TO: Prospective Bidders Project: UMPI Solar Array€¦ · "main array - grading and erosion control...

July 8, 2020

TO: Prospective Bidders

RE: Addendum Number 01

Project: UMPI Solar Array

This Addendum forms a part of the Contract Documents and modifies the original Bidding

Documents dated June 27, 2020, as noted below. Please acknowledge receipt of the Addendum in

the space provided on the Bid Form. Failure to do so may subject bidder to disqualification.

Addendum 01 consists of the following:

-Pre-Bid Meeting Attendance List & Meeting Presentation

-Geotechnical Subsurface Investigation and Engineering Report

PRE-BID MEETING ATTENDANCE LIST & MEETING PRESENTATION

1. The following attendees (listed alphabetically by firm represented) to the non-mandatory pre-

bid meeting acknowledged attendance via e-mail:

a. County Electric, Inc. – Patrick J. LaJoie, Controller. [email protected]

17 Birdseye Ave. P.O. Box 954 Caribou, ME 04736.

Tel: (207) 498-8231

Fax: (207) 498-8719

b. ReVision Energy – Nick Sampson, Employee-Owner. [email protected]

758 Westbrook St, South Portland, ME 04106

Tel: (207) 756-4159

Fax: (207) 358-7944

c. RL Todd & Son, Inc. – Timothy Todd, President. [email protected]

414 Main St. Caribou, ME 04736

Tel: (207) 496-1671

Fax: (207) 498-8810

d. Soderberg Construction Co. – Carl Soderberg. [email protected]

460 York St. Caribou, ME 04736

Tel: (207) 498-6300

Fax: (207) 498-6535

2. A PDF copy of the pre-bid presentation is attached to this addendum.

GEOTECHNICAL SUBSURFACE INVESTIGATION AND ENGINEERING REPORT

3. A PDF copy of the report is attached to this addendum.

CLARIFICATIONS

4. The selected contractor shall be responsible for performing stakeout survey for ground-

mounted array racking and equipment pad locations.

END OF ADDENDUM 01

UMPI SOLAR ARRAYPre-Bid Virtual Conference

July 7, 2020

Welcome

Jacob OlsenProject ManagerCapital Planning & Project Management

Walter ShannonAssistant DirectorCapital Planning & Project Management

Stuart BaileyProject Manager/Senior Electrical Engineer

Send Bid Period Qs & RFIs to: [email protected]

Introductions

mailto:[email protected]

1. Document Access

2. Project Objective

3. Site Location

4. Scope of Works

5. Schedule/Milestones

6. Miscellaneous

7. Discussion & Wrap Up

Agenda

All project info is on UMPI’s website:https://www.umpi.edu/offices/facilities/capital-construction/

Bidders are expected to check the website regularly updatedbid documents and addendaNote: There is no tracking of those who download info

If unable to access the site/documents, email:[email protected] [email protected]

Document Access





Goals & Priorities

• To construct a solar photovoltaic field to provide no less than 450,000 kWh to the campus through its existing infrastructure.

• Provide pole-mounted residential solar array at he President’s residence to demonstrate the University’s commitment to renewable energy.

Project Objectives

Scope of Work

• Construction of a 377kWdc/300kWac fixed-tilt ground-mount solar photovoltaic array. ‘Behind-the-Meter’ installation to include removal of existing equipment, new racking and solar modules, inverters, main switchgear, Low-voltage (LV)/ medium-voltage (MV) transformer, monitoring system, MV/LV and DC string wiring, containment, balance of system, roads, fencing, equipment racking and pads;

• Construction of a 5.5kWdc/3.8kWac manual-adjustable pole-mount solar photovoltaic array. ‘Behind-the-Meter’ installation to include new racking and solar modules, inverter, switchgear, web-based monitoring system, LV and DC string wiring, containment, balance of system, and equipment pad.

Scope

Project Location

Site Plan

Ground-Mount Array Plan

President’s Array Plan

Photos

Photos

Photos

Photos

Photos

Photos

Photos

June 27, 2020 Begin bidding

July 7, 2020 Pre-bid Virtual Meeting

July 8, 2020 Addendum #1 issued


July 15, 2020, 4 pm Final date for bidding questions


July 21, 2020, 2 pm General Contractor bids due

August 10, 2020 Begin construction

December 15, 2020 Substantial Completion

December 31, 2020 Final Completion

Schedule

Miscellaneous

• Project includes removal of existing redundant wind turbine transformer;

• UMPI will procure, purchase and deliver new transformer to site. Contractor to take ownership upon delivery for installation and handover.

Look for updates on UMPI’s website:https://www.umpi.edu/offices/facilities/capital-construction/

Closing

All attendees please email [email protected]


Closing

Discussion

Closing

Thank you for your interest in this project

300 Pearl Street, Suite 130 | Buffalo, NY 14202 | p (716) 551-6281

www.labellapc.com

June 29, 2020

Mr. Jacob Olsen 5765 Service Building, Room 108 Orono, ME 04469 RE: Geotechnical Subsurface Investigation and Engineering Report Proposed Campus Solar Arrays University of Maine at Presque Isle Presque Isle, Maine LaBella Project Number: 2200127

Dear Mr. Olsen: LaBella Associates, D.P.C. has completed the geotechnical engineering services for the above referenced project. Our report presents the results of the subsurface investigation and provides geotechnical recommendations for foundation type(s) and allowable bearing pressures, anticipated settlements, along with a discussion of construction considerations such as site preparation, earthwork and excavations, fill and backfill material and placement criteria, and control of water. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report, please contact us. Respectfully submitted, LABELLA ASSOCIATES, D.P.C.

Thomas J. Zaso Stephen L. Gauthier, P.E. Senior Geotechnical Engineer Senior Engineer

GEOTECHNICAL SUBSURFACE INVESTIGATION

and ENGINEERING REPORT

PROPOSED CAMPUS SOLAR ARRAYS

UNIVERSITY OF MAINE AT PRESQUE ISLE PRESQUE ISLE, MAINE

Prepared for: University of Maine at Presque Isle

181 Main Street Presque Isle, ME 04769

Prepared by: LaBella Associates, D.P.C. 300 State Street, Suite 201

Rochester, New York 14614

LaBella Project No.: 2200127

June 29, 2020

GEOTECHNICAL SUBSURFACE INVESTIGATION & ENGINEERING REPORT PROPOSED CAMPUS SOLAR ARRAYS

UNIVERSITY OF MAINE AT PRESQUE ISLE

NOTE

This report is written using U.S. Customary Units unless otherwise noted. The professional services provided in this project include only the specific geotechnical aspects of the subsurface conditions at the site. The presence or implication of possible surface or subsurface contaminants from any source are outside the terms of reference for this geotechnical study and have not been investigated or addressed herein. Coal seam hazard evaluation, fire and gas hazard evaluation, site subsidence hazard evaluation, wetland impact study, septic field hazard or impact evaluation, slope stability and landslide hazard analysis, and a detailed site-specific seismic hazard evaluation are beyond the scope of work for this project. The subsurface soil profile and design parameters provided in this report are estimated based on the results of the soil borings as indicated by: the boring logs, visual classification of the recovered soil and/or rock samples, geotechnical laboratory results (where applicable), analytical laboratory results (where applicable) and/or generally published soil and/or rock property correlations. Actual subsurface conditions beyond the soil borings and below the depths explored may vary, as well as subsurface conditions encountered in the field during and/or as a result of construction activity. The recommendations contained within this report are based on the subsurface conditions encountered and the information provided in the project plans titled, “Campus Solar Array”. More specifically, the plan for the Main Solar Array is shown on Sheet C201 titled, “Main Array – Site and Utility Plan”, dated April 2020; and the plan for the President’s Solar Array is provided on Sheet C202 titled “Presidents Array – Existing Conditions, Demolition, Site, Utility, Grading, and Erosion Control Plan”, dated April, 2020. Civil Plan Drawings for the project were prepared by LaBella Associates, DPC. These plans are not included in this report. If subsurface conditions or the arrangement of arrays or equipment vary from those presented within this report or on the plans referenced, the geotechnical engineer shall be notified immediately to identify if the recommendations provided herein are still applicable. PRIOR TO CONDUCTING ANY SUBSURFACE EXCAVATIONS, THE CONTRACTOR IS OBLIGATED TO CONTACT THE LOCAL ONE-CALL SERVICE TO MARK OUT UTILITIES. FOR PROJECTS THAT OCCUR ON PRIVATE PROPERTY, THE CONTRACTOR IS OBLIGATED TO HIRE A THIRD PARTY UTILITY LOCATING SERVICE.

This report was prepared by LaBella Associates, D.P.C.

Written by: Reviewed by:

Thomas J. Zaso Senior Geotechnical Engineer

(electronic or copied signature unless in blue ink)

Stephen L. Gauthier, P.E. Senior Engineer

(electronic or copied signature unless in blue ink)



TABLE OF CONTENTS

Page 1.0 INTRODUCTION ................................................................................................................................. 1

2.0 SUBSURFACE EXPLORATION PROGRAM ............................................................................................ 1

3.0 SUBSURFACE SOIL AND GROUNDWATER CONDITIONS SUMMARY .................................................. 2

3.1 Subsurface Conditions ................................................................................................................... 2 3.2 Groundwater Conditions ............................................................................................................... 2 3.3 Expansive Soils and Hydrologic Soil Group .................................................................................... 3

4.0 SEISMIC CONSIDERATIONS ................................................................................................................ 3

5.0 GEOTECHNICAL RECOMMENDATIONS .............................................................................................. 4

5.1 Engineering Evaluation .................................................................................................................. 4 5.1.1 Shallow Spread Footing Foundations .................................................................................... 4 5.1.2 Lateral and Uplift Load Resistance for Shallow Foundations ................................................. 6 5.1.3 Deep Foundation System (For President’s Array) – Drilled Shaft .......................................... 7 5.1.4 Drilled Shaft Construction Considerations ............................................................................. 7 5.1.5 Deep Foundation System (For Main Array) – Screw Piles ...................................................... 7

5.2 Site Preparation ............................................................................................................................. 8 5.3 Temporary Excavations and Buried Structures .............................................................................. 9 5.4 Frost Depth .................................................................................................................................... 9 5.5 Uplift Forces due to Adfreezing Stress .......................................................................................... 9

6.0 FILL & BACKFILL ............................................................................................................................... 10

6.1 On-Site Borrow Material ............................................................................................................. 10 6.2 Select Granular Fill Material ........................................................................................................ 10 6.3 Filling & Backfilling Methodology ................................................................................................ 11

7.0 CONSTRUCTION OBSERVATIONS & TESTING ................................................................................... 12

8.0 CLOSING .......................................................................................................................................... 12

9.0 DISPOSITION OF SAMPLES ............................................................................................................... 12

APPENDICIES A - FIGURES B - BORING LOGS C - WENNER 4-PIN RESISTIVITY FIELD REPORT



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1.0 INTRODUCTION LaBella Associates, D.P.C. (LaBella) is pleased to present this report for the subsurface exploration and geotechnical engineering evaluation for the proposed Campus Solar Arrays, located at the University of Maine at Presque Isle (UMPI), 181 Main Street, Presque Isle, Maine as shown on the Location Map included in Appendix A. For this investigation a total of five (5) test borings were advanced at the locations depicted on Exploration Location Plan 1 and 2, also included in Appendix A. The planned improvements, provided by LaBella Associates, DPC, are depicted on Sheet C201 titled, “Main Array – Site and Utility Plan”, dated April 2020; and the plan for the President’s Solar Array is provided on Sheet C202 titled “Presidents Array – Existing Conditions, Demolition, Site, Utility, Grading, and Erosion Control Plan”, dated April, 2020, which are not included in this report. The existing area where the Main Array is planned was used as an agricultural field. The area where the President’s Array is proposed is in a residential setting. Main Street provides access to the proposed solar arrays. Plans to develop the Site include:

Installing arrays of solar panels at the President’s Residence and a Main Array within a field south of an existing wind turbine;

Installing transformers on equipment pads;

Constructing a gravel access road to access the Main Array; and

Installing a perimeter security fence around the Main Array;

LaBella’s Scope of Services included advancing Test Borings, preparing subsurface exploration logs, and preparing this report that contains geotechnical recommendations for developing the site. These services were performed in accordance with LaBella’s proposal dated May 6, 2020.

2.0 SUBSURFACE EXPLORATION PROGRAM The subsurface exploration was performed by Summit Geoengineering Services (SGS). On May 26 and 27, 2020 SGS advanced Boring B-1 at the President’s Residence and Borings B-2 through B-5 at the location of the Main Array. The Borings were advanced using a track mounted AMS Power Probe 9500 VTR drill rig, equipped with 2-¼" I.D. hollow stem augers. Soil Sampling and Standard Penetration Testing (SPT) were conducted using a 140-pound automatic safety hammer dropping 30 inches to drive a 2 inch O.D. split barrel sampler in general conformance with ASTM Standard Practice D1586. A portion of each soil sample retrieved was placed and sealed in glass jars. Upon completion of each Test Boring, the borehole was backfilled with auger cuttings to grade to closely match the existing ground surface. Prior to advancing any subsurface explorations, Summit Geoengineering Services contacted the local one-call utility locating service to clear public utilities. Utility conflicts were not identified at any of the five subsurface exploration locations. Soil samples were logged and visually classified by a SGS geotechnical engineer. The visual soil classifications were made using a modified Burmister Classification System. In this system, the soil is divided into Gravel, Sand, Silt/Clay (fines). The predominant fraction is listed first and if it is more than 50-percent of the matrix it will be capitalized. Modifiers are also provided to establish a sense of the percentage of the remaining fractions. The modifiers are as follows:

Modifier Percentage Modifier Percentage

trace 1 – 10 some 21 – 35

little 11 – 20 and 36 – 50



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3.0 SUBSURFACE SOIL AND GROUNDWATER CONDITIONS SUMMARY The subsurface conditions discussed below have been generalized from the Soil Boring Logs provided in this report. The information provided on the Soil Boring Logs is representative of the location where each subsurface exploration was conducted. Subsurface conditions between exploration locations and depths sampled may vary. The stratification lines indicated on the logs are approximate and may indicate gradational changes. Please, refer to the attached Soil Boring Logs for conditions encountered at the time, location, and depth of each sampling.

3.1 Subsurface Conditions Surfacings: The surface material at each boring consisted of approximately 2 to 4 inches of brown to dark brown fine sandy, silty Topsoil with vegetative matter (e.g., roots). Glacial Soils: Beneath the Surfacings is Glacial Till overlying bedrock with localized glacial marine deposit above the glacial till at Boring B‐3. The glacial till is considered predominantly granular with slight plasticity fines and is visually classified as gray to brown sand and gravel with some clayey silt in accordance with Burmister Soil Identification Method. Upper portions of the glacial till contain less sand & gravel, consisting of clayey silt with some sand and gravel. The glacial marine deposit encountered at Boring B‐3 is considered to be fine grained soil with low plasticity and is visually classified as light brown silt and clay with little fine sand. Weathered Bedrock and Bedrock: Refusal on bedrock was encountered at a depth range of approximately 11 to 19 feet in four of five borings. No bedrock was encountered in Boring B‐2, explored to a depth of 20 feet. Slow auger advancement through decomposed or highly weathered bedrock was possible in several borings due to relatively low hardness of the decomposed weathered bedrock. Mapping by the Maine Geological Survey indicates bedrock at the site part of the Silurian Spragueville Formation consisting of well‐bedded metasandstone, thinly laminated metasiltstone, and metashale (slightly metamorphosed mudstone). Provided below is a summary of the depths and approximate elevations where weathered bedrock was encountered and auger refusal occurred at each boring.

Test Boring

Surface Elevation

(ft)

Decomposed Weathered

Bedrock Depth (ft)

Decomposed Weathered

Bedrock Elev. (ft)

Auger Refusal Depth

(ft)

Auger Refusal

Elev. (ft)

B-1 ±520.7 Not Encountered -- 16.2 ±504.5

B-2 ±540.7 Not Encountered -- Not Encountered --

B-3 ±543.1 10.5 ±532.6 11.2 ±531.9

B-4 ±544.9 16.1 ±528.8 19.0 ±525.9

B-5 ±545.5 12.5 ±533.0 18.5 ±527.0

3.2 Groundwater Conditions Groundwater was encountered during the drilling and prior to backfilling of boreholes B-2 through B-5 at depths ranging from approximately 6.5 and 12.0 feet bgs, which corresponds to elevations ranging from approximately 529 to 537 feet. Groundwater was not encountered within Boring B-1. If groundwater is encountered above the depths listed above, it is anticipated that the use of local sumps and pumps should be adequate to control groundwater fluctuations. If continuous pumping of infiltrating water is required, the pump shall be placed within crushed stone in a sump area that is dug outside of the planned shallow foundation footprint. The crushed stone shall be separated from the subgrade soil with a geotextile fabric (i.e., Mirafi 140N or equivalent) so that continuous pumping of fines (i.e., fine sand, silt)



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does not occur. Perched or trapped water may be encountered within soil layers of differing gradation, particularly within fill layers. For spread footing foundations that are installed below the water table, a well point system will most likely be required in order to keep the groundwater surface a minimum of two-feet below the bottom of the deepest footing. Groundwater levels will fluctuate due to seasonal affects and/or construction related activities.

3.3 Expansive Soils and Hydrologic Soil Group Based on naked-eye visual examination of the retrieved soil samples, it is LaBella’s professional opinion that potentially expansive materials were not identified. The USDA-NRCS Web Soil Survey was used to identify aspects of the surficial soils at the site. The table below provides a summary of surficial soils with regards to Hydrologic Soil Group, Hydric Rating, and the Risk of Corrosion to Concrete and Steel.

Map Unit Symbol

Map Unit Name Area (ac.)

Hydrologic Soil Group

Hydric Soil Rating

Risk of Corrosion

Concrete Steel

CgB Caribou Gravelly Loam, 6 to 8 percent slopes 7.1 B No Moderate High

The “risk of corrosion” pertains to potential soil-induced electrochemical or chemical action that corrodes or weakens concrete and/or unprotected steel. The rate of corrosion is based mainly on the following characteristics:

For concrete: Sulfate (SO4) content, chloride (Cl) content, and acidity (pH);

For steel: Resistivity/electrical conductivity, reduction/oxidation (Redox) potential, presence of sulfides, and acidity (pH);

For concrete & steel: soil moisture content, and grain size distribution Based on the USDA-NRCS Soil maps, LaBella recommends that soil samples be tested for the parameters listed above to identify if a special type of cement (e.g., Type IV – Sulfate resistant) must be used and/or if some type of special coating or cathodic protection will be required for buried metal items (e.g., utilities).

4.0 SEISMIC CONSIDERATIONS Based on the subsurface information obtained from the borings and our knowledge of the local geology, it is our opinion that Site Class D, “Stiff Soils”, as referenced in the International Building Code as adopted by Maine, may be used for the site. Interpolated probabilistic ground motion parameters for the project site were obtained from the Applied Technology Council (ATC) website using the seismic hazard tool. This tool accesses the United States Geologic Survey (USGS) Seismic Design Maps. Based on the latitude-longitude coordinates of the site, earthquake ground motion parameters were developed in general accordance with the American Society of Civil Engineers (ASCE) 7-16 Standard. Based upon this information, the following ground motion parameters with 2% probability for exceedance, in 50 years, may be used for this site:

0.2 second period mapped spectral response acceleration (SS): 0.234g;

1.0 second period mapped spectral response acceleration (S1): 0.085g;

MCE spectral response acceleration at short period (SMS): 0.375g;

MCE spectral response acceleration at 1.0 second period (SM1): 0.204g;



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Five percent damped spectral response acceleration at short period (SDS): 0.250g;

Five percent damped spectral response acceleration at 1.0 second period (SD1): 0.136g; and

Peak Ground Acceleration (PGA): 0.122g. Based on these parameters the Seismic Design Category for this site is C for a Risk Category II Structure. Based upon additional data obtained from the USGS website (2016 Earthquake Probability Mapping) the probability that a magnitude 6.0 earthquake on the Richter scale might occur within 100 years and 50 Km of the project site is less than 1%.

5.0 GEOTECHNICAL RECOMMENDATIONS The geotechnical evaluations and recommendations contained within this report are based on the subsurface conditions encountered and the plan depicted on Sheet C201 titled, “Main Array – Site and Utility Plan”, dated April 2020; and the plan for the President’s Solar Array which is provided on Sheet C202 titled “Presidents Array – Existing Conditions, Demolition, Site, Utility, Grading, and Erosion Control Plan”, dated April, 2020 and prepared by LaBella Associates, DPC. If subsurface conditions or the arrangement of the arrays or equipment vary from those presented within this report or on the plans referenced, the geotechnical engineer should be notified immediately to identify if the recommendations provided herein are still applicable.

5.1 Engineering Evaluation Based on the subsurface conditions encountered within the borings performed at the subject site, it is our opinion that the proposed Main Solar Array may be founded on shallow footings consisting of isolated spread and continuous strip foundations bearing upon approved native soils or the Main Solar Array may be supported by screw piles. The proposed solar array planned for the President’s Residence is planned to be supported by a drilled pier. The equipment pads for the planned transformers may be supported on a mat foundation (with modifications as noted in Section 5.1.1 due to in-situ fine grained soils). LaBella recommends that if site grades are to be altered, cuts and fills should be placed no steeper than 2.5 horizontal to 1 vertical (2.5H:1V) for areas where maintenance is not required and 3H:1V for areas where maintenance is required (e.g., mowing). If steeper side slopes are required (e.g., 2H:1V), the Geotechnical Engineer must conduct a Slope Stability Evaluation. The Geotechnical Engineer must be provided with information that includes but is not limited to the following in order to model the proposed slopes correctly.

• Final Site Grading plan that depicts the slopes and the location of all equipment; • Final loading conditions for all foundation elements within the fill area (e.g., shallow spread

footing, slab-on-grade, drilled shafts); • Identification of the source of fill material (if applicable); • Geotechnical properties of the fill material (if applicable); and • Geotechnical properties of the cut area by means of advancing borings and/or test pits.

5.1.1 Shallow Spread Footing Foundations It is anticipated the equipment pads for the planned transformers will be a “mat” spread footing foundation construction. As reported above, the underlying soils contain an appreciable amount of Silt and/or Clay (material passing the No. 200 sieve). As such, these soils can be considered as frost susceptible. In addition, these soils are not well draining due to the amount of Silt and/or Clay being present. For these reasons, LaBella recommends that all mat spread footing foundations bear either at a



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depth of 4-feet below finished ground surface –OR– be placed on Controlled Low Strength Material (CLSM [i.e., flowable fill/lean concrete]), with a compressive strength of 500 to 750 psi, placed between the bottom of the mat foundation and a depth of 4-feet bgs. By using CLSM in lieu of Select Granular Fill beneath the mat foundations, a “bath-tub” effect will not be present for water to collect from precipitation events, thus minimizing Adfreeze stresses. Furthermore, using CLSM beneath the spread footing foundations will provide added weight to overcome Adfreeze stresses and minimize frost heaving effects. For the Solar Array, the governing factor is not bearing but rather uplift and overturning due to wind loading. For these spread footings, a strip footing was modeled at a depth of 4-feet on 0.5-foot of Select Granular Fill compacted to 95% of the maximum modified density (ASTM D1557). The purpose of the 6-inch layer of Select Granular Fill is to provide a leveling surface for the strip footing as well as a work surface for construction. Based on the existing site grades, it is anticipated that the foundation bearing materials will either be approved native medium stiff to stiff silty CLAY/clayey SILT or approved compact SAND and Gravel with variable amounts of clayey silt. LaBella conducted bearing capacity evaluations for shallow strip spread footings founded on 6-inches of Select Granular Fill compacted as stated above and for shallow mat spread footings founded on 2 feet of CLSM to identify an allowable bearing pressure for the new equipment that will bear within each material. In addition to the bearing capacity evaluation, LaBella conducted settlement analysis using the Schmertmann Method. It is anticipated that most settlement will occur during construction. LaBella modeled a shallow spread footing using the data obtained from the above report sections to identify the bearing capacity for the areas where arrays and equipment are planned for the site. LaBella anticipates that the bottom of the shallow foundations will be located at a depth of approximately 4 feet bgs which is less than 1.5 times the width of the footing (1.5 x Bf) from the design groundwater surface. Therefore, corrections for ground water (i.e. using the submerged unit weight for the soil column to calculate the Effective Overburden Stress, and a ground water correction factor based on the geometry and modeled depth of the foundation) are required to calculate the ultimate bearing capacity. The allowable bearing capacity is subsequently calculated by dividing the ultimate bearing capacity by a factor of safety. The ultimate bearing capacity was calculated using the following bearing capacity formula developed by Terzaghi and modified by Meyerhoff:

Qult = (c x Nc x Sc) + (q x Nq x Sq) + (0.5 x x bf x N x S) Where: Qult = Ultimate Bearing Capacity (psf); c = cohesion (psf); Nc = cohesive bearing capacity factor = 5.14; Nq = non-cohesive bearing capacity factor (1 when cohesive soils are encountered);

N = footing bearing capacity factor; Sc, Sq, S = footing shape factors;

q = effective overburden stress (psf); = unit weight of soil directly beneath footing (pcf); and bf = width of footing (ft)

Qall = Qult x GWCF

FOS Where: Qall = Allowable Bearing Capacity; GWCF = Groundwater Correction Factor ≤ 1.0; and FOS = Factor of Safety = 3.0

The shallow spread footings modeled are as follows:



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Equipment Location Footing

Size Footing Depth

Allowable Bearing Capacity

Calculated Settlement

Equipment Pad Boring B-2 10’w x 20’l x 2’t 2’ bgs 2,000 psf <1”

<3/4” differential

Solar Panel Boring B-3 4’w x 100’l x 1’t 4’ bgs 1,500 psf <1”


Solar Panel Boring B-4 4‘w x 100’l x1’t 4’ bgs 2,500 psf <1”


LaBella recommends that the preparation of the site (e.g., preparing soil bearing grades, installation of controlled compacted fill, placement of CLSM, etc.) be observed and evaluated by a representative of the geotechnical engineer. The exposed native soil bearing grades shall be thoroughly compacted using a manually operated compactor (e.g. plate compactor or walk behind roller) prior to placement of Select Granular Fill or CLSM, forms, and/or reinforcing steel. This should improve the consistency of the exposed grades and re-compact areas that were loosened during excavation activities. The exposed subgrade shall be approved by LaBella’s geotechnical representative prior to the placement of Select Granular Fill or CLSM, forms, and rebar to ensure that the subgrade is consistent with soils that meet or exceed the allowable bearing capacity reported above. The geotechnical representative will also observe the exposed grade to verify that it is free of loose soil, mud, water, frost, and/or deleterious materials. If unsuitable materials are encountered at the exposed subgrade for the planned foundations, these materials shall be removed by over-excavating and replaced with suitable imported structural fill (i.e., Select Granular Fill as described below in this report) that is compacted in accordance with the project specifications. For every one foot of vertical undercut within a footing excavation, the foundation area shall be widened one foot on all sides of the planned foundation footprint. If CLSM is used to fill the over-excavated area, the foundation area shall be widened a minimum of 6 inches on all sides of the planned footing footprint. The design strength for the CLSM should be in the range of 500 to 750 pounds per square inch (psi). Since the anticipated soil bearing materials tend to be moisture sensitive, the construction of the foundations should proceed as soon as possible after the acceptance of the soil bearing grade by the geotechnical representative.

5.1.2 Lateral and Uplift Load Resistance for Shallow Foundations Shallow foundations for the proposed solar array and equipment shall be designed to resist lateral, overturning, and uplift loads. The footings shall be designed for a factor of safety of 2.0 for sustained lateral, overturning, and uplift load conditions or 1.5 for transient lateral, overturning, and uplift load conditions. LaBella also recommends that the resultant of lateral and vertical loading be located within the middle 1/3 of the footing in order to minimize eccentric loading effects. Passive lateral resistance can be provided by a vertical excavation face if the cast-in-place concrete is poured neat up against the side of the excavation. To increase the uplift resistance for shallow foundations, the foundations can be embedded further below grade with the weight of the foundation in addition to the weight of the soil placed and compacted above the foundation used to resist uplift forces. The volume of soil that can be used is defined by a soil wedge extending out 20 degrees from the vertical edge of the top of the foundation to the ground surface. Passive resistance can be calculated using a passive earth pressure coefficient (kp) and sliding resistance can be calculated for the subgrade materials and the foundation bottom using an ultimate friction factor of 0.35. The following soil design values may be used to develop the resistive forces.



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Material1

Effective Friction Angle

() Cohesion

(c)

Moist Unit

Weight

(moist)

Submerged Unit Weight

(sub)

Equivalent Fluid

Pressure (EFP)

Earth Pressure Coefficients

Active (ka)

Passive (kp)

At Rest (ko)

Select Granular Fill 35° 0 psf 140 pcf 80 pcf 70 pcf 0.27 3.7 0.5

Native Soils 28° 300 pcf 120 pcf 60 pcf 50 pcf 0.36 2.8 0.5 Notes: 1. Values provided are based on each material placed & compacted to a minimum of 95% maximum modified density (ASTM D1557)

5.1.3 Deep Foundation System (For the President’s Array) – Drilled Shaft LaBella used Brom’s Method to calculate the lateral resistance of the soil for a 3-foot diameter drilled shaft. Our analysis that was performed in order to resist the loads provided by the Structural Engineer (Lateral load of 3,200 pounds at a height of 11 feet and a vertical load of 22,000 pounds) resulted in a drilled shaft that is 6-feet deep. The 3-foot diameter shaft that is 6 feet deep yields a factor of safety of 2.2. If the shaft is advanced 1-foot deeper, the FOS rises to 3.4. Using the Bearing Capacity Equation developed by Terzaghi and modified by Meyerhoff for a 2.66’ x 2.66’ square footing (3-foot diameter equivalent), a net loading of 3,300 psf and an allowable bearing capacity of 6,000 psf was calculated for the planned drilled shaft for the President’s Array.

5.1.4 Drilled Shaft Construction Considerations Temporary steel casing will be required during the excavation of any drilled shafts advanced on the site. It is anticipated that the temporary steel casing shall be installed and seated within the native soils in order to stabilize the sides of the shaft during construction and to minimize the potential for inflow of water into the shaft prior to placing the steel reinforcing cage and concrete. Water, fractured weathered rock, and loose soil shall be removed from the bottom of the shaft prior to the placement of concrete. The steel reinforcing cage shall be equipped with “boots” and centralizers to keep the reinforcement off the bottom of the drilled shaft and within the center of the shaft as concrete is poured. The bottom of the casing and bottom of the concrete pump hose shall be no less than 5 feet below the surface of the concrete during placement. This is to ensure that the sidewall soils are not incorporated into the concrete. Concrete shall be placed as soon as possible after the shaft excavation is completed in order to minimize the degradation of the shaft bottom. A representative of the geotechnical engineer shall be retained to perform the special inspection during the construction of the drilled shaft in order to verify that the soil conditions are consistent with the conditions encountered during this subsurface exploration.

5.1.5 Deep Foundation System (For the Main Array) – Screw Piles Depending on the depth range required to resist uplift forces for various pile types, the soil conditions indicate that screw piles may be a viable alternative option for the Main Solar Array at this site. It should be taken into account that weathered bedrock was encountered at relatively shallow depths within borings B-3 through B-5. By using a deep foundation system, the solar panel rack system could possibly be directly connected to the stem of the screw pile. One type of screw pile consists of a main shaft (i.e., square or pipe) with individual helices at the leading end. These types of piles are referred to as Helical Piles which allows the pile to be screwed into the subsurface thus causing little to no vibration. Sections of the main shaft (without helices) are added as the pile is advanced to the underlying bearing strata. The load is subsequently transferred down the shaft



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to the lead helices. When pipes are used as the main shaft, these piles can be filled with grout/concrete which provides additional rigidity to the main shaft and are primarily used as end-bearing piles. Another type of screw pile that is often used to support solar array panels is known as a soil screw anchor. This type of pile looks like a large screw with an auger (thread) that extends along a portion of or the entire shaft. This type of pile is able to develop high tension capacities. The auger along the shaft provides tension/uplift resistance to account for wind loading. This type of pile/anchor can also be filled with grout/concrete to provide additional rigidity if needed for lateral loading. A third type of screw pile consists of a main shaft (i.e., pipe) with a soil displacement helix at the leading end with a reverse spiral auger along the remaining portion of the main shaft. These types of piles are referred to as Drilled-in Displacement Micropiles (DDM). As the DDM is advanced into the ground, high strength grout is added to the main shaft which subsequently drains through grout ports. The reverse auger works to push the grout down the outside of the pile and mix it with the surrounding soils. The combination of the steel pipe, interior and exterior grout provides a high strength “mini pile” that can be used as an end-bearing and/or friction pile and can develop lateral resistance such that battering of the piles may not be required. Screw piles are often installed using a small excavator or “skid steer” equipped with a rotating drive head. For this project, there is a possibility that when advancing the screw piles at the site, cobbles could be encountered that may require the pile to be removed and/or relocated. If the obstruction cannot be removed and the pile fetches up significantly shallower than the design depth, the Engineer of Record should be consulted and it is possible that additional Screw Piles along with reconfiguring the pile cap (if one is used) at a specific location may be required. The design of these three types of Screw Piles is proprietary with regards to the type of pile and configuration. After the type of screw pile is chosen, the installer shall provide a design drawing. LaBella recommends that load and pullout testing be conducted prior to installing any production piles. This will require that reaction piles be installed and a reaction frame used to jack against during the test. A geotechnical representative from LaBella should be on-site to witness and record the pile load tests as well as during pile installation to record as-built pile locations, resistance to advancement, and termination depths for review by the Engineer of Record.

5.2 Site Preparation The first step in preparing the site will be stripping any organic-laden soils from the proposed access road alignment. The exposed subgrade for the access road shall be observed by a representative of the geotechnical engineer at this stage to evaluate the stability of the gravel roadway area prior to any filling operations. Upon satisfactorily exposing the planned subgrade, the surface shall be graded, sealed, and subsequently proofrolled using a minimum 10-ton (operating weight) smooth steel-drum roller on vibratory mode on a dry day, free of rain. Proofrolling will consist of five passes over the prepared subgrade at walking speed in the presence of LaBella’s geotechnical representative. If pumping or weaving is observed while proof rolling, the unsuitable soil shall be removed and replaced with Select Granular Fill (as described in this report). Immediately following a satisfactory proofroll, the Contractor shall install Select Granular Fill, to achieve subgrade elevation in a quality controlled manner. If the approved subgrade must remain exposed for any length of time, unnecessary trafficking of vehicles across the subgrade shall be avoided.



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5.3 Temporary Excavations and Buried Structures Temporary excavations must be conducted in accordance with the U.S. Department of Labor – Occupational Safety and Health Administration (OSHA) 29 CFR Part 1926 Subpart P titled “Excavations”. OSHA and NYCRR pertain to safety aspects of excavations such as: soil classification, sloping and benching, shoring, and assistance with selecting the appropriate protective system. Prior to workers entering the excavation a Competent Person, as defined by OSHA, must inspect the excavation and deem it safe for entry. For excavations 5 feet deep and greater, the Contractor will be required to provide excavation protection (e.g., sloping of the side walls, shielding, trench box) and if necessary an Excavation Protection System (EPS) (e.g., shoring, support of excavation). The EPS must be designed by a professional structural or professional geotechnical engineer licensed in the state where the work is being conducted who is familiar with such systems. The Contractor shall also place excavated spoils no closer to the excavation than the minimum setback distance prescribed by OSHA such that the stability of the excavation and/or EPS is not compromised. In addition, the Contractor should consider installing small berms/swales where necessary to control surface water runoff from entering excavations. The shallow excavations should be able to be made in the proposed structure/equipment pad areas using conventional open-cut methods and standard construction techniques and equipment.

5.4 Frost Depth According to the local Code Enforcement Office, the minimum burial depth of foundations and/or un-insulated utility lines, including water and sewer pipelines, should not be less than the frost penetration depth of 48 inches or 4.0 feet. Spread footing foundations and utilities that are susceptible to freezing should be placed below this depth or should be protected from frost. Insulation should be provided if pipelines are buried with soil cover less than the frost penetration depth. The insulation should be rigid polystyrene composition (Styrofoam Hi-load 40 or equivalent) and be a minimum of 4-inches in thickness. It is recommended that the minimum depth to the top of the insulation be no less than 1.5-feet below finished grade. Depending upon the insulation properties, additional layers may be required. For pipelines the insulation will extend outwards from the center line of the pipe. The total width of the insulation to be centered over the center line of the pipe can be calculated below.

W = [d + (2 x (F - I))]

Where: d = pipe diameter (ft) F = seasonal frost penetration depth (ft) I = insulation depth below finished grade (ft).

5.5 Uplift Forces due to Adfreezing Stress An adfreeze upward stress of 0.35 tsf (700 psf) is recommended to be applied to the bottom of any foundation element (e.g., equipment slab-on-grade, pile shaft, pile cap) that is less than 4-feet bgs and a value of 85 psf should be used for the sides of the foundation element that is less than 4-feet bgs. If non-frost susceptible fill material (e.g., Select Granular Fill as described in Section 6.2 of this report) is used, the Adfreeze value of 85 psf for the side of the foundation element can be ignored. In addition, if the bottom of the foundation element is located greater than 4-feet bgs, the Adfreeze value of 700 psf can also be ignored. If the dead load of the foundation element and applied load are less than 700 psf, the foundation element must be modified to withstand this uplift force. Where frost-jacking and transient uplift loads (such as wind loads) occur simultaneously, these two loads need not be considered together,



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the larger of the two should be used. If the top of the foundation element is greater than 48 inches below finished grade adfreeze stresses can be neglected.

6.0 FILL & BACKFILL It is the Contractor’s responsibility to identify a source of fill material prior to the work beginning. LaBella recommends that the Contractor submit geotechnical laboratory test results a minimum of 2 weeks prior to any of the earth work commencing for the following analysis:

• Moisture Content (ASTM D2216); • Soil Gradation without Hydrometer (ASTM C117 & C136); and • Modified Proctor (ASTM D1557).

It is also recommended that the test results be no more than 6-months old and that testing shall be conducted for all sources of fill material the Contractor intends to use during the project. No fill material shall be allowed to be brought on-site until the Geotechnical Engineer has been able to review and comment on the laboratory results.

6.1 On-Site Borrow Material On-site native soil contains an appreciable amount of Silt and/or Clay and may be re-used as backfill around isolated spread foundations for planned solar arrays and equipment mat foundations. The on-site soils will be sensitive to moisture, therefore compaction requirements may be difficult to achieve, in which case imported structural fill should be used. Imported structural fill shall be used on the inside of any building foundation walls and in areas where driveways/roadways are planned. If additional passive resistance is needed for the isolated spread foundations, in order to resist overturning or uplift forces, then Select Granular Fill (as described below) will be required.

6.2 Select Granular Fill Material Structural Fill and Subbase Course Material shall consist of Select Granular Fill that shall consist of well-graded sand and gravel or crushed rock product which is capable of being compacted to the required density at the proper moisture content. Select Granular FILL shall be free of deleterious materials, trash, roots, debris, frozen material, organic or other foreign matter. Select Granular Fill material shall be accepted based on gradation, plasticity index and a well-defined Moisture-Density Relationship Curve. Plasticity Index for material passing the No. 40 sieve shall not exceed 5.0. Gradation requirements are as provided in the following table.

Standard Sieve Size % Passing by Dry Weight

4-inch 100

3-inch 90 to 100

2-inch 75 to 100

1-inch 50 to 80

1/2-inch 30 to 60

No. 4 15 to 40

No. 200 0 to 6 Note: Gradation conforms to those provided in the Maine Department of

Transportation Standard Specification Section 703.06 for Type C Aggregate for Base and Subbase.



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6.3 Filling & Backfilling Methodology The exposed grade shall be sealed and proofrolled as described above in this report. All filling and backfilling planned for this project shall be accomplished according to good industry practice and installed in a quality controlled manner with prequalified materials. LaBella recommends that structural tests and inspections be conducted in accordance with the following recommendations:

The area to receive fill shall be properly prepared and dewatered (where applicable). All backfilling shall be conducted in the dry on days without rain.

Fill material shall be placed on the satisfactory subgrade to minimize segregation and shall be placed in nearly horizontal lifts. The lowest elevation fill area shall be where fill/backfill operations begins and then proceed with each lift upward and outward from the lower lift.

The moisture content of the material shall be adjusted prior to application of compaction such that it is within 2 to 3% of the Optimum Moisture Content and may involve adding water when the fill material is too dry, or discing and aerating to reduce moisture when the fill material is too wet.

The compacted lift thickness and minimum in-place field density shall conform to the recommendations provided in the following table:

When the test results indicate that insufficient compaction has been obtained, the Contractor shall take action to modify or alter the moisture content of the soil, provide additional compaction and/or make other adjustments to increase the in-place soil density. If the Contractor cannot obtain satisfactory compaction due to material properties, the Contractor shall remove the unsatisfactory material and replace with new material.

Material which is frozen, or includes: mud, debris, organics or other deleterious materials shall be removed and replaced with clean specified material.

Material shall not be placed over an area or lift of fill that has not been tested and achieved the minimum in-place density requirements.

A minimum of one compaction test per 1,000 square feet shall be performed on each lift of material placed as mass fill areas and a minimum of one test per 20 linear feet per lift placed in confined fill areas.

If inclement weather occurs after achieving acceptable test results, areas subjected to the inclement weather shall be retested to identify if those areas require repair or replacement prior to placing additional fill.

Minimum In-Place Density1

Maximum Compacted Lift

Thickness2

Location

95% 12 inches Mass fill areas where self-propelled compaction equipment is used.

95% 8 inches Confined fill areas (e.g., trenches, foundation walls) when walk-behind compaction equipment is used.

Notes: 1. As determined using ASTM D1557, Modified Effort Proctor. 2. Or compactor manufacturer’s recommended thickness, whichever is less.



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7.0 CONSTRUCTION OBSERVATIONS & TESTING A representative of the geotechnical engineer should be on-site during site preparation activities (e.g., proofrolling), installation of screw piles or drilled shafts, installation of fill, preparation of foundation bearing grades, and any other geotechnical construction related activities. An independent testing lab shall be retained by the owner to perform compaction testing at frequencies noted earlier in this report.

8.0 CLOSING LaBella has prepared this report for the use by University of Maine at Presque Isle exclusively. LaBella’s recommendations with regard to the design of the planned solar arrays are based upon our understanding of the proposed construction and the information obtained from the subsurface exploration. Variations in the subsurface conditions may occur between boring locations or there may be changes in the planned construction during the design phase. As this may be the case, changes to our recommendations may be warranted. Generally accepted soil mechanics and geotechnical engineering practices were used to develop the recommendations stated in this report. Our services were conducted in a manner that is in accordance with generally accepted geotechnical engineering practice. The geotechnical engineer of record should review the final design plans and specifications to evaluate their consistency with LaBella’s recommendations. Prospective bidders should understand that this report was prepared for design purposes only and may not contain sufficient information to prepare an accurate bid. We recommend that LaBella be retained to monitor and observe the bearing grades and subgrades, as well as the push/pull load testing of screw piles prior to construction and during the installation of screw piles.

9.0 DISPOSITION OF SAMPLES LaBella will hold all soil, rock, and/or pavement core samples for 90 days after the date of this report. If the Client desires that these samples be retained for a longer period of time the Client shall notify LaBella in writing and make arrangements to obtain the samples from LaBella prior to the expiration of the 90 day time period; otherwise the samples will be properly disposed by LaBella.



APPENDIX A

FIGURES

GEOENGINEERING SERVICES

SUMMIT

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NORTH

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LaBELLA ASSOCIATES

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PREPARED FOR

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UNIVERSITY OF MAINE AT PRESQUE ISLE - 181 MAIN ST. - PRESQUE ISLE, ME

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CAMPUS SOLAR ARRAY

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LOCATION MAP

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FILE: 20133 BOR

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CHECKED BY: WMP

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SCALE: 1" = 400'

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DRAWN BY: KRF

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JOB: 20133

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DATE: 6-3-2020

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AERIAL IMAGE (SEPTEMBER 28, 2013) WAS OBTAINED FROM GOOGLE EARTH.

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PLAN REFERENCE

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Tel.: (207) 576-3313

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LEWISTON, ME 04240

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145 LISBON ST. - SUITE 701

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www.summitgeoeng.com

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Tel.: (207) 318-7761

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ROCKLAND, ME 04841

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173 PLEASANT STREET

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PRESIDENT'S

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RESIDENCE

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SOLAR ARRAY

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PRESIDENT'S

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RESIDENCE

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SOLAR ARRAY

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FIELD

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SOLAR ARRAY

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FIELD

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SOLAR ARRAY


SUMMIT

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B-1

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NORTH

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LaBELLA ASSOCIATES

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PREPARED FOR

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CAMPUS SOLAR ARRAY

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EXPLORATION LOCATION PLAN 1

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FILE: 20133 BOR

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CHECKED BY: WMP

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SCALE: 1" = 40'

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DRAWN BY: KRF

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JOB: 20133

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DATE: 6-3-2020

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LEGEND

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SUMMIT TEST BORING

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B-1

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"PRESIDENT'S ARRAY - EXISTING CONDITIONS, DEMOLITION, SITE, UTILITY, GRADING AND EROSION CONTROL PLAN - CAMPUS SOLAR ARRAY", DATED APRIL 2020, PREPARED BY LaBELLA ASSOCIATES.

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PLAN REFERENCE

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(MAY 26, 2020)

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Tel.: (207) 576-3313

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LEWISTON, ME 04240

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Tel.: (207) 318-7761

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ROCKLAND, ME 04841

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173 PLEASANT STREET


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B-4

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B-5

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B-3

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B-2

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RESISTIVITY TEST #1

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RESISTIVITY TEST #2

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NORTH

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LaBELLA ASSOCIATES

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PREPARED FOR

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CAMPUS SOLAR ARRAY

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EXPLORATION LOCATION PLAN 2

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FILE: 20133 BOR

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CHECKED BY: WMP

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SCALE: 1" = 80'

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DRAWN BY: KRF

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JOB: 20133

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DATE: 6-3-2020

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LEGEND

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SUMMIT TEST BORING

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B-1

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"MAIN ARRAY - GRADING AND EROSION CONTROL PLAN, CAMPUS SOLAR ARRAY, UNIVERSITY OF MAINE AT PRESQUE ISLE", DATED APRIL 2020, PREPARED BY LaBELLA ASSOCIATES.

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PLAN REFERENCE

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(MAY 26-27, 2020)

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Tel.: (207) 576-3313

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LEWISTON, ME 04240

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Tel.: (207) 318-7761

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ROCKLAND, ME 04841

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173 PLEASANT STREET

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RESISTIVITY TEST LINE



APPENDIX B

BORING LOGS

Exploration Key

145 Lisbon Street (PO Box 7216) Lewiston, Maine 04243 | (207) 576‐3313173 Pleasant Street Rockland, Maine 04841 | (207) 318‐7761 www.summitgeoeng.com

EXPLORATION COVER SHEET The exploration logs are prepared by the geotechnical engineer from both field and laboratory data. Soil descriptions are based upon the Unified Soil Classification System (USCS) per ASTM D2487 and/or ASTM D2488 as applicable. Supplemental descriptive terms for estimated particle percentage, color, density, moisture condition, and bedrock may also be included to further describe conditions. Drilling and Sampling Symbols: S = Split Spoon Sample Hyd = Hydraulic Advancement of Drilling Rods UT = Thin Wall Shelby Tube Push = Direct Push of Drilling Rods SSA = Solid Stem Auger WOH = Weight of Hammer HSA = Hollow Stem Auger WOR = Weight of Rod RW = Rotary Wash PI = Plasticity Index SV = Lab Shear Vane (Torvane) LL = Liquid Limit PP = Pocket Penetrometer MC = Natural Moisture Content C = Rock Core Sample USCS = Unified Soil Classification System FV = Field Vane Shear Test Su = Undrained Shear Strength SP = Concrete Punch Sample Su(r) = Remolded Shear Strength Water Level Measurements: Water levels indicated on the boring logs are the levels measured in the boring at the times indicated. In pervious soils, the indicated elevations are considered reliable groundwater levels. In impervious soils, the accurate determination of groundwater elevations may not be possible, even after several days of observations. Groundwater monitoring wells may be required to record accurate depths and fluctuation. Gradation Description and Terminology: Boulders: Over 12 inches Trace: Less than 5% Cobbles: 12 inches to 3 inches Little: 5% to 15% Gravel: 3 inches to No.4 sieve Some: 15% to 30% Sand: No.4 to No. 200 sieve Silty, Sandy, etc.: Greater than 30% Silt: No. 200 sieve to 0.005 mm Clay: less than 0.005 mm Density of Granular Soils and Consistency of Cohesive Soils:

CONSISTENCY OF COHESIVE SOILS DENSITY OF GRANULAR SOILS

SPT N‐value blows/ft Consistency SPT N‐value blows/ft Relative Density

0 to 2 Very Soft 0 to 4 Very Loose

2 to 4 Soft 5 to 10 Loose

5 to 8 Firm 11 to 30 Compact

9 to 15 Stiff 31 to 50 Dense

16 to 30 Very Stiff >50 Very Dense

>30 Hard

SOIL BORING LOG Boring #: B-1Project: UMPI Campus Solar Array Project #: 20133Location: 181 Main Street Sheet: 1 of 1City, State: Presque Isle, Maine Chkd by: ELS

Drilling Co: Summit Geoengineering Services, Inc. Boring Elevation: 520.7 ft Ref: Boring Locations-Presidents Array and Main Array, Figure 2 & 4Driller: Shawn Floyd LaBella Project #:2200127Summit Staff: Erika Stewart, P.E. Date started: 5/26/2020 Date Completed: 5/26/2020

DRILLING METHOD SAMPLER ESTIMATED GROUND WATER DEPTHVehicle: Track Length: Date Depth Elevation ReferenceModel: 9500 VTR Diameter: 5/26/2020 NE NE None observedMethod: 2¼-inch HSA Hammer:Hammer Style: Auto Method:Depth Elev. SAMPLE Geological/ Geological

(ft.) No. Pen/Rec (in) Depth (ft) blows/6" (ft.) DESCRIPTION Test Data StratumS-1 24/6 0 - 2 4 Loose, brown, SILT and SAND, rootlets, damp TOPSOIL

1 3 520.4 Loose, brown, SILT, little Sand and Gravel, damp 0.3'2 GLACIAL TILL

2 2S-2 24/18 2 - 4 1 Loose, brown, SILT, little Sand and Gravel, damp

3 7 Compact, gray-brown, SAND, some Gravel and 2.3'6 Clayey Silt, damp

4 8

5S-3 24/18 5 - 7 9 Compact to dense, gray-brown SAND, some Gravel and

6 16 Clayey Silt, humid to damp15

7 13S-4 24/24 7 - 9 12 Compact, gray-brown, SAND and GRAVEL, some


9 12

10S-5 24/24 10 - 12 11 Compact to dense, gray-brown, SAND and GRAVEL,

11 24 some Clayey Silt, damp21

12 22

13

14

15S-6 15/12 15 - 16.2 11 Compact to dense, gray-brown, SAND and GRAVEL,

16 14 some Clayey Silt, damp50/3"

17 504.5 End of Exploration at 16.2', Spoon & Auger Refusal 16.2'on Bedrock BEDROCK

18

19

20

21

22

NOTES: PP = Pocket Penetrometer, MC = Moisture Content, Soil Moisture ConditionGranular Soils S = Split spoon sample, LL = Liquid Limit, PI = Plasticity Index, Dry: S = 0%

Blows/ft. Blows/ft. Consistency Humid: S = 1 to 25%0-4 <2 V. soft (Slaty rock) = Gravel particles consisting of flat, elongated Damp: S = 26 to 50%5-10 2-4 Soft jagged weathered rock fragments. Moist: S = 51 to 75%11-30 5-8 Firm Wet: S = 76 to 99%31-50 9-15 Stiff Saturated: S = 100%>50 16-30 V. Stiff Boulders = diameter > 12 inches, Cobbles = diameter < 12 inches and > 3 inches

>30 Hard Gravel = < 3 inch and > No 4, Sand = < No 4 and >No 200, Silt/Clay = < No 200

24" SS2"OD/1.5"ID140 lbASTM D1586

V. LooseLoose

CompactDense

V. Dense

0-10% trace10-20% little20-35% some35-50% and

BURMISTER SOIL IDENTIFICATION METHODCohesive Soils % Composition

DescriptionDensity



DRILLING METHOD SAMPLER ESTIMATED GROUND WATER DEPTHVehicle: Track Length: Date Depth Elevation ReferenceModel: 9500 VTR Diameter: 5/27/2020 12 ft +/- 528.7 ft Observed moisture contentMethod: 2¼-inch HSA Hammer: 5/27/2020 Caved at 10.1 ft - Dry Measured in open boreholeHammer Style: Auto Method:Depth Elev. SAMPLE Geological/ Geological

(ft.) No. Pen/Rec (in) Depth (ft) blows/6" (ft.) DESCRIPTION Test Data StratumS-1 24/18 0 - 2 1 Soft, brown SILT, little Sand, rootlets, damp TOPSOIL

1 2 540.6 Loose, brown, fine SAND, some Clayey Silt, little 0.1'3 Gravel, damp GLACIAL TILL

2 3S-2 24/0 2 - 4 3 No sample recovery

3 44

4 54'+/-

5S-3 24/18 5 - 7 6 Compact, brown, SAND and GRAVEL, some

6 6 Clayey SILT, damp6

7 8S-4 24/12 7 - 9 9 Compact, gray-brown, SAND and GRAVEL, some Clayey

8 12 Silt, damp14

9 15

10S-5 24/24 10 - 12 8 Compact, gray-brown SAND and GRAVEL, some

11 9 Clayey Silt, damp to moist9

12 8

13

14

15S-6 24/15 15 - 17 6 Compact, gray-brown, SAND and GRAVEL, some Clayey

16 6 Silt, moist to wet7

17 7

18

19

20520.7 End of Exploration at 20', No Refusal 20'

21

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24" SS2"OD/1.5"ID140 lbASTM D1586

V. LooseLoose

CompactDense

V. Dense



DescriptionDensity



DRILLING METHOD SAMPLER ESTIMATED GROUND WATER DEPTHVehicle: Track Length: Date Depth Elevation ReferenceModel: 9500 VTR Diameter: 5/26/2020 Caved at 5.8 ft - Dry Measured in open boreholeMethod: 2¼-inch HSA Hammer: 5/26/2020 6.5 ft 536.6 ft Observed moisture contentHammer Style: Auto Method:Depth Elev. SAMPLE Geological/ Geological

(ft.) No. Pen/Rec (in) Depth (ft) blows/6" (ft.) DESCRIPTION Test Data StratumS-1 24/24 0 - 2 1 Soft, brown SILT, little Sand, rootlets, damp TOPSOIL

1 2 543.0 Soft, brown to light brown, SILT & CLAY, little fine PP = 2,000 to 0.1'1 Sand, damp 4,000 psf GLACIAL MARINE

2 2 DEPOSITS-2 24/24 2 - 4 4 Stiff, light brown, SILT & CLAY, occasional fine PP = 3,000 to

3 6 Sand lenses, damp to moist 6,000 psf5

4 6

5S-3 24/24 5 - 7 3 Firm, light brown, Clayey SILT, and fine Sand, moist PP = 3,000 to

6 3 to wet 5,000 psf3

7 5 536.6 Compact, brown and mottled, SAND and GRAVEL, some Water at 6.5' 6.5'S-4 24/12 7 - 9 8 Clayey Silt, wet GLACIAL TILL

8 84 Compact, brown to gray, SAND and GRAVEL, some

9 5 Clayey Silt, wet

10S-5 10/10 10 - 10.8 9 Compact, brown to gray, same as above, wet

11 50/4" 532.6 Weathered rock in spoon tip. Spoon refusal at 10.8' 10.5' WEATHERED ROCK532.1 Auger advanced 3 inches into bedrock 11' BEDROCK

12 531.9 End of Exploration at 11.2', Auger Refusal on Bedrock 11.2'

13

14

15

16

17

18

19

20

21

22




24" SS2"OD/1.5"ID140 lbASTM D1586

V. LooseLoose

CompactDense

V. Dense



DescriptionDensity



DRILLING METHOD SAMPLER ESTIMATED GROUND WATER DEPTHVehicle: Track Length: Date Depth Elevation ReferenceModel: 9500 VTR Diameter: 5/27/2020 9.1 ft 535.8 ft Measured in open borehole,*rained overnight*Method: 2¼-inch HSA Hammer: 5/26/2020 12 ft +/- 532.9 ft Observed moisture contentHammer Style: Auto Method:Depth Elev. SAMPLE Geological/ Geological

(ft.) No. Pen/Rec (in) Depth (ft) blows/6" (ft.) DESCRIPTION Test Data StratumS-1 24/24 0 - 2 2 Firm, dark brown, SILT, some Sand, rootlets, damp TOPSOIL

1 2 544.8 Firm, brown, Clayey SILT, little Sand and Gravel, damp PP = 3,000 to 0.1'3 5,000 psf GLACIAL TILL

2 3S-2 24/15 2 - 4 4 Stiff, brown and mottled, Clayey SILT, some Sand and

3 7 Gravel (slaty rock), damp6

4 84'+/-

5S-3 24/12 5 - 7 7 Compact, gray-brown, SAND and GRAVEL, some


7 12S-4 24/24 7 - 9 10 Dense, gray-brown, SAND and GRAVEL, some Clayey

8 16 Silt, humid to damp19

9 21Water at 9.1'*

10 *(Rained overnight)S-5 24/24 10 - 12 12 Dense, gray-brown, SAND and GRAVEL, some Clayey

11 23 Silt, damp to moist26

12 25

13

14

15S-6 14/14 15 - 16.1 9 Compact, gray-brown, SAND and GRAVEL, some

16 16 Clayey Silt, moist 50/2"

17 528.8 Spoon Refusal on Bedrock at 16.1'. Auger advanced 16.1'slowly into bedrock. BEDROCK

18

19525.9 End of Exploration at 19', Auger Refusal 19'

20

21

22




24" SS2"OD/1.5"ID140 lbASTM D1586

V. LooseLoose

CompactDense

V. Dense



DescriptionDensity



DRILLING METHOD SAMPLER ESTIMATED GROUND WATER DEPTHVehicle: Track Length: Date Depth Elevation ReferenceModel: 9500 VTR Diameter: 5/27/2020 9.2 ft 536.3 ft Measured in open borehole,*rained overnight*Method: 2¼-inch HSA Hammer: 5/26/2020 10 ft +/- 535.5 ft Observed moisture contentHammer Style: Auto Method:Depth Elev. SAMPLE Geological/ Geological

(ft.) No. Pen/Rec (in) Depth (ft) blows/6" (ft.) DESCRIPTION Test Data StratumS-1 24/18 0 - 2 2 Firm, dark brown, SILT, some Sand, rootlets, damp TOPSOIL

1 2 545.4 Firm, brown and mottled, Clayey SILT, some Sand, little PP = 4,000 to 0.1'2 Gravel (slaty rock), damp 6,000 psf GLACIAL TILL

2 3S-2 24/18 2 - 4 3 Stiff, same as above, damp

3 33 Firm to loose, brown-gray and mottled, SILT and 3' +/-

4 3 fine Sand, moist

5 4.5' +/-S-3 24/15 5 - 7 8 Compact, brown and mottled, SAND and GRAVEL, some

6 12 Clayey Silt, humid to damp17 (Rock in spoon tip, pushed cobble)

7 20S-4 24/24 7 - 9 7 Compact gray-brown, SAND and GRAVEL, some Clayey

8 11 Silt, damp15

9 16Water at 9.2'*

10 *(Rained overnight)S-5 24/24 10 - 12 9 Compact, gray-brown, SAND and GRAVEL, some Clayey

11 13 SILT, damp to moist12

12 11

13 533.0 Increased auger resistance on dense stratum at 12.5', 12.5' +/-presumed to be weathered rock. Auger advanced to 15'. WEATHERED ROCK

14

15S-6 3/0 15-15.2 50/3" 530.5 Attempted spoon at 15', no sample recovery. Spoon 15' +/-

16 Refusal on Bedrock at 15'. Auger continued to BEDROCKadvance slowly into bedrock.

17

18

19 527.0 End of Exploration at 18.5' 18.5'

20

21

22




Dense

2"OD/1.5"ID140 lbASTM D1586

V. Dense

24" SS



DescriptionDensityV. LooseLoose

Compact



APPENDIX C

WENNER 4-PIN RESISTIVITY FIELD REPORT

Date: 5/27/2020

Project: UMPI Campus Solar Array

Project #: 20133

Summit Personnel: Erika Stewart, P.E.

Site Location:

Field Summary:

Test Results:

Factor 191.5

A-Spacing RT-1 (Ohm) RT-2 (Ohm) RT-1 (Ohm-cm) RT-2 (Ohm-cm) RT-1 (Ohm-m) RT-2 (Ohm-m)

2 450 240 172,350 91,920 1,724 919

5 100 48 95,750 45,960 958 460

10 25 19 47,875 36,385 479 364

15 16 16 45,960 45,960 460 460

20 16 7 61,280 26,810 613 268

25 13 9 59,844 40,694 598 407

30 20 6 114,900 34,470 1,149 345

35 8 6 50,269 40,215 503 402

40 6 7 42,130 49,790 421 498

45 2 1 17,235 11,203 172 112

50 5 5 43,088 43,088 431 431

MINIMUM: 17,235 11,203 172 112

MAXIMUM: 172,350 91,920 1,724 919

AVERAGE: 68,244 42,409 682 424

Remarks:

WENNER 4 PIN RESISTIVITY FIELD REPORT

University of Maine at Presque Isle - 181 Main Street, Presque Isle, Maine

Performed Wenner 4-Pin resistivity test #1 (RT-1) west to east from B-2 towards B-3 in the proposed solar array footprint. Resistivity test #2 (RT-2) was performed north to south adjacent to B-3 and B-5 in the proposed solar array footprint. Resistivity testing was performed using a Miller 400A. Resistivity testing was performed using the Wenner Four Probe method in accordance with ASTM G57. Probe spacing ranged from 2 to 50 feet for RT-1 and RT-2. Resistivity results for the pin spacing are presented in the following table. Resistivity values were calculated using the following equations:

Resistivity (p) in ohm-cm = 2*π*a*R (a=electrode spacing in cm, R=resistance in ohms)

Resistivity (p) in ohm-cm = 191.5*a*R (a=electrode spacing in ft, R=resistance in ohms)

145 Lisbon Street (PO Box 7216), Lewiston, Maine 04243, (207) 576‐3313

173 Pleasant Street, Rockland, Maine 04841, (207) 318‐7761

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