SW3221202_Response To Comments_20230627

EAGLE ENGINEERING
June 27, 2023
NCDEMLR
RE: Piper Meadows
3rd Review Comments
We are in receipt of your 3rd review comments for Piper Meadows located on New Town Road in
Waxhaw,NC. Please find below the edited responses to the requested information.
NCDENR COMMENTS
Contact:Jim Farkas
1) Prior Comment 4d— "As designed, the forebays do not appear to meet the requirements of Wet Pond
MDCs 3 & 5b... at least 6" of sediment storage must be provided over both the excavated bottom
elevation of the entrance & exit of the forebay (Wet Pond MDC 3)..." As designed, there does not
appear to be at least 6" of sediment storage provided over the forebay exit for either wet pond. For
example, for Wet Pond#1, the top of the sediment storage zone is located at elevation 621' and the
forebay bottom elevation at the exit is at elevation 621'. Please refer to attached image for guidance
(the forebay for Wet Pond #1 appears to be designed correctly, it just does not appear to be shown
correctly). Please revise as needed.
i) Forebay labeling for Wet Pond #1 has been revised. Grading and labels for Wet Pond #2 have
been revised.
2) Prior Comment 5a — "Application, Section IV, 10 — As noted earlier, there appears to be a
discrepancy with the information shown in this table..."BUA accounting issues have been grouped
together and follow the prior comments.
i) BUA calculations have been corrected. Please see response for comment 8 for full breakdown
of revisions.
3) Prior Comment 6aii— "Supplement-EZ Form, Cover Page, Line 7—Please include the width of the
required vegetated setback from surface waters (15A NCAC 02H.1017(10))for this item. It is noted
that the setback and water shown on the plans are not subject to 15A NCAC 02H.1003(4),per email
correspondence with Margie during the administrative completeness review for this project,
however we ask that this value be included. Lines 8-10 may be left as-is. If you are concerned about
this setback width being confused for the one shown on the plans, you can elaborate in the
additional information section on the Drainage Area Page."The waterbody shown on the plans and
20' setback are subject to a different rule/regulatory program than the vegetated setback referenced
on Line 7 of the Cover Page. Our rule, 15A NCAC 02H .1017(10), only applies to surface waters
that are shown on USGS topographic maps. Since the waterbody indicated on the plans is not shown
on the USGS topographic map, it is not subject to 15A NCAC 02H .1017(10) and can use the
previously approved 20' setback instead of the 30' vegetated setback required per 15A NCAC 02H
.1017(10), however, since the project is still subject to 15A NCAC 02H .1017, the vegetated setback
distance from (regulated) surface waters still needs to be indicated on the form (even if there are no
regulated surface waters located on-site). The plans do not need to be changed (since the waterbody
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Piper Meadows
Project#: UNION-2022-006
3rd Review Comments
shown on them is not regulated under our program) and clarifying language will be added to the
permit to avoid future confusion. Please update this information on the Supplement-EZ Form.
i) The cover sheet of the Supp EZ form, as well as the description on the Drainage area sheet, have
been updated to 30'per the comment above.
4) Prior Comment 6bi — "Supplement-EZ Form, Drainage Areas Page, Entire Site Column — Please
complete this column. The information in this column is an accounting of the entire project area
(similar to how the drainage area columns are an accounting of the entire drainage area to the
SCM). The "drainage area"for the entire site column is equal to the project area. NOTE: This
column is not merely a summation of the other columns (although it can be). If there is BUA that is
located on-site and does not drain to an SCM, it would be accounted for in this column, but not in
the drainage area columns."Lines 5 & 6 of the Entire Site Column should correspond to the project
area (Section IV, 7 of the Application) and Line 18 of the Entire Site Column should correspond to
the percent BUA for the entire project area(Section IV, 8 of the Application). Please also refer to the
later comment about the BUA allocated to the individual lots. Please revise as needed. While not
required, you can include a bypass column on this page of the Supplement-EZ Form so that the on-
site portions of all of the columns (SCM drainage areas and bypass)add up to the entire site column.
i) Lines 5 and 6 of the Entire Site column have been revised to reflect the total project area as
shown on the application Section IV, 7 and line 18 now matches the impervious area % as
shown on the application Section IV, 8.
ii) BUA calculations have been corrected. Please see response for comment 8 for full breakdown of
revisions.
iii) A Bypass column has been added to account for the difference in drainage area from the 2 wet
ponds and the entire site. Please note that no BUA is proposed within this Bypass drainage area
and consists primarily of off lot and undisturbed areas on site.
5) Prior Comment 6bii 1 — "Supplement-EZ Form, Drainage Areas Page, Columns 1 & 2 —As noted
earlier, there appears to be a discrepancy with the information shown in these columns... " BUA
accounting issues have been grouped together and follow the prior comments.
i) BUA calculations have been corrected. Please see response for comment 8 for full breakdown
of revisions.
6) Prior Comment 6cvi— "Line 37— This item refers to the diameter of the small drawdown orifice (2"
& 2.5')." The Wet Pond #1 column indicates that the diameter of the drawdown orifice is 2.5"
(plans and calculations indicate 2.0"). Please revise as needed.
i) Line 37 of Wet Pond#1 has been revised to show 2" as the drawdown orifice size to match the
calculations and plans.
7) Prior Comment 6cvii— "Supplement-EZ Form, Wet Pond Page, Line... 44... " See earlier comment
with regard to the forebay exits.
i) Depth of forebay at entrance and exit (lines 43 and 44) have bee revised to reflect the new
forebay grading and providing at minimum 0.5"of sedimentation at the exit.
8) There still appears to be issues with the BUA accounting for this project,please revise as needed:
a) Per the provided deed restriction document, 5,600 sf of BUA is allocated to each individual
lot. Since this project is proposing a total of 80 lots, this results in a total amount of BUA
allocated to the individual lots of 448,000 sf(5,600 sf/ lot * 80 lots = 448,000 sf). Per the
Supplement-EZ Form (Drainage Areas Page, Entire Site Column, Line 9), the total amount
of BUA shown allocated to the individual lots is 316,132 sf. The amount of BUA allocated
to the individual lots as shown in the deed restriction document and Supplement-EZ Form
should be the same. Please revise as needed3
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Piper Meadows
Project#: UNION-2022-006
3rd Review Comments
b) The BUA breakdown in the Application (Section IV, 10) does not match the breakdown as
shown in the Supplement-EZ Form (Drainage Areas Page). For example, for Wet Pond #1,
the Application (and calculations) shows a total of 81,218 sf of BUA allocated to the
individual lots (Buildings/Lots), 38,384 sf of BUA for streets, 13,590 sf for sidewalks, and
12,000 sf for future. The Supplement-EZ Form indicates 93,318 sf allocated to the
individual lots (Line 9), 38,384 sf of BUA for streets (roadways), 13,590 sf for sidewalks,
and 0 sf for future. The accounting should be the same throughout the submittal materials.
NOTE: "Future" BUA refers to common area BUA reserved for a future use and is not
included in the BUA allocated to individual lots. Please revise as needed.
c) Section IV, 7 & 8 of the application indicate that there is approximately 9.49 ac
(approximately 413,000 sf) of BUA associated with this project (28.9% BUA for a project
area of 32.83 ac)whereas the Supplement-EZ Form indicates 453,722 sf.
i) BUA calculations have been revised as follows:
ii) The deed restriction document has been revised to allow only 4,220 SF. lot. This number
accounts for the proposed house pad, driveway, sidewalk in front of the lot along the roadway,
as well as 500 additional sf. per lot for future patios, sheds, and leadwalks. This new total lot
BUA is now 337,600 sf.
iii) The Supp EZ form has been revised to show this 337,600 sf. as BUA on subdivided lots for the
entire site and split as needed amongst Wet Ponds 1 and 2.
iv) The BUA breakdown on the application has been revised:
a) The BUA on lots has been increased as mentioned above to match the revised deed
restriction total.
b) The street areas stayed generally the same (though we found very minor discrepancies when
re-comping these areas and have updated accordingly).
c) The sidewalk areas have been drastically reduced since the majority of the sidewalks is now
lumped into the on lot BUA as mentioned above. The remaining sidewalk area listed here
includes just those sidewalks which do not directly front a lot.
d) The `Future' row has been removed entirely and this area is now lumped into the on-lot
BUA. This future impervious was intended to be additional patios, sheds, etc. that may be
installed by homeowners at a future point. Since that is not the intention of this row,we have
removed it.
e) The application breakdown should now perfectly match breakdown shown in both the
calculations map and the Supp EZ form.
v) All impervious area%'s have been corrected(application Section IV, 8 as well as Supp EZ form
row 18).
2) Please revise the 620' contour for the forebay of Wet Pond #1 as it appears to be off(it is a straight
line instead of a loop).
i) The 620 contour of this forebay has been corrected to correctly loop within itself.
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 July 17,2023,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 SW3221202 on all correspondence.
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2013-A Van Buren Avenue
Indian Trail,NC 28079
Ph 704 882 4222
Fax [phone]

Piper Meadows
Project#: UNION-2022-006
3rd Review Comments
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.
As you have any questions,please do not hesitate to contact our office.
Sincerely,
Eagle Engineering Inc.
Steven Prophet
Senior Project Manager
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2013-A Van Buren Avenue
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