SW3181201_Response To Comments_20220407

benesch
March 28, 2022
TO: Jim Farkas
Environmental Engineer
North Carolina Department of Environmental Quality
Division of Energy, Mineral, & Land Resources — Stomiwater Prograin
450 W. Hanes Mill Road, Office 640E
Raleigh, NC 27604
RE: Response to Comments Letter — Rob Wallace Park Phase IIB
County: Cabarrus
City: Midland
Address: 12900 Bethel School Road
Submitted By: Alfred Benesch & Company
Mr. Farkas,
Alfred Benesch & Company
2359 Perimeter Pointe Parkway, Suite 350
Charlotte, NC 28208
www.benesch.com
P 704-521-9880
F704-521-8955
The following are the response to your email, regarding the stormwater permit for the Rob Wallace Park Phase
IIB Project, received by my office on 3/15/22. These responses to comments include the original request for
information, reply, and where any revisions that have been made can be found. Please see the following
comments and responses with my replies in BOLD.
• lx hard copy of the Designer Certification for the project. This item is required per Section II, lb of the
Application and per 15A NCAC 02H .1042(4)(a). The
o A hard copy original of the Designer Certification for the Rob Wallace Phase II project has
been included and completed as requested.
2x hard copies of a full-sized plan sheet showing the following (NOTE: Only updated plan sheets need to
be provided, we do not require brand new sets of plans):
o Drainage area map for the proposed vegetated conveyances. This item is required per Section VI,
8o of the Application and 13A NCAC 02H .1042(2)(g)(iv). It is noted that a drainage area map
was provided, however, this DA map appears to be a delineation of DAs to the stormwater
inlets/culverts, not the vegetated conveyances (for example, the vegetated conveyance running
along the west side of the proposed shelter does not have a DA delineated to it, there are other
examples, this one is just easiest to describe). Please also ensure that 2x hard copies of the
drainage area map are provided.
■ The Erosion Control Post Development Sheet (C303) has been revised to show the
drainage areas for both the culverts and the swales as requested. 2 hard copies of
this sheet have been included in this package. The Drainage Area Map (DA-1) was
also updated to reflect these changes and is also included in the package.

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o Wetland delineation or a note on the plans stating that there are no wetlands located on -site
(Required per Section Vl, 8m of the Application and 15A NCAC 02H .1042(2)(g)(iii)). Please
also list the name of the individual that made this determination in a note on the plans. It is noted
that the project narrative states that there are no wetlands located on -site, however this
information is required to be shown in the amain plan set.
■ No wetlands are located onsite. This has been noted on the plan set as required
(Erosion Control Post Development - Sheet C303).
o On -site surface water delineation and vegetated setback delineation. These items are required per
Section V1,81i & 8p of the Application and 15A NCAC 02H .1042(2)(g)(iii).
■ Both Muddy Creep and the vegetative setback have been delineated on the plan set
as requested (Erosion Control Post Development - Sheet C303).
NOTE: This is an administrative completeness review, not a detailed engineering review. The following items
were noted during this review, but do not need to be addressed for this submission to be administratively complete
and accepted for review (but these issues, and possibly others. will probably be brough up during the engineering
review):
• The project area (Section 1V, 7 of the Application and Line 2 of the Cover Page of the Supplement-EZ
Fonm) do not correspond to the project area from the original approval. You may also wish to include the
originally approved vegetated conveyances on the Supplement-EZ Form so that all of the information for
this project/permit is located in one place.
o The project area has been corrected on Line 2 of the Cover Page of the Supplemental-EZ
Form to correspond to the original permit approval. The existing swales under that permit
have also been added per your suggestion.
• Culvert 3B appears as though it could be shortened in order to better adhere to the lore -density project
criteria outlined in 15A NCAC 02H .1003(2)(c).
o Culvert 3B has been shortened to the furthest possible extent. The current design has
minimum cover (approx. V), minimal slope (0.5%) and is as short as possible (reduced from
123' to 99') in order to daylight. However, we would like to discuss the placement of the
discharge further as we believe its current location may create a health concern as it is
located in a high traffic area. If this topic can be revisited during the review it would be
greatly appreciated.
+ The provided vegetated conveyance detail shows the side slopes of the channel as 2:1. Per 15A NCAC
02H .1003(2)(c)(1), side slopes for vegetated conveyances are required to be 3:1 or flatter unless a site
specific soil investigation & engineering calculations are provided demonstrating stability in perpetuity.
o This detail has been revised to reflect the 3:1 slope requirement as requested.

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• Some of the proposed walking trails appears to be located within the 30' vegetated setback from Muddy
Creek and these trails do not appear to meet the BUA exemption in G.S. 143-214,7(b2)(2) which is not
allowed per 15A NCAC 02H .1003(4),
o The trail location has been revised to remain outside the 30' vegetative setback from Muddy
Creek and the new location is shown on the plan set (Erosion Control Post Development -
Sheet C303).
If you have any questions about the above responses to comments, or need any additional information, please feel
free to contact me at your convenience. 1 can be reached via email at MBlackmongbenesch.com or by phone at
[phone] (Office) or [phone] (Mobile),
Sincerely,
//1 ;7 142�
Matt Blackmon, PE — Project Engineer
Alfred Benesch & Company
CC: Mr. Kyle Bilafer — Cabarrus County
Paul Krynski — C Design
Jeff Ashbaugh — Alfred Benesch & Company