COMMONWEALTH OF MASSACHUSETTS

ENERGY FACILITIES SITING BOARD DEPARTMENT OF PUBLIC UTILITIES

SUPPLEMENTAL NOTICE OF ADJUDICATION AND PUBLIC COMMENT HEARING

EFSB 22-03/D.P.U. 22-21

NSTAR Electric Company d/b/a Eversource Energy

Pursuant to G.L. c. 164, §§ 69J, 72, NSTAR Electric Company d/b/a Eversource Energy (“Eversource” or the “Company”), located at 247 Station Drive, Westwood, Massachusetts 02090, has filed two related petitions with the Energy Facilities Siting Board (“Siting Board”) and the Department of Public Utilities (“Department”) in connection with the Company’s proposal to construct, operate and maintain: (1) eight new 115-kilovolt (“kV”) underground transmission lines that will be housed in a total of five new duct banks, totaling approximately 8.3 miles, in portions of Cambridge, Somerville and the Allston/Brighton area of Boston (the “New Lines”); (2) a new 115/14-kV substation, which will be located in an underground vault on a property between Broadway and Binney Streets in Cambridge (the “New Substation”); and (3) modifications to certain existing substation facilities in Cambridge, Somerville, and Allston/Brighton. This work is collectively referred to as the Greater Cambridge Energy Program, or the “Project.” The Company states that the Project is designed to address long-term reliability needs in the Cambridge area, which is experiencing rapid economic development and sustained load growth.

Siting Board staff directed the Company to evaluate a potential hybrid alternative route through Cambridge and Somerville to connect the proposed New Substation with the Company’s existing Somerville Substation. This new alternative route is referred to as the Noticed Hybrid Alternative Route S15 and it is described further below.

The purpose of this supplemental public notice is to inform abutters to this new Noticed Hybrid Alternative Route S15 that is being proposed by the Company, as well as previously noticed abutters to Proposed Route S1A (and Route Variation S1) and Noticed Alternative Route S11C. The Siting Board will conduct a remote public comment hearing regarding the Project using Zoom videoconferencing on November 10, 2022 at 6 p.m. Information on accessing the remote public comment hearing is provided below.

The Siting Board will conduct a second remote public comment hearing regarding the Project using Zoom videoconferencing on November 10, 2022, at 6:00 pm. Attendees can join by clicking (or entering) the following link https://us06web.zoom.us/j/83646572343 from a computer, smartphone, or tablet. No prior software download is required. For audio-only participation, attendees can dial in at 1 646 558 8656 (not toll free) and then enter the Webinar ID: 83646572343. Any additional updates will be posted on the Siting Board’s website at: https://www.mass.gov/info-details/greater-cambridge-energy-project.

The Siting Board will accept additional public comments, and additional petitions to intervene or to participate as a limited participant in the Siting Board’s review of the Project relating to the new Noticed Hybrid Alternative Route S15 by November 25, 2022.

If you anticipate providing comments via Zoom during the public comment hearing, please send an email to [email protected] with your name, email address, and mailing address by

November 10, 2022. If you anticipate commenting by telephone, please leave a voicemail message at (617) 305-3529 with your name, telephone number, and mailing address by November 10, 2022. Additional commenters may be allowed during the public comment hearing, at the discretion of the Presiding Officer.

The Siting Board will accept written comments on the Project. Written comments will be most useful to the Siting Board if submitted by November 25, 2022.

Persons or groups who wish to be involved in the Siting Board proceeding beyond providing comments at the public comment hearing or submitting written comments may seek either to intervene as a party or to participate as a limited participant. A petition to intervene or participate must be filed with the Siting Board in electronic format, by email or email attachment, to [email protected] and to [email protected] no later than the close of business (5:00 p.m.) on November 25, 2022.

Simultaneous English-to-Spanish, Portuguese, Chinese (Mandarin), and Haitian Creole interpretation will be provided on Zoom. All attendees should select their preferred language to hear the Interpreter translate into that language. Press the globe icon pastedGraphic.png and then choose the desired language.

Public Comment Hearing

At the public comment hearing, Eversource will present an overview of the Project and the additional proposed route. Public officials and members of the public will then have an opportunity to ask questions and make comments about the proposed Project. The public comment hearing will be recorded by a court reporter. A recording of the public comment hearing will be posted to the Department’s YouTube channel after the public comment hearing.

Intervention and Participation

Persons or groups who wish to be involved in the Siting Board proceeding may seek either to intervene as a party or to participate as a limited participant. Intervention as a party allows the person or group to participate fully in the evidentiary phase of the proceeding, including the right to participate in evidentiary hearings and to appeal a final decision. A limited participant would receive documents in the proceeding and may file a brief as well as file written comments and/or present oral comments regarding the Tentative Decision to the Siting Board.

 Any person wishing to intervene as a party or to participate as a limited participant in this proceeding must file a written petition with the Presiding Officer (see Filing Instructions below). A petition to intervene or be a limited participant must satisfy the timing and substantive requirements of 980 CMR 1.00, the Siting Board’s procedural rules, which can be found on the Siting Board’s website at: https://www.mass.gov/doc/980-cmr-1-rules-for-the-conduct-of-adjudicatory-proceedings/download. To be allowed, a petition to intervene filed pursuant to 980 CMR 1.05 must demonstrate that the petitioner may be substantially and specifically affected by this proceeding.

Filing Instructions

Written comments on the Project, or a petition to intervene or participate as a limited participant in this proceeding, must be filed in two places:

 

First, the petition to intervene or participate, and comments, must be filed with the Siting Board in electronic format, by email or email attachment to [email protected]; and to [email protected] no later than the close of business on November 25, 2022. The text of the e-mail must specify: (1) the docket number of the proceeding (EFSB 22-03/D.P.U. 22-21); (2) the name of the person or entity submitting the filing; and (3) a brief description of the document. The electronic filing should also include the name, title, and telephone number of a person to contact in the event of questions about the filing. Second, the petition or comments must be sent electronically to counsel for the Company, David S. Rosenzweig, Esq., Keegan Werlin LLP, 99 High Street, Suite 2900, Boston, MA 02110, [email protected].

Siting Board Jurisdiction

Under G.L. c. 164, §§ 69H, 69J, the Siting Board will review the Company’s filing to determine whether the Project would provide a reliable energy supply with a minimum impact on the environment at the lowest possible cost. Under G.L. c. 164, § 72, the Siting Board will determine whether the proposed Project is necessary, serves the public convenience, and is consistent with the public interest.

Public Review of the Company’s Petitions

The petition to construct the Project includes the following information: (1) a description of the Project; (2) an analysis of the need for the Project; (3) a description of the alternatives to the Project; and (4) a description of the environmental impacts of the Project. Copies of the Company’s petitions, including all attachments, are available for public inspection in hard-copy format at the following locations:

  • Energy Facilities Siting Board, One South Station, 5th Floor, Boston, MA 02110
  • Cambridge Public Library, Main Branch, 449 Broadway, Cambridge, MA 02138
  • Cambridge Public Library, O’Connell Branch, 48 Sixth Street, Cambridge, MA 02141
  • Cambridge City Clerk, 795 Massachusetts Avenue, Cambridge, MA 02139
  • Boston Public Library, Brighton Branch, 40 Academy Hill Road, Brighton, MA 02135
  • Boston City Clerk, 1 City Hall Square, Room 601, Boston, MA 02201
  • Somerville Public Library, 79 Highland Avenue, Somerville, MA 02143
  • Somerville City Clerk, 93 Highland Avenue, 1st Floor, Somerville, MA 02143

In addition, the Company’s petitions, including all attachments, are electronically available via the Energy Facilities Siting Board’s website at: https://eeaonline.eea.state.ma.us/DPU/Fileroom/dockets/bynumber/EFSB22-03. The Siting Board has created a special information webpage for this proceeding and will update it during the course of the proceeding. https://www.mass.gov/info-details/greater-cambridge-energy-project.

The Company’s information is also available on the Company’s website at the following address:

https://www.eversource.com/content/general/residential/about/transmission- distribution/projects/massachusetts-projects/greater-cambridge-energy-project

To request materials in accessible formats for people with disabilities (Braille, large print, electronic files, or audio format) contact the Siting Board’s ADA coordinator at [email protected] or 617-626-1282.

Accommodation Requests

Reasonable accommodations for people with disabilities are available upon request. Include a complete description of the accommodation you will need and a way we can contact you if we need more information. Please provide as much advance notice as possible. Please allow at least two weeks (14 days) advance notice. Last minute requests will be accepted, but we may be unable to fulfill the request. Please send your requests to: Melixza G. Esenyie, ADA and Diversity Manager at the Executive Office of Energy and Environmental Affairs at [email protected] or call 617- 626-1282 no later than October 27, 2022.

Interpretation services for those with limited English language proficiency are available upon request. Include in your request the language required, and a way to contact you if we need more information. Please provide as much advance notice as possible, by October 27, 2022, if possible. Last-minute requests will be accepted but may not be able to be accommodated. Contact the Presiding Officer (contact information below).

Any person desiring further information regarding this Notice, including information about intervention or participation in the proceeding may also contact the Presiding Officer at the address or telephone number below:

Donna Sharkey, Presiding Officer Energy Facilities Siting Board One South Station

Boston, MA 02110 [email protected] (617) 305-3625

Figure 1: Somerville Study Area

 

Somerville Noticed Hybrid Alternative Route S15 (Hybrid of Preferred Route S1A, Noticed Alternative Route S11C, and South Street)

Noticed Hybrid Alternative Route S15 is approximately 1.35-miles long and is located within Cambridge and Somerville. Noticed Hybrid Alternative Route S15 heads west from the New Substation Site in Cambridge onto Broadway for about one block before turning north across the Galileo Galilei Way intersection onto a City-owned parcel of land (Assessors’ Map 30, Parcel 43) abutting the east side of the MassDOT Railroad and Transit Grand Junction Railroad corridor. The route continues north on property parallel and adjacent to both sides of the Grand Junction Railroad corridor passing the Cornelius Way / Michael Way / Wellington Harrington Memorial Way residential neighborhoods and the Cambridge Housing Authority’s Miller River Apartment Complex. The route collocates within the proposed future alignment of the City of Cambridge’s Grand Junction Multi-Use Path from Broadway to Medford Street/Gore Street at the Cambridge/Somerville city line, including switching from City-owned land on the east side of the existing railroad corridor to future City-owned land on the west side of the railroad corridor. These crossovers would occur at the following at-grade street crossings: Binney Street, Cambridge Street and Medford/Gore Street. The Noticed Hybrid Alternative Route S15 exits the Grand Junction Railroad corridor at Medford Street/Gore Street and continues for about 300 feet on Medford Street before heading west on South Street. The route then follows South Street to the end where it intersects with Windsor Street. At this juncture, the route continues in a westerly direction across a private parcel of land (a salvaged auto parts facility) to Columbia Street.

Based on discussions with the City of Somerville, it is possible that, in the near future, South Street will be relocated in a more southerly direction than what is currently contemplated for the Noticed Hybrid Alternative Route S15; however, the Company further understands those design details remain in flux and have not yet been finalized by the City of Somerville and the developer of Boynton Yards. It is also possible that, based on further input from the City of Somerville, the Company may be steered to a variation of the route to the north along Harding Street to Thoroughfare 1 (Archibald Query Way), before connecting along a short segment of Windsor Place. Accordingly, the Company is presenting two noticed variations to the Noticed Hybrid Alternative Route S15 in the event such variations are needed or desirable.

The intent of the proposed segment of Noticed Hybrid Alternative Route S15 is to follow the future alignment of South Street up to Columbia Street and collocate with future re-development plans for the area. From Columbia Street, the route turns north before crossing a private commercial parking lot at the corner of Columbia Street and Windsor Place and then a second commercial parking lot north of Windsor Place associated with Royal Hospitality Services. From the Royal Hospitality Services commercial parking lot, the route crosses beneath the Massachusetts Bay Transportation Authority (“MBTA”) Fitchburg commuter tracks and new Green Line extension tracks, using a trenchless crossing technique. After crossing the tracks, the route travels in a westerly direction parallel to the MBTA railroad tracks and the new MBTA Union Station platform, before turning north parallel to Prospect Street (and around the approximate limits of a building footprint under construction), and then west across Prospect Street where it enters the Somerville Substation.

The Company’s New Substation

The New Substation will be constructed underground on a parcel of land that is currently occupied by the Kendall Center Blue Garage at #290 Binney Street in East Cambridge. The New Substation site is bordered by Binney Street to the north; the access driveway into the existing garage facility to the east; Broadway to the south; and Galileo Galilei Way to the west.

For the site to be developed for the New Substation, the landowner (Boston Properties, Inc. or “BXP”) will demolish the existing Kendall Center Blue Garage and replace it with underground parking in roughly the same location. Following demolition of the existing parking garage facility, the New Substation will occupy roughly one-third of the parcel, or approximately 35,000 square feet (or 0.8 acres). The balance of the existing site will ultimately be re-developed by BXP as part of the Kendall Square MXD Substation Plan.

The New Substation will be constructed to a depth of approximately 110-feet below grade. Except for vent stacks, a freight elevator headhouse and stair access headhouse, the New Substation will be completely underground. At grade level, above the underground substation, the area will be designed and created as publicly accessible open space, integrated into the larger BXP development project.

As part of the engineering design, the underground New Substation would have the following components: 115-kV gas-insulated switchgear (“GIS”); twenty-two 115-kV circuit breakers; six 115 kV series inductors; control rooms with protective relay and control equipment; communication equipment and control batteries; three 90-MVA, 115/14-kV transformers; distribution switchgear; and six 14-kV, 9.6-MVAR capacitor banks. There will also be space reserved for an additional transformer, switchgear, capacitor bank, and shunt reactor, if and when needed in the future.

Figure 2: 3-D Rendering of Proposed New Substation

 

The Company’s Proposed Transmission Line Routes

As noted above, the Project includes eight new 115-kV underground transmission lines within five new duct banks (8.3 miles in total, primarily in public roadways in portions of Cambridge, Somerville and the Allston-Brighton area of Boston), each of which would connect to the New Substation in Cambridge. The six Proposed Routes of the Project including the new proposed hybrid route known as Somerville Noticed Hybrid Alternative Route S15 (Hybrid of Preferred Route S1A, Noticed Alternative Route S11C, and South Street) are summarized below.

Somerville Proposed Route S1A (Hampshire Street/D2 Site) and Route Variation S1

The Proposed Route (designated as “S1A”) is approximately 1.3-miles long, connecting the New Substation to the existing Somerville Substation. This route heads west from the New Substation onto Broadway for about one block before turning northwest onto Hampshire Street. From Hampshire Street, the route heads north on Columbia Street. The route follows Columbia Street into Somerville to its intersection with Windsor Place. The route crosses Windsor Place and heads north across a private commercial parking lot towards the MBTA commuter rail tracks (Fitchburg Route Main Line). The railroad tracks would be crossed using a trenchless construction technique. After crossing the tracks, the route travels in a westerly direction across the D-2 Block-Union Square Project development (“D2 Site”), parallel to the MBTA railroad tracks and the MBTA’s new Green Line train station platform, turning north running parallel to Prospect Street (and around the approximate limits of a building that is presently under construction on the D2 Site), and then west across Prospect Street where it enters the Somerville Substation.

Route Variation S1 follows the same alignment described above for the Proposed Route S1A, except that it travels in a northwesterly direction around the eastern edge of the site of the MBTA’s new Union Square train station platform, across the D2 Site, generally following the approximate alignment of two future roadways associated with the development, identified as Milk Alley and Bennett Court. The route then crosses over Prospect Street and accesses the Somerville Substation from the east. This route variation does not add any appreciable length or costs relative to the Proposed Route S1A.

Kendall Proposed Route K5A (Linskey Way)

The Proposed Route (designated as “K5A”) is approximately 0.6 miles long, connecting the New Substation to the existing East Cambridge Substation. This route heads east from the New Substation onto Broadway, then turns northeast to the abutting U.S. Department of Transportation John A. Volpe National Transportation Systems Center (“Volpe Center Site”) property and transitions onto Third Street near its intersection with Potter Street. The route crosses the Volpe Center Site to avoid utility congestion in parts of Third Street and specifically the Third Street/Broadway intersection. The route then turns east onto Linskey Way and south onto Second Street, where it connects into the existing East Cambridge Substation.

Putnam Proposed Route P13 (Ames Street)

The Proposed Route (designated as “P13”) is approximately 0.5-mile long, located entirely within Cambridge. This route heads east from the proposed New Substation facility in East Cambridge onto Broadway and south on Ames Street. The route follows Ames Street through the Main Street intersection, and the Massachusetts Bay Transit Authority (“MBTA”) Red Line subway tunnel beneath it, to the intersection with Memorial Drive. At Memorial Drive, the route ends in a “T” configuration with the line being spliced into existing Eversource transmission line(s) to the east and west on Memorial Drive.

Brighton Proposed Route B2A East (Magazine Beach HDD) and Route Variation B2AN

The Proposed Route (designated as “B2A”) is approximately 2.9-miles long, heading east from the New Substation to the existing Brighton Substation. This route heads east from the New Substation onto Broadway before turning south onto Ames Street. The route follows Ames Street through the Main Street intersection, and the MBTA Red Line subway tunnel beneath it, to the intersection with Memorial Drive. At Memorial Drive, the route turns to the west following the east bound lanes to the Massachusetts Department of Conservation and Recreation’s (“MassDCR”) Magazine Beach property. Magazine Beach and the Memorial Drive segment are located within the Charles River Reservation and are under the care and custody of MassDCR. At the Magazine Beach property, the route crosses beneath the Charles River into Boston via Horizontal Directional Drill (“HDD”), which is preliminarily anticipated to be approximately 1,750 feet in length. After crossing beneath the Charles River, the route follows the general alignment of the anticipated new street, referred to as the Lincoln Street Connector, that is proposed to be constructed as part of MassDOT’s Allston Multimodal Project. From there, the route goes onto Cambridge Street, following Cambridge Street to Empire Street and Lincoln Street where it terminates at the Brighton Substation.

The Company proposed a route variation to Route B2A East across the MassDOT Allston Multimodal Project Site. The Proposed Route B2A East generally follows the future alignment of the Lincoln Street Connector through the multimodal site and Route Variation B2AN East generally runs parallel

with the southerly property line of the multimodal site. Route Variation B2AN East provides routing flexibility if MassDOT’s Allston Multimodal Project does not advance into construction as currently proposed, while also minimizing potential future development constraints by locating the transmission line and manhole infrastructure in areas of the site that will not negatively affect the present landowner’s (Harvard University) ability to develop the property in the future. This route variation does not add any appreciable length or costs relative to the Proposed Route B2A East.

Brighton Proposed Route B29F West (River Street Bridge)

The Proposed Route (designated as “B29F”) is approximately 3.0-miles long, heading west from New Substation to the existing Brighton Substation. This route heads west from the New Substation onto Broadway before turning south onto Galileo Galilei Way to Vassar Street. The route follows Vassar Street before crossing northwest through a parking lot, a portion of which is owned by MIT and the MBTA. From the parking lot, the route crosses the Grand Junction Railroad using a pipe jacking or other similar trenchless crossing technique to reach a parking lot on a second parcel of land owned by MIT (referred to as #634 Memorial Drive). The route then follows Waverly Street to Brookline Street through the Reid Rotary at the Boston University Bridge, continuing west on Memorial Drive to the River Street Bridge. At this location, the route turns to the west across the River Street Bridge, over the Charles River, and onto Cambridge Street in Boston. The bridge crossing would be accomplished by installing the transmission cable in the bridge deck/roadway pavement. On the Boston side of the Charles River, the route would cross over the I-90 ramps following the approximate location of Cambridge Street if it is reconstructed at-grade as part of MassDOT’s Allston Multimodal Project. After passing through a short stretch of wooded, undeveloped land (~500-feet) adjacent to the roadway shoulder(s), the route transitions back onto Cambridge Street until it reaches Lincoln Street. The route follows Lincoln Street to the Brighton Substation.

The Company’s Noticed Alternative Transmission Line Routes

The six Noticed Alternative routes are as follows:

Somerville Noticed Alternative Route S11C (Grand Junction RR Multi-Use Pathway)

The Noticed Alternative Route (designated as “S11C”) is approximately 1.6-miles long, connecting the New Substation to the existing Somerville Substation. This route heads west from the New Substation onto Broadway for about one block before turning north onto a parcel of land owned by the City of Cambridge abutting the east side of the MBTA Grand Junction Railroad corridor. The route continues north on the City of Cambridge owned properties parallel to the east side of the MBTA Grand Junction Railroad corridor. From Broadway to Medford Street in Somerville, the route collocates with the potential future alignment of Cambridge’s Grand Junction Multi-Use Path, which requires crossing from City of Cambridge-owned land on the east side of the existing railroad corridor to City of Cambridge-owned land on the west side of the railroad corridor. These crossovers would occur at the following at-grade street crossings: Binney Street, Cambridge Street and Medford Street. The Cambridge/Somerville municipal boundary is located just south of Medford Street. After crossing Medford Street, Route S11C continues north along the western edge of the MBTA ROW up to the intersection of the Grand Junction railroad tracks and the MBTA commuter rail tracks (Fitchburg Route Main Line). The route would then cross beneath the MBTA commuter rail tracks and McGrath Highway (Route 28) using a trenchless construction technique, to reach an Eversource- owned parcel of land on Linwood Street.  The transmission line would then transition back to

conventional open-trench construction as it turns northwest onto Linwood Street, Washington Street and Prospect Street where it connects with the Somerville Substation.

Somerville Noticed Hybrid Alternative Route S15 (Hybrid of Preferred Route S1A, Noticed Alternative Route S11C, and South Street)

Noticed Hybrid Alternative Route S15 is approximately 1.35-miles long and is located within Cambridge and Somerville. Noticed Hybrid Alternative Route S15 heads west from the New Substation Site in Cambridge onto Broadway for about one block before turning north across the Galileo Galilei Way intersection onto a City-owned parcel of land (Assessors’ Map 30, Parcel 43) abutting the east side of the MassDOT Railroad and Transit Grand Junction Railroad corridor. The route continues north on property parallel and adjacent to both sides of the Grand Junction Railroad corridor passing the Cornelius Way / Michael Way / Wellington Harrington Memorial Way residential neighborhoods and the Cambridge Housing Authority’s Miller River Apartment Complex. The route collocates within the proposed future alignment of the City of Cambridge’s Grand Junction Multi-Use Path from Broadway to Medford Street/Gore Street at the Cambridge/Somerville city line, including switching from City-owned land on the east side of the existing railroad corridor to future City-owned land on the west side of the railroad corridor. These crossovers would occur at the following at-grade street crossings: Binney Street, Cambridge Street and Medford/Gore Street. The Noticed Hybrid Alternative Route S15 exits the Grand Junction Railroad corridor at Medford Street/Gore Street and continues for about 300 feet on Medford Street before heading west on South Street. The route then follows South Street to the end where it intersects with Windsor Street. At this juncture, the route continues in a westerly direction across a private parcel of land (a salvaged auto parts facility) to Columbia Street.

Based on discussions with the City of Somerville, it is possible that, in the near future, South Street will be relocated in a more southerly direction than what is currently contemplated for the Noticed Hybrid Alternative Route S15; however, the Company further understands those design details remain in flux and have not yet been finalized by the City of Somerville and the developer of Boynton Yards. It is also possible that, based on further input from the City of Somerville, the Company may be steered to a variation of the route to the north along Harding Street to Thoroughfare 1 (Archibald Query Way), before connecting along a short segment of Windsor Place. Accordingly, the Company is presenting two noticed variations to the Noticed Hybrid Alternative Route S15 in the event such variations are needed or desirable.

The intent of the proposed segment of Noticed Hybrid Alternative Route S15 is to follow the future alignment of South Street up to Columbia Street and collocate with future re-development plans for the area. From Columbia Street, the route turns north before crossing a private commercial parking lot at the corner of Columbia Street and Windsor Place and then a second commercial parking lot north of Windsor Place associated with Royal Hospitality Services. From the Royal Hospitality Services commercial parking lot, the route crosses beneath the Massachusetts Bay Transportation Authority (“MBTA”) Fitchburg commuter tracks and new Green Line extension tracks, using a trenchless crossing technique. After crossing the tracks, the route travels in a westerly direction parallel to the MBTA railroad tracks and the new MBTA Union Station platform, before turning north parallel to Prospect Street (and around the approximate limits of a building footprint under construction), and then west across Prospect Street where it enters the Somerville Substation.

Kendall Noticed Alternative Route K11 (Fifth Street)

The Noticed Alternative Route (designated as “K11”) is approximately 0.6-miles long connecting the New Substation to the existing East Cambridge Substation. This route heads east from the New Substation onto Broadway before turning north across the abutting Volpe Center Site to Potter Street. From Potter Street, the route heads north onto 5th Street and west onto Munroe Street before crossing over Third Street onto Linskey Way. Potter Street, 5th Street, and Munroe Street are private roads. The route follows Linskey Way in an easterly direction before turning south onto Second Street to its interconnection point within the East Cambridge Substation.

Putnam Noticed Alternative Route P11 (Massachusetts Avenue)

The Noticed Alternative Route (designated as “P11”) is approximately 0.9-miles long, located entirely within Cambridge. This route heads east from the New Substation onto Broadway and then south onto Ames Street to the intersection with Main Street. The route heads west on Main Street parallel to the MBTA Red Line subway tunnel before crossing over the tunnel onto Vassar Street. The route heads south on Vassar Street to Massachusetts Avenue, where it then turns towards the southeast on Massachusetts Avenue to Memorial Drive. At Memorial Drive, the route ends in a “T” configuration with the line being spliced into existing Eversource transmission line(s) to the east and west on Memorial Drive.

Brighton Noticed Alternative Route B31 East (River Street Bridge)

The Noticed Alternative Route (designated a “B31”) is approximately 3.3-miles long, heading east to connect the New Substation to the existing Brighton Substation. The route follows Ames Street to the intersection with Memorial Drive. At Memorial Drive, the route turns to the west (following the east bound lanes of Memorial Drive) to the Reid Rotary at the Boston University Bridge, continuing west on Memorial Drive to the River Street Bridge. At this location, the route turns to the west across the River Street Bridge, over the Charles River, and onto Cambridge Street in Boston. The bridge crossing would be accomplished by installing the cable in the bridge deck/roadway pavement. On the Boston side of the Charles River, the route would cross over the I-90 ramps following the approximate location of Cambridge Street if it is reconstructed at-grade as part of MassDOT’s Allston Multimodal Project. After passing through a short stretch of wooded, undeveloped land (~500-feet) adjacent to the roadway shoulder(s), the route transitions back onto Cambridge Street until it reaches Lincoln Street. The route follows Lincoln Street to the Brighton Substation.

Brighton Noticed Alternative Route B30 West (Anderson Street Bridge)

The Noticed Alternative Route (designated as “B30”) is approximately 3.4-miles long, heading west from the New Substation to the existing Brighton Substation. The route follows Green Street to Putnam Avenue where it turns north and then west onto Mt. Auburn Street. The route follows Mt. Auburn Street to John F. Kennedy Street. The route then heads south along John F. Kennedy Street to the Anderson Memorial Bridge over the Charles River. The bridge crossing would be accomplished by installing the cable in the bridge deck/roadway pavement. On the Boston side of the Charles River, the route follows North Harvard Street to Franklin Street and Lincoln Street before terminating at the Brighton Substation.

Ancillary Project Work

The Project includes work at five existing substations to accommodate new transmission lines: Somerville Substation #402, Putnam Bulk Substation #831, East Cambridge Substation #875, Brighton Substation #329, and North Cambridge Substation #509. All work to be done at these existing stations will be performed within the existing station fence lines.

Somerville Substation #402 Improvements

Project-related work at Station #402 will consist of installing new below-grade duct banks, above- grade cable terminations (in the location of the existing terminators), cable pulling/termination, and control and protection changes.

East Cambridge Substation #875 Improvements

The 115-kV bus at the East Cambridge Substation #875 is the terminal for the output cable of the adjacent Vicinity Energy Generating Unit and two supply cables that connect to the existing transmission system. To integrate the New Substation into the transmission system, the output cable of the Vicinity Energy Generating Unit will be disconnected from the 115-kV bus and connected to a proposed new line connecting directly to the New Substation. A new 115-kV line proposed from the New Substation will be connected to the switching position formerly utilized by the Vicinity Energy Generating Unit. Work will consist of reconfiguring duct banks in the station yard, cable pulling/termination and control and protection changes.

Putnam Bulk Substation #831 Improvements

The 115-kV lines supplying the Putnam Bulk Substation #831 are proposed to be reconfigured at a location outside of the station footprint on Memorial Drive. Work at this substation facility will consist of protection and control changes. All work will be confined to the interior of the 115-kV relay room.

Brighton Substation #329 Improvements

Project-related work at the Brighton Substation #329 will consist of installing new below-grade duct banks, above-grade cable terminations (in the location of the existing terminators), cable pulling/termination, and control and protection changes.

North Cambridge #509 Substation Improvements

The 115-kV bus at North Cambridge Substation #509 is the source of the two 115-kV supply lines to Putnam Bulk Substation #831. To balance flows on the transmission system, air-core current limiting reactors (“CLRs”) will be installed at Station #509 near the location of the existing line terminations towards the center of the site. In addition to the installation of the CLRs and their associated foundations, a small section of air-insulated bus will be replaced with gas-insulated bus to achieve required electrical clearances. There will also be work associated with required modifications to protection and control equipment. The substation is bordered on all sides by developed areas including the MBTA railroad tracks to the north; Alewife Brook Parkway to the east; a shopping center and medical offices to the south; and residential apartments to the west.

Miscellaneous Distribution System Upgrades

The Company will also be installing a set of 36 distribution feeders and associated duct banks and other equipment that connects the New Substation to the existing distribution network in public ways immediately adjacent to the New Substation. While distribution lines are not jurisdictional to the Siting Board’s review under G.L. c. 164, §69J or §72, as part of the Project, the Company has nevertheless provided information about its build-out of the electric distribution system to identify the full scope of facilities that will be constructed in concert with the Project.