CHAPTER 4

ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES

4.1 COMMUNITY IMPACTS

The East Span Seismic Safety Project (East Span Project) does not lie within the boundaries of any established residential neighborhood. Land within the project area is under institutional, residential, and commercial use. Project alternatives were analyzed for potential impacts to local communities, including impacts on employment; community services; potential for displacement of residences, businesses, or public facilities; and consistency with existing land uses and development policies.

4.1.1 Social and Economic Impacts

Project alternatives were analyzed for potential social and economic impacts. Socioeconomic impacts are considered to occur if a project:

The East Span Project is not expected to have adverse social or economic impacts on established neighborhoods or communities because of the project’s location in an institutional and industrial setting with limited residential use and because the alternatives do not change existing transportation capacity. Any project-related changes to social or economic conditions in Bay Area neighborhoods or communities are expected to result from the employment impacts of the large construction labor force that would be needed to construct the build alternatives.

Employment

Project build alternatives would generate demand for workers during the construction period. Construction would have a positive impact by generating direct construction jobs and spin-off service employment opportunities within the region. Workers are expected to be recruited from the local labor force, with specialty skills being provided by workers from inside and outside the region.

The Bay Area has a large labor force and strong economy; thus, it is expected that the vast majority of the construction labor force would be workers already living in the area. However, some specific work, such as bridge iron work, can only be done by a limited number of national contractors, resulting in a need to import specialist workers. In a worst-case scenario, in which there are many major construction projects occurring concurrently (compared to the base level), a shortfall of construction workers could develop in the region.

If a shortage developed, other workers would commute from outside the region (Central Valley) or take up temporary residence. Temporary construction workers often rent rooms stay in motels, or seek other types of temporary housing during the work week, leaving their families behind. In addition to motels and rooms, there are more than 700,000 rental units within the Bay Area. Although there is a low vacancy rate in the Bay Area, the potential impact of the project labor force would not be noticeable on the housing market. The Bay Area is a large and dynamic region. At any given time, some companies and agencies are reducing their labor force while others are increasing. There is a movement of workers and households in and out of the Bay Area at all times, and the demand generated by East Span construction activities would not cause an adverse impact on the general availability of labor supply, the housing market, or school enrollment.

Construction materials, such as steel and concrete, are not produced in the project vicinity and are likely to be purchased from other areas. Thus, the local primary economic benefits of the project would be the direct construction jobs and the economic multiplier caused by local spending of the construction labor force. The Association of Bay Area Governments (ABAG) estimates that the number of local secondary jobs created is 1.44:1 construction job. Because the region has a large design and engineering labor force, this effect is likely to occur locally as well, providing additional labor jobs.

No-Build Alternative. The No-Build Alternative would not generate additional employment opportunities because no construction work beyond the prior Interim Retrofit Project would be undertaken.

Retrofit Existing Structure Alternative. Engineering design and construction of the Retrofit Existing Structure Alternative are expected to generate approximately 2,356 total person years of employment not otherwise predicted for the Bay Area economy (see Table 4.1-1). A forecast of construction workers required to retrofit the existing East Span, by trade, assumes 60 iron workers, 60 pile drivers, 100 operating engineers, 60 carpenters, 40 concrete finishers, 40 laborers and miscellaneous workers.

Table 4.1-1 Potential Project Construction Employment Impacts of Build Alternatives

 

 

Alternative

Construction

Cost ($000)

 

Construction Person Yrs.(a)

Engineering

Design Cost ($000)

Design Person Yrs. (b)

Total Person Years

Retrofit Existing

$818,000

1,636

$90,000

720

2,356

N-2c

$1,476,000

2,952

$160,000

1,280

4,232

N-6 (Preferred) c

$1,485,000

2,970

$165,000

1,320

4,290

S-4c

$1,475,000

2,952

$160,000

1,280

4,232

Sources: Caltrans, September 1998.

Assumptions: (a) 19% of construction cost = labor @ $95,000/person year (includes overhead).

(b) 100% of design & engineering = labor @ $125,000/person year.

(c) High range of cost estimate for this alternative is presented in Table 2.4-1.

Note: The cost information in this table represents the estimated cost of the various alternatives based on information available in 1998. They do represent the current costs of the alternatives, which would be greater, but still have the same relative relationship. See Section 2.4.2 — Costs for more information.

Replacement Alternatives

A forecast of construction workers required to construct a replacement bridge was estimated based on average annual employment of 600 people over the estimated seven-year construction period, which includes dismantling the existing bridge. (The number of employees required would increase if the construction period is shortened.) Estimated direct labor by trade is: 102 iron workers, 100 pile drivers, 168 operating engineers, 100 carpenters, 65 concrete finishers, and 65 laborers and miscellaneous workers. With a peak period of two years for structural work on a new bridge, a peak demand of approximately 175 iron workers would be required.

Replacement Alternatives N-2, N-6 (Preferred), and S-4 are each calculated to generate slightly more than 4,000 total person years of employment over the construction period (see Table 4.1-1).

Impacts of Build Alternatives. Build alternatives would generate direct and indirect labor demand during a period lasting up to seven years. Workers are expected to be drawn from the regional labor pool with specialty trades generating demand from outside the Bay Area. A portion of the specialty trades may be attracted to the Bay Area for the duration of the project. Because of the large Bay Area economy, consisting of approximately three million jobs, worker-generated demands for housing or community services are not expected to have a noticeable effect on San Francisco, Oakland, or other Bay Area community housing stocks or services. The project is expected to have a beneficial impact on San Francisco and Oakland economies by generating direct and indirect jobs. The community would benefit through direct and secondary employment opportunities and no mitigation is required.

Neighborhoods

San Francisco (Yerba Buena Island). Construction of the Retrofit Existing Structure Alternative and replacement alternatives all have the potential to cause temporary impacts to residents on Yerba Buena Island (YBI), including USCG housing and occupied former Navy housing. (See Section 4.14 — Temporary Impacts during Construction Activities for more details.) There would be no permanent impacts.

Oakland. A construction staging area could be built at the former Oakland Army Base (OARB). Construction activity would not affect neighborhoods in West Oakland. Because the project would be built within San Francisco Bay, there would be no impacts to community cohesiveness or other permanent impacts to West Oakland neighborhoods.

4.1.2 Community Services

No impacts to community services were identified under any of the categories: utilities, fire protection services, and police services. Permanent utility service would not be disrupted by the project (see Section 4.12 — Utilities Relocation for more details); police and fire protection services would not change as a result of the project, and access to the Treasure Island (TI) elementary school would not be affected by the project.

One of the columns of Replacement Alternative S-4 would be placed on the East Bay Municipal Utility District (EBMUD) pipeline that feeds into the dechlorination facility on the Oakland Touchdown. If Replacement Alternative S-4 is carried through to final design, the column could be moved to avoid the pipeline. However, even if the column is relocated under Replacement Alternative S-4, there would be insufficient vertical clearance between the bridge structure and the road used by large chemical supply tractor-trailer trucks to serve the dechlorination facility. To maintain EBMUD's access to its facility, the road, the facility, or both would need to be relocated (see Section 4.1.4 — Impacts to Existing Land Use for further details).

4.1.3 Environmental Justice

There are no identified minority or low-income populations or communities in the project area. (FHWA defines populations as "readily identifiable groups or clusters of minority persons and/or low-income persons who are in the project study area.") Outside the project area limits on TI and in West Oakland there are communities which are comprised of minority and low-income populations.

Title VI Policy Statement

Appendix L contains Caltrans policy regarding compliance with Title VI of the Civil Rights Act of 1964, the Civil Rights Restoration Act of 1987, and Title 29 CFR Part 21.

No-Build Alternative

There would be no change in the existing environment in the neighborhoods outside of the project area limits.

Retrofit Existing Structure and Replacement Alternatives

Only minimal impacts are expected on the TI community. During construction of the project, temporary changes in access and bridge closures would affect mobility of the TI community. Caltrans is continuing to investigate the number and timing of partial or full bridge closures in an effort to simultaneously minimize public inconvenience, facilitate construction and maximize public safety. Short-term closures would be timed during off peak hours and Caltrans would implement a traffic management plan to manage impacts to traffic. Those who live or work on TI would be notified of any bridge closures or changes in access through signage and possibly direct mailings. Final notification procedures would be determined through the Traffic Management Plan.

Emergency access to TI/YBI would be provided at all times.Communities in West Oakland are not expected to encounter any traffic or access problems or other adverse impacts from the project.

As indicated in Section 4.1.1 — Social and Economic Impacts, construction of any of the build alternatives could provide increased employment opportunities from which both the TI and West Oakland neighborhoods could benefit. In addition, the benefits of the completed project including improved traffic operations and safety, would be provided to all adjacent neighborhoods.

It was determined that there are no minority or low-income populations in the project area that would be adversely affected by the East Span Project. Based on the environmental analysis in other sections of the FEIS, the Preferred Alternative or other build alternatives would not cause disproportionately high and adverse impacts (including any indirect impacts) on minority or low-income populations outside the project limits.

4.1.4 Impacts to Existing Land Use

This section describes changes in land use that would occur as a result of the project alternatives.

Changes in Land Use

Potential project-related changes to existing land uses on YBI and at the Oakland Touchdown are summarized in the following section. Permanent impacts are addressed here. Short-term construction-period impacts are addressed in Section 4.14 — Temporary Impacts During Construction Activities.

Land Use Impacts on Yerba Buena Island.

No-Build Alternative. Implementation of the No-Build Alternative would not cause a change in any existing land uses on YBI. No impacts would result and no mitigation would be required.

Retrofit Existing Structure Alternative. With the exception of temporary impacts during construction, the Retrofit Existing Structure Alternative would not cause any changes to existing land uses in the project area. The footprint of Columns YB1, YB2, YB3, YB4, and E1 would be expanded in size but would remain in their current locations. Because the towers and cross-members would be encased in concrete, current views through the towers would be blocked (refer to Figure 4-15a in Appendix A and see Section 4.3 — Visual Impact Analysis). No new columns would be constructed on the island. No permanent impacts would result from the retrofit alternative and no mitigation would be required.

Replacement Alternatives. The new bridge structure for each replacement alternative would begin east of the YBI tunnel portal. The areas of impact for each of the three alternatives overlap. Many of the same buildings on the eastern edge of the island would be affected by all of the alternatives.

Replacement Alternative N-2. Replacement Alternative N-2 is positioned to the north of the existing East Span. The alternative would place 26 bents between the YBI tunnel eastern portal and the eastern end of YBI. The alternative would also require construction of temporary detours to be used while the viaduct is retrofitted and transition structures on YBI are constructed. (Refer to Appendix A for alignment and temporary detour drawings.) Impacts of the temporary detours are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

An existing road providing access to the northeast end of the island would be blocked (see Section 4.2.1 — Vehicular Circulation and Access). The alternative would not remove existing structures or block access to existing uses on the island.

Replacement Alternative N-2 would cross approximately 53 meters (175 feet) above the ground at vacant Navy Building 262, but would not place columns at locations which would obstruct future access to the building. Navy Building 213 (fire truck storage) would be removed to allow for construction of the temporary detours (which would require placement of a column through the building.) The alternative would be approximately 10 meters (33 feet) closer horizontally to Quarters 1 than the existing East Span (i.e., approximately 40 meters [130 feet] south of Quarters 1). However, the proximity of the span would not affect access to this building or place the columns permanently within the boundaries of the Senior Officers’ Quarters Historic District.

Replacement Alternative N-2 would displace Buildings 30 (storage), 40 (administration), 75 (storage), and 270 (vacant) to relocate the USCG access road and gate and Building 213 to allow for temporary detour construction. Construction of Replacement Alternative N-2 would require that the existing access road and gate to the USCG facility be moved south. Replacement Alternative N-2 has not been identified as the Preferred Alternative.

Mitigation:

If Replacement Alternative N-2 were constructed, Caltrans would work with the USCG and Navy to provide replacement buildings of like size, construction, construction materials, and quality, built to current code requirements for Buildings 30, 40, 75, 213, and 270. The USCG and Navy would need to provide suitable sites for the replacements outside state right-of-way.

Replacement Alternative N-6 (Preferred). Replacement Alternative N-6 is located to the north of the existing East Span in an alignment similar to Replacement Alternative N-2. The alternative would place approximately 19 bents between the eastern portal of the YBI tunnel and the eastern edge of YBI. The alternative would require construction of temporary detours to be used while the viaduct is retrofitted and transition structures on YBI are constructed. (Refer to Appendix A for alignment and temporary detour drawings.) Impacts of the temporary detours are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

Replacement Alternative N-6 would cross approximately 53 meters (175 feet) above the ground at vacant Building 262, but would not place columns at locations which would obstruct future access to the building. Building 213 (fire truck storage) would be removed to allow for construction of the temporary detours. The alternative would be approximately 10 meters (33 feet) closer horizontally to Quarters 1 than the existing East Span, which is approximately 40 meters (130 feet) south of the building. However, the proximity of the span would not affect access to the building or place columns permanently within the boundaries of the Senior Officers’ Quarters Historic District.

Replacement Alternative N-6 would displace Buildings 30, 40, 75, and 270 to relocate the USCG access road and gate and Building 213 to allow for temporary detour construction. Construction of Replacement Alternative N-6 would require that the existing access road and gate to the USCG facility be moved south.

Mitigation:

If Replacement Alternative N-6 were constructed, Caltrans would work with the USCG and Navy to provide buildings of like size, construction, construction materials, and quality, built to current code requirements for Buildings 30, 40, 75, 213, and 270. The USCG and Navy would need to provide suitable sites for the replacements outside state right-of-way.

Replacement Alternative S-4. Construction of Replacement Alternative S-4 across YBI would require 24 bents between the eastern portal of the YBI tunnel and the eastern shoreline of the island. Temporary detours would be required on YBI during construction.

Replacement Alternative S-4 would displace Buildings 30, 40, 75, and 270 to relocate the USCG access road. Replacement Alternative S-4 would be located approximately 50 meters (164 feet) from Quarters 1, which is 10 meters (33 feet) farther than the existing East Span, and 60 meters (190 feet) from Navy Building 262.

Mitigation:

If Replacement Alternative S-4 were constructed, Caltrans would work with the USCG to provide buildings of like size, construction, construction materials, and quality, built to current code requirements for Buildings 30, 40, 75, and 270. The USCG and Navy would need to provide suitable sites for the replacements outside state right-of-way.

Land Use Impacts at the Oakland Touchdown Area. Replacement Alternatives N-2 and N-6 touch down to the north of the existing East Span while Replacement Alternative S-4, the southern alternative, touches down south of the existing structure.

No-Build Alternative. Implementation of the No-Build Alternative would not cause a change in any existing land uses in the Oakland Touchdown area. No impacts would result and no mitigation would be required.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would not cause any changes to existing land uses in the Oakland Touchdown area. The bridge footprint would be modified only to increase the size of Column E23 at the western end of the touchdown area. No permanent impacts would result from the retrofit alternative and no mitigation would be required.

Replacement Alternatives.

Replacement Alternatives N-2 and N-6 (Preferred). Replacement Alternatives N-2 and N-6, located to the north of the existing span, would have a similar approach to the Oakland Touchdown area. The northern alternatives would require the permanent displacement of 0.2 hectare (0.5 acre) of land north of the existing bridge that the City of Oakland has designated as Resource Conservation Area.

Replacement Alternative S-4. As shown in Figures 2-11.4 and 2-11.5 in Appendix A, Replacement Alternative S-4 would occupy the westernmost portion of the vacant OARB land to the south of the existing East Span and open storage areas just north of the vacant OARB land used by Caltrans.

Replacement Alternative S-4 is currently designed to place a column in the pipeline east of the EBMUD dechlorination facility. While the column could be redesigned to avoid the pipeline, the vertical clearance between the structure and the service road is insufficient to allow for delivery vehicles to the dechlorination facility. Consequently, if Replacement Alternative S-4 were selected, there would be a conflict with the facility.

Several solutions were evaluated to possibly eliminate the conflict. They include:

Mitigation:

If Replacement Alternative S-4 were constructed, Caltrans would work with EBMUD to relocate the service road and/or the dechlorination facility to maintain EBMUD's operations. Caltrans would obtain necessary permits/permit amendments, fund relocation costs, and implement any necessary mitigation. Caltrans would assure continual operation of EBMUD's discharge system during relocation.

4.1.5 Development Trends

The purpose of this section is to evaluate the relationship between the proposed project and anticipated development trends at YBI and the Oakland Touchdown area.

Yerba Buena Island/Treasure Island Draft Reuse Plan Consistency

The Treasure Island Draft Reuse Plan (1996 Draft Reuse Plan) includes "minimum" development scenarios, based upon the existing traffic capacity and access and a guiding policy for development of Naval Station Treasure Island, which states that development should be limited to uses for which access can be accommodated primarily by ferry.

Vehicular access is a major constraint to development on YBI/TI. The East Span Project would not increase the SFOBB’s capacity nor would it improve the access points from the SFOBB to YBI/TI. The eastbound on-ramp to the SFOBB would be replaced with a ramp that provides a standard acceleration lane as opposed to the current stop-sign design, resulting in improved eastbound access to the bridge from YBI.

The 1996 Draft Reuse Plan envisions that development of YBI/TI would occur in five phases. Each phase would build on the previous phase in order to generate the revenue necessary to make needed infrastructure improvements. In turn, this infrastructure would allow for more intensive development in subsequent phases. The phased implementation process is projected to extend over a period of 35 years. Development on YBI is envisioned to occur within the first three phases of plan implementation, which are projected to occur over a 15-year period. To the extent the implementation plan was premised on release by the U.S. Navy and CCSF of a final NEPA/CEQA document several years ago, the phasing schedule appears to be approximately three years behind schedule, as the U.S. Navy and CCSF have not yet released the draft NEPA/CEQA document.

Planned development near the bridge on YBI includes a 5,600-square meter (60,000-square foot) conference center, 13 artisan cottages, and 75 live/work units. This development is in Phase 3 and is scheduled to begin in 2007. The three implementation phases affecting YBI are summarized below.

Phase 1

Phase 1 was anticipated to begin in 1997 and continue through 2001 as closure of the base occurred. In this phase, limited interim uses of the existing facilities are planned. On YBI, Phase 1 assumes that all of the existing buildings would continue in civilian uses, including provision of housing for the homeless and use of Quarters 1 through 7 as a conference/ meeting center. (Note: Housing for the homeless is now in process on TI. No housing for the homeless is planned for YBI.)

Phase 2

Phase 2 improvements are listed in the 1996 Draft Reuse Plan as scheduled to occur between 2002 and 2006. Phase 2 envisions the beginning of improvements to the TI shoreline, including causeway reinforcement between TI and YBI and creating a secure land link to the SFOBB and the proposed ferry terminal on TI. After infrastructure improvements are made, a theme park, sports complex, maritime administration, and expansion of the film studios on TI are proposed as part of Phase 2.

On YBI, Phase 2 includes redevelopment of the existing housing on the west side of the island for housing and hotel uses.

According to the 1996 Draft Reuse Plan, expansion of the Treasure Island Marina was originally scheduled for Phase 2 development. Since the plan was written, the marina project has been accelerated and is currently in the planning stage (see Figure 4-23 in Appendix A).

Construction of the Treasure Island Marina is scheduled to begin in mid to late 2001, after approval of the final plan, preparation and approval of the environmental document, and acquisition of permits.

Phase 3

Phase 3 improvements are listed in the 1996 Draft Reuse Plan as scheduled to occur between 2007 and 2011, which is after completion of the East Span Project (2006). Consequently, there would be no construction conflicts between the two projects. In Phase 3, improvements would be made to stabilize the eastern shoreline on TI, which would allow completion of the theme park. Development of a hotel/retail area is also envisioned in this phase.

On YBI, Phase 3 improvements would include development of the conference center and artisan cottages on the eastern end of the island.

The development potential of YBI would be affected but not precluded by the physical location of the project. Due to the steep topography of most of the island, the eastern end is considered by the CCSF to be the only viable location for development. Also, because the 1996 Draft Reuse Plan will be subject to a number of environmental and regulatory reviews prior to its implementation (including a BCDC federal consistency determination and permit, discussed in Section 4.1.6 — Adopted Goals and Policies), the amount and location of new development on the eastern end of YBI may vary widely from the current development concepts. An analysis of the impacts on the development trends on YBI is described below.

No-Build Alternative. The No-Build Alternative would not conflict with the 1996 Draft Reuse Plan development scenarios, although vehicular access to and from the East Bay could be affected in the aftermath of a major earthquake.

Retrofit Existing Structure Alternative. Expansion of existing East Span columns on YBI would not conflict with redevelopment scenarios for YBI. Since the 1996 Draft Reuse Plan was developed with the bridge in its current location, the conceptual land uses proposed in the plan could be developed under the Retrofit Existing Structure Alternative.

The Retrofit Existing Structure Alternative is consistent with the 1996 Draft Reuse Plan in that it does not include modifications to YBI on- and off-ramps that would change the capacity of existing vehicular access. YBI ramps are not owned by Caltrans and are not critical to providing a lifeline connection in the project corridor. Therefore, the retrofit alternative would not conflict with the transportation access assumptions of the 1996 Draft Reuse Plan.

No long-term impacts would result from implementation of the Retrofit Existing Structure Alternative and no mitigation measures would be required. Temporary impacts during construction are addressed in Section 4.14 — Temporary Impacts During Construction Activities.

Replacement Alternatives N-2 and N-6 (Preferred). The northern alternatives would require placement of footings and columns across the eastern end of YBI. The conceptual development scenario contained in the 1996 Draft Reuse Plan (Figure 4-1 in Appendix A) could be implemented under either Replacement Alternative N-2 or N-6. The number of live/work units and the size of the conference center would be reduced, due to the presence of footings and columns for the northern replacement alternatives; however, the overall concepts could be implemented. Development could occur on 3.15 hectares (7.8 acres) of land, including 1.17 hectares (2.9 acres) beneath the structures, subject to review and approval by Caltrans.

The northern alternatives are consistent with the transportation element of the Reuse Plan because they would not modify YBI on- and off-ramps to change the capacity of existing vehicular access. The ramps are not owned by Caltrans and are not critical to providing a lifeline connection in the project corridor. One eastbound on-ramp is proposed for modification under the replacement alternatives, but would not change access capacity to the island. Therefore, Replacement Alternatives N-2 and N-6 would not conflict with the transportation access assumptions of the 1996 Draft Reuse Plan.

Construction-related impacts are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

Caltrans has initiated consultation with the CCSF concerning the impacts of the northern alternatives on reuse plans. Caltrans will continue to coordinate with CCSF through the final design and construction periods.

Replacement Alternative S-4. Replacement Alternative S-4 would locate the replacement structure to the south of the existing East Span and remove the existing bridge. As a result, the project would open up some additional areas for YBI redevelopment. Approximately 0.8 hectare (2.0 acres) of land that is currently occupied by the existing span could become available for development. This would be a beneficial impact as it relates to CCSF’s redevelopment of YBI. The area suitable for development would be 3.7 hectares (9.1 acres), including 0.6 hectare (1.4 acre) beneath the structures.

As with the northern alternatives, Replacement Alternative S-4 is consistent with the transportation element of the Reuse Plan.

USCG Property Impacts

The development potential of the USCG property would be impacted by the project build alternatives. In April 1998 as part of the BRAC process, the Navy transferred 4.3 hectares (10.6 acres) to the USCG. Of this land, 1.1 hectares (2.7 acres) is within the project area and approximately 0.41 hectares (1 acre) is developable (the remainder is constrained by steep slopes). No specific master plan has been developed for expansion of the existing USCG facility because the USCG has delayed final master plan preparation pending outcome of the TI BRAC process and final design for the East Span Project.

No-Build Alternative. The No-Build Alternative would not affect existing USCG facilities. The No-Build Alternative would not limit future redevelopment beyond the limitations currently imposed by the existing East Span.

Retrofit Existing Structure Alternative. Expansion of existing columns and footings would not conflict with existing USCG facilities or limit future redevelopment beyond the limitations currently imposed by the existing East Span. Temporary construction impacts are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

Replacement Alternatives N-2 and N-6 (Preferred). The northern replacement alternatives would have no permanent impact on USCG usable land area.

Replacement Alternative S-4. Footings and support columns for Replacement Alternative S-4 would use the southeastern portion of YBI and span approximately 1.5 hectares (3.8 acres) of the 17-hectare (41-acre) USCG facility. USCG land under the bridge could be developed, subject to review and approval by Caltrans. Although the USCG does not have a master plan for the YBI facility, Replacement Alternative S-4 would restrict future facility development.

Oakland Touchdown Area

The Oakland Army Base Reuse Authority (OBRA) is in the process of designating land south of Burma Road for light industrial/research and development uses with supporting retail and business services. BCDC amended the San Francisco Bay Plan and the Seaport Plan in January 2001 to delete this area from the "Port Priority Use" designation to permit implementation of OBRA's plan.

The 1998 Draft Final Reuse Plan for the Oakland Army Base designates 5.9 hectares (14.7 acres) of the westernmost portion of the former Army Base on the Oakland Touchdown as the site of a proposed public park. The OBRA is considering reducing the amount of land to 4.9 hectares (12 acres), but has yet to release a revised Reuse Plan. The proposed Gateway Park is a Section 4(f) resource.

The Port and City of Oakland are participants in a planning effort to establish the Gateway Park at the Oakland Touchdown area. (See discussion of Public Parks and Open Space below.) The Port has stated its intention to work with the Oakland Gateway Planning Group to develop design concepts which accommodate the East Span Project, Port activities, public access, and open space in the Oakland Touchdown area.

No-Build Alternative. The No-Build Alternative would not conflict with OBRA's redevelopment plans.

Retrofit Existing Structure. The Retrofit Existing Structure Alternative would not require the use of the former OARB property and would not conflict with OBRA's redevelopment concepts.

Replacement Alternatives N-2 and N-6 (Preferred). The northern alternatives would not use the former OARB property and would not conflict with OBRA's redevelopment concepts.

Replacement Alternative S-4. Replacement Alternative S-4 would conflict with the proposed public park discussed below but would not conflict with OBRA's other redevelopment concepts.

Oakland Touchdown Area — Public Parks and Urban Open Space

With EBRPD as the lead, planning has been initiated with the City of Oakland, the Port of Oakland, EBRPD, ABAG/Bay Trail, OBRA, National Park Service (NPS), and BCDC to create a Gateway Park at the Oakland Touchdown. Decisions about the replacement alternatives are critical to the park planning process.

No-Build Alternative. The No-Build Alternative would not impact EBRPD development of OBRA-designated parkland on the southern border of the Oakland Touchdown area; therefore, no impact to parkland development would occur and no mitigation would be required.

Retrofit Existing Structure. The Retrofit Existing Structure Alternative would not impact EBRPD development of parkland on the southern border of the Oakland Touchdown area; therefore, no impact to development of parkland would occur and no mitigation would be required.

Replacement Alternatives N-2 and N-6 (Preferred). The northern alternatives would not impact EBRPD development of parkland on the southern border of the Oakland Touchdown area; therefore, no impact to development of parkland would occur and no mitigation would be required.

Replacement Alternative S-4. Replacement Alternative S-4 would negatively affect the Gateway Park development at the Oakland Touchdown. This alternative would require approximately 3 hectares (7.4 acres) of the proposed 5.9-hectare (14.7-acre) park for construction of the bridge, thereby reducing its size by one-half and bisecting the land designated for park use by OBRA. The park's reduced size and location would limit its intended function as a regionally significant recreational area and as a gateway to the East Bay. To minimize the impact to the proposed Gateway Park, the land required for Replacement Alternative S-4 could be replaced by acquiring land nearby to contribute toward another smaller park in the area. For further information on the park, see Chapter 6 — Section 4(f) Evaluation.

Impacts to Required Bay Access Sites

As part of the I-880/Cypress Freeway Replacement Project, Caltrans is required by BCDC to provide and maintain a public access bicycle/pedestrian pathway system connecting the Cities of Emeryville and Oakland between Shellmound Street and Nelson Mandela Parkway, through the distribution structure for I-80 to the Oakland Touchdown area. Caltrans is also required to provide two scenic overlooks, a 465-square-meter (5,000-square-foot) outlook on the north side of the Oakland Touchdown area and a 232-square-meter (2,500-square-foot) lookout area on the south side of the Touchdown area. Both overlooks include public amenities such as parking, restrooms, benches, a fish cleaning facility, trash cans, and native landscaping. Caltrans submitted a request to BCDC to amend Permit 11-93 to delay implementation of the access areas until completion of East Span construction. On July 31, 1998, BCDC amended Permit 11-93 to extend the period for construction of the public access areas to December 31, 2006. The permit includes an in-lieu-fee provision that allows Caltrans to pay a sum equal to the costs of the required amenities should construction of some or all of the public access prove infeasible. Payment of the in-lieu fee is subject to BCDC approval. BCDC may disburse the funds to the EBRPD to improve public access where feasible. Each replacement alternative would require ongoing consultation with BCDC to determine the optimum locations of these public access overlooks.

No-Build Alternative. The No-Build Alternative would not interfere with implementation of the public access improvements required under BCDC Permit 11-93. No impact would occur and no mitigation would be required.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would not conflict with provision of the public access improvements required under BCDC Permit 11-93.

Replacement Alternatives N-2, N-6 (Preferred), and S-4. Each of the proposed replacement alternatives would have an impact on the public access required under BCDC Permit 11-93. The northern alternatives would preclude construction of the public access overlook required by the BCDC for the northern side of the Oakland Touchdown. Replacement Alternative S-4 would preclude the development of the public access overlook on the south side of the Oakland Touchdown area, bicycle path, access roadway, and parking area required by BCDC Permit 11-93.

Caltrans will consult and coordinate with BCDC to determine necessary public access modifications and/or permit requirements under Permit 11-93. Modifications to the public access requirements could be identified as conditions in a future amendment to Permit 11-93 and/or incorporated into a new permit for a bridge replacement alternative.

4.1.6 Adopted Goals and Policies

The purpose of this section is to evaluate the relationship between the proposed project and existing land use, transportation, and coastal policies which will guide future development in the western and eastern touchdown areas.

Land Use Policies

Treasure Island Draft Reuse Plan (The City and County of San Francisco). The replacement of the East Span would have no impact on CCSF’s program to implement the guiding policies of the 1996 Draft Reuse Plan nor on the CCSF’s program to implement the goals and policies of the CCSF’s Master Plan. The 1996 Draft Reuse Plan and the CCSF’s Master Plan both assume that the East Span will continue to provide an essential link for auto traffic between YBI and the East Bay.

As discussed in Section 4.1.5, Replacement Alternatives N-2 and N-6 are generally compatible with the 1996 Draft Reuse Plan. The 1996 Draft Reuse Plan has not been formally adopted, and it would be subject to environmental and regulatory review, which could alter what is currently envisioned for eastern YBI in the draft plan. The DEIR/DEIS for the reuse plan has not been issued yet.

The goals and policies of the 1996 Draft Reuse Plan also identify the existing bridge and ramps as one of the continuing institutional uses on YBI, as the bridge provides an essential link for auto traffic between YBI and the East Bay. Planned uses on the western side of YBI and on Treasure Island would not be affected by the East Span Project.

City of Oakland (Envision Oakland). The East Span Project is consistent with Oakland’s policies for future development and land uses within the project area. With the exception of one conflict (discussed in Section 4.1.4 — Impacts to Existing Land Use), replacement of the SFOBB East Span would have no impact on the City’s program to implement the goals and policies of the General Plan. Construction of either Replacement Alternative N-2 or N-6 would conflict with the Resource Conservation Area land use designation, which applies to all of the land on the Oakland Touchdown area, north of the existing alignment. The northern alternatives would displace 0.2 hectare (0.5 acre) of the Resource Conservation Area. The City of Oakland has been an active participant in the planning efforts to establish the Gateway Park. As mentioned previously, Replacement Alternative S-4 would negatively impact Gateway Park development. In the City’s comments on the DEIS, Acting Planning Director Leslie Gould noted, "Of the proposal alignments, the City prefers Replacement Alternative N-6 because it would have the fewest impacts on planned land uses."

The SFOBB is an integral part of the existing system that supports Oakland’s vision of the City’s "primacy as a transportation hub connecting the Bay Area with the Pacific Rim and the rest of the United States (Envision Oakland General Plan)."

The Oakland Touchdown area is located immediately adjacent to the City’s seaport area (i.e., Port of Oakland facilities). The seaport area is classified as a showcase district in the City’s General Plan. Showcase districts are dynamic areas that can respond to broad trends and market demands. The policy framework of the plan supports these districts in their continued growth and regional importance. The SFOBB provides an important link between the City’s showcase districts, San Francisco, and the San Francisco Peninsula.

Oakland Policies T4.5, T4.9, and T6.3 support preparation of a Bicycle and Pedestrian Master Plan, the creation of a "gateway" public access area at the east terminus of the East Span, and making the waterfront accessible to bicyclists and pedestrians. The East Span Project includes cooperation by Caltrans with planning efforts to create public access areas in the Oakland Touchdown area that will support implementation of these City policies. These characteristics of the SFOBB project also support the Waterfront Goals of the General Plan, relative to promoting public access to the waterfront.

The "New Bay Bridge," as the SFOBB East Span Project is described in Regional Access: Policies in Action, Chapter 3 of the City’s General Plan, provides opportunities for increased bicycle, pedestrian, and transit access to the bridge. Additionally, the General Plan recommends that new parks and open space at the Oakland Touchdown should be integral components of the project. The replacement alternatives include features, such as the bicycle and pedestrian facilities which are consistent with the City’s policies. All replacement alternatives would accommodate public access through BCDC Permit 11-93 and park development by EBRPD, but Replacement Alternatives N-2 and N-6 substantially more so than Replacement Alternative S-4 because Replacement Alternative S-4 would reduce the size of the proposed park by approximately one-half while Replacement Alternatives N-2 and N-6 would have no impact on the development of the proposed park.

Since the Retrofit Existing Structure Alternative does not provide improved bicycle or pedestrian access, it is not consistent with this Oakland General Plan policy.

Port of Oakland. The SFOBB East Span Project is consistent with the Port and City of Oakland’s plans for an office and commercial development along the shoreline of the Oakland Touchdown area east of the envisioned park. This activity would not be precluded by any of the proposed build alternatives.

U.S. Coast Guard (USCG). The USCG does not currently have a master plan in place for the YBI facility. In general, the USCG plans to maintain its current level of operations at the YBI facility, including 24-hour search and rescue, repair and maintenance of buoys, vessel traffic service, and law enforcement. Replacement Alternatives N-2 and N-6 would not substantially affect current level of operations. Replacement Alternative S-4 would encroach over the USCG facility and would restrict the USCG’s ability to utilize its portion of YBI. The replacement bridge would span approximately 1.5 hectares (3.8 acres) of the 17 hectares (41 acres) of USCG property.

East Bay Regional Park District (EBRPD). As noted in earlier sections, the OBRA’s 1998 Reuse Plan designates 5.9 hectares (14.7 acres) at the westernmost end of the former OARB property for a Public Benefit Conveyance to the EBRPD for a future park. Construction of Replacement Alternatives N-2 and N-6 and the Retrofit Existing Structure Alternative are consistent with the OBRA Reuse Plan and EBRPD’s intention to develop a park after the East Span Project is constructed. Replacement Alternative S-4 would negatively impact the Gateway Park development by taking 3 hectares (7.4 acres) of the proposed park area. (Refer to Chapter 6 — Final Section 4(f) Evaluation for additional information on the proposed Gateway Park and the project alternatives.

Transportation Policies

City of Oakland ­ Envision Oakland. Oakland’s transportation policy includes the following:

Objective T4. Increase use of alternative modes of transportation.

Policy T4.8 - Accommodating Multiple Types of Travel on the Bay Bridge. The City should encourage the design and engineering for the new Bay Bridge to accommodate multiple means of access and travel by automobiles, trucks, transit, bicycles, pedestrians, and future mass transit.

Each of the East Span Project replacement alternatives would accommodate multi-modal travel on the bridge. High-occupancy vehicle (HOV) bypass ramps would remain in operation at both the west and east bridge approaches to encourage carpools, vanpools, and bus transit use. Provision for future mass transit would be accommodated by continuation of Alameda-Contra Costa Transit District (AC Transit) bus service and by design of the replacement structures to accommodate loading for future light rail transit vehicles. Replacement alternative designs also include a bicycle/pedestrian path. The proposed project is consistent with this policy.

Policy T4.8 - "Gateway" Public Access Area. The City, in concert with the EBRPD, Port of Oakland, Oakland Base Reuse Authority, and BCDC, should support development of a significant new "gateway" public park area at the terminus of the SFOBB East Span that can be reached by auto, bicycle, or walking.

The East Span Project includes coordination with the agencies concerned with future uses of land in the Oakland Touchdown area. Collaborative planning efforts involving the City of Oakland, Port of Oakland, EBRPD, BCDC, NPS, and the Army are in progress.

City and County of San Francisco Master Plan. The CCSF’s transportation policy includes the following:

Objective 1.

Policy 1. Involve citizens in planning and developing transportation facilities and services, and in further defining objectives and policies as they relate to district plans and specific projects.

The East Span Project is consistent with this policy as it has provided many opportunities for public involvement in the process. (See Appendix E for a summary of public involvement activities.)

Objective 4.

Policy 2. Where significant transit service is provided by buses, bridges and freeways should have exclusive bus lanes.

Efficient bus operations as part of the East Span Project alternatives are facilitated by provision of bus/carpool (HOV) bypass lanes at the west and east bridge approaches. Provision of exclusive bus lanes has been considered as part of the East Span Project. It was determined that dedicated facilities would not provide any benefits. (See Section 2.5.)

Objective 5.

Policy 3. The existing vehicular capacity of the bridges, highways and freeways should not be increased and should be reduced where possible.

The East Span Project is consistent with this policy as it does not increase capacity.

Objective 8.

Policy 4. Accommodate bicycles on regional transit facilities and important regional transportation links.

The East Span Project replacement alternatives include designs for a bicycle/pedestrian path. The replacement alternatives are consistent with this policy.

Association of Bay Area Governments ­ The Bay Trail. ABAG’s plans for trails include the following:

Transportation Access Policies.

30. Bridges and roads will be important connections in the Bay Trail system, providing not only commute routes, but enhancing the recreational use of the Trail by creating trail loops which will allow a greater number of people to enjoy the Trail.

31. In the short term, attention should be focused on improving safe access to the bridges, possible expansion of bicycle shuttle services, and public transit accommodations of bicycles to allow crossbay access.

32. In the long term, unconstrained access on bridge structures is preferred. This can more easily be accomplished in planning future facilities, as long as public access is a requirement for new structures. Legislative action which would require bicycle and pedestrian access on new facilities should be actively sought.

33. Opportunities for cooperative funding of pedestrian and bicycle accessways should be investigated in order to make financing feasible.

The East Span Project would be consistent with these policies because the replacement alternatives would provide the first link of a transbay crossing by providing a path to YBI. (The feasibility of a West Span path is under review by the MTC and Caltrans.) A path on the East Span would be an important connection to Bay Trails on both sides of the Bay. The East Span Project would improve access to the bridge and would enhance the safety of the bridge itself. The bicycle/pedestrian path is to be funded as outlined in Section 188 of the California Streets and Highways Code (CSHC).

San Francisco Bay Plan (Bay Conservation and Development Commission) Policies.

Land Use. BCDC requires that every project provide the maximum feasible public access to the Bay consistent with the project. In planning meetings for the conceptual Gateway Park at the Oakland Touchdown area, BCDC concurred that it would consider combining the requirements for public access specified in Permit 11-93 with any additional public access requirements for the East Span Project. (Note: Section 60604.5 of the Streets and Highways Code states, "Notwithstanding any other provision of law, local and state permitting authorities shall not impose any requirement that a bicycle, pedestrian, or mass transit facility be constructed on the San Francisco-Oakland Bay Bridge as a condition for issuing any permit, granting any easement, or granting any other form of approval needed, for the construction of a new bridge." As a result of this law, BCDC cannot require a bicycle or pedestrian facility on the bridge as a permit condition.)

The East Span Project would be consistent with BCDC’s public access policy as Caltrans would provide bicycle, pedestrian, and vehicular access to the Oakland Touchdown area as part of both the East Span Project and BCDC’s previous conditions of approval for the I-880 and I-80 projects (see the Permit 11-93 discussion in Section 3.1.3 — Adopted Goals and Policies for further details). Public access to the Bay is required as part of the I-880 and I-80 projects. If the public access improvements, including the overlooks and bikeway alignments prove infeasible due to replacement of the bridge, the permit conditions allow Caltrans to pay an in-lieu fee to construct the improvements subject to BCDC approval. BCDC may disburse the funds to the EBRPD or another entity to improve public access where feasible.

The proposed project is consistent with the BCDC’s policies for future development as contained in the San Francisco Bay Plan and the Seaport Plan; the replacement of the East Span would have no impact on the BCDC’s program to promote its policies guiding land use and development around the Bay. The Bay Plan strongly encourages that new transportation facilities be designed to encourage use of mass transit. The proposed project is consistent with this policy, as the proposed alternatives would maintain the HOV bypass lanes at the toll plaza and west approach that presently take buses and carpools around congestion points. The Bay Plan also strongly encourages development and use of public parks. The configuration of overlooks required as part of the I-880 and I-80 projects would be affected by the East Span Project. Given the intent of EBRPD and other parties to provide a much larger area for public access and amenities south of the bridge, public access requirements for parks and overlooks are expected to be fulfilled with any replacement alternative, though with a lesser quality park configuration under Replacement Alternative S-4. EBRPD plans for the Gateway Park are independent of the East Span Project.

Transportation. The BCDC Bay Plan includes the following:

Policy 4. If a route must be located across a waterway, the following provisions should apply:

a. The crossing should be placed on a bridge or in a tunnel, not on solid fill.

b. Structures should provide adequate clearance for commercial ships, Navy ships, and pleasure boats to have uninterrupted passage at all times.

c. Toll plazas, service yards, or other ancillary features should not be located on new fill.

d. To provide maximum ultimate capacity on any new route that is allowed over or under a waterway (and thus to minimize the number that might have to be allowed in the Bay), the design of the route should, if feasible, accommodate future mass transit facilities and subsequent installation of automatic power and guidance elements for vehicles.

The East Span Project is consistent with BCDC policy "a". All alternatives propose a bridge crossing. Concerning policy "b", the height of all alternatives under consideration has been set in consultation with the USCG to provide adequate navigational clearance. Project alternatives would not require new fill for ancillary facilities. The project alternatives are, therefore, consistent with policy "c". Although the project does not propose a new route over the Bay, project alternatives are consistent with policy "d" in that consideration is being given to accommodation of structural loading requirements for future light rail transit.

Dredging and Fill. Bay Plan Dredging Policy 2 establishes a preferential hierarchy for disposing of dredged material. This hierarchy is intended to minimize impacts to the Bay from dredge disposal activities. The policy states that dredged material should be disposed of by:

Dredging required for the project would result from construction activities (see Section 4.14.10 — Construction Excavation and Dredging). Caltrans has initiated consultation with BCDC and other regulatory agencies through the Dredged Material Management Office (DMMO) concerning disposal of dredged materials (see correspondence in Appendix G). Dredged material would be disposed of at locations approved by the DMMO and subject to BCDC review for policy consistency.

Section 66605 of the McAteer-Petris Act (discussed in Section 3.1 — Community Setting) and the Bay Plan regulate Bay fill, requiring that fill be minimized and permitted only if it meets certain conditions. Under Section 66605, bridges are considered to be water-oriented uses for which fill can be placed in the Bay. (Refer to Section 4.9.1 — Placement of Fill in the San Francisco Bay for a discussion of Bay fill quantities.) Permanent Bay fill associated with the build alternatives include bridge piles, pile caps, piers, and decks, and engineered fill for the westbound roadway and Caltrans' maintenance road at the Oakland Touchdown area. Temporary Bay fill associated with the build alternatives include trestles, falsework, cofferdams, barge mooring facilities, and other construction facilities.

Visual. Bay Plan policies related to the appearance and design of bridge structures and the visual prominence of bridge towers are advisory only. Policies relating to maximizing views to the Bay from bridges are enforceable. The Retrofit Existing Structure Alternative is generally consistent with these policies because it would not change existing railing heights or add substantial new superstructure that would decrease motorists’ views. Modifications to the substructure including addition of two bridge columns and expansion of existing columns would not change the basic visual form of the existing structure.

The replacement alternatives are consistent with the Bay Plan’s visual policies. Bay Plan policies concerning views to and from the bridge and tower type and design were incorporated into design recommendations developed by the Metropolitan Transportation Commission's (MTC's) Bay Bridge Design Task Force (Task Force) and the Engineering and Design Advisory Panel (see Appendix E).

Construction of the build alternatives (including the Retrofit Existing Structure Alternative) would require a permit from BCDC pursuant to the McAteer-Petris Act and a concurrence from BCDC that the project is consistent with the Commission’s federally approved Coastal Zone Management Program (CZMP). Both the required development permit and the concurrence must establish that construction of the replacement alternatives is consistent with the McAteer-Petris Act, the San Francisco Bay Plan (including the "Park Priority Use" designation at YBI), and the Seaport Plan.

Caltrans has initiated consultation with BCDC concerning consistency of the East Span Project with the Commission’s CZMP. In a letter dated February 4, 2000, BCDC provided a preliminary concurrence for the East Span Project. (Refer to Appendix G: Agency Consultation Letters.)

After the Record of Decision has been approved, the FEIS and detailed engineering will be provided to BCDC during final project design for its use in the federal consistency concurrence and Bay Plan permit process.

4.2 TRANSPORTATION

Each of the proposed alternatives would retain five eastbound and five westbound traffic lanes on the East Span. Replacement alternatives would require roadway modifications on YBI and the Oakland Touchdown area (as summarized below), but none of the alternatives would create long-term impacts to local traffic, transit, and maritime traffic. Construction-related impacts are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

4.2.1 Vehicular Circulation and Access

For each alternative, changes in vehicular traffic circulation, operations, and access are identified and design considerations are described that would be incorporated into the alternatives.

SFOBB Traffic Operations

Traffic operations under the No-Build Alternative and the Retrofit Existing Structure Alternative would remain the same as under existing conditions. Each of the East Span replacement alternatives may improve traffic operations on the SFOBB: the addition of 3-meter (10-foot) shoulders on both sides of the roadway would provide refuge for disabled vehicles. This may reduce non-recurrent congestion caused by minor accidents or stalls that block one or more lanes of traffic. However, the extent of non-recurrent congestion caused by major incidents is unlikely to be affected by the addition of shoulders. The addition of shoulders would also reduce the number of lane closures for maintenance.

During traffic incidents, all of the proposed replacement alternatives for the East Span Project may experience traffic operational impacts in the opposite travel direction from the incident as a result of rubbernecking. When an incident occurs on a typical freeway segment, secondary congestion frequently occurs in the opposite direction of travel as a result of drivers slowing to view the incident. When an incident occurs on either the upper or lower deck of the existing SFOBB, there is currently no impact to traffic headed in the opposite direction because drivers are unable to see opposing traffic or incidents. The proposed replacement structures would place eastbound and westbound traffic at the same level and 15 meters (50 feet) apart, creating opportunities for drivers to see incidents on the opposite structure, which may cause delays in the non-incident travel direction.

Yerba Buena Island

There would be no long-term impacts to traffic circulation, access, or transit operations on YBI from the No-Build Alternative, Retrofit Existing Structure Alternative, or the replacement alternatives. The replacement alternatives would, however, create long-term changes in the alignment of certain YBI roadways as described below. These roadway modifications would be required for each replacement alternative. No loss of access would result under the replacement alternatives. Neither the No-Build nor the Retrofit Existing Structure Alternative would require long-term roadway modifications.

Required roadway modifications as a result of the Preferred Alternative are described in detail in Section 2.6.2 — Bridge Replacement Alternatives and summarized below:

The vertical and horizontal changes to the roadways would be slightly different for each replacement alternative, depending on the bridge alignment.

Oakland Touchdown Area

No-Build Alternative, Retrofit Existing Structure Alternative, Replacement Alternatives N-2 and N-6 (Preferred). The No-Build Alternative, Retrofit Existing Structure Alternative, and Replacement Alternatives N-2 and N-6 would have no long-term impacts to traffic circulation, access, or transit. Under the northern replacement alternatives, the existing Caltrans maintenance road would be realigned, but there would be no loss of access.

Replacement Alternative S-4. Replacement Alternative S-4 would not affect existing transit service in the Oakland Touchdown area, but would require modification of existing access patterns.

Under Replacement Alternative S-4, the existing Caltrans maintenance road would need to be realigned (see Figures 2-11.4 and 2-11.5 in Appendix A). The southern shoreline east of Replacement Alternative S-4 would continue to be accessed by Burma Road, which would be truncated at existing Terminal Seven. The portion of Burma Road that would be eliminated would not affect traffic circulation or access to any buildings in the area. No loss of access would occur to Caltrans maintenance buildings because access would be configured to the south using the realigned maintenance road. The vertical clearance between the new bridge approach structure and the EBMUD service road would be insufficient to allow large delivery truck access to the EBMUD dechlorination facility. Relocation of the service road, the facility, or both would be required (see Section 4.1.4 — Impacts to Existing Land Use for further discussion).

Local access roadway reconfigurations would be part of the construction of Replacement Alternative S-4. Realigned access roadways would serve existing facilities and any future park development, with the exception of the dechlorination facility. Relocation of the dechlorination facility is discussed in Section 4.1.4 — Impacts to Existing Land Use. No other impacts due to change in access would result; therefore, no mitigation is proposed.

4.2.2 Non-Motorized Traffic: Bicycles and Pedestrians

Pedestrian and non-motorized traffic are currently prohibited on the existing East Span and no dedicated, signed bicycle/pedestrian paths currently exist within the project area. Project alternatives have been assessed for the potential to accommodate planned and proposed pathway connections, and the replacement alternatives each incorporate a bicycle/pedestrian path.

Citizen participation in planning for the bicycle/pedestrian path on the East Span has been facilitated by the MTC and Caltrans through the Bay Bridge Bicycle/Pedestrian Advisory Committee (BPAC).

Yerba Buena Island

Project alternatives have no permanent impacts to bicycle and pedestrian circulation on YBI. The 1996 Draft Reuse Plan proposes bicycle and pedestrian modes as the primary modes of transportation on YBI. There are currently no signed bicycle paths or lanes on YBI and the Navy and the CCSF have no plan in place for the creation of bicycle/pedestrian facilities on the island. Bicycle and pedestrian use of public street rights-of-way on YBI would be possible under any East Span Project alternative. The bicycle/pedestrian path proposed for the Preferred Alternative (Replacement Alternative N-6) and Replacement Alternatives N-2 and S-4 would terminate on the eastern side of YBI. In the final design phase for a replacement alternative, Caltrans would work with the Navy and/or the CCSF to design appropriate path connections to the local roadway network. Caltrans would consult with the Navy and/or other property owners on YBI about their interest in having directional signage installed for path users on the bridge. If consultation results in agreement on the nature and placement of the signs, Caltrans would install the signage. To the extent the Navy and CCSF believe the SFOBB bicycle/pedestrian path would create excessive demand on Navy/CCSF facilities on YBI, Caltrans would limit access to YBI at the request of the Navy and/or the CCSF. Should the Navy or the CCSF desire YBI access to be specifically directed, limited, or prohibited, Caltrans would work with these agencies to design signage or barriers. Caltrans does not have responsibility or authority for areas of YBI and TI once path users leave the path on the East Span.

Caltrans and MTC are currently preparing a feasibility study for a possible bicycle/pedestrian/maintenance path from San Francisco across the West Span and a connection around YBI to a path on the replacement East Span. The preliminary design in this study locates the potential West Span path at the upper deck level outward of the existing stiffening trusses on both sides of the West Span. The pathway would descend into San Francisco on elevated structures west of the current San Francisco anchorage and terminate near the intersection of Harrison and Fremont Streets. East of the YBI anchorage, the path would continue on elevated structures which would connect to an at-grade path along the south side of YBI, generally along the existing Treasure Island Road, that would then connect to the East Span path. Any future pathway on the West Span and on YBI would be a separate project. The East Span path could accommodate connections to a possible path on the West Span.

Oakland Touchdown Area

No-Build and Retrofit Existing Structure Alternatives. The No-Build and Retrofit Existing Structure Alternatives would have no impacts to bicycle and pedestrian circulation in the Oakland Touchdown area.

Replacement Alternatives. The replacement alternatives, including the Preferred Alternative (Replacement Alternative N-6), would create no negative impacts to bicycle and pedestrian circulation in the Oakland Touchdown area. Access to and from the replacement alternatives would be from the south side of the eastbound structure. Each of the replacement alternatives would provide bicycle/pedestrian access to the bridge and would provide sufficient vertical clearance where necessary to permit a bicycle and rider to travel under bridge structures. The Bay Trail would connect with the East Span structure from West Oakland along a bikeway adjacent to I-80 to be provided by Caltrans under the requirements of BCDC Permit 11-93. This Oakland-to-Emeryville segment of the Bay Trail will be funded by Caltrans as part of the I/880 Cypress Freeway Replacement Project. Implementation of this Bay Trail segment will be coordinated with the East Span Project and Gateway Park plans.

East Span Bicycle/Pedestrian Access

Proposed alternatives have been evaluated for their potential to provide bicycle and pedestrian access to and on the East Span. Criteria used to assess project impacts are:

No-Build and the Retrofit Existing Structure Alternatives.

Path Accommodation and Placement. The No-Build and the Retrofit Existing Structure Alternatives do not incorporate a new bicycle and pedestrian path. The existing cross section of the bridge has five 3.5-meter (11.7-foot) travel lanes with no roadway shoulders, limiting the ability to restripe the bridge deck to accommodate a path on the bridge. It may be possible to add a bicycle/pedestrian path to the existing bridge in the future under the No-Build or Retrofit Existing Structure Alternatives; however, MTC has provided funding only for a path on a replacement alternative.

Replacement Alternatives N-2, N-6 (Preferred), and S-4.

Path Accommodation. A bicycle and pedestrian path has been incorporated into each replacement alternative (see Figure 2-8 in Appendix A). A path would be constructed on the south side of the eastbound structure for each replacement alternative. The path would be 4.7 meters (15.5 feet) wide and 0.3 meter (1 foot) higher than the adjacent travel lanes and would include viewing areas, referred to as belvederes. The five belvederes on the skyway would be approximately 12 meters (39 feet) long by 1.2 meters (4 feet) deep. Caltrans is still investigating whether to include one or two belvederes on the main span; they would be 20 meters (66 feet) long by 1.2 meters (4 feet) deep. This configuration was developed with input from the BPAC and was approved by the MTC. Provision of bicycle/pedestrian access on the East Span would be a beneficial impact.

Consistency with Local Plans and Policies

Each of the East Span replacement alternatives, including the Preferred Alternative, would provide a bicycle and pedestrian path between YBI and the Oakland Touchdown area. Provision of the path would be consistent with the following local plans:

Impacts to SFOBB Bicycle Shuttle Service

All East Span Project alternatives could accommodate the existing Caltrans bicycle shuttle service.

4.2.3 Parking

For each alternative, changes in long-term parking supply resulting from project alternatives have been identified. It should be noted that Caltrans' temporary construction easement (TCE) includes the majority of the Parade Grounds, where YBI parking is available. A small portion of the Parade Grounds is owned by Caltrans. The TCE shall terminate when Caltrans determines that it no longer is required , at which time the property will revert to the federal government.

Yerba Buena Island

No-Build Alternative. The No-Build Alternative would not modify the number of parking spaces on YBI.

Retrofit Existing Structure. Strengthening of existing Column YB3 under the Retrofit Existing Structure Alternative would eliminate approximately four informal parking spaces in the paved area east of Quarters 1. Given the large undeveloped area available for parking, the loss of four parking spaces at the eastern end of this area would not contribute to unmet parking demand and would not create an impact. No mitigation would be necessary for this minor change in parking supply.

Replacement Alternatives. Each of the East Span Replacement Alternatives, including the Preferred Alternative, would eliminate between 6 and 8 informal parking spaces in the paved area east of Quarters 1. Given the large undeveloped area available for parking, the loss of this small number of parking spaces would not contribute to unmet parking demand and would not create an impact. No mitigation would be necessary for this minor change in parking supply.

Oakland Touchdown Area

There would be no long-term loss of parking spaces under any of the project alternatives. The project would add day-use parking as part of public access. There would be a new parking lot near the entrance to the bicycle/pedestrian path on the bridge. The parking lot would be temporary to avoid conflicts with plans for the Gateway Park and could eventually be incorporated into the park design. The size of the lot is undetermined at this time, but would, at a minimum, satisfy the parking requirements of BCDC Permit 11-93 for six parking spaces.

4.2.4 Marine Traffic

The potential for ship collisions with the East Span alternatives has been evaluated. Impacts to the structures from vessel types likely to use the waters under the bridge are presented below.

Methodology

Information regarding type, size, and frequency of vessels that use the shipping channel east of YBI was collected to determine vessels likely to pass under the East Span in open water. The largest vessels currently using the main navigation opening are fuel barges traveling to and from the oil refinery at Point Richmond.

American Association of State Highway and Transportation Officials (AASHTO) specifications were used to estimate impact loads on towers and columns. Head-on and side-impact collisions were considered. To evaluate worst-case impacts, it was assumed that cruise ships could use the east channel under potential development scenarios for TI. The vessel’s speed, mass, and crushing of its hull were considered in developing impact loads. Cruise ships, being larger than existing barges using the eastern navigation channel, would generate the largest impact loads.

No-Build Alternative

The No-Build Alternative would not modify the existing East Span and would not change navigation patterns through the main navigation opening. No modifications to the bridge are proposed under this alternative; therefore, no modifications would be constructed to minimize impacts of future ship collisions. Should a collision occur, existing fenders would protect the existing bridge. Existing deteriorated fenders are being repaired, and these fender systems would also be repaired as required following vessel collisions.

Retrofit Existing Structure Alternative

The Retrofit Existing Structure Alternative would strengthen existing columns in the main navigation opening, shorten spans, increase the ability of the structure to withstand impact from a maximum-design cruise ship at the main span columns and impacts of barges at the shorter span columns. More columns would increase the likelihood of a collision between a vessel and a column. The additional columns would also narrow the existing main navigation opening. The alternative would maintain a width of at least 147 meters (481 feet) between columns in the main navigation opening, and a vertical clearance of 42 meters (138 feet) over mean high water. The resulting channel width, while slightly less than the 152 meters (500 feet) recommended by the USCG, would be adequate for navigation. Following construction of Columns E2A and E2B in the existing main navigation opening, column protection, such as fenders, would be needed at least in the three new main navigation openings. The USCG is evaluating whether or not column protection would be needed in other navigation openings. Column protection would be provided where identified as necessary by the USCG.

Replacement Alternatives N-2, N-6 (Preferred), and S-4

As part of the bridge design, protective fenders are proposed at the main tower and skyway columns to provide sufficient standoff to prevent vessels from hitting columns and reduce pile cap damage on impact. The fenders could be either pile-supported or pile cap-mounted. One possible fender system would have a timber-rubbing face and remain elastic up to a particular level of impact energy. Beyond this level, it absorbs energy by damage to the concrete and timber, but is designed to be easily repaired. The system also provides a wearing surface on the column for minor collisions and bumps from merchant and recreational vessels.

All skyway foundations would be able to withstand the impact of a light drifting barge, and skyway columns would be able to withstand the maximum-design barge impact. The main towers and skyway column foundations would be capable of sustaining impacts for the maximum-design cruise ship.

No potential for significant damage to replacement structures has been identified, due to design of columns and fender systems, and no mitigation is required.

Each of the replacement alternatives would narrow the existing main navigation opening approximately 57 meters (187 feet). The replacement alternatives would have a navigation opening width of 348 meters (1,142 feet) and a vertical clearance of 43 meters (140 feet) over mean high water, and the resulting horizontal and vertical clearance would conform to USCG recommendations. The project would install all applicable navigation aids, such as fenders and lights.

4.2.5 Air Traffic

The No-Build and Retrofit Existing Structure Alternatives would not change the location or height of towers and would not require changes to obstruction markings or lighting to alert aircraft to the presence of the existing East Span.

The replacement alternatives, including the Preferred Alternative, would change existing obstruction markings and lighting. Federal Aviation Administration (FAA) Form 7460-1, "Notice of Proposed Construction or Alteration," would be filed with the FAA. The form would disclose the location and height of a cable-supported tower. The main span tower of the replacement alternatives would be higher than 150 meters (500 feet) above mean sea level and would require warning lights. Warning lights are required because the tower would exceed 61 meters (200 feet), which is FAA’s maximum height for which warning lights are not required.

4.3 VISUAL IMPACT ANALYSIS

The purpose of the visual impact analysis is to evaluate the large-scale visual impacts of the project on the Bay Area.

The focus of the visual impact assessment is on the visual impacts of the Retrofit Existing Structure Alternative and design variations of the replacement alternatives (skyway and main span) and alignments of replacement alternatives (Replacement Alternatives N-2, N-6, and S-4) in terms of visual obstruction, dominance within the viewshed, and design quality in terms of vividness, intactness, and unity. These issues are also considered with respect to the types of viewers that would be affected by the project (residents, office workers, motorists, pedestrians, bicyclists, and recreational users).

The visual simulation figures (4-4 through 4-17c) in Appendix A include the Retrofit Existing Structure Alternative and Replacement Alternatives N-6 and S-4. Replacement Alternatives N-6 and S-4 were chosen because they demonstrate most clearly the differences between a northern and southern alignment. Replacement Alternative N-2 was not used in the photo simulations because it is located between the two other alternatives and would not enhance the representation of differences between a northern and southern alignment.

The following sections describe the visual impacts of the various project alternatives on each of the landscape units which make up the project area (Section 4.3.1), as well as the changes in visual quality that would be experienced from the 20 representative viewpoints around the Bay Area (Section 4.3.2). The changes in visual quality for motorists traveling on the East Span are also discussed (Section 4.3.3). Impacts and mitigation for tree removal and slope disturbance are summarized in Section 4.3.4.

Various bridge types other than cable-stayed, self-anchored suspension (preferred design variation), and skyway designs are not discussed in this section. An earlier process was established to evaluate the merits of these other bridge design types. The process began with meetings of the MTC Bay Bridge Design Task Force. The Task Force initiated an open request for ideas about the design of the main span of the East Span and held numerous public meetings. The Task Force also received an evaluation of various designs by a distinguished panel of engineering and architectural experts (the Engineering and Design Advisory Panel) and elected officials. (See Appendix E — Consultation and Coordination for more details.)

4.3.1 Visual Impacts Resulting in Changes Within Landscape Units

Landscape units are geographically distinct portions of the study area which have a particular visual character. The change to each of the five landscape units described in Section 3.3.2 — Existing Landscape Units and Visual Image Types was assessed for each of the four build alternatives and a number of design variations. The impact on landscape units and visual image types is evaluated for the period when the bridge is in full operation. Each landscape unit would be affected differently according to the combination of these alternative/design variations.

Yerba Buena Island

Retrofit Existing Structure Alternative. The retrofit alternative would not require alteration of visual features on the island. Operations would be identical to what exists today. All visual image types within this landscape unit would remain intact. Adding substantial structural members on the outside of the cantilever superstructure would add clutter and mass to existing bridge.

Skyway/Main Span Design Variations. Following construction and dismantling of the existing bridge, the YBI landscape unit would appear altered by the removal of portions of woodlands to the north and south of the span. The removal of vegetation would be a substantial alteration of this landscape unit and, depending on the size and species of the replacement planting, would require approximately 10 to 20 years to reestablish itself to its current density. It is probable, depending on the amount of clearing required, that residential structures currently obscured by the vegetation would become visible. Mitigation is discussed in Section 4.3.4 — Impacts Due to the Removal of Vegetation and Slope Disturbance.

The slope to the south of the East Span is extremely steep and, though the steepness of the slope would restrict the amount of construction activity which could take place on it, some access would be necessary to construct temporary and permanent columns on and near the slope. The appearance of this part of the slope may be permanently altered after construction, since the extreme angle of the slope and the characteristics of the underlying geology may not permit the slope to be returned to its original grade.

In addition, the footprint of the bridge itself would be altered because the single-deck roadway design would be more than three times the width of the existing span and require approximately 25-30 columns which would affect views to and from the island.

Replacement Alternative S-4 would reduce the size of the USCG facilities, although the structures that could be removed are not currently visible from the existing span. Similarly, Replacement Alternatives N-6 (Preferred) and N-2 would reduce the image type represented by removing Buildings 30, 40, 75, and 270. These structures are not currently visible from the existing span.

Main Span

Retrofit Existing Structure Alternative. Following the seismic strengthening measures, the landscape unit would reflect a slight increase in view blockage as a result of the introduction of two new columns, encasing other columns, and the installation of cross pieces. This would not be considered a substantial visual impact. The Bay would remain the predominant visual image type within this landscape unit.

Skyway Design Variation. Following the construction and dismantling period, this landscape unit would appear much different. The bridge deck would exhibit a much thinner profile than the existing structure because the cantilever element would not be present. In addition, the bridge would be a single-deck rather than a double-deck roadway. The steel cross beams that extend from the upper to lower deck on the existing structure would no longer be present. The skyway design variation profile would consist of a simple concrete sidewall along either side of the deck, reading like a ribbon from points north and south. The predominant visual image type within this landscape unit would be the Bay.

Main Span Bridge Design Variation. Following the construction and dismantling period, the landscape unit would be dominated by a much taller and different tower element. The contrast between the existing cantilever and truss elements and the proposed single-tower element would be dramatic. The bridge would also be modified through the removal of the double-deck roadway. The single-deck side-by-side roadway would produce a much thinner profile, and the image of the bridge would be sleeker and lighter, because there would no longer be steel beams connecting the upper and lower decks. The predominant visual image type would remain the Bay.

Incline Section

Retrofit Existing Structure Alternative. The retrofit alternative would produce the least amount of change from the existing span. The span would continue to have two bridge decks connected by steel beams. The predominant visual image type of the incline section would remain the Bay. No change in the SFOBB’s alignment would occur, and the bridge would appear visually much as it does today.

Skyway/Main Span Bridge Design Variations. Both the skyway and main span design variations would provide a skyway deck along this portion of the span. The greatest change to this landscape unit involves the replacement of the existing double-deck structure with side-by-side single decks. This change would cause the bridge to be more than double in width, while the height of the deck area would be reduced as a result of the reduced height of the bridge rail and the absence of the upper deck.

Replacement Alternative S-4 would offer the greatest change in viewshed as it follows a more southerly alignment, while Replacement Alternatives N-6 (Preferred) and N-2 remain closer to the SFOBB’s existing alignment along this section of the bridge.

Oakland Touchdown

Retrofit Existing Structure Alternative. The retrofit alternative would produce the least amount of change from the existing span. The visual image types currently present at the touchdown area would not be altered with the implementation of the retrofit alternative. The alignment of the East Span would not change and additional right of way would not be required for its construction. The predominant visual image types would remain marsh and estuary areas and light industrial.

Skyway/Main Span Bridge Design Variations. Replacement Alternatives N-6 (Preferred) and N-2 would require construction within a portion of the area to the north of the existing span designated for resource conservation by the City of Oakland. Replacement Alternative S-4 would require construction within undeveloped and light industrial land to the south of the existing span. The result of this change in the SFOBB’s existing alignment would be a reduction in the visual image types (marsh, estuary, and light industrial) associated with the land taken by the replacement alternatives. Replacement Alternatives N-2 and N-6 (Preferred) may involve adding fill along the north side of the Oakland Touchdown to support bridge approach structures. Addition of fill would change the appearance of this portion of the touchdown.

The bridge itself would produce a much narrower profile and would be a lighter, more streamlined structure. The steel cross beams that currently extend between decks would not be present, and the single decks would be placed side by side rather than stacked one on top of another. The structure would be similar to what exists today as the bridge at this point is rejoining the SFOBB’s existing alignment as it approaches the toll plaza.

SFOBB Toll Plaza

The toll plaza area would not undergo substantial change as a result of the project. The proposed replacement alternatives, including the Preferred Alternative, would rejoin the existing roadway at the toll plaza. The location of the toll booths would not change, and the realignment of the roadway to the north or south would not substantially affect the existing visual appearance of this landscape unit.

4.3.2 Impacts on Views from the Bridge

The following section describes the visual changes that motorists traveling on the SFOBB East Span would experience under the retrofit and replacement alternatives. To aid in this evaluation, an animation of the motorists’ views was created for the replacement alternative’s main span bridge design variations. Still pictures of key views from this animation are presented in Figures 4-2 to 4-3b in Appendix A. The complete set of animation is provided on a CD-ROM included in the Visual Impact Assessment Report which can be reviewed at locations identified in the Preface and on the worldwide web at www.dot.ca.gov/dist4.

Retrofit Existing Structure Alternative

The retrofit alternative would only slightly change motorists’ views from the existing East Span. The current double-deck structure would be maintained, including its solid steel sidewalls that block some motorists’ views of the Bay. Steel crossbeams that extend from the upper to the lower deck would be modified to permit large displacements at specified joints. As a result, views would continue to be restricted, especially in the eastbound direction where the presence of the westbound deck overhead results in a further obstruction to the viewshed. Adding substantial structural members on the outside of the cantilever superstructure would add clutter and mass to the existing bridge.

Skyway Design Variation

The skyway design variation would result in substantial changes to the motorists’ view, because it would create side-by-side roadway decks with concrete side barriers and railings designed to facilitate views from the structure unlike the existing structure that has steel cross beams that extend from the upper to the lower structure. Because the skyway design variation would not include a main span tower, views would remain unobstructed throughout the length of the East Span.

With Replacement Alternatives N-6 (Preferred) and S-4, views toward the skyline of San Francisco would be expanded for westbound travelers, while Replacement Alternative N-2 would produce views similar to the existing span. Eastbound travelers would experience expansive views toward the Port of Oakland and toward the hills above the communities of Oakland, Berkeley, and Alameda, although visibility to the south may be compromised by the presence of a 4.7-meter (15.5-foot) wide bicycle/pedestrian lane and railings.

Although views from the East Span with the skyway design variation would be greatly expanded, three design issues would have an impact upon the extent of views from the structure. First, the roadways would be placed side by side. The impact of side-by-side roadways would be that viewers would have a five-lane roadway in the foreground of their view to the north (when traveling in the eastbound direction) or south (when traveling in the westbound direction). Second, the addition of a 3-meter (10-foot) shoulder on each side of the roadway further expands the structure in the motorists’ foreground view. Finally, the creation of a 4.7-meter (15.5-foot) wide bicycle/pedestrian path on the south side of the eastbound bridge deck would affect views southward from the East Span. The bicycle and pedestrian lane would be raised 0.3 meter (1 foot) above the flow of auto traffic, further restricting views to the south.

When comparing replacement alternatives, Replacement Alternatives N-6 (Preferred) and S-4 would expand westbound views toward San Francisco by allowing views around YBI, because of their northerly and southerly locations, respectively, in comparison with the existing East Span. Replacement Alternative N-2 would expand views to a lesser degree because it closely follows the alignment of the existing East Span.

Main Span Design Variations

The main span design variations would also expand views from the East Span because, as with the skyway design variation, the East Span would be constructed with side-by-side roadways, concrete side barriers, and railings designed to facilitate views from the structure. The main span tower and cables would somewhat obstruct views as vehicles pass through the main span section. However, overall views would increase greatly when compared with the existing structure. In addition, views of the towers and cables while driving on the incline would increase the vividness of the view from the incline.

As with the skyway design variation, Replacement Alternative N-6 (Preferred) and Replacement Alternative S-4 would produce expanded views toward the skyline of San Francisco for westbound travelers, while Replacement Alternative N-2 would produce an effect similar to the existing span. Eastbound travelers would experience expansive views toward the Port of Oakland and toward the hills above the communities of Oakland, Berkeley, and Alameda, although views to the south may be compromised by the presence of a 4.7-meter (15.5-foot) wide bicycle/pedestrian lane and railings.

The design issues noted above for the skyway design variation would have a similar impact on views from the main span tower. The creation of side-by-side single decks, the addition of 3-meter (10-foot) shoulders, and the construction of a 4.7-meter (15.5-foot) bicycle/pedestrian path would restrict views from the East Span to the north and south. Figures 4-2, 4-3a, and 4-3b in Appendix A depict a motorist’s view while driving on the main span variation.

When comparing replacement alternatives, Replacement Alternatives N-6 (Preferred) and S-4 would expand westbound views toward the city of San Francisco by allowing views around YBI, because of their northerly and southerly locations, respectively, in comparison with the existing East Span. Replacement Alternative N-2 would expand views to a lesser degree, because it would closely follow the alignment of the existing East Span.

4.3.3 Impacts on Views to the Bridge

The changes in visual quality due to the project alternatives have been analyzed from 20 viewpoints around the Bay Area, as described in Section 3.3.3 — Viewer Groups and Viewpoints. Generally, the changes that would occur with each of the various project alternatives and design variations would be similar from each of the viewpoints. The analysis from five viewpoints has been included in the FEIS to represent the changes in visual quality from each location. These viewpoints are Richmond (from the north), the Oakland Touchdown area (from the east), the Oakland-San Francisco Ferry (from the south), TI (from the west), and the Nimitz House on YBI. This analysis included computer-generated visual simulations.

Impact of Build Alternatives

The retrofit alternative would have a negligible impact on visual quality from distant viewpoints, because the structural elements added to the East Span would not be perceptible. For some of the closer viewpoints, the retrofit alternative would have a minimally adverse impact on viewers, as the additional structural elements (new columns and strengthening of existing columns) would obstruct views underneath the bridge.

The main span design variations (self-anchored suspension [preferred design variation] and cable-stayed) would result in the most favorable impact upon visual quality regardless of the viewpoint location. Typically, this is due to the increase in the vividness of the span. Also, overall unity would occur with the self-anchored suspension main span. While conditions would vary at individual viewpoints, overall the three replacement alternatives (N-2, N-6 [Preferred], and S-4) would result in virtually identical visual impacts.

The skyway design variation would result in the greatest reduction in visual quality. Typically, this impact would be due to a reduction in the vividness and intactness of the span caused by the simpler structure and thinner bridge deck. While conditions would vary at individual viewpoints, overall the alignments of the three replacement alternatives under the skyway design variation would result in virtually identical visual impacts.

Analysis from Representative Viewpoints

Richmond Marina.

Retrofit Existing Structure Alternative. The retrofit alternative would have a negligible impact on visual quality. The long distance from this viewpoint to the East Span would make changes to the columns and support structures imperceptible.

Skyway Design Variation. The skyway design variation would have a minimally adverse impact on visual quality, due to its reduction in vividness (see Figure 4-4 in Appendix A). While it would remain at a favorable viewing angle, the simplicity of the structure would eliminate the striking and distinctive nature of the existing East Span.

Main Span Design Variations. The self-anchored suspension (preferred design variation) and cable-stayed design variations would have a minimally beneficial impact on the visual quality of the view towards the East Span. The main span tower would add landmark strength and distinctiveness, but the distance between the viewpoint and the East Span would make its distinct elements difficult to discern.

The self-anchored suspension (preferred design variation) and cable-stayed design variations would have a beneficial impact on the overall visual quality from the Richmond Marina, due to the increase in the vividness of the East Span and overall unity of the view (see Figure 4-5 in Appendix A). Unity would increase the greatest amount (from moderate-to-high to high) for the self-anchored suspension main span, due to the visual similarity, prominence, and shape compared with the SFOBB West Span (which is visible from the vantage point). Unity would increase less (remaining at moderate-to-high) with the cable-stayed main span, because its shape would not echo the cable forms of the SFOBB West Span.

Oakland Touchdown Area.

Retrofit Existing Structure Alternative. The retrofit alternative would result in a minimally adverse impact on visual quality of the view toward the East Span, due to the increase in view obstruction. New support columns and other structural elements added as part of the retrofit alternative would decrease views beneath the East Span.

Skyway Design Variation. The skyway design variation would result in a minimally adverse impact on visual quality, due to the slight decrease in the vividness of the East Span (although the East Span’s close proximity and prominence mean vividness would still remain high) (see Figure 4-6 in Appendix A). In addition, with Replacement Alternatives N-2 and N-6 (Preferred), there would be a slight increase in view obstruction. These alternatives would provide views similar to the existing East Span, although its more gradual rise from east to west would obstruct views from beneath the East Span to the north.

Main Span Design Variations. The self-anchored suspension (preferred design variation) and cable-stayed design variations would result in a minimally beneficial impact on visual quality of the view toward the East Span, due to the increase in vividness and unity and the fact that the East Span occupies much of the larger view (see Figure 4-7 in Appendix A). The main span tower would add landmark strength and distinctiveness. Vividness would increase the most with Replacement Alternatives N-6 (Preferred) and S-4, because the main span tower would be at a more favorable viewing angle (closer to 45 degrees) than Replacement Alternative N-2.

Unity would increase most with Replacement Alternatives N-2 and N-6 (Preferred), though the overall impact is slightly lessened by the high visibility, from this viewpoint, of approximately 30 support columns on YBI. Compared to Replacement Alternatives N-2 and N-6, Replacement Alternative S-4 would produce less of an increase in unity because portions of the SFOBB West Span would be visually obstructed. With all replacement alternatives, unity would increase more with the self-anchored suspension main span, due to the visual similarity, prominence, and shape compared with the SFOBB West Span and Golden Gate Bridge (which are visible from the vantage point). Unity would increase less with the cable-stayed main span, because its shape does not echo the cable forms of the SFOBB West Span.

Oakland-San Francisco Ferry.

Retrofit Existing Structure Alternative. The retrofit alternative would result in a negligible impact on visual quality. New support columns and other structural elements added as part of the retrofit alternative would decrease views beneath the East Span. However, views beneath the East Span would be constantly changing as the ferry travels across the Bay, thereby minimizing the view obstruction created by the new columns and structural elements.

Skyway Design Variation. The skyway design variation would result in a minimally adverse impact on visual quality, due to the decrease in its vividness (see Figure 4-8 in Appendix A). While it would remain at a favorable viewing angle and would be relatively close, the simplicity of the skyway design variation would reduce the distinctive nature of the existing East Span. The reduction in the vividness would be less perceptible with Replacement Alternative S-4, because it is the closest replacement alternative to this viewpoint. Vividness would reduce the most with Replacement Alternative N-6 (Preferred).

Main Span Design Variations. The self-anchored suspension (preferred design variation) and cable-stayed design variations would result in a minimally beneficial impact on the visual quality of the view toward the East Span, due to the increase in its vividness (see Figure 4-9 in Appendix A). The main span would add landmark strength and distinctiveness to the East Span. When comparing replacement alternatives, vividness would be most increased with Replacement Alternative S-4, because it is nearest to this viewpoint.

The self-anchored suspension (preferred design variation) and cable-stayed design variations would result in a minimally beneficial impact on the overall visual quality of the view toward the East Span, due to the increase in its unity and vividness. The close proximity and visual dominance of the East Span mean that changes to it would substantially affect the overall visual quality of the larger view. Unity would increase more with the self-anchored suspension main span, due to the visual similarity, prominence, and shape compared with the SFOBB West Span (which is visible from this viewpoint). With the cable-stayed main span, unity would increase over existing conditions but less than with the self-anchored suspension main span, because its shape does not echo the catenary forms of the SFOBB West Span.

Treasure Island ­ Viewpoint 1.

Treasure Island - Viewpoint 1 is located on the south end of TI at Clipper Cove looking east at the main portion of the East Span.

Retrofit Existing Structure Alternative. The retrofit alternative would result in a minimally adverse impact on visual quality. This impact is due to the increase in view obstruction from the addition of shear walls on support structures under the bridge toward the city and Port of Oakland (see Figure 4-10 in Appendix A).

Skyway Design Variation. The skyway design variation would result in a minimally adverse impact on the visual quality of the view toward the East Span (see Figures 4-11 and 4-12 in Appendix A). With Replacement Alternative N-6 (Preferred), this decrease would be due to reduced vividness (these impacts are somewhat offset by improved views over the East Span). With Replacement Alternative N-2, the reduction in visual quality would be due to the reduced vividness. With Replacement Alternative S-4, any reduction in visual quality would be due to reduced vividness and additional view obstruction caused by the way the columns would align.

The skyway design variations would result in a minimally adverse impact on the overall visual quality from TI. The close proximity and visual dominance of the East Span within the larger view mean that changes to it would substantially affect the overall visual quality. The reasons for the reduction in overall visual quality are the same as those cited in the preceding paragraph.

Main Span Design Variations. The self-anchored suspension (preferred design variation) and cable-stayed design variations would result in a minimally beneficial impact on the visual quality of the view toward the East Span (see Figures 4-13 and 4-14 in Appendix A). With Replacement Alternative N-6 (Preferred), this impact would be due to the increase in the vividness of the East Span because of the closer proximity of the bridge and its tower and cable systems. In addition, views of the East Bay under the bridge would be less obstructed. With Replacement Alternative N-2, there would be an increase in vividness as with Replacement Alternative N-6. However, Replacement Alternative N-2 would cause view obstruction similar to that of the existing East Span. With Replacement Alternative S-4, vividness would increase over the existing East Span, but would be less than with Replacement Alternatives N-6 and N-2, due to the poor viewing angle and increased distance to the tower and cable systems. Blockage of views to the East Bay under the bridge would be worse with Replacement Alternative S-4 when compared to the existing bridge and Replacement Alternatives N-6 and N-2.

Treasure Island ­ Viewpoint 2.

Treasure Island ­ Viewpoint 2 is located generally in the same location as Treasure Island ­ Viewpoint 1, but further to the east and looking south as opposed to east.

This viewpoint was added to the visual analysis in response to agency comments on the Draft EIS. As a result, this viewpoint is discussed in this FEIS, but not included in the Visual Impact Assessment technical report.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would result in a minimally adverse impact on visual quality. This impact is due to the increase in view obstruction from addition of shear walls on support structures under the bridge (see Figure 4-17a in Appendix A).

Skyway and Main Span Design Variations. The skyway and main span design variations would result in similar negligible to minimally adverse impacts on visual quality of the view toward the East Span (see Figures 4-17b and 4-17c in Appendix A). The tower and cable structures associated with the main span design variations are not visible because they are just to the east of this view. With Replacement Alternative N-6 (Preferred), there would be a negligible impact on visual quality because a similar number of columns would be visible when compared to the existing East Span. In addition, Replacement Alternative N-6 roadway decks would have a similar appearance as the existing East Span’s double-decks because the side-by-side decks of the Replacement Alternatives would be separating in elevation to allow transition into the double-deck Yerba Buena tunnel.

Replacement Alternatives N-2 and S-4 would result in minimally adverse impacts on visual quality because of the additional support columns required on the island to support the side-by-side roadway decks. These columns would create additional blockage of views under the bridge when compared to the existing East Span. This adverse impact is somewhat offset by the reduced depth of the roadway deck that is provided by the side-by-side configuration of the Replacement Alternatives.

Nimitz House, Yerba Buena Island.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would result in an adverse impact on the visual quality of the view toward the East Span, due to the increase in view obstruction and shadows caused by the reinforcement of the existing columns (see Figure 4-15a in Appendix A).

Skyway Design Variation. The skyway design variation would result in a range of impacts from negligible to minimally adverse on the overall visual quality of the view toward the East Span, depending upon the replacement alternative. With Replacement Alternatives N-2 and N-6 (Preferred), there would be a minimally adverse impact, due to the increase in the number and thickness of the visible columns beneath the span. Nimitz House users would likely notice a tangible change and minimal reduction in the visual quality of this view. With Replacement Alternative S-4, there would be a negligible impact, as the increase in the intactness of the East Span (more of the length of the East Span would be visible) would be offset by the increase in view obstruction caused by the increase in the number and thickness of the visible columns beneath the span. However, the columns would be farther away as compared to the northern replacement alternatives. This would open up the immediate foreground.

Main Span Design Variations. The self-anchored suspension (preferred design variation) and cable-stayed design variations would result in a negligible impact on the visual quality of the view toward the East Span (see Figures 4-15b and 4-15c in Appendix A). For all replacement alternatives, there is a negligible impact, because the increase in the intactness of the East Span (more of the length and/or the main span tower of the East Span would be visible) would be offset by an increase in view obstruction (due to the increase in the number and thickness of the visible columns beneath the span).

Yerba Buena Island.

This viewpoint was added to the visual analysis in response to agency comments on the Draft EIS. As a result, this viewpoint is discussed in this FEIS, but not included in the Visual Impact Assessment technical report.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would result in an adverse impact on visual quality. This impact is due to the increase in view obstruction from addition of shear walls on support structures under the bridge (see Figure 4-16a in Appendix A). The addition of the shear walls would reduce views of vegetation on the hills of Yerba Buena Island. However, the vividness and intactness of the bridge would remain relatively unchanged.

Skyway and Main Span Design Variations. Both the skyway and main span design variations would result in similar impacts on visual quality from this viewpoint because the tower and cable structures associated with the main span design variations are not visible from this viewpoint (see Figures 4-16b and 4-16c in Appendix A).

Replacement Alternative N-6 (Preferred) would result in a minimally adverse impact on visual quality. This replacement alternative would result in additional support columns being constructed on Yerba Buena Island. From this viewpoint, these columns would visually line up to create additional blockage of views of vegetation on the hills of Yerba Buena Island. Vividness of the bridge would increase with Replacement Alternative N-6 because the bridge would move closer to this viewpoint, providing a more dramatic sense of the scale of the bridge in relationship to the island and the Nimitz House. There would be a negligible change in intactness of this view because the basic elements of this view (the bridge, Nimitz House, trees and dense vegetation of Yerba Buena Island) would not be substantially changed.

Replacement Alternatives N-2 and S-4 would also result in minimally adverse impacts on visual quality, with Replacement Alternative S-4 resulting in the least adverse impact because of its more southerly location. The reduction in visual quality is primarily due to the number of columns that would be constructed on Yerba Buena Island and the view blockage they would create. As indicated above, the intactness of this view would not change substantially with any of the replacement alternatives. Replacement Alternative S-4 would result in a slight reduction in vividness because it would be the furthest alignment from this viewpoint. While Replacement Alternative N-2 would result in a slight increase in vividness compared to the existing East Span, but somewhat less than Replacement Alternative N-6.

4.3.4 Impacts Due to the Removal of Vegetation and Slope Disturbance on Yerba Buena Island and at the Oakland Touchdown Area

Impacts

All build alternatives would require the removal of woodland vegetation. The Retrofit Existing Structure Alternative would require the removal of 150 trees, while the three replacement alternatives would require the removal of approximately 325 to 350 trees from 15 centimeters to 1.8 meters (6 inches to 6 feet) in diameter within the project’s construction limits on YBI. The trees that would be removed would be within the Caltrans temporary construction easement on Navy-owned land. A large grove of mature trees, primarily eucalyptus, would be removed from the east-facing slopes of the island to accommodate any of the proposed replacement alternatives and associated temporary detours. The average height of the trees is 12 meters (39 feet). The visual impact of the existing trees is dramatic, since they soften the island’s appearance from a distance and screen a number of residences on the island from the bridge. Since the current tree density on YBI constitutes a high fuel load for potential fires, the San Francisco Fire Department has proposed tree thinning on YBI to decrease the risk of fire.

The Retrofit Existing Structure Alternative would result in no vegetation loss at the Oakland Touchdown area because the area was already cleared as part of interim seismic retrofit work that occurred in 1998. All three replacement alternatives would require the removal of a number of trees within the project’s construction limit on the Oakland Touchdown area. Replacement Alternatives N-6 (Preferred) and N-2 would necessitate the removal of 71 mature pine trees. Replacement Alternative S-4 would necessitate the removal of 12 mature pine trees.

The removal of this vegetation on both YBI and the Oakland Touchdown area would constitute a substantial adverse visual impact, and approximately 10 to 20 years would be required before the vegetation could reestablish itself to the density that exists today. The loss of this many trees would be highly noticeable during the construction period and subsequent years until the vegetation has reestablished itself. Views from the bridge, from the East Bay, and views westward from the eastern end of YBI would be affected by the removal of this vegetation. Table 4.3-1 includes the amount of total area disturbed and number of trees removed by alternative.

Table 4.3-1 Tree Removal Estimates

 

 

 

Total Area Disturbed

Maximum

Number of Trees Removed

Yerba Buena Island

   

Alternative N-2

9.4 hectares/23.2 acres

350

Alternative N-6 (Preferred)

10.3 hectares/25.5 acres

350

Alternative S-4

9.4 hectares/23.2 acres

325

Retrofit

5.2 hectares/12.8 acres

150

Oakland Touchdown Area

   

Alternative N-2

3.8 hectares/9.4 acres

71

Alternative N-6 (Preferred)

3.8 hectares/9.4 acres

71

Alternative S-4

5.5 hectares/13.6 acres

12

Retrofit

None

0

Source: Caltrans, August 1998.

The hillside on YBI to the south of the East Span is extremely steep and, though its steepness would restrict the amount of construction activity which would take place on it, some access would be necessary to construct temporary and permanent columns on and near it. The appearance of this slope may be permanently altered as a result of construction efforts. Returning the slope to its original grade may be difficult due to the underlying soil and geology and the steepness of the slope.

Mitigation:

Yerba Buena Island

Caltrans would develop construction limits that minimize impacts to YBI by preserving selected vegetation and maintaining some screening of structures on the island to the maximum extent possible. Specifically, special consideration would be given to preserving the two mature coast live oak trees behind Quarters 1 and all or part of the vegetation which currently screens Quarters 1 from the existing bridge. In addition, the contractor would be required to submit an access plan that would be approved by Caltrans before work on the island is begun. The plan would detail construction activities such as grading of slopes, placement of access roads, removal of vegetation, and locations of platforms needed for large equipment. Caltrans would use this construction access information to ensure that key vegetation is preserved to the maximum extent possible and to aid in tailoring a revegetation plan to pre-construction site conditions. Caltrans would then develop and implement a revegetation plan designed to reestablish vegetation in affected areas, including the planting of mature trees, monitoring, and replanting as necessary to return disturbed areas to a natural appearance and to establish visual screening of the bridge comparable to the existing condition to the maximum extent feasible. This planting plan would be developed in coordination with local agencies and implemented within two years after the bridge construction is completed. Some planting in sensitive areas may be replaced as part of the bridge construction contract.

The contractor would be required to protect the stability of the slope in areas of construction for structure footings positioned on hillside areas. Sheet pile shoring would be used to back the excavated slope and cement-modified soil backfill or other retention systems that would be conducive to revegetation would be used to stabilize the temporary detour foundations. Permanent soil stability measures such as walls and planting would be developed as part of the final design of a replacement alternative.

Oakland Touchdown Area

Mitigation for visual impacts would include development of a master planting plan in coordination with affected local agencies, including the City of Oakland, Port of Oakland, BCDC, and East Bay Regional Park District (EBRPD). The planting plan would be implemented within two years after bridge construction is completed. The Caltrans master replanting plan for the Oakland Touchdown area will be coordinated with the park design being led by the EBRPD. Replanting may take place simultaneously with the construction of the park.

4.4 AIR QUALITY

All the proposed alternatives would maintain five lanes of traffic in both directions on the East Span during and after construction and would not affect traffic volumes on or capacity of the bridge and adjacent freeways. As such, there should not be any change in air pollutant emissions from bridge traffic due to any of the proposed alternatives compared to a No-Build condition. In addition, air quality analyses are typically not required for safety projects such as the East Span Project because the Federal Transportation Conformity Rule exempts safety projects from having to include emission analyses.

However, a possible air quality issue does arise with the replacement alternatives, each of which includes a bicycle/pedestrian path. Users of a bicycle/pedestrian path would be located adjacent to the bridge roadway. A microscale carbon monoxide (CO) analysis was conducted to ensure that sufficient consideration was given to the preservation of air quality along areas of the bridge that might be used for a bicycle/pedestrian path.

This section considers the potential for exceeding state and federal ambient air quality standards for CO along the proposed bicycle/pedestrian path due to project operations. Short-term air quality impacts during construction are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

  1. Methodology

A microscale dispersion analysis of CO emissions was performed using the EMFAC7F emission factor model and CALINE4 dispersion model. Traffic along a typical replacement structure was modeled under year 2005 conditions to determine CO concentrations 5.5 meters (18 feet) from the outside edge of the travel lanes, representing the center of a bicycle/pedestrian path. There would be no other public receptors in the immediate vicinity of the bridge span.

Background concentrations for the year 2005 were determined to be 1.9 parts per million (ppm) for one-hour average and 1.3 ppm for eight-hour average. These background concentrations were determined using Bay Area Air Quality Management District (BAAQMD) isopleth maps and rollback factors. Isopleth maps are maps that show contour lines of CO concentration. The contours are based on monitoring data and can be used to interpolate concentrations where there are no monitoring stations. Rollback factors are used to reduce current CO background levels as an estimate of future levels. It is assumed that CO levels will decline in the future because newer motor vehicles will presumably have better emission controls.

4.4.2 Impacts

Worst-case one-hour and eight-hour average CO concentrations (project roadway contribution plus background concentration) predicted by the CALINE4 model for the bicycle/pedestrian path are 2.7 ppm for a one-hour average and 1.9 ppm for an eight-hour average. These values are well below the federal and state standards. Federal one-hour and eight-hour standards are 35 ppm and 9 ppm, respectively. State standards are 20 ppm for one hour or 9 ppm for eight hours. In conclusion, neither state nor federal CO standards would be exceeded on the bicycle/pedestrian path regardless of location.

4.4.3 Air Quality Conformity

Air quality conformity evaluations for federal transportation projects and regionally significant non-federal projects are conducted pursuant to the Federal Clean Air Act Transportation Conformity Rule. A federal transportation project is defined as any highway or transit project which is proposed to receive funding assistance and approval through the Federal-Aid Highway Program or the Federal Mass Transit Program, or requires Federal Highway Administration (FHWA) or Federal Transit Administration (FTA) approval for some aspect of the project. The East Span Project is federally approved and will use federal funds (see Section 2.4.1 — Comparison of Alternatives Characteristics, Funding). As a result, the East Span Project must meet the transportation conformity requirements described in Section 3.4.1 — Air Quality, Regulatory Context of this FEIS. The East Span Project is included in the currently conforming Metropolitan Transportation Commission’s (MTC) 1998 Regional Transportation Plan (RTP) approved on January 21, 1999 and the 2000/01 Federal Statewide Transportation Improvement Program (FSTIP), which includes as a component the TIP developed by MTC for the Bay Area. MTC’s TIP was jointly approved on October 5, 2000 by FHWA and FTA. The design concept and scope of the proposed project have not changed since inclusion into these documents and do not interfere with the timely implementation of transportation control measures in the applicable State Implementation Plan (SIP).

Projects located in federal CO non-attainment or maintenance areas are subject to a project-level CO analysis under the federal Transportation Conformity Rule. The analysis must show that a project’s build alternatives would not cause exceedances of federal CO standards. Additionally, in non-attainment areas, the project cannot generate CO emissions that would worsen existing violations or delay timely attainment of CO standards.

A microscale CO analysis was conducted, following guidance provided in the Transportation Project-Level Carbon Monoxide Protocol developed by Caltrans and the Institute of Transportation Studies at the University of California, Davis, for the project to determine project level conformity to the SIP as required by the Environmental Protection Agency’s Transportation Conformity Rule. The analysis assumptions were developed in coordination with MTC and are consistent with assumptions used in the regional emissions analysis for the RTP and TIP for those inputs required in both analyses. The analysis shows that there are no CO violations expected in the project area. Since the Bay Area is not considered a federal PM10 non-attainment area, PM10 conformity requirements in the Transportation Conformity Rule are not applicable.

Based on the above information, it is concluded that the East Span Project is in conformity with the SIP. This air quality conformity determination is in accordance with the provisions of 40 Code of Federal Regulations (CFR) Parts 51 and 93.

4.5 NOISE AND VIBRATION

Traffic noise impacts have been analyzed and are presented in this section. Traffic noise impacts are addressed using FHWA Noise Abatement Criteria (NAC) as defined in 23 CFR 772 and Caltrans approved noise policies.

4.5.1 Noise Levels on Yerba Buena Island, Treasure Island, and Oakland Touchdown Area

The noise impact analysis involved modeling for future predicted noise levels for the five alternatives (No-Build, Retrofit Existing Structure, and the N-2, N-6 (Preferred), and S-4 Replacement Alternatives). Potential impacts have been assessed for each alternative for noise-sensitive uses on Yerba Buena Island (YBI), Treasure Island (TI), and the Oakland Touchdown area. The modeled peak-noise-hour levels are shown in Table 4.5-1. A detailed noise impact assessment technical report has been prepared and is available for review at locations listed in the Preface.

In general, future predicted peak-noise-hour levels resulting from Replacement Alternatives N-2, N-6, and S-4 decrease by 1 dBA to 14 dBA compared to the existing condition. The causes of the decrease in modeled noise levels for the future replacement scenarios are:

Impacts

This section describes expected changes in future noise levels for the project alternatives. Receptor locations are shown on Figures 3-12, 3-13, and 3-14 in Appendix A.

No-Build Alternative and Retrofit Existing Structure Alternative. The No-Build Alternative and the Retrofit Existing Structure Alternative would not result in any increase in traffic capacity, any change in geometry, or any change in traffic speeds. Future predicted noise levels under these alternatives would remain unchanged from existing peak-noise-hour levels. Therefore, no requirement exists for a noise assessment of the No-Build Alternative and the Retrofit Existing Structure Alternative.

Replacement Alternative N-2. Replacement Alternative N-2 would lie to the north of the existing East Span and transition from the double-deck viaduct to two parallel structures over YBI. Generally, future noise levels would decrease by 1 to 14 decibels compared to the existing, No-Build, and Retrofit Existing Structure Alternatives, resulting in many of the receptors experiencing future predicted noise levels below FHWA NAC. This would eliminate the need for noise abatement at these locations.

Replacement Alternative N-6 (Preferred). Generally, future predicted noise levels resulting from Replacement Alternative N-6 decrease by 1 dBA to 14 dBA compared to the existing bridge. The lower noise levels are less than the FHWA NAC at many receptors, thus eliminating the need for abatement at these locations

Abatement

FHWA requires consideration of noise abatement (e.g., construction of a noise barrier such as a masonry wall or earthen berm) to attenuate noise when the future predicted peak-noise-hour levels approach or exceed FHWA NAC for appropriate land use categories as described in Section 3.5.3 — Noise Abatement Criteria and Analysis Guidelines. Factors to consider in evaluating noise abatement include effectiveness, cost, visual quality, and public acceptance. For the East Span Project, in which the travel lanes are on a bridge structure, such measures as earthen berms would not be possible. Buffer zones or acquiring additional right-of-way to avoid impacts are not feasible as adjacent land owners (such as the USCG) cannot be easily relocated. Abatement measures in the form of noise barriers along the roadway where it touches on YBI were evaluated in the Noise and Vibration Study for the project (a summary is presented in Appendix P and figures showing possible barrier locations are presented in Appendix A as Figures 4-18 through 4-20).

The sound walls evaluated as part of the noise analysis would not meet current FHWA-approved cost-effectiveness criteria. There are few noise-sensitive locations, and the walls would need to be very long to protect those locations, resulting in a high cost per benefited location.

In addition, the presence of sound walls would conflict with maintaining the aesthetics of the proposed bridge design and views to and from the bridge. Sound walls in which the upper portion of the walls would have see-through panels were considered, but they were rejected for several reasons. Most importantly, Caltrans does not permit the use of see-through panels adjacent to high-speed, high-volume freeways because they have not been crash-tested. Until such testing has been done and this safety concern has been successfully resolved, see-through panels are not permitted adjacent to state highways. See-through panels would have to be cleaned on a periodic basis and would require replacement due to breakage and impacts from fog, salt water, high humidity, and ultraviolet radiation. Even with the use of see-through panels, the visual impact would still remain for viewers of the bridge and for users of the bridge.

During the public involvement process for this project, no public comments were received requesting soundwalls. Proponents of the Gateway Park have expressed interest in retaining views rather than attenuating noise.

Based on the above discussion, it has been determined that noise abatement would not be constructed as part of a replacement bridge.

4.5.2 Noise on the Bicycle/Pedestrian Path

All replacement alternatives would include a bicycle/pedestrian path along the south side of the eastbound structure. To assess future predicted noise levels on the bicycle/pedestrian path, Caltrans performed a noise study of the existing bike path adjacent to Route 24 between Orinda and Lafayette in Contra Costa County. Noise readings of 82 dBA Leq were measured from the center of the bike path, a distance of 7.5 meters (24 feet), to the center of the nearest freeway lane during off-peak traffic (10:30 a.m. ­ 11:30 a.m.). Traffic counts were conducted and average speeds were determined. The results were then adjusted to reflect peak-period traffic on the bridge, a noisier condition. No profile grade adjustments were made. Route 24 has a profile grade of three percent, while the proposed new East Span would have a profile of less than two percent. Not adjusting for profile grade results in a conservative estimate, because a steeper grade contributes to higher noise levels from trucks.

The conclusion of the noise study was that future predicted noise on the bicycle/pedestrian path on a new East Span would be approximately 0-2 dBA higher than the Route 24 bike path, or 82-84 dBA, during the noisiest hour of the day.

The future predicted noise levels on the path are typical of those in a busy restaurant or in the kitchen with a garbage disposal running and requires shouting to be heard at 1 meter (3.3 feet); most people would perceive the noise as being loud. Two cyclists riding single-file would have difficulty communicating by shouting. The U.S. Occupational Safety & Health Administration (OSHA) has established a health-based criteria of exposure for eight hours to noise levels of 90 dBA. This level was selected to prevent hearing damage in most individuals who are subjected to the noise level for a 40-hour work week over ten years. Because noise levels on the bridge would be lower than the OSHA standard and people would be subjected to it for a period much shorter than the eight-hour period assumed for the standard, exposure to typical noise levels on the bridge would not cause hearing problems.

Other potential noise concerns for path users include the potential to be startled by short-duration loud noises. In a relatively quiet environment where cyclists and pedestrians are not expecting loud traffic noise (such as a truck passing by), these noise levels could startle an individual, resulting in possible loss of balance or control of a bicycle. Because bridge riders would experience steady elevated noise levels and trucks frequently passing by, this is not anticipated to be a substantial safety concern to bridge riders.

Since bridge path users would not experience noise levels significantly different from what users of other Bay Area bike paths adjacent to freeways would experience, Caltrans does not propose noise attenuation measures for the bicycle/pedestrian path.

4.5.3 Vibration

As noted in the affected environment section, existing vibration levels from traffic operations (i.e., heavy-truck traffic) would probably be below the levels of human perception at distances of more than 30 meters (100 feet) from the bridge support columns where ground-borne measurements were performed. Vibration levels from future bridge operations at nearby locations, including the film studios on TI, are predicted to remain below perception and criterion levels for all of the project alternatives and would be lower for the replacement bridge alternatives than for the retrofit alternative. The replacement alternatives would create less groundborne vibration compared to the existing structure due to the higher mass associated with their steel-reinforced concrete construction. There are other sources of vibrations more likely to affect operations at the film studios than bridge traffic. Possible sources include someone walking in the studio, loud music, wave action from the Bay, and wind. Construction-related vibrations from the East Span Project are discussed in Section 4.14.5 — Construction-period Noise and Vibration.

Hazardous and contaminated materials have the potential to adversely affect human health and the environment. The design, construction, and operation of the East Span Project would incorporate design elements and construction and operation techniques to minimize these potential adverse impacts.

Caltrans will work with all potentially responsible parties and all responsible regulatory agencies to ensure that hazardous wastes the project disturbs are appropriately managed and remediated, if necessary. Additionally, the Navy has identified certain hazardous waste sites in portions of the area previously under its ownership, and if the Navy requires access from Caltrans to investigate and/or remediate such wastes, it is entitled to such access under the provisions of the land transfer.

A Hazardous Wastes Assessment report has been prepared for the East Span Project and is available for review at the locations identified in the Preface.

4.6.1 Summary and Comparison of Alternatives

Table 4.6-1 and the following subsections summarize and compare potential impacts by alternative for the Yerba Buena Island (YBI) and Oakland Touchdown areas. The discussion focuses on potentially contaminated sites discussed in Section 3.6 — Hazardous Wastes and identified on Figures 3-15a and 3-15b in Appendix A.

Yerba Buena Island

No-Build Alternative. There are no new impacts associated with the No-Build Alternative. There would be a continuation of existing conditions; i.e., lead paint continuing to flake off into the ground and into the Bay. Maintenance of the existing bridge would continue to incorporate lead-containment systems during painting.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would likely affect the following sites:

 

Alternatives

Impact Sites

No-Build

Retrofit

Alt. N-2

Alt. N-6

Alt S-4

YBI Sites

IR Site 11, Former Landfill

   

ü


ü


ü

IR Site 29, East Side Contaminated Bridge Soils





ü



ü



ü



ü

IR Site 8, Former Army Point Sludge Disposal Area





ü



ü



ü



ü

Fuel Lines, Building 213

 


ü


ü


ü


ü

Building 270a LUST Site

   

ü

ü

ü

Building 204/208b
LUST Site

   


ü


ü


ü

Building 40 LUST Site

   

ü

ü

ü

IR Site 13, Section E, Storm Water Off-Shore Sediments

       



ü

SFOBB Structure

 

ü

ü

ü

ü

East Span

         

Bay Sediment

 

ü

ü

ü

ü

SFOBB Structure

 

ü

ü

ü

ü

Oakland Touchdown Area

         

Bridge footings
(eastern approach area)




ü



ü



ü

 

ü

Army Site #1 (western end of Burma Road)


ü

Caltrans Maintenance Facility and Undeveloped Median Area

   

 

ü

 

ü

 

EBMUD Dechlorination Facility

       


ü

SFOBB Structure

 

ü

ü

ü

ü

Source: Hazardous Wastes Assessment, September 1998.

Note: a Leaking underground storage tank.

b Buildings 204 and 208 have been removed.

Inappropriate handling and disposal of asbestos-containing, hazardous, or petroleum-contaminated materials could degrade water quality. Inappropriate discharge of any contaminated groundwater removed from excavations could degrade water quality. Piles constructed through any existing contaminated water-bearing zone into a lower water-bearing zone could create a conduit for migration of any existing contaminants. Exposure to these materials could present potential human health hazards or adverse ecological impacts.

Replacement Alternatives N-2, N-6 (Preferred), and S-4. Construction of any of the three replacement alternatives may affect the following sites:

Replacement alternatives would require more construction activity at these sites than would the Retrofit Existing Structure Alternative. Contamination from IR Site 29 and IR Site 8 is at or very near to the ground surface. Groundwater contamination would also likely be encountered at IR Site 11, Building 270 LUST, Building 40 LUST, and possibly from Site 204/208 LUST and the fuel lines at Building 213.

In addition, Replacement Alternative S-4 would likely affect IR Site 13, Section E, Storm Water Off-Shore Sediments. Off-shore sediments from storm water discharges may have an impact due to columns being constructed within IR Site 13. Contaminants may bind to soil particles carried to the Bay by storm water runoff and deposited in the sediments.

As mentioned for the Retrofit Existing Structure Alternative, inappropriate handling and disposal of contaminated materials could degrade water quality.

Oakland Touchdown Area

No-Build Alternative. There are no new impacts associated with the No-Build Alternative. There would be a continuation of existing conditions; i.e., lead paint continuing to flake off into the ground and into the Bay. Maintenance of the existing bridge would continue to incorporate lead-containment systems during painting.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would likely encounter contamination that was detected around the bridge footings and bents of the eastern approach to the SFOBB. Contaminants of concern include total recoverable petroleum hydrocarbons (TRPH), volatile organic compounds (VOCs), pesticides, polychlorinated biphenyls (PCBs), and metals. The past use of lead-based paint and asbestos on the bridge structure would also be a concern during retrofitting activities. Concerns include both those associated with worker health and safety and handling and disposal of contaminated materials.

Replacement Alternatives N-2 and N-6 (Preferred). Replacement Alternatives N-2 and N-6 would likely encounter soil and groundwater contamination that was detected around the bridge footings and bents of the eastern approach to the SFOBB. Exposure to this source area may be less than for the Retrofit Existing Structure Alternative, because the alignment is shifted north of the existing touchdown area. As such, only the southern edge of Replacement Alternative N-2 should be close enough to the footings to disturb contaminated soil. Materials contaminated with lead from motor vehicle exhaust emissions may be encountered at excavations along the existing freeway shoulders. The past use of lead-based paint and asbestos on the bridge structure would also be a concern during construction and dismantling activities. Asbestos-containing materials may be present in bridge appurtenances.

The proposed realignment of the Caltrans maintenance road under the northern alternatives would impact the undeveloped median area near the Caltrans maintenance facility. During construction, workers may encounter soils contaminated with elevated soluble lead levels.

Replacement Alternative S-4. Replacement Alternative S-4 may affect three sites:

As mentioned in the YBI discussion, inappropriate handling and disposal of contaminated materials during construction of the build alternatives could degrade the Waters of the State.

Differences in impacts resulting from exposure to these identified contaminant sources would depend on the exact location and nature of proposed construction activities and nature and extent of contamination in these areas.

4.6.2 Further Investigations

This section identifies data gaps and describes the actions necessary to characterize the known and potential contaminant sources that may be affected by the proposed SFOBB East Span Project alternatives.

Yerba Buena Island Data Gaps

The YBI area has been fairly well characterized. Once the National Environmental Policy Act (NEPA) process is complete, a complete and thorough data review would be conducted to identify the status of existing sites and whether any new concerns have been identified. Copies of pending reports from the Navy would be requested. Results of subsurface investigations identified currently as proposed would also be requested. Current analytical data from existing groundwater monitoring wells would also be requested and analyzed.

Oakland Touchdown Area Data Gaps

While the western portion of the touchdown area along the existing East Span has been well studied, reasonable uncertainty about environmental conditions exists in several other areas. Areas needing further investigation include:

Additional Investigations — All Areas

The following information will be developed during final engineering design:

Once an alternative has been selected and additional available information reviewed, a Phase II Environmental Site Investigation would be conducted for the selected alternative to sufficiently characterize contaminant management and disposal concerns during construction and to identify worker and health and safety issues that will need to be addressed. The Phase II investigation would be scoped to address identified contaminants of concern and would consider proposed construction activities. The Phase II efforts would consider the areas identified above (i.e., data gaps) for which limited data are known. All Phase II investigation efforts would focus on developing specific information about contaminated sites that could affect construction of the selected alternative and develop hazardous wastes specifications covering handling and disposal procedures for inclusion in the construction bid documents. Phase II investigations would be limited to the level of investigation required to prepare sufficient contractor bid documents (e.g., contaminant management and health and safety procedures). Additional sampling and testing would be required during construction to ensure the proper management of contaminated media encountered.

4.6.3 Mitigation

Mitigation: All Build Alternatives.

Contaminant Management. All excavated waste material would be disposed of in conformance with federal, state, and local laws and regulations. Caltrans will work with all potentially responsible parties and all responsible regulatory agencies to ensure that hazardous wastes are appropriately managed and remediated, if necessary. If additional sampling is required to characterize the material, a sampling plan would be prepared based on guidelines in the Environmental Protection Agency publication SW 846, "Test Methods for Evaluating Solid Waste, Volume II: Field Manual Physical/Chemical Methods." Sampling and analysis would be performed prior to removing the material from the project limits.

Excavated materials that contain lead from vehicle emissions within the ranges specified in the variance granted to Caltrans by the California Department of Toxic Substance Control (DTSC) would be reused in this project or at another site within highway right-of-way along the project corridor. The materials would be placed to minimize leaching into groundwater and erosion due to wind or rain. Materials that cannot be reused in accordance with the variance will be transported to an appropriate disposal facility.

If dewatering is required to construct upland foundations and other appurtenances in areas of contaminated groundwater, the excavation would be hydraulically isolated from the groundwater by using sheet piling, casing, or other methods that would reduce the volume of groundwater discharges. In addition to reducing discharge volumes, isolation of the excavation would prevent cross-contamination of water-bearing zones.

Prior to discharge, groundwater containing contaminants, including suspended solids at concentrations that could cause adverse impacts to water quality, would be treated using the best available and economically feasible technology to reduce the concentrations of the contaminants of concern to acceptable levels in conformance with all federal, state, and local laws and regulations. The treated effluent would be reclaimed for dust control, discharged to a publicly owned treatment facility, or discharged to the Bay. If treatment of the groundwater could not be accomplished on-site, it would be transported to an appropriate off-site treatment facility.

Once the project area has been sufficiently characterized and construction activities sufficiently defined, contract specifications would be developed to address site-specific procedures for contaminant monitoring and identification, temporary storage, handling, treatment, and disposal of materials in accordance with applicable federal, state, and local laws and regulations. Requirements for coordination with the Navy in its CERCLA responsibilities will be included.

Contingency Planning. In the event hazardous materials are unexpectedly encountered during construction, contract specifications would establish procedures for temporary stoppage of work, securing of the area, notification of the discovery, and proper management of such materials. All procedures would be consistent with Caltrans’ guidelines and federal, state, and local laws and regulations and coordinated with responsible parties and regulatory agencies.

Dismantling. Contract specifications for dismantling of all structures, such as the existing SFOBB and Buildings 30, 40, 75, 270, and 213, would include procedures for the abatement, handling, and disposal of lead-based paint and asbestos, as well as the health and safety of workers and nearby residents (including USCG and Navy personnel). Prior to dismantling, asbestos and lead-based paint surveys would be performed to identify these materials. All procedures and permitting requirements would be consistent with Caltrans’ guidelines and all federal, state, and local laws and regulations and coordinated with responsible parties and regulatory agencies. The Bay Area Air Quality Management District would be notified per District Regulation 11-2-401.3 ­ Asbestos Demolition/Renovation.

Workers performing activities on-site that may involve contact with contaminated soil, lead-based paint, asbestos, or groundwater would be required to have appropriate health and safety training in accordance with federal and state regulations. To reduce the risk of exposure, a Worker Health and Safety Plan would be prepared and implemented during construction by a Certified Industrial Hygienist (CIH). The Health and Safety Plan would include provisions for:

The plan would address reduction of potential worker, Navy and USCG personnel, and public exposure to airborne contaminants by incorporating dust suppression techniques in construction procedures. Procedures would be in place to handle contaminated soils.

4.7 GEOLOGY, SOILS, AND SEISMICITY

This section describes the relationships between project features and expected soil conditions in the project area and also describes issues related to possible seismic events.

4.7.1 Soil and Rock Stability and Settlement

No-Build and Retrofit Existing Structure Alternatives

The No-Build and Retrofit Existing Structure Alternatives would not change area topography and, as such, would not affect slope stability within the project area. Design of the Retrofit Existing Structure Alternative has been based on current soils information, and foundation improvements would reduce the risk of settlement.

Replacement Alternatives N-2, N-6 (Preferred), and S-4

Replacement Alternatives N-2, N-6, and S-4 were developed to respond to the changing geological conditions along the general alignment, including Young Bay Muds, which cover the majority of the Bay bottom between Yerba Buena Island (YBI) and the Oakland Touchdown area. In general, sediments become increasingly thicker eastward from YBI to the Oakland Touchdown area. This means the distance to bedrock is deepest near the Oakland Touchdown, approximately 100 meters (328 feet). Construction of a main span tower is best anchored to bedrock; therefore, placing a new tower as part of a replacement alternative in the eastern portion of the project area is not feasible.

Yerba Buena Island. Initial geotechnical data indicate that several slope stability-related issues could be associated with design of the land and marine tower foundations in the vicinity of YBI. These issues include: the gross stability of the east-facing slope of YBI and the potential for slope failures in the vicinity of the west foundation for the main span.

The slope stability issues have been evaluated through geologic mapping performed on YBI, marine exploration, and laboratory testing of bedrock. Stability analyses for the various potential slope failure modes have been performed. The results show that there is no gross instability at the marine tower foundation, but wedge failures (as described in Section 3.7.3 — Geology and Geotechnical Conditions in the Project Area) are anticipated for the west column foundation on YBI. Rock anchors with or without shotcreted wire mesh and rock bolts are recommended project design features to prevent wedge failures.

There are pre-existing slope stability and erosion problems on parts of YBI in the vicinity of the USCG facility. Both have the potential to interfere with USCG operations. Slope failures and erosion may cause soils and other materials to obstruct the USCG road at the base of the hillside next to the USCG facility.

In addition, the temporary intersection which would be constructed south of the intersection on Treasure Island Road and Southgate Road would require a temporary road through an existing slope approximately 35 meters (115 feet) south of Building 206 and Quarters 8. This intersection would serve traffic exiting the bridge onto YBI on the east side of the island during the time when temporary detours are in use.

Mitigation:

Caltrans would ensure that the project does not exacerbate pre-existing problems within Caltrans’ right-of-way or its temporary construction easements either during or after construction. Consultation with the USCG and collection of information on slope stability prior to and during construction would be conducted.

Caltrans will require the contractor to prepare a conceptual plan for slope stability and erosion control on the hillside above the USCG facility. This plan would include Best Management Practices (BMPs) to reduce impacts from storm water runoff which can cause erosion. Caltrans would solicit comments on the conceptual plan from the USCG. Caltrans would be responsible for implementation of the plan. The conceptual plan would be adjusted and revised during construction based on site conditions identified during construction.

Caltrans would monitor the hillside within the project right-of-way and temporary construction easements to detect ground movements during construction that may be associated with project construction activities. If Caltrans determines that slope stability problems are due to its construction, it would correct the problem. Caltrans would prepare a slope restoration concept using standard practices and techniques and would solicit comments from the USCG after which it would finalize and implement the restoration plan.

In order to minimize the impact to the slope from construction of the temporary road, temporary retaining walls would be used. The ramps would be reconstructed and the excavation required for construction of the wall would be filled in.

Oakland Touchdown Area. The fill material at the end of the Oakland shore from the current ground elevation to between 3 and 5 meters (10 and 16 feet) below mean sea level (MSL) is potentially liquefiable material. The potential for liquefaction exists for the fill that lies beneath the water table. Liquefaction is the loss of strength that can occur in loose, saturated soil during or following seismic shaking. The loss of strength is due to the tendency of loose soils to contract and compress when shaken. In a seismic event, liquefaction can produce a number of ground effects, including lateral spreading, boils, ground lurching, and settlement of the fill material. In the case of the Oakland Touchdown, damage would most likely consist of small earth slumps, differential settlement, and cracking of fill embankments. Such damage could be quickly repaired. Pile-supported structures on the Oakland Touchdown would be subject to impacts from liquefaction, such as induced loads, but these structures are designed to accommodate these impacts and would meet lifeline criteria.

To compensate for potential settlement at the Oakland Touchdown area, at-grade approach structures would be created by placing embankment fill on certain sections of the landfall that may be prone to settlement due to consolidation of the soft clay and partially in the Bay to further support approach structures.

The westbound fill design includes the following components to address soil settlement issues:

The eastbound and maintenance road fill design takes advantage of the need for relatively low fill heights (4.5 meters [14.8 feet]) and their inland position away from the shoreline. Existing fill would be excavated and replaced to higher grades with lightweight cellular concrete fill.

4.7.2 Seismicity

The project area will likely experience strong to very strong seismically induced ground shaking within the design life of all build alternatives. Under all replacement alternatives, some damage to bridge components would be expected to occur during a major seismic event; however, the components should still be able to substantially perform their design functions. In general, strong ground shaking can cause one or more of the following:

Surface fault rupture and resulting displacement is not expected since there are no known active faults along the alignments.

No-Build Alternative

Under the No-Build Alternative, the existing East Span would be able to withstand a moderate earthquake. However, it is anticipated that the existing East Span would experience multiple failures at structure joints and potential collapse into the Bay in the event of a Maximum Credible Earthquake (MCE).

Retrofit Existing Structure

The Retrofit Existing Structure Alternative would provide additional support to the existing East Span compared to the No-Build Alternative. Following retrofit construction, the bridge should be able to withstand an MCE. However, it is anticipated that in the event of an MCE, the retrofitted East Span would experience damage to truss members in the steel superstructure. The addition of new Columns E2A and E2B would eliminate an existing imbalance in the existing main span, which would reduce structural damage. Although the retrofitted main span would be expected to withstand an MCE or smaller event, it is likely that the main span structure (the cantilever section), and potentially other shorter spans, would require extensive repair (possibly requiring closure of the bridge for a six-month to one-year period) or complete replacement of the entire structure, depending on the extent of the damage.

Replacement Alternatives N-2, N-6 (Preferred), and S-4

The replacement alternatives are designed to meet current lifeline seismic safety standards. It is expected that replacement alternatives would withstand an MCE on the San Andreas or Hayward faults. Seismic design criteria for all replacement alternatives are intended to ensure both non-collapse and serviceability of structures when subjected to ground motions during a seismic event.

Potential for damage resulting from an MCE exists. The main span tower structure near YBI would be sited on shallow, sloping bedrock, requiring foundations deep into rock. Damage due to tower settlement in an MCE would most likely be minor and confined to local deflection, cracking, and misalignment of pavement on the main span. Anticipated damage could easily be repaired to permit the East Span to serve a lifeline function.

4.7.3 Tsunamis

The possibility of tsunamis in the Bay Area would most likely be related to a seismic event. Based on U.S. Geological Survey (USGS) map information, it appears that most of the Oakland Touchdown area, which ranges in elevation from about 0 to 3.6 meters (0 to 12 feet) would be subject to inundation from a 200-year-return-period tsunami. At lower return periods (for example, 25 to 100 years), the potential for inundation decreases substantially.

The impacts of a tsunami would be flood damage, erosion, and damage caused by wave and water forces on structures. People, automobiles, and buildings could be washed away as during a flood. Tsunami warnings are a component of the regional emergency warning system and would be implemented in the case of a threat of tsunami inundation.

The structural design of the existing East Span and the replacement structure on the Oakland Touchdown area includes the capability of resisting water/wave/current-induced loading.

4.8 WATER QUALITY

This section discusses potential impacts to water quality in the project area and associated control measures. For each of the replacement alternatives, the water quality impacts and design considerations discussed in this section would be the same.

4.8.1 Surface Water Quality

No-Build Alternative

The No-Build Alternative would not modify current water quality conditions as current methods of operation and maintenance would continue. The current practice of sweeping the bridge decks would continue and storm water would continue to discharge directly into the Bay.

Retrofit Existing Structure Alternative

The Retrofit Existing Structure Alternative may have a temporary water quality impact during construction activities. These activities may include dredging, dewatering, concrete pouring, welding, and other activities that have the potential to impact water quality (see Section 4.14.7 — Temporary Impacts, Water Resources and Water Quality for discussion of construction-related impacts). Potential long-term impacts have also been evaluated, and it has been determined that there are no long-term impacts because the existing facility would not be modified in terms of its operation and drainage system. The current practice of sweeping the bridge decks would continue and storm water would continue to discharge directly into the Bay.

Replacement Alternatives N-2, N-6 (Preferred), and S-4

All replacement alternatives have similar potential to affect water quality in San Francisco Bay, both during and after construction (see Section 4.14 — Temporary Impacts During Construction Activities for discussion of construction-related impacts).

The replacement alternatives would consist of two parallel bridge decks, each accommodating five standard travel lanes and standard shoulders. The overall width of the westbound bridge deck is proposed to be 25 meters (82 feet). The width of the eastbound bridge deck, which includes a 4.7-meter (15.5-foot) bicycle/pedestrian path, is proposed to be 29.7 meters (97.5 feet). The replacement alternatives would increase the surface area exposed to precipitation. A corresponding increase in the quantity of pavement storm water runoff from the East Span during a rainfall event is expected; however, variances in the frequency and intensity of such events make efforts to determine specific volume increases unreliable.

Pollutants commonly found in highway storm water runoff include heavy metals, oil and grease, suspended and dissolved solids, nutrients, bacteria, and some of the hydrocarbons in the gasoline and diesel range. Pollutants less common in highway storm water runoff include volatile organics, semi-volatile organics, phenols, pesticides, polychlorinated biphenyls, and synthetic biocides, depending on the characteristics and location of the highway.

Impacts. Similar to the existing condition, all storm water runoff on a replacement bridge would flow into the Bay.

The proposed replacement alternatives would not be expected to increase concentration levels of those pollutants commonly found in highway runoff, nor is the design expected to elevate the levels of less common constituents. The existing pollution mass is based on total vehicle hours on the structure. For the total mass of pollution to change, either the total usage hours must increase or the pollutant generation rate must increase. Given that the improvements in operations on a replacement bridge should decrease the generation rate due to reduction in stop-and-go traffic, the actual mass of pollutants should decrease. Increased interception of rainfall on a wider structure would not increase the mass of pollutants. In other words, the bridge runoff quantity is not linked to pollutant mass.

The bridge deck drainage area and total runoff volume compared to the overall existing watershed area is on the order of magnitude of 1 to 106. Based on this relatively small runoff volume, the pollutant loads would be negligible when compared to the overall pollutant loadings to the Bay from the entire watershed and would not have a net impact on the overall water quality of the Bay.

Water Quality Benefits. There are inherent water quality benefits in the design of the replacement bridge, especially when the features are compared to the existing bridge. Bridge runoff quality is expected to be improved based on the following features:

In addition to the benefits provided by a replacement bridge and the removal of the lead source, there are several measures already in place that would continue to help prevent the discharge of pollutants to the Bay. Caltrans has an aggressive emergency response plan for responding to spills of varying magnitudes on the highway system. The current emergency response plan includes monitoring cameras, call boxes, and a 24-hour towing service. The towing service constantly patrols the entire span of the bridge while remaining in communication with both Caltrans and Highway Patrol staff that monitor the bridge via the aforementioned cameras. This plan is updated annually to ensure that on-call contractors have the proper training, equipment, and procedures to respond to spills. In addition to this plan, Caltrans and the California Highway Patrol would continue to prohibit the transportation of hazardous and flammable materials across the bridge.

Considering the design features of the new bridge, the project as planned is expected to improve the overall water quality of bridge runoff.

Best Management Practices. Several best management practices (BMPs) for addressing potential pollutants generated by storm water runoff within the project limits were evaluated. This evaluation was based on right-of-way requirements (area), constructibility, maintenance, safety, feasibility, and cost-effectiveness. Caltrans has prepared a Treatment BMP Feasibility Study for the East Span Project, which describes the evaluation in more detail. This report was submitted to the RWQCB and is available for review at Caltrans District 4 offices

The pollutants addressed in the evaluation are:

These pollutants can potentially be treated by various techniques such as constructed wetlands, detention basins, infiltration basins, infiltration trenches, and sweeping. Some techniques can treat more than one pollutant. Most of the BMPs are land-based facilities (i.e., constructed wetlands, detention basins, infiltration trenches, etc.) that require storm water to be collected and piped off the bridge to a land-based facility. These land-based facilities were not considered to be appropriate primarily because of the high cost associated with placing the piping system on the bridge in contrast to the amount of pollutant removal benefit obtained. The conditions that resulted in the BMPs being considered infeasible are summarized as follows:

Caltrans is investigating the effectiveness of enhanced sweepers such as vacuum and regenerative air sweepers to vacuum up the fine particles to which pollutants adhere. Because a replacement bridge would have shoulders and wider lane widths, sweeping effectiveness is expected to be improved; however, enhancement of the sweeper equipment is expected to be consistent with the decisions made for sweeping on a statewide basis. Currently such enhanced sweepers have technological limitations that call their effectiveness into question. These include problems maintaining the vacuum between the machinery and the pavement which is essential to the effectiveness of the device; the tendency of the equipment to act as a plow, pushing the fine materials into drainage outlets; and reduced performance of the equipment on rough pavement.

4.8.2 Groundwater Quality

All Project Alternatives

There are no known long-term impacts to groundwater quality as a consequence of the construction of this project. Section 4.14.7 discusses the potential construction-related water quality impacts, including impacts to groundwater. These would be mitigated with the proper implementation of a Storm Water Pollution Prevention Plan (SWPPP) developed for this project as required by NPDES Permit No. CAS000003. See Section 4.14.7 — Temporary Impacts, Water Resources and Water Quality for more details. The SWPPP would address all construction management practices that have the potential to impact water quality and would identify appropriate control measures to be taken by the Contractor to minimize such potential impacts. The SWPPP will include specific Best Management Practices (BMPs) to be implemented to control and prevent the discharge of pollutants to surface waters as well as groundwater. These BMPs may include dewatering, controlling spills and concrete, sediment control using silt fences.

4.9 NATURAL RESOURCES

Permanent or temporary impacts to natural resources may occur in association with the build alternatives. This section discusses permanent impacts to wildlife species or habitat. Natural resources in the project area were evaluated in accordance with the provisions of state and federal environmental statutes and regulations listed in Section 3.9.1 — Natural Resources, Regulatory Setting. Mitigation measures, where appropriate, have been developed in consultation with regulatory and permitting agencies. Conceptual mitigation measures are described in Section 4.9.6 — Natural Resources, Mitigation.

Four resource and impact categories are discussed below: (1) permanent fill in San Francisco Bay (including opening and shallow water areas and special aquatic sites) and permanent fill in Other Waters of the U.S. (including open and shallow water areas); (2) special aquatic sites such as wetlands, eelgrass beds, or sand flats; (3) special status species such as endangered species, migratory birds, marine mammals, and fisheries; and (4) other natural resources such as coast live oak woodlands.

Temporary impacts to natural resources are identified as impacts from construction activities and are limited to the duration of construction as described in Section 4.14 — Temporary Impacts During Construction Activities.

4.9.1 Placement of Fill in San Francisco Bay

Placement or removal of fill in San Francisco Bay and Other Waters of the U.S. are subject to federal and state regulations. The ACOE regulates fill in Other Waters of the U.S. pursuant to Section 404 of the federal Clean Water Act (CWA). BCDC regulates fill in San Francisco Bay pursuant to the state McAteer-Petris Act. These regulations define fill differently.

Clean Water Act

The CWA is a 1977 amendment to the federal Water Pollution Control Act of 1972, which established regulations for discharging pollutants to Waters of the U.S., such as San Francisco Bay. The primary objective of the CWA is to restore and maintain the physical, chemical, and biological integrity of the nation's waters. The ACOE administers the CWA.

The CWA considers placement of fill in Waters of the U.S. as a negative impact because it may reduce the volume and surface area of water bodies. Under the CWA, fill is defined as "material used for the primary purpose of replacing an aquatic area with dry land, or a change in the bottom elevation of a water body" (Section 404, article 323.2.). Removal of fill is recognized as a beneficial impact because it may result in the restoration or maintenance of the physical, chemical or biological integrity of the nation’s waters.

San Francisco Bay’s shallow and open water areas are referred to in the text below as Other Waters of the U.S. The analysis of fill in Other Waters of the U.S. does not include fill in special aquatic sites such as wetlands, eelgrass beds, or sand flats. Impacts to special aquatic sites, as defined by the ACOE, are addressed separately in Section 4.9.2 — Special Aquatic Sites. Under the CWA, the ACOE considers fill in Other Waters of the U.S. to be solid material placed in jurisdictional waters below the mean high water line (MHW), which is approximately +1.42 meters National Geodetic Vertical Datum (NGVD) (+4.63 feet) at YBI and the Oakland Touchdown area.

Net Change in Volume of Other Waters of the U.S. ­ ACOE.

All replacement alternatives (N-2, N-6, and S-4) would increase the volume of Other Waters of the U.S. as compared to its current volume. Although the replacement alternatives would result in new fill in Other Waters of the U.S. as defined by the ACOE, removal of dredged sediments and the removal of the existing bridge would offset the volume of the new fill. The volume of Other Waters of the U.S. would increase as a result of the following construction activities:

Because the replacement alternatives would increase the volume of Other Waters of the U.S., they would have a beneficial impact on Other Waters of the U.S.

The Retrofit Existing Structure Alternative would decrease the volume of Other Waters of the U.S. as compared to its current volume. The Retrofit Existing Structure Alternative requires dredging only to install piles and does not remove the existing bridge. Because the retrofit alternative would decrease the volume of Other Waters of the U.S., it would have a negative impact on Other Waters of the U.S.

Table 4.9-1 summarizes the approximate net change in volume of Other Waters of the U.S. that would occur as a result of the build alternatives.

Table 4.9-1 Net Change in Volume of Other Waters of the U.S. ­ ACOE

 

Build Alternatives

Activity

N-6

N-2

S-4

Retrofit

New Fill from Construction (reduction in volume)

50,400 cubic meters

(66,000 cubic yards)

50,400 cubic meters

(66,000 cubic yards)

72,100 cubic meters

(94,400 cubic yards)

142,300 cubic meters

(186,200 cubic yards)

Removal of Sediment (increase in volume)a

371,000 cubic meters

(485,300 cubic yards)

371,000 cubic meters

(485,300 cubic yards)

375,000 cubic meters

(490,500 cubic yards)

116,000 cubic meters

(152,000 cubic yards)

Removal of Existing Bridge Piers and Fenders (increase in volume)

65,400 cubic meters

(85,600 cubic yards)

65,400 cubic meters

(85,600 cubic yards)

65,400 cubic meters

(85,600 cubic yards)

N/A

Net Change in Volume of Other Waters of the U.S.

Increase of:

386,000 cubic meters

(504,900 cubic yards)

Increase of:

386,000 cubic meters

(504,900 cubic yards)

Increase of:

368,300 cubic meters (481,700 cubic yards)

Decrease of:

26,300 cubic meters (34,200 cubic yards)

Source: Caltrans 2000.

a Removal of sediments for barge access and to prepare for pile installation increases the volume of Other Waters of the U.S. The removal of sediment does not include that portion of the barge access channel that will be restored for eelgrass habitat under the replacement alternatives as described in Section 4.9.6 — Natural Resources, Mitigation. Up to 32,100 cubic meters (42,000 cubic yards) of dredged material may be used to restore a portion of the barge access channel to pre-existing bathymetry.

Net Change in Surface Area of Other Waters of the U.S. ­ ACOE.

The ACOE also measures fill in Other Waters of the U.S. by surface area. All build alternatives would decrease the surface area of Other Waters of the U.S. as compared to its current surface area. Although all the build alternatives would remove sediments for barge access and to prepare for pile installation and would remove the existing bridge, the fill removal would not offset the surface area of the new fill in Other Waters of the U.S. Since the sediments are submerged, their removal does not contribute to an increase in the surface area of Other Waters of the U.S.

Because the build alternatives would decrease the surface area of Other Waters of the U.S., they would have a negative impact on Other Waters of the U.S. Table 4.9-2 summarizes the approximate net change in surface area of Other Waters of the U.S. that would occur as a result of the build alternatives.

Table 4.9-2 Net Change in Surface Area of Other Waters of the U.S. ­

ACOE

 

Build Alternatives

Activity

N-6

N-2

S-4

Retrofit

New Fill from Construction (reduction in surface area)

1.06 hectares

(2.61 acres)

1.06 hectares

(2.61 acres)

1.73 hectares

(4.29 acres)

1.70 hectares (4.19 acres)

Removal of Existing Sedimenta

N/A

N/A

N/A

N/A

Removal of Existing Bridge Piers and Fenders (increase in surface area)

0.80 hectare

(1.98 acres)

0.80 hectare

(1.98 acres)

0.80 hectare

(1.98 acres)

N/A

Net Change in Surface Area of Other Waters of the U.S.

Decrease of

0.26 hectare

(0.63 acre)

Decrease of

0.26 hectare

(0.63 acre)

Decrease of

0.93 hectare

(2.31 acres)

Decrease of

1.70 hectares

(4.19 acres)

Source: Caltrans 2000.

a Removal of submerged sediments to create barge access and to prepare for pile installation does not increase the surface area of Other Waters of the U.S.

McAteer-Petris Act

On the regional level, the San Francisco Bay Conservation Development Commission (BCDC) administers the McAteer-Petris Act, which was enacted by the state legislature in 1965. The McAteer-Petris Act recognizes that San Francisco Bay is a significant economic, environmental, and recreational resource. BCDC was established to address indiscriminant filling of San Francisco Bay.

The McAteer-Petris Act generally identifies the placement of fill in San Francisco Bay as a negative impact since it may reduce the Bay’s surface area and volume. Reducing the surface area and volume of the Bay impairs its ability to maintain adequate oxygen levels and assimilate and flush wastes. Removal of fill is considered a beneficial impact to the Bay and is consistent with the McAteer-Petris Act because it may increase the volume and surface area of the Bay.

As defined by BCDC, Bay fill is any solid, pile-supported, floating, cantilevered or suspended material that is placed bayward of the Mean High Tide Line (MHTL) which is approximately +0.82 meters NGVD (+2.68 feet) at YBI and +0.84 meters NGVD (+2.77 feet) at the Oakland Touchdown area, or the +1.5-meter (5.0-foot) contour line where marshlands are present. Unlike the ACOE, the analysis of fill in BCDC’s jurisdiction includes fill placed in special aquatic sites such as wetlands, eelgrass beds, and sand flats.

Net Change in Volume of San Francisco Bay ­ BCDC.

All replacement alternatives would increase the volume of San Francisco Bay as compared to its current volume. Although the replacement alternatives would result in new fill in San Francisco Bay as defined by BCDC, removal of dredged sediments and the removal of the existing bridge would offset the volume of the new fill. The volume of San Francisco Bay would actually increase as a result of the following construction activities:

Because the replacement alternatives would increase the volume of San Francisco Bay, they would have a beneficial impact on the Bay.

The Retrofit Existing Structure Alternative would decrease the volume of San Francisco Bay as compared to the current volume. The Retrofit Existing Structure Alternative requires dredging only to install piles and does not remove the existing bridge. Because the Retrofit Existing Structure Alternative would decrease the volume of San Francisco Bay, it would have a negative impact on the Bay.

Table 4.9-3 summarizes the approximate net change in volume of San Francisco Bay that would occur as a result of the build alternatives.

Table 4.9-3 Net Change in Volume of San Francisco Bay ­ BCDC

 

Build Alternatives

Activity

N-6

N-2

S-4

Retrofit

New Fill from Construction (reduction in volume)

78,900 cubic meters

(103,200 cubic yards)

78,900 cubic meters

(103,200 cubic yards)

67,800 cubic meters

(88,700 cubic yards)

132,500 cubic meters

(342,700 cubic yards)

Removal of Sediment (increase in volume)a

371,000 cubic meters

(485,300 cubic yards)

371,000 cubic meters

(485,300 cubic yards)

375,000 cubic meters

(490,500 cubic yards)

116,000 cubic meters

(152,000 cubic yards)

Removal of Existing Bridge Piers (increase in volume)

60,300 cubic meters

(78,800 cubic yards)

60,300 cubic meters

(78,800 cubic yards)

60,300 cubic meters

(78,800 cubic yards)

N/A

Net Change in Volume of the Bay

Increase of

352,400 cubic meters

(460,900 cubic yards)

Increase of

352,400 cubic meters

(460,900 cubic yards)

Increase of

367,500 cubic meters

(480,600 cubic yards)

Decrease of

16,500 cubic meters

(21,300 cubic yards)

Source: Caltrans 2000.

a Removal of sediments for barge access and to prepare for pile installation increases the volume of San Francisco Bay. The removal of sediment does not include that portion of the barge access channel that will be restored for eelgrass habitat under the replacement alternatives as described in Section 4.9.6 — Natural Resources, Mitigation. Up to 32,100 cubic meters (42,000 cubic yards) of dredged material may be used to restore a portion of the barge access channel to pre-existing bathymetry.

Net Change in Surface Area of San Francisco Bay ­ BCDC.

BCDC also measures fill in San Francisco Bay by surface area. BCDC’s definition of fill includes high-level suspended fill such as bridge decks or other structures that are placed bayward of the Mean High Tide Line. BCDC considers the footprint of the bridge decks to be fill even where the bridge decks are placed at a significant height above the Bay and generally do not result in adverse impacts to the Bay such as permanent shading of special aquatic sites.

The Retrofit Existing Structure Alternative would not result in a change to the surface area of the Bay as defined by BCDC because the new fill would be placed within the footprint of the existing bridge deck.

When compared to the high-level suspended fill for the existing bridge, the single side-by-side deck configuration for all replacement alternatives (N-2, N-6 and S-4) would result in a net decrease in the surface area of San Francisco Bay. Although all the replacement alternatives would remove sediments for barge access and to prepare for pile installation and would remove the existing bridge, the fill removal would not offset the surface area of new fill in San Francisco Bay: since the sediments are submerged, their removal does not contribute to an increase in the surface area of the Bay.

Because the replacement alternatives would decrease the surface area of San Francisco Bay, they would have a negative impact on the surface area of the Bay.

Table 4.9-4 summarizes the approximate net change in surface area of San Francisco Bay, including the loss of Bay surface area associated with high-level suspended fill, that would occur as a result of the replacement alternatives.

Table 4.9-4 Net Change in Surface Area of San Francisco Bay - BCDC

 

Build Alternatives

Activity

N-6

N-2

S-4

Retrofit

New Fill from Construction (reduction in surface area)a

19.02 hectares

(47.01 acres)

18.09 hectares (44.90 acres)

17.36 hectares

(42.90 acres)

N/A

Removal of Sedimentb

N/A

N/A

N/A

N/A

Removal of Existing Bridge Deck (increase in surface area)

5.06 hectares

(12.50 acres)

5.06 hectares

(12.50 acres)

5.06 hectares

(12.50 acres)

N/A

Net Change in Surface Area of the Bay

Decrease of

13.96 hectares

(34.51 acres)

Decrease of

13.03 hectares

(32.40 acres)

Decrease of

12.30 hectares

(30.40 acres)

N/A

Source: Caltrans 2000.

a Includes coverage of Bay surface area from two parallel bridge decks, which are considered high-level suspended fill.

b Removal of submerged sediments to create barge access and to prepare for pile installation does not increase the Bay surface area.

4.9.2 Special Aquatic Sites

Impacts to special aquatic sites, including wetlands, sand flats, and eelgrass beds, are subject to ACOE jurisdiction under Section 404 of the Clean Water Act and BCDC jurisdiction under Section 66605 of the McAteer-Petris Act. Sand flats in the project area provide feeding and resting habitat for shorebirds, and eelgrass provides spawning habitat for herring, among other functions. Section 3.9.3 — Estuarine Environment and Associated Species and Section 3.9.7 — Wetlands and Waters of the U.S. describe the functions and values of special aquatic sites. Table 4.9-5 presents a summary of permanent impacts to special aquatic sites. Temporary impacts are presented in Section 4.14.8 — Temporary Impacts, Natural Resources. A discussion of permanent impacts to special aquatic sites, including jurisdictional wetlands, is provided below.

No-Build and Retrofit Existing Structure Alternatives

The No-Build and Retrofit Existing Structure Alternatives would not affect wetlands, sand flats, or eelgrass beds. Special aquatic sites would be identified as environmentally sensitive areas (ESAs) and marked in the field to prevent disturbance from construction activity.

Table 4.9-5 Permanent Impacts to Special Aquatic Sites and Mitigation Measures

 

Wetlands

Sand Flats

Eelgrass Beds

Project Habitat

The tidal wetlands in the project area are located along the north shore of the Oakland Touchdown area and the north side of YBI. These wetlands possess a moderate level of functions and values since they contain non-native plant and animal species. These wetland areas do not provide extensive habitat for wildlife and are not considered high quality.

There is 0.5 hectare (0.12 acre) of two non-tidal wetlands located on the southern portion of the Oakland Touchdown area. These wetlands have limited functions and values due to human disturbance and lack of wetland species diversity. They are unlikely to provide habitat for wildlife species.

The sand flats located within the project area occur along the north side of the Oakland Touchdown area. These sand flats provide a moderate level of functions and values for plankton, a broad range of benthic organisms, certain species of fish at high tides, and feeding, bathing, and roosting habitat for a variety of shorebirds.

Five areas of eelgrass beds have been identified. There are two on the north shore of YBI, two on the south shore, and one on the north shore of the Oakland Touchdown area. Their functions are food source, nursery, spawning ground, and/or habitat for resident and migratory species of birds, fish, and invertebrates.

Table 4.9-5 Permanent Impacts To Special Aquatic Sites and Mitigation

Measures (Continued)

 

Wetlands

Sand Flats

Eelgrass Beds

Area Impacted by Replacement Alternative N-6

No permanent impact.

1.36 hectares (3.36 acres) at Oakland Touchdown as a result of construction of the westbound roadway and realignment of the Caltrans maintenance road and dredging for a barge access channel.

Permanent impacts to 0.21 hectare (0.52 acre) at the Oakland Touchdown area as a result of dredging and 0.01 hectare (0.03 acre) at YBI from construction of barge dock.

Area Impacted by Replacement Alternative N-2

No permanent impact.

1.36 hectares (3.36 acres) at Oakland Touchdown as a result of construction of the westbound roadway and realignment of the Caltrans maintenance road and dredging for a barge access channel.

Permanent impacts to 0.21 hectare (0.52 acre) at the Oakland Touchdown area as a result of dredging and 0.01 hectare (0.03 acre) at YBI from construction of barge dock.

Area Impacted by Replacement Alternative S-4

Permanent impacts to 0.05 hectare (0.12 acre) of non-tidal wetlands on the southern portion of the Oakland Touchdown area from construction.

0.01 hectare (0.03 acre) on south side of YBI as a result of dredging for a barge access channel.

0.15 hectare (0.37 acre) at YBI as a result of dredging and 0.01 hectare (0.03 acre) at YBI from construction of barge dock.

Area Impacted by Retrofit Existing Structure Alternative

No permanent impact.

No permanent impact.

No permanent impact.

 

Table 4.9-5 Permanent Impacts To Special Aquatic Sites and Mitigation Measures (Continued)

Mitigation

For Replacement Alternative S-4, off-site creation of non-tidal wetlands. For Replacement Alternatives N-6 and N-2 and the Retrofit Existing Structure Alternative, avoidance of habitat by marking the wetlands as Environmentally Sensitive Areas (ESAs). The ESAs would be marked in the field using fencing materials, buoys, or other appropriate, highly visible materials.

On-site restoration of portion of sand flats following construction and off-site creation of a tidal marsh ecosystem, including mudflats and tidal channels.

Harvesting eelgrass from within the barge access channel and replanting in adjacent beds as a pilot program; restoring portions of the barge access channel for colonization by eelgrass in area closest to the Oakland Touchdown; marking eelgrass beds outside barge access channel as ESAs; off-site creation of a tidal marsh ecosystem.

Source: Caltrans, 2000.

Replacement Alternatives N-2 and N-6 (Preferred)

Wetlands.

The wetlands located in the project area would not be affected by Replacement Alternatives N-2 and N-6. The wetlands would be identified as ESAs and marked in the field to prevent disturbance from construction activity.

Sand Flats.

Both northern replacement alternatives would affect intertidal sand flats. Replacement Alternatives N-2 and N-6 (Preferred) would permanently impact approximately 1.36 hectares (3.36 acres) of sand flats along the northern shore of the Oakland Touchdown area due to construction of the westbound roadway and realignment of the Caltrans maintenance road. Sand flats at this location provide habitat for shorebirds.

Eelgrass Beds.

Based on a 1999 eelgrass survey, Replacement Alternatives N-2 and N-6 would result in the loss of approximately 0.22 hectare (0.55 acre) of eelgrass beds due to dredging for barge access at the Oakland Touchdown area and for construction of a barge dock at YBI. These eelgrass beds are located on the northern shore of the Oakland Touchdown area and in Clipper Cove on YBI. As discussed in Section 3.9.4 — Wetlands and Waters of the United States, the eelgrass beds are comprised of scattered patches of eelgrass.

Replacement Alternative S-4

Wetlands.

Replacement Alternative S-4 would result in the loss of 0.05 hectare (0.12 acre) of non-tidal wetlands. The affected wetland areas are two non-tidal wetlands located on the southern portion of the Oakland Touchdown. The primary cause of the loss of wetland habitat is the construction of the eastbound roadway and construction staging.

Sand Flats.

Replacement Alternative S-4 would result in the loss of 0.01 hectare (0.03 acre) of sand flats located along the beach on the south side of YBI as a result of dredging for a barge access channel.

Eelgrass Beds.

Approximately 0.15 hectare (0.37 acre) of eelgrass located within Coast Guard Cove on YBI would be removed by dredging for Replacement Alternative S-4. In addition, construction of a barge dock would displace 0.01 hectare (0.03 acre) at YBI. No impacts are anticipated as a result of the new bridge structure because the bridge would be constructed high enough above the water surface to allow sunlight to penetrate the area from an angle to the north or south.

4.9.3 Special Status Species

Special status species include all plants and wildlife protected under the federal and state Endangered Species Acts, plants listed by the California Native Plant Society, avian species protected under the Migratory Bird Treaty Act, marine mammals protected under the Marine Mammal Protection Act, and fish species protected under the Magnuson-Stevens Act.

No-Build Alternative

Since the No-Build Alternative does not include any disturbance of the existing environment, there would be no impacts to special status plant and wildlife species.

Retrofit Existing Structure

The Retrofit Existing Structure Alternative would have no permanent impacts to special status plant and wildlife species..

Replacement Alternatives N-2, N-6 (Preferred), and S-4

The replacement alternatives would result in permanent impacts to marsh gumplant, double-crested cormorant, American peregrine falcon, western gulls, shorebirds, and Pacific herring. The replacement alternatives would not result in permanent impacts to the California least tern, California brown pelican, saltmarsh common yellowthroat, California clapper rail, Allen’s hummingbird, white-tailed kite, American bittern, bank swallow, marine mammals, and protected fish species. A discussion of these species is provided below.

Marsh Gumplant and Alameda Song Sparrow.

As shown in Figures 3-17 and 3-18 in Appendix A, marsh gumplant occurs in four areas within the project area. Impacts to marsh gumplant can be seen on Figures 4-21 and 4-22 in Appendix A. Only one location of marsh gumplant (on the north side of the Oakland Touchdown) would be impacted by the northern replacement alternatives. Replacement Alternative S-4 would result in the removal of marsh gumplant, located to the south of the existing bridge on Port of Oakland property. While these would be impacts to the local marsh gumplant, impacts would not affect the long-term viability of the species because marsh gumplant is widely distributed throughout the San Francisco Bay tidal marsh ecosystem. Marsh gumplant is potential supporting habitat for the Alameda song sparrow. The Alameda song sparrow is a species of concern, but is not listed under either the Federal or State Endangered Species Act. Since the viability of the marsh gumplant species would not be impacted, there would not be an impact to the Alameda song sparrow as a result of the East Span Project.

Double-Crested Cormorant.

Double-crested cormorants currently nest on the existing East Span. Construction of any replacement alternative would include the dismantling of the existing East Span bridge, which would result in the permanent removal of nesting sites for the double-crested cormorant.

American Peregrine Falcon.

A pair of American peregrine falcons nests on the existing East Span. Construction of a replacement alternative would include dismantling the existing East Span structure, which would result in the removal of the nesting site for the pair. Removal of the bridge could create a long-term impact to the American peregrine falcon. It is anticipated that the pair would nest on a replacement bridge, resulting in no long-term impact.

Shorebird Species.

Shorebirds include migratory birds which are protected under the Migratory Bird Treaty Act. Species of concern also included in this group are the common loon, long-billed curlew, and elegant tern. The replacement alternatives would not result in a direct impact to shorebird species; however, they would result in the removal of supporting roosting and feeding habitat. As discussed under Section 4.9.2, the northern replacement alternatives (Replacement Alternatives N-2 and N-6 [Preferred]) would result in the removal of sand flats. The loss of sand flats (1.36 hectares [3.36 acres]) along the northern portion of the Oakland Touchdown area would decrease the amount of available shorebird habitat. The loss in shorebird habitat is not anticipated to adversely impact shorebirds due to the relatively small area affected by the project.

Replacement Alternative S-4 would result in the removal of upland (0.21 hectare [0.51 acre]) known to be used by shorebirds. The upland area occurs on the south side of the Oakland Touchdown area and provides winter and high-tide roosting habitat for shorebirds.

Western Gull. Direct impacts to the western gull would occur if nests are present on column footings of the existing East Span prior to the dismantling of the structure.

California Least Tern. This species is not known to occur in the project area. However, new information has become available since concluding the endangered species consultation process with USFWS for the East Span Project; this information suggests the least tern may use former Oakland Army Base lands adjacent to the project area and portions of the southern shore of the Oakland Touchdown. These areas would not be permanently impacted by the East Span Project.

Black-crowned Night Heron, Allen’s Hummingbird, White-tailed Kite, Bank Swallow, and Bewick’s Wren. Permanent impacts to the night heron, Allen’s hummingbird, white-tailed kite, bank swallow, and Bewick’s wren are not anticipated because vegetation and trees removed during construction on YBI would be replaced as part of a revegetation plan implemented after construction is complete.

Saltmarsh Common Yellowthroat, California Clapper Rail, and American Bittern. Impacts to the saltmarsh common yellowthroat, California clapper rail, and American bittern are not anticipated because these species occur at the Emeryville Crescent, which is located outside of the project area.

California Brown Pelican. Impacts to the California brown pelican would not occur since this species does not nest in the project area.

Pacific Herring. Permanent impacts to Pacific herring as a result of Replacement Alternatives N-2, N-6, and S-4 would include loss of habitat such as eelgrass beds in the project area. Eelgrass beds would be permanently impacted due to dredging for barge access.

4.9.4 Other Natural Communities

Patches of natural communities such as coast live oak woodland, northern coastal scrub, and northern coastal saltmarsh occur within the project area. The replacement alternatives would result in permanent impacts only to the coast live oak woodland on YBI.

Coast Live Oak Woodland

Three patches of coast live oak woodland occur on slopes of YBI. Portions of two of these areas could be removed by the alteration of Macalla Road, which is required for all of the replacement alternatives, including the Preferred Alternative. Macalla Road would be realigned at a lower grade in an area located within the dripline of the tree canopy. This activity would damage the root zone of remaining trees and would result in a loss of six coast live oak trees. The coast live oak trees that would be affected range from 45 to 127 centimeters (18 to 50 inches) diameter-breast-height.

4.9.5 Consultation and Coordination

Consultation and coordination with federal, state, and regional agencies has occurred for the East Span Project. Pursuant to the NEPA/404 Integration Memorandum of Understanding (MOU), Caltrans and FHWA have consulted with U.S. Environmental Protection Agency (EPA), U.S. Fish and Wildlife Service (USFWS), U.S. Army Corps of Engineers (ACOE), and National Marine Fisheries Service (NMFS). Per the MOU, concurrence on the project’s Conceptual Mitigation Plan for Special Aquatic Sites was requested and received from EPA, ACOE, and USFWS. Although not signatories to the NEPA/404 Integration MOU, Caltrans also coordinated with California Department of Fish and Game (CDFG), the Regional Water Quality Control Board, and BCDC as part of the NEPA/404 process. A summary of the NEPA/404 Integration MOU process and concurrence letters are included in Appendix F.

The ACOE has made a jurisdictional determination in the delineation of waters of the U.S., including wetlands subject to Section 404 of the Clean Water Act. The ACOE concurrence letter can be found in Appendix F.

Consultation with USFWS for species protected under Section 7 of the Endangered Species Act has been concluded. The American peregrine falcon was the only endangered species identified by the USFWS as having the potential to be impacted by the project. The peregrine falcon has been removed from the Federal Endangered Species Act list, but remains on the California Endangered Species Act (CESA) list and is a USFWS species of concern. (See USFWS correspondence dated August 31, 1999 in Appendix G.) In addition, Caltrans is consulting with the California Department of Fish and Game (CDFG) regarding potential impacts to Pacific herring and species regulated under the CESA, such as the American peregrine falcon. Caltrans will also continue to coordinate with CDFG regarding potential impacts to the double-crested cormorant, a California species of concern.

Consultation with NMFS for species protected under Section 7 of the Endangered Species Act has been concluded. Consistent with the mandates of the Magnuson-Stevens Fishery Management and Conservation Act and the Endangered Species Act Section 7 formal consultation process, FHWA and Caltrans consulted with NMFS regarding Essential Fish Habitat (EFH) and/or species protected under Section 7 of the ESA. As requested by NMFS, essential habitat supporting managed fish species was addressed in an Essential Fish Habitat Assessment (provided as an appendix to the June 1999 Biological Assessment that can be reviewed at Caltrans District 4 offices). The NMFS rendered a not likely to adversely affect biological opinion for the project on September 23, 1999 (see Correspondence in Appendix G). Coordination will continue with NMFS concerning the potential for impacts to fish species protected under the Endangered Species Act, including the Chinook salmon and steelhead, and to marine mammals protected under the Marine Mammal Protection Act.

4.9.6 Mitigation

Retrofit Existing Structure Alternative

The impacts of the Retrofit Existing Structure Alternative would occur only during construction. These impacts and their mitigation are discussed in Section 4.14.8 — Temporary Impacts, Natural Resources.

Replacement Alternatives N-2, N-6 (Preferred), and S-4

Special Aquatic Sites.

Impacts to special aquatic sites would be mitigated by on-site restoration of portions of the eelgrass and sand flat habitats and by off-site creation of a tidal marsh ecosystem. Mitigation concepts have been identified in the Conceptual Mitigation Plan for Special Aquatic Sites, which was prepared in coordination with the following agencies: USFWS, ACOE, EPA, BCDC, CDFG, and RWQCB (see Appendix N). The objective of the mitigation is to provide enhanced functions and values relative to the impacted special aquatic sites. This approach is based on habitat evaluations and is consistent with mitigation for similar projects in the Bay Area.

Consultation with the state and federal agencies listed above will continue during the permitting process. Consultation will be concluded with the preparation and submittal of a Final Mitigation Plan for Special Aquatic Sites that identifies the specific habitat restoration methods, the criteria to be used for monitoring and evaluating the success of the mitigation effort, and a contingency plan if the mitigation fails. The Final Mitigation Plan will be based on the concepts developed in the Conceptual Mitigation Plan summarized below.

On-site restoration of eelgrass and sand flats would occur in the vicinity of the existing eelgrass beds, north of the Oakland Touchdown area. Restoration of the eelgrass beds and sand flats would include:

The goal of the on-site mitigation is to restore existing functions and values to the special aquatic sites in the project area.

Off-site mitigation for eelgrass beds and sand flats would occur at an appropriate site, such as the Breuner property in the City of Richmond, that is approved by state and federal resource agencies. Creation of a tidal marsh ecosystem from existing uplands would include mudflats, tidal channels, and tidal marsh habitat. Restoration of any adjacent uplands and existing jurisdictional wetlands is also included in the mitigation concept. It is anticipated that creation and restoration of complementary habitat types proposed for off-site mitigation would result in greater wetland functions and values than those that currently exist in the project area. Specifically, the new tidal marsh would provide new habitat for the plant and wildlife populations that utilize the Central Bay, including migratory shorebirds and local fish and avian populations. Mitigation would be provided at a 3:1 ratio to compensation for the loss of special aquatic sites.

Special Status Species.

American Peregrine Falcon. The removal of the existing bridge would result in the loss of nesting area for the peregrine falcon. Mitigation, summarized below, would be similar to that outlined in the contract between Caltrans and the Santa Cruz Predatory Bird Research Group (SCPBRG) for the interim seismic retrofit project.

During dismantling of the bridge, a monitor from the SCPBRG would observe the birds' nesting activities. If the dismantling work disturbs nesting activities, the eggs and/or chicks would be collected, raised off-site, and eventually released off-site.

A June 24, 1997 letter from USFWS indicates that peregrine falcons would likely nest on the new bridge once construction activities are complete (see Appendix G). Since these birds of prey are known to use bridges and tall buildings as surrogate nest sites, no nest structures would be created on the new bridge for them. When peregrines recolonize the new bridge, monitoring and off-site release efforts by the SCPBRG would continue as they have for the existing bridge to avoid potential impacts during scheduled maintenance activities.

Double-crested cormorant. Nesting habitat would be constructed on the new bridge.

Shorebird Species. Permanent loss of shorebird roosting habitat as a result of construction of Replacement Alternative S-4 would be offset by enhancement or creation of upland refugia as part of the creation of a tidal marsh ecosystem.

Pacific Herring. Permanent loss of herring habitat (i.e., eelgrass) would be offset by on-site restoration and off-site creation of a tidal marsh ecosystem.

Natural Communities.

Coast Live Oak Woodland. All the replacement alternatives would require realignment of Macalla Road, which could result in removal of or disturbance to the root zone and loss of six trees. Post-construction surveys would be conducted to determine the number of trees actually removed or affected. Oaks would be replaced in accordance with the CCSF tree ordinance. The oak trees would be replaced at a ratio of 3:1 in the same area to create a visual setting comparable to the existing pre-construction condition. Due to the root structure of mature oak trees, it is not certain that Caltrans would be able to successfully plant replacement trees of the same size. As a result, the replacement trees may be smaller than those displaced. After replanting, monitoring and additional replanting would be performed as necessary to ensure success of the new trees. A conceptual mitigation plan, specifying goals, replacement ratio, success criteria, and monitoring would be determined in coordination with the San Francisco Public Works Department that has authority under the CCSF tree ordinance.

4.10 HISTORIC AND CULTURAL RESOURCES

This section reports the potential for East Span Project alternatives to affect archaeological and historic resources. The discussion in this section focuses on historic properties listed or potentially eligible for the National Register of Historic Places (NRHP) pursuant to the National Historic Preservation Act. For a discussion of historic resources in relation to Section 4(f) of the Department of Transportation Act, see Chapter 6.

The consideration of historic resources under Section 4(f) of the Department of Transportation Act differs from their consideration under Section 106 of the National Historic Preservation Act. Section 4(f) applies only to programs and projects undertaken by the U.S. Department of Transportation and only to publicly owned public parks, recreation areas, and wildlife refuges and to historic sites on or eligible for the NRHP. For protected historic sites, Section 4(f) is triggered by the "use" or occupancy of a historic site by a proposed project. In contrast, Section 106 applies to any federal agency and addresses direct and indirect "effects" of an action on historic properties. Section 106 evaluates "effects" on a historic site, while Section 4(f) protects historic sites from "use" by a project. Therefore, even though there may be an "adverse effect" under Section 106 because of the effects upon the site, the provisions of Section 4(f) are not triggered if the project would not result in an "actual use" (occupancy of land) or a "constructive use" (substantial impairment of the features or attributes which qualified the site for the NRHP). Section 106 of the National Historic Preservation Act requires agencies to take into account the effects of their projects on historic properties eligible or listed on the NRHP. Impacts to resources are assessed by application of the Criteria of Effect and Adverse Effect (36 CFR Part 800.9). An undertaking is considered to have an adverse effect on a historic property when the undertaking may diminish the integrity of the property’s location, design, setting, materials, workmanship, feeling, or association. Pursuant to 36 CFR 800.9, an adverse effect on a historic property includes, but is not limited to: (1) physical destruction, damage, or alteration of all or part of the property; (2) isolation of the property from or alteration of the character of the property’s setting when that character contributes to the property’s eligibility; (3) introduction of visual, audible, or atmospheric elements that are out of character with the property or alter its setting; (4) neglect of a property resulting in its deterioration or destruction; and (5) transfer, lease, or sale of the property.

To satisfy the federal requirements for Section 106, Caltrans has prepared Finding of Effect Reports for NRHP listed and eligible resources within the project APE. The Section 106 Criteria of Effect and Adverse Effect were used to determine the effects of the proposed project on historic architectural resources and on archaeological resources. Caltrans and Federal Highway Administration (FHWA) have consulted with the SHPO concerning determination of effects (see letter in Appendix G from the SHPO dated September 10, 1998). Per Section 106 regulations, the SHPO concurred that the undertaking has an adverse effect on historic properties and did not comment or concur in what the specific effects to individual properties are.

Mitigation measures discussed in this section have been developed in consultation with the SHPO and Advisory Council on Historic Preservation (ACHP) (see Section 4.10.1 — Historic and Cultural Resources, Consultation for a summary of consultations). Views on mitigation measures have also been solicited from interested parties such as Native Americans, preservation organizations, and public agencies (e.g., the City of Oakland, the Navy, the USCG, and the CCSF).

In accordance with Section 106, measures to mitigate project effects on historic properties have been stipulated in an Memorandum of Agreement (MOA) executed among the FHWA, USCG, the SHPO, and the ACHP, with Caltrans as a concurring party (included in Appendix O). The Navy, local governments, and Native Americans were also invited to sign the MOA as concurring parties.

4.10.1 Consultation

A Finding of Effect for Archaeological Resources and a separate Finding of Effect for Historic Architectural Resources were submitted to the SHPO in July 1998. The SHPO responded concerning determination of effects in letters dated August 3 and September 10, 1998. Caltrans met with Oakland Landmarks Preservation Advisory Board on July 3, 1998, to discuss possible mitigation measures. Caltrans also met with Navy staff on August 25, 1998, to discuss project effects on the historic properties on YBI.

On December 10, 1998, Caltrans met with the City of Oakland and its Landmarks Preservation Advisory Board, the Oakland Heritage Alliance, and the Port of Oakland to discuss possible measures to mitigate project effects on historic properties. On February 1, 1999, representatives from ACHP, Caltrans, FHWA, the Navy, the USCG, CCSF, and the SHPO toured the project area and the historic properties. On February 2, 1999, Caltrans hosted two meetings with historic preservation organizations, ACHP, SHPO, Navy, USCG, FHWA, and city governments. The first meeting included discussion of the replacement alternatives and effects on Navy and USCG facilities of YBI and proposed measures to mitigate project effects on historic properties. The second meeting continued the discussion of measures to mitigate for the loss of the East Span under the replacement alternatives. In October 1999, an Addendum Finding of Adverse Effect and Consideration of Proposed Mitigation Measures (which included a draft MOA) were transmitted to the SHPO, ACHP, Navy, USCG, the CCSF, City of Oakland, and Bay Area historic preservation groups. Comments were received from the USCG, Navy, SHPO, and ACHP. A meeting with the Navy was held on March 1, 2000, to discuss its comments on the MOA. The MOA was revised based on consideration of comments received. The MOA was executed in May 2000, stipulating mitigation measures to be followed on this project (see Appendix O for a copy of the MOA).

4.10.2 Impacts to Archaeological Resources

Replacement Alternatives N-6 and S-4, including temporary detours, would have an impact on CA-SFr-04/H. Replacement Alternative N-2 would have no impact on the site (see Table 4.10-1).

Pursuant to the project MOA, Caltrans would prepare a treatment plan for pre-construction archaeological data recovery. It would be submitted to all parties to the MOA for review and comment. Interested Native Americans would also be invited to participate in development of the treatment plan.

Table 4.10-1 Summary of Effects to CA-SFr-04/H by Alternative

Alternative

 

Description of Impact to Prehistoric Midden Component of CA-SFr-04/H

No-Build

 

No work within site boundaries. No impact.

Retrofit Existing Structure

 

Excavation to strengthen Column YB3 would disturb site.

N-2

 

No excavation within site boundaries.

Temporary Detours

 

No impact.

N-6 (Preferred)

 

Columns for both east- and westbound permanent structures would disturb site.

Temporary Detours

 

One column for the westbound temporary detour would disturb site.

S-4

 

Permanent structures would not affect site.

Temporary Detours

 

Four columns for the westbound temporary detour would disturb site.

Source: Caltrans, San Francisco-Oakland Bay Bridge East Span Seismic Safety Project Finding of Effect for Archaeological Resources Located in the City and County of San Francisco and the City of Oakland, Alameda County, California, July 1998.

A Native American monitor would be present during all archaeological field investigations. If human remains are located, either Native American or non-Native American, Caltrans would ensure that treatment of the remains would comply with all applicable state and federal laws and regulations, including the Native American Graves Protection and Repatriation Act of 1990 (P.L. 101-601, 25 U.S.C. 3001-3013). California Public Resources Code Sections 5097.98 and 5097.99 require protection of Native American remains which might be discovered and outline procedures for handling any burials found.

In all cases where human remains are discovered, the County Coroner would be notified and, in the case of Native American remains, the state Native American Heritage Commission (NAHC) would be notified. Consultation with a Most Likely Descendant designated by the NAHC would be conducted.

If human remains are discovered during construction, all work would cease in the immediate vicinity of the discovery until the appropriate treatment has been completed.

Mitigation for Archaeological Resources: A Treatment Plan would be prepared by Caltrans for pre-construction archaeological investigations. See Stipulation VII of the MOA in Appendix O for more details.

The Treatment Plan would include a data recovery plan for the prehistoric component of CA-SFr-04/H, as well as guidelines for evaluation and data recovery of any other archaeological deposit within the area of the undertaking. The Treatment Plan would address treatment of unanticipated discoveries of any other archaeological deposits, such as historic archaeological remains, within the project construction area.

The Treatment Plan would be consistent with the Secretary of the Interior’s Standards and Guidelines for Archaeological Documentation and would take into account the ACHP’s publication, Treatment of Archaeological Properties: A Handbook, and SHPO guidelines.

Interested Native Americans will be invited to participate in the development of the Treatment Plan. In addition, Caltrans would also submit the Treatment Plan to all parties to the MOA, including interested Native Americans, for review and comment. Comments received within 30 days would be taken into account.

A Native American monitor would be present during archaeological field investigations. If any buried cultural materials are encountered during construction, work would cease in the vicinity of the discovery, and a Caltrans archaeologist would be contacted to evaluate the finds.

Caltrans would develop public interpretive materials covering historical and archaeological resources within the project area and would disseminate these materials to both the public at large and educational institutions. Interpretive materials may include, but are not limited to: a mobile exhibit on the archaeology and history of Yerba Buena Island (YBI), curriculum materials, a web site, and other public presentations.

4.10.3 Impacts to Historic Architectural Resources

Build alternatives have been determined to affect historical architectural resources within the project limits. Potential impacts are presented in this section. Under the Department of Transportation Act of 1966, all build alternatives result in Section 4(f) use of historic resources. See Chapter 6 — Section 4(f) Evaluation.

No-Build Alternative

The No-Build Alternative would not affect any of the historic architectural resources within the project APE.

Retrofit Existing Structure Alternative

Impacts to historic architectural properties from the Retrofit Existing Structure Alternative would result from modifying the existing SFOBB East Span and change in views to the Bay from Quarters 1. These changes would result in an impact. Impacts are summarized below.

San Francisco-Oakland Bay Bridge (SFOBB). The Retrofit Existing Structure Alternative would add new piles and pile caps at many columns, construct two new columns at the main span of the cantilever truss, and encase several steel columns in concrete. These changes to the existing structure would substantially alter the East Span portion of this historic structure, resulting in a loss of integrity of design and materials.

There would be no impact to the Caltrans Garage and Caltrans Electrical Substation on YBI, the Caltrans Electrical Substation at the Oakland Touchdown area, and the Key Pier Substation, which are associated with the SFOBB and contributors to the bridge’s nomination to the NRHP. The structures would be retained under the retrofit alternative.

Senior Officers’ Quarters Historic District (includes Quarters 1 to 7 and Buildings 83, 205, and 230). The retrofit of Columns YB2 through YB4 on YBI would result in encasement of the existing steel columns in concrete. The resulting walls would substantially impair the view from Quarters 1 across the eastern portion of San Francisco Bay. This would constitute a visual intrusion that would diminish an important aspect of the building’s setting.

Quarters 1. Retrofit of Columns YB2 through YB4 on YBI, as described above, would result in an impact on Quarters 1.

Quarters 8. No work related to the retrofit alternative would cause impacts to Quarters 8. This residence is located downslope from the existing structure within the USCG base. Bay views from the structure would not be modified by retrofit activities.

Quarters 9. No work related to the retrofit alternative would result in impacts to Quarters 9. This structure is located on Treasure Island Road facing southeast. Views from the structure to the Bay would not be affected, and access to the building would not be modified.

Quarters 10. No impacts would result to Quarters 10 from the Retrofit Existing Structure Alternative. This residence is located at an elevation equal to the bridge decks and is screened from view of the bridge by surrounding oak woodland vegetation.

Building 267. This building is a garage adjacent to Quarters 10 and is screened from view of the SFOBB by surrounding vegetation. No impact to this building would result from the retrofit alternative.

Building 262. The retrofit alternative would have no impact on Building 262. Work to strengthen existing columns on YBI and immediately offshore would not have an effect on the materials or craftsmanship which make the building significant or diminish the understanding of the relationship of the building to early military occupation on YBI.

The retrofitted structure would cause no permanent change in the noise levels from existing conditions.

Replacement Alternatives

Historic architectural resources on YBI and at the Oakland Touchdown area would be affected by some of the replacement alternatives. All replacement alternatives would affect the SFOBB. With the exception of Building 262, properties eligible for historic architectural significance and for association with military history would not be affected by the replacement alternatives; these characteristics which make the properties significant would remain intact after project implementation.

San Francisco-Oakland Bay Bridge (SFOBB). All of the replacement alternatives would require removal of the existing East Span. Dismantling of this historic structure would result in the removal of a structure eligible for listing on the NRHP.

The impacts to four buildings which are associated with the SFOBB and are contributors to the bridge’s nomination to the NRHP are discussed below:

Caltrans Garage (Yerba Buena Island). This contributing structure to the NRHP- eligible SFOBB would be removed under all replacement alternatives. This would remove a contributory structure to the NRHP- eligible SFOBB.

Caltrans Electrical Substation (Yerba Buena Island). This contributing structure to the NRHP- eligible SFOBB would be removed under all replacement alternatives.

Caltrans Electrical Substation (Oakland Touchdown Area). The electrical substation at the Oakland Touchdown area adjacent to the SFOBB would not be altered or removed to construct the replacement alternatives. Construction activities conducted adjacent to the substation are not expected to result in damage to the structure.

Key Pier Substation. The Key Pier Substation would not be altered or removed as a result of dismantling of the SFOBB. As a result, the DEIS stated that the Key Pier Substation will not be affected by any of the project alternatives. However, part of the building’s significance is as a contributing component of the Bay Bridge. Although the bridge would be dismantled under any of the replacement alternatives, the building would remain individually eligible for NRHP listing for its association with the Key System Railway, but its historic association with the SFOBB would be lost. All replacement alternatives would have an impact on the Key Pier Substation by removing the SFOBB. Also, construction work in the vicinity of the substation could result in inadvertent damage to the structure.

 

Senior Officers’ Quarters Historic District (includes Quarters 1 to 7 and Buildings 83, 205, and 230). Replacement Alternatives N-2 and N-6 would each place the westbound structure over the southeast corner of the historic district. Replacement Alternative N-2 extends approximately 10 meters (33 feet) north of the existing bridge, while Replacement Alternative N-6 extends approximately 12 meters (40 feet) north of the existing bridge, over the historic district. No contributing buildings or landscape features would be altered because no part of Replacement Alternatives N-2 or N-6 would touch any part of the district. No historic characteristics of the district would be diminished. Views from Quarters 1 would be slightly modified by placing concrete columns within view and removing the existing steel column from view.

Replacement Alternative S-4 would shift the new bridge slightly farther away from the historic district than the existing bridge. It would have no impact on the historic district.

Temporary detours (see Figures 2-16.2, 2.17.2 and 2-18 in Appendix A) required for the replacement alternatives would be in place for up to 4 years. Temporary detours would be placed over the historic district. These temporary detours would require construction of numerous column footings within the district. The affected areas would be restored to their prior condition at the completion of the project.

Quarters 1. See Senior Officers’ Historic District, above. Replacement Alternatives N-2 and N-6 would not have an effect on Quarters 1. Replacement Alternative S-4 would not have an impact on Quarters 1.

Temporary detours required for the replacement alternatives would be operational for approximately 2 years. The period from the beginning of construction to the end of their operational use would be approximately 4 years. The detours may be removed as soon as they are no longer needed to carry traffic or they may be removed as one of the last steps of bridge construction on YBI, because the contractor may use them as platforms from which to construct other portions of the bridge. Temporary detours would be placed adjacent to the south side of the residence, approximately 2 meters (7 feet) to the south for Replacement Alternatives N-2 and N-6 (Preferred) and 5 meters (16 feet) for Replacement Alternative S-4, with numerous column footings within the viewshed looking out from Quarters 1. Any affected areas within the footprint of the Quarters 1 National Register-described boundaries would be restored to prior condition at the completion of the project.

Quarters 8. Quarters 8 would not be affected by any of the replacement alternatives.

Temporary detours under all replacement alternatives would avoid Quarters 8. The detour structures would be temporary and the affected areas would be restored to their prior condition at the completion of the project.

Quarters 9. Quarters 9 would not be affected by any of the replacement alternatives.

No temporary detours under any of the replacement alternatives would affect Quarters 9.

Quarters 10. Quarters 10 would not be affected by any of the replacement alternatives.

No temporary detours under any of the replacement alternatives would affect Quarters 10. A temporary retaining wall would be constructed on Macalla Road adjacent to Quarters 10. Construction activities in the vicinity of Quarters 10 could result in inadvertent damage.

Building 267. Building 267, a garage, is a contributing structure to Quarters 10. No impact would result to Building 267 due to temporary detours for the replacement alternatives. Construction would require closure of the driveway to the building for approximately one day while the driveway is regraded to align with the new Macalla Road configuration.

Building 262. Replacement Alternatives N-2 and N-6 would have an impact on Building 262; replacement structures would pass above the building at approximately 53 meters (175 feet) above the ground in this area, and the two side-by-side decks would cover the entire length of the building. The close proximity of the new structures would introduce "visual, audible, or atmospheric elements that are out of character with the property." (See Figure 4-24 in Appendix A.) Construction activities in the vicinity and overhead could result in inadvertent damage.

Mitigation for Buildings and Structures: The measures listed below represent mitigation measures stipulated in the MOA (see Appendix O). The MOA is alternative neutral. While stipulations are identified for all alternatives, only those identified for the alternative selected in the Record of Decision will be carried out. The mitigation program for the East Span Project is intended to provide a publicly available record of information for the East Span and other historic properties that would be affected as a result of the proposed project.

Mitigation of Effects on the San Francisco-Oakland Bay Bridge:

Mitigation of Effects to the Senior Officers’ Quarters Historic District, Quarters 8, Quarters 10, Building 267, and Building 262:

Mitigation of Effects to the Caltrans Electrical Substation and Key Pier Substation at the Oakland Touchdown:

4.11 SCIENTIFIC RESOURCES

Potential exists for paleontologic resources to be disturbed during in-Bay construction to retrofit existing footings and columns for the Retrofit Existing Structure Alternative and construct new footings and columns for the replacement alternatives.

Mitigation: Should any paleontologic resources be discovered during in-Bay construction, Caltrans would ensure that provisions of the California Public Resources Code Section 5097.6 are implemented using their "Interim Guidance for the Identification, Assessment, and Treatment of Paleontological Resources." Any discovered remains would be evaluated by a professional paleontologist and deposited at an appropriate scientific repository such as the Paleontological Museum of the University of California, Berkeley.

4.12 UTILITIES RELOCATION

The backup water supply line on the existing East Span would be retained under the No-Build and Retrofit Existing Structure Alternatives but would be relocated, potentially to the new structures, under the replacement alternatives. In 1944, the Navy entered into an agreement with the State of California which stipulates that the Navy would pay for relocating the water line in the event that it is moved.

The EBMUD outfall, which extends into San Francisco Bay for a distance of approximately 1,600 meters (1 mile), is located to the south of the existing East Span. It is a zero-load facility that cannot support any weight and must be protected or spanned to prevent damage. For Replacement Alternatives N-2 and N-6, a temporary span over the land-based portion of the EBMUD sewer outfall may be necessary for the construction period and the contractor would coordinate it with EBMUD. Replacement Alternative S-4, which crosses the buried outfall line on the Oakland Touchdown, would require that a special design be used to sufficiently span the outfall facility to prevent damage during construction. Caltrans and the contractor will coordinate with EBMUD, if a southern alternative is chosen, to prevent damage to the pipe. Replacement Alternative S-4 would also interfere with access to EBMUD's dechlorination facility due to insufficient vertical clearance between the bridge and the existing service road. It would require relocation of the service road or the dechlorination facility. Caltrans would work with EBMUD to relocate the service road and/or the dechlorination facility to maintain EBMUD's operations during relocation. Caltrans would obtain necessary permits/permit amendments, fund relocation costs, and implement any necessary mitigation.

Electrical power to the islands is provided by PG&E via a Navy-owned pole line along the south side of the approach to the bridge that transitions near the incline to a 34.5 kilovolt submarine cable.

The contractor would have substantial disincentives for disruption of the primary power supply. If an occurrence should unavoidably require dependence on the existing backup power source and if the Navy/CCSF documents the additional cost of using the backup line, Caltrans or the contractor would pay the difference in cost. In addition, if the Navy/CCSF provides documentation for monetary loss in the event that the back-up line also fails, Caltrans or the contractor would also provide reimbursement for the documented losses.

Utilities located on the existing East Span would be maintained under the No-Build and Retrofit Existing Structure Alternatives, but would be relocated under the replacement alternatives. Timing of utility relocations would be set to avoid interruption of service when portions of the existing span would be removed or when it is not possible to maintain them on the existing structure. The Navy/CCSF and USCG will have the opportunity to review and comment on the proposed utilities plans and specifications.

Natural gas is provided to the islands by a 254-millimeter (10-inch) diameter high-pressure submarine gas main from Oakland. Submarine utilities would be avoided to the greatest extent possible. In addition, bridge footings would be located in such a manner as to avoid impacts to underwater utilities. Contract specifications would include a provision for the contractor to protect submarine utilities during construction. Coordination with utility providers has been initiated to verify locations of submarine utilities and to identify potential conflicts. Coordination with utility providers would continue through the final design process and construction period. If utilities cannot be avoided, they would be relocated or protected in place (e.g., placing a concrete slab over the utility or encasing it in a conduit). Caltrans or the contractor would also repair inadvertent damage resulting from construction activities.

As a result of the federal land transfer (see Section 3.1.1 — Existing Land Uses in the Project Vicinity for more information), Caltrans now owns land in fee on YBI. Caltrans is coordinating with the Navy, CCSF, and the USCG regarding their ability to access utilities within Caltrans' right-of-way.

4.13 ENERGY

4.13.1 Analysis Methodology

This section addresses the impact of the San Francisco Oakland Bay Bridge (SFOBB) build alternatives on indirect energy consumption (i.e., consumed during construction activities). NEPA requires a discussion of energy requirements and conservation measures with particular emphasis on avoiding or reducing inefficient, wasteful, and unnecessary consumption of energy (40 CFR 1502.16(e)). Energy generation and distribution issues in California in late 2000 and early 2001 have created renewed awareness of electrical energy supply, demand, and distribution.

A long-term energy impact assessment was not prepared for the East Span Project because current guidance for preparing energy analyses only requires a comparison among project alternatives of the barrels of oil consumed from long-term use of the facility. The East Span Project build alternatives do not add traffic capacity compared to the No-Build Alternative. Therefore, long-term oil consumption should be about the same for all project alternatives. There is the potential for the replacement alternatives, which include inside and outside shoulders, to improve traffic operations by minimizing the traffic congestion effects of accidents and breakdowns. The energy consumption benefits of the improved traffic operations of the replacement alternatives would be minimal in comparison to the long-term energy consumption of vehicles using the bridge. It is not possible to measure this slight potential energy reduction due to improved traffic operations of adding shoulders because of the lack of predictability of accidents and breakdowns.

The amount of electrical energy consumption for construction and ongoing electrical needs for this project (roadway lighting, substations, etc.) would be infinitesimal when compared to the energy expended by vehicles using the bridge. There would be no electrical energy savings associated with the project. Electrical usage would remain the same as existing conditions for the No-Build and Retrofit Existing Structure Alternatives since the existing electrical facilities would remain the same. For the replacement alternatives, any savings experienced by the use of new technology would be offset by the increases in electrical usage because a replacement bridge would be longer than the existing bridge and would require additional electrical fixtures.

Indirect energy impacts involve the one-time, non-recoverable energy costs associated with construction of roadways and transportation-related facilities such as bridges. Facility-related energy accounts for energy consumed during the following activities:

Construction of the build alternatives for the SFOBB would be a large-scale effort with many issues, techniques, and methods. Particular issues associated with this project include work to be conducted within the water, access to materials (either by land or water), dismantling activities, dredging activities, pile driving, and others. For a discussion of the construction scenario, see Chapter 2.

The indirect energy analysis was conducted using the Input-Output Method, a standard Caltrans method outlined in the Caltrans 1983 Energy and Transportation Systems Manual. This method was used to convert the 2002 construction dollars, identified in Table 2.4-1 of this document, into energy consumption. (See Section 2.4.2 — Costs for more information.) Although the cost of fuels varies from region to region, this is an appropriate method for analyzing construction energy when limited information is available.

Energy is measured in British thermal units (Btus). For this analysis the Btus were converted to the equivalent barrels of crude oil for comparison of alternatives. For purposes of comparison, 5.3 million barrels is approximately equivalent to the total daily amount of motor gasoline consumed in the United States or total gasoline sales in one week in California.

4.13.2 Impacts

The indirect energy consumption for construction-related activities for each alternative is summarized in Table 4.13-1. Over 90 percent of the energy expended on each of the build alternatives would be the result of structure and roadway construction. Other elements, such as bicycle/pedestrian paths and lighting would account for a very small portion of the total indirect energy consumption.

No-Build Alternative

There would be no construction costs associated with the No-Build Alternative and, therefore, no expenditure of indirect energy.

Retrofit Existing Structure Alternative

Based on 2002 construction costs of $900 million dollars, the Retrofit Existing Structure Alternative would consume approximately 20,091 billion Btus or 3.5 million barrels of oil during construction.

Replacement Alternative N-2

Based on 2002 construction costs of $1,350 million dollars, the skyway design variation would consume approximately 30,129 billion Btus or 5.2 million barrels of oil during construction. This design variation would not include lighting; therefore, no indirect energy would be expended for this element.

Table 4.13-1 Indirect Energy Analysis

 

Alternatives

 

Retrofit

Existing

Skyway

Cable-stayed Main Span

Design Option

Self-anchored

Suspension Bridge

Description

 

N-2

N-6

S-4

N-2

N-6

S-4

N-2

N-6 (Preferred)

S-4

2002 Construction Costs (millions) a

$900

$1,350

$1,350

$1,350

$1,550

$1,550

$1,600

$1,600

$1,650

$1,600

1977 Equivalent Construction Costs (millions) b

$287

$430

$430

$430

$494

$494

$510

$510

$526

$510

TOTAL BTUS CONSUMED (billions)c

20,091

30,129

30,129

30,129

34,601

34,601

35,716

35,716

36,838

35,716

TOTAL BARRELS OF OIL CONSUMEDd

3,464,000

5,195,000

5,195,000

5,195,000

5,966,000

5,966,000

6,158,000

6,158,000

6,351,000

6,158,000

Notes:

a Construction costs are derived from Table 2.4-1 of this document. The cost information in this table represents the estimated cost of the various alternatives based on information available in 1998. They do represent the current costs of the alternatives, which would be greater, but still have the same relative relationship. See Section 2.4.2 — Costs for more information.

b In order to use the factor of 70,100 Btus/1977 Construction Dollar, a dividing factor of 3.14 was used to convert 2002 construction dollars to 1977 construction dollars.

c Construction dollars converted to Btus based on construction energy factor of 70,100 Btus/1977 construction dollar (Caltrans 1983).

d Based on a conversion factor of 5.8 million Btus/Barrel of crude oil.

Source: Caltrans, September 2000.

The cable-stayed main span design variation would have a 2002 construction cost of $1,550 million dollars. The indirect energy consumption for this alternative would be approximately 34,601 billion Btus or 6.0 million barrels of oil. This alternative would include all facility elements described above.

The self-anchored suspension bridge design variation would have a 2002 construction cost of $1,600 million dollars. Construction energy consumption would be approximately 35,716 billion Btus or 6.2 million barrels of oil. This alternative would include all facility elements described above.

Replacement Alternative N-6 (Preferred)

With a 2002 construction cost of $1,350 million dollars, the skyway design variation would consume approximately 30,129 billion Btus or 5.2 million barrels of oil during construction. This alternative would consume the same energy as Replacement Alternative N-2.

The cable-stayed main span design variation would have a 2002 construction cost of $1,550 million dollars. The indirect energy consumption for this alternative would be approximately 34,601 billion Btus or 6.0 million barrels of oil. This alternative would consume the same energy as Replacement Alternative N-2.

The self-anchored suspension bridge design variation (Preferred design variation) would have a 2002 construction cost of $1,650 million dollars. Construction energy consumption would be approximately 36,838 billion Btus or 6.4 million barrels of oil. This alternative would consume slightly more energy, compared to Replacement Alternative N-2. This alternative would have the highest indirect energy consumption of any of the alternatives.

Replacement Alternative S-4

Based on a 2002 construction cost of $1,350 million dollars, the skyway design variation would consume approximately 30,129 billion Btus or 5.2 million barrels of oil to construct. This alternative would consume the same energy as Replacement Alternatives N-2 and N-6.

The cable-stayed main span design variation would have a 2002 construction cost of $1,600 million dollars. The indirect energy consumption for this alternative would be approximately 35,716 billion Btus or 6.2 million barrels of oil. This alternative would consume slightly more energy, compared to either Replacement Alternatives N-2 or N-6.

The self-anchored suspension bridge design variation would have a 2002 construction cost of $1,600 million dollars. Construction energy consumption would be approximately 35,716 billion Btus or 6.2 million barrels of oil. This alternative would consume the same amount of energy as Replacement Alternative N-2 and slightly less than Replacement Alternative N-6.

The following design considerations would reduce the amount of indirect energy consumed, but are not anticipated to have a significant overall reduction. These design considerations applied during the planning and construction phases would reduce the amount of indirect energy consumption. Therefore, design and construction of build alternatives would:

4.14 TEMPORARY IMPACTS DURING CONSTRUCTION

ACTIVITIES

This section describes potential temporary impacts of project alternatives that may occur during construction. Because the No-Build Alternative would not involve any project-related construction, discussions are focused on the build alternatives. Although construction techniques would vary between the retrofit and replacement alternatives, they would have similar construction issues with respect to scale of work and laydown areas on Yerba Buena Island (YBI) and the Oakland Touchdown. As a result, construction impacts on land would generally be similar for all build alternatives. In general, the potential for disruptive construction impacts would correspond to the type and location of activities proposed in each construction stage and to the duration of the overall construction process associated with each alternative.

The Retrofit Existing Structure Alternative is estimated to require about 6 years to construct. For the replacement alternatives, the estimated time required for bridge completion is 5 years, which includes construction of the over-water sections (main span and skyway) and construction of the transition and temporary detours on YBI. It is estimated that the entire project would be completed in 6 to 7 years, which includes dismantling the existing East Span.

4.14.1 Community Impacts

Potential construction period impacts to residents, government facilities on YBI, and businesses at the Oakland Touchdown area are addressed in the following section.

Neighborhoods and Businesses

During construction of the Retrofit Existing Structure Alternative, there would be no ramp closures, roadway modifications, or temporary detours on YBI and the Oakland Touchdown area. However, during construction there could be some delays for motorists as local streets are used for transport of workers, equipment, and materials.

For the replacement alternatives, ramp closures, roadway modifications, and temporary detours on YBI would affect motorists. One road on YBI (Southgate Road) would be closed during construction for a period of approximately 2 years, while other roadways could be subject to periodic lane closures. (See Section 4.14.2 — Transportation Impacts During Construction). Further delays would occur as construction trucks and equipment use local streets.

No matter which alternative is constructed, current uses of Quarters 1-7 would not be desirable during construction due to the following:

Building 262, located at the eastern end of YBI, would be accessible, but would not be usable during construction due to high levels of construction activity and limited access through the construction zone. Building 262 is planned for renovation in Phase 3 of Treasure Island Development Authority (TIDA) plans, expected to occur between 2007 and 2011. However, there are no immediate plans for use of this vacant building. Following construction, the availability of Building 262 would be restored. However, access to the building would be modified. A portion of the access road to Building 262 would be modified to avoid the footings of the eastbound temporary detour and to avoid columns of a replacement bridge. While the eastbound temporary detour is in place, the road would be temporarily realigned approximately 50 meters (164 feet) south of the existing road. For each replacement alternative, a portion of the access road leading to Building 262 would be permanently realigned approximately 15 meters (49 feet) to the south and would become a two-lane roadway that would conform to the existing single-lane dirt road approximately 115 meters (377 feet) from the eastern end of YBI. The roadway configuration would vary slightly for each replacement alternative to avoid different column locations.

Mitigation:

During the construction period, Caltrans would reimburse the City and County of San Francisco (CCSF) for documented loss of rental revenues for Quarters 1-7. As stated in Section 4.10.2 — Impacts to Historic Architectural Resources and the Memorandum of Agreement in Appendix O, a pre- and post-construction survey of Quarters 1-7 and Building 262 would be conducted and construction-related damage to the buildings repaired as necessary. Protective measures would be developed in consultation with property owners.

Construction-period Safety and Security

Heavy vehicle movements, possible hazardous wastes excavation and transport, and construction site activity could create potential safety concerns for construction workers and members of the public on YBI and at the Oakland Touchdown.

Mitigation:

Caltrans would require that best construction management practices be in place to ensure the safety of construction workers, local employees, and residents during construction of the build alternatives. The contractor would implement fencing, signage, and lighting of construction and staging areas; recognized safety practices for the utilization of heavy equipment; the movement of construction materials; and the handling of hazardous materials and wastes in such a way so as to avoid accidents. During construction, Caltrans would require that the project contractor be responsible for job-site safety and security and prepare a Health and Safety Plan. Temporary detours, lane blockages, and truck entrance locations would be well signed.

Caltrans would apprise police, fire, the Coast Guard, and other emergency response agencies of construction activities, temporary detours, and road blockages throughout the construction process.

The public would be alerted by Caltrans about temporary detours, lane blockages, and truck entrances. These locations would be well signed.

Construction Employment

Economic activity generated by the proposed build alternatives is anticipated to benefit the Bay Area region and would also follow the labor and material markets for highway bridge construction. Refer to Section 4.1.1 — Social and Economic Impacts for a complete discussion of employment-generation impacts of the project.

4.14.2 Transportation Impacts During Construction

Construction activities proposed under all build alternatives would temporarily affect transportation facilities within the project area as described below.

Once the alternative for the East Span Project is selected in the Record of Decision (ROD), Caltrans will prepare a Traffic Management Plan (TMP) with input from local public agencies. It is anticipated there would be no traffic disruptions requiring additional transit services to alleviate short-term impacts. The TMP would address in detail construction-related traffic issues, such as roadway closures, lane closures, access, impacts of "rubbernecking," and provisions for minimizing traffic disruptions. The TMP would include a public awareness campaign involving measures that allow communication of project information to residents, employers, commuters, the media, and public officials.

Traffic Disruptions

Construction activities under all build alternatives would result in some traffic disruption on I-80 and the East Span due to temporary full and partial bridge lane closures during off-peak travel times.

In general, construction of the Retrofit Existing Structure Alternative would result in longer and more frequent lane closures, compared to the replacement alternatives, because construction would occur on the bridge while it is open to traffic. Lane closures could be expected almost every day during the construction period. This condition would persist for much of the six years estimated to construct the retrofit alternative. Closures would be scheduled during periods of the day with lower traffic volumes, with most closures occurring at night.

During the initial stage of construction of the replacement alternatives, the temporary detours on YBI would be connected to the YBI viaduct just east of the tunnel portal. This construction would require closure of traffic lanes on the SFOBB during off-peak travel times. Caltrans is continuing to investigate lane and bridge closures to transition traffic from the existing bridge to the temporary detours and to a replacement bridge. Caltrans would plan the closures in an effort to simultaneously minimize public inconvenience, facilitate construction, and maximize public safety. The closures would be scheduled to occur during off-peak hours, to the maximum extent feasible.

The replacement alternatives could potentially create additional delays as "rubbernecking" drivers on the existing SFOBB watch construction of the new superstructure and as drivers watch dismantling of the existing bridge from the new bridge. Other activities would generally not be noticeable to drivers, given the restricted field of vision on the existing bridge and the proximity of a new bridge to the existing bridge.

Yerba Buena Island. Construction of any of the build alternatives could cause temporary traffic disruptions as construction-related traffic would be noticeable on local roadways (primarily on Macalla Road) and could contribute to localized congestion from time to time. Heavy trucks on Macalla Road may conflict with other vehicles due to the narrow width and steep grades of the roadway. Truck traffic on Macalla Road would be regulated by flaggers to ensure that there are no conflicts between oversized vehicles and other vehicles. Heavy construction vehicles would also likely cause damage to the pavement on Macalla Road. Local streets would be repaired following completion of East Span construction activities.

Equipment, materials, and work crews would be transported to YBI by motor vehicles and/or barges. As a result, there would be an increase in the volume of vehicles entering and exiting the island. Caltrans will investigate including traffic control measures in the contract specifications to minimize the impacts of the traffic volume increase, which could affect the capacity of the on- and off-ramps.

In addition to temporary traffic disruptions, there would be some longer-term disruptions to YBI roadways (i.e., closures and temporary detours) during the construction period of a replacement alternative. The westbound on-ramp and the eastbound off-ramp on the east side of the island would be closed for approximately 3 years. YBI would remain accessible from the SFOBB from both eastbound and westbound directions. The SFOBB would also remain accessible from YBI in the eastbound and westbound directions.

When the eastbound temporary detour is constructed, Southgate Road would be closed for approximately 2 years. As a result, access from one side of the bridge to the other, east of the tunnel, would be temporarily eliminated. Access from one side of the island to the other would be temporarily via Treasure Island Road. During this time, vehicles traveling to or from San Francisco on the south side of the island would need to make a U-turn at the Treasure Island/Macalla Road intersection.

Several roadways on YBI would require modifications as a result of construction of the new East Span. Macalla Road would be lowered and realigned in the vicinity of Southgate Road to avoid new bridge columns. The USCG road would also have to be realigned to avoid columns. The road that provides access to Building 262 would be modified in two phases (once to avoid the eastbound temporary detour and ultimately to avoid columns of the new bridge.) These roadways would remain open during realignment to allow for USCG Station access. However, there may be periods when traffic would be restricted to one lane and directed by flaggers.

Macalla Road would remain operable during construction; however, it may be completely closed for brief intervals to all traffic, including USCG traffic. The closures would be a safety measure implemented during certain construction operations, such as the movement of heavy materials that are suspended by crane over the road. The USCG requires emergency access to its facility 24 hours/7 days a week by police, fire, and ambulance services. To maintain access to the maximum extent feasible, Caltrans will investigate including emergency access in the contractor specifications. Requirements in the specifications could include a communication system between field personnel of the contractor and emergency response units to allow for early notification of the need to provide access, making the USCG aware of any closures in advance and setting a maximum time limit for each closure. Caltrans will continue to coordinate with the USCG to establish the most effective means of providing emergency access.

Because the eastern end of YBI would be used for construction staging, public access to the construction area would be restricted. There would be no public access to the Parade Grounds. However, the USCG would have access to its facilities through the construction zone.

A temporary restriction of access to Building 267, the garage at Quarters 10, would be required for construction of any replacement alternative. Vehicular access to the garage would not be available for approximately one day while the driveway is regraded to align with the new Macalla Road configuration. If determined necessary by Caltrans, temporary replacement parking and a temporary walkway from the parking area to Quarters 10 would be provided. The replacement parking would be located as close to Quarters 10 as feasible, such as near Building 240.

The staircase on YBI linking the USCG base with the bus stop at the top of the hill would be displaced due to the placement of the bridge footings for Replacement Alternatives N-2 and N-6. Under Replacement Alternative S-4, the stairway would remain at its current location, but would be closed during construction.

Mitigation:

To maintain access to the USCG facility, Caltrans would require that the contractor construct a detour around the column foundations to keep Macalla Road open or provide another travel way for USCG personnel.

Macalla Road would remain operable during construction; however, it may be completely closed for brief intervals to all traffic, including USCG traffic. To maintain access to the maximum extent feasible, Caltrans will investigate including emergency access in the contractor specifications. Requirements in the specifications could include a communication system between field personnel of the contractor and emergency response units to allow for early notification of the need to provide access, making the USCG aware of any closures in advance and setting a maximum time limit for each closure. Caltrans will continue to coordinate with the USCG to establish the most effective means of providing emergency access.

Temporary detours would be constructed and flaggers employed to ensure motorist safety for USCG vehicles in the construction zone. Barges would deliver wide and oversized construction loads, where possible.

Caltrans would limit contractor parking to the temporary construction easement.

With a northern alternative, Caltrans would construct a new stairway after consulting with USCG, Navy, and the CCSF about appropriate location. Construction-period shuttle service would be provided with any build alternative to take USCG personnel to and from the MUNI bus stop.

Oakland Touchdown Area. During construction, Replacement Alternatives N-2 and N-6 (Preferred) would require closing the restricted Caltrans maintenance access road on the north side of I-80, which is currently used by authorized vehicles only, eliminating vehicle access to the shoreline west of Radio Beach.

Higher volumes of construction-related vehicle traffic anticipated during construction of the Retrofit Existing Structure Alternative and the replacement alternatives may slightly affect traffic and transit operations. The increased number of trucks on Maritime Street, for example, could potentially cause minor delays to traffic and to Alameda-Contra Costa Transit District (AC Transit) Transbay Route A and Local Route 13. The delay would be roughly equivalent to a missed signal cycle and would be within the range of normal traffic conditions, particularly during peak commute hours. Burma Road and Maritime Street also serve the Port of Oakland and local industry and currently accommodate heavy trucks. The additional construction trucks that would operate on Burma Road and Maritime Street during construction would not likely increase traffic congestion on these streets. No mitigation is recommended for this minor potential delay.

Marine Operations

The in-water construction activities required to construct the retrofit and replacement alternatives would have similar impacts on the movement of commercial vessels and recreational boats. Non-project-related marine traffic would be diverted from areas of construction where barge mooring, pile driving operations, and trestles are in use. The main navigation opening near YBI would remain open during construction. The width of the navigation opening would be reduced during construction but not less than the minimum width required by the USCG. Although navigation routes may be modified, they would meet USCG regulations and standards, and vessels would be able to move unencumbered; any necessary modifications to existing marine traffic would be coordinated with the USCG.

Under the replacement alternatives, the nature, duration, and location of marine construction activities would continually vary due to in-water activities associated with construction of the main span and skyway and dismantling the existing East Span. The presence of barges, other construction vessels, and temporary falsework would restrict the navigation opening. Additionally, temporary closures of portions of the navigational opening could occur during critical construction points due to overhead hazards.

Mitigation:

Caltrans will consult with the USCG to implement a vessel warning system for periods when construction vessels are placed in the water within the bridge construction zone. Caltrans would obtain a permit to modify the existing bridge or construct a replacement bridge from the USCG pursuant to Section 9 of the Rivers and Harbors Act and the General Bridge Act of 1946. Notification to mariners and other requirements will be specified in the bridge permit.

4.14.3 Construction-period Visual Impacts

All construction activities, whether for seismic strengthening proposed under the Retrofit Existing Structure Alternative or for the replacement alternatives, would involve the use of barges, heavy equipment, stockpiles of soils and materials, and other visual signs of construction. While noticeable to residents on YBI and others in the vicinity, these short-term visual changes, limited to the construction period of approximately five years, would not substantially alter the character of the Bay or the communities on either side. These short-term visual changes do not include the long-term impacts of the clearing and grubbing operations. Approximately 350 trees on the eastern part of YBI would be removed to provide staging areas and clearances for heavy equipment. Most of these trees are eucalyptus with a few being coast live oaks. This visual impact would be mitigated as discussed in Section 4.3.4.

Residents of the Bachelor Enlisted Quarters and the USCG officers’ housing as well as users of YBI would experience the most noticeable visual changes during the construction period. Flat areas on YBI are expected to be used as a construction staging area. Activities at this location may block Bay views from Quarters 1-7. Retrofit of existing columns on YBI under the Retrofit Existing Structure Alternative could require temporary structures, such as scaffolding, that would interfere with existing views. New columns constructed under the replacement alternatives would add similar temporary structures.

Replacement alternatives, including the Preferred Alternative, would require the construction of temporary detours on YBI (see drawings of the temporary detours in Appendix A, Figures 2-16.2, 2-17.2, and 2-18). The detours would be operational for approximately 2 years. The period from the beginning of construction to the end of their operational use would be approximately 4 years. The detours may be removed as soon as they are no longer needed to carry traffic or they may be removed as one of the last steps of bridge construction on YBI, because the contractor may use them as platforms from which to construct other portions of the bridge. Columns approximately 2 meters (6.5 feet) in diameter would be constructed to support these temporary detours. The number of columns to be placed on YBI would range from 59 for Replacement Alternative S-4 to 91 columns for Replacement Alternative N-2. The temporary columns would likely restrict views from YBI and would be visible from close- and moderate-range views to the east side of YBI. However, these columns would be temporary and would be dismantled as soon as possible after opening the new bridge to traffic.

The temporary detours would impact the local vegetation, topography, and, consequently, the appearance of YBI. See Section 4.3.4 for a more detailed description of the impacts of each alignment.

Nighttime construction activities would involve the use of lighting equipment, which could cause glare, potentially affecting residents and marine traffic in the immediate vicinity.

Mitigation:

To reduce glare from lighting used during nighttime construction activities, Caltrans would require project contractors to direct lighting onto the immediate area under construction only and to avoid shining lights towards residences and marine traffic.

4.14.4 Construction-period Air Quality

During some stages of project construction, the Retrofit Existing Structure Alternative and the replacement alternatives would generate air pollutant emissions. The largest sources of anticipated pollutants would be dust generated by excavation, grading, and other ground-disturbing activities on YBI and the Oakland Touchdown, and exhaust emissions from equipment and marine vessels. All construction-related emissions would be temporary and would vary from day to day, depending on the type of work being done. Construction-related emissions would also be experienced at different locations during the construction process, depending on the area(s) under construction at any one time and the distance to likely receptors. Because of the changing nature of these conditions (i.e., construction activity, construction location, and distance to receptors), an exact estimate of total construction emissions and impacts is not possible.

Measures to reduce emissions during construction, as specified in Caltrans’ Standard Specifications, include the following:

Based on the requirement that these measures be included in all contract specifications, no mitigation is proposed.

An air quality evaluation of dredging operations has been completed as part of the Dredged Material Management Plan (DMMP) (see Appendix M) to address the Environmental Protection Agency’s (EPA) concerns about construction-period air quality. The analysis concludes that the emissions from dredging would represent an insignificant portion of the Bay Area emissions. Caltrans would provide the air quality analysis to allow the ACOE to comply with the Clean Air Act.

4.14.5 Construction-period Noise and Vibration

Construction Noise

The Retrofit Existing Structure Alternative and replacement alternatives would result in intermittent and varying levels of construction noise. The Transportation Research Board indicates that typical construction noise levels at a reference distance of 15 meters (50 feet) are:

Ground Clearing (e.g., backhoe)

80 dBA

Excavations (e.g., excavator)

85 dBA

Foundations (e.g., auger drill rig)

85 dBA

Erection of Structures (e.g., concrete mixer)

85 dBA

Finishing (e.g., paver)

85 dBA

Most construction activity related to this project would be associated with the last four categories (which include some of the noisiest operations). Dismantling activities, such as cutting steel and breaking concrete, would probably have similar noise levels. The Transportation Research Board information indicates that the typical noise level generated on a construction site could reach 85 dBA at a distance of 15 meters (50 feet). Noise levels generated by construction equipment (or by any "point source") decrease at a rate of approximately six decibels (dB) per doubling of distance away from the reference distance of 15 meters (50 feet). For instance, at a distance of 60 meters (200 feet) from a noise source, the noise levels would be about 12 dB lower than at the 15-meter (50-foot) reference distance. At Quarters 8, a residence close to all build alternatives (approximately 50 meters [164 feet] away from the construction area for the new bridge structure), the noise level resulting from typical construction activities would be approximately 75 dBA Leq. This is three dBA higher at this location than noise levels caused by existing peak-noise-hour traffic on the existing East Span and would not likely result in a perceptible change. Under the northern replacement alternatives, a noise level of 75 dBA Leq would also occur at Quarters 1, which is not occupied. During construction of the eastbound temporary detour, construction activities would occur approximately 22 meters (72 feet) from the Bachelor Enlisted Quarters. As a result, noise levels during temporary detour construction may be as loud as 82 dBA at this location, an increase of approximately 10 dBA over existing conditions. While construction of a replacement bridge would last a majority of the construction period (approximately 5 years of the total construction period of 7 years, which includes 2 years for dismantling the existing East Span), temporary detours would be constructed in a shorter period of time (approximately 2 years).

At a distance of 100 meters (328 feet), the noise from regular construction activities would be approximately 69 dBA Leq; at 200 meters (660 feet), construction noise levels would be approximately 63 dBA Leq; while at 400 meters (1,312 feet), the noise levels would be approximately 57 dBA Leq. Except for construction equipment and material staging areas, construction activities and associated noise would move along the project route as construction proceeded, and, thus, these levels would vary and be intermittent.

Two activities not mentioned in the Transportation Research Board list of noise­generating activities above are rivet busting and pile driving. The Retrofit Existing Structure Alternative would entail a substantial amount of rivet removal. Rivet busting may also be required during dismantling of the existing structure under the replacement alternatives. Observed unshielded noise levels for rivet removal have varied from 86 to 98 dBA at a distance of 15 meters (50 feet). The buildings closest to the existing structure (e.g., USCG Building 40 and Navy Building 213) may experience noise levels (approximately 80 to 92 dBA) when rivet removal is occurring on the bridge portions closest to them during the Retrofit Existing Structure Alternative. Building 40 is currently used for administration purposes and Building 213 is used to store a fire truck. These buildings would be displaced with the northern replacement alternatives. Building 40 would be displaced with Replacement Alternative S-4. The next closest building not displaced by a replacement alternative is Building 262, which is not occupied. Noise levels in this area from rivet busting would be approximately 79 to 91 dBA.

Pile driving during construction would generate noise that is unique in terms of noise level, audible characteristics, and time pattern. The higher levels of pile driver noise, which are maximum levels (Lmax) of approximately 105 dBA at a distance of 15 meters (50 feet), consist of very-short-duration impact sounds (a "bang" or "clang" noise) concentrated during a 10- to 30-minute period while an individual pile is being driven. These impact sounds attenuate with distance such that the maximum levels will be 99 dBA at 30 meters (100 feet), 93 dBA at 60 meters (200 feet), and 87 dBA at 120 meters (400 feet). Intermittent noise of this nature can be very intrusive to nearby receptors.

Pile driving on YBI would be performed intermittently over a period of about 2 years for all build alternatives. Most of the temporary detours would not require pile driving. The closest pile driving to buildings under the Retrofit Existing Structure Alternative would be 55 meters (180 feet) from Quarters 1 on YBI, resulting in noise levels around 95 dBA.

The replacement alternatives would have pile driving work as close as 45 meters (150 feet) to Building 262 and 80 meters (260 feet) to Quarters 8 and the Bachelor Enlisted Quarters. Quarters 8 and the Bachelor Enlisted Quarters, which are occupied, would experience noise levels from pile driving of approximately 92 dBA. Noise levels around Building 262, which is not occupied, would be approximately 96 dBA. Pile driving would also occur within 60 meters (200 feet) of Building 240 (occupied residential units on Macalla Road, northwest of Quarters 10). Noise levels during pile driving in the vicinity of this building would be approximately 93 dBA.

Based on noise levels recorded during the Pile Installation Demonstration Project, completed in December 2000, and assuming a drop-off rate of 6 dBA per doubling of distance, previous predictions of noise levels near the USCG facility are accurate within 2 dBA. It was also found that noise levels upwind from pile driving operations sometimes exceed the expected attenuation of 6 dBA per doubling distance from 3 to 8 dBA. That is, upwind locations are quieter than downwind locations at the same distance from a noise source. Winds in the Bay Area have a westerly component, which would put Treasure Island and YBI in an upwind (quieter) condition. Assuming a building attenuation of 25 dBA for the USCG quarters, it is expected that the highest interior noise levels during nearby pile driving operations will be approximately 67 dBA.

Construction noise is unavoidable, temporary, and limited to the time of the construction in any one location (except near the staging areas as noted above). Some nearby USCG residents could be adversely impacted by construction noise. The USCG operates a 24-hour search and rescue operation and, as such, has personnel working in shifts. As a result, there may be staff sleeping at various times of the day. During prolonged pile driving activities within 120 meters (400 feet) or less of USCG facilities, sleep may be problematic. Potential abatement measures may be a combination of attenuation at the noise source, and/or attenuation at the receptor. Caltrans has already investigated such measures as selecting a quieter pile driver, placing a shroud around the hammer, using portable shielding, sound blankets, and plywood sheets. These measures were found not to work for a variety of reasons, including not being effective, challenges in implementation on YBI due to wind conditions and elevation, and cost.

The film studios on TI are located more than 400 meters (1,312 feet) from the project construction site and a minimum of 610 meters (2,000 feet) from the closest pile driving. As a result, the film studios would experience noise levels below 57 dBA during general construction activities and maximum noise levels of approximately 74 dBA during pile driving. During the majority of the construction period, construction-related noise would be below background noise levels (modeled at 67 dBA) at the film studios. Pile driving could result in an increase of up to 7 dBA over existing conditions.

Construction-period Noise Abatement. All construction equipment would be required to conform to the provisions in Section 7-1.01I of the latest edition of Caltrans’ Standard Specifications to minimize noise from construction activities, such as maintaining equipment mufflers in proper operating order. The contractor will be required to comply with local noise control ordinances to the extent practicable.

Caltrans will continue to consult with the USCG to identify and implement as feasible reasonable measures to reduce construction-related noise levels at USCG facilities. In addition, Caltrans is continuing to investigate the possibility of limiting the hours for pile driving to reduce the construction noise impacts to residents of YBI and TI.

Data obtained from a Pile Installation Demonstration Project, completed in December 2000, have provided additional information on noise levels from pile driving. The final results will be used to refine appropriate mitigation measures. Caltrans could require contractors to install and use sound-attenuating fabric shrouds around the hammer/pile impact area of pile driver equipment during pile driving to the extent possible to reduce noise levels in sensitive areas such as at the Bachelor Enlisted Quarters. Over-water construction sites may not be suitable for this technique. Where practicable, pile holes would be pre-drilled to reduce impacts of pile driving.

Temporary Detour Traffic Noise

To allow for continued utilization of the SFOBB during construction, temporary detours would be constructed at YBI and at the Oakland Touchdown area. It is anticipated that these temporary detours would be in use by motor vehicles for approximately 2 years. The period from the beginning of construction to the end of their operational use would be approximately 4 years. The detours may be removed as soon as they are no longer needed to carry traffic or they may be removed as one of the last steps of bridge construction on YBI, because the contractor may use them as platforms from which to construct other portions of the bridge. These temporary detours vary in design and configuration depending upon the alternative.

Noise generated by detour traffic is anticipated to be similar to noise from existing traffic; e.g., less than 74 dBA at Quarters 1-7 and less than 72 dBA at the USCG residential units. Traffic on the temporary detours used for any of the replacement alternatives would be closer to some locations compared to the existing bridge structure. With the northern alternatives, the temporary detours would be slightly closer to Quarters 1-7 and farther away from the Bachelor Enlisted Quarters and recreational area compared to Replacement Alternative S-4. Noise modeling of the replacement alternatives indicates that noise levels might increase by 1 to 2 decibels at these locations when the temporary detours are closest to them, but these increases would generally not be perceivable.

For the northern replacement alternatives, traffic noise from the temporary detours at the Bachelor Enlisted Quarters would likely be less (1 to 2 decibels lower) than anticipated for Replacement Alternative S-4 due to the greater distance between the temporary detours and the USCG buildings.

Construction Vibration

Vibration levels from construction activities such as pile driving and dismantling of existing column foundations have the potential to cause building damage under certain circumstances. There are no federal or state standards for vibration levels. However, Caltrans has measured vibrations generated during various construction activities on projects throughout the state. Pile driving has frequently been done at distances of 8 to 15 meters (25 to 50 feet) from buildings without causing damage; however, damage that could occur includes displacement of soil and resulting lateral movement. In general, pile driving could produce ground-borne vibration levels that might be perceptible to humans within approximately 200 meters (660 feet) of the pile driving activity, but a building that is more than 15 to 30 meters (50 to 100 feet) from pile driving would not be damaged.

Each of the build alternatives would require work on YBI and at the Oakland Touchdown that would generate vibration. Potential for impacts to structures on YBI and at the Oakland Touchdown is discussed below. The film studios on TI are not discussed below because they are approximately 610 meters (2,000 feet) from the closest pile driving. Vibration guidance from the Federal Transit Administration (FTA) indicates that equipment highly sensitive to vibration would not be affected by pile driving activities more than 274 meters (900 feet) away. As a result, vibration from construction activities would not be perceptible at the film studios.

Retrofit Existing Structure Alternative. This alternative would require pile driving about 55 meters (180 feet) from the closest building (Quarters 1) and would require foundation dismantling about 45 meters (150 feet) from Building 262. At the Oakland Touchdown, the closest foundation dismantling would be about 45 meters (150 feet) from the Key Pier Substation.

Since these buildings are more than 30 meters (100 feet) away from construction activities that would generate vibration, it is expected that vibration levels experienced at these properties would be well below the architectural damage risk level.

Replacement Alternatives. Under the replacement alternatives, the closest building on YBI to pile driving and foundation dismantling would be Building 262. Pile driving would occur approximately 60 meters (195 feet) from this structure, while the closest foundation dismantling would be approximately 45 meters (150 feet) away. The closest pile driving on the Oakland Touchdown would be 110 meters (360 feet) from the Key Pier Substation, and the closest foundation dismantling would be about 45 meters (150 feet) away.

Since these buildings are more than 30 meters (100 feet) away from construction activities that would generate vibration, it is expected that vibration levels experienced at these properties would be well below the architectural damage risk level.

Vibration Abatement:

While no architectural damage is expected to occur as a result from the East Span Project, historic properties (the Senior Officers’ Quarters Historic District, Quarters 8, Quarters 10, Building 267, and Building 262) would be monitored for damage as a result of construction activities, including the possible use of vibration-measuring devices on the buildings. Caltrans would photographically document the condition of these buildings prior to the start of construction to establish the baseline condition for assessing damage. Caltrans would ensure that any damage to the buildings resulting from construction activities be repaired in accordance with the Secretary of the Interior’s Standards for Rehabilitation.

4.14.6 Hazardous Wastes

The potential for encountering pre-existing hazardous wastes is present during any construction project. Hazardous wastes sites are known to exist in the project area. Hazardous wastes impacts would occur if construction workers, members of the public, and/or Navy and USCG personnel were exposed to hazardous wastes during grading and excavation activities, or if the likelihood of hazardous waste migration were increased by construction activities.

Potential sources of contamination have been identified within all of the project alternative alignments. Areas known or likely to contain contaminated soil and/or groundwater were identified in Section 3.6 of this report. A comparison of potential impacts by alternative is in Section 4.6.

Mitigation: Construction and dismantling of all structures would include procedures for the identification, abatement, handling, and disposal of contaminated materials, as well as worker health and safety. Mitigation measures are discussed in more detail in Section 4.6.3 — Hazardous Wastes, Mitigation. All procedures would be consistent with Caltrans’ guidelines and all federal, state, and local laws and regulations.

4.14.7 Water Resources and Water Quality

The project could have adverse impacts on water quality related to construction activities. These include, but are not limited to: excavations for column foundations, resulting in possible groundwater contamination; potential surface water impacts from dredging and dewatering operations, concrete placement, and washout activities; management and application of chemical products; construction activities performed on barges; use of floating batch plants; and the potential for accidental spills from construction equipment and materials. Additional construction-related impacts are associated with the dismantling of the existing East Span, which could include discharges of waste material, accidental spills, and resuspension of bottom sediments.

Statewide NPDES Permit No. CAS000003 applies to the project facilities during construction. The NPDES permit requires that a Storm Water Pollution Prevention Plan (SWPPP) be prepared for any construction project that disturbs an area greater than five acres or for any project that is located within or near a water-related sensitive environment.

A SWPPP would be prepared for this project. The purpose of the SWPPP would be to:

The objectives of the SWPPP would be: 1) to minimize the degradation of off-site receiving waters to the maximum extent practicable with the current Best Management Practices (BMPs) for the construction industry and 2) to reduce the mass loading of chemicals and suspended solids to the downstream drainage systems and the receiving water bodies.

The preparation of the SWPPP would be based on the principles of BMPs, not numeric effluent limitations, to control and abate the discharge of pollutants into receiving waters. BMPs are structural devices, such as silt fences and straw bales, and non-structural devices, such as good housekeeping and construction-related waste management. Some of Caltrans’ BMPs are as follows:

The SWPPP would be amended whenever there is a change in construction or operations which may affect the discharge of substantial quantities of pollutants into the receiving waters.

Since the dismantling work of the existing East Span under the replacement alternatives would be performed under a separate contract, a SWPPP specific to the dismantling work would be prepared as part of the separate contract. The SWPPP would address specific dismantling activities and BMPs to be implemented to minimize the discharge of pollutants associated with these activities.

4.14.8 Natural Resources

Permanent or temporary impacts to natural resources may occur in association with the build alternatives. This section discusses temporary impacts to wildlife species or habitat. Natural resources in the project area were evaluated in accordance with the provisions of state and federal environmental statutes and regulations listed in Section 3.9.1 — Natural Resources, Regulatory Setting. Mitigation measures, where appropriate, have been developed in consultation with regulatory and permitting agencies.

Temporary impacts to natural resources could result from construction activities on land at YBI and the Oakland Touchdown area and in open water for all build alternatives. Three categories of temporary natural resource impacts are discussed below: (1) temporary fill in San Francisco Bay (including open and shallow water areas and special aquatic sites) and temporary fill in Other Waters of the U.S. (including open and shallow water areas); (2) special aquatic sites such as wetlands, eelgrass beds, and sand flats; and (3) wildlife such as endangered species, migratory birds, marine mammals, and fisheries.

Placement of Temporary Fill in San Francisco Bay and Other Waters of the U.S.

The temporary placement or removal of fill in San Francisco Bay and Other Waters of the U.S. are subject to federal and state regulations. The ACOE regulates fill in Other Waters of the U.S. pursuant to Section 404 of the federal Clean Water Act (CWA). BCDC regulates fill in San Francisco Bay pursuant to the state McAteer-Petris Act. The CWA and the McAteer-Petris Act define temporary fill differently. The regulatory definitions of fill are discussed in Section 4.9.1 — Placement of Fill in San Francisco Bay and Other Waters of the U.S. Impacts associated with permanent fill are also addressed in Section 4.9.1.

Two types of temporary impacts resulting from construction activities were evaluated for each of the build alternatives: (1) the temporary change in the volume of San Francisco Bay and Other Waters of the U.S.; and (2) the temporary change in the surface area of San Francisco Bay and Other Waters of the U.S.

Reductions in the volume and surface area of San Francisco Bay and Other Waters of the U.S. are recognized under the McAteer-Petris Act and the CWA as negative impacts. Temporary fill may impair the physical, chemical, and biological integrity of a water body. Temporary fill may also impact San Francisco Bay’s ability to maintain adequate oxygen levels and assimilate and flush wastes.

Temporary Change in Volume of San Francisco Bay and Other Waters of the U.S. All build alternatives would require the placement of temporary fill for in-Bay construction that would temporarily decrease the volume of San Francisco Bay and Other Waters of the U.S. Temporary fill for the replacement alternatives may include:

Construction of the Retrofit Existing Structure Alternative would require placement of cofferdams at new and existing piers and pile-supported trestles in shallow water areas to provide access for construction equipment and material (see Section 2.6.1 — Retrofit Existing Structure Alternative for a description of construction activities).

Although all fill for temporary structures would be removed at project completion, construction activities would temporarily decrease the volume and surface area of San Francisco Bay and Other Waters of the U.S. Some temporary fill, such as the cofferdams, geotube, falsework, and temporary support structures for the main span would be removed following completion of a particular segment of work. Other temporary fill, such as barge docks, access trestles, the small boat dock, and the concrete conveyor would be in place for the duration of construction, which is approximately six years.

As a result, the build alternatives would have a negative impact. Table 4.14-1 summarizes the temporary change in the volume of San Francisco Bay and Other Waters of the U.S. as a result of the build alternatives.

Table 4.14-1 Temporary Change in Volume of San Francisco Bay and

Other Waters of the U.S. ­ Build Alternatives

Build

Alternative

Change in Volume of Other Waters of the U.S. (ACOE Jurisdiction)

Change in Volume of

San Francisco Bay

BCDC Jurisdiction)

Replacement Alternative N-6 (Preferred)

Decrease of 41,000 cubic meters

(54,000 cubic yards)

Decrease of 48,000 cubic meters

(63,000 cubic yards)

Replacement Alternative N-2

Decrease of 41,000 cubic meters

(54,000 cubic yards)

Decrease of 48,000 cubic meters

(63,000 cubic yards)

Replacement Alternative S-4

Decrease of 45,000 cubic meters

(58,000 cubic yards)

Decrease of 42,000 cubic meters

(54,000 cubic yards)

Retrofit Existing Structure

Decrease of 13,000 cubic meters

(17,000 cubic yards)

Decrease of 12,000 cubic meters

(15,000 cubic yards)

Temporary Change in Surface Area of San Francisco Bay and Other Waters of the U.S. All build alternatives would require the placement of fill for in-Bay construction that would temporarily decrease the surface area of San Francisco Bay and Other Waters of the U.S. Temporary fill for the replacement alternatives may include:

Construction of the Retrofit Existing Structure Alternative would require placement of cofferdams at new and existing piers and pile-supported trestles in shallow water areas to provide access for construction equipment and material (see Section 2.6.1 — Retrofit Existing Structure Alternative for a description of construction activities).

Although all fill for temporary structures would be removed at project completion, construction activities would temporarily decrease the volume and surface area of San Francisco Bay and Other Waters of the U.S. Some temporary fill, such as the cofferdams, geotube, falsework, and temporary support structures for the main span would be removed following completion of a particular segment of work. Other temporary fill, such as barge docks, access trestles, the small boat dock, and the concrete conveyor would be in place for the duration of construction, which is approximately six years.

As a result, the build alternatives would have a negative impact. Table 4.14-2 summarizes the temporary change in the surface area of San Francisco Bay (including high-level suspended and cantilevered fill) and Other Waters of the U.S. that would occur as a result of the build alternatives.

Table 4.14-2 Temporary Change in Surface Area of San Francisco

Bay and Other Waters of the U.S. ­ Build Alternatives

 

 

 

Build Alternative

Change in Surface Area of Other Waters of the U.S. (ACOE Jurisdiction)

Change in Surface Area of San Francisco Bay (BCDC Jurisdiction)

Replacement Alternative N-6 (Preferred)

Decrease of 0.8 hectare

(1.97 acres)

Decrease of 7.12 hectares

(17.6 acres)

Replacement Alternative N-2

Decrease of 0.8 hectare

(1.97 acres)

Decrease of 7.07 hectares

(17.48 acres)

Replacement Alternative S-4

Decrease of 1.05 hectares

(2.59 acres)

Decrease of 6.25 hectares (15.44 acres)

Retrofit Existing Structure

Decrease of 0.36 hectare

(0.90 acre)

Decrease of 0.36 hectares

(0.90 acres)

Special Aquatic Sites

Temporary impacts and disturbance to special aquatic sites are summarized in Table 4.14-3.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would not cause temporary impacts or disturbance to wetlands, sand flats, or eelgrass. There would be no dredging for barge access channels where special aquatic sites are located.

Replacement Alternatives.

Wetlands. No temporary impacts to wetlands would occur as a result of Replacement Alternatives N-2, N-6, or S-4. Replacement Alternative S-4 would permanently remove the two non-tidal wetlands (see Section 4.9,2 — Special Aquatic Sites). The non-tidal wetlands south of the Oakland Touchdown and tidal wetlands at YBI would be avoided and marked as environmentally sensitive areas (ESAs). This would entail placing exclusion devices around them during construction.

Sand Flats. During construction of Replacement Alternatives N-2 and N-6, approximately 0.69 hectare (1.7 acres) of sand flats along the northern shore of the Oakland Touchdown area would be temporarily disturbed. Temporary impacts to intertidal sand flat habitat would result from the placement of a geotube for dewatering purposes and mud boils. Trestles used with Replacement Alternative S-4 would temporarily impact 0.01 hectare (0.02 acre) of sand flats along the south shore of YBI.

Eelgrass Beds. During construction of the replacement alternatives, 0.01 hectare (0.02 acre) of eelgrass would be temporarily disturbed north of the Oakland Touchdown area. Temporary impacts would be caused by increased turbidity from dredging, pile driving, barge maneuvering, and cofferdam construction.

Table 4.14-3 Temporary Impacts to Special Aquatic Sites

 

Wetlands

Sand Flats

Eelgrass Beds

Area Impacted by Replacement Alternative N-6

No temporary impact.

0.69 hectare (1.70 acres) at Oakland Touchdown as a result of placement of the geotube.

0.01 hectare (0.02 acre) at the Oakland Touchdown due to increased turbidity from dredging, barge maneuvering, pile driving, and cofferdam construction.

Area Impacted by Replacement Alternative N-2

No temporary impact.

0.69 hectare (1.70 acres) at Oakland Touchdown as a result of placement of the geotube.

0.01 hectare (0.02 acre) at the Oakland Touchdown due to increased turbidity from dredging, barge maneuvering, pile driving, and cofferdam construction.

Area Impacted by Replacement Alternative S-4

No temporary impact. However, there are permanent impacts (see Table 4.9-5).

0.01 hectare (0.02 acre) at YBI as a result of temporary trestle construction.

0.01 hectare (0.02 acre) at the Oakland Touchdown due to increased turbidity from dredging, barge maneuvering, pile driving, and cofferdam construction.

Area Impacted by Retrofit Existing Structure Alternative

No temporary impact.

No temporary impact.

No temporary impact.

Mitigation

Avoidance of habitat by marking the wetlands as Environmentally Sensitive Areas (ESAs). The ESAs would be marked in the field using fencing materials, buoys, or other appropriate, highly visible materials.

In addition to measures listed in Table 4.9-5, placing geotextile fabric and plywood onto the sand flats before placing the geotube to minimize mud boils.

Minimization of impacts to eelgrass through use of specific dredge types, including mechanical clamshell excavator equipment; a turbidity control program, which may possibly include turbidity curtains that control and contain turbidity; marking eelgrass beds outside the barge access channel as ESAs; harvesting eelgrass from within the barge access channel and replanting in adjacent beds as pilot program; restoring portions of the barge access channel and replanting with eelgrass to facilitate eelgrass colonization.

Source: Caltrans, 2000.

Mitigation for Replacement Alternatives:

Sand Flats. To minimize impacts to sand flats at the Oakland Touchdown area, Caltrans would place geotextile fabric and plywood onto the sand flats before placing the geotube. This measure would reduce the potential for mud boils. That portion of the sand flats affected by the temporary placement of a geotube and mud boils would be restored to pre-existing conditions following construction as described in Section 4.9.6 — Natural Resources, Mitigation.

Eelgrass Beds. Construction controls and ESAs would be included in the project plans, specifications, and estimates to avoid impacts as much as possible. Caltrans would monitor for turbidity due to dredging, pile driving, barge maneuvering, and mud boils. A turbidity control program, which may possibly include turbidity curtains, and limitations on barge and tug boat maneuvering would be required. Caltrans is continuing to investigate the design, maintenance, and effectiveness of turbidity curtains. Post-construction surveys to evaluate impacts of turbidity on eelgrass would also be implemented. If additional eelgrass beds have been affected during construction, Caltrans would consult with the permitting agencies to determine if additional mitigation is warranted.

Caltrans would restore a portion of the barge access channel to its original bathymetry. The restoration would occur following construction. Some of the dredged material and excavated sand from the project site suitable for in-Bay disposal would be stockpiled and used to restore the barge access channel to suitable depths for eelgrass re-colonization. The restored channel outside the area shadowed by the westbound structure may be replanted with eelgrass to facilitate re-colonization.

Wildlife

Temporary impacts associated with construction activities, such as loss of habitat or increased turbidity which may cause increased sediment suspension, may impact the American peregrine falcon, double-crested cormorant, chinook salmon, steelhead, green sturgeon, seals, and longfin smelt. A summary of mitigation measures for special status species is provided following the impact discussion.

American Peregrine Falcon. Construction activities for any build alternative may cause temporary impacts to the peregrine falcons during their reproductive cycle. A peregrine falcon pair nests on the existing East Span at Column E2. Construction activities on the existing East Span could induce defensive reactions by the peregrine falcons during the nesting season. Defensive reactions can adversely impact breeding success by jeopardizing egg laying and rearing and therefore result in wasted reproductive efforts.

Double-crested Cormorant. Work at Columns E5 through E15 along the East Span may impact the double-crested cormorant colony nesting on the bridge. Nesting activities may occur at any time within the breeding season between March and September. Construction work during this time period could disrupt some or all of the nesting or attempted-nesting activities.

Western Gull. Construction activities for the retrofit alternative or a replacement alternative could impact breeding and nesting of this species.

California Least Tern. This species is not known to occur in the project area. However, new information has become available since concluding the endangered species consultation process with USFWS for the East Span Project; this information suggests the least tern may use former Oakland Army Base lands adjacent to the project area and portions of the southern shore of the Oakland Touchdown. If portions of the southern shore of the Oakland Touchdown are needed for project construction staging, it would temporarily impact habitat that may be used by the California least tern.

Black-crowned Night Heron, Allen’s Hummingbird, White-tailed Kite, Bank Swallow, and Bewick’s Wren. Vegetation and tree removal on YBI may impact nesting on YBI.

Shorebirds. Sand flats would be temporarily impacted during construction of a replacement alternative. As a result, there would be a reduction in roosting and feeding habitat for shorebirds. In addition, a small portion of upland habitat located on the south side of the Oakland Touchdown could be temporarily impacted during construction of any of the build alternatives. The area could be used for construction staging. If this occurs, winter roosting and high-tide habitat would be displaced. Caltrans is investigating the feasibility of using this area for construction staging.

Harbor Seal and California Sea Lion. All build alternatives would include pile driving activities that could disturb marine mammals. Noise from pile driving activities may disturb the harbor seals when they are foraging in the waters east of YBI. The haul-out site on the south side of YBI is not used for pupping. It is possible that harbor seals swimming in the project vicinity may be exposed to elevated underwater sound pressure levels (generally 180-190 decibels [dB] or higher), which could produce temporary hearing loss and behavioral impacts (discussed below). Data obtained from a Pile Installation Demonstration Project (PIDP), completed in December 2000, has provided additional information on sound pressure levels produced by pile driving. Initial results indicate no impacts to harbor seals at the YBI haul-out site and minimal impacts to marine mammals at the PIDP site. The final results will be used to refine appropriate mitigation measures.

NMFS considers in-air noise levels below 85 dB to be safe for marine mammals. Marine mammals who have their heads above water at locations close to the pile driving activities may be affected by elevated noise levels. Potential impacts would be similar to those for high underwater sound pressure levels (temporary hearing loss and changes to behavioral patterns).

Behavioral responses of harbor seals and sea lions to noise can range from something as innocuous as a seal raising or turning its head, to permanent abandonment of an area. Noise may elicit short-term disruptions of normal activities, startle responses, agitation, and stress. Existing evidence shows that most marine mammals tend to avoid loud noises. Marine mammals in the water in the project vicinity would be temporarily displaced if they choose to avoid the area in response to high sound pressure levels.

Gray Whale. Noise from the pile driving activities may disturb gray whales passing through the shipping channel on their way to the southern San Bruno Shoals region. It is possible that gray whales swimming in the project vicinity may be exposed to elevated underwater sound pressure levels which may impact their behavior. Whales are sensitive to high-frequency noises, which are typically not caused by pile driving. It is likely that whales would avoid the pile driving area during the short duration in which they are observed in the Central Bay (typically December to March). Gray whales foraging in the Richardson Bay area are not likely to be impacted because of the distance from the construction site.

Winter-run, Spring-run, and Fall-run Chinook Salmon. Increased turbidity from construction activities such as dredging, pile driving, barge maneuvering, and cofferdam construction could disrupt the runs of Sacramento Valley and Central Valley chinook salmon Ecologically Sensitive Units (ESUs). Adverse impacts to critical habitat for chinook salmon are not expected since the designated critical habitat is located north of the bridge. There is also the potential for adverse impacts from elevated sound pressure levels generated by pile driving.

Steelhead. Migration periods for both the Central Valley steelhead and Central Coast steelhead are similar to that of the chinook salmon. Potential impacts to steelhead are expected to be similar to those for chinook salmon.

Green Sturgeon. Increased turbidity from construction activities associated with any of the build alternatives, such as dredging, may adversely impact this species. Although adult sturgeon may be present in the Bay all year, more sensitive periods occur when juveniles are present during the winter and spring months.

Longfin Smelt. This species is not generally present within the project area, due to the relative high saline conditions. However, if longfin smelt are present in the area during construction, they may be also impacted by increased turbidity.

Pacific Herring. Increased turbidity could adversely impact Pacific herring, a commercially and recreationally important species which spawns in the Bay. The herring attach their eggs to eelgrass, seaweed, pilings, and riprap. If dredging occurs during peak spawning season (January through March), eggs in the project area could be impacted.

Fish (In General). Pile driving during construction may have impacts on fish within the immediate vicinity. Impacts on fish from driving large piles in the Bay are not well documented. During the PIDP, injury and mortality of small fish (including anchovies, herring, and perch) were observed within the immediate vicinity of unattenuated pile driving operations.

Mitigation:

American Peregrine Falcon. , Caltrans and the USFWS have developed mitigation approaches to avoid impacts to the American peregrine falcon. Mitigation includes continuation of the monitoring and release efforts by SCPBRG as described in Section 4.9.6 — Natural Resources, Mitigation. If construction activities disturb nesting activities, the monitors would collect the eggs and/or capture and release any chicks present to a natural off-site location. These measures would apply even though the falcon has been delisted because this species is protected under the Migratory Bird Treaty Act and the California Endangered Species Act.

Double-crested Cormorant and Western Gull. Caltrans would monitor the double-crested cormorant colony during breeding season and prevent the birds from nesting on the existing bridge where potential impacts by construction activities could occur. The protocol to prevent double-crested cormorants from nesting would follow the methods implemented for maintenance activities on the existing bridge. This protocol involves washing partially constructed nests off the bridge with water when the nests are not actively occupied. If the nests are completed and the birds have laid eggs, the nests would not be disturbed. Similar measures would be used to prevent western gulls from nesting.

After construction activities for the Retrofit Existing Structure Alternative are complete, double-crested cormorants would most likely recolonize the same area on the existing bridge structure.

Black-crowned Night Heron, Allen’s Hummingbird, White-tailed Kite, Bank Swallow, and Bewick’s Wren. Prior to the removal of vegetation and trees during construction of any build alternative on YBI, a biological monitor would survey for nests. Any vegetation or trees with nests or those adjacent to areas with nests would not be removed until the nesting period is complete. Alternatively, to the extent feasible, vegetation and trees that need to be removed could be removed prior to the nesting season (after surveys have been conducted), so as to not affect the construction schedule. Nesting for these species usually occurs between January and July.

Shorebirds. Mitigation for the temporary loss of shorebird roosting habitat as a result of any build alternative would include enhancement or creation of upland refugia as part of creation of the tidal marsh ecosystem as described in Section 4.9.6 — Natural Resources, Mitigation.

Harbor Seal, California Sea Lion, and Gray Whale. The SFOBB Pile Installation Demonstration Project tested the effectiveness of two sound attenuation systems (a bubble curtain and a floating barrier with a contained aerating mechanism) to attenuate underwater sound pressure levels generated by pile driving. Results of the PIDP suggest that the sound attenuation devices tested reduce the sound pressure levels in the vicinity of pile driving activities. Methods, such as a sound attenuation system and/or monitoring, would be used to avoid or minimize impacts to marine mammals. The decision as to what measures to implement will be made in consultation with the NMFS.

Winter-run, Fall-run, and Spring-run Chinook Salmon, Steelhead, Green Sturgeon, and Longfin Smelt. Caltrans would implement a turbidity control program, which may possibly include turbidity curtains, to avoid and minimize impacts to critical habitat for chinook salmon and other fish. If construction sequencing permits, dredging would be avoided in shallow water during the peak juvenile outmigration period (January 1 through May 31). In addition, pile driving would be scheduled whenever possible to occur outside the peak juvenile outmigration period.

Pacific Herring. Construction activities that occur during the peak herring spawning season, generally January to March, would be monitored by a qualified biologist to watch for the presence of spawning herring. If the biologist (or CDFG) observes spawning in the project area, in-water construction activities such as pile driving and dredging would be suspended within 200 meters (660 feet) of observed spawn. In-water construction activities would not resume at that location for a period of up to 14 days (as determined by a qualified biologist), allowing herring eggs to hatch and larvae to disperse. In addition, the use of a turbidity control program, which may include turbidity curtains during dredging, would reduce the impacts of turbidity on the herring spawn.

Fish. The Biological Opinion from the National Marine Fisheries Service (NMFS) pursuant to the Federal Endangered Species Act states, "Pile driving activities will occur outside of the peak juvenile (salmonid) outmigration period of January 1 through May 31. Should construction extend past this construction window, noise insulation devices will be installed to reduce sound pressure and impulse levels." (See NMFS correspondence, September 24, 1999, in Appendix G.) While the results of the PIDP have not been finalized, preliminary results indicate that use of noise attenuation devices reduces impacts to small fish near pile driving. Caltrans will continue coordinating with NMFS regarding interpretation of the PIDP results. In compliance with NMFS' Biological Opinion, Caltrans will require that attenuation measures be used for any pile driving during the peak juvenile salmonid outmigration period, which would protect non-salmonid species as well.

4.14.9 Historic and Cultural Resources

Construction impacts on cultural resources are discussed along with permanent impacts in Section 4.10 — Historic and Cultural Resources.

4.14.10 Construction Excavation and Dredging

Each of the build alternatives would require excavation on land and dredging in water to retrofit existing, or place new, columns and to allow access to construction sites.

Dredging techniques can generally be categorized as either hydraulic (suction) or mechanical. Hydraulic dredging may involve the use of equipment such as cutterheads, dustpans, hoppers, hydraulic pipelines, and plain suction. The hydraulic technique typically minimizes disturbance and resuspension of sediments, but involves the entrainment of high volumes of water. The water and sediments would have to be discharged at a disposal location. Mechanical techniques involve the removal of material by equipment such as clamshell (open and closed bucket), dipper, or ladder dredges. Sediments are dislodged and excavated and then raised to the surface and discharged into a barge or scow. Caltrans is still investigating dredging techniques. Factors that will be taken into consideration include cost, feasibility, and minimization of turbidity.

It is the goal that the majority of dredged materials generated by the project would be beneficially reused at upland wetland restoration sites, if such sites are available and are cost-effective. In addition, portions of the barge access channel would be restored after construction for eelgrass habitat using dredged material and excavated sand from the sand flats, resulting in a beneficial reuse. Some dredged materials could be disposed of at approved in-Bay or deep ocean disposal sites. If sites (upland wetland reuse, in-Bay, or ocean) are not available for use or are not cost-effective, Caltrans may opt to beneficially reuse all dredged materials at landfill sites as daily cover.

Materials not suitable for wetland reuse or aquatic disposal would be taken to an appropriate upland landfill. A Dredged Material Management Plan (DMMP) was prepared for the project and is included as Appendix M. This plan assesses impacts from dredging activities associated with construction and evaluates a range of reuse/disposal options for the dredged material. Since publication of the DMMP in June 1999, estimated dredged quantities were further refined. An errata sheet explaining the changes is attached to the DMMP in Appendix M. Updated information in regard to quantities and impacts is also presented in this FEIS.

Anticipated construction scenarios for the build alternatives are discussed in Section 2.6. Excavation requirements of the alternatives are presented below. Impacts to environmental resources as a result of dredging activities and related mitigation measures are discussed within each specific resource discussion and not in this section. Information can also be found in the DMMP.

Retrofit Existing Structure Alternative

Bridge retrofit would require excavation of materials on YBI and in-Bay. Upland work would consist of excavation to expand and encase existing columns on YBI in concrete. Excavated materials on YBI would include soils and rock. These materials would be disposed of at a regulated landfill or used on-site as backfill, if possible.

In-Bay construction work for the Retrofit Existing Structure Alternative would require the construction of cofferdams at each existing and new pier. Dredging would be required in shallow water to create an access channel for barges. Cofferdam dredging would not be required as access dredging in the area of the cofferdams would provide adequate excavation. Estimated excavation quantities for the Retrofit Existing Structure Alternative are presented in Table 4.14-4.

Table 4.14-4 Dredging Quantities

ALTERNATIVE

ACTIVITY

 

Construction

Barge Access

Construction of New

Piers and Footings

Dismantling

Barge Access

Removal of Existing

Piers

Total Dredged Volume

 

Volume (m3)

Volume (yards3)

Volume

(m3)

Volume (yards3)

Volume (m3)

Volume (yards3)

Volume (m3)

Volume (yards3)

Volume (m3)

Volume (yards3)

Replacement Alternative N-6 (Preferred)

153,000

200,000

128,000

168,000

116,000

152,000

16,000

21,000

413,000

540,000

Replacement Alternative N-2

153,000

200,000

128,000

168,000

116,000

152,000

16,000

21,000

413,000

540,000

Replacement Alternative S-4

210,000

275,000

75,000

98,000

116,000

152,000

16,000

21,000

417,000

545,000

Retrofit Existing Structure Alternative

116,000

152,000

116,000

152,000

 

Source: Caltrans, November 2000.

Construction scenarios for the retrofit alternative would permit work in shallow water areas to take place from temporary construction trestles, shallow-draft barges, or conventional barges. Construction trestles could be constructed along both sides of the existing East Span from the Oakland Touchdown area westward until water depths allow for standard barge access, a minimum draft of 4.3 meters (14 feet) below mean sea level (MSL). The use of conventional barges instead of trestles would require dredging in the shallow water at the Oakland Touchdown area to 4.3 meters (14 feet) MSL. If dredging were to occur, it would be along the western edge of the Oakland Touchdown area only and would not encroach into the eelgrass or sand flat areas near the northern shore. Shallow-draft barges could also require dredging for access, depending on the type of barge selected and the nature of the construction activity.

Replacement Alternatives N-2, N-6 (Preferred), and S-4

As described in Section 2.6 — Construction Activities, construction of the replacement alternatives would require excavation of materials on YBI, the Oakland Touchdown area, and in-Bay. Upland work would consist of excavation to place footings for columns on YBI and the Oakland Touchdown, to place engineered fill and key in the rock slope protection at the Oakland Touchdown for the westbound roadway. Excavated materials on YBI would include soils and rock. These materials would be disposed of at a regulated landfill or used on-site as backfill, if possible.

Excavation at the Oakland Touchdown area would be required to place columns to support the structures as they come to grade. Soils excavated at the touchdown would be disposed of at off-site locations. Some of the soils may contain hazardous materials and would require disposal at approved upland sites.

Anticipated construction techniques for replacement alternatives would require the use of large-scale construction equipment such as pile drivers and cranes mounted on barges. These barges typically require a minimum draft of 4.3 meters (14 feet) MSL, which would require dredging in shallow water. This minimum draft includes a 0.6-meter (2-foot) additional depth to avoid the need for maintenance dredging over the five-year construction period and to provide a conservative estimate of potential total dredged material quantities. Where water depths are less than minimum barge draft, work could also be conducted from trestles near the Oakland shore, but access dredging would still be necessary. The width of the barge access channel would be 50 meters (165 feet). The access channel adjacent to the Oakland Touchdown would be reduced to a 3.7-meter (12-foot) depth and the width of the channel narrowed to 45 meters (150 feet) to minimize the impacts of dredging on special aquatic sites (see Section 4.14.8 — Temporary Impacts During Construction, Natural Resources). Anticipated dredge volumes for barge access are presented in Table 4.14-4.

In-Bay work to dismantle the existing East Span would require excavation to remove existing bridge piers. Cofferdams could be constructed at each pier to remove pile caps, piers, and footings below the existing mudline. Different approaches to pier removal are under consideration. One approach would use standard-draft barges similar to those proposed to construct replacement alternatives. This would require access dredging on one side of the existing East Span to allow barge access. Sections of the existing bridge would be lowered into barges for removal to onshore sites for further dismantling. Estimated excavation volumes for removal of the existing East Span are summarized in Table 4.14-4.

Volumes of dredged material would be generated throughout the construction and dismantling activities. Most of the volumes, however, would be generated during three periods:

Figure 4-23 in Appendix A shows anticipated monthly volumes over the course of new bridge construction and dismantling of the existing bridge. Approximately 97,000 cubic meters (127,000 cubic yards) would be dredged between months 2 and 7 for construction barge access. Volumes would drop between months 8 to 21 to about 7,400 cubic meters (9,600 cubic yards) per month when only sediment removal for pier construction for the skyway and main span would be occurring. Volumes would increase in months 22-24 as construction access for the Oakland approach would be conducted as well as some excavation for piers. Limited (approximately 460 cubic meters [600 cubic yards]) dredging would occur for pier construction during months 25-50. This volume amounts to less than one full barge trip per month. No sediment removal is anticipated between months 51 and 60.

As dismantling the existing bridge begins, approximately 116,000 cubic meters (152,000 cubic yards) would be dredged for creation of the barge access channel (months 41 to 72). Volumes during this time frame would be approximately 1,300 cubic meters (1,700 cubic yards) per month of sediment dredged to remove existing bridge footings and piles.

Reuse/Disposal of Excavated and Dredged Material

Some excavated upland soils from YBI and the Oakland Touchdown are expected to be contaminated and would require disposal at an approved upland disposal site.

A range of 36 potential in-Bay, ocean, and upland/wetland reuse sites listed in the 1998 San Francisco Bay Conservation and Development Commission (BCDC) Roadmap were initially considered in the DMMP. These sites were screened based on availability of the sites during the East Span Project construction time span (e.g., would the site be permitted and accepting dredged material by mid-2001) and the capability of the site to receive the volumes and type of material generated. Most of the sites considered were either reserved strictly for specific projects (e.g., federal channel maintenance dredging) or were planned but would not likely have environmental permits needed prior to the start of the East Span Project dredging activities.

The above assessment narrowed the list of potential in-Bay, ocean, and upland/wetland reuse sites candidates to four practicable candidates: 1) Alcatraz (SF-11); 2) the San Francisco Deep Ocean Disposal Site (SF-DODS); 3) the Hamilton Wetlands Restoration Project; and 4) the Montezuma Wetlands Restoration Project (Figure 4-1 in the DMMP [Appendix M]). These sites are already permitted or may be permitted by the start of dredging activities for the East Span Project. In addition to these sites, upland disposal at a landfill and sidecasting of the material (dredging and placing the material immediately to the side of the dredged channel) were also considered. Each of these options was evaluated in terms of affected environment, implementability of the option, environmental impacts, and economic factors. These are discussed in detail in the DMMP (Appendix M). Since publication of the DMMP, another beneficial reuse has been considered. As part of the on-site mitigation for special aquatic sites, Caltrans is proposing to restore up to approximately 0.7 hectare (1.7 acres) of the barge access channel with stockpiled dredged material and excavated sand to facilitate eelgrass colonization.

In determining the preferred reuse/disposal option, several criteria were used in the decision-making process. These included:

Table 7-1 of the DMMP (Appendix M) provides a comparison of the various sites based on the above criteria. The comparative evaluation suggested that no single reuse/disposal option was preferred for all dredged materials generated by the East Span Project, given the differences in capacity, suitability, costs, and logistics. In general, environmental impacts at the reuse/disposal sites were not an important factor because they were already mitigated at the reuse/disposal sites as part of the site design (e.g., Hamilton, Montezuma, landfills) or are kept to minimal levels through volume and seasonal restrictions on disposal (SF-11, SF-DODS). The results of the DMMP indicated that reuse of the sediment for upland wetland creation would have beneficial impacts. Sidecasting was the only option considered in the DMMP that could have potentially substantial environmental impacts. Caltrans does not propose to sidecast any of the dredged material.

Preferred Reuse/Disposal Option

The preferred reuse/disposal option outlined in the DMMP (Appendix M) would be to beneficially reuse the majority of the material at an available upland wetland restoration site, if such a site is available and cost-effective. If approved sites are not available, Caltrans may beneficially reuse materials at landfill sites as daily cover or dispose of materials at the deep ocean disposal site. Caltrans also plans on beneficially reusing some dredged material and excavated sand to restore a portion of the barge access channel at the Oakland Touchdown to facilitate eelgrass colonization. A much smaller amount of material is proposed for disposal at the Alcatraz site. This would consist of small quantities of material (approximately 460 cubic meters [600 cubic yards]) that would be generated on a monthly basis during pier construction. This option is being proposed due to the logistics of transporting and disposing of small monthly loads. Dredged material determined to be unsuitable for aquatic disposal or wetland reuse would be taken to an appropriate landfill for disposal. Determination of the suitability of material during construction would be based on the results of the sediment sampling and analysis described in Section 3.12.2. The Sediment Sampling and Analysis Report (available for review at Caltrans District 4 offices) presents testing results at multiple locations along the Preferred Alternative alignment. The DMMO reviewed this report and its conclusions in regard to the suitability of dredged materials for unconfined disposal are presented in Section 3.12.2. A copy of its October 31, 2000, letter is presented in Appendix G. The disposal goals for the project are consistent with the goals of the LTMS.

Aquatic disposal of excavated materials would require permits and approvals from federal, state, and regional permitting agencies. Caltrans has consulted with agencies, including the ACOE, BCDC, RWQCB, U.S. Fish and Wildlife Service (USFWS), EPA, California Department of Fish and Game (CDFG), and California Department of Toxic Substance Control (DTSC), regarding applicable permits and approvals to dispose of materials at specified sites.

4.15 CUMULATIVE IMPACTS

East Span Project build alternatives would contribute to both beneficial and negative cumulative impacts. Although all East Span Project build alternatives would be expected to contribute to cumulative impacts, the Retrofit Existing Structure Alternative would have fewer negative cumulative impacts than the replacement alternatives. This is due primarily to the increased construction footprint of the replacement alternatives.

The cumulative impacts analysis determined that some temporary cumulative impacts would result from construction activities. Temporary impacts caused by the construction of the East Span Project occurring simultaneously with impacts resulting from construction of other projects were combined to evaluate whether there are temporary cumulative impacts. Resource categories that would experience temporary cumulative impacts are land use, traffic, air and water quality, special status species, and energy consumption. Long-term cumulative impacts of the East Span Project replacement alternatives in combination with other projects would occur in the resource categories of land use, Bay fill, special aquatic sites, other natural communities, and archaeological resources. The East Span Project replacement alternatives would contribute to beneficial cumulative impacts in the resource categories of non-motorized transportation, long-term visual changes, and dredge material reuse/disposal.

      1. Regulatory Framework

NEPA regulations developed by the Federal Council on Environmental Quality (CEQ) require that the cumulative impacts of a proposed project be addressed in an EIS (40 CFR Section 1508.25). Cumulative impacts on the environment are those that result from the incremental impact of the proposed action when added to other past, present, and reasonably foreseeable future actions (40 CFR Section 1508.7). These impacts can result from individually minor impacts of multiple actions over time.

4.15.2 Methodology and Format

This cumulative analysis considers past, present, and reasonably foreseeable future projects that involve impacts to the same resource categories as those impacted by the East Span Project. Since eight commenters (EPA, ACOE, California Preservation Society, National Trust for Historic Preservation, Earth Island Institute, BART, City of Oakland Planning Department, and Save San Francisco Bay Association) commented on the Draft EIS cumulative impacts analysis, the entire cumulative impacts analysis has been updated and expanded.

The analysis addresses impact categories of a regional nature, such as natural resources, by consideration of actions that may result from the implementation of plans by regional agencies that manage or regulate potentially impacted resources. Regional plans consulted in this assessment include the Regional Transportation Plan (RTP), the Transportation Improvement Program (TIP), BCDC Bay Plan and Seaport Plan, the Long-Term Management Strategy for the Placement of Dredged Material in the San Francisco Bay Region (LTMS), the Baylands Ecosystem Habitat Goals Report, the State Implementation Plan for attaining air quality goals and the San Francisco Bay Regional Water Quality Control Board Basin Plan. Other known agency-sponsored or reviewed projects undertaken or planned that may not be included in these plans have also been addressed in this analysis. These projects are identified for each subject area.

Impact categories, such as land use, which are discussed at the local geographic level, are addressed in this cumulative analysis by consideration of the plans and projects being implemented by Caltrans, the City of Oakland, the City and County of San Francisco, and the East Bay Regional Park District. Recent projects and local development plans of the Port of Oakland, Port of San Francisco, Port of Richmond, and San Francisco International Airport are also incorporated into the analysis.

Regulatory and Geographic Context

The examination of each environmental resource category begins with a discussion of regulatory and geographic context. Regulatory context refers to the legal framework within which each environmental resource category is governed. For example, Section 404 of the federal Clean Water Act protects special aquatic sites such as wetlands, eelgrass, and sand flats. The cumulative impacts of the East Span Project and other actions are discussed in the context of policy requirements for no-net-loss of these protected resources. The geographic context varies by environmental resource category. For example, resource discussions such as dredging address geographically large areas because cumulative impacts are most accurately understood in the context of San Francisco Bay and not by jurisdictional boundaries of governmental entities. In the Bay Area, planning for dredged material disposal and reuse is taking place at a Bay-wide or regional level; therefore, the cumulative impacts are considered at a regional level.

The potential for cumulative impacts on some environmental issues such as land use are evaluated in a local geographic context. A local context applies to land use and transportation issues because the East Span Project would not change traffic capacity that could potentially alter regional land use planning decisions.

Trends for historical patterns of resource use are described for each resource category. A review of these trends provides context for the impacts analysis because there is limited information available about specific past projects that can be analyzed in consideration of other past, present, and future actions. For example, the trend for air quality in the Bay Area is based on reductions in pollutant emissions since passage of the federal Clean Air Act.

Past actions for each environmental resource are included in the description of context.

Because the goal of the cumulative analysis is to consider how the East Span Project, in combination with past, present, and reasonably foreseeable future actions cumulatively affects the resources, understanding trends in the stability, use, or viability of the resource over time is relevant. The timeframe in which each resource is examined is determined by the availability and relevance of "the best data we have or are able to collect" with regard to other projects and environmental trends for the resource (CEQ 1997). The timeframe for construction-period impacts is generally considered to be the construction timeframe for the East Span Project.

The discussion of each environmental resource category also provides a brief summary of the East Span Project’s impact and a reference to other sections of the EIS where the resource is described and the impact assessment is reported.

4.15.3 Land Use

Context

The regulatory context for examining cumulative land use impacts is at the local and regional planning levels. Comprehensive plans and redevelopment plans of the cities of San Francisco and Oakland set policies for current and future development within and around the project limits. Regional plans such as the BCDC Bay and Seaport Plans have been factors in recent planning actions and will influence future redevelopment decisions. The geographical context for land use is Yerba Buena Island (YBI) and the Oakland Touchdown area; the geographic context is also defined by the physical structure of the bridge which has influenced past land use decisions and may affect existing and future land uses (see Section 4.1.5 — Community Impacts, Development Trends). These regulatory and geographic contexts are based on the fact that the East Span Project would maintain the current traffic capacity of the SFOBB and, therefore, would not induce any new development growth nor would the East Span Project increase access, which could support more intense development.

Available planning documents and policies were considered to assess potential impacts of future projects over an approximately 20-year planning horizon. Future projects are the adopted or pending land use planning decisions for residential and mixed-use development on the YBI property anticipated to be released to the CCSF by the Navy and described in the Draft Naval Station Treasure Island Reuse Plan (1996 Draft Reuse Plan) and potential expansion of USCG facilities on YBI. Future projects at the Oakland Touchdown area are a proposed public park at the southwestern end of the Oakland Touchdown area as well as other development identified in the Draft Oakland Base Reuse Plan.

Yerba Buena Island. YBI has been owned by the U.S. government since 1868. The flat areas of the island have been developed for military uses since that time. Other than Building 213, Navy-owned buildings located on the flat portions of YBI have been removed. YBI was under the control of the U.S. Army from 1868 to 1897, at which time it was transferred to the U.S. Navy for use as a training station. Soon after the transfer, Congress made an appropriation to establish a Naval Training Station for apprentices on the Pacific Coast; during World War I, there were as many as 13,000 men training on the island.

In 1872, a USCG predecessor agency, the Lighthouse Service, was established on 12 hectares (29 acres) of YBI. A signal station and buoy depot were built and the lighthouse was constructed in 1875. When the Bureau of Lighthouses and the USCG merged in 1939, the USCG was given control of the 12 hectares (29 acres). In 1973, the radar facilities and control center of the USCG Vessel Traffic Service San Francisco were moved to YBI from Fort Mason in San Francisco.

Presently, the USCG conducts search and rescue missions; it also operates a buoy repair and navigation control center facility on YBI. It now encompasses approximately 17 hectares (41 acres). The Navy holds title to most of the remaining land on the island and is working with the CCSF to transfer the land to it through the Base Realignment and Closure (BRAC) process. Approximately 8 hectares (20 acres) of Navy land were recently transferred to Caltrans as permanent right-of-way for all alternatives under consideration, another 31 hectares (77 acres) were transferred for temporary construction easements. Of these 31 hectares (77 acres), 11 hectares (26 acres) are land and the remainder consists of former Navy waters surrounding Yerba Buena Island.

Sections 3.1.1 — Existing Land Uses in the Project Vicinity and 3.1.2 — Developable Land and Development Trends, Yerba Buena Island and Treasure Island further discuss existing and proposed land uses on YBI.

The SFOBB opened in 1936 and provided road access to the island. The adjacent Treasure Island (TI) was partly created from the materials excavated for the tunnel on YBI. TI was the site for the 1939-40 Golden Gate International Exposition.

The Navy and CCSF planning processes will influence future land use on the Navy-controlled portion of YBI. The CCSF prepared a 1996 Draft Reuse Plan that includes several scenarios of residential and mixed-use development on YBI (see 3.1.2 — Developable Land and Development Trends, Yerba Buena Island and Treasure Island). In addition, local land use will be influenced by BCDC’s Bay Plan, which states "If and when not needed by Navy or Coast Guard; redevelop released areas for recreational use." Implementation of the CCSF’s Draft Reuse Plan would require an amendment to the Bay Plan, to delete YBI’s designation as a park priority use.

Oakland Touchdown Area. The Oakland Touchdown area considered in this analysis is the portion of the peninsula west of the SFOBB Toll Plaza (see Figure 2-2 in Appendix A). The Oakland Touchdown area is a manmade peninsula that has expanded over time to serve transbay transportation facilities. Since the late 1880s land uses on the Oakland Touchdown have generally been for transportation purposes and later for military functions. It was the east end of the Key System pier, which connected the East Bay rail transit system to the Key System ferry terminal. In 1936, the peninsula was widened to the north for the bridge approach and toll plaza of the SFOBB. Existing land uses on the Oakland Touchdown area include an EBMUD dechlorination facility; the existing bridge and Caltrans maintenance facilities; industrial, maritime, transportation, and commercial activities related to the Port of Oakland; and a Resource Conservation area designated in the City of Oakland’s General Plan. Future trends are the same except for the conversion of 6 hectares (14.7 acres) of military land at the western end of the Oakland Touchdown area to park use. The affected environment of the Oakland Touchdown area is also discussed in Sections 3.1.1 — Existing Land Uses in the Project Vicinity and 3.1.2 — Developable Land and Development Trends.

Future land uses at the Oakland Touchdown area are the subject of current land use planning efforts by federal, state, and local agencies. The majority of this area was designated as a "port priority use area" in the April 1996 San Francisco Bay Seaport Plan Update, issued jointly by BCDC and MTC, and the BCDC San Francisco Bay Plan. This area is known as the Bay Bridge site. In addition, the Oakland Base Reuse Authority (OBRA) has designated a 6-hectare (14.7-acre) parcel, formerly part of the Oakland Army Base, as a future park. Amendments to the OBRA Draft Final Reuse Plan have been initiated with the goal of preserving the Port’s space requirements to meet future operational needs. BCDC recently deleted the Oakland Touchdown area as a port priority use from its Seaport and Bay Plans. The use of the Oakland Touchdown area is now the responsibility of the local government, the City of Oakland. BCDC can now approve any use of the site as long as it is consistent with BCDC’s permitting authority to ensure maximum feasible public access consistent with the proposed project and to minimize Bay fill.

The Resource Conversation Area designated in the Oakland General Plan includes landscaped uplands, sand flats, sand dunes, and tidal marshes along the north shore of the Oakland Touchdown and to the east and north of the project limits. The trend for these areas is their conservation and enhancement. Areas within the Emeryville Crescent to the east of the East Span Project limits have been incorporated into the East Shore State Park that is being planned and developed by the East Bay Regional Park District. A master planning process for the East Shore State Park was initiated in late 2000 and is expected to be completed in approximately two years. It is expected that the areas along the north shore of the Oakland Touchdown area would continue in their current use as landscaped uplands, sand flats, sand dunes, and tidal marshes with limited public access.

Impacts Analysis

Yerba Buena Island. Project impacts to land use on YBI are described in Section 4.1 — Community Impacts. Other, and greater, impacts on land uses on YBI would result from the planned transfer of the Navy-owned land to CCSF and any changes resulting from USCG planning.

With regard to land on YBI under jurisdiction of the USCG, the East Span Project impacts range from no impact under the Retrofit Existing Structure Alternative to the removal of four existing buildings, reconfiguration of the existing main facility access gate, and placement of columns supporting the new structure under Replacement Alternative S-4. More intense development could result from future redevelopment of the facility by the USCG. However, at this time, no specific master plan has been developed for expansion of the existing USCG facility because USCG delayed final master plan preparation pending outcome of the TI BRAC process and final design for the East Span Project. While the USCG facility does have undeveloped areas, it cannot be determined at this time what changes to land use might occur.

With regard to land to be redeveloped by the CCSF under the 1996 Draft Reuse Plan, many changes to existing land use are anticipated. Under the 1996 Draft Reuse Plan, developed through the BRAC process, more intensive development of live/work cottages and loft spaces, a conference center and potential commercial redevelopment of Building 262 at the easternmost point of YBI are planned.

The existing access to YBI provided by the SFOBB is an integral part of all reasonably foreseeable land use plans for the island. The USCG facility could continue to operate and the proposed land uses discussed in the 1996 Draft Reuse Plan could be implemented with any of the East Span Project alternatives. The East Span Project is not expected to influence land use decisions by the CCSF, although permitting authority of BCDC, market factors, and environmental resources may influence ultimate land use patterns. Reasonably foreseeable development plans of the USCG cannot be assessed. The implementation of both the East Span Project and the 1996 Draft Reuse Plan would increase the density of development on YBI compared to present conditions. The potential increase in density resulting from CCSF-sponsored redevelopment combined with the increased number of columns for the SFOBB on YBI would result in a cumulative impact on land use.

Oakland Touchdown Area. Since the late 1800s, land uses at the Oakland Touchdown area have been transportation and military. Since 1936, the Oakland Touchdown has accommodated the existing bridge approaches, the SFOBB Toll Plaza, and bridge maintenance facilities. The East Span Project alternatives would continue this pattern of development and therefore would not cumulatively influence land use at the Oakland Touchdown area. The other foreseeable future project in this area is a proposed public park.

The Retrofit Existing Structure Alternative and Replacement Alternatives N-2 and N-6 (Preferred) would not impact existing or proposed land uses at the Oakland Touchdown area, and would accommodate the development of the proposed Gateway Park whereas the alignment of Replacement Alternative S-4 would bisect it and reduce its size by approximately one-half.

The Resource Conservation Area designated in the Oakland General Plan on the north side of the Oakland Touchdown consists of landscaped uplands, sand flats, sand dunes, and tidal marshes. The area would be impacted by Replacement Alternatives N-2 and N-6 (Preferred). Both alternatives would impact a portion of the sand flats that are on the westernmost portion of the Resource Conversation Area. The trend for the Resource Conservation Area is preservation and enhancement. The East Span Project northern replacement alternatives would reduce the total area of sand flats designated as a Resource Conservation Area, reversing the enhancement of the area. No other projects are known that would affect resource conservation areas in Oakland. A cumulative impact is not expected to occur.

Replacement Alternative S-4 would conflict with the proposed Gateway Park. However, a cumulative impact would not be expected to result from the conflict because, although Replacement Alternative S-4 would change the area and configuration of the proposed Gateway Park, both of the uses could be accommodated.

4.15.4 Transportation

Context

The regulatory context for the transportation analysis is the transportation policies and plans of federal, state, and regional agencies that oversee planning, funding and maintenance of transportation facilities crossing the San Francisco Bay. The geographic context for transportation is the Transbay Bay Bridge Corridor, which extends from the 5th Street I-80 vehicular on-ramp to the SFOBB in San Francisco to the distribution structure in Alameda County. The corridor includes proposed connections to the Bay Trail as well as the Transbay Transit Terminal in San Francisco. It also includes the north-south navigation openings beneath the existing SFOBB. The SFOBB is a regional transportation facility and is designated as an Interstate highway. Because there would be no change in the traffic capacity of the facility, the project alternatives would only influence transportation facilities within the Transbay Bay Bridge Corridor.

The Transbay Bay Bridge Corridor connects Alameda, Contra Costa, and San Francisco counties. It has been a transportation corridor since the development of an integrated system of trains and ferries in the late 1800s. The train and ferry system was followed by the SFOBB which was completed in 1936, the BART Transbay Tube in the 1960s, and re-introduction of ferry service connecting San Francisco to Oakland and Alameda in the 1980s. This past trend as a central transportation corridor for the Bay Area is anticipated to continue in the future.

The Transbay Bay Bridge Corridor includes cars, buses, and other high-occupancy vehicles (e.g., carpools and vanpools, BART, and ferries), trucks, motorcycles, boats, and bicycles that use both the Caltrans bike shuttle and BART. Transportation impacts discussed in this section are those which affect the movement of people and goods via these forms of transportation. There is an increasing demand for transportation services in the Transbay Bay Bridge Corridor. A number of actions are being studied to address the need to provide additional transportation capacity in the corridor. The Metropolitan Transportation Commission (MTC) conducted a study of potential new Bay crossings in 1991 and is currently updating it to consider how traffic operations systems, new rail services, and additional bridges crossing Central San Francisco Bay could increase transportation capacity in the corridor to address a continuing increase in demand for multi-modal transportation services.

Other trends are an expanded Bay Area ferry network and increasing demand for transbay bus service. Ferry service in the Transbay Bay Bridge Corridor includes Alameda-San Francisco and Jack London Square-San Francisco routes. A Regional Ferry Plan for the San Francisco Bay Area conducted in 1992 called for a 45 percent increase in ferry service throughout the Bay. Capital improvements to support increased service would include terminal facility upgrades and new high-speed ferries. Sources for additional funding to implement recommended service improvements have not been identified.

AC Transit provides commuter bus service in the Transbay Bay Bridge Corridor. Statistics show that ridership increased from 8,800 to 13,600 between 1996 and 1999. AC Transit conducted a CEQA environmental review of options to expand transbay bus service in 1997 and concluded that there would be no adverse impacts to such an expansion.

Pedestrian facilities are not currently provided in the Transbay Bay Bridge Corridor. Public planning sessions for the East Span Project and MTC-led studies addressing provision of a bicycle/pedestrian path on the SFOBB West Span have identified a desire for bicycle/pedestrian facilities in the Transbay Bay Bridge Corridor.

Foreseeable projects in the Transbay Bay Bridge Corridor include the West Approach Seismic Retrofit, the West Span Seismic Retrofit, the YBI Tunnel Retrofit, the West Viaduct YBI Retrofit, the distribution structure seismic retrofit, reconstruction of the SFOBB Toll Plaza, bicycle/pedestrian improvements on YBI and TI, and planned expansion of the Bay Trail. A redesign or replacement of the Transbay Transit Terminal is planned and AC Transit will install bicycle racks on transbay buses by early 2001. The 1996 Draft Reuse Plan envisions ferry service between San Francisco and Treasure Island.

Impacts Analysis

Vehicular. All build alternatives would maintain existing traffic capacity on the SFOBB and would therefore have minimal impacts on vehicular transportation.

While redevelopment on YBI and TI (see Section 4.15.3 — Land Use) could generate additional transportation demand in the Transbay Bay Bridge Corridor, the 1996 Draft Reuse Plan is based on existing bridge capacity and calls for ferry service to accommodate additional transportation demand to and from YBI and TI. Vehicular traffic from YBI and TI would be adequately accommodated by the current transportation capacity of the bridge and ramps, assuming the 1996 Draft Reuse Plan is implemented as described. Other projects affecting transbay vehicular traffic (e.g., additional bridge crossings) are too speculative to evaluate at this time.

Bicycle and Pedestrian. The Retrofit Existing Structure Alternative would not accommodate bicycles and pedestrians on the East Span, but would be consistent with planning to extend the Bay Trail to the west end of the Oakland Touchdown area. The Retrofit Existing Structure Alternative in combination with planned Bay Trail improvements would have negligible impacts on bicycle and pedestrian traffic within the Transbay Corridor.

All replacement alternatives would improve bicycle and pedestrian access along the east half of the Transbay Bay Bridge Corridor through the addition of a bicycle and pedestrian path. This path would provide a link to the future Bay Trail connection at the Oakland Touchdown area and would support the 1996 Draft Reuse Plan’s encouragement of bicycle and pedestrian access and circulation on TI and YBI, assuming CCSF permits pedestrian and bicycle traffic to access YBI from the East Span Project bicycle/pedestrian path. This combination of projects would result in a cumulative expansion of bicycle and pedestrian travel opportunities on the eastern side of the Transbay Bay Bridge Corridor and a beneficial cumulative impact on bicycle and pedestrian circulation.

Impacts on Transportation During Construction

The potential for cumulative impacts to occur in the Transbay Bay Bridge Corridor exists due to the possible overlap of construction of the East Span Project with the West Approach Seismic Retrofit, the West Span Seismic Retrofit, the YBI Tunnel Retrofit, the West Viaduct Retrofit, the distribution structure seismic retrofit, and the reconstruction of the SFOBB Toll Plaza. Potential construction-period impacts for East Span Project build alternatives are discussed in Section 4.14.2 — Transportation Impacts During Construction. In combination with Port of Oakland traffic, there would be an increase in the number of trucks that would operate on Burma Road and Maritime Street during construction of the East Span Project.

As discussed in the Section 4.14.2 — Transportation Impacts During Construction, the Retrofit Existing Structure Alternative could contribute to construction-period impacts because it would result in disruption to traffic operations on the SFOBB during lane closures. This condition would persist for much of the nearly six-year period to complete this alternative.

As discussed in Section 4.14.2, all replacement alternatives would have minimal peak-period traffic impacts on the SFOBB. These alternatives could contribute to cumulative construction-period effects as a result of off-peak period closures for the diversion of traffic onto the temporary structures and later to a replacement structure.

The Oakland Army Base Reuse Authority (OBRA) reuse plan assesses the potential traffic impacts of its draft reuse plan. The traffic analysis, projected to the year 2010, indicates that the Maritime Street/Burma Road intersection would not meet City of Oakland peak-hour traffic requirements that intersections operate at level of service (LOS) D. With implementation of the draft reuse plan, the Maritime Street/Burma Road intersection would operate at LOS E in the morning peak period and LOS D in the evening peak period. The OBRA draft reuse plan recommends improvements to the morning LOS to meet the City of Oakland’s requirements. The OBRA draft reuse plan recommends that the intersection improvements be implemented in 2004.

If East Span Project construction trips on Burma Road occur during morning and evening peak periods, a cumulative traffic impact may result from East Span Project construction vehicle traffic combined with predicted future traffic generated by the implementation of the OBRA reuse plan. Typically, movement of construction vehicles and equipment is timed to avoid peak commute hours, which would reduce the potential for cumulative construction-period traffic impacts to occur in the vicinity of the Port of Oakland. Should OBRA implement intersection improvements recommended for 2004, additional intersection capacity would further reduce the potential for cumulative construction-period traffic impacts to occur in the vicinity of the Port of Oakland.

In combination with other projects in this context area, cumulative transportation impacts, such as increased congestion and travel delays primarily in off-peak travel times, could occur as a result of detours or lane closures occurring simultaneously.

However, Caltrans has successfully implemented consolidated and large-scale public information programs and transportation management plans for projects of the scale of the East Span Project and would do the same for this project. Caltrans is continuing to investigate lane and full bridge closures to transition traffic from the existing bridge to the temporary detours and to the replacement bridge. Caltrans would plan the closures in an effort to simultaneously minimize public inconvenience, facilitate construction, and maximize public safety. The closures would be scheduled to occur during off-peak hours, to the maximum extent possible. Motorists would be informed of construction activities on SFOBB seismic safety projects in the Transbay Corridor in advance through public information programs. Consequently, cumulative traffic impacts would be minimized through the traffic management plan.

4.15.5 Visual Quality

Context

The National Environmental Policy Act requires consideration of visual impacts of proposed actions. For the East Span Project, FHWA’s visual quality methodology for roadway projects was used to determine the visual impacts of project alternatives (see Section 4.3 — Visual Impact Analysis). The cumulative impacts on visual quality are analyzed in the local geographic context of YBI and the Oakland Touchdown area. The project analysis presented in Section 4.3 determined that visual impacts of the project would consist of loss of vegetation on YBI and at the Oakland Touchdown area; the project would not result in visual impacts in the larger context of the San Francisco Bay Area. Therefore, the cumulative impacts analysis considers the impacts of the East Span Project in combination with other projects that may alter local visual quality either long-term or during the construction period.

In the local context, past trends in visual quality on YBI have reflected military land uses. The appearance of the island has been greatly modified by the construction of military installations, the SFOBB, and introduction of non-native ornamental vegetation. The Oakland Touchdown area was created to provide for military and transportation uses and this trend continues today. More recent trends have been conversion of portions of the former OARB at the Oakland Touchdown area to industrial uses such as cargo container storage for the Port of Oakland. The existing visual quality of the Oakland Touchdown area is low because the predominant views are of industrial uses (e.g., containerized cargo storage and Caltrans maintenance and toll collection facilities). The vegetation on the south side of the Oakland Touchdown area is generally ruderal herbaceous plants and vegetation on the north side consists mostly of pine trees and ice plant.

Other projects at the local level that could affect the visual quality on YBI include YBI development described in the 1996 Draft Reuse Plan such as new buildings. Vegetation removal to reduce fuel load on YBI proposed by the San Francisco Fire Department may also affect visual quality. Projects in the Oakland Touchdown area include the proposed Gateway Park and reconstruction of the SFOBB Toll Plaza.

Impacts Analysis

Permanent Local Visual Impacts — Yerba Buena Island. CCSF Fire Department plans designating vegetation removal for fire fuel management were not available for review. Typically, fire fuel management focuses on reducing fuel load by removal of highly flammable trees and clearing vegetation immediately surrounding buildings.

The residential and commercial developments in the CCSF’s 1996 Draft Reuse Plan could result in the removal of vegetation. It is speculative to estimate the location or amount of vegetation that would be affected. However, a redevelopment concept shown in the 1996 Draft Reuse Plan indicates preservation of the vegetation along the northeastern shoreline of YBI and the ornamental landscaping in the Senior Officers’ Quarters Historic District.

The impacts of the East Span Project, the CCSF Fire Department fuel management, and the 1996 Draft Reuse Plan on vegetation would result in a cumulative visual change and some reduction of visual quality. However, because a revegetation plan for the East Span Project would include replacement of vegetation with mature vegetation as much as possible, long-term impacts to visual quality on YBI are not expected.

Permanent Local Visual Impacts — Oakland Touchdown Area. Other projects planned for the Oakland Touchdown area could result in an increase or decrease in vegetated areas. The proposed Gateway Park is not sufficiently advanced in the planning process to determine the amount and types of vegetation that might be included in the park design but it can be assumed that the park would have both landscaping and open space. Design concepts for the SFOBB Toll Plaza reconstruction are not sufficiently developed to determine impacts to pine trees near the existing facility, but this plan would probably include new landscaping. The City of Oakland’s plans for the eastern portion of the Oakland Touchdown area are not yet known; however, it is reasonable to assume that both open space and landscaping would be features of future redevelopment.

Based on available information concerning projects at the Oakland Touchdown and the inclusion of a master planting plan for the SFOBB replacement alternatives, it is expected that the long-term cumulative impacts on visual quality due to changes in the amount of vegetation would be beneficial.

Construction-Period Impacts to Viewsheds at Yerba Buena Island and the Oakland Touchdown Area. In addition to clearing and grubbing operations, all build alternatives would require construction activities involving the use of barges, heavy equipment, stockpiles of soils and materials, and other visual signs of construction. Selected views may be modified temporarily during construction because of the heavy equipment and removal of portions of woodland areas.

Visual impacts of development on YBI and TI envisioned in the 1996 Draft Reuse Plan would not occur in the same timeframe as construction of the East Span Project (see Section 4.1.5 — Community Impacts, Development Trends) and therefore the East Span Project would not contribute to local cumulative temporary visual impacts.

Redevelopment planning for the Oakland Army Base must be completed prior to initiating major construction projects on the Oakland Touchdown area. Although the timing of construction is subject to a number of variables, including regulatory and market conditions, it is likely that construction within the area would occur during the seven year construction period for the SFOBB East Span Project. Consequently, motorists are likely to view construction activities associated with former Oakland Army Base redevelopment in addition to construction activities associated with construction of the SFOBB East Span Project. Due to the combined construction activities at the Oakland Touchdown area, there would be a temporary construction-period cumulative impact on visual quality.

4.15.6 Air Quality

Context

From the regulatory perspective, transportation projects, including the East Span Project, are determined to be consistent with planning for air quality if they have been included in the regional air quality emissions analysis conducted by MTC and the Bay Area Air Quality Management District for the RTP and TIP and approved by the U.S. Environmental Protection Agency (see Section 3.4.1 — Regulatory Context for a discussion of conformity regulations). The geographic context for the analysis is the San Francisco Bay Area Basin, which is under the jurisdiction of the Bay Area Air Quality Management District. Other projects considered in the analysis are those in the Transbay Bay Bridge Corridor (see Section 4.15.4 — Transportation), Port of Oakland construction activities, and other transportation projects in the region identified in the RTP and TIP.

Since the federal Clean Air Act was passed in 1970, and amended in 1977 and 1990, air quality in the Bay Area has improved. Emissions levels and ambient concentrations for most pollutants are going down in the San Francisco Bay Area Air Basin despite increases in population and vehicle miles traveled. The one pollutant that has shown an increase over the last 15 years is particulate matter. This increase is due to a growth in area-wide sources, primarily fugitive dust sources. However, smaller particulate matter (PM10) concentrations, for the most part caused by combustion, are decreasing as a result of emission controls.

Implementation of the Clean Air Act Amendments of 1990, which includes stricter stationary and mobile source emission standards and controls, has contributed substantially to the decrease in air pollutant emissions. The implementation of even stricter emission controls in the future is expected to result in further improvements in air quality as stated in the 1999 California Almanac of Emissions and Air Quality issued by the California Air Resources Board.

Impacts Analysis

Air Quality Conformity. As discussed in Section 4.4 — Air Quality, there would not be a change in pollutant emissions resulting from operation of any of the build alternatives. In addition, FHWA has determined that the East Span Project is in conformance with the State Implementation Plan (SIP). (See Section 4.4.3 — Air Quality Conformity). Therefore, this project would not contribute to long-term air quality impacts.

Construction-Period Impacts. Construction-related air quality impacts resulting from this and other projects in the San Francisco Bay Area Air Basin including local projects in the Transbay Bay Bridge Corridor (see Section 4.15.4 — Transportation) and Port of Oakland construction activities could, depending on construction schedules, result in short-term cumulative air quality impacts within the Transbay Bay Bridge Corridor. Construction-period air quality impacts would include internal combustion engine emissions from construction equipment, dust generated by mechanical disturbance, and wind-blown dust from exposed soil. The pollutant usually generated in the largest amount during construction is particulate matter.

Projects that may be under construction simultaneously with the East Span Project include some of the other SFOBB improvements described in Section 1.3.6 — Other SFOBB Seismic Safety Projects. The West Approach Seismic Replacement would require structure dismantling and earthmoving activities that would cause temporary dust and particulate emissions.

Port of Oakland construction activities may also overlap with the East Span Project and be undertaken beginning in 2002 and continuing to the proposed buildout year, 2012. Construction activities could include demolition or rehabilitation of existing structures, dredging, and grading and paving of laydown areas which would increase air pollutant emissions.

The potential for cumulative impacts to occur would be minimized through inclusion of standard specifications employed by contractors of all projects, including the East Span Project (see Section 4.14.4 — Construction Period Air Quality for a listing of standard specifications).

4.15.7 Noise and Vibration

Context

The regulatory framework for noise assessments consists of FHWA’s Procedures for Abatement of Highway Traffic Noise and Construction Noise. The project-specific noise analysis is cumulative in approach because it uses projected future traffic data added to ambient noise to assess combined future noise (with and without project noise levels). Impacts are in terms of anticipated noise levels at land uses in proximity to the proposed project.

There is no regulatory guidance for assessment of vibration impacts of transportation projects (see Section 4.14.5 — Construction Period Noise and Vibration for a discussion of vibration impact assessment methodology used for the East Span Project). No long-term or construction-period cumulative vibration impacts would result from East Span Project alternatives.

For the East Span Project, the geographic context includes receptors on YBI, TI, and the Oakland Touchdown area at which noise levels could change as a result of the project. Land uses and receptors are discussed in Section 3.5.2 — Land Uses and Noise- and Vibration-sensitive Receptors. Past and present land use trends within the project limits indicate a mixture of transportation, industrial, and institutional uses that contribute to a noise environment in which noise-sensitive land uses (e.g., the BEQ in the USCG facility) have in the past and currently experience noise levels at or exceeding FHWA’s noise abatement criteria (see Section 3.5.3 — Noise Abatement Criteria and Analysis Guidelines). Future land uses on YBI and TI are expected to generate noise levels similar to existing conditions. The East Span would continue to be a major noise source affecting noise-sensitive land uses in the vicinity of the bridge. Reasonably foreseeable land use patterns at the Oakland Touchdown indicate that transportation and industrial noise sources would continue to predominate. In addition, 5.9 hectares (14.7 acres) at the westernmost end of the former Oakland Army Base property have been designated for a future park.

Other projects that could contribute to cumulative noise impacts include construction projects on YBI related to development scenarios outlined in the 1996 Draft Reuse Plan.

Impacts Analysis

Permanent Impacts. The Retrofit Existing Structure Alternative would not change existing noise levels. The replacement alternatives would reduce noise levels at many locations because of the use of certain types of road surface and construction materials and the single-deck bridge design (see Section 4.5 — Noise and Vibration).

Construction-Period Noise Impacts.

Based on the CCSF’s 1996 Draft Reuse Plan, redevelopment on YBI would occur after the East Span Project is completed. The Clipper Cove marina expansion could generate noise from pile driving and construction of new marina buildings. However, construction of the Clipper Cove expansion (which will commence on completion of environmental reviews and approvals) would not contribute to noise impacts to the land uses on YBI that would be impacted by the East Span Project alternatives because of the distance between the two construction sites. At distances greater than 480 meters (1,580 feet) sound attenuation would typically result in noise levels from construction activities that are not be distinguishable from existing noise levels. (See Section 4.14.5 — Construction-period Noise and Vibration for a discussion of construction noise attenuation over distance). Therefore, no cumulative impact is expected to result.

The City of Oakland’s plans for the Oakland Touchdown area and Caltrans’ reconstruction concepts for the SFOBB Toll Plaza have not been developed to a stage that would allow estimation of the type of construction activity or the timeline. These projects would require construction activities such as pile driving, excavation, and other noise generating activities. Should these projects be undertaken simultaneously with East Span Project construction at the Oakland Touchdown, combined noise levels could result in an increase in noise levels at the Oakland Touchdown area. There are no noise-sensitive land uses at the Oakland Touchdown area. The planned Gateway Park is a reasonably foreseeable action, but would not be constructed until the East Span Project construction is completed. Therefore, no noise-sensitive land uses would experience construction-period cumulative impacts

4.15.8 Hazardous Wastes

Context

The regulatory context for determining the environmental impacts of disturbance or release of contamination or hazardous wastes are federal, state, and local codes, regulations and guidance directing hazardous waste remediation, and the transport, storage and disposal of hazardous wastes (see Section 3.6.1 — Hazardous Wastes, Legal and Regulatory Requirements).

The geographic context is the eastern portion of YBI and the Oakland Touchdown area; ground disturbance related to construction projects in these areas could result in exposure of workers or nearby residents to hazardous wastes. Past and current land uses are discussed in Section 3.6.4 — Hazardous Wastes, Historical Information Update and Site Reconnaissance and Section 3.6.5 — Hazardous Wastes, Potential Sources of Contamination.

Past trends that may have contributed to the deposition of hazardous wastes on YBI include operation of military facilities and the SFOBB. At the Oakland Touchdown area, operation of the Port of Oakland, former Oakland Army Base, EBMUD treatment and outfall facilities, and the bridge and Caltrans maintenance facilities have contributed to the presence of hazardous wastes.

Foreseeable trends are decreasing deposition of hazardous wastes due to regulations controlling the use and disposal of hazardous wastes and materials. Future actions that could contribute to exposure of workers or residents to hazardous wastes are construction projects on YBI that may be undertaken to implement the CCSF’s 1996 Draft Reuse Plan and construction of the planned Gateway Park at the Oakland Touchdown area.

The quality of sediments in the Bay in terms of presence or absence of contaminants is addressed in Section 4.15.10 — Water Quality.

Impacts Analysis

Permanent Impacts. The Retrofit Existing Structure Alternative and Replacement Alternatives N-2, N-6 (Preferred), and S-4 would not result in deposition of hazardous wastes and would therefore not contribute to cumulative impacts (see Section 4.6.1 — Hazardous Wastes, Summary and Comparison of Alternatives). Remediation of hazardous wastes and/or sites as a result of construction of any of the alternatives combined with redevelopment on YBI and construction of the proposed Gateway Park at the Oakland Touchdown area would cumulatively result in decreased future risk of exposure to hazardous wastes within the project limits because the hazardous wastes would be removed from the area and placed at regulated disposal sites.

Construction-Period Impacts. Construction of the Retrofit Existing Structure Alternative and Replacement Alternatives N-2, N-6 (Preferred), and S-4 would have the potential to encounter contamination and increase the possibility of worker and public exposure to hazardous wastes. Other projects on YBI and at the Oakland Touchdown area could also encounter contamination and expose workers and the public to hazardous wastes. Although multiple projects increase the potential for contamination or exposure, the East Span Project alternatives and other projects on YBI and at the Oakland Touchdown area are currently employing or would use established exposure control procedures and safety plans to guide remediation activities. Therefore, cumulative impacts would be avoided.

      1. Geology, Soils, and Seismicity

Context

The regulatory context for the geology, soils, and seismicity analysis is federal, state, and local laws that establish building and structure safety codes. Compliance with these laws is ensured through the permit review process. The analysis has two geographic contexts; geology and soils impacts are addressed at a local level and seismic safety impacts are addressed at the regional level.

Geology and soils impacts are localized in nature; cumulative impacts would be based on the combined potential of projects to create unstable ground conditions that could result in danger to local populations or loss of resources. Therefore, the geographic context for the geology and soils cumulative impacts assessment is YBI, where unstable geologic conditions exist. The East Span Project would not contribute to potential geologic or soil stability impacts at any other locations (e.g., the Oakland Touchdown area). Projects that may contribute to cumulative impacts are limited to YBI redevelopment as described in the 1996 Draft Reuse Plan.

Past trends of development combined with natural erosion on steep slopes have contributed to unstable slopes on YBI.

The context for the seismicity assessment is the lifeline system of roads and bridges in the Bay Area region that Caltrans has designated to support emergency response. (See Section 1.2.1 — Lifeline Connection for an explanation of the lifeline transportation system.) Caltrans has designated a system of roadways and bridges in the Bay Area region which have designed, constructed or will be constructed to meet lifeline criteria at various locations on I-80 between San Francisco and the Nevada border, I-280, I-680, I-780, Route 24, Route 92, and Route 101. Projects included in the cumulative assessment are seismic retrofit projects in the Transbay Corridor, including the West Approach Seismic Retrofit, the East Span Seismic Retrofit, the West Viaduct Seismic Retrofit, the YBI Tunnel Retrofit, and the distribution structure seismic retrofit.

Trends for seismicity are increasing the seismic safety of existing roads and bridges through seismic retrofit.

Impacts Analysis

Long-term and construction-period impacts are combined in this section because construction activities on unstable slopes can result in both immediate geologic changes and unstable conditions that can contribute to longer-term geologic impacts.

Impacts to Geology and Soils. The Retrofit Existing Structure Alternative would not change local geologic conditions at YBI and would not contribute to cumulative impacts. The replacement alternatives would place bridge foundations on YBI in areas with steep slopes (i.e., greater than 30 percent). Excavation activities in these areas could destabilize and erode steep slopes. Caltrans would restore and stabilize slopes to minimize impacts from construction.

Unstable slopes above the USCG facilities are subject to slides during heavy rains. The USCG takes actions to stabilize slides. These actions would be expected to continue on slopes not impacted by the temporary detours for the East Span Project. The combination of the East Span Project and the USCG actions would contribute to a cumulative improvement in slope stability on the eastern portion of YBI.

The 1996 Draft Reuse Plan for redevelopment on YBI does not include development on steeply sloping areas; therefore, the East Span Project is the only project anticipated to involve steep (greater than 30 percent) areas. Thus, no cumulative impacts would result.

Seismicity Impacts. The East Span Project build alternatives would have a beneficial impact on seismic safety of the traveling public and no projects are known that would undermine the East Span Project improvements. Therefore, no cumulative impacts would occur.

4.15.10 Water Quality

Context

The regulatory context for the cumulative water quality analysis are federal, state, and regional regulations which address protection and enhancement of the beneficial uses of the water in San Francisco Bay and its tributaries. The geographic context is the Central Bay portion of the San Francisco Bay basin, which is described in the San Francisco Bay Regional Water Quality Control Board (RWQCB) Basin Plan.

The Basin Plan sets forth water quality objectives to protect and enhance the beneficial uses of the Bay and its tributaries. One of the mechanisms used by the RWQCB to maintain and/or attain the water quality objectives is to stipulate the objectives of the Basin Plan in National Pollutant Discharge Elimination System (NPDES) permits issued to municipalities and agencies for all projects in the San Francisco Bay basin. The East Span Project and other projects in the Central Bay would be subject to NPDES permitting.

Projects included in the analysis are those within the Central Bay. These projects include local construction activities such as private developments that increase runoff into the Bay and dredging for navigation purposes at the Ports of Oakland, Richmond, and San Francisco. Planned improvements for the Port of San Francisco include reuse of Piers ½, 3, and 5 and development of the International Cruise Ship Terminal. The Port of San Francisco projects are in the early phases of planning and project descriptions are not developed to the extent that potential water quality impacts can be estimated.

Since the Gold Rush the quality of the Bay’s water has historically been adversely affected by a variety of economic activities. Among these activities are hydraulic gold mining, agriculture, grazing, logging, major and minor shipping, ports, marinas, commercial and recreational fishing, waste water discharge, urban activities, and industrial development along the Bay shoreline. Past activities such as wastewater discharges, dumping of wastes, and industrial runoff have created numerous areas of contaminated sediment around the Bay. Common contaminants include metals, pesticides, and toxic organics. Despite these past activities, the San Francisco Bay basin supports diverse and productive environmental resources.

A Regional Monitoring and Assessment Strategy Program evaluates Bay water and sediment at approximately 20 locations throughout the Bay. In general, the results of this monitoring are:

In the Central Bay, where the East Span Project is located, water quality data from regional monitoring and the Caltrans monitoring program indicate that most of the water quality objectives in the Basin Plan are being met. This indicates a trend of water quality improvement in the Central Bay, although water quality objectives for the entire Bay are not being met.

Impacts Analysis

Permanent Impacts. The Retrofit Existing Structure Alternative would not impact the existing runoff level of the SFOBB into the Bay.

As discussed in Section 4.8.1 — Surface Water Quality, the replacement alternatives have features that would improve the quality of storm water runoff. There is an overall improvement in the type of materials such as concrete used in the replacement alternatives compared with the existing East Span. A replacement structure would be a predominately concrete structure that would have limited exposed steel, which reduces the need for painting and paint removal. Painting would occur once every 10 to 15 years with a non-lead paint. The elimination of lead-paint removal and painting on a replacement structure should provide a long-term reduction in adverse water quality associated with the existing structure. Other design features of the replacement bridge such as standard shoulders, standard lane widths, and increased sight distances would all contribute to improved water quality of bridge run-off by improving safety and traffic flow. Overall water quality of bridge run-off is expected to improve; therefore, the replacement alternatives would not contribute to cumulative adverse impacts on Bay water quality and in fact would have beneficial impacts.

From a cumulative perspective, the RWQCB will continue to permit projects in a manner intended to meet the objectives outlined in the Basin Plan, resulting in improved water quality in the San Francisco Bay.

Construction-Period Impacts. Construction activities for the build alternatives would result in an increase in turbidity containing pollutants due to dredging, pile driving, propeller wash from tugboats/barges, and mud boils. In combination with in-water construction activities for dredging for projects at the Ports of Oakland and Richmond (channel deepenings and improvements), cumulative impacts to water quality could occur as a result of increased turbidity. However, mitigation measures, detailed in Section 4.14.7 — Temporary Impacts During Construction Activities, Water Resources and Water Quality, would minimize turbidity and sediment mobilization to the greatest extent possible.

4.15.11 Natural Resources — Bay Fill

Context

The regulatory context for the Bay fill cumulative impacts analysis includes state laws regarding fill in San Francisco Bay (see Section 4.9.1 — Natural Resources, Placement of Fill in the San Francisco Bay, for a definition of fill and discussion of calculation of fill quantities). This cumulative impacts analysis uses the San Francisco Bay Conservation and Development Commission’s (BCDC’s) definition of fill because BCDC has the most comprehensive policies on placing fill in the Bay. BCDC administers the McAteer-Petris Act and the San Francisco Bay Plan, which governs the manner and purpose of filling San Francisco Bay and limits such fill to water-oriented uses such as improving public access or shoreline appearance. BCDC issues permits for solid, pile-supported, floating, cantilevered, and high-level suspended fill placed bayward of the mean high tide line or the +1.5-meter (+5.0-foot) contour mean sea level where marshlands are present. The cumulative impact assessment considers the impact of the East Span Project and other projects on the surface area of San Francisco Bay.

The geographic context for the Bay fill cumulative impacts analysis is Central San Francisco Bay. San Francisco Bay has been divided into subregions in the planning documents of several regulatory agencies and organizations including the San Francisco Bay Area Wetlands Ecosystem Goals Project (Goals Project) and BCDC’s Bay Plan. The Central Bay subregion includes the main body of San Francisco Bay and extends along the western shore from Point San Pedro in Marin County to Coyote Point in San Mateo County and along the eastern shore from approximately the Emeryville Crescent to San Leandro Marina in Alameda County.

In the last 200 years filling and diking have reduced the Bay from its historic size of 1,761 square kilometers (680 square miles) to approximately 1,114 square kilometers (430 square miles). BCDC was established in 1965 to limit indiscriminate filling of San Francisco Bay. Since that time the trend of filling the Bay has been reversed. In 1999, BCDC approved projects that will result in a net increase of 105 hectares (258 acres) of Bay surface area. This increase in the size of the Bay’s surface area has been a consistent trend for the past several years.

BCDC’s annual report provides data (new Bay surface area minus new Bay fill area) on Bay fill trends for the entire Bay. The data were analyzed to assess the East Span Project’s cumulative impacts on Bay fill. Between 1970 and 1999, the net increase in Bay surface area was approximately 701 hectares (1,731 acres). Past projects included in these figures are the Port of San Francisco’s enhancements at and near the Ferry Building; the commercial fishing harbor near Hyde Street Pier; Pier 39 Limited Partnership; Port of San Francisco’s Forbes Island Project; and the Westbound Carquinez Bridge Replacement Project.

Fill types included in the cumulative impacts analysis for the East Span Project include placement of pile-supported fill for piles and pile caps; solid fill for the westbound roadway; high-level suspended fill for the bridge decks; and temporary pile-supported fill for access trestles and docks required to construct projects within the Bay. High-level suspended fill from bridges crossing the Bay is included in the analysis because such fill is regulated by BCDC. However, this type of fill generally does not cause permanent shading or result in other environmental impacts to the Bay because of its substantial height above the surface of the Bay.

Projects included in the cumulative impacts analysis are within Central San Francisco Bay and involve fill in the Bay. These projects are the San Mateo-Hayward Bridge Trestle Widening Project; Port of San Francisco Pier 1 Enhancements; the San Francisco International Airport Runway Reconfiguration Project; Port of Oakland’s Harbor Navigation Improvement (-50-foot) Project; and the Port of Oakland Berth 55-58 Project. Other Port of San Francisco projects, such as the International Cruise Ship Terminal and redevelopment of Piers ½, 3, and 5 are in the planning stages; Bay fill associated with these projects cannot yet be estimated.

Impacts Analysis

The methodology for the fill impacts analysis considers the permanent change in the surface area of the Bay. Temporary fill associated with projects is also regulated by BCDC but is not included in the cumulative impacts analysis because temporary fill does not contribute to long-term trends for change in the size of San Francisco Bay. (See Section 4.14.8 — Temporary Impacts During Construction Activities, Natural Resources, for calculation of temporary fill quantities.) All build alternatives would add fill in San Francisco Bay as defined by BCDC.

The Retrofit Existing Structure Alternative would increase the amount of solid and pile-supported fill but would not increase the amount of high-level suspended and cantilevered fill since the fill would be placed within the footprint of the existing bridge. Solid and pile-supported fill required to retrofit the existing East Span would be added under the deck area of the existing East Span (see Section 4.9.1 — Placement of Fill in San Francisco Bay, for a discussion of BCDC regulated fill).

Replacement alternatives would increase the amount of pile-supported and solid fill by adding new piles and pile caps and constructing the westbound roadway; they w1ould also increase the amount of high-level suspended and cantilevered fill by replacing the existing double-deck East Span with two parallel bridge decks. The resulting decrease in Bay surface area would be approximately 18 hectares (45 acres) for Replacement Alternative N-2, approximately 19 hectares (47 acres) for Replacement Alternative N-6, and approximately 17 hectares (43 acres) for Replacement Alternative S-4 (see Section 4.9.1 — Placement of Fill in San Francisco Bay for a discussion of the BCDC regulated fill impacts of the replacement alternatives).

Table 4.15-1 summarizes the available information about the area of Bay fill for other recent and planned projects included in the cumulative impacts analysis.

Combined with the East Span Project replacement alternatives, these projects would result in a net decrease in the surface area of the Bay. This is largely from the high-level suspended fill associated with the East Span Project which generally does not adversely impact the Bay. Nevertheless this could be considered inconsistent with the McAteer-Petris Act and the Bay Plan policies to minimize fill in the Bay and regional efforts to increase the size of San Francisco Bay through fill removal and habitat restoration. A cumulative impact would result from the combined actions.

The East Span Project and each of the recent and planned projects listed in Table 4.15-1 would have mitigation measures. that if successfully implemented and if high-level suspended fill is excluded from the impacts analysis, would result in a net increase in Bay surface area.

Table 4.15-1 Bay Surface Area Fill Summary

Project

Change in San Francisco Bay Surface Area in Hectares (Acres)

East Span Project Replacement Alternatives

17 to 19 hectares (43 to 47 acres) decrease in surface area of the Bay

San Mateo-Hayward Bridge Trestle Widening Project

0.02 hectare (0.04 acre) decrease in surface area of the Bay

Port of San Francisco Pier 1 Enhancements

0.09 hectare (0.22 acre) decrease in surface area of the Bay

San Francisco International Airport Runway Reconfiguration Project

607 hectares (1,500 acres) decrease in surface area of the Bay

Port of Oakland, Oakland Harbor Navigation Improvement (-50 foot) Project

10.9 hectares (27 acres) decrease in surface area of the Bay

Port of Oakland Berth 55-58 Project

4.4 hectares (11 acres) increase in surface area of the Bay

Source: Caltrans, January 2001.

4.15.12 Natural Resources — Special Aquatic Sites

Context

The regulatory context for the cumulative impacts analysis of special aquatic sites is Section 404 of the Clean Water Act. The ACOE regulates fill in special aquatic sites (wetlands, eelgrass, and sand flats) in Waters of the United States. The ACOE has a no-net-loss policy that requires each project to avoid and minimize impacts to special aquatic sites and to mitigate for unavoidable impacts to special aquatic sites. The McAteer-Petris Act and the San Francisco Bay Plan administered by BCDC also regulate fill in San Francisco Bay including special aquatic sites. However, the Section 404 regulations administered by the ACOE are used in this cumulative impacts analysis because their regulations are more comprehensive than BCDC policies in terms of special aquatic sites. Mitigation for unavoidable impacts to special aquatic sites and success criteria are developed in coordination with the ACOE, RWQCB, USFWS, EPA, BCDC, and CDFG.

The geographic context for the special aquatic sites cumulative impacts analysis is Central San Francisco Bay. San Francisco Bay has been divided into subregions in the planning documents of several regulatory agencies and organizations including the San Francisco Bay Area Wetlands Ecosystem Goals Project (Goals Project) and BCDC’s Bay Plan as described above.

The trend in the last 200 years has been the loss of special aquatic sites due to diking and filling for agriculture and development. Approximately 93 percent of Central San Francisco Bay’s original 5,447 hectares (13,461 acres) of tidal marshes have been lost (Baylands Ecosystem Habitat Goals, 2000). The approximately 383 hectares (947 acres) of remaining wetlands are threatened by development, erosion, pollution, and sea level rise (USGS and Chavez, et al. 1995). In addition, watershed nutrient and sediment loading from the Delta as well as Bay dredging and filling have affected eelgrass although recent data suggest a possible expansion of eelgrass habitat in the Central Bay since 1987 (Merkel and Associates, unpublished data). Factors affecting wetlands and eelgrass have also contributed to the loss of tidal flats. Approximately 70 percent of San Francisco Bay’s original 5,476 hectares (13,532 acres) of tidal flats have been lost (Baylands Ecosystem Habitat Goals, 2000). Tidal flats, including the large grain sand flats found within the East Span Project limits, have been created in the Bay by millennia of natural accretion of sediments.

The methodology for this assessment uses the Goals Project, information concerning upland wetland reuse projects identified during development of the Dredged Material Management Plan (See Appendix M), and consultation with ACOE, RWQCB, BCDC, EPA, USFWS, and CDFG. This qualitative approach was employed absent a database of San Francisco Bay wetland impacts or Section 404 applications.

Impacts Analysis

Because a database of past, current, and reasonably foreseeable future projects in the Central Bay that would impact special aquatic sites is not available, it is not possible to specifically measure the cumulative impacts to existing special aquatic sites. Accordingly, impacts have been estimated in the context of regional planning for the enhancement and restoration of special aquatic sites.

The Retrofit Existing Structure Alternative would not impact any special aquatic sites.

The replacement alternatives would have permanent impacts to sand flats, eelgrass beds, and non-tidal wetlands (see Section 4.9.2 — Special Aquatic Sites). The total areas impacted are summarized in Table 4.15-2.

Table 4.15-2 Summary of Replacement Alternative Permanent Impacts to Special Aquatic Sites

Special Aquatic Sites

Replacement Alternative N-2

Replacement Alternative N-6

Replacement Alternative S-4

Non-tidal Wetland

0.00

0.00

0.05 hectare

(0.12 acre)

Sand Flats

1.36 hectares

(3.36 acres)

1.36 hectares

(3.36 acres)

0.01 hectare

(0.03 acre)

Eelgrass

0.22 hectare

(0.55 acre)

0.22 hectare

(0.55 acre)

0.15 hectare

(0.37 acre)

TOTAL

1.58 hectares

(3.91 acres)

1.58 hectares

(3.91 acres)

0.21 hectare

(0.52 acre)

Although a comprehensive database of potential impacts to wetlands is not available, two projects in planning stages that would affect Central Bay wetlands or other special aquatic sites are the San Francisco International Airport Runway Reconfiguration Project and the Port of Oakland’s port and airport expansion. The San Francisco International Airport Runway Reconfiguration Project could fill approximately 607 hectares (1,500 acres) of Bay surface area to add new runways. It is not known what portions of the total area are tidal flats or shallow Bay habitats that may be special aquatic sites as defined by Section 404 of the Clean Water Act. The Port of Oakland’s airport expansion would fill approximately 2.8 hectares (7 acres) of wetlands. The Port of Oakland’s dredging project would impact 0.08 hectare (0.2 acre) of eelgrass but would add approximately 6 hectares (15 acres) of shallow water eelgrass habitat as part of the Middle Harbor Enhancement Area.

Review of ACOE permit applications for work in Central San Francisco Bay for the years 1999 and 2000 documented two projects that impacted Central San Francisco Bay wetlands. The Eden Landing Ecological Reserve tidal marsh restoration project will restore 230 hectares (570 acres) of tidal marsh. Small areas of non-tidal wetlands within the Eden Landing parcel will be replaced with tidal marsh wetlands. The second project, a roadway expansion project in San Mateo County, will have permanent impacts to 0.27 hectare (0.68 acre) of wetlands. Impacts caused by the roadway expansion project will be mitigated through the creation of 0.53 hectare (1.3 acres) of wetlands. Combined, these two projects will result in the net addition of 230 hectares (570 acres) of restored tidal marsh in Central San Francisco Bay.

Caltrans has coordinated with federal and state resource agencies to develop mitigation measures to offset project impacts to special aquatic sites (the conceptual mitigation plan is described in Section 4.9.6 — Natural Resources, Mitigation). The replacement alternatives would impact up to 1.58 hectares (3.91 acres) of special aquatic sites (see Table 4.15-2). Proposed mitigation for impacts to special aquatic sites includes the on-site restoration of portions of the sand flats and eelgrass beds and off-site creation of a tidal marsh ecosystem. The out-of-kind mitigation concepts are designed to replace the functions and values of the sand flats and eelgrass beds, to the extent possible, through creation of a tidal marsh ecosystem consistent with the objectives of the Baylands Habitat Ecosystem Goals Project. The East Span Project would contribute to a cumulative impact on existing special aquatic sites, but would replace the special aquatic sites at a 3:1 ratio.

The East Span Project in combination with known projects that may impact special aquatic sites would contribute to a cumulative loss of special aquatic sites. However, each project that impacts special aquatic sites must comply with federal Clean Water Act Section 404 requirements implemented by the ACOE, which has a policy of no-net-loss of special aquatic sites. The conceptual mitigation plan for the East Span Project would result in a net increase in the total acres of special aquatic sites in San Francisco Bay. Combined with mitigation to ensure no-net-loss for other recent projects impacting wetlands, in addition to recent tidal marsh restoration projects such as the Eden Landing Ecological Reserve, a net increase in special aquatic sites in Central San Francisco Bay would occur. This net increase would contribute to a reversal of the historic trend for loss of special aquatic sites in San Francisco Bay.

4.15.13 Natural Resources — Special Status Species

Context

The regulatory context for the special status species cumulative impacts analysis is the federal and state laws which protect species. The federal and California Endangered Species Acts provide protection for species listed as rare, threatened, or endangered. Avian species are protected by the federal Migratory Bird Treaty Act, marine mammals are protected by the Marine Mammal Protection Act, and fish species protected under the Magnuson-Stevens Act. Species that may be impacted by the East Span Project are migratory birds and shorebirds, American peregrine falcon, double-crested cormorant, Pacific herring, Chinook salmon, steelhead, green sturgeon, longfin smelt, harbor seal, California sea lion, and gray whale.

The overall geographic context for the special status species cumulative analysis is San Francisco Bay (including San Pablo Bay) and marine and shoreline habitats. Geographic contexts vary by type of species. The geographic context for avian species consists of roosting sites in the San Francisco Bay Area. The geographic context for fish is Central San Francisco Bay and the geographic context for marine mammals (harbor seals) are the haul-out sites in Central San Francisco Bay. These geographic limits are further described in the sections below.

Past trends affecting aquatic habitat for fish and marine mammals are water quality degradation discussed in Section 4.15.10 — Water Quality and reduction in the area of San Francisco Bay described in Section 4.15.11 — Bay Fill. Trends in water quality and land development have placed pressure on species that have historically used the Bay for foraging and nesting. The result has been increased pressure on remaining habitat to support the special status species that may be present in the East Span Project area.

Past trends in the Bay Area for the protected avian species have been reductions in their numbers due to loss of habitat from development and impacts of chemicals such as DDT, which has caused eggshell thinning and thereby reduced birth rates. In recent years, some avian species have increased in numbers due to the ban on DDT and successful captive breeding. Peregrine falcons have adapted to non-traditional habitats such as tall buildings and bridges; double-crested cormorants have also adapted to non-traditional habitats such as bridges and power lines in water. As a result, both species have shown significant increases in population in recent years. In fact, the falcon was recently removed from the federal endangered species list because of the increase in its numbers.

Other projects considered in the analysis are the Richmond-San Rafael Bridge Retrofit Project, construction activities and dredging for projects at the Port of Oakland, and seismic retrofits of the Carquinez, Benicia-Martinez, Richmond-San Rafael, and Golden Gate bridges.

Impacts Analysis

Permanent Impacts to Avian Species. The Retrofit Existing Structure Alternative would retain existing habitat for the American peregrine falcon and double-crested cormorants. If the peregrine falcons are disturbed during construction such that nesting is adversely impacted, the biologists monitoring them can relocate eggs or chicks. Retrofit of the existing structure would not change roosting habitat for migratory birds and foraging and resting habitats for shorebirds would not be affected.

Replacement Alternatives N-2, N-6 (Preferred), and S-4 would remove habitat for the peregrine falcon. Measures consistent with the Migratory Bird Treaty Act would minimize direct impacts (see Section 4.9.6 — Natural Resources, Mitigation). Peregrine falcons would likely nest on a replacement bridge once construction activities associated with the project are complete. The continuing trend of recovery of the species combined with the potential for the replacement alternatives to provide new nesting habitat indicates that a loss in nesting habitat would not occur as a result of the East Span Project combined with other actions. No other projects have been identified that would remove existing nesting sites. Therefore, cumulative impacts are not expected to occur.

Development in the Bay has resulted in reductions of suitable habitat for the double-crested cormorant, which have caused them to adapt to non-traditional habitats such as the SFOBB and the Richmond-San Rafael Bridge. The colony on the SFOBB is the second largest one in Northern California. The colony at the Farallon Islands marine sanctuary is the largest in Northern California. The replacement alternatives would remove the habitat for the double-crested cormorant colony. Seismic retrofit of the Richmond-San Rafael Bridge, the only other planned project known to have potential to impact cormorants, is not expected to affect them. The Richmond-San Rafael Bridge seismic retrofit will not remove active nests. Provision of nesting habitat on replacement alternatives or its retention on the Retrofit Existing Structure Alternative on the East Span Project and retention of nesting habitat on the Richmond-San Rafael bridge would avoid cumulative impacts to double-crested cormorants.

Development in the Bay has resulted in reductions of suitable nesting habitat for migratory birds. The Migratory Bird Treaty Act protects nesting activities of migratory birds and does not regulate development that impact habitat for avian species. The replacement alternatives would not restrict nesting activities of migratory birds and therefore would not, in combination with other projects, contribute to long-term cumulative impacts to migratory birds.

Shorebirds use sand flats within the project limits for foraging and resting. As described in Section 4.15.12 — Natural Resources, Special Aquatic Sites, the replacement alternatives would contribute to a cumulative impact to special aquatic sites and therefore a cumulative impact to shorebirds. Special aquatic sites mitigation for the replacement alternatives would contribute to an overall increase in sand flats in Central San Francisco Bay (see Section 4.15.12).

Construction-Period Impacts to Avian Species. Nesting and breeding activities of the peregrine falcon, double-crested cormorants, and other migratory birds on the existing structure could be disrupted by noise and other construction activities related to the build alternatives. Mitigation measures would include monitoring the peregrine falcon during nesting and removing eggs or chicks if monitors determine that the disturbance is adversely affecting nesting activities and prevention of double-crested cormorants and other migratory birds from nesting on the structure (see Section 4.14.8 — Temporary Impacts During Construction Activities, Natural Resources). Under the conditions of the Migratory Bird Treaty Act, a nest cannot be disturbed if nesting activities have begun. Specifications for the Richard-San Rafael Bridge seismic retrofit call for prevention of nesting during retrofit activities but if nesting has begun the nests cannot be disturbed. Because the East Span Project replacement alternatives would dismantle the existing East Span after construction of the Richmond-San Rafael bridge seismic retrofit work is complete, there is no potential for cumulative construction period impacts.

Construction of the replacement alternatives will disturb sand flats at the Oakland Touchdown area used by shorebirds for resting and foraging. In combination with construction activities for the project considered in Section 4.15.12, a reduction in shorebird resting and foraging habitat could occur. This would cause a cumulative impact.

Mitigation for impacts due to temporary disturbance to special aquatic sites is required for all projects will also provide mitigation for temporary disturbance of shorebird resting and foraging habitat (see Section 4.14.8 — Temporary Impacts During Construction Activities, Natural Resources for a discussion of East Span Project impacts to sand flats).

Permanent Impacts to Fish Species. No permanent impacts to fish would result from the build alternatives.

Construction-Period Impacts to Fish Species. Construction activities for the build alternatives could result in an increase in turbidity that could impact migratory fish species including Pacific herring, Chinook salmon, steelhead, green sturgeon, and longfin smelt. In combination with dredging for projects at the Port of Oakland that could be underway during construction of the East Span Project, the potential for cumulative impacts to occur as a result of increased turbidity to these species was assessed. Investigation of sediment transport from East Span Project dredging activities indicates that sedimentation and turbidity impacts are localized and temporary, with suspended material settling rapidly. Analysis indicated a low potential for the East Span Project build alternatives to contribute to sediment increases in the vicinity of the Port of Oakland (see response to Comment 4 of the Port of Oakland’s letter responding to the DMMP dated July 21, 1999 in Volume II, Section 2 — DMMP Comments and Responses). Therefore, large areas of increased turbidity would not result from the projects considered in the assessment and cumulative impacts would not occur.

Pile driving for East Span Project build alternatives may have impacts on fish within the immediate vicinity. Impacts on fish from driving large piles in the Bay are not well documented. During the Pile Installation Demonstration Project (PIDP) completed in December of 2000, injury and mortality to small fish were observed within the immediate vicinity of pile driving operations. While the results of the PIDP have not been finalized, preliminary results indicate that use of noise attenuation devices reduces impacts to small fish near pile driving. Caltrans will continue coordinating with NMFS regarding interpretation of the PIDP results. In compliance with NMFS' Biological Opinion, Caltrans would require that sound attenuation measures be included in pile driving specifications for any pile driving during the peak juvenile salmonid outmigration period of January 1 through May 31. Provision of sound attenuation during the peak outmigration period would avoid construction-period cumulative impacts to special status fish and would also benefit other fish species during that period.

Because there is limited information available concerning potential for fish kill due to pile driving in the Bay, cumulative impacts to fish cannot be determined.

Permanent Impacts to Marine Mammals. No long-term impacts to marine mammals would result from the build alternatives.

Construction-Period Impacts to Marine Mammals. Underwater sound pressure levels generated by pile driving for all build alternatives could result in temporary impacts to harbor seals. There are 12 harbor seal haul-out sites and rookeries in the Bay; of those, only eight are used by more than a few animals at a time. Three sites in the Bay regularly host more than 40 harbor seals at any one time. The three closest sites to the project area are YBI, Angel Island, and Castro Rocks near the Richmond-San Rafael Bridge. Surveys at these sites indicate that pupping activities occur at Castro Rocks but do not occur at the YBI haul-out site.

Retrofit of the Richmond-San Rafael Bridge, scheduled for completion by March 2004, could also result in temporary impacts to harbor seals. A mitigation and monitoring plan has been developed to protect them. The plan includes restriction of certain retrofit activities near Castro Rocks to avoid impacts to harbor seals during pupping season, regular monitoring of haul-out sites in the Bay, and collection of data by direct observation, analysis of videotape data, and surface and underwater audio analysis. No other projects in San Francisco Bay, including the seismic retrofit of the Carquinez or Benicia-Martinez Bridges, are anticipated to impact harbor seals because no harbor seal haul-out sites are located in the vicinity of these projects.

Data indicate that harbor seals return to haul-out sites when construction activities cease. The East Span and Richmond-San Rafael Projects do not physically impact the haul-out sites and activities related to these projects that may impact harbor seals would be intermittent (e.g., pile driving, vessel traffic passing haul-out sites, or increased human activity). Because the haul-out sites would not be directly used for construction activities and the activities would be intermittent, cumulative impacts during construction of the East Span Project in combination with the seismic retrofit of the Richmond-San Rafael Bridge are expected to be minimal.

Potential East Span Project impacts to marine mammals were evaluated during the Pile Installation Demonstration Project. The PIDP was completed in December 2000 and data from the project are being analyzed. Initial results indicate no impacts to marine mammals at the YBI haul-out site and minimal impacts to marine mammals at the PIDP site. Once this analysis is complete, a mitigation and monitoring plan would be prepared in coordination with the NMFS to address potential construction-related impacts to harbor seals. Actions to avoid harassment of marine mammals would be implemented during construction.

4.15.14 Other Natural Communities

Context

The regulatory context for assessment of cumulative impacts to terrestrial natural communities is the California Department of Fish and Game’s listing of Natural Communities of Special Concern.

Coast live oak woodlands exist along the coastline from Sonoma County to Baja California. Development has resulted in losses of oak woodlands. Apparent problems with regeneration of the species and infectious disease have raised concern for the health of oak woodlands. Oak woodlands are also subject to urbanization, changes in logging practices resulting in increased oak removal to accelerate conifer growth, the expanding wine industry, and livestock grazing.

Past trends since settlement by Europeans have been conversion of oak woodlands, including coast live oak woodlands, to range land. This trend is best documented in inland oak woodlands; from 1945 to 1973, over a million acres of land were cleared to provide rangeland. A general change in the perception of the value of oak woodlands emerged in the 1970s and 1980s. Aesthetic considerations and increased awareness of the habitat value of the woodlands led to consideration of their protection and enhancement. Subsequent actions have included local and county tree preservation ordinances to address continuing loss of woodlands due to commercial and residential development, logging, and viticulture.

The geographic context for the other natural communities analysis is YBI. Woodlands on YBI are the only coast live oak woodlands within the project limits. Other projects that may contribute to cumulative impacts to coast live oak woodlands in the project limits are the 1996 Draft Reuse Plan and the City of San Francisco Fire Department’s fuel load reduction project. The Oakland Touchdown area is not included in the geographic context because it is man-made.

Impacts Analysis

The Retrofit Existing Structure Alternative would not impact coast live oak woodlands. The replacement alternatives would impact coast live oak woodlands by removal of trees due to the realignment of Macalla Road. The trees on YBI would be replaced in-kind and woodland areas would be delineated as environmentally sensitive areas (ESAs) where possible. The master planting plan for YBI would include mitigation and monitoring for the coast live oak woodland impacted by the replacement alternatives.

Other projects on YBI are the 1996 Draft Reuse Plan and the San Francisco Fire Department fuel management program. No plans or schedules are in place to determine if woodlands would be impacted by these activities. Because there is limited information available concerning future uses that may affect coast live oak woodlands, cumulative impacts to the trees cannot be determined. However, mapping of coast live oak woodlands is available to ensure that redevelopment and forest management plans take into account the presence of the woodland, thereby minimizing the potential for cumulative impacts.

4.15.15 Historic Resources: Historic Bridges

Context

The regulatory context for cumulative impacts to cultural resources is the National Historic Preservation Act (NHPA) (see Section 3.10.1 — Historic and Cultural Resources, Regulatory Context). Cultural resources include historic bridges, historic buildings, and archaeological sites. The NHPA establishes the National Register of Historic Places (National Register), which is the nation’s list of historic properties significant in American history, architecture, engineering, and archaeology. Section 106 review requires that federal agencies consider project impacts on historic properties listed on or eligible for listing on the National Register. Properties are determined eligible for listing or listed on the National Register at the national, state, and/or local levels of significance.

The geographic context includes major crossings of San Francisco Bay. Existing major crossings of San Francisco Bay are the large engineering structures that are components of the Bay Area transportation network. These major Bay crossings are the Antioch Bridge; the Southern Pacific (Union Pacific) railroad bridge at the eastern end of the Carquinez Strait, located adjacent to the Benicia-Martinez Bridge; the Benicia-Martinez Bridge; the eastbound and westbound Carquinez Bridges between Crockett and Vallejo; the Golden Gate Bridge; the Richmond-San Rafael Bridge; the San Francisco-Oakland Bay Bridge; the San Mateo-Hayward Bridge; and the Dumbarton Bridge. Of these major crossings, four have been determined eligible or are listed on the National Register. They are the Southern Pacific railroad bridge (Carquinez), the westbound Carquinez Bridge, the Golden Gate Bridge including the Marina and Presidio viaducts, and the San Francisco-Oakland Bay Bridge. These Bay crossings are listed, in the process of being listed, or determined eligible for the National Register at the national level of significance (except for the Carquinez Bridge which was determined eligible at the state level) based on engineering and transportation attributes. Retrofitting and replacement projects are underway or have been completed for these historic structures, except for the Southern Pacific railroad bridge. The retrofits may result in changes to their historic characteristics. Future status of these historic properties is not a factor in determining listing or eligibility for the National Register.

Among these historic San Francisco Bay crossings, the vehicular bridges are being retrofitted or replaced to meet current seismic safety standards. The trends for historic vehicular bridges are either changes to their historic characteristics due to retrofitting or their loss due to their replacement; both retrofitting and replacements provide seismic safety. See Table 4.14-3 below for a list of projects on historic vehicular bridges and see Section 4.15.4 — Transportation for a discussion of other SFOBB projects). Neither major seismic retrofit nor replacement of the Southern Pacific railroad bridge has been proposed. Proposed actions are summarized in Table 4.15-3.

Table 4.15-3 Historic Vehicular Bridges Crossing San Francisco Bay

Structure

Seismic Strategy

Westbound Carquinez Bridge

Removal of historic bridge following construction of replacement bridge

Golden Gate Bridge

Retrofit of main span would have minor impacts to its historic characteristics. Retrofit of the Presidio and Marina viaducts have changed their historic characteristics.

SFOBB West Approach (5th Street to the San Francisco Anchorage at Rincon Hill)

Removal of the historic bridge and construction of a replacement bridge

SFOBB West Span

Retrofit of existing bridge would change its historic characteristics.

SFOBB East Span

Removal of historic bridge following construction of replacement bridge

Source: Caltrans, February 2001.

Impacts Analysis

A cumulative impact to historic San Francisco Bay crossings would result from their replacement or retrofit. Memoranda of Agreement (MOA) pursuant to NHPA for the SFOBB, Carquinez Bridge, and viaducts and main span of the Golden Gate Bridge stipulate measures to document the historic features of the bridges. This documentation would be implemented partially through a museum exhibit, which would describe the historic context in which they were constructed and operated, and their influences on patterns of history and transportation in the San Francisco Bay Area. Because there are no plans to replace or retrofit the Southern Pacific railroad bridge, it would not contribute to cumulative impacts.

4.15.16 Historic Resources: Historic Buildings

Context

The regulatory context for cumulative impacts to historic buildings is the National Historic Preservation Act (see Section 3.10.1 — Historic and Cultural Resources, Regulatory Context).

The geographic context for historic buildings is comprised of the historic buildings on military bases surrounding San Francisco Bay that have been or are being closed under the Base Realignment and Closure (BRAC) process. The geographic context best represents the types of historic buildings that could be affected by the East Span Project. Naval Station Treasure Island (NSTI) is within the East Span Project limits. Historic buildings at the former NSTI on YBI within the East Span Project limits are the structures in the Senior Officers’ Quarters Historic District, Building 10 and the associated garage, Building 267, and Building 262. Historic buildings within the former Oakland Army Base are located outside of the East Span Project limits. The Key Pier Substation, a historic transportation building located within the East Span Project limits, would be affected by the replacement alternatives. (See Section 3.10.3 — Historic and Cultural Resources, Historic Architectural Resources for a description of buildings within the East Span Project limits.)

NEPA environmental reviews have been conducted for BRAC actions at Bay Area military bases. There is a general trend of preservation of historic buildings at the closed bases. Available information on BRAC actions affecting historic buildings is summarized in Table 4.15-4.

Although some historic buildings are being removed as a result of BRAC closures, the general trend is toward preservation of historic buildings at former military bases in the San Francisco Bay Area. The East Span Project alternatives would be consistent with this general trend because the project would not remove historic buildings at former military bases in the San Francisco Bay Area.

The geographic context for historic transportation buildings is the historic buildings in the San Francisco Bay Area. This includes historic structures such as the San Francisco Embarcadero (Ferry Building), railroad depots along the San Francisco peninsula and in the East Bay, and the remaining structures associated with the Key System railroad. The trend for historic transportation buildings is their preservation. Historic railroad depots on the San Francisco peninsula and along the Northwestern Pacific Railroad in Marin and Sonoma Counties have been rehabilitated for transportation use or are being preserved.

Table 4.15-4 Trends in BRAC Closure Impacts to Historic Buildings

Military Installation

Impacts to Historic Buildings

Alameda Naval Air Station

Information not available

Hamilton Army Airfield

Eight buildings within the historic district are likely to be removed.

Hunters Point Naval Ship Yard

No historic buildings expected to be removed. MOA prepared to ensure preservation of buildings in the Commercial Dry Dock Historic District

Mare Island Naval Ship Yard

No historic buildings expected to be removed. MOA prepared to promote preservation of historic buildings.

Naval Air Station Moffett Field

De-established as a military facility and currently managed by NASA. No impacts to historic buildings.

Naval Station Treasure Island

National Register listed and eligible buildings are located on north TI and YBI. An MOA is being developed concerning future treatment of historic buildings. It is anticipated that no historic buildings would be removed.

Former Oakland Army Base

The Northwest and Northeast Historic Districts have been determined eligible for the National Register. Buildings within the historic districts would be removed.

Oakland Fleet Industrial Supply Center

Historic buildings would be removed from the Naval Supply Center, Oakland Historic District, and North Training Wall. MOA developed to record representative sample of structures to be removed.

Point Molate Naval Supply Center

National Register eligible historic resources existing within the base. They are being incorporated into the reuse plan and would be preserved.

Presidio of San Francisco

Restoration and adaptive reuse program for historic buildings is being implemented.

Impacts Analysis

Permanent Impacts. The cumulative impacts analysis for historic buildings considers the impacts of East Span Project build alternatives combined with other actions that may result in removal of historic buildings at closed military bases surrounding the San Francisco Bay or historic transportation buildings in the Bay Area. No historic military or transportation buildings would be removed by the project.

The East Span Project build alternatives would not contribute to a cumulative impact to historic military and transportation buildings because none would be modified or removed as a result of any of the build alternatives.

Construction-Period Impacts. Construction-period cumulative impacts to historic buildings at the BRAC bases considered in the impacts analysis (Naval Station Treasure Island and Oakland Army Base) could occur if construction activities at these locations occur simultaneously. Based on information in the 1996 Draft Reuse Plan, redevelopment work that would affect historic buildings on YBI would not be underway during East Span Project construction (See Section 4.1.5 — Community Impacts, Development Trends).

A construction schedule for the Oakland Army Base reuse plan is not available to use as the basis for evaluating construction-period cumulative impacts. Because the construction zones for the projects are not contiguous, there is no possibility of combined construction-period impacts.

4.15.17 Cultural Resources: Archaeological Resources

Context

The regulatory context for archaeological resources is the NHPA (see Section 3.10.1 — Historic and Cultural Resources, Regulatory Context). Besides the NHPA, the federal Native American Grave Protection and Repatriation Act and California Public Resources Code Sections 5097.98 and 5097.99 concern Native American remains.

The geographic context for the analysis is the perimeter of San Francisco Bay. The perimeter of the Bay was identified as the appropriate geographic context since it is where very large shellmounds, an important type of archaeological site, are located. This site type is not typically found elsewhere in California. In 1909, Nels Nelson of the University of California recorded 425 shellmounds around the margins of the Bay. Of these 425 shellmounds, approximately five are still visible and considered to be fairly intact. In terms of past trends approximately 400 of the shellmounds originally recorded by Nelson have been disturbed, most by leveling for development. At several of these sites, portions of largely intact archaeological deposits are known to remain below contemporary ground levels. It is possible that intact deposits remain below ground in many other locations, but quantifying the number of partially intact shellmounds that remain along the perimeter of the Bay is difficult: many have been covered by development. Identifying remaining deposits usually occurs during construction activities unless pre-construction archaeological investigations take place.

One shellmound, CA-SFr-04/H, has been recorded within the Area of Potential Effect for the East Span Project. The prehistoric component of the site is a contributing element to the site’s potential National Register eligibility (see Section 3.10.2 — Historic and Cultural Resources, Archaeological Resources). The portion of CA-SFr-04/H visible at the time of Nelson’s 1909 survey has been removed, but the field program conducted in connection with the East Span Project established that it still has intact subsurface deposits.

Impacts Analysis

As discussed in Section 4.10.2 — Cultural Resources, Impacts to Archaeological Resources, the Retrofit Existing Structure Alternative and Replacement Alternatives N-6 (Preferred) and S-4, including the temporary detours for the replacement alternatives, could affect the prehistoric midden component of site CA-SFr-04/H. Replacement Alternative N-2 would avoid the site.

The removal of a portion of CA-SFr-04/H as a result of the East Span Project has an incremental impact on the preservation of shellmounds on the fringes of the Bay. It is unknown how many other shellmounds with subsurface, intact deposits still exist around the Bay or how many of these could be affected by construction in the reasonably foreseeable future. However, certain recent and reasonably foreseeable projects which could or have already affected shellmounds include the development of an office complex in Emeryville, potential construction of a parking lot in Berkeley, and a planned residential development in South San Francisco. These projects, combined with the East Span Project, would have a cumulative impact.

FHWA, USCG, SHPO, and ACHP have entered into an MOA with Caltrans as a concurring party, committing Caltrans to prepare a treatment plan for pre-construction archaeological data recovery in order to mitigate impacts to CA-SFr-04/H. The development of the treatment plan would involve all parties to the MOA as well as interested Native Americans.

Other projects along the Bay’s shores could potentially affect archaeological resources. Such projects are subject to state and/or federal regulatory review under NEPA, NHPA, and/or CEQA. These reviews result in mitigation measures that would minimize any cumulative impacts to archaeological resources and ensure that data from such resources is documented and preserved.

4.15.18 Energy

Context

The regulatory context for the energy analysis is the NEPA mandate to include discussion of energy requirements and conservation measures in NEPA environmental documents (40 CFR 1502.16 (e)). A long-term energy impact assessment is not necessary for the project and thus a cumulative impacts determination is not required. This is because the regulatory context for the energy analysis requires a comparison among project alternatives of the barrels of oil consumed from long-term use of the facility and the East Span Project alternatives do not add traffic capacity compared to the No-Build Alternative. Therefore, long-term energy use is equal among all the project alternatives. There is the potential for the replacement alternatives, which include inside and outside shoulders, to improve traffic operations by reducing the traffic congestion impacts of accidents and breakdowns. The energy consumption benefits of the improved traffic operations of the replacement alternatives is minimal in comparison to the long-term energy consumption of vehicles using the bridge. It is not possible to measure this slight potential energy reduction due to improved traffic operations of adding shoulders because of the lack of predictability of accidents and breakdowns.

The energy analysis for the East Span Project compares the necessary energy to construct the build alternatives (see Section 4.13 — Energy) consistent with NEPA guidance. The geographic context for the construction-period energy analysis is the United States. The other actions that could contribute to cumulative expenditure of energy during the East Span Project construction period are energy-consuming activities in the United States that would occur during East Span Project construction.

Trends for energy use are improvements to energy efficiency of construction equipment to reduce construction energy demands.

Impacts Analysis

Construction-Period Energy Consumption Impacts. East Span Project build alternatives would consume 3.5 to 6.5 million barrels of oil over the multi-year construction period (see Section 4.13.2 — Energy, Impacts for energy consumption of the build alternatives). This amount is negligible compared to available statistics indicating that U.S. consumption in the late 1990s was approximately 18 million barrels of oil per day. In the context of the U.S. energy market, East Span Project build alternatives have a minimal contribution to cumulative energy consumption measured in barrels of oil per day.

4.15.19 Dredging

Context

The regulatory context for the dredging cumulative impacts analysis is the Long-Term Management Strategy for the Placement of Dredged Materials in the San Francisco Bay Region (LTMS). The LTMS sets policies and addresses the cumulative impacts on in-Bay dredged material disposal. A NEPA environmental impact statement/CEQA programmatic environmental impact report for the LTMS was completed in 1999. This strategy document was cooperatively developed by the EPA, ACOE, State Water Quality Control Board, RWQCB, and BCDC. These agencies have also established an interagency Dredged Material Management office (DMMO) that is responsible for coordinating review of dredging activities and disposal of dredged materials from all projects in San Francisco Bay. Past trends have been in-Bay disposal of dredged materials, for example near Alcatraz Island. This disposal has adversely affected water quality, clarity, and aquatic species. Foreseeable trends, due to implementation of the LTMS, are a decrease in in-Bay disposal of dredge materials.

The geographic context for the cumulative impacts analysis is the San Francisco Bay region, consistent with the LTMS. Large-scale dredging for navigation purposes and to maintain berthing areas has occurred in the Bay for over 100 years. At present, an average of four million cubic meters (six million cubic yards) of sediments must be dredged each year to maintain safe navigation in San Francisco Bay.

The LTMS environmental document takes a regional approach to the impacts of dredging such as loss and degradation of water quality due to increased turbidity. (See Section 4.15.10 — Water Quality for a discussion of the types of cumulative impacts that can result from in-Bay work.)

Impacts Analysis

All East Span Project build alternatives would require the disposal of dredged material as a component of the construction scenario. Estimated volumes of dredging material and a discussion of dredging activities and impacts are provided in Section 4.14.10 —Construction Excavation and Dredging.

Projects that will generate dredged materials are considered in LTMS estimates. The LTMS annual Low-, Mid-, and High-Range in-Bay dredged material volume estimates for San Francisco Bay (1995-2045) are 2,653,005; 3,486,370; and 4,533,810 cubic meters/year respectively (3,740,000, 4,560,000 and 5,930,000 cubic yards/year). These numbers are estimates of dredged material quantities and do not constitute allowable limits for in-Bay disposal. Conservatively, the Retrofit Existing Structure Alternative would constitute approximately 2.5 percent of the annual LTMS estimates (percentages calculated using annual project dredging volumes as a percentage of Low-Range dredged material volume estimates). All Replacement Alternatives would constitute approximately 16 percent of the annual LTMS volumes.

The LTMS Programmatic EIS/EIR reported the potential cumulative impacts of LTMS action alternatives. Action alternatives included combinations of in-Bay, deep ocean, and upland/wetland reuse strategies for disposal of dredged material. The LTMS cumulative impacts analysis reported potential for increases in air emissions from tugboats and truck trips, increases in volumes of waterborne transportation, changes in land use, and habitat conversion/modification related to upland/wetland reuse. Cumulative benefits of habitat restoration and reduced in-Bay disposal were also identified.

Reuse/disposal options for the dredged materials from the build alternatives are outlined in the East Span Project’s Dredged Material Management Plan (DMMP) (see Appendix M). Beneficial reuse/disposal scenarios are proposed for the replacement alternatives, to the extent that upland/wetland reuse sites are available to accept dredged materials consistent with construction schedules and costs. This approach would be consistent with LTMS policies. Reuse/disposal options for the East Span Project are consistent with the trend for reducing the volume of in-Bay disposal of disposal of dredged material.

Based on consultation with DMMO member agencies during preparation of the DMMP, reuse/disposal options are available to receive East Span Project dredged materials that have been determined to be suitable for unconfined aquatic disposal. Placement of East Span Project dredged materials at locations (upland, ocean, or in-Bay) available to receive materials would be consistent with LTMS goals to limit in-Bay placement of dredged materials and would contribute to a beneficial cumulative impact of reducing in-Bay dredged material disposal.

4.16 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT OF RESOURCES

The No-Build Alternative would not directly involve the use of resources. The build alternatives would involve the commitment of a range of natural, physical, human, and fiscal resources.

The Retrofit Existing Structure Alternative would require approximately 9.3 square meters (100 square feet) of the Senior Officers’ Quarters Historic District in order to expand the footing of Column YB2. The replacement alternatives would require right-of-way on both Yerba Buena Island and the Oakland Touchdown. The land used for the proposed project is considered an irreversible commitment during the time period that the land is used for a transportation facility. It should be noted that land in the vicinity of the existing bridge would become available once the bridge is dismantled.

All of the replacement alternatives would affect habitat areas, special aquatic sites, and vegetation to some extent. Mitigation measures would be implemented, but creation/restoration sites may not be in the project area.

Considerable amounts of fossil fuels, labor, and construction materials (such as cement, aggregate, steel) would be expended. It is estimated that 3.5 million barrels of oil would be used during construction of the Retrofit Existing Structure Alternative and over 6 million barrels of oil for the replacement alternatives. It is forecasted that average annual employment during construction would be 360 people for the Retrofit Existing Structure Alternative and 600 people for the replacement alternatives. Workers are expected to be drawn from the regional labor pool, with specialty trades generating demand from outside the Bay Area.

Additionally, large amounts of labor and natural resources are used in the fabrication and preparation of construction materials. These materials are generally not retrievable. However, they are not in short supply, and their use would not have an adverse effect upon continued availability of these resources.

The build alternatives would require a substantial expenditure of funds, which would not be retrievable. It is expected that the Retrofit Existing Structure Alternative would cost approximately $0.9 billion and the replacement alternatives would have a cost range of $1.5 to $1.65 billion, depending on final design.

The commitment of these resources is based on the concept that the Bay Area region would benefit from a seismically upgraded vehicular crossing. The benefits of a lifeline vehicular connection outweigh the commitment of these resources.

4.17 RELATIONSHIP BETWEEN LOCAL SHORT-TERM USES OF THE ENVIRONMENT AND THE MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUCTIVITY

As described in Section 4.14, the East Span Project would result in temporary construction-related increases in noise, traffic congestion and delays, and air pollutants and would involve impacts to Waters of the U.S. and special aquatic sites (wetlands, sand flats, and eelgrass beds). In addition, the dismantling of the existing East Span represents the loss of a historic structure. The build alternatives may also impact land use patterns on YBI.

These and other short-term environmental impacts (i.e., "uses" of the environment) identified in Section 4.14 would be balanced by achieving improved seismic and traffic safety and the related project needs identified in Chapter 1. Maintaining a lifeline connection for emergency response, commerce, and the movement of goods and people would enhance long-term productivity in the event of an MCE.