SW3191101_Responce to Comments_20191223

TM
BOHLER
E N G I N E E R I N G
North Carolina DEQ
Energy, Mineral, and Land Resources
512 North Salisbury St.
1612 Mail Service Center
Raleigh, NC 27699
1927 S. Tryon St, Suite 310
Charlotte, NC 28203
PHONE [phone]
December 20, 2019
Re: Comment Response Letter
Cambridge Commons
Multi -Family Development
North Pilot Knob Road &
Cresset Dellinger Road
Denver, North Carolina
BE 4NCC172159
Bohler Engineering is pleased to submit on behalf of Cambridge Commons MF, LLC the revised
Construction Documents for the Cambridge Commons Multi -Family Development located at the corner
of North Pilot Knob Road and Cresset Dellinger Road in Denver, North Carolina. The following is our
comment response letter addressing comments received from the North Carolina Department of
Environmental Quality dated December 9, 2019. Each comment is addressed and responded to as
follows:
Comment 1: The provided coordinates are close to the project site but should be located on the
property that the permit is being applied for (Section I, 4). Please provide coordinates that
are located on the property of the subject project.
Response 1: Coordinate for a point located on the southern portion of the site have been provided
Comment 2: Since the applicant is a purchaser, please provide a copy of the pending sales agreement
for the property (Section III, lc). If the property has since been conveyed, please correct
this section to show the applicant as the owner.
Response 2: A copy of the purchase agreement has been included with this submittal.
Comment 3: Please provide the name of the signing official for the property owner organization
(Section III, 2a).
Response 3: Steve Bailey, President, BBC Cambridge LLC has been added to the application as
requested
Comment 4: There are no existing surface waters shown on the USGS topographic map for the project
site (Section IV, 6 & Section VI, 8h). If there are existing surface waters within this
project area, please delineate them and their required buffers, if not, please recalculate the
total project area.
Response 4: No surface waters present. Section updated accordingly.

Comment Response Letter
Cambridge Village Multifamily
NCC172159
December 19, 2019
Page 2 of 4
Comment 5: The surface area of the wet ponds is not considered impervious area and does not need to
be accounted for or treated (Section IV, 10). If you like, you may reallocate this
impervious area to the future column or remove it from the table and calculations.
Response 5: Noted Application has been updated accordingly.
Comment 6: Please complete a Supplement-EZ Form for each SCM. The Supplement-EZ Form can be
found here: https:Hdeq.nc.gov/about/divisions/energy-mineral-land-resources/energy-
mineral-land-permit-guidance/stormwater-bmp-manual (Section V & Section VI, 3).
Response 6: Supplemental EZ forms have been provided
Comment 7: The O&M Agreement Form is missing some pages (Section V & Section VI, 3). Please
ensure that both "Enable Editing" and "Enable Content" are clicked on the spreadsheet.
Once the information is entered into the spreadsheet, click on the "Click to update O&M
manual" link to generate the additional pages. A similar process will need to be done for
the Supplement-EZ form to generate all of the pages.
Response 7. O&MAgreement has been updated to include the full form.
Comment 8: Please provide a USGS topographic map showing the project location (Section VI, 6)
Response 8: USGS map has been provided in the appendix section of the Stormwater Report.
Comment 9: Please ensure that all sheets (As applicable) include a north arrow. For example, sheets
C-908, C-909, and possibly others are missing north arrows (Section VI, 8e).
Response 9: North arrows have been added to all sheets.
Comment 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, 8m).
Response 10: No wetlands are located within the project area. The commercial development adjacent
to the site had a delineation performed That development impacted both wetlands and
streams. A copy of that permit showing the study area and locations of wetlands and
streams within that study area have been included with this submittal. A note has been
added to sheet C-401.
Comment 11: Please provide official documents showing the affiliation of the person listed in Section
III, la with North Pilot Road, LLC (Section VI, 11).
Response 11: Documentation provided
Comment 12: Please provide official documents showing that Steven Bailey is able to sign on behalf of
BBC Cambridge, LLC (Section IX).
Response 12: Documentation provided
Comment 13: The person signing the Applicant's Certification (Section X), Tadd Miller, is not the
same person as listed in Section III, la, Jacob Jacobson. Please revise for consistency.
Response 13: Application updated accordingly.

Comment Response Letter
Cambridge Village Multifamily
NCC172159
December 19, 2019
Page 3 of 4
Comment 14: Please QA/QC the package prior to the next submission. Some noted errors include, but
are not limited to the following:
a. Sheet C-908
I. The inflow invert is below the bottom of the wet pond.
ii. The top of the pond is below the permeant pool elevation.
iii. The project name shown in the BMP Insert Table is incorrect.
Response 14: The plans and report have been checked for inconsistencies and typos. The above
comments have been addressed
Comment 15a: Wet Pond 1: The provided stage storage tables in the SWM report do not match the plan
drawings, for example, the shelf elevations.
Response 15a: Stage storage calculations are available in the wet pond calculations and HydroCAD
routing in the appendix section of the report.
Comment 15b: Wet Pond 1: The wet pond, as designed, short circuits from STM B-10 to STM B-60 Wet
Pond MDC 4).
Response 15b: A permanent baffle wall has been proposed to prevent short circuiting.
Comment 15c: Wet Pond 1: The provided forebay is larger than 20% of the main pool volume (Wet
Pond MDC 5).
Response 15c: Forebay volumes have been adjusted
Comment 15d: Wet Pond 1: The design volume drawdown time is too slow (Wet Pond MDC 7). Check
your calculations, the pond height is not 792.0'.
Response 15d: Calculations have been updated
Comment 16a: Wet Pond 2: The main pool average depth appears to be too shallow and is calculated
incorrectly (Wet Pond MDC 2). Please refer to the Stormwater Design Manual, Part C-3
for average depth calculation equations.
Response 16a: Average depth calculation updated to utilize equation 3 under MDC2.
Comment 16b: Wet Pond 2: The provided forebay is smaller than 15% of the main pool volume (Wet
Pond MDC 5).
Response 16b: Forebay volumes have been adjusted
Comment 16c: Wet Pond 2: The design volume drawdown time is too slow (Wet Pond MDC 7). Check
your calculations, the pond height is not 783.0'.
Response 16c: Calculations have been updated

Comment Response Letter
Cambridge Village Multifamily
NCC172159
December 19, 2019
Page 4 of 4
Comment 16d: Wet Pond 2: Based on the information shown on sheet C-301, the main pool of the wet
pond is not located on the property. Please provide an agreement between the applicant
and the adjoining property owner (Cambridge -Denver, LLC) allowing for the
construction of an off -site SCM.
Response 16d. The pond is located within an existing easement. A copy of the recorded drainage
easement has been provided
Comment 16e: Wet Pond 2: The proposed main pool area of this facility appears to be covered under an
existing stormwater permit, SW3160904. Please clarify the extents of this existing permit
and if constructing the proposed wet pond in this location will cause a reduction in the
water quality treatment provided by the existing facility.
Response 16e: Wet Pond 2's location does not conflict with the existing facilities permitted under
SW316094. The existing facilities associated with that permit number are located at the
following coordinates (35°2649.85 "N, 80°5938.95 "W) and (3502651.34 "N,
80059'43.82" i).
Comment 17: 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/Fonns/SW Project_Submittal
Response 17: Documents have been uploaded
Comment 18: While it is not required, it is recommended that Wet Pond 2 be equipped with an
emergency spillway. Even though the wet pond is sized to handle the 100-year storm, an
emergency spillway can prevent structural failure of the embankment if the outlet
structure became clogged or obstructed during a large storm event.
Response 18: There is currently no embankment for this pond It is sitting in a low point. The point
of relief is located along the existing back of curb of the commercial development.
Should you have any questions regarding this project or require additional information, please do not
hesitate to contact me at [phone].
Sincerely,
Bohler Engineering
Steve Farmartino, P.E.
Project Manager