SW3220805_Wetland Determination/Report_20220921

July 18, 2022
Mr. Tim Thompson
LGI Homes
724 Hawley Street
Charlotte, North Carolina 28214
Email: [e-mail]
SUMMIT
ENGINEERING • LABORATORY • TESTING
A Universal Engineering Sciences Company
Subject: Estimated Seasonal High Water Table (ESHWT) Determinations
Village at Granite Phase III
Limestone Terrace
Cornelius, North Carolina
SUMMIT Project No. 3554.G0150
Dear Mr. Thompson
SUMMIT Engineering, Laboratory and Testing, Inc. (SUMMIT) is pleased to submit this letter
summarizing our observations of the soil test borings as related to Estimated Seasonal High
Water Table Elevation (ESHWT) determinations in the proposed stormwater BMP ponds to be
constructed for the proposed project listed above. This report contains a brief description of the
project information provided to us, general site and subsurface conditions revealed during this
exploration.
PURPOSE OF EXPLORATION
The primary purpose of this exploration was to obtain information regarding the subsurface
conditions in the proposed stormwater BMP ponds, assess the engineering characteristics of the
subsurface materials, and determination of the estimated seasonal high water table mark (if
evident).

Summary of ESHWT Determinations SUMMIT Project No. 3554.G0150
Village at Granite Phase III July 18, 2022
This report contains the following items:
• Site Vicinity Map and Hand Auger Boring Location Plan,
• Summary of Test Boring Observations, visual soil classifications and descriptions,
• A general review of the subsurface soils and estimated seasonal high water table depth
from existing ground surface (if evident),
• Groundwater level measurements.
EXPLORATION PROCEDURES
SUMMIT visited the site on July 14t" of 2022 and performed two hand auger borings (identified
as HA-1 and HA-2) in the proposed stormwater BMP ponds. The approximate location of the
boring is shown on Figure 2 — "Hand Auger Boring Location Plan" provided in Appendix 2. The
client (LGI Homes) provided SUMMIT a plan sheet titled "Grading Plan & Pipe Schedules"
prepared by Bohler Engineering NC, PLLC, dated March 15, 2022, that indicated the approximate
locations of the proposed stormwater BMP ponds. The borings were located by professionals
from our office using the provided plan, recreation -grade handheld GPS, existing topography,
and aerial maps as reference. Since the boring locations were not surveyed, the location of the
borings should be considered approximate. We recommend the actual boring location be
surveyed to determine the actual boring location and existing ground elevation.
Hand Auger Borings HA-1 and HA-2 were generally advanced by manually twisting a bucket auger
into the ground to approximate depths of 8 and 10 feet below the existing ground surface,
respectively. The soil samples collected were visually examined and classified in general
accordance with ASTM D-2488. Water level measurements were attempted at the termination
of drilling. The classification symbols are depicted on the "Hand Auger Boring Logs" provided in
Appendix 2.
GENERALIZED SUBSURFACE STRATIGRAPHY
General subsurface conditions observed during our geotechnical exploration are described
herein. For more detailed soil descriptions and stratifications at the test location, the respective
"Hand Auger Boring Logs" provided in Appendix 2 should be reviewed. The horizontal

Summary of ESHWT Determinations SUMMIT Project No. 3554.G0150
Village at Granite Phase III July 18, 2022
stratification lines designating the interface between various strata represents approximate
boundaries. Transitions between different strata in the field may be gradual in both the
horizontal and vertical directions.
Beginning from the ground surface, a layer of topsoil (surficial organic soils) was observed with
thicknesses of approximately 3 inches. Beneath the topsoil layer in Hand Auger HA-1, fill
(disturbed) soils that consisted of lean clays (CL) were encountered to an approximate depth of
2 feet below the existing ground surface. Beneath the fill soils in Hand Auger HA-1 and the topsoil
layer in HA-2, residual (undisturbed) soils were encountered that generally consisted of lean clays
(CL) and sandy silts (ML). Hand auger refusal conditions were encountered in Hand Auger Boring
HA-1 at an approximate depth of 8 feet below the existing ground surface.
GROUNDWATER LEVEL MEASUREMENTS
At the time of drilling and after waiting more than 24 hours, groundwater was not observed in
the borings. It should also be noted that groundwater levels tend to fluctuate with seasonal and
climatic variations, as well as with some types of construction operations. Therefore, water may
be encountered during construction at depths not indicated in the borings performed for this
exploration.
ESTIMATED SEASONAL HIGH WATER TABLE
ESHWT is defined as the shallowest depth to a wet soil layer as a result of "true" or "permanent"
groundwater at any time during the year. The ESHWT is typically identified with a change in the
color of the soil layer due to water staining (typically, gray redoximorphic depletions and
mottling). Spots or blotches of different color or shades of color interspersed with a dominant
color in soil, commonly referred to as mottling. Mottling is a historic indication for the presence
of groundwater caused by intermittent periods of saturation and drying, and may be indicative
of poor aeration and impeded drainage. Mottling is a "general indication of groundwater" flow
through this layer, but it is not known whether the groundwater flow was recent.

Summary of ESHWT Determinations SUMMIT Project No. 3554.G0150
Village at Granite Phase III July 18, 2022
CONCLUSIONS
Based on our observations, ESHWT indicators were not evident in soils sampled in the hand auger
borings. Where the ESHWT is defined as the shallowest depth to a wet soil layer as a result of
"true" or "permanent" groundwater at any time during the year. The BMP designer should take
into consideration that perched water conditions may exist above the low permeable PWR
stratum.
The following table summarizes the results of the borings and our observations.
Summary Table of the Boring Results and Our Observations
Approx.
GW Depth
Hand Auger
Boring
ESHWT
GW Depth
After
Refusal
Test
Depth
Depth
ATD
24 Hours
Depth
Location
(Feet)'
(Feet)
(Feet)'
(Feet)'
(Feet)'
HA-1
8
NE
NE
NE
8
HA-2
10
NE
NE
NE
NE
1 Depths from existing ground surface.
NE — Not Encountered in boring
The analyses submitted in this report were based, in part, on data obtained from this exploration.
If the above -described project conditions are incorrect or changed after the issuing of this report,
or subsurface conditions encountered during construction are different from those reported,
SUMMIT should be notified and these recommendations should be re-evaluated based on the
changed conditions to make appropriate revisions. We have prepared this report according to
generally accepted geotechnical engineering practices. No warranty, express or implied, is made
as to the professional advice included in this report.

Summary of ESHWT Determinations SUMMIT Project No. 3554.G0150
Village at Granite Phase III July 18, 2022
CLOSING
SUMMIT appreciates the opportunity to provide our professional services for you on this project.
If you have any questions concerning the information in this proposal or if we may be of further
service, please contact us at 704.504.1717.
Sincerely,
SUMMIT ENGINEERING, LABORATORY & TESTING, INC.
��I�tiIIJii{t��
` RO`'
FAL r+�
042323 '
.y� 7/18/202?
L ON
111110
Robert L. Price, P.E.
Chief Engineer
LIST OF APPENDICES
"Xty111111111.,
CAR p4��,��'
SUMMIT
m : Engineering, Laboratory : oz
8 Testing, Inc.
No. F-1454
<
Appendix 1 Figure No. 1— Site Vicinity Map
Adam Jordan
Assistant Project Manager
Figure No. 2 — Hand Auger Boring Location Plan
Appendix 2 Hand Auger Boring Logs

Summary of ESHWT Determinations
Village at Granite Phase III
SUNEMT Project No. 3554.G0150
July 18, 2022
SUMMIT
ENGINEERING • LABORATORY • TESTING
A Universal Engineering Sciences Company
APPENDIX 1
Figures

Oak Dr
9..
Figure 1
Site Location Plan
Village at Granite Phase III
Limestone Terrace
Granity Quarry, North Carolina
SUMMIT
SCALE: NTS
SUMMIT Project No.: 3554.G0150
n u.N. l e�i—d.g sd.­ C.. W"
3575 Centre Circle
Fort Mill, South Carolina 29715
[phone]

m
MWE
Ofso
1.
E�j8]
INS .��I®�®�� -•��rs-�.
Ow, m
m, won
'• �� Lt la©��i .�� III •� ,� ; �
.r
• ��II�1®IIhI��I�'ti i"'qii®Ids �-�®�I�f�ll�
�r�l®1llli�l�lf� �'' �'► mull®1® � �Ilil il�s,®�
�I Homes - Village at Gra�nllte �
stone Terrace
•.'gyp ® _� �© I�-� ® B
Figure 2
Village at GranitePhase
III
Hand Auger Boring Location
Limestone Terrace 1AM
Plan SUMMIT
Granity Q•Carolina

Summary of ESHWT Determinations
Village at Granite Phase III
SUMMIT Project No. 3554.G0150
July 18, 2022
SUMMIT
ENGINEERING • LABORATORY • TESTING
A Universal Engineering Sciences Company
APPENDIX 2
Hand Auger Boring Logs

/Ak
HAND AUGER BORINGS & DCP TESTING SHEET
Project Name: Villages at Granite Townhomes Project No.: 3554.G0150
SUMMIT [ ]D 7 n) 77 7�
ENGINEERING • LABORATORY • TESTING Performed By. N. Sacks / R. F1tZGlbbon Date. 0 //14/2022
A Universal Engineering Sciences Company
Location*
Depth*
feet
Soil Descri tion
Depth*
feet
DCP Blows Per 13/4-inch
1st
2nd
3rd
Av .
0 — 0.25
Approx. 3 inches of Topsoil
-1
9
6
is
12.0
HA-1
0.25 1
FILL: Olive Brown, Reddish Brown, and Gray Sandy Lean
CLAY
-2
9
15+
15+
-3
15+
15+
1-2
Dark Gray, Dark Brown, and Reddish Brown Lean CLAY
-4
14
15+
15+
2-5
RESIDUUM: Brown Sandy SILT
-5
15+
15+
5-6
Dark Brown Micaceous Sandy SILT with Rock Fragments
-6
15+
15+
6-8
Brown Sandy SILT
-7
15+
15+
-8
15+
15+
HAR at 8 feet bgs on Rock
Boring Terminated at 8 feet bgs
Groundwater not encountered at time of digging
0 — 0.25
Approx 3 inches of Topsoil
-1
15+
15+
HA-2
0.25 - 1
RESIDUUM: Reddish Brown Sandy Lean CLAY
-2
15+
15+
1-2
Reddish Brown Sandy Lean CLAY
-3
15+
15+
2-5
Reddish Brown Slightly Clayey Sandy SILT
-4
13
15+
15+
5-7
Reddish Brown Sandy SILT
-5
11
15+
15+
7-10
Reddish Brown and Yellowish Brown Sandy SILT with
Manganese Stains
-6
10
13
15+
15+
-7
13
13
13
13.0
-8
12
13
12
12.5
Boring Terminated at 10 feet bgs.
-9
15+
Groundwater not encountered at time of digging
-10
ELI
15+
IL��J
Notes: * From Existing Ground Elevation
* HAR — Hand Auger Refusal.