SW3190704_Response to comments_10/11/2019

` AMERICAN
Engineering
October 7, 2019
North Carolina DEQ
Mooresville Regional Office
Stormwater Permitting
610 East Center Avenue, Suite 301
Mooresville, NC 28115
RE: Response to Stormwater Management Permit Review Comments for
Request for Additional Information
Stormwater Permit No. SW3190704
Skyland Drive Townhomes — Cabarrus County
DEMLR Comments (Jim Farkas, Environmental Engineer):
1. Please indicate whether or not the project site is located within 5 miles of a public airport (Section 11,
5).
There are no public airports located within a five -mile radius of the site.
2. It appears that the applicant is the property owner. If this is the case, please correct Section 111, 1.c
and do not include Section 1112.a & b or Section IX. If not, please clarify.
The applicable sections have been corrected and are being resubmitted.
3. The drainage area information only needs to be completed for the area that drains to the proposed
SCM, not the entire site (Section IV, 10).
The information in Section IV, 10 has been revised to reflect the drainage area
contributary to the SCM.
4. Please clarify what the "Other on-site"BUA is (Section IV, 10).
The "other" on -site BUA was the existing water feature located on the site. It has been
removed from the proposed BUA calculation.
5. Please complete a Supplement EZ form for each SCM. (Section V).
A Supplement EZ form has been completed and is being submitted.
6. The additional pages of the O&M Agreement, explaining the nature of the agreed to maintenance,
must be included in the submission. Please have the form, with all pages included, re -signed and
notarized (Section V & Section Vl, 3).
The additional pages of the O&M Agreement are included in the re -submittal.
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 Vl, 1).
A copy of the signed application is included in the re -submittal.
American Engineering Associates — Southeast, PA
8008 Corporate Center Drive, Suite 110, Charlotte, NC28226 # 704-375-2438 0 www.Americcin-EA.com

State Proj. No. SW3190704
September 16, 2019
Page 2
B. Since the property will be subdivided, please provide a notarized Deed Restriction (Section Vl, 2 &
Section Vll).
The Deed Restriction document is included in the re -submittal.
9. 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 Vl, 8.m).
A wetland determination was performed on October 2, 2019 by Summit Engineering.
Any wetlands were determined to be located in the man-made water feature and its
associated drainage feature to the southeast. Proposed development will not impact
this area. A copy of the wetland report is included with this submittal.
10. Please show the surface water buffer on the plans (Section Vl, 8.p).
The 35-foot surface water buffer is shown on the revised plan set.
11. Please include a boring log and SHWT elevation for the proposed SCM (Section VI, 9 & Sand Filter
MDC 1).
A soil boring has not been performed at this time. A confirmatory boring will be
performed at the time of excavation for the BMP. The reports of the boring results will
be provided to the Engineer for review prior to final excavation. A liner is proposed for
the sand filter as a precaution that a high water table is encountered.
12. The provided property deed shows that the property is owned by S & C Carolina Group, LLC while the
application states that the property owner is Coulston Enterprises, Inc. (Section VI, 10) Please clarify.
The application has been revised to reflect the current owning entity, S&C Carolina
Group LLC.
13. The storage volume in the sediment chamber and sand chamber should be the same (Sand Filter
MDC 2).
The required water quality volume for the area draining to the BMP is 915 c.f. The
storage volume provided for the sediment chamber at elevation 668 is 1,652 c.f., and
the storage volume provided for the sand filter at elevation 668 is 3,341 c.f.
14. Please provide calculations showing that the sand filter is sized in accordance with the Stormwater
Design Manual (Sand Filter MDC 3 & General MDC 1).
The sand filter was sized using the simple method for the 1" rainfall depth. The sand
filter design calculation sheet is attached.
15. As designed, the provided SCM does not treat enough impervious area. If you are using the runoff
Treatment Method, you are required to treat the net increase in BUA in one or more SCMs. Since
there is no BUA on the site in existing conditions, all BUA added needs to drain to the SCM. The new
BUA in drainage areas B1, B2, B3, & B4 does not drain to any SCM and is therefore untreated.
The site drainage has been revised to ensure all new impervious areas are draining to
the SCM.
American Engineering Associates — Southeast, PA o North Carolina Engineering License C-3881
8008 Corporate Center Drive, Suite 110, Charlotte, NC28226 •704-375-2438 0 www.American-EA.com

State Proj. No. SW3190704
September 16, 2019
Page 3
16. Provide pdfs of all revisions, 2 hardcopies of the revised plan sheets, and 1 hardcopy of other
documents. Pdfs must be uploaded using the form at:
https://edocs.deg.nc.gov/Forms/SW Project Submittal
The above referenced materials are included in this submission.
Sincerely,
American Enjix�eering Associates —Southeast, PA
Barry'*fvt!Fay. PE
Principal
[e-mail]
American Engineering Associates — Southeast, PA • North Carolina Engineering License C-3881
8008 Corporate Center Drive, Suite 110, Charlotte, NC 28226 • 704-375-2438 • www.American-EA.com