SWA000022__07 Comment Response_5/19/2020

May 13, 2020
Brian Rossi, PE
301 McCullough Drive, Suite 109
Charlotte, NC 28262
Subject: Request for Additional Information
Stormwater Permit No. SWA000022
Courtyards at Emerald Lake
Union County
Dear Mr. Rossi:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on February 19, 2020. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
1. The following comments were originally mentioned in the November 6t'', 2019 request for
additional information and have not been provided/addressed. To ensure all comments are
addressed during the next submission, please provide a point -by -point response to the comments
with the next submittal. Please correct the following issues with the Final Permit Submittal
Checklist and supporting documents:
a. Item 1 Application Form SWU 101:
i. Section VI Please initial these required items indicating that they have been
included in the application. You must initial (with a pen) these items. Your
initials indicate that you have included these items with the Application.
Response: Addressed
ii. Section VI 2 Please provide the original, notarized, deed restriction document.
Please provide the deed restrictions that limit the amount of BUA per lot that
were placed on these subdivided lots.
Response: This comment has been removed based upon our email
correspondence.
iii. Section VI,11 Please provide documents showing that Mr. Kardos is affiliated
with Epcon Marvin, LLC. It is noted that the Applicant organization has been
changed to "EPCON Lawyers Road, LLC". Please provided documentation form
the NC Secretary of State indicating Mr. Kardos' affiliation with the Applicant
organization.
Response: The requested document has been provided with this
resubmittal.
b. Item 2 Supplement EZ Form:
i. Drainage Areas Sheet:
1. Please fill out the `Entire Site " column. The entire site column is not
necessarily just a summation of the two separate drainage areas. It is an

accounting of the BUA that is located within the property area. As such,
there are no off -site components (Lines 8 & 9) or design requirements (Lines
17 — 19). Also, it is noted that the amount of BUA for the entire site (On
original design plan sheet C 3.1 is listed as 19.06 acres which is significantly
larger than the 465,144 sf (10.68 ac) reported. Please either revise or describe
this discrepancy.
Response: The Supplement EZ Form has been updated to reflect the
entire site. We believe that the initial plan sheet BUA had an error and
was overly conservative in the estimated BUA. A CAD drawing was
created which has hatched out the areas according to the EZ form
categories. The model and report correlate with these hatched areas.
2. Line 19 Design volume should be the WQ volume, not the total volume that
can be stored above the permanent pool. Since this project is located
in the Goose Creek Watershed (15A NCAC 02B .0600), the WQ volume
needed for these SCMs is the difference between the pre -development and
post -development runoff from the 1-year storm. Please update the
calculations and forms as needed.
Response: Water quality calculations and model has been updated to
reflect the difference between the I -year pre -development and post -
development runoff.
ii. Wet Pond Sheet:
1. Line 2 & 35 Design volume should be the WQ volume, not the total
volume that can be stored above the permanent pool. See prior
clarification for the WQ volume.
Response: Addressed
2. Line 19 The stage storage tables have only been provided for the
temporary storage areas and the forebay of BW 3. Please provide As- built
stage storage table for the main pools and the forebay ofBW I &
2. Stage -storage tables must be provided for the main pool, and forebay to
ensure that they are adequately designed/sized per Wet Pond MDCs 1, 2,
& 5.
Response: Stage -storage tables for all main pool and forebays have been
added to the plan sheets
3. Line 27 This value should be the volume of the permanent pool that is not
located in the forebay. Providing the stage -storage tables (As noted
above) will allow us to verify these values. Also, please provide the main
permanent pool volume for the drainage area 1 column.
Response: Addressed
4. Line 34 Lines 20 & 21 indicate that the cleanout depth is 12 inches and this
line indicates that it is 6 inches. Please revise for consistency. Since having
initially issued this comment, I have received clarification that the
cleanout depth is the distance from the permanent pool elevation to the top
of the sediment storage ("Maximum Sediment Storage" on the as-
builts).
Response: EZ form has been updated to reflect this depth.
S. Line 42 Berms and baffles do not appear to be provided. Berms and
baffles are additional design elements that are added to a wet pond that
increase the length of the flow path. It does not appear that either of these
design elements are included in the design.
Response: EZ form has been revised to say "no" for these items.
c. Item 7. c Wet Pond Planting Plan:
i. Please provide a planting plan for the wet ponds. As -built sheet C 5.7 does not
include a planting plan, please revise.
Response: A table for what was actually planted onsite has been added to the
plan sheet.
d. Item 8 Recorded Documents:
i. 8. b Please provide the original, notarized deed restriction document. Please
provide the deed restrictions that limit the amount of BUA per lot that were

placed on these subdivided lots.
Response: This comment has been removed based upon our email
correspondence.
e. Item 9 As -Built Designer NDDC Certification:
i. Wet Pond I (Sheet CS. 6)
1. As -Built Designer's Certification for General NIDC
a. Treatment Requirements
2) Project does not meet Runoff Volume Match. The
project was never designed to meet Runoff Volume
Match. This item should be "N/A" instead of ' N".
Response: Addressed
b. Stormwater Outlets
i. Provide riprap sizing calculations to verify this. Provide
these calculations to ensure that the riprap is sized correctly.
Response: Please see the HWl riprap calculations
provided with this submittal
ii. Wet Pond 2 (Sheet CS. 7)
1. As -Built Designer's Certification for General AIDC
a. Treatment Requirements
i. 2) Project does not meet Runoff Volume Match. The
project was never designed to meet Runoff Volume
Match. This item should be "N/A" instead of ' N".
Response: Addressed.
ii. 7) The following NDDCs are not met: 10. Wet Pond
MDC 10 refers to the vegetated shelf planting plan (See
prior comment).
Response: Planting plan has been added to the sheet.
Plan reflects what was actually planted within the
littoral shelf.
b. Stormwater Outlet
i. Provide riprap sizing calculations to verify this. Provide
these calculations to ensure that the riprap is sized
correctly.
Response: Please see the FES6 riprap calculations provided
with this submittal
f. Item 10 As -Built Permittee Certification Please provide anew As -built Permittee
Certification with the below changes made.
i. Deed Restrictions/BUA Records
1. Provide deed restriction information. Please provide the deed restrictions that
limit the amount of BUA per lot that were placed on these
subdivided lots.
Response: This comment has been removed based upon our email
correspondence.
ii. Single Family Residential Lots
1. SCMs are not located on individual lots. These should all be `NIA ".
Self-explanatory.
Response: Addressed.
iii. O&MAgreement
1. ])Final recorded plat should reference the O&MAgreement. It does not
matter that the O&MAgreement was signed before the plat was recorded.
Self-explanatory.
Response: This comment has been removed based upon our email
correspondence and the plat cannot be revised as the development is sold
out.
2. 2) Provide documentation of this. Please provided documentation showing
that the O&M Agreement is recorded with the register of deeds

and is in the title chain.
2. Please provide original signatures on all updated forms. For example, the as -built forms provided
with the prior submittal were photocopies.
Response: Addressed
3. Please correct the following issues (In addition to any previously mentioned comments) with the
Supplement-EZ Form:
a. Drainage Areas Sheet
i. Line 6 — This item should be an accounting of all of the BUA that is located
within subdivided lots, within the entire site or drainage areas. The entire site
column value for this item should match the sum of BUA shown on the deed
restriction document.
Response: BUA has been updated on the EZ form.
ii. Line 7 —This item is an accounting of all of the BUA that is located outside of the
subdivided lots in public or shared places (Such as roadways, clubhouse areas,
etc.), within the entire site or drainage areas. For this project, the total
BUA (Line 5) should equal the sum of Lines 6 & 7.
Response: BUA has been updated on the EZ form.
iii. Line 10 —These items are an accounting of all of the BUA that is located outside of the
subdivided lots in public or shared places, broken down by type, within the entire site
or drainage areas. For this project, Line 7 should equal the sum of the items of Line
10.
Response: BUA has been updated on the EZ form.
iv. Entire Site Column, Line 16 — This item and Section IV, 8 should correspond revise one
or the other for consistency.
Response: BUA has been updated on the EZ form.
v. Drainage Area Columns, Line 17 — Since this project is located within the Goose
Creek Watershed, please revise the design storm so it is consistent with the
applicable rules.
Response: Design storm has been updated to reflect the requirements
within the Goose Creek Watershed.
vi. Drainage Area Columns, Line 19 — The design volume is calculated using the
Simple Method or the Discrete NRCS Curve Number Method. Please refer to
Part B of the Manual for more information on these methods.
Response: The HydroCAD 10.0 computer program was used
to calculate the design volume. HydroCAD uses the Discrete
NRCS Curve Number Method. EZ form has been revised.
b. Wet Pond Sheet:
i. Line 55 — Please clarify the situation regarding the trash racks (Line 51 and an
MDC) for the wet ponds.
Response: Standard grates were installed to protect the outlet structure in
lieu of trash racks.
4. Please correct the following issues (In addition to any previously mentioned comments) with the
As -Built Designer's Certification Forms:
a. Check off the "Check here if this is part of a Fast -Track As -Built Package Submittal"
box.
Response: Addressed
5. The width of the vegetated shelf as shown on as -built C 5.6 is significantly less than the minimum
6 feet wide (Wet Pond MDC 6) and less than the 10 feet wide as shown on the Supplement-EZ
Form (There are sections of the vegetated shelf that are approximately 3 feet wide).
Response: The previous submittal stopped the littoral shelf at the edge of water. Hatch
has been revised to reflect the approximately 8 feet wide shelf.

6. As -built sheet C 5.6 — Cross-section C-C shows the maximum sediment storage elevation as 627
ft while the bottom of the pond is shown as 628 ft. Please revise.
Response: Depth has been revised.
NOTE: Per Division policy, the next review of this application will be the final review. Failure to
provide the requested information will result in the project being returned as incomplete. The
return of a project will necessitate resubmittal of all required items, including the application fee.
8. 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:
https:Hedocs.deq.nc.gov/Forms/SW Project_ Submittal
Please note that this request for additional information is in response to a preliminary review.
The requested information should be received by this Office prior to April 20, 2019, or the
application will be returned as incomplete. The return of a project will necessitate resubmittal
of all required items, including the application fee. Please reference the State assigned project
number SWA000022 on all correspondence.
If you need additional time to submit the information, please submit your request for a time
extension to the Division at the contact below. The request must indicate the date by which you
expect to submit the required information. The Division is allowed 90 days from the receipt of
a completed application to issue the permit.

The construction of any impervious surfaces, other than a construction entrance under an
approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject
to enforcement action pursuant to NCGS 143-215.6A.
If you have any questions concerning this matter please feel free to contact me at
Jim.Farkasgncdenr.gov or [phone].
Sincerely,
Jim Farkas
Environmental Engineer
Stormwater Program
cc: Mooresville Regional Office

User Input Data
Calculated Value
Reference Data
Designed By: MBA Date: 4/9/202(
checked By: Date:
company: EMH&T
Project Name: Courtyards at Emerald Lake
Project No.: 2014-1128
Site Location (City/Town) Stallings
Culvert Id. HW1
Total Drainage Area (acres) Outfall from Wet Pond
Step 1. Determine the tailwater depth from channel characteristics below the
pipe outlet for the design capacity of the pipe. If the tailwater depth is less
than half the outlet pipe diameter. it is classified nummum tailwater condition.
If it is greater than half the pipe diameter, it is classified maximum condition
Pipes that outlet onto wide flat areas with no defined channel are assumed
to have a nunimum tailwater condition unless reliable flood stage elevations
show otherwise.
Outlet pipe diameter, Do (in.) 15
Tailwater depth (in.) 0
Minimum/Maximum tailwater? Min TW (Fig. 8.06a)
Discharge (cfs) 16.8
Velocity (ft./s) 13.69
Step 2. Based on the Wwater conditions determined in step 1. enter Figure
8.06a or Figure 8.06b, and determine d50 riprap size and minimum apron length
(Q. The d,, size is the median stone size in a well -graded nprap apron_
Step 3. Determine apron width at the pipe outlet_ the apron shape, and the
apron width at the outlet end from the same figure used in Step 2.
Minimum TW Maximum TW
Figure 8.06a Figure 8.06b
Riprap d50, (ft.) 0.7
Minimum apron length, La (ft.) 17
Apron width at pipe outlet (ft.) 3.75 3.75 provided = 10
Apron shape Trapezoid
Apron width at outlet end (ft.) 18.25 1.25 provided = 30
Step 4. Determine the maximum stone diameter-
dm„ = 1.5 x dso
Minimum TW Maximum TW
Max Stone Diameter, dmax (ft.) 1.05 0
Step 5. Deteniiine the apron thickness:
Apron thickness = 1,5 x d_
Minimum TW Maximum TW
Apron Thickness(ft.) 1.575 0
Step 6. Fit the riprap apron to the site by making n level for the minimum
length. L, from Figure 8.06a or Figure 8.06b. Extend the apron farther
downstream and along channel banks until stabiliry is assured. Keep the
apron as straight as possible and align it with the flow of the receiving stream.
Make any necessary alignment bends near the pipe outlet so that the entrance
into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure
stability.
It may be necessary to increase the size of riprap where protection of the
channel side slopes is necessary (Appendix 8.05}. Where oveffalls exist at
pipe outlets or flows are excessive, a plunge pool should be considered, see
page 8.06.8.

User Input Data
Calculated Value
Reference Data
Designed By: MBA Date: 4/9/202(
checked By: Date:
company: EMHST
Project Name: Courtyards at Emerald Lake
Project No.: 2014-1128
Site Location (City/Town) Stallings
Culvert Id. FES6
Total Drainage Area (acres) Outfall from Detention Pond
Step 1. Determine the tailwater depth from channel characteristics below the
pipe outlet for the design capacity of the pipe. If the tailwater depth is less
than half the outlet pipe diameter. it is classified nummum tailwater condition.
If it is greater than half the pipe diameter, it is classified maximum condition
Pipes that outlet onto wide flat areas with no defined channel are assumed
to have a nunimum tailwater condition unless reliable flood stage elevations
show otherwise.
Outlet pipe diameter, Do (in.) 24
Tailwater depth (in.) 0
Minimum/Maximum tailwater? Min TW (Fig. 8.06a)
Discharge (cfs) 6.64
Velocity (ft./s) 5.44
Step 2. Based on the Wwater conditions determined in step 1. enter Figure
8.06a or Figure 8.06b, and determine d50 riprap size and minimum apron length
(Q. The d,, size is the median stone size in a well -graded nprap apron_
Step 3. Determine apron width at the pipe outlet_ the apron shape, and the
apron width at the outlet end from the same figure used in Step 2.
Minimum TW Maximum TW
Figure 8.06a Figure 8.06b
Riprap d50, (ft.)
Minimum apron length, La (ft.)
Apron width at pipe outlet (ft.) 6
Apron shape Trapezoid
Apron width at outlet end (ft.) 14
Step 4. Determine the maximum stone diameter:
dm„ = 1.5 x dso
Minimum TW
Max Stone Diameter, dmax (ft.) 0.75
Step 5. Deteniiine the apron thickness:
Apron thickness = 1,5 x d_
Minimum TW
Apron Thickness(ft.) 1.125
0.5
12
6 provided = 12
2 provided = 22
Maximum TW
0
Maximum TW
0
Step 6. Fit the riprap apron to the site by making n level for the minimum
length. L, from Figure 8.06a or Figure 8.06b. Extend the apron farther
downstream and along channel banks until stabiliry is assured. Keep the
apron as straight as possible and align it with the flow of the receiving stream.
Make any necessary alignment bends near the pipe outlet so that the entrance
into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure
stability.
It may be necessary to increase the size of riprap where protection of the
channel side slopes is necessary (Appendix 8.05}. Where oveffalls exist at
pipe outlets or flows are excessive, a plunge pool should be considered, see
page 8.06.8.

I
3 0
Outlet H ■ po + La
Pipe I
diameter (Do)
La —it
ilwater 0.5D0
1
lyal���
p1 Qp 60
50
I TTT 1
�a
0
3 5 10 20 50 160 200 500 100D
Discharge (ft3lsec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flawing full, minimum tailwaler condition (T. < 0.5 diameter)
Rey. 12'93 8.06.3

Figure 8.06b: Design of outlet protection from a round pipe flowing full, maximum
tailwater condition (Tw>=0.5 diameter)
300
T
outlet W = Oo + 0.41.4 120 --- —
pi
pe IF
��
diameter (q,)j— to0.500
100
77
7.
i
e
o
PQ� 70
f r
..7
v0 / J �. I _ • bl I ` 1
ti
10. !!!!!! .3
/ 1
to J
a + a n 1
i
1 v-hoist ,
I l i r I I o
3 5 10 20 5o 100 200 500 1000
Discharge (931sec)
Curves may not be extrapolated.
Figure 8.06b Design of outlet protection from a round pipe flowing cull, maximum faiWater condition (T,. > 0,5 diameter).
8.06.4 R., 1293

V
3 0
Outlet W ■ po + La
Pipe
diameter (0o)
La 01
water c 0.5Do
1
of Pp 60
so . .
�`� .thll�t•r .
TTT I
D
3 5 10 20 50 100 200 500 iODD
Discharge (ft3/sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet proteclon protection from a round pipe flowing full, minimum tailwaler condition (T. < 0.5 diameter)
Rey. 12'93
8.06.3

Figure 8.06b: Design of outlet protection from a round pipe flowing full, maximum
tailwater condition (Tw>=0.5 diameter)
300
T
outlet W = Oo + 0.41.4 120 --- —
pi
pe IF
��
diameter (q,)j— to0.500
100
77
7.
i
e
o
PQ� 70
f r
..7
v0 / J �. I _ • bl I ` 1
ti
10. !!!!!! .3
/ 1
to J
a + a n 1
i
1 v-hoist ,
I l i r I I o
3 5 10 20 5o 100 200 500 1000
Discharge (931sec)
Curves may not be extrapolated.
Figure 8.06b Design of outlet protection from a round pipe flowing cull, maximum faiWater condition (T,. > 0,5 diameter).
8.06.4 R., 1293