SW4240703_Response To Comments_20241031

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2524 Reliance Avenue Phone:[phone]
Apex,North Carolina 27539 [e-mail]
FOR: NCDEQ- Brianna Holland
512 N. Salisbury Street
Raleigh, NC 27604
DATE: October 31, 2024
RE: Cane Creek Subdivision Phase 8—Comment Response#1
SW4240703
To Whom It May Concern:
Comments:
NCDEQ Staff have identified the following review comments to be addressed for the above-referenced plans. Staff
reserves the right to identify additional review comments necessary for compliance with the Land Development
Ordinance and the Standard Specifications and Construction Details based on plan resubmittal.
Stormwater Comments
Brianna Holland [e-mail] [phone]
1. The Property Owner and Developer listed on the Cover Page is not consistent with the Application and
provided deed.
Response: Cover page as well as all applications have been updated with new
Owner/Developer information.
2. Per the Application, Section IV, 5, the total property area is 45.36 acres. Per the cover sheet of the
plans and the narrative, the property area is 44.1 acres. Revise the package as needed for
consistency.
Response: The package has been revised so that all are the same. The correct property area is
44.1 acres.
3. The calculations reference a stormwater wetland, but the remainder of the package is for a low-density
subdivision with dry ponds.
Response: Calculations have been revised to reference dry ponds.
4. The impervious areas described in the narrative are not consistent with the remainder of the package.
Response: The impervious area has been revised so that it is the same in all areas of the
submittal package.
5. The swale calculations provided in the narrative are not consistent with the Supplement-EZ swales
table.
Response: Swale calculations have been revised so that it is the same in all areas of the
submittal package.
6. The drainage areas shown in the Supplement-EZ Drainage Areas Page and Application Section IV, 10
need to be consistent.

Bateman Civil Survey Company,PC
Page 2
Response: Drainage areas have been revised so that it is the same in all areas of the submittal
package.
7. Please identify the surface area of all on-site BUA(Section VI, 8j). The surface area information shown in
the application/supplement form of all proposed BUA should be able to be verified on the plans. Certain
regular geometric shapes can be verified solely based on the provided dimensions whereas areas of
irregular shapes(such the existing BUA)cannot easily be determined solely from the provided plans.You
may wish to provided surface area callouts, add surface areas to existing callouts, or add a table, similar to
the one in Section IV, 10 of the application.
Response: BUA table has been added to sheets C200 and C400.
8. This project drains to Nutrient Sensitive Waters(NSW). Please ensure that the design complies with 15A
NCAC 02H .1017(9)(c). Projects located in areas draining to Nutrient Sensitive Waters shall use SCMs that
reduce nutrient loading,while still incorporating the stormwater controls required for the project's density
level.The primary purpose of dry pond is to attenuate and delay stormwater runoff peaks, but the overall
pollutant removal efficiency of dry ponds is low.
Response: Our site meet the nutrient requirements of the Jordan Lake watershed. Snap tool
worksheet is being provided with this submittal.
9. 15A NCAC 02H.1003(2)(c): Side slopes for vegetated conveyances shall be no steeper than 3:1 unless
it is demonstrated that the soils and vegetation will remain stable in perpetuity based on engineering
calculations and on-site soil investigation. In reviewing the submitted items, documentation supporting
the steeper slopes could not be found. Please either provide 3:1 side slopes in the vegetated
conveyance or provide engineering calculations and an on-site soil evaluation supporting the steeper
slopes will remain stable in perpetuity and will not erode during the peak flow form the 10-year storm.
Response: All side slopes are now 3:1 side slopes.
10.Please provide permanent swale details in the main set of plans (Section VI, 81).
Response: Detail has been added to sheet C405.
11.MDC 1. SEPARATION FROM THE SHWT. The lowest point of the dry pond shall be a minimum of six 6
inches above the SHWT.
a. 15A NCAC 02H .1044 (3) (c)when an SCM that has an MDC requiring evaluation of the
SHWT or the soil infiltration rate, the applicant shall include the signed, sealed, and dated
soils report based on field evaluation indicating the depth of SHWT within the footprint of the
SCM, and a map of the boring locations, and boring logs. Soils reports shall be signed and
sealed by a licensed professional. A soils report regarding suitability for septic systems was
provided, however, information necessary for determining compliance with MDC 1 was not
provided.
Response: SHWT Report is included with this submittal. MDC 1 is being met.
12.MDC 6: DRAWDOWN TIME. The design volume shall draw down between two and five days. The
applicable design storm must be detained not less than 2 days and not greater than 5 days. Please
revise.
Response: Drawdown time for each dry pond is between 2 and 5 days. The supplement-EZ form
has been updated to reflect that.
13. Supplement-EZ Form
a. Line 7-8—Per 15A NCAC 02H .1017(10), the minimum vegetated setback width from surface
waters is 30 ft and must remain vegetated. Please revise.

Bateman Civil Survey Company,PC
Page 3
Response: Line 7-8 has been revised.
b. Line 4-There are currently 2:1 side slopes shown in the plans.
Response: Revisions have been made so that all side slopes are 3:1.
c. Line 5-This is the largest value in the Vactual column of the swales table.
Response: Acknowledged, this column has been revised.
d. Swales table- Maximum Allowable Velocity—The maximum allowable velocity in a vegetated
conveyance is limited by the type of vegetation used in the conveyance and the underlying soils
(We have a table in Part C-11 of the Manual that you can use if you like, but actual values
should be entered into the table). Please revise the Vallow column accordingly.
Response: The column has been revised. Each swale is lined with Eronet P300 product,
which allows for a design velocity of up to 16 ft/s.
e. Line 18, 19: Please fill out.
Response: Lines 18,19 have been filled out with the SHWT elevations.
f. Line 26: Additional berms and baffles do not appear to have been provided in the plans (This
refers to measures designed to increase the flow path in addition to the berm that delineates
the forebay).
Response: Line 26 has been revised.
g. Line 28: This is inconsistent with the provided calculations. The design volume for a dry pond is
the volume between the temporary pool elevation and outlet drain elevation.
Response: Design volume numbers have been revised.
h. Line 29: If the spreadsheet is automatically rounding this to be inconsistent with the plans,
please provide the actual orifice diameters in Line 37, or overwrite the PDF.
Response: Line 29 has been revised to not round the numbers.
i. Line 36: Per Dry Pond MDC 9, trees and woody shrubs shall not be allowed.
Response: Noted.
14. The provided O&M Form is outdated and therefore incomplete. Please use the most up to date form,
which can be found on our website at the following address:
https://www.deq.nc.gov/about/divisions/energy-mineral-and-land- resources/stormwater/stormwater-
program/stormwater-design-manual (O&M EZ Form). NOTE: It is recommended to get a second copy
of this form signed & notarized for the Applicant's records (it will be helpful when they go to record it
with the Register of Deeds).
Response: Revised O&M forms have been provided with this submittal.
15.Please show the drainage areas for the dry ponds on the main set of plans so that calculations and
sizing requirements can be verified (Section VI, 8, o).
Response: Drainage area to each SCM is shown on each individual SCM sheet.
16.Label the bottom of the SCMs and top of forebay 15A NCAC 02H .1042(2)(h).
Response: The bottom of the SCM and top of Forebay has been labled on each individual SCM
sheet.

Bateman Civil Survey Company,PC
Page 4
17.Specify the type of vegetation on the plans to ensure compliance with Dry Pond MDC 9.
Response: Landscaping note has been added to each individual SCM sheet.
Kind Regards,
Douglas B. Cooper, PE, PLS
Civil Engineering &Land Development
P: 919.577.1080
[e-mail]