Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation under the

prepared for

New England Power Company d/b/a National Grid Waltham, MA

July 2013

Project No. 53411

prepared by

Burns & McDonnell Engineering Company, Inc. Kansas City, Missouri

COPYRIGHT © 2013 BURNS & McDONNELL ENGINEERING COMPANY, INC.

Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Executive Summary EXECUTIVE SUMMARY

Burns & McDonnell (BMcD) was requested to conduct an investigation into the feasibility and costs for installing the new S-145 and T-146 circuits under Salem Harbor via a Horizontal Directional Drill (HDD) for the purposes of avoiding a land installation through parts of Salem, MA. In support of this request, BMcD, along with their subconsultant Haley & Aldrich, Inc. (H&A), has prepared this Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor. Please note the following clarifications: • This Feasibility Study is limited to the installation of electrical cables under Salem Harbor via HDD and does not reflect on other electrical cable or HDD projects. All other projects should be evaluated independently on their own merits. • This Feasibility Study does not compare the installation of the cables via HDD to other potential installation alternatives including underground or overhead cables. • This Feasibility Study does not identify, or include the cost of obtaining, the environmental, construction and zoning permits required for the installation of electrical cables under Salem Harbor via HDD, nor does it make a determination of the feasibility of acquiring said permits.

In conducting this study, representatives of New England Power Company d/b/a National Grid (NEP), BMcD, and H&A visited the project site to evaluate proposed horizontal directional drill work zones. Based on the electrical and physical installation requirements of the project, the appropriate cable technology for the installation was selected. Available information from internal and external sources was then compiled and reviewed relative to subsurface conditions, including areas of contaminated ground. Additionally, reports prepared for the City of Salem and the US Army Corps of Engineers relative to planned and existing use of Salem Harbor were obtained and reviewed. Finally, utilizing this accumulated information, the following issues associated with this installation were evaluated:

• Work area for drilling and pipe installation • HDD alignments across Salem Harbor, including potential platform locations. • Existing geological conditions • Existing biological conditions in the harbor • Contamination of existing soil and water in the planned work locations • Future land uses such as a proposed deep water cruise terminal • Existing utilities and structure foundations along the proposed alignment(s) • Street or land-based construction from the HDD end points to the substations

New England Electric Power Company 1 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Executive Summary • Cost and schedule risks associated with the installation of the harbor crossing via HDD construction • Estimates of probable construction costs for this project alternative.

As this evaluation was performed with regard to technical feasibility only, it does not address permitting or property rights acquisition associated with the HDD installation.

The results of this investigation are summarized below.

Installation Summary NEP seeks to install two 115 kV circuits (the S-145 and the T-146) connecting the Company’s Salem Harbor Substation and its Canal Street Substation. High-Pressure Fluid-Filled (HPFF) cable is recommended for use for this HDD project alternative. An HPFF cable system consists of three cables, one of each phase, installed in a single cable pipe. To meet the required ratings, each circuit will consist of three cables per phase; therefore, six total cable pipes will be necessary for the two circuits for the length of the project. For the HDD portion, each cable pipe would be installed via a single bore from a given launch point to a given receive point, with a minimum separation between each as necessary to achieve the ratings at various points along the HDD alignment.

Each circuit would enter Salem Harbor near the Salem Harbor Power Plant, and exit Salem Harbor at the Palmer baseball field. Due to the subsurface space constraints, the two circuits would be split between two launch locations for the northeastern HDD end points near the Salem Harbor Power Plant. These locations are shown on the figure below as Entry/Exit Point #1 and Entry/Exit Point #2.

Due both to the need for cable pull points, and to the lack of work space at the end points of the HDDs for assembling pipe for long pulls across the harbor, temporary, pile-supported mid-harbor platforms would be needed. Utilizing these platforms, the pipe could be assembled adjacent to land and floated into position for pullback at reasonable lengths. The following figure shows the anticipated alignment, platform locations, and segment identifications:

New England Electric Power Company 2 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Executive Summary

Segment D would consist of six separate bores for both circuits, Segment A three separate bores for one circuit, and Segment E three separate bores for one circuit. It is possible that further evaluation of subsurface conditions within the harbor could lead to the conclusion that Segment E (the longest segment) is infeasible to construct. In that case, Segment E could be split into Segments B and C, requiring the addition of a second mid-harbor platform. Therefore, either 12 or 15 individual bores would be required to install the two circuits.

Approximately 1.0 to 1.5 miles of land-based construction through City of Salem streets would also be required to bring the S-145 and T-146 circuits from the southwest end of the HDD at the Palmer Cove baseball field to the Canal Street Substation. Due to the width of the corridor necessary to house three parallel steel pipes, the two circuits would follow separate routes for most of the distance between the baseball field and the substation. Shorter land-based cables would also be required within the Salem Harbor Power Plant site to bring the S-145 and T-146 cables from the HDD end point to the substation.

Factors Affecting HDD Feasibility There are several risk factors that could affect the ease with which the HDD can be completed. First, there is limited information available on the existing geological conditions for the harbor. This increases the likelihood of discovering unfavorable subsurface conditions. Unfavorable subsurface conditions

New England Electric Power Company 3 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Executive Summary could lead to potential drill stem or pipe failure or collapse of the bore hole. Either of these results could increase the duration or the cost (or both) of the HDD.

In addition, available data suggests that contaminated soils may be present at both the Salem Harbor Power Plant site and the Palmer Cove baseball field, which is located on the site of a capped landfill. Cross-contamination could occur during the HDD if a bore hole were to transmit contaminated ground water to previously uncontaminated areas or underground aquifers. An environmental mitigation plan would decrease, but not eliminate, the likelihood of such cross-contamination.

The HDD process may also result in inadvertent return of drill mud to the surface (frac-out) at unplanned locations (i.e. a location in between launch and receive points). As pressured mud is used to maintain borehole integrity and to remove soil cuttings, success of the drilling operation could be jeopardized.

Because of the long pull length required for this project, HPFF cable is recommended for this installation. However, there is currently only one manufacturer of HPFF cable in the United States. As of the issuance of this report, that manufacturer is quoting lead times of twenty-four to thirty months for new cable orders. Thus, it may be impossible for NEP to obtain the required materials and construct the project before the proposed Footprint Plant expects to come online.

Cost The anticipated cost of the HDD installation, including both HDD and land-based installation of the steel cable pipes plus cable and dielectric fluid installation, is estimated to be $109,640,000 at a tolerance level of +50/-25%. This cost estimate does not include the costs related to improvements needed at the Canal Street and Salem Harbor substations, permitting costs for the cables or substation improvements, or AFUDC and similar costs.

Schedule The total duration of the HDD installation alternative is expected to be approximately fourteen to sixteen months. This includes seven to nine months actual drilling and pipe installation time from a platform (or platforms) in Salem Harbor, concurrent land-based installation, plus the remaining time to pull and splice cables, make final pipe welds around the splices, overboard the platform-constructed splices into the harbor, and disassemble and remove the platforms.

Long Term Maintenance Issues A permanent installation of this type presents several long-term maintenance issues. First, should a cable failure occur along the under-harbor portion, it would be difficult to identify and locate the problem area.

New England Electric Power Company 4 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Executive Summary Once the problem area is located, a similar level of effort as the initial construction would be needed in order to remedy the issue. This effort would include the construction of a mid-harbor platform, excavation of the direct-buried splice, pulling of the new cable, and reinstalling the repaired splice back into the harbor. Any leakage of the dielectric fluid from a damaged cable pipe would be released into Salem Harbor.

Additionally, permanent restrictions would be required within the harbor near the location(s) of the mid- harbor platform(s), due to the shallow burial of the cable pipes in those locations. The total trench lengths at the mid-harbor platform(s) are anticipated to be approximately 300 feet long. The permanently restricted areas would be approximately 200 feet wide by 500 feet long at each platform location so to encompass a portion of the HDD-installed pipe as it dives to a deep enough depth below the sea floor to be considered safe from outside impacts. Examples of the type of activities that could be prohibited within this zone would include dredging, exploratory borings, installation of new moorings, use of spud barges, and anchoring of larger ships.

Finally, because HPFF cables would be necessary, there would be regular inspection and maintenance needs for the dielectric fluid pumping plant, as well as the added maintenance procedure to rotate the spare cable reel(s) every three months in order to keep the cable impregnated with the dielectric fluid.

Summary Overall, the project appears to be technically feasible, but with risks, costs, and other considerations as identified and discussed in detail within this document. It should be noted that this analysis is specific to this project only and the various factors associated with it. For other projects that may be proposed for different purposes and/or with different location-specific constraints and considerations, a potential HDD installation would be evaluated based on the unique and particular aspects of those projects, and may yield different results.

New England Electric Power Company 5 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Table of Contents

TABLE OF CONTENTS

Page No.

1.0 INTRODUCTION ...... 1-1

2.0 ELECTRICAL REQUIREMENTS ...... 2-1 2.1 Cable Technology ...... 2-1 2.2 Ampacity Requirements ...... 2-2 2.3 Determination of Size and Number of Cables Required ...... 2-3

3.0 HDD INSTALLATION ...... 3-1 3.1 Existing Harbor Conditions ...... 3-1 3.2 Factors Affecting HDD Feasibility ...... 3-10 3.3 Evaluation of HDD Alignments ...... 3-15 3.4 HDD Pipe Stresses ...... 3-24 3.5 HDD Feasibility Factors ...... 3-28 3.6 Project Risk Register ...... 3-37 3.7 Conclusions and Recommendations ...... 3-45

4.0 CABLE PULLING ...... 4-1

5.0 LAND ROUTES ...... 5-1 5.1 Canal Street Substation ...... 5-1 5.2 Salem Harbor Substation ...... 5-2

6.0 COMPLICATIONS AND LONG TERM MAINTENANCE ISSUES ...... 6-1

7.0 CONSTRUCTION COST ESTIMATE OVERVIEW ...... 7-1 7.1 Summary of Construction and Easement Acquisition Costs ...... 7-1

8.0 ANTICIPATED CONSTRUCTION SCHEDULE ...... 8-1

APPENDIX A CABLE PULLING CALCULATIONS

APPENDIX B LAND ROUTE COST ESTIMATES

New England Electric Power Company i Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Table of Contents APPENDIX C HDD DURATION OF INSTALLATION AND ESTIMATED COSTS

APPENDIX D EASEMENT ACQUISITION ESTIMATED COSTS

APPENDIX E PIPE STRESS CALCULATIONS

APPENDIX F SOURCES OF INFORMATION

New England Electric Power Company ii Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 List of Figures

LIST OF FIGURES

Page No.

Figure 2-1 HPFF Pulling Head ...... 2-1 Figure 2-2 Required Duct Bank Cable Ampacity Summary ...... 2-4 Figure 3-1 Salem Harbor Depth of Water at Low Tide ...... 3-2 Figure 3-2 Natural Resources in Salem Harbor ...... 3-7 Figure 3-3 Harbor Dredging Plan ...... 3-9 Figure 3-4 Borehole Upsizing as a Percentage of Final Product Pipe Size ...... 3-11 Figure 3-5 Maxi Rig Typical Layout with Surface Support Equipment ...... 3-12 Figure 3-6 Typical Multi Drill Set Up for Maxi Rig ...... 3-13 Figure 3-7 Typical HDD Pipe Side Operations ...... 3-14 Figure 3-8 HPFF Pipe Being Assembled for Pull Back ...... 3-15 Figure 3-9 Ocean Avenue Area with Dense Residential Housing ...... 3-16 Figure 3-10 Blaney Street Wharf Area ...... 3-16 Figure 3-11 Salem Harbor Power Plan South Side – Potential HDD Work Zone ...... 3-17 Figure 3-12 Steel Sheeting at Shipping Berth, South Side of Salem Harbor Power Plant .... 3-18 Figure 3-13 Palmer Cove Ball Field ...... 3-19 Figure 3-14 Palmer Cove ...... 3-19 Figure 3-15 HDD Work Zone North Side of Salem Harbor Power Plant ...... 3-21 Figure 3-16 Bedrock Outcrop (In Red) on North Side of Salem Harbor Power Plant ...... 3-21 Figure 3-17 Typical Mid-Harbor Drilling Platform ...... 3-22 Figure 3-18 Typical Profile of HDD Approach to Harbor Platform ...... 3-23 Figure 3-19 Recommended HDD Alignments and Platforms ...... 3-24 Figure 3-20 HDD Segment Designations ...... 3-25 Figure 3-21 Bottom of Clay Contours at Tank Farm South of Power Plant ...... 3-31 Figure 3-22 Record Information on Steel Sheet Pile Seawall at Shipping Berth, South Side of Power Plant ...... 3-34 Figure 3-23 Approximate HDD Alignments from North and South Sides of Power Plant ... 3-35 Figure 3-24 HDD Alignment from Platform 1 to Palmer Cove Ball Field ...... 3-37 Figure 3-25 Increase in Risk (As a Percentage of Baseline Construction Cost) by Length of Bore and Geology ...... 3-38 Figure 4-1 Cable Pulling Calculation Summary ...... 4-1 Figure 5-1 Canal Street Substation Land Paths ...... 5-2 Figure 5-2 Salem Harbor Substation Land Routes ...... 5-3 Figure 7-1 Summary of Construction Costs ...... 7-1 Figure 8-1 Schedule ...... 8-1

New England Electric Power Company iii Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Introduction 1.0 INTRODUCTION

Burns & McDonnell (BMcD) has teamed with Haley & Aldrich (H&A) to perform a feasibility analysis of a potential Horizontal Directional Drill (HDD) installation under Salem Harbor for the replacement of the S-145 and the T-146 115-kV circuits. This study identifies potential launch and receive points for the HDD, identifies land routes from the HDD launch points to the Canal Street and Salem Harbor Substations, provides cost estimates for the HDD and for on-land construction, and evaluates potential constructability and long term maintenance issues associated with an under-harbor cable.

H&A has investigated the directional drilling and casing installation, and BMcD has evaluated the land portion and overall cable installation. The following document describes BMcD’s and H&A’s methodology and results from this investigation with regard to the feasibility and risk associated with the harbor crossing.

New England Electric Power Company 1-1 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Electrical Requirements 2.0 ELECTRICAL REQUIREMENTS

2.1 CABLE TECHNOLOGY There are two basic types of cable technology suited for use in underground transmission projects: HPFF cables; and solid-dielectric cables with cross-linked polyethylene (XLPE) insulation. For an HDD installation across Salem Harbor, the most appropriate cable technology is HPFF cables. There are three primary reasons that this technology is superior to other cable technologies for this project: allowable pull length, borehole diameter, and sheath bonding requirements.

2.1.1 Allowable Pull Length Typically, HPFF cables allow for cable pulls approximately 25 to 50 percent longer than pulls for a comparable XLPE cable. At the time of installation, HPFF cables are individually smaller and lighter than a comparable XLPE cable, because the dielectric fluid that serves as the primary cable insulation is installed after the cables are pulled. The lighter weight of the HPFF cable allows for longer cable length on a reel. Additionally, as all three phase cables are pulled into a single cable pipe as a bundle, the tension during the pull is distributed between the three cables via use of a pulling head attached to all three conductors as shown in Figure 2-1.

Figure 2-1 HPFF Pulling Head

New England Electric Power Company 2-1 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Electrical Requirements 2.1.2 Borehole Diameter Because three cables are installed in a single cable pipe for an HPFF installation, as opposed to one cable installed in a single conduit for an XLPE installation, the total number and/or size of bore holes required is significantly less for an HPFF installation. For this project, each set of three HPFF cables would be able to be installed in a single 8-inch diameter steel pipe, which would consequently require an approximate 12- to 15-inch-diameter bore hole (bore holes for HDD installations are typically required to be approximately 1.5 times the diameter of the pipe or conduit to be pulled through). This contrasts with an XLPE installation in which individual conduits would be required for each cable of each phase, and therefore require a much larger (24 to 36 inches) bore hole to carry a group of three or six conduits, or, if each conduit were installed in a separate small bore hole comparable to that required for a single HPFF pipe, a larger total number of bore holes.

2.1.3 Sheath Bonding Requirements Conventional land-based XLPE cables use a sheath grounding scheme to minimize circulating currents and maximize ratings. These types of schemes (single point- or cross-bonding) require the installation and maintenance of accessible link boxes, which are typically installed at manhole locations. In a submarine setting, there would be no manholes, and therefore no means of installing and maintaining link boxes. The submarine XLPE cable system therefore would have to employ a multi-point bonding arrangement for grounding. This arrangement would result in increased circulating currents and reduced cable ampacity, and thus require additional cable to meet the ratings requirement. Furthermore, a submarine splice on an XLPE system is not typically done, and would therefore require a custom splice design.

2.2 AMPACITY REQUIREMENTS The new S-145 and T-146 transmission lines are required to achieve a summer normal rating of 300 MVA and a 12-hour summer emergency rating of 400 MVA. The ampacities were calculated based on the following assumptions:

• Maximum conductor temperatures of 85ºC (HPFF) under normal operating conditions and 105 ºC under emergency operating conditions • Emergency calculations completed for a 12-hour duration • All emergency calculations assume 100% steady state 300 MVA preload before entering emergency conditions, even if this is less than then maximum achievable normal loading of the cables.

New England Electric Power Company 2-2 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Electrical Requirements • Actual maximum calculated normal ampacity, based on a conductor temperature equal to 85°C, may exceed required normal rating; however, cables operated in this condition will not meet the required emergency rating. • Load Factor is assumed to be 0.90 for all configurations

2.3 DETERMINATION OF SIZE AND NUMBER OF CABLES REQUIRED Based on the potential HDD alignments and landfall locations discussed in Section 3.0 of this report, three controlling locations were analyzed as part of this study to determine the size and number of cables required: at the Salem Power Plant, at the midpoint of the alignment under Salem Harbor, and at the ball field west of Palmer Cove. The following assumptions were made regarding the thermal resistivity of the soils (“thermal rho”) and the ambient earth temperatures at these locations, based on previous work in the Northeast United States:

• Thermal rho: 150 ºC cm/W at the ball field; 250 ºC cm/W at the midpoint of the alignment under Salem Harbor; and 220 ºC cm/W at the sea wall. • Summer ambient earth temperature: 20 ºC at the ball field; 15 ºC at the midpoint of the alignment under Salem Harbor; and 18 ºC at the sea wall.

The three controlling locations are discussed in further detail as follows:

2.3.1 Power Plant Installation Location At the entrance/exit point south of the Salem Harbor Power Plant, the HDD would need to descend to a depth of approximately 70 feet to pass under a seawall without damaging the existing sheeting and piles. Most of the soil in this area is fill that was used to build up this area of the power plant site. The fill would likely consist of large pieces of broken concrete and large aggregate fill with large void areas in which heat could be trapped. This trapped heat would raise the temperature of the cables and cause a de- rating of the cable. This de-rating impact contributes to the number of cables per phase needed to reach the required ratings.

2.3.2 Harbor Mid-Point Installation Location The second location that was analyzed was at the mid-point of the harbor, well away from the mid-harbor drilling platform. At this location, the bores would be approximately 60 to 70 feet below the bottom of the harbor. The harbor floor contains a thick stratum of organic matter that can trap the heat below the surface. This trapped heat would raise the temperature of the cables and cause a de-rating of the cable. This organic layer along with the needed depth contributes to the number of cables required per circuit.

New England Electric Power Company 2-3 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Electrical Requirements 2.3.3 Baseball Field Installation Location The final location analyzed was the point where the bores surface within the ball fields west of Palmer Cove. In this area, the bores are at their shallowest position as they ascend to the surface. The soil in this area has the potential to be best for the bores as it relates to thermal properties. The combination of better thermal properties of the soil and shallow depth leads to a drastic decrease in the required separation of the bores. If the further investigation reveals that this area was once a landfill that contains highly organic soil and large voids, the minimum separation will need to be increased.

2.3.4 Summary Table Based on the three locations identified above, Figure 2-2 shows the cable size and minimum separation between cables pipes necessary to achieve the ampacity rating required for the project.

Figure 2-2 Required Duct Bank Cable Ampacity Summary Location Number Required Minimum Separation Ratings (edge-to-edge) (MVA) Location 1 (3500 kcmil HPFF Cable, 300 Normal, 30’ three cables per phase), Salem Harbor 400 Emergency Power Plant Location 2 (3500 kcmil HPFF Cable, 300 Normal, 35’ three cables per phase), Salem Harbor 400 Emergency Mid-Point Location 3 (3500 kcmil HPFF Cable, 300 Normal, 5’ three cables per phase), Ball Field 400 Emergency

New England Electric Power Company 2-4 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.0 HDD INSTALLATION

H&A completed a thorough feasibility analysis of the installation of cable pipes under Salem Harbor using HDD technology. This analysis begins with an examination of existing conditions within Salem Harbor and at the proposed HDD entrance/exit points at the Salem Harbor Power Plant site and the Palmer Cove baseball field (Section 3.1). Section 3.2 presents a summary of the factors that can affect the feasibility of HDDs generally. Section 3.3 addresses issues associated with HDDs from the north and south sides of the power plant site to the Palmer Cove baseball field, and addresses the use of mid-harbor platforms to complete the drill. Section 3.4 evaluates potential stresses on the HDD pipe along each potential drill alignment to verify that the proposed drills are feasible from a pipe stress perspective. Section 3.5 evaluates the impact of existing contamination and geological conditions on the feasibility of each drill segment. Section 3.6 catalogs the risk factors that could impede progress on each segment of the drill, resulting in higher costs, a longer schedule, or failure of the HDD. Finally, Section 3.7 summarizes the evaluation of HDD feasibility.

3.1 EXISTING HARBOR CONDITIONS 3.1.1 Introduction The potential HDD alignments cross Salem Harbor in a roughly northeast-southwest trending arc with entrance/exit points at or adjacent to the Salem Harbor Power Plant on the west side of , and in or just south of Palmer Cove and Palmer Cove Park and Playground. Sources of geologic and topographic information in the vicinity of the proposed HDD alignment include the NOAA Provisional Chart for Salem, Marblehead, and Beverly Harbors, USGS Open-File Report 2006-1260B: Surficial Geologic Map of the Salem Depot-Newburyport East-Wilmington-Rockport 16-Quadrangle area in Northeast and the accompanying surficial geologic map of Salem Quadrangle, as well as existing geotechnical and environmental data reports by H&A, Ransom Environmental Consultants, Inc., and GEI Consultants, Inc. Environmental conditions along the potential HDD entrance, exit and alignment paths were assessed by reviewing available information on listed disposal sites on the Massachusetts Department of Environmental Protection (MassDEP) website and at the MassDEP Northeast Region office located in Wilmington, Massachusetts.

3.1.2 Harbor Bathymetry As shown in Figure 3-1 below, depths from mean low-low water level to the mudline range from 1 to 10 feet in Cat Cove, and from 0.5 to 8 feet in the Palmer Cove area. In Salem Harbor, depths to the mudline in the vicinity of the proposed alignment range from approximately 1 to 15 feet, with the exception of the

New England Electric Power Company 3-1 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation area along the dredged Salem alignment, where depths range from 29 to 37 feet. Widths across the channel range from approximately 150 to 200 feet.

Figure 3-1 Salem Harbor Depth of Water at Low Tide

3.1.3 Stratigraphy Overburden soils, when present in the area, are expected to consist of Fill, Organic Soil, Marine Clay Deposits, and Glacial Till Deposits. The Glacial Till Deposits can be expected to contain cobbles and boulders. This sequence reflects the general order of occurrence of these units below ground surface. One or more of these units may be absent at a specific location.

Bedrock in the vicinity of the proposed alignment is believed to consist of igneous Salem Gabbro-Diorite. The Salem Gabbro-Diorite is generally a massive dark gray to green, medium to fine grained, augite- biotite-hornblende Diorite and Gabbro. The bedrock tends to be highly jointed with numerous shear zones and minor faults, which may impact the HDD methods, depending on the orientation, frequency and material in the shear zones. Typical physical parameters for the Salem Gabbro-Diorite, based on information from existing project files, are: unit weight of 180 pounds per cubic foot (pcf), and unconfined compressive strength of 20,000 to 32,000 pounds per square inch (psi). The contractor that

New England Electric Power Company 3-2 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation installed the HubLine Gas Transmission project in nearby Beverly Harbor by HDD noted in a published report that it encountered rock as hard as 40,000 psi, which required the manufacture of special tooling.

The USGS Surficial Geologic map of Salem Harbor identifies numerous bedrock outcrops in the vicinity of the proposed alignment, including at the north end of Salem Neck (between Cat and Collins ), at the south end of Palmer Cove, and in the vicinity of Forest River Park (near Pickering Point). Data available from limited test borings performed in the area indicate depths to bedrock near Cat Cove may range from 4 to 90 feet; borings in the Derby Street area encountered bedrock from 55 to 60 feet below ground surface. Based on the available information, it is anticipated that the bedrock surface topography will be highly variable.

3.1.4 Environmental Conditions 3.1.4.1 Palmer Cove Area The southwestern entrance/exit point for the potential HDD alignments would be located at Palmer Cove, approximately 4,000 feet southwest of the Salem Harbor Power Plant (see Figure 3-20). The Palmer Cove Yacht Club is located in this area, as are the Palmer Cove Ball Field and Park.

The Palmer Cove ball field is believed to be located on a capped landfill. No information is available in MassDEP files for former and current landfills in Salem, Massachusetts. However, aerial photographs depict the landfill area as cleared in 1955, while the baseball diamond and apartments currently located in this area are clearly depicted in the 1977, 1986, 1995, 2006, and 2008 aerial photographs.

An 18 August 2011 correspondence with David Adams of MassDEP indicated that although the Palmer Cove Dump is listed as a formerly active landfill in the City of Salem, it is not mapped on the MassDEP GIS maps. Mr. Adams stated that it was likely that the landfill, which likely included both the baseball field and apartment area, was filled in over time in increments with its final closure in 1970.

Soil containing concentrations of petroleum compounds and total lead (RTN: 3-17202) above applicable Massachusetts Contingency Plan (MCP) 310 CMR 40.0000, Reportable Concentrations was discovered at the intersection of Leavitt and Congress Streets, located just north of the Palmer Cove ball field, in August 1998. Impacted soil was disposed of off-site and confirmatory testing of surficial soil indicated that soil excavated from Leavitt and Congress Streets which exceeded RCS-1 concentrations had been removed. A Utility Related Abatement Measure (URAM) Completion Statement was submitted to MassDEP in September 1998. Additional response actions are unknown and are not listed on MassDEP’s Reportable Release Lookup website.

New England Electric Power Company 3-3 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation A 2006 release of approximately 200 gallons of cable oil occurred from an underground oil-filled transmission cable located approximately 1,800 feet northeast of the Palmer Cove ball field at the intersection of Derby Street and Lafayette Street (RTN: 3 26124). The disposal site included an approximately 950-square-foot area surrounding the release. Soil and groundwater were impacted and the extent of contamination was defined. Eight cubic yards of impacted soil was disposed of off-site and impacted groundwater was removed from monitoring wells between 2006 and 2009. More than ½ inch of cable oil is present at the release site. A Method 1 Risk Characterization concluded that “No Significant Risk” existed. Additionally, although petroleum hydrocarbons are present in soil and groundwater at the release site at concentrations above the applicable Method 1 Standards, and LNAPL was present at a thickness of greater than ½ inch, a Substantial Hazard did not exist. A Temporary Solution, or Class C-2 Response Action Outcome (RAO) was achieved at the release site and response actions to achieve a Permanent Solution are ongoing.

3.1.4.2 Salem Harbor Station Area (24 Fort Avenue) The northeast entrance/exit points for the potential HDD alignment would be located at the site of the Salem Harbor Power Plant, an active coal and oil-fired power plant. Soil and groundwater at the Salem Harbor Station site have been impacted by a release of metals in the vicinity of four former unlined wastewater treatment system (WWTS) basins and a former storage area located in the eastern side of the power plant property. The disposal site is listed at the MassDEP under RTN: 3 21283.

The four unlined WWTS basins and storage area were used as part of the WWTS for settling of oil ash, coal fly ash and bottom ash, coal pile runoff, neutralized rinse water from a make-up demineralizer and washwater from boiler, air pre-heater, and stack washing since approximately 1968.

The source of the metals contamination in soil and groundwater appears to be the WWTS solids that settled in and were dredged from the basins. The use of WWTS basins for coal ash settling ended in 1980, oil ash settling ended in 2000 and the WWTS basins were permanently taken out of use in 2001.

The WWTS basins were closed under a Closure Plan approved by MassDEP in October 2001. The Closure Plan included the removal of WWTS solids from the basins and storage area. Approximately 15,200 tons of WWTS solids were dredged, dewatered and disposed of off-site.

Groundwater sampling was also completed as part of the Closure Plan. Concentrations of Vanadium were detected in groundwater above applicable Reportable Concentration (RCGW 2). Nickel and beryllium were also identified in groundwater above RCGW 2 standards. Supplemental groundwater

New England Electric Power Company 3-4 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation sampling was conducted in 2004 and 2005 and included analysis of extractable petroleum hydrocarbons (EPH), volatile petroleum hydrocarbons (VPH), volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), polycyclic aromatic hydrocarbons (PAHs), dissolved metals, chloride, hexavalent chromium, cyanide, nitrate nitrogen, salinity and sulfate. With the exception of vanadium, concentrations of tested metals were detected at or near background.

A Phase IV Remedy Implementation Plan (RIP) was submitted to MassDEP in November 2005. The RIP outlined a conceptual plan comprising of backfilling of the WWTF basins and long-term groundwater monitoring with an Activity and Use Limitation (AUL) to address the existing on-site conditions. The Phase IV Status Report was submitted to MassDEP in September 2006 and the release site achieved regulatory closure in November 2007 via a Class A 3 RAO.

In addition to the contamination associated with the WWTS, there have been various small releases of transformer/cable oil related to NEP’s Salem Harbor substation. The majority of the releases have achieved regulatory closure via Class A-1 RAOs. Contamination was not reduced to background (cable oil impacted soil remains on site) in three additional on-site releases; these achieved regulatory closure via Class A-2 RAOs.

3.1.4.3 Harbor Sediments The US Army Corps of Engineers (USACE) conducts sediment sampling and testing in Salem Harbor in conjunction with USACE channel maintenance activities for the Federal Channel leading to the Salem Power Plant and several smaller channels within the harbor. The purpose of this sampling and testing is to determine the suitability of the sediments for various disposal options.

The latest sampling and testing was conducted in July of 1998 and July of 1999. The July 1999 sampling focused on the South River area. The USACE Report determined that the “shoal material” in the upper reaches of the South River channel would most likely not be found suitable for unconfined open water disposal, and recommended additional testing. However, the report further stated that the sediments from the 32-foot-deep main channel and from the entrance channel to the South River/Derby Wharf area would be suitable for unconfined ocean disposal.

3.1.5 Summary of Environmental Conditions The limit of solid waste and thickness of the landfill cover at the Palmer Cove Dump is not known. However, typical cover systems of landfills closed in the 1970s in Massachusetts include 18 to 24 inches of granular soil cover with 6 to 12 inches of loam. There is a high probability that the solid waste extends

New England Electric Power Company 3-5 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation into the groundwater causing contamination of the groundwater. It is expected that groundwater would be encountered within about 8 to 10 feet below ground surface at both the HDD entrance and exit located at the Palmer’s Cove Ball Field and the Salem Harbor Station. The soils located at the HDD entrance and exit locations are expected to be similar to urban fill type materials containing low levels of metals and petroleum hydrocarbons. The HDD entrance and exit locations are located within filled land and the fill soils generated during drilling would likely require management off-site at a lined or unlined landfill. The underlying natural soils are not expected to be contaminated based on the information reviewed.

The sediment quality in Salem Harbor along the HDD alignment cannot be determined based on a review of available information. However, based on our understanding of typical harbor sediments in relatively industrialized locations, it is likely that the top 2 to 4 feet of sediment contain elevated levels of metals, possibly PCBs, and petroleum hydrocarbons. Harbor sediments are typically relatively high in organic carbon. The organic carbon present within the sediment could preferentially sorb (i.e., chemicals could attach to the carbon particles in the sediment) compounds such as semi-volatile organic compounds present in fuel oils and lubricants used at boat marinas. In addition, in an industrialized urban environment, it is typical that stormwater runoff containing a high total suspended solids and other petroleum hydrocarbons flow into an urban harbor.

3.1.6 Sub-Aqueous Ecological Conditions Two key natural resources within Salem Harbor are shellfish beds and eel grass. Figure 3-2 indicates the approximate limits of eel grass in 1995 and again in 2001 and the approximate limits of shellfish beds. As can be seen in Figure 3-2, the area of eel grass in the middle of the harbor was significantly reduced in size between 1995 and 2001. Further investigation would be needed to determine the current extent of eel grass (if any) in this area.

New England Electric Power Company 3-6 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-2 Natural Resources in Salem Harbor

New England Electric Power Company 3-7 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.1.7 Future Harbor Conditions The City of Salem has plans to improve the amenities of Salem Harbor. These plans, documented in the 2008 Salem Harbor Plan prepared for the City by Fort Point Associates, include the eventual construction of a cruise ship terminal in the area of the Salem Wharf located immediately west of the Salem Harbor Power Plant. The Salem Harbor Plan envisions deepening the harbor by approximately 26 feet below mean low water in the area of the proposed cruise ship terminal, deepening the channel leading to Palmer Cove Yacht Club to 15 feet, and deepening other areas of the harbor from 5 to 10 feet below mean low water. The current Federal Shipping channel leading to the coal docks at the Salem Harbor Power Plant is maintained at an average of 32 feet below mean low water by the UCACE. Existing and proposed dredging depths are shown in Figure 3-3, which is taken from the Salem Harbor Plan.

New England Electric Power Company 3-8 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-3 Harbor Dredging Plan

New England Electric Power Company 3-9 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.2 FACTORS AFFECTING HDD FEASIBILITY The feasibility of a HDD in a given location is dependent on a variety of factors related to both subsurface conditions along the drilling alignment and the availability of space at each end of the alignment to accommodate HDD work zones and the assembly of pipes. This section outlines the general impact of subsurface conditions and work space availability on HDD feasibility. A site-specific analysis of the potential HDD alignments under Salem Harbor is provided in Section 3.5.

3.2.1 Subsurface Conditions 3.2.1.1 Subsurface Contamination Particular care must be taken on several fronts when drilling through contaminated areas. First and foremost, contaminated soils must be appropriately handled and disposed of. Second, care must be taken to ensure that bore holes do not become conduits allowing contaminated groundwater to flow to areas that are not contaminated. This cross-contamination of previously uncontaminated areas can be prevented or mitigated through careful design and execution of the HDD. Third, downhole equipment must be decontaminated between bores. This is especially important when equipment is being used at multiple sites.

Subsurface contamination would not typically prove to be a fatal flaw for a proposed HDD alignment. However, because drilling in contaminated areas requires additional precautions, attempts typically are made during the engineering process to relocate the alignment to avoid known contaminants. Where this is not possible, mitigation plans should be put in place prior to commencing work to manage the risk.

3.2.1.2 Geological The most critical issue affecting the success or failure of horizontal directional drill operations is geology. Geology affects the type of drill mud used, additives to the drill mud, downhole borehole pressures, rate of installation, borehole stability, and selection of equipment. The geology will affect the production rate of drilling through the ground, and determine how many passes will be required to obtain a borehole large enough to install the product pipe (see Figure 3-4 below).

New England Electric Power Company 3-10 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-4 Borehole Upsizing as a Percentage of Final Product Pipe Size

In addition, certain types of geology can increase the baseline construction costs of an HDD project. The cost impact is generally identified in terms of percentage increase to a baseline construction cost. For example, the baseline cost of a drill may be increased by approximately 60 percent for an HDD alignment greater than 3,000 feet and passing through mostly glacial till due to increased difficulty, slowed drill production rates, and associated requirements. The significant increase in estimated cost is also due to the potential for boreholes to become unstable in glacial till and the potential for boulders within the till falling out of formation and into the boreholes. This has the potential of jamming the drill stem or product pipe during pull back. Section 3.6 of this report analyzes the specific risks associated with each proposed HDD alignment under Salem Harbor.

3.2.2 HDD Work Zones Another factor affecting the feasibility of an HDD operation is the availability of sufficient work space at either end of the drilling alignment. In a typical arrangement, a drilling rig is located at one end of the HDD, while the pipe to be installed (product pipe) is located in preassembled form on the opposite side. For longer drills in difficult geology, an HDD process known as the “Intersect Method” may be used. This method requires HDD drilling operations to proceed from both sides of the crossing, with the drill heads meeting in the middle. Thus, sufficient space for a drill rig is needed at both ends of the HDD. The product pipe is still pulled back from one side of the crossing.

3.2.2.1 Drill Rig Side Sufficient work space is needed at one end of the HDD to accommodate the drilling rig and ancillary equipment, including equipment and materials storage and generators to power the rig. For a drill under Salem Harbor, an HDD rig known as a “Maxi Rig” would be required. Maxi rigs typically require work

New England Electric Power Company 3-11 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation zones of approximately 150 feet x 250 feet to lay out all of the required surface support equipment. Figure 3-5 shows a typical layout of equipment.

Figure 3-5 Maxi Rig Typical Layout with Surface Support Equipment

When multiple drills are conducted from the same location, much of the equipment can remain in a strategic location to support all the drills. However, the actual rig must be relocated by a minimum of 10 feet between drills to prevent interference with other drills occurring from the same location.

Figure 3-6 below indicates a typical separation where two drills occurred from the same work space. Note the separation where the drill rig had to be moved over. This project is for twin 230 kV power transmission lines under a major river in the southeast US.

New England Electric Power Company 3-12 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-6 Typical Multi Drill Set Up for Maxi Rig (Note the Second Drilled-in Pipe to Right of Drill Rig)

3.2.2.2 Pipe Side The pipe side of a HDD operation generally requires less space than the drill rig side. Generally, a small crane or tracked excavator is needed to remove and/or add drill stem as required for reaming operations. In some instances, a smaller rig may be set up in this area to assist in reaming operations to increase borehole size. Figure 3-7 shows a typical equipment layout for the pipe side of an HDD.

In Figure 3-7, the product pipe (i.e., the pipe to be installed) runs out to the right of the diagram. As a general practice, the product pipe for an HDD is preassembled to minimize interruptions to the pullback operation. This is especially desirable when geologic conditions are unstable (e.g., in collapsing ground

New England Electric Power Company 3-13 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation or in squeezing clay1) to prevent pipe or drill stem failure during pull back operations. For example, for a 4,000 feet drill, 4,000 feet of pipe should ideally be assembled and ready for pull back when required. This requires a space 4,100 feet long by approximately 20 feet wide. If this space is not available, a substantial space should still be available to minimize the number of times it is necessary to stop and add pipe. For HPFF Pipe, each stop requires approximately 4 hours to weld pipe, inspect pipe, and add special coating system before the pullback can continue.

Figure 3-7 Typical HDD Pipe Side Operations

Figure 3-8, below, is a typical pipe assembly for long pulls. In this case, the pull exceeds 6,000 feet. Four of the drill strings are each approximately 1,400 feet long, and one drill string is approximately 400 feet long.

1 Squeezing clay is a geotechnical term where, when drilling through a dry clay (aka lean clay), the water from the drill mud causes the clay to expand and thus squeeze around the drill pipe or product pipe. This can stop a pull back or significantly increase pull loads to the point of failure of the drill pipe or product pipe during pull back operations.

New England Electric Power Company 3-14 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-8 HPFF Pipe Being Assembled for Pull Back

3.3 EVALUATION OF HDD ALIGNMENTS Four potential alignments were evaluated for an HDD across Salem Harbor:

• From Ocean Avenue on the southwest side of Salem Harbor to Blaney Street Wharf • From Ocean Avenue to Salem Harbor Power Plant • From the baseball field adjacent to Palmer Cove to the south side of the Salem Power Plant, and • From the baseball field adjacent to Palmer Cove to the north side of the Salem Power Plant. Use of these alignments is dependent on the acquisition of necessary property rights.

3.3.1 Ocean Avenue Area to Blaney Street Wharf, and Ocean Avenue Area to Salem Harbor Power Plant The two alignments that begin in the Ocean Avenue area were eliminated from consideration after a site visit to the area. The site visit revealed that the Ocean Avenue area lacks open space that could be used for either a horizontal directional drilling rig work zone or a pipe assembly area. Figure 3-9 is a photo of the area.

New England Electric Power Company 3-15 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-9 Ocean Avenue Area with Dense Residential Housing

The Blaney Street Wharf area also was judged to be inappropriate for HDD operations. The Blaney Street Wharf has recently been converted into a terminal for commuter boats to with a new building and parking facilities (see Figure 3-10). It is also the site of the City’s proposed future cruise ship terminal. The placement of a submarine electric cable in this area could interfere with the City’s plans for the Blaney Street Wharf. In addition, an alignment between Blaney Street Wharf and the Palmer Cove ball field would require an almost 90-degree bend that would result in bending stresses in the pipe that exceed the allowable limits.

Figure 3-10 Blaney Street Wharf Area

New England Electric Power Company 3-16 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.3.2 Salem Harbor Power Plant (South Side) to Palmer Cove Ball Field Figure 3-11 depicts a large open area at the south side of the Salem Harbor Power Plant that has features that would make it ideal for horizontal directional drilling operations, including a large open space for equipment, easy access, and stable, flat ground. However, an existing steel sheet pile seawall adjacent to the shipping berth is estimated to extend to elevation 45 (mean low water datum). The sheet pile seawall extends approximately 150 feet from the shipping berth to the power plant cooling water outlet channel. Figure 3-12 is a picture of this seawall. Record information (as-built drawings) indicates that the seawall is supported by battered H-piles driven to refusal in the deeper glacial till (see Figure 3-22). Based on nearby geotechnical borings conducted by H&A, we estimate that the top of glacial till is located at approximately elevation 50 to 60 below mean low water. The H-piles are spaced 9 feet on center along the wall.

In order to avoid potential conflict with the seawall and support piles, the HDD alignment would need to pass under the seawall and its piles, at an elevation of approximately 70 feet below mean low water. At an entry angle of 14 degrees for the HDD rig (normal is 8 to 16 degrees), this would require a setback of approximately 450 feet from the seawall (to the north).

Figure 3-11 Salem Harbor Power Plant South Side – Potential HDD Work Zone

New England Electric Power Company 3-17 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-12 Steel Sheeting at Shipping Berth, South Side of Salem Harbor Power Plant

At the launch point on the south side of the Salem Harbor Power Plant, the required separation between each HPFF pipe is approximately 20 feet at the surface, aligned to achieve a spread of 30’ at the point they pass under the seawall. Each power transmission circuit requires 3 pipes. One circuit therefore requires a minimum spacing of 60 feet at the surface. As a result, only one circuit can be installed from the south side of the Power Plant. Also, there is limited-to-no space at this site for assembling the approximately 6,000 feet of steel pipe to be installed between this location and the Palmer Cove ball field. It is estimated that there is less than 300 feet available between the HDD entry point and the nearby power plant support equipment to assemble pipe.

At the Palmer Cove ball field there is sufficient space for large HDD operations and the spacing of all six HPFF pipes. The depth of the pipes pinning the water craft floats at Palmer Cove is unknown. Figure 3-13 shows the Palmer Cove ball field. Figure 3-14 shows Palmer Cove. As with the south side of the Salem Harbor Power Plant, available space for pipe assembly is an issue. It is estimated that there is less than 200 feet between the HDD entry point and the nearby public street to assemble pipe for actual installation.

New England Electric Power Company 3-18 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-13 Palmer Cove Ball Field

Figure 3-14 Palmer Cove

3.3.3 Salem Harbor Power Plant (North Side) to Palmer Cove Ball Field At the north side of the Salem Harbor Power Plant is a large open area that is well suited for horizontal directional drilling operations, with a large open space for equipment, easy access, and stable, flat ground.

Figure 3-15 is a photo of this area. In this area there is no known seawall similar to that on the south side of the power plant. However, bedrock is anticipated to

New England Electric Power Company 3-19 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation be only 0 to 20 feet below the surface based on geotechnical data from the adjacent South Essex Sewerage District Wastewater Treatment Plant. Figure 3-16 shows the locations of bedrock outcrops in the area.

It is possible to complete HDD operations through solid rock; though, in some cases special tooling is required. For example, it has been reported that special tooling was manufactured to cut through the extremely hard rock encountered when the HubLine Gas Line was installed in nearby Beverly Harbor. However, if the top of bedrock is irregular, there is an increased potential of frac-out if the top of bedrock is weathered or fractured.

The area on the north side of the Salem Harbor Power Plant, along with the access road on the WWTP property, will allow for assembly of approximately 750-foot-long pipe strings. Assembly in this location would have to be planned and carefully coordinated with the WWTP operations and operations at the Power Plant, and could require temporary relocation of some of the temporary structures. The only other viable pipe assembly area would be on at the former US Guard Station. The preassembled pipe would then be floated into the harbor and pulled into location for pull back operations from the proposed mid harbor platforms.

New England Electric Power Company 3-20 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-15 HDD Work Zone North Side of Salem Harbor Power Plant

Figure 3-16 Bedrock Outcrop (In Red) on North Side of Salem Harbor Power Plant

New England Electric Power Company 3-21 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.3.4 Mid-Harbor Platforms One option to address the issue of limited pipe assembly area is to assemble pipe on land with sufficient space, and then float the pipe to a mid-harbor platform where pipe can be pulled in. The use of mid- harbor platforms also reduces the length of each drill segment, thus reducing overall installation stresses. Mid-harbor platforms can be either barges or temporary pile-supported platforms. In this instance, the change in tide levels ranges from elevation 11.1 to -1.2 (mean low water datum) during full and new moon phases. This 12 foot change in tide levels would make it difficult to conduct drilling operations or pull back operations from a barge, as the variation in barge elevation will induce additional stresses in the pipe. The use of Jack Up or Spudded Barges does not improve the condition. Jacked up or Spudded Barges cannot resist the high lateral loads induced on the barge during pull back operations. Therefore, a temporary pile supported platform is recommended. This will provide a stable platform that can be constructed above storm surge.

A typical platform is shown in Figure 3-17. This is from a project across a major river in the southeast part of the US for a major Power Company.

Figure 3-17 Typical Mid-Harbor Drilling Platform

New England Electric Power Company 3-22 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation Mid-harbor platforms are also used to pull cable through pipe and to splice cable together. A special steel sleeve encloses pipe when completed. The completed pipe is then over boarded over the side of the platform and laid into a pre-excavated trench or jetted into harbor bottom (depending on geology). A burial depth of between 5 and 10 feet is recommended to accommodate future dredging. The trench length can be assumed to be 300 feet long; however actual length and width will depend on depth of burial and harbor geology. To protect the cable from potential anchor drag of small water craft, rip rap or articulated concrete mats would be laid over the top of the trench. This installation would result in overall permanently restricted areas of approximately 200 feet wide by 500 feet long at each platform location. These restricted areas are longer than the actual trench width so to encompass a portion of the HDD- installed pipe as it dives to a deep enough depth below the sea floor to be considered safe from outside impacts.

Figure 3-18 below is a typical profile of pipe approach to platform. This figure shows a pile supported platform with drill pipe in the position required for drilling and pull back. The figure also shows final resting position of product pipe in trench.

Figure 3-18 Typical Profile of HDD Approach to Harbor Platform

The installation of the S-145 and T-146 circuits under Salem Harbor would require the use of at least one, and possible two, mid-harbor platforms. The recommended platform locations are indicated in Figure

New England Electric Power Company 3-23 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3-19. Note that Platform 1 will disturb the eel grass (as indicated on Figure 3-2). However, the platform locations shown do not interfere with the major dredged channels. Although the platform itself is expected to occupy a small portion of the harbor anchorage area for small water craft, installation of the HDD during the summer months could adversely impact boating activities and access to moorings as the pre-assembled pipe is floated in in preparation for pullback.

Figure 3-19 Recommended HDD Alignments and Platforms (See Figure 3-2 for Limits of Eel Grass)

3.4 HDD PIPE STRESSES H&A undertook an analysis of the stresses on each segment of the potential HDD under Salem Harbor to verify that the alignments are feasible from the standpoint of pipe stress. For the purposes of this evaluation, the HDD alignments have been divided into individual segments as shown in Figure 3-20 below:

New England Electric Power Company 3-24 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-20 HDD Segment Designations

The design calculations for the various alignments are based on the following assumptions:

Pipe type: ASTM A 523 - Standard Specification for Plain End Seamless and Electric-Resistance-Welded Steel Pipe for High-Pressure Pipe-Type Cable Circuits

Outer diameter: 8.625 in.

Wall thickness: 0.375 in.

Specific minimum yield strength: 35,000 psi

Young’s modulus: 30,000,000 psi

The geology along the HDD alignments has a major influence on the selections of the geometry of the alignment, depth of installation, entry/exit angles, and calculation of pulling loads and stresses. The

New England Electric Power Company 3-25 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation calculations in this report are based on limited geological data available at this time, and the assumption that the site location possesses suitable geology for horizontal directional drilling.

Below is a summary of pipe stress calculations by segment:

GEOMETRY OF HDD SEGMENTS Segment A Segment B Segment C Segment D Segment E Drill length in plan view (ft) 2,800 1,747 2,772 3,178 4,438 No. of vertical curves 2 2 2 2 2 Vertical curve radius (ft) 1,000 1,000 1,000 1,000 1,000 Vertical curve length in plan view (ft) 242 139 242 242 242 No. of horizontal curves 0 1 1 1 1 Horizontal curve radius (ft) 0 1,200 1,200 1,200 1,200 Horizontal curve length in plan view (ft) 0 524 578 566 712

PULL LOADS AND STRESS ANALYSIS OF THE HDD SEGMENTS Segment A Segment B Segment C Segment D Segment E Maximum pull load (lbf) 30,839 33,728 54,921 63,201 90,665 Maximum tensile stress (psi) 3,173 3,470 5,651 6,503 9,328 Maximum bending stress (psi) 10,781 10,781 10,781 10,781 10,781 Maximum external hoop stress (psi) 511 673 817 782 1,227 Maximum tensile and bending stress factor (safe if less than 1) 0.50 0.51 0.58 0.60 0.69 Maximum tensile, bending and hoop stress factor (safe if less than 1) 0.24 0.24 0.32 0.36 0.49

A brief description of each alignment and the respective parameters are provided in the following sections.

3.4.1 Segment A: South of Salem Harbor Power Plant to Mid-Harbor Platform 1 This is a straight alignment with two vertical curves and no horizontal curve. The alignment needs to pass well below the sheet pile seawall in order for the HDD to be successful. To accomplish this, the entry point for this alignment must be located approximately 450 feet to the north of the seawall, assuming the entry location is to the south of the power plant. The entry/approach angle is set at 14 degrees in order to achieve the required depth below the seawall. The depth to be achieved is 70 feet below mean low water datum, assuming that the geologic conditions are suitable for HDD.

New England Electric Power Company 3-26 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.4.2 Segment B: North of Salem Harbor Power Plant to Mid-Harbor Platform 2 This is a curved alignment with a single horizontal curve and two vertical curves. The entry and exit angles for this alignment are assumed to be 8 degrees and the depth of installation is 30 feet below mean low water datum, assuming that the geologic conditions are suitable for HDD. The depth of drill is relatively shallow to attempt to stay above the bedrock at that location. The alignment which experiences maximum pipe stresses has been chosen for design calculations. It is assumed that other alignments will be to the west of the calculated alignment and thus would experience lesser stresses. However, the alignments to the west of the calculated alignment are subject to availability of required space between the alignments and the south jetty of the power station cooling water outfall.

3.4.3 Segment C: Mid-Harbor Platform 2 to Mid-Harbor Platform 1 This is a curved alignment with a single horizontal curve and two vertical curves. The entry and exit angles for this alignment are assumed to be 14 degrees and the depth of installation is 70 feet below mean low water datum. The alignment which experiences maximum pipe stresses has been chosen for design calculations. It is assumed that the other alignments will be to the west of the calculated alignment and thus would experience lesser stresses. However, the alignments to the west of the calculated alignment are subject to availability of required space between the alignments and the south jetty of the power station cooling water outfall. Based on record information, there appears to be pile structures buried within the jetty. Therefore, drilling under the jetty should be avoided.

3.4.4 Segment D: Mid-Harbor Platform 1 to Palmer Cove Ball Field This is a curved alignment with a single horizontal curve and two vertical curves. The entry and exit angles for this alignment are assumed to be 14 degrees and the total depth achieved is 70 feet below mean low water datum. The alignment which experiences maximum pipe stresses has been chosen for design calculations. It is assumed that the other alignments will be to the north of the calculated alignment and thus would experience lesser stresses. However, the alignments to the north of the calculated alignment are subject to availability of required space between the alignments and Palmer Cove.

3.4.5 Segment E: North of Salem Harbor Power Plant to Mid-Harbor Platform 1 (No Mid-Harbor Platform 2) This alignment was analyzed to investigate the effect of eliminating Mid-Harbor Platform 2 and drilling directly from the entry/exit point north of the Power Plant to Mid-Harbor Platform 1. This is a curved alignment with a single horizontal curve and two vertical curves. The pipe stress calculations for this alignment indicate that the combined stresses (combination of tensile, hoop and bending stresses) are high

New England Electric Power Company 3-27 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation due to the length of the bend. The stresses on the curves could be reduced by offsetting the alignment to the west; however, this offset may not be feasible due to the presence of piles below the south jetty of the power station cooling water outfall and the lack of required space from the jetty to the other alignments.

3.5 HDD FEASIBILITY FACTORS 3.5.1 Hazardous Materials 3.5.1.1 Salem Harbor Power Plant (South Side) As discussed in Section 3.1.4.2, concentrations of Vanadium above applicable Reportable Concentration (RCGW-2) were detected in groundwater in the area on the south side of the Salem Harbor Power Plant. Nickel and beryllium were also identified in groundwater above RCGW-2 standards. Supplemental groundwater sampling was conducted in 2004 and 2005 and included analysis of extractable petroleum hydrocarbons (EPH), volatile petroleum hydrocarbons (VPH), VOCs, SVOCs, polycyclic aromatic hydrocarbons (PAHs), dissolved metals, chloride, hexavalent chromium, cyanide, nitrate nitrogen, salinity and sulfate. With the exception of vanadium, concentrations of other compounds were detected at or near background.

The potential risk associated with this groundwater contamination can be controlled by installing a conductor sleeve from the surface into competent ground. A conductor sleeve is a steel casing which provides a barrier between the contaminated ground and drill stem/drill pipe/drill mud. The steel casing will minimize the inflow of groundwater with elevated concentrations of metals.

Based on available chemical testing data, the soil at the entry/exit location south of the Power Plant is not known to be contaminated. However, additional explorations and testing will be needed to investigate this further.

3.5.1.2 Salem Harbor Power Plant (North Side) There is limited data available on environmental conditions on the north side of the Salem Harbor Power Plant. Based on MassDEP files, the north side of the Power Plant property is located outside the limits of known disposal sites and appears to be outside the potential source areas of suspected contaminants. Therefore, based on the limited soils testing data available, it is anticipated that the soils are typical urban fill soils with relatively low levels of contamination. However, additional explorations and testing are needed to further investigate this area.

New England Electric Power Company 3-28 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.5.1.3 Mid-Harbor Platform(s) The mid-harbor platform or platforms will require approximately 10-foot-deep trenches 300 feet long by 25 to 100 feet wide (depending on geotechnical engineering properties of mud). Preliminarily, the available information indicates sandy clay soil. It is expected that the trench will be approximately 35 feet wide in this type of geology, but the exact width cannot be determined until additional information is obtained. Based on the review of reports by several environmental consultants regarding Salem Harbor, any contamination in harbor sediments is anticipated to reside in the top 1 to 2 feet of the harbor (bay mud). As noted in Section 3.1.4.3 of this report, the harbor sediments, except for in the upper reaches of the South River, are considered suitable for open water disposal. Therefore, no special handling and disposal is expected.

3.5.1.4 Palmer Cove Ball Field The baseball field and park adjacent to Palmer Cove is reported to be a former landfill that was “capped” in the early 1970s. It was not until after it was capped that MassDEP began maintaining detailed records on various landfills throughout the state. It is expected that the cap consists of 2 to 3 feet of ordinary soil cover. The contents of the landfill are unknown. Should large objects such as household appliances be in the path of the horizontal directional drilled alignment, there is potential that they could be obstructions to the HDD drill head. These obstructions could also make it difficult to install conductor sleeves. Either of these potential issues will require revising the alignment or removal of the obstructions. During preliminary design, it is recommended that Ground Penetrating Radar (GPR) or some other form of geophysical survey be used to determine the potential for large objects.

With respect to smaller objects that are also common in city landfills (i.e., common household trash), voids may exist between the smaller objects. The drill mud used in HDD operations could follow these voids and surface in an undesirable location, or block the return of drill mud to the drill pit for processing. Either one of these issues complicates the HDD process. It should be noted that a common landfill is not a fatal flaw, assuming it is possible to obtain permits to conduct the HDD in this area. However, additional costs would be incurred to mitigate the issues. The additional costs would need to be determined based on field conditions.

The landfill may also contain hazardous materials. These issues could be mitigated with proper planning and measures during construction, but could result in significant additional costs.

New England Electric Power Company 3-29 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.5.2 Geological Conditions 3.5.2.1 Salem Harbor Power Plant (South Side) The geological conditions in the area on the south side of the Salem Harbor Power Plant are highly variable in terms of materials and thickness of clay deposits which overlie glacial till. The geological conditions in the area of the proposed HDD entry/exit point are unknown, but can be assumed to be filled land. Below the fill is stiff clay. The elevation of the bottom of the clay is assumed to be at elevation 40 feet or higher based on known data at the tank farm. See Figure 3-20. Below the clay is glacial till.

Drilling into and through the stiff clays is feasible, and in some cases desired. However, drilling into and through the glacial till can be problematic with respect to borehole stability, and tooling of the drill bit. Various additives to the drill mud may be required to stabilize boreholes and transport soil cuttings. This, in combination with the potential brackish groundwater and potentially contaminated ground, will make control and monitoring of drill mud critical to the success of the drill. It is recommended that a specialist in drill mud (commonly referred to as a Mud Doctor) be on-site during all drilling operations.

In addition to the potential drill mud issue, the different drill head tooling requirements may require frequent trip outs. A trip out is when the drill stem is removed from the bore hole to access the drill head in order to change the tooling on the drill head. The drill head and drill stem are then reinstalled into the borehole. A trip out is time-consuming and thus costly. It may be necessary to change the drill head from a spade or modified spade suitable for stiff clays to a modified spade or rock bit suitable for dense glacial till.

Finally, the steel sheet pile wall may interfere with signals from the electronic devices used in tracking and steering the drill head, causing misalignment of the drill. This risk can be addressed by using a more expensive gyroscope device for at least the first drill to ensure alignment accuracy.

New England Electric Power Company 3-30 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-21 Bottom of Clay Contours at Tank Farm South of Power Plant (Note Deep Trough Under Bank B-4 Running into Harbor and Adjacent Contours)

New England Electric Power Company 3-31 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.5.2.2 Salem Harbor Power Plant (North Side) The geological conditions in the area on the north side of the Salem Harbor Power Plant are highly variable in terms of material and depth to bedrock. The geological conditions in the area of the proposed HDD entry/exit point are unknown, but can be assumed to be filled land. Below the fill is 10 to 15 feet of stiff clay. Below the clay is very dense glacial till approximately 2 to 10 feet thick. Below the till is a fairly competent, slightly weathered rock, although there appears to be a trend of more highly weathered rock closer to the shoreline. The depth to rock is assumed to be between 0 and 20 feet below ground surface based on data from the South Essex Sanitary District Wastewater Treatment Plant located adjacent to the proposed HDD entry/exit. In some of the geotechnical boring data closer to the Power Plant, incinerator ash is noted in the boring logs.

As discussed above for the HDD entry/exit location south of the Power Plant, drilling into and through the stiff clays is feasible, and in some cases desired. However, drilling into and through the glacial till can be problematic with respect to borehole stability, and tooling of the drill bit. Various additives to the drill mud may be required to stabilize boreholes and transport soil cuttings. This, in combination with the potential brackish groundwater and contaminated ground, will make control and monitoring of drill mud critical to the success of the drill.

Drilling through varying materials may also require frequent trip outs to change drill bits required for the different materials along the drill path. In addition, depending on the angle of the drill head relative to the soil/rock interface, additional undesirable bends could be introduced into the final alignment, thus increasing installation stresses on the product pipe.

3.5.2.3 Mid-Harbor Platform Because there is insufficient space on land for pipe assembly and pull back, pipe will need to be assembled at a predetermined location in lengths of approximately 1,500 feet each and floated into place at the mid-harbor platform. Once floated into place, the pipe can be pulled back from the platform to land (or from platform to platform for the middle section if both platforms are required). Consideration should be given to performing the welding and assembly on land on the eastern side of power plant cooling water outlet, and floating the pipe section alongside the power plant where it can be held until needed. Pullback should be scheduled for winter months when there are typically no small water craft in anchorage.

Platform 1 is located in an area that contained eel grass as recently as 2001. The Platform was located in this area to avoid navigation channels, to minimize impacts to small water craft anchorage, and to

New England Electric Power Company 3-32 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation optimize pipe stress issues. As discussed previously in this report, the extent of the eel grass decreased substantially between 1995 and 2001, and it is unknown if any remains in the area of Platform 1.

The vertical alignment for this reach can be relatively shallow, as there are no major navigation channels to pass under. However, rock may exist near the surface of the bay bottom. Additional field investigations are recommended to determine top of rock elevations and properties of the rock and harbor mud. This should include both geophysical survey and geotechnical borings.

3.5.2.4 Palmer Cove Ball Field Information on subsurface conditions in the area of the Palmer Cove Ball Field is not available. As a result, a detailed discussion of geologic conditions and their impact on the HDD is not possible. Subsurface exploration and testing will be required to further evaluate the ball field as an entry/exit location.

3.5.3 Horizontal Directional Drill Alignments 3.5.3.1 Segment A – South of Salem Harbor Power Plant to Mid-Harbor Platform 1 As previously discussed, the HDD entry point in this location will need to be set back approximately 450 feet from the steel sheet pile seawall at the shipping berth in order to gain sufficient depth to pass safely under the wall. Figure 3-22 shows the record information on the design of this wall.

The geology is expected to be variable as described above, with fill, soft clays, and very dense glacial till overlying bedrock.

New England Electric Power Company 3-33 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-22 Record Information on Steel Sheet Pile Seawall at Shipping Berth, South Side of Power Plant

3.5.3.2 Segment B – North of Salem Harbor Power Plant to Mid-Harbor Platform 2 This alignment will begin on the north side of the Power Plant. The entry angle is assumed to be relatively shallow (approximately 8 degrees) to allow for the installation of a conductor sleeve while not hitting rock. However, depending on the angle of the rock face that may intersect the drill head, it may be more advantageous to enter at a steeper angle in order to enter the rock at a steeper angle to prevent the drill head from skipping or deflecting off the rock face.

Platform 2 will be located approximately 500 feet north of the Federal Shipping Channel and 400 feet north of the eastern end of the former pier (now the jetty of the Power Plant cooling water outlet). This location was selected to avoid risks associated with an HDD alignment under the jetty. Record information reviewed indicated that piles from a former pier in this area still exist. The overall alignment follows an arc to avoid the former pier area. The arc in the alignment increases pipe stresses during pull back operations and may result in buckling or failure of the pipe. The pipe stress calculations for a combination of tensile, bending and hoop stresses as indicated in Section 3.4 result in a value of 0.4 for the horizontal curve with the allowable limit for these combined stresses being 1.

New England Electric Power Company 3-34 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation Figure 3-23 indicates the approximate alignment from both the north side and south side of the Power Plant.

Figure 3-23 Approximate HDD Alignments from North and South Sides of Power Plant

3.5.3.3 Segment C – Mid-harbor Platform 2 to Mid-Harbor Platform 1 There are several issues associated with drilling from Platform 1 to Platform 2. The first is to obtain sufficient depth beneath the existing Federal shipping channel. Currently, the USACE maintains the depth of the channel at elevation -32 feet below mean low water datum. According to discussions with the USACE, there are no plans to deepen the channel in the future. Therefore, the proposed depth should be approximately 70 feet below mean low water datum, allowing 30 to 40 feet of cover over the drill to reduce the possibility of inadvertent return of drill mud (frac out) into the bottom of the shipping channel. The geology is expected to be variable as described above, with fill, soft clays, very dense glacial till, and potentially hard irregular bedrock.

New England Electric Power Company 3-35 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation The horizontal alignment also passes under the small water craft anchorage area. This should not be a concern in most locations, since the mooring anchors in this area likely do not penetrate more than a few feet into the harbor bottom. In locations where the cable rises to the temporary platform(s)s, however, the cable would be buried at a depth of only 5 to 10 feet below the harbor bottom. In these locations, the cable can be protected from anchor drag by covering it with riprap or articulating concrete block mats. Some moorings may be temporarily disturbed during HDD operations. It is expected that each platform location will be occupied for a period of 8 to 12 months to complete drilling, cable installation, cable splicing, and burial of the cable.

3.5.3.4 Segment D – Mid-Harbor Platform 1 to Palmer Cove Ball Field The alignment between Platform 1 and the Palmer Cove Ball Field does not need to be as deep as the other alignments, since there are no deep navigation channels to pass under. However, the depth must be sufficient to pass under the pile system that supports piers or “floats” at the Palmer Cove Yacht Club. The horizontal alignment will pass directly under the Palmer Cove Yacht Club “floats” and the public gardens adjacent to the Palmer Cove Ball Field. Figure 3-24 indicates the approximate HDD alignment in this area. A portion of the alignment passes close to a point of land with a large building.

The geology is expected to be fill and mostly clay overlying some glacial till. The top of bedrock may be as shallow as 50 feet below ground surface.

New England Electric Power Company 3-36 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation

Figure 3-24 HDD Alignment from Platform 1 to Palmer Cove Ball Field (Note the “Floats” at Palmer Cove Yacht Club)

3.5.3.5 Segment E – North of Salem Harbor Power Plant to Mid-Harbor Platform 1 (No Mid-Harbor Platform 2) The need for a second mid-harbor platform could be eliminated by use of an alignment directly from the north side of the Power Plant to Platform 1. This alignment, which is illustrated in Figure 3-20, would be essentially the same as Segments B and C, but with Platform 2 eliminated.

An analysis of this alignment indicates that the longer drill would increase the total combination of stresses in the pipe during pull back to approximately 0.7. This high combination ratio could either increase or decrease depending on actual geological conditions, drill mud mix, geometry of alignment, and entry/exit locations. These parameters must be considered during final design to ensure that the combined stresses on the pipe are safe for pull back.

3.6 PROJECT RISK REGISTER Underground construction work is subject to considerable uncertainty with respect to cost and schedule, regardless of the construction method that is employed. Trenchless installation methods such as HDD have a higher degree of risk to cost and schedule because of limited access to the equipment while it is being deployed. For example, there is no access to drill heads on long waterway crossings. Unforeseen

New England Electric Power Company 3-37 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation conditions can result in lost production, lost equipment, damage to other utilities and nearby structures due to ground movement, and property damage. In addition to the risk associated with subsurface conditions, there are risks with construction impacts to surface activities caused by inappropriate work zone locations. For example, subsurface conditions could lead to structural failure of the drill stem or product pipe. As this project is considered to be high-risk due to the many complexities involved, Engineers and Contractors allowed to bid on the work should be prequalified with a minimum requirement of having worked on similar HDD projects of comparable complexity.

There are also varying degrees of risk associated with geologic conditions as shown below in Figure 3-25.

Figure 3-25 Increase in Risk (As a Percentage of Baseline Construction Cost) by Length of Bore and Geology Silt, Sand and Hole Length Gravel Soft Rock Hard Rock Clay <2,000 ft 0% 20% 10% 30%

2,000 to 3,000 ft 10% 40% 20% 50% >3,000 ft 20% 60% 30% 50 to 100%

Percentage Price Increase for Risk Associated with Hole Length as a Function of Geology

With any underground construction work, a thorough understanding of the subsurface conditions is essential for managing the risk associated with the chosen construction method. With respect to general risk, the following is a good rule of thumb for impact to cost and schedule.

• Low Risk: No surrounding structures - the entire length of the proposed drive is accessible from the surface. The ground is stable. Drive lengths are normal for pipe diameter.

• Medium Risk: Unstable ground. Limited areas of surface access over drive length. Drive lengths are near maximum for given pipe size.

• High Risk: Unstable ground. No access from surface for majority of drive length. Long drive lengths for given pipe size.

Project risk is generally addressed on a case-by-case basis using a risk register that identifies each specific risk, its cause, and the potential effect on the project. Each risk is assigned a probability of occurring and an impact rating. Multiplied together, these provide a risk score that can be used to prioritize risk management.

New England Electric Power Company 3-38 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation The risk register below identifies the specific risks associated with each pipe segment identified in Figure 3-20. For the purpose of this risk register evaluation, the following rating system was used:

1. Probability scale 1 to 9 with 1 = very low probability and 9 = very high probability

2. Impact scale 1-10 with 1 = very low impact and 10 = failure

3. Risk score below 39 = Monitor risk (Low Risk), between 40 and 65 = Consider risk mitigation plan (Medium Risk), 66 to 90 = Implement risk mitigation plan (High Risk).

The largest risk in general is caused by the unknown subsurface conditions. The rock near the surface in the north portion of the project causes the highest risk. However, the long Segment E (if utilized) has a high risk of failure due to the high friction loads caused by the long curve. The long drill also requires higher downhole mud pressure to move particles. The higher downhole pressures increase the risk of frac-out or lost mud return, causing the drill to fail.

The risk register covers only risk associated with the actual drilling process. Additional risk factors are associated with the installation of cables within the pipes, and with the acquisition of the permits and property rights needed to complete the installation. To complete the HDD project, it will be necessary to obtain easements across Salem Harbor and for the entry/exit area near the Palmer Cove ball field. Obtaining such easements will likely involve federal, state, and city agencies. Additional environmental assessments must be conducted to assess risk and mitigation methods. Salem, along with Salem Harbor dates back to the early 1600's and is a well-known historical area. There may, therefore; be additional risk associated with potential archaeological impacts. An archeological study should be performed during the early design phase of the project in order to identify any artifacts of historical value that may be disturbed. Permits to disturb these artifacts may be required. At this time, it is not possible for us to quantify the potential risks and costs associated with property rights and easements, environmental, or archaeological impacts.

New England Electric Power Company 3-39 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation RISK REGISTER – SEGMENT A Risk Cause Effect Probability Impact Score Misalignment of drill path Magnetic anomaly from steel Reduction in circuit rating 5 6 30 sheeting seawall interfering with guidance system used for steering Misalignment of drill path Magnetic anomaly from steel Alignment higher than designed, 5 9 48 sheeting seawall interfering with putting alignment closer to the guidance system used for surface. Potential frac-out into harbor steering Misalignment of drill path Magnetic anomaly from steel Drill exit not at planned location 5 8 40 sheeting seawall interfering with (e.g., into small craft anchorage). guidance system used for steering Migration of contaminated Conduit created by bore hole Cross contamination into previously 4 9 36 ground from south of power uncontaminated ground. plant Frac out into harbor Irregular geology Drill mud exiting ground and entering 6 9 54 harbor bottom. Drill stem failure Irregular geology Drill stems failure due to induced 6 9 54 unplanned bends in alignment. Re- drill required, extending schedule. Pipe failure during pull back Irregular geology Drill stems failure due to induced 6 10 60 unplanned bends in alignment. Re- drill required, extending schedule by several months as new pipe will be required. Damage to pipe Steel piles supporting steel Long term failure of pipe causing leak 5 10 50 sheeting sea wall may damage of dielectric fluid into ground. pipe Damage to pipe Steel piles supporting steel Long term failure of pipe due to 5 10 50 sheeting sea wall may damage corrosion causing leak of dielectric pipe coating fluid into ground. 1. Probability scale 1 to 9 with 1 = very low probability and 9 = very high probability. 2. Impact scale 1-10 with 1 = very low impact and 10 = failure. 3. Risk score below 39 = monitor risk, between 40 and 65, consider risk mitigation plan, 66 to 90 – implement risk mitigation plan.

New England Electric Power Company 3-40 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation RISK REGISTER – SEGMENT B Risk Cause Effect Probability Impact Score Extended construction Hard rock closer to the surface Longer overall construction duration 7 6 42 duration extending into additional season. Frac out into harbor Irregular geology Drill mud exiting ground and entering 7 9 63 harbor bottom covering shell fish bed. Drill stem failure Irregular geology Drill stems failure due to induced 7 9 63 unplanned bends in alignment. Re- drill required, extending schedule Pipe failure during pull back Irregular geology Drill stems failure due to induced 7 10 70 unplanned bends in alignment. Re- drill required, extending schedule by several months as new pipe will be required. Delay due to unknown sea Depth of seawall on north side Redesign of alignment, delaying 5 8 40 wall depth of power plant unknown project completion 1. Probability scale 1 to 9 with 1 = very low probability and 9 = very high probability. 2. Impact scale 1-10 with 1 = very low impact and 10 = failure. 3. Risk score below 39 = monitor risk, between 40 and 65, consider risk mitigation plan, 66 to 90 – change design or conduct additional investigations to design mitigation.

New England Electric Power Company 3-41 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation RISK REGISTER – SEGMENT C Risk Cause Effect Probability Impact Score Misalignment of drill path Magnetic anomaly from steel Reduction in circuit rating 3 6 18 hull ships passing thru Federal; shipping Channel interfering with guidance system used for steering, Misalignment of drill path Magnetic anomaly from steel Alignment higher than designed, 3 9 27 hull ships passing thru Federal; putting alignment closer to the shipping Channel interfering surface. Potential frac-out into with guidance system used for harbor, possibly into shipping steering, channel. Misalignment of drill path Magnetic anomaly from steel Drill exit not at planned location 3 8 24 hull ships passing thru Federal; (e.g.., into small craft anchorage) shipping Channel interfering with guidance system used for steering, Frac out into harbor Irregular geology Drill mud exiting ground and entering 5 9 45 harbor bottom, covering eel grass Drill stem failure Irregular geology Drill stems failure due to induced 6 9 54 unplanned bends in alignment. Re- drill required, extending schedule. Pipe failure during pull back Irregular geology Drill stems failure due to induced 6 10 60 unplanned bends in alignment. Re- drill required, extending schedule by several months as new pipe will be required. 1. Probability scale 1 to 9 with 1 = very low probability and 9 = very high probability. 2. Impact scale 1-10 with 1 = very low impact and 10 = failure. 3. Risk score below 39 = monitor risk, between 40 and 65, consider risk mitigation plan, 66 to 90 – change design or conduct additional investigations to design mitigation.

New England Electric Power Company 3-42 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation RISK REGISTER – SEGMENT D Risk Cause Effect Probability Impact Score Misalignment of drill path Obstructions in land fill Reduction in circuit rating 3 6 18 Misalignment of drill path Obstructions in landfill Alignment higher than designed, 3 9 27 putting alignment closer to the surface. Potential frac-out into harbor Misalignment of drill path Obstructions in landfill Drill exit not at planned location 3 8 24 (e.g., into small craft anchorage). Migration of contaminated Conduit created by bore hole Cross contamination into previously 3 9 27 ground from south of power uncontaminated ground. plant Frac out into harbor Irregular geology Drill mud exiting ground and 5 9 45 entering harbor bottom in area of shell fish beds or eels grass. Drill stem failure Irregular geology Drill stems failure due to induced 6 9 54 unplanned bends in alignment. Re- drill required, extending schedule. Pipe failure during pull back Irregular geology Drill stems failure due to induced 6 10 60 unplanned bends in alignment. Re- drill required, extending schedule by several months as new pipe will be required. Damage to pipe during pull Wood piles at Palmer Cove Damage to pipe or pipe coating. 4 10 40 back Yacht Club extend into drill path Failure of pipe causing leak of alignment dielectric fluid into ground. Frac out at Palmers Cover Wood piles at Palmer Cove Failure of drill due to no mud return. 6 9 54 Yacht Club Yacht Club extend into drill path alignment creating path for drill mud to come to surface 1. Probability scale 1 to 9 with 1 = very low probability and 9 = very high probability. 2. Impact scale 1-10 with 1 = very low impact and 10 = failure. 3. Risk score below 39 = monitor risk, between 40 and 65, consider risk mitigation plan, 66 to 90 – change design or conduct additional investigations to design mitigation.

New England Electric Power Company 3-43 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation RISK REGISTER – SEGMENT E Risk Cause Effect Probability Impact Score Extended construction Hard rock closer to the surface Longer overall construction duration 7 6 42 duration extending into additional season. Misalignment of drill path Magnetic anomaly from steel Reduction in circuit rating 3 6 18 hull ships passing thru Federal; shipping Channel interfering with guidance system used for steering Misalignment of drill path Magnetic anomaly from steel Alignment higher than designed, 3 9 27 hull ships passing thru Federal; putting alignment closer to the shipping Channel interfering surface. Potential frac-out into harbor with guidance system used for and specifically shipping channel. steering Misalignment of drill path Magnetic anomaly from steel Drill exit not at planned location (e.g., 3 8 24 hull ships passing thru Federal; into small craft anchorage). shipping Channel interfering with guidance system used for steering Pipe failure during pull back Long pull through long curve Pipe failure due to high pull back 8 10 80 stresses caused by higher friction induced by side wall loading thru curve. Frac out into harbor Irregular geology Drill mud exiting ground and entering 7 9 63 harbor bottom. Drill stem failure Irregular geology Drill stems failure due to induced 7 9 63 unplanned bends in alignment. Re- drill required, extending schedule. Pipe failure during pull back Irregular geology Pipe failure due to induced unplanned 7 10 70 bends in alignment. Re-drill required, extending schedule by several months as new pipe will be required. Delay due to unknown sea Depth of seawall on north side Redesign of alignment delaying 5 8 40 wall depth of power plant unknown project completion. 1. Probability scale 1 to 9 with 1 = very low probability and 9 = very high probability. 2. Impact scale 1-10 with 1 = very low impact and 10 = failure. 3. Risk score below 39 = monitor risk, between 40 and 65, consider risk mitigation plan, 66 to 90 – change design or conduct additional investigations to design mitigation.

New England Electric Power Company 3-44 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation 3.7 CONCLUSIONS AND RECOMMENDATIONS The proposed Horizontal Directional Drill alignment from the Salem Harbor Power Plant under Salem Harbor to the southwest shoreline is feasible but complex. There are significant risks which are likely to increase the cost from that which is estimated and extend the schedule of the drill. These risks are associated with:

• Insufficient information and unknown data for geological features

• Limited to no space available for pipe assembly on land

• Potentially contaminated ground at all land falls

• Unknown and buried structures at all land falls

• Potential alignment control issues due to magnetic interference from steel sheeting

• Potential inadvertent drill mud return into the harbor bottom

• Disruption to small water craft movement during construction activities in the harbor

Most of these risks can be mitigated with proper planning and engineering. For example, a substantial subsurface geotechnical investigation should be conducted along the entire alignment with borings approximately 100 feet deep placed every 300 feet along the alignment. The reason for the close spacing is to better define the variation in top of rock and general subsurface stratigraphy. Geophysical surveys should also be conducted. On a number of crossings with this type of risk, side-scan sonar and magnetic anomaly surveys are conducted to identify submerged sunken boats that may exist since these can affect the HDD installation and guidance systems. Salem Harbor has a long history of activity and there is a high potential for sunken water craft of all types.

On land, additional investigations should be conducted to better define subsurface conditions, including potential contaminated ground.

For design of the HDD, it will be necessary to perform laboratory testing of soil and rock samples to determine the engineering properties of these materials.

Because of the complexity of this project, the engineer selected to complete the final design of the HDD should be highly experienced in this type of work and have completed several similar projects. The

New England Electric Power Company 3-45 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 HDD Installation contractors selected to perform the HDD construction also should be highly experienced. In H&A’s opinion, there are approximately six contractors in North America capable of completing a project of this complexity.

If two mid-harbor platforms are used, the HDD would consist of Segments A, B, C, and D. The estimated cost of installing just the cable pipes to contain the S-145 and T-146 circuits via HDD using the A-B-C-D Segment Option is $25.2M2 with a drilling and cable pipe installation duration of 8.1 months.3 This work may extend at least through one full summer season, depending on when work begins, and possibly into two summer seasons should technical difficulties be encountered. The risk for the A-B-C–D Segment option is high because of the harbor geology, irregular top of bedrock, and the long drill segments as well as contaminated property on two of the three on land work zones.

If Platform 2 is not constructed, Segments B and C are eliminated and replaced by Segment E. The estimated cost of installing pipes to contain the S-145 and T-146 circuits using the A-E-D Segment Option is $24.3M2 with a drilling and cable pipe installation duration of 7 months.3 This may extend at least through one full summer season, depending on when work begins, and possibly into two summer seasons should technical difficulties be encountered. The risk for the A-E–D Segment option is high because of the harbor geology, irregular top of bedrock, and the long drill segments as well as contaminated property on two of the three on land work zones.

Platform 1 is estimated to remain in place for between 7 and 8.1 months for HDD operations plus additional time for cable installation and pipe over boarding, depending on which option is used. Under the A-B-C-D Segment Option, Platform 2 is estimated to be in place for approximately 3.0 months for HDD operations plus additional time for cable installation and pipe over boarding. Under the A-E-D Segment Option, Platform 2 will not be needed.

The Palmer Cove ball field is expected to be occupied for approximately 2.8 months, although it could be longer if technical difficulties arise.

2 See Section 7 for summary of overall installation costs, including HDD, land installation, cable installation, and easements. 3 See Section 8 overall installation schedule, including HDD, land installation, and cable installation.

New England Electric Power Company 3-46 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Cable Pulling 4.0 CABLE PULLING

As part of this evaluation, BMcD analyzed the feasibility of pulling cable through the cable pipes installed via HDD. BMcD modeled the route using SKM Cable, a three-dimensional cable pulling tension and sidewall pressure calculation software application, and determined that, preliminarily, four of the five HDD segments will pull satisfactorily. The only segment that may fail is Segment E, the segment that bypasses Mid-Harbor Platform 2. The assumptions used for cable pulling at this stage of an analysis are very conservative, and it is possible that during the course of final design, use of Segment E would prove to be feasible. If it is not feasible, Mid-Harbor Platform 2 could be used in conjunction with segments B and C. A summary of the model output is provided in Figure 4-1. The full model output is provided in Appendix A of this report.

Figure 4-1 Cable Pulling Calculation Summary

New England Electric Power Company 4-1 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Land Routes 5.0 LAND ROUTES

Land routes will need to be established in order to get the cables from the respective substations to the launch/receive areas.

5.1 CANAL STREET SUBSTATION At the Canal Street end of the HDD, the S-145 and T-146 cables would land at the Palmer Cove Ball Field. From this point, the HPPF cables must be routed through the streets of Salem to the Canal Street Substation. Figure 5-1 depicts four possible land routes from the baseball field to the Canal Street Substation, ranging in length from 0.46 to 0.90 miles and ranging in cost from $18.0M to $30.1M.4 Due to the size of the installation, which is controlled by the number of cables determined necessary for the HDD portion of the installation, two of these land routes would be needed, each carrying one circuit consisting of three cable pipes. For Paths #1, 2 and 3, a single splice vault location would be needed at some point between the baseball field and the substation. Because a single splice vault can only accommodate two cables, two splice vaults would be required at that location to accommodate all three cables per phase of the circuit. The longest route, Path #4, would require two splice vaults locations between the baseball field and the substation.

Installation of the S-145 and T-146 cables would result in impacts to the streets along the route, including excavation for the cable pipe and splice vaults, pipe installation including welding, backfilling and repaving.

4 Further detailed cost estimates for the land based cable options can be found in Appendix B

New England Electric Power Company 5-1 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Land Routes

Figure 5-1 Canal Street Substation Land Paths

5.2 SALEM HARBOR SUBSTATION Figure 5-2 depicts possible land routes for the S-145 and T-146 cables extending from the launch locations adjacent to the Salem Harbor Power Plant back into NEP’s Salem Harbor Substation. These two routes are 0.22 miles and 0.25 miles, respectively. Due to the relatively short length of the land routes, splice vaults would not be needed between the launch points and the substation.

New England Electric Power Company 5-2 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Land Routes

Figure 5-2 Salem Harbor Substation Land Routes

New England Electric Power Company 5-3 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Long Term Maintenance Issues 6.0 LONG TERM MAINTENANCE ISSUES

In addition to the installation issues discussed in Sections 3, 4 and 5, above, a cable installation across Salem Harbor raises long term maintenance issues that would not be associated with an underground installation. These include the additional time to locate and repair cable failures, the potential for dielectric fluid releases into Salem Harbor, the need for storage and rotation of spare cable, and the future availability of replacement cable.

6.1 Cable Failure Should any of the cables in a location under Salem Harbor fail during the lifetime of the system, it will be difficult to locate and diagnosis the problem. Specialized equipment and contractors would likely need to be mobilized to the site to locate the fault. Once the fault is located and identified, the entire section of cable containing the fault would likely need to be replaced, since the majority of this installation is inaccessible. The process of replacing the cable would be very similar to the original installation process. First, a mid-harbor platform would be installed and the direct buried splice would be uncovered and placed on the platform. Then the dielectric fluid would be removed from the circuit (or portion thereof). Next, the cable pipe around the splice would be cut away and the failed cable removed from the cable pipe. Following that, a new cable would be pulled in, spliced, new pipe welded around the splice, and dielectric fluid replaced and pressurized. Finally, the cable pipe would be over boarded back into the channel and the circuit tested and re-energized. The time and effort involved in this repair process would be comparable to the installation time frame for the cables. Further, considerable effort would be needed to obtain the emergency permits to construct and excavate within Salem Harbor. Overall, the time required to place a faulted cable back in service would likely be two to three months.

6.2 Cable Storage Spare reel(s) of cable should be kept on hand for use in replacing a faulted cable. Due to the overall length of under-harbor cable pulls, the cable reels would be significantly longer than would typically be necessary for a land based installation, which has more frequent splice points. Cable vendors recommend that the cable reels be rotated approximately every three months to prevent the oil impregnated within the cable from settling to the bottom cable wraps of the reel. Rotating the reels allows all of the cable to maintain oil impregnation and not dry out. These reels would contain upwards of 3,500 feet of cable and would weigh in excess of 55,000 pounds; consequently, a heavy crane would be required to perform the rotation. A crane would also be required to move the cables from storage onto a vehicle capable of transporting the cable to the harbor should the need arise.

New England Electric Power Company 6-1 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Long Term Maintenance Issues 6.3 Leakage Concerns To meet the ampacity and pull length needs of this proposed installation, High Pressure, Fluid-Filled (HPFF) cable is proposed. This type of cable consists of three cables contained in a coated steel pipe with pressurized dielectric fluid insulation. This is the same general type of fluid insulation currently used for the existing S-145 and T-146 cables. While not anticipated, the possibility exists for damage to the steel pipe to allow dielectric fluid to leak into the surrounding ground and into the waters of the harbor. In comparison, the installation of solid dielectric cables within the streets of Salem would not require the use of dielectric fluid and therefore would not be subject to leakage.

6.4 Cable Availability Currently there is only one manufacturer of HPFF cable in North America. Due to the limited number of manufacturers for this cable, future availability of replacement cable for these circuits is considered a risk. Also, due to current high demand for cable from this manufacturer, lead times are currently being quoted at twenty-four to thirty months for new orders.

New England Electric Power Company 6-2 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Construction Cost Estimate Overview 7.0 CONSTRUCTION COST ESTIMATE OVERVIEW

7.1 SUMMARY OF CONSTRUCTION AND EASEMENT ACQUISITION COSTS The overall cost of installing the S-145 and T-146 cables under Salem Harbor would include the following components:5

• HDD drilling costs for the harbor crossing; • Cable installation costs for the harbor crossing; • Land-based construction of the cable pipe and manhole system from the Palmer Cove Ball Field landing point to Canal Street Substation; • Land-based construction of the cable pipe and manhole system from the Salem Harbor station landing points to the Salem Harbor substation; • Cable installation costs for the land-based portions, and; • Easement acquisition costs. Appendix B provides construction cost estimates for the land-based cables. A detailed explanation of the drilling and cable costs for the harbor crossing is provided as Appendix C. Appendix D provides easement cost estimates. The cost estimates provided in Figure 7.1 assume that the least-cost installation is feasible. The HDD cost estimates assume use of a single mid-harbor platform and Segments A, D and E. The cost estimates for the land-based cables between the Palmer Cove Ball Field and Canal Street substation assume that the two shortest routes (Paths #1 and #3) are used. If a second mid-harbor platform is required, or if one or both of the two shortest land routes prove to be infeasible, overall costs would increase accordingly.

Figure 7-1 Summary of Construction Costs

Route Length (miles) Cost Canal Street Substation Land Path #1, Civil Installation 0.51 $11,100,000 Canal Street Substation Land Path #1, Cable Installation 0.51 $8,100,000 Canal Street Substation Land Path #3, Civil Installation 0.46 $10,500,000 Canal Street Substation Land Path #3, Cable Installation 0.46 $7,500,000 Salem Harbor Substation Land Path #1, Civil Installation 0.22 $3,600,000 Salem Harbor Substation Land Path #1, Cable Installation 0.22 $3,500,000 Salem Harbor Substation Land Path #2, Civil Installation 0.25 $4,000,000 Salem Harbor Substation Land Path #2, Cable Installation 0.25 3,800,000

5 Cost estimates provided in this report are at a tolerance level of +50%/-25%

New England Electric Power Company 7-1 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Construction Cost Estimate Overview Salem Harbor HDD Crossing, Civil Installation 1.98* $24,300,000 Salem Harbor HDD Crossing, Cable Installation 1.98* 32,100,000 Easement Acquisition Costs n/a $1,140,000 Total Cost $109,640,000 * Length includes Segments A, D and E.

New England Electric Power Company 7-2 Burns & McDonnell Feasibility Study of Constructing the New S-145 and T-146 Transmission Lines via a Horizontal Directional Drill Installation Under the Salem Harbor July 2013 Anticipated Construction Schedule 8.0 ANTICIPATED CONSTRUCTION SCHEDULE

Figure 8-1 shows the overall anticipated construction duration for the HDD project alternative utilizing Segment E. This schedule accounts for all construction activities, including cable pipe installation via HDD through the harbor and trenched construction over land, and cable installation and splicing after cable pipe installation is complete.

Figure 8-1 Schedule

New England Electric Power Company 8-1 Burns & McDonnell

APPENDIX A CABLE PULLING CALCULATIONS

Pulling Forces Friction Factor = 0.25

35000

30000

25000

20000 Forward Reverse 15000 lling Forces (lbs) u u P

10000

5000

0 12345 Span Number Sidewall Pressure Friction Factor = 0.25

1000

750

Forward 500 Reverse all Pressure (lbs/ft) ww Side

250

0 12345 Span Number Salem Harbor HDD - Segment A.txt Date: Oct 14, 2011 Time: 15:14:31 CABLE REPORT ------Reel Tension: 500 Cable Configuration: Three Cables, Triangular CONDUCTOR DATA ------Cable OD: 2.970 in. Cable Area: 6.930 sq in Lbs/Ft/Cable: 14.000 lb No. Of Cables: 3 Total Area: 20.790 sq i Total Lbs/Ft: 42.000 lb RACEWAY DATA ------Raceway Diameter: 8.625 in. Raceway Area: 58.43 sq in. PULL CRITERIA ------Design Tension: 2694 lbs/sq in. Design SWP: 500 lbs/ft Coefficient of Friction: 0.25 Low SWP Over 150 lbs 0.25 High SWP

CALCULATED DATA ------Effective Coef. of Frict.: 0.294 Low SWP Over 150 lbs 0.294 High SWP

Jam Ratio w/5% Cable tolerance: 2.766 Jam Ratio w/5% Raceway tolerance: 3.049

Cable/Raceway Clearance(no tolerance): 2.662 5% Cable Tolerance Clearance: 2.322 Percent Raceway fill: 35.573

INPUT DATA - FORWARD PULL DIRECTION ------Section Pull Type Length Radius Angle Description ft ft degree ------1 Slope Down 100.0 0.0 14.0 2 Concave Bend Down 244.3 1000.0 14.0 3 Horizontal Pull 2800.0 0.0 0.0 4 Concave Bend Up 244.3 1000.0 14.0 5 Slope Up 100.0 0.0 14.0

PULL DATA ------FORWARD PULL REVERSE PULL ------Section Pull Total Total SWP PULL Total Total SWP PULL Type Length Pounds lbs/ft Limits Length Pounds lbs/ft Limits ------1 SD 100.0 681.1 PASS 3488.7 43032.7 PASS 2 CvBD 344.3 5134.9 3.0 PASS 3388.7 40819.4 24.0 PASS 3 HP 3144.3 39683.3 PASS 3144.3 39683.3 PASS 4 CvBU 3388.7 40819.4 24.0 PASS 344.3 5134.9 3.0 PASS 5 SU 3488.7 43032.7 PASS 100.0 681.1 PASS ------* Note: HP - Horizontal Pull VD - Vertical Dip HBr - Horizontal Bend Right CxBD - Convex Bend Down HBl - Horizontal Bend Left CxBU - Convex Bend Up SU - Slope Up CvBD - Concave Bend Down SD - Slope Down CvBU - Concave Bend Up Page 1 Salem Harbor HDD - Segment A.txt ------

PULL SUMMARY ------Pull Forces Forward Pull Direction Reverse Pull Direction lbs/conductor psi/conductor lbs/conductor psi/conductor ------3 Cables 14344.2 2069.9 14344.2 2069.9

Page 2 Salem Harbor HDD - Segment B.txt Date: Oct 14, 2011 Time: 15:14:10 CABLE REPORT ------Reel Tension: 500 Cable Configuration: Three Cables, Triangular CONDUCTOR DATA ------Cable OD: 2.970 in. Cable Area: 6.930 sq in Lbs/Ft/Cable: 14.000 lb No. Of Cables: 3 Total Area: 20.790 sq i Total Lbs/Ft: 42.000 lb RACEWAY DATA ------Raceway Diameter: 8.625 in. Raceway Area: 58.43 sq in. PULL CRITERIA ------Design Tension: 2694 lbs/sq in. Design SWP: 500 lbs/ft Coefficient of Friction: 0.25 Low SWP Over 150 lbs 0.25 High SWP

CALCULATED DATA ------Effective Coef. of Frict.: 0.294 Low SWP Over 150 lbs 0.294 High SWP

Jam Ratio w/5% Cable tolerance: 2.766 Jam Ratio w/5% Raceway tolerance: 3.049

Cable/Raceway Clearance(no tolerance): 2.662 5% Cable Tolerance Clearance: 2.322 Percent Raceway fill: 35.573

INPUT DATA - FORWARD PULL DIRECTION ------Section Pull Type Length Radius Angle Description ft ft degree ------1 Slope Down 100.0 0.0 8.0 2 Concave Bend Down 139.6 1000.0 8.0 3 Horizontal Bend R 1885.0 1200.0 90.0 4 Concave Bend Up 139.6 1000.0 8.0 5 Slope Up 100.0 0.0 8.0

PULL DATA ------FORWARD PULL REVERSE PULL ------Section Pull Total Total SWP PULL Total Total SWP PULL Type Length Pounds lbs/ft Limits Length Pounds lbs/ft Limits ------1 SD 100.0 1137.3 PASS 2364.2 29502.2 PASS 2 CvBD 239.6 3357.9 2.0 PASS 2264.2 27695.8 16.3 PASS 3 HBr 2124.6 27867.5 13.6 PASS 2124.6 27867.5 13.6 PASS 4 CvBU 2264.2 27695.8 16.3 PASS 239.6 3357.9 2.0 PASS 5 SU 2364.2 29502.2 PASS 100.0 1137.3 PASS ------* Note: HP - Horizontal Pull VD - Vertical Dip HBr - Horizontal Bend Right CxBD - Convex Bend Down HBl - Horizontal Bend Left CxBU - Convex Bend Up SU - Slope Up CvBD - Concave Bend Down SD - Slope Down CvBU - Concave Bend Up Page 1 Salem Harbor HDD - Segment B.txt ------

PULL SUMMARY ------Pull Forces Forward Pull Direction Reverse Pull Direction lbs/conductor psi/conductor lbs/conductor psi/conductor ------3 Cables 9834.1 1419.1 9834.1 1419.1

Page 2 Salem Harbor HDD - Segment C.txt Date: Oct 14, 2011 Time: 15:14:51 CABLE REPORT ------Reel Tension: 500 Cable Configuration: Three Cables, Triangular CONDUCTOR DATA ------Cable OD: 2.970 in. Cable Area: 6.930 sq in Lbs/Ft/Cable: 14.000 lb No. Of Cables: 3 Total Area: 20.790 sq i Total Lbs/Ft: 42.000 lb RACEWAY DATA ------Raceway Diameter: 8.625 in. Raceway Area: 58.43 sq in. PULL CRITERIA ------Design Tension: 2694 lbs/sq in. Design SWP: 500 lbs/ft Coefficient of Friction: 0.25 Low SWP Over 150 lbs 0.25 High SWP

CALCULATED DATA ------Effective Coef. of Frict.: 0.294 Low SWP Over 150 lbs 0.294 High SWP

Jam Ratio w/5% Cable tolerance: 2.766 Jam Ratio w/5% Raceway tolerance: 3.049

Cable/Raceway Clearance(no tolerance): 2.662 5% Cable Tolerance Clearance: 2.322 Percent Raceway fill: 35.573

INPUT DATA - FORWARD PULL DIRECTION ------Section Pull Type Length Radius Angle Description ft ft degree ------1 Slope Down 100.0 0.0 14.0 2 Concave Bend Down 244.3 1000.0 14.0 3 Horizontal Bend R 942.5 1200.0 45.0 4 Horizontal Pull 500.0 0.0 0.0 5 Horizontal Bend R 942.5 1200.0 45.0 6 Concave Bend Up 244.3 1000.0 14.0 7 Slope Up 100.0 0.0 14.0

PULL DATA ------FORWARD PULL REVERSE PULL ------Section Pull Total Total SWP PULL Total Total SWP PULL Type Length Pounds lbs/ft Limits Length Pounds lbs/ft Limits ------1 SD 100.0 681.1 PASS 3073.6 39908.0 PASS 2 CvBD 344.3 5134.9 3.0 PASS 2973.6 37694.7 22.1 PASS 3 HBr 1286.8 17065.4 8.4 PASS 2729.3 36775.1 18.0 PASS 4 HP 1786.8 23234.7 PASS 1786.8 23234.7 PASS 5 HBr 2729.3 36775.1 18.0 PASS 1286.8 17065.4 8.4 PASS 6 CvBU 2973.6 37694.7 22.1 PASS 344.3 5134.9 3.0 PASS 7 SU 3073.6 39908.0 PASS 100.0 681.1 PASS ------* Note: HP - Horizontal Pull VD - Vertical Dip Page 1 Salem Harbor HDD - Segment C.txt HBr - Horizontal Bend Right CxBD - Convex Bend Down HBl - Horizontal Bend Left CxBU - Convex Bend Up SU - Slope Up CvBD - Concave Bend Down SD - Slope Down CvBU - Concave Bend Up ------

PULL SUMMARY ------Pull Forces Forward Pull Direction Reverse Pull Direction lbs/conductor psi/conductor lbs/conductor psi/conductor ------3 Cables 13302.7 1919.6 13302.7 1919.6

Page 2 Salem Harbor HDD - Segment D.txt Date: Oct 14, 2011 Time: 15:15:11 CABLE REPORT ------Reel Tension: 500 Cable Configuration: Three Cables, Triangular CONDUCTOR DATA ------Cable OD: 2.970 in. Cable Area: 6.930 sq in Lbs/Ft/Cable: 14.000 lb No. Of Cables: 3 Total Area: 20.790 sq i Total Lbs/Ft: 42.000 lb RACEWAY DATA ------Raceway Diameter: 8.625 in. Raceway Area: 58.43 sq in. PULL CRITERIA ------Design Tension: 2694 lbs/sq in. Design SWP: 500 lbs/ft Coefficient of Friction: 0.25 Low SWP Over 150 lbs 0.25 High SWP

CALCULATED DATA ------Effective Coef. of Frict.: 0.294 Low SWP Over 150 lbs 0.294 High SWP

Jam Ratio w/5% Cable tolerance: 2.766 Jam Ratio w/5% Raceway tolerance: 3.049

Cable/Raceway Clearance(no tolerance): 2.662 5% Cable Tolerance Clearance: 2.322 Percent Raceway fill: 35.573

INPUT DATA - FORWARD PULL DIRECTION ------Section Pull Type Length Radius Angle Description ft ft degree ------1 Slope Down 100.0 0.0 14.0 2 Concave Bend Down 244.3 1000.0 14.0 3 Horizontal Pull 2000.0 0.0 0.0 4 Horizontal Bend R 942.5 1200.0 45.0 5 Concave Bend Up 244.3 1000.0 14.0 6 Slope Up 100.0 0.0 14.0

PULL DATA ------FORWARD PULL REVERSE PULL ------Section Pull Total Total SWP PULL Total Total SWP PULL Type Length Pounds lbs/ft Limits Length Pounds lbs/ft Limits ------1 SD 100.0 681.1 PASS 3631.2 45245.4 PASS 2 CvBD 344.3 5134.9 3.0 PASS 3531.2 43032.2 25.3 PASS 3 HP 2344.3 29812.3 PASS 3286.8 41742.8 PASS 4 HBr 3286.8 44240.7 21.7 PASS 1286.8 17065.4 8.4 PASS 5 CvBU 3531.2 45716.0 26.9 PASS 344.3 5134.9 3.0 PASS 6 SU 3631.2 47929.3 PASS 100.0 681.1 PASS ------* Note: HP - Horizontal Pull VD - Vertical Dip HBr - Horizontal Bend Right CxBD - Convex Bend Down HBl - Horizontal Bend Left CxBU - Convex Bend Up Page 1 Salem Harbor HDD - Segment D.txt SU - Slope Up CvBD - Concave Bend Down SD - Slope Down CvBU - Concave Bend Up ------

PULL SUMMARY ------Pull Forces Forward Pull Direction Reverse Pull Direction lbs/conductor psi/conductor lbs/conductor psi/conductor ------3 Cables 15976.4 2305.4 15081.8 2176.3

Page 2 Salem Harbor HDD - Segment E.txt Date: Oct 14, 2011 Time: 15:29:22 CABLE REPORT ------Reel Tension: 500 Cable Configuration: Three Cables, Triangular CONDUCTOR DATA ------Cable OD: 2.970 in. Cable Area: 6.930 sq in Lbs/Ft/Cable: 14.000 lb No. Of Cables: 3 Total Area: 20.790 sq i Total Lbs/Ft: 42.000 lb RACEWAY DATA ------Raceway Diameter: 8.625 in. Raceway Area: 58.43 sq in. PULL CRITERIA ------Design Tension: 2694 lbs/sq in. Design SWP: 500 lbs/ft Coefficient of Friction: 0.25 Low SWP Over 150 lbs 0.25 High SWP

CALCULATED DATA ------Effective Coef. of Frict.: 0.294 Low SWP Over 150 lbs 0.294 High SWP

Jam Ratio w/5% Cable tolerance: 2.766 Jam Ratio w/5% Raceway tolerance: 3.049

Cable/Raceway Clearance(no tolerance): 2.662 5% Cable Tolerance Clearance: 2.322 Percent Raceway fill: 35.573

INPUT DATA - FORWARD PULL DIRECTION ------Section Pull Type Length Radius Angle Description ft ft degree ------1 Slope Down 100.0 0.0 8.0 2 Concave Bend Down 139.6 1000.0 8.0 3 Horizontal Bend R 1361.4 1200.0 65.0 4 Horizontal Pull 1500.0 1200.0 45.0 5 Horizontal Bend R 1361.4 1200.0 65.0 6 Concave Bend Up 139.6 1000.0 8.0 7 Slope Up 100.0 0.0 8.0

PULL DATA ------FORWARD PULL REVERSE PULL ------Section Pull Total Total SWP PULL Total Total SWP PULL Type Length Pounds lbs/ft Limits Length Pounds lbs/ft Limits ------1 SD 100.0 1137.3 PASS 4702.0 66185.3 FAIL 2 CvBD 239.6 3357.9 2.0 PASS 4602.0 64378.9 37.8 FAIL 3 HBr 1601.0 20694.2 10.1 PASS 4462.3 63076.3 30.9 FAIL 4 HP 3101.0 39202.3 PASS 3101.0 39202.3 PASS 5 HBr 4462.3 63076.3 30.9 FAIL 1601.0 20694.2 10.1 PASS 6 CvBU 4602.0 64378.9 37.8 FAIL 239.6 3357.9 2.0 PASS 7 SU 4702.0 66185.3 FAIL 100.0 1137.3 PASS ------* Note: HP - Horizontal Pull VD - Vertical Dip Page 1 Salem Harbor HDD - Segment E.txt HBr - Horizontal Bend Right CxBD - Convex Bend Down HBl - Horizontal Bend Left CxBU - Convex Bend Up SU - Slope Up CvBD - Concave Bend Down SD - Slope Down CvBU - Concave Bend Up ------

PULL SUMMARY ------Pull Forces Forward Pull Direction Reverse Pull Direction lbs/conductor psi/conductor lbs/conductor psi/conductor ------3 Cables 22061.8 3183.5 22061.8 3183.5

Page 2

APPENDIX B LAND ROUTE COST ESTIMATES

Land Route Cost Estimates

Route Option Electrical Cost Civil Cost Total Cost Canal Street #1$ 8,116,230 $ 11,139,919 $ 19,256,149 Canal Street #2$ 9,715,296 $ 12,779,655 $ 22,494,951 Canal Street #3$ 7,511,286 $ 10,509,251 $ 18,020,537 Canal Street #4$ 13,684,280 $ 16,452,360 $ 30,136,640 Salem Power Plant #1$ 3,477,276 $ 3,584,813 $ 7,062,089 Salem Power Plant #2$ 3,814,995 $ 3,963,212 $ 7,778,208

APPENDIX C HDD DURATION OF INSTALLATION AND ESTIMATED COSTS

File No. 36094-000

Sheet 1 of 1

Burns & Date 10/12/2011 Client McDonnell Project Salem Harbor HDD Feasibility Study Computed By Abhinav Huli

Subject Duration of Installation and Estimated Costs Checked By Dennis Doherty

Duration of installation of various HDD segments Segment A, including Segment B, including Platform 1 Platform 2 Segment C Segment D Segment E Estimated total project construction cost $6,866,759 $5,210,298 $3,387,552 $9,670,294 $7,743,726 Duration of HDD (months): Includes drilling of pilot hole, reaming and pull back (including 50% downtime) 1.3 1.0 1.1 1.6 0.9 Duration for mobilization, demobilization, equipment setup and HDD related time (months) 1.0 .5 .4 1.2 1.0 Duration to construct and deconstruct Platforms 1 and 2, respectively 1.0 .5 Total duration to complete each segment (months) 2.3 1.5 1.5 2.8 1.9

Option 1: Alignments Option 2: Alignments A,B,C & D A, D & E Total project cost $25,134,903 $24,280,779 Total duration (months) 8.1 7.0 Total duration of occupancy of Platform 1 (months) 6.6 7.0 Total duration of occupancy of Platform 2 (months) 3.0 N/A

Notes: 1) Assumes Mobilization and Platform construction concurrent. 2) Assumes HDD Operations 2 shifts per day – 7 days per week to reduce time impact on public. Salem Harbor HDD HPFF Cable F&I Only Costs

Segment Length Circuits Cable and install Oil qty Oil Cost Splice Qty Splice Cost Total D 3178 2$ 9,721,820 56,823 $ 795,517 6$ 154,500 $ 10,671,837 A 2800 1$ 4,282,740 25,032 $ 350,448 3$ 77,250 $ 4,710,438 C 2772 1$ 4,239,913 24,782 $ 346,944 3$ 77,250 $ 4,664,106 B 1747 1$ 2,672,124 15,618 $ 218,655 3$ 77,250 $ 2,968,028 $ 23,014,409 Contingency (40%) $ 9,205,764 TOTAL $ 32,220,173

Optional Arrangement Segment Length Circuits Cable and install Oil qty Oil Cost Splice Qty Splice Cost Total D 3178 2$ 9,721,820 56,823 $ 795,517 6$ 154,500 $ 10,671,837 A 2800 1$ 4,282,740 25,032 $ 350,448 3$ 77,250 $ 4,710,438 E 4519 1$ 6,912,036 40,400 $ 565,598 3$ 77,250 $ 7,554,884

$ 22,937,159 Contingency (40%) $ 9,174,864 TOTAL $ 32,112,023

APPENDIX D EASEMENT ACQUISITION ESTIMATED COSTS

HDD Alternative Route Analysis Salem Underground Reinforcement Project June 6, 2013

As part of the Horizontal Directional Drill Installation Alternative, several locations have been identified where additional easement rights will need to be acquired to support the land based portions of this alternative. Please refer to Burns & McDonnell Figure 5-1 and Figure 5-2 for the locations of the routes evaluated in this document.

Palmer Cove Park Figure 5-1

Acquisition of new easement rights for a 50’ wide right of way extending from Salem Street, through the city park know as Palmer Cove Park, to Salem Harbor at the location of the Palmer Cove Yacht Club, approximately 600’ in length, consisting of approximately 30,000 sq/ft.

Easement acquisition estimate = $25,000

Note: Construction at this location would impact the use of the park’s ball field and community gardens (maintained by 91 local families).

Footprint Power Property Figure 5-2

Salem Harbor Land Path #1

Acquisition of new easement rights for a right of way extending from Salem Harbor 45 substation, across land of Footprint running southeast and southwest to Salem Harbor, approximately 1200’ in length with a varying width of 30’ to 100’, consisting of approximately 127,500 sq/ft.

Easement acquisition estimate = $835,200

Salem Harbor Land Path #2

Acquisition of new easement rights for a right of way extending from Salem Harbor 45 substation, across land of Footprint running northeast to Salem Harbor, approximately 750’ in length with a varying width of 30’ to 100’, consisting of approximately 43,500 sq/ft.

Easement acquisition estimate = $278,400

Note: This is a High Level estimate and the land value was based on the current assessed land values. Note: This Estimate does not include fees associated with the acquisition of necessary Franchise Rights or Waterway Permitting/Licensing.

APPENDIX E PIPE STRESS CALCULATIONS

File No. 36094‐000 Sheet 1 of 6 Client Burns & McDonnell Date 10/12/2011 Project Salem Harbor HDD Feasibility Study Computed By Abhinav Huli Subject Pipe Stress Calculationn ‐ HDD segment A Checked By Dennis Doherty

SEGMENT A

Pull Load 30,839 Pull load (lbf) 150,345 Maximum allowable pull load (lbf)

Stress analysis Vertical curve (Entry) Vertical curve (Exit) 420 Tensile stress (psi) 2,947 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 31,500 Allowable tensile stress (psi) 10,781 Bending stress (psi) 10,781 Bending stress (psi) 26,250 Allowable bending stress (psi) 26,250 Allowable bending stress (psi) 511 External hoop stress (psi) 511 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.42 Tensile & bending stress (psi) 0.50 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) 0.16 Combination of tensile, bending & hoop (psi) 0.24 Combination of tensile, bending & hoop (psi) Safe if < 1Allowable tensile, bending & hoop stress (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi) File No. 36094‐000 Sheet 2 of 6 Client Burns & McDonnell Date 10/12/2011 Project Salem Harbor HDD Feasibility Study Computed By Abhinav Huli Subject Pipe Stress Calculation ‐ HDD segment B Checked By Dennis Doherty

SEGMENT B

Pull Load 33,728 Pull load (lbf) 150,345 Maximum allowable pull load (lbf)

Stress analysis Vertical curve (Entry) Vertical curve (Exit) 756 Tensile stress (psi) 2,986 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 31,500 Allowable tensile stress (psi) 10,781 Bending stress (psi) 10,781 Bending stress (psi) 26,250 Allowable bending stress (psi) 26,250 Allowable bending stress (psi) 283 External hoop stress (psi) 283 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.43 Tensile & bending stress (psi) 0.51 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) 0.17 Combination of tensile, bending & hoop (psi) 0.24 Combination of tensile, bending & hoop (psi) Safe if < 1Allowable tensile, bending & hoop stress (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi)

Horizontal curve (Entry) 2,215 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 8,984 Bending stress (psi) 26,250 Allowable bending stress (psi) 673 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.41 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bending (psi) 0.16 Combination of tensile, bending & hoop (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi) File No. 36094‐000 Sheet 3 of 6 Client Burns & McDonnell Date 10/12/2011 Project Salem Harbor HDD Feasibility Study Computed By Abhinav Huli Subject Pipe Stress Calculation ‐ HDD segment C Checked By Dennis Doherty

SEGMENT C

Pull Load 54,921 Pull load (lbf) 150,345 Maximum allowable pull load (lbf)

Stress analysis Vertical curve (Entry) Vertical curve (Exit) 843 Tensile stress (psi) 5,233 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 31,500 Allowable tensile stress (psi) 10,781 Bending stress (psi) 10,781 Bending stress (psi) 26,250 Allowable bending stress (psi) 26,250 Allowable bending stress (psi) 511 External hoop stress (psi) 511 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.44 Tensile & bending stress (psi) 0.58 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) 0.17 Combination of tensile, bending & hoop (psi) 0.32 Combination of tensile, bending & hoop (psi) Safe if < 1Allowable tensile, bending & hoop stress (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi)

Horizontal curve (Entry) 3,241 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 8,984 Bending stress (psi) 26,250 Allowable bending stress (psi) 817 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.45 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bending (psi) 0.19 Combination of tensile, bending & hoop (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi) File No. 36094‐000 Sheet 4 of 6 Client Burns & McDonnell Date 10/12/2011 Project Salem Harbor HDD Feasibility Study Computed By Abhinav Huli Subject Pipe Stress Calculation ‐ HDD segment D Checked By Dennis Doherty

SEGMENT D

Pull Loads 63,201 Pull load (lbf) 150,345 Maximum allowable pull load (lbf)

Stress analysis Vertical curve (Entry) Vertical curve (Exit) 843 Tensile stress (psi) 6,084 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 31,500 Allowable tensile stress (psi) 10,781 Bending stress (psi) 10,781 Bending stress (psi) 26,250 Allowable bending stress (psi) 26,250 Allowable bending stress (psi) 511 External hoop stress (psi) 511 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.44 Tensile & bending stress (psi) 0.60 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) 0.17 Combination of tensile, bending & hoop (psi) 0.36 Combination of tensile, bending & hoop (psi) Safe if < 1Allowable tensile, bending & hoop stress (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi)

Horizontal curve (Entry) 3,855 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 8,984 Bending stress (psi) 26,250 Allowable bending stress (psi) 782 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.46 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bending (psi) 0.21 Combination of tensile, bending & hoop (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi) File No. 36094‐000 Sheet 5 of 6 Client Burns & McDonnell Date 10/12/2011 Project Salem Harbor HDD Feasibility Study Computed By Abhinav Huli Subject Pipe Stress Calculation ‐ HDD segment E Checked By Dennis Doherty

SEGMENT E

Pull Loads 90,665 Pull load (lbf) 150,345 Maximum allowable pull load (lbf)

Stress analysis Vertical curve (Entry) Vertical curve (Exit) 843 Tensile stress (psi) 8,910 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 31,500 Allowable tensile stress (psi) 10,781 Bending stress (psi) 10,781 Bending stress (psi) 26,250 Allowable bending stress (psi) 26,250 Allowable bending stress (psi) 511 External hoop stress (psi) 511 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.44 Tensile & bending stress (psi) 0.69 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) Safe if < 1 Allowable tensile and bendingbending (p(psi)si) 0.17 Combination of tensile, bending & hoop(psi) 0.49 Combination of tensile, bending & hoop(psi) Safe if < 1Allowable tensile, bending & hoop stress (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi)

Horizontal curve (Entry) 5,780 Tensile stress (psi) 31,500 Allowable tensile stress (psi) 8,984 Bending stress (psi) 26,250 Allowable bending stress (psi) 1,227 External hoop stress (psi) 16,489 Allowable external hoop stress (psi) 0.53 Tensile & bending stress (psi) Safe if < 1 Allowable tensile and bending (psi) 0.28 Combination of tensile, bending & hoop (psi) Safe if < 1 Allowable tensile, bending & hoop stress (psi)

APPENDIX F SOURCES OF INFORMATION

SOURCES OF INFORMATION

1. Coneco Engineers & Scientists “Release Abatement Measure Completion Report and Class A-2 Response Action Outcome Statement, Salem No. 1 Substation, 25 Peabody Street, Salem, Massachusetts, Release Tracking Number 3-26270,” July 2009.

2. Earth Tech, Inc., “Response Action Outcome, RTN 3-18040, No. 6 Oil Spill, Salem Harbor Station, Salem, Massachusetts,” June 1999.

3. Earth Tech, Inc., “Response Action Outcome Statement, RTN 3-18780, No. 2 Oil Release, Salem Harbor Station, Salem, Massachusetts,” January 2000.

4. Earth Tech, Inc., “Phase I Initial Site Investigation Letter Report & Tier Classification – Salem Harbor Station, Unlined Treatment Basin, 24 Fort Avenue, Salem, Massachusetts, Release Tracking Number 3-21283,” November 2002.

5. Earth Tech, Inc., “Response Action Outcome, Unlined Treatment Basins, Salem Harbor Station, 24 Fort Avenue, Salem, Massachusetts, Release Tracking Number (RTN): 3-21283,” November 2007.

6. Fort Point Associates, “Salem Harbor Plan,” January 2008.

7. H&A, Inc., “Soil & Foundation Investigations: Fuel Oil Storage Tanks B-3, B-4: Salem Harbor Station,” 1968

8. H&A, Inc., “Soil & Foundation Investigations: Fuel Oil Storage Tanks TK-1 and TK-6: Salem Harbor Station,” 1973

9. H&A, Inc., “Proposed Building Addition: Salem Evening News,”1977.

10. H&A, Inc., “Soil & Foundation Investigations: Fuel Oil Storage Tanks TK-2: Salem Harbor Station,” 1977.

11. H&A, Inc., “Soil & Foundation Investigations: Fuel Oil Storage Tanks TK-5: Salem Harbor Station,” 1978.

12. H&A, Inc., “Proposed Apartment Building, Salem, MA,” 1978.

13. H&A, Inc., “Tunnel Feasibility Study, Salem/Beverly, MA,” 1991. 14. H&A, Inc., “Geotechnical Engineering Evaluation: SESD-WWTP Expansion,”1993.

15. H&A, Inc., “Proposed North River Crossing,” 2000.

16. H&A, Inc., “Soil & Foundation Investigations: Fuel Oil Storage Tanks NE & NW: Salem Harbor Station,” 2000.

17. Ransom Environmental Consultants, Inc., “Results of Geotechnical Investigation, Salem Harbor Power Plant Substation Expansion, Fort Avenue, Salem, Massachusetts,” March 2005.

18. Ransom Environmental Consultants, Inc., “Class B-1 Response Action Outcome (RAO) Statement, Proposed Northern Expansion Area, 24 Fort Avenue, Salem, Massachusetts, Reportable Condition Discovery Date: January 21, 2005,” May 2005.

19. Ransom Environmental Consultants, Inc., “Phase II Comprehensive Site Assessment Report, Historical Cable Oil Releases, Salem Harbor Power Plant, 24 Fort Avenue, Salem, Massachusetts, MA DEP Release Tracking No. 3-24678,” March 2008.

20. Ransom Environmental Consultants, Inc., “Class A-2 Response Action Outcome (RAO) Statement, Historical Cable Oil Releases, Salem Harbor Power Plant, 24 Fort Avenue, Salem, Massachusetts, MA DEP Release Tracking No. 3-24678,” July 2008.

21. TRC Environmental Corporation “Release Notification From and Class A-1 Response Action Outcome, Dominion Energy New England, Inc., No. 2 Fuel Oil Release, 24 Fort Avenue, Salem, Massachusetts, RTN 3-28203,” February 2009.