HomeMy WebLinkAbout20250121_NOI_CCS_Part 6_Part1
Attachment H
Stormwater Management Report and Checklist
(prepared by Burns & McDonnell)
NSTAR ELECTRIC COMPANY D/B/A
E VERSOURCE ENERGY
STORMWATER
M ANAGEMENT STUDY
WEST BARNSTABLE STATION EXPANSION
PROJECT NO. 152841
R EVISION 3
JANUARY 6, 2025
CONTENTS
1.0 Project Overview .................................................................................................... 1-1
1.1 Location & Project Description ................................................................................ 1-1
1.2 Floodplain................................................................................................................. 1-1
1.3 Soils .......................................................................................................................... 1-1
1.4 Pre-Development Site Conditions ............................................................................ 1-2
1.5 Post-Development Site Conditions .......................................................................... 1-2
2.0 MassDEP Stormwater Standards Compliance........................................................ 2-1
2.1 Rainfall Data ............................................................................................................. 2-1
2.2 Runoff Data .............................................................................................................. 2-1
2.3 Standard 1 – No New Untreated Stormwater Discharges ....................................... 2-2
2.4 Standard 2 – Post-Development Peak Discharge Rates ........................................... 2-2
2.5 Standard 3 – Recharge to Groundwater .................................................................. 2-4
2.6 Standard 4 – Water Quality Treatment ................................................................... 2-4
2.7 Standard 5 – Land Uses with Higher Pollutant Loading ........................................... 2-5
2.8 Standard 6 – Discharges to Critical Areas ................................................................ 2-5
2.9 Standard 7 – Redevelopment .................................................................................. 2-5
2.10 Standard 8 – Erosion and Sediment Controls .......................................................... 2-5
2.11 Standard 9 – Long Term Operation and Maintenance Plan .................................... 2-5
2.12 Standard 10 – Illicit Discharges ................................................................................ 2-5
3.0 Conclusion .............................................................................................................. 3-1
APPENDIX A – SITE LOCATION MAP
APPENDIX B – FEMA FIRM
APPENDIX C – SOIL DATA
APPENDIX D – WATERSHED MAPS
APPENDIX E – HYDROLOGIC CALCULATIONS
APPENDIX F – WQV & RECHARGE CALCULATIONS
APPENDIX G – EROSION CONTROL PLAN & DETAILS
APPENDIX H – OPERATIONS & MAINTENANCE PLAN
APPENDIX I – MASSDEP STORMWATER CHECKLIST
APPENDIX J – ILLICIT DISCHARGE COMPLIANCE STATEMENT
TABLES
Table 1-1: NRCS Soil Types ........................................................................................................ 1-1
Table 2-1: Type-III Design Storm Frequency-Depth .................................................................. 2-1
Table 2-2: Standard Runoff Curve Numbers ............................................................................. 2-1
Table 2-3: Pre-Development Model Data ................................................................................. 2-2
Table 2-4: Post-Development Model Data ............................................................................... 2-2
Table 2-5: Substation Yard Stone (Basin) Volumes ................................................................... 2-3
Table 2-6: Basin Water Surface Elevation (WSE) ...................................................................... 2-3
Table 2-7: Site Analysis Point Peak Flow Rates ......................................................................... 2-3
Table 2-8: Recharge Volume Summary ..................................................................................... 2-4
Table 2-9: Water Quality Volume Summary ............................................................................. 2-4
January 2025 Stormwater Management Study Revision 3
List of Abbreviations Eversource Energy
List of Abbreviations
Abbreviation Term/Phrase/Name
AC Acres
BMP Best Management Practice
Burns & McDonnell Burns & McDonnell Engineering Company, Inc.
CF Cubic Feet
CFS Cubic Feet per Second
CN Curve Number
FEMA Federal Emergency Management Agency
FIRM Flood Insurance Rate Map
MassDEP Massachusetts Department of Environmental Protection
NOAA National Oceanic and Atmospheric Administration
NRCS National Resource Conservation Service
SCS Soil Conservation Service
TR-55 Technical Release 55 Urban Hydrology for Small Watersheds
TSS Total Suspended Solid
WQv Water Quality Volume
USDA United States Department of Agriculture
USGS United States Geological Survey
January 2025 Stormwater Management Study Revision 3
Index and Certification Eversource Energy
Index and Certification
NSTAR Electric Company d/b/a
Eversource Energy
Stormwater Management Study
Project No. 152841
Report Index
Chapter
Number Chapter Title Number
of Pages
1.0 Project Overview 3
2.0 MassDEP Stormwater Standards Compliance 6
3.0 Conclusion 1
Appendix D Watershed Maps 2
Appendix E Hydrologic Calculations 66
Appendix F WQv & Recharge Calculations 3
Appendix G Erosion Control Plan & Details 2
Appendix H Operation & Maintenance Plan 12
Appendix I MassDEP Stormwater Checklist 8
Appendix J Illicit Discharge Compliance Statement 1
Certification
I hereby certify, as a Professional Engineer in the Commonwealth of Massachusetts, that the information in this
document was assembled under my direct personal charge. This report is not intended or represented to be
suitable for reuse by Eversource Energy or others without specific verification or adaptation by the Engineer.
Robbyn L. Reed, P.E. (MA 49782)
Date:
Reference information provided by others and not certified by the above sealing Engineer:
Appendix A Site Location Map
Appendix B FEMA FIRM
Appendix C Soil Data
Digitally Sealed 01/06/2025
1/6/25
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Project Overview Eversource Energy
1-1
1.0 Project Overview
1.1 Location & Project Description
Burns & McDonnell has prepared this Stormwater Management Study on behalf of NSTAR Electric Company d/b/a
Eversource Energy in support of the West Barnstable Station Expansion project (“Project”). The Project is in the
Town of Barnstable, Massachusetts (“Site”). A site location map is included for reference in Appendix A. The
Project will require an expansion of the existing substation yard in the northeast and a rebuilding of the existing
station gravel driveway. Project work will consist of vegetation clearing, site grading, and the installation of three
retaining walls to provide a level station pad for the installation of new electrical equipment. Ancillary activities
include both overhead and underground transmission line construction on and adjacent to the Site and related site
preparation activities.
The Project parcel is 11.95 acres and is owned by Eversource Energy. The Site includes an isolated vegetated
wetland subject to jurisdiction under the Barnstable Wetlands Protection Bylaw and associated 100-foot buffer
zone preceding Oak Street to the west, a wooded area to the east, residential properties to the north, and Route 6
(Mid-Cape Highway) to the south. Elevations within the station expansion area vary from 140 to 174-feet, as
referenced to the North American Vertical Datum of 1988 (NAVD88).
1.2 Floodplain
According to the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) Number
25001C0561J for Barnstable, Massachusetts, Effective Date 7/16/2014, the Site is located within “Zone X,” an
“area of minimum flood hazard,” which represents areas outside the 500-year floodplain. The FEMA FIRM is
included for reference in Appendix B.
1.3 Soils
The National Resources Conservation Service (NRCS) Web Soil Survey identifies the existing soil types and their
assigned hydrologic soil group (HSG) as listed in Table 1-1 below. The HSG is noted to be HSG “A” within the Site
area. Group A soils, as defined by the USDA, indicate “a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well-drained to excessively drained sands or gravelly sands.” (NRCS
Web Soil Survey). Furthermore, USDA National Engineering Handbook, Part 630, Chapter 7 notes that HSG A
designated soils exhibit “saturated hydraulic conductivity of all soil layers [in excess of] 40.0 micrometers per
second (5.67 inches per hour). The depth to any water or impermeable layer is greater than 50 centimeters [20
inches]”. The NRCS report is included for reference in Appendix C.
Table 1-1: NRCS Soil Types
Soil Map
Symbol Soil Map Unit Name HSG
483C Plymouth-Barnstable complex, rolling, very bouldery A
483D Plymouth-Barnstable complex, hilly, very bouldery A
494C Barnstable-Plymouth-Nantucket complex, rolling, very bouldery A
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Project Overview Eversource Energy
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A geotechnical investigation was performed and detailed in the report: Report on Eversource QP700 Project Station
921 Additions 661 Oak Street, West Barnstable, Massachusetts (“Geotechnical Report”), prepared by Haley and
Aldrich, Inc., revised February 2023. Site and subsurface conditions of the subsoil were generally noted in the
report as “very loose to medium dense brown and yellow-brown silty SAND with gravel (SM), poorly graded SAND
(SP), or silty SAND (SM).” Fill conditions were recorded as “loose to medium dense yellow brown poorly graded
SAND with gravel.” Moraine deposits were encountered as “silty SAND with gravel (SM), silty SAND (SM), well-
graded SAND with silt (SW-SM), or poorly graded SAND with silt (SP-SM).” Glacial stratified deposits were labeled
as “loose to dense stratified poorly graded SAND (SP) or well-graded SAND (SW).” The Geotechnical Report is
provided for reference in Appendix C.
Infiltration testing was also performed at the Site. Based on a falling head in-situ slug test, Haley and Aldrich
calculated and recommended a soil hydraulic conductivity, Kh, of 0.013 cm/sec (18.4 inch/hour) near the location
of the proposed substation yard section. Haley and Aldrich evaluated the groundwater conditions and did not
observe groundwater at any test borings. However, at boring B4, a possible perched water table was observed
approximately 15 ft below the ground surface.
1.4 Pre-Development Site Conditions
The existing Site is partially developed with a substation consisting of a gravel driveway and a 6-inch-thick layer of
3/4-inch crushed stone yard, perimeter fence, and electrical equipment. The remainder of the site is a mixture of
brush and wooded areas. From an analysis of topographical data provided in a Site survey by Eversource on August
29, 2024, most of the Site generally drains north towards the adjacent Eversource Station 920. The wooded area
on the eastern portion of the Site has a high point, which is considered the limit of the eastern watersheds being
analyzed. The high point is treated as a ridge line that splits runoff flow towards the north and the south.
Three “analysis points” were selected, and four pre-development watersheds were delineated to encompass the
limit of disturbance of the Site. These watersheds, EDA-01, EDA-02, EDA-03, and EDA-04, are predominantly
distinguished by their respective contributing runoff areas. The Pre-Development Watershed Map is provided for
reference in Appendix D.
EDA-01 consists of the wooded area east of the existing substation yard and a portion of the area developed by the
proposed yard expansion. Several gravel trails cross through the wooded area. It also includes a small section of
brush that buffers the section between the edge of the existing yard and tree line. This area drains via overland
flow to a localized depression called analysis point “Offsite-South.”
EDA-02 consists of the existing substation yard and brush areas that drain into the yard section called analysis
point “Substation.” EDA-03 encompasses a large portion of the area being developed. This watershed is a wooded
area on the east side, which drains north to a brush area and the existing gravel driveway into the existing
substation yard.
EDA-04 consists of the brush and meadow areas west of the existing gravel driveway draining to the isolated
wetland on the west side of the Site. EDA-03 and EDA-04 drain via overland flow to analysis point “Offsite-North.”
1.5 Post-Development Site Conditions
The proposed Site will be developed with an expanded substation yard. Adjacent areas of the Site will be re-graded
or disturbed to accommodate the installation of two retaining walls. Disturbed areas will be reseeded and
modeled as meadow. Undisturbed areas will remain wooded or covered with brush. Similar to pre-development
conditions, three “analysis points” were selected, and four post-development watersheds were delineated to
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encompass the limit of disturbance of the Site. These watersheds, PDA-01, PDA-02, PDA-03, and PDA-04, are
predominantly distinguished by their respective contributing runoff areas. The Post-Development Watershed Map
is provided for reference in Appendix D.
PDA-01 still consists of the wooded area east of the existing substation yard, the proposed yard expansion, and the
adjacent disturbed areas to be reseeded. This area still drains via overland flow to a localized depression called
analysis point “Offsite-South.”
PDA-02 consists of the existing substation yard and most of the proposed yard expansion that drains into the yard
section called analysis point “Substation.” The proposed yard expansion is bordered by retaining walls or adjacent
riprap 2H:1V slopes that form the watershed's boundary. The Site retains the drainage patterns outside the yard
expansion by meeting the existing grade along the wall.
PDA-03 has been reduced significantly by the proposed substation yard expansion. Like PDA-01, the watershed
includes disturbed areas to be reseeded and undisturbed wooded and brush areas north and east of the substation
yard expansion. Additionally, a portion of the gravel driveway is still contained within PDA-03.
PDA-04 consists of the area draining to the isolated vegetated wetland to the west side of the Site. The meadow
has expanded to encompass the proposed grading, and part of the gravel driveway has been graded to drain
towards this wetland. PDA-03 and PDA-04 are still drained via overland flow to the analysis point “Offsite-North.”
The post-development improvements increase impervious cover at the Site from 3,228 square feet in existing
conditions to 19,823 square feet in post-development, a 16,595 square foot increase. The foundations associated
with the new electrical equipment and control house within the yard expansion drive the increase.
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2.0 MassDEP Stormwater Standards Compliance
This stormwater management study has been developed to demonstrate compliance with state and local
regulations and mitigate the downstream effects of development at the Site. The stormwater requirements set
forth by the Massachusetts Department of Environmental Protection (MassDEP) in the Massachusetts Stormwater
Handbook (“Handbook”), dated February 2008, were followed to the maximum extent practicable as described
herein.
2.1 Rainfall Data
NOAA Atlas 14, Precipitation-Frequency Atlas of the United States, Volume 10, Version 3 published in 2019
provides rainfall intensity information. Type-III 24-hour rainfall depths for the Site were obtained from NOAA’s
online precipitation frequency data server (https://hdsc.nws.noaa.gov/hdsc/pfds/). Pertinent rainfall data is
summarized in Table 2-1, Full NOAA precipitation frequency data is provided in Appendix E.
Table 2-1: Type-III Design Storm Frequency-Depth
Return Frequency
(yr)
24-Hour Depth
(in)
2 3.40
10 4.95
100 7.42
2.2 Runoff Data
Runoff calculations were completed using the SCS TR-20 runoff curve number method in HydroCAD version 10.10-
4b modeling software. The input values used in the HydroCAD model are presented in Tables 2-2 through 2-4.
Table 2-2: Standard Runoff Curve Numbers
Land Cover Type Soil Type Curve
Number
Substation Yard Stone (Basin) A 98
Substation Yard Stone (Non-Basin) A 85
Wetland --- 98
Impervious --- 98
Gravel A 96
Brush – Fair Condition A 35
Woods – Good Condition A 30
Meadow A 30
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Table 2-3: Pre-Development Model Data
Watershed ID Area (sf) Curve
Number
Time of Concentration
(min)
EDA-01 42,106 32 6.0
EDA-02 31,383 87 6.0
EDA-03 64,833 39 6.0
EDA-04 27,421 41 6.0
Table 2-4: Post-Development Model Data
Watershed ID Area (sf) Curve
Number
Time of Concentration
(min)
PDA-01 33,588 30 6.0
PDA-02 66,610 96 6.0
PDA-03 31,609 41 6.0
PDA-04 33,939 45 6.0
A minimum time of concentration (Tc) of 6 minutes was applied to watersheds with calculated time of
concentrations below 6 minutes, in compliance with TR-55. Watershed maps of the pre-development and post-
development conditions are included in Appendix D.
2.3 Standard 1 – No New Untreated Stormwater Discharges
Standard 1 requires that “no new stormwater conveyances (e.g. outfalls) may discharge untreated stormwater
directly to or cause erosion in wetlands or waters of the Commonwealth” (Handbook Vol. 1, Ch. 1, pg. 4).
The Best Management Practices (“BMPs”) included in the proposed stormwater management system have been
designed in accordance with the Massachusetts Stormwater Handbook and Eversource Best Management
Practices Manual for Massachusetts and Connecticut. Supporting information and computations are presented in
this report, demonstrating compliance with Standard 1 where no new untreated runoff will be discharged from the
site. Treatment is provided using practices designed in accordance with Standards 4 through 6, as described in the
following sections.
2.4 Standard 2 – Post-Development Peak Discharge Rates
Standard 2 requires that post-development peak discharge rates do not exceed pre-development peak discharge
rates for the 2-year and 10-year, 24-hour storm events. The proposed condition of the stormwater runoff peak
flow rate will be reduced versus that of existing conditions due to the runoff detention properties of the substation
yard stone section.
For the Site, a substation yard crushed stone pad BMP is used to treat and control stormwater runoff. The
substation yard crushed stone pad is modeled as a basin in pre-development and post-development conditions.
The basin volume or “available storage” is calculated using the substation yard surface area minus the concrete
foundations and roof areas, multiplied by a depth of 6 inches and a void ratio of 40%. The bottom of the yard
section is set at elevation 152.50-feet NAVD88, and the top of the finished grade (top of stone) is set at elevation
153.00-feet NAVD88 in pre-development and post-development conditions. The basin was modeled using a
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default Rawls infiltration rate of 2.41 inches/hour for Loamy Sand (HSG A), which is more conservative than the
field-observed rate described in Section 1.3. The overflow weir length was measured using the distance along the
northern fence line of the yard in pre-development conditions and along the northern yard grade break in post-
development conditions.
Table 2-5: Substation Yard Stone (Basin) Volumes
Pre-Development Post-Development
Net Stone
Surface Area
(sf)
Available
Storage (cf)
Net Stone
Surface Area
(sf)
Available
Storage (cf)
23,343 4,668 44,606 8,921
Table 2-6: Basin Water Surface Elevation (WSE)
Return
Frequency (yr)
Pre-
Development
Peak WSE (ft)
Post-
Development
Peak WSE (ft)
2 152.52 152.57
10 152.60 152.69
100 152.80 152.95
The pre- and post-development conditions were modeled in HydroCAD to determine the associated peak flow
rates according to the watershed maps. Table 2-7 summarizes the peak flow rates for the Site and the retention of
flow achieved by the substation yard stone section. Refer to Appendix E for the comprehensive HydroCAD
modeling results.
Table 2-7: Site Analysis Point Peak Flow Rates
Analysis Point
Return
Frequency
(yr)
Pre-Development
Flow (cfs)
Post-Development
Flow (cfs)
Net Change
(cfs)
Offsite-South
2 0 0 0
10 0 0 0
100 0.12 0.04 -0.08
Offsite-North
2 0 0 0
10 0.05 0.05 0
100 0.90 0.61 -0.29
Substation
2 0 0 0
10 0 0 0
100 0 0 0
Per Table 2-7, the peak discharge rates in post-development conditions are the same or reduced from the existing
conditions for the modeled storm events and, therefore, comply with Standard 2 of the Handbook.
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2.5 Standard 3 – Recharge to Groundwater
The infiltration volume for groundwater recharge required by the Handbook is determined by soil type, infiltration
rate, and the increase in impervious area to the Site. At a minimum, the annual recharge from the post-
development Site shall approximate the annual recharge from pre-development conditions based on soil type. Site
soils are classified as Hydrologic Soil Group (HSG) Type A, and therefore, the required recharge volume is 0.60
inches of runoff over the proposed impervious area. The recharge volume is summarized in Table 2-8.
Table 2-8: Recharge Volume Summary
Volume Required
(cf)
Volume
Provided (cf)
991 8,921
The substation stone yard section functions as a recharge system for the Site. This infiltration BMP has been
designed to drain completely within 72 hours. It is concluded that Standard 3 is met by providing a recharge
volume that exceeds the required volume of the Handbook. Calculations for groundwater recharge are included in
Appendix F.
2.6 Standard 4 – Water Quality Treatment
The Handbook requires that the stormwater system be designed to remove 80% of the average annual post-
construction load of Total Suspended Solids (TSS). As defined in Volume 1 of the Handbook, the Site qualifies as an
area with a rapid infiltration rate (greater than 2.4 inches per hour); thus, the required water quality volume for
treatment equals 1.0 inches times the total impervious area of the pre-development. The water quality volume is
summarized in Table 2-9.
Table 2-9: Water Quality Volume Summary
Volume Required
(cf)
Volume
Provided (cf)
1,652 8,921
Volume 3 of the Massachusetts Stormwater Handbook states that often, one BMP is sized to provide both water
quality treatment and recharge. Since 80% of the TSS load is not proposed to be fully removed prior to discharge to
the infiltration BMP (substation yard stone section) and due to site constraints, the substation yard stone section is
being used to fulfill the requirements of both Standards 3 (Recharge) and 4 (Water Quality Treatment). In such
instances, the recharge system must be sized to treat or hold the target volume, which is larger than the required
water quality volume (WQV) and recharge volume. As stated, the total recharge volume provided in the substation
stone yard section exceeds the required water quality volume of the Handbook. Calculations for water quality
volume are included in Appendix F.
Additionally, the TSS removal matrix within the Handbook guidelines grants 80% removal of TSS for infiltration
BMPs, provided they are combined with one or more pre-treatment BMPs prior to infiltration. Runoff from
impervious areas (control enclosure roof and equipment foundations) is disconnected and will sheet flow directly
onto the crushed rock surfacing for filtering, providing pretreatment prior to infiltration.
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2.7 Standard 5 – Land Uses with Higher Pollutant Loading
The Site does not have a use type or on-site materials that would qualify it for high pollutant load; therefore, this
standard does not apply to the Site.
2.8 Standard 6 – Discharges to Critical Areas
The Handbook defines critical areas as Outstanding Resource Waters, Special Resource Waters, recharge areas for
public water supplies, bathing beaches, and shellfish growing areas. Based on a review of publicly available GIS
data, the Site is not part of and does not discharge into a critical area; therefore, this standard does not apply to
the Site.
2.9 Standard 7 – Redevelopment
The proposed construction does not qualify as a redevelopment project, as defined by the Handbook; therefore,
this standard does not apply to the proposed construction.
2.10 Standard 8 – Erosion and Sediment Controls
Erosion and sediment control BMPs will be implemented at the Site prior to construction and land disturbance
activities and are to remain in working order until construction activities cease and the Site is stabilized. All
erosion and sediment controls at the Site will be required to comply with the Massachusetts Erosion and Sediment
Control Guidelines for Urban and Suburban Areas: A Guide for Planners, Designers, and Municipal Officials, May
2003 and Eversource standards. The erosion control measures to be utilized during the substation construction are
shown in Appendix G. The construction stormwater pollution prevention plan implements the following BMPs:
· Silt fence and silt sock along the downgradient portions of the Site, as depicted on the record permit
drawings approved by the Barnstable Conservation Commission.
· To minimize dust and sediment tracking on adjacent roads, a vehicle construction entrance shall be
installed as necessary in accordance with Eversource’s BMP manual where construction vehicles enter
and exit the Site from Oak Street.
· At a minimum, erosion and sediment controls shall be inspected weekly and after storm events.
· Inlet protection is installed on catch basins using silt sack inserts.
· Sump pits for dewatering construction excavations.
· Soil stockpiles are covered or seeded and surrounded by a silt fence.
· Concrete washouts at least 50-feet from the isolated vegetated wetland.
2.11 Standard 9 – Long Term Operation and Maintenance Plan
The Project’s stormwater-related Operation and Maintenance Plan is included in Appendix H. The Operation and
Maintenance Plan defines the responsibilities that the owner of the Site must undertake to comply with required
inspections and maintenance to ensure the long-term functionality of the Site’s stormwater BMPs.
2.12 Standard 10 – Illicit Discharges
Illicit discharges to the stormwater management system are not entirely comprised of stormwater. According to
the Handbook, an illicit discharge does not include discharges from the following activities or facilities: firefighting,
water line flushing, landscape irrigation, uncontaminated groundwater, potable water sources, foundation or
footing drains, water used for street washing and water used to clean residential buildings without detergents. The
current Site layout, grading and proposed stormwater system design ensures that no illicit discharges occur on-
site. A copy of the signed Illicit Discharge Compliance Statement is provided in Appendix J.
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Conclusion Eversource Energy
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3.0 Conclusion
The proposed substation development has been designed to fully comply with the Barnstable Wetlands Protection
Bylaw and implementing regulations, Massachusetts Stormwater Handbook and Eversource Best Management
Practices Manual for Massachusetts and Connecticut. No new untreated stormwater discharges are added to the
Site. The stormwater management system is designed so that the post-development conditions do not result in an
increase in stormwater runoff peak discharge rate when compared to pre-development conditions for the required
design storms. The substation stone yard section is designed to meet infiltration requirements per the
Massachusetts Stormwater Handbook. Water quality treatment is provided for the post-development conditions
by utilizing the substation stone yard section for infiltration, with required pretreatment and sizing for the water
quality volume. The Project does not constitute a use with higher pollutant loads, and no critical areas are
identified for the Site. Temporary erosion and sedimentation controls will be employed during construction to
minimize construction impacts on the downstream property, storm drain systems and waters. As always, post-
development operations and maintenance are imperative to the functionality of the post-construction stormwater
management systems.
APPENDIX A – SITE LOCATION MAP
SITE
USGS QUAD MAP
HYANNIS, MA
Scale: 1"=1000'
APPENDIX B – FEMA FIRM
National Flood Hazard Layer FIRMette
0 500 1,000 1,500 2,000250
Feet
Ü
SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
SPECIAL FLOOD
HAZARD AREAS
Without Base Flood Elevation (BFE)
Zone A, V, A99
With BFE or DepthZone AE, AO, AH, VE, AR
Regulatory Floodway
0.2% Annual Chance Flood Hazard, Areas
of 1% annual chance flood with average
depth less than one foot or with drainage
areas of less than one square mileZone X
Future Conditions 1% Annual
Chance Flood HazardZone X
Area with Reduced Flood Risk due to
Levee. See Notes.Zone X
Area with Flood Risk due to LeveeZone D
NO SCREEN Area of Minimal Flood Hazard Zone X
Area of Undetermined Flood HazardZone D
Channel, Culvert, or Storm Sewer
Levee, Dike, or Floodwall
Cross Sections with 1% Annual Chance
17.5 Water Surface Elevation
Coastal Transect
Coastal Transect Baseline
Profile Baseline
Hydrographic Feature
Base Flood Elevation Line (BFE)
Effective LOMRs
Limit of Study
Jurisdiction Boundary
Digital Data Available
No Digital Data Available
Unmapped
This map complies with FEMA's standards for the use of
digital flood maps if it is not void as described below.
The basemap shown complies with FEMA's basemap
accuracy standards
The flood hazard information is derived directly from the
authoritative NFHL web services provided by FEMA. This map
was exported on 9/19/2022 at 3:24 PM and does not
reflect changes or amendments subsequent to this date and
time. The NFHL and effective information may change or
become superseded by new data over time.
This map image is void if the one or more of the following map
elements do not appear: basemap imagery, flood zone labels,
legend, scale bar, map creation date, community identifiers,
FIRM panel number, and FIRM effective date. Map images for
unmapped and unmodernized areas cannot be used for
regulatory purposes.
Legend
OTHER AREAS OF
FLOOD HAZARD
OTHER AREAS
GENERAL
STRUCTURES
OTHER
FEATURES
MAP PANELS
8
B 20.2
The pin displayed on the map is an approximate
point selected by the user and does not represent
an authoritative property location.
1:6,000
70°21'19"W 41°41'23"N
70°20'42"W 41°40'56"N
Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020
APPENDIX C – SOIL DATA
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Barnstable County,
Massachusetts
QP700 - West Barnstable
Natural
Resources
Conservation
Service
October 11, 2022
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................8
Soil Map (QP700 - West Barnstable)...................................................................9
Legend................................................................................................................10
Map Unit Legend (QP700 - West Barnstable)....................................................11
Map Unit Descriptions (QP700 - West Barnstable).............................................11
Barnstable County, Massachusetts.................................................................13
483C—Plymouth-Barnstable complex, rolling, very bouldery.....................13
483D—Plymouth-Barnstable complex, hilly, very bouldery.........................15
494C—Barnstable-Plymouth-Nantucket complex, rolling, very bouldery....17
Soil Information for All Uses...............................................................................20
Soil Properties and Qualities..............................................................................20
Soil Qualities and Features.............................................................................20
Hydrologic Soil Group (QP700 - West Barnstable).....................................20
References............................................................................................................25
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
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6
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
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7
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8
9
Custom Soil Resource Report
Soil Map (QP700 - West Barnstable)461566046157104615760461581046158604615910461596046160104616060461566046157104615760461581046158604615910461596046160104616060387500 387550 387600 387650 387700 387750 387800
387500 387550 387600 387650 387700 387750 387800
41° 41' 18'' N 70° 21' 6'' W41° 41' 18'' N70° 20' 52'' W41° 41' 4'' N
70° 21' 6'' W41° 41' 4'' N
70° 20' 52'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 19N WGS84
0 100 200 400 600Feet
0 30 60 120 180Meters
Map Scale: 1:2,100 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:25,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Barnstable County, Massachusetts
Survey Area Data: Version 19, Sep 9, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Sep 5, 2020—Sep 7,
2020
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
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Map Unit Legend (QP700 - West
Barnstable)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
483C Plymouth-Barnstable complex,
rolling, very bouldery
3.8 30.1%
483D Plymouth-Barnstable complex,
hilly, very bouldery
7.2 56.8%
494C Barnstable-Plymouth-Nantucket
complex, rolling, very
bouldery
1.7 13.2%
Totals for Area of Interest 12.7 100.0%
Map Unit Descriptions (QP700 - West
Barnstable)
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
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The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
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Barnstable County, Massachusetts
483C—Plymouth-Barnstable complex, rolling, very bouldery
Map Unit Setting
National map unit symbol: 98rz
Elevation: 0 to 1,000 feet
Mean annual precipitation: 40 to 50 inches
Mean annual air temperature: 45 to 55 degrees F
Frost-free period: 140 to 240 days
Farmland classification: Not prime farmland
Map Unit Composition
Plymouth and similar soils:55 percent
Barnstable and similar soils:20 percent
Minor components:25 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Plymouth
Setting
Landform:Moraines
Landform position (two-dimensional):Shoulder
Landform position (three-dimensional):Side slope
Down-slope shape:Convex
Across-slope shape:Convex
Parent material:Loose sandy glaciofluvial deposits and/or loose sandy ablation till;
loose sandy glaciofluvial deposits and/or loose sandy ablation till
Typical profile
H1 - 0 to 3 inches: loamy coarse sand
H2 - 3 to 29 inches: gravelly loamy coarse sand
H3 - 29 to 64 inches: gravelly coarse sand
Properties and qualities
Slope:8 to 15 percent
Surface area covered with cobbles, stones or boulders:2.0 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Excessively drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat):High to very high (6.00
to 20.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Available water supply, 0 to 60 inches: Low (about 3.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6s
Hydrologic Soil Group: A
Ecological site: F149BY005MA - Dry Outwash
Hydric soil rating: No
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Description of Barnstable
Setting
Landform:Moraines
Landform position (two-dimensional):Shoulder
Landform position (three-dimensional):Side slope
Down-slope shape:Convex
Across-slope shape:Convex
Parent material:Friable loamy ablation till over reworked sandy glaciofluvial
deposits; loamy ablation till over reworked sandy outwash
Typical profile
H1 - 0 to 1 inches: sandy loam
H2 - 1 to 23 inches: sandy loam
H3 - 23 to 64 inches: coarse sand
Properties and qualities
Slope:8 to 15 percent
Surface area covered with cobbles, stones or boulders:1.6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00
in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Available water supply, 0 to 60 inches: Low (about 4.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6s
Hydrologic Soil Group: A
Ecological site: F149BY011MA - Well Drained Till Uplands
Hydric soil rating: No
Minor Components
Hinckley
Percent of map unit:10 percent
Hydric soil rating: No
Carver
Percent of map unit:10 percent
Hydric soil rating: No
Nantucket
Percent of map unit:5 percent
Hydric soil rating: No
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483D—Plymouth-Barnstable complex, hilly, very bouldery
Map Unit Setting
National map unit symbol: 98s0
Elevation: 0 to 1,000 feet
Mean annual precipitation: 40 to 50 inches
Mean annual air temperature: 45 to 55 degrees F
Frost-free period: 140 to 240 days
Farmland classification: Not prime farmland
Map Unit Composition
Plymouth and similar soils:55 percent
Barnstable and similar soils:20 percent
Minor components:25 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Plymouth
Setting
Landform:Moraines
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Side slope
Down-slope shape:Linear
Across-slope shape:Convex
Parent material:Loose sandy glaciofluvial deposits and/or loose sandy ablation till;
loose sandy glaciofluvial deposits and/or loose sandy ablation till
Typical profile
H1 - 0 to 3 inches: loamy coarse sand
H2 - 3 to 29 inches: gravelly loamy coarse sand
H3 - 29 to 64 inches: gravelly coarse sand
Properties and qualities
Slope:15 to 25 percent
Surface area covered with cobbles, stones or boulders:2.0 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Excessively drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat):High to very high (6.00
to 20.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Available water supply, 0 to 60 inches: Low (about 3.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6s
Hydrologic Soil Group: A
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Ecological site: F149BY005MA - Dry Outwash
Hydric soil rating: No
Description of Barnstable
Setting
Landform:Moraines
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Side slope
Down-slope shape:Linear
Across-slope shape:Convex
Parent material:Friable loamy ablation till over reworked sandy glaciofluvial
deposits; loamy ablation till over reworked sandy outwash
Typical profile
H1 - 0 to 1 inches: sandy loam
H2 - 1 to 23 inches: sandy loam
H3 - 23 to 64 inches: coarse sand
Properties and qualities
Slope:15 to 25 percent
Surface area covered with cobbles, stones or boulders:1.6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00
in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Available water supply, 0 to 60 inches: Low (about 4.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6s
Hydrologic Soil Group: A
Ecological site: F149BY011MA - Well Drained Till Uplands
Hydric soil rating: No
Minor Components
Carver
Percent of map unit:10 percent
Hydric soil rating: No
Hinckley
Percent of map unit:10 percent
Hydric soil rating: No
Nantucket
Percent of map unit:5 percent
Hydric soil rating: No
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494C—Barnstable-Plymouth-Nantucket complex, rolling, very bouldery
Map Unit Setting
National map unit symbol: 98q2
Elevation: 0 to 1,000 feet
Mean annual precipitation: 40 to 50 inches
Mean annual air temperature: 45 to 55 degrees F
Frost-free period: 140 to 240 days
Farmland classification: Not prime farmland
Map Unit Composition
Barnstable and similar soils:35 percent
Plymouth and similar soils:30 percent
Nantucket and similar soils:20 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Barnstable
Setting
Landform:Moraines
Landform position (two-dimensional):Shoulder
Landform position (three-dimensional):Side slope
Down-slope shape:Convex
Across-slope shape:Convex
Parent material:Friable loamy ablation till over reworked sandy glaciofluvial
deposits; loamy ablation till over reworked sandy outwash
Typical profile
H1 - 0 to 1 inches: sandy loam
H2 - 1 to 23 inches: sandy loam
H3 - 23 to 64 inches: coarse sand
Properties and qualities
Slope:8 to 15 percent
Surface area covered with cobbles, stones or boulders:2.0 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00
in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Available water supply, 0 to 60 inches: Low (about 4.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6s
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Hydrologic Soil Group: A
Ecological site: F149BY011MA - Well Drained Till Uplands
Hydric soil rating: No
Description of Plymouth
Setting
Landform:Moraines
Landform position (two-dimensional):Shoulder
Landform position (three-dimensional):Side slope
Down-slope shape:Convex
Across-slope shape:Convex
Parent material:Loose sandy glaciofluvial deposits and/or loose sandy ablation till
Typical profile
H1 - 0 to 3 inches: loamy coarse sand
H2 - 3 to 29 inches: gravelly loamy coarse sand
H3 - 29 to 64 inches: gravelly coarse sand
Properties and qualities
Slope:8 to 15 percent
Surface area covered with cobbles, stones or boulders:1.6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Excessively drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):High to very high (6.00
to 20.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Available water supply, 0 to 60 inches: Low (about 3.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6s
Hydrologic Soil Group: A
Ecological site: F149BY005MA - Dry Outwash
Hydric soil rating: No
Description of Nantucket
Setting
Landform:Moraines
Landform position (two-dimensional):Shoulder
Landform position (three-dimensional):Side slope
Down-slope shape:Convex
Across-slope shape:Convex
Parent material:Friable coarse-loamy eolian deposits over dense loamy lodgment
till
Typical profile
H1 - 0 to 5 inches: sandy loam
H2 - 5 to 27 inches: sandy loam
H3 - 27 to 64 inches: loam
Properties and qualities
Slope:8 to 15 percent
Surface area covered with cobbles, stones or boulders:1.6 percent
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Depth to restrictive feature:20 to 34 inches to densic material
Drainage class:Well drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat):Moderately low to
moderately high (0.06 to 0.60 in/hr)
Depth to water table:About 24 to 30 inches
Frequency of flooding:None
Frequency of ponding:None
Available water supply, 0 to 60 inches: Low (about 3.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 7s
Hydrologic Soil Group: B
Ecological site: F149BY009MA - Well Drained Dense Till Uplands
Hydric soil rating: No
Minor Components
Boxford
Percent of map unit:5 percent
Hydric soil rating: No
Carver
Percent of map unit:5 percent
Hydric soil rating: No
Merrimac
Percent of map unit:3 percent
Hydric soil rating: No
Hinckley
Percent of map unit:2 percent
Hydric soil rating: No
Custom Soil Resource Report
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Soil Information for All Uses
Soil Properties and Qualities
The Soil Properties and Qualities section includes various soil properties and
qualities displayed as thematic maps with a summary table for the soil map units in
the selected area of interest. A single value or rating for each map unit is generated
by aggregating the interpretive ratings of individual map unit components. This
aggregation process is defined for each property or quality.
Soil Qualities and Features
Soil qualities are behavior and performance attributes that are not directly
measured, but are inferred from observations of dynamic conditions and from soil
properties. Example soil qualities include natural drainage, and frost action. Soil
features are attributes that are not directly part of the soil. Example soil features
include slope and depth to restrictive layer. These features can greatly impact the
use and management of the soil.
Hydrologic Soil Group (QP700 - West Barnstable)
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
20
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer at
or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Custom Soil Resource Report
21
22
Custom Soil Resource Report
Map—Hydrologic Soil Group (QP700 - West Barnstable)461566046157104615760461581046158604615910461596046160104616060461566046157104615760461581046158604615910461596046160104616060387500 387550 387600 387650 387700 387750 387800
387500 387550 387600 387650 387700 387750 387800
41° 41' 18'' N 70° 21' 6'' W41° 41' 18'' N70° 20' 52'' W41° 41' 4'' N
70° 21' 6'' W41° 41' 4'' N
70° 20' 52'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 19N WGS84
0 100 200 400 600Feet
0 30 60 120 180Meters
Map Scale: 1:2,100 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:25,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Barnstable County, Massachusetts
Survey Area Data: Version 19, Sep 9, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Sep 5, 2020—Sep 7,
2020
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
23
Table—Hydrologic Soil Group (QP700 - West Barnstable)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
483C Plymouth-Barnstable
complex, rolling, very
bouldery
A 3.8 30.1%
483D Plymouth-Barnstable
complex, hilly, very
bouldery
A 7.2 56.8%
494C Barnstable-Plymouth-
Nantucket complex,
rolling, very bouldery
A 1.7 13.2%
Totals for Area of Interest 12.7 100.0%
Rating Options—Hydrologic Soil Group (QP700 - West
Barnstable)
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
24
References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
25
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
26
www.haleyaldrich.com
REPORT ON
EVERSOURCE QP700 PROJECT
STATION 921 ADDITIONS
661 OAK STREET, WEST BARNSTABLE, MASSACHUSETTS
by
Haley & Aldrich, Inc.
Rocky Hill, Connecticut
for
Eversource Energy
c/o Burns & McDonnell
File No. 0206317‐000‐01
December 2022
Revised February 2023
HALEY & ALDRICH, INC.
100 Corporate Place Suite 105
Rocky Hill, CT 06067 860.282.9400
www.haleyaldrich.com
Revised 24 February 2023
Revised 23 December 2022
21 November 2022
File No. 0206317‐000‐01
Burns & McDonnell
10 N. Park Place, Suite 330
Morristown, NJ 07960
Attention: John Troiano, Project Manager
Subject: Eversource QP700 Project – Station 921 Additions
661 Oak Street
West Barnstable, Massachusetts
Ladies and Gentlemen:
This report presents geotechnical engineering recommendations for the proposed additions and
alterations at the existing Eversource Station 921 in West Barnstable, Massachusetts. The work is part
of the larger QP700 Project, also known as the Mid‐Cape Solution Project. This report has been updated
based on design drawings received from Burns & McDonnell on 16 February 2023.
The data included in this report are based on subsurface explorations performed at the project site for
the proposed additions. The substation is along the existing Eversource 115‐kV Transmission Line Right‐
Of‐Way. This report includes recommendations for support of proposed structures and considerations
for construction.
Sincerely yours,
HALEY & ALDRICH, INC.
Jennifer N. Buchanon, P.E.*
Sr. Project Manager
*P.E. in CT & NY
John G. DiGenova, P.E.
Technical Expert
Timothy Crowl, P.E.
Program Manager
*P.E. in CT, NY & VA
Enclosures
\\haleyaldrich.com\share\CF\Projects\0206317\Deliverable\01_West Barnstable\2022‐1214_HAI‐R‐Sta 921 West Barnstable‐QP700 Project Geotechnical
Report_rev2 2023‐0224.docx
TABLE OF CONTENTS
Page
_Toc128131365
List of Tables v
List of Figures v
1. Introduction 6
1.1 PROJECT DESCRIPTION 6
1.2 PURPOSE AND SCOPE 2
1.3 ELEVATION DATUM 2
1.4 LIMITATIONS 2
2. Site & Subsurface Conditions 3
2.1 GENERAL 3
2.2 VACUUM EXCAVATION 3
2.3 TEST BORINGS 3
2.4 SUBSURFACE CONDITIONS 4
2.4.1 Soil 4
2.4.2 Groundwater 5
3. Field & Laboratory Testing Program 6
GEOTECHNICAL LABORATORY TESTING 6
FIELD RESISTIVITY TESTING 6
FIELD INFILTRATION TESTING 6
LABORATORY THERMAL RESISTIVITY TESTING 6
4. Geotechnical Engineering Recommendations 7
4.1 FOUNDATION DESIGN 7
4.1.1 Foundation Type 7
4.1.2 Foundation Design Criteria – Control House 8
4.1.3 Foundation Design Criteria – GIS Pad 8
4.1.4 Foundation Design Criteria – Pad‐Mounted Equipment 9
4.1.5 Settlement 9
4.1.6 Seismic Design 9
4.1.7 Retaining Walls 9
4.1.8 Permanent Soil Slopes 11
4.2 BACKFILL MATERIALS 11
4.2.1 Compacted Granular Fill 11
4.2.2 Crushed Stone Fill 12
4.2.3 Geotextile 12
4.2.4 Impervious Fill 12
4.2.5 Common Fill 12
4.2.6 Compaction 13
iv
4.3 USE OF ON‐SITE EXCAVATED SOIL 13
5. Construction Considerations 14
5.1 GENERAL 14
5.2 EXCAVATION AND TEMPORARY LATERAL SUPPORT 14
5.3 FOUNDATION CONSTRUCTION 14
5.3.1 Drilled Shafts 14
5.3.2 Shallow Foundation Bearing Surfaces 15
5.4 DEWATERING 15
5.6 EARTHWORK DURING FREEZING WEATHER 15
5.7 FINAL DESIGN REQUIREMENTS 16
Tables
Figures
Appendix A – Test Boring Logs
Appendix B – Geotechnical Laboratory Test Results
Appendix C – Field Resistivity Results
Appendix D – Thermal Laboratory Test Results
List of Tables
Table No. Title
I Summary of Subsurface Explorations
II Geotechnical Parameters for Foundation Design
III Seismic Design Parameters
List of Figures
Figure No. Title
1 Project Locus
2 Exploration Location Plan
1. Introduction
1.1 PROJECT DESCRIPTION
Eversource plans to upgrade the existing Station 921 substation in West Barnstable, Massachusetts. To
support Burns & McDonnell’s engineering design for the project, Haley & Aldrich performed subsurface
investigations and field testing to provide the engineering data necessary to design the project.
Our understanding of the project is based on the information included in the Scope of Work document
for “Subsurface Investigation and Geotechnical Report, West Barnstable Substation, Barnstable,
Massachusetts,” dated 12 July 2022 and the following drawings provided by Burns & McDonnell on 16
February 2023:
Drawing 921‐6200 “West Barnstable Station Foundation Location Plan,” Revision B dated 30
January 2023;
Drawing 921‐6102 “West Barnstable 345kV Station Grading & Drainage Plan,” Revision A dated
December 2022;
Drawing 921‐6036 “West Barnstable 345/115kV – Pad, Pier & Slab Fdn’s w/Anchor Bolts,”
Revision B dated 30 January 2023;
Drawing 921‐6037 “West Barnstable Station Firewall Foundation Details,” Revision B dated 30
January 2023;
Drawing 921‐6038 “West Barnstable Station 345kV Auto Transformer and Oil Containment,”
Revision B dated 30 January 2023; and,
“West Barnstable Station 920 & 921 QP700 Vineyard Wind Interconnect Existing Conditions
Survey,” prepared by SGC Engineering, LLC dated 21 October 2022
The project consists of expanding the substation with new equipment, including a new 345kV Gas
Insulated Switchgear (GIS) and supporting breakers, Control House, 345kV underground transmission
line connections, and associated equipment in a new yard area to be constructed at the northeast
corner of the existing station. Upgrades to the existing substation include a new transformer, relay &
control equipment, and overhead connections to the new substation area. Additionally, new overhead
transmission line structures will be installed as riser structures to support the underground/overhead
transition from the planned new underground 345kV line entering the substation from the south.
Based on the current grading plan, finish yard elevation for the GIS area is at El. 153, approximately at
grade with the existing Station 921. Existing ground surface elevations within the proposed GIS area
range from El. 149 to El. 174. To accommodate the change in grade required to make a level pad area at
El. 153, two retaining walls are planned. A fill retaining wall will support a 3 to 14 ft grade raise on the
northwest side of the GIS pad area. At the east end of the fill retaining wall there is an approximately 80‐
ft long break before the grading at the site transitions to a cut. This area is planned as an approximately
2.5H:1V soil slope. Beginning at the north end of the GIS pad area and continuing around the east and
south sides, the second retaining wall will support a cut of up to 20 ft.
The site location is shown on the Project Locus, Figure 1.
1.2 PURPOSE AND SCOPE
This report has been prepared for specific application to the Station 921 project and presents subsurface
data and engineering design recommendations based on the information collected from subsurface
explorations performed at the substation.
The scope of work was defined in the document referenced above. The work was performed in general
accordance with the specifications.
The scope of our work included the following:
Planning and monitoring a geotechnical subsurface exploration program;
Performing field testing, tabulating, and analyzing the data;
Laboratory geotechnical and thermal resistivity testing;
Developing geotechnical engineering recommendations based on engineering evaluations; and,
Summarizing our subsurface explorations, engineering evaluations, and recommendations in
this report.
1.3 ELEVATION DATUM
Elevations in this report are in feet and refer to the North American Vertical Datum (NAVD) 1988 vertical
datum. Elevations referenced in this report were interpolated from the existing conditions survey for
West Barnstable Station 920 & 921, prepared by SGC Engineering, LLC, dated 21 October 2022. .
1.4 LIMITATIONS
This report has been prepared for specific application to the Eversource Station 921 project as it is
currently planned. In the event that changes in the nature, design, or location of proposed construction
occurs, the information contained in this report should not be considered valid unless the changes are
reviewed, and this report modified or verified in writing. The information presented in this report is
based upon data obtained from referenced explorations. The nature and extent of variations between
the explorations may not become evident until construction. If variations then appear evident, it will be
necessary to reevaluate the recommendations of this report. This report is prepared for the exclusive
use of the design team in connection with the geotechnical aspects of the project.
The data provided in this report are based solely on the scope of work conducted by Haley & Aldrich and
the sources of information referenced herein. This work was undertaken in accordance with generally
accepted geotechnical engineering practices.
Our work scope did not include an assessment of the presence of oil or hazardous materials at the site,
the characterization of excavated soil or groundwater that may be generated as a result of planned
construction activity, or evaluation of the need to prevent migration of contaminated vapors into nearby
structures.
Our work scope did not include the development of criteria or procedures to minimize the risk of mold
or other biological pollutant infestations in or near any structure.
2. Site & Subsurface Conditions
2.1 GENERAL
Station 921 is located on the south side of Oak Street in West Barnstable, Cape Cod, Massachusetts. The
substation is oriented north‐south, perpendicular to the existing 115‐kV and 23‐kV overhead
transmission lines that pass just north of the site. The substation provides switchgear to distribute the
115‐kV power south and east to the greater Cape Cod area. The substation consists of two enclosed
areas. The northern enclosure contains a control house and switchgear for the incoming 23‐kV overhead
lines. The southern enclosure contains a control house, an autotransformer, switch gear, breakers, and
other supporting equipment to transition the incoming 115‐kV overhead lines.
The site is bounded by a small wetland area preceding Oak Street to the west, a densely wooded area to
the east, residential properties to the north, and Route 6 (Mid‐Cape Highway) to the south.
The existing substation site is relatively flat at approximately El. 152 to El. 153. Ground surface slopes up
at about 2H:1V to the wooded area to the east, which is the site of the planned substation expansion.
This area is generally 10 to 20 ft higher in elevation than the existing station. Beyond the substation
limits to the south, ground surface slopes gently up towards Route 6.
Boulders 2 to 6 ft diameter are scattered around the ground surface and were encountered at depth in
some of the test borings. Around test borings B6 and B7 (southern area of the proposed GIS pad)
numerous boulders are visible at the ground surface. After six attempts to advance test boring B6
beyond boulders at 5 to 6 ft below ground surface, the boring could not be completed. Test boring B14
was offset five times due to boulders encountered at a similar 5 ft depth below ground surface.
2.2 VACUUM EXCAVATION
On 21 October 2022, Moran Environmental Recovery, Randolph, Massachusetts, vacuum excavated the
upper 6 ft of soil at test borings B1, B2, B12, B13, and UG‐9 which are all located either within the
existing substation yard or near a known underground electric duct bank. Test borings were drilled at
the cleared location after vacuum excavation was completed.
2.3 TEST BORINGS
Nineteen test borings (B1, B2, B4 to B16, OH/UG‐6, OH/UG‐7, and UG‐9) were drilled at the site
between 3 and 21 October 2022 and between 7 and 10 November 2022 at the locations shown on
Figure 2. Due to proximity to nearby boring locations and limitations for test boring access inside the
existing substation, test boring B‐3 was eliminated from the subsurface investigation program. The
explorations were advanced using an ATV‐mounted or truck‐mounted drill rig to depths between 22 and
72 ft below ground surface. The borings were drilled by Seaboard Drilling, Inc., Chicopee, Massachusetts
and Terracon Consultants, Inc., Manchester, New Hampshire.
The test borings were advanced by standard hollow stem auger (HSA) drilling techniques using 4.25‐in.
O.D. augers. Soil samples were obtained by driving a standard split‐spoon sampler (1‐3/8‐in. I.D., 2 in.
O.D.) a distance of 24 in. under the impact of a 140‐lb hammer free‐falling 30 in. as specified in ASTM
D1586. The number of blows required to drive the sampler from 6 to 18 in. of sampling depth is
referred to as the SPT “N” Value (in units of blows per foot) and is used as an indicator of soil density or
consistency.
Borings indicated with lower case letters (i.e. “a, b”) were attempted several times due to refusal on
boulders before the boring was completed to the required depth.
Soil samples were classified according to the Unified Soil Classification System. Refer to Appendix A for
the test boring reports.
Approximate locations of the borings are shown on Figure 2. Boring locations were estimated by taping
from site features. Ground surface elevations at test borings were interpolated from the existing
conditions survey.
2.4 SUBSURFACE CONDITIONS
2.4.1 Soil
Subsurface conditions encountered at the explorations are described below. Refer to the Test Boring
Logs in Appendix A for detailed descriptions. Soil strata encountered in the explorations include crushed
stone fill (inside the station only), sandy fill, or topsoil and subsoil at the ground surface overlying glacial
deposits. These strata can generally be described as follows.
Crushed Stone – an approximately 6‐in. thick layer of ¾‐in. size crushed stone covers the ground
surface within the substation.
Topsoil – A thin 2 to 3‐in. thick topsoil layer was observed at borings B5, B8, B9, and B14 to B16.
Subsoil – Subsoil consisting of very loose to medium dense brown and yellow‐brown silty SAND
with gravel (SM), poorly‐graded SAND (SP), or silty SAND (SM). Subsoil was observed at borings
B5, B8 to B10, B14, and B16 directly below the topsoil.
Fill – At B1, B2, and B4, approximately 5 to 7 ft of fill was observed. The fill resembles the natural
material at the site, but appears to be re‐worked. Fill consists of loose to medium dense yellow‐
brown poorly‐graded SAND with gravel. Note B1 and B2 were vacuum‐excavated and the
thickness of fill at these locations is based on observations of the excavation sidewalls and
comparison to nearby borings, such as B4.
Glacial Stratified Deposits – Loose to very dense stratified poorly‐graded SAND (SP), well‐graded
SAND (SW), silty SAND with gravel (SM), silty SAND (SM), poorly‐graded SAND with silt (SP‐SM).
Gravel is present irregularly throughout the deposit. Boulders are common throughout this
deposit. At B14, the boring was offset five times due to refusal on boulders. At B6, the boring was
offset six times due to refusal on boulders at depths between 5 and 6 ft below ground surface.
After these attempts, the boring could not be advanced beyond the boulders in the area of B6.
2.4.2 Groundwater
Groundwater was not observed at any test borings. However, at borings B4, OH/UG‐6, and OH/UG‐7 a
possible perched water table was observed at approximately 15 to 35 ft below ground surface. These
borings are adjacent to the wetland area on the west side of the site.
Groundwater levels will fluctuate with season, precipitation, level in the nearby wetlands and
waterbodies, and nearby construction activity.
3.Field & Laboratory Testing Program
GEOTECHNICAL LABORATORY TESTING
The following geotechnical laboratory tests were performed on selected soil samples by Haley & Aldrich,
Inc.:
Grain Size Analysis – six samples (B5‐INF‐1, S3; B7, S5; B12, S3; B13, S2; OH/UG‐6, S5, and
OH/UG‐7, S6) were submitted for sieve analysis. Testing was performed in general accordance
with ASTM D422.
Percent Passing the #200 Sieve – 21 samples (B2, S5; B4, S10; B5, S5; B7, S7; B8, S8; B9, S5; B10,
S8; B11, S6; B12, 25; B13, S4 and S11; B14, S6; B15, S5; B16, S6 and S9; OH/UG‐6, S11 and S15;
and UG‐9, S3) were submitted for fines analysis. Testing was performed in general accordance
with ASTM D1140.
Laboratory test results have been incorporated on the test boring logs in Appendix A and sieve test
reports are in Appendix B.
FIELD RESISTIVITY TESTING
Field resistivity testing was completed at an off‐site location selected by Burns & McDonnell. The testing
was completed on 18 November 2022. Results of field resistivity testing are provided in Appendix C.
FIELD INFILTRATION TESTING
Groundwater was not encountered at any of the test borings. Based on conversations with the Burns &
McDonnell engineering team, a shallow (5 ft deep) well was installed at the preferred location of a
proposed underground stormwater system near B5. A second shallow well (B5‐a) was installed
approximately 5 ft east of this well on 10 November 2022. A third shallow well was installed at OH/UG‐6
on 7 November 2022. On 25 October and 11 November 2022, falling head in‐situ slug tests were
completed at these locations to estimate soil hydraulic conductivity.
The table below presents a summary of estimated hydraulic conductivity ranges for the natural soil
based on the results of field infiltration testing.
Location ID Estimated Hydraulic Conductivity (k, cm/sec)
Field Permeability Test
B5_INF‐1 1 x 10‐2
B5‐a_INF‐2 1 x 10‐3
OH/UG‐6_INF‐3 5 x 10‐3
LABORATORY THERMAL RESISTIVITY TESTING
Four samples (two from OH/UG‐6 and two from UG‐9) were submitted to Geotherm USA, Cypress, TX
for laboratory thermal resistivity testing. Results of thermal analysis are included in Appendix D.
4. Geotechnical Engineering Recommendations
4.1 FOUNDATION DESIGN
Table II provides parameters for use in LPile and/or MFAD to design drilled shaft foundations for
overhead structures at each boring, including ultimate end bearing and side friction values for design of
axial loading, and recommended criteria for lateral capacity for the soil conditions at Station 921. Note
that the values provided on Table II are ultimate, and a factor of safety was not applied to estimate the
end bearing and side friction capacities. We have assumed that foundation concrete having a minimum
compressive strength (fc’) of 4,000 pounds per square inch (psi) will be used for design.
Additional foundation design recommendations are also provided below based on the anticipated
foundation types for the planned structures.
4.1.1 Foundation Type
The following sections provide foundation design recommendations for proposed equipment, including
the transformer, GIS Pad, Control House, Firewalls, and miscellaneous pad‐mounted equipment.
For all foundations, the following general recommendations are provided:
Design foundations to bear on undisturbed Glacial Stratified or Moraine Deposits. Footings
bearing on these deposits could be designed for a maximum net allowable bearing pressure of 3
kips per square foot (ksf). Mats for station equipment (not including the GIS Pad) may be
designed using a coefficient of subgrade reaction of 20 pounds per cubic inch (pci).
Topsoil, Subsoil, and Fill are not suitable materials for foundation bearing and should be
removed (over‐excavated) within a 1H:1V splay below the foundation (bearing zone) if present
at the design foundation bearing level. Over‐excavations to remove these materials should be
backfilled with Compacted Granular Fill or with Crushed Stone placed over a filter fabric
separating the stone from the underlying natural soil.
The recommended allowable bearing pressure is for footings 3 ft or larger in width. For footings
smaller than 3 ft, the maximum net allowable bearing pressure should be proportionally
reduced by the ratio of the actual footing width to 3 ft.
Design for a minimum footing width of 18 in.
For loading combinations that include transient loads such as seismic and wind loads, the
maximum net allowable bearing pressure may be increased by 33 percent.
Locate foundations to bear below a 1.5:1V slope from the bottom of existing foundations, new
or existing utility pipes, pits, or other planned localized excavations.
Where possible, locate new footings to bear at the same level as existing or new adjacent
footings.
The design frost depth is 4 ft below adjacent final grades.
Refer to the construction considerations section for details regarding subgrade preparation for
foundations.
4.1.2 Foundation Design Criteria – Control House
We understand the Control House is a pre‐fabricated structure that is typically supported on small
diameter circular piers bearing a minimum of 4 ft below ground surface. The piers should be deepened
as necessary to extend through unsuitable soils and bear on Glacial Stratified or Moraine Deposits.
Alternately, if the piers are installed with an open excavation as described below, unsuitable soils may
be removed and replaced with Compacted Granular Fill.
We anticipate piers will be installed either as cast‐in‐place in pre‐augered holes or as pre‐cast or
concrete‐filled tubes placed in an open excavation and then backfilled. It may be difficult to keep pre‐
augered holes open and therefore concrete should be installed as soon as possible after excavation. A
temporary form could be used to keep the augered hole open before concrete is poured. For open cut
excavations, the concrete pier should be backfilled in lifts with Compacted Granular Fill.
Table II provides parameters for use in LPile and/or MFAD to analyze the standard pier support design
for the soil conditions at Station 921. The parameters in Table II apply to undisturbed soils encountered
in the borings. For piers designed as shallow foundations, the recommendations provided in Section
4.1.1 above should be used.
For piers installed as open‐cut and backfilled with Compacted Granular Fill (CGF), the following
parameters should be used for analysis of the pier in LPile and/or MFAD.
Total Unit Weight – 115 pcf
Effective Unit Weight (below ground water) – 52.6 pcf
Friction Angle – 30 degrees
Soil Modulus (k) Above Groundwater – 25 pci
Soil Modulus (k) Below Groundwater – 20 pci
Deformation Modulus (Ep) – 300 psi
Ultimate End Bearing – 6 ksf
4.1.3 Foundation Design Criteria – GIS Pad
We understand the GIS will be supported on a 3‐ft thick reinforced concrete mat with dimensions of
approximately 108 ft x 93 ft. Settlement tolerance is low for the pad, with maximum ½‐in. total and ¼‐
in. differential settlement recommended by GIS vendors. Although actual loads are not known at this
time, we understand the GIS equipment is relatively light. Based on the available information, the GIS
pad (without equipment) will apply a gross bearing pressure of approximately 0.5 kips per sq. foot (not
considering net effects of stress reduction from soil removed to construct the mat).
Unsuitable soils (existing fill, topsoil and subsoil) should be removed from the mat bearing zone until
undisturbed Glacial Stratified are encountered. Boulders found at the subgrade level should be
removed. Backfill overexcavations with crushed stone placed over geotextile fabric. Refer to Section 5
for details regarding subgrade preparation.
Design the mat using a coefficient of subgrade reaction of 10 pci. The mat should bear on a minimum
12‐in. thick layer of ¾‐in. size crushed stone, underlain by a geotextile fabric, placed over natural Glacial
Stratified Deposits. Stone should be placed to a minimum depth of 4 ft below finished grade for frost
protection. Refer to Section 5 for additional subgrade preparation recommendations.
4.1.4 Foundation Design Criteria – Pad‐Mounted Equipment
We understand general substation yard equipment is typically supported on concrete slabs bearing
directly on undisturbed soils. Placement of a minimum 6‐in. thick layer of ¾‐in. size crushed stone,
underlain by a geotextile fabric, would help to protect the subgrade prior to placing concrete for the
slab.
Unsuitable soils should be removed from the slab bearing zone until undisturbed Glacial Stratified or
Moraine Deposits are encountered. Backfill overexcavation with crushed stone. It is possible excavated
subsoil could be re‐used as compacted backfill below pad‐mounted equipment foundations provided
the equipment can withstand some frost heave. If equipment is sensitive to movement, then
recommendations provided above for the GIS Building mat should also be followed for pad‐mounted
equipment.
4.1.5 Settlement
Except as noted above for the GIS Pad, foundations designed for the recommended footing bearing
pressures are anticipated to settle 1 in. or less. Differential settlement between adjacent foundations is
estimated to be 0.5 in. or less. Most of the settlement will occur during construction as load is applied.
4.1.6 Seismic Design
Seismic design parameters were calculated in accordance with the 9th Edition of the State of
Massachusetts Building Code 780 CMR (MABC) and are shown on Table III. The site structural design
should address seismic design considerations, including distribution of forces at the foundation level.
The soils at the site do not appear to be liquefaction susceptible.
4.1.7 Retaining Walls
The foundation design criteria provided in Section 4.1.1 above should be applied to design of cast‐in‐
place concrete retaining walls.
If mechanically stabilized earth (MSE) walls are considered, they are typically founded at about 2 ft
below finish grade; however deeper embedment will be needed (for bearing capacity/global stability) if
there is a downhill slope at the base of the wall. The embedment depth will depend on the grading
plan, but might be on the order of 2 to 4 ft below ground surface at the base of the wall. Backfill type
behind MSE walls is typically specified by the wall vendor, but should be free‐draining and may have
similar properties to Compacted Granular Fill (refer to Section 4.2). The wall designer should consider
the location of equipment pads and possible future substation buildouts when designing MSE walls as
the geogrid reinforcement zone may conflict with future development.
At walls in cut areas, use of permanent soil nail walls with concrete facing may be considered provided
that there is sufficient space for soil nails to remain within the property limits. Easements may be
required where soil nails extend beyond the property line. Soil nails should be aligned to avoid damage
to existing buried utilities that may be located behind the wall.
Foundation wall drains are recommended. Drains should be installed to provide gravity flow of
accumulated water behind the wall. At cast‐in‐place concrete walls, the drains should be contained
within a stone layer, wrapped in filter fabric, and continuing up the full height of the wall. Cleanouts
should be included at intervals along the wall.
Based on the preliminary grading plan, fill retaining wall heights will be up to 14 ft and cut retaining wall
heights will be up to 20 ft. Final site grades will determine the required wall height.
4.1.7.1 Lateral Earth Pressures
Retaining walls may be designed using the following at‐rest, active, and seismic lateral earth pressures.
The recommended parameters assume the retaining wall is drained full height, backfill consists of
Compacted Granular Fill (properties provided in Section 4.1.2) or on‐site natural Glacial Deposits
(properties provided on Table 2), and there is no surcharge or inclination of the ground surface behind
wall.
At‐Rest Lateral Earth Pressure – Equivalent fluid unit weight equal to 60 pounds per square
foot (psf) per foot height of wall.
Active Lateral Earth Pressure – Equivalent fluid unit weight equal to 40 psf per foot height of
wall.
Seismic Lateral Earth Pressure – 3H2 pounds per lineal foot of wall (total force to be
distributed as an inverse triangle over the height of the wall, where H is the height of wall
measured as the difference in elevation of finished ground surface in front of and behind
the wall).
For seismic loading conditions, walls should be designed to resist static plus seismic earth pressures.
4.1.7.2 Passive Earth Pressure Resistance
We recommend ignoring passive earth pressure resistance in front of walls. Grade in front of the wall
can change over time, therefore the design thickness of soil fill in front of the wall providing the passive
resistance is not reliable long‐term. However, we understand the design team may elect to use passive
pressure resistance in stability calculations for sliding and overturning. We recommend including a long‐
term maintenance plan for walls designed using passive earth pressure resistance. The plan should
require scheduled inspection and maintenance of the backfill in front of the wall to maintain the design
assumptions.
If passive earth pressure resistance is included in the analysis, the net (passive minus active) lateral
resistance provided by the compacted fill placed in front of the wall can be estimated using an
equivalent fluid unit weight of 200 pcf. This value assumes that backfill within 5 ft laterally against the
wall is systematically compacted in lifts. The top of the assumed passive zone should be a minimum 2‐ft
below the top of the adjacent soil or backfill surface.
4.1.7.3 Resistance to Lateral Loads
For cast‐in‐place or pre‐cast concrete retaining walls, lateral loads may be resisted using a combination
of friction between footings bases and underlying soils. The resistance to lateral loads provided by
friction between footing concrete and underlying natural Glacial Deposits or CGF should be calculated
using a coefficient of friction (ultimate) equal to the following:
Cast‐in‐place concrete – 0.35
Pre‐cast concrete – 0.30
Such walls should be designed with a minimum factor of safety equal to 1.5 for both sliding and
overturning.
4.1.7.4 Global Stability
Note that the global stability of the selected wall system should be checked prior to construction.
Global stability check of the retaining wall system is beyond our current scope of services.
4.1.8 Permanent Soil Slopes
Permanent cut and fill slopes in glacial deposits should be 3H:1V, or flatter. Special slope protection
does not appear necessary. Permanent soil cut and fill slopes may be steepened to 2H:1V if covered by
riprap. Riprap could be made from bedrock obtained from local quarries and/or boulders and large
cobbles removed during site earthwork if a significant cut is planned to lower grade in the substation
expansion area. Slope areas should be evaluated for potential seepage breakout on a case by case basis
once the final grading plan has been completed.
4.2 BACKFILL MATERIALS
4.2.1 Compacted Granular Fill
Granular fill is recommended to backfill foundation excavations. Granular fill should be placed
in maximum 12‐in. thick lifts and compacted to at least 95 percent of the maximum dry density
determined by ASTM D1557. In confined areas, use maximum 6‐in. thick lifts. Compaction
equipment in confined areas may consist of hand‐guided vibratory equipment or mechanical
tampers. Granular fill should consist of sandy gravel or gravelly sand, free of organic material,
environmental contaminants, snow, ice, frozen soil, or other unsuitable material, and be well‐
graded within the following limits:
U.S. Standard
Sieve Size
Percent Finer
by Weight
6 in. * 100
No. 4 30‐80
No. 40 10‐50
No. 200 0‐8
*use a maximum 3‐in. size for fill placed within 6 in. of concrete slabs or footings
4.2.2 Crushed Stone Fill
Crushed Stone may be used below footings or mats as required to replace frost‐susceptible soils
or protect bearing surfaces. Crushed Stone should consist of No. 6 crushed stone (3/4‐in. size) in
accordance with Massachusetts Highway Department (MHD) Standard Specification Designation
M2.01.4. Where crushed stone is used it should be underlain by a non‐woven medium‐duty
geotextile filter. Crushed stone should be placed in maximum 12‐in. thick lifts compacted with at
least four coverages using heavy vibratory compaction equipment.
4.2.3 Geotextile
A filtration‐type geotextile is recommended between crushed stone and surrounding soil, which
allows for transmission of water while working to keep the crushed stone free from fine
particles. It should consist of Mirafi Construction Products 160N, or equivalent.
4.2.4 Impervious Fill
Impervious fill is recommended as the final 12 in. thickness of fill at ground surface above
foundation and retaining wall backfill. Impervious fill is not required where the area above the
foundation wall backfill has pavement or a floor slab. Impervious fill should consist of common
fill (see below) with a minimum 20 percent passing a No. 200 sieve. In general, the natural Glacial
Deposits found at the site are not suitable for use as impervious fill due to typically very low fines
content. However, near borings B8 and B9 the natural Glacial Deposits have higher fines content
and may be suitable for use as Impervious Fill. Based on the preliminary grading plan, these
materials will be excavated during earthwork to lower the site grade and could be available for
reuse on‐site as Impervious Fill.
4.2.5 Common Fill
Common Fill should consist of uncontaminated mineral sandy or gravelly soil, predominantly
free from clay, organic matter, plastic, metal, wood, ice, snow, debris or other deleterious
material and should have the characteristic that it can be readily placed and compacted.
Common Fill imported to the site should have a maximum of 80 percent passing the No. 40 sieve
and a maximum of 30 percent finer than the No. 200 sieve. The maximum particle size should
be the smaller of 2/3 the lift thickness or 6 in. Silty common fill soils will require moisture
control during placement and compaction. Natural Glacial Deposits found at the site are suitable
for use as common fill.
4.2.6 Compaction
Recommended compaction requirements are as follows:
Location Minimum Compaction Requirements
To Backfill
Excavations for Foundations, including
Excavations for Removal of Unsuitable Soils 95%
As final layer at ground surface 92%
Above foundation and retaining walls
(Impervious Fill )
Minimum compaction requirements refer to percentages of the maximum dry density
determined in accordance with ASTM D1557.
4.3 USE OF ON‐SITE EXCAVATED SOIL
Excavation is expected to be in crushed stone, topsoil, subsoil, fill, and glacial deposits. These materials
may be reused on‐site as needed for general site filling, but are generally not suitable for use as
Compacted Granular Fill (CGF). Oversize rocks, boulders, and cobbles (greater than 8‐in. dia. or greater
than 2/3 of the loose lift thickness) should be removed prior to reusing. It may be possible to reuse
natural glacial deposits as CGF, however careful control of moisture, protection of stockpiles (from
precipitation and freezing), and protection of compacted subgrades will be required as the glacial
deposits will be easily susceptible to disturbance once placed.
5. Construction Considerations
5.1 GENERAL
This section provides comments related to foundation construction, earthwork, and other geotechnical
aspects of the project. It will aid those responsible for the preparation of contract plans and
specifications and those involved with construction monitoring. Contractors must evaluate potential
construction problems based on their own knowledge and experience in the area and based on similar
localities, taking into account their own proposed construction methods and procedures.
5.2 EXCAVATION AND TEMPORARY LATERAL SUPPORT
Excavation for foundations is anticipated to be up to 20 ft deep and possibly deeper depending on the
final grading plan for the GIS Building addition area. Excavation will be in crushed stone, topsoil, subsoil,
fill, Glacial Stratified Deposits, and Moraine Deposits.
Excavation geometry should conform to OSHA excavation regulations contained in 29 CFR Part 1926,
latest revision. Temporary, dewatered soil slopes of 1.5H:1V appear appropriate but should be
confirmed during construction based on conditions at the time of excavation.
It appears that open cuts are feasible; however, care should be taken when excavating near existing
equipment pads and foundations. Excavation should not be performed below a 1.5H:1V zone beneath
existing foundations, cable trenches, and below‐grade utilities. If this geometry cannot be maintained,
underpinning or steel sheetpiles may be required to support the utility or foundation during the work. If
sheeting is utilized, adjacent structures must be monitored for movement and care should be exercised
by the Contractor since vibratory loads may induce settlement of these structures.
5.3 FOUNDATION CONSTRUCTION
5.3.1 Drilled Shafts
Drilled shaft foundations constructed for the new transmission towers will be advanced to bear in the
Moraine Deposits and Glacial Stratified Deposits.
Bedrock is not anticipated to be encountered; however, cobbles and boulders are expected to be
present at most locations. There may be instances where boulders may be encountered but not noted
on test boring logs as foundation diameters will be much larger than test boring diameters. The depths
and limits of boulders present beyond test boring limits are not known. Foundation contractors should
have the proper tools available to remove boulders as they are encountered. Foundations should not
bear partially on a boulder and partially on the adjacent ground.
Temporary casing and possibly drilling fluid may be required to maintain open drill holes in soils.
Running sands may be encountered where foundation excavations are advanced below the
groundwater table, and should be mitigated with drilling mud or other means as necessary.
It is anticipated that foundations will be advanced using a combination of augers and core barrels (used
to advance through boulders). Drilling through cobbles and boulders will result in foundation diameters
larger than those expected, and this should be considered when estimating concrete volumes.
5.3.2 Shallow Foundation Bearing Surfaces
Subgrades at excavations for foundations will consist of Glacial Stratified Deposits or Moraine Deposits.
Foundation subgrades should be compacted with at least four coverages using a vibratory plate
compactor with a minimum 5,000 lbs. dynamic force. Similar compaction should be performed on
subgrades prior to placing Compacted Granular fill or Crushed Stone where overexcavation is required. If
soft or unsuitable material is encountered at exposed subgrades, remove the unsuitable material, and
then backfill with Compacted Granular Fill or Crushed Stone until a firm and stable surface is achieved.
We recommend that excavation for footings be conducted in a manner that minimizes disturbance to
soil bearing surfaces. Preferably, final excavation should be made with equipment having a smooth‐
edged bucket. Care should be taken to prevent surface water from collecting on exposed soil bearing
surfaces. Worker and equipment traffic on earing surfaces should be minimized.
In the event that a boulder becomes partially exposed at the footing bearing level, one of the following
options should be utilized: 1) remove the boulder, and fill the void with lean concrete, or 2) remove a
portion of the boulder sufficient to provide placement of 6 in. of ¾‐in. size crushed stone beneath the
footing over the boulder. Each such encounter should be resolved individually in the field.
The glacial soils will be easily softened and susceptible to disturbance from construction activities when
wet. To avoid this disturbance, the contractor should form and pour concrete for footings on the same
day as excavation. If this is not possible, bearing surfaces should be protected by a minimum 6‐in.
thickness of compacted Crushed Stone over a geotextile filter.
5.4 DEWATERING
Final excavation, subgrade preparation, filling, foundation construction, and utility construction should
be conducted "in the dry". Excavation for shallow foundations and buried utilities is not anticipated to
extend below groundwater level. Construction dewatering to control accumulation of precipitation and
surface water runoff into excavations may be required. Filtered sumps appear feasible for dewatering
excavations.
5.6 EARTHWORK DURING FREEZING WEATHER
Precautions should be taken if work takes place while temperatures are below freezing. Frozen soil or
soil containing snow or ice should not be used as compacted fill. Placement of fill should not be
conducted when air temperatures are below freezing. Soil bearing surfaces below foundations must be
protected against freezing, before and after placement of concrete. Frost protection should be provided
as soon as possible after foundations are constructed.
Fill should not be placed on snow, ice, or frozen subgrades. At the end of each day's operations, the last
lift of placed fill should be rolled by a smooth‐wheeled roller to eliminate ridges of uncompacted soil to
aid runoff and drainage.
5.7 FINAL DESIGN REQUIREMENTS
The results of the subsurface investigation discussed in this report and the recommendations provided
herein need to be reviewed and revised as necessary based on the final site layout. Detailed
geotechnical criteria (e.g. drainage systems, retaining walls, construction considerations, and other
geotechnical related items) may change based on the final proposed site design.
HALEY & ALDRICH, INC.
Page 1 of 1
TABLE 1
SUMMARY OF SUBSURFACE EXPLORATIONS
EVERSOURCE QP700 PROJECT ‐ STATION 921 ADDITIONS
WEST BARNSTABLE, MASSACHUSETTS
B1 152 32.0 0.5 ‐‐‐‐7> 24.5 ‐‐‐‐
B2 152 47.5 0.5 ‐‐‐‐7> 40 ‐‐‐‐
B4 152 47.0 ‐‐‐‐‐‐5> 42.0 15.0 137.0
B5 164 49.0 ‐‐0.2 3.8 ‐‐> 45.0 ‐‐‐‐
B6‐a‐b‐c‐d‐e 160 5.0 ‐‐0.5 ‐‐‐‐> 5.5 ‐‐‐‐
B7 174 32.0 ‐‐0.5 ‐‐‐‐>31.5 ‐‐‐‐
B8 172 32.0 ‐‐0.3 6.7 ‐‐> 25.0 ‐‐‐‐
B9 169 32.0 ‐‐0.2 4.8 ‐‐> 27.0 ‐‐‐‐
B10 148 32.0 ‐‐‐‐2 ‐‐> 30.0 ‐‐‐‐
B11 140 32.0 ‐‐‐‐‐‐‐‐> 32.0 ‐‐‐‐
B12 148 32.0 ‐‐‐‐‐‐‐‐> 32.0 ‐‐‐‐
B13 150 72.0 ‐‐‐‐‐‐‐‐> 72.0 ‐‐‐‐
B14‐a‐b‐c‐d 169 50.0 ‐‐0.2 4.8 ‐‐> 45.0 ‐‐‐‐
B15 168 50.0 ‐‐0.2 ‐‐‐‐> 49.8 ‐‐‐‐
B16 150 50.0 ‐‐0.3 5.7 ‐‐> 44.0 ‐‐‐‐
OH/UG‐6 140 72.0 ‐‐0.5 ‐‐‐‐> 71.5 35.0 105.0
OH/UG‐7 147 72.0 ‐‐0.5 ‐‐‐‐> 71.5 23.0 124.0
UG‐9 140 22.0 ‐‐‐‐‐‐‐‐> 22.0 ‐‐‐‐
NOTES:
1. "‐‐" indicates not encountered or not known
">" indicates greater than (strata not penetrated)
2. Elevations are in feet and reference NAVD88.
3. Ground surface elevations for explorations were estimated from the survey plan titled "West Barnstable Station 920 & 921, QL700 Vineyard
Wind Interconnect, Existing Conditions Survey, Barnstable, Massachusetts", prepared by SGC Engineering, LLC, dated 21 October 2022.
4. Groundwater observed at B4, OH/UG‐6, and OH/UG‐7 appears to be perched and related to the nearby wetland.
WATER LEVEL (FT)
DEPTH (FT) ELEV. (FT)
EXPLORATION
IDENTIFICATION
TOTAL
DEPTH
(FT)
THICKNESS OF STRATA (FT)
GRAVEL
ESTIMATED
GROUND
SURFACE
ELEVATION (FT)
GLACIAL STRATIFIED
DEPOSITSFILLSUBSOILTOPSOIL
12/14/2022
HALEY & ALDRICH, INC.TABLE IIGEOTECHNICAL PARAMETERS FOR FOUNDATION DESIGNEVERSOURCE QP700 PROJECT ‐ STATION 921 ADDITIONSWEST BARNSTABLE, MASSACHUSETTSBoring NumberB1 B2 B3 B4 B5 B6-a-b-c-d-e B7 B8 B9 B10 B11 B12G.S. Elevation152 152 152 164 160 174 172 169 148 140 148Recommended Design Water Level (ft)20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0Depth of Layer 1 (ft)0.0-7.0 0.0-7.0 0.0-5.0 0.0-4.0 0.0-2.0 0.0-20.0 0.0-7.0 0.0-2.0 0.0-2.0 0.0-2.0 0.0-32.0Soil/Rock Layer 1VACUUM EXCAVATEDVACUUM EXCAVATEDNOT USED Loose Fill SubsoilGlacial Stratified LooseGlacial Stratified LooseSubsoil Subsoil SubsoilGlacial Stratified LooseGlacial Stratified MDTotal Unit Weight (pcf) 110 110 -- 110 115 120 120 115 115 115 120 120Effective Unit Weight (pcf) BGW 48 48 -- 48 53 58 58 53 53 53 58 58Friction Angle (degrees) 28 28 -- 28 26 30 30 26 26 26 30 32Shear Strength (psf) 0 0 -- 0 0 0 0 0 0 0 0 0Soil-Modulus, k (pci) AGW2525--252525252525252560Soil-Modulus, k (pci) BGW2020--202020202020202040e50------------------------Rock Mass Modulus, Em (psi)-- -- -- -- -- -- -- -- -- -- -- --RQD (%)-- -- -- -- -- -- -- -- -- -- -- --UCS (psi)------------------------Ultimate Side Friction (tsf)----------0.500.50------0.501.00Ultimate End Bearing (tsf)----------3.003.00------3.005.00Depth of Layer 2 (ft)7.0-15.0 7.0-13.55.0-20.0 4.0-17.5 2.0-4.0 20.0-32.0 7.0-32.0 2.0-10.0 2.0-5.0 2.0-32.0Soil/Rock Layer 2Glacial Stratified LooseGlacial Stratified MDNOT USEDGlacial Stratified LooseGlacial Stratified MDGlacial Stratified MDGlacial Stratified MDGlacial Stratified MDGlacial Stratified LooseGlacial Stratified LooseGlacial Stratified MDNOT USEDTotal Unit Weight (pcf)120120--120120120120120120120120--Effective Unit Weight (pcf) BGW5858--5858585858585858--Friction Angle (degrees)3032--3032323232303032--Shear Strength (psf)00--00000000--Soil-Modulus, k (pci) AGW2560--2560606060252560--Soil-Modulus, k (pci) BGW2040--2040404040202040--e50------------------------Rock Mass Modulus, Em (psi)-- -- -- -- -- -- -- -- -- -- -- --RQD (%)-- -- -- -- -- -- -- -- -- -- -- --UCS (psi)------------------------Ultimate Side Friction (tsf)0.501.00--0.501.001.001.001.000.500.501.00--Ultimate End Bearing (tsf)3.005.00--3.005.005.005.005.003.003.005.00--Depth of Layer 3 (ft)15.0-23.5 13.5-30.020.0-25.0 17.5-39.0 4.0-6.010.0-32.0 5.0-32.0Soil/Rock Layer 3Glacial Stratified MDGlacial Stratified LooseNOT USEDGlacial Stratified MDGlacial Stratified LooseGlacial Stratified DenseNOT USED NOT USEDGlacial Stratified MDGlacial Stratified MDNOT USED NOT USEDTotal Unit Weight (pcf)120120--120120125----120120----Effective Unit Weight (pcf) BGW5858--585863----5858----Friction Angle (degrees)3230--323034----3232----Shear Strength (psf)00--000----00----Soil-Modulus, k (pci) AGW6025--6025225----6060----Soil-Modulus, k (pci) BGW4020--4020125----4040----e50------------------------Rock Mass Modulus, Em (psi)-- -- -- -- -- -- -- -- -- -- -- --RQD (%)-- -- -- -- -- -- -- -- -- -- -- --UCS (psi)------------------------Ultimate Side Friction (tsf)1.000.50--1.000.502.00----1.001.00----Ultimate End Bearing (tsf)5.003.00--5.003.0010.00----5.005.00----Depth of Layer 4 (ft)23.5-32.0 30.0-47.525.0-47.0 39.0-49.0Soil/Rock Layer 4Glacial Stratified LooseGlacial Stratified MDNOT USEDGlacial Stratified DenseGlacial Stratified MDNOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USEDTotal Unit Weight (pcf)120120--125120--------------Effective Unit Weight (pcf) BGW5858--6358--------------Friction Angle (degrees)3032--3432--------------Shear Strength (psf)00--00--------------Soil-Modulus, k (pci) AGW2560--22560--------------Soil-Modulus, k (pci) BGW2040--12540--------------e50------------------------Rock Mass Modulus, Em (psi)-- -- -- -- -- -- -- -- -- -- -- --RQD (%)-- -- -- -- -- -- -- -- -- -- -- --UCS (psi)------------------------Ultimate Side Friction (tsf)0.501.00--2.001.00--------------Ultimate End Bearing (tsf)3.005.00--10.005.00--------------Bottom of Exploration (ft)32.047.5--47.049.06.032.032.032.032.032.032.0Notes:1. Elevations are in feet and reference NAVD88. Elevations are estimated using Massachusetts Online GIS MassMapper. 2. The strata thicknesses and depths noted on this table are presented for use as input for the Lpile Program and some layers may include more than one stratum. Refer to logs of test borings for more detailed information regarding subsurface conditions. 3. Recommended design water level is based on measured depth to groundwater in the borehole, nearby surface water features, readings at nearby boreholes, topography, and soil conditions. Boring Removed from Program12/19/2022
HALEY & ALDRICH, INC.TABLE IIGEOTECHNICAL PARAMETERS FOR FOUNDATIONEVERSOURCE QP700 PROJECT ‐ STATION 921 ADDWEST BARNSTABLE, MASSACHUSETTSBoring NumberG.S. ElevationRecommended Design Water Level (ft)Depth of Layer 1 (ft)Soil/Rock Layer 1Total Unit Weight (pcf)Effective Unit Weight (pcf) BGWFriction Angle (degrees)Shear Strength (psf)Soil-Modulus, k (pci) AGWSoil-Modulus, k (pci) BGWe50Rock Mass Modulus, Em (psi)RQD (%)UCS (psi)Ultimate Side Friction (tsf)Ultimate End Bearing (tsf)Depth of Layer 2 (ft)Soil/Rock Layer 2Total Unit Weight (pcf)Effective Unit Weight (pcf) BGWFriction Angle (degrees)Shear Strength (psf)Soil-Modulus, k (pci) AGWSoil-Modulus, k (pci) BGWe50Rock Mass Modulus, Em (psi)RQD (%)UCS (psi)Ultimate Side Friction (tsf)Ultimate End Bearing (tsf)Depth of Layer 3 (ft)Soil/Rock Layer 3Total Unit Weight (pcf)Effective Unit Weight (pcf) BGWFriction Angle (degrees)Shear Strength (psf)Soil-Modulus, k (pci) AGWSoil-Modulus, k (pci) BGWe50Rock Mass Modulus, Em (psi)RQD (%)UCS (psi)Ultimate Side Friction (tsf)Ultimate End Bearing (tsf)Depth of Layer 4 (ft)Soil/Rock Layer 4Total Unit Weight (pcf)Effective Unit Weight (pcf) BGWFriction Angle (degrees)Shear Strength (psf)Soil-Modulus, k (pci) AGWSoil-Modulus, k (pci) BGWe50Rock Mass Modulus, Em (psi)RQD (%)UCS (psi)Ultimate Side Friction (tsf)Ultimate End Bearing (tsf)Bottom of Exploration (ft)B13 B14-a-b-c-d B15B16OH/UG-6 OH/UG-7UG-915016916815014014714020.020.020.020.020.020.020.00.0-8.00.0-5.00.0-5.00.0-6.00.0-2.0 0.0-25.0 0.0-15.0Glacial Stratified MDSubsoilGlacial Stratified LooseSubsoilGlacial Stratified LooseGlacial Stratified LooseGlacial Stratified Loose120115120115120120120585358535858583226302630303000000006025252525252540202020202020--------------------------------------------------------1.00--0.50--0.500.500.505.00--3.00--3.003.003.008.0-15.0 5.0-18.5 5.0-42.0 6.0-42.0 2.0-50.0 25.0-40.0 15.0-22.0Glacial Stratified DenseGlacial Stratified MDGlacial Stratified MDGlacial Stratified MDGlacial Stratified MDGlacial Stratified MDGlacial Stratified MD12512012012012012012063585858585858343232323232320000000225606060606060125404040404040--------------------------------------------------------2.001.001.001.001.001.001.0010.005.005.005.005.005.005.0015.0-40.0 18.5-25.0 42.0-50.0 42.0-50.0 50.0-72.0 40.0-72.0Glacial Stratified MDGlacial Stratified LooseGlacial Stratified DenseGlacial Stratified DenseGlacial Stratified DenseGlacial Stratified DenseNOT USED120120125125125125--585863636363--323034343434--000000--6025225225225225--4020125125125125----------------------------------------------------------1.000.502.002.002.002.00--5.003.0010.0010.0010.0010.00--40.0-72.0 25.0-50.0Glacial Stratified DenseGlacial Stratified MDNOT USED NOT USED NOT USED NOT USED NOT USED125120----------6358----------3432----------00----------22560----------12540------------------------------------------------------------------2.001.00----------10.005.00----------72.050.050.050.072.072.022.0Notes:1. Elevations are in feet and reference NAVD88. Elevations are estimated using Massachusetts Online GIS MassMapper. 2. The strata thicknesses and depths noted on this table are presented for use as input for the Lpile Program and some layers may include more than one stratum. Refer to logs of test borings for more detailed information regarding subsurface conditions. 3. Recommended design water level is based on measured depth to groundwater in the borehole, nearby surface water features, readings at nearby boreholes, topography, and soil conditions. 12/19/2022
Page 1 of 1TABLE II
SEISMIC DESIGN CRITERIA
EVERSOURCE QP700 PROJECT
STATION 921 ADDITIONS
661 OAK STREET, WEST BARNSTABLE, MA
Site Class D
Peak Ground Acceleration
SS (short period)0.162 g
S1 (1-second period)0.049 g
Site Coefficients
FA 1.6
FV 2.4
Maximum Earthquake Spectral Response Acceleration
SMS (short period)0.259 g
SM1 (1-second period)0.118 g
Design Spectral Response Acceleration
SDS (short period)0.173 g
SD1 (1-second period)0.078 g
Notes:
1. Criteria based on requirements of MA Building Code, 9th Edition 780 CMR Section 16, including ASCE 7-16.
Item Recommended
Parameter
HALEY & ALDRICH, INC.
\\haleyaldrich.com\share\CF\Projects\0206317\Deliverable\01_West Barnstable\HAI-QP700-Station 921Table 3 Seismic.xls APRIL 2009
APPROXIMATE SCALE: 1 INCH = 2,000 FEET
41°41'13"N, 70°20'59"W
FIGURE 1MAP SOURCE: USGS
206317-0-LOCUS HALEYALDRICH\JBUCHANONOCTOBER 2022
SITE COORDINATES:
PROJECT LOCUS
EVERSOURCE QP700 PROJECT
STATION 921 ADDITIONS
661 OAK STREET, WEST BARNSTABLE, MASSACHUSETTS
B8
B6-a-b-c-d-eXX X
X
X
XXXXXXXXXXXXXXX
X
X
X XXXXX XB7
B14-a-b-c-d
B5_INF-1
B1
B2
B13
B12 B16 B15
B9
B10
B11UG-9
B4
OH/UG-7
OH/UG-6
\\HALEYALDRICH.COM\SHARE\CF\PROJECTS\0206317\CAD\2022-1027_AS DRILLED ELP WEST BARNSTABLE.DWGBUCHANON, JENNIFER N.HA-FIG-A-P2/23/2023 5:52 AM Sheet:Printed:Saved by:FIGURE 2
EVERSOURCE QP700 PROJECT
STATION 921-ADDITIONS
661 OAK STREET, WEST BARNSTABLE, MASSACHUSETTS
EXPLORATION LOCATION PLAN
SCALE: AS SHOWN
OCTOBER 2022
0 50 100
SCALE IN FEET
LEGEND
APPROXIMATE LOCATION OF EXPLORATION PERFORMED
BETWEEN 2 AND 21 OCTOBER 2022 BY SEABOARD DRILLING,
INC., CHICOPEE, MA AND BY TERRACON CONSULTANTS, INC.
BETWEEN 7 AND 10 NOVEMBER 2022.
NOTES
1. PROPOSED SITE LAYOUT TAKEN FROM DRAWING 921-6102 "WEST
BARNSTABLE 345KV STATION GRADING & DRAINAGE PLAN, CIVIL PLAN
AND DETAILS", REVISION A DATED DECEMBER 2022.
LIMITS OF PROPOSED
PERIMETER FENCE
PROPOSED FILL
RETAINING WALL
PROPOSED
TRANSFORMER
PROPOSED
GIS PAD
PROPOSED
CONTROL HOUSE
PROPOSED CUT
RETAINING WALL
APPENDIX A
TEST BORING LOGS
7.0
9.0
10.0
12.0
15.0
17.0
S112
S212
S317
10548
6354
3576
151.50.5
145.07.0 SM
SM
SM
-GRAVEL-
Note: Boring vacuum-excavated to 6 ft below ground surface to clear
utilities prior to drilling.
-VACUUM EXCAVATED / FILL-
Loose red-gray silty SAND with gravel, no odor, moist
Similar to S1
Similar to S2, except medium dense
-GLACIAL STRATIFIED DEPOSITS-
10
10
10
15
15
15
30
30
30
25
25
25
15
15
15
5
5
5
32.0
Cutting Head
Dilatancy: R - Rapid S - Slow N - None
Toughness: L - Low M - Medium H - High
Cuttings
Elapsed Riser Pipe
Field Tests:
Drill Mud:
Summary
Casing
Casing:
PID Make & Model:
Hoist/Hammer:
Depth (ft) to:
--
-
-
4.25
Sampler
Overburden (ft)
S - Split Spoon Sample
Rock Cored (ft)
Well Diagram
Samples
Water
Concrete
Hammer Fall (in.)
Drilling Equipment and Procedures
Plasticity: N - Nonplastic L - Low M - Medium H - High
Dry Strength: N - None L - Low M - Medium H - High V - Very High
1 3/8
140
--Truck Mounted Mobile Drill B53
Spun
Not Encountered
of Hole
Date Bottom
Filter Sand
Barrel
Sample ID
Bit Type:
B1
-of Casing
Bottom
*Note: Maximum particle size (mps) is determined by direct observation within the limitations of sampler size.
Time
Water Level Data
Note: Soil identification based on visual-manual methods of the USCS as practiced by Haley & Aldrich, Inc.
O - Open End Rod
T - Thin Wall Tube
U - Undisturbed Sample
Time (hr.)
Rig Make & Model:
Grout
B1
Bentonite Seal
Screen
Boring No.
S
None
Boring No.
-
-30 WinchAutomatic Hammer
HSA
Inside Diameter (in.)
Type
Hammer Weight (lb)
6S
Start 21 October 2022
21 October 2022
Driller
Datum
of
Finish
2
152.0 (est.)
Sheet No.
T. Danaher
Location See Plan
File No.
Elevation
0206317-000
J. Nitsch
H&A Rep.
None
1Client
Contractor
Project
BURNS & MCDONNELL
SEABOARD DRILLING, INC./TERRACON CONSULTANTS, INC.
EVERSOURCE QP700 - STATION 921, WEST BARNSTABLE, MA
SampleDepth (ft)H&A-TEST BORING-07-1 0206317HA-LIB09.GLB HA-TB+CORE+WELL-07-1.GDT \\HALEYALDRICH.COM\SHARE\CF\PROJECTS\0206317\GINT\0206317-WEST BARNSTABLE TBLOGS_DRAFT.GPJ Dec 19, 22TEST BORING REPORT
Depth (ft)0
5
10
15
20 Sample No.& Rec. (in.)Sampler Blowsper 6 in.StratumChangeElev/Depth (ft)USCS SymbolVISUAL-MANUAL IDENTIFICATION AND DESCRIPTION
(Density/consistency, color, GROUP NAME, max. particle size*,
structure, odor, moisture, optional descriptions
GEOLOGIC INTERPRETATION)
Gravel Sand Field Test
% Fine% Coarse% Medium% Fine% FinesDilatancy% CoarseToughnessPlasticityStrengthField Test
20.0
22.0
25.0
27.0
30.0
32.0
S414
S516
S615
7476
6456
8555
120.032.0
SW-
SM
SW-
SM
SW-
SM
Medium dense red-gray well-graded SAND with silt, no odor, moist
-GLACIAL STRATIFIED DEPOSITS-
Loose red-gray well-graded SAND with silt, no odor, moist
Loose red-gray well-graded SAND with silt and gravel, no odor, moist
Bottom of Exploration at 32.0 ft.
Note: Borehole backfilled with cuttings upon completion.
5
5
5
15
15
15
40
40
35
30
30
30
10
10
105
B1
Sheet No.of
Boring No.
File No.
Boring No.
B1
0206317-000
22
Note: Soil identification based on visual-manual methods of the USCS as practiced by Haley & Aldrich, Inc.SampleDepth (ft)H&A-TEST BORING-07-1 0206317HA-LIB09.GLB HA-TB+CORE+WELL-07-1.GDT \\HALEYALDRICH.COM\SHARE\CF\PROJECTS\0206317\GINT\0206317-WEST BARNSTABLE TBLOGS_DRAFT.GPJ Dec 19, 22TEST BORING REPORT
Depth (ft)20
25
30 Sample No.& Rec. (in.)Sampler Blowsper 6 in.StratumChangeElev/Depth (ft)USCS SymbolVISUAL-MANUAL IDENTIFICATION AND DESCRIPTION
(Density/consistency, color, GROUP NAME, max. particle size*,
structure, odor, moisture, optional descriptions
GEOLOGIC INTERPRETATION)
Gravel Sand Field Test
% Fine% Coarse% Medium% Fine% FinesDilatancy% CoarseToughnessPlasticityStrengthField Test
7.0
9.0
10.0
12.0
15.0
17.0
S114
S28
S317
37108
7131310
5444
151.50.5
145.07.0 SM
SM
SM
-GRAVEL-
Note: Boring vacuum-excavated to 6 ft below ground surface to clear
utilities prior to drilling.
-VACUUM EXCAVATED / FILL-
Medium dense red-gray silty SAND with gravel, no odor, moist
Similar to S1
Loose red-gray silty SAND with gravel, no odor, moist
-GLACIAL STRATIFIED DEPOSITS-
10
10
10
15
15
15
30
30
30
25
25
25
15
15
15
5
5
5
47.5
Cutting Head
Dilatancy: R - Rapid S - Slow N - None
Toughness: L - Low M - Medium H - High
Cuttings
Elapsed Riser Pipe
Field Tests:
Drill Mud:
Summary
Casing
Casing:
PID Make & Model:
Hoist/Hammer:
Depth (ft) to:
--
-
-
4.25
Sampler
Overburden (ft)
S - Split Spoon Sample
Rock Cored (ft)
Well Diagram
Samples
Water
Concrete
Hammer Fall (in.)
Drilling Equipment and Procedures
Plasticity: N - Nonplastic L - Low M - Medium H - High
Dry Strength: N - None L - Low M - Medium H - High V - Very High
1 3/8
140
--Truck Mounted Mobile Drill B53
Spun
Not Encountered
of Hole
Date Bottom
Filter Sand
Barrel
Sample ID
Bit Type:
B2
-of Casing
Bottom
*Note: Maximum particle size (mps) is determined by direct observation within the limitations of sampler size.
Time
Water Level Data
Note: Soil identification based on visual-manual methods of the USCS as practiced by Haley & Aldrich, Inc.
O - Open End Rod
T - Thin Wall Tube
U - Undisturbed Sample
Time (hr.)
Rig Make & Model:
Grout
B2
Bentonite Seal
Screen
Boring No.
S
None
Boring No.
-
-30 WinchAutomatic Hammer
HSA
Inside Diameter (in.)
Type
Hammer Weight (lb)
9S
Start 21 October 2022
21 October 2022
Driller
Datum
of
Finish
2
152.0 (est.)
Sheet No.
T. Danaher
Location See Plan
File No.
Elevation
0206317-000
J. Nitsch
H&A Rep.
None
1Client
Contractor
Project
BURNS & MCDONNELL
SEABOARD DRILLING, INC./TERRACON CONSULTANTS, INC.
EVERSOURCE QP700 - STATION 921, WEST BARNSTABLE, MA
SampleDepth (ft)H&A-TEST BORING-07-1 0206317HA-LIB09.GLB HA-TB+CORE+WELL-07-1.GDT \\HALEYALDRICH.COM\SHARE\CF\PROJECTS\0206317\GINT\0206317-WEST BARNSTABLE TBLOGS_DRAFT.GPJ Dec 19, 22TEST BORING REPORT
Depth (ft)0
5
10
15
20 Sample No.& Rec. (in.)Sampler Blowsper 6 in.StratumChangeElev/Depth (ft)USCS SymbolVISUAL-MANUAL IDENTIFICATION AND DESCRIPTION
(Density/consistency, color, GROUP NAME, max. particle size*,
structure, odor, moisture, optional descriptions
GEOLOGIC INTERPRETATION)
Gravel Sand Field Test
% Fine% Coarse% Medium% Fine% FinesDilatancy% CoarseToughnessPlasticityStrengthField Test