CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.1 LAND-USE, WIND, AND SHADOW 5-1 

CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND 

MITIGATION MEASURES 

This chapter analyzes the potential impacts of the proposed project and suggests mitigation 

measures for the impacts identified. Long-term effects -- those associated with operation of the 

project or that result from project right-of-way requirements -- short-term, construction phase 

impacts, and cumulative impacts are addressed. Discussions are organized by environmental 

topic area, except that construction phase impacts are discussed together, following the 

presentation of longer-term effects. In order to avoid repetition, a few environmental issues are 

addressed primarily in the construction phase impacts section, because their associated effects 

would derive primarily from construction activities. 

NEPA and CEQA incorporate differing provisions affecting identification and mitigation of 

impacts. CEQA requires identification of impact level of significance in an EIR, whereas NEPA 

considers level of significance in determining whether or not to prepare an EIS and, once the 

decision to prepare an EIS is made, reports project impacts without defining level of 

significance. Similarly, CEQA requires mitigation only for significant adverse impacts, while 

NEPA allows for mitigation of all of the impacts of a project. This combined NEPA/CEQA 

document reports all of the impacts of the proposed project, and proposes mitigation wherever 

practicable to reduce the impacts identified. Chapter 7 provides specific discussion of impact 

significance and mitigation in accordance with CEQA. 

5.1 LAND-USE, WIND, AND SHADOW 

This section evaluates long-term land-use, wind and shadowing impacts of the proposed project. 

Construction-phase impacts are addressed in Section 5.21. 

5.1.1 Land Use Impacts 

The land use impacts resulting from each of the three project components are considered and 

compared to the No-Project Alternative. A discussion is also included of the overall effects of 

the project on neighborhood character and its consistency with existing plans and policies. 

5.1.1.1 Transbay Terminal Land Use Impacts 

The proposed Transbay Terminal would be located at the site of the existing terminal structure 

on Mission Street at First, Fremont and Beale Streets, approximately 150 feet to the west of the 

present terminal footprint. The existing Terminal would be demolished and a new multi-modal 

transit facility would be constructed in its place. There are two alternatives being considered for 

the new Transbay Terminal: the West Ramp and Loop Ramp Alternative. The main differences 

between the West Ramp Alternative and the Loop Ramp Alternative are the size of the terminal, 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-2 5.1 LAND-USE, WIND, AND SHADOW 

amount of ramp area, and the potential availability of land opened up for new development by 

removing sections of the existing ramp network. 

West Ramp Alternative. Under the West Ramp Alternative, the Transbay Terminal would be 

one story taller than under the Loop Ramp Alternative, but would be constructed approximately 

on the footprint of the existing terminal, but about 150 feet to the west. This would result in the 

terminal structure no longer spanning Beale Street. The existing ramp segments on the east side 

of the Transbay Terminal (north of Howard Street, just east of Beale Street, then looping south 

and west to Essex Street) would be removed. However, the I-80 Fremont Street off-ramp would 

remain in place west of Fremont Street. Circulation between the Terminal and the Bay Bridge 

would occur on a ramp segment oriented on a north-south axis. In terms of land use, the West 

Ramp Alternative would open up new developable area on the blocks south and east of the 

Terminal at Beale and Howard Streets and Folsom at Beale and Main Streets, and would create 

opportunities for mid-block pedestrian throughways between towers fronting on Folsom Street or 

increase the amount of mid-block open space. 

Loop Ramp Alternative. Under the Loop Ramp Alternative, the existing ramp segments on the 

east side of the terminal would be rebuilt in generally the same location and would continue to 

provide circulation between the Terminal and the Bay Bridge. Thus, in terms of land use, the 

Loop Ramp Alternative would provide less land area for future new transit-oriented 

development. When compared with the West Ramp Alternative, the Loop Ramp Alternative 

would lessen the amount of developable area on the blocks south and east of the Terminal at 

Beale and Howard Streets and Folsom at Beale and Main Streets, and would possibly limit 

planned mid-block pedestrian throughways between towers fronting on Folsom Street or 

decrease the amount of mid-block open spaces. In addition, the ramps would continue to be seen 

by some as a barrier in the district, walling off uses inside of the loops from uses located outside. 

Under any Terminal Alternative, however, the I-80 Fremont Street off-ramp will continue to 

impinge on the development along Fremont Street north of Folsom Street. 

Impacts Common to Both Transbay Terminal Alternatives. Land use impacts would result 

under either Transbay Terminal Alternative. Development of the Terminal and the temporary 

terminal would require the acquisition of 11 parcels and demolition of five buildings (see 

Section 5.2, Displacements and Relocation). 

Additional impacts would occur due to off-site staging and parking requirements for both 

AC Transit and Golden Gate Transit. Buses would be stored under the West Approach to the 

Bay Bridge between Stillman, Perry, Second and Fourth Streets, a site currently used for 

automobile parking. The project would include the construction of a parking deck immediately 

west of Fourth Street between Perry Street to the north and Stillman Street to the south, to make 

up for the loss of surface parking being used as a transit storage area. 

The new terminal, regardless of the design alternative selected, would cause an increase in 

pedestrian traffic in the vicinity of the transit facility, creating a possible heightened demand for 

ground-floor retail uses, including, but not limited to restaurants, cafes and convenience retail, to 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.1 LAND-USE, WIND, AND SHADOW 5-3 

serve the increased numbers of transit patrons. The new Transbay Terminal could intensify land 

uses in its vicinity. Other land use effects resulting from the proposed Terminal would mainly be 

associated with the construction and operation of its ramps and the temporary bus storage 

facilities required during the construction of the terminal structure. 

No-Project Alternative. Under the No-Project Alternative, a new Transbay Terminal would not 

be constructed. The existing terminal would be retrofitted and low-capital-cost transportation 

improvements would be implemented. Opportunities for revitalization in the Transbay area, 

such as establishing new open spaces, would be substantially less for the No-Project Alternative 

compared to the West Ramp Transbay Terminal Alternative, for example. Under the No-Project 

Alternative, the existing ramp network would continue to act as a barrier by dividing proposed 

new development and existing land uses in the area. Additionally, the ramps occupy 

considerable ground area that would not be available for future development and also may limit 

future development of adjacent lots. 

5.1.1.2 Caltrain Downtown Extension Land Use Impacts 

Two alignment alternatives are considered for the Caltrain Downtown Extension: the Second-toMain Alternative and the Second-to-Mission Alternative. Both a cut-and-cover and tunneling 

option have been defined for each Caltrain Extension Alternative. The alternatives and options 

present distinct engineering opportunities and constraints. The cut-and-cover construction 

method for either alternative would involve the acquisition and demolition of up to 23 existing 

buildings. Land use impacts associated with the loss of these buildings are described in this 

section, while more detail regarding the parcels and buildings that would be acquired is provided 

in Section 5.2. Interim disruptions to land uses that remain in the project area could be 

anticipated for either alternative, as described in Section 5.21. 

The affected properties for both Caltrain Alternatives are located in the vicinity of Second and 

Howard Streets, with additional properties on Mission Street affected under the Second-toMission Street Alternative. Eleven additional parcels with 10 building in the Second and 

Townsend Streets area would be acquired and demolished under the Cut-and-Cover Option but 

would remain under the Tunneling Option. See also Figure 4.1-1, in Chapter 4, which shows the 

land use context for these affected properties. 

Affected properties would be purchased according to the procedures set forth in the Real 

Properties Acquisition Act. Structures would then be demolished to facilitate cut-and-cover 

construction of the tunnel. 

At the Townsend and Second Streets intersection, cut-and-cover construction would require 

demolition of structures located mainly along the north side of Townsend Street (west of Second 

Street) and the west side of Second Street (north of Townsend). Land uses at this location 

consist mainly of industrial uses, with some office uses and two residential buildings. The 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-4 5.1 LAND-USE, WIND, AND SHADOW 

affected structures were constructed between 1906 and 1927 (although some have been dated 

earlier), and one contemporary residential building was constructed in 1996. 

At the Second/Howard Street intersection, the project would require demolition of structures 

generally located on the east side of Second Street (between Minna and Howard Streets) and on 

the north side of Howard Street (east of Second Street). These structures contain industrial, 

office, residential and restaurant uses. The affected structures were constructed between 1906 

and 1921, and one contemporary residential building was constructed in 1980. Three structures 

slated for demolition as part of the project (Class B and C office buildings) are located within the 

New Montgomery-Second Street Conservation District, which overlaps the Second and Howard 

Streets Historic District. Two structures south of the Second/Howard Street intersection would 

also require demolition to permit cut-and-cover construction. These structures are located along 

Second Street and include Class C office uses (built between 1906 and 1912). There is also a 

vacant lot used for surface parking. 

The existing land uses described above would be displaced by project construction. Once project 

construction is completed, the cleared properties would be made available for development. 

Future land uses on these sites would be required to conform to the area’s zoning, General/Area 

Plan requirements, and Redevelopment Agency’s Guidelines (for properties located within the 

Redevelopment Area). 

In addition, there is at least one major development proposal that has the potential to conflict 

with the Second-to-Mission Caltrain Extension Alternative – a 605-foot tall, 1,068,400 gross 

square foot mixed use development proposed at 301 Mission Street (Assessors Block 3719, lots 

1 and 17). This proposal has completed its environmental review and has received various 

approvals from City decision-makers. The current proposed configuration of the foundation 

piling and underground parking for 301 Mission takes into account the need for a small amount 

of property on the southern-most part of the parcel by the Transbay Terminal/Caltrain 

Downtown Extension Project for the Second-to-Main Caltrain Extension Alternative, the 

adopted LPA. 

In the long-term, however, the Transbay Terminal/Caltrain Downtown Extension project would 

not disrupt or divide the physical arrangement of the established community. Because many of 

the buildings that would be removed are older buildings, some of which are listed or eligible for 

listing in the National Register of Historic Places (as described in Section 5.14), there would be a 

change in the character of the area. This change would be lessened by the fact that there are 

already many new buildings in the general vicinity. The majority of the square footage that 

would be demolished is in office use, representing only a small portion of the office space 

throughout the City. Loss of this office space would not adversely affect the City’s supply, 

particularly given that many of the recently constructed buildings in the area provide additional 

office space. 
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5.1 LAND-USE, WIND, AND SHADOW 5-5 

5.1.1.3 Redevelopment Land Use Impacts 

As described in Chapter 2, two redevelopment alternatives are proposed: the Full-Build 

Alternative and the Reduced Scope Alternative. Each alternative would include zoning changes 

and the establishment of a redevelopment area that generally would allow land uses that are 

currently allowed in the Transbay Study Area, with the exception of the P-zoned properties 

where the former freeway and ramps were located. Because the project would provide for new 

development, notable changes would be expected in the Transbay Redevelopment Area, 

especially with respect to urban form and the intensity of land use. 

Full-Build Alternative. The Full Build Alternative would result in a mix of residential, office, 

hotel, and retail uses. This alternative would consist of land uses that are already permitted 

within the vicinity of the Transbay Study Area. As described in Chapter 2 and shown on 

Figure 2.2-22, the Full Build Alternative would result in development of 5.6 million square feet 

of residential uses (4,667 residential units, including affordable housing), close to 1.2 million 

square feet of office uses, 475,600 square feet of hotel uses, and more than 355,400-square feet 

of retail uses, or about 7.6 million square feet of development, overall. 

Proposed changes to existing zoning would occur predominately along the blocks on Folsom 

Street, as well as those at the site occupied by the Transbay Terminal and along its ramps to the 

west of Essex Street to First Street. Existing parcels zoned P would be rezoned to either C-3-O 

or C-3-O (SD) to facilitate and further the goals of the redevelopment plan. Proposed changes to 

the height and bulk regulation would occur on the same blocks. These changes are identified in 

Table 5.1-1 and on Figures 5.1-1, 5.1-2, and 5.1-3. 

As indicated in Table 5.1-1, existing height and bulk limits range from 30-X at the site of the 

current Transbay Terminal to 400-S at Mission and Beale Streets. Existing height limits are, on 

average, approximately 80 feet. Under the Full Build Alternative, height limits would range 

from 150 feet around Essex Street to 400 feet along Folsom Street. The maximum height limit 

established under the Full Build Alternative would be 550 feet, at a proposed hotel site at 

Mission and Fremont Streets, adjacent to the proposed Transbay Terminal. 

Reduced Scope Alternative. The Reduced Scope Alternative would result in less commercial 

and retail development and is weighted more toward housing. This alternative assumes 

approximately four million square feet of residential development (approximately 3,430 dwelling 

units), 350,000 square feet of hotel uses, and approximately 260,000 square feet of retail 

development, or 4.7 million square feet overall. The base zoning changes proposed under the 

Reduced Scope would be identical to those proposed under the Full Build, although the height 

and bulk designations are different. Existing parcels zoned P (Public) would be zoned to C-3-O 

or C-3-O (SD) to accommodate housing or retail uses. 
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5-6 5.1 LAND-USE, WIND, AND SHADOW 

Figure 5.1-1 Proposed Zoning, Full Build and Reduced Scope Alternatives 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.1 LAND-USE, WIND, AND SHADOW 5-7 

Figure 5.1-2 Proposed Height and Bulk Districts Full Build Alternative 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-8 5.1 LAND-USE, WIND, AND SHADOW 

Figure 5.1-3 Proposed Height and Bulk Districts Reduced Scope Alternative 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.1 LAND-USE, WIND, AND SHADOW 5-9 

Table 5.1-1: Existing and Proposed Zoning in the 

Proposed Transbay Terminal Redevelopment Area 

Zoning Districts Height/Bulk Districts Assessor’s 

Block Block Bounded by: Existing Proposed* Existing Full 

Build 

Reduced 

Scope 

3718 Mission, Main, Howard, 

and Beale Streets 

P, C-3-0, 

C-3-0 (SD) C-3-0 80-X, 80X \ 400S 300-S 350-U

3720 Mission, Fremont, 

Howard, and First Streets P C-3-0 30-X / 80-X 550-S 400-U

3736 Howard, First, Folsom, 

and Second Streets P C-3-0 (SD) 80-X \ 200-S 350-S 400-U

3737 Howard, Fremont, 

Folsom, and First Streets P, C-3-0 (SD) C-3-0 (SD) 80-X 350-S 400-U

3738 Howard, Beale, Folsom, 

and Fremont Streets P C-3-0 (SD) 80-X 350-S 350-U

3739 Howard, Main, Folsom, 

and Beale Streets 

P, C-3-0, C-3-0 

(SD), C-3-S C-3-0 (SD) 80-X, 90-X, 200-S 350-S 350-U

3740 Howard, Spear, Folsom, 

and Main Streets P, C-3-S C-3-0 (SD) 40-X, 200-S 250-S 200-U

3749 Folsom, First, Harrison, 

and Second Streets M-1 C-3-0 (SD) 84-X 150-S 150-U 

3764 Harrison, Rincon, Bryant, 

and Second Streets P C-3-0 (SD) 50-X 150-S 150-U 

Zoning Districts: C-3-0: Downtown commercial office; C-3-0 (SD): Downtown commercial office (special development); C-3-

S: Downtown support; M-1: Light industrial; P: Public use; S: See Planning Code Section 270(d) or refer to Height and Bulk 

maps 1H, 2H and 7H of the Zoning Map; U: Maximum plan dimensions for buildings over 80 feet but less than 300 feet in 

height: 100 feet (length), 125 feet (diagonal dimension); buildings greater than 300 feet: 115 feet (length). 145 feet (diagonal 

dimension). Building setbacks would be required pursuant to Planning Code Section 253.2. 

* proposed zoning district designation for both the Full Build and Reduced Scope/Variant Alternatives are identical 

Source: The San Francisco Planning Department, June 2001

The Reduced Scope Alternative differs from the Full Build scenario in the proposed the heights 

and bulks of the proposed new structures on certain blocks. Under the Reduced Scope 

Alternative, Assessor Block 3720 would accommodate a hotel at a height of approximately 400 

feet, which would be up to 150 feet shorter than allowed under the Full Build Alternative. The 

Reduced Scope Alternative would permit building heights of up to 50 feet higher than under the 

Full Build Alternative on the blocks between Beale and Main and Mission and Folsom Streets, 

and on Folsom Street, along the southern boundary of the Transbay Redevelopment Area 

boundary. 

As indicated in Table 5.1-1, existing height and bulk limits range from 30-X at the site of the 

current Transbay Terminal to 400-S at Mission and Beale Streets. Existing height limits are, on 

average, approximately 80 feet. Under the Full Build Alternative, height limits would range 

from 150 feet around Essex Street to 400 feet along Folsom Street. The maximum height limit 

established under the Full Build Alternative would be 550 feet, at a proposed hotel site at 

Mission and Fremont Streets, adjacent to the proposed Transbay Terminal. 
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5-10 5.1 LAND-USE, WIND, AND SHADOW 

Reduced Scope Alternative. The Reduced Scope Alternative would result in less commercial 

and retail development and is weighted more toward housing. This alternative assumes 

approximately four million square feet of residential development (approximately 3,430 dwelling 

units), 350,000 square feet of hotel uses, and approximately 260,000 square feet of retail 

development, or 4.7 million square feet overall. The zoning changes proposed under the 

Reduced Scope would be identical to those proposed under the Full Build. Existing parcels 

zoned P (Public) would be zoned to C-3-O or C-3-O (SD) to accommodate housing or retail 

uses. 

The Reduced Scope Alternative differs from the Full Build scenario in the proposed the heights 

and bulks of the proposed new structures on certain blocks. Under the Reduced Scope 

Alternative, Assessor Block 3720 would accommodate a hotel at a height of approximately 400 

feet, which would be up to 150 feet shorter than allowed under the Full Build Alternative. The 

Reduced Scope Alternative would permit building heights of up to 50 feet higher than under the 

Full Build Alternative on the blocks between Beale and Main and Mission and Folsom Streets, 

and on Folsom Street, along the southern boundary of the Transbay Redevelopment Area 

boundary. The main difference between the Reduced Scope and Full Build Alternative would be 

in building mass. Under the Reduced Scope, new towers would have, on average, smaller floor 

plates and would be more slender than those under the Full Build, due to the maximum diagonals 

of the building towers in the proposed U bulk district (see Table 5.1.3). The smaller, more 

slender floor plates also would result in increased spacing between towers, compared to bulkier 

building towers in the Full Build Alternative. 

North of Folsom Street, there would be an expansion of office development, including high-rises, 

particularly near the site of the existing Transbay Terminal. As under the Full Build Alternative, 

the existing terminal at First and Mission Streets is proposed to be demolished, and a new 

terminal would be constructed at this site. Both alternatives would result in an expansion of 

educational and institutional uses, with open space surrounded by mid-rise structures. Farther 

west, existing historic buildings in the New Montgomery-Second Street Conservation District 

would remain, except for those buildings that would be demolished as part of the right-of-way 

acquisition for the Caltrain Downtown Extension alignment, providing a moderating buffer in 

building scale between Yerba Buena Gardens and the northwest corner of the Transbay 

Redevelopment Area. The Second Street corridor could become an increasingly attractive 

destination for street-level retail and restaurants and a pedestrian link between downtown and 

Pacific Bell Park at China Basin. 

The main difference between the Reduced Scope and Full Build Alternatives would be in 

building mass. Under the Reduced Scope, new towers would have, on average, smaller floor 

plates and would be more slender than those under the Full Build, due to the maximum diagonals 

of the building towers in the proposed U bulk district (see Table 5.1.3). The smaller, more 

slender floor plates also would result in increased spacing between towers, compared to bulkier 

building towers in the Full Build Alternative. 
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5.1 LAND-USE, WIND, AND SHADOW 5-11 

North of Folsom Street, there would be an expansion of residential development, including highrises, particularly near the site of the existing Transbay Terminal. As under the Full Build 

Alternative, the existing terminal at First and Mission Streets is proposed to be demolished, and a 

new terminal would be constructed at this site. Both alternatives would result in an expansion of 

educational and institutional uses, with open space surrounded by mid-rise structures. Farther 

west, existing historic buildings in the New Montgomery-Second Street Conservation District 

would remain, except for those buildings that would be demolished as part of the right-of-way 

acquisition for the Caltrain Downtown Extension alignment, providing a moderating buffer in 

building scale between Yerba Buena Gardens and the northwest corner of the Transbay 

Redevelopment Area. The Second Street corridor could become an increasingly attractive 

destination for street-level retail and restaurants and a pedestrian link between downtown and 

Pacific Bell Park at China Basin. 

Draft Transbay Redevelopment Area Design for Development Vision (August 2003). 

Implementation of the current Design for Development Vision would result in a mix of 

residential, retail, office and hotel uses that would be similar to those uses under both the Full 

Build and Reduced Scope Alternatives. The Design for Development Vision would consist of 

land uses already permitted within the vicinity of the Transbay Area, and would result in 

development of roughly 4.14 million square feet of residential uses (3,378 residential units, 

including affordable housing), approximately 965,000 square feet of office uses, 475,000 square 

feet of hotel uses, and approximately 30,670 square feet of retail commercial use, with a total of 

about 5.6 million square feet of development. 

 

This Design for Development Vision proposes land uses that would be consistent with the 

General Plan and the Planning Code, as they now exist and may be amended from time to time 

in the future. The Transbay Redevelopment Area Design for Development Vision would consist 

of three main land use zones: the Transbay Residential Zone (Zone 1), the Transbay C-3 Zone 

(Zone 2), and the Transbay Terminal and Ramp Environs (Zone 3). Because the Design for 

Development Vision would be consistent with the Full Build and Reduced Scope Alternatives, the 

changes to land uses in the Transbay Redevelopment area would be essentially the same as those 

illustrated on Figure 5.1-1. 

The Redevelopment Area Design for Development Vision would result in land use effects 

identified for both the Full Build and Reduced Scope Alternatives. The Design for Development 

Vision would generally construct shorter buildings and fewer towers (specifically along Folsom 

Street) and fewer dwelling units than proposed under the Full Build Alternative. The 

Redevelopment Area Design for Development Vision would also include mid-block pedestrian 

passages, public open space in the form of parks, and private open spaces in the interiors of 

private residential developments. 

 

Because the Redevelopment Area Design for Development Vision would be consistent with land 

uses analyzed for the Full Build and Reduced Scope Alternatives and because its proposed 

development program would be less dense (e.g., fewer dwelling units, less office and retail 

square footage) than the Full Build Alternative, the land use effects of the Design for 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-12 5.1 LAND-USE, WIND, AND SHADOW 

Development Vision would also not be adverse. As with both the Full Build and Reduced Scope 

Alternatives, rather than disrupting or dividing the community or adversely affecting its 

character, implementation of the Design for Development Vision could do the opposite by 

lending a positive neighborhood identity to an area that would provide a cohesive mix of jobs, 

housing and support services. 

Impacts Common to Both Redevelopment Alternatives. Both alternatives are expected to 

result in substantial open space areas in several portions of the Transbay Redevelopment Area, to 

complement the more intensive development. Folsom Street itself could be transformed from a 

relatively quiet (except at rush hour) street bordered by numerous undeveloped parcels to a builtout boulevard with residential and commercial uses side-by-side and a large amount of 

pedestrian traffic. This street would play an important role in defining the identity of the 

Transbay Redevelopment Area as a cohesive neighborhood, providing a mix of jobs, housing 

and support services. 

No-Project Alternative. Under the No-Project Alternative new development, driven by market 

forces, is anticipated in the Transbay area. Existing programmed land uses would continue to the 

year 2020. Growth of office and residential uses would continue, but more slowly than under the 

above-described alternatives, and perhaps with less design guidance. Without any coordinated 

planning effort in the Transbay area, development in the district would occur on a per-parcel 

basis depending on the demands placed on the market. Development would occur under existing 

zoning and height and bulk regulations. Any proposed development would also be subject to 

Proposition M requirements concerning the amount of office space to be built, the timing of such 

development, and the impacts of the office square foot limitations (Planning Code Sections 320 

and 321) on development. Sponsors seeking to develop the parcels zoned P (Public) would be 

required to seek a rezoning as part of their projects. 

Because the area is designated as part of the Downtown Plan’s Financial District north of Folsom 

Street, it could be assumed that office uses would locate in the area. There is a considerable 

amount of under-used land in the Transbay area and, depending on market forces, the area would 

act as an expansion area for high-density office uses that would otherwise occur north of Market 

Street. Most of the increase in residential development likely would occur on or near Rincon 

Hill. Because development would continue to occur in a less directed manner, the area could 

continue to lack definition or strong neighborhood identification, particularly compared to the 

Full Build or Reduced Scope Alternatives. 

5.1.1.4 Neighborhood Character and Compatibility 

An important goal of the Transbay redevelopment planning effort is to promote the development 

of a new mixed-use neighborhood. Both alternatives of the project’s redevelopment component 

anticipate the development of residential, office, retail, service, and entertainment uses in a 

neighborhood in which these uses co-exist side-by-side or even within the same building. The 

potential incompatibility among uses is minimized by the exclusion of heavy industrial uses. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.1 LAND-USE, WIND, AND SHADOW 5-13 

While the project could indirectly result in notable changes in land uses in the Transbay area, 

future development would be expected to intensify the urban character of the area and, 

particularly if planning efforts are successful, to result in a more cohesive neighborhood with a 

true mixture of residential and commercial activities. Rather than disrupting or dividing the 

community or adversely affecting its character, realization of the project’s goals could do the 

opposite. 

5.1.1.5 Consistency with Existing Plans and Policies 

A review was conducted to assess the project’s conformity with the plans and policies that guide 

land use development in the study area. These plans include the San Francisco General Plan 

(with subsequent elements including: the Urban Design Element, the Commerce and Industry 

Element, the Transportation Element, the Residence Element, and the Recreation and Open 

Space Element); and local area plans contained within the General Plan, such as the Downtown 

Plan, the South of Market Plan, the Rincon Hill Plan, the Northeastern Waterfront Plan. Project 

compliance with San Francisco Redevelopment Agency Area Plans was also evaluated. These 

plans include the Rincon Point-South Beach Redevelopment Plan, the Yerba Buena Center 

Redevelopment Plan, and the Mission Bay North Redevelopment Plan. The proposed project 

would not conflict with any of the policies contained in the documents stated above. 

The City’s General Plan, which provides general policies and objectives to guide land use 

decisions, contains some policies that relate to physical environmental issues. The current 

project would not obviously or substantially conflict with any such policy that would apply to the 

project. 

In general, any potential conflicts with the General Plan are considered by decision makers 

independently of the environmental review process, as a part of the decision whether to approve 

or disapprove a proposed project. Any potential conflict not identified here could be considered 

in that context, and would not alter the physical environmental effects of the proposed. 

No mitigation measures are indicated. Relocation impacts and mitigation are addressed in 

Section 5.2. 

5.1.2 Wind Impacts 

A wind tunnel test was performed for two massing scenarios, as documented in the Wind Test 

Technical Memorandum and summarized in this section. The first massing scenario represents 

the Full Build Alternative and consists of generic building masses constructed to the height and 

bulk limits for each parcel or block. The second massing scenario represents the Reduced Scope 

Alternative. It contains nearly 35 percent less floor area but has towers that are taller and more 

slender than those of the Full Build Alternative. 
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5-14 5.1 LAND-USE, WIND, AND SHADOW 

The new Transbay Terminal design was used in both tests. For the wind tunnel testing, adverse 

impact was defined as wind conditions that exceed the City of San Francisco Planning Code 

Section 148 wind hazard criterion of 26 miles per hour for more than one full hour per year. 

5.1.2.1 Wind Test Point Locations 

Wind test locations are shown in Figure 5.1-4. The study evaluated conditions under the four 

prevailing wind directions (northwest, west-northwest, west and southwest) that are the most 

common in San Francisco. 

In general, the testing focused on public streets and sidewalks located (generally near high-rise 

building sites) throughout the Transbay Terminal Redevelopment Area.1 For purposes of this 

analysis, test locations were grouped into four subareas, as follows:2

• Adjacent to or near the Transbay Terminal building (15 test points). 

• Within the redevelopment area bounded by Mission, Main, Folsom, and Beale Streets 

(17 test points). 

• Within the redevelopment area adjacent to Folsom Street (31 test points). 

• Within the redevelopment area adjacent to or near Essex Street (6 test points). 

5.1.2.2 Full-Build Alternative, Wind Impacts 

Development proposed as part of the Full-Build Redevelopment Plan would introduce new 

buildings at heights and massing greater than under current conditions. Wind conditions would 

be considered moderate to windy; the average for all 61 test points would be about seven mph, 

about 1.5 mph higher than the average for the existing conditions. Wind speeds in the pedestrian 

areas would range from one mph (No. 10) to 18 mph (No. 57). Wind speeds of 14 mph or higher 

would occur at three locations (Nos. 52, 57, 59). Fifty-two of the 61 locations would meet the 

Planning Code’s pedestrian-comfort criterion value of 11 mph, while nine locations (Nos. 42, 48, 

49, 52, 53, 56-59) would not. Under this Alternative, the Planning Code’s wind hazard criterion 

would be exceeded at one of the 61 test locations: test site number 57 in the Essex Street wind 

study subarea. 

Transbay Terminal Wind Study Subarea. Winds in this area would be moderate to windy, 

with speeds ranging from one mph (No. 10) to 10 mph (No. 2). Of the 15 points in this subarea, 

all would continue to meet the Planning Code’s pedestrian-comfort criterion value of 11 mph. 

 

1 For purposes of this analysis, local north-south runs along Second Street and parallel streets, and east-west runs 

along Mission Street and parallel streets. Wind directions will refer to true compass directions. 

2 Note that in describing the wind test locations for the four subareas, some points were referred to in more than one 

group. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.1 LAND-USE, WIND, AND SHADOW 5-15 

Figure 5.1-4: Wind Test Point Location Map 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-16 5.1 LAND-USE, WIND, AND SHADOW 

Mission, Main, Folsom, and Beale Streets Wind Study Subarea. Winds would increase 

slightly compared to existing conditions, ranging from two mph (No. 30) to eight mph (Nos. 22, 

24, 25, 29, 31). Of the 17 points in this subarea, all would continue to meet the Planning Code’s 

pedestrian-comfort criterion value of 11 mph. 

Folsom Street Wind Study Subarea. Winds would continue to be moderate to windy, and 

would range from two mph (No. 30) to 14 mph (No. 52). Of the 31 points in this subarea, 26 

would continue to meet the Planning Code’s pedestrian-comfort criterion value of 11 mph. 

Table 5.1-2 identifies the five test sites at which the comfort criterion would be exceeded. 

Essex Street Wind Study Subarea. Winds would substantially increase in some portions of 

this area, with speeds ranging from nine mph (No. 55) to 18 mph (No. 57). Of the six points in 

this subarea, only one would continue to meet the Planning Code’s pedestrian-comfort criterion 

of 11 mph. One site (No. 57) would exceed the hazard criterion, for a total duration of one hour 

per year. Site No. 57 is west of Essex Street just east of the intersection of Harrison and Second 

Streets. Table 5.1-2 identifies the test sites at which the comfort and/or hazard criteria are 

exceeded. 

Table 5.1-2: Full Build Alternative Exceedences of Comfort and Hazard Criteria 

Wind Study 

Subarea Location 

Locations with 

Exceedence of 

Comfort Criterion 

Locations With 

Exceedence of 

Hazard Criterion 

Folsom Street South sidewalk of Folsom Street Nos. 42, 49, 53 - 

Subarea North sidewalk of Folsom Street Nos. 48 and 52 - 

East of Essex Street Nos. 53 and 56 - Essex Street 

Subarea West of Essex, near Second 

Street Nos. 57, 58, and 59 No. 57 

Source: Environmental Science Associates, Wind Study Technical Memorandum, 2001 

5.1.2.3 Reduced Scope Alternative, Wind Impacts 

Under this Alternative, development would result in greater building heights and massing than 

under existing conditions. This variant assumes that new buildings would be slightly taller and 

more slender than those associated with the Full Build Alternative. 

Wind conditions would be considered moderate to windy, with an average of 6.8 mph (for all 61 

test points). This is approximately 0.2 mph lower than the average for the Full Build Alternative 

conditions. Wind speeds in the pedestrian areas would range from three mph (Nos. 8, 9, 12, 14, 

15, 17, 26, 31-33, 50) to 18 mph (No. 57). Wind speeds of 14 mph or higher would occur at four 

locations (Nos. 52, 57-59). Under this Alternative, the highest wind speeds would continue to 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.1 LAND-USE, WIND, AND SHADOW 5-17 

occur at the same location as under the Full-Build Alternative (No. 57) just east of the 

intersection of Harrison and Second Streets, with a speed of 18 mph. 

Wind conditions under this Alternative would be very similar to those under the Full-Build 

Alternative. Fifty-four of the 61 test sites would meet the Planning Code’s pedestrian-comfort 

criterion value of 11 mph. This option would exceed the comfort criterion at a total of seven 

locations, two fewer than under the Full-Build Alternative. Six of these locations (Nos. 49, 52, 

53, 57-59) would also experience exceedences under the Full-Build Alternative. The seventh 

exceedence is located at test site number 60, as shown in Table 5.1-3. With this Alternative, the 

wind hazard criterion would remain exceeded for one hour per year at the point just east of the 

intersection of Harrison and Second Streets (No. 57). 

Table 5.1-3: Reduced Scope Alternative Exceedences of 

Comfort and Hazard Criteria

Wind Study 

Subarea Location 

Locations with 

Exceedence of 

Comfort Criterion 

Locations With 

Exceedence of 

Hazard Criterion 

South sidewalk of Folsom Street Nos. 49 and 53 - 

North sidewalk of Folsom Street No. 52 - Folsom Street 

Subarea 

Between Folsom and Tehema St. No. 60 - 

Essex Street East of Essex Street No. 53 - 

Subarea West of Essex, near Second Street Nos. 57, 58, and 59 No. 57 

Source: Environmental Science Associates, Wind Study Technical Memorandum, 2001 

5.1.2.4 Draft Transbay Redevelopment Area Design for Development Vision (August 2003) 

Because the Design for Development Vision would construct an overall less intense (in terms of 

square footage) and less dense (in terms of the number of towers and more slender aspect of the 

towers) development program, wind effects would be less or essentially the same as those 

analyzed for both the Full Build and Reduced Scope Alternatives. 

5.1.2.5 No-Project Alternative 

The No-Project Alternative would result in less total development between the present and the 

horizon year 2020 than under the Full Build and Reduced Scope alternatives. The No-Project 

Alternative would be expected to have fewer tall buildings and thus fewer areas with increased 

ground level winds than the other alternatives considered. The wind conditions expected with 

this alternative would be expected to be similar or less substantial increases than those described 

under either build alternative. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-18 5.1 LAND-USE, WIND, AND SHADOW 

5.1.2.6 Mitigation Measures 

During the environmental review process that would precede the approval of any individual 

project proposed for the proposed Transbay Redevelopment Area, potential wind effects of that 

project shall be considered and, if necessary, wind tunnel testing shall be performed in 

accordance with City Planning Code Section 148. If exceedences of the wind hazard criterion 

should occur for any individual project, design modifications or other mitigation measures would 

be required to mitigate or eliminate these exceedences. Mitigation measures would need to be 

tailored to the individual needs of each project. Examples of mitigation measures that could be 

used include articulation of building sides and softening of sharp building edges. 

5.1.3 Shadows 

Shading impacts were evaluated for the Redevelopment Plan Alternatives using the two massing 

scenarios described in Section 5.1.2, above. The analysis included the shadow effect of the 

proposed Transbay Terminal, determined by using the 60-foot height of the West Ramp 

Alternative (worst-case shadow) for both Transbay Terminal Alternatives (West Ramp or Loop 

Ramp). Shadow effects attributable to the project were analyzed for representative times of day 

(9 a.m., 12 noon, and 3 p.m.) during the four seasons of the year: in December on the winter 

solstice, when the sun is at its lowest and shadows are at their longest; and in June on the 

summer solstice, when the sun is at its highest and shadows are at their shortest; at the spring 

equinox, when shadows are midway through a period of shortening; and at the fall equinox, 

when shadows are midway through a period of lengthening. Shadows on any other day of the 

year would be within the range of shadows presented during the seasons and times of day 

described above. 

Given the height limits for high-rise towers in the Reduced Scope and Full-Build alternatives, it 

appears that the project would conform to Section 295. That means the project would appear not 

to cast new shadow on any open space under the jurisdiction of the San Francisco Recreation and 

Park Commission within or outside of the study area between one hour after sunrise and one 

hour before sunset. However, the City would still require a shadow analysis application for each 

individual development proposal. The discussion below identifies the shadow effects that would 

occur on open space areas. 

5.1.3.1 Shading Impacts of the No-Project Alternative 

The No-Project Alternative would result in a lesser total amount of development between now 

and 2020 than would the Full Build or Reduced Scope alternatives. Thus, the No-Project 

Alternative would be expected to have substantially less shadow effect than either of these two 

alternatives. Subsequent development projects greater than 40 feet in height would be subject to 

project-specific shadow analyses. No mitigation is indicated. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.1 LAND-USE, WIND, AND SHADOW 5-19 

5.1.3.2 Shading Impacts of the Full-Build Alternative 

The new shading caused by the project would not appear to affect open spaces protected by 

Section 295 of the Planning Code, such as South Park or South Beach Park. Future development 

would also be regulated by Sections 146 and 147 of the Planning Code, which protect sunlight 

access to streets and sidewalks and provide for reduction of shadows on public and publicly 

accessible open spaces within the C-3 districts. However, some publicly accessible, privately 

owned open spaces would be expected to see an increase in shading during certain periods of the 

day and the year, as described below. 

Spring. In spring, new project shadow would generally fall in a northwesterly direction during 

the morning. Shadow from the proposed towers would extend from the southeast corner of 

Folsom Street to shade much of First, Fremont, Beale, and Main Streets to Howard Street. 

Surface parking on the south side of Howard Street could be shaded in the morning hours by 

proposed towers on Folsom Street. 

At noon in spring, project shadows would be relatively short and would fall to the north. The 

Transbay Terminal shadow would cover Minna Street and the east side of Beale Street near the 

Terminal, as well as shading the proposed plaza area in front of the Terminal on Mission Street. 

New shadows cast from the proposed towers along Folsom Street would fall mid-block between 

Folsom and Howard Streets, shading less of First, Fremont, Beale, and Main Streets than they 

would have during the morning hours. To the east, new project shadow from the towers on 

Howard Street would shade Main Street from Folsom to Mission Streets. 

During the afternoon hours, new shadows would lengthen and be cast more easterly. New 

shadows from the hotel and Transbay Terminal would fall mid-block on Assessor’s Block 3718, 

which lies just east of the Transbay Terminal at Beale and Howard Streets. New shadows from 

the towers along Folsom Street would reach Folsom Street in the late afternoon. Under the Full 

Build Alternative, shadows would extend east just past the intersection of Steuart and Folsom 

Streets; under the Reduced Scope Alternative, shadows would also extend toward Steuart Street, 

but would fall short of the intersection. 

Summer. During the summer solstice morning hours, shadows would fall to the west. Minna 

Street, directly north of the Transbay Terminal, would be in shadow. The Transbay Terminal 

would shade a portion of Mission Street between First and Fremont Streets, and the shadow 

would extend halfway to Market Street. New shade would be added to a portion of Howard 

Street between Main and Beale Streets. The southerly half of the block on Folsom Street between 

Essex and First Streets would also be newly shaded during morning hours. 

 

During midday, relatively little new shading would occur, but would be in a northerly direction. 

Small portions of First, Fremont, Beale, Main and Spear Streets would be newly shaded by the 

proposed towers on Folsom Street. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-20 5.1 LAND-USE, WIND, AND SHADOW 

During the late afternoon, shadows would fall to the east. New shading would occur along 

Folsom Street fronting the project towers. Shadows from the proposed towers would be longer 

and cross over the southern side of Folsom, specifically at Beale and Main Streets, but allow 

sunlight to reach the street. Guy Place would be shaded in the late afternoon hours from the 

proposed development on the corner of Folsom and Essex Streets. 

Autumn. By the fall equinox, the position of the sun is lower in the sky, causing shadows to be 

longer. During the mid-morning through midday, new shadow caused by the project would 

extend generally northwest. The Transbay Terminal would create new shade on small sections of 

First and Fremont Streets, just south of Mission Street. New shadows from towers on Howard 

Street would cover Beale Street between Mission and Howard Streets. The northern half of 

First, Fremont, Beale, and Main Streets, between Folsom and Howard Streets, would be shaded 

by the proposed towers on Folsom Street. Because shadows would fall to the northwest, Folsom 

Street would generally not be shaded during the morning hours. 

During midday, shadows would fall to the north. The proposed hotel in front of the Transbay 

Terminal would shade the intersection of Mission and Fremont Streets. The Transbay Terminal 

would shade the plaza in front of the Terminal. Along Howard Street, only the section between 

Beale and Main Streets would experience new shading. Along Folsom Street, shadow from the 

proposed towers on Folsom Street would be cast to the north, away from Folsom Street, but 

would fall on private mid-block open spaces just north of those project towers. 

In the late afternoon hours, shadows would fall generally to the east. Folsom Street would be 

shaded both on the north and south sides of the street. Shadows cast by the proposed towers on 

Folsom Street would extend eastward to the intersection of Folsom and Spear Streets. The 

proposed high-rise on Folsom and Essex Streets would cast shadows in an easterly direction and 

partially shade Guy Place. 

Winter. During the morning hours, the new shadows cast by the project would extend their 

farthest northwest during the winter season. Considerable shadowing occurs under existing 

winter conditions, so relatively little new shadow would be cast on the streets and sidewalks. To 

the north, the Transbay Terminal, the hotel and other project towers, would cast new shadows on 

Mission Street that would reach almost halfway up the block on First and Fremont Streets. New 

shadow would fall on both the north and south side of Howard Street, between Beale and Main 

Streets. In the morning, Folsom Street would not be shaded by the new development, except for 

new shadow that would occur between Essex and First Streets. New shadows cast by the 

proposed towers along Folsom Street would fall to the northwest and would shade mid-block 

throughways and planned open spaces, but would not shadow Folsom Street. 

At midday, shadows would be cast to the north. New towers would shade interior block spaces 

along Folsom between First and Spear Streets. Shadows would reach east to the Gap Building. 

In the late afternoon hours, shadows would lengthen and reach their easternmost extent. With the 

exception of the shadow from the proposed towers along Folsom Street, new shadow would be 

minimal in the area due to the extensive existing shadow. Shadows from most new towers 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.2 DISPLACEMENTS AND RELOCATION 5-21 

would generally be cast on adjacent towers and not reach the street. However, in the late 

afternoon, shadows from the tower proposed at the corner of Folsom and Spear Streets could 

reach the planned Rincon Park and shade a small southern portion of the park. 

5.1.3.3 Shading Impacts of the Reduced Scope Alternative 

The effects of this alternative would be very similar to those of the Full-Build. The following 

discussion identifies specific locations in which the impacts differ. 

Spring. In the late afternoon, new shadows from the towers along Folsom Street would reach 

Folsom Street and extend east toward Steuart Street, but would fall short of the intersection 

between Folsom and Steuart Streets. (This intersection would be in shadow under the Full-Build 

Alternative.) 

Summer. During the late afternoon, shadows would fall to the east. Under the Reduced Scope 

Alternative, shadows from the Transbay Terminal and the proposed redevelopment would add 

new shadow on Howard Street between Beale and Main Streets. Shadows from the proposed 

towers along Folsom Street would generally not extend as far south (i.e., would not cross Folsom 

Street) as under the Full Build scheme, but greater lengths of Folsom Street would be shaded. 

Autumn. The effects of the Reduced Scope Alternative would be identical to those of the FullBuild Alternative. 

Winter. The effects of the Reduced Scope Alternative would be identical to those of the FullBuild Alternative. 

5.1.3.4 Shading Impacts of the Draft Transbay Redevelopment Area Design for 

Development Vision (August 2003) 

Because the Design for Development Vision would have fewer towers and because those towers 

would be taller and more slender than those of the Full Build Alternative, shadowing effects 

would be generally less than those of the Full Build Alternative and more similar to those of the 

Reduced Scope Alternative. No adverse effects to sites under the control of the Recreation and 

Parks Department would found. Therefore, these shading effects would not be adverse. 

5.2 DISPLACEMENTS AND RELOCATION 

5.2.1 No-Project Alternative 

No residential or non-residential displacements would occur directly as a result of the No-Project 

Alternative. Therefore, this section focuses on the displacement effects of the proposed 

Transbay Terminal, Caltrain Downtown Extension, and Redevelopment Plan. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-22 5.2 DISPLACEMENTS AND RELOCATION 

5.2.2 Transbay Terminal 

Properties to be acquired for construction of the Transbay Terminal are shown in Table 5.2-1. 

These properties are shown as blue on Figures 5.2-1, 5.2-2 and 5.2-3. Movement of the Transbay 

Terminal footprint to the west would require the acquisition of four additional properties for the 

terminal. These properties were formerly identified in the Draft EIS/EIR as necessary 

acquisitions under both Caltrain Extension Alternatives, so the properties were anticipated to be 

acquired for the Project in any event. The properties are now required for the terminal rather 

than the Caltrain Extension and are shown in the table in italics. 

 

Table 5.2-1: Property Acquisitions for the 

Transbay Terminal Alternatives 

Block & Lot Number Address 

Full Acquisitions 

3721 45A 70 Natoma Street [a] 

3721 46 78-80 Natoma Street [a] 

3721 53 81 Minna Street [a] 

3721 54 65 Minna Street [a] 

3736 74 57 Tehama [b] 

3739 2 Vacant lot on Main Street 

3739 6 272 Main Street 

3739 4 & 7 200 Folsom 

3736 88 60 Tehama 

Partial Acquisitions 

3721 16 546 Howard 

Few feet from northeast corner of building 

3719 17 101-129 Fremont Street 

(Southern portion of this parcel near the Transbay Terminal) 

Notes: 

[a] Assumed for acquisition as part of the Caltrain Extension in the Draft EIS/EIR. Now assumed for acquisition 

as part of the Transbay Terminal in this Final EIS/EIR due to proposed movement of the terminal to the west. 

[b] Additional property required for acquisition due to the necessary revisions between the Draft and Final 

EIS/EIR regarding the permanent bus ramp to the terminal. 

Source: Sedway Group, Parsons, 2004.
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MIT

5.2 DISPLACEMENTS AND RELOCATION 

Figure 5.2-1: Property Acquisitions for Transbay Terminal 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-24 5.2 DISPLACEMEN

Figure 5.2-2: Property Acquisitions for Transbay Terminal 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MIT

5.2 DISPLACEMENTS AND RELOCATION 

Figure 5.2-3: Property Acquisitions for Transbay and Second-to-Main Caltrain Extension Alt
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-26 5.2 DISPLACEMENTS AND RELOCATION 

An additional property would be required for the permanent bus ramp. This property – Block 

3736, Lot 74 (57 Tehama Street) – was not identified in the Draft EIS/EIR. The additional 

property is required due to necessary revisions to the permanent bus ramp resulting from: (1) 

responses to comments from Caltrans on the Draft EIS/EIR regarding the ramp structure shown 

in the Draft EIS/EIR, and (2) movement of the terminal to the west. This additional property is 

also shown in the table in italics. 

5.2.3 Caltrain Downtown Extension 

Properties that would need to be acquired or for which an underground easement would be 

required for either Caltrain Downtown Extension Alternative are shown in Table 5.2-2 and on 

Figure 5.2-4. Acquisition and demolition of these properties would occur for the Cut-and-Cover 

Option. Underground easement would be required for these properties for the Caltrain Extension 

Tunneling Option. A construction easement will also be required for a portion of the private 

property (southern portion of Block 3718 – Lot 025) associated with 201 Mission Street, namely 

the parking area and access road to the loading docks for this structure. Temporary access will 

be provided from Main Street to the loading area for this structure during the construction 

period for the Caltrain Extension tail tracks. 

Properties that would need to be acquired and demolished for each of the Caltrain Downtown 

Extension Alternatives are shown in Tables 5.2-3 and 5.2-4. Properties shown as red on 

Figure 5.2-3 would be acquired for the Second-to-Main Alternative. Properties shown in red on 

Figures 5.2-5 and 5.2-6 would be required for the Second-to-Mission Alternative. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MIT

5.2 DISPLACEMENTS AND RELOCATION 

Figure 5.2-4: Property Acquisitions and Demolition for Caltrain Extension Cut-and-C

Easements for Tunnel Option 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-28 5.2 DISPLACEMENTS AND RELOCATION 

Table 5.2-2: Properties to be Acquired or Underground Easement 

Properties 

(Either Second-to-Main or Second-to-Mission Caltrain Extension Alternative)

Block and Lot Number Address 

Acquisitions and Demolition or Underground Easement [1] 

3788 74 through 85 164 Townsend Street 

3788 10 148-154 Townsend Street 

3788 9A 144-146 Townsend Street 

3788 9 136 Townsend Street 

3788 8 130 Townsend Street 

3788 43 670 Second Street 

3788 44 678-80 Second Street 

3788 49 to 73 650 Second Street 

3788 2 640 Second Street 

3788 38 35 Stanford Street 

3788 37 301 Brannan Street 

Underground Easement for 

Either Cut-and-Cover or Tunneling Option 

3788 12 166-178 Townsend Street 

Temporary Construction Easement 

(Second-to-Main Alternative – Locally Preferred Alternative) 

3718 025 201 Mission (southern portion of site) 

Notes: 

[1] Properties listed would be acquired and demolished under the Cut-and-Cover Option. For 

the Tunneling Option, underground easement would be required for the listed properties. 

Source: Sedway Group, Parsons, 2004.
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5.2 DISPLACEMENTS AND RELOCATION 5-29 

Table 5.2-3: 

Property Acquisitions & Demolitions 

Second-to-Main 

Caltrain Extension Alternative 

Table 5.2-4: 

Property Acquisitions & Demolitions 

Second-to-Mission 

Caltrain Extension Alternative 

Block & Lot Number Address Block & Lot Number Address 

3736 95 217 Second Street 3736 95 217 Second Street 

3736 96 205-215 Second Street 3736 96 205-215 Second Street 

3736 97 201 Second Street 3736 97 201 Second Street 

3721 22 191Second Street 3719 1 301-315 Mission Street 

(northern portion) 

3721 23 181 Second Street 3719 17 101-129 Fremont Street 

3721 25 171 Second Street 3721 22 191 Second Street 

3721 47 90 Natoma Street 3721 23 181 Second Street 

3721 95 580-586 Howard Street 3721 25 171 Second Street 

3721 108 81-83 Natoma Street 3721 47 90 Natoma Street 

3721 109 through 118 85 Natoma Street 3721 95 580-586 Howard Street 

3721 29 77-79 Natoma Street 3721 108 81-83 Natoma Street 

3721 20 568-576 Howard Street 3721 109 through 118 85 Natoma Street 

3721 31 * Natoma Street 3721 29 77-79 Natoma Street 

3721 20 568-576 Howard Street 

3721 31 * Natoma Street 

Notes: 

* indicates no address listed 

Source: Sedway Group, Parsons Transportation Group, 

2001. 

 Notes: 

* indicates no address listed 

Source: Sedway Group, Parsons Transportation 

Group, 2004

5.2.4 Transbay Redevelopment Plan 

Properties identified for redevelopment as part of the Redevelopment Plan are principally 

occupied by surface parking. Impacts to parking are discussed in Section 5.19.5. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-30 5.2 DISPLACEMEN

Figure 5.2-5: Property Acquisitions for Second-to-Main Caltrain Alternative 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MIT

5.2 DISPLACEMENTS AND RELOCATION 

Figure 5.2-6: Property Acquisitions for Second-to-Main Caltrain Extension Alternativ
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATIONS MEASURES 

5-32 5.2 DISPLACEMENTS AND RELOCATION 

5.2.5 Business and Residential Displacements 

Field surveys and public records searches were performed to determine the potentially affected 

properties, the number and types of businesses occupying these properties, and the general 

character of the land uses. Businesses were consolidated into the following categories, as shown 

in Table 5.2-5: small or specialty retail, office/business services, restaurant/bar, industrial, 

warehouse, and parking. The estimated number of employees who may be displaced was 

determined from public business records or estimated by applying per-square-foot factors to the 

building areas of the affected properties. Estimates of affected employees are in full-time 

equivalents in all cases. 

Because of the varied types of businesses in the SOMA, the high incidence of small specialty 

firms, and the relatively rapid changes in business activity, it is difficult to estimate accurately 

the number of businesses and employees that may be affected by acquisitions that would take 

place three to five years from now. The estimated acquisitions and displacements presented in 

this section are representative of conditions that may exist when the Transbay Terminal and 

Caltrain Downtown Extension would be implemented. Information would be updated during 

final design and during pre-construction surveys. 

Residential Displacement. Construction of the Transbay Terminal and the Caltrain Downtown 

Extension could require acquisition of up to 60 residential units, including 14 live/work units. 

Twelve of these units have operating commercial businesses. Up to 120 persons per alternative 

would be relocated, assuming an average of two residents per unit. 

Business Displacement. The Transbay Terminal and Caltrain Downtown Extension could 

displace up to 67 businesses, plus 12 businesses currently operating in the live/work units. Up to 

an estimated 1,600 respective employees could be displaced. 

Federal and state laws require consistent and fair treatment of owners of properties to be taken, 

including just compensation for their properties. Uniform and equitable treatment of temporarily 

or permanently displaced businesses is also required by these laws. Acquisition costs are 

discussed in Section 5.6. 

5.2.6 Relocation Resources 

Acquisition of private properties required for the Caltrain Downtown Extension would represent 

a loss of up to 742,000 square feet of building space, of which up to 478,000 square feet is 

estimated to be office space; 127,000 square feet is estimated to be industrial space; 20,000 

square feet is estimated to be retail/restaurant space; and 117,000 square feet is residential space. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AN

5.2 DISPLACEMENTS AND RELOCATION 

Table 5.2-5: Estimated Residential and Non-Residential Acquisitions for 

Transbay Terminal, Caltrain Downtown Extension and Redevelopment Program 

RESIDENCES

Estimated Number of Residential Units Displaced by T

Multi-Family Project Component/ Alternatives No. of Properties Acquired Total Est. Land Area in Sq. Ft. Total Est. Building Sq. Ft. Total Single Family Units Mobile Homes Buildings Un

Transbay Terminal & Redevelopment Area No Residential Units Affected Caltrain Downtown Extension (Cut-and-Cover Option)Second-to-Main 4 41,000 117,000 0 0 4 6Second-to-Mission 4 41,000 117,000 0 0 4 6Caltrain Downtown Extension (Tunneling Option)Second-to-Main 2 14,000 50,000 0 0 2 2Second-to- Mission 2 14,000 50,000 0 0 2 2

BUSINESSES

Estimated Number of Businesses Displaced by Typ

Project Component/ 

Alternatives 

No. of 

Properties 

Acquired 

Total Est. 

Land Area 

in Sq. Ft. 

Total Est. 

Building 

Sq. Ft. Retail Office/Bus. Services Rest. / Bar Industrial Warehouse 

Transbay Terminal and Redevelopment Area 6 36,000 82,000 0 9 0 0 0 Caltrain Downtown Extension (Cut-and-Cover Option)Second-to-Main 25 224,000 433,000 6 32 4 2 1 Second-to-Mission 27 274,000 543,000 6 42 4 2 1 Caltrain Downtown Extension (Tunneling Option)Second-to-Main 16 81,000 146,000 5 29 4 0 0 Second-to-Mission 18 131,000 256,000 5 39 4 0 0 Source: Sedway Group, Parsons Transportation Group, 2001 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-34 5.2 DISPLACEMENTS AND RELOCATION 

Based on current market conditions for commercial and residential space, most businesses and 

residents should be able to be relocated within the study area. The study area is part of the 

broader South of Market Area (SOMA), which has witnessed a dramatic transformation over the 

past seven years with older buildings rehabilitated and new buildings constructed on previously 

vacant or underutilized parcels. This area was the epicenter of the “dot com” boom in 1999 and 

2000, during which multimedia, technology, and Internet companies, fueled by venture capital, 

exhibited a healthy appetite for real estate. Correspondingly, vacancy rates plummeted, rents and 

sales prices spiked, and new development and redevelopment was widespread throughout 

SOMA. 

However, by the end of 2000, stock market reductions hit the technology and Internet sector and 

space was increasingly placed on the market for sublease. In 2001, the overall economy has 

substantially slowed, affecting demand for space. As a result, vacancy rates have increased. The 

properties located at Second and Howard streets are within the South of Market Financial 

District office submarket, which posted a 12 percent vacancy on an inventory of 20.8 million 

square feet as of the end of September 2001. The properties located at Second and Townsend 

streets are in the SOMA South office submarket, which has been more severely affected by the 

downturn. As of September 2001, this market had a vacancy rate of 26 percent on a total 

inventory of 5.5 million square feet. 

As demand for office space has deteriorated, so has demand for industrial and retail space. The 

residential market, while not as severely affected, has also experienced increasing vacancy rates, 

lowered rents, and, with respect to “for-sale” projects, lower sales prices and longer marketing 

periods. A recovery is expected, but may not commence until at least the end of 2002. An 

improvement in the market to the point of the extremely strong conditions experienced in 1999 

and 2000 is not expected for a number of years. Therefore, displaced businesses and residents 

interested in relocating within SOMA would likely find an ample supply of comparable office, 

industrial, retail, or residential space. 

The federal Uniform Relocation Act (Public Law 91-646) and the California Relocation Act 

(Chapter 16, Section 7260 et seq. of the Government Code) and related laws and regulations 

contain specific requirements that govern both land acquisition and relocation. All real property 

to be acquired will be appraised to determine its fair market value before an offer is made to each 

property owner. Minimum relocation payments are detailed in the laws, and include moving and 

search payments for businesses. For purposes of the relocation acts, parking lots are considered 

businesses. 

The City and County of San Francisco and the Transbay Joint Powers Authority will provide 

information, assistance and payments to all displaced businesses in accordance with these laws 

and regulations. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.3SOCIOECONOMICS 5-35 

5.3 SOCIOECONOMICS 

5.3.1 No-Project Alternative 

The No-Project Alternative would not directly affect residential or business access or the 

character of neighborhoods so as to adversely influence location choices or the local economy. 

5.3.2 Transbay Terminal 

Construction of the proposed Transbay Terminal would increase pedestrian activity and as a 

result would potentially contribute to the intensification of land uses and the redevelopment of 

underutilized parcels in the vicinity of the Terminal; thereby improving the economic vitality of 

the area. 

Four nonresidential units would be displaced due to implementation of the Transbay Terminal. 

No residential units would be displaced by the Transbay Terminal component. 

5.3.3 Caltrain Downtown Extension 

The Caltrain Downtown Extension would provide improved access to the major employment 

center in the heart of downtown San Francisco, and therefore would enhance economic activity 

in this area. 

Construction of the cut-and-cover tunnel configuration between Fifth Street and the Transbay 

Terminal would entail the acquisition and demolition of all existing buildings under which the 

Downtown Extension alternative alignments would pass. Following construction of the 

underground extension, however, it is anticipated that new buildings would be constructed as 

vacant sites become available for resale. 

Construction of the Caltrain Downtown Extension Tunneling Option would involve fewer 

acquisitions and displacements. Specifically, underground easements would be required for the 

properties along Townsend and Brannan Streets and in the 600 block of Second Street, but these 

properties would not be demolished or vacated. 

As described in Section 5.2.2, the Caltrain Downtown Extension Cut-and-Cover Option would 

displace up to 60 residential units, including 14 live/work units, with either the Second-to-Main 

or the Second-to-Mission alternatives. An estimate of up to 120 persons per alternative would be 

relocated, assuming an average of two residents per unit. All homeowners or renters displaced as 

a result of the project would be offered relocation assistance and replacement housing. 

For the Cut-and-Cover Option, up to an estimated 58 businesses would be displaced for the 

Second-to-Mission Alternative. The lowest number of business displacements would occur for 

the Second-to-Main Tunneling Option, with an estimated 40 business displacements. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-36 5.3 SOCIOECONOMICS 

The City and County of San Francisco or the TJPA will acquire the properties, and each business 

owner will be offered relocation assistance. In the event the displaced businesses chose not to 

relocate within the area, a loss of jobs would result. The maximum number of jobs lost if no 

businesses relocated in the area is estimated to be between 425 for the Second-to-Main 

Tunneling Option to 1,422 jobs for the Second-to-Mission Cut-and-Cover Option. 

In all likelihood, a number of the affected businesses would relocate nearby or elsewhere within 

the City and County of San Francisco. Also, other businesses might relocate or expand in the 

area, in part because of the general improvement in transportation facilities. As a result, net job 

loss attributable to the project would be minimal. Fiscal and economic impacts of residential and 

business displacements are discussed in Section 5.6. 

5.3.4 Redevelopment Area Alternatives 

The Redevelopment Area alternatives are expected to intensify the urban character of the area 

and to result in a more cohesive neighborhood with a balanced mixture of residential and 

commercial uses. Consequently, proposed development is anticipated to improve rather than to 

disrupt or adversely affect the character of the existing socioeconomic environment. 

Displacement impacts will be mitigated in accordance with the relocation assistance programs 

summarized in Section 5.2, Displacements and Relocation. Since no other long-term impacts to 

residential populations, neighborhoods, community cohesion or land use patterns in the study 

area are anticipated, no further mitigation is suggested. Potential project impacts on community 

facilities and services, parklands, schools and churches are discussed in Sections 5.4, Community 

Facilities and Services, and 5.5, Parklands, Schools, and Religious Institutions. 

5.3.5 Environmental Justice 

Executive Order 12898 (Federal Actions to Address Environmental Justice in Minority 

Populations and Low-income Populations), dated February 11, 1994, calls on federal agencies to 

identify and address disproportionately high and adverse human health or environmental effects 

of federal programs, policies, and activities on minority populations and low- income 

populations. In 1997, the U.S. Department of Transportation (DOT) issued its DOT Order to 

establish procedures for use in complying with EO 12898 for its operating administrations, 

including FTA. 

Impacts and benefits of transportation projects result from the physical placement of such 

facilities, and also from their ability to improve or impede access to neighborhoods or portions of 

the region. This analysis examines whether ethnic minority and/or low-income populations in 

the project area would experience these types of impacts, and if they are inconsistent with the 

benefits created. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.4COMMUNITY FACILITIES AND SERVICES 5-37 

As noted in Section 4.2, the study area as a whole consists of relatively smaller percentages of 

ethnic and minority populations as compared to overall percentages for the City of 

San Francisco. Census Tract 180 at the west end of the study area, however, reveals higher 

concentrations of Black/African American and Hispanic populations relative to percentages 

citywide. With the exception of Census Tract 180, the percentage of residents below the federal 

poverty level was comparable to the citywide average. Auto ownership within the study area is 

slightly less than for the city as a whole. 

The construction of the proposed Transbay Terminal, Caltrain Downtown Extension and 

Redevelopment Plan would have no long-term adverse effects on minority, low-income and 

transit dependent communities. As described above, the study area, particularly Census Tracts 

176.02 and 179.01 where the majority of the project impacts would occur, has relatively lower 

percentages of minority and low-income populations as compared to the greater San Francisco 

area. Census Tract 180, where higher concentrations of minority populations occur, would have 

fewer project impacts. Minority populations are not disproportionately represented among those 

who would be displaced by the project or who would live adjacent to the project. Therefore, the 

project would have neutral environmental justice implications. The proposed project components 

would improve mobility for transit-dependent populations and would enhance intermodal 

connectivity. All transit services would remain continuous during the construction period. The 

proposed community revitalization and redevelopment plan, including the provision of 

affordable housing, would be an added benefit to the community. 

5.4 COMMUNITY FACILITIES AND SERVICES 

5.4.1 No-Project 

Implementation of the No-Project Alternative would have no effect on existing community 

facilities and services. The demand for police protection, fire prevention, emergency medical 

services and waste management facilities as a result of No-Project development would be 

adequately accommodated through the horizon year 2020. Therefore, no impacts are anticipated 

with the implementation of the No-Project Alternative, and no mitigation measures are proposed. 

5.4.2 Transbay Terminal 

5.4.2.1 Public and Community Facilities 

None of the public and community facilities described in Section 4.3 would be displaced, 

relocated, or otherwise affected by construction of either of the Transbay Terminal Alternatives. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-38 5.4 COMMUNITY FACILITIES AND SERVICES 

5.4.2.2 Safety and Emergency Services 

Police. Implementation of either the West Ramp or the Loop Ramp Alternative would increase 

the amount of pedestrian activity within the Terminal and general vicinity, and thus the potential 

for crimes reported in the area. Currently, the Terminal falls under the jurisdiction of the 

California Highway Patrol, but this would change with the change in Terminal ownership and 

the TJPA would need to determine how it would obtain police services for the new Terminal. 

According to Lieutenant Pardini of the San Francisco Police Department (SFPD), the SFPD’s 

Southern Station does not have the sufficient personnel to realign its staff and provide offices 

exclusively for the Terminal.3 Southern Station currently has no patrol officers assigned to the 

Terminal. Sources at the Department anticipate that a minimum of two Southern Station patrol 

officers would need to be assigned (24 hours per day, seven days per week), and this increase in 

demand could not be met by reorganizing existing staff and would require a funding 

arrangement between the terminal and SFPD.

It is likely that some Terminal police and protection services would remain with the security 

forces associated with Terminal transit agencies, including AC Transit and Golden Gate Transit. 

It is anticipated that these agencies would extend their security responsibilities to accommodate 

the new Terminal under either the West Ramp or Loop Ramp Alternative. 

Fire and Emergency Medical Services. The development of the Transbay Terminal at a height 

and massing greater than the existing Terminal, coupled with an increase in the intensity of land 

uses associated with the site would increase demand for fire prevention and suppression and 

emergency services under either of the new terminal alternatives (West Ramp or Loop Ramp). 

Demand for fire prevention and suppression and emergency services would be expected to be 

greater under the West Ramp Alternative due to the increased mix of land uses, including the 

pedestrian concourse level with retail, commercial, conference, and cultural uses. 

To ensure that adequate life safety measures and emergency access will be incorporated into the 

design and construction of either of the design alternatives, the Fire Department will review 

project plans at the time of permitting. The San Francisco Fire Department will require “a risk 

analysis to accurately determine the number of personnel necessary to maintain an acceptable 

level of service” (written communication, Aaron Stevenson, San Francisco Fire Department, 

May 29, 2001).” To reduce the potential for impacts to occur under either the West Ramp or 

Loop Ramp Alternative, development and implementation of a life safety plan will be required. 

A life safety plan will include provision of on-site measures such as a fire command post at the 

Terminal, the Fire Department’s 800-megahertz radio system and all necessary fire suppression 

equipment. 

 

3 Lieutenant Albert Pardina, Planning Division, SFPD, letter to Joan Kugler, January 10, 2003. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.4COMMUNITY FACILITIES AND SERVICES 5-39 

5.4.2.3 Solid Waste Management 

The West Ramp Alternative would provide for a greater intensity and mix of land uses, and thus 

would be expected to generate more solid waste than the Loop Ramp Alternative, which would 

entail about 110,000 square feet less space. Under either of the two alternatives, however, the 

generation of solid waste would be small when compared to the waste stream generated citywide 

(1.39 million tons). Impacts associated with the demolition of the existing Terminal would 

include a short-term increase in the amount of solid waste and debris disposed of which, 

according to sources at the Solid Waste Management Program, could be adequately 

accommodated by existing landfills. 

Although an increase in solid waste generation and disposal would occur due to implementation 

of either the West Ramp or Loop Ramp Alternative, new or expanded facilities would not be 

required to accommodate the demand for Solid Waste Management Services, and therefore no 

mitigation measures are required. The following measures are recommended to achieve the 50 

percent reduction goal specified in the California Integrated Solid Waste Management Act of 

1989 (AB 939). In addition, compliance with all City and County ordinances regarding the 

minimization of waste though recycling would be expected to occur. 

Short-term measures include utilizing recycled construction materials where feasible, 

encouraging recycling of construction and demolition materials, and including built-in 

compartmentalized recyclable material collection bins into the proposed developments. 

Long-term measures include creating and implementing a long-term waste management plan for 

comprehensive recycling of materials. Such a plan would be developed in coordination with 

existing recycling programs in the area, and should target materials generated by office, 

residential and retail land uses such as paper, glass, aluminum beverage containers, and plastic. 

In addition, proposed development should have a designated space for the collection and storage 

of recyclable materials. 

5.4.3 Caltrain Downtown Extension 

5.4.3.1 Public and Community Facilities 

None of the public and community facilities described in Section 4.3 would be displaced, 

relocated, or otherwise affected by construction of the Caltrain Downtown Extension 

Alternatives. 

5.4.3.2 Safety and Emergency Services 

Police. Implementation of either of the Caltrain Downtown Extension alternatives would not 

result in impacts to police protection services. As both alternatives would be located 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-40 

underground, construction and use of the alignments would not be expected to require additional 

police staff or new or expanded police facilities. Caltrain security officers would continue to 

patrol the Caltrain vehicles en route towards the Transbay Terminal. Therefore, no mitigation 

measures are proposed. 

Fire and Emergency Medical Services. Implementation of either of the proposed alternatives 

would be expected to increase the demand for fire prevention and suppression and emergency 

medical services during the construction and occupancy of the underground tunnel. To ensure 

that adequate life safety measures and emergency access would be incorporated into the design 

and construction of the design alternatives, the Fire Department will review project plans at the 

time of permitting. To reduce the potential for impacts to occur under either of the design 

alternatives, development and implementation of a life safety plan will be required. A life safety 

plan will include provision of on-site measures such as a fire command post near the tunnel 

operations, the Fire Department 800-megahertz radio system and all necessary fire suppression 

equipment located on the premises, if applicable, as well as adequate access to the underground 

tunnel. 

5.4.3.3 Solid Waste Management 

Impacts associated with implementation of either of the proposed underground Caltrain 

Downtown Extension alternatives would be limited to short-term construction impacts associated 

with tunnel-bore operations. Construction impacts associated with the Caltrain Downtown 

Extension are addressed in greater detail in Section 5.21. The City’s Solid Waste Management 

Program previously determined that the amount of construction debris generated and disposed of 

could be adequately accommodated by existing landfills. 

5.4.4 Transbay Redevelopment Area 

The proposed project’s redevelopment component would occur over time (through the year 

2020). Generally, increases in population result in incremental increases in the demand for 

public services, in this case specifically for police and fire services. In written communication 

provided by both the police and fire departments, these providers plan to maintain the necessary 

staffing levels and equipment to meet the level and scope of service needs of the citizens of 

San Francisco, and to address the future growth resulting from the project. 

5.4.4.1 Public and Community Facilities 

None of the public and community facilities described in Section 4.3 would be displaced, 

relocated, or otherwise affected by construction of the Redevelopment Alternatives. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

 5-41 

5.4.4.2 Safety and Emergency Services 

Police. On the basis of the current ratio of police staffing to the population, the Police 

Department would require an estimated additional 85 to 115 staff under the Reduced Scope 

Alternative and Full-Build Alternative, respectively4. It is anticipated that an increase in demand 

such as this could be met by reorganizing existing staff (i.e., adjusting schedules, re-deploying 

officers), instead of hiring new staff. There are currently no plans for additional police facilities 

to serve this area. 

The San Francisco Police Department divides the City into different geographic areas, known as 

patrol sectors. In the South of Market area, there are currently five patrol sectors. The 

Transbay Terminal Area is within the southern patrol sector and serviced by the Southern 

Station. The southern patrol sector extends from Market Street on the north, Bryant Street on the 

south, The Embarcadero on the east, and Third Street on the west. If additional police presence 

in the southern patrol sector would be required, the police department could reorganize staff 

allocated to specific patrol sectors or could reconfigure the geographic area of a specific patrol 

sector by reducing the geographic area of the southern patrol sector and increasing another 

patrol sector where service demands are less (personal communication, Lt. Al Pardini, 

San Francisco Police Planning Division, July 2, 2003). 

Implementation of either development alternative would not be expected to require new or 

expanded facilities, and therefore no mitigation measures are required. To ensure adequate 

security measures are incorporated into the design of all new development, creation and 

implementation of a security plan, which would include measures that provide for state-of-the-art 

security and communications capabilities in each of the new facilities, is recommended. 

Fire and Emergency Medical Services. The Fire Department anticipates that implementation 

of either the Full-Build Alternative or Reduced Scope Alternative could impact the Department’s 

level of service in the study area. Demand may be great enough to require additional fire 

suppression personnel to maintain an adequate level of service. It is anticipated, however, that 

an increase in demand could be met through the reorganization of existing staff instead of hiring 

new staff. Furthermore, a proposal to build a new fire station in the nearby Mission Bay area 

could potentially offset any adverse impact to the Department’s level of service in the area. 

According to the San Francisco Fire Department (SFFD), response times for Station 1 and 

Station 2 are approximately three to five minutes, and development of the proposed project is not 

expected to adversely affect existing response times (personal communication, Battalion Chief 

Paul Chin, June 27, 2003). 

 

4

Projections based on Port of San Francisco Waterfront Land Use Plan (San Francisco Planning Department, 1997). It is likely 

that these figures are over estimated due to the fact that they were calculated based on a standard ratio of officers per capita, and 

do not reflect the most realistic estimates of how the need for additional staff changes as population of a neighborhood changes. 

Police Department staff were not able to provide more accurate figures. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-42 

As part of the building permit process required for all new construction or building renovation, 

the building owner/developer must show evidence of the proposed work meeting current 

building and safety standards. In the case of renovations, additions such as new sprinkler 

systems, fire alarms or new exits are likely, thus improving a structure’s overall fire protection. 

For new construction, some projects would require the demolition of older buildings, thus 

reducing the existing fire hazards they may pose. Therefore, any level of future development in 

the Redevelopment Area would result in improved fire protection due to an increase in the 

number of structures that adhere to the most recent fire and safety code requirements. 

Future development is assumed to result in a decrease in the amount of industrial square footage 

in the area. As the amount of industrial space diminishes and new construction activity results in 

the cleaning up of contaminated sites, the potential for fires or other incidents related to 

hazardous materials would be reduced. In addition, existing hazardous materials programs 

would likely be able to expand and receive additional financial support as the number of feepaying businesses increases.

Additional development under either of the redevelopment area alternatives could adversely 

affect emergency medical resources, especially during daytime hours. Demand may be great 

enough to require larger staffing, but in most cases new staffing could be supported by new user 

fees, provided fee allocations allow for it. 

5.4.4.3 Solid Waste Management 

The City’s Solid Waste Program calculates citywide solid waste generation by adjusting yearly 

taxable sales, the California Consumer Price Index (CPI), population growth, and employment. 

The annual diversion rate is then calculated by using the known disposal tonnage and the 

adjusted waste generation figure. The current diversion rate is 42 percent, which could likely 

increase to more than 50 percent by the horizon year 2020. Accordingly, solid waste generation 

tonnage could vary from approximately 1.39 million tons towards more than 1.5 million tons by 

2020. 

Based on development projections for recent studies in the Transbay Area, it is estimated that the 

Redevelopment Area would generate at least 15,000 tons and dispose of at least 12,000 tons per 

year of combined residential and commercial waste under the Full Build Alternative.5 Given 

that the total citywide waste stream is approximately 1.39 million tons per year, the occupancy 

waste from development under either of the alternatives would constitute less than 0.9 percent of 

the entire solid waste stream. 

 

5

This figure was estimated using a 42 percent diversion rate and the following waste generation assumptions used by the City’s 

Solid Waste Program: 3 lbs. per residential square foot during construction, 1.02 tons per household during occupancy, 11.5 lbs. 

per commercial square foot during construction, 2.6 lbs. per square foot of office space per year during occupancy and 3.1 lbs.

per square foot of commercial space per year during occupancy. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.5PARKLANDS, SCHOOLS, AND RELIGIOUS INSTITUTIONS 5-43 

As implementation of either the Full-Build or Reduced Scope alternatives would not result in an 

impact to Solid Waste Management Services, no mitigation measures are required. The 

measures outlined previously for the Transbay Terminal alternatives could potentially reduce the 

short-term and long-term impacts to Solid Waste Management, including the City’s ability to 

achieve the state mandated 50 percent reduction goal (AB 939). In addition, compliance with 

current City and County ordinances regarding the minimization of waste through recycling 

would be required. 

5.5 PARKLANDS, SCHOOLS, AND RELIGIOUS INSTITUTIONS 

The No-Project Alternative would have no effect on parks, schools, or religions institutions. The 

remainder of this section therefore focuses on the Terminal/Extension/Redevelopment project 

effects. 

With the exception of the set-back and porte-cochere (semi-circular drive) immediately in front 

of the existing Transbay Terminal, none of the open spaces, parks, recreational facilities, 

universities, or churches described in Section 4.4 would be displaced or affected as part of any of 

the Transbay Terminal, Downtown Extension or Redevelopment alternatives, except to the 

extent that transit access and traffic patterns would change. 

5.5.1 Parklands 

Both the Transbay Terminal alternatives would displace the set-back and porte-cochere located 

in front of the existing Transbay Terminal. The existing area is almost entirely paved, and would 

not be considered a “park” in most senses of the word, although the 1994 Draft Downtown 

Streetscape Plan developed by the San Francisco Planning Department calls for “retaining the 

area in front of the Terminal or other suitable areas for much needed open space,” and “retaining 

. . . a garden walk pedestrian connection and open space,” on the former freeway parcels south of 

the Terminal. The current concept for the new Transbay Terminal includes an open plaza for 

public use and a grand staircase as the front entrance to the new terminal. 

Both Redevelopment Alternatives would introduce new public open space into the Transbay 

Redevelopment Area, an area currently lacking public open space and parks. The current open 

space concept for the area includes four primary public open spaces, with two open spaces 

forming Fremont Square, a primarily hardscaped plaza that would be adjacent to the new 

Terminal and would replace the existing open space and two new “green” open spaces. Natoma 

Green would be located between Minna and Natoma Streets and would serve as a mixed-use 

educational and cultural center, and Essex Green would be located between Tehama and 

Clementina Streets. In addition, smaller open spaces such as pocket parks, sitting areas, and 

playgrounds are proposed for the area. The addition of new public open space to the Transbay 

Redevelopment Area would represent an improvement over current conditions. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-44 5.5PARKLANDS, SCHOOLS, AND RELIGIOUS INSTITUTIONS 

5.5.2 Schools 

No schools would be displaced, relocated, or disrupted by the project. Private schools and 

colleges located within the vicinity of the Terminal, such as Golden Gate University, would 

likely benefit from the improved transit operations and the creation of new transit-oriented 

development (retail, cultural, commercial uses). Moreover, the new, aesthetic design of the 

Terminal would create a distinct point of interest in the Transbay Area, which could in turn 

attract new patrons. Short-term construction effects such as noise, redistribution of traffic, and 

dust would be anticipated to occur; these are discussed in Section 5.21.7, Construction Impacts 

on Parks, Schools, and Religious Institutions. 

Increased public school enrollment at the K-12 level generated by proposed residential 

development in the Transbay Redevelopment Area would increase demand for school facilities. 

Based on the student generation rate of 0.203 students per new housing units used by the San 

Francisco Unified School District (SFUSD) for planning purposes, the number of students that 

could potentially be added to the Transbay Redevelopment Area would range from about 685 

students under the Reduced Scope Alternative (3,373 housing units) to about 737 students under 

the Full Build Alternative (3,630 housing units). 

Funding for school construction is generated by fees on new development, at levels capped by 

the State legislature. The current State legislature establishes a maximum fee for residential 

development at $1.93 per square foot, and $0.31 per square foot of commercial development. 

The San Francisco Board of Education has not adjusted the fees in the San Francisco Unified 

School District (SFUSD) since 1994; current SFUSD fees are $1.72 per square foot of residential 

development, $0.24 per square foot of office, and $0.13 per square foot of retail. Fees of $0.08, 

$0.09, $0.15, and $0.22 per square foot of lodging, warehouse, heavy industrial, and light 

industrial development, respectively, are also charged by the SFUSD. At the current rate fees, 

development proposed for the Transbay Redevelopment Area under the Full Build Alternative 

would generate about $10 million in fees, and about $7 million in fees would be generated under 

the Reduced Scope Alternative. 

School development fees are considered under Senate Bill 50 (SB50) to mitigate any potential 

effect associated with the implementation of proposed residential development under either 

development alternative. 

5.5.3 Religious Institutions 

Due to their distance from the proposed improvements, none of the religious institutions 

identified in Section 4.4 would experience long-term impacts of the project components, 

although there would be limited short-term construction effects such as noise, redistribution of 

traffic, and dust. These impacts are addressed in Section 5.21.7. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.6FISCAL AND ECONOMIC IMPACTS 5-45 

As there would be no long-term adverse effects to parklands, schools, and churches, no 

mitigation is proposed. 

5.6 FISCAL AND ECONOMIC IMPACTS 

5.6.1 No-Project Alternative 

The No-Project Alternative is the reference point for estimating the fiscal and economic impacts 

of the proposed project alternatives and therefore, by definition, would have no impacts. The 

rest of this section therefore focuses on the impacts of the Terminal/Extension/Redevelopment 

project. 

5.6.2 Transbay Terminal/Caltrain Extension/Redevelopment 

Because the Transbay Terminal, Caltrain Downtown Extension, and Redevelopment components 

are very closely related from the point of view of fiscal and economic impacts, these effects are 

discussed together in this section. 

To construct the Caltrain Downtown Extension from Fourth and Townsend Streets to the site of 

the Transbay Terminal, land and buildings will need to be acquired, and permanent underground 

easements will need to be secured. Due to Caltrain design standards, local geology, and the 

resultant depth of the Caltrain alignment, the construction of either alternative, as presently 

envisioned, may involve the acquisition and demolition of buildings under which the alignment 

would pass, depending on the construction technique selected (cut-and-cover versus tunneling). 

After the underground extension is constructed, these properties would be available for resale as 

vacant sites ready for new construction. The properties that would be affected by the extension 

are detailed in Section 5.2. 

Properties identified in Section 5.2 are in private ownership; publicly-owned properties are 

excluded from this fiscal analysis. These publicly-owned properties would be transferred to the 

Transbay Joint Powers Authority (TJPA – see Section 1.3, Project Sponsors) and the 

Redevelopment Agency from the State of California (see Section 6). 

5.6.2.1 Net Order-of-Magnitude Land Building and Easement Cost 

This analysis estimates the order of magnitude cost to acquire the privately-owned land, 

buildings, and easements needed to construct the Caltrain Downtown Extension Alternative. 

This order of magnitude cost estimate also includes the following items: 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-46 5.6 FISCAL AND ECONOMIC IMPACTS 

• Estimated premium associated with eminent domain proceedings, such as legal fees, 

appraisal costs, and other consulting and administrative costs; 

• Estimated cost to relocate commercial and residential tenants and owner-occupants; and 

• Estimated building demolition costs. 

The cost estimate does not include payments associated with business interruption, loss of 

goodwill, and “nuisance” costs associated with the construction of the extension, including loss 

of property access. Costs would be partially offset by the estimated proceeds from resale of the 

properties as vacant sites become available for new construction. 

Acquisition Costs. Compensation to owners of the acquisition parcels would be based on 

accepted appraisal techniques, specifically comparison to sales of other buildings in the broader 

South of Market neighborhood. Because the individual properties exhibit a wide range of 

building sizes, conditions, tenancies, etc., a broad price range was used to prepare the order of 

magnitude cost estimate. Individual properties have not been appraised at this stage; however, if 

a property recently transferred ownership, the actual transaction was factored into the analysis. 

Using such sources as First American Real Estate Solutions, Comps Inc., and Marshall Valuation 

Service, estimated cost ranges were determined for each land use type to be acquired under each 

alternative and option. Based on these estimates, Tables 5.6-1, 5.6-2 and 5.6-3 provide a 

summary of the estimated acquisition costs for the Transbay Terminal and the two Caltrain 

Downtown Extension Alternatives for both the Cut-and-Cover and Tunneling Options. 

Estimates include an assumed premium associated with possible eminent domain proceedings 

and relocation costs, which is based on information provided by the San Francisco 

Redevelopment Agency and professional experience with other redevelopment and eminent 

domain projects. 

Table 5.6-1: Summary of Acquisition Cost Estimates 

Transbay Terminal & Redevelopment Properties 

 Low High 

Estimated Acquisition Cost [1] $34,000,000 $46,400,000 

Relocation Cost $300,000 $300,000 

Demolition Cost $300,000 $300,000 

Total Net Acquisition Costs $34,600,000 $47,000,000

Notes: 

[1] Includes premium for possible condemnation proceedings. 

Sources: Sedway Group; City of San Francisco; First American Real Estate Solutions; 

Comps Inc.; Marshall Valuation Service, August 2001.
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.6FISCAL AND ECONOMIC IMPACTS 5-47 

Table 5.6-2: Summary of Acquisition Cost Estimates 

Second-to-Main Alternative 

Low High 

Cut-and-Cover Option

Estimated Acquisition Cost [1] $124,400,000 $202,400,000 

Easements 1.200,000 1,200,000 

Relocation Cost $4,100,000 $4,100,000 

Demolition Cost $3,200,000 $3,200,000 

Resale Proceeds ($27,200,000) ($88,100,000) 

Total Net Acquisition Costs $105,700,000 $122,800,000

Tunneling Option

Estimated Acquisition Cost 

 Fee [1] $46,000,000 $69,800,000 

 Easements $2,200,000 $2,200,000 

Relocation Cost $2,400,000 $2,400,000 

Demolition Cost $1,100,000 $1,100,000 

Resale Proceeds ($7,600,000) ($24,900,000) 

Total Net Acquisition Costs $44,100,000 $50,600,000

Note: [1] Includes premium for condemnation. 

Sources: City of San Francisco; Sedway Group; First American Real Estate Solutions; 

Comps Inc.; Marshall Valuation Service, August 2001.

Table 5.6-3: Summary of Acquisition Cost Estimates 

Second-to-Mission Alternative 

 Low High 

Cut-and-Cover Option

Estimated Acquisition Cost [1] $188,100,000 $277,800,000 

Relocation Cost $4,500,000 $4,500,000 

Demolition Cost $3,800,000 $3,800,000 

Resale Proceeds ($66,000,000) ($148,500,000) 

Total Net Acquisition Costs $130,400,000 $137,600,000

Tunneling Option

Estimated Acquisition Cost 

 Fee [1] $109,800,000 $145,300,000 

 Easements $1,000,000 $1,000,000 

Relocation Cost $2,800,000 $2,800,000 

Demolition Cost $1,800,000 $1,800,000 

Resale Proceeds ($46,400,000) ($85,200,000) 

Total Net Acquisition Costs $69,000,000 $65,700,000

Notes: [1] Includes premium for condemnation. 

Sources: City of San Francisco; Sedway Group; First American Real Estate Solutions; Comps 

Inc.; Marshall Valuation Service, 2001. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-48 5.6 FISCAL AND ECONOMIC IMPACTS 

Relocation costs are estimated at $35,000 per unit for residential units, $40,000 per business for 

small- and medium-sized businesses, and $120,000 for large businesses. The relocation costs 

used here are estimates to be used for planning and budgeting purposes. Actual relocation 

payments will be determined at the time of project implementation using state and federal 

guidelines. 

Demolition costs are based upon cost estimates provided by Marshall Valuation Service. 

Depending upon the construction type of the building and other individual factors, demolition 

costs range from $3.60 to $8.10 per square foot of building area. An average of $5.85 per square 

foot of building was used. 

After construction of the Caltrain Extension, the properties would be available for resale as 

developable vacant sites. The estimated resale proceeds would partially offset the estimated 

acquisition costs, resulting in a net acquisition cost estimate. Resale proceeds estimates are 

based upon land prices per square foot of land area. A broad range is used to reflect the wide 

variety of locations of the individual properties and their respective unknown redevelopment 

potentials. For commercial sites, the estimated range is $100 to $300 per square foot of land 

area, while for residential properties, the range is from $200 to $760 per square foot of land 

area.6 As shown in the tables, estimated resale proceeds range from $34 to $113 million for the 

Second-to-Main Alternative and from $69 to $153 for the Second-to-Mission Alternative. 

5.6.2.2 Total Net Acquisition Cost Estimate 

Based on each of the acquisition components described above, the net acquisition cost estimate 

for the Transbay Terminal and the Caltrain Downtown Extension (in 2001 constant dollars), 

including land, buildings, and easement, is as follows: 

Estimated net acquisition costs for properties required for: 

• Transbay Terminal - $34.6 to $47.0 million 

• Second to Main Caltrain Downtown Extension 

o Cut-and-Cover Option – $105.7 to $122,8 million 

o Tunneling Option – $44.1 to $50.6 million 

• Second to Mission Caltrain Downtown Extension Alternative 

o Cut-and-Cover Option – $130.4 to $137.6 million 

o Tunneling Option - $65.7 to $69.0 million. 

These cost ranges include estimated premiums associated with eminent domain proceedings, 

relocation costs, and demolition costs. Business interruption, loss of goodwill, and “nuisance” 

costs are not included. 

 

6 The two properties on Mission Street for the Second-to-Mission Alternative are estimated at $700 to $790 per square foot of 

land area, due to a recent partial transfer of these properties. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.6FISCAL AND ECONOMIC IMPACTS 5-49 

5.6.2.3 Fiscal Implications of Land Acquisition for Caltrain Downtown Extension 

The acquisition of real estate parcels for construction of the Caltrain Downtown Extension would 

result in fiscal impacts to the City and County of San Francisco. These effects are anticipated to 

be short-term, lasting only for the duration of the construction period and any subsequent period 

required for property resale. This analysis assumes that all of the acquired properties are 

ultimately resold to private parties. If the properties remain in public ownership, the implications 

would be longer-term. 

The properties identified for acquisition currently generate revenues to the City and County of 

San Francisco through taxation, both directly and indirectly. These revenues include property 

taxes, payroll taxes, retail sales taxes, parking taxes, and other less significant taxes, such as 

utility taxes. Once the properties are purchased by a public entity for construction of the 

Transbay Terminal and Caltrain Downtown Extension, they would no longer generate property 

taxes to the City and County of San Francisco, because public entities’ owners are exempt from 

such taxation. In addition, the ultimate demolition of existing development will result in the loss 

of occupancy-related taxes, such as payroll taxes paid by existing businesses, retail sales taxes 

generated by existing restaurants and retailers, retail sales taxes generated by subject property 

residents, and parking taxes paid by existing parking operators. 

Property Tax. The properties to be acquired for the Caltrain Downtown Extension for the Cutand-Cover Option have a year 2000 assessed valuation of $76.0 million for the Second-to-Main 

Alternative and $104.0 million for the Second-to-Mission Alternative.7 Pursuant to the annual 

allowable property value increase of two percent under Proposition 13, and a recent area real 

estate transaction involving 301-315 Mission Street and 101-129 Fremont Street8 (which 

properties lie within the alignment for the Second-to-Mission Alternative), these assessed 

valuations for the year 2001 are assumed to increase to approximately $77.6 million for the 

Second-to-Main Alternative and $127.6 million for the Second-to-Mission Alternative.9 Given 

the City and County of San Francisco’s current property tax rate of 1.136 percent, these 

properties generate annual property tax revenues to various City and County funds of $881,109 

for the Second-to-Main Alternative and $1,449,109 for the Second-to-Mission Alternative. For 

the Tunneling Option, fewer parcels will need to be acquired. Therefore, the property tax 

revenues associated with these properties are lower, estimated at $517,379 for the Second-toMain Alternative and $841,426 for the Second-to-Mission Alternative. Regardless of option, the 

property tax revenues associated with the properties requiring acquisition for the Transbay 

Terminal total an additional $97,536. 

 

7

 Assessed valuation as reported by First American Real Estate Solutions, August 2001. 

8

 Eighty percent interests in these properties were recently sold for $40 million, implying a $50 million total 

valuation. It is assumed the County Tax Assessor will include this total valuation in the 2001 property tax rolls. 

9

The full figures are $77,562,377 for Second-to-Main and $127,562,377 for Second-to-Mission.
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-50 5.6 FISCAL AND ECONOMIC IMPACTS 

These revenues would be lost to the City and County of San Francisco for the time period the 

properties are under public ownership. However, many of the properties could be resold 

following construction of the Caltrain Downtown Extension. If the properties were resold to 

private parties following construction of the Downtown Extension, property tax revenues would 

again accrue to the City and County of San Francisco (and the San Francisco Redevelopment 

Agency pending formulation of a redevelopment project area). To the extent subsequent 

development occurs, higher property tax revenues might ultimately accrue to the City and 

County of San Francisco due to higher assessed values associated with new, more intense 

development with higher values than the present uses. Thus in the long run, the short-term 

property tax losses may be recouped and even exceeded following new development reflecting 

the highest and best use of each property. 

Payroll Tax. Payroll taxes, assessed at a rate of 1.5 percent of gross payroll, are a significant 

revenue source to the City and County of San Francisco. There are up to 67 operating businesses 

located in the properties identified for acquisition for the Downtown Extension and the Transbay 

Terminal, depending upon alternative and option. An estimate of the number of employees 

associated with these businesses and their average annual payroll provides a basis for 

formulating a general estimate of annual payroll and associated payroll taxes. If any of these 

businesses were to close or relocate out of San Francisco, their payroll taxes would be lost to San 

Francisco. Although area-related payroll taxes would resume following redevelopment of the 

properties, any taxes lost during the construction and property resale period would not be 

recouped by San Francisco, unless these businesses were successfully relocated within 

San Francisco prior to or during construction. If these businesses were successfully relocated 

within San Francisco prior to or during construction, their payroll taxes would be preserved, both 

during and after construction. 

For each alternative and option, the total square feet by land use and a square-foot-per-employee 

estimate provides a basis for estimating total affected employment. This, coupled with an annual 

per capita payroll estimate, provides an estimate of the maximum payroll taxes that would be 

foregone as a result of business closures and relocations out of San Francisco with the Caltrain 

Downtown Extension. The calculated results per alternative are presented in Table 5.6-4, which 

estimates that for the Cut-and Cover Option, 1,089 jobs are associated with the Second-to-Main 

Alternative properties and 1,219 jobs are associated with the Second-to-Mission Alternative 

properties. For the Tunneling Option the figures are lower, totaling 424 employees for the 

Second-to-Main Alternative and 762 employees for the Second-to-Mission Alternative. 

Assuming an annual average payroll of $52,000 per employee,10 estimated annual payroll taxes 

for the Cut-and-Cover Option are $849,420 for the Second-to-Main Alternative and $1,113,060 

for the Second-to-Mission Alternative. For the Tunneling Option, these figures are $330,720 for 

the Second-to-Main Alternative and $594,360 for the Second-to-Mission Alternative. While not 

included in Table 5.6-4, the Transbay Terminal properties have an additional estimated 200 

office employees, with an associated payroll tax estimate of $156,000. 

 

10

Derived from County Business Patterns data for all San Francisco employees. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.6FISCAL AND ECONOMIC IMPACTS 5-51 

These are revenues that would be retained in both the short-term and long-term by the City and 

County of San Francisco if the affected businesses were to be successfully relocated within 

San Francisco. They would be lost only if the businesses were to close or relocate out of 

San Francisco following demolition of their existing space. 

Retail Sales Tax. Retail sales taxes accrue to the City and County of San Francisco at a rate of 

1.25 percent of total taxable sales. Retail sales taxes would accrue from the retail businesses and 

restaurants within the affected properties as well as from citywide spending by residents who live 

in the affected properties. As presented in Table 5.6-4, there are 19,680 square feet of retail and 

restaurant space included in the properties that would need to be acquired for both the Cut-and 

Cover and Tunneling Options. There are no additional retail properties associated with the 

Transbay Terminal. At a conservative $200 taxable sales per square foot annually, these 

operations generate an estimated $49,200 in retail sales taxes to the City and County of San 

Francisco annually. These revenues would be lost only if the affected businesses were to close 

or relocate outside of San Francisco. As with the payroll taxes, these retail sales taxes would be 

preserved if these operations were to be successfully relocated within San Francisco prior to or 

during construction. 

For both Alternatives under the Cut-and-Cover Option, construction of the Caltrain Downtown 

Extension will require the acquisition and demolition of 60 residential units, including 14 

live/work units. This translates into the relocation of an estimated 120 persons, assuming an 

average of two residents per unit. Under the Tunneling Option, only 23 residential units will be 

acquired and demolished. If each resident spends $7,20011 in taxable retail sales in San 

Francisco, the total annual sales tax contribution to the City and County of San Francisco would 

amount to a rather low $10,800 for the Cut-and-Cover Option and $4,140 for the Tunneling 

Option. Thus retail sales taxes at risk of loss would total only $60,000 per year for the Cut-andCover Option and $53,340 for the Tunneling Option. These taxes would be lost to the city only if 

all of the affected residents were to do all of their spending elsewhere. There are no residential 

units associated with the Transbay Terminal; hence no additional retail sales tax impacts. 

Other Tax. Other taxes generated by real estate may also be interrupted or cease subsequent to 

acquisition of the properties for construction of the Caltrain Downtown Extension. These include 

utility user taxes, franchise fees, and, for the three existing parking facilities (with less than an 

estimated 100 spaces), parking taxes. These tax revenues are likely to be very insubstantial 

relative to the preceding taxes, especially property and payroll taxes, and were not quantified. 

 

11

 Assumes $9,000 per capita in retail sales expenditures, with 80 percent captured by San Francisco retailers. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-52 5.6 FISCAL AND ECONOMIC IMPACTS 

Table 5.6-4: Estimated 2001 Payroll Tax Revenue Generated by 

Business Displaced by Construction of the 

Caltrain Downtown Extension Alternatives 

Cut-and-Cover Option Tunneling Option 

Second-toMain Second-toMission Second-toMain Second-toMission 

Industrial Space 

 Square Feet 126,880 126,880 2,600 2,600 

 Square Feet Per Employee 750 750 750 750 

 Total Employment 169 169 3 3 

Office Space 

 Square Feet 286,358 396,315 124,157 234,114 

 Square Feet Per Employee 325 325 325 325 

 Total Employment 881 1,219 382 720 

Retail/Restaurant 

 Square Feet 19,680 19,680 19,680 19,680 

 Square Feet Per Employee 500 500 500 500 

 Total Employment 39 39 39 39 

Total Employment 1,089 1,427 424 762 

Average Annual Payroll (1) $52,000 $52,000 $52,000 $52,000 

Payroll Tax Rate (2) 1.5% 1.5% 1.5% 1.5% 

Annual Payroll Tax Revenue $849,420 $1,113,060 $330,720 $594,360 

Notes: 

(1) Annual payroll reflects countywide average annual payroll for all San Francisco workers in 1999 

inflated three percent annually to 2001 dollars. 

(2) Current payroll tax rate in San Francisco County 

Sources: First American Real Estate Solutions; County Business Patterns; U.S. Bureau of the Census, 1999, 

San Francisco, CA; Office of the Treasurer and Tax Collector, City of San Francisco; and Sedway Group.

Summary Tax Implications. Table 5.6-5 summarizes the major annual tax revenues 

attributable to the properties that would be involved in the acquisition process for the Transbay 

Terminal and the Caltrain Downtown Extension. For the Cut-and-Cover Option, these revenues 

total $1.8 million for the Second-to-Main Alternative and $2.6 million for the Second-to-Mission 

Alternative. For the Tunneling Option, these revenues are much lower at approximately $0.9 

million for the Second-to-Main Alternative and $1.5 million for the Second-to-Mission 

Alternative. The net increment attributable to the Transbay Terminal is estimated at 

approximately $250,000.
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.7AIR QUALITY 5-53 

Table 5.6-5: Annual 2001 San Francisco Taxes at 

Risk of Loss Due to Property Acquisitions

Cut-and-Cover Option Tunneling Option Type of 

Tax Second-toMain 

Second-toMission Secondto-Main Second-toMission 

Transbay 

Terminal 

Property $881,109 $1,449,109 $517,379 $841,426 $97,536 

Payroll $849,420 $1,113,060 $330,720 $594,360 $156,000 

Retail 

Sales 

$60,000 $60,000 $53,340 $53,340 $0 

Total $1,790,529 $2,622,169 $901,439 $1,489,126 $253,536 

At worst, all of these revenues would be lost to the City and County of San Francisco following 

acquisition of the properties to construct the Downtown Extension. At least, property taxes – 

which comprise the greatest portion of the total revenues – would be lost during the construction 

period due to public ownership of the property until the extension was constructed. The other 

revenue sources, however, might or might not be interrupted, depending upon whether or not the 

affected businesses and residents were successfully relocated within San Francisco prior to or 

during construction. To the extent they were successfully relocated, there would be no disruption 

in these tax revenues. Alternatively, if all of the businesses were not successfully relocated, some 

portion of the tax revenues would be lost, until such time as the properties were resold and 

redeveloped. 

Given the size and nature of existing development, it is likely that subsequent redevelopment 

would be more intense and would more accurately reflect the highest and best use of the 

properties. Thus, in the long run, the short-term property and other tax losses may be recouped 

and even exceeded. 

5.7 AIR QUALITY 

This section considers long-term impacts and benefits of the three project components with 

regard to regional air quality. It also considers the project’s conformity with the applicable State 

Implementation Plan (SIP), as required by the Clean Air Act amendments of 1993. Impacts are 

assessed by comparing conditions under the No-Project and project alternatives, and by 

comparing projected concentrations of pollutants to the ambient air quality standards (AAQS). 

5.7.1 Regional Air Quality 

Provision of a multi-modal transit facility and extension of Caltrain to Downtown San Francisco 

is projected to reduce the number of miles traveled by autos in the region, which in turn would 

result in an overall reduction of air emissions. This section estimates the direct auto travel and 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-54 5.7 AIR QUALITY 

air emissions reduction anticipated as part of the Caltrain Extension as calculated by the 

transportation modeling and ridership projections. As the Transbay Terminal is a replacement of 

an existing facility, anticipated auto travel reductions were not included in the modeling 

projections. To the extent that a new Terminal would attract new bus riders, auto travel and air 

emissions may be further reduced beyond the estimates provided. 

The proposed redevelopment would generate additional trips, and the air emissions implications 

of these trips at local intersections are evaluated in Section 5.7.2. However, by locating largescale, high density residential, commercial and institutional development near the site of a transit 

hub, the project can be expected to divert to public transit many trips that would otherwise be 

made by the private automobile. This transit-oriented development is expected to improve 

transit’s ability to attract a larger mode share of persons commuting to jobs in the region, in that 

the Terminal and Caltrain Extension would provide an attractive transportation option to the 

automobile for new residents and workers in the area. 

Auto travel and air emission reductions from the Caltrain Downtown Extension. Future 

emissions from automobile traffic were projected to evaluate the effect of the Caltrain 

Downtown Extension, based on projected ridership, which is expected to be identical for both the 

Second-to-Mission and the Second-to-Main alternatives. The effect of the Caltrain Downtown 

Extension on regional emissions of pollutants was calculated based on the number of vehicle 

miles diverted from private automobiles and public buses to the electric-powered trains operating 

on the Downtown Extension. The proposed project is expected to produce a decrease in vehicle 

miles of travel (VMT), and would therefore result in a reduction of emissions associated with 

automobiles. Specifically, the total daily VMT in the region (under either the Second-to-Main or 

Second-to-Mission alternatives) would be about 260,000 less than under the No-Project 

Alternative, including a 3,668 reduction in bus VMT. This decrease would result in incremental 

regional reductions in the projected daily local emissions burden (measured in pounds per day or 

tons per year) of some pollutants, as shown in Table 5.7-1. 

Table 5.7-1: Reductions in Air Pollution Emissions Resulting from the 

Caltrain Downtown Extension [1] 

Pollutant Reduction in Emissions 

(pounds per day) 

Reduction in Emissions 

(tons per year) 

Reactive organic gases (ROG) 329 52 

Carbon monoxide (CO) 5,211 820 

Oxides of nitrogen (Nox) 899 142 

Particulate matter (PM10) 30 5 

Oxides of sulphur (Sox) 18 3 

[1] The results are identical for either Caltrain Downtown Extension alternative (Second-to-Main or Second-toMission). 

Source: Terry A. Hayes Associates, September 2001; Parsons, September 2001 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.7AIR QUALITY 5-55 

5.7.2 Microscale Air Quality 

Existing local carbon monoxide (CO) conditions were assessed using the carbon monoxide 

dispersion computer model CAL3QHC. The model uses state and federally approved emissions 

factors,12 meteorological data, traffic volume, speed, and vehicle mix inputs. The results of the 

model are then added to the background or “ambient” conditions to provide an estimate of local 

conditions. 

Within the urban setting, vehicle exhaust is the main source of CO. Therefore, the highest 

concentrations of CO are found near busy intersections. CO is a localized gas, and its 

concentrations decrease substantially as distance from the source (intersection) increases. To 

provide a worst-case simulation of CO concentrations within the area that may be affected by the 

proposed project, CO concentrations at sidewalks adjacent to eight area intersections were 

modeled. The study intersections (listed in Table 5.7-2 along with existing CO concentrations) 

were selected based on their potential to experience the greatest impacts with regard to volume, 

capacity, and level of service, and are intended to represent the “worst case” for impacts among 

the 27 intersections that were evaluated in the project traffic report.13

Table 5.7-2: Existing (2001) Weekday P.M. Peak Hour Carbon Monoxide 

Concentrations at Study Intersections (ppm)

Highest Concentration at Intersection (ppm)

Study Intersection

1-Hour 

Concentration 

Standard Exceeded? 

 (State-20.0 ppm 

Federal-35 ppm) 

8-Hour 

Concentration 

Standard 

Exceeded? 

(State & Federal-9.0 ppm)

First/Market 11.7 No 8.2 No 

First/Mission 12.4 No 8.7 No 

First/Howard 14.3 No 10.0 Yes 

Beale/Howard 12.0 No 8.4 No 

Second/Folsom 12.7 No 8.9 No 

Second/Harrison 12.1 No 8.5 No 

Fremont/Harrison 10.9 No 7.6 No 

Main/Harrison 10.2 No 7.1 No 

Source: California Air Resources Board and Terry A. Hayes Associates, LLC. September 2001. 

 

12 California Air Resources Board, MVEI7G Emissions Factors, Run, Date: 6/18/01. 

13 Wilbur Smith Associates, Transbay Terminal Area/Caltrain Extension Traffic Analysis, September 7, 2001. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-56 5.7 AIR QUALITY 

5.7.2.1 Existing Carbon Monoxide at Local Intersections 

For each of the eight intersections modeled, traffic-related CO contributions were added to the 

background conditions discussed above. Traffic CO contributions were estimated using the 

CAL3QHC dispersion model. As demonstrated in Table 5.7-2, none of the eight study 

intersections currently exceeds the state or federal one-hour CO concentration standard of 

20.0 ppm. The intersection of First and Howard Streets, however, currently exceeds the state 

and federal eight-hour standard of 9.0 ppm. 

5.7.2.2 Future Carbon Monoxide Concentrations at Study Intersections 

The CAL3QHC micro-scale dispersion model was used to calculate CO concentrations for year 

2020 No-Project Alternative and “project” conditions. The evaluation of project conditions 

assumed the Downtown Extension, with a “worst case”14 development scenario (i.e., maximum 

development) that included the Full-Build Alternative and the Transbay Terminal West Loop 

Alternative. 

Overall, CO concentrations are expected to be lower than existing conditions in the year 2020 

due to stringent state and federal mandates for lowering vehicle emissions. Although traffic 

volumes would be higher in the future both with and without implementation of the proposed 

project, increases in traffic volumes are expected to be offset by increases in cleaner-running cars 

as a percentage of the entire vehicle fleet on the road. 

Projected CO concentrations at the eight “worst case” intersections are shown in Table 5.7-3. As 

indicated, one-hour CO concentrations under project conditions would range from approximately 

4.0 ppm to 5.7 ppm at these intersections. Project eight-hour CO concentrations are anticipated 

to range from approximately 2.8 ppm to 4.0 ppm. The state and federal one-hour standards 

would not be exceeded at any of the eight study intersections. Similarly, none of the eight 

intersections is anticipated to exceed the state or federal eight-hour standard. Incremental 

increases in CO concentrations at all intersections under both the one-hour and eight-hour 

scenario would be less than one part per million. 

 

14

 Maximum development was considered “worst case” for this analysis, because it would generate incrementally more 

automobile trips than the Reduced Scope and Loop Ramp alternatives. Nevertheless, the number of automobile trips generated 

by any of the project alternatives is considered low. As stated in Section 5.19, the traffic analysis assumed a greater transit mode 

share than could be achieved in a location that does not have the transit access of the proposed Transbay Terminal 

Redevelopment Area. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.7AIR QUALITY 5-57 

Table 5.7-3: Future (2020) Weekday P.M. Peak Hour Carbon Monoxide 

Concentrations at “Worst Case” Intersections 

Intersection 1-Hour Concentration (ppm) 8-HourConcentration (ppm) 

No Project With Project [1] Change Impact? No Project With Project [1] Change Impact? 

First/Market 4.6 4.7 0.1 No 3.2 3.3 0.1 No 

First/Mission 4.8 5.0 0.2 No 3.4 3.5 0.1 No 

First/Howard 5.4 5.7 0.3 No 3.8 4.0 0.2 No 

Beale/Howard 4.6 5.0 0.4 No 3.2 3.5 0.3 No 

Second/Folsom 4.8 5.1 0.3 No 3.4 3.6 0.2 No 

Second/Harrison 4.5 4.6 0.1 No 3.2 3.2 0.0 No 

Fremont/Harrison 4.1 4.1 0.0 No 2.9 2.9 0.0 No 

Main/Harrison 3.9 4.0 0.1 No 2.7 2.8 0.1 No 

[1] “Project” includes the Caltrain Downtown Extension, as well as the Redevelopment and Transbay Terminal alternatives 

with the greatest development impact (the Full-Build and West Loop Alternatives) 

Source: Terry A. Hayes Associates, LLC. September 2001.

5.7.3 Supplemental Air Quality Impact Analysis of the Permanent Bus Storage Area 

In response to public comments on the Draft EIS/EIR, a supplemental air quality assessment was 

completed for the proposed permanent mid-day bus storage facility under the West Approach to 

the Bay Bridge between Second and Fourth Streets. The supplemental assessment evaluated the 

effect of the proposed relocation of the Transbay Terminal bus layover and storage area from 

the immediate terminal area to a new location between Second and Fourth Street and north of 

Stillman Street underneath the aerial structure of I-80. The assessment identified the change in 

year 2020 concentrations of three criteria pollutants that would typically have a direct localized 

effect on adjacent sensitive land uses, i.e. carbon monoxide, nitrogen dioxide and PM10. 

Sensitive locations within approximately 500 feet of the relocated bus storage/layover area were 

evaluated. 

The assessment was based on year 2020 diesel bus emission factors as set forth by the California 

Air Resources Board (CARB). These emission factors reflect the projected diesel bus fleet mix 

for the year 2020 and were adjusted to include bus models from the year 2008 until 2020 only, 

which reflects the anticipated fleet mix for the proposed project. CARB considers clean diesel 

technology when calculating its emission factors but does not assume that all buses running in 

the year 2020 will be clean diesel. 

The air quality analysis incorporated meteorological data taken from the Arkansas Street air 

monitoring station, which is approximately one mile south of the proposed bus storage facility. 

Local wind patterns, as measured from the station, were taken into account in order to estimate 

pollution concentrations, including those associated with diesel buses. The analysis took into 

account the cumulative effect of various pollutant sources on the area. Included in the analysis 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-58 5.7 AIR QUALITY 

is the ambient background concentration as measured by the nearest air monitoring station as 

well as pollutant concentrations generated by street traffic and freeway traffic. 

The proposed storage area is currently used for vehicular parking, and an additional vehicular 

parking structure is proposed to replace the existing parking (or a fraction thereof) lost as a 

result of the proposed project. The amount of vehicular parking would remain the same or 

decrease under the proposed Project scenario, and emissions from street traffic, which reflect 

traffic generated by the current parking lots, were included in the overall pollution concentration 

levels projected for future conditions. Thus, impacts from the proposed replacement parking 

structure were considered in the air analysis, and concentration levels due to the proposed 

parking lot would remain equal to or below the amount generated from existing parking. 

The assessment assumed that buses would be running at the storage site for a few minutes each 

day. Specifically, when estimating pollutant concentration, it was assumed that the buses would 

be idling for three minutes and that they would be moving at 15 miles per hour on the dedicated 

ramps – a conservative estimate. It would take between six and 11 minutes for the buses to 

travel to the terminal from the proposed storage facility at this speed. 

The analysis evaluated sensitive receptors within 500 feet of the proposed bus storage facility. 

These sensitive receptors include residences, parks, and schools. The analysis addressed air 

pollution concentrations (including PM10) associated with buses, including pollutant emissions 

associated with diesel exhaust fumes, at the proposed bus storage facility. 

For the sensitive receptor locations identified near the proposed off-site bus storage facility, air 

quality is heavily influenced by three primary sources: (1) vehicular traffic using the grid of 

surface arterials in the area (e.g., Harrison Street, Bryant Street, Brannan Street, etc.); 

(2) traffic volumes on the elevated segment of Interstate 80 that crosses the project area carrying 

between 218,000 to 232,000 vehicles daily; and (3) the volume of urban bus traffic servicing the 

Transbay Terminal. 

The influence and added contribution of these mobile sources on localized pollutant 

concentration levels was calculated using the Industrial Source Complex Short Term Phase 3 

(ISCST3) dispersion model. This model is used throughout California as well as other states to 

compute short term pollutant concentrations from multiple sources on specific locations. The 

United States Environmental Protection Agency (USEPA) recognizes ISCST3 as an accepted 

regulatory air model. 

Table 5.7-4 illustrates year 2020 concentrations, along with their corresponding California 

Ambient Air Quality Standard (CAAQS), of criteria pollutants that would have a direct effect on 

adjacent land uses because of their localized dispersion characteristics. Estimates are given 

both for the bus storage and layover area remaining near its current location as well as for the 

relocated storage area. These estimated Year 2020 concentrations include the ambient 

background plus localized sources modeled in ISCST3 such as surface street traffic, freeway 

traffic and bus operations surrounding the Transbay Terminal area. Ambient background 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.7AIR QUALITY 5-59 

concentrations were added to ensure that a worst-case scenario would be calculated. The 

ISCST3 model calculated year 2020 pollutant concentrations through the inclusion of several 

line and area sources of pollutant emissions. Line sources included emissions from local street 

traffic within 500 feet of the storage facilities, emissions from bus traffic along access ramps 

leading in and out of existing and future facilities, bus circulation within the new storage areas, 

and freeway traffic from the elevated freeway. Area sources included emissions from idling 

buses in the current and future bus storage areas. 

Pollution rates were derived using San Francisco County EMFAC2002 emission factors for the 

year 2020. For vehicle emissions on local streets and on the freeway, peak hour traffic volumes 

were multiplied by emission factors for model years 1975 (the earliest year in the model) to 

2020. Bus emissions were calculated based on information provided for both AC Transit and 

Golden Gate Transit that included bus model years, fuel type, and the number of buses in use 

during peak hours. Bus emission factors were calculated based on the assumption that all buses 

in use in the year 2020 would be model year 2008 or higher and would be diesel buses. 

Urban diesel bus idling emission factors are not provided by EMFAC2002. School diesel bus 

idling emission factors, however, are calculated in EMFAC2002. The characteristics of school 

diesel buses most closely match those of urban diesel buses, and for purposes of this analysis, 

idling emission factors for diesel school buses were substituted for the missing urban diesel bus 

emission factors. By using these emission factors, a worst-case scenario is anticipated in that 

urban buses are expected to be technologically superior to school buses in limiting the amount of 

pollutant emissions, and school buses would most likely generate higher pollutant 

concentrations. 

As shown on the table, the supplemental air quality analysis concluded that pollutant 

concentrations would not exceed the CAAQS, which are designated to protect public health with 

an adequate margin of safety, and thus, would not have an adverse impact at any sensitive 

receptor locations. Additional information can be found in the Supplemental Air Quality 

Analysis Report, which is available for review by appointment at the Planning Department. 

An important design feature of the bus storage facilities is the addition of a sound wall along the 

south perimeter of the area to mitigate noise impacts on surrounding residents (see 

Section 5.8.6). The sound wall would also serve the dual purpose of changing the dispersion 

pattern and effectively elevating the release height of pollutant emissions from buses circulating 

and idling in the bus storage area. Thus, the emission release height would be equal to the 

height of the wall. The higher the release height, the lower the pollutant concentration would be 

at adjacent sensitive receptors. 

Pollutant concentrations at all receptors are expected to remain below the applicable CAAQS 

even without the inclusion of the sound wall. Therefore, the sound wall will provide even further 

assurance that pollution levels would not adversely affect residents adjacent to the bus storage 

facilities. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-60 5.7 AIR QUALITY 

Table 5.7-4: Estimated Year 2020 Concentrations With and Without Bus Layover 

Storage Relocation [b]

Sensitive Receptors

CO (1 hr) 

ppm 

(CAAQS = 20)

CO (8-hr) 

ppm 

(CAAQS = 9)

NOX (1-hr) 

ppm 

(CAAQS = 0.25)

PM10 (24-hr) 

ug/m3 

(CAAQS = 50)

ID Type w/o with w/o with w/o with w/o with

1 Residential-2nd and Bryant 

Streets 

2 2 2 2 0.14 0.20 31 30 

2 Residential-Stillman St. 

Between 2nd & 3rd Sts. 

2 2 2 2 0.14 0.15 31 31 

3 Residential-Stillman St. 

Between 2nd & 3rd Sts. 

2 2 2 2 0.14 0.14 31 30 

4 Residential-3rd and Stillman 

Streets 

2 2 2 2 0.13 0.15 30 30 

5 Residential-3rd and Bryant 

Streets 

2 2 2 2 0.11 0.12 29 29 

6 Residential-Bryant St. 

Between 2nd and 3rd

2 2 2 2 0.11 0.11 29 29 

7 Residential-Bryant St. 

Between 2nd & 3rd Sts. 

2 2 2 2 0.11 0.11 28 28 

8 Residential-Bryant St. 

Between 2nd & 3rd Sts. 

2 2 2 2 0.11 0.12 29 29 

9 Residential-Park Ave. 

Between 2nd & 3rd Sts. 

2 2 2 2 0.11 0.11 28 28 

10 Residential-Park Ave. 

Between 2nd & 3rd Sts. 

2 2 2 2 0.10 0.11 28 28 

11 Residential-Park Ave. 

Between 2nd & 3rd Sts. 

2 2 2 2 0.10 0.11 28 28 

12 Park 2 2 1 1 0.09 0.10 27 27 

13 Residential-3rd St. Between 

Bryant and Brannan Streets 

2 2 1 1 0.09 0.10 27 27 

14 Residential-3rd and Harrison 

Streets 

2 2 2 2 0.13 0.16 30 31 

15 Residential 3rd and Harrison 

Streets 

2 2 2 2 0.11 0.11 29 29 

16 School 2 2 2 2 0.11 0.11 28 28 

/a/ Concentrations include ambient background concentrations added to the concentrations calculated by the ISCST3 model 

for each pollutant. 

Source: Terry A Hayes Associates LLC 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.7AIR QUALITY 5-61 

The potential impact of pollutant trapping inside the storage area due to the sound wall and 

overhead freeway is regulated by the U.S. Occupational Safety and Health Administration’s 

(OSHA) standards for air toxic exposure in the work place. OSHA has determined the interior 

threshold levels of CO, NOx, and PM10 air concentrations to be 50 ppm, 5 ppm, and 5000 

μg/m3 respectively. These standards are well above the projected concentration levels of the 

pollutants inside the storage facility, as determined by the supplemental air quality impact 

analysis. Thus, no adverse air quality impact based on these standards would be anticipated. 

Should pollutant concentration levels exceed these limits, OSHA has established appropriate 

procedures for ventilating such pollutants to acceptable levels. 

The criteria used to evaluate air quality impacts from the proposed project are the CAAQS. 

These outdoor air quality standards are adopted by the State's enforcement agency, the CARB, 

as provided for in the California Health and Safety Code section 39606. These standards set 

legal limits on outdoor air pollution and are designed to protect public health and welfare. 

Ambient air quality standards define clean air, and are established to protect even the most 

sensitive individuals. Typically, the outdoor CAAQS are more stringent and provide a wider 

margin of safety than indoor air quality standards promulgated by such agencies as OSHA. 

An air quality standard defines the maximum amount of a pollutant that can be present in 

outdoor air without harm to the public's health. The standards are based on the CARB's ongoing review of scientific studies on the health effects of individual air pollutants. As new 

scientific information on public health consequences becomes available the CAAQS are 

periodically revised. In light of new information and studies, CARB is responsible for 

determining whether CAAQS need to be revised to adequately protect human health, particularly 

sensitive population groups. For example, The Children's Environmental Health Protection Act 

(CEHPA, California Senate Bill 25, Escutia 1999) required the CARB and other state agencies 

to evaluate all ambient air quality standards by December 2000 to determine whether these 

standards adequately protect human health, particularly that of infants and children. The 

CEHPA also required staff to prioritize those standards found to be inadequate for full review 

and possible revision. The evaluation found that health effects may occur in infants, children, 

and other potentially susceptible groups exposed to pollutants at levels near several of the 

current standards, with PM10, ground-level ozone (O3) and nitrogen dioxide (NO2) receiving 

the highest priority for review and revision. 

5.7.4 Conformity Assessment 

FTA cannot approve funding for project activities beyond preliminary engineering until it has 

reviewed the project in accordance with the Environmental Protection Agency (EPA) 

transportation air quality conformity regulations (40 CFR Part 93) and has found that the project 

conforms. This regulation, which became effective in December 1993, establishes criteria for 

project conformity that cover all possible situations. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-62 5.7 AIR QUALITY 

The RTIP has been demonstrated by MTC to conform to the state air quality implementation 

plan (SIP) for the Bay Area Air Basin. The carbon monoxide modeling results presented in 

Table 5.7-3 demonstrate that the Terminal/Extension Project will neither cause nor contribute to 

any carbon monoxide violations in the year 2020. The conformity criteria that the 

Terminal/Extension Project must satisfy and the status of the project in meeting these criteria are 

as follows. 

•§93.110 The conformity determination must be based on the latest planning assumptions. 

Assumptions used in the transportation and traffic analyses for this project, upon which the 

microscale carbon monoxide and regional criteria pollutant analyses are based, are derived from 

the MTC's most recently adopted population, employment, travel, and congestion estimates. 

Travel forecasts are based on MTC's growth assumptions for the Year 2020. 

•§93.111 The conformity determination must be based on the latest emission estimation 

model available. 

All emissions estimates are based on the latest available version of the California Air Resources 

Board's model. Carbon monoxide modeling was conducted using the CAL3QHC model. 

•§93.112 The Metropolitan Planning Organization must make the conformity determination 

according to the consultation procedures of this rule and the implementation plan revision 

required by §51.390. 

The most current SIP is called the Revised 2001 Bay Area Ozone Attainment Plan, which was 

adopted by the MTC, ABAG, and BAAQMD in October 2001 and by ARB in November 2001. 

The EPA’s approval of the Bay Area mobile source emissions budget was published in the 

Federal Register in February 2002 allowing MTC to make a conformity finding on the 2001 

RTP. MTC’s, FHWA’s and FTA’s conformity approval in March 2002 lifted the conformity 

lapse that had existed in the region since January 2002.15 MTC’s followed the consultation 

procedures in 40 CFR Part 93, as amended. 

•§93.114 There must be a currently conforming transportation plan and currently 

conforming TIP at the time of project approval. 

The current transportation plan and TIP are, respectively, the 2001 Regional Transportation Plan 

(RTP) and the 2003 Regional Transportation Improvement Program (RTIP). The air quality 

conformity analysis for the 2001 RTP was approved by MTC in March 2002. The 2003 TIP was 

federally approved in February 2003. The proposed project is included in the 2003 TIP. 

 

15 Under new FHWA/FTA guidance, circulation of this draft EIS/EIR would have been allowed, with or without a conformity 

lapse. However, FTA can make a finding of conformity in the Final EIS/EIR for this project only following the lifting of the 

conformity lapse. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.7AIR QUALITY 5-63 

•§93.115 The project must come from a conforming transportation plan and program. 

The Transbay Terminal / Caltrain Downtown Extension / Redevelopment Project is included as 

one of the top funding priorities in the financially constrained portion (called “Track 1”) of the 

Regional Transit Expansion Policy (RTEP).16 The RTEP is the transit element of the 2001 

Regional Transportation Plan (RTP). The 2001 RTP, including the RTEP, was adopted by the 

MTC in December 2001. 

•§93.116 The FHWA/FTA project must not cause or contribute to any new localized carbon 

monoxide or PM10 violations or increase the frequency or severity of any existing carbon 

monoxide and PM10 violations in carbon monoxide and PM10 nonattainment and maintenance 

areas. 

By its nature, the Terminal/Extension Project would result in changes in travel patterns and 

concentrations of motor vehicle traffic in the vicinity of the Transbay Terminal area, which 

would cause small increases in pollutant concentrations for these road segments, but no standards 

would be violated. At the same time, the proposed project would result in a decrease in regional 

vehicle trips and vehicle miles of travel, which would reduce the emission of criteria pollutants, 

when compared to the No-Project Alternative. 

The microscale carbon monoxide analysis indicates that the project would neither cause nor 

contribute to new carbon monoxide violations during operation. The source of PM10 emissions 

typically associated with transportation is the effect of tires stirring up dust on roadways. PM10

is not associated with electric commuter rail transit operations. The project can be considered 

beneficial in terms of PM10, in that it would remove vehicle trips from area roadways. 

•§93.117 The FHWA/FTA project must comply with PM10 control measures in the 

applicable implementation plan. 

The project would comply with all PM10 control measures in the most recent SIP document for 

the region. 

•§93.118 The transportation plan and TIP must be consistent with the motor vehicle 

emissions budget(s) in the applicable implementation plan (or implementation submission). 

The RTP and RTIP are consistent with the motor vehicle emissions budget in the applicable 

implementation plan, as indicated by the MTC’s approval of the conformity analysis in 

December 2001. 

 

16 The Project is identified as the “Caltrain Downtown Extension/Rebuilt Transbay Terminal” in the RTEP and 

RTP. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-64 5.8 NOISE AND VIBRATION 

No exceedences of state or federal AAQS are projected under either alternative in the future 

analysis year of 2020, and no mitigation is proposed for long-term air quality effects resulting 

from project operation. 

5.8 NOISE AND VIBRATION 

This section analyzes anticipated increases in noise and vibration resulting from the proposed 

project. Sources of noise and vibration considered include airborne noise from trains operating 

along Seventh and Townsend Streets south and west of the subway portal near Fifth Street, 

traffic noise from any increases in traffic volumes or changes in traffic patterns, storage yard 

noise, and ground-borne vibration from trains operating both above and below ground. 

5.8.1 Sensitive Receptors 

A visual survey of the project area was conducted to determine the location of residential land 

uses (including live/work units) that might be affected by changes in noise or vibration. Noise 

monitoring sites identified in Section 4.7 and shown in Figure 4.7-1 were selected to satisfy the 

conditions of being noise-sensitive receptors and being representative of other neighborhoods in 

the study area with similar noise characteristics. Residential land uses are generally considered 

most sensitive to changes in noise and vibration, except where research or manufacturing 

activities require vibration sensitive instrumentation or where background noise can pose a 

problem, such as in recording studios. Although multi-media companies are located within the 

study area, their operations are not uniquely sensitive to outside noise and vibration except where 

studio recordings are being prepared. Based on a visual survey of the study area, the closest 

recording studio is approximately 700 feet from the proposed Caltrain Downtown Extension 

alignments, and impact from rail noise or vibration is therefore extremely unlikely. 

5.8.2 FTA Criteria for Noise and Vibration 

The FTA noise impact criteria17 are founded on well-documented research on community 

reaction to noise and are based on change in noise exposure using a sliding scale. The amount 

that the transit project is allowed to change the overall noise environment is reduced with 

increasing levels of existing noise. FTA's noise criteria consider the combination of existing 

noise exposure and project-specific increases in relation to three sensitive land use categories: 

• Category 1: buildings or parks where quiet is an essential element of their purpose; 

• Category 2: residences and buildings where people normally sleep; and 

• Category 3: institutional land uses with primarily daytime and evening use (e.g., 

schools, libraries, churches). 

 

17 Transit Noise and Vibration Impact Assessment, Federal Transit Administration, 1995. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.8NOISE AND VIBRATION 5-65 

There are two levels of impact included in the FTA criteria: “severe” and “impact”: 

• Severe: Severe noise impacts are considered "significant" as this term is used in the 

National Environmental Policy Act (NEPA) and implementing regulations. Noise 

mitigation will normally be specified for severe impact areas unless there is no practical 

method of mitigating the noise. 

• Impact: This range is sometimes referred to as moderate impact. In this range, other 

project-specific factors are considered to determine the magnitude of the impact and the 

need for mitigation. Other factors can include predicted increases over existing noise 

levels, types and numbers of noise-sensitive land uses affected, existing outdoor-indoor 

sound insulation, and the cost effectiveness of mitigating noise to more acceptable levels. 

Noise impact criteria are summarized in Table 5.8-1. The first column shows the existing noise 

exposure, and the remaining columns show the additional noise exposure caused by the transit 

project. Future noise exposure would be the combination of the existing noise exposure and the 

additional noise exposure caused by the project. 

Table 5.8-2 gives the information from Table 5.8-1 in terms of the allowable increase in 

cumulative noise exposure (noise from existing sources plus project noise) as a function of 

existing noise exposure. As the existing noise exposure increases, the amount that the transit 

project can increase the overall noise exposure before there is impact decreases. 

Vibration criteria for three categories of sensitive receptors are summarized in Table 5.8-3. 

Ground-borne vibration from transit trains is characterized in terms of the root mean square 

(RMS) vibration velocity amplitude. A one second RMS time constant is assumed. This is in 

contrast to vibration from blasting and other construction procedures that have the potential of 

causing building damage. It is very rare that ground-borne vibration from any type of train 

operations will be high enough to cause any sort of building damage, even minor cosmetic 

damage. The only real concern is that the vibration will be intrusive to building occupants or 

interfere with vibration sensitive equipment. 

The threshold of vibration perception for most humans is around 65 VdB, levels in the 70 to 75 

VdB range are often noticeable but acceptable, and levels in excess of 80 VdB are often 

considered unacceptable. For urban transit systems with 10 to 20 trains per hour throughout the 

day, limits for acceptable levels of residential ground-borne vibration are usually between 70 and 

75 VdB. 

For human annoyance, there is some relationship between the number of events and the degree 

of annoyance caused by the vibration. More frequent vibration events, or events that last longer, 

will be more annoying to building occupants. To account for this effect, FTA’s Guidance 

Manual includes an eight VdB higher impact threshold if there are fewer than 70 trains per day. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-66 5.8 NOISE AND VIBRATION 

Because it is projected that as many as 132 trains per day would eventually use the proposed 

tunnel, the adjustment for infrequent events is not applicable. 

Table 5.8-1: FTA Noise Impact Criteria 

Project Noise Exposure Impact Thresholds (dBA) 

Category 1 or 2 Sites Category 3 Sites 

Existing Noise 

Exposure* 

Leq or Ldn Impact Severe Impact Impact Severe Impact 

<43 Amb.+10 Amb.+15 Amb.+15 Amb.+20 

43-44 52 58 57 63 

45 52 58 57 63 

46-47 53 59 58 64 

48 53 59 58 64 

49-50 54 59 59 64 

51 54 60 59 65 

52-53 55 60 60 65 

54 55 61 60 66 

55 56 61 61 66 

56 56 62 61 67 

57-58 57 62 62 67 

59-60 58 63 63 68 

61-62 59 64 64 69 

63 60 65 65 70 

64 61 65 66 70 

65 61 66 66 71 

66 62 67 67 72 

67 63 67 68 72 

68 63 68 68 73 

69 64 69 69 74 

70 65 69 70 74 

71 66 70 71 75 

72-73 66 71 71 76 

74 66 72 71 77 

75 66 73 71 78 

76-77 66 74 71 79 

>77 66 75 71 80 

Notes: * Ldn is used for land uses where nighttime sensitivity is a factor; 1-hour Leq is used for 

land use involving only daytime activities. 

Source: Transit Noise and Vibration Impact Assessment, Federal Transit Administration, 1995.
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.8NOISE AND VIBRATION 5-67 

Table 5.8-2: Increase in Cumulative Noise Levels Allowed by 

FTA Criteria 

Impact Threshold for Increase in 

Cumulative Noise Exposure(dBA) 

Category 1 and 2 Sites Category 3 Sites 

Existing Noise 

Exposure* 

Leq or Ldn Impact Severe Impact Impact Severe Impact 

45 8 14 12 19 

46 7 13 12 18 

47 7 12 11 17 

48 6 12 10 16 

49 6 11 10 16 

50 5 10 9 15 

51 5 10 8 14 

52 4 9 8 14 

53 4 8 7 13 

54 3 8 7 12 

55 3 7 6 12 

56 3 7 6 11 

57 3 6 6 10 

58 2 6 5 10 

59 2 5 5 9 

60 2 5 5 9 

61 1.9 5 4 9 

62 1.7 4 4 8 

63 1.6 4 4 8 

64 1.5 4 4 8 

65 1.4 4 3 7 

66 1.3 4 3 7 

67 1.2 3 3 7 

68 1.1 3 3 6 

69 1.1 3 3 6 

70 1.0 3 3 6 

71 1.0 3 3 6 

72 0.8 3 2 6 

73 0.6 2 1.8 5 

74 0.5 2 1.5 5 

75 0.4 2 1.2 5 

Notes: 

* Ldn is used for land uses where nighttime sensitivity is a factor; 1-hour Leq is used for 

land use involving only daytime activities. 

Source: Transit Noise and Vibration Impact Assessment, Federal Transit 

Administration, 1995.FTA Noise/Vibration Criteria, 2001. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-68 5.8 NOISE AND VIBRATION 

Table 5.8-3: Ground-Borne Vibration and Noise Impact Criteria 

Ground-Borne Vib. Impact 

(VdB re 1 micro-inch/sec) 

Ground-Borne Noise Impact 

(dB re 20 micro-Pascals) 

Land Use Category 

Frequent [1]

Events 

Infrequent [2]

Events 

Frequent [1] 

Events 

Infrequent [2]

Events 

Category 1: Buildings where low 

ambient vibration is essential for interior 

operations. 

65 VdB [3] 65 VdB[3] - [4] - [4] 

Category 2: Residences and buildings 

where people normally sleep. 72 VdB 80 VdB 35 dBA 43 dBA 

Category 3: Institutional land uses with 

primarily daytime use. 75 VdB 83 VdB 40 dBA 48 dBA 

Notes: 

[1] Frequent Events" is defined as more than 70 vibration events per day. Most rapid transit projects fall into this category.

[2] "Infrequent Events" is defined as fewer than 70 vibration events per day. This category includes most commuter rail 

systems. 

[3] This criterion limit is based on levels that are acceptable for most moderately sensitive equipment such as optical 

microscopes. Vibration sensitive manufacturing or research will require detailed evaluation to define the acceptable vibration

levels. Ensuring lower vibration levels in a building often requires special design of the HVAC systems and stiffened floors. 

[4] Vibration-sensitive equipment is not sensitive to ground-borne noise. 

Source: Transit Noise and Vibration Impact Assessment, Federal Transit Administration, 1995. 

There are some buildings, such as concert halls, TV and recording studios, and theaters that can 

be very sensitive to vibration and noise but do not fit into any of the three categories shown in 

Table 5.8-3. Because of the sensitivity of these buildings, they usually warrant special attention 

during the environmental assessment of a transit project. Table 5.8-4 gives criteria for 

acceptable levels of ground-borne vibration and noise for various types of special buildings. 

Table 5.8-4: Ground-Borne Vibration and Noise Impact Criteria for 

Special Buildings 

Ground-Borne Vibration Impact Levels

(VdB re 1 micro-inch/sec) 

Ground-Borne Noise Impact Levels

(dB re 20 micro-Pascals) Type of Building or Room Frequent [1] 

Events 

Infrequent [2] 

Events 

Frequent [1] 

Events 

Infrequent [2]

Events 

Concert Halls 

TV Studios 

Recording Studios 

Auditoriums 

Theaters 

65 VdB 

65 VdB 

65 VdB 

72 VdB 

72 VdB 

65 VdB 

65 VdB 

65 VdB 

80 VdB 

80 VdB 

25 dBA 

25 dBA 

25 dBA 

30 dBA 

35 dBA 

25 dBA 

25 dBA 

25 dBA 

38 dBA 

43 dBA 

Notes: [1] "Frequent Events" is defined as more than 70 vibration events/day. Most transit projects fall into this category.

[2] "Infrequent Events" is defined as fewer than 70 vibration events/day. This category includes most commuter rail systems. 

[3] If the building will rarely be occupied when the trains are operating, there is no need to consider impact. As an example,

consider a commuter rail line next to a concert hall. If no commuter trains will operate after 7 pm, it should be rare that the 

trains interfere with the use of the hall. 

Source: Harris Miller Miller and Hanson, 2001
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.8NOISE AND VIBRATION 5-69 

5.8.3 Train Noise 

The Caltrain Downtown Extension is the only component of the proposed project that would 

result in train noise. For both the Second-to-Main and Second-to-Mission Alternative, the 

proposed rail line would be in a tunnel, except for a short section south of the intersection of 

Seventh Street and Townsend Street. This is the only track section where train operations have 

potential to create noise impact. The land use along this segment of the alignments is almost 

exclusively commercial and industrial. In a walking survey, the closest noise sensitive receptors 

were found to be live/work lofts on Townsend Street, more than 1,500 feet from the subway 

portal. There is no impact predicted at this building from the train noise. 

5.8.4 Traffic Noise 

5.8.4.1 Methodology 

The traffic noise impact assessment was based on a comparison of the Transbay Terminal/ 

Caltrain Downtown Extension/Redevelopment Alternatives to the No-Project Alternative. A 

screening procedure was used to locate areas of potential noise impact where a more detailed 

assessment of traffic noise may be required. Areas were identified in which the projected 

increase in traffic volume (under the “worst case conditions” – i.e., Full Build Alternative) could 

cause a noticeable increase in noise exposure at residential land uses and other noise-sensitive 

receptors in the study area. It is generally assumed that a two to three dBA increase in noise 

exposure is required before residents consider the increase to be of any consequence. This 

translates to an increase in traffic volume of at least 60 percent before there is potential for noise 

impact. The screening procedure used was based on the logarithmic ratio of the project 

alternatives to the No-Project Alternative. The formula used was: 

Approximate Change in Noise Exposure = 10 x log (No. of vehicles/No. of base vehicles). 

All areas where the approximate increase in noise exposure exceeded one dBA were identified. 

The Full Build Alternative and No-Project traffic volumes were derived from the one-hour 

turning movements results for all the streets in the study area using the traffic studies performed 

by the San Francisco County Transportation Authority. This included numbers for afternoon and 

morning peak hours. 

5.8.4.2 Results of Traffic Noise Analysis 

The noise predicted at each of the street sections for the project alternatives was compared to the 

future No-Project Alternative. Results of the traffic noise analysis are summarized in 

Table 5.8-5. The table lists street sections and corresponding cross streets where there is at least 

a one dBA increase in either direction. The numbers for both directions are included to provide a 

complete picture along the segment being analyzed. The modeled number of vehicles for the 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-70 5.8 NOISE AND VIBRATION 

Full Build and No-Project Alternatives are also shown. The last column shows the decibel 

increase (or decrease, as the case may be) for the build Alternatives as compared to the NoProject Alternative. A traffic volume increase of 25 percent or greater is necessary for a onedecibel increase in noise exposure. 

Table 5.8-5: Summary of Traffic Noise Analysis 

TOTAL Vehicles 

Street Dir. From Street To Street No Project Build 

Approximate 

Change in 

Noise Level (dBA)

Weekday PM Peak Hour 

NE First St. Fremont St. 639 817 1 1. Mission St. SW Fremont St. First St. 637 700 0 

SW Beale St. Fremont St. 1461 1843 1 2. Howard St. NE Fremont St. Beale St. 350 390 0 

SW Main St. Beale St. 830 1324 2 3. Howard St. NE Beale St. Main St. 410 455 0 

4. Folsom St. NE First St. Fremont St. 1063 1345 1 

5. Folsom St. NE Fremont St. Beale St. 1015 1272 1 

SW Spear St. Main St. 136 290 3 6. Folsom St. NE Main St. Spear St. 780 878 1 

NE Spear St. The Embarcadero 967 1086 1 7. Folsom St. SW The Embarcadero Spear St. 183 264 2 

NE First St. Fremont St. 84 130 2 8. Harrison St. SW Fremont St. First St. 1431 1547 0 

9. Beale St. SE Howard St. Folsom St. 975 1314 1 

10. Spear St. SE Howard St. Folsom St. 563 813 2 

SE Folsom St. Harrison St. 195 252 1 11. Main St. NW Harrison St. Folsom St. 334 456 1 

Source: San Francisco County Transportation Authority, Harris Miller Miller & Hanson, Wilbur Smith 

Associates, 2001. 

There are a total of eleven road segments where a noise exposure increase of one decibel or 

greater is projected for the build alternatives during the weekday PM peak hour. The areas with 

the greatest traffic increases and the potential for noise impacts are: 

• Mission Street between First Street and Fremont Street. The land use in this area is 

almost exclusively commercial and office space. No noise impact from the increased 

traffic noise is projected. 

• Howard Street between Fremont Street and Main Street. There are no noise-sensitive 

receptors in this area. 

• Folsom Street between First Street and Beale Street. The land use in this area is 

primarily office space, industrial space, and parking, with some residential space near 

Folsom and Beale Streets. No noise impact from the increased traffic noise is projected. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.8NOISE AND VIBRATION 5-71 

• Folsom Street between Main Street and The Embarcadero. The land use in this area is 

mostly office space and parking. Between Main and Spear Streets, the hourly traffic 

volume in the southwest direction is projected to increase from 136 vehicles per hour to 

290 vehicles per hour. Since traffic volume in the opposite direction is approximately 

800 to 900 vehicles per hour, the volume increase in the southwest direction will not 

contribute significantly to noise exposure when compared to the volume in the northeast 

direction. Therefore, no noise impact from the increased traffic noise is projected. 

• Harrison Street between First Street and Fremont Street. The hourly traffic volume in the 

northeast direction is projected to increase from 84 vehicles per hour to 130 vehicles per 

hour. Since traffic volume in the opposite direction is approximately 1,500 vehicles per 

hour for the No-Project Alternative, the volume increase in the northeast direction will 

not affect overall noise exposure and no impact is projected. 

• Beale Street between Howard Street and Folsom Street. There are no noise-sensitive 

receptors in this area. 

• Spear Street between Howard Street and Folsom Street. The land use in this area is 

mostly office space. No noise impact from the increased traffic noise is projected. 

• Main Street between Folsom Street and Harrison Street. The land use in this area is 

mostly office space and parking. No noise impact from the increased traffic noise is 

projected. 

In no case does the projected noise exposure increase exceed one decibel in both directions. In 

residential areas, the projected change in noise exposure does not exceed one decibel. In other 

office, industrial, commercial, and parking areas, the projected change in noise exposure does 

not exceed three decibels. The potential noise exposure increase for all other road segments is 

clearly below FTA impact thresholds. 

5.8.5 Caltrain Storage Yard Noise 

Normally storage yards and layover facilities can be a significant source of noise because much 

of the activity takes place during nighttime or early morning hours. Diesel locomotives are 

required to idle for a short amount of time before starting revenue service operations and are 

usually a source of annoyance near storage yards. 

A live/work loft at 388 Townsend Street is currently the only residential area near the planned 

storage yard. A lot located to the southwest is expected to undergo residential development in the 

near future and was included in the noise assessment. Under existing conditions, noise at both 

the live/work loft on Townsend and the proposed new residential development is often 

dominated by Caltrain noise, trains entering or departing the station, or idling locomotives. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-72 5.8 NOISE AND VIBRATION 

Projections are that the proposed project will result in lower noise levels at both noise sensitive 

receptors near the storage yard because most locomotives would be electric instead of the current 

diesel. This would virtually eliminate the noise from idling locomotives. 

5.8.6 Bus Storage Facility Noise 

Noise would also be generated by operations at the bus storage facilities proposed beneath the 

Bay Bridge approach (between Fourth and Third Streets, between Third and Second Streets, and 

immediately east of Second Street). Noise would occur as vehicles enter and exit these storage 

lots, and while engines warm up before starting revenue operations. 

In response to public comment on the Draft EIS/EIR, a supplemental noise assessment was made 

of the proposed permanent off-site bus storage facility under the Western Approach to the Bay 

Bridge between Second and Fourth Streets. The assessment was conducted using bus source 

noise levels and noise projection formulas contained in the FTA Guidance Manual. Noise 

projections were made for noise sensitive receptors near the bus storage facility and compared 

with the appropriate impact criteria. Where noise impact is projected, mitigation measures are 

recommended. 

Existing noise conditions were based on the nearest long-term noise measurement conducted as 

a part of the noise and vibration study for the EIS/EIR. Long-term (24-hour) noise 

measurements were made in July 1995 at a parking lot near the intersection of Brannan and 

Second Street. This measurement was used to characterize the ambient noise at sensitive 

receptors near the proposed bus storage facility. 

Since the bus facility would be in use only during the morning and evening peak-hour periods, 

the noise assessment was based on the existing ambient hourly Leq for the hours of operation of 

the bus storage facility. Table 5.8-6 summarizes the measurement results for the time periods 

that the bus storage facility would be in use. The hourly Leqs shown in the table were used in 

the assessment of noise impact at sensitive receptors near the bus storage facility. 

Table 5.8-6: Existing Noise Levels 

Site # Location Date Time Hourly Leq 

(dBA) 

7/95 7:00am 64 

7/95 8:00am 68 

7/95 4:00pm 61 

7/95 5:00pm 61 

1 Parking Lot (Brannan & Second) 

7/95 6:00pm 62 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.8NOISE AND VIBRATION 5-73 

The methodology used for the impact assessment follows that described in the detailed noise 

assessment section of the FTA Guidance Manual. Projections of Project noise levels from the 

bus storage facility were based on source noise levels contained in the FTA Guidance Manual 

and formulas for projecting noise from both bus idling and bus operations. The operations data, 

including information on the number of buses using the facility, bus speeds in the facility and on 

the ramp, and durations of bus idling in the facility during the afternoon is based on the terminal 

facility operations assumed as part of the Project. For purposes of analysis, it was assumed that 

approximately 104 buses (71 Golden Gate Transit buses and 33 AC Transit buses) would enter 

the proposed storage facility in the peak morning hour of 8:00 AM. In addition, a total of 119 

buses (67 Golden Gate Transit buses and 52 AC Transit buses) would leave the proposed 

storage facility, and a total of 57 AC Transit buses would arrive at the proposed storage facility 

during the peak afternoon hour of 4:00 PM. Buses were assumed to be traveling at a speed of 

15 mph on average and idling for approximately three minutes in the storage facility before 

leaving in the afternoon. In the morning, Golden Gate Transit buses would gain access the 

storage facility via Fourth Street at Perry and AC Transit buses would gain access to the facility 

via the ramp structure east of Second Street. In the afternoon, both the Golden Gate Transit and 

AC Transit buses would use the dedicated ramp when leaving the proposed storage facility. 

The projected noise levels for the peak hour of activity (4:00 PM) at the closest noise-sensitive 

receptors adjacent to the storage facility are shown in Table 5.8-7. The results indicate that 

noise impacts are projected at residences to the north and south of the AC Transit storage 

facility. 

Table 5.8-7: Bus Storage Facility Projected Noise Levels 

Sound Level 

(Leq, dBA) 

FTA Noise Impact 

Location Criteria (Leq, dBA) 

Existing Project Impact Severe 

Impact?

Residences North of AC Transit Facility at 

Perry and Third Street 61 66 59 64 Severe

Residences South of AC Transit Facility along 

Stillman Street 61 62 59 64 Impact

Residences South of the Golden Gate Transit 

Facility along Stillman Street 61 59 59 64 Impact

Residences South of AC Transit Facility along 

Stillman Street 61 55 59 64 No 

Source: Harris Miller Miller, Hanson, 2003. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-74 5.8 NOISE AND VIBRATION 

5.8.7 Noise Mitigation 

Based on this analysis, there appears to be no need to mitigate train noise, traffic noise, or 

Caltrain storage yard noise. 

Based on the results of the noise assessment, mitigation is recommended at three locations 

adjacent to the bus storage facility. The proposed noise mitigation locations are: 

• Residences North of the AC Transit Facility. Severe noise impact is projected for the 

residences to the north of the AC Transit facility at the corner of Perry and Third Street. 

Because of the configuration of the site, noise barriers are not an option for noise 

mitigation. Therefore, sound insulation will be installed to mitigate the noise impacts at 

this location. At a minimum, sound insulation will be applied to the façade facing the bus 

storage facility (the south façade). 

• Residences South of the AC Transit Facility. Noise impact is projected for the residences 

to the south of the AC Transit facility along Stillman Street. For these residences, a 

combination of two barriers would mitigate the noise impacts. The first noise barrier 

will be approximately 10-12 feet high and run along the southern edge of the AC Transit 

storage facility. The second noise barrier will be approximately 5-6 feet high and will be 

located on the portion of the ramp at the southwestern corner of the AC Transit facility. 

To minimize the potential for reflections off the underside of the freeway, noise barriers 

will be treated with an absorptive material on the side facing the facility. 

• Residences South of the Golden Gate Transit Facility. Noise impact is projected for the 

residences to the south of the Golden Gate Transit facility along Stillman Street. A noise 

barrier would mitigate the impacts. The barrier will be approximately 10-12 feet high 

and run along the southern and a portion of the eastern edge of the Golden Gate Transit 

storage facility. To minimize the potential for reflections off the underside of the freeway, 

the noise barriers will be treated with an absorptive material on the side facing the 

facility. 

Noise walls will be landscaped, although the actual design will be developed in cooperation with 

area residents. The walls will be constructed prior to the development of the permanent bus 

facilities. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.8NOISE AND VIBRATION 5-75 

5.8.8 Ground-Borne Vibration 

5.8.8.1 Methodology 

The ground-borne vibration and ground-borne noise projections are based on the force density 

curve developed from train noise tests described in Section 4.7, and based on transfer mobility 

data derived from vibration propagation tests described in Section 4.7. One factor that the 

vibration analysis has not been able to account for is that only electric locomotives would be 

used in the new tunnel, and these electric-powered locomotives will generate different vibration 

levels than the existing diesel locomotives. 

Another factor that could not be accounted for is that, in many cases, the subway structure will 

be founded in bedrock and the building foundations will be in soil, sometimes supported by piles 

that have been driven down to the bedrock. The vibration path from the subway foundation 

though the bedrock, into the soil overburden and finally into the building foundation will tend to 

be a less efficient vibration path than what was measured at the vibration test sites. Vibration 

propagation tests were all performed at the surface, meaning that the testing force was in the soil 

layer rather than the rock layer. 

The vibration projections are based on the most representative vibration propagation test. All of 

the ground-borne vibration projections include a five decibel “safety factor” to account for 

vibration amplification that will occasionally be caused when floor resonances are excited by the 

ground vibration, and to account for the normal fluctuation in ground-borne vibration caused by 

variations in ground conditions. 

In most cases, the measurements were at closer distances than the subway would be. The 

additional distance was accounted for using the attenuation curves from the propagation tests at 

sites VP2 and VP3. These were the only sites in the corridor where there was sufficient open 

space to obtain information on vibration attenuation with distance. 

5.8.8.2 Results of Ground-Borne Vibration Analysis 

Vibration projections were developed for all buildings along Townsend and Second streets that 

appear to have residential occupants. Projections of ground-borne vibration and ground-borne 

noise were developed for all buildings along the proposed corridor that were identified as having 

residential uses. These include live/work lofts, apartment buildings, row houses, and a new hotel 

under construction that was under construction during the testing. The vibration projections are 

summarized in Table 5.8-6. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-76 5.8 NOISE AND VIBRATION 

Buildings at which vibration impacts are projected without mitigation are listed below. 

• 388 Townsend Street: The projections indicate vibration levels will exceed the FTA 

72 VdB impact threshold by three VdB, and the ground-borne noise will exceed the 35 dBA 

impact threshold by 10 dBA. 

• Clocktower Building: Projected vibration levels exceed the FTA impact threshold by two 

VdB at the hallway site. 

• Second Street Apartment Building and new Marriott Courtyard: The projections at 

these two buildings are based on the measurements at the Marine Firefighter’s Union 

building. It was not possible to obtain permission to test at the apartment building and the 

Marriott Courtyard was still under construction. The projections at the test location closest to 

the front of the building exceed the vibration and noise impact thresholds by less than one 

VdB. No mitigation is indicated. 

After mitigation, groundborne noise impact at 388 Townsend Street and vibration impact at the 

Clocktower Building would still exceed the impact threshold by one decibel. This level of impact 

would not constitute a substantial adverse change requiring further mitigation, in terms of FTA 

guidance. The next level of mitigation that would be effective would be to install floating slab 

under the Caltrain alignment trackage for 600 to 800 feet on either side of each building (at a 

construction cost of $1,000 per linear foot), which would add installed costs approaching one 

million dollars or even more per building. Such high mitigation costs would not be a prudent 

and reasonable expenditure to eliminate the last one decibel of impact at these two sites.18

There are four buildings at which projected vibration exceeds FTA impact thresholds. Only one 

location – 388 Townsend Street – is projected to exceed the FTA thresholds by more than a 

marginal amount. 

 

18 Per FTA guidelines, “to be feasible, the measure, or combination of measures, must be capable of providing a significant 

reduction of the vibration levels, at least 5 dB, while being reasonable from the standpoint of the added cost.” 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.8NOISE AND VIBRATION 5-77 

Table 5.8-8: Summary of Vibration Projections 

Without Mitigation 

(stiff DF fasteners) 

With Mitigation 

(resilient track system) Location 

Horiz. 

Distance 

(feet) 

Depth to 

Top of 

Rail 

(ft) 

Train 

Speed 

(mph) Vib. 

(VdB) 

Noise 

(dBA) 

Vib. 

(VdB) 

Noise 

(dBA) 

Live/Work Condos, 388 Townsend Street (VP0, Hubbell and Seventh) 

Front rooms 70 32 35 75 45 72 36 

San Francisco Residences on Bryant (VP2, Harrison Parking Lot Site) 

Building 1 120 74 35 61 28 -- -- 

Building 2 150 74 35 60 26 -- -- 

Building 3 170 74 35 59 25 -- -- 

Clock Tower Building (VP4) 

Hallway 30 82 35 74 38 73 33 

Elevator 30 82 35 72 29 72 25 

Room 132 30 82 35 70 25 70 21 

Room 131 30 82 35 69 18 69 16 

2nd Floor Stair 30 82 35 66 28 65 22 

Second Street High Rise and new Marriott Courtyard (VP1, Marine Firefighter's Union) 

Inside, 16 ft 30 69 35 73 35 72 31 

Inside, 37 ft 30 69 35 69 30 68 26 

Inside, 58 ft 30 69 35 65 23 64 20 

Notes: 

All projections include a five-decibel safety factor to account for potential that there will be amplification from floor 

resonances and to allow for normal fluctuations caused by variations in ground conditions. 

Numbers in bold indicate where projections exceed the FTA impact threshold for residential land uses. The applicable 

thresholds are 72 VdB for ground-borne vibration and 35 dBA for ground-borne noise.

Source: Harris Miller Miller and Hanson, 2001. 

5.8.8.3 Vibration Mitigation 

As shown in Table 5.8-6, the projected ground-borne vibration and ground-borne noise levels 

can be mitigated with the use of high-resilience track fasteners or a resiliently supported tie 

system. With this mitigation measure, the projected vibration levels would be reduced by zero to 

three VdB, and the projected noise levels would be reduced by four to nine dBA.19

 

19 The variation is caused by the differences in the frequency spectrum of the vibration. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-78 5.9 GEOLOGY AND SEISMICITY 

5.9 GEOLOGY AND SEISMICITY 

This section focuses on the potential for geologic or seismicity features of the project area to 

affect the proposed project, or for the project to increase the potential exposure of people to 

hazard from geologic or seismic risks. In this context, the No-Project Alternative does not have 

potential impacts, but serves as a basis of comparison with the Project Extension Alternatives. 

5.9.1 Geology 

The primary geologic elements that could affect the proposed project include Bay Mud and 

artificial fill. Impacts associated with these elements can be mitigated through appropriate 

design and are discussed below. 

For the Transbay Terminal and Redevelopment sites, fill soils possess adverse characteristics 

such as rubble, heterogeneity of composition and depth, and locally high permeability. Similar 

to Bay Mud, these characteristics could affect the stability of excavations and resultant ground 

deformations. 

Bay Mud overlain by artificial fill would be encountered beneath the southwestern portions of 

the Caltrain Downtown Extension alternatives, and would be the primary factor potentially 

affecting non-seismic settlement of the storage yard, surface tracks, rail stations, and cut-andcover subways. 

Differential settlement of Bay Mud is expected to occur within the storage yard and along the 

surface tracks; however, the degree of settlement is expected to be relatively minor. Without 

appropriate foundation support, settlement of the rail facilities would occur due to the presence 

of the mud. With respect to cut-and-cover and station construction, the low strength and 

moderate deformation characteristics of Bay Mud could affect the stability of the face of the 

tunnel, the stability of excavations, the degree of ground deformation caused by the excavations, 

and the resulting response of adjacent structures. 

Core drillings were taken in the corridor in 1996, and the rock was identified as “fractured rock.” 

A panel of experts20 recommended that a “specialized tunneling” technique known as “spiling” 

be used in this rock. Because the proposed Caltrain Extension Alternatives Tunneling Option 

includes a larger tunnel (three tracks instead of two) than was proposed in 1996 and would pass 

under historic structures, a tunneling technique known as “stacked drift” is now proposed. This 

technique, which is designed to assure no tunnel collapse, is described in the Construction 

Section 5.20. Additional core drillings are proposed along the tunneling portion of the Caltrain 

Extension Alternatives to assure that this is the best tunneling approach. 

 

20 The panel included professor Thomas D. O’Rourke of Cornell University, Professor Tor L. Brekke of the University of 

California, Berkeley, and Mr. Norman A. Nadel, of Nadel Associates, Brewster, New York. The Panel was chaired by 

Demetrious Koutsoftas, URS, San Francisco, who has extensive experience with development and tunnel projects in the Project 

Area and a substantial knowledgeable regarding the Project area’s geology. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

 5-79 

5.9.2 Seismicity 

Seismically-induced ground shaking could damage a new Transbay Terminal, Caltrain 

Downtown Extension, or new development. The primary hazards related to seismically-induced 

ground motion are liquefaction and associated ground deformation (e.g., subsidence and lateral 

spreading). Portions of the Transbay Terminal/Caltrain Extension, and redevelopment sites are 

underlain by soft sediments that are susceptible to amplified ground motion. 

Seismic shaking may cause subsidence and lateral spreading of the ground surface as a result of 

liquefaction of saturated fill soils. This type of ground deformation could damage or obstruct the 

surface train lines or limit the use of the new Transbay Terminal or Caltrain storage yard and 

surface tracks until track repairs are completed. Up to 50 feet of soil sediments consisting of fill, 

Bay Mud, and loose to medium dense marine sands would be encountered along the 

northernmost cut-and-cover Caltrain segment between Folsom Street and the new terminal. The 

invert elevation of the subway would be below the base of the fill layer, thereby mitigating 

liquefaction hazards associated with the fill. However, the subway may be subjected to 

amplified ground motion. 

The potential liquefaction hazard associated with the marine sands is considered to be minor. 

Moreover, since the terminal would be supported on deep foundations, the effects of liquefaction 

and earthquake ground motion would be minimal. 

Portions of the tunnel sections of the Caltrain Downtown Extension would intersect Bay Mud 

along Seventh and Townsend to Fifth Street. Bay Mud extends to depths of almost 100 feet 

below the ground surface along this portion of the alignment. Because Bay Mud is a primary 

contributing factor to ground motion amplification during earthquakes, this section of the 

alignment is considered to be the most susceptible to amplified ground motion of any portion of 

the proposed project alignment. As noted above, liquefaction of fill soils should not affect the 

cut-and-cover subway because its invert depth lies below the base of the fill layer. 

The cut-and-cover subway would encounter Bay Mud only immediately east of the Fifth Street 

portal. Although fill soils along the tunnel alignment are susceptible to liquefaction, the 

proposed subway depth should place the subway invert below the bottom of fill deposits, except 

at the portal. 

Due to the rock formations, the alignment between Fifth and Folsom Streets would be the least 

affected by ground motion and should not have major ground deformation related to earthquakes, 

regardless of the alignment alternative. 

The geologic impacts and seismic concerns discussed above are similar to those associated with 

numerous high-rise buildings in downtown San Francisco, and with the BART and Muni tunnels. 

Mitigation of these impacts will be accomplished through the application of geotechnical and 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-80 5.10 WATER RESOURCES 

structural engineering principles and conventional construction techniques, similar to the design 

and construction of high-rise buildings and tunnels throughout the downtown area. 

Consistent with current practice along other portions of the Caltrain corridor that overlie soft 

soils, potential settlement of the storage yard and surface tracks is best mitigated by regular 

maintenance of the tracks. Track repairs will be performed as part of Caltrain’s ongoing track 

maintenance program. 

Potential settlement of the surface and underground stations will be mitigated through proper 

design and construction of pile supported foundations for both structures. Stability of the 

excavations for both stations and the resultant impacts on adjacent structures can be controlled 

within tolerable limits by proper design and implementation of the excavation shoring systems. 

Mitigation of seismic impacts on surface tracks may be handled in two ways: reinforcement or 

stabilization of soils beneath the tracks, or implementation of contingency plans for rapid repair 

of damaged rails resulting from ground shaking. Reinforcing or stabilizing soils beneath the rails 

is very expensive and may not guarantee that the tracks would remain operable after a strong 

earthquake. Consistent with current practice along other portions of the Caltrain corridor that 

overlie soft soils, potential impacts due to seismically induced ground motion are best mitigated 

by provisions for rapid rail repair. At present, these provisions include emergency 

communications links and work stations to expedite mobilization of personnel and equipment to 

damaged areas. 

Structural components of the project will be designed and constructed to resist strong ground 

motions approximating the maximum anticipated earthquake (0.5g). The cut-and-cover portions 

would require pile supports to minimize non-seismic settlement in soft compressible sediments 

(Bay Mud). These supports would also serve to minimize settlement and lateral displacement 

resulting from seismic shaking. The underground Caltrain station at Fourth and Townsend 

would require pile-supported foundations due to the presence of underlying soft sediments. 

These foundation designs combined with seismically resistant building structures should 

adequately mitigate seismic impacts to the stations. 

5.10 WATER RESOURCES 

No impacts to surface or groundwater resources would result from the No-Project Alternative. 

Piles underlain by Bay Mud would be used to support the Transbay Terminal and portions of the 

Caltrain Extension Alternatives. Although the piles could create a conduit for contaminants in 

shallow groundwater to migrate to deeper groundwater zones (as discussed in Section 5.21.14), 

the geotechnical properties of Bay Mud suggest that a tight seal will develop around the piles, 

minimizing downward migration of contaminated groundwater. 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.11FLOODPLAIN 5-81 

Stormwater along the Caltrain Extension Alternatives will discharge to the City’s combined 

storm/sanitary sewer system. During construction, sediment transported by stormwater would 

not affect surface water bodies in China Basin or San Francisco Bay. For further discussion on 

the effects to water resources during construction, see Section 5.21.11. No mitigation measures 

are required for impacts to water resources. 

5.11 FLOODPLAIN 

No portions of the Transbay Terminal/Caltrain Downtown Extension/Redevelopment Project 

area would encounter surface water bodies, including creeks or reservoirs. Also, according to 

the City and County of San Francisco Planning Department, no portions of the project area lie 

within recognized flood hazard zones with the exception of potential tsunami inundation. No 

flood hazard zones have been mapped by the Federal Emergency Management Agency (FEMA) 

in San Francisco. Mitigation measures are not required. 

5.12 UTILITIES 

As noted in Chapter 4, the Transbay Terminal/Caltrain Downtown Extension/Redevelopment 

area is served by the City and County of San Francisco combined storm drain, sanitary sewer 

system, water supply and fire suppression system. Numerous communications systems exist in 

the area. The Transbay Terminal and the redevelopment would connect to these utility systems 

consistent with utility provider requirements. 

The Project includes the proposal to increase development in the proposed Redevelopment Area. 

Thus, the Project would increase the demand for and use of water and energy consumption, but 

not in excess of the amounts expected and provided for in the area. There would be no need for 

major expansion of power or water facilities due to the Project. 

San Francisco consumers have recently experienced rising energy costs and uncertainties 

regarding the supply of electricity. The root causes of these conditions are under investigation 

and are the subject of much debate. Part of the problem is thought to be that the State does not 

generate sufficient energy to meet its demands and must import energy from outside sources. 

Another part of the problem may be the lack of cost controls as a result of deregulation. The 

California Energy Commission (CEC) is currently considering applications for the development 

of new power-generating facilities in San Francisco, the Bay Area, and elsewhere in the State. 

These facilities could supply additional energy to the power supply “grid” within the near 

future. These efforts, together with conservation, will be part of the statewide effort to achieve 

energy sufficiency. The Project would not be built and occupied until after 2008; therefore, 

additional generating facilities may have been completed by the time the Project components are 

utilizing electricity. The Project-generated demand for electricity would be negligible in the 

context of the overall demand within San Francisco and the State and would not in and of itself 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-82 5.12 UTILITIES 

require a major expansion of power facilities. Therefore the energy demand associated with the 

proposed Project would not result in a major, adverse environmental effect. 

The cut-and-cover portion of the Caltrain Extension Alternatives would require the relocation of 

utilities or the utilities would be supported in place along the cut-and-cover segments on 

Townsend, Second, Mission, and Main streets. Utilities intercepted or blocked by cut-and-cover 

excavation would experience the greatest potential effects. Pressure lines crossing tunnels would 

either be relocated out of the excavation or supported in place during construction. Gravity 

sewer lines would have to be rerouted around tunnels or routed over/under by siphon and/or 

pumping. Large consolidation sewers are especially problematic. Rerouting of these sewers 

would require extensive planning and coordination with the San Francisco Department of Public 

Works during all phases of design and construction. 

Utilities crossing the alignments will typically be supported in place from the excavation crossbracing. Large utility crossings (36-inch and larger) may require specially designed supporting 

structures. Longitudinally running utilities will be permanently relocated outside the excavation 

area or temporarily supported along the side of the excavation, then permanently relocated over 

the subway during street restoration. 

Substantially fewer utilities would be affected by the Tunneling Option, which would be 

constructed below the level of utilities. A summary of anticipated utility impacts for cut-andcover segments along the Second-to-Main and Second-to-Mission Caltrain Alternatives is 

provided below for the Caltrain Extension Alternatives and options. 

Utility modifications will need to be evaluated in more detail during final design. Careful and 

continuous coordination with utility providers will be initiated during preliminary engineering 

and will continue through final design and construction. Utilities will be avoided, relocated, 

and/or supported as necessary during construction activities to prevent damage to utility systems 

and to minimize disruption and degradation of utility service to local customers. Coordination 

efforts will focus on identifying potential conflicts, planning utility reroutes, and formulating 

strategies for overcoming problems that may arise. 

5.12.1 Sewer and Storm Drains 

Townsend Street from about 100 feet east of Fifth Street to Clarence Place (for both 

Caltrain Extension Alternatives) – a three foot by five foot brick sewer would be affected. 

Cross street sewers affected include a 6.5-foot circular sewer at Fourth Street and three by 

five-foot brick sewer at Luck, Ritch, and Third Streets. 

Second Street from Brannan to Howard Streets (for the Cut-and-Cover Option) or from 

Folsom to Howard Streets (for the Tunneling Option) -- both Caltrain Extension 

Alternatives) – a three by five-foot brick sewer would be affected. Cross street sewers affected 

include three by five-foot brick sewer at Brannan, and a three by five-foot brick sewer at Bryant, 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5.13ELECTROMAGNETIC FIELDS 5-83 

Folsom, and Howard streets (east side of Second), and Natoma street (east side of Second 

Street). 

Main Street from Howard Street towards the Transbay Terminal (Second-to-Main 

Alternative only) – a four by six-foot concrete sewer would be affected. Cross street sewers 

affected include seven-foot circular concrete sewer at Howard Street (east side of Main), a three 

by five-foot brick sewer at Howard Street (west side of Main), and a three by five-foot brick 

sewer at Folsom Street (east and west of Main Street). 

Mission Street from Beale to Main Streets (Second-to-Mission Alternative only) – a 3.5 by 

5.25-foot concrete sewer would be affected. Cross street sewers affected include a four by 

six-foot concrete sewer at Main Street (south of Mission) and a three-foot force main at The 

Embarcadero (north and south Mission Street). 

5.12.2 Communications 

Relocation of Pacific Bell’s existing conduit and manhole structures, particularly underneath 

Second Street, would, according to Pacific Bell, require construction of duplicate structures on 

different paths, placing new copper and fiber optic cable, and splicing the existing cable to the 

replacement cable and removal of the existing cables on the existing path. Pacific Bell notes that 

structure construction and the cable replacements would take many years to complete, provided 

that new paths could be found. Pacific Bell would require specific details and an in-depth study 

before commenting on the feasibility of the Terminal/Extension Project as it relates to their 

facilities. 

5.13 ELECTROMAGNETIC FIELDS 

Although short-term human health effects from exposure to electromagnetic fields (EMFs) are 

well established, such as effects on the central nervous system and heating of the body, the longterm effects from EMF exposures are not clear. Several reports have proposed a link between 

EMF exposures and such health problems as cancer, including childhood leukemia. However, 

the preponderance of authoritative scientific studies has found no firm evidence of long-term 

health risks from low-intensity EMF exposures. Despite the lack of scientific evidence of harm, 

the public continues to express concern, and health and regulatory agencies continue to study the 

matter. 

5.13.1 Regulatory Setting 

Neither the federal government nor the State of California has set standards for EMF exposures. 

The Federal Drug Administration, Federal Communications Commission, Department of 

Defense, and Environmental Projection Agency at various times have considered guidelines. The 
CHAPTER 5: ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES 

5-84 5.13 ELECTROMAGNETIC FIELDS 

California Department of Education has established a policy of “prudent avoidance” for the 

location of schools in the vicinity of high voltage power lines. Several states and other countries 

have standards for electrical field exposures. The International Radiation Protection Association 

has proposed limiting electric field exposure to five kV/m and magnetic field exposure to 

2000 mG. 

5.13.2 Impacts 

EMF effects of the Transbay Terminal / Caltrain Downtown Extension / Redevelopment Area 

Project pertain mainly to the implementation of electrified passenger rail service and its attendant 

systems in the area between the current Caltrain terminal and the proposed new terminus at the 

site of the present Transbay Terminal. The extension of rail service would result in new sources 

of EMF generation and exposure to passengers and to individuals working on commuter rail 

systems or passing in the vicinity of such systems. The main sources of EMF generation include 

overhead train power distribution systems; power substations with connecting lines to the major 

utility lines; passenger facilities, with their various electrical systems for lighting, 

communications, utilities, fare machines, among other systems, and their proximity to power 

distribution networks; and electrically powered locomotives or commuter rail passenger vehicles. 

EMF intensities associated with trains vary considerably. The greatest potential fields, and 

therefore potential for exposures, are for passengers within the electric rail vehicle. Stations 

would also be a location of EMF exposure to passengers and any station personnel. Train 

operator and attendants’ exposure would also be greatest in the motorized vehicle. Other worker 

exposure would likely be greatest when working close to an activated overhead contact system 

and substations. 

Strong fields that carry a greater possibility of health risks are not associated with these 

environments, however. The field strengths of electrified rail systems are low and below 

recommended exposure levels. Measurements of direct current (DC) magnetic fields at 

substations on the San Francisco Bay Area BART system, which receives alternating current 

(AC) power at 34.5 kV, 60 Hertz from two parallel transmission lines, found field strengths to be 

small where public exposure might occur and diminishing rapidly. At the substation fence 

perimeter, field strengths above background ranged from 0.3 to 13.0 mG and averaged four mG, 

a typical exposure level of household appliances. At approximately 14 feet from the fence line, 

magnetic field strength was at natural background levels, or around 400-500 mG (Summary of 

Draft Environmental Impact Report/Supplemental Draft Environmental Impact Statement, 

BART-San Francisco Airport Extension), BART/U.S. Department of Transportation; SamTrans, 

January 1995). On-board BART trains, which contain major propulsion equipment below floor 

level, field strengths are higher, with measurements ranging from 1,600 to 2,000 mG total, which 

is four to five times the natural background level.