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HomeMy WebLinkAbout8.2 Attch 7 Mitigation Measures Exh C EXHIBIT C FINDINGS CONCERNING SIGNIFICANT IMPACTS AND MITIGATION MEASURES Pursuant to Public Resources Code section 21081 and CEQA Guidelines section 15091, the City Council hereby makes these findings with respect to the potential for significant environmental impacts from implementation of the Heritage Park project PLPA-2013-00002 ("Project") and means for mitigating those impacts. For the purpose of these findings, the term "EIR" means the Draft and Final EIR documents collectively, unless otherwise specified. These findings do not attempt to describe the full analysis of each environmental impact contained in the EIR. Instead, the findings provide a summary description of each impact, describe the applicable mitigation measures identified in the EIR and adopted by the City, and state the findings on the significance of each impact after imposition of the adopted mitigation measures. A full explanation of these environmental findings and conclusions is in the EIR, and these findings hereby incorporate by reference the discussion and analysis in those documents supporting the EIR's determinations regarding mitigation measures and the Project's impacts and mitigation measures designed to address those impacts. The facts supporting these findings are found in the record as a whole for the Project. In making these findings, the City ratifies, adopts, and incorporates into these findings the analysis and explanation in the EIR, and ratifies, adopts, and incorporates into these findings the determinations and conclusions of the EIR relating to environmental impacts and mitigation measures,except to the extent that any such determinations and conclusions are specifically and expressly modified by these findings. Impact 3.2-1: Short-term Construction Emissions. The proposed project may result in future short-term air quality impacts associated with construction activities, including grading, operation of equipment, and demolition of existing structures on the project site. This is a potentially significant impact. MM 3.2-1a: Implement Short-term Construction Best Management Practices. Prior to issuance of any Grading or Demolition Permit, the City Engineer and the Chief Building Official shall confirm that the Grading Plan, Building Plans, and contract specifications stipulate that the proposed project adhere to the most recent BAAQMD CEQA guidelines regarding short-term construction best management practices. These may include the following: • Water all active construction areas to maintain 12 percent soil moisture. • All grading shall be suspended when winds exceed 20 miles per hour. • All haul trucks transporting soil, sand, or other loose material off-site shall be covered. Pave,apply water two times daily,or apply(non-toxic)soil stabilizers on all unpaved access roads,parking areas, and staging areas at construction sites. Hydroseed or apply non-toxic soil stabilizers to inactive construction areas (previously graded areas inactive for ten days or more). Enclose, cover, water twice daily or apply non-toxic soil binders to exposed stockpiles (dirt, sand, etc.). 1 • All visible mud or dirt track-out onto adjacent public roads shall be removed using wet power vacuum street sweepers at least once per day. Install sandbags or other erosion control measures to prevent silt runoff to public roadways. • Site access points from public roadways shall be paved or treated to prevent track-out. • Replace vegetation in disturbed areas as quickly as possible. • All vehicle speeds on unpaved roads shall be limited to 15 mph. • All roadways, driveways, and sidewalks to be paved shall be completed as soon as possible. • Idling times shall be minimized either by shutting equipment off when not in use or reducing the maximum idling time to two minutes. Clear signage shall be provided for construction workers at all access points. • All construction equipment shall be maintained and properly tuned in accordance with manufacturer's specifications. All equipment shall be checked by a certified mechanic and determined to be running in proper condition prior to operation. • Post a publicly visible sign with the telephone number and person to contact at the City regarding dust complaints. This person shall respond and take corrective action within 48 hours. The BAAQMD's phone number shall also be visible to ensure compliance with applicable regulations. MM 3.2-1 b: Implement NOX Reduction Measures. The following measures shall be implemented during construction to reduce NOx related emissions. They shall be included in the Grading Plan, Building Plans,and contract specifications and shall include the following: • All construction equipment, diesel trucks, and generators shall be equipped with Best Available Control Technology for emission reductions of NOx. • All contractors shall use equipment that meets the California Air Resources Board's most recent certification standard for off-road heavy duty diesel engines. • The idling time of diesel powered construction equipment shall be minimized to two minutes. • The project shall develop a plan demonstrating that the off-road equipment(more than 50 horsepower)to be used in the construction project (i.e., owned, leased, and subcontractor vehicles) would achieve a project wide fleet-average 20 percent NOx reduction and 45 percent PM reduction compared to the most recent California Air Resources Board fleet average. Acceptable options for reducing emissions include the use of late model engines, low-emission diesel products, alternative fuels, engine retrofit technology, after-treatment products, add-on devices such as particulate filters, and/or other options as such become available. • Utilize existing power sources(i.e.,electrical power)when available. This measure would minimize the use of higher polluting gas or diesel generators. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. 2 Rationale for Finding: Implementation of the mitigation measures will reduce exhaust emissions from construction equipment and trucks by nearly half as shown in DEIR Table 3,2-5;the reduced emissions would comply with BAAQMD thresholds for NOx emissions. Including the NOx reduction measures in grading and other construction plans ensures that the measures will be implemented in the construction process. Implementation of the measures will reduce nuisance fugitive dust emissions as recommended by BAAQMD. Therefore, after applying the mitigation measure, the impact would be less than significant. Impact3.2-2: Long-Term Operational Emissions—Regional Emissions. Implementation of the proposed project could result in regional air emissions from operational sources in exceedance of BAAQMD significance thresholds. This is a potentially significant impact, MM 3.2-2: Implement only natural gas hearths in residential units. The proposed project shall include natural gas hearths only in the proposed on-site residential units. These shall be incorporated into the project design to reduce operational ROG air emissions to ensure consistency with BAAQMD emission thresholds. The project applicant shall demonstrate the incorporation of natural gas hearths priorto approval of final design documents. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the project which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: Restricting hearths in the residences to natural gas only would substantially reduce area emissions from the Project, resulting in emissions well below the ROG thresholds. Therefore, after applying the mitigation measure, the impact would be less than significant. Impact 3.2-4: Long-Term Operational Emissions—Toxics Air Contaminants. The proposed project could expose sensitive receptors to substantial long-term operational pollutant concentrations, particularly from vehicles and trucks on adjacent roadways. These impacts are potentially significant. Mitigation Measures 3.2-1a and 1b. See above description. MM 3.2-4: Provide Upgraded Ventilation Systems. Prior to the issuance of building permits,the Community Development Director shall confirm that all building plans and contract specifications require residential dwelling units within 600 feet of the north edge of the 1-580 general purpose lanes to be equipped with sealed heating, ventilation, and air-conditioning (HVAC)systems. The sealed air system shall be designed so that all ambient air introduced into the interior living space would be filtered to remove diesel particulate matter(DPM)and other particulate matter at minimum of up to 75 percent of particulates of 0.3 micron or larger in size from the ambient air that is introduced to the system, and 90 percent of particulates of 1 micron or larger. This mitigation measure also requires a commitment by the applicant to ensure regular maintenance and replacement of filters as needed. This requirement will be included as part of the conditions of approval and could be done as part of the responsibility of the Home Owner's Association. Project design specifications shall stipulate that the heating ventilation and air conditioning (HVAC) system intakes shall be placed as far away from 1-580 as feasible. The design shall also require positive pressure with the HVAC system in all occupied spaces to prevent the incursion of outside air that bypasses the HVAC filters. 3 Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: Implementation of the mitigations will reduce exposure to diesel exhaust for the residences within 600 feet of 1-580 to less than applicable exposure thresholds . The mitigations employ a combination of techniques to reduce such exposure. The mitigations require use of sealed ventilation systems to filter and remove diesel and other particulates so the amount entering the homes would be reduced by 75% or more. By requiring positive pressure in the ventilation system, the mitigation further limits the amount of diesel exhaust exposure to residents because outside air would not bypass the filters. By requiring the HOA to maintain and replace the filters, the mitigation ensures that the filtration system will function as intended. In addition to filtering,the measure ensures that ventilation system intakes are located as far from the freeway as feasible since the exposure decreases with distance from the freeway,thereby further decreasing exposure to residents. Therefore, after applying the mitigation measure, the impact would be less than significant. Impact 3.2.6: Long-Term Operational Emissions—Clean Air Plan Consistency. Construction-related and operational criteria pollutant emissions may conflict with or obstruct implementation of the applicable Air Quality Plan. Therefore, implementation of the proposed project would result in a potentially significant impact. Mitigation Measure 3.2-2. See above description. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: By restricting the use of residence hearths to natural gas only, the mitigation ensures that implementation of the Project would reduce ROG emissions to below applicable standards,thus ensuring compliance with state ozone standards and the 2010 Bay Area Clean Air Plan. Therefore, after applying the mitigation measure, the impact would be less than significant, Impact 3.3-2: Archaeological Resources. The proposed project has been previously disturbed with development of the Heritage Park commercial/office complex. However, based on the existence of the archaeological resources within and adjacent to the Dublin Village Area Specific Plan,there is a high probability of identifying Native American archaeological resources and encountering historic-period archaeological resources within the Specific Plan area and at the project site, Therefore, this is a potentially significant impact. MM 3.3-2a: Archaeological Monitoring. An archaeological monitor shall be present at the project site during ground disturbing activities (e.g. grading and excavation) during construction of the proposed project. If anything is discovered during the archaeological monitoring, the project applicant shall implement Mitigation Measure 3.3-2b. MM 3.3-2b: Halt Work/Archaeological Evaluation/Site Specific Mitigation. If any potential archaeological, pre-historic or cultural artifacts are encountered during site grading or other construction activities, all ground 4 disturbance within 50 feet of the discovery shall be halted until a qualified archaeologist can identify and evaluate the resource(s)in accordance with State CEQA Guidelines 15064.5(f). The archeological consultant shall immediately notify the project sponsor and the City staff of the encountered archeological deposit. If the deposit does not qualify as an archaeological resource,then no further protection or study is necessary. If the deposit does qualify as an archaeological resource then the impacts shall be avoided by project activities. If the deposit cannot be avoided,adverse impacts to the deposit shall be addressed in accordance with State CEQA Guidelines 15126.4(b). Measures may include, but are not limited to archaeological data recovery,etc. Upon completion of the assessment by the archaeologist, a professional-quality report shall be submitted to the City, the project applicant, and the Northwest Information Center at Sonoma State University in Rohnert Park. The project applicant shall fund and implement the mitigation in accordance with Section 15064.5(c)through (f)of the CEQA Guidelines and Public Resources Code 21083.2. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: The mitigations ensure that currently unknown archeological resources will not be inadvertently disturbed or destroyed as a result of construction activities. Through the requirement for an archeological monitor, the mitigations also ensure that a knowledgeable professional will be present during construction activities to recognize and identify potential artifacts or other resources. Therefore,after applying the mitigation measure, the impact would be less than significant. Impact 3.3-3: Paleontological Resources. No paleontological resources are known to exist within the project vicinity. However, the presence of unknown paleontological resources could be discovered during site preparation and grading activities, which would be a potentially significant impact. MM 3.3-3: Halt Work/Paleontological Evaluation/Site Specific Mitigation. If paleontological resources are encountered during subsurface construction activities, all work within 50 feet of the discovery shall be redirected until a qualified paleontologist can evaluate the finds. If the paleontological resources are found to be significant,they shall be avoided by project construction activities and recovered by a qualified paleontologist. Upon completion of the recovery, a paleontological assessment shall be conducted by a qualified paleontologist to determine if further monitoring for paleontological resources is required. The assessment shall include: l)the results of any geotechnical investigation prepared for the project area; 2) specific details of the construction plans for the project area; 3) background research; and 4) limited subsurface investigation within the project area. If a high potential to encounter paleontological resources is confirmed,a monitoring plan of further project subsurface construction shall be prepared in conjunction with this assessment. After project subsurface construction has ended, a report documenting monitoring, methods, findings, and further recommendations regarding paleontological resources shall be prepared and submitted to the Director of Community Development. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. 5 Rationale for Finding: The mitigations ensure that currently unknown paleontological resources will not be inadvertently disturbed or destroyed as a result of construction activities. Therefore, after applying the mitigation measure, the impact would be less than significant. Impact 3.3-4: Disturb Human Remains Interred Outside of Formal Cemeteries. Due to the disturbed nature of the project site, there are no known human remains interred outside of formal cemeteries that are anticipated to be disturbed during short-term construction activities, However, human remains could be discovered during site preparation and grading activities, which would be a potentially significant impact. MM 3.3-4: Halt Work/Coroner's Evaluation/Native American Heritage Consultant/Compllance with Most Likely Descendent Recommendations. In the event that human remains are encountered during grading and site preparation activities,all ground-disturbing work within 50 feet of the remains shall cease immediately and a qualified archaeologist shall notify the Office of the Alameda County Coroner and advise that office as to whether the remains are likely to be Native American. If determined to be Native American, the Alameda County Coroner's Office shall notify the Native American Heritage Commission of the find, which in turn will then appoint a"Most Likely Descendent. (MLD)."The MILD in consultation with the archaeological consultant and the project sponsor will advise and help formulate an appropriate plan for treatment of the remains,which might include recordation, removal, and scientific study of the remains and any associated artifacts, After completion of the analysis and preparation of the report of findings, the remains and associated grave goods shall be returned to the MLD for burial. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: The mitigations ensure that currently unknown human remains will not be inadvertently disturbed or destroyed through ground disturbance as a result of construction activities. Therefore, after applying the mitigation measure, the impact would be less than significant. Impact 3.4-3: Exposure of People or Structures to Seismic Ground Shaking. Ground shaking is likely to occur at the project site and in the project vicinity in the event of a major earthquake on one of the nearby faults resulting in the exposure of people and/or structures to potentially significant adverse effects,including the risk of loss, injury or death. This is considered a potentially significant impact. MM 3.4-3: Preparation of Design-Level Geotechnical Report. The project applicant shall consult with a registered geotechnical engineer to prepare a design level geotechnical report that incorporates the recommendations in the geotechnical investigation by Stevens Ferrone and Bailey Engineering Company, Inc, (March 2012). These include maintaining a minimum 25 foot setback from the center line of the Calaveras fault trace,construction of post-tensioned slab foundations,and over-excavation of disturbed weak soils and fill. The design level geotechnical report shall address site preparation and grading (including measures to address potential liquefaction and expansive soils), building foundations, CBC seismic design parameters, and preliminary pavement sections. This report shall be submitted in conjunction with Building Permit application(s) and reviewed and approved by the City. Recommendations from the design-level geotechnical report shall be incorporated into the project design and construction documents. Net Impact After Mitigation: Less than Significant 6 Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: The Project is subject to the California Building Code ("CBC") which recognizes the seismic risk of developing in this state and includes stringent design and construction requirements and engineering applicable not only to future Project structures but also to grading,foundations,retaining walls and other structures. The Project also prepared site- and project-specific geotechnical studies with recommendations which the City peer-reviewed as part of the EIR process, Building from the background of the CBC regulatory scheme and the existing preliminary geotechnical studies,the identified mitigation sets forth the next steps for the Project, consistent with City requirements for design-level geotechnical studies to show how the CBC requirements and the preliminary study recommendations will be implemented through specific structural and improvement design. Though the mitigation,the Project will continue the process of increasingly refined engineering review to ensure that ground shaking is addressed at each step of the development process. Therefore, after applying the mitigation measure, the impact would be less than significant. Impact 3.4-4: Exposure of People or Structures to Liquefaction. The proposed project could expose people or structures to potential substantial adverse effects of liquefaction. This is a potentially significant impact. MM 3.4-3: Preparation of Design-Level Geotechnical Report. See above description. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: The required design-level geotechnical report will build on the existing geotechnical studies to show how liquefaction regulations in the CBC, and the City's standard engineering practices and design criteria for soil stability will be implemented in project construction and improvement. The mitigation will ensure that proper soil engineering, foundation design and construction will be implemented to avoid hazards from seismic-related ground failure such as liquefaction. Therefore,after applying the mitigation measure,the impact would be less than significant. Impact 3.4-6: Exposure to Expansive Soil. Implementation of the proposed project would include future development within an area that has expansive soils. With adherence to the City's Building Code and CBC requirements, this is a potentially significant impact. MM 3.4-3: Preparation of Design-Level Geotechnical Report. See above description. Net Impact After Mitigation: Less than significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: The required design-level geotechnical report will build on the existing geotechnical studies to show how regulations in the CBC, and the City's standard engineering practices and design criteria 7 for soil stability will be implemented in project construction and improvement. The mitigation will ensure that proper soil engineering, foundation design and construction will be implemented to avoid hazards from expansive soils. Therefore, after applying the mitigation measure, the impact would be less than significant. Impact 3.6-4: Accidental Conditions During Construction. Construction activities at the project site may result in accidental conditions as a result of potentially contaminated groundwater underlying the project site. This is a potentially significant impact. MM 3.6-4: Review Files for the former Dublin Square Shopping Center and Prepare a Worker Safety Plan. Prior to issuance of a grading permit, an environmental consultant with Phase II/site characterization experience shall review the existing files maintained by the Department of Toxic Substances and Control, the Regional Water Quality Control Board, and the Alameda County Department of Environmental Health for the Heritage Park site and prepare a worker safety plan to ensure construction worker safety during grading/excavation activities. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: The mitigation recognizes the potential for contaminated groundwater from previous underground storage tank releases and ensures that an effective construction worker safety program will be crafted based on existing information from regulatory agencies,so as to limit exposure of workers to hazardous materials. Therefore, after applying the mitigation measure, the impact would be less than significant. Impact 3.6-5: Accidental Conditions During Operation. During operation of the proposed project,there is the potential for the residential uses to be exposed to hazardous vapors as a result of contaminated groundwater in the vicinity of the project site. potentially significant impact. MM 3.6-5: Conduct a Vapor Intrusion Investigation. Prior to issuance of building permits, vapor intrusion investigations shall be conducted by a qualified Environmental Professional, in consultation with the Alameda County Department of Environmental Health (ACDEH) or other appropriate agency if applicable. Should the environmental professional determine that proposed buildings could be impacted by vapor intrusion, the Environmental Professional shall recommend specific design measures to be incorporated into the building design that would reduce these indoor air quality concentrations to below applicable regulatory thresholds. Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: The mitigation follows up on the existing Phase I ESA to determine if vapor intrusion will occur from prior onsite and offsite uses. The mitigation requires that the nature and extent of the vapor encroachment will be identified, if any, and that appropriate design measures will be implemented to ensure that applicable indoor air quality standards are met, in compliance with county and state regulatory requirements. Therefore, after applying the mitigation measure, the impact would be less than significant. 8 Impact 3.9-1: Exposure to Short-term Construction Related Noise and Vibration. The proposed project may result in short-term construction-related noise at nearby noise sensitive land uses. This is a potentially significant impact. MM 3.9.1: Implement Short-Term Construction Best Management Noise Practices. Prior to issuance of any Grading Permit, the Public Works Director and the Building Official shall confirm that the Grading Plan, Building Plans, and specifications stipulate that the following basic construction mitigation measures shall be implemented for all construction projects: All construction equipment shall be equipped with mufflers and sound control devices (e.g., intake silencers and noise shrouds) no less effective than those provided on the original equipment and no equipment shall have an un-muffled exhaust. The contractor shall maintain and tune-up all construction equipment to minimize noise emissions. Stationary equipment shall be placed so as to maintain the greatest possible distance to the sensitive receptors. ' Idling times shall be minimized either by shutting equipment off when not in use or reducing the maximum idling time to five minutes (as required by the California airborne toxics control measure Title 13, Section 2485 of California Code of Regulations[CCR]).Clear signage shall be provided for construction workers at all access points. All equipment servicing shall be performed so as to maintain the greatest possible distance to the sensitive receptors. A qualified"Noise Disturbance Coordinator"shall be designated amongst the construction crew whom shall be responsible for responding to any local complaints about construction noise. When a complaint is received,the Disturbance Coordinator shall notify the City within 24 hours of the complaint and determine the cause of the noise complaint(e.g.,starting too early, malfunctioning muffler, etc.)and shall implement reasonable measures to resolve the compliant, as deemed acceptable by the Planning Department. Select demolition methods to minimize vibration,where possible(e.g.,sawing masonry into sections rather than demolishing it by pavement breakers). ® Construction trucks shall utilize a route that is least disruptive to sensitive receptors, preferably major roadways(San Ramon Road, and Interstate 580). Construction trucks should,to the extent practical,avoid the weekday and Saturday a,m, and p.m. peak hours (7:00 a.m. to 9:00 a,m. and 4:00 p.m, to 6:00 p.m.). Net Impact After Mitigation: Less than Significant Finding: Changes or alterations have been required in, or incorporated into, the Project, which avoid or substantially lessen the significant environmental effect identified in the EIR. Rationale for Finding: The mitigation measure ensures that construction traffic will be limited to less noise sensitive periods of the day, that construction equipment is operated and maintained to reduce noise levels, and that staging and storage areas are located as far from sensitive receptors as feasible. Through this variety of measures, the mitigation ensures that construction noise impacts will be reduced to less than significant. Therefore, after applying the mitigation measure, the impact would be less than significant. 2277291.1 9