ABSTRACT: This Supplemental EIS/EIR describes and summarizes the environmental and transportation impacts, along with measures to improve, avoid, minimize or mitigate impacts for the Central Subway Project Alternatives, that would be Phase 2 of the Third Street Light Rail (T-Third Line) connecting Visitation Valley, Bayview/Hunters Point and Mission Bay with the downtown retail district and Chinatown in San Francisco, California. The term ‘supplemental’ is used for this environmental document because it tiers off of a previous EIS/EIR for the two-phase Third Street Light Rail Project that was evaluated under the National Environmental Policy Act (NEPA) and the California Environmental Quality Act (CEQA) (Case No. 96.281E) in 1998. The Phase 1 Initial Operating Segment (IOS), now the T-Third Line, opened for operation in April of 2007. The San Francisco Municipal Transportation agency (MTA) is the Project Sponsor.
This document for the Phase 2 Central Subway updates information in the 1998 EIS/EIR for the Study Area and focuses on changes to the Project that have occurred since the certification of the Final EIS/EIR. These changes include: a new double-track segment along Fourth [begin deletion] and Stockton [end deletion] Street [begin deletion] s [end deletion] between Brannan and Market Streets as an alternative to use of Third [begin deletion] , Harrison, Kearny, [end deletion] and Geary Street [begin deletion] s [end deletion] ; extension of the planning horizon year from 2015 to 2030; the addition of above ground ventilation shafts for tunnel segments and stations; the use of off-street access to stations; a deep tunnel under Market Street; and the potential extension of a construction tunnel to the north end of the Project near Washington Square under Columbus Avenue for removing the tunnel boring machine. Three alternatives are evaluated in this SEIS/SEIR for the Central Subway Project:
• Alternative 1 - No Project/Transportation Systems Management, developed in conformance with NEPA and CEQA guidelines to represent a baseline for comparison with build alternatives. This alternative includes the T-Third Line and associated bus changes for the Phase 1 Third Street Light Rail Project.
• Alternative 2 - Enhanced EIS/EIR Alignment, as analyzed in the 1998 FEIS/FEIR, that would use King, Third, Harrison, Kearny, and Geary Streets as well as Fourth and Stockton Streets, with a shallow tunnel crossing of Market Street and four subway stations at Moscone, Market Street, Union Square and Chinatown, and a surface platform at Third and King Streets. The enhancements to this original alternative include: above-ground ventilation shafts to meet fire code, off-sidewalk station entries to minimize pedestrian congestion on busy downtown sidewalks, and the provision of a closed-barrier fare system.
• Alternative 3 – The Fourth/Stockton Alignment was developed during preliminary engineering and community outreach to avoid or minimize potential impacts identified in the 1998 FEIS/FEIR for the Central Subway phase of the Third Street Light Rail Project. This alternative would operate exclusively on Fourth and Stockton Streets, avoiding impacts along Third, Harrison, Kearny, and Geary Streets, and would include a deep (rather than shallow) tunnel under Market Street to minimize conflicts with a major sewer line. Two design options are included in this alternative; Option A with a double-track portal on Fourth Street between Townsend and Brannan Streets and three subway stations at Moscone, Union Square/Market Street, and Chinatown (the entrance between Sacramento and Clay Streets on the east side of Stockton Street, adjacent to Hang Ah Alley and Willie “Woo Woo” Wong park/playground), and Option B with a double-track portal on Fourth Street between Bryant and Harrison Streets to reduce the length of the tunnel, and a surface platform on Fourth Street at Brannan Street to serve local residents, and subway stations at Moscone, Union Square/Market Street and Chinatown. The primary entrance to the Union Square station for Option B would be on the Geary Street side of the plaza rather than the Stockton Street side [begin deletion] ; [end deletion] and vent shafts [begin insertion] , but [end insertion] would be in the Ellis/O’Farrell garage [begin deletion] rather than the plaza [end deletion] , minimizing impacts to the [begin deletion] plaza [end deletion] [begin insertion] park [end insertion] . The Chinatown Station entrance for Option B would be located on the west side of Stockton Street [begin insertion] between [end insertion] [begin deletion] at the corner of [end deletion] Clay and Washington Streets, and would not affect Willie “Woo Woo” Wong Playground. Alternative 3 also includes a construction tunnel extension to Columbus Avenue near Washington Square Park for purposes of extraction of the tunnel boring machine.
Impacts discussed in this SEIS/SEIR include: displacement of businesses and residences; removal of on-street parking at stations and along the surface portion of the alignments; removal of parking in three garages for vent shafts; use of a small portion of Union Square plaza for a station entry; degraded traffic service levels at intersections along Third and Fourth Streets where the surface alignments would be located; potential affects to historic architectural properties and historic districts adjacent to the tunnel portals and station entries; impacts to archaeological resources; and construction related impacts (localized noise, vibration, traffic, visual affects) for an estimated five to six year construction period. As required for CEQA, mitigation measures are described for all impacts determined to be significant to reduce them to less-than-significant. Unavoidable impacts are described for: traffic at Third and King, Fourth and King, Fourth and Harrison, and Sixth and Brannan Streets; displacement of affordable housing units; and for prehistoric archaeological resources during construction and potential impacts to [begin deletion] potentially eligible [end deletion] historic architectural buildings and [begin insertion] Districts in [end insertion] the Chinatown [begin insertion] and Union Square station areas [end insertion] [begin deletion] Historic District [end deletion] . [begin deletion] Impacts to Section 4(f) properties meet the criteria for a “de minimis” finding. [end deletion]
For additional information concerning this document, contact:
Mr. Ray Sukys, Office of Program Management Ms. Joan A. Kugler
U.S. Department of Transportation Planning Department
Federal Transit Administration, Region IX City and County of San Francisco
201 Mission Street, Suite 1650 1650 Mission Street, Suite 400
San Francisco, 94105 San Francisco, CA 94103
415-744-3133 415-575-6925