Here are some highlights of the meeting of the Green Line Extension (GLX) Design Working Group/Construction Working Group held Thursday, Oct. 2, at the Center for the Arts at the Armory in Somerville:
GLX AND SUSTAINABILITY
Andrew Brennan, Director of Environmental Affairs for the MBTA, gave a presentation demonstrating how the GLX is a major part of the MBTA’s sustainability program and also MassDOT’s GreenDOT initiative, one of whose goals is to triple the number of transit, bicycling and walking trips statewide by 2030. Brennan noted that extending mass transit service into areas like Somerville helps sustain densely populated urban developments by making them more accessible to people without having to drive (44% of Somerville households do not have access to a car, he noted). The GLX stations further discourages driving by offering only 240 parking spaces for cars at the seven new stations, compared to 1,113 parking spaces for bicycles.
Water and water management are major issues for the GLX, especially since much of the extension will be built below grade level in a “cut” where commuter rail lines currently run and flooding sometimes is a problem due to antiquated draining systems. Water management concern is heightened due to the anticipated impacts of climate change and the likelihood of more severe and more frequent rain events.
To help prevent flooding, each GLX station platform will have a rain storage area underneath it to hold stormwater during a rain event for released late
To reduce the amount of stormwater runoff, a green roof is being considered for the Green Line maintenance facility, and the MBTA also is exploring the feasibility of installing a “blue roof” that would allow rain water to be captured for use washing Green Line vehicles
Other sustainability measures that are part of the GLX include:
+ Repurposing granite blocks and existing viaduct material into the station designs
+ Recycling 75% of demolition debris
+ Reusing soil removed in excavation, preferably at nearby construction sites such as North Point
+ Use of low-toxic, sustainable materials in all elements of the design
+ Station designs focus on energy management efficiency including ample amounts of glass to allow in natural light, and high-efficiency mechanical equipment (the MBTA is the largest consumer of electricity in Massachusetts)
+ Designing extra protection of the power delivery system from catastrophic rain events/flooding
+ Use of hardy, native plants in landscaping
+ Utilizing the Envision system guidelines which rate and certify public works projects for sustainability (similar to LEED for private development)
+ Including the design and construction of the Community Path, which complements the GLX and serves as “bicycle and pedestrian highway” through Somerville, providing non-car access to municipal buildings, schools, shopping and dining areas, parks, and houses of worship
Brennan noted that sustainability is an important part of the MBTA’s application for federal funding for the project, which is to be submitted soon and decided upon by the Federal Transit Administration (FTA) over the winter.
Responding to a question about the potential for solar panels on station roofs, Brennan said opportunities were limited due to small station roof surfaces, and poor economics. He noted that as a tax-exempt entity, the MBTA is not eligible for the tax credits and other such incentives that help make solar projects more financially viable. However, there may be opportunities for an arrangement to be made with a private company to erect a solar power generation facility on a GLX station ¬– Lechmere being the most conducive – as was done at the Wonderland MBTA station, with the MBTA buying back the power from a third party.
PROJECT OVERVIEW AND UPDATES
Mike McBride of HDR/Gilbane, co-program manager, reported that a Notice to Proceed was given today for the start of early construction work on Phase 2 (Lechmere Station to Washington Station) and Phase 2A (Lechmere Station to Union Square). Early construction activity includes surveying, soil testing, utility relocation, Millers River drainage improvements, and procurement of long lead items such as bridge steel, special track work, and signal and electrical equipment. A notice to proceed on the remaining Phase 2/2A work is expected in the spring, pending the receipt of a Full Funding Grant Agreement from the FTA. the FFGA is undergoing final review and will be submitted soon.
Additional construction schedule milestones presented were:
+ Start of construction of commuter rail track interlocking at Tufts/College Avenue: March 2015
+ Start of Phase 4 construction (Lowell Street, Gilman Square, Ball Square and College Avenue stations): November 2015
+ Vehicle maintenance facility construction (Phase 3): February 2016 to January 2019
+ Opening of Lechmere, Washington Street and Union Square stations: December 2017
+ Opening of Phase 4 stations: Summer 2020
STATION DESIGN UPDATES
Randy Henke of AECOM/HNTB reported that the 90% designs of the Lechmere, Washington Street and Union Square stations are under review and that 100% designs are due for submittal on Nov. 21, 2014.
The designs of the Gilman Square, Lowell Street, Ball Square and College Avenue stations currently are at 60%; the schedule calls for 90% design to be reached in February 2015 and 100% design in March 2015.
Henke announced that in response to suggestions from the community, two locations for “bulb-outs” on either side of the Community Path between Washington Street and Lechmere Station have been identified. Designed as places to rest, these areas would be approximately 15 to 18 feet long and 7 feet wide, allowing for which would allow for a bench.
TUFTS DEVELOPMENT AT COLLEGE AVENUE
Robert Chihade, Director of Real Property at Tufts University, gave a brief overview of a conceptual plan for an academic building that Tufts is considering building on the site of a maintenance complex behind College Avenue Station. The building would partially be built in the station air rights and could potentially feature a pedestrian walkway above Boston Avenue. The conceptual plan also would allow for a direct, at-grade path from Burget Avenue to the station plaza, rather than current proposal: an elevated path that curves down toward the station along a new retaining wall. Tufts also is proposing that the right-turn lane from College Avenue to Boston Avenue, which is part of the current plan, be eliminated to allow for a larger station plaza, and that the right-turn lane be added as one of three lanes on the existing College Avenue bridge.
CURRENT PROJECT COST ESTIMATE
A Working Group member asked for details on the recent project cost estimate increase from $1.6 billion to $1.9 billion. Andrew Brennan explained that the lower figure is the one the MBTA anticipates the project to cost if it is completed on time, as expected; the larger figure includes $300 million that the FTA requested the MBTA set aside as a contingency to cover potential costs of a completion delay of up to one year. The FTA also requested the MBTA use the $1.9 billion cost estimate in its full funding grant application, half of which the FTA would match if it approves the application.
Answering a follow-up question about how the project cost previously escalated from $1.3 billion to $1.6 billion, Mary Ainsley, Senior Director of Design and Construction at the MBTA, cited many factors, including:
+ Inclusion of the design and construction of the Community Path from Lowell Street Station in Somerville to Water Street in Cambridge, which includes design and construction of an elevated half-mile viaduct between Washington Street Station and Lechmere Station
+ An increase in the number of utility conflicts from 220 when design work started to now more than 500
+ Additional design and construction work for the Millers River drainage system from Washington Street Station to the Charles River outfall, addressing longstanding regional draining issues
+ Additional environmental remediation at Washington Street Station due to the discovery of a contaminated plume in 2013
+ Lengthening the platforms at Lechmere Station and other key locations to accommodate future four-car Green Line cars
+ Deeper foundation requirements and new designs for viaduct piers due to information provided from additional geotechnical boring
+ Newly quantified real estate acquisition and business relocation costs related to the maintenance facility location
Tuesday, October 28: Lechmere Station meeting, 6 to 8 p.m., Cambridge Multicultural Arts Center, 41 Second St., East Cambridge
Thursday, November 6: Union Square and Washington Street stations meeting, 6 to 8 p.m., Somerville Holiday Inn, 30 Washington St.
Community Path meeting: Fall 2015
January 2015: Design Working Group meeting
- Ken Krause, Medford Green Line Neighborhood Alliance