete O&M Agreement Form will have at least one page per SCM
indicated on the cover page plus the cover page itself.
The O&M Agreement Form has been corrected, and now has the O&M procedures
included for the proposed Dry Detention Basin.
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9. Please note that, since the dry detention pond is not a State required stormwater
management component, it was not reviewed for compliance with the MDC.
It is understood that the dry detention pond is not a State required SCM. The dry
detention pond is a requirement based on Siler City's Stormwater ordinances, and
the design has been reviewed by the City's designated engineer.
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