SECTION 1.0 EXECUTIVE SUMMARY

1.1    INTRODUCTION

This Draft Environmental Impact Report (Draft EIR) assesses the potential environmental impacts associated with the proposed Trans Bay Cable (TBC) Project (Project). The City of Pittsburg has prepared this Draft EIR in order to satisfy the requirements of the California Environmental Quality Act (CEQA). The City of Pittsburg is the Lead Agency under CEQA for preparation of this EIR. The Notice of Preparation for this EIR was issued on August 23, 2004. The Project is proposed by Trans Bay Cable LLC, an affiliate of Babcock & Brown, in cooperation with the City of Pittsburg and Pittsburg Power Company, a municipal utility.

A consortium of Siemens Power Transmission & Distribution, Inc. (Siemens) and Prysmian Cavi e Sistemi Energia S.r.L (Prysmian) would provide the converter station and cable technology. Siemens, using Prysmian (or comparable) cable and installation technology, would provide converter technology, engineering, and procurement and construction management.

The proposed Project is a 400 megawatt (MW) high voltage direct current (HVDC) transmission line consisting of installation of an approximately 57-mile-long HVDC cable in San Francisco Bay and the Carquinez Straits, from a terminus in the City of Pittsburg in Contra Costa County to a terminus in the City of San Francisco in the vicinity of Potrero Point (refer to Figure 1-1). The Project is proposed to transmit electrical power from a converter station in Pittsburg to a converter station in San Francisco, providing a dedicated connection between the East Bay and San Francisco. This electrical power delivered to San Francisco would help meet the City of San Francisco's electrical demand projected for 2012 and beyond. The Project is designed to be a cost-effective, energy-efficient solution addressing San Francisco's need for additional transmission capacity, while improving transmission reliability and load-serving capability. The HVDC transmission line would provide San Francisco with a highly reliable, secure source of the electricity needed to service the load in San Francisco.

The California Independent System Operator (CAISO) is a not-for-profit public benefit corporation that acts as the impartial operator of the state's wholesale power grid, maintaining reliability and directing the electricity traffic on the transmission grid that connects energy suppliers with the energy providers that serve over 30,000,000 Californians. The CAISO identified three transmission system reinforcements to meet the long–term reliable load-serving plan. The following are the three reinforcements with the Project included as the third component to meet the CAISO objectives:

The primary goal of the Project is to deliver electricity to San Francisco to meet demand projected beginning in 2012 and beyond (e.g., at least 40 years). The proposed Project would be expected to:

The CAISO Management and Board of Governors have determined the Trans Bay Cable Project is required to ensure reliable operation of the transmission system serving the San Francisco Bay area.

On September 8, 2005, the CAISO staff recommended and the Board of Governors approved the Trans Bay Cable Project as the preferred long-term transmission alternative to address the identified reliability concerns in northern San Mateo County and San Francisco beginning in 2012. The CAISO staff and Board of Governors support the early implementation of the Project for operation by 2009.

The proposed HVDC transmission system for the Project is made up of the following primary components:

The proposed offshore submarine cable system is planned to be buried to a typical target depth of 3 to 6 feet below the Bay bottom, with the potential for local burial to greater depths if required, using a Hydroplow (or equivalent technology), which would minimize disturbance and suspension of sediments.

This EIR includes the following report sections:

Sections 1.0 through 11.0 and Appendix A are presented in this Volume 1 of the Draft EIR. Technical Appendices B through K are presented in Volume 2 of the Draft EIR.

1.2    SUMMARY OF POTENTIALLY SIGNIFICANT IMPACT FINDINGS

The impact findings, including a listing of identified potentially significant impacts, proposed mitigation measures, and residual impact findings are presented by resource topic in Table 1‑1 for the proposed Project. The table presents the summary findings for the proposed Project in the following order: 1) San Francisco HWC Converter Station site; 2) Pittsburg Standard Oil Converter Station site; and 3) Offshore Cable Route. A summary of key impact findings for the Project alternatives is presented in Section 1.3.4. Refer to Section 5.0 for more information regarding the impact findings for the Project alternatives and to Section 6.0 for a comparison of alternatives, including the proposed Project.

While many impacts associated with implementation of the proposed Project are considered to be potentially significant, with implementation of the proposed mitigation measures only one impact related to cultural resources would remain significant. The residual significant impact finding for cultural resources is associated with the proposed demolition of two potentially historic warehouses on the proposed San Francisco HWC Converter Station site, and potentially significant impacts to the Station A Complex on the adjacent Mirant Power Plant property associated with the proposed AC cable route between the HWC Converter Station and the PG&E Potrero Substation.

The resource topics addressed in this EIR and a summary of residual impact findings for the proposed Project follow:

Issue/Resource Topic

Resulting Level of Significance
With Implementation of Mitigation

  • Air Quality

Less than Significant

  • Geologic Resources and Soils

Less than Significant

  • Water Resources and Quality

Less than Significant

  • Terrestrial Biological Resources

Less than Significant

  • Marine Biological Resources

Less than Significant

  • Cultural Resources

Significant (only at HWC Site)

  • Land Use and Recreation

Less than Significant

  • Marine Transportation and Commercial Fishing

Less than Significant

  • Traffic and Transportation

Less than Significant

  • Noise and Vibration

Less than Significant

  • Public Services and Utilities

Less than Significant

  • Visual Resources/Aesthetics

Less than Significant

  • Hazardous Materials and Waste Management

Less than Significant

  • Paleontological Resources

Less than Significant

The following discussions summarize the potentially significant impact findings by resource topic, for the proposed Project.

1.2.1    Air Quality

Construction of the proposed Project would generate fugitive dust and heavy equipment and truck exhaust emissions at the onshore facility locations in San Francisco and Pittsburg over the estimated 27- to 30-month construction period. Maximum emissions would be expected to occur over an approximate 8-month period during demolition and site preparation activities. Additionally, installation of the proposed offshore submarine HVDC cable system would generate substantial emissions from the marine vessels required to install the submarine cable over an estimated 4- to 5-month period. Project-related fugitive dust emissions and onshore equipment exhaust emissions (Impacts AIR-1 and AIR-2, respectively) are considered to be potentially significant. With implementation of proposed mitigation measures (Mitigation Measures AIR-1 and AIR-2), these potentially significant impacts would be reduced or limited to a less-than-significant level.

Marine vessel emissions of criteria pollutants (Impacts AIR-3) (e.g., estimated 0.7 tons per day of NOx) and toxic air contaminants (Impact AIR-4) associated with installation of the proposed offshore submarine HVDC cable system would be potentially significant over a 4- to 5-month period. With implementation of proposed Mitigation Measures AIR-3 and AIR-4, potentially significant Impacts AIR-3 and AIR-4 would be reduced or limited to less-than-significant levels.

Operation of the proposed Project would result in periodic emissions from required testing of one diesel-fueled emergency generator and two diesel-fueled fire pumps. This potential impact would be negligible and would be considered less than significant.

1.2.2    Geologic Resources and Soils

Construction of the proposed Project would involve excavation and grading activities at the converter station sites and onshore cable routes during the construction phase in San Francisco and Pittsburg. The construction activities would cause soil erosion (Impact GEO‑1). With implementation of proposed Mitigation Measure GEO-1, this potentially significant impact would be reduced to a less-than-significant level.

Subsurface construction activities at the proposed San Francisco HWC Converter Station site could encounter serpentinite which is an asbestos bearing rock. Asbestos containing serpentinite could be disturbed and asbestos could be released during construction and this is considered to be a potentially significant impact (Impact GEO-2). With implementation of proposed Mitigation Measure GEO-2, this potentially significant impact would be reduced to a less-than-significant level.

Project facilities (i.e., converter stations and onshore cables) would potentially be subject to multiple significant geologic hazards (strong ground shaking, liquefaction, and shrink-swell/subsidence [Impacts GEO-3 through GEO-5]). With implementation of proposed Mitigation Measures GEO-3 through GEO-5, these potentially significant geologic hazards would be reduced to acceptable, less-than-significant levels.

1.2.3    Water Resources and Quality

Onshore Project-related construction activities could increase the potential for uncontrolled runoff laden with sediments or other pollutants that could significantly impact surface water quality. Additionally, operation and maintenance of the proposed converter station sites in San Francisco and Pittsburg could significantly impact surface water quality (e.g., San Francisco Bay) through inadvertent spills or discharges (Impact WATER-1). With implementation of proposed Mitigation Measure WATER-1, these potentially significant impacts would be reduced to less-than-significant levels.

Installation of the proposed HVDC cable in San Francisco and Pittsburg as well as the proposed HVAC cable in Pittsburg at the landfalls adjacent to the Bay would involve horizontal directional drilling (HDD) or comparable technology which could significantly impact water quality in the Bay and/or groundwater resources due to the potential release of drilling fluids (e.g., bentonite clay and inert, non-toxic polymers)(Impacts WATER-2 and WATER-3). These potentially significant impacts would be reduced to less-than-significant levels with implementation of proposed Mitigation Measures WATER-2 and WATER-3.

Construction and operation at the proposed Pittsburg Standard Oil Converter Station, including ancillary facilities, could significantly increase stormwater runoff to Kirker Creek within the Kirker Creek Watershed (Impact WATER-4). This potentially significant impact would be reduced to a less-than-significant level with implementation of Mitigation Measure WATER-4.

Installation of the offshore submarine cable system could significantly impact water quality in the Bay associated with the proposed use of a Hydroplow or equivalent technology (Impact WATER-5) and limited dredging activities (Impact WATER-6) if the construction zones contain contaminated sediments. These potentially significant impacts would be reduced to less-than-significant levels with implementation of proposed Mitigation Measures WATER-5 and WATER-6.

The proposed installation of the offshore submarine cable system would involve the use of marine vessels, which could result in an accidental vessel fuel spill. Although this event has a low probability of occurring, a potentially significant spill with associated water quality impacts could occur (Impact WATER-7). With implementation of proposed Mitigation Measure WATER-7, this potentially significant impact would be reduced to a less-than-significant level.

1.2.4    Terrestrial Biological Resources

The proposed San Francisco HWC Converter Station site and ancillary facilities are located on previously disturbed developed properties on artificial fill soils. No potentially significant impacts to terrestrial biological resources would be expected to result from construction or operation of the proposed Project facilities in San Francisco.

Construction of proposed Pittsburg Standard Oil Converter Station, including onshore cable route, proposed access road bridge construction, and laydown areas, has the potential to significantly impact wetlands and waters of the United States as well as special-status plant and animal species and the habitats that support them (Impacts TBIO-1 through TBIO-7). Potentially impacted habitats include vernal pools, salt marsh, and Kirker Creek. Potentially present and impacted fauna include: salt marsh harvest mouse, Giant garter snake, western pond turtle, California clapper rail, California black rail, short-eared owl, salt marsh yellow throat, white-tailed kite, raptors, and vernal pool shrimp. In addition, various special-status/rare plants could be impacted.

With implementation of proposed Mitigation Measures TBIO-1 through TBIO-7, potential construction-related impacts TBIO-1 through TBIO-7 would be reduced to less-than-significant levels.

No operations-related Project impacts to terrestrial biological resources would be expected to occur.

1.2.5    Marine Biological Resources

Potential Project-related impacts to marine biological resources would be limited to installation and operation of proposed offshore submarine cable system which is planned to typically be buried 3-6 feet below the bottom of the Bay. The actual burial depth will be determined by the forthcoming marine survey and Risk Analysis, and Insurance Company requirements. The construction phase for the offshore cable installation is planned to occur over a 4- to 5-month period between June 1 and November 30, thereby avoiding the sensitive life stages of salmonids (Chinook and steelhead), which are listed on the Endangered Species Act (ESA) list, and the typical Pacific herring spawning period. In addition, the proposed cable route was selected to avoid potentially sensitive marine habitat such as eelgrass beds and pinniped (e.g., seals and sea lions) haulout areas. Cable installation impacts on benthic organisms associated with use of the Hydroplow or equivalent technology burial method would be expected to be localized and minor. Potential operations-related impacts on marine organisms associated with electric and magnetic fields and cable heat are also expected to be insignificant. In summary, no potentially significant impacts to marine biological resources would be expected to occur associated with the proposed Project.

1.2.6    Cultural Resources

Potential Project-related impacts to cultural resources include construction-related impacts to historic resources and possibly archaeological resources that may be present in subsurface areas associated with proposed facilities in San Francisco. In addition, archaeological resources (shipwrecks) may be present along the offshore submarine cable system route between San Francisco and Pittsburg. Construction of the proposed San Francisco HWC Converter Station would require the demolition of two steel and concrete warehouses on the HWC site (435 23rd Street) that have been previously determined by a qualified architectural historian to be eligible for the California Register of Historic Resources. These structures are the last remaining structures of the Western Sugar Refinery complex dating from the 1920s; the Western Sugar Refinery ceased its operations in 1948. These warehouses are considered to be potential historic resources by the City of San Francisco and are therefore considered to be historic resources in this Draft EIR for the purposes of CEQA compliance. The proposed demolition of the historic resources at the HWC site is considered to be a potentially significant impact (Impact CUL-2). Proposed mitigation measures CUL-2a, b, and c would reduce the impact level but the impact would remain significant and a statement of overriding considerations would be required in accordance with CEQA-related project approvals.

Construction of the proposed San Francisco HWC Converter Station could also potentially impact subsurface archaeological resources that may be present on the Mirant Power Plant property, which is associated with the proposed AC cable interconnection between the HWC site and Pacific Gas and Electric Company's (PG&E's) Potrero substation (Impact CUL-1). With implementation of Mitigation Measures CUL-1a, b, and c, this potentially significant impact would be reduced to a less-than-significant level.

Construction and operation of the proposed Pittsburg Standard Oil Converter Station, including ancillary facilities, would not be expected to result in any potentially significant onshore impacts to cultural resources (archaeological or historic). Installation of the proposed offshore submarine cable, including the proposed AC cable associated with the proposed Pittsburg Standard Oil Converter Station site, has the potential to significantly impact submerged and buried shipwrecks (Impact CUL-3). Implementation of proposed Mitigation Measures CUL-3a, b, and c would reduce this potentially significant impact to a less-than-significant level.

1.2.7    Land Use and Recreation

In general, construction and operation of the proposed San Francisco Converter Station and ancillary facilities would not be expected to result in any potentially significant land use-related impacts. However, Project implementation at the HWC site may conflict with San Francisco Bay Conservation and Development Commission (BCDC) policies for future uses (e.g., expansion of Bay Trail) which stress the importance of public access to the Bay. The proposed San Francisco Converter Station would be located directly adjacent to the waterfront and, as proposed, would not improve public access to the Bay; this impact is considered to be potentially significant (Impact LU-1). With implementation of proposed Mitigation Measure LU-1, this potentially significant impact could be reduced to a less-than-significant level.

The proposed San Francisco HWC Converter Station site is currently zoned M-2 (Heavy Industrial) and the proposed Project is consistent with this zoning designation. The San Francisco Planning Department has proposed to rezone the site from M-2 to PDR. The PDR zoning would prohibit residential and most office developments. Utilities are described as a core use within the PDR district. Although the allowed uses within the PDR district are still being refined, City staff have indicated that they plan on adding a broad range of industrial uses within the PDR district and that the proposed converter station would be consistent with what they intend to propose.

Implementation of the proposed Project at the Pittsburg Standard Oil Converter Station could potentially exceed established building/structure height allowances in the City of Pittsburg. This impact is considered to be potentially significant (Impact LU-2). With implementation of proposed Mitigation Measure LU-2, this potentially significant impact would be reduced to a less-than-significant level.

The proposed Pittsburg Standard Oil Converter Station site includes construction of a new access road to the Pittsburg-Antioch Highway, including a new bridge over Kirker Creek. The proposed access road/bridge over Kirker Creek could be inconsistent with the City of Pittsburg's General Plan policy to use the Kirker Creek easement as a creek side trail; this potential policy inconsistency is considered to be potentially significant (Impact LU-3). With implementation of proposed Mitigation Measure LU-3, this potentially significant impact would be reduced to a less-than-significant level.

Installation of the proposed offshore submarine cables would involve a temporary (4 to 5 months) increase in vessel traffic on the Bay, which could conflict with recreational uses of the Bay. This potentially significant impact (Impact LU-4) would be reduced to a less-than-significant level with implementation of proposed mitigation measures LU-4a and b. Implementation of proposed Mitigation Measure LU-5 would ensure that installation of the proposed offshore cable system would not conflict with established local land use plans or policies.

1.2.8    Marine Transportation and Commercial Fishing

Construction and operation of the proposed onshore facilities (converter stations and ancillary facilities) in San Francisco and Pittsburg would not impact marine transportation or commercial fishing. Potential Project-related impacts to marine transportation and commercial fishing would be limited to the planned 4- to 5-month offshore submarine cable system installation phase. Potentially significant marine transportation-related Project impacts consist of the creation of potential navigation hazards due to the presence of Project-related marine vessels in the Bay during submarine cable installation (Impact MTRANS-1). With implementation of proposed Mitigation Measures MTRANS-1a, b, and c, this potentially significant impact would be reduced to a less-than-significant level.

Potentially significant Project-related impacts to commercial fishing operations could occur if the offshore submarine cable system installation activities coincided in time and place with commercial herring fishing/harvesting operations in the Bay (Impact MTRANS-2). With implementation of proposed Mitigation Measure MTRANS-2a and b, this potentially significant impact would be reduced to a less-than-significant level.

The proposed offshore cable system installation vessels could cross and conflict with commercial sport fishing vessel paths as they pursue migratory sport fish (e.g., salmon, striped bass, and steelhead) in the Bay. This potentially significant impact (Impact MTRANS-3) would be reduced to a less-than-significant level with implementation of proposed Mitigation Measures MTRANS-3a and b.

1.2.9    Traffic and Transportation

Construction of the proposed onshore Project components over a 27- to 30-month period would involve substantial truck traffic on the regional and local road networks in the Bay Area, San Francisco, and Pittsburg. The equipment to be installed at the proposed converter stations in San Francisco and Pittsburg would be delivered primarily to the Port of Oakland via container ships and then be trucked over the regional and local road networks to the converter station sites and/or construction laydown areas. Truck shipments would include a limited number of oversize loads (e.g., transformers and cable reels). Construction activities would also include truck traffic associated with hauling construction debris (e.g., demolished buildings) and possibly contaminated soil, as well as construction workforce commute trips.

Truck traffic associated with construction of the proposed San Francisco Converter Station would contribute to cumulative traffic impacts on regional roadways that are already operating with significant delays during peak periods (e.g., Interstate 280 and U.S. 101). The proposed Project's contribution of additional traffic during the peak periods on these roadways is considered to be a potentially significant cumulative traffic impact on regional road networks. With implementation of proposed Mitigation Measure TRAFFIC-1, this potentially significant impact would be reduced to a less-than-significant level. This potentially significant impact also applies to the proposed Pittsburg Standard Oil Converter Station site relative to the Project's contribution to cumulative traffic levels on Interstate 80 and State Route 4. Proposed Mitigation Measure TRAFFIC-1 would also reduce the potentially significant cumulative impact to a less-than-significant level for the Pittsburg converter station.

Another potentially significant traffic-related impact identified for the proposed San Francisco and Pittsburg converter stations consists of the transport of oversize loads (Impact TRAFFIC-2). This potentially significant impact would be reduced to a less-than-significant level via implementation of proposed Mitigation Measure TRAFFIC-2.

Additional potentially significant, localized traffic-related impacts identified for the construction phase of the proposed San Francisco HWC Converter Station and ancillary facilities are as follows: Impact TRAFFIC-3 – Temporary Street Closures Affecting Traffic, Bicycle, and Pedestrian Circulation; and Impact TRAFFIC-4 – Impact on Metro East Light Rail Facility. With implementation of proposed Mitigation Measures TRAFFIC-3 and -4, these potentially significant impacts would be reduced to less-than-significant levels.

The proposed Pittsburg Standard Oil Converter Station includes a new access road that would connect to the Pittsburg-Antioch Highway. Construction-related truck traffic utilizing this proposed new access road would create a potentially significant unsafe condition (Impact TRAFFIC-5) at the transition point between the Pittsburg-Antioch Highway and the new access road. With implementation of proposed Mitigation Measure TRAFFIC-5, this potentially significant impact would be reduced to a less-than-significant level.

No potentially significant operations-related traffic impacts have been identified for the proposed Project.

1.2.10  Noise and Vibration

Construction of the proposed Project facilities in San Francisco and Pittsburg would result in short-term (approximately 20 months) increases in ambient noise levels associated with the use of construction equipment, pile driving (4- to 5-month duration), and truck traffic. Operation of the proposed converter station would also generate noise associated with transformers, filters, heating and air conditioning units, circuit breakers, and emergency generators. Based on the results of the noise modeling performed, no potentially significant construction- or operations-related noise impacts have been identified for the proposed San Francisco HWC Converter Station. Although no potentially significant construction noise impacts have been identified for the construction phase at the proposed Pittsburg Standard Oil Converter Station (including ancillary facilities), a potentially significant noise impact (Impact NOISE-1) has been identified for the operations phase due to the estimated unmitigated noise level of 77 to 79 dbA Ldn at the property lines, which exceeds the City of Pittsburg's 75 dbA Ldn requirement. With implementation of proposed mitigation measure NOISE-1, this potentially significant noise impact would be reduced to a less-than-significant level.

No potentially significant noise impacts have been identified associated with installation of the proposed offshore submarine cable system.

1.2.11  Public Services and Utilities

Construction and operation of the proposed Project have the potential to require and adversely impact public services (e.g., fire, police, medical facilities, schools) and utilities (e.g., water, wastewater, and electrical supply). In addition, the proposed offshore submarine cable route crosses multiple utilities (fiber optic cables and pipelines, BART tube, etc.) that are present in the floor of the Bay.

Construction of the proposed converter stations in San Francisco and Pittsburg have the potential to result in significant impacts related to: creation of construction fire hazards (Impact PS-1); and damage to existing onshore underground utilities (Impact PS-2). With implementation of proposed Mitigation Measures PS-1 and -2, these potentially significant impacts would be reduced to a less-than-significant level.

Operations at the proposed converter stations in San Francisco and Pittsburg could create a fire hazard that is considered to be potentially significant (Impact PS-3). With implementation of proposed Mitigation Measure PS-3, this potentially significant impact would be reduced to a less-than-significant level.

Implementation of the proposed Project at the Pittsburg Standard Oil Converter Station site could result in a potentially significant impact related to the current lack of a fire hydrant within 1,500 feet of the site (Impact PS-4). With implementation of proposed Mitigation Measure PS-4, this potentially significant impact would be reduced to a less-than-significant level.

1.2.12  Visual Resources/Aesthetics

Implementation of the proposed Project in San Francisco and Pittsburg has the potential to result in long-term visual impacts associated with the proposed San Francisco and Pittsburg converter stations. Construction of the proposed converter stations at the HWC site in San Francisco and the Standard Oil site in Pittsburg would result in potentially adverse, but not significant, visual impacts associated with the facilities' domination of views (Impact VIS-1) from key observation points/public viewing locations. These include views of the HWC site from Warm Water Cove Park in San Francisco and views of the Standard Oil site from the Pittsburg-Antioch Highway. With implementation of proposed Mitigation Measures VIS-1a and b, these potentially adverse impacts would be reduced to a less-than-significant level.

The proposed San Francisco HWC Converter Station could also result in a potentially significant visual impact on viewers at Warm Water Cove Park related to the creation of visual clutter (Impact VIS-3). With implementation of proposed Mitigation Measure VIS-3, this potentially significant impact would be reduced to a less-than-significant level.

Operation of the proposed converter stations in San Francisco and Pittsburg could also result in adverse, but less than significant, visual impacts related to creation of substantial light and glare (Impact VIS-2) as viewed from key observation points in San Francisco (Warm Water Cove Park and Potrero Hill) and Pittsburg (Pittsburg-Antioch Highway). With implementation of proposed Mitigation Measure VIS-2, these potentially adverse visual impacts would be reduced to a less-than-significant level.

1.2.13  Hazardous Materials and Waste Management

The proposed Project has the potential to result in significant hazardous material- and waste management-related impacts associated with construction and operation of the onshore converter stations and ancillary facilities as well as the offshore submarine cable system. Potentially significant hazardous material and waste management impacts associated with installation of the offshore submarine cable system are addressed in the Water Resources and Quality assessment. Construction of the proposed San Francisco HWC Converter Station and the Pittsburg Standard Oil Converter Station, including ancillary facilities, would involve demolition of existing structures and excavation/remediation of potentially contaminated soil material related to past activities at the sites and adjacent areas.

Development of the proposed Project at the San Francisco HWC Converter Station site would require demolition of buildings that likely contain hazardous building materials (e.g., asbestos and lead-based paint), excavation and remediation of subsurface, contaminated soil, and possibly groundwater. Development of the proposed Pittsburg Standard Oil Converter Station site, including ancillary facilities, would also involve demolition activities and excavation of potentially contaminated soils. Although the same impact categories generally apply to the proposed HWC and Standard Oil sites, the hazardous material/waste conditions for the HWC site in San Francisco are more substantial. Implementation of the proposed Project at the HWC site would also involve an AC cable interconnection from the HWC Converter Station to the PG&E Potrero substation, including a portion on the Mirant Potrero property, which is known to have subsurface contamination issues as well. The following potentially significant impacts have been identified for both the proposed HWC and Standard Oil converter station sites, including ancillary facilities (as applicable):

With implementation of proposed Mitigation Measures HAZ-1 through HAZ-12, all 12 potentially significant hazardous material- and waste management-related impacts would be reduced to less-than-significant levels.

1.2.14  Paleontological Resources

Construction of the proposed Project at the San Francisco HWC and Pittsburg Standard Oil sites, including ancillary facilities, has the potential to significantly impact fossil resources during subsurface excavation activities. Development of the proposed converter station sites may involve excavation of undisturbed quaternary alluvium (Qal) that may be present under the site areas. Qal deposits have a high potential for containing significant fossil resources. If excavations associated with construction involved disturbance of Qal, a potentially significant impact to paleontological resources could occur (Impact PALEO-1). With implementation of proposed Mitigation Measure PALEO-1, this potentially significant impact would be reduced to a less-than-significant level.

No potentially significant impacts to paleontological resources would be expected to occur associated with installation of the proposed offshore submarine cable system.

1.2.15  Summary

With implementation of the proposed mitigation measures, the majority of the identified potentially significant impacts would be reduced to levels that are less than significant. Implementation of the proposed Project would be expected to result in one unavoidable adverse significant impact—Disturbance of Historical Architectural Resources (Impact CUL-2). This impact would occur associated with development of the proposed San Francisco HWC Converter Station site, which would require demolition of the historic buildings on the site that date from the 1920s and represent the last remaining structures of the Western Sugar Refinery. The proposed mitigation measures would reduce the impact severity, however, the residual impact is still considered to be significant.

1.3    ALTERNATIVES CONSIDERED

1.3.1    Introduction

The primary goal of the Trans Bay Cable Project is to deliver 400 MW of generator-like electric capacity and energy to San Francisco to meet demand projected for the beginning of 2012 and beyond. The proposed Project is anticipated to meet CAISO planning and reliability standards while improving load serving capability and creating economic benefit compared to Project costs. Should the Project be approved it will potentially reduce the need for in-city generation in the City of San Francisco, decrease transmission grid congestion in the East Bay, increase the overall security and reliability of the electrical system, improve the load serving capability, and provide potential savings to ratepayers.

The Project proposes to meet the primary goals by constructing an approximately 57-mile-long 400 MW HVDC subsea cable in San Francisco Bay from Pittsburg in Contra Costa County to the Potrero area in San Francisco as well as converter stations on each end and associated AC cables to connect the converter stations with the existing PG&E substations near Pittsburg and in San Francisco. In accordance with CEQA Guidelines (Section 14126[a]), this EIR assesses a reasonable range of alternatives to the proposed Project that are potentially capable of meeting the Project goals and objectives, including:

a)     Project Alternatives

b)    Pittsburg to San Francisco land-based transmission routes

c)     Reconductoring and/or retrofitting of the existing transmission grid

d)    New generation capacity in San Francisco

e)     Transmission grid enhancements/demand management

f)     No Project Alternative

1.3.2    Alternatives Considered But Eliminated From Further Consideration

Alternative categories b, c, d, and e (above) were subjected to a screening process to assess their potential feasibility and capability to meet the Project goals and objectives; none of these potential alternatives to the proposed Project were determined to be feasible and/or capable of meeting the Project goals and objectives. Accordingly, these alternative categories were eliminated from further consideration in this EIR.

Refer to Section A.8.3 in Appendix A of this EIR for more information regarding these potential alternatives, the screening process used, and the rationale for eliminating these alternatives from further consideration.

1.3.3    No Project Alternative

The No Project Alternative would involve taking no action to provide additional electrical transmission capacity to San Francisco—i.e., status quo. Under the No Project Alternative, the potential environmental impacts and benefits of the proposed Trans Bay Cable Project would not occur as a direct consequence of Project implementation. However, the No Project Alternative is incapable of meeting the Project goals and objectives, or the CAISO's objectives for solving the near-term and long-term electrical supply and reliability issues in San Francisco and the northern Peninsula area. One potential consequence of the No Project Alternative would be that the relatively inefficient and polluting Mirant Potrero Power Plant may need to continue to run in the future to meet San Francisco's electrical supply needs. Another potential consequence of the No Project Alternative would be the lost potential to save an estimated 20 MW of electrical power that is currently expended in electrical line losses, which would be avoided by the proposed HVDC Project. In summary, the No Project Alternative does not constitute a reasonable alternative to the proposed Project.

1.3.4    Project Alternatives

The following Project Alternatives are assessed in detail in Section 5.0, and compared to each other and the proposed Project in Section 6.0 of this EIR:

In general, the potentially significant impacts of the various Project alternatives are the same or similar to those associated with the proposed Project. Key issues potentially associated with the Project alternatives are summarized below.

1.3.4.1    San Francisco Mirant Potrero Converter Station Alternative

Similar to the proposed San Francisco HWC Converter Station, development at this alternative site (at all three site layouts under consideration) would result in an unavoidable adverse significant cultural resource impact associated with the need to demolish historic structures (Station A Complex) during site preparation (Impact CUL‑2).

1.3.4.2    San Francisco Sheedy Converter Station Alternative

No unavoidable significant impacts have been identified for this alternative site.

1.3.4.3    Pittsburg West Tenth Street Converter Station Alternatives 1 and 2

Two alternative sites/layouts (Alternative 1 [East/West] and Alternative 2 [North/South]) are considered at this alternative site area. The Pittsburg West Tenth Street Alternative 1 site would not result in any identified unavoidable adverse significant impacts. Implementation of the proposed Project on the Pittsburg West Tenth Street Alternative 2 site would result in unavoidable adverse significant noise impacts associated with pile driving activities (4-5 months) during the construction phase and long-term visual impacts. However, the alternative Pittsburg West Tenth Converter Station (Alternatives 1 and 2) would avoid the need to install offshore/onshore AC/DC cables between the PG&E Pittsburg substation and the proposed Standard Oil Converter Station site as well as avoid the need to construct a new access road over Kirker Creek adjacent to the Pittsburg-Antioch Highway.

1.3.4.4    Pittsburg Mirant Converter Station

No unavoidable adverse significant impacts have been identified for the Pittsburg Mirant Converter Station Alternative. As discussed above for the alternative Pittsburg West Tenth Street Converter Station Alternatives 1 and 2, the Pittsburg Mirant Converter Station would avoid the need to install offshore/onshore AC/DC cables to the proposed Standard Oil site and avoid the need to construct a bridge over Kirker Creek.

1.3.5    Environmentally Superior Alternative

The No Project Alternative would result in the fewest environmental effects. However, the No Project Alternative would not meet the Project/CAISO goals and is not considered to be a reasonable or feasible alternative. Numerous "non-Project" alternatives were also considered, as discussed in Section A.8.3 in Appendix A of this EIR. None of the various alternatives evaluated are considered to be capable of meeting all of the Project objectives and the related screening criteria for "feasibility" and "environmental impacts avoidance and minimization." Therefore, none of the potential non-Project alternatives were retained for further consideration in this EIR.

The Trans Bay Cable Project is considered by the City of Pittsburg to be the only feasible alternative for meeting the Project and CAISO objectives at this point in time.

It is difficult to determine, however, which of the Trans Bay Cable Project converter station site alternatives in San Francisco and Pittsburg is the environmentally superior alternative as, with few exceptions, the sites are very similar to each other in terms of potential impacts. The San Francisco Sheedy Converter Station Alternative would avoid the unavoidable adverse significant impact to historic architectural resources associated with the proposed HWC and alternative San Francisco Mirant sites. However, Mirant already plans to demolish the buildings considered to be historic (i.e., Station A Complex) on the San Francisco Mirant property due to their deteriorated condition and seismic safety concerns. Locating the proposed Trans Bay Cable Project San Francisco converter station on any one of the three alternative San Francisco Mirant site layouts would consolidate the electrical station facilities (i.e., PG&E Potrero Substation and the Trans Bay Cable San Francisco converter station) at one location and would avoid potential conflicts with possible future improvements to public access to San Francisco Bay (Impact LU-1) associated with both the San Francisco HWC and Sheedy sites. In addition, the required electrical interconnection (115 kV AC) between the Sheedy Converter Station site and the PG&E Potrero Substation is problematic due to potential conflicts with existing underground utilities along Illinois Street. At this stage of the EIR process, no one site in San Francisco is clearly environmentally superior to another.

Of the proposed and alternative converter station sites in Pittsburg (including ancillary facilities), it is also difficult to determine the clearly environmentally superior alternative at this stage of the EIR process. Due to the unavoidable adverse significant noise and visual impacts associated with the Pittsburg West Tenth Street Alternative 2 site, this alternative site is the least preferable from an environmental impact perspective. The Pittsburg West Tenth Street Alternative 1 and Pittsburg Mirant sites both avoid various potentially significant impacts (e.g., potential water quality impacts due to dredging and potential onshore biological impacts associated with installation of AC/DC cables) that would be associated with the proposed Standard Oil Converter Station site. Accordingly, the Pittsburg West Tenth Street Alternative 1 and Pittsburg Mirant alternative sites are considered to be environmentally superior to the proposed Standard Oil Converter Station site and the Pittsburg West Tenth Street Alternative 2 site. At this stage of the EIR process, it is not possible to clearly differentiate the environmentally superior alternative in Pittsburg between the West Tenth Street Alternative 1 site and the Pittsburg Mirant site.


TABLE 1-1
SUMMARY OF POTENTIALLY SIGNIFICANT ENVIRONMENTAL IMPACTS
AND PROPOSED MITIGATION MEASURES


Potentially Significant Impact

Proposed Mitigation Measure(s)

Resulting Level of Significance

San Francisco HWC Converter Station Site

   

AIR-1: Fugitive Dust Emissions. The Project proposes to use fugitive dust suppression with water and other methods to control construction-related emissions. The use of chemical additives is not planned. Controlled worst-case fugitive dust is estimated to be 29 pounds per day; 0.32 tons per month; and 2.6 tons over the 27- to 30-month construction period for the San Francisco site. Without fugitive dust control measures the impact is considered potentially significant.

AIR-1: Fugitive Dust Controls. Best achievable control measures (BACM) shall be utilized during construction phases of the Project. Fugitive dust control measures are stipulated by BAAQMD Regulation 6 (BAAQMD, 1999) and shall include all of the following as applicable to the Project site:

  • Water all active construction areas at least twice daily
  • Cover all trucks hauling soil, sand, and other loose materials or require all trucks to maintain at least two feet of freeboard
  • Pave, apply water three times daily, or apply (non-toxic) soil stabilizers on all unpaved access roads, parking areas and staging areas at construction sites
  • Sweep daily (with water sweepers) all paved access roads, parking areas, and staging areas at construction sites
  • Sweep streets daily (with water sweepers) if visible soil material is carried onto adjacent public streets
  • Hydroseed or apply (non-toxic) soil stabilizers to inactive construction areas (previously graded areas inactive for 10 days or more)
  • Enclose, cover, water twice daily or apply (non-toxic) soil binders to exposed stockpiles (dirt, sand, etc.)

Less than significant

AIR-2: Equipment Exhaust Emissions. See Table 4.2-10 for emissions estimates for the San Francisco HWC Converter Station site. The impact of these emissions would be considered to be potentially significant.

AIR-2: Exhaust Controls.T The following controls pertaining to equipment emissions (BAAQMD, 1999) shall be implemented during construction to reduce emissions from construction equipment exhaust:

  • Use alternative fueled construction equipment, as practical
  • Minimize idling time
  • Maintain properly tuned equipment
  • Limit the hours of operation of heavy duty equipment and/or the amount of equipment in use

Less than significant

GEO-1: Soil Erosion and Compaction. Construction activities would lead to soil compaction and could lead to soil erosion. This impact is considered to be potentially significant.

GEO-1: Design Project for Erosion Control. Standard Best Management Practices (BMPs) shall be incorporated into the Storm Water Pollution Prevention Plans (SWPPPs) for construction and operation, and shall minimize onsite soil erosion and offsite sedimentation. Temporary erosion control measures shall be required during the construction period to help maintain water quality, protect property from erosion damage, and prevent accelerated soil erosion or dust generation.

Less than significant

GEO-2: Asbestos-containing Serpentine. The San Francisco site is potentially underlain with asbestos-containing soils and rocks. Asbestos could be released during construction phases at the San Francisco sites. Asbestos is a human health hazard when airborne. This is considered a potentially significant impact.

GEO-2: Controls for Excavation of Serpentine. Prior to Project construction, previously-prepared geotechnical reports and boring and trenching logs from the site would be reviewed to identify areas of serpentinite bedrock that would be disturbed during excavation and Project construction. An Asbestos Dust Mitigation Plan would be submitted to the Bay Area Air Quality Management District (BAAQMD) for approval in accordance with the Final Regulation Order Asbestos Airborne Toxic Control Measure for Construction, Grading, Quarrying, and Surface Mining Operations.

Less than significant

GEO-3: Strong Ground Shaking. There is a high risk of strong ground shaking in the event of a large earthquake in the area. This impact is considered potentially significant.

GEO-3: Design to Seismic Design Requirements. Due to the site's proximity to earthquake faults and the characteristics of the soil profile, a site-specific study shall be conducted to develop seismic design criteria. Project facilities shall be designed and constructed at a minimum to the seismic design requirements for ground shaking specified in the Uniform Building Code for Seismic Zone 4. Additionally, to satisfy the provisions of the 1998 California Building Code, these facilities shall be designed to withstand ground motions equating to approximately a 500-year return period (10 percent probability of exceedance in 50 years). For design purposes, site-specific ground motions shall be calculated for all project sites.

Less than significant

GEO-4: Liquefaction. There is a potential for liquefaction at the Project site. This impact is considered potentially significant.

GEO-4: Design Project for Liquefiable Deposits. A site-specific program of exploratory borings and accompanying laboratory testing shall be required in order to delineate potentially liquefiable materials beneath the construction area. Geotechnical investigations shall be required for consideration prior to foundation design and development of site-specific design criteria.

Less than significant

GEO-5: Shrink-Swell/Subsistence. The proposed San Francisco HWC Converter Station site is potentially underlain with expansive soils, which requires specific attention during grading to avoid future heaving and cracking of overlying materials. The potential for damage due to shrink-swell/subsidence to site facilities is potentially significant.

GEO-5: Design Project for Shrink-Swell/Subsistence. A program of site-specific exploratory borings and accompanying laboratory testing shall be required to delineate any potentially expansive materials underneath the proposed Project facility sites and to evaluate the potential for site subsidence and identify and implement appropriate design measures (e.g. pile supports or replacement of undesirable materials) in accordance with applicable codes.

Less than significant

WATER-1: Erosion and Contaminated Runoff. Erosion and contaminated runoff during construction and operation could significantly impact water quality within San Francisco Bay. This is considered a potentially significant impact.

WATER-1: Erosion Control and Contaminant Source Control. Apply for and comply with NPDES construction permit, and Industrial Activities General Permit. Requirements for the permits include submittal of a Notice of Intent, development of a Stormwater Pollution Prevention Plan (SWPPP), monitoring and inspections, and submittal of annual compliance reports.

Less than significant

WATER-2: Surface Water Quality Impacts from HDD. HDD could have significant water quality impacts through loss of drilling fluids and disruption of Bay bottom sediment at the sediment surface where the borehole emerges. This is considered a potentially significant impact.

WATER-2: Spill Prevention and Control Plan for HDD. Drilling shall be performed in accordance with a site-specific Spill Prevention and Control (SPCC) Plan for HDD Operations for Drill Fluids and Cuttings. Spill response measures included in this plan, should a spill occur, shall include reducing fluid pressures, thickening the fluid mixture, and/or adding pre-approved loss circulation materials (LCMs) to the mixture.

Less than significant

WATER-3: Groundwater Quality Impacts from HDD. HDD could have significant water quality impacts through loss of drilling fluids that would increase suspended material in groundwater. This would be considered a potentially significant impact.

WATER-3: Use of Pilot Hole and Reaming. HDD shall be performed using a pilot hole plus reaming technique to minimize the potential for impacts to groundwater. To prevent significant water quality impacts, drilling muds shall consist of naturally occurring materials such as water and bentonite clay, plus inert, non-toxic polymers.

Both the drilling technique and early detection and response shall be used to minimize release of fluids to the environment. HDD shall start with completion of a small-diameter pilot hole. The pilot hole is gradually enlarged using reaming. This technique acts to prevent sudden loss of large volumes of drilling fluids.

Early detection and rapid response shall be implemented to minimize loss of drilling fluids. In the event loss of drilling fluids is detected, natural LCMs such as cotton dust, cottonseed hulls, wood fiber, mica, and cedar fiber shall be added to the drilling fluid. Alternative actions that shall be considered and implemented, as required, include reduction in drilling pressure, thickening of the fluid mixture, and construction of spill control structures, pits, and silt fences onshore, or silt curtains offshore.

Less than significant

CUL-1: Disturbance of Archaeological Resources. Buried historical resources may exist on the Mirant Potrero Power Plant site. Construction of the AC cable route from the converter station across the power plant property to the PG&E Potrero substation may disturb these resources. This is considered a potentially significant impact.

CUL-1a: Archeological Resource Testing. Due to the potential for buried cultural resources within the Mirant Potrero Power Plant portion of the Project area, it is recommended that subsurface survey (i.e., testing) of the cable route across the plant utilizing mechanical exploratory borings be initiated prior to construction activities. The subsurface survey should be implemented as a means to determine the presence and extent of buried archaeological resources within the plant area as well as to evaluate the potential significance of any resources encountered. Identified remains would be evaluated against the NRHP/CRHR significance criteria. If the resources are not eligible for the NRHP/CRHR, then no further consideration of these resources would be required. If the resources are eligible for the NRHP/CRHR, additional mitigation measures may be required.

The testing program would be documented within a technical report. The report would include the aforementioned resource evaluations, if any, and provide recommendations for the further management of cultural resources. Such recommendations could include data recovery excavations as well as the monitoring of all ground-disturbing activities associated with the project.

CUL-1b: Archaeological Resource Data Recovery. Based upon the results of the testing program, it may be necessary that a data recovery excavation be implemented. CEQA stipulates that if avoidance of the important archaeological resource is not feasible, a data recovery excavation may be warranted. When data recovery through excavation is the only feasible mitigation, a data recovery plan, which makes provisions for adequately recovering the scientifically consequential information from and about the resource, shall be prepared and adopted prior to any excavation being undertaken. The development of this plan as well as the implementation of field work, would be conducted in consultation with the SHPO, and, if the site is of aboriginal association, with the NAHC and local Native American community as well.

CUL-1c: Archaeological Resource Construction Monitoring. Following completion of the archaeological testing efforts, it may be determined that construction monitoring is necessary to prevent significant impacts to important cultural resources. In the event monitoring is warranted, a qualified professional archaeologist shall be retained to observe all ground-disturbing activities associated with the Project. If archaeological materials are observed by the monitoring archaeologist, he/she would have the authority to halt all ground-disturbing activities within the vicinity of the exposed materials until the nature and significance of the find could be evaluated and mitigation measures implemented, if needed. The development of mitigation measures would be conducted in consultation with SHPO and, if the site is of aboriginal association, with the NAHC and local Native American community as well.

Less than significant

CUL-2: Disturbance of Historical Architectural Resources. The construction of the converter station would require demolition of historical resources. This action would cause a significant adverse change to these historical resources under CEQA. This is considered a significant impact.

CUL-2a: Recording Architectural Resources. Recording would ensure a permanent record of the present appearance and context of the historical resources. Under this mitigation proposal, the Project proponent would ensure that the historical resources to be demolished would be recorded to Historic American Buildings Survey (HABS) or Historic American Engineering Record (HAER) standards prior to any construction activities. The HABS/HAER documentation would be filed with the SHPO, the HABS/HAER collection in the Library of Congress, the University of California Bancroft Library, the San Francisco Landmarks Preservation Advisory Board files at the San Francisco Planning Department, the Foundation for San Francisco's Architectural Heritage (FSFAH), and the San Francisco Public Library.

It is possible the discharge tunnel associated with Station A would be exposed during construction activities. If the tunnel were sufficiently exposed during such activity, work would be halted until a qualified architectural historian could record a representative cross section of the tunnel to HAER standards. Recordation would include appropriate photographs and drawings as well as archival documentation, if available. Although recording eliminates one adverse impact of demolition (the loss of historical information) it does not prevent the physical loss of historically significant resources.

CUL-2b: Architectural Resource Interpretive Display and/or Interpretive Material. The Project proponent would develop a display or interpretive material for public exhibition and dispersal. The display or interpretive material, such as a printed brochure, could be based on the photographs produced in the HABS/HAER documentation, and the historic archival research previously prepared for the resources in and near the project. This display and/or interpretive material would be provided to the City of San Francisco.

CUL-2c: Architectural Resource Salvage Opportunities. After recording and at least 30 days prior to demolition, the interested parties would have the opportunity to salvage architectural elements for re-use or curation. Items selected would be removed in a manner that minimizes damage to those items..

Remains significant

LU-1: Potential Conflict with Public Access Improvements. San Francisco and BCDC policies stress the importance of public access to the Bay. The proposed San Francisco HWC Converter Station site would be located directly adjacent to the waterfront and would not improve public access to the Bay. This impact is considered to be potentially significant.

LU-1: Public Access The Project proponent shall obtain any necessary permits from applicable agencies, including BCDC, and meet requisite conditions of approval including any conditions to provide Bay access in the vicinity of the Project site.

Less than significant

TRAFFIC-1: Cumulative Traffic Impacts. Project-related trips to and from the HWC Converter Station site would contribute to delays on the regional roadway system, a potentially significant impact.

TRAFFIC-1: Coordination to Reduce Cumulative Traffic Impacts. Truck shipments on the regional roadway shall be scheduled for non-peak periods when delays are less prevalent, as practical. The construction contractor shall coordinate with Caltrans to identify appropriate routings and times for site deliveries and comply with Caltrans recommendations. This mitigation measure would successfully mitigate the Project's contribution to cumulative impacts occurring on the regional roadway system.

Less than significant

TRAFFIC-2: Oversized Loads. Oversized shipments would require a permit from Caltrans that identifies the permitted hours of operation and the size of the truck to transport the shipment on the regional roadway network. If the permit conditions were not followed adequately, this would constitute a potentially significant adverse impact.

TRAFFIC-2: Coordination of Oversized Loads. Coordination with Caltrans and local jurisdictions shall be conducted to ensure proper permitting for oversized loads, which shall be required in advance of construction.

Less than significant

TRAFFIC-3: Temporary Street Closures Affecting Traffic, Bicycle, and Pedestrian Circulation. The temporary closure of streets for Project-related construction would affect traffic circulation in the study area and may impede the delivery and access to businesses in the area and the use of the Bay Trail and bicycle circulation for short intervals. This impact is considered to be potentially significant.

TRAFFIC-3: Signage for Temporary Street Closures. Any needed temporary closure of local streets in San Francisco will be mitigated by coordinating street closures with the San Francisco Department of Parking and Traffic (DPT) and, if appropriate, erecting signage that reroutes traffic onto neighboring streets. The coordination would account for providing continued access for emergency vehicles in the study area and ensure that the City of San Francisco's Emergency Operations Plan could be activated without impediment. With these mitigation measures, temporary construction impacts on traffic circulation would be mitigated to a less-than-significant level.

Less than significant

TRAFFIC-4: Impacts on Metro East Light Rail Facility. If truck shipments were destined for the proposed laydown area (Western Pacific site) at the same time MUNI begins using 25th Street to dispatch light rail vehicles to Third Street, they could conflict with the most active light rail dispatch and return hours at the beginning and end of the peak periods. This is considered to be a potentially significant impact.

TRAFFIC-4: Reducing Impact on the Movement of MUNI Light Rail Vehicles into and out of the Metro East Maintenance Facility. Construction contractor will coordinate with MUNI to define times for scheduling of truck deliveries to the proposed laydown area (Western Pacific site) if the truck deliveries were to occur during the peak period. Alternatively, particularly if the peaker project is implemented at the Western Pacific site at the same time as the Trans Bay Cable Project is under construction, the Project laydown area could be located at Pier 94/96. As indicated in Section 4.10.3.2.1, Construction-related Impacts, truck deliveries to the Pier 94/96 laydown area would not produce significant impacts along Cargo Way and would avoid a potential conflict with the movement of MUNI light rail vehicles along 25th Street.

Less than significant

PS-1: Construction Fire Hazards. Without appropriate precautions, construction activities requiring the use of flammable and combustible materials could create fire hazards. The potential to increase fire events could affect the level of service by the fire department to the surrounding area. This impact is considered potentially significant.

PS-1: Construction Fire Prevention. A Construction Fire Prevention and Protection Program shall be developed for the Project to be followed throughout all phases of construction. The program will specifically address:

  • General requirements
  • Responsibilities
  • Housekeeping
  • Employee alarm/communication system
  • Portable fire extinguishers
  • Fixed fire-fighting equipmentp>
  • Fire controlp>
  • Flammable and combustible liquid storage
  • Use and handling of flammable and combustible liquids
  • Dispensing and disposal of flammable and combustible liquids
  • Servicing and refueling areas
  • Training

Less than significant

PS-2: Existing Onshore Underground Utilities. Without appropriate precautions, installation of proposed underground utility lines could impact existing underground utilities and public service connections. This impact would be considered potentially significant.

PS-2: Utility Survey. Prior to any excavation work a survey shall be conducted to identify locations of subsurface utilities.

Less than significant

PS-3: Operations Fire Hazards. Without appropriate precautions, operations requiring the use of flammable and combustible materials could induce fire hazards. The potential to increase fire events could affect the level of service by the fire department to the surrounding area. This impact is considered potentially significant.

PS-3: Operations Fire Prevention. An Operations Fire Prevention and Protection Program shall be developed for the Project to be followed throughout all phases of operation. The program will specifically address:

  • Names and/or job titles responsible for maintaining equipment and accumulation of flammable or combustible material
  • Procedures in the event of fire
  • Fire alarm and protection equipment
  • System and equipment maintenance
  • Monthly inspections
  • Annual inspections
  • Fire-fighting demonstrations and training
  • Housekeeping practices
  • Training

Less than significant

VIS-1: Converter Station Domination of View. Since the architectural design character of the building and the general character of proposed landscaping have not been identified in detail, there is the possibility of generating potentially significant visual impacts based upon the potential of the Project to dominate the scene or become obtrusive on views from Warm Water Cove Park.

While this impact has been classified as less than significant without design controls, it may still be adverse. This adversity can be lessened through the application of Mitigation Measures VIS-1a and VIS-1b.

VIS-1a: Plan Submittal Requirements for Building Materials and Colors. All major Project features, including buildings, structures, fencing, and sign backgrounds (excluding electric switch gear and related wires and cables, etc. which shall be galvanized gray as shown in the simulations) shall be painted with neutral tan or gray colors that will minimize the size and height of the facility, blend with adjacent structures and be compatible with natural landscapes where applicable. A specific painting plan shall be developed for approval by the agency with local jurisdiction to ensure that the proposed colors do not unduly contrast with the surrounding landscape colors. All treatments shall be in non-reflective colors. The painting plan shall be submitted sufficiently early to ensure that any pre-colored buildings, structures and linear facilities shall have colors approved and included in bid specifications for such buildings or structures.

VIS-1b: Plan Submittal Requirements for Landscaping. A specific landscaping plan shall be prepared showing the location of proposed landscaping, the varieties and sizes of plants to be planted, and the proposed time of maturity for each species. Plants shall be selected from the approved species list prepared by the agencies with jurisdiction.

Less than significant

VIS-2: Converter Station will Create Substantial Light and Glare. There is potential for the Project to cast more ambient light into the immediate area than the existing conditions. There is also the possibility that the luminaries of some of the lighting fixtures may be seen directly by either residents of Potrero Hill or users of Warm Water Cove Park, which through the abrupt contrast of the fixtures' light with the surrounding general darkness, may create the effect of glare.

While this impact has been classified as less than significant, without design controls it may still be adverse. This adversity can be lessened through the application of Mitigation Measure VIS-2.

VIS-2: Plan Submittal Requirements for Lighting. Except as required by security and worker-safety requirements, night lighting shall be hooded to direct illumination downward and inward toward the areas to be illuminated in order to minimize nighttime light and glare, backscatter to the nighttime sky, and visibility of lighting to public viewing areas. A specific lighting plan consistent with operational and safety needs and limiting the general lighting levels to a maximum reasonable level shall be submitted to each agency with jurisdiction for approval. The plan shall include provisions for timed and/or motion detection-controlled switches.

Less than significant

VIS-3: Creation of Visual Clutter. There is the possibility that views of the proposed HWC Converter Station from Warm Water Cove Park would be adversely affected without supplemental screening landscaping along the waterfront given the potential for the Project to be more obtrusive than the existing condition. This impact would be considered potentially significant.

VIS-3: Landscaping Plan. The view of the proposed HWC Converter Station from Warm Water Cove Park shall be improved by addition of landscaping screening. In order to improve views northward from Warm Water Cove Park, the applicant shall develop a landscape plan which provides screening foliage where consistent with facility location and safety. The landscaping plans shall be reviewed and approved by agencies with jurisdiction.

Less than significant

HAZ-1: Removal of Potentially Hazardous Building Materials Resulting from Demolition. Structures on the converter station site contain or potentially contain ACMs and LBP. Improper removal or remediation of these materials could result in a potentially significant environmental impact

HAZ-1: Complete an ACM Abatement Plan and an LBP Abatement Plan. Complete ACM and LBP investigation and characterization on the converter station site to fill data gaps and to support development of worker safety procedures, in accordance with regulatory requirements to protect construction workers and the public. The ACM and LBP Abatement Plans shall be completed in compliance with application regulations based on the historical and newly acquired ACM and LBP data. If ACM and LBP are confirmed to be present in concentrations above regulatory limits, the Project proponent shall use ACM- and LBP-certified removal contractors and trained asbestos and lead-based paint removal workers, conduct dust monitoring, and properly dispose of generated wastes offsite. The Project proponent shall also prepare a site Health and Safety Plan for this work.

Less than significant

HAZ-2: Soil Removal. Soils removed during construction of the converter station and cable routes could be contaminated. Improper sampling, handling, analyzing, or characterizing of the soils could result in a potentially significant environmental impact. Soils at the HWC site are likely to be contaminated with metals and either TPH or PAHs, depending on location. In the middle of the site, a naturally occurring subsurface serpentinite ridge may require excavation. Serpentinite contains naturally occurring asbestos and these soils, if disposed of offsite, would likely require disposal as California hazardous waste.

HAZ-2: Soil Removal Protocols. Previously uncharacterized soils that are stained or odiferous shall be segregated on plastic, sampled, and characterized for onsite use or offsite disposal. The Soil and Groundwater Management plans (SMP, GMP) shall detail storage, transportation, and disposal options for soil and groundwater excavated/extracted during the converter station construction. They would also specify dust monitoring needs for soil excavation and management.

Previously characterized hazardous soils shall be loaded onto trucks for offsite disposal. Hazardous soil disposal requires that hazardous waste manifests accompany the waste. Hazardous waste transporters shall be required to haul hazardous soils to a Class I hazardous waste landfill. The personnel handling the hazardous soils are required to have met the OSHA hazardous work operations training requirements. A Health and Safety Plan shall be prepared for this work.

Previously characterized non-hazardous soils shall be stockpiled for onsite or offsite reuse or offsite disposal, as needed.

Less than significant

HAZ-3: Construction-phase Hazardous Materials Use. Hazardous materials would be used during construction activities. Misuse, inadequate storage, or improper disposal of these materials could result in a potentially significant environmental impact.

HAZ-3: Reduction of Hazards During Construction Phase. The hazards presented by the use of hazardous materials during the construction phase are well understood, and the appropriate management controls to mitigate potential impacts shall be implemented. These controls include: 1) developing required management plans, e.g., a Spill Prevention, Control, and Countermeasure Plan (see HAZ-5 for more SPCC Plan details); 2) secondary containment; 3) separate storage of incompatible materials; and 4) proper training of personnel.

Additionally, construction personnel shall be trained in safety and defensive emergency response procedures. Construction personnel shall also receive hazardous-waste-related training that focuses on recognition of potentially contaminated soil and/or groundwater that may be encountered during subsurface excavations for foundations or pipeline/cable trenches. If such contaminated soil or groundwater is suspected, contingency procedures shall be followed to protect worker safety and public health. All vehicles and construction equipment shall be inspected to ensure that no fluids are leaking (e.g., oil, hydraulic fluid, lubricants, or brake fluid) and that all fuels and fluids are stored in proper, clearly labeled containers.

Hazardous materials that must be disposed of will be disposed of as hazardous waste in accordance with the appropriate regulations for storage, transportation, and disposal of hazardous waste.

Less than significant

HAZ-4: Construction-phase Waste Streams. Improper storage and disposal of solid waste and hazardous construction wastes could result in a potentially significant environmental impact.

HAZ-4: Management of Construction-phase Waste Streams. The onsite management and offsite disposal procedures of solid wastes (including potentially contaminated soil) shall be in a Solid Waste Management Plan for the Project. Waste shall be stockpiled temporarily before disposal offsite. The local fire department and emergency management team shall be provided a list of the waste material expected to be generated and stored onsite.

Hazardous wastes generated during construction shall be collected in hazardous waste accumulation containers near the point of generation and moved daily to the construction contractor's 90-day hazardous waste storage area at the converter station site. The accumulated waste shall be delivered to an authorized waste management facility.

The exact volume of hazardous wastes to be generated at the San Francisco HWC Converter Station site cannot be estimated at this time, but the estimated amount of excavated soil that would need to be disposed of offsite is estimated at approximately 15,000 cubic yards for this converter station site. Even if this entire amount of excavated soil would need to be disposed of as hazardous waste, it would not exceed a significant portion of the available hazardous waste landfill capacity in California. The capacity details of various landfills for both non-hazardous and hazardous waste are detailed in Table 4.14-5. The capacity and estimates for daily volumes of waste received were verified, as detailed in the personal communications provided in the references for this section.

Less than significant

HAZ-5: Construction-phase Accidental Spills. An accidental spill or a release of hazardous materials could occur during construction. This impact is considered potentially significant.

HAZ-5: Construction-phase Spill Prevention, Control, and Countermeasures. The following shall be implemented both to prevent spills from occurring and to minimize impacts in the event that they do occur:

  • All spills shall be cleaned up quickly and all workers shall be adequately trained to recognize the hazards associated with such spills.
  • A Spill Prevention, Control, and Countermeasure (SPCC) Plan for the converter station shall be prepared in accordance with federal and state regulations. This plan must be prepared if petroleum products are stored onsite in ASTs with a capacity that equals or exceeds 55 gallons for a single tank or equals or exceeds 1,320 gallons aggregate for more than one tank. The SPCC Plan must be prepared before the delivery of petroleum products to the site. The SPCC Plan shall include information on spill response procedures and fuel storage.
  • Material Safety Data Sheets (MSDSs) for each chemical used during construction shall be kept onsite. Construction employees shall be informed of the location and content of the MSDSs, as required by OSHA's Hazard Communication Standard, Title 29 of the Code of Federal Regulations (CFR) Section 1910.1200.
  • In case of an accident, the City and County of San Francisco Fire Department shall be notified as the first responder. All other federal, state, and local notification requirements shall be followed for any release that exceeds the reportable quantity or threatens to have a significant impact.
  • The Project shall comply with all transportation requirements for hazardous materials on state highways. These requirements apply to both hazardous materials coming onto the site and hazardous wastes leaving the site.
  • All vehicles and construction equipment shall be inspected to ensure that there are no leaking fluids (e.g., oil, hydraulic, lubricants, or brake fluid) and that all fuels and fluids are stored in proper, labeled containers. Any observation of spills, leaking fluids, or improperly stored fluids shall trigger the issuance of a "stop work" notice until the problem is resolved, including the removal of any soil contaminated by vehicle fluids. The Project shall comply with all transportation requirements for hazardous materials on state highways. These requirements apply to both hazardous materials coming onto the site and hazardous wastes leaving the site.

Less than significant

HAZ-6: Construction-phase Dust and Volatilization of Contaminants. Excavation of contaminated soil and generation of hazardous waste soils could result in construction dust and volatilization of contaminants that pose environmental and human health risks, particularly to construction workers. This impact is considered potentially significant.

HAZ-6: Reduction of Construction Dust and Volatilization of Contaminants. Dust control measures (i.e., keeping the soil wet during excavation) shall be implemented during excavation and construction activities, and dust monitoring shall be performed. Suspected contaminated soil that is stockpiled on the site shall be covered daily with plastic to prevent volatilization of contaminants and to control dust. Contaminated soil may also be loaded directly onto trucks for transport to an appropriate offsite disposal facility. The loaded soils shall be properly covered and manifested as necessary. Dust monitoring shall be performed during excavation and loading of hazardous soils. The accumulated waste will then be delivered to an authorized waste management facility. Dust monitoring shall confirm that the dust control measures are effectively protecting site workers and the public.

Less than significant

HAZ-7: Contaminated Groundwater. The San Francisco HWC Converter Station site is known to have contaminated groundwater. Groundwater may be encountered during construction and groundwater dewatering. The lead regulatory agency associated with the proposed Project may require control or remediation of the site groundwater for redevelopment of the property. Failure to control the contaminated groundwater flow could result in a potentially significant impact.

HAZ-7: Contaminated Groundwater Control. If groundwater was encountered during construction at the converter station site, the water shall be collected onsite in a tank or tanks, sampled, and analyzed. Based on the analytical data, the water shall be characterized for disposal by one of the following methods:

  • Used onsite for dust control.
  • Treated onsite and discharged under the authority of a general National Pollutant Discharge Elimination System (NPDES) permit. Treatment options would include, but are not limited to, filtration or filtration and treatment by granular-activated carbon [GAC]. Treatment residuals would be sampled, analyzed, characterized, and disposed of offsite in compliance with applicable regulations.
  • Disposed of offsite at a commercial water treatment facility in compliance with applicable regulations.

If groundwater was encountered at the Pittsburg Standard Oil Converter Station site and it was found to be contaminated, it is possible that the RWQCB would require groundwater control as part of the development plan for the Project on that site. Potential groundwater-remedial strategies would depend on a number of factors including: site contaminants, evaluation of impacts to human health and the environment, and evaluation of the technical merits of available remedial strategies. Based on these factors the final selection would be negotiated between the RWQCB and TBC. The potential remedial options provided herein are for informational purposes only. Potential groundwater control methodologies include installing a slurry wall around a portion or the entire contaminated site combined with groundwater pump and treatment and discharge of treated groundwater to a storm drain/sewer system under the authority of an NPDES permit. Other alternative technologies include in situ biological treatment and in situ oxidation or reduction, depending on the site-specific contaminants and hydrogeological conditions.

Less than significant

HAZ-8: Operations-phase Hazardous Materials Usage. Hazardous materials shall be used during operations and maintenance activities. Misuse, inadequate storage, or improper disposal of these materials could result in a potentially significant environmental impact.

HAZ-8: Control of Operations-phase Hazardous Materials. A Hazardous Materials Business Plan (HMBP) shall be developed and implemented prior to turnover of site management from the construction contractor to the operating company. All hazardous materials shall be handled and stored in accordance with applicable codes and regulations. Storage quantities of all hazardous materials shall be minimized, and non-hazardous materials shall be substituted for hazardous materials at the converter station to the extent practicable. Small-quantity chemicals used for maintenance tasks shall be kept in appropriate inflammable material or corrosive material storage lockers. Bulk chemicals shall be stored in ASTs, and all other chemicals shall be stored in their original shipping containers. Incompatible materials shall be stored in separate storage containment areas. Chemical storage areas and transfer areas shall be equipped with secondary containment sufficient in size to contain the volume of the largest container or tank, including an allowance for rainwater. Areas susceptible to potential leaks and/or spills shall be paved and bermed or otherwise secondarily contained. Specifically, the transformers and the diesel ASTs would have secondary containment. Periodic inspections shall be conducted to ensure that all containers are secure and properly marked. Piping and tanks will be protected from potential traffic hazards by concrete or other barriers. Hazardous materials will be delivered to the converter station periodically. Transportation of these materials shall comply with all applicable regulations of the U.S. Department of Transportation, the EPA, DTSC, the California Highway Patrol, and the State Fire Marshal. An HMBP shall be prepared prior to delivery of specified hazardous materials to the converter station in conformance with Title 19 of the California Code of Regulations (CCR) and California Health and Safety Code Section 25504. The HMBP requires facilities to develop the following information:

  • Facility map showing locations of hazardous materials and emergency response equipment
  • Hazardous materials inventory, including MSDSs for all hazardous materials stored and used onsite
  • Emergency contact information
  • Emergency response plans and procedures
  • Emergency notification procedures
  • Emergency response training for all employees

Less than significant

HAZ-9: Operations-phase Waste Streams. Improper storage and disposal of operational wastes could result in a potentially significant environmental impact.

HAZ-9: Manage Waste Generation, Storage, and Disposal During Operations Phase. Before facility start-up, an application shall be made to DTSC for a hazardous waste generator number. The facility shall not treat, store, or dispose of hazardous waste in a manner that will cause the facility to be characterized as a treatment, storage and disposal facility (TSDF). A detailed waste management plan shall be prepared prior to start-up to ensure proper storage, labeling, packaging, record keeping, manifesting, minimization, and disposal of all hazardous materials and wastes. The waste management plan will include:

  • A description of each hazardous waste stream
  • Handling, transport, treatment, and disposal procedures for each waste
  • Preparedness, prevention, contingency, and emergency procedures
  • Personnel training

Scrap materials such as paper, packing materials, glass, metal, and plastic shall be segregated and managed for recycling. Non-recyclable inert wastes shall be stored in covered trash bins in accordance with local ordinances and picked up by an authorized local trash hauler on a regular basis for transport and disposal in suitable landfill. Skimmed oil collected from equipment drains and other liquids from equipment shall be transported by an authorized carrier to a certified recycling facility.

Less than significant

HAZ-10: Operations-phase Accidental Spills. Non-compliance with regulatory requirements associated with storage, use, and containment of hazardous materials and/or petroleum hydrocarbons could result in accidental spills. The impact from accidental spills of these materials is considered potentially significant.

HAZ-10: Operations-phase Spill Prevention, Controls, and Countermeasures. The following shall be implemented during operations:

  • All workers shall be adequately trained to recognize the hazards associated with accidental spills. Training shall include ensuring that personnel who maintain the facility are adequately trained to recognize the hazards associated with such spills. Personnel who maintain the facility will be trained in the use of fire suppression equipment, evacuation, notification, and other defensive emergency response procedures. Maintenance personnel will also be trained in hazardous materials and hazardous waste awareness, handling, and management, as required for their level of responsibility.
  • The proper use of safety procedures and development and implementation of a project-specific SPCC Plan will help prevent such incidents. The SPCC Plan will include information on spill response procedures and fuel storage.
  • An MSDS will be kept onsite for each onsite chemical.
  • The programs to be implemented to protect worker health and safety shall also benefit public safety. Facility design shall include redundant controls and monitoring systems to minimize the potential for conditions in which accidental spills could occur. Potential public health impacts associated with facilities operation will be mitigated by development and implementation of Emergency Response Plans, an SPCC Plan, secondary containment structures for oils and other hazardous materials, safety programs, and employee training.

Less than significant

HAZ-11: Operations-phase Fire and Explosion Risk. Non-compliance with regulatory requirements associated with storage, use, and containment of flammable materials could result in a fire or explosion. The impact of a fire or explosion is considered potentially significant. If the onsite fire protection equipment could not address the fire, outside agencies would need to be called. This impact is considered potentially significant.

HAZ-11: Reduction of Fire and Explosion Risk and Emergency Support During Operations Phase. The flashpoints of transformer oil and diesel fuel are 295°F and 100°F, respectively, and the auto ignition points are 484°F and 494°F, respectively (Sax, 1992; MSDS for transformer oil; MSDS for diesel fuel). The National Fire Prevention Association (NFPA) assigns lubricating oils a fire hazard rating of 1, meaning that the materials "must be preheated before ignition can occur. Materials of these types require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur" (Siemens, 2006).

The converter station shall have onsite fire protection systems (including emergency backup systems). During the detailed design phase of the proposed Project, potential fire protection designs and systems shall be reviewed with local agencies to finalize design details.

In general, the fire protection system shall consist of automatic detection and firefighting equipment. The fire detection control panel will be located in the control room and will be connected to the control and protection system for remote annunciation. The fire alarm will be initiated automatically by smoke, heat, or flame detectors, or manually by push-button. A combination of detectors will be used, including infrared and ultraviolet detectors, ionization and optical smoke detectors, and rate-of-rise temperature-sensitive detectors, depending on the equipment and/or space being monitored.

Audible alarms and flashing lights will be activated in the event of a fire. The equipment or area where the alarm is triggered will be indicated on the control panel. The firefighting equipment would initiate automatically, using water sprays and curtains or an appropriate gas-extinguishing agent.

Fire detection and automatic firefighting equipment will be connected to a power supply within the fire-detection control panel, which will be connected to the mains via a power supply/battery charger unit with an internal 24-volt battery. A pump house shall be included within the facility with 2 diesel fire-water pumps, each 225 kW. The fire-water pump and backup emergency lighting will be electrically powered by a diesel-powered generator capable of operating at full standby without refueling for 96 hours, as required in a seismically active area.

Less than significant

HAZ-12: Impacts from Seismic Activity. Failure to abide by the building code for Seismic Zone 4 could lead to damage to the facility and resulting spills of hazardous materials. This impact could be potentially significant.

HAZ-12: Manage Seismic Activity. To minimize seismic damage to the facility and the resulting hazardous materials spills, the designers and construction contractor shall follow the Uniform Building Code for Seismic Zone 4. This action would reduce Impact HAZ-12 to a less-than-significant level.

Less than significant

PALEO-1: Disturbance of Fossil Resources. There are no known significant fossil resources at this location. However, excavations associated with construction have the potential to penetrate into undisturbed Qal sediments, which could contain significant fossil resources. This impact would be considered potentially significant.

PALEO-1: Potential Fossil Resources Protection. The following measures shall be implemented:

  • Pre-construction meetings shall be held with key construction personnel to provide brief discussions pertaining to paleontological resource significance, visual identification, and discovery notification procedures.
  • Proposed construction areas containing geological units designated with a potentially moderate or high sensitivity rating shall be monitored by a professional paleontologist during construction, to insure that subsurface paleontological resources are adequately protected.
  • If unique paleontological resources are discovered, all significant fossil material shall be collected, prepared, identified, and curated, and then placed into a state-designated scientific repository.
  • Salvage operations shall be conducted in accordance with professional paleontological (e.g., SVP) standards.

Less than significant


Potentially Significant Impact

Proposed Mitigation Measure(s)

Resulting Level of Significance

Pittsburg Standard Oil Converter Station Site

   

AIR-1: Fugitive Dust Emissions. The fugitive dust emissions impact (Impact AIR-1) described in Section 4.2.3.2.1 applies to the Pittsburg Standard Oil Converter Station site. The Project proposes to use fugitive dust suppression with water and other methods to control construction-related emissions. The use of chemical additives is not planned. Controlled worst-case fugitive dust is estimated to be 39 pounds per day; 0.43 tons per month; and 3.4 tons over the 27- to 30-month construction period for the Pittsburg site. Without fugitive dust control measures the impact is considered to be potentially significant.

AIR-1: Fugitive Dust Controls. Mitigation Measure AIR-1 described in Section 4.2.3.2.1 shall be applied at the Pittsburg Standard Oil Converter Station site.

Less than significant

AIR-2: Equipment Exhaust Emissions. The equipment exhaust emissions impact (Impact AIR-2) described in Section 4.2.3.2.1 applies to the Pittsburg Standard Oil Converter Station site. See Table 4.2-13 for emissions estimates for this site. Without mitigation measures this impact is considered to be potentially significant.

AIR-2: Exhaust Controls. Mitigation Measure AIR-2 described in Section 4.2.3.2.1 shall be applied to the Pittsburg Standard Oil Converter Station site.

Less than significant

GEO-1: Soil Erosion and Compaction. The soil erosion and compaction impact (Impact GEO-1) described in Section 4.3.3.2.1 applies to the Pittsburg Standard Oil Converter Station site.

GEO-1: Design Project for Erosion Control. Mitigation Measure GEO-1 described in Section 4.3.3.2.1 shall be applied at the Pittsburg Standard Oil Converter Station site.

Less than significant

GEO-3: Strong Ground Shaking. The strong ground shaking impact (Impact GEO-2) described in Section 4.3.3.2.2 applies at the Pittsburg Standard Oil Converter Station site.

GEO-3: Design to Seismic Design Requirements. Mitigation Measure GEO-3 described in Section 4.3.3.2.2 shall be applied at the Pittsburg Standard Oil Converter Station site.

Less than significant

GEO-4: Liquefaction. The liquefaction impact (Impact GEO-4) described in Section 4.3.3.2.2 applies to the Pittsburg Standard Oil Converter Station site.

GEO-4: Design Project for Liquefiable Deposits. Mitigation Measure GEO-4 described in Section 4.3.3.2.2 shall be applied to the Pittsburg Standard Oil Converter Station site.

Less than significant

GEO-5: Shrink-Swell/Subsidence. The proposed Pittsburg Standard Oil Converter Station site is potentially underlain with expansive soils, which requires specific attention during grading to avoid future heaving and cracking of overlying materials. The potential for damage due to shrink-swell/subsidence to site facilities is potentially significant.

GEO-5: Design Project for Shrink-Swell/Subsidence. A program of site-specific exploratory borings and accompanying laboratory testing shall be required to delineate any potentially expansive materials underneath the proposed Project facility sites and to evaluate the potential for site subsidence and identify and implement appropriate design measures (e.g. pile supports or replacement of undesirable materials) in accordance with applicable codes.

Less than significant

WATER-1: Erosion and Contaminated Runoff. The erosion control and runoff impact (Impact WATER-1) described in Section 4.4.3.2.1 applies at the Pittsburg Standard Oil Converter Station site.

WATER-1: Erosion Control and Contaminant Source Control. Mitigation Measure WATER-1 described in Section 4.4.3.2.1 shall be applied for the Pittsburg Standard Oil Converter Station site.

Less than significant

WATER-2: Surface Water Quality Impacts from HDD. Impact WATER-2 described in Section 4.4.3.2.1 applies at the Pittsburg Standard Oil Converter Station site.

WATER-2: Spill Prevention and Control Plan for HDD. Mitigation Measure WATER-2 described in Section 4.4.3.2.1 shall be applied for the Pittsburg Standard Oil Converter Station site.

Less than significant

WATER-3: Groundwater Quality Impacts from HDD. Groundwater quality impacts from HDD (Impact WATER-3) described in Section 4.4.3.2.1 applies to the proposed subsurface Kirker Creek crossing associated with the onshore cable route at the Pittsburg Standard Oil Converter Station site.

WATER-3: Use of Pilot Hole and Reaming. Mitigation Measure WATER-3 is applicable at the Kirker Creek crossing for the Pittsburg Standard Oil Converter Station site.

Less than significant

WATER-4: Impacts to Kirker Creek Watershed Drainage Area Construction and operations of the Standard Oil Converter Station, onshore AC/DC cable routes, laydown areas, and access roads are all within the Kirker Creek Watershed. Project construction and operations could increase runoff to the creek. This impact is considered potentially significant.

WATER-4: Kirker Creek Stormwater Management. Comply with Pittsburg Municipal Code (Chapter 15.104 – Stormwater Management Plan for Kirker Creek Watershed Drainage Area) which states that new development within the Kirker Creek Watershed Drainage Area must:

  • Construct an onsite infiltration system, associated with small storm flows, that would detain and control the rate of stormwater runoff to the adjacent Kirker Creek Watershed

Less than significant

TBIO-1: Trenching Near Pools Providing Habitat for Special-status Species. This is a potentially significant impact.

TBIO-1a: Avoidance and Prevention Measures for Work Near Vernal Pool Habitat. Cable construction along Arcy Lane shall be placed a minimum of 8 feet away from the vernal pool edge of the roadway and all construction activities shall maintain a 15-foot buffer to the hydrologic edge of the pool. The vernal pool edge of the roadway pool shall be fenced with a silt fence with hay bundles placed at the outside base of the fence to avoid impacts to this wetland. All construction personnel, work crews, and project staff shall be restricted from entering the vernal pool areas, staging equipment or depositing any waste disposal soils, littering in or otherwise in any way entering these sensitive habitats. Due to the fact that this portion of the Project area is relatively flat, significant erosion or soil movement is not expected from trenching activities within the adjacent roadway.

TBIO-1b: Awareness Training for Workers. Prior to construction, all construction workers shall take part in a USFWS-approved worker environmental awareness program on vernal pool crustaceans given by a USFWS-approved biologist.

TBIO-1c: Biological Monitoring Requirement. A USFWS-approved biologist shall be present on site during any construction activities adjacent to vernal pool crustacean habitat.

Less than significant

TBIO-2: Trenching Near Saltmarsh and Wetland Habitats (Pickleweed, Bulrush, and Cattail). The proposed Project has the potential to significantly impact, either directly or through habitat modifications, terrestrial endangered, rare, or threatened species, as listed in Title 14 of the California Code of Regulations (Sections 670.2 or 670.5) or in Title 50, Code of Federal Regulations (Sections 17.11 or 17.12).

TBIO-2a: Marking Habitat and Implementing Physical Avoidance Measures. In order to protect wildlife habitat and prevent disturbance or take of salt marsh harvest mouse, black rail, or California clapper rail, a silt fence with hay bundles placed at the outside base of the fence shall be installed by a qualified biologist along the entire Arcy Lane portion (0.5 mile) of the proposed onshore cable route. All construction personnel, work crews, and project staff shall be restricted from crossing this fence at the edge of the dirt road, staging equipment or depositing any waste disposal soils, littering in or otherwise in any way entering these sensitive habitats. Due to the fact that this portion of the Project area is relatively flat, significant erosion or soil movement is not expected from trenching activities within the adjacent roadway. The fencing shall not be removed until all construction and clean-up activities were completed in the area.

TBIO-2b: Monitoring Requirements for Salt Marsh Species. . In order to protect wildlife habitat and prevent disturbance or take of salt marsh harvest mouse, black rail, or California clapper rail, a qualified biological monitor familiar with the species shall be present during each day of construction and site preparation adjacent to these species potential habitats (i.e., salt marsh, grassland near salt marsh, pickleweed). As applicable, the biological monitor shall be authorized to require remedial protective measures in the field.

TBIO-2c: Awareness Training for Construction Personnel. Prior to construction, all construction workers shall take part in a USFWS-approved worker environmental awareness program concerning these species given by a USFWS-approved biologist. The biological monitor shall train work crews in standard procedures for identifying and avoiding impacts to these species prior to the start of construction activities.

TBIO-2d: Halting Work to Remove Endangered Species from Job Site. If a salt marsh harvest mouse, black rail, or California clapper rail is observed in or near the Project area, all construction shall cease until the mouse or bird moves out of the project area or, in the case of salt marsh harvest mouse, is captured by a qualified biologist and removed from the Project area for relocation.

TBIO-2e: Check Under Parked Vehicles. The area beneath vehicles or equipment parked in the Project area shall be checked for the presence of salt marsh harvest mouse before being moved, during construction in the roadway and staging activities within the entire Arcy Lane habitat unit. Vehicle speed limits in this area shall not exceed 10 miles per hour.

TBIO-2f: Pre-construction Nesting Surveys. A qualified wildlife biologist shall perform pre-construction nesting surveys for all bird and raptor species within the Project area and immediate vicinity a maximum of 30 days before construction begins. If an active raptor nest is located, no activities shall occur within 0.25 mile of the nest until young are fledged and the nest is abandoned. If construction activities occur outside of the nesting period (nesting period is typically between February and August) no nesting surveys shall be required.

Less than significant

TBIO-3: Disturbance or Fill of Wetlands and Streams. Potential jurisdictional wetlands and streams exist in the project area that may be filled or altered during construction, due to project trenching for onshore cables associated with the Pittsburg Standard Oil Converter Station site. Other temporary and permanent impacts would occur from proposed bridge construction activities for the access road from the Pittsburg-Antioch Highway to the converter station site. Other wetlands occur in portions of proposed laydown area. This is a potentially significant impact.

TBIO-3a: Implement HDD or Comparable Technology Techniques to Avoid Impacts to Kirker Creek and Associated Floodplain Wetlands. As stated in the project description of this document (Section 3.0 and Appendix A), onshore cable route for the proposed site would incorporate HDD or comparable technology techniques from the west end of the paved road on the Delta Energy Center property all the way to the northeast corner of the Pittsburg Standard Oil Converter Station site. The HDD shall be drilled at a minimum of 15 feet below the bottom of the Kirker Creek streambed in order to avoid a "frac-out" (i.e., release of drilling mud). The temperatures associated with the buried AC cable are expected to be warmer than ambient soil temperatures over a limited area (refer to Appendix F for more information). The required minimum HDD depth shall also remove any potential for impacts to these wetlands or streams due to potential heating from the buried cable. Implementation of the HDD or comparable technology techniques will avoid impacts to wetlands and streams within this portion of the onshore cable route.

TBIO-3b: Wetland and Jurisdictional Waters Delineation Survey. Prior to construction, the Applicant shall hire a qualified wetland delineator (i.e., biologist) familiar with the wetland types in the east Bay Area to survey the proposed onshore cable route, laydown areas and other portions of the Project area. The biologist shall mark the outer upland edges of potential wetlands and streams in the Project area and oversee installation of silt fences around the edges of these features in order to avoid Project impacts.

TBIO-3c: Wetland and Pool Avoidance. Wetlands and a seasonal pool, representing vernal pool crustacean habitat for endangered species, shall be avoided by all construction activities in order to avoid fill or alteration of wetlands and streams in the project area and to avoid impacts to sensitive species or their habitats. No trenching or equipment shall enter within a minimum of 15 feet from the edge of the target seasonal pool boundaries and areas of hydrologic influence. In addition, no construction personnel shall be allowed to enter or disturb the seasonal pool or vegetated habitat immediately surrounding it. A trained biological monitor shall be present during all trenching activities occurring adjacent to vernal pool wetlands in the Project area. If disturbance occurs in any such feature during Project construction then the biological monitor shall immediately notify the USFWS and inform them of potential "take" of these federally endangered species. Any impacts to these habitats shall be considered "take" of these species and will require agency consultation to develop appropriate mitigation measures.

TBIO-3d: Obtain Streambed Alteration Agreement. Potential impacts or alteration of streambeds from bridge construction over and HDD or comparable technology drilling beneath Kirker Creek at two locations would require a Streambed Alteration Agreement (Section 1600-1616) through CDFG.

Less than significant

TBIO-4: Potential Impacts to Giant Garter Snake and Western Pond Turtle. The proposed Project has the potential to significantly impact, either directly or through habitat modifications, terrestrial endangered, rare, or threatened species, as listed in Title 14 of the California Code of Regulations (Sections 670.2 or 670.5) or in Title 50, Code of Federal Regulations (Sections 17.11 or 17.12).

TBIO-4a: Avoidance of Habitat and Timing of Construction. No grading, excavating, or filling may take place in or within 50 feet of the marsh, wetland or stream edges within the Project area between October 1 and May 1 unless otherwise authorized by the USFWS and CDFG.

TBIO-4b: Worker Training for Giant Garter Snake and Western Pond Turtle. Prior to construction, all construction workers shall take part in a Service-approved worker environmental awareness program given by a USFWS-approved biologist.

TBIO-4c: Biological Monitoring for Giant Garter Snake and Western Pond Turtle. A USFWS-approved biologist shall be present on site during any construction activities within western pond turtle or giant garter snake habitat. If a giant garter snake or western pond turtle is found in the work area, all work shall cease until the snake or turtle leaves the work area. Monitoring and avoidance measures shall follow protocols established by the USFWS (see Appendix F for details).

Less than significant

TBIO-5: Potential Impacts to Special-status Raptors and Birds in Construction Laydown Area. The proposed Project has the potential to significantly impact, either directly or through habitat modifications, terrestrial endangered, rare, or threatened species, as listed in Title 14 of the California Code of Regulations (Sections 670.2 or 670.5) or in Title 50, Code of Federal Regulations (Sections 17.11 or 17.12).

TBIO-5: Pre-construction Nesting Surveys at Construction Laydown Area. A qualified wildlife biologist shall perform pre-construction nesting surveys for all bird and raptor species within the construction laydown area and immediate vicinity at least 30 days prior to start of construction. If an active raptor nest is located no activities will occur within 0.25 mile of the nest until young are fledged and the nest is abandoned. If construction activities occur outside of the nesting period (nesting period is typically between February and August), no nesting surveys would be required.

Less than significant

TBIO-6: Potential Impacts to Special-status Plants. The undeveloped grasslands, seasonal wetlands (e.g., saltgrass and seasonal pool) and marshes adjacent to and within the onshore cable route for the Pittsburg Standard Oil Converter Station site would require trenching, drilling, and related construction activities. These areas contain native soils that provide potential habitat for numerous special-status plant species. This is a potentially significant impact.

TBIO-6a: Rare Plant Surveys. Because spring surveys have not yet been conducted in the Project area, prior to construction the entire Pittsburg Standard Oil Converter Station onshore cable route and undeveloped laydown areas, not including the developed and disturbed proposed converter station site or other roads or developed areas along the route, shall be surveyed by qualified botanist(s) for special-status plants at the appropriate flowering period using established CNPS and CDFG protocols (Appendix F).

TBIO-6b: Avoidance of Rare Plant Populations or Compensation for Loss. If special-status plants are detected within the construction zone, or the immediate vicinity, mitigation to avoid impacts within 50 feet of these plants or to compensate for unavoidable impacts or degradation of suitable habitat for these plants shall be identified in coordination with CDFG in accordance with Section 1913(c) of the California Fish and Game Code. Mitigation includes protection of existing rare plant occurrences and habitats by rerouting alignments, as practical, to avoid impacts to special-status plant species, and protecting other grassland and seasonal wetland habitats in the areas where the plants occur. This shall be accomplished through the purchase of credits (at a 1:1 ratio) in an existing service-approved mitigation bank.

Avoidance can also be managed by narrowing the construction ROW at the plant population location and rerouting the cable to the other side of the easement. As a least-desired option, salvage of plants and potential seed bank soils and placement of these plants and materials in adjacent potential habitat that will remain undisturbed may also be considered. Any such salvage process should be planned and coordinated through oversight from a qualified plant ecologist or botanist.

Less than significant

TBIO-7: Potential Impacts to Special-status Plants from Laydown Areas. Use of the proposed and alternative Pittsburg Standard Oil Converter Station laydown areas has the potential to cause disturbance to existing plants and surface soils from construction activities and equipment, and alteration of the sites. These areas may contain native soils that provide potential habitat for special-status plant species. This is a potentially significant impact.

TBIO-7a: Rare Plant Surveys in Laydown Areas. Prior to construction, undeveloped portions of the proposed and alternative laydown areas (e.g., grassland) shall be surveyed by a qualified botanist for special-status plants at the appropriate flowering period using established CNPS and CDFG protocols (Appendix F). These portions of the Project area shall receive both early season (March-May) and late season (July-September) rare plant surveys by a qualified botanist.

TBIO-7b: Avoidance of Special-status Plants. If special-status plants are detected within the laydown areas, or the immediate vicinity, mitigation to avoid impacts within 30 feet of these plants will be implemented. Mitigation includes protection of existing rare plant occurrences and habitats by preventing equipment, materials or other project related activities from disturbing the plants in order to avoid impacts to special-status plant species. Any special-status plant populations located during surveys shall be clearly identified, marked and fenced in order to adjust the extent of the laydown area to avoid the plants. Additionally, following surveys and identification of any sensitive resources, the perimeter of all laydown areas utilized will be fenced with a silt fence in order to prevent disturbances (e.g., soil disturbance, soil compaction, spills) outside of the designated laydown area.

Less than significant

LU-2: Exceedance of Height Allowance. The Project structures exceed height allowances in the City of Pittsburg. This impact is considered to be potentially significant.

LU-2: Height Allowance. The Project proponent shall either: 1) apply for and be granted a height variance from the current zoning to allow for height requirements of the Project; or 2) ensure that the 64-foot-tall structure is located beyond a 14-foot setback from all sides of the property, and also ensure that the poles that make up part of the static electricity grounding grid are no more than 10 percent of the ground area covered by the structure to which they are accessory.

Less than significant

LU-3: Potential Conflict with Kirker Creek Policy. The proposed access road to the Standard Oil site could be inconsistent with the General Plan policy to use Kirker Creek easement as a creekside trail. This impact is considered to be potentially significant.

LU-3: Kirker Creek Policy. The Project proponent shall coordinate with the City of Pittsburg to ensure that the construction of the proposed access road is consistent with future planned development of Kirker Creek creekside trail, to the extent feasible.

Less than significant

TRAFFIC-1: Cumulative Traffic Impacts. The Cumulative Traffic Impacts (Impact TRAFFIC-1) on the regional roadway system described in Section 4.10.3.2.1 applies to the Pittsburg Standard Oil Converter Station site.

TRAFFIC-1: Coordination to Reduce Cumulative Traffic Impacts. Mitigation Measure TRAFFIC-1 described in Section 4.10.3.2.1 shall be applied at the Pittsburg Standard Oil Converter Station site. No other significant cumulative transportation-related impacts would be expected to occur on local roads.

Less than significant

TRAFFIC-2: Oversized Loads. The Oversized Loads impact (Impact TRAFFIC-2) described in Section 4.10.3.2.1 applies to the Pittsburg Standard Oil Converter Station site.

TRAFFIC-2: Coordination of Oversized Loads. Mitigation Measure TRAFFIC-2 described in Section 4.10.3.2.1 shall be applied at the Pittsburg Standard Oil Converter Station site.

Less than significant

TRAFFIC-5: Traffic Impacts During Construction. The new road providing access to the Standard Oil site from the Pittsburg-Antioch Highway would have no traffic controls. At maximum allowable speeds of 50 miles per hour, truck left-turn movements from the Pittsburg-Antioch Highway onto the proposed access road would not be safe without traffic controls, and would result in a potentially significant impact.

TRAFFIC-5: Improve Vehicular Safety. A Traffic Control Plan that identifies measures to improve vehicular safety in this location shall be developed and submitted to the City of Pittsburg for approval prior to project implementation.

Less than significant

NOISE-1: Converter Station Operations Sound Levels. Sound levels from the operation of the Standard Oil Converter Station would range from 77 to 79 dBA Ldn at the property lines, which exceeds the Pittsburg 75 dBA Ldn requirement. This is considered a potentially significant impact.

NOISE-1: Noise Barrier Installation for Converter Station. An acoustical barrier approximately 10 feet high would be erected around a portion of the converter station and an acoustical barrier approximately 13 feet high would be erected around a portion of the emergency generator. If final design determined that an acoustical barrier were unnecessary, it shall not be required.

Less than significant

PS-1: Construction-related Fire Hazards. The construction-related fire hazards impact (Impact PS-1) discussed in Section 4.12.3.2.1 applies at the Pittsburg Standard Oil Converter Station site.

PS-1: Fire Water Service. Mitigation Measure PS-1 discussed in Section 4.12.3.2.1 shall be conducted at this site.

Less than significant

PS-2: Existing Underground Utilities. The underground utilities impact (Impact PS-2) discussed in Section 4.12.3.2.1 applies at the Pittsburg Standard Oil Converter Station site.

PS-2: Utility Survey. Mitigation Measure PS-2 described in Section 4.12.3.2.1 shall be conducted at this site.

Less than significant

PS-3: Operations Fire Hazards. The operations fire hazards impact (Impact PS-3) discussed in Section 4.12.3.2.2 applies at the Pittsburg Standard Oil Converter Station site.

PS-3: Operations Fire Prevention. Mitigation Measure PS-3 discussed in Section 4.12.3.3.2 shall be conducted at the Pittsburg Standard Oil Converter Station site.

Less than significant

PS-4: Water Service. The nearest fire hydrant to the Standard Oil site is located approximately 1,500 feet from the site. Fire protection and water supply services could be impacted due to current unavailability of fire hydrants.

PS-4: Water Service. The Project proponent shall request that an access and water supply review and fire flow test be conducted by the City of Pittsburg. This shall include water supply and flow required for construction. If the water and flow are not adequate, the proponent shall supply water independent of the City's water system. If the water and flow are determined to be adequate, the proponent shall either bring in their own water during construction or obtain a meter with the City Finance Department to tie into a designated fire hydrant during construction.

Less than significant

VIS-1: Converter Station Domination of View. The Pittsburg Standard Oil Converter Station would be visible from the Pittsburg-Antioch Highway. Since the architectural design character of the building and the general character of proposed lighting have not been identified in detail, there is the possibility of generating significant visual impacts based upon the potential of the Project to dominate the scene or become obtrusive on views from the Pittsburg-Antioch Highway.

While this impact has been classified as less than significant, without design controls it could still be adverse. This adversity can be lessened through the application of mitigation measures VIS-1a, VIS-1b and VIS1c.

VIS-1a: Plan Submittal Requirements for Building Materials and Colors. Mitigation Measure VIS-1a described in Section 4.13.3.2 shall be applied at the Pittsburg Standard Oil Converter Station site. Architectural design and site plans, plus a color and material palette, shall be reviewed and approved by the Pittsburg Planning Commission. Final architectural plans and conditions of approval shall be reviewed and signed off by the appropriate planning and building officials prior to operation of the Project.

VIS-1b: Plan Submittal Requirements for Landscaping. Mitigation Measure VIS-1b described in Section 4.13.3.2 shall be applied at the Pittsburg Standard Oil Converter Station site. Landscape design plans shall be reviewed and approved by the Pittsburg Planning Commission. Final landscape plans shall be reviewed and signed off by the appropriate planning and engineering officials prior to operation of the Project.

VIS-1c: Landscaping Plan. The Applicant shall extend the landscape screening along the eastern property line, using plants compatible with the existing vegetation screen along the Pittsburg-Antioch Highway. Such screening would be most visible from KOP P-2 along the side of the facility. In addition, several clusters of major trees from the Pittsburg planting list shall be located to help visually break up the large vertical planes of the DC/valve hall. The intent is not to completely screen the structure, but to soften its mass by providing intervening tree forms. Landscape design plans shall be reviewed and approved by the Pittsburg Planning Commission. Final landscape plans shall be reviewed and signed off by the appropriate planning and engineering officials prior to operation of the Project.

Less than significant

VIS-2: Converter Station will Create Substantial Light and Glare. There is potential for the Project to cast more ambient light into the immediate area than the existing conditions. There is also the possibility that the luminaries of some of the lighting fixtures may be seen directly by travelers along the Pittsburg-Antioch Highway which through the abrupt contrast of the fixtures' light with the surrounding general darkness, may create the effect of glare.

While this impact has been classified as less than significant, without design controls it may still be adverse. This adversity can be lessened through the application of Mitigation Measure VIS-2.

VIS-2: Plan Submittal Requirements for Lighting. Mitigation Measure VIS-2 described in Section 4.13.3.2 shall be applied at the Pittsburg Standard Oil Converter Station site. Lighting plans shall be reviewed and approved by the Pittsburg Planning Commission. Final lighting plans shall be reviewed and signed off by the appropriate planning and building officials prior to operation of the Project.

Less than significant

HAZ-1: Removal of Potentially Hazardous Building Materials Resulting from Demolition. Existing structures on the converter station site contain or potentially contain ACMs and LBP. Improper removal or remediation of these materials could result in a potentially significant environmental impact.

HAZ-1: Complete an ACM Abatement Plan and an LBP Abatement Plan. Phase II ACM and LBP surveys on the converter station site shall be conducted to fill data gaps and to support development of worker safety procedures, in accordance with regulatory requirements to protect construction workers and the public. The ACM and LBP Abatement Plans shall be completed in compliance with applicable regulations based on the historical and newly acquired ACM and LBP data. If ACM and LBP were confirmed to be present in concentrations above regulatory limits, the Project proponent shall use certified asbestos and lead-based paint removal workers, conduct dust monitoring, and dispose of generated wastes offsite. A site Health and Safety Plan shall also be prepared for this work.

Less than significant

HAZ-2: Soil Removal. Soils removed during construction of the converter station and cable routes could be contaminated. Improper sampling, handling, analyzing, or characterizing of the soils could result in a potentially significant environmental impact.

HAZ-2: Soil Removal Protocols. Previously uncharacterized soils that are stained or odiferous shall be segregated on plastic, sampled, and characterized for onsite use or offsite disposal. The Soil and Groundwater Management Plans shall detail storage, transportation, and disposal options for soil and groundwater excavated/extracted during the converter station construction. The plans shall also specify dust monitoring needs for soil excavation and management.

Previously characterized hazardous soils shall be loaded onto trucks for offsite disposal. Hazardous soil disposal requires that hazardous waste manifests accompany the waste. Hazardous waste transporters shall be required to haul hazardous soils to a hazardous waste landfill that can properly accept them. The personnel handling the hazardous soils are required to have met the OSHA hazardous work operations training requirements. A Health and Safety Plan shall be prepared for this work.

Previously characterized non-hazardous soils shall be stockpiled for onsite or offsite reuse or offsite disposal, as needed.

Less than significant

HAZ-3: Construction-phase Hazardous Materials Use. Hazardous materials would be used during construction activities. Misuse, inadequate storage, or improper disposal of these materials could result in a significant environmental impact.

HAZ-3: Reduction of Hazards During Construction Phase. The hazards presented by the use of hazardous materials during the construction phase are well understood, and the appropriate management controls to mitigate potential impacts shall be implemented. These controls include: 1) developing required management plans; 2) secondary containment; 3) separate storage of incompatible materials; and 4) proper training of personnel.

Additionally, construction personnel shall be trained in safety and defensive emergency response procedures. Construction personnel shall also receive hazardous waste-related training that focuses on the recognition of potentially contaminated soil and/or groundwater that may be encountered during subsurface excavations for foundations or pipeline/cable trenches. If such contaminated soil or groundwater is suspected, contingency procedures shall be followed to protect worker safety and public health. All vehicles and construction equipment shall be inspected to ensure that no fluids are leaking (e.g., oil, hydraulic fluid, lubricants, or brake fluid) and that all fuels and fluids are stored in proper, clearly labeled containers.

Hazardous materials that must be disposed of will be disposed of as hazardous waste in accordance with the appropriate regulations for storage, transportation, and disposal of hazardous waste.

Less than significant

HAZ-4: Construction-phase Waste Streams. Improper storage and disposal of solid waste and hazardous construction wastes could result in a potentially significant environmental impact.

HAZ-4: Management of Construction-phase Waste Streams. The onsite management and offsite disposal procedures of solid wastes (including potentially contaminated soil) shall be detailed in a Solid Waste Management Plan for the Project. Waste shall be stockpiled temporarily before disposal offsite. The local fire departments and emergency management teams shall be provided a list of the waste material expected to be generated and stored onsite.

Hazardous wastes generated during construction shall be collected in hazardous waste accumulation containers near the point of generation and moved daily to the construction contractor's 90-day hazardous waste storage area at the converter station site. The accumulated waste shall be delivered to an authorized waste management facility.

The exact volume of hazardous wastes to be generated at the converter station site cannot be estimated at this time, but the estimated amount of excavated soil that would need to be disposed of offsite is estimated at approximately 15,000 cubic yards for this converter station site. Even if this entire amount of excavated soil would need to be disposed of as hazardous waste, it would not exceed a significant portion of the available hazardous waste landfill capacity in California. The capacity details of various landfills for both non-hazardous and hazardous waste are detailed in Table 4.14-5, above. The capacity and estimates for daily volumes of waste received were verified, as detailed in the personal communications provided in the references for this section.

Management of these wastes shall be the responsibility of the construction contractor(s). Typical management practices required for contractor waste include recycling when possible, proper storage of waste and debris, including covering daily to prevent wind dispersion, and weekly pickup of waste with disposal of non-hazardous wastes at local Class III landfills.

Less than significant

HAZ-5: Construction-phase Accidental Spills. An accidental spill or a release of hazardous materials could occur during construction. This impact is considered potentially significant.

HAZ-5: Construction-phase Spill Prevention, Control, and Countermeasures. The following shall be implemented both to prevent spills from occurring and to minimize impacts in the event that they do occur:

  • All spills shall be cleaned up quickly and all workers shall be adequately trained to recognize the hazards associated with such spills.
  • A Spill Prevention, Control, and Countermeasure (SPCC) Plan for the converter station shall be prepared in accordance with federal and state regulations. This plan must be prepared if petroleum products are stored onsite in ASTs with a capacity that equals or exceeds 55 gallons for a single tank or equals or exceeds 1,320 gallons for more than one tank. The SPCC Plan must be prepared before the delivery of petroleum products to the site. The SPCC Plan shall include information on spill response procedures and fuel storage.
  • A Hazardous Materials Business Plan shall be prepared to detail locations and volumes of hazardous materials kept on site. Copies of the HMBP shall be provided to the local Fire Department as provided by the regulations.
  • Material Safety Data Sheets (MSDSs) for each chemical used during construction shall be kept onsite. Construction employees shall be informed of the location and content of the MSDSs, as required by OSHA's Hazard Communication Standard, Title 29 of the Code of Federal Regulations (CFR) Section 1910.1200.
  • In case of an accident, the CCCFPD shall be notified as the first responder. All other federal, state, and local notification requirements shall be followed for any release that exceeds the reportable quantity or threatens to have a significant impact.
  • The Project shall comply with all transportation requirements for hazardous materials on state highways. These requirements apply to both hazardous materials coming onto the sites and hazardous wastes leaving the sites.
  • All vehicles and construction equipment shall be inspected to ensure that there are no leaking fluids (e.g., oil, hydraulic, lubricants, or brake fluid) and that all fuels and fluids are stored in proper, labeled containers. Any observation of spills, leaking fluids, or improperly stored fluids shall trigger the issuance of "stop work" notice until the problem is resolved, including the removal of any soil contaminated by vehicle fluids.

    Less than significant

    HAZ-6: Construction-phase Dust and Volatilization of Contaminants. Excavation of contaminated soil and the generation of hazardous waste soils could result in construction dust and volatilization of contaminants that pose environmental and human health risks, particularly to construction workers. This impact is considered potentially significant.

    HAZ-6: Reduction of Construction Dust and Volatilization of Contaminants. Dust control measures (i.e., keeping the soil wet during excavation) shall be implemented during excavation and construction activities, and dust monitoring shall be performed. Suspected contaminated soil that is stockpiled on the sites shall be covered daily with plastic to prevent volatilization of contaminants and to control dust. Contaminated soil may also be loaded directly onto trucks for transport to an appropriate offsite disposal facility. The loaded soils shall be properly covered and manifested as necessary. Dust monitoring shall be performed during excavation and loading of hazardous soils. The accumulated waste shall then be delivered to an authorized waste management facility. Dust monitoring shall confirm that the dust control measures are effectively protecting site workers and the public.

    Less than significant

    HAZ-7: Contaminated Groundwater. The converter station site may have contaminated groundwater. This groundwater may be encountered during excavation, construction dewatering, or other subgrade activities. Control or remediation of the site groundwater may be a requirement for redevelopment of the property by the lead regulatory agency for the proposed Project. Failure to properly treat and/or dispose of water collected during dewatering activities or to control the contaminated groundwater flow could result in a potentially significant impact to the site or to downgradient sites and/or water bodies.

    HAZ-7: Contaminated Groundwater Control. If groundwater is encountered during construction at the converter station site, the water shall be collected onsite in a tank or tanks, sampled, and analyzed. Based on the analytical data, the water shall be characterized for disposal by one of the following methods:

    • Used onsite for dust control.
    • Treated onsite and discharged under the authority of a general National Pollutant Discharge Elimination System (NPDES) permit. (Treatment options would include, but are not limited to, filtration or filtration and treatment by granular-activated carbon [GAC]. Treatment residuals would be sampled, analyzed, characterized, and disposed of offsite in compliance with applicable regulations.)
    • Disposed of offsite at a commercial water treatment facility in compliance with applicable regulations.

    If groundwater was encountered at the Pittsburg Standard Oil Converter Station site and it was found to be contaminated, it is possible that the Regional Water Quality Control Board would require groundwater control as part of the development plan for the Project on the site. Contamination at the Pittsburg Standard Oil site, if any, would likely be caused by offsite sources which would probably not require onsite remedial action. Potential groundwater-remedial strategies would depend on a number of factors including: site contaminants, evaluation of impacts to human health and the environment, and evaluation of the technical merits of available remedial strategies. Based on these factors the final selection would be negotiated between the RWQCB and TBC. Potential remedial options provided herein are for informational purposes only. Potential groundwater control methodologies include installing a slurry wall around a portion or the entire contaminated site combined with groundwater pump and treatment and discharge of treated groundwater to a storm drain/sewer system under the authority of an NPDES permit. Other alternative technologies include in-situ biological treatment and in-situ oxidation or reduction, depending on the site-specific contaminants and hydrogeological conditions.

    Less than significant

    HAZ-8: Operations-phase Hazardous Materials Usage. Hazardous materials shall be used during operations and maintenance activities. Misuse, inadequate storage, or improper disposal of these materials could result in a potentially significant environmental impact.

    HAZ-8: Control of Operations-phase Hazardous Materials. A Hazardous Materials Business Plan (HMBP) shall be developed and implemented prior to turnover of site management from the construction contractor to the operating company. All hazardous materials shall be handled and stored in accordance with applicable codes and regulations. Storage quantities of all hazardous materials shall be minimized, and non-hazardous materials shall be substituted for hazardous materials at the converter station to the extent practicable. Small-quantity chemicals used for maintenance tasks shall be kept in appropriate inflammable material or corrosive material storage lockers. Bulk chemicals shall be stored in ASTs, and all other chemicals shall be stored in their original shipping containers. Incompatible materials shall be stored in separate storage containment areas. Chemical storage areas and transfer areas shall be equipped with secondary containment sufficient in size to contain the volume of the largest container or tank, including an allowance for rainwater. Areas susceptible to potential leaks and/or spills shall be paved and bermed or otherwise secondarily contained. Specifically, the transformers and the diesel ASTs would have secondary containment. Periodic inspections shall be conducted to ensure that all containers are secure and properly marked. Piping and tanks will be protected from potential traffic hazards by concrete or other barriers. Hazardous materials will be delivered to the converter station periodically. Transportation of these materials shall comply with all applicable regulations of the U.S. Department of Transportation, the EPA, DTSC, the California Highway Patrol, and the State Fire Marshal. An HMBP shall be prepared prior to delivery of specified hazardous materials to the converter station in conformance with Title 19 of the California Code of Regulations (CCR) and California Health and Safety Code Section 25504. The HMBP requires facilities to develop the following information:

    • Facility map showing locations of hazardous materials and emergency response equipment

    • Hazardous materials inventory, including MSDSs for all hazardous materials stored and used onsite

    • Emergency contact information
    • Emergency response plans and procedures
    • Emergency notification procedures
    • Emergency response training for all employees

    Less than significant

    HAZ-9: Operations-phase Waste Streams. Improper storage and disposal of operational wastes could result in a significant environmental impact. This impact is considered potentially significant.

    HAZ-9: Manage Waste Generation, Storage, and Disposal During Operations Phase. Before facility start-up, an application shall be made to DTSC for a hazardous waste generator number. The facility shall not treat, store, or dispose of hazardous waste in a manner that will cause the facility to be characterized as a treatment, storage and disposal facility (TSDF). A detailed waste management plan shall be prepared prior to start-up to ensure proper storage, labeling, packaging, record keeping, manifesting, minimization, and disposal of all hazardous materials and wastes. The waste management plan will include:

    • A description of each hazardous waste stream
    • Handling, transport, treatment, and disposal procedures for each waste
    • Preparedness, prevention, contingency, and emergency procedures
    • Personnel training

    Scrap materials such as paper, packing materials, glass, metal, and plastic shall be segregated and managed for recycling. Non-recyclable inert wastes shall be stored in covered trash bins in accordance with local ordinances and picked up by an authorized local trash hauler on a regular basis for transport and disposal in suitable landfill.

    Skimmed oil collected from equipment drains and other liquids from equipment shall be transported by an authorized carrier to a certified recycling facility.

    Less than significant

    HAZ-10: Operations-phase Accidental Spills. Non-compliance with regulatory requirements associated with storage, use, and containment of hazardous materials and/or petroleum hydrocarbons could result in accidental spills. The impact from accidental spills of these materials is considered potentially significant.

    HAZ-10: Operations-phase Spill Prevention, Controls, and Countermeasures. The following shall be implemented during operations:

    • All workers shall be adequately trained to recognize the hazards associated with accidental spills. Training shall include ensuring that personnel who maintain the facility are adequately trained to recognize the hazards associated with such spills. Personnel who maintain the facility will be trained in the use of fire suppression equipment, evacuation, notification, and other defensive emergency response procedures. Maintenance personnel will also be trained in hazardous materials and hazardous waste awareness, handling, and management as required for their level of responsibility.
    • The proper use of safety procedures and development and implementation of a project-specific SPCC Plan will help prevent such incidents. The SPCC Plan will include information on spill response procedures and fuel storage.
    • An MSDS will be kept onsite for each onsite chemical.
    • The programs to be implemented to protect worker health and safety shall also benefit public safety. Facility design shall include redundant controls and monitoring systems to minimize the potential for conditions in which accidental spills could occur. Potential public health impacts associated with facilities operation will be mitigated by development and implementation of Emergency Response Plans, an SPCC Plan, secondary containment structures for oils and other hazardous materials, safety programs, and employee training.

    Less than significant

    HAZ-11: Operations-phase Fire and Explosion Risk. Non-compliance with regulatory requirements associated with storage, use, and containment of flammable materials could result in a fire or explosion. If the onsite fire protection equipment could not address the fire, outside agencies would need to be called. This impact is considered potentially significant. The impact of a fire or explosion is considered potentially significant.

    HAZ-11: Reduction of Fire and Explosion Risk and Emergency Support During Operations Phase. The flashpoints of transformer oil and diesel fuel are 295°F and 100°F, respectively, and the auto ignition points are 484°F and 494°F, respectively (Sax, 1992; MSDS for transformer oil; MSDS for diesel fuel). The National Fire Prevention Association (NFPA) assigns lubricating oils a fire hazard rating of 1, meaning that the materials "must be preheated before ignition can occur. Materials of these types require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur" (Siemens, 2006).

    The converter station shall have onsite fire protection systems (including emergency backup systems). During the detailed design phase of the proposed Project, potential fire protection designs and systems shall be reviewed with local agencies to finalize design details.

    In general, the fire protection system shall consist of automatic detection and firefighting equipment. The fire detection control panel shall be located in the control room and shall be connected to the control and protection system for remote annunciation. The fire alarm shall be initiated automatically by smoke, heat, or flame detectors; or manually by push-button. A combination of detectors shall be used, including infrared and ultraviolet detectors, ionization and optical smoke detectors, and rate-of-rise temperature-sensitive detectors, depending on the equipment and/or space being monitored.

    Audible alarms and flashing lights shall be activated in the event of a fire. The equipment or area where the alarm is triggered shall be indicated on the control panel. The firefighting equipment would initiate automatically, using water sprays and curtains or an appropriate gas-extinguishing agent.

    Fire detection and automatic firefighting equipment shall be connected to a power supply within the fire-detection control panel, which will be connected to the mains via a power supply/battery charger unit with an internal 24-volt battery. A pump house shall be included within the facility with 2 diesel fire-water pumps, each 225 kW. The fire-water pump and backup emergency lighting shall be electrically powered by a diesel-powered generator capable of operating at full standby without refueling for 96 hours, as required in a seismically active area.

    Less than significant

    HAZ-12: Impacts from Seismic Activity. Failure to abide by the building code for Seismic Zone 4 could lead to damage to the facilities and resulting spills of hazardous materials. This impact could be potentially significant.

    HAZ-12: Manage Seismic Activity. To minimize seismic damage to the facilities with resulting hazardous materials spills, the designers and construction contractor shall follow the Uniform Building Code for Seismic Zone 4. This action would reduce Impact HAZ-12 to a less-than-significant level.

    Less than significant

    Potentially Significant Impact

    Proposed Mitigation Measure(s)

    Resulting Level of Significance

    Offshore Cable Route

       

    AIR-3: Marine Construction – Criteria Pollutants. Based on Project marine emissions rates in comparison to background levels, the air quality impacts of criteria pollutant emissions of the marine construction phase are considered to be potentially significant. Based on Project marine emissions rates in comparison to background levels, the air quality impacts of criteria pollutant emissions of the marine construction phase are considered to be potentially significant.

    AIR-3: Marine Vessel Emission Controls. The following shall be implemented to control emissions from vessels owned by Prysmian:

    • Use California diesel, Purinox, biodiesel, or other fuel (whichever is feasible and would result in lowest emissions)
    • Minimize diesel engine fuel usage as much as possible
    • Use shore-side power when docked instead of running engines, where feasible

    Less than significant

    AIR-4: Marine Construction – Toxic Air Contaminants. Although there are no established impact significance criteria set forth by BAAQMD, the diesel PM emissions from marine construction may be potentially significant.

    AIR-4: Implement Mitigation AIR-3. Implement Mitigation Measure AIR-3.

    Less than significant

    WATER-5: Water Quality Impacts from Cable Laying Operation. Nearshore and offshore sediment in the Potrero area is contaminated with elevated levels of PAHs. Disturbance of these sediments could result in substantial water quality impacts. This would be considered a potentially significant impact.

    WATER-5: Avoidance of Sediment Contamination. To avoid potential known nearshore and offshore sediment contamination, the HDD shall be completed as far offshore as is feasible and remote from RMP station CB012S near Potrero Point in San Francisco. Hydroplow or equivalent technology activities shall also avoid known contamination in the area of station CB012S. Confirmation sediment sampling shall be performed at the location where the HDD emerges into the Bay and the results would be considered and addressed prior to commencement of construction near this location.

    Less than significant

    WATER-6: Water Quality Impacts from Dredging and Dredge Material Disposal. Dredging at two locations in New York Slough and disposal of the dredge material has the potential to significantly impact water quality in the Bay.

    WATER-6: Dredging Controls and Sediment Testing Program. A consolidated Dredging – Dredge Material Reuse/Disposal permit shall be obtained through the San Francisco DMMO. In accordance with this permit, a dredged sediment testing program shall be conducted on dredged material to determine whether the material is suitable for reuse. If sediment is not suitable for reuse, it would need to be transported to an acceptable disposal site.

    Less than significant

    WATER-7: Water Quality Impacts from Vessel Fuel Spills. Water quality degradation from vessel fuel spills would likely not be significant in light of its low probability and the past record. However, a potentially significant spill could still occur. This event would constitute a potentially significant impact.

    WATER-7: Vessel Fuel Spill Response Plan. All vessel operators associated with the proposed Project shall update their contingency plans and continue to use emergency response services for pollution incidents. Review of updates and modifications to plans shall be done under the USCG's regular oversight of oil spill contingency plans. The work of updating and expanding the spill response plans shall be based on NOAA's Environmental Sensitivity Index (ESI), which involves the systematic compilation in a standardized format of information related to coastal shoreline sensitivity, biological resources, and human uses.

    Less than significant

    CUL-3: Offshore Cable Route Archaeological Resources. Submerged and buried archaeological resources have been identified along the offshore AC cable route associated with the Pittsburg Standard Oil Converter Station and the entire offshore DC cable route. Disturbance of these historical resources is considered a potentially significant impact.

    CUL-3a: Archaeological Resources Geophysical Survey. A geophysical remote-sensing survey shall be conducted along the offshore cable route to detect any potential submerged or sub-bottom archaeological resources. Depending on the geographic or bathymetric setting, an appropriate remote-sensing field survey could include deployment of a side scan sonar, sub-bottom profiler, and magnetometer to help detect these resources. The results of the geophysical survey will be reviewed by a qualified marine archaeologist and a report documenting these efforts and interpreting the results shall be produced.

    CUL-3b: Archaeological Resources Avoidance. Potential submerged and/or buried archaeological resources detected through the geophysical survey shall be avoided unless they can satisfactorily be determined to not represent archaeological resources (e.g., modern debris, existing infrastructure) as documented in the technical report.

    CUL-3c: Archaeological Resources Supplemental Underwater Investigation. If it is infeasible to avoid potential submerged and/or buried archaeological resources, follow-up diver survey or Remote Operated Vehicle investigations might be required to positively identify the targets. If targets are determined to be archaeological resources, they should be evaluated against the NRHP/CRHR significance criteria. If the resources are not eligible for the NRHP/CRHR, then no further consideration of these resources is required. If the resources are eligible for the NRHP/CRHR, Data Recovery (Mitigation Measure CUL-1b) may be required.

    Less than significant

    LU-4: Increased Vessel Traffic. Project construction activities would temporarily increase vessel traffic in the Bay. Recreational users of the Bay could experience a temporary increased risk from additional vessel traffic. This impact is considered to be potentially significant.

    LU-4a: Vessel Crew Procedures. Marine crews shall watch for navigational hazards (i.e., during periods of high use by recreational boaters including windsurfers within the vicinity of selected terminal locations; during periods of high recreational use, such as weekends or race events; or when weather hazards exist) to reduce the risk of incidents involving construction vessels and recreational users in the Bay.

    LU-4b: Coast Guard Coordination. Construction crew management shall coordinate construction activities with the USCG Safety Branch to ensure that no marine recreational events conflicts arise. The Project coordinator would include information to the USCG which would issue a Local Notice to Mariners. In addition, each affected harbor district will be made aware of the timing of water-based Project activities such as the cable laying operations. Applicable navigation rules will be enforced including the Cable Act of 1992 (47 CFR §76) which states that other vessels must maintain a 1.15 mile (1-nm) separation from a vessel laying or repairing an undersea cable.

    Less than significant

    LU-5: Potential Conflict with Local Plans and Policies. Cable installation is not expected to conflict with local jurisdictions plans or policies. Based on available feedback, no apparent conflict in land use plans or policies would occur with installation of the submarine cable. However, Contra Costa County has indicated that their agency would incur some level of responsibility and could require relocation of utilities where necessary. In addition, the City of Martinez requires a Conditional Use Permit for installation of the offshore cable. Not obtaining appropriate planning permits or coordinating with local agencies would be considered a potentially significant impact.

    LU-5: Local Plans and Policies Coordination. The Project proponent shall coordinate with the City of Martinez and Contra Costa County to provide adequate notification and gain the appropriate permits and authorization required for installation of the submarine cable.

    Less than significant

    MTRANS-1: Vessel Navigation Hazards. For the duration of construction, the vessels engaged in cable laying would present a potential hazard to navigation on the Bay. The cable-laying vessels themselves would be "restricted in their ability to maneuver." This means that the nature of the vessels themselves or of their operations limits their ability to take actions to avoid collisions that would be expected of otherwise fully maneuverable vessels. Vessels are by definition restricted in their ability to maneuver when engaged in laying, servicing, or picking up a navigational mark, submarine cable, or pipeline. Statutory navigation rules define the responsibilities of vessels restricted in their ability to maneuver, and of other vessels operating in their vicinity, all aimed at preventing collisions or other incidents. Non-compliance with these rules would be considered to result in a potentially significant impact.

    MTRANS-1a: Project Registration, Information and Pilotage. Large construction vessels like the C/S Giulio Verne and any support vessels shall be required to notify the VTS at the beginning and end of each transit, and would be monitored continuously. The USCG would also notify operators of vessels in the area of the construction activities via Notices to Mariners. To ensure safe entrance into the Bay, all ships operating under foreign registry, like the Giulio Verne, are required to have a San Francisco Bar Pilot navigate the ship into the Bay.

    MTRANS-1b: Compliance with Navigation Rules. The vessels involved in cable laying shall be required to identify themselves and operate in accordance with the COLREGS. The applicable navigation rules for San Francisco Bay shall regulate the cable laying operations and are designed to prevent collisions. Within the Bay, the operators of all vessels engaged in the Project shall have the legal responsibility to preclude hazardous situations, according to the applicable navigation rules

    MTRANS-1c: Precautionary Area. A safety precautionary area shall be established around the construction vessels, and will be identified via the USCG Notice to Mariners to make vessels operating in the area aware of Project activities. All cable-laying vessels shall also operate in accordance with the applicable navigation rules including the Cable Act of 1992.

    Less than significant


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