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Environmental Compliance

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Link21 Environmental Analysis

Link21 is planning ahead so that all work supports and complies with federal and state laws for
environmental analysis. The United States Department of Transportation guidance regarding
Planning and Environmental Linkages (PEL) is guiding the Program’s planning and public input
process. Link21 is committed to a fully integrated planning and environmental process with
public and stakeholder input.

National Environmental Policy Act (NEPA)

NEPA requires federal agencies to consider and disclose the effects of their actions on the quality of the human and natural environment. Because federal funding is anticipated for Link21, the Program will prepare NEPA-compliant environmental documents, including an Environmental Impact Statement (EIS) for proposed projects, which includes analyses of:

  • Environmental impacts and potential benefits of the proposed action
  • Potential mitigations for adverse impacts
  • Adverse impacts that cannot be avoided

Stakeholders, including public agencies, tribal nations, and the public, will be involved in the Link21 NEPA evaluation.

California Environmental Quality Act (CEQA)

CEQA requires public agencies to regulate activities that may affect the quality of the environment so that major consideration is given to preventing damage to the environment. 

CEQA applies to all governmental agencies at all levels in California, including local agencies, regional agencies, state agencies, boards, districts, and commissions. The San Francisco Bay Area Rapid Transit (BART) and Capitol Corridor Joint Powers Authority (Capitol Corridor) will be the lead agencies for the CEQA process, which will include an Environmental Impact Report (EIR) identifying potential project alternatives, adverse and beneficial impacts, and possible mitigations if required.

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Preliminary Purpose & Need

Under the National Environmental Policy Act (NEPA), any federally authorized or funded project must include a purpose and need statement. The purpose is the positive outcome(s) expected from the project, and the need identifies the problem(s) the project would address. A preliminary purpose and need statement has been developed for Link21, and will be used as the basis for defining the project and potential alternatives to be formally evaluated during the project's environmental phase. This statement was developed based on Link21's Goals and Objectives, planning and technical work, and input from stakeholders and agencies. The purpose and need statement will continue to evolve throughout the planning and environmental phases.

What are the Megaregional Needs that Give Link21 a Purpose?

Insufficient Passenger Rail Connectivity

  • Need: Existing rail services and networks are not sufficiently integrated and do not meet the needs of Bay Area residents and businesses or provide adequate connectivity for the megaregion. Limited service frequency, especially in off-peak periods, long travel times and inadequate transfer points are among the factors constraining the network from operating optimally.
  • Purpose: Integrate the megaregion’s passenger rail network by connecting and leveraging existing and planned systems and optimize the network’s performance, tapping into nearby undeserved markets in order to enhance access to economic opportunities and boost the region’s economy and its global competitiveness.

Existing Passenger Rail Systems and Operations Insufficiently Address Mobility Needs of Marginalized Communities

  • Need: Marginalized communities, including Link21’s priority populations (PP), disproportionately rely on transit to reach employment, healthcare, education centers, government services, and social destinations. Lack of accessibility to rail combined with limited service within the existing Transbay Corridor limit the mobility of PP. Many PP residents lack safe, affordable, and connected rail transit services, especially outside of traditional commute periods. Marginalized communities are negatively impacted by prior infrastructure investments and have suffered displacement.
  • Purpose: Expand access to improved and affordable passenger rail service for priority populations (PP), while proactively reducing potential displacement from new investments in transit.

Passenger Rail Capacity Constraints

  • Need: Existing infrastructure in the Transbay Corridor is insufficient to meet pre-pandemic and projected future travel needs resulting in crowding and lack of availability. Forecasted growth in this corridor will exacerbate its capacity issues.
  • Purpose: Increase passenger rail capacity in the Transbay Corridor to meet long- term forecasted travel demand.

Lack of Redundancy

  • Need: Rail service in the Transbay Corridor is vulnerable to disruption due to the existence of only a single rail crossing – the BART Transbay Tube which is 50 years old. Any disruption to its service negatively impacts travelers regionwide. Intercity or regional rail passengers are dependent on this single crossing and the congested freeway and bridge system.
  • Purpose: Expand redundancy and resiliency in the Transbay Corridor to minimize service disruptions and maintain mobility.

Negative Transportation-Related Impacts

  • Need: Regional greenhouse gas (GHG) reduction targets cannot be met without major reductions in vehicle miles traveled (VMT). Automobile accidents and fatalities are increasing throughout California. The Bay Area has one of the worst average commute times in the nation, and commuters spend over 100 hours a year stuck in traffic with a cost to the economy of $2.4 billion (2019)
  • Purpose: Enhance sustainability and quality of life through greater mobility, a reduction in transportation-related regional greenhouse gas (GHG) emissions, and reduction in automobile-related accidents, injuries and fatalities.

Environmental Constraints and Opportunities

To inform initial concept development and support an integrated planning process also known as Planning and Environmental Linkages (PEL), an inventory of environmental constraints and opportunities was assembled for the 21-county Megaregion. This included known resources such as biological, cultural, and community, along with existing infrastructure related to transportation and utilities. The inventory included other considerations such as equity communities, hazardous waste concerns, and future sea level rise inundation. The inventory was summarized in the program's Environmental Constraints and Opportunities (ECO) Report. Read the full report.

Critical Environmental Constraints

A critical environmental constraint is a physical or social condition that may impede the ability for Link21 to meet its vision, goals and objectives, and ultimately its preliminary purpose and need. Environmental constraints can impede the ability of equity communities to experience the benefits of Link21. Potential impacts to critical constraints associated with future Link21 infrastructure should be considered during concept development as they could result in substantial effects on people and the environment.

Critical Environmental Constraints Evaluated by Link21

Biological ResourcesNavigable waters, wetlands, streams, critical habitats, and protected areas (conservations easements, mitigation banks, etc.)San Francisco Bay; Wildcat Creek; eelgrass; Alameda Nature Reserve
Cultural ResourcesBuilt resources that are eligible for, or listed on, the California Register of Historical Resources (CRHR) or the National Register of Historic Places (NRHP) and archaeological sites *Port of San Francisco Embarcadero Historic District; USS Hornet; buried archaeological resources
Community ResourcesResidential areas, public schools, colleges/universities, hospitals, police stations, fire stations, and faith-based facilitiesCollege of Alameda; Civicorps Job Training Center; Alameda County Sheriff’s Office; Oakland Fire Department Station 1; UCSF Hospital; East Bay First Korean Baptist Church
Hazardous Waste or Materials SitesNational Priorities List (NPL) sitesAMCO Chemical Superfund site
Sea Level Rise (SLR) and HydrologyAreas forecasted for SLR inundation and Federal Emergency Management Agency (FEMA) floodplainsSLR inundation forecasted for the shorelines of Alameda, Oakland, and Hercules; 100-year floodplain located near the BART Oakland Coliseum Station
Section 4(f) ResourcesPublicly owned park and recreation lands (public trails, recreational areas of public schools open to the public, publicly owned golf courses, etc.), publicly owned wildlife and waterfowl refuges, and historic sites listed on or eligible for listing on the NRHPSan Francisco Bay Trail; Raimondi Park; Alameda Waterfront Park; Epic Charter School
TransportationMajor public transportation infrastructure, maritime facilities, and navigable waterwaysPort of Oakland; anchorage areas in the San Francisco Bay; San Francisco Central Subway; Interstate-980
Major UtilitiesMajor electrical transmission lines, gas/water pipelines, aqueducts, wastewater treatments plants, and power plantsTrans Bay Cable; Alameda- North Bay Farm Island Water Pipeline; Southeast Wastewater Treatment Plant
Equity CommunitiesPriority populations (PP) and Environmental Justice (EJ) communitiesCensus tracts identified in communities throughout the Bay Area with potential minority, low-income, and/or other equity communities

* Note: Archaeological sites and sensitive areas for Native American tribes are confidential and
therefore not noted on the website. This information was shared within the program to support
concept development and refinement.

Critical Environmental Opportunities

A critical environmental opportunity could improve the environmental performance of Link21 by reducing impacts or promoting benefits and opportunities for collaboration between Link21 and other resources that could advance other environmental priorities. Critical environmental opportunities are specific aspects of environmental resources that can help Link21 meet goals and objectives, and ultimately its preliminary purpose and need.

Critical Environmental Opportunities Evaluated by Link21

TransportationExisting passenger train lines and stations, airports, and existing ferry terminals; major bicycle trailsClay Street Ferry Terminal; San Francisco International Airport; Cross Alameda Trail
Community ResourcesUniversities, hospitals, and major museumsUCSF Medical Center at Mission Bay; California State University - East Bay; San Francisco Museum of Modern Art
Recreational ResourcesRegional recreational facilities (greater than 10 acres), sports stadiums, and event centersSan Pablo Bay Regional Park; Chase Center
Sea Level Rise (SLR)Collaboration opportunities with local and regional SLR adaptation planningCity and County of San Francisco SLR resiliency efforts
Serving Equity CommunitiesPriority populations (PP) and Environmental Justice (EJ) communitiesCensus tracts identified in communities throughout the Bay Area with minority, low- income, and/or other equity communities
Land UseTargeted growth areas and priority development areasTargeted growth areas within Oakland, Alameda, and Emeryville

Yellow Flags

Yellow flags are major critical constraints representing environmental risks that may result in challenges for project design or implementation. These risks would be addressed during environmental review and permitting and may require extensive mitigation to address. These risks were flagged for consideration in Link21’s Business Case analysis.

Help Shape Northern California’s Future Train Travel

To support refinement of the Link21 concepts, critical environmental constraints and opportunities were further evaluated and yellow flags, were noted for consideration in the Preliminary Business Case. The executive summary of the Environmental Input to Link21 Concepts Report outlines this assessment. 

Link21 is currently conducting pre-CEQA/NEPA planning to examine, and identify project concepts for formal study in the environmental phase. Concepts for formal study will be determined by the BART and Capitol Corridor Boards.


train passing by a lake