Sacramento Municipal Utility District Station E Substation Project. Initial Study and Mitigated Negative Declaration Addendum March 2017

Transcription

1 Sacramento Municipal Utility District Station E Substation Project Initial Study and Mitigated Negative Declaration Addendum March 2017

2 Sacramento Municipal Utility District Station E Substation Project Initial Study and Mitigated Negative Declaration Addendum March 2017 Lead Agency: Sacramento Municipal Utility District 6201 S Street, MS B203 Sacramento, CA or P.O. Box 15830, MS B203 Sacramento, CA Attn: Jose Bodipo-Memba (916) or Jose.Bodipo-Memba@smud.org Prepared by: AECOM 2020 L Street, Suite 400 Sacramento, CA Contact: Peter Boucher peter.boucher@aecom.com

3 TABLE OF CONTENTS Station E Substation Project March INTRODUCTION PROJECT DESCRIPTION Civil Site Work (July 31 October 22, 2015) Partial Clean Closure Activities Beginning in ENVIRONMENTAL IMPACT EVALUATION Aesthetics Air Quality Biological Resources Cultural Resources Geology and Soils Greenhouse Gas Emissions Hazards and Hazardous Materials Hydrology and Water Quality Noise Noise Level Measurements and Noise Standards Comparison of Project Noise to Applicable Noise Standards Comparison of Project Noise to Existing Noise Environment Traffic Utilities CONCLUSIONS REFERENCES Tables Table 1. SMAQMD Thresholds of Significance for Criteria Pollutants Table 2. Construction Emissions 2015 Excavation Table 3. Construction Emissions Site Restoration Table 4. Greenhouse Gas Emissions 2015 Site Remediation Table 5. Greenhouse Gas Emissions Site Restoration Table 6. Summary of Ambient Noise Level Survey Results, 2013 Station E* Table 7. Site Remediation/Restoration Equipment and Calculated Noise Levels Table 8. Calculated Noise Levels at the Nearest Noise-Sensitive Uses Table 9. Construction Truck Traffic Noise Levels at the Nearest Noise-Sensitive Uses Page 1 of 37

4 Exhibit Station E Substation Project March 2017 Exhibit 1. Station E Substation Haul Routes Appendices A Figures from the Post Closure Land Use Plan, Brown & Caldwell, March 2017 Figure 1 Figure 5a Figure 9a Figure 9b Figure 11 Site Location Development Plan Excavation Plan Waste to be Removed and Cap Over Remaining Waste Haul Routes B CalEEMod Air Modeling Results Page 2 of 37

5 Station E Substation Project March 2017 ACRONYMS AND OTHER ABBREVIATIONS AB Assembly Bill ARB California Air Resources Board Blvd. Boulevard Blue Diamond Blue Diamond Growers BMP best management practice CalEEMod California Emissions Estimator Model CalRecycle California Department of Resources Recycling and Recovery CEQA California Environmental Quality Act City City of Sacramento db decibel(s) dba A-weighted decibel(s) EMD Emergency Management Department ESA environmental site assessment FHWA Federal Highway Administration GHG greenhouse gas I-5 Interstate 5 IS initial study ITE Institute of Transportation Engineers kv kilovolt(s) L 50 noise level equaled or exceeded during 50 percent of the measured time interval lb/day pounds per day L dn day-night average noise level LEA Lead Enforcement Agency L eq energy-equivalent noise level LT long-term MMRP mitigation monitoring and reporting plan MND mitigated negative declaration MTCO 2 e metric tons of carbon dioxide equivalent NO X oxides of nitrogen PCB polychlorinated biphenyl PM 2.5 fine particulate matter with a diameter less than 2.5 micrometers PM 10 respirable particulate matter with a diameter less than 10 micrometers ROG reactive organic gases RWQCB Regional Water Quality Control Board SMAQMD Sacramento Metropolitan Air Quality Management District SMUD Sacramento Municipal Utility District SR State Route ST short-term SWPPP storm water pollution prevention plan TPH-d/-mo total petroleum hydrocarbons in the diesel and motor oil ranges tpy tons per year Page 3 of 37

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7 Station E Substation Project March INTRODUCTION Sacramento Municipal Utility District (SMUD) is replacing the North City substation, located north of midtown Sacramento near the intersection of North B Street and 20th Street. The project involves constructing a new substation that will be named Station E and demolishing and removing the existing North City substation. The existing substation has required numerous repairs and has reached its planned operational end of life. Figure 1 in Appendix A 1 shows the project site, including the existing North City substation and the proposed location of the new Station E. As originally planned, and as approved in 2014, the project included importing and compacting 47,000 cubic yards of fill to bring the site up to grade and provide soil with suitable bearing capacity for construction of the new substation. The plan involved trucking the required fill, new substation components, and demolition debris through the city of Sacramento on C Street and 16th Street/State Route 160. The approved project also includes reconfiguration of power lines to direct existing 115-kilovolt (kv) transmission lines to the new Station E, and to convey power from Station E to Stations A and B located in downtown and midtown Sacramento, respectively. The Station E Substation Project was described and its environmental impacts evaluated in a draft initial study/mitigated negative declaration (IS/MND) that was distributed to the State Clearinghouse of the Governor s Office of Planning and Research, and to the City of Sacramento (City), relevant resource agencies, and local libraries. The draft IS/MND was published on January 3, 2014, followed by a 30-day public review period and a public meeting. A notice of intent to adopt the MND was distributed to property owners and occupants of record within 500 feet of the project boundary. SMUD then published a final IS/MND on March 20, 2014, containing responses to comments and a mitigation monitoring and reporting plan (MMRP) with mitigation measures to address the project s potential impacts on air quality, biological resources, cultural resources, geology and soils, hazards and hazardous materials, and hydrology and water quality. SMUD s Board of Directors certified the final IS/MND and approved the project on April 3, The NOD was filed on April 7, During the CEQA process, SMUD conducted outreach to the community through mailers and community meetings. Public meetings were held for residents in adjacent neighborhoods to provide information on the work and address residents concerns. No public comments were provided at the public hearing. Before construction commenced, SMUD conducted several hazardous-waste investigations of the site. Historical records showed that the site is adjacent to the City s historic 28th Street landfill and that two landfill cells, Cell #1 and Cell #17, may have extended just into the northern boundary of the substation site (see Figure 1 in Appendix A). Contaminated soils were sampled during Phase I (Tetra Tech EM 2009) and Phase II (Tetra Tech EM 2011a) environmental site assessments (ESAs). A Phase III ESA (Brown and Caldwell 2011b) focused on characterizing ash from a former Blue Diamond Growers (Blue Diamond) 1 The figures used in Appendix A of this IS addendum are from the Post Closure Land Use Plan prepared by Brown and Caldwell in March 2017 (Brown and Caldwell 2017). The numbering of the figures reflects the numbering used in that document. Page 5 of 37

8 Station E Substation Project March 2017 cogeneration plant that was located south of the existing North City substation. In July and August 2013, Blue Diamond removed approximately 124 cubic yards of cogeneration plant ash and contaminated soil from the eastern part of the site for off-site disposal. With these studies and actions completed, SMUD initiated construction of Station E in SMUD prepared this addendum to the 2014 IS/MND because new circumstances have arisen that require additional analysis. In August 2015, several months after the start of project excavation, construction crews unexpectedly encountered buried waste in the northeastern portion of the site. The physical nature of the waste included organics, partially burned municipal waste, ash, metal, deformed glass, and construction debris (see Figure 1 in Appendix A). The waste was stockpiled onsite and characterized for disposal. SMUD documented the off-site disposal in a letter to the Sacramento County Environmental Management Department (EMD) in December The site is now under regulatory oversight by Sacramento County EMD acting as the Lead Enforcement Agency (LEA) with support from CalRecycle. The California Central Valley Regional Water Quality Control Board (RWQCB) and California Department of Toxic Substances Control (DTSC) are copied on all key deliverables and correspondence, but have abstained up until this time from regulatory approval and oversight. Additional regulatory approvals may also be required by the Sacramento Metropolitan Air Quality Management District (SMAQMD). Construction on the project may not resume until the LEA, in consultation with CalRecycle, has approved the Station E Construction Soil Management Plan and Post Closure Land Use Plan (Brown and Caldwell 2017) (referred to in this addendum as the Post Closure Land Use Plan) in accordance with the following: Clean closure and post closure land use activities are addressed in Title 27 of the California Code of Regulations (27 CCR) Sections 21090(f) and 21810, and the LEA Advisory #16 Clean Closure Guidance on appropriate screening procedures for waste and Site characterization (CalRecycle 1994) Station E Substation Project Section samples, analytical testing requirements, etc. at burn dumps are provided in the Protocol for Burn Dump Site Investigation and Characterization (Department of Toxic Substances Control 2) LEA Advisory #56, Process for Characterizing Burn Dumps in California (CalRecycle 1998) The LEA directed SMUD to complete additional investigations to determine the nature and extent of remaining waste at the site, complete confirmation sampling for previously excavated areas and prepare a Post Closure Land Use Plan for future excavation activities required to complete construction of the Station E substation. SMUD conducted extensive characterization of excavated soil, soil from test pits, soil gas, and groundwater. The soil and waste were found to becontaminated with arsenic, lead, total petroleum hydrocarbons in the diesel and motor oil ranges (TPH-d/-mo), polychlorinated biphenyl (PCB)-1260, and benzo(a)pyrene. The soil gas also contained detectable levels of benzene. The groundwater contained arsenic, chromium, benzene, and TPH-d/-mo. Page 6 of 37

9 Station E Substation Project March 2017 Following approval by the regulatory agencies, the next phase of work will involve the closure activities planned for This will involve excavation, segregation, stockpiling, testing, waste removal, confirmation sampling, recompaction, and rough grading. Before this work begins, SMUD will comply with all required public and agency noticing associated with project activities and the schedule. SMUD has determined the remedial work required for removal and disposal of contaminated soil and ash and restoration of the site is an additional part of the previously approved Station E Substation Project, for which SMUD has already complied with the California Environmental Quality Act (CEQA) by preparing and approving the 2014 IS/MND. The additional work is addressed in this IS/MND addendum. This document addresses the additional site work, which involves: removing and disposing of contaminated waste, soil and ash; restoring additional excavated areas of the site through over-excavation and soil recompaction of environmentally and geotechnically suitable material, as well as compaction of additional import material to bring the site to rough grade; installing the underground connections southwest of the Station E property for the 115 kv lines that connect into the City of Sacramento. This work entails installing two large underground manholes to intercept the existing high pressure oil-filled cable, installing new duct bank from the manholes to the Station E site. A portion of underground 115 kv line will be installed underneath Union Pacific Railroad tracks; and capping the remaining waste. This addendum describes the modifications to the Station E Substation Project and documents SMUD s determination that the modifications do not require preparation of a subsequent or supplemental IS/MND. This determination is necessary because after an IS/MND has been approved, CEQA requires an agency, as part of any further discretionary approvals, to evaluate any project modifications that necessitate changes or additions to the IS/MND. If the project modifications are substantial and require major changes to the previous IS/MND because of new significant environmental effects or a substantial increase in the severity of previously identified effects, then the agency must prepare a subsequent or supplemental MND. For project modifications that do not rise to this level but necessitate some revisions to the MND, the agency must prepare an addendum to describe the project modifications and explain why a subsequent or supplemental MND is not required. Accordingly, a technical analysis of the incremental environmental effects posed by the modifications was completed, using the project as described in the IS/MND as the baseline. This addendum describes that analysis, which concludes that the modifications would not cause new significant environmental effects or a substantial increase in the severity of previously identified effects (CEQA Guidelines Section 15164). There are also no changes in circumstances or new information that should have been known with reasonable diligence materialize that will substantially affect the project as SMUD conducted extensive site diligence prior to initial excavation of the Station E site. As described above, these efforts included a Phase I Environmental Site Assessment, North Substation Property (Tetra Tech EM 2009); Phase II Site Investigation Summary Report for Sacramento County Assessor Parcel Numbers /-022/-023 (Tetra Tech EM 2011a); and Phase III Site Investigation (Brown and Caldwell 2011a, Tetra Tech EM 2011). Page 7 of 37

10 Station E Substation Project March 2017 This addendum to the Station E Substation Project IS/MND revisits the environmental impact assessment completed for the 2014 IS/MND and addresses the impacts of the project changes, including the unplanned waste removal work completed in 2015, and the closure work that will begin in 2017 (excavation, segregation, stockpiling, testing, waste removal, confirmation sampling, recompaction, and rough grading). It focuses on the potential for additional air quality, noise, and traffic impacts from excavating and removing contaminated material and importing clean soil for backfill. It does not, however, revisit the 2014 IS/MND on CEQA checklist issues that are unaffected by additional work at the substation site: agriculture and forestry, land use and planning, minerals, population and housing, public services, and recreation. These areas were unaffected by the project as originally planned or had less-than-significant impacts. SMUD has determined that the previous evaluation of these resources areas would be unaffected by the project changes of additional excavation and waste disposal. Pursuant to the CEQA Guidelines Section 15164(b), the addendum concludes that the additional work would not require major revisions to the previous IS/MND or result in new significant environmental effects. Page 8 of 37

11 Station E Substation Project March PROJECT DESCRIPTION This section describes the changes to the project description that are analyzed in this IS/MND addendum. The 2014 IS/MND described replacement of the North City substation with Station E, import of 47,000 cubic yards of engineered fill, assembly of the substation, erection of perimeter fencing, construction of a retaining wall, and subsequent operations and maintenance. The 2014 IS/MND covered the import of 47,000 cubic yards of fill but did not address the excavation and disposal of contaminated soil and waste, or the required increase in truck trips. The following sections describe the additional work covered in this addendum in two phases: Soil remediation and waste disposal (2015) Remaining soil remediation and site restoration (2017) 2.1 Civil Site Work (July 31 October 22, 2015) Construction of the approved substation began in November 2014, including site preparation, building and utility removal, grading, and construction of on-site roadways. In August 2015, construction of the substation was put on hold because excavation unexpectedly encountered buried waste and contaminated soil in the northeastern portion of the site. Following disposal activities SMUD documented the off-site disposal in a letter to the Sacramento County EMD dated December 10, SMUD developed a draft plan (Brown and Caldwell 2016) and submitted the plan for review and approval. The plan outlined SMUD s plans to excavate the site, segregate the waste from the clean soil, test all material excavated, dispose of the segregated hazardous and geotechnically unsuitable materials, recompact environmentally and geotechnically suitable on-site materials, as well as to import clean, compactable fill. Between July 31 and August 20, 2015, SMUD excavated and disposed of 17,501 tons of material from Areas E-1 through E-23 shown in Appendix A, Figure 9a. Of this material, 13,376 tons of ash and contaminated soil were segregated from clean soil and disposed of at Class I hazardous-waste management facilities: 9,685 tons at the Kettleman Hills Landfill in Kettleman Hills, California (215 miles from the project site) and 3,691 tons at the Buttonwillow Landfill in Buttonwillow, California (260 miles from the site). A smaller amount of nonhazardous waste (4,125 tons) was disposed of at L&D Landfill at 8635 Fruitridge Road in Sacramento (10 miles from the project site). The waste that required landfill disposal was found in Areas W-1 through W-5 as shown in Appendix A, Figure 9a. In addition, 17,519 tons of demolition debris consisting of metal and concrete was either processed into aggregate base and re-used onsite or was taken to a recycling facility at Schnitzer Steel at Folsom Boulevard in Rancho Cordova, California (20 miles from the site). The materials that required disposal in a hazardous waste management facility were contaminated with arsenic, lead, total petroleum hydrocarbons in the diesel and motor oil ranges (TPH-d/-mo), polychlorinated biphenyl (PCB)-1260, and benzo(a)pyrene. SMUD has conducted extensive confirmation sampling in areas previously excavated and recompacted in 2015, for Page 9 of 37

12 Station E Substation Project March 2017 soil, groundwater, and landfill gases to ensure those areas meet the cleanup goals of the Post Closure Land Use Plan. The concrete, scrap metal, and other solid waste that was approved for recycling was stockpiled on the west end of the site before it was either loaded and removed for recycling or processed into aggregate base and re-used onsite. Some of the excavated material (60,000 cubic yards) was retained for reuse on-site. This material was used to backfill the eastern, approximately 5-acre portion of the site (see Figures 9a and 9c in Appendix A) in a way that would ensure sufficient bearing capacity to support the new substation. This required storing the material onsite, using it to backfill the excavation, and recompacting it to bring the site back up to grade. To ensure sufficient compaction and bearing capacity, the backfill was placed in layers (i.e., lifts ) and compacted before the next layer was added. This process was completed until the site elevation was raised to its rough grade elevation. Approximately one-third of the site was restored to rough grade when the contractor erected a security fence, installed stormwater best management practices (BMPs), and ceased work in October 2015 with the onset of the rainy season. To minimize noise and traffic impacts on the adjacent neighborhood, most of the truck trips were directed to the north across the Blue Diamond property, along the levee adjacent to the American River (maintained by the American River Flood Control District), south across the Bell Marine property, east across the City s historic 28th Street landfill, south on 28th Street, east on C Street, south on 29 th Street, and onto the Capital City Freeway using ramps at either E Street or H Street (see Figure 11 in Appendix A). From the Capital City Freeway, the trucks hauled the material to the landfill and recycling facilities described above using the routes shown on Exhibit 1. Returning empty trucks used the same combination of local streets, including 28th Street and the levee road. SMUD also excavated a large infiltration basin (see Figure 5a in Appendix A) and constructed a drainage system, grading the area around the site perimeter to slope toward the basin and contain the site s stormwater. The material excavated for the infiltration basin is included in the excavation volumes presented above. In total, for the unplanned waste removal activities and construction work completed between July 31 and October 22, 2015, SMUD transported 35,000 tons of waste off-site, which required approximately 1,000 truck trips. These truck trips used the route described above between 7 a.m. and 6 p.m. on weekdays. This phase of the project required 2,840 truck trips over 32 days, or (rounded to 90) truck trips per day. 2.2 Partial Clean Closure Activities Beginning in 2017 SMUD plans to resume construction and continue the waste removal process, including site restoration, in SMUD submitted a draft closure plan to Sacramento County EMD, CalRecycle, DTSC and the RWQCB in August 2016, a revised draft (Post Closure Land Use Plan) in November 2016, and final plan in March The plan outlines SMUD s overall plan for site closure, including waste removal, stockpiling, testing and disposal; backfilling and grading, capping remaining waste, and long-term maintenance and monitoring. Construction will resume when Sacramento County EMD and CalRecycle, DTSC, or the RWQCB approve the work plan. Page 10 of 37

13 Station E Substation Project March 2017 Source: Brown and Caldwell 2016, adapted by AECOM 2017 Exhibit 1. Station E Substation Haul Routes Page 11 of 37

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15 Station E Substation Project March 2017 SMUD will remove approximately 11,900 cubic yards of residual waste from off-site waste areas Off-1, Off-2, and Off-3, as shown on Attachment 2. This addendum assumes that the entire remaining volume of excavated material from these three off-site areas will require off-site disposal. Exhibit 1 shows the potential routes for trucks hauling excavated material to a landfill or recycling facility (see red lines). Most trucks will exit the site at 20 th Street and use C Street, 19 th Street, D Street, and 16 th Street to access I-5. Once on I-5, trucks will take I-5 south to Class I disposal sites in the southern San Joaquin Valley (Clean Harbors Buttonwillow Landfill or Waste Management Kettleman Hills Landfill). Class II waste will be transported to landfills in Dixon (Recology Ostrom Road) or Vacaville (Recology Hay Road Landfill). A smaller number trucks may infrequently exit the site at 20 th Street and take C Street east to 29 th Street to transport a minimal amount of waste using Highway 50 east to the Class III Kiefer landfill in southwest Sacramento County, or recycling facilities such as Schnitzer Steel in Rancho Cordova. The construction contractor will backfill the excavated area (see Areas E-1 to E-23 in Appendix A, Figure 9a) with approximately 128,642 cubic yards of clean fill that will be imported to bring the site up to rough grade. The fill will be placed in lifts and compacted as described above to ensure sufficient bearing capacity. The top 2 feet of the final grade will consist of clean, imported fill to minimize human and ecological exposure to subsurface soils. The backfill soil and other materials will be transported to the site using either the levee haul road described above or the haul route described in the 2014 IS/MND (Figure 11 in Appendix A). Exhibit 1 shows the range of potential routes for hauling backfill to the site using the major highways that enter Sacramento (see yellow lines) from the north and south. To enter the site via 20th Street, trucks will use C Street, 19th Street, D Street, and 16th Street (State Route 160). To enter the site at 28th Street, trucks will use the Capital City Freeway and 28th Street east of midtown Sacramento, and the levee haul road. Because either haul route may be used, the traffic evaluation provided herein is conservative and assumes that all truck traffic will use one route or the other, but not both. The source of the backfill material will be determined by the construction contractor and therefore has not yet been determined. Because the site remediation will not remove all contaminated waste, part of the remediation plan is to cap the areas on the western margin of the site where known buried waste and contaminated soil remain. SMUD will cap the remaining waste with thick pavement. When capping this 68,800-square-foot area (Figure 9c in Appendix A), SMUD will use asphalt/ concrete to limit stormwater infiltration. The area will also have a 1-foot-thick foundation layer. The volume of these materials is accounted for in the clean-fill import volume (128,642 cubic yards) described above. Construction of the asphalt cap will likely occur after the site has been backfilled to rough grade, and possibly after the site has been filled to final grade, to avoid damaging the cap during construction activities. Decommissioning of the existing North City Substation will require SMUD to construct four new underground 115 kv transmission lines to convey power from the new Station E substation to down-line substations at Station A (downtown) and Station B (midtown). North City Substation decommissioning was covered by the 2014 Station E IS/MND; however, the remediation project has required reconfiguration of the transmission lines that exit the site. The construction will require excavating a trench from Station E to the site entrance at 20th Street. It will also require tunneling (jack and bore) under the Union Pacific Railroad tracks (see Figure 5a in Appendix A) and constructing underground vaults or freeze pits, and grounding. This aspect of construction Page 13 of 37

16 Station E Substation Project March 2017 will generate additional excavated material that will require hauling and disposal, including 5,800 cubic yards for trench spoils and 15,700 cubic yards for conduit and grounding spoils. These construction activities will likely occur after the site has been backfilled to rough grade. Other work required to complete partial clean closure activities at the site pursuant to the clean closure plan includes installing drainage infrastructure and final surfaces. The site drainage plan and infiltration basin design was provided to the Sacramento County EMD as an attachment to the Post Closure Land Use Plan. The area excavated for the infiltration basin will be completed and the entire 15-acre site will be outfitted with drainage infrastructure that will collect and direct site stormwater to the infiltration basin. The final surfaces will include crushed rock and paving of the perimeter and maintenance roads. Other activities will include installation of stormwater BMPs, gas monitoring wells, and security fencing. Once this work is completed, SMUD will prepare a partial clean closure results report and commence the postclosure monitoring period. This next phase of construction will require approximately 9.7 months, with material hauling occurring 5 days per week during the entire 9.7 months. The waste capping and installation of the 115 kv power line could be deferred until SMUD estimates that with waste removal, import of clean backfill, asphalt for capping, and excess soil generated by construction of the underground power lines, this next phase of construction will require the transport of approximately 162,000 cubic yards of material (128,642 import, 11,900 export, and 21, kv line) and approximately 16,200 truck trips transporting 10 cubic yards per trip. The trucks will enter or depart from the site via one of the routes described above. The noise and traffic evaluations in this addendum evaluate scenarios in which all trucks use one route. This approach ensures a worst-case scenario evaluation for noise and traffic to be conservative. In reality, the trucks that import fill will likely have multiple origins and will use different routes. Assuming that these 16,200 trips occur 5 days per week for 9.7 months (39 weeks, 195 work days), this phase of the project will require approximately 83 truck trips per day. Page 14 of 37

17 Station E Substation Project March ENVIRONMENTAL IMPACT EVALUATION This section evaluates the environmental impacts of the additional work required for the Station E Substation Project to remove and dispose of ash and contaminated soil and to restore the site. The approved project included and the 2014 IS/MND evaluated the transport of 47,000 cubic yards of excavated material and imported fill to bring the site up to grade (approximately 4,940 truck trips). This activity will now occur in However, the change to the project will require the transport of more material than was evaluated in the 2014 document to bring the site up to grade. In addition, as described in Section 2, this change includes the off-site transport of excavated ash and contaminated soil and capping of remaining waste. SMUD estimates that the project will now require a total of approximately 19,000 truck trips. The following sections address the environmental impacts of the project with the larger excavation and fill volumes. 3.1 Aesthetics The 2014 IS/MND addressed compacting soils and constructing the new substation. The additional remedial and site restoration work will occur primarily below grade, including excavation, backfilling, compaction, and final surfacing. In addition, the work will be intermittent and temporary. After the addition of clean backfill, the area will be restored through revegetation and landscaping. The additional remedial work will have no impact on scenic vistas or scenic resources within a state scenic highway. Furthermore, the remedial work will not substantially degrade the character of the area, but rather will remove existing debris piles and bring the area up to grade. Moreover, the additional work will not introduce any new sources of light or glare beyond the security lighting for the approved substation. Thus, any aesthetic impacts of site remediation and restoration will be temporary and consistent with those evaluated in the 2014 IS/MND and will not require mitigation. 3.2 Air Quality This section revisits the CEQA IS questions a) and b) for Air Quality by calculating the incremental increase in emissions from the added earthwork and truck trips required for remediation and backfill. The estimates are based on the cubic yards of ash and soil removed in 2015 and the additional remediation and site restoration planned for 2017, including truck trips for disposal and transporting clean fill to backfill the site. The calculations presented in this section account for the import of 47,000 cubic yards of soil, as evaluated and approved in the 2014 IS/MND, and report the incremental impact of the project on air quality resulting from the added earthwork and truck trips required for remediation and backfill. Results of California Emissions Estimator Model (CalEEMod) modeling are presented in Appendix B. The U.S. Environmental Protection Agency has identified federal nonattainment and attainment areas, and the California Air Resources Board (ARB) has identified state nonattainment and attainment areas for each criteria air pollutant. The Sacramento Valley Air Basin is currently considered a state nonattainment area for ozone and respirable particulate matter with a Page 15 of 36

18 Station E Substation Project March 2017 diameter less than 10 micrometers (PM 10 ) and a federal nonattainment area for ozone and fine particulate matter with a diameter less than 2.5 micrometers (PM 2.5 ). SMAQMD published the Guide to Air Quality Assessment in Sacramento County, which provides air quality guidance when preparing CEQA documents. This document, last updated in December 2016, establishes significance thresholds for criteria pollutants that SMAQMD recommends using when evaluating air quality impacts in Sacramento County (SMAQMD 2016). Table 1 lists the SMAQMD-adopted thresholds of significance for criteria pollutant emissions and their application. Table 1. SMAQMD Thresholds of Significance for Criteria Pollutants Pollutant/Precursor Emissions (pounds per day) Construction Phase NO X 85 ROG None PM (and 15 tpy) PM (and 14.6 tpy) Note: NO X = oxides of nitrogen; PM 2.5 = fine particulate matter with a diameter less than 2.5 micrometers; PM 10 = respirable particulate matter with a diameter less than 10 micrometers; ROG = reactive organic gases; tpy = tons per year The particulate matter thresholds apply to projects that impose the Sacramento Metropolitan Air Quality Management District s best available control technology or best management practices, as feasible. Source: SMAQMD 2017; data compiled by AECOM in 2016 and 2017 The particulate matter thresholds included in the above table were not approved by the SMAQMD Board of Directors until 2015 (May 28); thus, they were not used in the analysis of the 2014 project. This does not represent a change in the regulatory context that would generate a new or substantially increased environmental impact compared to the 2014 IS/MND. AECOM estimated construction and operational emissions associated with the revised project. 2 Table 2 and Table 3 display the calculated total construction emissions from the proposed project as two phases: the work completed between September 16, 2015, and October 23, 2015, and the additional construction planned for The emissions generated for particulate matter are well below the emission limits; however, emissions of oxides of nitrogen (NO X ) exceed the adopted emission threshold for construction emissions, resulting in a potentially significant impact. See Appendix B for more detail. 2 Emissions were estimated using the latest version of CalEEMod. Version was used in this analysis. CalEEMod allows the user to enter information specific to the project, when available and when project-specific information is not available, conservative CalEEMod default values were used. See Appendix B of this IS/MND addendum for more information. Page 16 of 36

19 Station E Substation Project March 2017 Table 2. Construction Emissions 2015 Excavation Year and ROG NOX 1 1 Maximum (lb/day) SMAQMD Threshold Exceeds Threshold Yes No No Notes: lb/day = pounds per day; NO X = oxides of nitrogen; PM 2.5 = fine particulate matter with a diameter less than 2.5 micrometers; PM 10 = respirable particulate matter with a diameter less than 10 micrometers; ROG = reactive organic gases; SMAQMD = Sacramento Metropolitan Air Quality Management District 1 PM 10 emissions shown include the sum of particulate matter with aerodynamic diameter 0 to 2.5 micrometers and particulate matter with aerodynamic diameter 2.5 to 10 micrometers. Source: Calculated by AECOM in 2017 Table 3. Construction Emissions Site Restoration Year and ROG NOX 1 1 Maximum (lb/day) SMAQMD Threshold Exceeds Threshold No No No Notes: lb/day = pounds per day; NO X = oxides of nitrogen; PM 2.5 = fine particulate matter with a diameter less than 2.5 micrometers; PM 10 = respirable particulate matter with a diameter less than 10 micrometers; ROG = reactive organic gases; SMAQMD = Sacramento Metropolitan Air Quality Management District 1 PM 10 emissions shown include the sum of particulate matter with aerodynamic diameter 0 to 2.5 micrometers and particulate matter with aerodynamic diameter 2.5 to 10 micrometers. Source: Calculated by AECOM in 2017 Compared to construction emissions estimates presented in the 2014 IS/MND, the revised estimates reflect the additional construction activity needed to remove contaminated soil at the project site. The revised estimates of construction emissions exceed SMAQMD emissions thresholds for NO X. Therefore, SMUD will incorporate Mitigation Measure AIR-1 from the 2014 IS/MND to address short-term emissions, with appropriate updates specified in SMAQMD s latest recommended standard construction mitigation. 3 These measures will maintain NO X emissions generated during site remediation and restoration below the SMAQMD mass emission threshold for NO X. As discussed in the 2014 IS/MND, Mitigation Measure AIR-1 includes a combination of construction equipment emission reductions such as a 20 percent reduction compared to the average ARB fleet mix, use of model year 2010 or newer trucks, verification reporting, and payment of mitigation offset fees. These measures will reduce the impacts of the added site remediation and restoration to less than significant. 3 For more detail, please refer to SMAQMD s Web site at Land-Use-Planning/Mitigation. Page 17 of 36

20 Station E Substation Project March Biological Resources The project change will involve work outside the original site boundary, including haul trucks using the levee road and construction of a 115 kv power line that will connect to the existing grid at 20th Street at the southwest corner of the site. Therefore, the additional affected areas were surveyed for biological resources on September 1, Specifically, a reconnaissance survey of the haul road and power line trenching area was conducted to evaluate the areas potential to provide wildlife habitat, or support special-status species or sensitive natural communities, including wetlands. The levee haul road is an existing dirt road through existing commercial operations and adjacent to a city park. The area in which the 115 kv lines will be constructed was highly disturbed by previous access road construction, the Union Pacific Railroad tracks, fencing, and power lines. This area supported ruderal vegetation and was heavily affected by dumping of asphalt, soil, and trash. The 2016 reconnaissance survey did not reveal the presence of wildlife habitat, such as trees, valley elderberry bushes, grasslands, or wetlands. Power line construction will not have direct effects on these resources and no additional mitigation beyond the existing Mitigation Measures BIO-1 and BIO-2 for valley elderberry beetle and heritage trees, respectively, is required. The elderberry shrubs on the site s southern perimeter have been fenced and will be protected through the remediation and restoration process. To avoid potential impacts on nesting birds, SMUD will implement Mitigation Measure BIO-2 from the 2014 IS/MND, which requires a preconstruction survey if construction starts during the nesting season. This survey will determine if nests are present within 250 feet of construction and ensure that existing nests are protected, as needed. Therefore, the remedial work will have no significant impacts on biological resources beyond those identified and mitigated in the 2014 IS/MND. No additional mitigation measures are required. 3.4 Cultural Resources The area of the proposed 115 kv lines was also evaluated for potential impacts on cultural resources. The levee haul road consists of fill and was not evaluated. An intensive pedestrian archaeological survey was completed for the 115 kv line area on October 24, The ground surface was inspected for evidence of prehistoric and historic-era use, including evidence of topographic disturbance, soil discoloration, charcoal, modified stone or bone, and exotic materials. No historic resources were identified during this survey. As described in the 2014 IS/MND, the soil in the project area consists of fill up to 20 feet deep, underlain by fluvial deposits from the American River (Brown and Caldwell 2011a). In addition, there is little ethnographic or archaeological evidence of past human occupation of the south bank of the American River. The project area has low potential for the discovery of buried archaeological deposits because the area consists of fill soil to the depth of the completed and planned excavations and because of the lack of archaeological evidence that Native Americans occupied the south bank of the American River. However, the potential exists to uncover historical resources. Any impacts on these resources will be addressed by the existing mitigation measures described in the 2014 IS/MND, including Mitigation Measure CUL-1 for archaeological and historic resources, Mitigation Measure CUL-2 Page 18 of 36

21 Station E Substation Project March 2017 for paleontological resources, and Mitigation Measure CUL-3 for potential discovery of human remains. These mitigation measures will reduce any impacts on cultural resources to less than significant. No additional mitigation measures are required for the additional remedial work. 3.5 Geology and Soils The project is being constructed in an area with soils prone to liquefaction and SMUD is implementing Mitigation Measure GEO-1, which requires over-excavation and recompaction of soils over much of the site to improve soil bearing capacity. The project also requires implementation of Mitigation Measure GEO-2, which calls for compliance with stormwater regulations and preparation of a storm water pollution prevention plan (SWPPP). The additional remedial work will take place within the same geologic setting as the substation construction project described in the 2014 IS/MND. The remediation activity has required removal of ash and contaminated soil and import of a larger volume of backfill than originally envisioned to bring the site up to grade. Thus, Mitigation Measure GEO-1, which requires SMUD to ensure stable subsurface soil conditions, will be applied to a larger area. However, no additional geotechnical mitigation measures are required. Remediation and site restoration will require handling larger volumes of material than evaluated in the 2014 IS/MND. To manage and mitigate potential erosion, SMUD will implement Mitigation Measure GEO-2. The SWPPP will present BMPs to control erosion from soil stockpiles, including wetting and covering the piles with plastic sheeting and sandbags, and conducting regular inspections to ensure that the BMPs are effective. The stormwater drainage plan and SWPPP will also require the construction contractor to construct drainage swales, riprap slopes, and retaining walls, and implement other measures to control postclosure erosion. Because the drainage design, Post Closure Land Use Plan, and SWPPP will cover the potential impacts of remedial activities, no additional erosion control mitigation measures are required. 3.6 Greenhouse Gas Emissions The State of California adopted Assembly Bill (AB) 32, the California Global Warming Solutions Act of 2006, which serves as the primary climate change legislation in the state. AB 32 focuses on reducing greenhouse gas (GHG) emissions in California by requiring that such emissions be reduced to 1990 levels by the year AB 32 also identifies ARB as the state agency responsible for the design and implementation of emissions limits, regulations, and other measures to meet the target. In October 2014, SMAQMD adopted an annual GHG emissions threshold of 1,100 metric tons of carbon dioxide equivalent (MTCO 2 e) for construction projects. This significance threshold was developed with the intent of allowing projects to assess their consistency with the statewide framework for reducing GHG emissions. At the time of the 2014 IS/MND analysis, SMAQMD had not established a construction-related threshold for GHG emissions; thus, basic construction emission control practices and best performance standards were used as guidelines to determine significance. During construction, GHG emissions will be generated by construction equipment and by vehicles driven to and from the project site by construction workers and vendors. Constructionrelated exhaust emissions were estimated for construction worker commutes, haul trucks, and Page 19 of 36

22 Station E Substation Project March 2017 the use of off-road equipment. Estimated construction emissions for the work performed September 16, 2015 through October 23, 2015, were 190 MTCO 2 e, while the anticipated additional construction occurring in 2017 is estimated to produce approximately 885 MTCO 2 e (Table 4 and Table 5). Table 4. Greenhouse Gas Emissions 2015 Site Remediation Emissions (MTCO 2 e/year) 190 SMAQMD Threshold 1,100 Exceed Threshold? No Notes: MTCO 2 e/year = metric tons of carbon dioxide equivalent per year; SMAQMD = Sacramento Metropolitan Air Quality Management District Source: Calculated by AECOM in 2016 Table 5. Greenhouse Gas Emissions Site Restoration Emissions (MTCO 2 e/year) 885 SMAQMD Threshold 1,100 Exceed Threshold? No Notes: MTCO 2 e/year = metric tons of carbon dioxide equivalent per year; SMAQMD = Sacramento Metropolitan Air Quality Management District Source: Calculated by AECOM in 2016 As shown in Table 4, the remediation work completed in 2015 did not exceed the annual SMAQMD threshold. Additionally, as shown in Table 5, the remaining remediation and restoration work planned for 2017 will not exceed the annual GHG emissions threshold of 1,100 MT CO 2 e for construction emissions. SMUD will implement Mitigation Measure GHG-1 as described in the 2014 IS/MND, which incorporates SMAQMD S guidance for construction GHG emissions reductions, including improved fuel efficiency (e.g., reduced idling time, equipment maintenance, recycling, and efficient water use). The project will implement the most current guidance at the time of construction. With the additional implementation of best performance standards as outlined in Mitigation Measure GHG-1, the project s GHG emissions impacts will be less than significant. 3.7 Hazards and Hazardous Materials Construction of the approved substation began in November 2014 and complied with Mitigation Measure HAZ-1, which required a hazardous materials transportation and handling safety plan. When construction crews encountered additional ash and contaminated soil, SMUD developed a Post Closure Land Use Plan outlining plans to excavate the site, segregate the ash (and ashcontaminated soil) from the clean soil, and dispose of the segregated hazardous materials. Handling of this material, which is contaminated with polycyclic aromatic hydrocarbons and heavy metals, was subject to the project s existing mitigation requirements for materials handling and worker safety. The plan includes several requirements for conducting the remediation, including a range of protective measures for site workers and the community. SMUD and the construction contractor prepared a health and safety plan to comply with Page 20 of 36

23 Station E Substation Project March 2017 California Division of Occupational Safety and Health standards. The health and safety plan s compliance measures included identification of anticipated hazards, use of protective measures, worker training, site access control, and use of personal protective equipment, such as protective suits, gloves, boots, and dust masks. The health and safety plan also included an excavation safety plan that covered the design of shoring, bracing, sloping, and other design measures to protect workers. Furthermore, it established exclusion zones around excavations to prevent unauthorized personnel from entering the area, and contaminant reduction and decontamination zones around areas with ash and contaminated soils. SMUD s contractor also implemented BMPs to control fugitive dust emissions, including limiting vehicle speeds, covering or wetting haul loads, and spraying work areas (e.g., excavation area, stockpiles, haul roads, and disturbed areas) with water before and during work. The BMPs included monitoring the air for dust, lead, and methane. Dust monitoring focused on PM 10. For trucking of hazardous materials, including ash and contaminated soil, SMUD has complied and will comply with federal and state hazardous-materials transportation laws, including Title 49, Sections of the Code of Federal Regulations, which specify hazard communication, training, and security requirements, and packaging and container specifications. California Department of Transportation regulations require driver training and proper labeling and reporting. Furthermore, because the accidental release of hazardous materials was identified as a potentially significant impact in the 2014 IS/MND, SMUD developed Mitigation Measure HAZ-1, which requires development of a hazardous-materials transportation and handling safety plan with project-specific protocols for the transport and handling of hazardous materials, including identification of transportation routes and avoidance of sensitive land uses (such as the Courtyard Elementary School). For future operations, SMUD identified potential concerns regarding accumulation of soil gas in the substation building. The Post Closure Land Use Plan requires that the substation s control building be constructed to minimize gas infiltration. It also requires landfill gas monitoring and foundation design, as specified in Title 27, Section of the California Code of Regulations, to reduce landfill gas accumulation. SMUD will conduct periodic monitoring for methane in the building and will install a methane sensor. Compliance with this requirement will be reviewed by Sacramento County and approved before construction. In combination with SMUD s Mitigation Measure HAZ-1 to reduce the potential impacts of transporting hazardous materials, SMUD will comply with a range of other site remediation and closure requirements (e.g., health and safety plan, excavation safety, exclusion zones, dust monitoring). These measures have been approved and are required and enforceable by the Sacramento County Environmental Management Department (which is acting as the local enforcement agency), Central Valley RWQCB, California Department of Toxic Substances Control, and SMAQMD. With SMUD s Mitigation Measure HAZ-1 and the requirements outlined in the Post Closure Land Use Plan, any impacts of handling and transporting ash and contaminated soil will be reduced to less than significant. No additional mitigation measures are required. 3.8 Hydrology and Water Quality The project requires over-excavation and recompaction of soils to improve soil bearing capacity. To address potential erosion, SMUD has implemented Mitigation Measure HYD-1 (see Page 21 of 36

24 Station E Substation Project March 2017 Mitigation Measure GEO-2), which requires compliance with stormwater regulations and preparation of a SWPPP. The SWPPP presents BMPs to control erosion from soil stockpiles, including wetting and covering the piles with plastic sheeting and sandbags, and regular inspection to ensure that the BMPs are effective. The stormwater drainage plan and SWPPP also require the construction contractor to construct drainage swales, riprap slopes, and retaining walls, and to implement other measures to control post-closure erosion. Because the drainage design, Post Closure Land Use Plan, and SWPPP cover the remedial and restoration activities, no additional erosion-control mitigation measures are required. For trucking of ash and contaminated soil, SMUD evaluated the potential risks of hauling the material along the levee road and the potential for an accident that could release excavated material and affect water quality in the American River which parallels the levee haul road. Site reconnaissance showed that the portion of the levee road that parallels the river is approximately 19 feet wide and adequate to support the project s 20-ton dump trucks. In addition, the road is approximately 130 feet from the river and a secondary road parallels the river to the north, closer to the water. A spill of ash or soil in this area would not directly affect the river and would be immediately reported and cleaned up, and the material would be disposed of with other project waste. SMUD will arrange for use of the levee road with the American River Flood Control District. The remediation work will be conducted in a manner that protects the site s groundwater. The primary measure will be removal of ash and contaminated soil and capping of the remaining waste as required by the Post Closure Land Use Plan. Removing and capping this source of potential groundwater contamination will reduce the potential for rainwater infiltration to contact site contamination and transport it to groundwater. SMUD has conducted extensive sampling and testing, using methods developed and approved by the Central Valley RWQCB, to ensure that the site cleanup is protective of groundwater. In addition, the closure plan design requires an infiltration basin to manage site stormwater as well as run-on stormwater from adjacent areas to minimize contact with subsurface waste and soils. Moreover, SMUD will monitor the site long term and coordinate site monitoring with closure and monitoring of the adjacent North City Landfill and will report the data to the Central Valley RWQCB. Combined with SMUD s Mitigation Measure HYD-1, the required measures outlined in the Post Closure Land Use Plan to protect water quality will address water quality concerns. No additional mitigation measures are required. 3.9 Noise This section addresses the potential noise impacts of site remediation and restoration. Vibration impacts, operational noise, and other issues such as aircraft noise are not addressed, as they were sufficiently evaluated in the 2014 IS/MND. Noise Level Measurements and Noise Standards The project site is surrounded by a mix of commercial, industrial, and residential uses. Ambient noise levels are affected by automobile and rail traffic on adjacent roadways and Union Pacific Railroad lines to the south and west. Table 6 lists the ambient noise levels measured at the nearest noise-sensitive receptors for the 2014 IS/MND, and the results of an additional short- Page 22 of 36

25 Station E Substation Project March 2017 term measurement completed in 2017 for this addendum to evaluate noise from construction of the transmission lines. Table 6. Summary of Ambient Noise Level Survey Results, 2013 Station E* Receptor Location Land Use Measured Noise Levels, dba L 50 (Daytime) LT-1 End of 21st Street 48 LT-2 End of 24th Street 47 LT-3 End of North 18th Street 46 ST-1* 20th Street north of C Street** 56 L eq, dba Notes: dba = A-weighted decibels; L 50 = noise level equaled or exceeded during 50 percent of the measured time interval; L eq = energy-equivalent noise level (the sound energy averaged over a continuous 15-minute to 1-hour period); LT = long-term; ST = short-term. * Noise-level measurement completed on Monday, January 9, 2017, using a Larson Davis Laboratories Model 824 precision integrating sound-level meter. The meter was calibrated before the measurements using a Larson Davis Laboratories Model CAL200 acoustical calibrator. The meter was programmed to record A- weighted sound levels using a slow response. The equipment complied with all pertinent requirements of the American National Standards Institute for Class 1 sound-level meters. ** Dominant noise sources at the ST-1 location include surface traffic noise, industrial noise from the Blue Diamond Growers plant, and railway noise. Source: Data compiled by URS in 2013 and AECOM in 2017 The long-term (LT) measurement locations are shown in Figure 3-13 of the 2014 IS/MND. LT-1 is near single-family residences on 21st Street approximately 300 feet south of the site boundary. LT-2 is located approximately 500 feet southeast of the site on 24th Street between C Street, B Street, and the C Street Alley. LT-2 is also near Courtyard Elementary School. LT-3 is approximately 1,000 feet northwest of the existing substation and 1,250 feet northwest of the remediation site near residences on 18th Street in between Dreher Street and Basler Street. The new short-term measurement (ST-1) was conducted near homes on the east side of 20th Street between the Union Pacific Railroad tracks and C Street. Policy EC (Construction Noise) of the Sacramento 2030 General Plan Noise Element (City of Sacramento 2014a), and the City Noise Ordinance (Section D [Exemptions] of the Sacramento City Code) were used to evaluate potential noise impacts. Project noise will be considered significant in residential areas if it exceeds 55 A-weighted decibels (dba) energyequivalent noise level (L eq ) during daytime hours (7 a.m. 10 p.m.) or 50 dba L eq during nighttime hours (10 p.m. 7 a.m.). These criteria are the most restrictive City criteria and provide the most conservative assessment of noise impacts. In terms of interior noise level standards, Policy EC (Interior Noise Standards) of the Noise Element states that the City shall require new development to include noise mitigation to assure acceptable interior noise levels appropriate to the land use type: 45 dba day-night average noise level (L dn ) for residences, transient lodgings, hospitals, nursing homes, and other uses where people normally sleep; and 45 dba L eq (peak hour) for office buildings and similar uses. Section of the City Noise Ordinance establishes construction noise exempt hours between 7 a.m. and 6 p.m., on Monday, Tuesday, Wednesday, Thursday, Friday, and Saturday, and between 9 a.m. and 6 p.m. on Sunday. Page 23 of 36

26 Comparison of Project Noise to Applicable Noise Standards Station E Substation Project March 2017 The project will generate temporary and short-term construction noise, primarily from excavation and grading equipment and haul trucks (see Section 2.0, Project Description ). Site remediation and restoration noise was estimated using the Federal Highway Administration s (FHWA s) Roadway Construction Noise Model (FHWA 2006) and a list of typical earthwork and power line construction equipment (Table 7). This equipment will generate unmitigated noise levels of approximately dba at a distance of 50 feet (Table 7). Assuming standard spherical spreading loss (-6 decibels [db] per doubling of distance), the noise levels at the nearest noisesensitive uses were estimated to be dba L eq in 2015 and dba L eq in 2017 for earthwork and site restoration activities, and 66 dba L eq in 2017 for the 115 kv line construction activities (Table 8). These unmitigated noise levels exceeded the City s threshold of 55 dba L eq. Table 7. Site Remediation/Restoration Equipment and Calculated Noise Levels Construction Activity Noise Level at 50 feet, db Earthwork Excavation, Disposal, Over-excavation, Compaction (2015) 87 Site Restoration Earthwork (excavation, disposal, backfilling, over-excavation, 85 compaction) (2017) 115 kv Lines (trench, jack and bore pits, vaults, backfill) 84 Notes: db = decibels; kv = kilovolt; L eq = energy-equivalent noise level (the sound energy averaged over a continuous 15-minute to 1-hour period) Source: Data compiled by AECOM in 2017 L eq Table 8. Calculated Noise Levels at the Nearest Noise-Sensitive Uses Receiver Location Shortest Distance (feet) between Noise- Sensitive Uses and Proposed Construction Areas Ambient Noise Noise Level, db L eq Exterior Interior Maximum Project Construction Noise (2017) Project Noise, Doors/ Windows Open (2017) Project Noise, Doors/ Windows Closed (2017) LT-1 End of North 18th Street (69) 56 (54) 46 (44) LT-2 End of 21st Street (65) 52 (50) 42 (40) LT-3 End of 24th Street 1, (59) 46 (44) 36 (34) ST-1 20th Street north of C Street (66) (51) (41) Notes: db = decibels; L eq = energy-equivalent noise level (the sound energy averaged over a continuous 15-minute to 1-hour period); LT = long-term; ST = short-term 1 Assuming no reduction for the levee and rail bed shielding db reduction for doors/windows open (EPA 1974) db reduction for doors/windows closed (EPA 1974). Source: Data compiled by AECOM in 2017 However, these results overstate actual noise exposure because they do not consider noise attenuation associated with ground and atmospheric absorption. Actual construction noise Page 24 of 36

27 Station E Substation Project March 2017 levels will be substantially less because of the area s topography and the presence of a wide earthen levee (railroad berm) that projects approximately 10 feet higher than the line of sight between the noise source (construction equipment at the substation site) and the receiver (the nearest home). An earthen berm such as a levee or railroad berm can provide noise attenuation of up to 15 dba if it is several feet higher than the line of sight between the noise source and the receiver (FHWA 2011). Therefore, given the location of the railroad berm in relation to the noise source and nearby homes, project construction noise levels at the nearest noise-sensitive uses were estimated to be approximately dba L eq for earthwork and site restoration activities in 2015, dba L eq for earthwork and site restoration activities in 2017, and 51 dba L eq for the 115 kv line construction activities (Table 8). Furthermore, Section (e) of the City Noise Ordinance exempts excavation and other construction activities between 7 a.m. and 6 p.m. Monday through Saturday, and between 9 a.m. and 6 p.m. on Sunday. The City recognizes that construction noise is temporary, generally acceptable when limited to daylight hours, and expected as part of a typical urban noise environment (along with sirens). Also, site remediation and restoration will not extend into the nighttime hours (10 p.m. to 7 a.m.), and thus, will not exceed the applicable nighttime threshold of 45 dba L eq. Therefore, because project noise levels will comply with the applicable daytime and nighttime noise exposure limits established by the Sacramento 2030 General Plan and City Noise Ordinance, construction noise impacts are less than significant. Haul trucks will generate noise on city streets as they haul excavated material to landfills (i.e., L&D Landfill, Kettleman Hills Landfill) and transport backfill to the site (see Exhibit 1). Table 9 lists the roadways that will be used by haul trucks and construction traffic noise levels at 50 feet away from the noise source, estimated using FHWA s Roadway Noise Model (FWHA RD ). The peak truck-trip noise generation will occur when excavated/fill material is being exported from and imported to the site. During the initial remediation (2015), the estimated truck traffic volume was 90 daily truck trips and 20 construction worker vehicles. The second phase of work, planned for 2017, will require approximately 83 daily truck trips and 20 construction worker vehicles. This analysis assumes that construction will occur during an 8-hour workday (7 a.m. to 3 p.m.), and that construction trucks will operate continuously throughout the day. Therefore, based on an even distribution of truck trips throughout the 8-hour day, the project will result in a peak traffic volume of approximately 11 and 10 truck trips per hour, in 2015 and 2017, respectively. Construction worker commute trips will occur once during the morning commute and once during the afternoon commute. Therefore, peak worker trips will be approximately 20 trips per hour. Table 9 represents the predicted noise levels for 90 truck trips per day. Construction traffic noise levels in 2017 (83 truck trips per day) will be 0.1 db less than in Because this difference is negligible, the noise levels in Table 9 were used to represent both years. Construction truck traffic will generate unmitigated noise levels of approximately 57.3 to 62.4 dba L eq (Table 9) at 100 feet from the roadway centerline, assuming that all the vehicles use the levee haul route and 28th Street. The distance of 100 feet was chosen based on field reconnaissance and measurement of the distances from the roadways to backyard areas and open areas in Stanford Park. Noise levels in these areas will exceed the threshold of 55 dba L eq and the existing traffic noise along these roadways by 1.3 to 7.9 db. As shown in Table 9, traffic noise levels will increase by 4.9 to 7.9 db along the first two segments of 28th Street from the project site to C Street. These roadway segments are adjacent to Stanford Park. Page 25 of 36

28 Station E Substation Project March 2017 If the haul trucks use a route from C Street to Garden Highway, project truck traffic will generate unmitigated noise levels of approximately 56.7 to 67.1 dba L eq at 100 feet from the roadway centerline. These noise levels will exceed the threshold of 55 dba L eq and the existing traffic noise along these roadways by 0.4 to 17.4 db. As shown in Table 9, traffic noise levels will increase by 4.8 to 17.4 db along the first two segments of 20th Street from the project site to C Street, along C Street from 20th Street to 19th Street, and along D Street from 17th Street to 16th Street. If the 20 th Street exit is used, some trucks may use C Street between 20 th Street and 29 th Street to access Highway 50 and disposal sites southwest of Sacramento (e.g., Kiefer Landfill, Schnitzer Steel). This route would be used infrequently for small volumes of waste. Noise impact along this segment of C Street would be lower than those shown in Table 9 for C Street and D Street (noise increase of 4.3 db). However, these results overstate actual noise exposure because they do not consider noise attenuation associated with ground and atmospheric absorption, and shielding provided by buildings. Actual construction noise levels will be substantially less because of the area s topography and the presence of buildings between the roads and the sensitive-use areas (backyards). A long building, or a row of buildings parallel to the adjacent roadway, can shield other more distant structures or open areas from noise. One study shows that a two-story building can reduce noise levels on the side of the building away from the noise source by about 13 dba (FHWA 2011). Therefore, haul truck noise levels in backyard areas will be reduced by as much as 13 db because of the presence of building shielding. Also, as described above, this noise evaluation is based on the worst-case assumption that the haul trucks and worker vehicles will use one of the described haul routes exclusively. Workers will likely use multiple different routes to commute to the site. In addition, the truck trips may be split between the two routes depending on their destination (L&D Landfill or Kettleman Hills Landfill) or their origination point. The source of the fill material is not currently known and could be multiple locations where suitable backfill soil is available. The fill material will be identified, procured, and transported by the construction contractor, which will use the most efficient route to access the Station E site. Furthermore, SMUD will implement standard construction measures to reduce noise impacts. These measures will be similar to those used during the 2015 remediation activities and will include conducting public outreach, limiting hauling to the daytime hours as required by the City Noise Ordinance, and avoiding residential areas where practicable. With these measures, the noise impact from the additional haul trucks will be less than significant. Page 26 of 36

29 Station E Substation Project March 2017 Table 9. Construction Truck Traffic Noise Levels at the Nearest Noise-Sensitive Uses Roadway Segment Distance (feet) Existing Traffic Noise Noise Level, db L eq Construction Traffic Noise Route Levee Haul Road to 28th Street (or reverse) Existing plus Construction Traffic Noise Increase, db 28th Street From project site to B Street th Street From B Street to C Street th Street From C Street to D Street th Street From D Street to E Street E Street From 28th Street to 29th Street th Street From E Street to F Street th Street From F Street to G Street th Street From G Street to H Street Route C Street to Garden Highway (or reverse) 20th Street From project site to C Street C Street From 20th Street to 19th Street th Street From C Street to D Street D Street From 19th Street to 18th Street D Street From 18th Street to 17th Street D Street From 17th Street to 16th Street th Street From D Street to C Street th Street From C Street to North A Street th Street From North A Street to North B Street th Street From North B Street to North C Street th Street From North C Street to Dreher Street th Street From Dreher Street to Sproule Avenue th Street From Sproule Avenue to Richards Blvd SR 160 From Richards Blvd. to Northgate Blvd Northgate From SR 160 to Garden Blvd. Highway/Arden Garden Connector Garden Highway From Northgate Blvd. to Truxel Road Garden From Truxel Road to Natomas Park Highway Drive Garden From Natomas Park Drive to I-5 Highway ramps on Garden Highway Notes: Blvd. = Boulevard; db = decibels; I-5 = Interstate 5; L eq = energy-equivalent noise level; SR = State Route The db increase values presented in bold values are discussed in the text and occur in areas with low baseline traffic levels. Source: Data compiled by AECOM in 2017 Page 27 of 36

30 Comparison of Project Noise to Existing Noise Environment Station E Substation Project March 2017 The following discussion evaluates project noise, including earthwork for remediation and restoration; construction of the underground power lines; and transport of construction equipment, earthen material, and workers in comparison to existing ambient noise levels. Excavation and grading equipment on the remediation/restoration site will generate unmitigated noise levels of approximately 87 dba at a distance of 50 feet (Table 7). Assuming standard spherical spreading loss (-6 db per doubling of distance), the noise levels at the nearest noisesensitive use were estimated to be dba L eq in 2015 and dba L eq in 2017 for earthwork and site restoration activities and 66 dba L eq for construction of the 115 kv lines in 2017 (Table 8). However, as described above, these results overstate actual noise exposure because they do not consider the elevation difference that blocks the line of sight between the construction areas and the receivers (the nearest homes). Based on FHWA (2011) data, the elevation difference in this area will provide an estimated noise attenuation of up to 15 dba. Therefore, given the location of the railroad berm in relation to the noise source and nearby homes, construction noise levels at the nearest noise-sensitive receptors were determined to be attenuated to approximately dba L eq for earthwork and site restoration activities in 2015 and dba L eq (Table 8) for earthwork and site restoration activities in 2017 (Table 8). Measured ambient noise levels at the nearest noise-sensitive uses to these activities ranged between 46 dba and 48 dba during the daytime hours (7 a.m. 10 p.m.) (Table 8). The estimated project-related construction noise level of 56 dba L eq at noise-sensitive uses closest to the site will increase the exterior ambient noise levels of dba by up to approximately 8 10 db. This noise-level increase will exceed the established threshold of 5 db above ambient noise levels. Also, the unmitigated noise level produced by construction of the 115 kv transmission lines will be approximately 84 dba at a distance of 50 feet (Table 7). Assuming standard spherical spreading loss (-6 db per doubling of distance) and a distance of approximately 400 feet to the nearest noise-sensitive uses on 20th Street, and given the location of the railroad berm in relation to the noise source and nearby homes, noise levels at these nearest noise-sensitive uses from construction of the transmission lines were estimated at 51 dba L eq (Table 8). Measured ambient noise levels near this construction activity are 56 dba L eq during the daytime hours (7 a.m. 10 p.m.) (Table 8). This level is below the measured ambient noise level of 56 db L eq at the nearest noise-sensitive use. Haul truck noise levels will be approximately dba L eq (Table 8) and will exceed existing traffic noise levels by 4.9 to 7.9 db along 28th Street from the project site to C Street, and by 4.8 to 17.4 db along 20th Street from the project site to C Street, along C Street from 20th Street to 19th Street, and along D Street from 17th Street to 16th Street. However, as described above, the row of buildings parallel to the truck routes can reduce noise levels in noise-sensitive areas (side yards and backyards) by approximately 13 dba (FHWA 2011). This will reduce the maximum traffic noise increase of 17.4 to 5.4 db. The standard construction measures described below will further reduce traffic noise at the sensitive uses. If the 20 th Street exit is used, some trucks may use C Street between 20 th Street and 29 th Street to access Highway 50. This route would be used infrequently for small volumes of waste and any noise increases would be would be lower than those shown in Table 9 for C Street and D Street. Page 28 of 36

31 Station E Substation Project March 2017 As described above, noise from site restoration (placement of backfill in the remediated area) and haul trucks could exceed ambient noise levels. However, as during the 2015 remediation, SMUD will implement standard construction measures to reduce noise impacts. These measures include conducting public outreach, limiting construction to the daytime hours as required by the City Noise Ordinance, locating stationary equipment (e.g., generators, compressors) at the north side of the site, using sound control devices and temporary noise barriers to address localized noise effects, rerouting construction truck traffic away from houses in selected locations, and minimizing equipment idling time. The public outreach process will include recommendations to reduce indoor noise levels by keeping doors and windows closed. SMUD s construction managers will ensure that stationary equipment is located in the northern part of the construction area to the extent practicable. SMUD will also ensure that construction trailers, storage bins, and construction materials that do not generate noise are placed in the area south of the remediation area so that they reduce project noise in adjacent areas such as Grant Park. With these standard construction measures, the impact of noise from site restoration and haul trucks (and from construction of the 115 kv lines, which would be below measured ambient levels) will be less than significant Traffic This section addresses traffic and transportation impacts associated with the remediation and restoration activities required at Station E. The analysis describes the routes between the project site and roadways leading to area freeways that haul trucks will use to transport excavated material from and backfill material to the site, and the potential impacts on transportation (bicycle, pedestrian, and transit circulation). The remediation and restoration work will be temporary and will not result in substantial changes in traffic during substation operations that were not addressed in the 2014 IS/MND. Therefore, this analysis does not address long-term impacts using level of service or vehicle miles traveled as impact thresholds. For construction impacts, this analysis used the Institute of Transportation Engineers (ITE) (1988) criterion for assessing temporary construction impacts. To account for the large percentage of heavy trucks associated with typical construction projects, ITE recommends a threshold level of 50 or more new peak-direction (one-way) trips during the peak hour. In addition, this evaluation considered the Mobility Element of the Sacramento 2030 General Plan, including policies related to connectivity, walking, biking, transit, and parking. Policy M requires evaluation of potential conflicts between bicyclists and motor vehicles on streets, and bicyclists and pedestrians on multiuse trails and sidewalks. Specifically, this analysis evaluates whether the hauling activity associated with site remediation and restoration will degrade the performance of any roadway or intersection to an unacceptable level; inconvenience motorists with prolonged road closures; cause conflicts between vehicles, pedestrians, and bicyclists; or adversely affect public transit. As described in Section 2.0, Project Description, the remedial work completed in 2015 required 90 daily truck trips (11 trips per hour), plus worker vehicles. The remediation and restoration work planned for 2017 will require approximately 83 daily truck trips (10 trips per Page 29 of 36

32 Station E Substation Project March 2017 hour), plus worker vehicles. Workers will commute in passenger vehicles from their places of residence. The streets associated with the two haul routes are listed above in Table 9. Site remediation and restoration is not expected to adversely affect roadway traffic or transportation patterns. The project s truck trip volume (11 trips per hour) plus incoming or outgoing commutes (20) is substantially less than the ITE criterion of 50. Thus, truck and worker traffic will not conflict with an applicable plan, ordinance, or policy establishing measures of effectiveness for the performance of the circulation system, taking into account all modes of transportation including mass transit and nonmotorized travel and relevant components of the circulation system, including but not limited to intersections, streets, highways and freeways, pedestrian and bicycle paths, and mass transit. Furthermore, the project will not add sufficient trips to degrade existing operations and will not conflict with the City s applicable congestion management program (City of Sacramento 2014b), including but not limited to level of service standards and travel demand measures, or other standards established by the City for designated roads or highways. With respect to traffic safety, haul trucks and workers will use existing roads and no new access roads or other transportation infrastructure will be needed. The paved roads that would be used are designed to carry high volumes of heavy-duty vehicles and the project will not require changes to the existing roadway design or introduce incompatible uses or traffic hazards. Thus, the safety of the local transportation network will not be affected by hazards due to a design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment). Furthermore, the project will not require any road closures. Therefore, traffic flow will not be significantly interrupted on any roadway. Construction-related traffic increases will be minimal relative to roadway capacity, and will be temporary. Therefore, remediation and restoration activities will not impair or interfere with emergency access to local roads, and will not result in traffic delays that could substantially increase in emergency response times or reduce emergency vehicle access. Similarly, no public transit, bicycle, or pedestrian facilities are available near the project site. Construction-related traffic will cross multiple Sacramento Regional Transit bus routes along the assumed construction truck routes; however, the project-related truck traffic will be minimal (10 11 truck trips per hour) and will not interfere with any transit routes or service, or with operation of public transit, bicycle, or pedestrian facilities. Therefore, the project will not conflict with adopted policies, plans, or programs regarding public transit, bicycle, or pedestrian facilities, nor will it otherwise decrease the performance of such facilities. Overall, the traffic resulting from the project remediation and restoration activities will be minimal (10 11 trips per hour), short-term, and temporary and will be below any applicable thresholds. Therefore, traffic and transportation impacts will be less than significant and no mitigation is required Utilities The proposed substation construction project, as described in the 2014 IS/MND, accounted for only minor off-site disposal of contaminated material uncovered during excavation. However, Page 30 of 36

33 Station E Substation Project March 2017 because of the discovery of additional ash and contaminated soil in 2015, SMUD will excavate and dispose of hazardous waste, solid waste, and recyclable materials that were not evaluated in the 2014 IS/MND. Between September 16 and October 23, 2015, SMUD excavated 90,000 cubic yards of material. Of this material, 30,117 cubic yards of ash and contaminated soil were segregated from clean soil and disposed of at Class I hazardous waste management facilities, including 9,685 tons at the Kettleman Hills Landfill (215 miles from the project site) and 3,691 tons at the Buttonwillow Landfill in Buttonwillow, California (260 miles from the site). A smaller amount of nonhazardous waste (4,125 tons) was disposed of at the L&D Landfill at 8635 Fruitridge Road in Sacramento (10 miles from the project site). The waste that required landfill disposal was found in Areas W-1 through W-5 as shown in Appendix A, Figure 9a. In addition, 17,519 tons of Class II waste (demolition debris consisting of metal, brick, concrete, and glass) were taken to a recycling facility at Schnitzer Steel at Folsom Boulevard in Rancho Cordova, California (20 miles from the project site). In 2017, SMUD will remove approximately 11,900 cubic yards of residual waste from off-site waste areas Off-1, Off-2, and Off-3 (Appendix A, Figure 9a). In addition, SMUD will excavate approximately 21,500 cubic yards of soil for construction of the 115 kv power lines. This addendum assumes that the entire remaining volume of excavated material from these areas will require off-site disposal. In total, the project will generate more than 60,000 cubic yards of ash and contaminated soil for off-site disposal, and smaller amounts of solid waste and recyclable materials. To date, the project s hazardous-material disposal needs have been met by the Kettleman Hills and Buttonwillow hazardous waste management facilities. According to CalRecycle (2016), the Kettleman Hills Landfill has approximately 6 million cubic yards of remaining capacity should materials generated in 2017 require a Class I disposal facility. The L&D Landfill has a remaining capacity of more than 4 million cubic yards. Therefore, the project has been served by landfills with sufficient permitted capacity and that have capacity to accommodate the second phase of the project. SMUD will continue to recycle solid waste produced by the project to the maximum extent practicable. Therefore, any impacts on landfill capacity would be less than significant. Page 31 of 36

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35 Station E Substation Project March CONCLUSIONS SMUD has determined that the changes to the Station E Substation Project will not have a significant effect on the environment and that with the existing mitigation measures required by the 2014 IS/MND and MMRP, and standard construction measures that will be implemented by the construction contractor, any impacts will be reduced to less than significant. Therefore, this addendum, which considers the effects of the Station E site remediation and restoration, is consistent with the MND adopted by the SMUD Board of Directors in Jose Bodipo-Memba Environmental Management Specialist Date Page 33 of 36

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37 Station E Substation Project March REFERENCES Brown and Caldwell. 2011a. Final Phase II Investigation Summary Report for Sacramento County Assessor Parcel Numbers (APNs) /-022/-023. Letter Report. Prepared for Sacramento Municipal Utility District, Sacramento, CA b. Phase III Site Investigation. Letter Report. November 17, (March). Station E Construction Soil Management Plan and Post Closure Land Use Plan, Station E Substation Construction Project, Sacramento, California. Prepared for Sacramento Municipal Utility District, Sacramento, CA. California Department of Resources Recycling and Recovery Solid Waste Information System. Facility/Site Summary Details: Sacramento County Landfill (Kiefer) (34 AA 0001). Available: Accessed November 11, CalRecycle LEA Advisory #16 Clean Closure Guidance. Available: January 23, Accessed March 2, LEA Advisory #56, Characterizing Burn Dumps in California, Appendix 1. Available: November. Accessed March 2, CalRecycle. See California Department of Resources Recycling and Recovery. City of Sacramento. 2014a. Sacramento 2030 General Plan. Noise Element. Sacramento, CA b. Sacramento 2035 General Plan. Mobility Element. Sacramento, CA. Department of Toxic Substances Control. 2. Protocol for Burn Dump Site Investigation and Characterization. Available: June. Accessed March 2, EPA. See U.S. Environmental Protection Agency. Federal Highway Administration Roadway Construction Noise Model Noise Barrier Design Handbook. FHWA. See Federal Highway Administration. Institute of Transportation Engineers Traffic Access and Impact Studies for Site Development. Transportation Planners Council, Washington, DC. ITE. See Institute of Transportation Engineers. Page 35 of 36

38 Station E Substation Project March 2017 Sacramento Metropolitan Air Quality Management District (September). Guide to Air Quality Assessment in Sacramento County. Originally published December 2009; last updated September Sacramento, CA Air Quality Pollutants and Standards. Available: Accessed January SMAQMD. See Sacramento Metropolitan Air Quality Management District. Tetra Tech EM Phase I Environmental Site Assessment, North Station Property. Prepared for Sacramento Municipal Utility District. November Phase II Site Investigation Summary Report for Sacramento County Assessor Parcel Numbers (APNs) /-022/-023, Sacramento, California. Final. Prepared for Sacramento Municipal Utility District. March U.S. Environmental Protection Agency (March). Information on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety. Washington, DC. Page 36 of 36

39 APPENDIX A: FIGURES FROM THE FINAL POST CLOSURE LAND USE PLAN, BROWN & CALDWELL, NOVEMBER 2016

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41 Document Path: bcsac01 \\bcdav01\projects\49000\ SMUD Substation E\GIS\_MAPDOCS\WORKING\Fig1_SiteLocationSubstationE_ mxd Legend Project Boundary Blue Diamond Alm ond Growers Dellar Trust North City Substation Parcel Boundaries Approximate Landfill Cell Boundary (HLA, 1988) Note: Aerial Photo circa 2010 Levee American River UPRR Tracks Cell #1 Levee Blue Diamond Almond Growers Cell #25 Existing SMUD North City Substation Sedimentation Basin Cell #17 Former Cogeneration Plant Cell #9 Dellar Trust SMUD Station E Substation (Formerly Blue Diamond Almond Growers) Cell #10 Cell #16 UPRR Tracks 21ST ST Cell #8 22ND ST C ST Feet 23RD ST 24TH ST SITE TITLE SMUD Station E Substation, Sacramento, California B ST Site Location PROJECT DATE Figure 6/13/2016 1

42 D D D D D D D D D D D D D D D D D D D D D D D D D D D Document Path: bcsac01 \\bcdav01\projects\49000\ SMUD Substation E\GIS\_MAPDOCS\WORKING\Fig5a_DevPlan_11x17_ mxd Le ge n d Project Boundary Access/Maintenance Road Building Infiltration Basin Leach Field D D Fence Source: Black & Veatch Underground (U/G) Duct Banks/Cable Trench/Manholes/Conduit/Pipes Feet D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D Turn in g Po le s D D D D D D D D D D D Ove rhe ad(o/h) Co n ducto r D D D D D 115kV U/GDuctBan k D D D Le ach Fie ld D D D D D D D D D D D D D D D D D 21kVU/GDuctBan k D D D D Pumpin g Plan t Co n tro lbuildin g D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D 115kVYARD D D D D In filtratio n Bas in D D D D D D D D D D D D D D D D D D D 21kV YARD D D D D D D D D D D D SITE TITLE D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D SMUDStatio n ESubs tatio n,sacrame n to,califo rn ia Statio n EDe s ign De ve lo pme n tplan PROJECT DATE /21/2016 Figure 5a

43 " D D D D D D D D D D D D D D D D D D D D D D D D D D D Document Path: bcsac01 \\bcdav01\projects\49000\ SMUD Substation E\GIS\_MAPDOCS\WORKING\Fig9a_Overexcavation_11x17_ mxd Legend 6.5 Project Boundary Excavation Areas Stockpile Area Cross Section Location Lines Approxim ate Over-Excavation Depth (ft.) $1 Landfill Gas M onitoring Well "/ Monitoring Wells, SM UD Station E Substation Source: Youngdahl, 2016 Notes: Topographic Contours December 2015 E-1 = Excavation Area Feet D D D D D $1 D D D D D D D D D D D D D D D 4 E-23 (4 ft Wide by 4 ft Deep Trench for Fence Line) 2,579 sq ft 15 OFF-3 8,869 sq ft A GAS-E-10 D D D D 12 OFF-2 2,396 sq ft 20 E-22 2,577 sq ft " $1 D D D 15 OFF-1 10,555 sq ft GAS-E-9 19 E-21 2,913 sq ft " " D D " D D D Off-Site Excavation " 13 E-18 4,482 sq ft 15 E-19 5,986 sq ft 17 E-20 3,732 sq ft Stockpile Area GAS-E-1 $1 D D D D D D D D D D D D 11 E-17 11,207 sq ft " D D D " 10 E-16 10,953 sq ft 4.5 E-8 2,612 sq ft 9 E-15 53,489 sq ft D D D D D D $1 " GAS-E-2 11 E-11 8,391 sq ft 8 E-14 49,131 sq ft B' " D D 13 E-10 7,432 sq ft D D " 7 E-13 38,453 sq ft 4 E-7 1,998 sq ft " 15 E-9 19,050 sq ft 6 E-12 15,126 sq ft "/ " B' $1 3 E sq ft D D D D D D D D " Stockpile Area OVEREXCAVATED AREA COMPLETED 3.5 E-6 2,412 sq ft SM UD 1 " GAS-E-3 SITE TITLE " " "/ 7.5 E-1 2,523 sq ft 6.5 E sq ft SM UD E sq ft 4 E sq ft $1 D D D D D D D D D D D D D D D D D $1 GAS-E-6 A' GAS-E-5 D D D D D D D D D D D D D D $1 D D D D D D D D Excavation Plan GAS-E-4 SMUD Station E Substation, Sacramento, California PROJECT DATE /30/2016 Figure 9a

44 GAS-E-10 $1 OFF-1 10,555 sq ft W-5 Waste Area 14,838 sq ft LIMIT OF EXCAVATION Document Path: bcsac01 \\BCDAV01\Projects\49000\ SMUD Substation E\GIS\_MAPDOCS\WORKING\Fig9c_CapRem ainwaste_11x17_20161.mxd Legend Project Boundary Cap Over Remaining Waste Limit of Excavation Area Waste to be Removed as Part of Excavation Plan $1 Landfill Gas M onitoring Well "/ Monitoring Wells, SM UD Station E Substation Cap Area = 68,805 sq ft Source: Youngdahl (2015) Notes: Extent of waste is estimated based on data from the soil borings, test pits, historical aerial photographs, and work performed to-date. Topographic Contours December Feet GAS-E-9 OFF-2 2,396 sq ft CAP OVER REMAINING WASTE $1 OFF-3 8,869 sq ft NO EXCAVATION PLANNED GAS-E-1 $1 W-4 Waste Area 6,365 sq ft LIMIT OF EXCAVATION LIMIT OF EXCAVATION GAS-E-2 $1 W-2 Waste Area 8,402 sq ft W-3 Waste Area 14,602 sq ft W-1 Waste Area 15,986 sq ft SITE TITLE "/ LIMIT OF EXCAVATION Excavation Area = 269,557 sq ft OVER-EXCAVATED AREA COMPLETE SM UD 1 $1 GAS-E-3 "/ SM UD $1 GAS-E-6 $1 GAS-E-5 $1 GAS-E-4 SMUD Station E Substation, Sacramento, California Waste to be Removed and Cap Over Remaining Waste PROJECT DATE 10/03/2016 Figure 9b