SW3190803_JGA_JamesFarkas-SalemLeasingCorp-123019_12/31/2019

Jordan Grant & Associates, PLLC
JORDAN
GRANT
ENGINEERING • SURVEYING • PLANNING
December 30, 2019
Jim Farkas
Environmental Engineer
Stormwater Program
Division of Energy, Mineral and Land Resources
North Carolina Department of Environmental Quality
1612 Mail Service Center
Raleigh, NC 27699-1612
Reference: Response to request for Additional Information
Stormwater Permit No. SW 3190803
Salem Leasing Corporation
Iredell County
Dear Jim:
Thank you for your letter dated September 13, 2019, requesting additional information to continue the
review of the subject project. In accordance with your request, I offer the following information:
1. Since the applicant is the property owner, Section III, 2a & b are not required. Please see revised
application.
2. The river basin that this project is located in is the "Yadkin Pee Dee" basin (Section IV, 3).
"South Yadkin" is the 8-digit subbasin. Please see revised application.
3. Please clarify the total property area calculations (Section IV, 4 - 7). Item 7 (11.7 acres) should
not be larger than item 4 (10.725 acres). Please see revised application.
4. Ensure that Section IV, 8 is calculated correctly, reflecting any changes made to item 7 from the
prior comment. Please see revised application and the signed, sealed, and dated calculations.
Based on the provided contours, it appears that there will be some off -site areas draining onto
your site, Delray Street for example. Please include all off -site areas that will drain to the
proposed SCM in the drainage area table (Section IV, 10 & 11). Please see revised stormwater
plan sheets C30, C31, C32, which illustrate the total drainage areas including off -site.
Delray Street has curb and gutter, which directs the storm runoff away from the subject
site.
6. Please provide the original, signed copy of the Supplement-EZ form (Section V & Section VI, 3).
Please find enclosed the original, signed copy of the revised Supplement-EZ form.
7. A single signed application was provided with this submittal. We require that the original
application and a copy of the signed application be provided. Please provide a copy of the signed
application with your next submission (Section VI, 1). Please find enclosed the original signed
application and a copy of the signed application, which has been revised.
8. Please provide signed, sealed, and dated design calculations (Section VI, 7). Calculations should
include, but are not limited to: Please find enclosed signed, sealed, and dated revised
calculations, which address the following:
P.O. Box 151 Statesville, NC 28687 [phone]
jordan-grant.com

Jordan Grant & Associates, PLLC
JORDAN
GRANT
ENGINEERING • SURVEYING • PLANNING
a. Calculations showing how the design volume for the wet pond was determined
(General MDC 1). See page 49.
b. Calculations showing that the inlet of the wet pond is sufficient to prevent erosion during
the peak flow from the 10-year storm (General MDC 4). See page 48.
C. Calculations showing that the wet pond is sufficiently sized, using either the HRT or
SA/DA method (Wet pond MDC 1). See page 49.
d. Calculations showing that the average depth of the wet pond is between three and eight
feet (Wet pond MDC 2). See page 49.
e. Calculations showing that the forebay is adequately sized (Wet pond MDC 5). A stage -
storage table for the forebay, like the one provided for the main pool, will suffice.
See page 47.
f. Calculations showing that the wet pond draws down the design volume between two and
five days (Wet pond MDC 7). See page 50.
g. Calculations for the anti -flotation block sizing. See page 50.
9. Please dimension all of the proposed BUA on sheet C3, similarly to how the office and shop are
(Section VI, 8, A These values should correspond to the values used in the drainage area table
and Supplement-EZ form. Please see revised stormwater plan sheets C30, C31, C32, which
illustrate the BUA.
10. Please delineate the wetlands on the plans or provide a note stating that no wetlands exist.
Provide documentation of the qualifications and identity of the individual who made this
determination (Section VI, 8, m). Please find wetlands report enclosed.
11. Please show the drainage area for the SCM on the plans (Section VI, 8, o). Please see revised
stormwater plan sheets C30, C31, C32, which illustrate the drainage area for the SCM.
12. Please provide a soils report with the Seasonal High Water Table (SHWT) elevation indicated as
well as an NRCS soils map (Section VI, 9). Please find soils report enclosed.
13. Property owner authorization is not required since the applicant is the property owner
(Section IX). Please see revised application.
14. Please have the applicant sign and notarize the application in Section X. Please see revised
application.
15. Please correct the following issues with the Supplement-EZ form: Please see revised
Supplement-EZ form, which addresses the following:
a. Cover Page
i. Line 2 — Ensure this value is correct.
b. Drainage Areas Page
Line 16 — Ensure that the "Entire Site" column is for the entire site and the "1"
column is for the area that drains to the wet pond. For example, if there are
P.O. Box 151 Statesville, NC 28687 [phone]
jordan-grant.com

Jordan Grant & Associates, PLLC
JORDAN
GRANT
ENGINEERING • SURVEYING • PLANNING
sections of pervious property area that do not drain to the wet pond (Like the
section of the site adjacent to the PIN: 4724-87-5616 property) they should not
be accounted for in the "1" column.
ii. Line 19 —Design volume is calculated using either the "Simple Method" or the
"Discrete NRCS Method".
C. Wet Pond Page
i. Line 5 — The side slope should be that of the above -water embankment of the
pond.
ii. Line 8 — The riser structure appears to have overflow/bypass features for storm
events larger than F.
iii. Line 15 —Please indicate "Yes" or "No" for this item.
iv. Line 23 — Permanent pool elevation shown here (898) does not match plans
(899.5). Please revise for consistency.
V. Line 25 — Temporary pool elevation shown here (900) does not match plans
(900.5). Please revise for consistency.
vi. Line 26 — Please use the permanent pool surface area. This value should match
the provided stage -storage table.
vii. Line 27 — This value should match the provided stage -storage table.
viii. Line 33 — The forebay volume (3090 cf) is more than 20% of the main pool
volume (15102 cf). 3090 cf / 15102 cf = 20.46% > 20%
ix. Lines 36, 38, & 39 — The temporary storage volume is drawn down via an orifice,
so the weir information does not need to be included.
X. Line 42 — Please indicate the berms/baffles on the plan sheet.
16. Please include a maintenance access and easement on the plans (General MDC 8 & 9).
Please see revised stormwater plan sheets C30, C31, C32, which illustrate the maintenance
access and easement.
17. Sheet C3-1
Please see revised stormwater plan sheet C32, which replaces sheet C3-1 and illustrates the
following:
a. Please indicate the cross -slope and width of the vegetated shelf on the cross-section.
b. Please label the contours on the wet pond plan view.
18. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, and 1 hardcopy of other
documents. Pdfs must be uploaded using the form at:
h!!ps://edocs.deg.nc.gov/Forfns/SW Project_Submittal
While it is not required, it is recommended that:
P.O. Box 151 Statesville, NC 28687 [phone]
jordan-grant.com

Jordan Grant & Associates, PLLC
JORDAN
GRANT
ENGINEERING • SURVEYING • PLANNING
An emergency spillway be added to the wet pond. While the wet pond is designed to handle the
100-year storm event, a more intense storm or a malfunction in the outlet could cause
embankment overtopping and the pond to fail catastrophically. Emergency spillways are
typically constructed in undisturbed soil. The topography on the subject site is not suitable
for an emergency spillway in undisturbed soil, therefore, an emergency spillway will not be
used.
The width of the maintenance access be increased to 25 feet as wet ponds generally require larger
maintenance equipment. Please see revised stormwater plan sheets C30, C31, C32, which
illustrate the maintenance access easement to be 25-feet wide.
Either the wet pond or existing pipes be relocated to avoid a conflict. Replacing and/or
maintaining these pipes will be much more difficult if they are buried under the supporting slope
of the wet pond. Please see revised stormwater plan sheets C30, C31, C32, which illustrate
the wetpond relocated eastward away from the existing storm drainpipe and structure.
Thank you for the opportunity to provide you with additional information.
Sincerely,
Jordan Grant & Associates, PLLC
7
Matthew I. Grant, PE, PLS
CEO
mattiordan-grant.com
[phone]
P.O. Box 151 Statesville, NC 28687 [phone]
jordan-grant.com