HomeMy WebLinkAboutNarrative - Hwy 421 N - Wilmington NC - 1st Submittal_v1Site Narrative
7-Eleven Convenience Store
3705 N. US Hwy 421
Wilmington, NC
Prepared For
Encore-Cliffdale, LLC
1646 W. Snow Ave.
Tampa, FL 33606
Dated: 11/11/24
Prepared By:
Page 2
7-ELEVEN CONVENIENCE STORE
3705 N. US HWY 421
WILMINGTON, NC
TABLE OF CONTENTS
Section Page
1.0 PROJECT SUMMARY ........................................................................................................ 3
2.0 UTILITIES ............................................................................................................................ 3
3.0 STORMWATER MANAGEMENT ........................................................................................ 3
APPENDIX A GEOTECH REPORT
APPENDIX B STORMWATER CALCULATIONS
APPENDIX C WATER DEMAND CALCUALTIONS
APPENDIX D SANITARY SEWER DEMAND CALCULATIONS
Page 3
SITE NARRATIVE
7-Eleven Convenience Store
3705 N. US Hwy 421
Wilmington, NC
1.0 Project Summary:
The site is located at 3705 N. US Hwy 421 in New Hanover County, NC. According to
the County GIS, the existing property is identified with the PIN# R03200-001-012-000.
The site is currently partially developed with an existing building and parking lot. The
parcel is zoned to I-2 Industrial. The site is surrounded by similarly zoned properties.
The proposed development will include the clearing of the existing lot in preparation for
the construction of the new 7-Eleven convenience store, fuel canopy, and parking lot.
Off-site improvements are limited to the construction of a new commercial entrance and
turn lane along US Hwy 421. The entirety of the proposed improvements will result in
approximately 5.19 acres of total land disturbance.
2.0 Utilities:
Water
The proposed water services will tap off of the new 8” water main extension that was
installed as part of the Colonial Materials development. A new tap and 1.5” meter is
proposed for the proposed domestic service line. Any existing water meters that will not
be reused will be abandoned in place. There is an existing fire hydrant that was also
installed as part of the colonial materials development located directly in front of the site
that will provide fire protection for the proposed buildings.
Sanitary Sewer
The proposed sanitary sewer service will required the installation of an engineered
septic field located just south of the proposed building location.
3.0 Stormwater Management
Based upon geotechnical investigation, the existing soils are classified as poorly graded
sand. The development will result in approximately 5.19 Ac. of land disturbance The
topography splits the site into two major drainage areas. The majority of the site sheet
flows to the northwest toward the existing overhead power line easement that runs
through the property. This area is identified in the plans as drainage area DA-B.
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A small portion of the site is collected by stormwater infrastructure that was installed as
part of the Colonial Materials construction plans. This area is identified in the plans as
drainage area A. The infrastructure installed as part of the Colonial Materials plans
anticipated this area to be heavily developed using a CN=94.
The proposed on-site improvements have been designed to ensure that each of the
existing drainage areas will see a net reduction in the peak flows from the 2, 10, 25 and
100 year storm events. This net reduction in run-off for drainage area DA-B will be
achieved through on-site detention and infiltration through an infiltration basin BMP. The
infiltration basin has been sized to hold the entirety of the of all storm events up to the
25yr storm without leaving the site. The run-off released from the BMP during the 100 yr
storm event will still result in a significant reduction from the pre developed conditions.
The net reduction in run-ff for drainage area DA-a will be achieved through the reduction
in impervious area based on the proposed improvements shown on the construction
plans for Colonial Materials development.
The SCS TR-55 method was used in calculating pre and post development flow rates.
Due to the small size of the drainage areas and the impervious coverage, a minimum of
5 minutes for the time of concentration was used for all calculations.
Table 1.0 below provides a summary of the pre and post development runoff rates for
the 2, 10, 25 and 100yr storms. More details stormwater calculations for each drainage
area are included in Appendix D of this documents.
Table 1.0 - Pre to Post Summary Table.
1yr 10yr 25yr 100yr 1yr 10yr 25yr 100yr
Pre-Development 1.69 2.67 3.07 3.88 1.22 6.45 9.04 15.09
Post-Development 1.32 2.06 2.40 3.12 0.31 1.30 1.77 2.85
Storm Event (cfs)Site Condition
DA-A
Storm Event (cfs)
DA-B
Page 5
APPENDIX A
GEOTECHNICAL REPORT
Report Cover Page
7-Eleven
3705 Highway 421
Wilmington, NC
Geotechnical Engineering Report
July 29, 2024 | Terracon Project No. K6245049
Prepared for:
Encore Real Estate
1646 West Snow Avenue, Suite #63
Tampa, Florida 33606
2108 Capital Drive
Wilmington, North Carolina 28405
P (910) 478-9915
North Carolina Registered Firm: F-0869
Terracon.com
Facilities | Environmental | Geotechnical | Materials
Report Cover Letter to Sign July 29, 2024
Encore Real Estate
1646 West Snow Avenue, Suite #63
Tampa, Florida 33606
Attn: Pat Budronis
P: (813) 495-6536
E: pbudronis@encore-re.com
Re: Geotechnical Engineering Report
7-Eleven
3705 Highway 421 North
Wilmington, North Carolina
Terracon Project No. K6245049
Dear Mr. Budronis:
We have completed the scope of Geotechnical Engineering services for the above
referenced project in general accordance with Terracon Proposal No. PK6245049 dated
June 20, 2024. This report presents the findings of the subsurface exploration and
provides geotechnical recommendations concerning earthwork and the design and
construction of foundations, floor slabs, pavements, and Stormwater Control Measures
(SCMs) for the proposed project.
We appreciate the opportunity to be of service to you on this project. If you have any
questions concerning this report or if we may be of further service, please contact us.
Sincerely,
Terracon
Michael P. Delaney, P.E. Andrew A. Nash, P.E.
Senior Staff Engineer Geotechnical Department Manager
Registered, NC 056487
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials i
Table of Contents
Introduction .................................................................................................... 1
Project Description .......................................................................................... 1
Site Conditions ................................................................................................ 3
Geotechnical Characterization ......................................................................... 3
Seismic Considerations .................................................................................... 5
Geotechnical Overview .................................................................................... 6
Earthwork ....................................................................................................... 7
Shallow Foundations ..................................................................................... 14
Floor Slabs .................................................................................................... 17
Below-Grade Structures................................................................................. 18
Pavements .................................................................................................... 19
Stormwater Control Measures ........................................................................ 23
General Comments ........................................................................................ 24
Figures
GeoModel
Attachments
Exploration and Testing Procedures
Site Location and Exploration Plans
Exploration and Laboratory Results
Supporting Information
Note: This report was originally delivered in a web-based format. Blue Bold text in the
report indicates a referenced section heading. The PDF version also includes hyperlinks
which direct the reader to that section and clicking on the logo will bring you
back to this page. For more interactive features, please view your project online at
client.terracon.com.
Refer to each individual Attachment for a listing of contents.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 1
Introduction
This report presents the results of our subsurface exploration and Geotechnical
Engineering services performed for the proposed 7-Eleven to be located at 3705
Highway 421 North in Wilmington, North Carolina. The purpose of these services was to
provide information and geotechnical engineering recommendations relative to:
■ Exploration logs with field and laboratory data
■ Stratification based on visual soil classification and published
■ Groundwater levels observed during and/or after the completion of drilling
■ Site Location and Exploration Plans
■ Subsurface exploration procedures
■ Description of subsurface conditions
■ Recommended foundation options and engineering design parameters
■ Estimated settlement of foundations
■ Recommendations for design and construction of interior floor slabs
■ Seismic site classification
■ Liquefaction Potential
■ Earthwork recommendations including site/subgrade preparation
■ Recommended pavement options and design parameters
■ Stormwater management considerations
The geotechnical engineering Scope of Services for this project included the
advancement of electronic Cone Penetrometer Test (CPT) soundings and Macro-Core
sampling, laboratory testing, engineering analysis, and preparation of this report.
Drawings showing the site and exploration locations are shown on the Site Location
and Exploration Plan, respectively. The results of the laboratory testing performed on
soil samples obtained from the site during our field exploration are included on the
exploration logs and as separate graphs in the Exploration and Laboratory Results
section.
Project Description
Our initial understanding of the project was provided in our proposal and was discussed
during project planning. A period of collaboration has transpired since the project was
initiated, and our final understanding of the project conditions is as follows:
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 2
Item Description
Information
Provided
Project information was obtained via email correspondence
between Terracon and Encore on June 18, 2024. The following
attachments were provided to Terracon:
■ Hwy 421 N - Wilmington - Concept 6
■ Civil Design Guidelines - 2023 Q2 (7-Eleven)
Project
Description
Plans for the project include the construction of a new 4,815
square-foot 7-Eleven convenience store with associated
parking/drives, underground storage tanks, fueling canopies,
and a stormwater control measure (SCM).
Building
Construction Anticipated to be metal-framed or CMU with slab-on-grade
Finished Floor
Elevation Not provided; anticipated to be within 2 feet of existing grade
Maximum Loads
Anticipated structural loads were not provided. In the absence
of information provided by the design team, we used the
following loads in estimating settlement and developing
foundation recommendations based on our experience with
similar projects.
■ Columns: 50 kips
■ Walls: 3 kips per linear foot (klf)
■ Slabs: 150 pounds per square foot (psf)
Grading/Slopes We assume less than 2 feet of cut or fill is anticipated to
develop final grade, excluding remedial grading requirements.
Below-Grade
Structures
Three (3) 20,000-gallon and underground fuel storage tanks are
planned for the fuel facility. The planned bottom of tank
elevation was not provided.
Pavements
We understand both rigid (concrete) and flexible (asphalt)
pavement sections will be constructed.
The provided traffic loading information from the 7-Eleven Civil
Design Guide is as follows:
■ Light Duty (Auto) - Flexible: 94,000 ESALs
■ Light Duty (Auto) - Rigid: 2,130,000 ESALs
■ Heavy Duty (Truck) - Flexible: 534,000 ESALs
■ Heavy Duty (Truck) – Rigid: 2,528,000 ESALs
The pavement design period is 15 years.
Building Code 2018 International Building Code (IBC)
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 3
Terracon should be notified if any of the above information is inconsistent with the
planned construction, especially the grading limits, as modifications to our
recommendations may be necessary.
Site Conditions
The following description of site conditions is derived from our site visit in association
with the field exploration and our review of publicly available geologic and topographic
maps.
Item Description
Parcel
Information
The project is located at 3705 Highway 421 North in Wilmington,
North Carolina. The site spans approximately 5.16 acres.
See Site Location
Existing
Improvements
The site is currently developed with a single-story building with
associated parking and drives on the eastern portion of the site.
The remainder of the site is undeveloped and bound by an
overhead electrical right of way to the northwest.
Current Ground
Cover Asphalt, grass and woods
Existing
Topography
The site is relatively flat with elevations ranging from 11 feet to
13 feet MSL based on publicly available GIS information
provided by Google Earth ProTM.
Geotechnical Characterization
Geologic Setting
The project site is located within the Atlantic Coastal Plain physiographic province.
Bedrock of the Late Mesozoic age is present at depths of greater than 2,000 feet, and is
overlain by Lower and Upper Cretaceous, Tertiary, Pleistocene and Recent Sediments.
The Coastal Plain soils consist mainly of marine sediments that were deposited during
successive periods of fluctuating sea level and moving shoreline. The soils include sands,
silts, and clays with irregular deposits of shells, which are typical of those lain down in a
shallow sloping sea bottom. Recent alluvial sands, silts, and clays are typically present
near rivers and creeks.
According to USGS Mineral Resources On-Line Spatial Data based on the 1998 digital
equivalent of the 1985 Geologic Map of North Carolina, the site is mapped within the
Peedee Formation (Cretaceous).
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 4
Soil Profile
We have developed a general characterization of the subsurface conditions based upon
our review of the subsurface exploration, laboratory data, geologic setting and our
understanding of the project. This characterization, termed GeoModel, forms the basis of
our geotechnical calculations and evaluation of the site. Conditions observed at each
exploration point are indicated on the individual logs. The individual logs can be found in
the Exploration and Laboratory Results and the GeoModel can be found in the
Figures attachment of this report.
As part of our analyses, we identified the following model layers within the subsurface
profile. For a more detailed view of the model layer depths at each boring location, refer
to the GeoModel. Surficial materials (topsoil, asphalt, etc.) are not included in the
GeoModel.
Model
Layer Layer Name General Description
1 Loose to Medium
Dense Sand Sand with varying amounts of silt and clay
2 Medium Dense to
Dense Sand
Sand with varying amounts of silt and clay, clay
lenses at varying depths
Groundwater Conditions
Based on the measured water levels during exploration, cave in depths, CPT data, and
moisture condition of the soil samples, groundwater is anticipated between depths of 6
feet and 8 feet below the existing ground surface. It should be noted that groundwater
levels are typically at their deepest in the current season.
Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall,
runoff and other factors not evident at the time the soundings were performed.
Therefore, groundwater levels during construction or at other times in the life of the
structure may be higher or lower than the levels indicated on the exploration logs. The
possibility of groundwater level fluctuations should be considered when developing the
design and construction plans for the project.
A soil scientist licensed in the state of North Carolina was contracted to evaluate the
seasonal-high water table and perform infiltration testing at locations SCM-01 and SCM-
02. The SHWT and infiltration results are presented in the attached Stormwater Soil
Evaluations Report within Supporting Information.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 5
Seismic Considerations
Site Classification
The seismic design requirements for buildings and other structures are based on Seismic
Design Category. Site Classification is required to determine the Seismic Design
Category for a structure. The Site Classification is based on the upper 100 feet of the
site profile defined by a weighted average value of either shear wave velocity, standard
penetration resistance, or undrained shear strength in accordance with Section 20.4 of
ASCE 7 and the International Building Code (IBC). Based on the soil properties observed
at the site and as described on the exploration logs and results, our professional opinion
is for that a Seismic Site Classification of D be considered for the project. Subsurface
explorations at this site were extended to a maximum depth of 49.5 feet. The site
properties below the exploration depth to 100 feet were estimated based on our
experience and knowledge of geologic conditions of the general area.
Liquefaction
Liquefaction occurs when a rapid buildup in water pressure, caused by ground motion,
pushes sand particles apart, resulting in a loss of strength and later densification as the
water pressure dissipates. This loss of strength can cause bearing capacity failure while
the densification of liquefied layers after the earthquake can cause excessive settlement
of the ground surface and structures.
The liquefaction potential of a site depends on the design earthquake’s peak ground
acceleration, which depends on the design earthquake’s magnitude and the distance
from the site to the design seismic event. The liquefaction potential also depends on the
presence of granular soils below the water table, the relative densities of the granular
soils, the percent fines of the soils, and the geologic ages of the soil deposits. The
amount of ground surface settlement is dependent on the initial relative densities of the
soils which liquefy due to the earthquake. Based on the relatively mild ground motions
associated with the design earthquake, the potential for liquefaction is negligible at this
site.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 6
Geotechnical Overview
Based upon the geotechnical conditions encountered in our exploration, the site
generally appears suitable for the proposed construction, provided that the
recommendations given herein are implemented in the design and construction phases
of this project. Our earthwork recommendations include vibratory rolling the subgrade
and remediation of soils that are not improved. Following the recommended earthwork,
the proposed construction can be supported on shallow foundations.
The near-surface soils generally consisted of sand that can be compacted in place,
provided that it is free of groundwater. Please note however, that clean sand (SP) and
slightly silty sand (SP-SM) with less than 12% fines have very little “binder” and can be
difficult to compact and maintain a stable fill surface upon. The on-site soils and locally
available soils are predominantly these soils types. Clean fine sands (SP) are common in
the vicinity of the site and are locally known as “sugar sands”. These soils typically
require the addition of large amounts of water, even during wet, cool weather
conditions, to achieve compaction. If the fill dries out, they will tend to fail compaction
tests, degrade upon drying, and rut under construction traffic. The fill surfaces need to
be covered with additional fill or ABC stone base immediately. Alternatively, if they are
allowed to dry out, they can be moisture conditioned, re-compacted, and re-testing prior
to subsequent fill or pavement material placement.
Effective drainage should be completed early in the construction sequence and
maintained throughout the life of the proposed development to avoid potential issues
associated with a wet subgrade. If possible, the grading should be performed during the
warmer and drier times of the year. If grading is performed during the winter months,
an increased risk for possible undercutting and replacement of unstable subgrade will
persist. Further details are provided in the Earthwork section of this report.
The recommendations contained in this report are based upon the results of field and
laboratory testing (presented in the Exploration and Laboratory Results),
engineering analyses, and our current understanding of the proposed project. The
General Comments section provides an understanding of the report limitations.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 7
Earthwork
Earthwork is anticipated to include demolition, clearing and grubbing, excavations, and
engineered fill placement. The following sections provide recommendations for use in the
preparation of specifications for the work. Recommendations include critical quality
criteria, as necessary, to render the site in the state considered in our geotechnical
engineering evaluation for foundations, floor slabs, and pavements.
Demolition
Site preparation should begin with the demolition of the existing structures/pavements
and debris removal. As part of the demolition, buried utilities and/or concrete
foundations should also be removed. Existing utilities that are to be abandoned should
be removed or filled with grout. The excavations resulting from foundation and utility
removal should be properly backfilled with compacted structural fill as described in the
following subsections. Utilities that are to remain in service should be accuratel y located
horizontally and vertically to minimize conflict with new foundation construction.
Site Preparation
Prior to placing fill, existing vegetation, topsoil, and root mats should be removed.
Complete stripping of the topsoil should be performed in the proposed building and
parking/driveway areas. Mature trees are located within or near the footprint of some of
the proposed construction, which will require removal at the onset of construction. Tree
root systems can remove substantial moisture from surrounding soils. Where trees are
removed, the full root ball and all associated dry and desiccated soils should be
removed. The soil materials which contain less than 5 percent organics can be reused as
engineered fill provided the material is moisture conditioned and properly compacted.
Although no evidence of fill or underground facilities (such as septic tanks, cesspools,
basements, and utilities) was observed during the exploration and site reconnaissance,
such features could be encountered during construction. If unexpected existing fill soils
or underground facilities are encountered, such features should be removed, and the
excavation thoroughly cleaned prior to backfill placement and/or construction.
Subgrade Preparation
After stripping and removing topsoil and once any areas of cut have been excavated to
proposed subgrade elevation, the exposed subgrade soils in the building and pavement
footprints should be densified in place using a medium weight vibratory roller. The
purpose of the vibratory rolling is to densify the exposed subgrade soils for floor slab
and pavement support and to potentially improve the foundation bearing soils. The roller
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 8
should make at least six passes across the site, with the second set of three passes
perpendicular to the first set of three passes with intermittent vibration activated. If
water is brought to the surface by the vibratory rolling, the operation should be
discontinued until the water subsides. Vibratory rolling should be completed during dry
weather. Static rolling and additional repairs should be anticipated for areas too wet for
vibratory rolling.
After the vibratory rolling, pore pressures should be allowed to dissipate for a minimum
of 16 hours. After the waiting period, proofrolling should be performed on the exposed
subgrade soils in areas to receive fill or at the subgrade elevation with a loaded,
tandem-axle dump truck (15 to 20 ton total vehicle weight) or similar rubber-tired
construction equipment. Proofrolling is recommended as a means of detecting areas of
soft or unstable subgrade soils. The proofrolling should be performed during a period of
dry weather to avoid degrading an otherwise suitable subgrade. The proofrolling
operations should be observed by a representative of the geotechnical engineer.
Subgrade soils that exhibit excessive rutting or deflection during proofrolling should be
repaired as directed by the field representative. Typical repairs include overexcavation
followed by replacement with either properly compacted fill or by a subgrade
stabilization fabric in conjunction with a sand fill or crushed stone.
If subgrade soils are unsuitable, they will require removal and replacement; however, if
they are unstable due to excessive moisture, the most economical solution for
remediation may be to scarify, dry and recompact the material. This remediation is
most effective during the typically hotter months of the year (May to October). If
construction is performed during the cooler period of the year, the timeline for
scarifying, drying, and recompacting typically increases considerably and may lead to
alternative remediation solutions. These solutions can include overexcavation of some or
all of the unstable material to be backfilled with either approved structural fill or
geotextile and ABC Stone. Potential undercutting can be reduced if the site preparation
work is performed during a period of dry weather and if construction traffic is kept to a
minimum on prepared subgrades. We recommend that the contractor submit a unit rate
cost for undercutting as part of the bidding process.
Excavation Considerations
We anticipate that excavations for the proposed construction can generally be
accomplished with conventional earthmoving equipment.
Excavation Safety: As a minimum, excavations should be performed in accordance
with OSHA 29 CFR, Part 1926, Subpart P, “Excavations” and its appendices, and in
accordance with any applicable local and/or state regulations.
Excavations or other activities resulting in ground disturbance have the potential to
affect nearby structures, pavements, and utilities. Our scope of services does not include
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 9
review of available final grading information or consider potential temporary grading
performed by the contractor for potential effects such as ground movement beyond the
project limits. A preconstruction/ precondition survey should be conducted to document
nearby property/infrastructure prior to any site development activity. Excavation or
ground disturbance activities should be monitored or instrumented for potential ground
movements that could negatively affect nearby structures, pavements, and utilities.
Excavation should not be conducted below a downward 1:1 projection from existing
foundations without engineering review of shoring requirements and geotechnical
observation during construction.
Construction site safety is the sole responsibility of the contractor who controls the
means, methods, and sequencing of construction operations. Under no circumstances
shall the information provided herein be interpreted to mean Terracon is assuming
responsibility for construction site safety or the contractor's activities; such
responsibility shall neither be implied nor inferred.
Construction Dewatering: The groundwater table could affect overexcavation efforts,
especially for overexcavation and replacement of lower strength soils. A temporary
dewatering system consisting of sumps with pumps may be necessary to achieve the
recommended depth of overexcavation depending on groundwater conditions at the time
of construction. Backfill consisting of clean gravel (such as AASHTO Size No. 57 stone)
wrapped in geotextile fabric is often most suitable for undercut depths exceeding that of
the water table.
The responsibility for dewatering of construction excavations and preventing excessive
damage of existing and new buildings, structures, utilities, and other site improvements
due to dewatering should lie solely with the contractor. This information is provided only
as a service and under no circumstance should Terracon be assumed to be responsible
for the effectiveness of the construction dewatering method(s) selected by the
contractor.
Permanent Dewatering
Since design grades are not known at this time, permanent site dewatering of the
shallow groundwater in the proposed building and pavement areas may or may not be
necessary. Raising site grades in the proposed building and pavement areas above the
existing ground surface could eliminate the need for permanent dewatering, such as
French drains or blanket drains. Once a preliminary grading plan has been prepared, it
should be provided to Terracon for review and comment regarding the need for
permanent dewatering of the shallow groundwater at the site.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 10
Fill Material Types
Fill required to achieve design grade should be classified as structural fill and general fill.
Structural fill is material used below or within 10 feet of structures, pavements, site
retaining walls, stormwater control measures, or constructed slopes. General fill is
material used to achieve grade outside of these areas.
Material property requirements for on-site soil for use as general fill and structural fill
are noted in the table below:
Property General Fill Structural Fill
Composition Free of deleterious
material Free of deleterious material
Maximum particle size
6 inches
(or 2/3 of the lift
thickness)
3 inches
Fines content Not limited Not limited
Plasticity Not limited Maximum liquid limit of 50
Maximum plasticity index of 20
Earthen materials used for structural or general fill should meet the following material
property requirements:
Soil Type1 USCS Classification Acceptable Location for
Placement
Imported Soil GW, GP, GM, GC, SM, SP,
SP-SM, SP-SC, SC-SM All locations and elevations
On-Site Soils SP, SP-SM, SM, SC
(LL<50 or PI<20) All locations and elevations
1. Structural fill should consist of approved materials free of organic matter and
debris. Frozen materials should not be used, and fill should not be placed on frozen
subgrade. A sample of each material type should be submitted to the Geotechnical
Engineer for evaluation prior to use on this site.
Fine-grained soils such as clays and silts should not be reused as structural fill due to
their moisture sensitivity when compared to the sandier soils available. Reuse of clayey
sand (SC) material could lead to delays in construction depending on moisture conditions
at the site at that time. The soils encountered within the proposed stormwater control
measure may be evaluated for reuse as structural fill across the site.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 11
Fill Placement and Compaction Requirements
Structural and general fill should meet the following compaction requirements.
Item Structural Fill General Fill
Maximum Lift
Thickness
8 inches or less in loose thickness when
heavy, self-propelled compaction equipment
is used
4 to 6 inches in loose thickness when hand-
guided equipment (i.e. trench roller,
jumping jack, or plate compactor) is used
Same as
structural fill
Minimum
Compaction
Requirements 1,2,3
95% of maximum
98% of maximum in upper 1 foot of
structural fill
92% of max.
Water Content
Range 1, 3
Within 3 percent of optimum moisture
content
As required to
achieve min.
compaction
requirements
1. Fill should be tested for moisture content and compaction during placement. If in-
place density tests indicate the specified moisture or compaction limits have not
been met, the area represented by the tests should be reworked and retested as
required until the specified moisture and compaction requirements are achieved.
2. It is not necessary to achieve 95% compaction on the existing ground prior to
placing fill or beginning construction. However, the subgrade should be evaluated
by the Geotechnical Engineer prior to placing fill or beginning construction.
3. Maximum density and optimum water content as determined by the standard
Proctor test (ASTM D 698).
4. Materials not amenable to density testing should be placed and compacted to a
stable condition observed by the Geotechnical Engineer or representative.
Pipe Bedding and Trench Backfill
Pipe bedding and trench backfill should be in accordance with the applicable public works
standard details and specifications for the type of pipe to be supported. (For example,
the NCDOT has published standard pipe bedding and backfilling details for flexible and
rigid pipe for normal earth foundation, rock foundation, and unsuitable material
foundation conditions.) Backfill materials, placement, and testing should be in
accordance with the publics works requirements or the earthwork recommendations
given in this report, whichever are more stringent. If open-graded materials, such as No.
78 or No. 57 stone, are used, they should be completely wrapped in a woven geotextile
that can be used for both separation and filtration (e.g., Mirafi HP270).
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Earthwork Construction Considerations
Upon completion of filling and grading, care should be taken to maintain the subgrade
water content prior to construction of grade-supported improvements such as floor slabs
and pavements. Construction traffic over the completed subgrades should be avoided.
The site should also be graded to prevent ponding of surface water on the prepared
subgrades or in excavations. Water collecting over or adjacent to construction areas
should be removed. If the subgrade freezes, desiccates, saturates, or is disturbed, the
affected material should be removed, or the materials should be scarified, moisture
conditioned, and recompacted prior to floor slab construction.
Groundwater encountered in deeper excavations should be pumped out from sumps or
well points if applicable. Pumping water, as required, should continue until excavations
are completely backfilled.
All grades must provide effective drainage away from the building during and after
construction and should be maintained throughout the life of the structure. Water
retained next to the building can result in soil movements greater than those discussed
in this report. Greater movements can result in unacceptable differential floor slab
and/or foundation movements, cracked slabs and walls, and roof leaks. The roof should
have gutters/drains with downspouts that discharge onto splash blocks at a distance of
at least 10 feet from the building.
Construction Observation and Testing
The earthwork efforts should be observed by the Geotechnical Engineer (or others under
their direction). Observation should include documentation of adequate removal of
surficial materials (vegetation, topsoil, and pavements), evaluation and remediation of
existing fill materials, as well as proofrolling and mitigation of unsuitable areas
delineated by the proofroll.
Each lift of compacted fill should be tested, evaluated, and reworked, as necessary, as
recommended by the Geotechnical Engineer prior to placement of additional lifts. Each
lift of fill should be tested for density and water content at a frequency of at least one
test for every 2,500 square feet of compacted fill in the building areas and 5,000 square
feet in pavement areas. Where not specified by local ordinance, one density and water
content test should be performed for every 100 linear feet of compacted utility trench
backfill and a minimum of one test performed for every 12 vertical inches of compacted
backfill.
In areas of foundation excavations, the bearing subgrade should be evaluated by the
Geotechnical Engineer. The bottom of footings should be checked with hand augers and
Dynamic Cone Penetrometer (DCP) testing that extend through any new or existing fill
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material. If unanticipated conditions are observed, the Geotechnical Engineer should
prescribe mitigation options.
In addition to the documentation of the essential parameters necessary for construction,
the continuation of the Geotechnical Engineer into the construction phase of the project
provides the continuity to maintain the Geotechnical Engineer’s evaluation of subsurface
conditions, including assessing variations and associated design changes.
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July 29, 2024 | Terracon Project No. K6245049
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Shallow Foundations
If the site has been prepared in accordance with the Earthwork section, the following
design parameters are applicable for shallow foundations for the building and canopies.
Design Parameters – Compressive Loads
Item Description
Maximum Net Allowable Bearing
Pressure 1, 2 2,000 psf
Required Bearing Stratum 3 Approved existing soils or structural fill
Minimum Foundation Dimensions
Per NC Building Code:
Columns: 24 inches
Continuous: 16 inches
Sliding Resistance 4 0.35 ultimate coefficient of friction -
granular material
Minimum Embedment below
Finished Grade 5 12 inches
Estimated Total Settlement from
Structural Loads 2 Less than about 1 inch
Estimated Differential Settlement 2, 6 About 1/2 of total settlement
1. The maximum net allowable bearing pressure is the pressure in excess of the
minimum surrounding overburden pressure at the footing base elevation. Values
assume that exterior grades are no steeper than 20% within 10 feet of structure.
The maximum net allowable bearing pressure may be increased by 1/3 for transient
wind loads and seismic loads.
2. Values provided are for maximum loads noted in Project Description. Additional
geotechnical consultation will be necessary if higher loads are anticipated.
3. Unsuitable or soft soils should be overexcavated and replaced per the
recommendations presented in Earthwork.
4. Can be used to compute sliding resistance where foundations are placed on suitable
soil/materials. Frictional resistance for granular materials is dependent on the
bearing pressure which may vary due to load combinations. For fine-grained
materials, lateral resistance using cohesion should not exceed ½ the dead load.
5. Embedment necessary to minimize the effects of frost and to achieve recommended
allowable bearing pressure with a factor of safety of at least 2.5. For sloping
ground, maintain depth below the lowest adjacent exterior grade within 5 horizontal
feet of the structure.
6. Differential settlements are noted for equivalent-loaded foundations and bearing
elevation as measured over a span of 50 feet.
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July 29, 2024 | Terracon Project No. K6245049
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Design Parameters – Overturning and Uplift Loads
Shallow foundations subjected to overturning loads should be proportioned such that the
resultant eccentricity is maintained in the center-third of the foundation (e.g., e < b/6,
where b is the foundation width). This requirement is intended to keep the entire
foundation area in compression during the extreme lateral/overturning load event.
Foundation oversizing may be required to satisfy this condition.
Uplift resistance of spread footings can be developed from the effective weight of the
footing and the overlying soils with consideration to the IBC basic load combinations.
Foundation Construction Considerations
The foundation bearing materials should be evaluated at the time of the foundation
excavation. This is an essential part of the construction process. A representative of the
geotechnical engineer should use a combination of hand auger borings and dynamic
cone penetrometer (DCP) testing to determine the suitability of the bearing materials for
the design bearing pressure. DCP testing should be performed to a depth of 3 to 5 feet
below the bottom of foundation excavation and through the existing fill soils. Excessively
soft, loose, or wet bearing soils should be over excavated to a depth recommended by
the geotechnical engineer. The excavated soils should be replaced with structural fill or
washed, crushed stone (NCDOT No. 57) wrapped in a geotextile fabric (Mirafi 140 N or
equivalent). The need for the geotextile fabric with the crushed stone should be
determined by the Geotechnical Engineer during construction based on sloughing/caving
soils and excavation observations. However, footings could bear directly on the soils
after over excavation if approved by the Geotechnical Engineer.
The base of all foundation excavations should be free of water and loose soil prior to
placing concrete. Concrete should be placed soon after excavating to reduce bearing soil
disturbance. Should the soils at bearing level become excessively disturbed or saturated,
the affected soil should be removed prior to placing concrete.
Item Description
Soil Moist Unit Weight 110 pcf
Soil Effective Unit Weight1 48 pcf
Soil weight included in uplift
resistance
Soil included within the prism extending up from
the top perimeter of the footing at an angle of 20
degrees from vertical to ground surface
1. Effective (or buoyant) unit weight should be used for soil above the foundation level
and below a water level. The high groundwater level should be used in uplift design
as applicable.
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Overexcavation for structural fill placement below footings should be conducted as
shown below. The overexcavation should be backfilled up to the footing base elevation,
with structural fill placed, as recommended in the Earthwork section or washed crushed
stone (NCDOT No. 57) wrapped in a woven geotextile that can be used for both
separation and filtration (e.g., Mirafi HP270).
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7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials 17
Floor Slabs
Design parameters for floor slabs assume the requirements for Earthwork have been
followed. Specific attention should be given to positive drainage away from the structure
and positive drainage of the aggregate base beneath the floor slab.
Floor Slab Design Parameters
Item Description
Floor Slab
Support1
Suitable existing soils or new structural fill compacted in
accordance with Earthwork section of this report.
Estimated Modulus
of Subgrade
Reaction2
150 pounds per square inch per inch (psi/in) for point loads
Aggregate Base
Course/Capillary
Break3
■ Minimum 4 inches of free-draining granular material
(less than 5% passing the U.S. No. 200 sieve)
■ Aggregate Base Course can be used for slabs above
exterior grade (minimum 6 inches)
1. Floor slabs should be structurally independent of building footings or walls to reduce
the possibility of floor slab cracking caused by differential movements between the
slab and foundation.
2. Modulus of subgrade reaction is an estimated value based upon our experience with
the subgrade condition, the requirements noted in Earthwork, and the floor slab
support as noted in this table. It is provided for point loads. For large area loads
the modulus of subgrade reaction would be lower.
3. Free-draining granular material should have less than 5% fines (material passing
the No. 200 sieve). Other design considerations such as cold temperatures and
condensation development could warrant more extensive design provisions.
The use of a vapor retarder should be considered beneath concrete slabs on grade
covered with wood, tile, carpet, or other moisture sensitive or impervious coverings,
when the project includes humidity-controlled areas, or when the slab will support
equipment sensitive to moisture. When conditions warrant the use of a vapor retarder,
the slab designer should refer to ACI 302 and/or ACI 360 for procedures and cautions
regarding the use and placement of a vapor retarder.
Saw-cut contraction joints should be placed in the slab to help control the location and
extent of cracking. For additional recommendations, refer to the ACI Design Manual.
Joints or cracks should be sealed with a waterproof, non-extruding compressible
compound specifically recommended for heavy duty concrete pavement and wet
environments.
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Where floor slabs are tied to perimeter walls or turn-down slabs to meet structural or
other construction objectives, our experience indicates differential movement between
the walls and slabs will likely be observed in adjacent slab expansion joints or floor slab
cracks beyond the length of the structural dowels. The Structural Engineer should
account for potential differential settlement through use of sufficient control joints,
appropriate reinforcing or other means.
Floor Slab Construction Considerations
On most project sites, the site grading is generally accomplished early in the
construction phase. However, as construction proceeds, the subgrade may be disturbed
due to utility excavations, construction traffic, desiccation, rainfall, etc. As a result, the
floor slab subgrade may not be suitable for placement of base stone and concrete and
corrective action will be required to repair the damaged areas.
Finished subgrade, within and for at least 10 feet beyond the floor slab, should be
protected from traffic, rutting, or other disturbance and maintained in a relatively moist
condition until floor slabs are constructed. If the subgrade should become damaged or
desiccated prior to construction of floor slabs, the affected material should be removed,
and structural fill should be added to replace the resulting excavation. Final conditioning
of the finished subgrade should be performed immediately prior to placement of the floor
slab support course.
The Geotechnical Engineer should observe the condition of the floor slab subgrades
immediately prior to placement of the floor slab support course, reinforcing steel, and
concrete. Attention should be paid to high traffic areas that were rutted and disturbed
earlier, and to areas where backfilled trenches are located.
Below-Grade Structures
Terracon understands that below-grade fuel tanks are proposed; however, their
embedment depths have not been provided. Deep excavations for installation of the fuel
storage tanks can likely be performed with conventional support of excavation (SOE)
systems, and/or open cut excavations with benching and sloping in accordance with
OSHA 29 CFR, Park 1926, Subpart P, “Excavations”. Groundwater was estimated to be
between depths of 6 feet and 8 feet beneath existing grade at the time of exploration.
As such, a temporary dewatering system consisting of sumps with could be necessary to
achieve the required excavation depths. Dewatering is a means and methods
consideration for the contractor. If dewatering is necessary, groundwater levels should
be maintained at least 2 feet below the bottom of excavation.
Where open-graded Crushed Stone is used to backfill the tank excavation, it should be
separated from soil subgrades, excavation sidewalls, and granular backfill using a
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geotextile separation fabric such as Mirafi 140 N, or as specified by the tank designer. If
a separation fabric is not used, settlement may occur around the tank as soil migrates
into the voids within the stone.
Ground water levels at the site should be considered when determining the depth of the
proposed USTs. If the bottom of the UST extends below the groundwater table, the
buoyant forces exerted on the tanks by the groundwater may cause uplift if the tanks
are drained. If the USTs are proposed to bear below the groundwater table, they must
be designed to resist uplift pressures when empty. Possible uplift control measures
include hold-down straps and deadman anchors or concrete pads.
Pavements
General Pavement Comments
Pavement designs are provided for the traffic conditions and pavement life conditions as
noted in Project Description and in the following sections of this report. A critical
aspect of pavement performance is site preparation. Pavement designs noted in this
section must be applied to the site which has been prepared as recommended in the
Earthwork section.
Design Traffic
The following table lists the design traffic loading information used for this project. This
table also provides our estimates for 20-year 18-kip Equivalent Single Axle Loads
(ESALS) for the assumed vehicle types and average daily traffic.
Pavement Light Duty Heavy Duty
Asphalt 94,000 534,000
Concrete 2,130,000 2,528,000
1. Per the 7-Eleven Civil Design Guideline.
If the project will include any public pavements (NCDOT or local municipality), we need
the projected average daily traffic, percent dual axle trucks, and percent tractor trailer
trucks in order to provide recommended pavement sections for the public pavements.
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Pavement Design Parameters
Design of Asphaltic Concrete (AC) pavements are based on the procedures outlined in
the AASHTO Guide for Design of Pavement Structures 1993 Method. Design of Portland
Cement Concrete (PCC) pavements are based upon American Concrete Institute (ACI)
330; Guide for Design and Construction of Concrete Parking Lots.
A California Bearing Ratio (CBR) of 10 was used for the subgrade for the asphaltic
concrete (AC) pavement designs. A modulus of subgrade reaction of 200 pci was used
for the portland cement concrete (PCC) pavement designs. The value was empirically
derived based upon our experience with the sandy subgrade soils and our expectation of
the quality of the subgrade as prescribed by the Site Preparation conditions as outlined
in Earthwork. A modulus of rupture of 580 psi was used in design for the concrete
(based on correlations with a minimum 28-day compressive strength of 4,000 psi).
Pavement Section Thicknesses
The 7-Eleven standard- and heavy-duty pavement sections listed in the Division 3
Geotechnical Guidelines – Items 3.8.1.4 and 3.8.1.5 will meet or exceed 7-Eleven’s
target ESAL values for a 15-year pavement life as noted in Project Description.
The tables below provide options for AC and PCC Sections that are based on the
previously mentioned 7-Eleven ESAL targets, our laboratory test results, and the soil
conditions encountered at this site.
The following table provides our opinion of minimum thickness for AC sections:
Asphaltic Concrete Design
Layer
Thickness (inches)
NCDOT
Grading 1
Automobile Areas
(Light Duty)
Main Drives and
Truck Access Areas
(Medium Duty)
AC Surface S-9.5B 3 2 1.5
AC Intermediate I-19.0C -- 2.5
Aggregate Base ABC 6 8
1. All materials should meet the current North Carolina Department of Transportation
Standard Specifications
2. Placed in two equal lifts.
3. See Project Description for more specifics regarding traffic assumptions.
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July 29, 2024 | Terracon Project No. K6245049
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The following table provides our estimated minimum thickness of PCC pavements.
Portland Cement Concrete Design
Layer Specification 1
Thickness (inches)
Automobile
Areas
(Light Duty)
Main Drives and
Truck Access Areas
(Medium Duty)
Heavy
Duty 2
PCC 4,000 psi 6 8
Aggregate Base ABC 3 4 4
1. All materials should meet the current North Carolina Department of Transportation
(NCDOT) Standard Specifications.
2. In areas of anticipated heavy traffic, fire trucks, delivery trucks, or concentrated loads
(e.g. dumpster pads), and areas with repeated turning or maneuvering of heavy
vehicles.
3. Crushed Aggregate Base Course is recommended for construction purposes. Concrete
could be placed directly on an approved subgrade. However, stormwater can quickly
degrade exposed subgrades without the crushed aggregate base course leading to
additional subgrade repair.
4. See Project Description for more specifics regarding traffic assumptions.
The placement of a partial pavement thickness for use during construction is not
suggested without a detailed pavement analysis incorporating construction traffic. If the
actual traffic varies from the information outlined in Project Description, we should be
contacted to update our recommendations as necessary.
Recommendations for pavement construction presented depend upon compliance with
recommended material specifications. To assess compliance, observation and testing
should be performed under the direction of the geotechnical engineer.
Areas for parking of heavy vehicles, concentrated turn areas, and start/stop maneuvers
could require thicker pavement sections. Edge restraints (i.e. concrete curbs or
aggregate shoulders) should be planned along curves and areas of maneuvering
vehicles.
The base course layer is recommended to help reduce potential for slab curl, shrinkage
cracking, and subgrade pumping through joints. Proper joint spacing will also be
required to prevent excessive slab curling and shrinkage cracking. Joints should be
sealed to prevent entry of foreign material and doweled where necessary for load
transfer. PCC pavement details for joint spacing, joint reinforcement, and joint sealing
should be prepared in accordance with ACI 330 and ACI 325.
Where practical, we recommend early-entry cutting of crack-control joints in PCC
pavements. Cutting of the concrete in its “green” state typically reduces the potential for
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micro-cracking of the pavements prior to the crack control joints being formed,
compared to cutting the joints after the concrete has fully set. Micro-cracking of
pavements may lead to crack formation in locations other than the sawed joints, and/or
reduction of fatigue life of the pavement.
Openings in pavements, such as decorative landscaped areas, are sources for water
infiltration into surrounding pavement systems. Water can collect in the islands and
migrate into the surrounding subgrade soils thereby degrading support of the pavement.
Islands with raised concrete curbs, irrigated foliage, and low permeability near-surface
soils are particular areas of concern. The civil design for the pavements with these
conditions should include features to restrict or collect and discharge excess water from
the islands. Examples of features are edge drains connected to the stormwater collection
system, longitudinal subdrains, or other suitable outlets and impermeable barriers
preventing lateral migration of water such as a cutoff wall installed to a depth below the
pavement structure.
The placement of a partial pavement thickness for use during construction is not
suggested without a detailed pavement analysis incorporating construction traffic. If the
actual traffic varies from the assumptions outlined in Project Description we should be
contacted to update our recommendations as necessary.
Pavement Drainage
Pavements should be sloped to provide rapid drainage of surface water. Water allowed
to pond on or adjacent to the pavements could saturate the subgrade and contribute to
premature pavement deterioration. In addition, the pavement subgrade should be
graded to provide positive drainage within the granular base section. Appropriate sub-
drainage or connection to a suitable daylight outlet should be provided to remove water
from the granular subbase.
Based on the possibility of shallow and/or perched groundwater, we recommend
installing a pavement subdrain system to control groundwater, improve stability, and
improve long-term pavement performance.
Pavement Maintenance
The pavement sections represent minimum recommended thicknesses and, as such,
periodic upkeep should be anticipated. Preventive maintenance should be planned and
provided for through an on-going pavement management program. Maintenance
activities are intended to slow the rate of pavement deterioration and to preserve the
pavement investment. Pavement care consists of both localized (e.g., crack and joint
sealing and patching) and global maintenance (e.g., surface sealing). Additional
engineering consultation is recommended to determine the type and extent of a cost-
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effective program. Even with periodic maintenance, some movements and related
cracking may still occur, and repairs may be required.
Pavement performance is affected by its surroundings. In addition to providing
preventive maintenance, the civil engineer should consider the following
recommendations in the design and layout of pavements:
■ Final grade adjacent to paved areas should slope down from the edges at a
minimum 2%.
■ Subgrade and pavement surfaces should have a minimum 2% slope to promote
proper surface drainage.
■ Install pavement drainage systems surrounding areas anticipated for frequent
wetting.
■ Install joint sealant and seal cracks immediately.
■ Seal all landscaped areas in or adjacent to pavements to reduce moisture
migration to subgrade soils.
■ Place compacted, low permeability backfill against the exterior side of curb and
gutter.
■ Place curb, gutter and/or sidewalk directly on clay subgrade soils rather than on
unbound granular base course materials.
Stormwater Control Measures
We understand that Stormwater Control Measures (SCMs) will be constructed for the
project. The SCMs should be designed, constructed, and maintained in accordance with
the NCDEQ Stormwater Design Manual1.
The soil composition of many SCMs is vital to achieving their intended purpose. Soil
permeability is an important design factor for SCMs. The infiltration rate of in-situ soils
is required for design of infiltration devices and permeable pavement. It is also
advantageous and sometimes necessary to have low permeability in-situ soil for systems
where permanent ponded water is required (e.g., stormwater wetlands and wet ponds).
The attached report by Terrain Environmental Consulting (within Supporting
Information) provides a summary of the infiltration rates measured at the locations
tested.
1 https://www.deq.nc.gov/about/divisions/energy-mineral-and-land-resources/stormwater/stormwater-
program/stormwater-design-manual
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Determining the elevation of the seasonal high water table (SHWT) is also an important
step in the hydrogeologic design process for SCMs. To function properly, some SCMs
(e.g., infiltration systems, permeable pavements, and bioretention basins) require a
minimum separation of 2 feet from the bottom of the SCM down to the SHWT elevation.
The attached report by Terrain Environmental Consulting (within Supporting
Information) provides a summary of the seasonal high water table depths elevations at
the locations evaluated.
Many SCMs will include some volume of water storage for water treatment and/or water
quantity control. The most common type of storage facility is the earthen impoundment.
These structures sometimes are simply excavated from existing soil and are below
grade, but others include fill material and dams. Embankments should have slopes no
steeper than 3H:1V to allow maintenance equipment and to maintain ground cover.
Without performing detailed slope stability analyses, cut slopes and fill slopes should
also be no steeper than 3H:1V due to potential slope stability considerations.
When the bottom of an impoundment (e.g., wet pond, stormwater wetland) is located
above the SHWT and/or the underlying soils are too permeable, a liner may be needed
to sustain a permanent pool of water. Acceptable liner options include: 6 to 12 inches of
clay soil (with a maximum permeability of 1x10-5 cm/sec), a 30-mil poly-liner, or a
bentonite liner. Properly placed and compacted Clayey SAND (SC), SILT (ML, MH), or
CLAY (CL, CH) can generally be used as liner material. Samples of proposed liner
material should be tested prior to construction to ensure it meets the maximum
permeability requirement. Soil liner material should be placed in loose lifts no more than
8 inches thick and should be compacted with a sheepsfoot roller to at least 95% of its
standard Proctor maximum dry unit weight at a minimum of 2% wet of the soil’s
optimum moisture content as determined by ASTM D698. Construction of an SCM liner
may require dewatering efforts to provide a relatively dry, stable subgrade on which to
construct the liner.
General Comments
Our analysis and opinions are based upon our understanding of the project, the
geotechnical conditions in the area, and the data obtained from our site exploration.
Variations will occur between exploration point locations or due to the modifying effects
of construction or weather. The nature and extent of such variations may not become
evident until during or after construction. Terracon should be retained as the
Geotechnical Engineer, where noted in this report, to provide observation and testing
services during pertinent construction phases. If variations appear, we can provide
further evaluation and supplemental recommendations. If variations are noted in the
absence of our observation and testing services on-site, we should be immediately
notified so that we can provide evaluation and supplemental recommendations.
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Our Scope of Services does not include either specifically or by implication any
environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or
identification or prevention of pollutants, hazardous materials or conditions. If the owner
is concerned about the potential for such contamination or pollution, other studies
should be undertaken.
Our services and any correspondence are intended for the sole benefit and exclusive use
of our client for specific application to the project discussed and are accomplished in
accordance with generally accepted geotechnical engineering practices with no third-
party beneficiaries intended. Any third-party access to services or correspondence is
solely for information purposes to support the services provided by Terracon to our
client. Reliance upon the services and any work product is limited to our client and is not
intended for third parties. Any use or reliance of the provided information by third
parties is done solely at their own risk. No warranties, either express or implied, are
intended or made.
Site characteristics as provided are for design purposes and not to estimate excavation
cost. Any use of our report in that regard is done at the sole risk of the excavating cost
estimator as there may be variations on the site that are not apparent in the data that
could significantly effect excavation cost. Any parties charged with estimating excavation
costs should seek their own site characterization for specific purposes to obtain the
specific level of detail necessary for costing. Site safety and cost estimating including
excavation support and dewatering requirements/design are the responsibility of others.
Construction and site development have the potential to affect adjacent properties. Such
impacts can include damages due to vibration, modification of groundwater/surface
water flow during construction, foundation movement due to undermining or subsidence
from excavation, as well as noise or air quality concerns. Evaluation of these items on
nearby properties are commonly associated with contractor means and methods and are
not addressed in this report. The owner and contractor should consider a
preconstruction/precondition survey of surrounding development. If changes in the
nature, design, or location of the project are planned, our conclusions and
recommendations shall not be considered valid unless we review the changes and either
verify or modify our conclusions in writing.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials
Figures
Contents:
GeoModel (4 pages)
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
EL
E
V
A
T
I
O
N
(
M
S
L
)
(
f
e
e
t
)
Layering shown on this figure has been developed by thegeotechnical engineer for purposes of modeling the subsurfaceconditions as required for the subsequent geotechnical engineeringfor this project.Numbers adjacent to soil column indicate depth below ground
surface.
NOTES:
B-01MC B-01 B-02 B-03 B-04MC B-04
Legend
This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.
GeoModel
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049
7-Eleven - Hwy 421
2108 Capital Dr, Ste 103
Wilmington, NC
First Water Observation
Groundwater levels are temporal. The levels shown are representativeof the date and time of our exploration. Significant changes arepossible over time.Water levels shown are as measured during and/or after drilling. Insome cases, boring advancement methods mask the presence/absenceof groundwater. See individual logs for details.
Topsoil Poorly-graded Sand
Soil Behavior Type (SBT)
8 Very stiff sand to clayey sand7 Gravelly sand to dense sand
1 Sensitive, fine grained
4 Silt mixtures - clayey silt to silty clay 5 Sand mixtures - silty sand to sandy silt
2 Organic soils - clay
9 Very stiff fine grained
6 Sands - clean sand to silty sand
3 Clay - silty clay to clay
Model Layer Layer Name General Description
1 Sand with varying amounts of silt
2 Sand with varying amounts of silt and clay, clay lenses atvarying depths
CPT Assumed Water Depth
Loose to MediumDense Sand
Medium Dense toDense Sand
1
8
10
1
2
13
49.7
8
1
2
12.5
20.1
7.5 1
2
10.5
20.1
6.5 16.5
10
1
2
10.5
20.1
6.5
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
14
16
EL
E
V
A
T
I
O
N
(
M
S
L
)
(
f
e
e
t
)
Layering shown on this figure has been developed by thegeotechnical engineer for purposes of modeling the subsurfaceconditions as required for the subsequent geotechnical engineeringfor this project.Numbers adjacent to soil column indicate depth below ground
surface.
NOTES:
B-05MC B-05
B-06 B-07MC B-07
B-08
Legend
This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.
GeoModel
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049
7-Eleven - Hwy 421
2108 Capital Dr, Ste 103
Wilmington, NC
First Water Observation
Groundwater levels are temporal. The levels shown are representativeof the date and time of our exploration. Significant changes arepossible over time.Water levels shown are as measured during and/or after drilling. Insome cases, boring advancement methods mask the presence/absenceof groundwater. See individual logs for details.
Topsoil Poorly-graded Sand
Soil Behavior Type (SBT)
8 Very stiff sand to clayey sand7 Gravelly sand to dense sand
1 Sensitive, fine grained
4 Silt mixtures - clayey silt to silty clay 5 Sand mixtures - silty sand to sandy silt
2 Organic soils - clay
9 Very stiff fine grained
6 Sands - clean sand to silty sand
3 Clay - silty clay to clay
Model Layer Layer Name General Description
1 Sand with varying amounts of silt
2 Sand with varying amounts of silt and clay, clay lenses atvarying depths
CPT Assumed Water Depth
Loose to MediumDense Sand
Medium Dense toDense Sand
1
8
10
1
2
12.5
20.1
8
1
2
12.5
20
8
1
8.5
10
1
2
14
20.1
8.5
1
2
1
2
2
5
11
20.1
6.5
0
2
4
6
8
10
12
14
16
18
EL
E
V
A
T
I
O
N
(
M
S
L
)
(
f
e
e
t
)
Layering shown on this figure has been developed by thegeotechnical engineer for purposes of modeling the subsurfaceconditions as required for the subsequent geotechnical engineeringfor this project.Numbers adjacent to soil column indicate depth below ground
surface.
NOTES:
P-01
P-02
P-03
P-04MC P-04
P-05
P-06 P-07MC P-07 P-08
Legend
This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.
GeoModel
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049
7-Eleven - Hwy 421
2108 Capital Dr, Ste 103
Wilmington, NC
First Water Observation
Groundwater levels are temporal. The levels shown are representativeof the date and time of our exploration. Significant changes arepossible over time.Water levels shown are as measured during and/or after drilling. Insome cases, boring advancement methods mask the presence/absenceof groundwater. See individual logs for details.
Topsoil Poorly-graded Sand
Soil Behavior Type (SBT)
8 Very stiff sand to clayey sand7 Gravelly sand to dense sand
1 Sensitive, fine grained
4 Silt mixtures - clayey silt to silty clay 5 Sand mixtures - silty sand to sandy silt
2 Organic soils - clay
9 Very stiff fine grained
6 Sands - clean sand to silty sand
3 Clay - silty clay to clay
Model Layer Layer Name General Description
1 Sand with varying amounts of silt
2 Sand with varying amounts of silt and clay, clay lenses atvarying depths
CPT Assumed Water Depth
Loose to MediumDense Sand
Medium Dense toDense Sand
1
2
1
1.5
3.5
10.1
7
1
10.1
7.5
1
10.1
8
1
5 1
10.1
8
1
10.1
7.5
1
2
1
4.5
8.5
10.1
6.5
1
5 1
10.1
5 1
10.1
6.5
0
2
4
6
8
10
12
14
16
18
EL
E
V
A
T
I
O
N
(
M
S
L
)
(
f
e
e
t
)
Layering shown on this figure has been developed by thegeotechnical engineer for purposes of modeling the subsurfaceconditions as required for the subsequent geotechnical engineeringfor this project.Numbers adjacent to soil column indicate depth below ground
surface.
NOTES:
P-09
P-10
P-11
P-12
P-13MC P-13
SCM-01
SCM-02MC SCM-02
Legend
This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.
GeoModel
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049
7-Eleven - Hwy 421
2108 Capital Dr, Ste 103
Wilmington, NC
First Water Observation
Groundwater levels are temporal. The levels shown are representativeof the date and time of our exploration. Significant changes arepossible over time.Water levels shown are as measured during and/or after drilling. Insome cases, boring advancement methods mask the presence/absenceof groundwater. See individual logs for details.
Topsoil Poorly-graded Sand
Soil Behavior Type (SBT)
8 Very stiff sand to clayey sand7 Gravelly sand to dense sand
1 Sensitive, fine grained
4 Silt mixtures - clayey silt to silty clay 5 Sand mixtures - silty sand to sandy silt
2 Organic soils - clay
9 Very stiff fine grained
6 Sands - clean sand to silty sand
3 Clay - silty clay to clay
Model Layer Layer Name General Description
1 Sand with varying amounts of silt
2 Sand with varying amounts of silt and clay, clay lenses atvarying depths
CPT Assumed Water Depth
Loose to MediumDense Sand
Medium Dense toDense Sand
1
2
8.5
10.1
7.5
1
2
6.5
10.1
8
1
10.1
6
1
10.1
6.5
1
5 1
10.1
8
1
10.1
7
1
7
10
1
10.1
7
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials
Attachments
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials
Exploration and Testing Procedures
Field Exploration
Number of Soundings Approximate Sounding
Depth (feet) 1 Location
2 (B-01, B-02) 20 to 49.5 Proposed Building
2 (B-03 through B-07) 20 Proposed Canopies
1 (B-08) 20 Proposed Underground Fuel
Storage Tanks
13 (P-01 through P-13) 10 Proposed Pavement
2 (SCM-01, SCM-02) 10 Proposed Stormwater Pond
1. Referenced from existing ground surface.
Exploration Layout and Elevations: Terracon personnel provided the exploration
layout using handheld GPS equipment (estimated horizontal accuracy of about ±20 feet)
and referencing existing site features. Approximate ground surface elevations were
estimated using Google Earth ProTM. If elevations and a more precise exploration layout
are desired, we recommend our locations be surveyed.
Subsurface Exploration Procedures: The subsurface exploration was performed by a
track mounted power drilling rig utilizing direct push, cone penetration testing (CPT) to
advance into the subsurface. Additionally, eight (8) Macro-Core sampling tubes were
advanced to depths of 5 feet to 10 feet below existing grades to obtain laboratory
samples and visually classify near-surface soils. Samples were tagged for identification,
sealed to reduce moisture loss, and taken to our laboratory for further examination, testing,
and classification.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials
Cone Penetration Testing (CPT): The CPT hydraulically pushes an
instrumented cone through the soil while nearly continuous readings are
recorded to a portable computer. The cone is equipped with electronic load
cells to measure tip resistance and sleeve resistance and a pressure
transducer to measure the generated ambient pore pressure. The
face of the cone has an apex angle of 60° and an area of 10 cm2.
Digital data representing the tip resistance, friction resistance, pore
water pressure, and probe inclination angle are recorded about every 2
centimeters while advancing through the ground at a rate between
1½ and 2½ centimeters per second. These measurements are
correlated to various soil properties used for geotechnical design. No
soil samples are gathered through this subsurface investigation technique.
CPT testing is conducted in general accordance with ASTM D5778
"Standard Test Method for Performing Electronic Friction Cone and
Piezocone Penetration Testing of Soils." Upon completion, the data collected
was downloaded and processed by the project engineer.
Shear wave velocity testing is a supplement to the CPT with added instrumentation used
to determine shear wave velocity with depth. This additional information is collected via
an accelerometer placed above the instrumented cone. A shear wave is generated at
the ground surface, such as a hammer striking a steel plate on the end, which
propagates through the soil and is recorded by the accelerometer at selected intervals
(typically 1 meter). From this data, the interval shear wave velocities of the soil are
calculated. These interval velocities can be used to develop the shear wave velocity
profile for the site and can be used to determine a seismic site classification.
Laboratory Testing
The project engineer reviewed the field data and assigned laboratory tests. The
laboratory testing program included the following types of tests:
■ Moisture Content
■ Grain-Size Analysis
■ Atterberg Limits
The laboratory testing program often included examination of soil samples by an
engineer. Based on the results of our field and laboratory programs, we described and
classified the soil samples in accordance with the Unified Soil Classification System.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials
Site Location and Exploration Plans
Contents:
Site Location
Exploration Plan
Note: All attachments are one page unless noted above.
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials
Note to Preparer: This is a large table with outside borders. Just click inside the table
above this text box, then paste your GIS Toolbox image.
When paragraph markers are turned on you may notice a line of hidden text above
and outside the table – please leave that alone. Limit editing to inside the table.
The line at the bottom about the general location is a separate table line. You can edit
it as desired, but try to keep to a single line of text to avoid reformatting the page.
Site Location
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY USGS, 2020
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials
Note to Preparer: This is a large table with outside borders. Just click inside the table
above this text box, then paste your GIS Toolbox image.
When paragraph markers are turned on you may notice a line of hidden text above
and outside the table – please leave that alone. Limit editing to inside the table.
The line at the bottom about the general location is a separate table line. You can edit
it as desired, but try to keep to a single line of text to avoid reformatting the page.
Exploration Plan
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS
SITE PLAN PROVIDED BY CLIENT
Exploration and Laboratory Results
Contents:
CPT Sounding and Macro-Core Logs
-B-01 through B-08
-P-01 through P-13
-SCM-01, SCM-02
Grain Size Distribution
Moisture-Density Relationship
Report for California Bearing Ratio
Note: All attachments are one page unless noted above.
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID B-01
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
Shear Wave Velocity, Vs(ft/sec)
250 500 750 1000
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 49.5 Feet
>>>>>>
>>>>>>>>>>
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
See B-01MC for the adjacent test's full details.
Topsoil Thickness = 4 inches
Cave In Depth = 8 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2938° Longitude: -77.9728°
CPT Completed: 7/3/2024
8 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 7/3/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
B-
0
1
M
C
M
a
t
e
r
i
a
l
De
s
c
r
i
p
t
i
o
n
11.7
9
7
5
2
TOPSOIL, 4 inches
POORLY GRADED SAND (SP), fine to medium, gray and brown
NO RECOVERY
POORLY GRADED SAND (SP), fine to medium, light gray
NO RECOVERY
Boring Terminated at 10 Feet
Boring Log No. B-01MC
Wa
t
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Ob
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s
De
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(
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)
5
10
Facilities | Environmental | Geotechnical | Materials
Gr
a
p
h
i
c
L
o
g
Mo
d
e
l
L
a
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e
r
2NP
0.3
3.0
5.0
7.0
10.0
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 Wilmington, NC
2108 Capital Dr, Ste 103
Drill RigGeoprobe 7822DT
Hammer TypeN/A
DrillerT. Whitehead
Logged byZ. Burt
Boring Started07-05-2024
Boring Completed07-05-2024
Abandonment Method
Advancement MethodDirect PushNotes
Water Level Observations
Cave In (dry)
Estimated based on cpt data and cave in depth
See Exploration and Testing Procedures for a description of field and laboratory procedures used andadditional data (If any).
See Supporting Information for explanation of symbols and abbreviations.
Elevation Reference: Approximate elevations obtained using Google Earth Pro
7-Eleven - Hwy 421
Sa
m
p
l
e
T
y
p
e
Pe
r
c
e
n
t
Fi
n
e
s
Elevation: 12 (Ft.) +/-
AtterbergLimits
LL-PL-PI
See Exploration PlanLocation:
Latitude: 34.2938° Longitude: -77.9728°
Depth (Ft.)
1
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID B-02
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 20.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 5 inches
Cave In Depth = 7 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 13 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2936° Longitude: -77.9726°
CPT Completed: 6/28/2024
7.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID B-03
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 20.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Surface Materials: 3" Asphalt / 3" ABC
Cave In Depth = 6 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2937° Longitude: -77.9729°
CPT Completed: 6/27/2024
6.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID B-04
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 20.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
See B-04MC for the adjacent test's full details.
Topsoil Thickness = 3 inches
Cave In Depth = 5 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2936° Longitude: -77.9730°
CPT Completed: 6/27/2024
6.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
B-
0
4
M
C
M
a
t
e
r
i
a
l
De
s
c
r
i
p
t
i
o
n
11.7
9
7
4
2
TOPSOIL, 3 inches
POORLY GRADED SAND (SP), fine to medium, light gray
NO RECOVERY
POORLY GRADED SAND (SP), fine to medium, light gray
-Color change to brown
NO RECOVERY
Boring Terminated at 10 Feet
Boring Log No. B-04MC
Wa
t
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Ob
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s
De
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10
Facilities | Environmental | Geotechnical | Materials
Gr
a
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Mo
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L
a
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0.3
3.0
5.0
8.0
10.0
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 Wilmington, NC
2108 Capital Dr, Ste 103
Drill RigGeoprobe 7822DT
Hammer TypeN/A
DrillerT. Whitehead
Logged byZ. Burt
Boring Started07-05-2024
Boring Completed07-05-2024
Abandonment Method
Advancement MethodDirect PushNotes
Water Level Observations
Cave In (dry)
Estimated based on cpt data
See Exploration and Testing Procedures for a description of field and laboratory procedures used andadditional data (If any).
See Supporting Information for explanation of symbols and abbreviations.
Elevation Reference: Approximate elevations obtained using Google Earth Pro
7-Eleven - Hwy 421
Sa
m
p
l
e
T
y
p
e
Pe
r
c
e
n
t
Fi
n
e
s
Elevation: 12 (Ft.) +/-
AtterbergLimits
LL-PL-PI
See Exploration PlanLocation:
Latitude: 34.2936° Longitude: -77.9730°
Depth (Ft.)
1
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID B-05
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 20.1 Feet
>>
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
See B-05MC for the adjacent test's full details.
Topsoil Thickness = 5 inches
Cave In Depth = 4 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2941° Longitude: -77.9726°
CPT Completed: 6/27/2024
8 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
B-
0
5
M
C
M
a
t
e
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i
a
l
De
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i
p
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i
o
n
11.6
9
7
3
2
TOPSOIL, 5 inches
POORLY GRADED SAND (SP), fine to medium, brown
-Color change to tan
NO RECOVERY
POORLY GRADED SAND (SP), fine to medium, light tan
NO RECOVERY
Boring Terminated at 10 Feet
Boring Log No. B-05MC
Wa
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10
Facilities | Environmental | Geotechnical | Materials
Gr
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L
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0.4
3.0
5.0
9.0
10.0
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 Wilmington, NC
2108 Capital Dr, Ste 103
Drill RigGeoprobe 7822DT
Hammer TypeN/A
DrillerT. Whitehead
Logged byZ. Burt
Boring Started07-05-2024
Boring Completed07-05-2024
Abandonment Method
Advancement MethodDirect PushNotes
Water Level Observations
Cave In (dry)
Estimated based on cpt data
See Exploration and Testing Procedures for a description of field and laboratory procedures used andadditional data (If any).
See Supporting Information for explanation of symbols and abbreviations.
Elevation Reference: Approximate elevations obtained using Google Earth Pro
7-Eleven - Hwy 421
Sa
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Pe
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t
Fi
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s
Elevation: 12 (Ft.) +/-
AtterbergLimits
LL-PL-PI
See Exploration PlanLocation:
Latitude: 34.2941° Longitude: -77.9726°
Depth (Ft.)
1
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID B-06
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 20 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 4 inches
Cave In Depth = 6 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 14 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2938° Longitude: -77.9724°
CPT Completed: 6/27/2024
8 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID B-07
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 20.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
See B-07MC for the adjacent test's full details.
Topsoil Thickness = 6 inches
Cave In Depth = 9 feet
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 14 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2936° Longitude: -77.9723°
CPT Completed: 6/28/2024
8.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
B-
0
7
M
C
M
a
t
e
r
i
a
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De
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c
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i
p
t
i
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13.5
11
9
5
4
TOPSOIL, 6 inches
POORLY GRADED SAND (SP), fine to medium, gray
-Color change to light gray
-Color change to brown
NO RECOVERY
POORLY GRADED SAND (SP), fine to medium, tan
NO RECOVERY
Boring Terminated at 10 Feet
Boring Log No. B-07MC
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10
Facilities | Environmental | Geotechnical | Materials
Gr
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L
a
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1NP
0.5
3.0
5.0
9.0
10.0
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 Wilmington, NC
2108 Capital Dr, Ste 103
Drill RigGeoprobe 7822DT
Hammer TypeN/A
DrillerT. Whitehead
Logged byZ. Burt
Boring Started07-05-2024
Boring Completed07-05-2024
Abandonment Method
Advancement MethodDirect PushNotes
Water Level Observations
Cave In
Estimated based on cpt data
See Exploration and Testing Procedures for a description of field and laboratory procedures used andadditional data (If any).
See Supporting Information for explanation of symbols and abbreviations.
Elevation Reference: Approximate elevations obtained using Google Earth Pro
7-Eleven - Hwy 421
Sa
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p
l
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T
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Pe
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c
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t
Fi
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e
s
Elevation: 14 (Ft.) +/-
AtterbergLimits
LL-PL-PI
See Exploration PlanLocation:
Latitude: 34.2936° Longitude: -77.9723°
Depth (Ft.)
1
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID B-08
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
-40
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 20.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 4 inches
Cave In Depth = 5 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 11 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2941° Longitude: -77.9729°
CPT Completed: 6/27/2024
6.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-01
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 4 inches
Cave In Depth = 6 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2942° Longitude: -77.9727°
CPT Completed: 6/27/2024
7 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-02
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Surface Materials: 1.5" Asphalt / 4" ABC
Cave In Depth = 7 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 13 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2940° Longitude: -77.9724°
CPT Completed: 6/27/2024
7.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-03
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 6 inches
Cave In Depth = 6 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 14 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2937° Longitude: -77.9722°
CPT Completed: 6/28/2024
8 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-04
Approx.Elev.(ft)
15
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
See P-04MC for the adjacent test's full details.
Topsoil Thickness = 5 inches
Cave In Depth = 6 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 16 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2934° Longitude: -77.9722°
CPT Completed: 6/28/2024
8 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
P-
0
4
M
C
M
a
t
e
r
i
a
l
De
s
c
r
i
p
t
i
o
n
15.6
13
11
TOPSOIL, 5 inches
POORLY GRADED SAND (SP), fine to medium, light gray
-Color change to tan
NO RECOVERY
Boring Terminated at 5 Feet
Boring Log No. P-04MC
Wa
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5
Facilities | Environmental | Geotechnical | Materials
Gr
a
p
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i
c
L
o
g
Mo
d
e
l
L
a
y
e
r
0.4
3.0
5.0
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 Wilmington, NC
2108 Capital Dr, Ste 103
Drill RigGeoprobe 7822DT
Hammer TypeN/A
DrillerT. Whitehead
Logged byZ. Burt
Boring Started07-05-2024
Boring Completed07-05-2024
Abandonment Method
Advancement MethodDirect PushNotes
Water Level ObservationsGroundwater not encountered
See Exploration and Testing Procedures for a description of field and laboratory procedures used andadditional data (If any).
See Supporting Information for explanation of symbols and abbreviations.
Elevation Reference: Approximate elevations obtained using Google Earth Pro
7-Eleven - Hwy 421
Sa
m
p
l
e
T
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p
e
Pe
r
c
e
n
t
Fi
n
e
s
Elevation: 16 (Ft.) +/-
AtterbergLimits
LL-PL-PI
See Exploration PlanLocation:
Latitude: 34.2934° Longitude: -77.9722°
Depth (Ft.)
1
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-05
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 3 inches
Cave In Depth = 5 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 14 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2936° Longitude: -77.9724°
CPT Completed: 6/28/2024
7.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-06
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Surface Materials: 2" Asphalt / 3" ABC
Cave In Depth = 5 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2939° Longitude: -77.9729°
CPT Completed: 6/27/2024
6.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-07
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
See P-07MC for the adjacent test's full details.
Topsoil Thickness = 5 inches
Cave In Depth = 4 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2941° Longitude: -77.9733°
CPT Completed: 7/3/2024
5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 7/3/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
P-
0
7
M
C
M
a
t
e
r
i
a
l
De
s
c
r
i
p
t
i
o
n
11.6
9
7
TOPSOIL, 5 inches
POORLY GRADED SAND (SP), fine to medium, gray
-Color change to tan
-Color change to orange
NO RECOVERY
Boring Terminated at 5 Feet
Boring Log No. P-07MC
Wa
t
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Ob
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5
Facilities | Environmental | Geotechnical | Materials
Gr
a
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Mo
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L
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0.4
3.0
5.0
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 Wilmington, NC
2108 Capital Dr, Ste 103
Drill RigGeoprobe 7822DT
Hammer TypeN/A
DrillerT. Whitehead
Logged byZ. Burt
Boring Started07-05-2024
Boring Completed07-05-2024
Abandonment Method
Advancement MethodDirect PushNotes
Water Level ObservationsGroundwater not encountered
See Exploration and Testing Procedures for a description of field and laboratory procedures used andadditional data (If any).
See Supporting Information for explanation of symbols and abbreviations.
Elevation Reference: Approximate elevations obtained using Google Earth Pro
7-Eleven - Hwy 421
Sa
m
p
l
e
T
y
p
e
Pe
r
c
e
n
t
Fi
n
e
s
Elevation: 12 (Ft.) +/-
AtterbergLimits
LL-PL-PI
See Exploration PlanLocation:
Latitude: 34.2941° Longitude: -77.9733°
Depth (Ft.)
1
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-08
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.3 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 3 inches
Cave In Depth = 4 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2938° Longitude: -77.9731°
CPT Completed: 6/27/2024
6.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/27/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-09
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 4 inches
Cave In Depth = 4 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 13 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2935° Longitude: -77.9729°
CPT Completed: 6/28/2024
7.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-10
Approx.Elev.(ft)
15
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 6 inches
Cave In Depth = 7 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 16 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2932° Longitude: -77.9726°
CPT Completed: 6/28/2024
8 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-11
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 5 inches
Cave In Depth = 4 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2938° Longitude: -77.9735°
CPT Completed: 6/28/2024
6 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-12
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.2 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 5 inches
Cave In Depth = 5 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 13 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2935° Longitude: -77.9733°
CPT Completed: 6/28/2024
6.5 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID P-13
Approx.Elev.(ft)
15
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.2 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
See P-13MC for the adjacent test's full details.
Topsoil Thickness = 5 inches
Cave In Depth = 6 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 16 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2933° Longitude: -77.9730°
CPT Completed: 6/28/2024
8 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
P-
1
3
M
C
M
a
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e
r
i
a
l
De
s
c
r
i
p
t
i
o
n
15.6
12.5
11
TOPSOIL, 5 inches
POORLY GRADED SAND (SP), fine to medium, gray
-Color change to orange
NO RECOVERY
Boring Terminated at 5 Feet
Boring Log No. P-13MC
Wa
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Ob
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s
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(
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5
Facilities | Environmental | Geotechnical | Materials
Gr
a
p
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i
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L
o
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Mo
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e
l
L
a
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4NP
0.4
3.5
5.0
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 Wilmington, NC
2108 Capital Dr, Ste 103
Drill RigGeoprobe 7822DT
Hammer TypeN/A
DrillerT. Whitehead
Logged byZ. Burt
Boring Started07-05-2024
Boring Completed07-05-2024
Abandonment Method
Advancement MethodDirect PushNotes
Water Level ObservationsGroundwater not encountered
See Exploration and Testing Procedures for a description of field and laboratory procedures used andadditional data (If any).
See Supporting Information for explanation of symbols and abbreviations.
Elevation Reference: Approximate elevations obtained using Google Earth Pro
7-Eleven - Hwy 421
Sa
m
p
l
e
T
y
p
e
Pe
r
c
e
n
t
Fi
n
e
s
Elevation: 16 (Ft.) +/-
AtterbergLimits
LL-PL-PI
See Exploration PlanLocation:
Latitude: 34.2933° Longitude: -77.9730°
Depth (Ft.)
1
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID SCM-01
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
Topsoil Thickness = 6 inches
Cave In Depth = 5 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 12 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2944° Longitude: -77.9732°
CPT Completed: 6/28/2024
7 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
Depth(ft)
0
5
10
15
20
25
30
35
40
45
50
CPT Sounding ID SCM-02
Approx.Elev.(ft)
10
5
0
-5
-10
-15
-20
-25
-30
-35
10 20 30 40
Tip Resistance, qt(tsf)
100 200 300 400
Facilities | Environmental | Geotechnical | Materials
Friction Ratio, Fr(%)
1 2 3 4
Sleeve Friction, fs(tsf)
0.25 0.50 0.75 1.00
0.025 0.050 0.075 0.100
MaterialDescriptionNormalized CPTSoil Behavior Type
1 2 3 4 5 6 7 8
Pore Pressure, u2(tsf)
0.0 0.5 1.0 1.5
Hydrostatic Pressure
CPT Terminated at 10.1 Feet
1 Sensitive, fine grained
Normalized Soil Behavior Type(Robertson 1990)See Exploration and Testing Procedures for a description of fieldand laboratory procedures used and additional data, if any.
See Supporting Information for explanation of symbols andabbreviations.
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Notes
Test Location: See Exploration Plan
See SCM-02MC for the adjacent test's full details.
Topsoil Thickness = 5 inches
Cave In Depth = 4 feet (dry)
Elevation Reference: Approximate elevations obtained using Google Earth Pro
Elevation: 13 (ft) +/-
CPT Equipment
Terracon Project No. K6245049
3 Clay - silty clay to clay
2 Organic soils - clay
Auger anchors used as reaction force
CPT sensor calibration reports available upon request
Probe No. 5632 with net area ratio of 0.85
U2 pore pressure transducer location
Manufactured by Geoprobe Systems- Calibrated 4/5/2024
Tip and sleeve areas of 10 cm2 and 150 cm2
Ring friction reducer with O.D. of 2 in
Latitude: 34.2946° Longitude: -77.9730°
CPT Completed: 6/28/2024
7 ft estimated water depth
(used in normalizations and correlations)
CPT Started: 6/28/2024
9 Very stiff fine grained
4 Silt mixtures - clayey silt to silty clay
8 Very stiff sand to clayey sand
7 Gravelly sand to dense sand
6 Sands - clean sand to silty sand
5 Sand mixtures - silty sand to sandy silt
Operator: T. Whitehead
CPT Rig: Geoprobe 7822DT
2108 Capital Dr, Ste 103
Wilmington, NC
Water Level Observation
SC
M
-
0
2
M
C
M
a
t
e
r
i
a
l
De
s
c
r
i
p
t
i
o
n
12.6
10
8
5
3
TOPSOIL, 5 inches
POORLY GRADED SAND (SP), fine to medium, light gray
NO RECOVERY
POORLY GRADED SAND (SP), fine to medium, brown
-Color change to dark brown
-Color change to brown and tan
NO RECOVERY
Boring Terminated at 10 Feet
Boring Log No. SCM-02MC
Wa
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L
e
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e
l
Ob
s
e
r
v
a
t
i
o
n
s
De
p
t
h
(
F
t
.
)
5
10
Facilities | Environmental | Geotechnical | Materials
Gr
a
p
h
i
c
L
o
g
Mo
d
e
l
L
a
y
e
r
3NP
0.4
3.0
5.0
8.0
10.0
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 Wilmington, NC
2108 Capital Dr, Ste 103
Drill RigGeoprobe 7822DT
Hammer TypeN/A
DrillerT. Whitehead
Logged byZ. Burt
Boring Started07-05-2024
Boring Completed07-05-2024
Abandonment Method
Advancement MethodDirect PushNotes
Water Level Observations
Cave In (dry)
Estimated based on cpt data
See Exploration and Testing Procedures for a description of field and laboratory procedures used andadditional data (If any).
See Supporting Information for explanation of symbols and abbreviations.
Elevation Reference: Approximate elevations obtained using Google Earth Pro
7-Eleven - Hwy 421
Sa
m
p
l
e
T
y
p
e
Pe
r
c
e
n
t
Fi
n
e
s
Elevation: 13 (Ft.) +/-
AtterbergLimits
LL-PL-PI
See Exploration PlanLocation:
Latitude: 34.2946° Longitude: -77.9730°
Depth (Ft.)
1
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110100
16 2044 100
U.S. Sieve Numbers
632 10 14 506 2001.5 83/4
1/23/8 30 403 601 140
HydrometerU.S. Sieve Opening in Inches
Grain Size Distribution
SandGravel
Grain Size (mm)
coarse fine coarse finemedium
Silt or ClayCobbles
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
W
e
i
g
h
t
Pe
r
c
e
n
t
F
i
n
e
r
b
y
W
e
i
g
h
t
100
90
80
70
60
50
40
30
20
10
0
ASTM D422 / ASTM C136 / AASHTO T27
Facilities | Environmental | Geotechnical | Materials
LL PL PI Cc CuDescription
POORLY GRADED SAND
POORLY GRADED SAND
POORLY GRADED SAND
POORLY GRADED SAND
POORLY GRADED SAND
2.0
1.3
4.5
4.4
2.9
NP
NP
NP
NP
NP
1.25
1.23
1.40
1.38
1.30
NP
NP
NP
NP
NP
NP
NP
NP
NP
NP
%CobblesD60
0.421
0.422
0.374
0.394
0.399
D100
2.66
2.62
3.00
2.94
2.57
%Clay%Sand%Gravel
0.0
0.0
0.9
0.0
0.0
98.0
98.7
94.6
95.6
97.1
0.0
0.0
0.0
0.0
0.0
D10
0.158
0.161
0.125
0.134
0.156
D30
0.288
0.289
0.255
0.27
0.284
4.75
2
9.5
2
2
%Fines %Silt
Boring ID
1 - 2
1 - 2
1 - 3
1 - 2
6.5 - 7.5
B-01MC
B-07MC
P-08
P-13MC
SCM-02MC
1 - 2
1 - 2
1 - 3
1 - 2
6.5 - 7.5
Depth (Ft)Boring ID
B-01MC
B-07MC
P-08
P-13MC
SCM-02MC
Depth (Ft)
2108 Capital Dr, Ste 103
Wilmington, NCTerracon Project No. K6245049
3705 US-421 North | Wilmington, NC
7-Eleven - Hwy 421
USCS
SP
SP
SP
SP
SP
50
54
58
62
66
70
74
78
82
86
90
94
98
102
106
110
114
118
122
126
130
134
138
142
0 5 10 15 20 25 30 35 40 45
Curves of 100% Saturationfor Specific Gravity Equal to:
2.80
2.70
2.60
Moisture-Density Relationship
Dr
y
D
e
n
s
i
t
y
(
p
c
f
)
Water Content (%)
ASTM D698-Method A
Facilities | Environmental | Geotechnical | Materials
2108 Capital Dr, Ste 103
Wilmington, NCTerracon Project No. K6245049
3705 US-421 North | Wilmington, NC
7-Eleven - Hwy 421
Description of Materials
Optimum Water Content(%)Maximum Dry Density(pcf)Test Method
ASTM D698-Method A 104.8 14.75 NP NP NP
Fines(%)PIPLLL
POORLY GRADED SAND(SP)
Fraction>4.75 mm size
0.9
P-08 1 - 3
Depth (Ft)Boring ID
0
1
2
3
4
5
6
7
8
9
10
11
12
13
104.0 104.2 104.4 104.6 104.8 105.0
California Bearing Ratio
ASTM D1883-072
Dry Density (pcf)
So
a
k
e
d
C
B
R
(
%
)
(
C
O
R
R
E
C
T
E
D
)
Facilities | Environmental | Geotechnical | Materials
0
50
100
150
200
250
300
350
0 0.10 0.20 0.30 0.40 0.50
Penetration (in)
Pe
n
e
t
r
a
t
i
o
n
R
e
s
i
s
t
a
n
c
e
(
p
s
i
)
P-08 1.0
POORLY GRADED SAND(SP)
PL PI
Description ofMaterial
Atterberg Limits
Percent Fines
Remarks:
NPNPNP
LL
% Retained No. 4 Sieve: 0.9
Source ofMaterial
4.5
2108 Capital Dr, Ste 103
Wilmington, NCTerracon Project No. K6245049
3705 US-421 North | Wilmington, NC
7-Eleven - Hwy 421
104.8
14.7
14.0
18.7
12.0
Soaked
ASTM 698A
0.04
10.00
104.28
1
Bearing Ratio, (%)
Swell, (%)
Surcharge, (lbs)
Top 1" After Soaking
After Compaction
Moisture Content, (%)
Dry Density before Soaking, (pcf)
Optimum Moisture Content, (%)
Maximum Dry Density, (pcf)
Compaction Method
Sample No.
Sample Condition
Supporting Information
Contents:
General Notes
CPT General Notes
Unified Soil Classification System
Stormwater Soils Evaluation Report
Note: All attachments are one page unless noted above.
GeoProbeMacro Core
or Large
Bore
Facilities | Environmental | Geotechnical | Materials
> 4.00
2.00 to 4.00
1.00 to 2.00
0.50 to 1.00
0.25 to 0.50
less than 0.25
Unconfined CompressiveStrengthQu (tsf)
7-Eleven - Hwy 421
3705 US-421 North | Wilmington, NC
Terracon Project No. K6245049 2108 Capital Dr, Ste 103
Wilmington, NC
N
(HP)
(T)
(DCP)
UC
(PID)
(OVA)
Standard Penetration TestResistance (Blows/Ft.)
Hand Penetrometer
Torvane
Dynamic Cone Penetrometer
Unconfined CompressiveStrength
Photo-Ionization Detector
Organic Vapor Analyzer
Water Level After aSpecified Period of Time
Water Level Aftera Specified Period of Time
Cave InEncountered
Water Level Field Tests
Water InitiallyEncountered
Sampling
Water levels indicated on the soil boring logs are the
levels measured in the borehole at the times
indicated. Groundwater level variations will occur over
time. In low permeability soils, accurate
determination of groundwater levels is not possible
with short term water level observations.
General Notes
Location And Elevation Notes
Exploration point locations as shown on the Exploration Plan and as noted on the soil boring logs in the form of Latitude and Longitude are
approximate. See Exploration and Testing Procedures in the report for the methods used to locate the exploration points for this project. Surface
elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface
elevation was approximately determined from topographic maps of the area.
Soil classification as noted on the soil boring logs is based Unified Soil Classification System. Where sufficient laboratory data exist to classify the
soils consistent with ASTM D2487 "Classification of Soils for Engineering Purposes" this procedure is used. ASTM D2488 "Description and
Identification of Soils (Visual-Manual Procedure)" is also used to classify the soils, particularly where insufficient laboratory data exist to classify the
soils in accordance with ASTM D2487. In addition to USCS classification, coarse grained soils are classified on the basis of their in-place relative
density, and fine-grained soils are classified on the basis of their consistency. See "Strength Terms" table below for details. The ASTM standards
noted above are for reference to methodology in general. In some cases, variations to methods are applied as a result of local practice or
professional judgment.
Exploration/field results and/or laboratory test data contained within this document are intended for application to the project as described in this
document. Use of such exploration/field results and/or laboratory test data should not be used independently of this document.
Relevance of Exploration and Laboratory Test Results
Descriptive Soil Classification
> 30
15 - 30
8 - 15
4 - 8
2 - 4
Hard
> 50 Very Stiff
Stiff
Medium Stiff
Soft
Very Soft
30 - 50
10 - 29
4 - 9
0 - 3Very Loose
Loose
Medium Dense
Dense
Very Dense
Relative Density of Coarse-Grained Soils
(More than 50% retained on No. 200 sieve.)Density determined by Standard PenetrationResistance
Consistency of Fine-Grained Soils
(50% or more passing the No. 200 sieve.)Consistency determined by laboratory shear strength testing, field visual-manualprocedures or standard penetration resistance
0 - 1
Relative Density ConsistencyStandard Penetration orN-Value(Blows/Ft.)
Standard Penetration orN-Value(Blows/Ft.)
Strength Terms
Facilities | Environmental | Geotechnical | Materials
Kulhawy, F.H., Mayne, P.W., (1997). "Manual on Estimating Soil Properties for Foundation Design," Electric Power Research Institute, Palo Alto, CA.Mayne, P.W., (2013). "Geotechnical Site Exploration in the Year 2013," Georgia Institue of Technology, Atlanta, GA.
Robertson, P.K., Cabal, K.L. (2012). "Guide to Cone Penetration Testing for Geotechnical Engineering," Signal Hill, CA.
Schmertmann, J.H., (1970). "Static Cone to Compute Static Settlement over Sand,"Journal of the Soil Mechanics and Foundations Division,96(SM3), 1011-1043.
1 Sensitive, fine grained
2 Organic soils - clay
3 Clay - silty clay to clay
DESCRIPTION OF GEOTECHNICAL CORRELATIONS
RELATIVE RELIABILITY OF CPT CORRELATIONS
WATER LEVEL
CONE PENETRATION SOIL BEHAVIOR TYPE
REFERENCES
Unit Weight,
Relative Density, Dr
Constrained Modulus, M
Permeability, k
Effective Friction Angle, '
Low Reliability High Reliability
10.1 10
NORMALIZED FRICTION RATIO, Fr
NO
R
M
A
L
I
Z
E
D
C
O
N
E
R
E
S
I
S
T
A
N
C
E
,
q
t /
a
t
m
1
100
10
1000
DESCRIPTION OF MEASUREMENTSAND CALIBRATIONS
improves with seismic Vs measurements
Reliability of CPT-predicted N60 values ascommonly measured by the StandardPenetration Test (SPT) is not provided dueto the inherent inaccuracy associated withthe SPT test procedure.
Small Strain Modulus, G0* andElastic Modulus, Es*
CPT GENERAL NOTES
4 Silt mixtures - clayey silt to silty clay
5 Sand mixtures - silty sand to sandy silt
6 Sands - clean sand to silty sand
7 Gravelly sand to dense sand
8 Very stiff sand to clayey sand
9 Very stiff fine grained
atm = atmospheric pressure = 101 kPa = 1.05 tsf
REPORTED PARAMETERS
Sensitivity, St
Undrained Shear Strength, Su
Over Consolidation Ratio, OCR
CPT logs as provided, at a minimum, report the data as required by ASTM D5778 and ASTM D7400 (if applicable). Thisminimum data include qt, fs, and u. Other correlated parameters may also be provided. These other correlated parameters areinterpretations of the measured data based upon published and reliable references, but they do not necessarily represent theactual values that would be derived from direct testing to determine the various parameters. To this end, more than onecorrelation to a given parameter may be provided. The following chart illustrates estimates of reliability associated withcorrelated parameters based upon the literature referenced below.
Over Consolidation Ratio, OCR OCR (1) = 0.25(Qtn)1.25
OCR (2) = 0.33(Qtn)
Undrained Shear Strength, Su Su = Qtn x 'V0/Nkt Nkt is a soil-specific factor (shown on Su plot)
Sensitivity, St St = (qt - V0/Nkt) x (1/fs)
Unit Weight, = (0.27[log(Fr)]+0.36[log(qt/atm)]+1.236) x water
V0 is taken as the incremental sum of the unit weights
Small Strain Shear Modulus, G0 G0 (1) = Vs2
G0 (2) = 0.015 x 10(0.55Ic + 1.68)(qt - V0)Relative Density, Dr Dr = (Qtn / 350)0.5 x 100
Constrained Modulus, M
M = M(qt - V0)
For Ic > 2.2 (fine-grained soils)
M = Qtn with maximum of 14
For Ic < 2.2 (coarse-grained soils) M = 0.0188 x 10(0.55Ic + 1.68)
Hydraulic Conductivity, k For 1.0 < Ic < 3.27 k = 10(0.952 - 3.04Ic)
For 3.27 < Ic < 4.0 k = 10(-4.52 - 1.37Ic)
Es (1) = 2.6 G0 where = 0.56 - 0.33logQtn,clean sand Es (2) = G0 Es (3) = 0.015 x 10(0.55Ic + 1.68)(qt - V0)
Es (4) = 2.5qt
Soil Behavior Type Index, Ic Ic = [(3.47 - log(Qtn))2 + (log(Fr) + 1.22)2]0.5
SPT N60 N60 = (qt/atm) / 10(1.1268 - 0.2817Ic)
Elastic Modulus, Es (assumes q/qultimate ~ 0.3, i.e. FS = 3)
Shear Wave Velocity, Vs Measured in a Seismic CPT and provides direct measure of soil stiffness
To be reported per ASTM D7400, if collected:
Normalized Friction Ratio, Fr The ratio as a percentage of fs to qt, accounting for overburden pressure
Sleeve Friction, fs Frictional force acting on the sleeve divided by its surface area
Pore Pressure, u Pore pressure measured during penetration u1 - sensor on the face of the cone u2 - sensor on the shoulder (more common)
Where a is the net area ratio, a lab calibration of the cone typically between 0.70 and 0.85
Corrected Tip Resistance, qt Cone resistance corrected for porewater and net area ratio effects qt = qc + u2(1 - a)
Uncorrected Tip Resistance, qc Measured force acting on the cone divided by the cone's projected area
To be reported per ASTM D5778:
Normalized Tip Resistance, Qtn Qtn = ((qt - V0)/Pa)(Pa/ 'V0)n
n = 0.381(Ic) + 0.05( 'V0/Pa) - 0.15
The groundwater level at the CPT location is used to normalize the measurements for vertical overburden pressures and as a result influences the normalized soil behavior typeclassification and correlated soil parameters. The water level may either be "measured" or "estimated:" Measured - Depth to water directly measured in the field Estimated - Depth to water interpolated by the practitioner using pore pressure measurements in coarse grained soils and known site conditionsWhile groundwater levels displayed as "measured" more accurately represent site conditions at the time of testing than those "estimated," in either case the groundwatershould be further defined prior to construction as groundwater level variations will occur over time.
Clay and Silt
Sand
Sand Clay and Silt
Sand
Clay and Silt
Clay and Silt
SandClay and Silt
Sand
SandClay and Silt
Clay and Silt
Clay and Silt
Sand
3
2
4
1
5
6
9
87
Typically, silts and clays have high Fr values and generate largeexcess penetration porewater pressures; sands have lower Fr'sand do not generate excess penetration porewater pressures.The adjacent graph (Robertson et al.) presents the soilbehavior type correlation used for the logs. This normalizedSBT chart, generally considered the most reliable, does not usepore pressure to determine SBT due to its lack of repeatabilityin onshore CPTs.
The estimated stratigraphic profiles included in the CPT logs arebased on relationships between corrected tip resistance (qt),friction resistance (fs), and porewater pressure (u2). Thenormalized friction ratio (Fr) is used to classify the soil behaviortype.
Effective Friction Angle, ' ' (1) = tan-1(0.373[log(qc/ 'V0) + 0.29]) ' (2) = 17.6 + 11[log(Qtn)]
Geotechnical Engineering Report
7-Eleven | Wilmington, North Carolina
July 29, 2024 | Terracon Project No. K6245049
Facilities | Environmental | Geotechnical | Materials
Unified Soil Classification System
Criteria for Assigning Group Symbols and Group Names Using
Laboratory Tests A
Soil Classification
Group Symbol Group Name B
Coarse-Grained Soils: More than 50% retained
on No. 200 sieve
Gravels: More than 50% of
coarse fraction retained on No. 4
sieve
Clean Gravels: Less than 5% fines C
Cu≥4 and 1≤Cc≤3 E GW Well-graded gravel F
Cu<4 and/or [Cc<1 or Cc>3.0] E GP Poorly graded gravel F
Gravels with Fines:
More than 12% fines C
Fines classify as ML or MH GM Silty gravel F, G, H
Fines classify as CL or CH GC Clayey gravel F, G, H
Sands: 50% or more of
coarse fraction passes No. 4 sieve
Clean Sands: Less than 5% fines D
Cu≥6 and 1≤Cc≤3 E SW Well-graded sand I
Cu<6 and/or [Cc<1 or Cc>3.0] E SP Poorly graded sand I
Sands with Fines:
More than 12% fines D
Fines classify as ML or MH SM Silty sand G, H, I
Fines classify as CL or CH SC Clayey sand G, H, I
Fine-Grained Soils: 50% or more passes the No. 200 sieve
Silts and Clays: Liquid limit less than
50
Inorganic: PI > 7 and plots above “A” line J CL Lean clay K, L, M
PI < 4 or plots below “A” line J ML Silt K, L, M
Organic: 𝐿𝐿 𝑛𝑣𝑑𝑛 𝑑𝑟𝑖𝑑𝑑
𝐿𝐿 𝑛𝑛𝑡 𝑑𝑟𝑖𝑑𝑑<0.75 OL Organic clay K, L, M, N
Organic silt K, L, M, O
Silts and Clays: Liquid limit 50 or
more
Inorganic: PI plots on or above “A” line CH Fat clay K, L, M
PI plots below “A” line MH Elastic silt K, L, M
Organic: 𝐿𝐿 𝑛𝑣𝑑𝑛 𝑑𝑟𝑖𝑑𝑑
𝐿𝐿 𝑛𝑛𝑡 𝑑𝑟𝑖𝑑𝑑<0.75 OH Organic clay K, L, M, P
Organic silt K, L, M, Q
Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-inch (75-mm) sieve. B If field sample contained cobbles or boulders, or both, add “with
cobbles or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well-
graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay.
D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM
poorly graded sand with silt, SP-SC poorly graded sand with clay.
E Cu = D60/D10 Cc =
F If soil contains ≥ 15% sand, add “with sand” to group name.
G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
H If fines are organic, add “with organic fines” to group name. I If soil contains ≥ 15% gravel, add “with gravel” to group name.
J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or
“with gravel,” whichever is predominant. L If soil contains ≥ 30% plus No. 200 predominantly sand, add
“sandy” to group name. M If soil contains ≥ 30% plus No. 200, predominantly gravel, add
“gravelly” to group name. N PI ≥ 4 and plots on or above “A” line.
O PI < 4 or plots below “A” line. P PI plots on or above “A” line.
Q PI plots below “A” line.
6010
2
30
DxD
)(D
July 24, 2024
Terracon Consultants, Inc.
2108 Capital Drive, Suite 103
Wilmington, NC 28405
Attention: Mr. Justin DeNicola, P.E.
Subject: Stormwater Soil Evaluations
Project No. 24-030-SS
US Highway 421 Site
New Hanover County, NC
Dear Mr. DeNicola:
Terrain Environmental Consulting, PLLC (TEC) appreciates the opportunity to provide
you with this report for stormwater soil evaluation services associated with the design
of stormwater control measures (SCM) at the above referenced project site. The
results of the testing are presented below.
PROJECT BACKGROUND
TEC was contracted by Terracon to perform stormwater soil evaluation services,
specifically seasonal high water table (SHWT) evaluations and hydraulic conductivity
(Ksat) testing, to assist with the future design of an SCM at the above referenced
project site. An aerial photograph showing the locations (SCM-01 and SCM-02) was
provided and the test locations were marked in the field prior to our mobilization.
Review of the Web Soil Survey showed the areas at test locations being mapped with
the Leon soil series. This soil series is generally described as poorly drained soils
formed in marine sediments on flats, depressions, stream terraces and tidal areas with
an expected SHWT between 6 to 18 inches below the ground surface.
RESULTS
Seasonal High Water Table Evaluation
The SHWT evaluations were performed on July 22, 2024 by advancing hand auger
borings at the test locations, as shown on the attached Stormwater Soil Evaluations
sketch (Figure 1). The hand auger borings were advanced to depths ranging from
approximately 72 to 76 inches below the existing ground surface. Soils were evaluated
by a Licensed Soil Scientist for evidence of SHWT influence. This evaluation involved
looking at the actual moisture content in the soil and observing the matrix and mottle
colors. Depending on the soil texture, the soil color will indicate processes that are
Terrain Environmental Consulting Project 24-030-SS July 24, 2024
US Highway 421 Site
2
driven by SHWT fluctuations such as iron reduction and oxidation and organic matter
staining.
At both of the test locations, soils consisted mainly of fine sand with loamy sand to
sandy loam subsurface horizons representing deterirorating organic pans and/or hard
pans or a horizon of slight clay accumulation. Approximatley 31 inches of potential
sandy fill was observed at SCM-02. The SHWT was estimated to range between 39 to
54 inches below the ground surface.
A Soil Profile Description sheet, which provides a description of the observed soil
horizons and the estimated SHWT depths, has also been included with this report.
Ksat Testing
TEC personnel performed in-situ saturated hydraulic conductivity (Ksat) testing at the
test locations after the SHWT evaluations were complete. Specifically, the constant-
head well permeameter technique (also known as shallow well pump-in technique and
bore hole permeameter method) was used. This procedure is described in Methods of
Soil Analysis, Part 1., Chapter 29 – Hydraulic Conductivity of Saturated Soils: Field
Methods, 29 – 3.2 Shallow Well Pump In Method, pp. 758-763 and in the Soil Science
Society of America Journal, Vol. 53, no. 5, Sept. – Oct. 1989, “A Constant-head
Permeameter for Measuring Saturated Hydraulic Conductivity of the Vadose Zone”
and “Comparison of the Glover Solution with the Simultaneous – Equations Approach
for Measuring Hydraulic Conductivity.” This method involves allowing a measured
volume of water to percolate through the soil until a steady rate of flow is achieved.
The steady state rate is used to calculate the Ksat of the soil horizon using the Glover
equation.
The Ksat tests were performed approximatley two feet above the SHWT. The Ksat
rates were calculated to range from 23.32 to 23.7 inches per hour.
See Table 1 below for a summary of the soil evaluation results.
TABLE 1
TEST
LOCATION
SHWT
(inches below
ground
surface)
OWT
(inches below
ground
surface)
Ksat
Testing Interval
(inches below
ground surface)
Ksat RATE
(inches per
hour)
SCM-01 39 inches 72 inches 12 to 18 inches 23.7 in/hr
SCM-02 54 inches Not Observed 24 to 30 inches 23.32 in/hr
DISCUSSION
Potential fill was observed to a depth of approximately 31 inches at SCM-02 as
evidenced by inconsistent, mixed-up soil horizon development, observed roots in the
buried native A horizon, and the higher elevation at and around the test location
Terrain Environmental Consulting Project 24-030-SS July 24, 2024
US Highway 421 Site
3
relative to nearby areas. The potential fill was observed to be sandy textured and
appears to have naturalized. Mature pine trees were and a new surface A horizon has
developed. It is our opinion that this material is suitable for stormwater treatment.
The Ksat testing was performed approximately two feet above the SHWT at both
locations. At SCM-02, a potentially perching Bh horizon with few cement sands was
observed from 41 to 46 inches, between the testing interval and SHWT. Soils
immediately beneath this horizon did not exhibit the low-chroma colors indicative of
SHWT conditions. The Ksat test was not run in this horizon as it is very thin compared
to the remaining sandy textured soils above and below it, thus it did not appear to be
representative of the overall soil profile. At SCM-01, this horizon was much less
pronounced and did not contain the few cemented sands observed at SCM-02.
However, this horizon could affect stormwater infiltration throughout the overall SCM
and we recommend excavating it out and backfilling with the overlying sandy soils to
maintain the two-foot minimum separation above SHWT.
CLOSING
We appreciate the opportunity to provide stormwater soil evaluation services. If you
have any questions, please do not hesitate to contact me.
Sincerely,
Paul Masten, LSS, PWS
President/Owner
Attachments
Figure 1 – Stormwater Soil Evaluations
Soil Profile Descriptions
³0 10050Feet
Figure 1 - Stormwater Soil Evaluations
US Highway 421 Site
New Hanover County, NC
Sutto
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a
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1
NC CGIA, Maxar, Microsoft
SOIL PROFILE DESCRIPTIONS
US Highway 421 Site
New Hanover County, NC
Location Horizon Depth
(inches)
Matrix Mottles Texture, Structure, Consistence
SCM-1 A 0-5 2.5Y 3/1 Very dark gray fine sand, single
grain, loose
E 5-10 10YR 5/1 Gray fine sand, single grain, loose
E/Bh 10-16 5YR 2.5/2 7.5YR 4/4 Dark reddish brown fine sand,
single grain, loose, organic
accumulation; common reddish
brown streaks
2E1 16-21 10YR 5/4 10YR 6/3 Yellowish brown fine sand, single
grain, loose; common pale brown
streaks
2E2 21-39 10YR 6/3 10YR 7/3
10YR 5/8
Pale brown fine sand, single grain,
loose; common very pale brown
redox depletions and yellowish
brown redox concentrations
Bw 39-61 10YR 6/4 10YR 7/2
10YR 6/2
Light yellowish brown loamy
sand, granular, very friable;
common light gray to light
brownish gray redox depletions
C 61-76 10YR 6/2 10YR 5/6 Light brownish gray fine sand,
single grain, loose; common
yellowish brown redox depletions
Seasonal High Water Table = 39 inches below the existing ground surface. Water table observed
at 72 inches below the ground surface.
SOIL PROFILE DESCRIPTIONS
US Highway 421 Site
Page 2
Location Horizon Depth
(inches)
Matrix Mottles Texture, Structure, Consistence
SCM-2 Potential
Fill
0-3 10YR 6/2 Light brownish gray fine sand,
single grain, loose
Potential
Fill
3-8 10YR 4/3 10YR 4/4 Brown fine sand, single grain,
loose; dark yellowish brown
streaks
Potential
Fill
8-31 10YR 6/4 10YR 5/3
10YR 5/8
10YR 6/2
10YR 6/1
2.5Y 6/6
Light yellowish brown fine sand,
single grain, loose; brown,
yellowish brown light brownish
gray, gray and olive yellow sands
Ab 31-34 10YR 3/1 Very dark gray fine sand, single
grain, loose, roots present
E 34-41 10YR 6/2 Light brownish gray fine sand,
single grain, loose
Bh 41-46 10YR 3/3 10YR 3/2
10YR 5/3
Dark brown loamy sand, granular,
very friable, few cemented pieces;
common very dark grayish brown
organic accumulations and brown
redox depletions
2E 46-54 2.5Y 6/3 10YR 5/6 Light yellowish brown fine sand,
single grain, loose; common
yellowish brown redox
concentrations
2Bt 54-63 2.5Y 5/2 2.5Y 4/1
10YR 5/8
Grayish brown sandy loam, weak,
medium sub-angular blocky,
friable; common dark gray redox
depletions and yellowish brown
redox concentrations
C 63-72 10YR 7/1 10YR 5/8 Light gray fine sand, single grain,
loose; common yellowish brown
redox concentrations
Seasonal High Water Table = 54 inches below the existing ground surface. Water table not
observed.
Page 6
APPENDIX B
STORMWATER CALCULATIONS
Site Conditions Analysis
Project: 2002.25
Project Name: Hwy 421- 7-Eleven
Computed By: GAF
Date: 11-Nov-24
City:
Existing Conditions
Total Disturbed Area 225,938.00 sq. ft.5.19 Ac 100.00 %
Proposed Impervious Area
Structures 7,248.00 sq. ft.0.17 Ac 3.21 %
Concrete 2,167.00 sq. ft.0.05 Ac 0.96 %
Asphalt 23,218.00 sq. ft.0.53 Ac 10.28 %
Gravel 0.00 sq. ft.0.00 Ac 0.00 %
Total Impervious 32,633.00 sq. ft.0.75 Ac 14.44 %
Proposed Pervious Area
Grass 193,305.00 sq. ft.4.44 Ac 85.56 %
Total Pervious Area 193,305.00 sq. ft.85.56 %
Proposed Site Conditions (On-site)
Total Disturbed Area 225,938.00 sq. ft.5.19 Ac 100.00 %
Proposed Impervious Area
Structures 4,813.00 sq. ft.0.11 Ac 2.13 %
Concrete 61,458.00 sq. ft.1.41 Ac 27.20 %
Asphalt 52,233.00 sq. ft.1.20 Ac 23.12 %
Gravel 0.00 sq. ft.0.00 Ac 0.00 %
Total Impervious 118,504.00 sq. ft.2.72 Ac 52.45 %
Proposed Pervious Area
Pervious Concrete 0.00 sq. ft.0.00 Ac 0.00 %
Grass 107,434.00 sq. ft.2.47 Ac 47.55 %
Total Pervious Area 107,434.00 sq. ft.2.47 Ac 47.55 %
Site Improvement Analysis
Existing Impervious Area 32,633.00 sq. ft.14.44 %
Proposed Impervious Area 118,504.00 sq. ft.52.45 %
Total Impervious Area Increase 85,871.00 sq. ft.38.01 %
Wilmington
Page 1 of 1
Time of Concentration
Project:2002.25
Project Name:Hwy 421- 7-Eleven
Computed By:G. Franks
Date:11-Nov-24
DA-A (Existing) DA-A (Proposed)
Overland Flow Time of Concentration for all proposed
drianage areas is 5 min.
L = length, ft 100
P= 2yr-24hr, in. 3.8
s= slope, ft/ft 0.01
n=mannings 0.07
t=0.11 hr.
t=6.45 min.
Shallow Concentrated Flow
L = length, ft 250
V = Velocity, ft/s 3
t=0.02 hr.
t=1.39 min.
Channel Flow
a = area, sf 15.0
pw = wetted perimeter, ft 10.0
r= 1.5
s=slope, ft/ft 0.001
n=mannings 0.05
V= 1.23 ft/s
L=flow length, ft 0 ft
t=0.00 hr.
t=0.00 min.
Total Tt =7.84 min.
𝑇௧=.()బ.ఴ
మబ.ఱ௦బ.ర
𝑇௧ =𝐿
3600𝑉
𝑇௧ =𝐿
3600𝑉𝑉=1.49𝑟ଶ ଷ⁄𝑠ଵ ଶ⁄
𝑛
𝑟=𝑎
𝑝௪
DA-B (Exisitng) DA-B (Proposed)
Overland Flow Time of Concentration for all proposed
drianage areas is 5 min.
L = length, ft 100
P= 2yr-24hr, in. 3.8
s= slope, ft/ft 0.01
n=mannings 0.07
t=0.11 hr.
t=6.45 min.
Shallow Concentrated Flow
L = length, ft 429
V = Velocity, ft/s 5
t=0.02 hr.
t=1.43 min.
Channel Flow
a = area, sf 15.0
pw = wetted perimeter, ft 10.0
r= 1.5
s=slope, ft/ft 0.001
n=mannings 0.03
V= 2.06 ft/s
L=flow length, ft 0 ft
t=0.00 hr.
t=0.00 min.
Total Tt =7.88 min.
𝑇௧=.()బ.ఴ
మబ.ఱ௦బ.ర
𝑇௧ =𝐿
3600𝑉
𝑇௧ =𝐿
3600𝑉𝑉=1.49𝑟ଶ ଷ⁄𝑠ଵ ଶ⁄
𝑛
𝑟=𝑎
𝑝௪
Portsmouth, Va 23704
Ph: 757-908-2372
PROJECT: 7-Eleven - Cliffdale and Bunce
DATE: 11/11/2024
DESIGNER: Gary Franks
TEMPORARY SEDIMENT BASIN #1 REQ. VOLUME CALCULATION:
Drainage Area: 5.19 acres or 225,938 sf
Required Wet Storage = 67 cy/ac 348 cy or 9,389 cf
Wet Storage provided at elevation 11.50 45,697 cf
Required Dry Storage = 67 cy/ac 348 cy or 9,389 cf
Dry Storage provided at elevation 12.00 10,421 cf
TEMPORARY SEDIMENT TRAP WET/DRY VOLUME CALCULATION:
STAGE-STORAGE DATA
DELTA
ELEVATION AREA AREA DEPTH STORAGE
9.00 16210.00
17025.50 1.00
10.00 17841.00 17025.50
18687.50 1.00
11.00 19534.00 35713.00
19967.00 0.50
11.50 20400.00 45696.50
20841.00 0.50
12.00 21282.00 56117.00
Wet Storage Information:
Storage Required =9,389 Cu. Ft.BEGINS AT ELEVATION 9.00
Storage Provided =45,697 Cu. Ft.OCCURS AT ELEVATION 10.00
Dry Storage Information:
Storage Required =9,389 Cu. Ft.BEGINS AT ELEVATION 10.00
Storage Provided =10,421 Cu. Ft.OCCURS AT ELEVATION 11.00
457 Court Street
Page 7
EXISTING CONDITIONS
Project Description
Existing Conditions.SPF
Project Options
CFS
Elevation
SCS TR-55
User-Defined
Hydrodynamic
YES
YES
Analysis Options
00:00:00 0:00:00
00:00:00 0:00:00
00:00:00 0:00:00
0 days
0 01:00:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
1 seconds
Number of Elements
Qty
1
2
2
0
2
0
0
0
0
0
0
0
0
0
0
0
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
49 Time Series 2-yr Cumulative inches North Carolina New Hanover 2.00 4.60 SCS Type III 24-hr
Antecedent Dry Days ................................
File Name ................................................
Flow Units ...............................................
Elevation Type ..........................................
Hydrology Method ....................................
Time of Concentration (TOC) Method ........
Link Routing Method .................................
Enable Overflow Ponding at Nodes ...........
Skip Steady State Analysis Time Periods ....
Start Analysis On ......................................
End Analysis On .......................................
Start Reporting On ...................................
Storage Nodes ...................................
Runoff (Dry Weather) Time Step ................
Runoff (Wet Weather) Time Step ...............
Reporting Time Step .................................
Routing Time Step ....................................
Rain Gages ..............................................
Subbasins................................................
Nodes......................................................
Junctions ...........................................
Outfalls .............................................
Flow Diversions .................................
Inlets ................................................
Outlets ..............................................
Pollutants ................................................
Land Uses ...............................................
Links........................................................
Channels ..........................................
Pipes .................................................
Pumps ..............................................
Orifices .............................................
Weirs ................................................
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 DA-A 0.47 484.00 94.23 4.60 3.94 1.85 1.69 0 00:07:50
2 DA-B 4.24 484.00 49.44 4.60 0.51 2.17 1.22 0 00:07:52
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time
ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft) (days hh:mm) (ac-in) (min)
1 Out-A Outfall 14.74 0.00 0.00
2 Out-B Outfall 11.72 0.00 0.00
Project Description
Existing Conditions.SPF
Project Options
CFS
Elevation
SCS TR-55
User-Defined
Hydrodynamic
YES
YES
Analysis Options
00:00:00 0:00:00
00:00:00 0:00:00
00:00:00 0:00:00
0 days
0 01:00:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
1 seconds
Number of Elements
Qty
1
2
2
0
2
0
0
0
0
0
0
0
0
0
0
0
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
49 Time Series 10-yr Cumulative inches North Carolina New Hanover 10.00 7.10 SCS Type III 24-hr
Antecedent Dry Days ................................
File Name ................................................
Flow Units ...............................................
Elevation Type ..........................................
Hydrology Method ....................................
Time of Concentration (TOC) Method ........
Link Routing Method .................................
Enable Overflow Ponding at Nodes ...........
Skip Steady State Analysis Time Periods ....
Start Analysis On ......................................
End Analysis On .......................................
Start Reporting On ...................................
Storage Nodes ...................................
Runoff (Dry Weather) Time Step ................
Runoff (Wet Weather) Time Step ...............
Reporting Time Step .................................
Routing Time Step ....................................
Rain Gages ..............................................
Subbasins................................................
Nodes......................................................
Junctions ...........................................
Outfalls .............................................
Flow Diversions .................................
Inlets ................................................
Outlets ..............................................
Pollutants ................................................
Land Uses ...............................................
Links........................................................
Channels ..........................................
Pipes .................................................
Pumps ..............................................
Orifices .............................................
Weirs ................................................
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 DA-A 0.47 484.00 94.23 7.10 6.41 3.01 2.67 0 00:07:50
2 DA-B 4.24 484.00 49.44 7.10 1.67 7.09 6.45 0 00:07:52
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time
ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft) (days hh:mm) (ac-in) (min)
1 Out-A Outfall 14.74 0.00 0.00
2 Out-B Outfall 11.72 0.00 0.00
Project Description
Existing Conditions.SPF
Project Options
CFS
Elevation
SCS TR-55
User-Defined
Hydrodynamic
YES
YES
Analysis Options
00:00:00 0:00:00
00:00:00 0:00:00
00:00:00 0:00:00
0 days
0 01:00:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
1 seconds
Number of Elements
Qty
1
2
2
0
2
0
0
0
0
0
0
0
0
0
0
0
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
49 Time Series 25-yr Cumulative inches North Carolina New Hanover 25.00 8.10 SCS Type III 24-hr
Antecedent Dry Days ................................
File Name ................................................
Flow Units ...............................................
Elevation Type ..........................................
Hydrology Method ....................................
Time of Concentration (TOC) Method ........
Link Routing Method .................................
Enable Overflow Ponding at Nodes ...........
Skip Steady State Analysis Time Periods ....
Start Analysis On ......................................
End Analysis On .......................................
Start Reporting On ...................................
Storage Nodes ...................................
Runoff (Dry Weather) Time Step ................
Runoff (Wet Weather) Time Step ...............
Reporting Time Step .................................
Routing Time Step ....................................
Rain Gages ..............................................
Subbasins................................................
Nodes......................................................
Junctions ...........................................
Outfalls .............................................
Flow Diversions .................................
Inlets ................................................
Outlets ..............................................
Pollutants ................................................
Land Uses ...............................................
Links........................................................
Channels ..........................................
Pipes .................................................
Pumps ..............................................
Orifices .............................................
Weirs ................................................
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 DA-A 0.47 484.00 94.23 8.10 7.41 3.48 3.07 0 00:07:50
2 DA-B 4.24 484.00 49.44 8.10 2.25 9.55 9.04 0 00:07:52
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time
ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft) (days hh:mm) (ac-in) (min)
1 Out-A Outfall 14.74 0.00 0.00
2 Out-B Outfall 11.72 0.00 0.00
Project Description
Existing Conditions.SPF
Project Options
CFS
Elevation
SCS TR-55
User-Defined
Hydrodynamic
YES
YES
Analysis Options
00:00:00 0:00:00
00:00:00 0:00:00
00:00:00 0:00:00
0 days
0 01:00:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
1 seconds
Number of Elements
Qty
1
2
2
0
2
0
0
0
0
0
0
0
0
0
0
0
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
49 Time Series 100-yr Cumulative inches North Carolina New Hanover 100.00 10.20 SCS Type III 24-hr
Antecedent Dry Days ................................
File Name ................................................
Flow Units ...............................................
Elevation Type ..........................................
Hydrology Method ....................................
Time of Concentration (TOC) Method ........
Link Routing Method .................................
Enable Overflow Ponding at Nodes ...........
Skip Steady State Analysis Time Periods ....
Start Analysis On ......................................
End Analysis On .......................................
Start Reporting On ...................................
Storage Nodes ...................................
Runoff (Dry Weather) Time Step ................
Runoff (Wet Weather) Time Step ...............
Reporting Time Step .................................
Routing Time Step ....................................
Rain Gages ..............................................
Subbasins................................................
Nodes......................................................
Junctions ...........................................
Outfalls .............................................
Flow Diversions .................................
Inlets ................................................
Outlets ..............................................
Pollutants ................................................
Land Uses ...............................................
Links........................................................
Channels ..........................................
Pipes .................................................
Pumps ..............................................
Orifices .............................................
Weirs ................................................
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 DA-A 0.47 484.00 94.23 10.20 9.50 4.47 3.88 0 00:07:50
2 DA-B 4.24 484.00 49.44 10.20 3.62 15.34 15.09 0 00:07:52
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time
ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft) (days hh:mm) (ac-in) (min)
1 Out-A Outfall 14.74 0.00 0.00
2 Out-B Outfall 11.72 0.00 0.00
Page 8
PROPOSED CONDITIONS
Project Description
Proposed Conditions.SPF
Project Options
CFS
Elevation
SCS TR-55
User-Defined
Hydrodynamic
YES
YES
Analysis Options
00:00:00 0:00:00
00:00:00 0:00:00
00:00:00 0:00:00
0 days
0 01:00:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
1 seconds
Number of Elements
Qty
1
13
14
0
2
0
11
1
12
0
11
0
0
1
0
0
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
49 Time Series 2-yr Cumulative inches North Carolina New Hanover 2.00 4.60 SCS Type III 24-hr
Antecedent Dry Days ................................
File Name ................................................
Flow Units ...............................................
Elevation Type ..........................................
Hydrology Method ....................................
Time of Concentration (TOC) Method ........
Link Routing Method .................................
Enable Overflow Ponding at Nodes ...........
Skip Steady State Analysis Time Periods ....
Start Analysis On ......................................
End Analysis On .......................................
Start Reporting On ...................................
Storage Nodes ...................................
Runoff (Dry Weather) Time Step ................
Runoff (Wet Weather) Time Step ...............
Reporting Time Step .................................
Routing Time Step ....................................
Rain Gages ..............................................
Subbasins................................................
Nodes......................................................
Junctions ...........................................
Outfalls .............................................
Flow Diversions .................................
Inlets ................................................
Outlets ..............................................
Pollutants ................................................
Land Uses ...............................................
Links........................................................
Channels ..........................................
Pipes .................................................
Pumps ..............................................
Orifices .............................................
Weirs ................................................
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 DA-A1 0.26 484.00 84.38 4.60 2.94 0.76 0.79 0 00:05:00
2 DA-A2 0.13 484.00 88.92 4.60 3.38 0.44 0.43 0 00:05:00
3 DA-B1 0.25 484.00 79.12 4.60 2.47 0.62 0.65 0 00:05:00
4 DA-B10 0.85 484.00 39.00 4.60 0.13 0.11 0.01 0 00:05:00
5 DA-B2 0.11 484.00 71.18 4.60 1.83 0.20 0.21 0 00:05:00
6 DA-B3 0.32 484.00 98.00 4.60 4.36 1.40 1.24 0 00:05:00
7 DA-B4 0.26 484.00 95.73 4.60 4.10 1.07 0.99 0 00:05:00
8 DA-B5 0.15 484.00 94.07 4.60 3.92 0.59 0.55 0 00:05:00
9 DA-B6 0.18 484.00 98.00 4.60 4.36 0.79 0.69 0 00:05:00
10 DA-B7 0.66 484.00 74.76 4.60 2.11 1.39 1.46 0 00:05:00
11 DA-B8 0.40 484.00 86.20 4.60 3.11 1.25 1.28 0 00:05:00
12 DA-B9 0.47 484.00 98.00 4.60 4.36 2.05 1.80 0 00:05:00
13 DA-BBypass 0.70 484.00 52.49 4.60 0.66 0.46 0.37 0 00:05:00
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time
ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft) (days hh:mm) (ac-in) (min)
1 Out-A Outfall 2.94 1.32 3.49
2 Out-B Outfall 11.72 0.31 11.72
3 B-10 Storage Node 7.00 13.00 0.00 0.00 8.62 9.98 0.00 0.00
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft) (ft) (ft) (%) (in) (cfs) (cfs) (ft/sec) (ft) (min)
1 A1-A2 Pipe A-1 A-2 150.93 7.97 7.52 0.3000 48.000 0.0130 0.77 78.43 0.01 2.12 0.27 0.07 0.00 Calculated
2 A2-OUTA Pipe A-2 Out-A 2.00 2.94 2.88 3.0000 48.000 0.0130 1.32 32.12 0.04 1.71 0.49 0.12 0.00 Calculated
3 B1-B2 Pipe B-1 B-2 92.00 11.65 11.20 0.4900 15.000 0.0130 0.63 4.52 0.14 2.29 0.34 0.27 0.00 Calculated
4 B2-B3 Pipe B-2 B-3 223.00 11.20 10.10 0.4900 15.000 0.0130 0.82 4.54 0.18 2.06 0.45 0.36 0.00 Calculated
5 B3-B6 Pipe B-3 B-6 124.00 10.10 9.50 0.4800 18.000 0.0130 2.03 7.31 0.28 2.34 0.74 0.49 0.00 Calculated
6 B4-B5 Pipe B-4 B-5 48.00 10.70 10.20 1.0400 15.000 0.0130 0.99 6.59 0.15 3.20 0.37 0.30 0.00 Calculated
7 B5-B6 Pipe B-5 B-6 68.00 10.20 9.50 1.0300 18.000 0.0130 1.53 10.66 0.14 2.11 0.66 0.44 0.00 Calculated
8 B6-B9 Pipe B-6 B-9 63.00 9.50 9.22 0.4400 24.000 0.0130 4.22 15.08 0.28 2.73 0.98 0.49 0.00 Calculated
9 B7-B8 Pipe B-7 B-8 180.00 10.85 9.95 0.5000 15.000 0.0130 1.41 4.57 0.31 2.74 0.55 0.44 0.00 Calculated
10 B8-B9 Pipe B-8 B-9 144.00 9.95 9.22 0.5100 18.000 0.0130 2.65 7.48 0.35 2.65 0.82 0.55 0.00 Calculated
11 B9-B10 Pipe B-9 B-10 22.00 9.22 9.00 1.0000 30.000 0.0130 8.62 41.02 0.21 5.36 0.90 0.36 0.00 Calculated
12 Weir-1 Weir B-10 Out-B 7.00 11.72 0.00
Inlet Summary
SN Element Inlet Manufacturer Inlet Number of Catchbasin Max (Rim) Initial Ponded Peak Peak Flow Peak Flow Inlet
ID Manufacturer Part Location Inlets Invert Elevation Water Area Flow Intercepted Bypassing Efficiency
Number Elevation Elevation by Inlet during Peak
Inlet Flow
(ft) (ft) (ft) (ft²) (cfs) (cfs) (cfs) (%)
1 A-1 FHWA HEC-22 GENERIC N/A On Sag 1 7.97 13.00 0.00 10.00 0.78 N/A N/A N/A
2 A-2 FHWA HEC-22 GENERIC N/A On Sag 1 2.94 13.80 0.00 10.00 0.43 N/A N/A N/A
3 B-1 FHWA HEC-22 GENERIC N/A On Sag 1 11.65 16.30 0.00 10.00 0.63 N/A N/A N/A
4 B-2 FHWA HEC-22 GENERIC N/A On Sag 1 11.20 15.25 0.00 10.00 0.20 N/A N/A N/A
5 B-3 FHWA HEC-22 GENERIC N/A On Sag 1 10.10 15.30 0.00 10.00 1.23 N/A N/A N/A
6 B-4 FHWA HEC-22 GENERIC N/A On Sag 1 10.70 15.95 0.00 10.00 0.99 N/A N/A N/A
7 B-5 FHWA HEC-22 GENERIC N/A On Sag 1 10.20 14.25 0.00 10.00 0.54 N/A N/A N/A
8 B-6 FHWA HEC-22 GENERIC N/A On Sag 1 9.50 13.40 0.00 10.00 0.69 N/A N/A N/A
9 B-7 FHWA HEC-22 GENERIC N/A On Sag 1 10.85 14.00 0.00 10.00 1.42 N/A N/A N/A
10 B-8 FHWA HEC-22 GENERIC N/A On Sag 1 9.95 14.00 0.00 10.00 1.26 N/A N/A N/A
11 B-9 FHWA HEC-22 GENERIC N/A On Sag 1 9.22 13.00 0.00 10.00 1.80 N/A N/A N/A
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 A1-A2 150.93 7.97 0.00 7.52 4.58 0.45 0.3000 CIRCULAR 48.000 48.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
2 A2-OUTA 2.00 2.94 0.00 2.88 -0.06 0.06 3.0000 CIRCULAR 48.000 48.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
3 B1-B2 92.00 11.65 0.00 11.20 0.00 0.45 0.4900 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
4 B2-B3 223.00 11.20 0.00 10.10 0.00 1.10 0.4900 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
5 B3-B6 124.00 10.10 0.00 9.50 0.00 0.60 0.4800 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
6 B4-B5 48.00 10.70 0.00 10.20 0.00 0.50 1.0400 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
7 B5-B6 68.00 10.20 0.00 9.50 0.00 0.70 1.0300 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
8 B6-B9 63.00 9.50 0.00 9.22 0.00 0.28 0.4400 CIRCULAR 24.000 24.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
9 B7-B8 180.00 10.85 0.00 9.95 0.00 0.90 0.5000 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
10 B8-B9 144.00 9.95 0.00 9.22 0.00 0.73 0.5100 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
11 B9-B10 22.00 9.22 0.00 9.00 2.00 0.22 1.0000 CIRCULAR 30.000 30.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 A1-A2 0.77 0 12:10 78.43 0.01 2.12 1.19 0.27 0.07 0.00 Calculated
2 A2-OUTA 1.32 0 12:10 32.12 0.04 1.71 0.02 0.49 0.12 0.00 Calculated
3 B1-B2 0.63 0 12:10 4.52 0.14 2.29 0.67 0.34 0.27 0.00 Calculated
4 B2-B3 0.82 0 12:10 4.54 0.18 2.06 1.80 0.45 0.36 0.00 Calculated
5 B3-B6 2.03 0 12:10 7.31 0.28 2.34 0.88 0.74 0.49 0.00 Calculated
6 B4-B5 0.99 0 12:10 6.59 0.15 3.20 0.25 0.37 0.30 0.00 Calculated
7 B5-B6 1.53 0 12:10 10.66 0.14 2.11 0.54 0.66 0.44 0.00 Calculated
8 B6-B9 4.22 0 12:10 15.08 0.28 2.73 0.38 0.98 0.49 0.00 Calculated
9 B7-B8 1.41 0 12:10 4.57 0.31 2.74 1.09 0.55 0.44 0.00 Calculated
10 B8-B9 2.65 0 12:10 7.48 0.35 2.65 0.91 0.82 0.55 0.00 Calculated
11 B9-B10 8.62 0 12:10 41.02 0.21 5.36 0.07 0.90 0.36 0.00 Calculated
Inlet Input
SN Element Inlet Manufacturer Inlet Number of Catchbasin Max (Rim) Inlet Initial Initial Ponded Grate
ID Manufacturer Part Location Inlets Invert Elevation Depth Water Water Area Clogging
Number Elevation Elevation Depth Factor
(ft) (ft) (ft) (ft) (ft) (ft²) (%)
1 A-1 FHWA HEC-22 GENERIC N/A On Sag 1 7.97 13.00 5.03 0.00 0.00 10.00 0.00
2 A-2 FHWA HEC-22 GENERIC N/A On Sag 1 2.94 13.80 10.86 0.00 0.00 10.00 0.00
3 B-1 FHWA HEC-22 GENERIC N/A On Sag 1 11.65 16.30 4.65 0.00 0.00 10.00 0.00
4 B-2 FHWA HEC-22 GENERIC N/A On Sag 1 11.20 15.25 4.05 0.00 0.00 10.00 0.00
5 B-3 FHWA HEC-22 GENERIC N/A On Sag 1 10.10 15.30 5.20 0.00 0.00 10.00 0.00
6 B-4 FHWA HEC-22 GENERIC N/A On Sag 1 10.70 15.95 5.25 0.00 0.00 10.00 0.00
7 B-5 FHWA HEC-22 GENERIC N/A On Sag 1 10.20 14.25 4.05 0.00 0.00 10.00 0.00
8 B-6 FHWA HEC-22 GENERIC N/A On Sag 1 9.50 13.40 3.90 0.00 0.00 10.00 0.00
9 B-7 FHWA HEC-22 GENERIC N/A On Sag 1 10.85 14.00 3.15 0.00 0.00 10.00 0.00
10 B-8 FHWA HEC-22 GENERIC N/A On Sag 1 9.95 14.00 4.05 0.00 0.00 10.00 0.00
11 B-9 FHWA HEC-22 GENERIC N/A On Sag 1 9.22 13.00 3.78 0.00 0.00 10.00 0.00
Roadway & Gutter Input
SN Element Roadway Roadway Roadway Gutter Gutter Gutter
ID Longitudinal Cross Manning's Cross Width Depression
Slope Slope Roughness Slope
(ft/ft) (ft/ft) (ft/ft) (ft) (in)
1 A-1 N/A 0.0200 0.0160 0.0620 2.00 0.0656
2 A-2 N/A 0.0200 0.0160 0.0620 2.00 0.0656
3 B-1 N/A 0.0200 0.0160 0.0620 2.00 0.0656
4 B-2 N/A 0.0200 0.0160 0.0620 2.00 0.0656
5 B-3 N/A 0.0200 0.0160 0.0620 2.00 0.0656
6 B-4 N/A 0.0200 0.0160 0.0620 2.00 0.0656
7 B-5 N/A 0.0200 0.0160 0.0620 2.00 0.0656
8 B-6 N/A 0.0200 0.0160 0.0620 2.00 0.0656
9 B-7 N/A 0.0200 0.0160 0.0620 2.00 0.0656
10 B-8 N/A 0.0200 0.0160 0.0620 2.00 0.0656
11 B-9 N/A 0.0200 0.0160 0.0620 2.00 0.0656
Inlet Results
SN Element Peak Peak Peak Flow Peak Flow Inlet Time of Total Total Time
ID Flow Lateral Intercepted Bypassing Efficiency Max Depth Flooded Flooded
Inflow by Inlet during Peak Occurrence Volume
Inlet Flow
(cfs) (cfs) (cfs) (cfs) (%) (days hh:mm) (ac-in) (min)
1 A-1 0.78 0.78 N/A N/A N/A 0 12:10 0.00 0.00
2 A-2 0.43 0.43 N/A N/A N/A 0 12:10 0.00 0.00
3 B-1 0.63 0.63 N/A N/A N/A 0 12:10 0.00 0.00
4 B-2 0.20 0.20 N/A N/A N/A 0 12:10 0.00 0.00
5 B-3 1.23 1.23 N/A N/A N/A 0 12:10 0.00 0.00
6 B-4 0.99 0.99 N/A N/A N/A 0 12:10 0.00 0.00
7 B-5 0.54 0.54 N/A N/A N/A 0 12:10 0.00 0.00
8 B-6 0.69 0.69 N/A N/A N/A 0 12:10 0.00 0.00
9 B-7 1.42 1.42 N/A N/A N/A 0 12:10 0.00 0.00
10 B-8 1.26 1.26 N/A N/A N/A 0 12:10 0.00 0.00
11 B-9 1.80 1.80 N/A N/A N/A 0 12:10 0.00 0.00
Storage Nodes
Storage Node : B-10
Input Data
7.00
13.00
6.00
0.00
-7.00
0.00
0.00
Storage Area Volume Curves
Storage Curve : BMP-B
Stage Storage Storage
Area Volume
(ft) (ft²) (ft³)
0 5716 0
1 5716 5716
1.01 9443 5791.8
2 15076 17928.71
3 17528 34230.71
4 20110 53049.71
5 23002 74605.71
6 25728 98970.71
Invert Elevation (ft) .................................................
Max (Rim) Elevation (ft) ...........................................
Max (Rim) Offset (ft) ...............................................
Initial Water Elevation (ft) .......................................
Initial Water Depth (ft) ............................................
Ponded Area (ft²) ....................................................
Evaporation Loss ....................................................
Storage Area Volume Curves
Storage Area Storage Volume
Storage Area (ft²)
24,00022,00020,00018,00016,00014,00012,00010,0008,0006,000
Storage Volume (ft³)
90,00080,00070,00060,00050,00040,00030,00020,00010,0000
St
a
g
e
(
f
t
)
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
St
a
g
e
(
f
t
)
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Storage Node : B-10 (continued)
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 Weir-1 Rectangular No 12.00 5.00 15.00 1.00 3.33
Output Summary Results
8.62
0.01
0
0
9.98
2.98
8.48
1.48
1 00:00
0
0
0
0
Max HGL Elevation Attained (ft) ...............................
Peak Inflow (cfs) .....................................................
Peak Lateral Inflow (cfs) .........................................
Peak Outflow (cfs) ..................................................
Peak Exfiltration Flow Rate (cfm) .............................
Total Time Flooded (min) ........................................
Total Retention Time (sec) ......................................
Max HGL Depth Attained (ft) ....................................
Average HGL Elevation Attained (ft) .........................
Average HGL Depth Attained (ft) ..............................
Time of Max HGL Occurrence (days hh:mm) ............
Total Exfiltration Volume (1000-ft³) .........................
Total Flooded Volume (ac-in) ..................................
Project Description
Proposed Conditions.SPF
Project Options
CFS
Elevation
SCS TR-55
User-Defined
Hydrodynamic
YES
YES
Analysis Options
00:00:00 0:00:00
00:00:00 0:00:00
00:00:00 0:00:00
0 days
0 01:00:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
1 seconds
Number of Elements
Qty
1
13
14
0
2
0
11
1
12
0
11
0
0
1
0
0
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
49 Time Series 10-yr Cumulative inches North Carolina New Hanover 10.00 7.10 SCS Type III 24-hr
Antecedent Dry Days ................................
File Name ................................................
Flow Units ...............................................
Elevation Type ..........................................
Hydrology Method ....................................
Time of Concentration (TOC) Method ........
Link Routing Method .................................
Enable Overflow Ponding at Nodes ...........
Skip Steady State Analysis Time Periods ....
Start Analysis On ......................................
End Analysis On .......................................
Start Reporting On ...................................
Storage Nodes ...................................
Runoff (Dry Weather) Time Step ................
Runoff (Wet Weather) Time Step ...............
Reporting Time Step .................................
Routing Time Step ....................................
Rain Gages ..............................................
Subbasins................................................
Nodes......................................................
Junctions ...........................................
Outfalls .............................................
Flow Diversions .................................
Inlets ................................................
Outlets ..............................................
Pollutants ................................................
Land Uses ...............................................
Links........................................................
Channels ..........................................
Pipes .................................................
Pumps ..............................................
Orifices .............................................
Weirs ................................................
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 DA-A1 0.26 484.00 84.38 7.10 5.28 1.37 1.38 0 00:05:00
2 DA-A2 0.13 484.00 88.92 7.10 5.79 0.75 0.71 0 00:05:00
3 DA-B1 0.25 484.00 79.12 7.10 4.69 1.17 1.20 0 00:05:00
4 DA-B10 0.85 484.00 39.00 7.10 0.80 0.68 0.45 0 00:05:00
5 DA-B2 0.11 484.00 71.18 7.10 3.83 0.42 0.44 0 00:05:00
6 DA-B3 0.32 484.00 98.00 7.10 6.86 2.20 1.91 0 00:05:00
7 DA-B4 0.26 484.00 95.73 7.10 6.59 1.71 1.56 0 00:05:00
8 DA-B5 0.15 484.00 94.07 7.10 6.39 0.96 0.86 0 00:05:00
9 DA-B6 0.18 484.00 98.00 7.10 6.86 1.23 1.07 0 00:05:00
10 DA-B7 0.66 484.00 74.76 7.10 4.21 2.78 2.88 0 00:05:00
11 DA-B8 0.40 484.00 86.20 7.10 5.48 2.19 2.17 0 00:05:00
12 DA-B9 0.47 484.00 98.00 7.10 6.86 3.22 2.79 0 00:05:00
13 DA-BBypass 0.70 484.00 52.49 7.10 1.95 1.37 1.38 0 00:05:00
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time
ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft) (days hh:mm) (ac-in) (min)
1 Out-A Outfall 2.94 2.06 3.63
2 Out-B Outfall 11.72 1.30 11.72
3 B-10 Storage Node 7.00 13.00 0.00 0.00 14.82 11.27 0.00 0.00
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft) (ft) (ft) (%) (in) (cfs) (cfs) (ft/sec) (ft) (min)
1 A1-A2 Pipe A-1 A-2 150.93 7.97 7.52 0.3000 48.000 0.0130 1.35 78.43 0.02 2.41 0.36 0.09 0.00 Calculated
2 A2-OUTA Pipe A-2 Out-A 2.00 2.94 2.88 3.0000 48.000 0.0130 2.06 32.12 0.06 1.80 0.77 0.23 0.00 Calculated
3 B1-B2 Pipe B-1 B-2 92.00 11.65 11.20 0.4900 15.000 0.0130 1.18 4.52 0.26 2.64 0.49 0.39 0.00 Calculated
4 B2-B3 Pipe B-2 B-3 223.00 11.20 10.10 0.4900 15.000 0.0130 1.59 4.54 0.35 2.28 0.71 0.57 0.00 Calculated
5 B3-B6 Pipe B-3 B-6 124.00 10.10 9.50 0.4800 18.000 0.0130 3.43 7.31 0.47 2.45 1.33 0.89 0.00 Calculated
6 B4-B5 Pipe B-4 B-5 48.00 10.70 10.20 1.0400 15.000 0.0130 1.55 6.59 0.24 3.46 0.82 0.65 0.00 Calculated
7 B5-B6 Pipe B-5 B-6 68.00 10.20 9.50 1.0300 18.000 0.0130 2.39 10.66 0.22 2.21 1.28 0.86 0.00 Calculated
8 B6-B9 Pipe B-6 B-9 63.00 9.50 9.22 0.4400 24.000 0.0130 6.85 15.08 0.45 3.00 1.88 0.94 0.00 Calculated
9 B7-B8 Pipe B-7 B-8 180.00 10.85 9.95 0.5000 15.000 0.0130 2.81 4.57 0.62 3.05 0.89 0.71 0.00 Calculated
10 B8-B9 Pipe B-8 B-9 144.00 9.95 9.22 0.5100 18.000 0.0130 4.91 7.48 0.66 3.16 1.41 0.94 0.00 Calculated
11 B9-B10 Pipe B-9 B-10 22.00 9.22 9.00 1.0000 30.000 0.0130 14.48 41.02 0.35 6.13 2.16 0.86 0.00 Calculated
12 Weir-1 Weir B-10 Out-B 7.00 11.72 0.00
Inlet Summary
SN Element Inlet Manufacturer Inlet Number of Catchbasin Max (Rim) Initial Ponded Peak Peak Flow Peak Flow Inlet
ID Manufacturer Part Location Inlets Invert Elevation Water Area Flow Intercepted Bypassing Efficiency
Number Elevation Elevation by Inlet during Peak
Inlet Flow
(ft) (ft) (ft) (ft²) (cfs) (cfs) (cfs) (%)
1 A-1 FHWA HEC-22 GENERIC N/A On Sag 1 7.97 13.00 0.00 10.00 1.37 N/A N/A N/A
2 A-2 FHWA HEC-22 GENERIC N/A On Sag 1 2.94 13.80 0.00 10.00 0.71 N/A N/A N/A
3 B-1 FHWA HEC-22 GENERIC N/A On Sag 1 11.65 16.30 0.00 10.00 1.18 N/A N/A N/A
4 B-2 FHWA HEC-22 GENERIC N/A On Sag 1 11.20 15.25 0.00 10.00 0.43 N/A N/A N/A
5 B-3 FHWA HEC-22 GENERIC N/A On Sag 1 10.10 15.30 0.00 10.00 1.91 N/A N/A N/A
6 B-4 FHWA HEC-22 GENERIC N/A On Sag 1 10.70 15.95 0.00 10.00 1.55 N/A N/A N/A
7 B-5 FHWA HEC-22 GENERIC N/A On Sag 1 10.20 14.25 0.00 10.00 0.86 N/A N/A N/A
8 B-6 FHWA HEC-22 GENERIC N/A On Sag 1 9.50 13.40 0.00 10.00 1.07 N/A N/A N/A
9 B-7 FHWA HEC-22 GENERIC N/A On Sag 1 10.85 14.00 0.00 10.00 2.83 N/A N/A N/A
10 B-8 FHWA HEC-22 GENERIC N/A On Sag 1 9.95 14.00 0.00 10.00 2.16 N/A N/A N/A
11 B-9 FHWA HEC-22 GENERIC N/A On Sag 1 9.22 13.00 0.00 10.00 2.79 N/A N/A N/A
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 A1-A2 150.93 7.97 0.00 7.52 4.58 0.45 0.3000 CIRCULAR 48.000 48.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
2 A2-OUTA 2.00 2.94 0.00 2.88 -0.06 0.06 3.0000 CIRCULAR 48.000 48.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
3 B1-B2 92.00 11.65 0.00 11.20 0.00 0.45 0.4900 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
4 B2-B3 223.00 11.20 0.00 10.10 0.00 1.10 0.4900 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
5 B3-B6 124.00 10.10 0.00 9.50 0.00 0.60 0.4800 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
6 B4-B5 48.00 10.70 0.00 10.20 0.00 0.50 1.0400 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
7 B5-B6 68.00 10.20 0.00 9.50 0.00 0.70 1.0300 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
8 B6-B9 63.00 9.50 0.00 9.22 0.00 0.28 0.4400 CIRCULAR 24.000 24.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
9 B7-B8 180.00 10.85 0.00 9.95 0.00 0.90 0.5000 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
10 B8-B9 144.00 9.95 0.00 9.22 0.00 0.73 0.5100 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
11 B9-B10 22.00 9.22 0.00 9.00 2.00 0.22 1.0000 CIRCULAR 30.000 30.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 A1-A2 1.35 0 12:10 78.43 0.02 2.41 1.04 0.36 0.09 0.00 Calculated
2 A2-OUTA 2.06 0 12:10 32.12 0.06 1.80 0.02 0.77 0.23 0.00 Calculated
3 B1-B2 1.18 0 12:10 4.52 0.26 2.64 0.58 0.49 0.39 0.00 Calculated
4 B2-B3 1.59 0 12:10 4.54 0.35 2.28 1.63 0.71 0.57 0.00 Calculated
5 B3-B6 3.43 0 12:10 7.31 0.47 2.45 0.84 1.33 0.89 0.00 Calculated
6 B4-B5 1.55 0 12:10 6.59 0.24 3.46 0.23 0.82 0.65 0.00 Calculated
7 B5-B6 2.39 0 12:10 10.66 0.22 2.21 0.51 1.28 0.86 0.00 Calculated
8 B6-B9 6.85 0 12:10 15.08 0.45 3.00 0.35 1.88 0.94 0.00 Calculated
9 B7-B8 2.81 0 12:10 4.57 0.62 3.05 0.98 0.89 0.71 0.00 Calculated
10 B8-B9 4.91 0 12:10 7.48 0.66 3.16 0.76 1.41 0.94 0.00 Calculated
11 B9-B10 14.48 0 12:10 41.02 0.35 6.13 0.06 2.16 0.86 0.00 Calculated
Inlet Input
SN Element Inlet Manufacturer Inlet Number of Catchbasin Max (Rim) Inlet Initial Initial Ponded Grate
ID Manufacturer Part Location Inlets Invert Elevation Depth Water Water Area Clogging
Number Elevation Elevation Depth Factor
(ft) (ft) (ft) (ft) (ft) (ft²) (%)
1 A-1 FHWA HEC-22 GENERIC N/A On Sag 1 7.97 13.00 5.03 0.00 0.00 10.00 0.00
2 A-2 FHWA HEC-22 GENERIC N/A On Sag 1 2.94 13.80 10.86 0.00 0.00 10.00 0.00
3 B-1 FHWA HEC-22 GENERIC N/A On Sag 1 11.65 16.30 4.65 0.00 0.00 10.00 0.00
4 B-2 FHWA HEC-22 GENERIC N/A On Sag 1 11.20 15.25 4.05 0.00 0.00 10.00 0.00
5 B-3 FHWA HEC-22 GENERIC N/A On Sag 1 10.10 15.30 5.20 0.00 0.00 10.00 0.00
6 B-4 FHWA HEC-22 GENERIC N/A On Sag 1 10.70 15.95 5.25 0.00 0.00 10.00 0.00
7 B-5 FHWA HEC-22 GENERIC N/A On Sag 1 10.20 14.25 4.05 0.00 0.00 10.00 0.00
8 B-6 FHWA HEC-22 GENERIC N/A On Sag 1 9.50 13.40 3.90 0.00 0.00 10.00 0.00
9 B-7 FHWA HEC-22 GENERIC N/A On Sag 1 10.85 14.00 3.15 0.00 0.00 10.00 0.00
10 B-8 FHWA HEC-22 GENERIC N/A On Sag 1 9.95 14.00 4.05 0.00 0.00 10.00 0.00
11 B-9 FHWA HEC-22 GENERIC N/A On Sag 1 9.22 13.00 3.78 0.00 0.00 10.00 0.00
Roadway & Gutter Input
SN Element Roadway Roadway Roadway Gutter Gutter Gutter
ID Longitudinal Cross Manning's Cross Width Depression
Slope Slope Roughness Slope
(ft/ft) (ft/ft) (ft/ft) (ft) (in)
1 A-1 N/A 0.0200 0.0160 0.0620 2.00 0.0656
2 A-2 N/A 0.0200 0.0160 0.0620 2.00 0.0656
3 B-1 N/A 0.0200 0.0160 0.0620 2.00 0.0656
4 B-2 N/A 0.0200 0.0160 0.0620 2.00 0.0656
5 B-3 N/A 0.0200 0.0160 0.0620 2.00 0.0656
6 B-4 N/A 0.0200 0.0160 0.0620 2.00 0.0656
7 B-5 N/A 0.0200 0.0160 0.0620 2.00 0.0656
8 B-6 N/A 0.0200 0.0160 0.0620 2.00 0.0656
9 B-7 N/A 0.0200 0.0160 0.0620 2.00 0.0656
10 B-8 N/A 0.0200 0.0160 0.0620 2.00 0.0656
11 B-9 N/A 0.0200 0.0160 0.0620 2.00 0.0656
Inlet Results
SN Element Peak Peak Peak Flow Peak Flow Inlet Time of Total Total Time
ID Flow Lateral Intercepted Bypassing Efficiency Max Depth Flooded Flooded
Inflow by Inlet during Peak Occurrence Volume
Inlet Flow
(cfs) (cfs) (cfs) (cfs) (%) (days hh:mm) (ac-in) (min)
1 A-1 1.37 1.37 N/A N/A N/A 0 12:10 0.00 0.00
2 A-2 0.71 0.71 N/A N/A N/A 0 12:10 0.00 0.00
3 B-1 1.18 1.18 N/A N/A N/A 0 12:10 0.00 0.00
4 B-2 0.43 0.43 N/A N/A N/A 0 12:10 0.00 0.00
5 B-3 1.91 1.91 N/A N/A N/A 1 00:00 0.00 0.00
6 B-4 1.55 1.55 N/A N/A N/A 1 00:00 0.00 0.00
7 B-5 0.86 0.86 N/A N/A N/A 1 00:00 0.00 0.00
8 B-6 1.07 1.07 N/A N/A N/A 1 00:00 0.00 0.00
9 B-7 2.83 2.83 N/A N/A N/A 0 12:10 0.00 0.00
10 B-8 2.16 2.16 N/A N/A N/A 1 00:00 0.00 0.00
11 B-9 2.79 2.79 N/A N/A N/A 1 00:00 0.00 0.00
Storage Nodes
Storage Node : B-10
Input Data
7.00
13.00
6.00
0.00
-7.00
0.00
0.00
Storage Area Volume Curves
Storage Curve : BMP-B
Stage Storage Storage
Area Volume
(ft) (ft²) (ft³)
0 5716 0
1 5716 5716
1.01 9443 5791.8
2 15076 17928.71
3 17528 34230.71
4 20110 53049.71
5 23002 74605.71
6 25728 98970.71
Invert Elevation (ft) .................................................
Max (Rim) Elevation (ft) ...........................................
Max (Rim) Offset (ft) ...............................................
Initial Water Elevation (ft) .......................................
Initial Water Depth (ft) ............................................
Ponded Area (ft²) ....................................................
Evaporation Loss ....................................................
Storage Area Volume Curves
Storage Area Storage Volume
Storage Area (ft²)
24,00022,00020,00018,00016,00014,00012,00010,0008,0006,000
Storage Volume (ft³)
90,00080,00070,00060,00050,00040,00030,00020,00010,0000
St
a
g
e
(
f
t
)
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
St
a
g
e
(
f
t
)
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Storage Node : B-10 (continued)
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 Weir-1 Rectangular No 12.00 5.00 15.00 1.00 3.33
Output Summary Results
14.82
0.4
0
0
11.27
4.27
9.16
2.16
1 00:00
0
0
0
0
Max HGL Elevation Attained (ft) ...............................
Peak Inflow (cfs) .....................................................
Peak Lateral Inflow (cfs) .........................................
Peak Outflow (cfs) ..................................................
Peak Exfiltration Flow Rate (cfm) .............................
Total Time Flooded (min) ........................................
Total Retention Time (sec) ......................................
Max HGL Depth Attained (ft) ....................................
Average HGL Elevation Attained (ft) .........................
Average HGL Depth Attained (ft) ..............................
Time of Max HGL Occurrence (days hh:mm) ............
Total Exfiltration Volume (1000-ft³) .........................
Total Flooded Volume (ac-in) ..................................
Inlet Summary
SN Element Inlet Manufacturer Inlet Number of Catchbasin Max (Rim) Initial Ponded Peak Peak Flow Peak Flow Inlet
ID Manufacturer Part Location Inlets Invert Elevation Water Area Flow Intercepted Bypassing Efficiency
Number Elevation Elevation by Inlet during Peak
Inlet Flow
(ft) (ft) (ft) (ft²) (cfs) (cfs) (cfs) (%)
1 A-1 FHWA HEC-22 GENERIC N/A On Sag 1 7.97 13.00 0.00 10.00 1.60 N/A N/A N/A
2 A-2 FHWA HEC-22 GENERIC N/A On Sag 1 2.94 13.80 0.00 10.00 0.82 N/A N/A N/A
3 B-1 FHWA HEC-22 GENERIC N/A On Sag 1 11.65 16.30 0.00 10.00 1.40 N/A N/A N/A
4 B-2 FHWA HEC-22 GENERIC N/A On Sag 1 11.20 15.25 0.00 10.00 0.52 N/A N/A N/A
5 B-3 FHWA HEC-22 GENERIC N/A On Sag 1 10.10 15.30 0.00 10.00 2.18 N/A N/A N/A
6 B-4 FHWA HEC-22 GENERIC N/A On Sag 1 10.70 15.95 0.00 10.00 1.77 N/A N/A N/A
7 B-5 FHWA HEC-22 GENERIC N/A On Sag 1 10.20 14.25 0.00 10.00 0.99 N/A N/A N/A
8 B-6 FHWA HEC-22 GENERIC N/A On Sag 1 9.50 13.40 0.00 10.00 1.22 N/A N/A N/A
9 B-7 FHWA HEC-22 GENERIC N/A On Sag 1 10.85 14.00 0.00 10.00 3.41 N/A N/A N/A
10 B-8 FHWA HEC-22 GENERIC N/A On Sag 1 9.95 14.00 0.00 10.00 2.52 N/A N/A N/A
11 B-9 FHWA HEC-22 GENERIC N/A On Sag 1 9.22 13.00 0.00 10.00 3.18 N/A N/A N/A
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 A1-A2 150.93 7.97 0.00 7.52 4.58 0.45 0.3000 CIRCULAR 48.000 48.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
2 A2-OUTA 2.00 2.94 0.00 2.88 -0.06 0.06 3.0000 CIRCULAR 48.000 48.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
3 B1-B2 92.00 11.65 0.00 11.20 0.00 0.45 0.4900 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
4 B2-B3 223.00 11.20 0.00 10.10 0.00 1.10 0.4900 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
5 B3-B6 124.00 10.10 0.00 9.50 0.00 0.60 0.4800 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
6 B4-B5 48.00 10.70 0.00 10.20 0.00 0.50 1.0400 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
7 B5-B6 68.00 10.20 0.00 9.50 0.00 0.70 1.0300 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
8 B6-B9 63.00 9.50 0.00 9.22 0.00 0.28 0.4400 CIRCULAR 24.000 24.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
9 B7-B8 180.00 10.85 0.00 9.95 0.00 0.90 0.5000 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
10 B8-B9 144.00 9.95 0.00 9.22 0.00 0.73 0.5100 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
11 B9-B10 22.00 9.22 0.00 9.00 2.00 0.22 1.0000 CIRCULAR 30.000 30.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 A1-A2 1.58 0 12:10 78.43 0.02 2.53 0.99 0.39 0.10 0.00 Calculated
2 A2-OUTA 2.40 0 12:10 32.12 0.07 1.80 0.02 0.82 0.23 0.00 Calculated
3 B1-B2 1.40 0 12:10 4.52 0.31 2.74 0.56 0.54 0.43 0.00 Calculated
4 B2-B3 1.90 0 12:10 4.54 0.42 2.33 1.60 0.90 0.72 0.00 Calculated
5 B3-B6 4.02 0 12:10 7.31 0.55 2.49 0.83 1.50 1.00 218.00 SURCHARGED
6 B4-B5 1.77 0 12:10 6.59 0.27 3.46 0.23 1.15 0.92 0.00 Calculated
7 B5-B6 2.73 0 12:10 10.66 0.26 2.21 0.51 1.50 1.00 86.00 SURCHARGED
8 B6-B9 7.94 0 12:10 15.08 0.53 3.12 0.34 2.00 1.00 326.00 SURCHARGED
9 B7-B8 3.33 0 12:10 4.57 0.73 3.10 0.97 1.09 0.88 0.00 Calculated
10 B8-B9 5.78 0 12:10 7.48 0.77 3.34 0.72 1.50 1.00 373.00 SURCHARGED
11 B9-B10 16.81 0 12:10 41.02 0.41 6.37 0.06 2.50 1.00 56.00 SURCHARGED
Inlet Input
SN Element Inlet Manufacturer Inlet Number of Catchbasin Max (Rim) Inlet Initial Initial Ponded Grate
ID Manufacturer Part Location Inlets Invert Elevation Depth Water Water Area Clogging
Number Elevation Elevation Depth Factor
(ft) (ft) (ft) (ft) (ft) (ft²) (%)
1 A-1 FHWA HEC-22 GENERIC N/A On Sag 1 7.97 13.00 5.03 0.00 0.00 10.00 0.00
2 A-2 FHWA HEC-22 GENERIC N/A On Sag 1 2.94 13.80 10.86 0.00 0.00 10.00 0.00
3 B-1 FHWA HEC-22 GENERIC N/A On Sag 1 11.65 16.30 4.65 0.00 0.00 10.00 0.00
4 B-2 FHWA HEC-22 GENERIC N/A On Sag 1 11.20 15.25 4.05 0.00 0.00 10.00 0.00
5 B-3 FHWA HEC-22 GENERIC N/A On Sag 1 10.10 15.30 5.20 0.00 0.00 10.00 0.00
6 B-4 FHWA HEC-22 GENERIC N/A On Sag 1 10.70 15.95 5.25 0.00 0.00 10.00 0.00
7 B-5 FHWA HEC-22 GENERIC N/A On Sag 1 10.20 14.25 4.05 0.00 0.00 10.00 0.00
8 B-6 FHWA HEC-22 GENERIC N/A On Sag 1 9.50 13.40 3.90 0.00 0.00 10.00 0.00
9 B-7 FHWA HEC-22 GENERIC N/A On Sag 1 10.85 14.00 3.15 0.00 0.00 10.00 0.00
10 B-8 FHWA HEC-22 GENERIC N/A On Sag 1 9.95 14.00 4.05 0.00 0.00 10.00 0.00
11 B-9 FHWA HEC-22 GENERIC N/A On Sag 1 9.22 13.00 3.78 0.00 0.00 10.00 0.00
Roadway & Gutter Input
SN Element Roadway Roadway Roadway Gutter Gutter Gutter
ID Longitudinal Cross Manning's Cross Width Depression
Slope Slope Roughness Slope
(ft/ft) (ft/ft) (ft/ft) (ft) (in)
1 A-1 N/A 0.0200 0.0160 0.0620 2.00 0.0656
2 A-2 N/A 0.0200 0.0160 0.0620 2.00 0.0656
3 B-1 N/A 0.0200 0.0160 0.0620 2.00 0.0656
4 B-2 N/A 0.0200 0.0160 0.0620 2.00 0.0656
5 B-3 N/A 0.0200 0.0160 0.0620 2.00 0.0656
6 B-4 N/A 0.0200 0.0160 0.0620 2.00 0.0656
7 B-5 N/A 0.0200 0.0160 0.0620 2.00 0.0656
8 B-6 N/A 0.0200 0.0160 0.0620 2.00 0.0656
9 B-7 N/A 0.0200 0.0160 0.0620 2.00 0.0656
10 B-8 N/A 0.0200 0.0160 0.0620 2.00 0.0656
11 B-9 N/A 0.0200 0.0160 0.0620 2.00 0.0656
Inlet Results
SN Element Peak Peak Peak Flow Peak Flow Inlet Time of Total Total Time
ID Flow Lateral Intercepted Bypassing Efficiency Max Depth Flooded Flooded
Inflow by Inlet during Peak Occurrence Volume
Inlet Flow
(cfs) (cfs) (cfs) (cfs) (%) (days hh:mm) (ac-in) (min)
1 A-1 1.60 1.60 N/A N/A N/A 0 12:10 0.00 0.00
2 A-2 0.82 0.82 N/A N/A N/A 0 12:10 0.00 0.00
3 B-1 1.40 1.40 N/A N/A N/A 0 12:10 0.00 0.00
4 B-2 0.52 0.52 N/A N/A N/A 0 12:10 0.00 0.00
5 B-3 2.18 2.18 N/A N/A N/A 1 00:00 0.00 0.00
6 B-4 1.77 1.77 N/A N/A N/A 1 00:00 0.00 0.00
7 B-5 0.99 0.99 N/A N/A N/A 1 00:00 0.00 0.00
8 B-6 1.22 1.22 N/A N/A N/A 1 00:00 0.00 0.00
9 B-7 3.41 3.41 N/A N/A N/A 0 12:10 0.00 0.00
10 B-8 2.52 2.52 N/A N/A N/A 1 00:00 0.00 0.00
11 B-9 3.18 3.18 N/A N/A N/A 1 00:00 0.00 0.00
Storage Nodes
Storage Node : B-10
Input Data
7.00
13.00
6.00
0.00
-7.00
0.00
0.00
Storage Area Volume Curves
Storage Curve : BMP-B
Stage Storage Storage
Area Volume
(ft) (ft²) (ft³)
0 5716 0
1 5716 5716
1.01 9443 5791.8
2 15076 17928.71
3 17528 34230.71
4 20110 53049.71
5 23002 74605.71
6 25728 98970.71
Invert Elevation (ft) .................................................
Max (Rim) Elevation (ft) ...........................................
Max (Rim) Offset (ft) ...............................................
Initial Water Elevation (ft) .......................................
Initial Water Depth (ft) ............................................
Ponded Area (ft²) ....................................................
Evaporation Loss ....................................................
Storage Area Volume Curves
Storage Area Storage Volume
Storage Area (ft²)
24,00022,00020,00018,00016,00014,00012,00010,0008,0006,000
Storage Volume (ft³)
90,00080,00070,00060,00050,00040,00030,00020,00010,0000
St
a
g
e
(
f
t
)
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
St
a
g
e
(
f
t
)
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Storage Node : B-10 (continued)
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 Weir-1 Rectangular No 12.00 5.00 15.00 1.00 3.33
Output Summary Results
17.52
0.7
0
0
11.75
4.75
9.42
2.42
1 00:00
0
0
0
0
Max HGL Elevation Attained (ft) ...............................
Peak Inflow (cfs) .....................................................
Peak Lateral Inflow (cfs) .........................................
Peak Outflow (cfs) ..................................................
Peak Exfiltration Flow Rate (cfm) .............................
Total Time Flooded (min) ........................................
Total Retention Time (sec) ......................................
Max HGL Depth Attained (ft) ....................................
Average HGL Elevation Attained (ft) .........................
Average HGL Depth Attained (ft) ..............................
Time of Max HGL Occurrence (days hh:mm) ............
Total Exfiltration Volume (1000-ft³) .........................
Total Flooded Volume (ac-in) ..................................
Project Description
Proposed Conditions.SPF
Project Options
CFS
Elevation
SCS TR-55
User-Defined
Hydrodynamic
YES
YES
Analysis Options
00:00:00 0:00:00
00:00:00 0:00:00
00:00:00 0:00:00
0 days
0 01:00:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
1 seconds
Number of Elements
Qty
1
13
14
0
2
0
11
1
12
0
11
0
0
1
0
0
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
49 Time Series 100-yr Cumulative inches North Carolina New Hanover 100.00 10.20 SCS Type III 24-hr
Antecedent Dry Days ................................
File Name ................................................
Flow Units ...............................................
Elevation Type ..........................................
Hydrology Method ....................................
Time of Concentration (TOC) Method ........
Link Routing Method .................................
Enable Overflow Ponding at Nodes ...........
Skip Steady State Analysis Time Periods ....
Start Analysis On ......................................
End Analysis On .......................................
Start Reporting On ...................................
Storage Nodes ...................................
Runoff (Dry Weather) Time Step ................
Runoff (Wet Weather) Time Step ...............
Reporting Time Step .................................
Routing Time Step ....................................
Rain Gages ..............................................
Subbasins................................................
Nodes......................................................
Junctions ...........................................
Outfalls .............................................
Flow Diversions .................................
Inlets ................................................
Outlets ..............................................
Pollutants ................................................
Land Uses ...............................................
Links........................................................
Channels ..........................................
Pipes .................................................
Pumps ..............................................
Orifices .............................................
Weirs ................................................
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 DA-A1 0.26 484.00 84.38 10.20 8.27 2.15 2.10 0 00:05:00
2 DA-A2 0.13 484.00 88.92 10.20 8.84 1.15 1.06 0 00:05:00
3 DA-B1 0.25 484.00 79.12 10.20 7.60 1.90 1.89 0 00:05:00
4 DA-B10 0.85 484.00 39.00 10.20 2.20 1.87 1.80 0 00:05:00
5 DA-B2 0.11 484.00 71.18 10.20 6.56 0.72 0.73 0 00:05:00
6 DA-B3 0.32 484.00 98.00 10.20 9.96 3.19 2.75 0 00:05:00
7 DA-B4 0.26 484.00 95.73 10.20 9.68 2.52 2.25 0 00:05:00
8 DA-B5 0.15 484.00 94.07 10.20 9.48 1.42 1.25 0 00:05:00
9 DA-B6 0.18 484.00 98.00 10.20 9.96 1.79 1.54 0 00:05:00
10 DA-B7 0.66 484.00 74.76 10.20 7.03 4.64 4.70 0 00:05:00
11 DA-B8 0.40 484.00 86.20 10.20 8.50 3.40 3.27 0 00:05:00
12 DA-B9 0.47 484.00 98.00 10.20 9.96 4.68 4.02 0 00:05:00
13 DA-BBypass 0.70 484.00 52.49 10.20 4.04 2.83 2.95 0 00:05:00
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time
ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft) (days hh:mm) (ac-in) (min)
1 Out-A Outfall 2.94 3.12 3.78
2 Out-B Outfall 11.72 2.85 11.72
3 B-10 Storage Node 7.00 13.00 0.00 0.00 23.60 12.07 0.00 0.00
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft) (ft) (ft) (%) (in) (cfs) (cfs) (ft/sec) (ft) (min)
1 A1-A2 Pipe A-1 A-2 150.93 7.97 7.52 0.3000 48.000 0.0130 2.07 78.43 0.03 2.73 0.44 0.11 0.00 Calculated
2 A2-OUTA Pipe A-2 Out-A 2.00 2.94 2.88 3.0000 48.000 0.0130 3.12 32.12 0.10 1.80 0.86 0.23 0.00 Calculated
3 B1-B2 Pipe B-1 B-2 92.00 11.65 11.20 0.4900 15.000 0.0130 1.85 4.52 0.41 2.89 0.75 0.61 0.00 Calculated
4 B2-B3 Pipe B-2 B-3 223.00 11.20 10.10 0.4900 15.000 0.0130 2.56 4.54 0.56 2.39 1.06 0.86 0.00 Calculated
5 B3-B6 Pipe B-3 B-6 124.00 10.10 9.50 0.4800 18.000 0.0130 5.15 7.31 0.70 2.91 1.50 1.00 648.00 SURCHARGED
6 B4-B5 Pipe B-4 B-5 48.00 10.70 10.20 1.0400 15.000 0.0130 2.22 6.59 0.34 3.41 1.25 1.00 562.00 SURCHARGED
7 B5-B6 Pipe B-5 B-6 68.00 10.20 9.50 1.0300 18.000 0.0130 3.45 10.66 0.32 2.11 1.50 1.00 622.00 SURCHARGED
8 B6-B9 Pipe B-6 B-9 63.00 9.50 9.22 0.4400 24.000 0.0130 10.14 15.08 0.67 3.39 2.00 1.00 657.00 SURCHARGED
9 B7-B8 Pipe B-7 B-8 180.00 10.85 9.95 0.5000 15.000 0.0130 4.65 4.57 1.02 3.79 1.25 1.00 11.00 SURCHARGED
10 B8-B9 Pipe B-8 B-9 144.00 9.95 9.22 0.5100 18.000 0.0130 7.91 7.48 1.06 4.47 1.50 1.00 678.00 SURCHARGED
11 B9-B10 Pipe B-9 B-10 22.00 9.22 9.00 1.0000 30.000 0.0130 21.96 41.02 0.54 6.82 2.50 1.00 618.00 SURCHARGED
12 Weir-1 Weir B-10 Out-B 7.00 11.72 0.94
Inlet Summary
SN Element Inlet Manufacturer Inlet Number of Catchbasin Max (Rim) Initial Ponded Peak Peak Flow Peak Flow Inlet
ID Manufacturer Part Location Inlets Invert Elevation Water Area Flow Intercepted Bypassing Efficiency
Number Elevation Elevation by Inlet during Peak
Inlet Flow
(ft) (ft) (ft) (ft²) (cfs) (cfs) (cfs) (%)
1 A-1 FHWA HEC-22 GENERIC N/A On Sag 1 7.97 13.00 0.00 10.00 2.09 N/A N/A N/A
2 A-2 FHWA HEC-22 GENERIC N/A On Sag 1 2.94 13.80 0.00 10.00 1.06 N/A N/A N/A
3 B-1 FHWA HEC-22 GENERIC N/A On Sag 1 11.65 16.30 0.00 10.00 1.87 N/A N/A N/A
4 B-2 FHWA HEC-22 GENERIC N/A On Sag 1 11.20 15.25 0.00 10.00 0.72 N/A N/A N/A
5 B-3 FHWA HEC-22 GENERIC N/A On Sag 1 10.10 15.30 0.00 10.00 2.75 N/A N/A N/A
6 B-4 FHWA HEC-22 GENERIC N/A On Sag 1 10.70 15.95 0.00 10.00 2.24 N/A N/A N/A
7 B-5 FHWA HEC-22 GENERIC N/A On Sag 1 10.20 14.25 0.00 10.00 1.25 N/A N/A N/A
8 B-6 FHWA HEC-22 GENERIC N/A On Sag 1 9.50 13.40 0.00 10.00 1.54 N/A N/A N/A
9 B-7 FHWA HEC-22 GENERIC N/A On Sag 1 10.85 14.00 0.00 10.00 4.65 N/A N/A N/A
10 B-8 FHWA HEC-22 GENERIC N/A On Sag 1 9.95 14.00 0.00 10.00 3.26 N/A N/A N/A
11 B-9 FHWA HEC-22 GENERIC N/A On Sag 1 9.22 13.00 0.00 10.00 4.01 N/A N/A N/A
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 A1-A2 150.93 7.97 0.00 7.52 4.58 0.45 0.3000 CIRCULAR 48.000 48.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
2 A2-OUTA 2.00 2.94 0.00 2.88 -0.06 0.06 3.0000 CIRCULAR 48.000 48.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
3 B1-B2 92.00 11.65 0.00 11.20 0.00 0.45 0.4900 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
4 B2-B3 223.00 11.20 0.00 10.10 0.00 1.10 0.4900 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
5 B3-B6 124.00 10.10 0.00 9.50 0.00 0.60 0.4800 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
6 B4-B5 48.00 10.70 0.00 10.20 0.00 0.50 1.0400 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
7 B5-B6 68.00 10.20 0.00 9.50 0.00 0.70 1.0300 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
8 B6-B9 63.00 9.50 0.00 9.22 0.00 0.28 0.4400 CIRCULAR 24.000 24.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
9 B7-B8 180.00 10.85 0.00 9.95 0.00 0.90 0.5000 CIRCULAR 15.000 15.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
10 B8-B9 144.00 9.95 0.00 9.22 0.00 0.73 0.5100 CIRCULAR 18.000 18.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
11 B9-B10 22.00 9.22 0.00 9.00 2.00 0.22 1.0000 CIRCULAR 30.000 30.000 0.0130 0.5000 0.5000 0.0000 0.00 No 1
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 A1-A2 2.07 0 12:10 78.43 0.03 2.73 0.92 0.44 0.11 0.00 Calculated
2 A2-OUTA 3.12 0 12:10 32.12 0.10 1.80 0.02 0.86 0.23 0.00 Calculated
3 B1-B2 1.85 0 12:10 4.52 0.41 2.89 0.53 0.75 0.61 0.00 Calculated
4 B2-B3 2.56 0 12:11 4.54 0.56 2.39 1.56 1.06 0.86 0.00 Calculated
5 B3-B6 5.15 0 12:10 7.31 0.70 2.91 0.71 1.50 1.00 648.00 SURCHARGED
6 B4-B5 2.22 0 12:10 6.59 0.34 3.41 0.23 1.25 1.00 562.00 SURCHARGED
7 B5-B6 3.45 0 12:10 10.66 0.32 2.11 0.54 1.50 1.00 622.00 SURCHARGED
8 B6-B9 10.14 0 12:10 15.08 0.67 3.39 0.31 2.00 1.00 657.00 SURCHARGED
9 B7-B8 4.65 0 12:10 4.57 1.02 3.79 0.79 1.25 1.00 11.00 SURCHARGED
10 B8-B9 7.91 0 12:10 7.48 1.06 4.47 0.54 1.50 1.00 678.00 SURCHARGED
11 B9-B10 21.96 0 12:10 41.02 0.54 6.82 0.05 2.50 1.00 618.00 SURCHARGED
Inlet Input
SN Element Inlet Manufacturer Inlet Number of Catchbasin Max (Rim) Inlet Initial Initial Ponded Grate
ID Manufacturer Part Location Inlets Invert Elevation Depth Water Water Area Clogging
Number Elevation Elevation Depth Factor
(ft) (ft) (ft) (ft) (ft) (ft²) (%)
1 A-1 FHWA HEC-22 GENERIC N/A On Sag 1 7.97 13.00 5.03 0.00 0.00 10.00 0.00
2 A-2 FHWA HEC-22 GENERIC N/A On Sag 1 2.94 13.80 10.86 0.00 0.00 10.00 0.00
3 B-1 FHWA HEC-22 GENERIC N/A On Sag 1 11.65 16.30 4.65 0.00 0.00 10.00 0.00
4 B-2 FHWA HEC-22 GENERIC N/A On Sag 1 11.20 15.25 4.05 0.00 0.00 10.00 0.00
5 B-3 FHWA HEC-22 GENERIC N/A On Sag 1 10.10 15.30 5.20 0.00 0.00 10.00 0.00
6 B-4 FHWA HEC-22 GENERIC N/A On Sag 1 10.70 15.95 5.25 0.00 0.00 10.00 0.00
7 B-5 FHWA HEC-22 GENERIC N/A On Sag 1 10.20 14.25 4.05 0.00 0.00 10.00 0.00
8 B-6 FHWA HEC-22 GENERIC N/A On Sag 1 9.50 13.40 3.90 0.00 0.00 10.00 0.00
9 B-7 FHWA HEC-22 GENERIC N/A On Sag 1 10.85 14.00 3.15 0.00 0.00 10.00 0.00
10 B-8 FHWA HEC-22 GENERIC N/A On Sag 1 9.95 14.00 4.05 0.00 0.00 10.00 0.00
11 B-9 FHWA HEC-22 GENERIC N/A On Sag 1 9.22 13.00 3.78 0.00 0.00 10.00 0.00
Roadway & Gutter Input
SN Element Roadway Roadway Roadway Gutter Gutter Gutter
ID Longitudinal Cross Manning's Cross Width Depression
Slope Slope Roughness Slope
(ft/ft) (ft/ft) (ft/ft) (ft) (in)
1 A-1 N/A 0.0200 0.0160 0.0620 2.00 0.0656
2 A-2 N/A 0.0200 0.0160 0.0620 2.00 0.0656
3 B-1 N/A 0.0200 0.0160 0.0620 2.00 0.0656
4 B-2 N/A 0.0200 0.0160 0.0620 2.00 0.0656
5 B-3 N/A 0.0200 0.0160 0.0620 2.00 0.0656
6 B-4 N/A 0.0200 0.0160 0.0620 2.00 0.0656
7 B-5 N/A 0.0200 0.0160 0.0620 2.00 0.0656
8 B-6 N/A 0.0200 0.0160 0.0620 2.00 0.0656
9 B-7 N/A 0.0200 0.0160 0.0620 2.00 0.0656
10 B-8 N/A 0.0200 0.0160 0.0620 2.00 0.0656
11 B-9 N/A 0.0200 0.0160 0.0620 2.00 0.0656
Inlet Results
SN Element Peak Peak Peak Flow Peak Flow Inlet Time of Total Total Time
ID Flow Lateral Intercepted Bypassing Efficiency Max Depth Flooded Flooded
Inflow by Inlet during Peak Occurrence Volume
Inlet Flow
(cfs) (cfs) (cfs) (cfs) (%) (days hh:mm) (ac-in) (min)
1 A-1 2.09 2.09 N/A N/A N/A 0 12:10 0.00 0.00
2 A-2 1.06 1.06 N/A N/A N/A 0 12:10 0.00 0.00
3 B-1 1.87 1.87 N/A N/A N/A 0 12:10 0.00 0.00
4 B-2 0.72 0.72 N/A N/A N/A 0 12:10 0.00 0.00
5 B-3 2.75 2.75 N/A N/A N/A 0 15:48 0.00 0.00
6 B-4 2.24 2.24 N/A N/A N/A 0 15:49 0.00 0.00
7 B-5 1.25 1.25 N/A N/A N/A 0 15:49 0.00 0.00
8 B-6 1.54 1.54 N/A N/A N/A 0 15:49 0.00 0.00
9 B-7 4.65 4.65 N/A N/A N/A 0 12:05 0.00 0.00
10 B-8 3.26 3.26 N/A N/A N/A 0 12:05 0.00 0.00
11 B-9 4.01 4.01 N/A N/A N/A 0 15:50 0.00 0.00
Storage Nodes
Storage Node : B-10
Input Data
7.00
13.00
6.00
0.00
-7.00
0.00
0.00
Storage Area Volume Curves
Storage Curve : BMP-B
Stage Storage Storage
Area Volume
(ft) (ft²) (ft³)
0 5716 0
1 5716 5716
1.01 9443 5791.8
2 15076 17928.71
3 17528 34230.71
4 20110 53049.71
5 23002 74605.71
6 25728 98970.71
Invert Elevation (ft) .................................................
Max (Rim) Elevation (ft) ...........................................
Max (Rim) Offset (ft) ...............................................
Initial Water Elevation (ft) .......................................
Initial Water Depth (ft) ............................................
Ponded Area (ft²) ....................................................
Evaporation Loss ....................................................
Storage Area Volume Curves
Storage Area Storage Volume
Storage Area (ft²)
24,00022,00020,00018,00016,00014,00012,00010,0008,0006,000
Storage Volume (ft³)
90,00080,00070,00060,00050,00040,00030,00020,00010,0000
St
a
g
e
(
f
t
)
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
St
a
g
e
(
f
t
)
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Storage Node : B-10 (continued)
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 Weir-1 Rectangular No 12.00 5.00 15.00 1.00 3.33
Output Summary Results
23.6
1.65
0.94
0
12.07
5.07
9.79
2.79
0 15:50
0
0
0
0
Max HGL Elevation Attained (ft) ...............................
Peak Inflow (cfs) .....................................................
Peak Lateral Inflow (cfs) .........................................
Peak Outflow (cfs) ..................................................
Peak Exfiltration Flow Rate (cfm) .............................
Total Time Flooded (min) ........................................
Total Retention Time (sec) ......................................
Max HGL Depth Attained (ft) ....................................
Average HGL Elevation Attained (ft) .........................
Average HGL Depth Attained (ft) ..............................
Time of Max HGL Occurrence (days hh:mm) ............
Total Exfiltration Volume (1000-ft³) .........................
Total Flooded Volume (ac-in) ..................................
Page 9
APPENDIX C
WATER DEMAND CALCULATIONS
SIZING WATER SERVICE LINES AND METERS
Customer: US Hwy 421 7-Eleven Address
Building Address: US Hwy 421 Zip Code
Subdivision Lot No. Blk No.
Type of Occupancy: Domestic Meter
Fixture Value No. of Fixture
Fixture 60 psi Fixtures Value
Bathtub 8 X = 0.0
Bedpan Washers 10 X = 0.0
Bidet 2 X = 0.0
Dental Unit 2 X = 0.0
Drinking Fountain - Public 2 X 1 = 2.0
Kichen Sink 2.2 X 2 = 4.4
Lavatory 1.5 X 2 = 3.0
Showerhead (Shower Only) 2.5 X = 0.0
Service Sink 4 X 4 = 16.0
Toliet Flush Valve 35 X 3 = 105.0
Tank Type 4 X = 0.0
Urinal Pedestal Flush Valve 35 X = 0.0
Wall Flush Valve 16 X 1 = 16.0
Wash Sink (Each Set of Faucets) 4 X 2 = 8.0
Dishwasher 2 X 1 = 2.0
Washing Machine 6 X = 0.0
Hose (50 ft Wash Down) 1/2 in. 5 X 2 = 10.0
5/8 in. 9 X = 0.0
3/4 in. 12 X = 0.0
X = 0.0
X = 0.0
X = 0.0
Combined Fixture Value Total 166.4
Customer Peak Demand From Fig. 4-2 or 4 - 3 x Press Factor = gpm
Add Irrigation Sections x 1.16 = 0 gpm
Hose Bibs x x Fixture Value x 0 gpm
Added Fixed Load = 0 gpm
TOTAL FIXED DEMAND =56.9 gpm
Figure 4-5 Water customer data sheet
Press. Factor =
What type of development?Option 1 Option 1 = Hotels, Shopping Centers, and Restaurants
Option 2 = Apartments, Condominium, and Campgrounds
Total Combined Fixture Value 166
Total Water Demand 56.9 gpm (includes irrigation)
Figure 4-2 Water flow demand per fixture value - low range
Total Water Demand 56.9 gpm (Peak Demand)
Required Water Meter 1.5 in.(Positive Displacement)
Page 10
APPENDIX D
SANITARY SEWER DEMAND CALCULATIONS
15A NCAC 02T .0114 WASTEWATER DESIGN FLOW RATES
(a) This Rule shall be used to determine wastewater flow rates for all systems governed by this Subchapter unless
alternate criteria are provided by a program-specific rule or for flow used for the purposes of 15A NCAC 02H .0105.
Higher flow rates shall be required where usage and occupancy are atypical, including those in Paragraph (e) of this
Rule. Wastewater flow calculations shall take hours of operation and anticipated maximum occupancies and usage
into account when calculating peak flows for design.
(b) In determining the volume of sewage from dwelling units, the flow rate shall be 120 gallons per day per
bedroom. The minimum volume of sewage from each dwelling unit shall be 240 gallons per day and each additional
bedroom above two bedrooms shall increase the volume by 120 gallons per day. Each bedroom or any other room or
addition that can function as a bedroom shall be considered a bedroom for design purposes. When the occupancy of
a dwelling unit exceeds two persons per bedroom, the volume of sewage shall be determined by the maximum
occupancy at a rate of 60 gallons per person per day.
(c) The following table shall be used to determine the minimum allowable design daily flow of wastewater
facilities. Design flow rates for establishments not identified below shall be determined using available flow data,
water-using fixtures, occupancy or operation patterns, and other measured data.
Type of Establishments Daily Flow For Design
Barber and beauty shops
Barber Shops 50 gal/chair
Beauty Shops 125 gal/booth or bowl
Businesses, offices and factories
General business and office facilities 25 gal/employee/shift
Factories, excluding industrial waste 25 gal/employee/shift
Factories or businesses with showers or food preparation 35 gal/employee/shift
Warehouse 100 gal/loading bay
Warehouse – self storage (not including caretaker residence) 1 gal/unit
Churches
Churches without kitchens, day care or camps 3 gal/seat
Churches with kitchen 5 gal/seat
Churches providing day care or camps 25 gal/person (child & employee)
Fire, rescue and emergency response facilities
Fire or rescue stations without on site staff 25 gal/person
Fire or rescue stations with on-site staff 50 gal/person/shift
Food and drink facilities
Banquet, dining hall 30 gal/seat
Bars, cocktail lounges 20 gal/seat
Caterers 50 gal/100 sq ft floor space
Restaurant, full Service 40 gal/seat
Restaurant, single service articles 20 gal/seat
Restaurant, drive-in 50 gal/car space
Restaurant, carry out only 50 gal/100 sq ft floor space
Institutions, dining halls 5 gal/meal
Deli 40 gal/100 sq ft floor space
Bakery 10 gal/100 sq ft floor space
Meat department, butcher shop or fish market 75 gal/100 sq ft floor space
Specialty food stand or kiosk 50 gal/100 sq ft floor space
Hotels and Motels
Hotels, motels and bed & breakfast facilities,
without in-room cooking facilities 120 gal/room
Hotels and motels, with in-room cooking facilities 175 gal/room
Resort hotels 200 gal/room
Cottages, cabins 200 gal/unit
Self service laundry facilities 500 gal/machine
Medical, dental, veterinary facilities
Medical or dental offices 250 gal/practitioner/shift
Veterinary offices (not including boarding) 250 gal/practitioner/shift
Veterinary hospitals, kennels, animal boarding facilities 20 gal/pen, cage, kennel or stall
Hospitals, medical 300 gal/bed
Hospitals, mental 150 gal/bed
Convalescent, nursing, rest homes without laundry facilities 60 gal/bed
Convalescent, nursing, rest homes with laundry facilities 120 gal/bed
Residential care facilities 60 gal/person
Parks, recreation, camp grounds, R-V parks and other outdoor activity facilities
Campgrounds with comfort station, without
water or sewer hookups 75 gal/campsite
Campgrounds with water and sewer hookups 100 gal/campsite
Campground dump station facility 50 gal/space
Construction, hunting or work camps with flush toilets 60 gal/person
Construction, hunting or work camps with chemical or
portable toilets 40 gal/person
Parks with restroom facilities 250 gal/plumbing fixture
Summer camps without food preparation or laundry facilities 30 gal/person
Summer camps with food preparation and laundry facilities 60 gal/person
Swimming pools, bathhouses and spas 10 gal/person
Public access restrooms 325 gal/plumbing fixture
Schools, preschools and day care
Day care and preschool facilities 25 gal/person (child & employee)
Schools with cafeteria, gym and showers 15 gal/student
Schools with cafeteria 12 gal/student
Schools without cafeteria, gym or showers 10 gal/student
Boarding schools 60 gal/person (student & employee)
Service stations, car wash facilities
Service stations, gas stations 250 gal/plumbing fixture
Car wash facilities 1200 gal/bay
Sports centers
Bowling center 50 gal/lane
Fitness, exercise, karate or dance center 50 gal/100 sq ft
Tennis, racquet ball 50 gal/court
Gymnasium 50 gal/100 sq ft
Golf course with only minimal food service 250 gal/plumbing fixture
Country clubs 60 gal/member or patron
Mini golf, putt-putt 250 gal/plumbing fixture
Go-kart, motocross 250 gal/plumbing fixture
Batting cages, driving ranges 250 gal/plumbing fixture
Marinas without bathhouse 10 gal/slip
Marinas with bathhouse 30 gal/slip
Video game arcades, pool halls 250 gal/plumbing fixture
Stadiums, auditoriums, theaters, community centers 5 gal/seat
Stores, shopping centers, malls and flea markets
Auto, boat, recreational vehicle dealerships/showrooms
with restrooms 125 gal/plumbing fixture
Convenience stores, with food preparation 60 gal/100 sq ft
Convenience stores, without food preparation 250 gal/plumbing fixture
Flea markets 30 gal/stall
Shopping centers and malls with food service 130 gal/1000 sq ft
Stores and shopping centers without food service 100 gal/1000 sq ft
Transportation terminals – air, bus, train, ferry, port and dock 5 gal/passenger
(d) Design daily flow rates for proposed non-residential developments where the types of use and occupancy are not
known shall be designed for a minimum of 880 gallons per acre, or the applicant shall specify an anticipated flow
based upon anticipated or potential uses.
(e) Design daily flow rates for residential property on barrier islands and similar communities located south or east
of the Atlantic Intracoastal Waterway and used as vacation rental as defined in G.S. 42A-4 shall be 120 gallons per
day per habitable room. Habitable room shall mean a room or enclosed floor space used or intended to be used for
living or sleeping, excluding kitchens and dining areas, bathrooms, shower rooms, water closet compartments,
laundries, pantries, foyers, connecting corridors, closets, and storage spaces.
(f) An adjusted daily sewage flow design rate shall be granted for permitted but not yet tributary connections and
future connections tributary to the system upon showing that the capacity of a sewage system is adequate to meet
actual daily wastewater flows from a facility included in Paragraph (b) or (c) of this Rule without causing flow
violations at the receiving wastewater treatment plant or capacity-related sanitary sewer overflows within the
collection system as follows:
(1) Documented, representative data from that facility or a comparable facility shall be submitted by
an authorized signing official in accordance with Rule .0106 of this Section to the Division for all
flow reduction requests, as follows:
(A) dates of flow meter calibrations during the time frame evaluated and indication if any
adjustments were necessary;
(B) a breakdown of the type of connections (e.g. two bedroom units, three bedroom units)
and number of customers for each month of submitted data as applicable. Identification
of any non-residential connections including subdivision clubhouses and pools,
restaurants, schools, churches and businesses. For each non-residential connection,
information identified in Paragraph (c) of this Rule (e.g. 200 seat church, 40 seat
restaurant, 35 person pool bathhouse);
(C) a letter of agreement from the owner or an official, meeting the criteria of Rule .0106 of
this Section, of the receiving collection system or treatment works accepting the
wastewater and agreeing with the adjusted design rate;
(D) age of the collection system;
(E) analysis of inflow and infiltration within the collection system or receiving treatment
plant, as applicable;
(F) if a dedicated wastewater treatment plant serves the specific area and is representative of
the residential wastewater usage, at least the 12 most recent consecutive monthly average
wastewater flow readings and the daily total wastewater flow readings for the highest
average wastewater flow month per customers, as reported to the Division;
(G) if daily data from a wastewater treatment plant cannot be used or is not representative of
the project area: 12 months worth of monthly average wastewater flows from the
receiving treatment plant shall be evaluated to determine the peak sewage month. Daily
wastewater flows shall then be taken from a flow meter installed at the most downstream
point of the collection area for the peak month selected that is representative of the
project area. Justification for the selected placement of the flow meter shall also be
provided; and
(H) an estimated design daily sewage flow rate shall be determined by calculating the
numerical average of the top three daily readings for the highest average flow month. The
calculations shall also account for seasonal variations, excessive inflow and infiltration,
age and suspected meter reading and recording errors.
(2) The Division shall evaluate all data submitted but shall also consider other factors in granting,
with or without adjustment, or denying a flow reduction request including: applicable weather
conditions during the data period (i.e. rainy or drought), other historical monitoring data for the
particular facility or other similar facilities available to the Division, the general accuracy of
monitoring reports and flow meter readings, and facility usage, such as whether the facility is in a
resort area.
(3) Flow increases shall be required if the calculations required by Subparagraph (f)(1) of this Rule
yield design flows higher than that specified in Paragraphs (b) or (c) of this Rule.
(4) The permittee shall retain the letter of any approved adjusted daily design flow rate for the life of
the facility and shall transfer such letter to a future permittee.
History Note: Authority G.S. 143-215.1; 143-215.3(a)(1);
Eff. September 1, 2006;
Readopted Eff. September 1, 2018.