5.6 UTILITIES AND ENERGY

5.6.1 Introduction

The following section describes the impacts and mitigation measures for major subsurface and above-ground utilities.  Conceptual plan drawings showing the location of the proposed facilities for the Central Subway Alternatives were used to identify impacts on existing utilities listed in Section 4.6.    In addition, energy considerations for Central Subway Alternatives are summarized below.

A Project is considered to have an adverse impact on utilities if it would conflict with waste water treatment requirements of the Bay Area Regional Water Quality Control Board (BARWQCB) or require construction of new storm water drainage facilities or if there were not sufficient water, wastewater treatment, or landfill facilities available to serve the Project needs.  Energy impacts would occur if the Project would encourage activities that result in large amounts of fuel, water, or energy or use of these resources in a wasteful manner.

The traction power substations for the Central Subway would be located underground in the Moscone and Chinatown Stations and would not be visible to the general public.  The design of these facilities would be integrated into the non-public areas of the stations.

5.6.2 IMPACTS TO Major Utilities

Alternative 1 - No Project/TSM

The No Project/TSM Alternative would not require modifications to utility lines in the Central Subway Corridor.  No utility impacts would occur.

Alternative 2 - Enhanced EIS/EIR Alignment

Operation Impacts

No operation impacts have been identified in association with the siting of the traction power substations.

Cumulative Impacts

No cumulative impacts have been identified.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Central Subway Fourth/Stockton Alignment Option A (LPA)

Operation Impacts

No operation impacts have been identified.

Cumulative Impacts

No cumulative impacts have been identified.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Central Subway Fourth/Stockton Alignment Option B (Modified LPA)

Construction Impacts

Operation Impacts

No operation impacts have been identified.

Cumulative Impacts

No cumulative impacts have been identified.

Mitigation Measures

No mitigation measures would be required.

5.6.3 energy impacts

The estimated energy consumption under each Alternative is summarized in Table 5-2.  The formula used to calculate energy is stipulated by FTA.  Since the formula does not consider articulated buses or light rail vehicles, the British Thermal Units (BTUs) represented in the table are approximate.

Alternative 1 – No Project/TSM

The No Project/TSM Alternative would result in increased diesel fuel and electric power consumption when compared to the current conditions as a result of growth in travel demand.  Without the rail investment proposed in the Build Alternatives, more auto trips would occur resulting in higher energy consumption.

TABLE 5-2

ESTIMATED CHANGE IN 2030 REGIONAL ENERGY CONSUMPTION BETWEEN THE NO PROJECT/TSM ALTERNATIVE AND THE CENTRAL SUBWAY ALTERNATIVES

Note:       Based on Vehicle Miles Traveled multiplied by an energy consumption factor for each technology/fuel type, and compared to the No Project/TSM Alternative.  In accordance with FTA guidance, the No Project/TSM Alternative serves as the baseline for calculations.

Source:    VMT – San Francisco Model, March 2007; Energy consumption factors - Oak Ridge National Laboratory, Transportation Energy Book:  Edition 16, 1996.

Alternative 2 – Enhanced EIS/EIR Alignment

Operation Impacts

Implementation of the Enhanced EIS/EIR Alignment would require electric power to operate the light rail line.  Muni’s traction power distribution system would be expanded as a part of the construction of the  Project for this purpose.  The electrical energy for the Enhanced EIS/EIR Alignment would be generated at the City’s Hetch Hetchy hydroelectric (clean-burning fuel) facility. Table 5-3 indicates that the Enhanced EIS/EIR Alignment would consume 16 million fewer total BTUs per year of energy than the No Project/TSM Alternative.

Additionally, the Enhanced EIS/EIR Alignment would reduce the consumption of fossil fuel for autos and diesel buses when compared to the No Project/TSM Alternative.

No additional Hetch Hetchy generating or transmission capacity would be necessary to accommodate the Enhanced EIS/EIR Alternative.  The Enhanced EIS/EIR Alignment would not result in energy impacts.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option A (LPA)

Operation Impacts

As with the Alternative 2, implementation of the Fourth/Stockton Alignment Option A would require expansion of Muni’s traction power distribution system.  Table 5‑3 indicates that the Fourth/Stockton Alignment Option A would consume slightly more, 243 million total BTUs per year of energy, than the No Project/TSM Alternative.  The Fourth/Stockton Alignment Option A would reduce the consumption of fossil fuel for autos and diesel buses when compared to the No Project/TSM Alternative, but not to the same extent as under Alternatives 2 or 3B.  Under this alternative, the increase in energy consumption associated with the increased operation of light rail vehicles would not be offset by the reduction in passenger vehicle use, as this alternative has the lowest transit ridership.

Though some additional BTU’s would be consumed by Alternative 3A, no additional Hetch Hetchy generating or transmission capacity would be necessary to accommodate for this small amount.  Fuel consumption by power construction equipment also could be accommodated with existing energy resources.  Therefore, the Fourth/Stockton Alignment Option A would not result in significant energy impacts to meet power demands.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option B (Modified LPA)

Operation Impacts

As with Alternative 2 and 3A, implementation of the Fourth/Stockton Alignment Option B would require expansion of Muni’s traction power distribution system.  Table 5‑3 indicates that the Central Subway Fourth/Stockton Alignment Option B would consume 1,049 million fewer total BTUs per year of energy than the No Project/TSM Alternative.  Additionally, the Central Subway Fourth/Stockton Alignment Option B would reduce the consumption of fossil fuel for autos and diesel buses, as this alternative would generate the highest ridership on the new rail line (more than 10,000 additional riders than either Alternative 2 or 3A).

No additional Hetch Hetchy generating or transmission capacity would be necessary.  Fuel consumption by power construction equipment also could be accommodated with existing energy resources.  Therefore, the Central Subway Fourth/Stockton Alignment Option B would not result in significant energy impacts to meet power demands.

Mitigation Measures

No mitigation measures would be required.

5.7 GEOLOGY AND SEISMICITY

5.7.1 Introduction

Implementation of the Central Subway would be considered to have an adverse effect relating to geology, soils, and seismicity if it would:  expose people or structures to major geological hazards, create or exacerbate geologic instability, or result in substantial soil erosion, loss of topsoil, or substantially change a unique geologic or physical feature.

5.7.2 exposure of CONSTRUCTION WORKERS AND/OR THE PUBLIC to geologic hazards AND potential DAMAGE TO PROJECT COMPONENTS

Alternative 1 - No Project/TSM

The No Project/TSM Alternative would not be expected to result in adverse effects on geology or soils, and would not result in increased hazards associated with seismic activity.  The No Project/TSM Alternative does not include new construction, and therefore would not expose new structures, or the users of new structures, to geologic hazards or soil erosion. 

Alternative 2 - Enhanced EIS/EIR Alignment

Operation Impacts

The alignment does not cross any known active faults, and therefore rupture of tunnels resulting from displacement along a fault is not likely to occur.  The tunnels would be subjected to “extremely high” levels of groundshaking.  However, the tunnels would be designed to withstand effects from the design earthquake on the San Andreas Fault (Magnitude ~7).  No identifiable damage to the BART/Muni Metro subway was caused by the Loma Prieta earthquake in 1989.[5]  The Enhanced EIS/EIR Alignment would be designed and built to current seismic standards to withstand the design earthquake, which would reduce potential Project impacts.

Cumulative Impacts

Other Projects (e.g., public transportation, commercial, and residential Projects) would also be constructed and operated in this seismically active region.  While the population of San Francisco and the region is projected to grow in the future and therefore additional people would be potentially exposed to hazards during a major seismic event, the Project would be built to current seismic standards to minimize the potential safety impact on the general population.  Therefore implementation of the Enhanced EIS/EIR Alignment would not result in a cumulative impact.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option A (LPA) and Option B (Modified LPA)

Operation Impacts

Operation impacts would be the same as described above for Alternative 2.

Cumulative Impacts

Cumulative impacts would be the same as described above for Alternative 2.

Mitigation Measures

No mitigation measures would be required.

5.7.3 DAMAGE TO EXISTING AND FUTURE IMPROVEMENTS FROM SETTLEMENT OR INSTABILITY OF SUBSURFACE MATERIALS

Alternative 1 - No Project/TSM

The No Project/TSM Alternative would not be expected to result in substantial impacts to geology, soils, and seismicity.  The No Project/TSM Alternative does not include new construction, and therefore would not expose new structures, or the users of new structures, to geologic hazards. 

Alternative 2 - Enhanced EIS/EIR Alignment

Operation Impacts

Portions of this alignment (Third and Fourth Streets between King and Brannan Streets) would consist of light rail track placed on existing road surfaces, and therefore would not be expected to result in significant settlement related to instability of geologic materials.  The remainder of this alignment would consist of subway tunnels under existing City streets.  Based on geologic profile as shown on Figure 5-14, the subway tunnels would be constructed in geologic materials consisting of artificial fill, dune sand, Bay Mud, and Alluvium.  Operational effects on the stability of geologic materials around the tunnels would not be expected since the reinforced tunnel lining would be placed against the exposed material upon excavation, limiting the expansion or contraction potential of the sediments. 

Figure 5-14

geologic profile for alternative 2

Source:  Geomatrix

Not to Scale

Cumulative Impacts

Settlement and geologic instability of subsurface materials is a site-specific condition that would not result in cumulative impacts.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option A (LPA)

Operation Impacts

A portion of this alignment (Fourth Street between King and Townsend Streets) would consist of light rail track placed on existing road surface, and therefore would not be expected to result in significant settlement related to instability of geologic materials.  The remainder of this alignment would consist of subway tunnels under existing city streets.  Based on the geologic profile shown in Figure 5-15, the subway tunnels would be constructed in geologic materials consisting of artificial fill, dune sand, Bay Mud, dense Colma Sand, and Bedrock.  Operational effects on the stability of geologic materials around the tunnels would not be expected since the reinforced tunnel lining would be placed against the exposed material upon excavation, limiting the expansion or contraction potential of the sediments. 

Cumulative Impacts

Settlement and geologic instability of subsurface materials is a site-specific condition that would not result in cumulative impacts.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option B (Modified LPA)

Operation Impacts

A portion of this alignment (Fourth Street between King and Bryant Streets) would consist of light rail track placed on existing road surface, and therefore would not be expected to result in significant settlement related to instability of geologic materials.  The remainder of this alignment would consist of subway tunnels under existing City streets.  Based on data obtained from soil borings along the alignment, the subway tunnels would be constructed in geologic materials consisting of artificial fill, dune sand, Bay Mud, and Alluvium (see Figure 5-16).  Operational effects on the stability of geologic materials

Figure 5-15

Geologic Profile for Fourth/Stockton Alternative Option A

Source:  Geomatrix

Not to Scale

FIGURE 5-16

Geologic Profile for Fourth/Stockton Alternative Option B

Source:  Geomatrix

Not to Scale

around the tunnels would not be expected since the reinforced tunnel lining would be placed against the exposed material upon excavation, limiting the expansion or contraction potential of the sediments. 

Cumulative Impacts

Settlement and geologic instability of subsurface materials are site-specific conditions that would not result in cumulative impacts.

Mitigation Measures

No mitigation measures would be required.

5.8 HYDROLOGY AND WATER QUALITY

5.8.1 INTroduction

Implementation of the Project would be considered to have an effect on hydrology or water quality if it would: violate any water quality standards or waste discharge requirements; expose people or structures to substantial new or increased flooding; result in the substantial degradation of surface or groundwater quality; substantially interfere with groundwater recharge; deplete groundwater supplies; substantially alter the existing drainage pattern of the site or area; or create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems.

5.8.2 FLOODING

Alternative 1 - No Project/TSM

Implementation of the No Project/TSM Alternative would not be expected to result in adverse flooding effects.  This alternative does not include facilities in flood-prone areas and, therefore, would not expose people or structures to new flooding hazards.

Alternative 2 - Enhanced EIS/EIR Alignment

Operation Impacts

The alignment for the Enhanced EIS/EIR Alignment is at elevations above 100-year tides or tsunami events.  Implementation of this alternative would not result in flooding impacts.

Cumulative Impacts

The Enhanced EIS/EIR Alignment is outside the 100-year high tide or tsunami impact area and therefore would not contribute to cumulative impacts.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option A (LPA)

Operation and Cumulative Impacts

Operation and Cumulative impacts would be the same as described for Alternative 2 above.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option B (Modified LPA)

Operation and Cumulative Impacts

Operation and Cumulative impacts would be the same as described for Alternative 2 above.

Mitigation Measures

No mitigation measures would be required.

5.8.3 water quality

Alternative 1 - No Project/TSM

Implementation of the No Project/TSM Alternative would not be expected to result in adverse effects from increases in storm water runoff. 

Alternative 2 - Enhanced EIS/EIR Alignment

Operation Impacts

Operation of the Enhanced EIS/EIR Alignment would result in the potential discharge of contaminants to the environment that could be transported by runoff to the City’s combined storm and sanitary sewer system.  The primary pollutants associated with operation of a light rail system include heavy metals, solvents, and petroleum hydrocarbons.  Metals enter the environment in several ways, such as through dust or grit produced from metal-on-metal (light rail vehicles on track) wear and spillage of materials containing metals (e.g. lubricants and waste oil).

Drainage conveyance structures already exist along the Enhanced EIS/EIR Alignment.  All storm water runoff from the alignment would be directed toward the City’s combined storm and sanitary sewer system.  The City’s combined storm and sanitary sewer system, which collects and treats storm water, is operated in accordance with existing NPDES permits.  The collection and treatment of storm water by the combined sewer system is an appropriate method of reducing the potential adverse effects of urban runoff on receiving waters.

Based on the high water table conditions and permeable soils, along with inflows of groundwater to the Powell Street Station, measures, such as horizontal wells, to encourage lateral groundwater flow past the Union Square Station will be incorporated into the project design if determined necessary based on hydrologic modeling.

Covering pervious surfaces, such as landscaped areas and exposed soil, with pavement or other impervious cover reduces the infiltration of water to the subsurface and increases surface runoff.  The Enhanced EIS/EIR Alignment would result in the construction of a light rail line with a portion constructed on existing roadway surfaces and the majority of the facility located underground; therefore no net increase in impervious surfaces would be expected.  Construction of the Enhanced EIS/EIR Alignment would not be expected to materially increase storm water runoff volume.

Cumulative Impacts

Increases in pollutant load resulting from construction of the Enhanced EIS/EIR Alignment, in conjunction with increases in pollutant load resulting from other projects, could result in cumulative impacts.  Under existing programs and procedures, the operators of the City’s treatment plants are required to manage inputs to the combined sewer system.  Applications for industrial discharge permits, if required for any of the cumulative projects, would be reviewed by the Public Utilities Commission to confirm that the treatment plants could accommodate the increased load prior to project approval.  Therefore, potential operational cumulative effects associated with storm water runoff would be reduced by existing programs.  However, there is heightened public interest in the issue of cumulative increases in flows to the City’s combined storm and sanitary sewer system, and the resulting potential for increases in the volume and duration of overflow events during wet weather.  Several major projects near the Study Area including the Mission Bay development, residential towers on Rincon Hill, and proposed Transbay Redevelopment Plan could result in increased flows to the City’s combined storm and sanitary sewer system.  Given the required industrial discharge permits for these other proposed projects and  total flows to the system’s Southeast Water Pollution Control Plant, which treats wastewater from the eastern portion of the City, it is expected that any increase in flows resulting from the Enhanced EIS/EIR Alignment would be within City guideline and standards.

In accordance with San Francisco Ordinance 19-92, Sections 118 and 123, a contractor would prepare and implement a SWPPP.  The SWPPP would include Best Management Practices (BMPs) designed to reduce potential adverse effects on surface water quality and off-site sedimentation throughout the construction phase of the Project.  Specific measures shall be included in the SWPPP to ensure that runoff from the construction sites does not drain directly to the Bay.  The SWPPP would include:

· Construction Storm Water Management Controls.  These controls would include practices to minimize the contact of construction materials, equipment, and maintenance supplies (e.g., fuels, lubricants, paints, solvents, adhesives) with storm water.  The SWPPP would specify properly designed centralized storage areas that would keep these materials out of the rain.  Spill cleanup materials (e.g. rags, absorbent materials, and secondary containment) would be kept at the work site when handling chemicals.

An important component of the storm water quality protection effort is knowledge of the SWPPP by the site supervisors and workers.  To educate on-site personnel and maintain awareness of the importance of storm water quality protection, site supervisors would conduct regular tailgate meetings to discuss pollution prevention.  The frequency of the meetings and required personnel attendance list would be specified in the SWPPP.

The SWPPP would specify a monitoring program to be implemented by the construction site supervisor, and would include both dry and wet weather inspections.  City personnel shall conduct regular inspections to ensure compliance with the SWPPP; an accepted standard procedure.

· Erosion and Sediment Control.  BMPs designed to reduce erosion of exposed soil may include, but are not limited to: soil stabilization controls, watering for dust control, perimeter silt fences, placement of straw wattles, and sediment basins.  The potential for erosion is generally increased if grading is performed during the rainy season as disturbed soil can be exposed to rainfall and storm runoff.  If grading must be conducted during the rainy season, the primary BMPs selected shall focus on erosion control, that is, keeping sediment in-place.  End-of-pipe sediment control measures (e.g., basins and traps) shall be used only as secondary measures.  Entry and egress from the construction site shall be carefully controlled to minimize off-site tracking of sediment.  Vehicle and equipment washdown facilities shall be designed to be accessible and functional during both dry and wet conditions.  Additional sources of information regarding BMPs are the California Storm Water Municipal and Construction Activity BMP Handbooks.^[6]

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option A (LPA)

Operation Impacts

Operation impacts would be the same as those described for Alternative 2.  During operation, runoff would be collected from drainage facilities incorporated into the design of the tunnels.  Drainage would be conveyed to the City’s combined storm and sanitary sewer system and storm water facilities.  Design measures to address groundwater flow [begin deletion] to the Powell Street BART/Muni Metro Station [end deletion] would be incorporated into the Union Square/Market Street Station.

Cumulative Impacts

Cumulative impacts would be the same as described above for Alternative 2.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option B (Modified LPA)

Operation Impacts

Operation impacts would be the same as those described for Alternative 2.  During operation, runoff would be collected from drainage facilities incorporated into the design of the tunnels.  Drainage would be conveyed to the City’s combined sewer and storm water facilities.  Design measures to address groundwater flow [begin deletion] to the Powell Street BART/Muni Metro Station [end deletion] would be incorporated into the Union Square/Market Street Station.

Cumulative Impacts

Cumulative impacts would be the same as described above for Alternative 2.

Mitigation Measures

No mitigation measures would be required.

5.8.4 GROUNDWATER RECHARGE

Alternative 1 - No Project/TSM

Implementation of the No Project/TSM Alternative would not interfere with groundwater recharge.

All Build Alternatives

Operation Impacts

Implementation of this alternative would not result in significant impacts to groundwater recharge.

Cumulative Impacts

No substantial amount of water would be recharged into the groundwater therefore this alternative would not contribute to cumulative impacts.

Mitigation Measures

No mitigation measures would be required.

5.9 BIOLOGICAL AND WETLAND RESOURCES

5.9.1 Introduction

Under CEQA implementation of the Project would be considered to have an adverse effect on biological or wetland resources if it would result in disturbance of critical habitat (including wetlands) or affect special-status species.  Removal of landscaping is also considered since trees and shrubbery provide wildlife habitat.  No special status species or wetlands were found in the Study Area.

5.9.2 impacts

Alternative 1 - No Project /TSM

Implementation of the No Project/TSM Alternative would not result in effects to critical habitat, special-status species, or removal of existing landscaping.  Therefore, implementation of this alternative would not result in impacts.

Alternative 2 - Central Subway Enhanced EIS/EIR Alignment

Operation Impacts

Operation of the Enhanced EIS/EIR Alignment would not result in biological or wetland impacts, since no vegetation or wildlife would be affected.

Cumulative Impacts

No impacts to biological and wetland resources have been identified for the Enhanced EIS/EIR Alignment; therefore, there would be no cumulative impact from operation of the light rail.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Central Subway Fourth/Stockton Alignment Option A (LPA) and Option B (Modified LPA)

Operation Impacts

Operation of Fourth/Stockton Alignment Option A would not result in biological or wetland impacts, since no vegetation or wildlife would be affected.

Cumulative Impacts

No impacts to biological and wetland resources have been identified from operation of the Fourth/Stockton Alignment Option A; therefore, there would be no cumulative impact from operation of the light rail.

Mitigation Measures

No mitigation measures would be required.

5.10 HAZARDOUS MATERIALS

5.10.1 Introduction

Implementation of the alternatives would be considered to have an effect on the environment and public health if the transport, use, production or disposal of materials would pose a hazard to people, animal, or plant populations in the area affected or if the Project would emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school or be located on a listed hazardous materials site pursuant to Government Code 659625 or Article 20 of the San Francisco Health code or degradation of water quality based on regulatory threshold and maximum contaminant levels.  Additional detailed information on hazardous materials is included in the background technical file available for review by appointment at the Planning Department, 1650 Mission Street, San Francisco.

5.10.2 Exposure of Site Workers and Public to Hazardous Materials

Alternative 1 - No Project/TSM

The No Project/TSM Alternative would not introduce additional hazardous materials into the Study Area, require new construction, require hazardous materials handling, nor result in increased exposure to the public or to the environment. Therefore, implementation of this alternative would not result in adverse effects associated with hazardous materials.

Alternative 2 – Enhanced EIS/EIR Alignment

Operation Impacts

Operation of the Central Subway Enhanced EIS/EIR Alignment would include the use, handling, and storage of hazardous materials.  Degreasers, lubricants, cleaning solutions, solvents, paints, and miscellaneous petroleum products may be used for maintenance activities.  In addition, maintenance of the light rail utility corridors may expose workers to hazardous materials if future excavation were to extend beyond the limits of excavation during construction.

Site workers exposed to potentially contaminated soils during light rail repair and maintenance and to hazardous materials during the use, handling, or storage of these materials may be adversely affected.  In addition, an accidental release of hazardous materials could occur at the maintenance facility, which could potentially affect the environment (soil, surface water, and groundwater).

State regulations have been established to ensure generally safe workplaces and employee work practices.  The California General Industry Safety Order requires all employers in California to prepare and implement the following plans and programs:

· [begin deletion] Emergency Action Plan [end deletion] .  The Plan designates employee responsibilities, evacuation procedures and routes, alarm systems, and training procedures.

· [begin deletion] Fire Prevention Plan [end deletion] .  The Plan identifies potential hazard areas, persons responsible for maintenance of fire prevention equipment or systems, fire prevention housekeeping procedures, and fire hazard training procedures.

· [begin deletion] Injury and Illness Prevention Program [end deletion] .  The Plan identifies safe practices for each job category, methods for informing workers of hazards, and procedures for correcting identified hazards.

Preparation and implementation of the plans, programs, and requirements identified above as well as those mentioned in Section 5.8, Hydrology and Water Quality would meet City requirements for workers, the public, and the environment.

Cumulative Impacts

The City’s combined storm and sanitary sewer system could potentially be affected if dewatered groundwater from planned or ongoing Projects, in addition to the Enhanced EIS/EIR Alignment, were to discharge into the City’s system.  Excessive discharge could potentially exceed the system’s capacity.

Procurement of a BWWD permit would be required prior to discharging into the combined sewer system; the permit requires identification of total estimated volume and duration of proposed discharge.  Therefore, the City would only allow discharges that would be within the capacity of the system.  If contaminant levels in the groundwater exceeded the BWWD permit levels, treatment of the groundwater could be required prior to discharge.  Therefore, potential cumulative construction effects associated with dewatered groundwater would be avoided with implementation of the existing requirements established by the City.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option A (LPA)

Operation Impacts

Operation impacts would be the same as described above for Alternative 2. 

Cumulative Impacts

Cumulative impacts would be the same as those described above for Alternative 2.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Fourth/Stockton Alignment Option B (Modified LPA)

Operation Impacts

Operation impacts would be the same as described above for Alternative 2. 

Cumulative Impacts

Cumulative impacts would be the same as those described above for Alternative 2.

Mitigation Measures

No mitigation measures would be required.

5.11 AIR QUALITY

5.11.1 INTRODUCTION

Implementation of the alternatives would be considered to have an effect on air quality if construction and/or operational effects would result in: violations of ambient air quality standards, contribution to an existing or Projected air quality violation, or exposure of sensitive receptors to substantial pollutant concentrations.  A Project impact resulting from construction operations would be considered significant if feasible BAAQMD construction control measures listed in the BAAQMD CEQA Guidelines were not incorporated into the design of any of the alternatives. ^[7]

Since publication of the 1998 EIS/EIR, approaches and analysis tools for evaluating air quality have changed.  The changes in methodological approaches are outlined below:

· Construction emissions vary substantially from day-to-day, depending on the level of activity, the specific type of construction operations and the prevailing weather in the case of dust emissions.  The BAAQMD does not recommend quantification of construction emissions.  As a result, attempts were not made in this document to estimate construction emissions.  Rather the discussion is based on feasible control measures that are being incorporated into the Project.

· The current approved motor vehicle emission factor model is EMFAC2002, which is an update to the EMFAC7G model used for the 1998 EIS/EIR.

· Since most of California is in attainment for CO, a Transportation Project-Level Carbon Monoxide Protocol (the Protocol) was developed by Caltrans and the Institute of Transportation Studies at the University of California, Davis (December 1997) to provide procedures for evaluating potential impacts without having to do dispersion modeling.[8]  The Protocol includes three potential tests: a qualitative analysis based on decision flowcharts, a quantitative screening analysis and a dispersion modeling analysis.  The goal of the decision flowcharts is to prescreen Project data to determine if the Project would cause CO violations of standards without actually running the model.  If results from the first test are not conclusive, then the next test is conducted.

5.11.2 SIGNFICANCE thresholds

BAAQMD has developed project operation thresholds of significance for CO, ROG, NO_x, and PM₁₀ (Table 5-3).[9]  Estimated CO, ROG, NO_x, and/or PM₁₀ emissions generated from project operations would be considered significant if any project emissions were to exceed BAAQMD thresholds.^[10]

TABLE 5-3

GENERAL THRESHOLDS of SIGNIFICANCE

FOR PROJECT OPERATIONS

                                                [begin deletion] Notes [end deletion] :     ppm = parts per million.

                                                                lb/day = pounds per day.

                                                                CO = carbon monoxide

                                                                ROG = reactive organic gases

                                                                NOx = nitrogen oxides

                                                                PM₁₀ = particulate matter less than 10 microns in

                                                                diameter (also includes PM_2.5)

Source:    Bay Area Air Quality Management District, CEQA

Guidelines Assessing the Air Quality Impacts of Projects

 and Plans, December 1999.

Projects that result in a modification to the forecasted total vehicle miles traveled (VMT) in a region have the potential of altering mobile source-related regional emissions in that area.  Regional emissions of CO, ROG, NO_x, and PM₁₀ have been estimated for existing conditions in 2006 and for 2030 for all alternatives.    Emission factors for PM_2.5 are not included in current approved emission factor models, so PM_2.5 emissions were not calculated. Particulate matter from fuel-combustion sources is primarily composed of PM_2.5.  Therefore, the PM_2.5 fraction of PM₁₀ emissions is estimated as approximately 99 percent.  Emissions were estimated based on the forecasted VMT, and composite emission factors obtained from the EMFAC2002 (for motor vehicles) and URBEMIS2002 (for re-entrained dust) models developed by CARB.

The 2030 No Project/TSM conditions were compared to existing conditions (2006) to identify any air quality issues that would occur if the proposed Project were not built.  It should be noted that the 2030 No Project/TSM conditions reflect development, growth, and infrastructure improvements that have been accounted for in regional planning documents.

Due to the nature of air quality, it is more appropriate to evaluate Project impacts based on the net difference in future conditions (i.e., how the proposed Project would affect future traffic patterns that already consider regional growth) than to compare to existing conditions.  This type of analysis also allows for changes in vehicle technology and fuels that may occur over the years to be removed from the comparison.  As a result, the No Project/TSM Alternative emission estimates (Table 5-4) serve as the baseline emissions against which to evaluate potential impacts for the other alternatives.  The net differences were then compared to BAAQMD significance thresholds.

TABLE 5-4

ESTIMATED 2030 REGIONAL EMISSIONS

GENERATED FROM VEHICULAR TRAFFIC (pounds per day)

Notes:   ¹    Emissions based on VMT data and emission factors from the EMFAC2002 and URBEMIS2002 models.  VMT data provided by the San Francisco Model, January 2007.

CO = Carbon Monoxide

ROG = Reactive organic gases.

NOx = Nitrogen oxides.

PM₁₀ = Particulate matter less than ten microns in diameter (includes PM_2.5) .

N/A = not applicable

The traffic analysis for the Project, and thus the air quality analysis, concentrated on five intersections (Third/King, Fourth/King, Fourth/Harrison, Sixth/Brannan, and Fourth/Bryant).  These intersections were chosen because they are representative of the key intersections that would be affected by implementation of the Project.  It is recognized that the entire Study Area experiences traffic congestion and that many of the intersections in the area operate at poor Level of Service (LOS).  The five intersections chosen, particularly the Sixth/Brannan, represent the highest traffic volumes and greatest delays in the Study Area.  Table 5-5 summarizes the peak hour traffic volumes and LOS for each intersection on which the air quality analysis is based.

TABLE 5-5

2030 PEAK HOUR TRAFFIC VOLUMES AND LEVEL OF SERVICE FOR STUDY INTERSECTIONS

*Under the Fourth/Stockton Option B Alternative, two sub-options are being considered.  On Fourth Street, the light rail vehicles would operate in one of two lane configurations: semi-exclusive or mixed-flow.  In a semi-exclusive operation, trains are physically separated from adjacent traffic except at intersections.  In a mixed-flow operation, trains and other vehicles share a trackway that is embedded in the street.

5.11.3 AIR POLLUTANT EMISSIONS

Alternative 1 - No Project/TSM

Operation Impacts

Regional Emissions.  Although development in San Francisco Bay Area would result in an increase in VMT in the future compared to 2006 conditions (refer to Table 4-15), CO, ROG and NO_x emissions would be less in 2030.  The emission factor model assumes that between 2006 and 2030 older motor vehicles would be replaced with cleaner vehicles and approved emission reduction programs would be implemented resulting in lower CO, ROG, and NO_x emissions per vehicle.  The lower emissions from new vehicles and the emission reduction programs would have less impact on PM₁₀ emission factors because vehicles emit PM₁₀ not only from exhaust; but also from tire wear, brake wear and re-entrained dust from the motor vehicle traveling over dusty roads.  In contrast, PM₁₀ emissions from vehicles are expected to increase with population growth.

Localized CO Analysis.  There has not been a violation of CO standards in San Francisco since 1988.[11]  This is attributable to more efficient motor vehicle controls and the introduction of cleaner fuels.  Therefore, it is assumed that the Study Area intersections under a No Project/TSM condition in 2030 would not violate CO standards.

Mitigation Measures

No mitigation measures would be required.

Alternative 2 - Enhanced EIS/EIR Alignment

Operation Impacts

Regional Emissions.  Implementation of the Enhanced EIS/EIR Alignment would result in a net reduction of daily VMT of about 1,390, compared to the No Project/TSM Alternative.  The reduction in VMT would consequently reduce regional emissions very slightly, compared to the No Project/TSM Alternative (refer to Table 5-4).  The reduction for most pollutants, with the exception of CO, would be about a pound per day.  CO emissions are reduced by 16 pounds per day.

Localized CO Analysis.  A CO analysis of the alternative was conducted following guidance provided in the Transportation Project-Level Carbon Monoxide Protocol developed to assess the CO impacts from changes in traffic patterns and congestion in the Study Area.[12] 

To determine if the proposed Project is likely to worsen air quality compared to a No Project/TSM for the same analysis year, the following questions must be answered:

· Does the proposed Project substantially increase (greater than two percent) the number of vehicles operating in cold start mode (starting a vehicle with a cold engine)?

· Does the proposed Project substantially increase traffic volumes (i.e., increases greater than five percent)?

· Does the proposed Project worsen traffic flow (i.e., any reduction in average travel speed within a range of 3 to 50 miles per hour for uninterrupted roadways or increase in average delay for intersections)?

The nature of the Project would not result in a substantial increase in cold start vehicles.  The Project would reduce the overall number of motor vehicle trips in the Study Area and therefore would reduce the number of vehicles operating in cold start mode.

Two roadway segments (King Street westbound between Third Street and Fourth Street and Brannan Street eastbound between Fifth Street and Third Street) would have increases in traffic volume greater than five percent.  The Enhanced EIS/EIR Alignment would increase the average delay at some of the intersections selected for analysis.  Because of these two issues, there is the potential for the Enhanced EIS/EIR Alignment to worsen air quality.

The Protocol requires a determination as to whether or not the Project could result in higher CO concentrations than those that currently exist in the Bay Area Air Basin, which is an attainment/maintenance area.  Since the Bay Area Air Basin currently meets ambient CO standards, no transportation facility operating within it creates a CO violation.  The assumption is that if a current intersection in an attainment area were modeled, the results would show concentrations less than ambient standards.  If it is determined that a Project-affected intersection is no worse than an existing intersection, the proposed Project is considered acceptable (i.e., would not violate any CO standard or contribute substantially to any existing or projected CO standard) and no further analysis is needed.

As required by the Protocol, a comparative analysis was conducted for the Study Area intersections that operate at LOS E or F or become E or F due to Project implementation (refer to Table 5-6).  These intersections under the Enhanced EIS/EIR Alignment include Third/King, Fourth/King, and Sixth/Brannan. 

The comparative analysis evaluates receptor locations, roadway geometry, traffic volumes, meteorology, percentage of vehicles in cold start mode, percentage of heavy-duty gas trucks, average delay, and background CO concentrations.

The Foothill Boulevard/Mission Boulevard intersection in Hayward was chosen for comparative purposes.[13]  This intersection is well known for having traffic congestion and high traffic volumes.  The peak hour traffic volume in 2005 was 13,600 vehicles.[14]  The Foothill Boulevard/Mission Boulevard intersection was also chosen because it is similar in climate, CO background levels, and existing peak hour traffic counts were readily available from the Traffic and Vehicle Data Systems Unit portion of Caltrans’ website. 

The Enhanced EIS/EIR Alignment passes the comparative intersection test outlined in the Protocol because the Study Area intersections were found to have lower traffic volumes and better meteorological conditions than the Foothill/Mission intersection.  Receptor locations, roadway geometry, average delay, percent of vehicles in cold start mode, percent of heavy-duty gas trucks, and background CO concentrations are similar.

The Enhanced EIS/EIR Alignment would satisfy transportation conformity requirements.  The proposed Project is included in current conforming regional transportation plans (the Transportation 2030 Plan and the 2005 Transportation Improvement Program).  Completion of the localized CO impact analysis indicates that CO concentrations would not cause or contribute to violations of ambient air standards.  Therefore, the Enhanced EIS/EIR Alignment is found to be in conformance.

Odors.  It is expected that the Enhanced EIS/EIR Alignment would not generate odor emissions.  The BAAQMD has developed a list of the types of facilities known to emit objectionable odors.  This list does not include light rail facilities like the Central Subway. 

Cumulative Impacts

An increase in Project-related short-term construction emissions in addition to emissions from other Projects in the Bay Area may result in cumulative effects to air quality for the Enhanced EIS/EIR Alignment.  However, construction activities are subject to control measures established by BAAQMD to reduce impacts from the Project.

Generally, if operation of a Project results in an increase of a pollutant above a significance threshold, then it would also be considered to contribute substantially to the cumulative effect.  The Enhanced EIS/EIR Alignment does not exceed BAAQMD significance thresholds for criteria pollutants; rather emissions for each pollutant are slightly lower than the No Project/TSM Alternative.

All planned development and growth has been included in the assumptions used to generate the traffic data.  Consequently, cumulative development is implicitly included in the air quality analysis because it made direct use of traffic volume data and assessed air emissions based on cumulative future traffic conditions.  Project emissions of criteria pollutants would not exceed thresholds when compounded with other cumulative emissions. 

Climate Change/Greenhouse Gas Impacts.  An individual Project does not generate enough greenhouse gas emissions to substantially influence global climate change.  Climate change is a cumulative impact.  However, changes to CO₂ emissions from the Project were estimated (Table 5-6).  CO₂ emissions are expected to increase between 2006 and 2030 due to an increase in VMT.  While motor vehicles are expected to be less polluting in the future, the improvement is not enough to offset the projected increase in VMT.  Since more than 80 percent of the total amount of greenhouse gases is CO₂, changes to CO₂ emissions is an indicator of impacts from all greenhouse gases.[15]

table 5-6

estimated carbon dioxide emissions for existing conditons (2006)

and 2030 generated by vehicular traffic (pounds per day)

N/A = not applicable

Implementation of the Enhanced EIS/EIR Alignment would result in relatively small changes in greenhouse gases.  During construction, Alternative 2 would increase greenhouse gases due to emissions generated by construction equipment.  Once the alternative is operational, there would be an overall reduction in greenhouse gases.  This is due to the fact that the reduction in motor vehicle miles traveled caused by the Project results in a bigger reduction in greenhouse gases than the increase in greenhouse gases generated by the electricity used to power the light rail trains.

There are currently no published thresholds of significance for measuring the impact of global climate change from a Project.  However, it can be noted that the Central Subway Project does not conflict with the greenhouse gas reduction strategies listed in Executive Order S-3-05 and the Climate Action Plan for San Francisco.  In accordance with these documents, the Central Subway Project will include measures to reduce idling of diesel-fueled construction equipment and vehicles.  It will also encourage the use of public transit as an alternative to driving by expanding light rail service.  The Project would also be consistent with City policy for Transit-Oriented Development because the Chinatown Station would include space for future housing development above the station.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Central Subway Fourth/Stockton Alignment A (LPA)

Operation Impacts

Regional Emissions.  Implementation of the Fourth/Stockton Alignment Option A would result in a net reduction of daily VMT of about 870, compared to the No Project/TSM Alternative.  The reduction in VMT would consequently reduce regional emissions very slightly, compared to the No Project/TSM Alternative (refer to Table 5-4).  The reduction for most pollutants, with the exception of CO, would be one pound per day or less.  CO emissions are reduced by 10 pounds per day.

Localized CO Analysis.  A CO analysis of the Fourth/Stockton Alignment Option A was conducted following the same methodology as described under Alternative 2.  Seven roadway segments would have increases in traffic volume greater than five percent.  The Fourth/Stockton Alignment Option A would increase the average delay at all of the intersections selected for analysis.  Because of these two issues, there is the potential for the Fourth/Stockton Alignment Option A to worsen air quality.

As required by the Protocol, a comparative analysis was conducted for the Study Area intersections that operate at LOS E or F or become E or F due to Project implementation (refer to Table 5-6).  These intersections under the Fourth/Stockton Alignment Option A include Third/King, Fourth/King, Fourth/Harrison, and Sixth/Brannan. 

The Fourth/Stockton Alignment Option A passes the comparative intersection test outlined in the Protocol because the Study Area intersections were found to have lower traffic volumes and better meteorological conditions than the Foothill/Mission intersection.  Receptor locations, roadway geometry, average delay, percent of vehicles in cold start mode, percent of heavy-duty gas trucks, and background CO concentrations are pretty similar.

Like Alternative 2, the Fourth/Stockton Alignment Option A would satisfy transportation conformity requirements. 

Odors.  As identified under Alternative 2, it is expected that the Fourth/Stockton Alignment Option A would not generate odor emissions.   

Cumulative Impacts

The cumulative impacts including greenhouse gas impacts for the Fourth/Stockton Alignment Option A would be the same as those identified under Alternative 2.

Mitigation Measures

No mitigation measures would be required.

Alternative 3 - Central Subway Fourth/Stockton Alignment B (Modified LPA)

Operation Impacts

Regional Emissions.  Implementation of the Fourth/Stockton Alignment Option B would result in a net reduction of daily VMT of about 1,730, compared to the No Project/TSM Alternative.  The reduction in VMT would consequently reduce regional emissions very slightly, compared to the No Project/TSM Alternative (refer to Table 5-4).  The reduction for most pollutants, with the exception of CO, would be one to two pounds per day.  CO emissions are reduced by 19 pounds per day.

Localized CO Analysis.  A CO analysis of the Fourth/Stockton Alignment Option B was conducted following the same methodology as described under Alternative 2. 

Nine roadway segments would have increases in traffic volume greater than five percent if the Fourth/Stockton Alignment Option B Alternative with a mixed flow lane configuration is chosen.  The number of roadway segments with traffic volume increases of greater than five percent increases to eleven if a semi-exclusive lane configuration is chosen.  The Fourth/Stockton Alignment Option B with either the mixed flow or semi-exclusive lane configuration would increase the average delay at all of the intersections selected for analysis.  Because of these two issues, there is the potential for the Fourth/Stockton Alignment Option B to worsen air quality.

As required by the Protocol, a comparative analysis was conducted for the Study Area intersections that operate at LOS E or F or become E or F due to Project implementation (refer to Table 5-5).  These intersections under the Fourth/Stockton Alignment Option B include Third/King, Fourth/King, Fourth/Harrison, and Sixth/Brannan. 

The Fourth/Stockton Alignment Option B passes the comparative intersection test outlined in the Protocol because the Study Area intersections were found to have lower traffic volumes and better meteorological conditions than the Foothill/Mission intersection.  Receptor locations, roadway geometry, average delay, percent of vehicles in cold start mode, percent of heavy-duty gas trucks, and background CO concentrations are pretty similar.

Like Alternatives 2 and 3A, the Fourth/Stockton Alignment Option B would satisfy transportation conformity requirements. 

Odors.  As identified under the Enhanced EIS/EIR Alignment, it is expected that the Fourth/Stockton Alignment Option B would not generate odor emissions.   

Cumulative Impacts

The cumulative impacts including greenhouse gas effects for the Fourth/Stockton Alignment Option B would be the same as those identified under Alternative 2.

Mitigation Measures

No mitigation measures would be required.

5.12 NOISE AND VIBRATION

5.12.1 INTRODUCTION

The FTA criteria for noise and vibration are described in Section 4.12.  In addition to the FTA criteria, the following noise and vibration criteria used by the San Francisco Planning Department are also applicable.

An adverse impact would occur if the Project would substantially increase the ambient noise levels above levels common and accepted in urban areas resulting in the exposure of people to noise levels in excess of local noise ordinance established standards and affect the use of enjoyment of nearby areas.  A noise increase of 10 db is perceived as a doubling of noise, and is generally considered substantial.  An adverse impact would also occur if the Project were to expose people to existing excessive ambient noise levels in the Project vicinity.

For vibration, an adverse impact would occur if the Project would expose people to excessive and intrusive ground-borne vibration or a ground-borne noise level substantially affecting adjacent land uses.  A vibration level of 75 VdB is generally considered intrusive for residential land uses.

5.12.2 IMPACTS

No Project/TSM Alternative

The principal source of future noise levels under the No Project/TSM Alternative would be increased traffic movements on the local arterials in the Study Area.  In general, a doubling of the traffic activity would be required for the noise levels to increase by 3 dBA; the point at which most listeners detect the change.  Changes in traffic volumes and speeds are also subject to the existing roadway capacities.  Increases in traffic volume would result in reduced speeds along streets with limited capacity.   

Traffic noise modeling was conducted at receivers along Third and Fourth Streets where the proposed LRT would operate at-grade.  As shown in Table 5-7, changes from the existing PM peak hour noise levels to projected levels in the year 2030 would range from 0.6 dB at the Avalon Yerba Buena Apartments (Site C) to 2.2 dB at the Beacon Condominiums (Site A).  As these increases would not reach 3 dBA, no noise impacts from increased traffic are anticipated under the No Project/TSM Alternative.  Although all rubber-tired transit vehicles and vehicular traffic can cause ground-borne vibration, the vibration is not usually perceptible because of the vibration is isolated to the roadway surface.  Therefore, vibration impacts are also not anticipated.  

Table 5-7

PROJECT TRAFFIC NOISE LEVELS

N/A – Not Applicable.  Third Street is not affected under the Alternative 3 alignment.

Source: PB/Wong, 2007

Alternative 2 - Enhanced EIS/EIR Alignment

Under this alternative LRT operations would occur at-grade along Third and Fourth Streets.  The northbound at-grade alignment on Third Street would extend from King Street to Freelon Street and the southbound alignment on Fourth Street from King Street to South Park.  The southbound alignment would then extend underground along Third Street to Harrison Street, Harrison to Fourth Street where it connects with the northbound alignment.  Both northbound and southbound alignments continue on Third Street through Market Street and along Stockton Street to the termini at Jackson Street.

Operation Impacts

Traffic Noise.  Under this alternative, Fourth Street would be one-way in the southern direction Townsend Street.  Between Townsend and King Streets, Fourth Street would maintain three southbound lanes and two northbound lanes.  Traffic noise levels under this alternative are expected to be the same or lower than the No Project/TSM Alternative (refer to Table 5-7).

LRT Noise.  At-grade operations would result in both wayside noise from train passby and the use of on-board warning devices that are sounded as the vehicles enter the stations and at grade crossings.  These on-board warning devices consist of a gong, bells, and horn that are used during various degrees of necessity.  In general, either the gong or bells are used when the LRT vehicles enter a station to alert passengers on the platforms of oncoming vehicles.  Since there are no at-grade crossings with gates as part of this alignment, warning horns would only be used in an emergency and are not included in the noise analysis.  The reference levels for the different on-board warning devices are 75 dBA for the gong and 95 dBA for the bells at a distance of 10 feet.

Where the alignment is located in an underground subway section, airborne noise levels from train operations would not be audible.  Potential noise impacts at the closest representative residential receivers located along the at-grade alignment have been identified as:  no impact, moderate impact, or severe impact, in accordance with FTA Noise Impact Criteria (see Table 5-8).  There are no moderate or severe noise impacts expected under this alternative.

LRT Ground-borne Noise and Vibration.  Table 5-9 shows the estimated ground vibration levels for those building structures along the at-grade and underground sections of the alignment.  Table 5-10 presents the projected interior ground-borne noise levels for those building structures along the underground subway section of the alignment.  The FTA vibration criteria used to determine both ground-borne noise and vibration impacts is based on frequent events of 70 or more train passbys per day.  Ground-borne noise impacts are limited to the underground subway segments.  Vibration impacts would be limited to interior land use activities and would not be perceptible for outdoor land uses such as parks and recreation facilities.  The ground-borne noise and vibration analysis includes the increased vibration levels at receivers close to the crossover trackwork under Stockton Street between Washington and Clay Streets.  The FTA vibration criteria of 72 VdB would be exceeded at one residential building, 570 Fourth Street at Freelon Alley  (second and third floor apartments over a first floor restaurant).  The FTA ground-borne noise criteria of 35 dBA would be exceeded at two residential buildings at 527 and 529 Third Street (apartments and lofts located over ground floor commercial spaces).  During final engineering design, vibration propagation will be conducted at 570 Fourth Street and 527/529 Third Street to confirm the predicted impact and finalize the mitigation measures.

Vent Shafts and Traction Power Substations.  Vent shafts are planned at the following locations: Moscone, Market Street, Union Square, and Chinatown Stations.  Potential noise levels at these locations would be from the passby of underground trains transmitting through the vent shaft to the street and the testing and operation of the emergency ventilation fans.  Traction power substations (TPSS) are planned to be integrated as part of the underground station design at Moscone and Chinatown Stations.  The vent shafts would be designed to meet the noise level limits of the San Francisco Noise Ordinance.  No adverse impacts are anticipated since these facilities would be designed to comply with the San Francisco Noise Ordinance.

Table 5-8

Project Noise Levels at Building Structures along the AT-GRADE Alignment

Table 5-9

SUMMARY OF INTERIOR GROUND VIBRATION ESTIMATES – ALTERNATIVE 2

Table 5-9 (Cont.)

SUMMARY OF INTERIOR GROUND VIBRATION ESTIMATES – ALTERNATIVE 2

¹          Special trackwork was assessed at this location.

²       Interior vibration levels are estimated to exceed the FTA criterion at 570 Fourth Street at Freelon Alley, 2^nd and Third floor apartments over a 1^st floor restaurant.

Source: PB/Wong, 2007

Table 5-10

Summary of Interior Ground-borne Noise Estimates – Alternative 2

¹    Special trackwork was assessed at this location.

²   Interior ground-borne noise levels are estimated to exceed the FTA criterion at 527 and 529 Third Streets.

Source:  PB/Wong, 2007

Cumulative Impacts

As the Enhanced EIS/EIR would exceed the FTA vibration and ground-born noise criteria, it would contribute to cumulative vibration and noise impacts, though the contribution would not be considered substantial.

Mitigation Measures

No mitigation would be required for wayside noise occurring as a result of the operation of the light rail service.  Measures for the abatement of noise levels from the vent shafts and TPSS will be determined during preliminary and final design.  Noise control measures used to meet the San Francisco Noise Ordinance will include enclosing TPSS in masonry structures with sound-rated doors or gates and providing sound attenuation on all ventilation openings of any ancillary facility buildings.

There are several operational measures that can be taken to assure that noise and vibration levels related to light rail operation remain at the levels Projected in the analysis.  Table 5-11 provides a list of measures that could be performed on a regular basis and identifies the benefit that each of the measures would provide.  Purchasing quiet light rail vehicles is another important step in minimizing noise impacts.

Table 5-11

Operational Mitigation Measures

During final engineering design, vibration propagation testing will be conducted at 570 Fourth Street and 527/529 Third Street to confirm the predicted impact and finalize the mitigation measures.  Where vibration impacts are confirmed, they will be reduced to meet the FTA criteria using one of the trackwork design measures described below, in addition to the operation measures presented in Table 5-12. 

Table 5-12

SUMMARY OF INTERIOR GROUND VIBRATION ESTIMATES – Alternative 3

¹          Special trackwork was assessed at this location.

²      Interior vibration levels are estimated to exceed the FTA criterion at 570 Fourth Street at Freelon Alley, 2^nd and Third floor apartments over a 1^st floor restaurant.

³      Option A ends at Brannan Street and Option B ends at Bryant Street.

Source:  PB/Wong, 2007

· High resilience (soft) direct fixation fasteners for embedded track and in underground subway tunnels; or

· Ballast mat for ballast and tie track.

Alternative 3 - Fourth/Stockton Alignment Option A (LPA)

Operation Impacts

Traffic Noise.  Fourth/Stockton Alignment Option A would keep Fourth Street as a one-way street in the southern direction to Townsend Street.  Between Townsend and King Street, Fourth Street would maintain three southbound lanes and two northbound lanes.  Traffic noise levels under this alternative are expected to be lower than the No Project/TSM Alternative at the Beacon Condominiums (Site A) and the Avalon Yerba Buena Apartments (Site C), no change at the Palms Condominiums (Site 1), and 0.4 dB higher at the Hotel Utah (Site B) (refer to Table 5-8).

LRT Noise.   The LRT noise impacts would be similar to those described under Alternative 2.  The Hotel Utah would not be expected to experience noise impacts from the Project.

LRT Ground-borne Noise and Vibration.  Table 5-13 shows the estimated ground vibration levels for those building structures along the at-grade and underground sections of the alignment.  Table 5-16 presents the projected ground-borne noise levels for those building structures along the underground subway section of the Fourth/Stockton Alignment Option A.  Ground-borne noise impacts are limited to the underground subway segments.  Vibration impacts would be limited to interior land use activities and would not be perceptible for outdoor land uses such as parks and recreation facilities.  The FTA vibration criteria of 72 VdB would be exceeded at one residential building, 570 Fourth Street at Freelon Alley  (second and third floor apartments over a first floor restaurant).  The FTA ground-borne noise criteria would not be exceeded at any of the buildings along this alignment.  During final engineering design, vibration propagation testing will be conducted at 570 Fourth Street to confirm the predicted impact and finalize the mitigation measures.

Vent Shafts and Traction Power Substations.  The impacts would be the same as described for Alternative 2.

Mitigation Measures

The mitigation measures would be the same as described for Alternative 2.

Table 5-13

Summary of Interior Ground-borne Noise Estimates – Alternative 3

¹          Special trackwork was assessed at this location.

²           Option A ends at Brannan Street and Option B ends at Bryant Street.

Source:  PB/Wong, 2007

Alternative 3 – Fourth/Stockton Alignment Option B (Modified LPA)

Operation Impacts

Traffic Noise.  Traffic noise has been analyzed for the mixed-flow and semi-exclusive suboptions:

· Option B Mixed Flow - Under this option, Fourth Street would become a two-way street between King Street and Bryant Street, with two southbound lanes and two northbound lanes.  Peak hour traffic noise are expected to range from 0.3 dB lower at the Avalon Yerba Buena Apartments (Site C) to 1.6 dB lower levels at the Palms Condominiums (Site 1) then the No Project/TSM Alternative (refer to Table 5-8).

· Option B Semi Exclusive - Under this option, Fourth Street would become a two-way street between King Street and Bryant Street, with two southbound lanes and one northbound lane.  Peak hour traffic noise would be lower than Option B Mixed Flow and would range from 0.4 dB lower at the Avalon Yerba Buena Apartments (Site C) to 2.0 dB lower at the Palms Condominiums (Site 1) then the No Project/TSM Alternative (refer to Table 5-8).

LRT Noise.   The LRT noise impacts would be the same as described under Alternatives 2 and 3A.

LRT Ground-borne Noise and Vibration.  The impacts would be the same as those described under Alternative 3A.

Vent Shafts and Traction Power Substations.  The location of the vent shafts and TPSS are the same under Alternative 3B, except the Union Square/Market Street Station vent shaft would be located in the Ellis/O’Farrell parking garage.  The vent shafts would be designed to meet the noise level limits of the San Francisco Noise Ordinance.  No adverse impacts are anticipated since these facilities would be designed to comply with the San Francisco Noise Ordinance.

Cumulative Impacts

As the Fourth/Stockton Alignment Option B would exceed FTA vibration criteria at one location, this alternative would contribute to cumulative vibration impacts, but not at a substantial level.

Mitigation Measures

Mitigation measures would be the same as those identified for Alternative 2.

[5]     Ramirez, Robert, Track Superintendent, Cable Car and Rail Systems, Municipal Railway (Muni), City and County of San Francisco, personal communication with BASELINE, 11 July, 1997.

^[6]     California Stormwater Quality Association (CASQA).  Stormwater Best Management Practice Handbooks, 2003.

^[7]     BAAQMD CEQA Guidelines for Assessing Impacts of Projects and Plans, December 1999.

[8]     California Department of Transportation and the Institute of Transportation Studies at the University of California, Davis, December, 1997.

[9]     The BAAQMD has not developed a specific threshold for PM_2.5.

^[10]   Thresholds of significance for construction-related emissions have not been developed by BAAQMD.

[11]   California Air Resources Board, the California Almanac of Emissions and Air Quality – 2006 Edition, April 2006.

[12]   California Department of Transportation and the Institute of Transportation Studies at the University of California, Davis, December, 1997.

[13]   Caltrans often uses this as a comparative intersection for their air quality analyses.

[14]   California Department of Transportation, 2005 All Traffic on the California State Highway System, Traffic and Vehicle Data Systems Unit, www.dot.ca.gov/hg/traffops/saferesr/trfdata/2005all.htm

[15]   Energy Information Administration, Emissions of Greenhouse Gases in the United States 2005, November 2006.