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Home My WebLink About; San Marcos Landfil Closure & Maintenance Plan; San Marcos Landfil Closure & Maintenance Plan; 2002-04-01[ c [ E 1^ I I SAN MARCOS LANDFILL FINAL CLOSURE AND POST-CLOSURE MAINTENANCE PLANS DPW#UJ1750 SCH# 2001101126 DRAFT ENVIRONMENTAL IMPACT REPORT April 2002 Preparedfor: County of San Diego Department of Public Works Environmental Services (0385) 5555 Overland Avenue San Diego, CA 92123 Contact: Julia M. Quinn (858) 874-4054 Prepared by: P&D Enviromnental Services 401 West A Street, Suite 2500 San Diego, CA 92101 Contact: Betty Dehoney (619) 232-4466 Project Proponent: Coimty of San Diego Department of Public Works Solid Waste Management (0383) 5555 Overland Avenue San Diego, CA 92123 Contact: Jon RoUin (858) 874-4004 E IP Draft EIR - April 2002 Table of Contents SAN MARCOS LANDFILL FINAL CLOSURE AND POST-CLOSURE MAINTENANCE PLANS EIR TABLE OF CONTENTS ^ge SUMMARY S-1 Project Synopsis S-1 In Summary of Significant Effects and Mitigation Measures that Reduce the Signricant Effects S-2 pi Project Altematives S-7 li Areas of Controversy S-12 Issues to be Resolved by the Decision-Making Body S-15 P iv CHAPTER 1.0 - PROJECT DESCRIPTION, LOCATION, AND ENVIRONMENTAL SETTING 1-1 1.1 - Proiect Description and Location 1-1 1.1.1. - Project Location 1-1 1.1.2. - Project Background 1-1 1.1.3. - Project Description 1-5 1.2 - Proiect Ob jectives 1-15 1.3 - Intended Use of the EIR 1-16 1.3.1. - Matrix of Project Approvals/Permits 1-17 1.4 - Environmental Setting 1-18 1.4.1. - Consistency of Proposed Project with Applicable Regional and General Plans 1-19 CHAPTER 2.0 - SIGNIFICANT ENVIRONMENTAL EFFECTS 2-1 2.1 - Transportation/Circulation 2-1 2.1.1. - Existing Conditions 2-4 2.1.2. - Thresholds of Significance 2-9 2.1.3. - Analysis of Project Effects and Determination of Significance 2-9 2.1.4. - Mitigation Measures 2-17 2.1.5. - Conclusions 2-20 2.2-AirOuahtv 2-46 2.2.1. - Existing Conditions 2-46 2.2.2. - Thresholds of Significance 2-50 2.2.3. - Analysis of Project Effects and Determination of Signiffcance 2-51 2.2.4. - Mitigation Measures 2-55 2.2.5. - Conclusions 2-56 San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Table of Contents Page 2.3 - Noise 2-64 2.3.1. - Existing Conditions 2-64 ^ 2.3.2. - Thresholds of Significance 2-66 2.3.3. - Analysis of Project Effects and Determination of Significance 2-68 2.3.4. - Mitigation Measures 2-71 — 2.3.5. - Conclusions 2-71 >•................ ............I * CHAPTER 3,0 - CUMULATIVE IMPACTS 3-1 3.1 - List of Past, Present, and Reasonably Anticipated Future Projects in the ^ Project Area 3-4 3.2 - Transportation/Circulation 3-6 3.2.1. - Existing Conditions 3-6 — 3.2.2. - Thresholds of Significance 3-6 3.2.3. - Analysis of Project Effects and Determination of Significance 3-7 " 3.2.4. - Mitigation Measures 3-11 3.2.5. - Conclusions 3-11 ^ 3.3 - Air Oualitv 3-13 3.3.1. - Existing Conditions 3-13 3.3.2. - Thresholds of Significance 3-13 m 3.3.3. - Analysis of Project Effects and Determination of Significance 3-13 ^ 3.3.4. - Mitigation Measures 3-15 3.3.5. - Conclusions 3-15 m 3.4 - Noise 3-17 3.4.1. - Existing Conditions 3-17 3.4.2. - Thresholds of Significance 3-17 3.4.3. - Analysis of Project Effects and Determination of Significance 3-18 3.4.4. - Mitigation Measures 3-19 3.4.5. - Conclusions 3-19 MM CHAPTER 4.0 - PROJECT ALTERNATIVES 4-1 ^ 4.1 - Rationale for Altematives Selection 4-1 4.2 - Analvsis of the No Proiect/No Development Altemative 4-2 4.2.1. - No Project Alternative Description and Setting 4-2 wm 4.2.2. - Comparison of the Effects of the No Project Altemative to the Proposed Project 4-3 4.2.3. - Staffs Rationale for Rejection of the No Project Altemative 4-6 w 4.3 - Analvsis of Alternative A: Prescriptive Cover Altemative as Modified bv ^ RWQCB Order No. 92-02 4-7 4.3.1. - Alternative A Description and Setting 4-7 m 4.3.2. - Comparison of the Effects of the Alternative A to the Proposed Project 4-8 M 4.3.3. - Staffs Rationale for Rejection of Alternative A 4-12 P m San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR ^ Draft EIR - April 2002 Table of Contents ^ Page 4.4 - Analvsis of Altemative B: Prescriptive Cover Alternative with Flexible Membrane Liner as Top Deck Barrier 4-13 ^ 4.4.1. - Alternative B Description and Setting 4-13 4.4.2. - Comparison of the Effects of Altemative B to the Proposed Project 4-13 pi 4.4.3. - Staffs Rationale for Rejection of Altemative B 4-16 Hi 4.5 - Analvsis of Altemative C: Prescriptive Cover Alternative as Modified bv RWOCB Order No. 92-02 with Court-Mandated Vegetative Cover 4-17 P 4.5.1. - Alternative C Description and Setting 4-17 Hi 4,5,2. - Comparison of the Effects of Altemative C to the Proposed Project 4-18 4.5.3, - Staffs Rationale for Rejection of Altemative C 4-20 4.6 - Analysis of Alternative D: Prescriptive Cover Altemative with Flexible * Membrane Liner as Top Deck Barrier Layer and Court-Mandated Vegetative Cover 4-21 4.6,1. - Alternative D Description and Setting 4-21 *" 4.6.2. - Comparison of the Effects of Altemative D to the Proposed Project 4-22 ^ 4.6.3. - Staffs Rationale for Rejection of Alternative D 4-24 CHAPTER 5.0 - LONG-TERM ENVIRONMENTAL EFFECTS 5-1 0m 5.1 - Growth-Inducing Impacts 5-1 ^ 5.2 - Significant Environmental Effects Which Cannot be Avoided if the Proposed Project is Implemented 5-2 CHAPTER 6,0 - ENVIRONMENTAL EFFECTS FOUND NOT TO BE SIGNIFICANT 6-1 6.1 - Effects Found Not to be Significant as Part of the EIR Process 6-1 •• 6,1.1 - Hydrology and Water Quality 6-1 6.2 - Effects Found Not to be Significant During Initial Study 6-19 * 6.2.1 - Aesthetics 6-19 6.2.2 - Agricultural Resources 6-20 6.2.3 - Biological Resources 6-20 6.2.4 - Cultural/Paleontological Resources 6-21 6.2.5 - Geology and Soils 6-22 6.2.6 - Hazards and Hazardous Materials 6-23 6.2.7 - Land Use and Planning 6-24 6.2.8 - Population and Housing 6-25 6.2.9 - Public Utilities and Service Systems 6-25 Mt LIST OF REFERENCES 7-1 San Marcos Landfill Closure and iii m Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Table of Contents Page LIST OF EIR PREPARERS AND PERSONS AND ORGANIZATIONS CONTACTED 8-1 EIR Preparers 8-1 Persons and Organizations Contacted 8-2 LIST OF MITIGATION MEASURES AND ENVIRONMENTAL DESIGN CONSIDERATIONS 9-1 Mitigation Measures Proposed for the Proiect 9-1 Environmental Design Considerations for the Proiect 9-2 TECHNICAL APPENDICES A Environmental Initial Study, Notice of Preparation, and Responses B Traffic Technical Study C Air Quality Technical Study D Noise Technical Study E Alternate Cover Evaluation Technical Study San Marcos Landfill Closure and iv Post-Closure Maintenance Plans BIR IF IM Draft EIR-April 2002 Table of Contents LIST OF FIGURES Page II Figure S-1 Proposed Project S-17 Figure S-2 Overview of Truck Routes S-19 m Figure S-3 Altemative B S-21 ^ Figure S-4 Altemative A S-23 Figure S-5 Altemative C S-25 P Figure S-6 Altemative D S-27 Figure 1-1 Regional Map 1-20 * Figure 1-2 Vicinity Map 1-21 li Figure 1-3 Project Setting 1-22 Figure 1-4 Landfill Overview 1-23 Figure 1-5 Drainage Plan 1-25 Figure 1-6 Drainage Details 1-27 Figure 1-7 Leachate Collection and Perimeter Berm Areas 1-29 Figure 1-8 Landfill Gas Monitoring and Collection System 1-31 Figure 1-9 Proposed Project 1-33 Figure 1-10 Grading Cross Sections 1-35 Figure 1-11 Grading Plan 1-37 Figure 1-12 Conceptual Revegetation Plan with Off-Fill Revegetation Areas 1-39 Figure 1-13 Temporary Imgation System 1-41 Figure 2.1-1 Overview of Tmck Routes 2-22 Figure 2.1-2 Truck Route 1 2-23 Figure 2.1-3 Truck Route 2 2-24 Figure 2.1-4 Truck Route 3 2-25 Figure 2.1-5 Truck Route 4 2-26 Figure 2.1 -6 Truck Route 5 2-27 Figure 2.1-7 Tmck Route 6 2-28 Figure 3-1 Cumulative Projects 3-21 Figure 4.3-1 Altemative A 4-25 Figure 4.4-1 Altemative B 4-27 Figure 4.5-1 Altemative C 4-29 Figure 4.6-1 Altemative D 4-31 Figure 6.1-1 Groundwater Elevations and Row Directions 6-27 Figure 6.1-2 Off-Site Well Locations 6-29 Figure 6.1-3 Hydrologic Subareas 6-30 San Marcos Landfill Closure and v Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Table of Contents LIST OF TABLES Page Table S-1 Summary of Project Impacts and Proposed Mitigation Measures S-29 Table S-2 Summary of Project Altematives S-35 Table 1-1 Physical and Chemical Soil Characteristics Required by the Modified LSA Plan 1-43 Table 1-2 Soil Mix Characteristics 1-43 Table 1-3 Coastal Sage Scrub Seed Mix 1-44 Table 1-4 Coastal Sage Scmb Container Plants 1-44 Table 1-5 Southem Mixed Chaparral Seed Mix 1-45 Table 1-6 Southem Mixed Chaparral Container Plants 1-45 Table 1-7 Non-Native Plants 1-46 Table 1-8 Monitoring, Inspection, Reporting, and Maintenance Requirements 1-47 Table 2.1-1 Existing Daily Traffic Volumes 2-29 Table 2.1-2 Route 1 Intersection and Segment Operations 2-31 Table 2.1-3 Route 2 Intersection and Segment Operations 2-33 Table 2.1-4 Route 3 Intersection and Segment Operations 2-35 Table 2.1 -5 Route 4 Intersection and Segment Operations 2-37 Table 2.1-6 Route 5 Intersection and Segment Operations 2-39 Table 2.1-7 Route 6 Intersection and Segment Operations 2-41 Table 2.1-8 Peak Hour Freeway Segment Summary 2-43 Table 2.1 -9 Sunmiary of Transportation/Circulation Impacts 2-44 Table 2.2-1 Ambient Air Quality Standards 2-59 Table 2.2-2 Air Quality Monitoring Summary 2-61 Table 2.2-3 Screening-Level Criteria for Air Quality Impacts 2-62 Table 2.2-4 Regional Mobile Source Exhaust Emissions 2-62 Table 2.2-5 Daily PMio Emissions 2-63 Table 2.3-1 Existing Noise Conditions 2-73 Table 2.3-2 Haul Traffic Noise Impact Assessment 2-74 Table 3-1 Cumulative Projects 3-22 Table 3-2 Cumulative Project Traffic Generation 3-26 Table 3-3 Cumulative Project Air Quality Analysis 3-28 Table 3-4 Cumulative Project Noise Analysis 3-29 Table 4-1 Sunmiary and Comparison of Altemative Cover Requirements 4-33 Table 4-2 Comparison of Proposed Project and Altematives 4-34 m n p San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR VI P to ^ Draft EIR - April 2002 Table of Contents MM ^ Page * Table 6.1-1 Water Quality Objectives Estabhshed by the RWQCB 6-31 1^ Table 6.1-2 Comparison of Historical VOC Concentrations in Corrective ^ Action Wells and RWQCB-Established Water Quality Objectives ("WQOs") 6-31 pi P P li San Marcos Landfill Closure and vii Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Acronyms ACRONYMS AAQS Ambient Air Quality Standards ACOE United States Army Corps of Engineers PM ADT Average Daily Trips AMSL Above Mean Sea Level 1 M APCD Air Pollution Control District AQL^L Air Quality Impact Assessments ARB Air Resources Board CAP Corrective Action Program CCR Califomia Code of Regulations CDFG Califomia Department of Fish and Game CEQA Califomia Environmental Quality Act CHP Califomia Highway Patrol CIWMB Califomia Integrated Waste Management Board CMP Cormgated Metal Pipe HI CNEL Commimity Noise Equivalent Level Hi CO Carbon Monoxide COC Constituents of Concern Mi CQA Constmction Quality Assurance Plan CSS Coastal Sage Scmb CUP Conditional Use Permit m dB Decibel m dB(A) A-weighting DG Decomposed Granite Soil •Hi EAF Environmental Analysis Form Mi ECe Electrical Conductivity m EIR Enviroimiental Impact Report EIS Environmental Impact Statement Mi EMP Evaluation Monitoring Program P EPA Environmental Protection Agency Hull FAA Federal Aviation Administration FHWA Federal Highway Administration p FML Flexible Membrane Liner m FPA Focused Planning Area FPCMP Final Post-Closure Maintenance Plan m HA Hydrologic Area M HSA Hydrologic Subarea 1-15 Interstate Highway 15 p 1-5 Interstate Highway 5 p ITE Institute of TrafRc Engineers LCRS Leachate Collection and Removal System p LEA Local Enforcement Agency (County of San Diego Department of m Environmental Health) San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR P vui Pi p HI P P Ml m m P Draft EIR-April 2002 Acronyms m p Im LEACHM Leaching Estimation and Chemistry Model Leq Equivalent Level LFG Landfill Gas LOS Level of Service MBAS Methol Blue Active Substances MCL Maximum Contaminant Levels MHCP Multiple Habitat Conservation Program MND Mitigated Negative Declaration MPH Miles per Hour M&RP Monitoring and Reporting Program NCCP Natural Community Conservation Plan NCRRF North County Resource Recovery Facility NOP Notice of Preparation NOx Nitrogen Oxides NSA Noise Sensitive Area NTU Nephelometric Turbidity Units O3 Ozone PCE Passenger Car Equivalents PMio Respirable Particulate Matter ppm parts per million RAQS Regional Air Quality Standards ROC Reactive Organic Compounds ROG Reactive Organic Gases RWQCB Regional Water Quality Control Board SANTEC San Diego Transportation Engineers' Council SAR Sodium Absorption Ratio SCAQMD South Coast Air Quality Management District SDAB San Diego Air Basin SEDAB Southeast Desert Air Basin SIP State Implementation Plan SOx Sulfur Oxides SR78 State Route 78 SWRCB State Water Resources Control Board TAG Toxic Air Contaminants T-BACT Toxics Best Available Control Technology TCO Technical Change Order TDS Total Dissolved Solids TKN Total Kjeldahl Nitrogen TWLTL Two-Way Left Tum Lane V/C Volume to Capacity Ratio VOC Volatile Organic Compound WDR Waste Discharge Requirements WQO Water Quality Objectives WQPS Water Quality Protection Standard San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR IX pi p Draft EIR - April 2002 Summary SUMMARY p Project Synopsis li m The Proposed Project consists of preparing and implementing the Final Closure and Post-Closure • Maintenance Plans for the San Marcos Landfill ("Landfill"). The Landfill is owned by the IP County of San Diego ("County") and is located within the City of San Marcos ("City") in • northem San Diego County. The Landfill is located adjacent to San Elijo (Questhaven) Road, P between Rancho Santa Fe Road and Elfin Forest Road. The Landfill covers approximately li 328 acres, including buffer land owned by the County. The fill area covers 102 acres. In accordance with Califomia Code of Regulations ("CCR") Title 27, the County of San Diego is required to prepare and implement final closure and post-closure maintenance plans for the Landfill. The main components of the Proposed Project include the final closure plan design; final cover soil design; soil hauling, mixing, and placement; revegetation plan; and post-closure monitoring and maintenance. The Califomia Superior Court has issued a writ of mandate directing the County to implement a court-approved revegetation plan, known as the "LSA Plan". In July 2001, the County and the City agreed to modifications to the LSA Plan to accommodate changes in soil characteristics needed to comply wath CCR Title 27 requirements. The LSA Plan, as amended, is described in this document as the "Modified LSA Plan". Closure of the Landfill v^ill comply with both CCR Title 27 and Modified LSA Plan requirements (Figure S-1). The closure plan includes an engineered altemative evapo-transpiration cover soil system. The cover soil will range in depth from five to eight feet. The Proposed Project will require the importation of approximately 420,000 cubic yards of soil (30,000 tmck trips) over an approximate seven-month period. The imported soil will be mixed with on-site soil and placed over the Landfill surfaces. The Landfill will be revegetated with a mix of coastal sage scmb ("CSS") and chaparral species. The Final Closure and Post-Closure Maintenance Plans will require approval from the Califomia Integrated Waste Management Board ("CIWMB"), San Diego Regional Water Quality Control San Marcos Landfill Closure and S-1 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Summary Board ("RWQCB"), San Diego County Air Pollution Control District ("APCD"), and County of San Diego Department of Environmental Health, Local Enforcement Agency ("LEA"). The objectives of the Proposed Project are as follows: • Close and maintain the Landfill in compliance with CCR Titie 27, CIWMB, RWQCB, APCD, and LEA. The closure will minimize the infiltration of water into the waste, thereby minimizing the production of leachate and gas as per CCR Title 27, Section 20950 (a)(2). • Maintain the Landfill in compliance with the Superior Court writ of mandate. The writ of mandate requires that the County of San Diego permanently close and revegetate the Landfill consistent with the Modified LSA Plan. • Close and maintain the Landfill at a reasonable cost consistent with protecting the health and safety of the public and the environment. • Implement the Final Closure and Post-Closure Maintenance Plans utilizing procedures to protect public health and safety. • Revegetate the closed Landfill with native habitats that provide visual compatibility with adjacent natural habitats, and add to the regional biological value of the site as passive open space. Summary of Significant Effects and Mitigation Measures that Reduce the Significant Effects Table S-1 identifies the significant impacts associated with the Proposed Project, proposed mitigation measures, and levels of significance of impacts after mitigation. Significant impacts San Marcos Landfill Closure and S-2 Post-Closure Maintenance Plans EIR IP p Draft EIR - April 2002 Summary related to the hauling of cover soil were identified for the Proposed Project, and include project- level and cumulative short-term transportation/circulation, air quality, and noise impacts. The Proposed Project will require the import of approximately 420,000 cubic yards of soil, for a total of 30,000 tmck trips. A tmck trip is defined as the loading of cover soil at the source site, p delivery of the material at the Landfill, and retum to the source site. Tmcks will only transport ^ material to the Landfill. The tmcks will be empty on the retum trip. The source of the cover soil il is unknowTi at this time; however, potential soil sources would in all probability have to be p routed along the Interstate Highway 5 ("1-5"), Interstate Highway 15 ("1-15"), or State Route 78 ii ("SR 78") corridors, tmless a source in the immediate vicinity is found. If that were to occur, the pi cover soil would be transported along at least a portion of one of the six tmck routes identified li and discussed in this document. The EIR evaluates six potential haul routes and the m environmental effects associated with each route. p" Figure S-2 depicts the potential tmck routes. Ifthe cover soil is located along the 1-15 corridor ^ (or SR 78 corridor), routmg would be via Tmck Route 1 (SR 78/Rancho Santa Fe Road/ f- San Elijo Road), Tmck Route 2 (SR78/E1 Camino Real/Olivenhain Road/Rancho Santa Fe Road/San Elijo Road), or Tmck Route 3 (I-15/Ninth Avenue/Auto Parkway/Harmony Grove ^ Road/Elfin Forest Road/San Elijo Road). If the cover soil is located along the 1-5 corridor, the ip ™ routing would be via Tmck Route 4 (I-5/Palomar Airport Road/El Camino Real/Olivenhain ^ Road/Rancho Santa Fe Road/San Elijo Road), Tmck Route 5 (I-5/La Costa Avenue/El Cammo Real/Olivenhain Road/Rancho Santa Fe Road/San Elijo Road), or Tmck Route 6 (I-5/Encinitas ^ Boulevard/El Camino Real/Olivenhain Road/Rancho Santa Fe Road/San Elijo Road). Cover soil P located along SR 78 could also be routed along Tmck Routes 4, 5, and 6. The transportation/circulation impacts of the Proposed Project result from tmcks hauling cover * soil to the Landfill (see Section 2.1.3). Significant project-level and ctmiulative short-term P impacts to the local circulation network would result along all Tmck Routes, pi il San Marcos Landfill Closure and S-3 p Post-Closure Maintenance Plans EIR li Draft EIR-April 2002 Summary The following is a summary of the transportation/circulation impacts with the Proposed Project and associated potential tmck routes. Figure S-2 depicts the tmck routes evaluated in the EIR. Intersection or Roadway Segment''^ Existing LOS<'»<^ LOS With Prefect Truck Route Rancho Santa Fe Road/SR 78 WB Ramps, AM peak hours (I) D E 1 Rancho Santa Fe Road/SR 78 EB Ramps, AM and PMjieak hours (1) F F 1 Rancho Santa Fe Road/San Marcos Boulevard, AM and PM peak hours (I) E&F E&F 1 Rancho Santa Fe Road/Melrose Drive, AM peak hours (I) D D 1 Rancho Santa Fe Road/San Elijo Road, PM peak hours (I) C D&E 1,2,4,5,6 Rancho Santa Fe Road - Descanso Boulevard to Grand Avenue (R) E F 1 Rancho Santa Fe Road - La Mirada Drive to Linda Vista Drive (R) D E 1 Rancho Santa Fe Road - San Marcos Boulevard to Lake San Marcos Drive (R) D D 1 Rancho Santa Fe Road - Lake San Marcos Drive to Melrose Drive (R) F F 1 Rancho Santa Fe Road - Melrose Drive to San Elijo Road (R) F F 1 El Camino Real/SR 78 WB Ramps, AM and PM peak hours (I) D D 2 El Camino Real/SR 78 EB Ramps, PM peak hours (I) D D 2 Palomar Airport Road/El Camino Real, AM and PM peak hours CD E E 2,4 E! Camino Real/Olivenhain Road, AM and PM peak hours (I) D&E D&E 2,4,5,6 Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue (R) F F 2,4,5 Rancho Santa Fe Road - Truck Bypass to San Elijo Road (R) F F 2,4,5 Valley Parkway/Auto Park Way, AM and PM peak hours (I) D&C D 3 Auto Park Way - Ninth Avenue to Valley Parkway (R) C D 3 Auto Park Way North (one-way) - Andreasen Drive to Howard Avenue (R) D D 3 Palomar Airport Road - Paseo Del Norte to Armada Drive (R) E E 4 La Costa Avenue - Piraeus Street to Saxony Road^) D D 5 Et Camino Real - Levante Street to Calle Barcelona (R) D D 5 Encinitas BouIevard/I-5 SB Ramps, PM peak hours (I) C D 6 Encinitas Boulevard/I-5 NB Ramps, PM peak hours (I) C D 6 Encinitas Boulevard/El Camino Real, AM and PM peak hours (I) E E 6 El Camino Real/Garden View Road, PM peak hours (I) D D 6 Encinitas Boulevard - Interstate Highway 5 to Saxony Road (R) E F 6 Interstate Highway 15 - Valley Parkway to Ninth Avenue (R) F F 1-3 Interstate Highway 5 - Santa Fe Drive to Encinitas Boulevard (R) F F 4-6 Interstate Highway 5 - Palomar Airport Road to Cannon Road (R) F F 4-6 State Route 78 - EI Camino Real to College Boulevard (R) D E 1,2 State Route 78 - Rancho Santa Fe Road to San Marcos Boulevard (R) E E 1,2 Notes: (1) (2) (3) I = Intersection Impact, R = Roadway Segment Impact. LOS = Level of Service. LOS D represents conditions approaching unstable flow, with traffic volumes profoundly affecting arterials. LOS E represents unstable roadway flow with some stoppages. LOS F represents forced flow, many stoppages, and low operating speeds. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR S-4 Ml Draft EIR-April 2002 Summan ^ Proposed mitigation measures to partially reduce short-term transportation/circulation impacts to roadway segments and intersections associated with the Proposed Project include limiting the delivery of cover soil to between 7:00 AM and 4:00 PM, and notifying local bicycle clubs along affected routes of the haul period schedule and routing associated with the Proposed Project. These proposed mitigation measures will partially mitigate the short-term traffic congestion; however, impacts to the local circulation network v^dll still remain significant. To mitigate impacts to below a level of significance, the number of tmck trips would need to be reduced. Even at 100 trips per day, there would be significant transportation/circulation impacts. ^ Reducing the number of trips correlates directly with the length of constmction. Thus, reducing the number of trips by 75 percent would result in a fourfold increase in the time requured to haul soil to the Landfill. [ P ll m P P Significant short-term project-level air quality and noise impacts were identified because of the ^ increased tmck trips associated with hauling cover soil to the Landfill. Significant short-term air ^ quality impacts would result from nitrogen oxide ("NOx") emissions and particulate matter ^ ("PMio") resulting from the excavation, loading, and transport of cover soil, and soil mixing and fc, grading operations at the Landfill. NOx is produced as part of exhaust emissions from vehicles. ^ PMio impacts are due to the large amount of cover soil that must be transported to the Landfill iM and placed on Landfill surfaces. m Significant short-term noise impacts on San Elijo Road (between Rancho Santa Fe Road and the ^ Landfill) will be mitigated to below a level of significance (Routes 1, 2, 4, 5, and 6). Significant P and unmitigable noise unpacts would occur on Tmck Route 3, because of the increased noise up from the cover soil transport tmcks traveling to and from the Landfill. Pi P Reducing the number of trips is infeasible, because the time reqmred to haul the cover soil to the Landfill also increases in a proportional manner. The reduction in number of daily trips, thereby lengthening the duration of the project, would create several undesirable consequences. Due to fixed overhead costs, it is a proven principle in the constmction industry that extending the duration of a constmction project will result in increased expense to complete the project. With a San Marcos Landfill Closure and S-5 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Summary landfill closure, extending the duration of closure results in an increased time period during which the Landfill is not covered by a permanent cover system. During the constmction process, the Landfill is more vulnerable to erosion of existing cover and infiltration of water into the layers of trash. Therefore, extension of the duration of installation of the permanent cover increases the possibility of undesirable environmental events, such as erosion or water infiltration. CCR Title 27 regulations require that the permanent cover be installed within 180 days of commencement of constmction. While this viall not be possible, and an extension must be obtained due to the magnitude of the task for this Landfill, the policy of the Regulations is clear: the application of the permanent cover should proceed as expediently as possible once started. The design of the evapo-transpiration cover system also dictates that a slower/longer soil hauling procedtire is not environmentally desirable. The potential for infiltration of water into the landfill trash is significantly slowed and prevented by the vegetative cover, which draws moisture out of the vegetative soil before it can infiltrate. Delaying the planting of the vegetative cover would also delay implementation of this key design feature. Lastly, the use of a faster/shorter hauling schedule reduces the duration of noise and air emission impacts when compared with a slower/longer haul schedule. Smce the unpacts are already significant, and cannot feasibly be reduced to a level of insignificance, it is desirable to reduce the duration of those impacts. Measures have been mcorporated for air quality and noise to reduce impacts to the extent feasible and practicable. Design measures for air quality include adherence to San Diego County APCD requirements for dust suppression and use of low-sulfur fuel for constmction equipment. Mitigation measures for noise include restricting constmction (and hauling) from starting before 7:00 AM. The Proposed Proj ect would result in significant short-term proj ect-level impacts for transportation/circulation, air quality, and noise. When the Proposed Project was considered with the cumulative projects, the contribution of other projects in the area would result in significant short-term cumulative impacts of transportation/circulation, air quality, and noise (see San Marcos Landfill Closure and S-6 Post-Closure Maintenance Plans EIR m Draft EIR-April 2002 Summarj' m ^ Chapter 3.0). Because the cumulative impacts (as well as the project impacts) will be short term. Kg, there is no practicable or feasible mitigation to reduce the short-term cumulative impacts associated with the Proposed Project to below a level of significance. m p p k p Project Alternatives Project altematives are summarized below and discussed in detail in Chapter 4.0 of this EIR. il The EIR analyzed four altematives to the Proposed Project, in addition to the No Project Altemative. Figure S-1 depicts the Proposed Project, and Figures S-3 through S-6 depict the four altematives. Table S-2 presents a summary of die Altematives and their impacts with regard to transportation/circulation, noise, and air quality. Hydrology/water quality is possibly negatively impacted only by die No Project Altemative. With tiie Proposed Project, and the other altematives, hydrology/water quality is positively impacted and improved, since those altematives would permanentiy close die Landfill and reduce the possibility of substantial infiltration of water through the refiise layers, which reduces the risk of leachate generation. The unprovement of the surface water drainage system with those altematives would also positively affect hydrology/water quality. Altemative B has been identified as the environmentally superior altemative and is discussed first. Alternative B: Prescriptive Cover Alternative with Flexible Membrane Liner as Top Deck Barrier Layer A complete discussion of Altemative B is presented in Section 4.4. Under Altemative B, the Landfill closure would be completed pursuant to the prescriptive cover requu-ements of CCR Titie 27 witii a modified top deck barrier (Figure S-3). This includes a two-foot foundation soil layer overlain by a flexible membrane liner ("FML") layer and one foot of vegetative soil layer on the top deck. The side slopes above the vertical expansion liner would be covered with a two- foot foundation soil layer overlain by a two-foot clay barrier soil layer and a one-foot vegetative soil layer. The Landfill surfaces would be revegetated witii a mixture of grasses and forbs. All other components of the Proposed Project would remain the same for this altemative. San Marcos Landfill Closure and S-7 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Summary Altemative B would require less soil (254,000 cubic yards, vs. 420,000 cubic yards for the Proposed Project) to be imported than the Proposed Project and, therefore, reduce the short-term transportation/cu-culation, air quality, and noise impacts compared to the Proposed Project. However, as discussed in the Proposed Project, the short-term transportation/circulation, air quality, and noise impacts would remain significant and would be infeasible to mitigate. Under this altemative, hauling would still be at the same rate per day (average of 300 trips). Under this altemative, only the length of time for hauling would be reduced (four months, vs. approximately seven months for the Proposed Project). The same roadway and intersection impacts identified for the Proposed Project would apply to this altemative. Altemative B has been identified as the Environmentally Preferred Altemative, because of the reduced number of tmck trips required to haul cover soil to the Landfill. Although Altemative B is considered the environmentally superior altemative, it is rejected because, among other reasons, it does not provide for the necessary three-foot vegetative cover soil necessary to support the native upland vegetation, and therefore does not comply with the court-ordered Modified LSA Plan. As discussed above, the vegetative cover is an essential element of the effective removal of water from the cover soil. While the short-term envhonmental impacts would be reduced using this altemative, it can be concluded that the long-term environmental goals and project objectives would be diminished under this altemative. No Project/No Development Alternative A discussion of the No Project/No Development Altemative is presented in Section 4.2. The No Project Ahemative would consist of the Landfill remaining in its present state. Currently, the Landfill has an intermediate cover, as prescribed by CCR Titie 27 and RWQCB order, although no final closure cover system is m place. The term "final closure cover system" means the placement of an engineered evapo-transpiration permanent cover system with landscaping. The rationale for rejection of the No Project Altemative is threefold. First, the County of San Diego has a legal requirement to place a permanent cover upon the Landfill pursuant to CCR San Marcos Landfill Closure and S-8 Post-Closure Maintenance Plans EIR Draft Em-April 2002 summary ^ Title 27. Therefore, in accordance with this legal requirement, tiiere are potential penalties for 1^ non-compliance tiiat make die No Project Altemative infeasible for legal and economic reasons. ^ Secondly, tiiere is a court-ordered mandated revegetation plan (Modified LSA Plan) for which k tiiere are potential penalties for non-compliance tiiat make tiie No Project Ahemative infeasible ^ for legal and economic reasons. Thirdly, tiie No Project Altemative is rejected because it could In cause significant impacts tiiat tiie Proposed Project is designed to prevent. If tiie Proposed Project were not implemented, the Landfill would continue to exist in hs current state, with a non-permanent intermediate cover, with little vegetation. This increases the possibility of infiltration of water into the refiise, and if tiiat occurs in sufficient volume, leachate contamination of tiie groundwater m the area could occur, potentially harmmg the environment. The principal objective of tiie Proposed Project is to minimize tiie infiltration of water into tiie waste, thereby minimizing die production of leachate and gas as per CCR Title 27, Section p 20950(a)(2). P 1^ hi Additionally, witiiout tiie Proposed Project, there is a greater likelihood of erosion of the existmg cover soil due to the lunited vegetation currently on site. The introduction and maintenance of the vegetative cover contemplated by die Landfill Closure and Post-Closure Maintenance Plans will significantly reduce soil erosion by wind and water. As noted in Section 6.2.1, Aesthetics, tirie vegetative cover will also improve the aesthetics of the Landfill mound. Alternative A: Prescriptive Cover Alternative as Modified by RWQCB Order No. 92-02 A complete discussion of Altemative A is presented in Section 4.3. Under Ahemative A, the Landfill closure would be completed using a "prescriptive" cover system described by CCR Titie 27, as modified by RWQCB Order No. 92-02 (Figure S-4). This includes a two-foot foundation soil layer overiain by a two-foot clay barrier soil layer, a FML, and a one-foot vegetative soil layer on the top deck. Side slopes above the vertical expansion liner mclude a two-foot foundation soil layer overlain by a two-foot clay barrier soil layer and a one-foot vegetative soil layer. Side slopes below the vertical expansion liner would be covered with a two-foot foundation soil layer overlain by a one-foot barrier soil layer and a one-foot vegetative P San Marcos Landfill Closure and S-9 m Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Summary soil layer. The Landfill surfaces would be revegetated with a mixture of grasses and forbs. All other components of the Proposed Project would remain the same for this altemative. Altemative A would require less soil (390,000 cubic yards, vs. 420,000 cubic yards for the Proposed Project) to be imported and, therefore, reduce the short-term transportation/circulation, an- quality, and noise impacts compared to the Proposed Project. However, the short-term transportation/circulation, air quality, and noise impacts would remain significant and would (as discussed in the Proposed Project) be infeasible to mitigate. This altemative would not meet the requirements of the Modified LSA Plan. The Superior Court writ of mandate requires that the Coimty implement the Modified LSA Plan. The Modified LSA Plan requires revegetation with CSS and chaparral species. Because these species require a minimum of three feet of vegetative soil, the one-foot vegetative layer proposed with this altemative will not support the CSS and chaparral species. Thus, this altemative would result in non-compliance with the Superior Court writ of mandate. Alternative C: Prescriptive Cover as Modified by RWQCB Order No. 92-02 with Court- Mandated Vegetative Cover A complete discussion of Altemative C is presented in Section 4.5. Under Altemative C, the Landfill closure would be completed pursuant to the prescriptive cover described by CCR Titie 27, as modified by RWQCB Order No. 92-02, and with the addition of the vegetative soil requirements of the Modified LSA Plan (Figure S-5). This mcludes a two-foot foundation soil layer overlain by a two-foot clay barrier soil layer, a FML, and a three-foot vegetative soil layer on the top deck. Side slopes above the vertical expansion liner would be covered with a two-foot foimdation soil layer overlain by a two-foot clay barrier soil layer and a three- to six-foot vegetative soil layer. Side slopes below the vertical expansion would be covered with a two-foot foundation soil layer overlam by a one-foot clay barrier soil layer and a three- to six-foot vegetative soil layer. The Landfill surfaces would be revegetated with a mixture of CSS and San Marcos Landfill Closure and S-10 Post-Closure Maintenance Plans EIR p m fm Draft EIR-April 2002 Summary chaparral species. All other components of the Proposed Project would remain the same for this I™ y altemative. In Altemative C would require tiie importation of approximately 57 percent more soil to tiie site (696,000 cubic yards, vs. 420,000 cubic yards for tiie Proposed Project). This would increase tiie li total number of tmck trips to 49,714 (approximately 19,700 more tmck trips tiian for tiie p Proposed Project), which would increase tiie traffic, noise, and air quality impacts described in li this document. It would also significantiy increase tiie expense of closure for the County associated with the transport of additional soil and lengtiien the period of significant short-term transportation/circulation, air quality, and noise impacts. Because the Proposed Project is projected to perfomi better tiian this altemative cover system, and because Ahemative C would increase short-term unpacts mentioned above and costs, Altemative C is rejected. Alternative D: Prescriptive Cover Alternative with Flexible Membrane Liner as Top Deck Barrier Layer and Court-Mandated Vegetative Cover A complete discussion of Altemative D is presented in Section 4.6. Under Ahemative D, the Landfill closure would be completed pursuant to requirements of CCR Title 27, with the inclusion of the vegetative cover soil requirements of the Modified LSA Plan and tiie modified top deck barrier layer (Figure S-6). This includes a two-foot foimdation soil layer overlain by a FML and three feet of vegetative soil on the top deck. Side slopes above the vertical expansion liner would be covered with a two-foot foundation soil layer overlain by a two-foot clay barrier soil layer and a three- to six-foot vegetative soil layer. Side slopes below the vertical expansion liner would be covered with a two-foot foundation soil layer overlain by a one-foot clay barrier soil layer and a three- to six-foot vegetative soil layer. Landfill surfaces would be revegetated with a mixture of CSS and chaparral species. All other components of the Proposed Project would remain the same for this altemative. Altemative D would require tiie importation of approxunately 33 percent more soil to the she (560,000 cubic yards, vs. 420,000 cubic yards for the Proposed Project). This would increase the San Marcos Landfill Closure and S-11 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Summary number of tmck trips to 40,000 (approximately 10,000 more tmck trips than the Proposed Project), which would increase the traffic, noise, and air quality impacts described in the document. It would also significantly increase the expense of closure for the County associated with the transport of additional soil, and lengthen the period of significant short-term transportation/circulation, air quality, and noise impacts. Because the Proposed Project is projected to perform better than this altemative cover system, and because Altemative D would mcrease short-term impacts mentioned above and costs, Altemative D is rejected. Areas of Controversy The Notice of Preparation ("NOP") of the Proposed Project was circulated on October 23, 2001 for a 30-day review period. Appendix A includes the NOP, list of NOP recipients, and comment letters from agencies and interested individuals in response to the NOP. Primary issues raised during the public comment period include the increase in traffic and degradation of existing roadways and intersection LOS, air quality, noise, water quality, and hazardous materials. A traffic impact study was prepared for the Proposed Project and is included in Appendix B. The analysis addressed project-related traffic with the existing conditions, as well as the cumulative effects of project traffic in conjunction with other projects in the vicinity. Project-specific transportation/circulation impacts are discussed in Section 2.1.3, and cumulative traffic impacts are discussed in Section 3.2.3. The traffic analysis concluded that the haulmg of cover soil would cause a significant short-term impact to numerous roadway segments and intersections. Partial mitigation measures to reduce short-term transportation/circulation impacts include: eliminating tmck trips in PM peak hours (4:00 PM to 6:00 PM), and notifying local bicycle clubs of the schedule. Hauling of cover soil at night was evaluated and determined not to be feasible, since night hauling would pose a significant noise impact to residential land uses along the haul routes. Additionally, constmction at night would result in an increased nuisance to adjacent residential properties from the high-wattage lighting that would be required to illuminate the Landfill work area. San Marcos Landfill Closure and S-12 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Summary Air quality concems expressed in responses include impacts from fiigitive dust from the ^ transportation and placement of fill material and impacts related to the Landfill Gas ("LFG") ^ system. The LFG system currently exists at tiie Landfill, but vdll be modified as part of tiie p Proposed Project. The Landfill currently has systems in place to detect and control the presence p of LFG that have been approved by regulatory agencies. The LFG system will continue to be iH maintained and monitored by the County An air quality technical report was prepared for the Proposed Project and is included in Appendix C. Project-specific air quality impacts are discussed in Section 2.2.3, and cumulative air quality impacts are discussed in Section 3.3.3. A design measure has been included in the project design to reduce fugitive dust, and is listed on IP li page 9-2. P ii p p m P m m P The Proposed Project will have significant short-term air quality impacts related to NOx and PMio- NOx is produced as part of exhaust emissions from vehicles and constmction equipment. PMio impacts are due to the large amount of cover soil that must be excavated, loaded, and transported to the Landfill, mixed, and placed on Landfill surfaces. Proposed design measures to reduce PMio impacts include covering soil loads on haul tmcks and using wet dust suppression techniques at the Landfill she. To reduce the impacts would requfre a substantial reduction m the number of daily trips and a corresponding increase in the time of constmction, and create several undesirable consequences. These include increased expense to complete the project, lengthening of project unpacts, and the mcreased possibility of cover erosion and water infiltration. These mitigation measures will not reduce significant project- nor cumulative-level short-term air quality impacts to below a level of significance. Concems were raised regarding noise generated from the transportation and placement of cover soil in relation to adjacent residential uses. An acoustical analysis was prepared for the Proposed Project and is included in Appendix D. Project-specific noise impacts are discussed in Section 2.3.3, and cumulative noise impacts are discussed in Section 3.4.3. Significant short- term project-level and cumulative noise impacts were identified for the Proposed Project. A mitigation measure to reduce noise impacts has been mcluded m the project to ensure that soil hauling activities do not begin before 7:00 AM. This measure wdll mitigate impacts on Routes 1, pi San Marcos Landfill Closure and S-13 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Summary 2, 4, 5, and 6 to below a level of significance. Route 3 will remain significant. Additionally, a design measure prohibiting constmction activities before 7:00 AM at the Landfill site has been included. Issues raised related to hazards and hazardous materials in the comment letters include the history of materials placed in the Landfill, methane flammability, and fire hazard. The Landfill was not authorized to accept any hazardous substances; therefore, the waste in the Landfill is non-hazardous. Decomposing waste generates LFG, including methane. Methane can be explosive at concentrations between five and 15 percent volume of air if it accumulates in enclosed spaces and is exposed to ignition sources. At higher concentrations, methane is flammable. The Landfill currently has systems in place to detect and control the presence of LFG that have been approved by the regulatory agencies. These systems are designed to prevent excessive surface emissions, LFG migration, fires, and explosions by controlling LFG. The LFG system will continue to be maintained and monitored by the County during the post-closure maintenance period. Concems were also raised regarding the source of the cover soil. The County is still seeking a source for the cover soil that would meet the chemical and soil composition requirements. However, any provider of cover soil will be required to certify that the provider has no knowledge of the existence of hazardous materials in the soil. In the event that a potential soil source presents a significant risk of importation of contaminated material, the source would be rejected. The County intends not to import soil that would pose an adverse risk to human health or the environment. Regarding the issue of wildfire potential, the Proposed Project would landscape the Landfill with native vegetation. The County will maintain and monitor the vegetation near the LFG Collection System wells and LFG piping to reduce the potential for accidental wildfires. Additionally, the San Marcos Landfill Closure and S-14 Post-Closure Maintenance Plans EIR p p p p p p p p Draft EIR-April 2002 Summary LFG Collection System is designed to shut down in the event of a fire, tiius decreasing the likelihood of methane gas ignition. y Issues to Be Resolved by the Decision-Making Body m y The foUovidng issues remain to be resolved by the San Diego County Board of Supervisors: P • Selection of Proposed Project or one of the project altematives. • Selection of mitigation measures, if any, to address transportation/chculation impacts. • Selection of mitigation measures, if any, to address air quality unpacts. p • Selection of mitigation measures, if any, to address noise impacts. San Marcos Landfill Closure and S-15 Post-Closure Maintenance Plans EIR r f r r Source: Brown & CaMweil 1 inch = 400feet '&D Environmental Services Proposed Project Figure S-1 /-t5/S/? 78 ROUTES* mmm Truck Route 1 -o-o-o- Truck Route 2 -o-o-o- Truck Route 3 1-5 ROUTES* Truck Route 4 -Doa- Truck Route 5 -®oo- Truck Route 6 Notes a: Truck Routes 2,4,5 and 6 will utilize Rancho Santa Fe Road from Olivenhain Road to San Elijo Road b: All Truck Routes except Route 3, utilize San Elijo Road from Ranclio Santa Fe Road to the Landfill. * Individual routes are detailed in Figures 2.1-2 through 2.1-7 liiligilD!:rEi: Interstate/Freeway No Scale Overview of Truck Routes Figure S-2 Draft EIR-April 2002 Summary (This page intentionally left blank.) San Marcos Landfill Closure and 5.20 Post-Closure Maintenance Plans EIR 1 J 1 J r L r t r k r iii ^ !ii t"'; - JOe- DECK \ LEGEND ^ Fia BOUNDARY FML FLEXIBLE MEKSRANE UNER NOTE: m. AREAS PLAMTED TO Gf^VSSES AND FORBES. •FMU T FOUHOWION SOIL {SEE NOTE) NOTE: THREE FEET OF EXISTING IhTTERIM TOP DECK COVER SOIL WILL BE REMOVED MD USED FOR BARRIER LAYER SOIL NEW FOUNDAHON SOIL WILL BE USED. Source: Brown & CaklweD 1 inch =400 feet Alternative B &D Environmental Services Figure S-3 r r k r t. r SOWCB: Brown & Cakhv^ 1 hch=400feet 0p &D Environmental Services Alternative A Figure S-4 r r r I. i Source: Brown & CaMweB 1 inch=400feet Alternative C '&D Environmental Services Figure S-5 f i r r ft. r L r Source: Brown & Cafctwel 1 inch =400 feet Alternative D '&D Environmental Services Figure S-6 r r wr^ r'"i Draft EIR-April 2002 Summary Table S-1 Summary of Project Impacts and Proposed Mitigation Measures IMPACT Significant and Unmitigable Transportation/Circulation (see Section 2.1) Truck Route 1 will cause a significant impact to the following intersections and roadway segments: Interstate Highway 15 - Valley Parkway to Ninth Avenue State Route 78 - El Camino Real to College Boulevard State Route 78 - Rancho Santa Fe Road to San Marcos Boulevard Rancho Santa Fe Road/SR 78 WB Ramps, AM peak hours Rancho Santa Fe Road/SR 78 EB Ramps, AM and PM peak hours Rancho Santa Fe Road/San Marcos Boulevard, AM and PM peak hours Rancho Santa Fe Road/Melrose Drive, AM peak hours Rancho Santa Fe Road/San Elijo Road, PM peak hours Rancho Santa Fe Road - Descanso Boulevard to Grand Avenue Rancho Santa Fe Road - La Mirada Drive to Linda Vista Drive Rancho Santa Fe Road - San Marcos Boulevard to Lake San Marcos Drive Rancho Santa Fe Road - Lake San Marcos Drive to Meh-ose Drive Rancho Santa Fe Road - Melrose Drive to San Elijo Road PROPOSED MITIGATION Acceptance of trucked soil at the Landfill between 7:00 AM and 4:00 PM only Notiiy local bicycle clubs of the haul period schedule and routing associated with the Proposed Project. SIGNIFICANCE AFTER MITIGATION Proposed mitigation measures will partially mitigate impacts to affected intersections and roadways under the Truck Route 1 scenario; however, measures will not reduce impacts to below a level of significance. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR S-29 Draft EIR - April 2002 Summary Table S-1 (Continued) IMPACT TVuck Route 2 will cause a significant impact to the following intersections and roadway segments: • State Route 78 - EI Camino Real to College Boulevard • State Route 78 - Rancho Santa Fe Road to San Marcos Boulevard • Rancho Santa Fe Road/San Elijo Road - PM peak hours • El Camino Real/SR 78 WB Ramps, AM and PM peak hours • El Camino Real/SR 78 EB Ramps, PM peak hours • EI Camino Real/Palomar Airport Road, AM and PM peak hours • El Camino Real/Olivenhain Road, AM and PM peak hours • Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue • Rancho Santa Fe Road - Truck Bypass to San Elijo Road • Rancho Santa Fe Road/San Elijo Road, PM peak hours PROPOSED MITIGATION IVuck Route 3 will have a significant impact to the following intersections and roadway segments: • Interstate Highway 15 - Valley Parkway to Ninth Avenue • Valley Parkway/Auto Park Way, AM and PM peak hours • Auto Park Way - Ninth Avenue to Valley Parkway • Auto Park Way North (one-way) - Andreasen Drive to Howard Avenue Acceptance of trucked soil at the Landfill between 7:00 AM and 4:00 PM only Notify local bicycle clubs of the haul period schedule and routing associated with the Proposed Project. Acceptance of trucked soil at the Landfill between 7:00 AM and 4:00 PM only Notify local bicycle clubs of the haul period schedule and routing associated with the Proposed Project. SIGNIFICANCE AFTER MITIGATION Proposed mitigation measures will partially mitigate impacts to affected intersections and roadways under the Truck Route 2 scenario; however, measures will not reduce impacts to below a level of significance. Proposed mitigation measures will partially mitigate impacts to affected intersections and roadways under the Truck Route 4 scenario; however, measures will not reduce impacts to below a level of significance. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR S-30 r ' r r 1 r ^ Draft EIR-April 2002 Summary Table S-1 (Continued) IMPACT TVuck Route 4 will cause a significant impact to the following intersections and roadway segments: Interstate Highway 5 - Santa Fe Drive to Encinitas Boulevard Interstate Highway 5 - Palomar Airport Road to Cannon Road El Camino Real/Palomar Airport Road, AM and PM peak hours El Camino Real/Olivenhain Road, AM and PM peak hours Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue Rancho Santa Fe Road - Truck Bypass to San Elijo Road Rancho Santa Fe Road/San Elijo Road, PM peak hours Palomar Airport Road - Paseo Del Norte to Armada Drive PROPOSED MITIGATION Acceptance of trucked soil at the Landfill between 7:00 AM and 4:00 PM only Notify local bicycle clubs of the haul period schedule and routing associated with the Proposed Project. SIGNIFICANCE AFTER MITIGATION Proposed mitigation measures will partially mitigate impacts to affected intersections and roadways under the Truck Route 4 scenario; however, measures will not reduce impacts to below a level of significance. TVuck Route 5 will cause a significant impact to the following intersections and roadway segments: • Interstate Highway 5 - Santa Fe Drive to Encinitas Boulevard • Interstate Highway 5 - Palomar Airport Road to Cannon Road • La Costa Avenue - Piraeus Street to Saxony Road • El Camino Real - Levante Street to Calle Barcelona • El Camino Real/Palomar Airport Road, AM and PM peak hours • El Camino Real/Olivenhain Road, AM and PM peak hours • Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue Acceptance of trucked soil at the Landfill between 7:00 AM and 4:00 PM only. Notify local bicycle clubs of the haul period schedule and routing associated with the Proposed Project. Proposed mitigation measures will partially mitigate impacts to affected intersections and roadways under the Truck Route 5 scenario, however, measures will not reduce impacts to below a level of significance. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR S-31 Draft EIR- April 2002 Summary Table S-1 (Continued) IMPACT • Rancho Santa Fe Road - Truck Bypass to San Elijo Road • Rancho Santa Fe Road/San Elijo Road, PM peak hours TVuck Route 6 will cause a significant impact to the following intersections and roadway segments: • Interstate Highway 5 - Santa Fe Drive to Encinitas Boulevard • Interstate Highway 5 - Palomar Airport Road to Cannon Road • Encinitas Boulevard/I-5 SB Ramp, PM peak hours • Encinitas Boulevard/I-5 NB Ramp, PM peak hours • Encinitas Boulevard/El Camino Real ~ AM and PM peak hours • Encinitas Boulevard - Interstate Highway 5 to Saxony Road • El Camino Real/Olivenhain Road, AM and PM peak hours • Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue • Rancho Santa Fe Road - Truck Bypass to San Elijo Road • Rancho Santa Fe Road/San Elijo Road, PM peak hours • El Camino Real/Garden View Road, AM peak hours PROPOSED MITIGATION Acceptance of trucked soil at the Landfill between 7:00 AM and 4:00 PM only Notify local bicycle clubs of the haul period schedule and routing associated with tiie Proposed Project. SIGNIFICANCE AFTER MITIGATION Proposed mitigation measures will partially mitigate impacts to affected intersections and roadways under the Truck Route 6 scenario; however, measures will not reduce impacts to below a level of significance. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR S-32 r 1 ir^ r™i Draft EIR-April 2002 Summary Table S-1 (Continued) IMPACT PROPOSED MITIGATION SIGNIFICANCE AFTER MITIGATION Significant and Unmitigable Air Oualitv (see Section 2.2) Significant impacts related to nitrogen oxides (NO^) and particulate emissions (PM,o). • Project will adhere to all applicable San Diego Air Pollution Control District requirements for low-sulfiir fuel and dust control measures. • No other mitigation measures are feasible to reduce impacts. Proposed mitigation measures will partially mitigate air quality impacts; however, measures will not reduce impacts to below a level of significance. Significant and Unmitigable Noise (see Section 2.3) Significant noise impacts from truck trips along the following road segments: • San Elijo Road fi-om Rancho Santa Fe Road to the Landfill (Truck Routes 1,2,4,5, and 6). • The entire length of Truck Route 3. • No construction will start before 7:00 AM. Proposed mitigation measure will mitigate noise impacts on Routes 1, 2, 4, 5, and 6 to below a level of significance. Noise impacts associated with Truck Route 3 will remain significant and unmitigable. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR S-33 Draft EIR-April 2002 5»m»,an^ (This page intentionally left blank.) San Marcos Landfill Closure and g_3^ Post-Closure Maintenance Plans EIR I J 1 Draft EIR - April 2002 Summary Table S-2 Summary of Project Altematives Proposed Project: Monolithic Cover Altemative A: Prescriptive Cover As Modified by RWQCB Order No. 92-02 Altemative B: Prescriptive Cover with Flexible Membrane Liner on Top Deck (Environmentally Superior) Altemative C: Prescriptive Cover as Modified by RWQCB Order No. 92-02 with Court-Mandated Vegetative Cover Alternative D: Prescriptive Cover with Flexible Membrane Liner on Top Deck and Coiut-Mandated Vegetative Cover No Project Altemative Top Deck - 42 acres Vegetative Soil Flexible Membrane Liner Barrier Soil Foundation Soil Minimum 3 feet w/CSS'"* None None 2 feet (existing) Minimum 1 foot w/grasses and forbs Yes 2 feet 2 feet (replace existing) Minimum 1 foot w/grasses and forbs Yes None 2 feet (replace existing) Minimum 3 foot w/CSS^''* Yes 2 feet 2 feet (replace existing) Minimum 3 fool w/CSS^'' Yes None 2 feet (replace existing) Side Slopes Above Vertical Expansion - 20 acres Vegetative Soil Barrier Soil Foundation Soil See Note (b) None 2 feet (existing) Minimum 1 foot w/grasses and forbs 2 feet 2 feet (existing) Minimum 1 foot w/grasses and forbs 2 feet 2 feet (existing) See Note (b) 2 feet 2 feet (existing) See Note (b) 2 feet 2 feet (existing) Side Slopes Below Vertical Expansion - 40 acres Vegetative Soil Barrier Soil Foimdation Soil See Note (b) None See Note (c) Minimum 1 foot w/grasses and forbs 1 foot See Note (c) Minimum 1 foot w/grasses and forbs 1 foot See Note (c) See Note (b) 1 foot See Note (c) See Note (b) 1 foot See Note (c) Hauling Requirements Total Cubic Yards Imported Total Truck Trips Estimated Time for Import in Months @ 200 Trips/Day Estimated Time for Import in Months @ 300 Trips/Day Estimated Time for Import m Months @ 400 Trips/Day 420.000 30,000 6.8 4.5 3.4 390,000 27,857 6.3 4.2 3.2 254,000 18,143 4.1 2.7 2.1 696,000 49,714 11.3 7.5 5.7 560,000 40,000 9.1 6.1 4.6 Analysis of Significance Transportation/Circulation Air Quality Noise Hydrology/Water Quality Significant, uimiitigable Significant, unmitigable Significant, uiunitigable Less than significant Significant, uiunitigable Significant, unmitigable Significant, urunitigable Less than significant Significant, unmitigable Significant, unmitigable Significant, unmitigable Less than significant Significant, immitigable Significant, immitigable Significant, unmitigable Less than significant Significant, uimiitigable Significant, unmitigable Significant, uimiitigable Less than significant Less than significant Less than significant Less than significant Potentially significant, unmitigable Notes: (a) CSS^_ Coas^^sa^^^^^^ ^^^^^^ ^^^^^ ^^^^^ vegetative soil with CSS. The remaining slopes (excluding benches and access roads) will receive five to six feet of vegetative soil and will be revegetated with chaparral. ^ .i^r ^ *• i (c) There is a minimum of two feet of existing interim cover soil (foundation soil) on all of the side slopes. The areas to the east and north side slopes below the first bench have up to 10 feet of foundation soii. (d) A truck trip is defined as the pickup of cover soil at the source site, delivery of the material at the Landfill, and return to the source site. Trucks will only transport cover soil to the Landfill. The return tnp will be empty. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR S-35 Draft EIR - April 2002 Project Description, Location, and Environmental Setting CHAPTER 1-Q PROJECT DESCRIPTION. LOCATION, AND ENVIRONMENTAL SETTING 1.1 Project Description and Location 1.1.1 Project Location The San Marcos Landfill ("Landfill") is located within the City of San Marcos ("City") in northem San Diego County (Figure 1-1). The Landfill is located adjacent to San Elijo (Questhaven) Road between Rancho Santa Fe Road and Elfin Forest Road (Figures 1-2 and 1-3). The Landfill is owned by, was operated by, and is maintained by the Coimty of San Diego ("County"). The total and permitted acreage of the Landfill covers approximately 328 acres, of which approximately 102 acres represent the former active landfill area. 1.1.2 Project Bacl^round Various references were used in the preparation of the Environmental Impact Report ("EIR") and are available for review at the County of San Diego, Solid Waste Management, 5469 Kearny Villa, Suite 305, San Diego, CA. The references cited in this document are in the List of References. (See Page 7-1 of this EIR.) An EIR was prepared in 1977 for the original development of the Landfill. Two additional EIRs have been prepared. The Draft and Final EIR for the San Marcos Landfill Expansion Project (MBA, 1990a) analyzed the impacts of the then-proposed horizontal and vertical expansion of the Landfill. In December 1990, the Christward Ministry filed a lawsuit challenging the adequacy of the EIR, and on July 23, 1991, the San Diego County Superior Court (Case No. 631783) ruled that the EIR did not adequately address surface water and groundwater impacts associated with daily operations. San Marcos Landfill Closure and 1-1 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Project Description, Location, and Environmental Setting In response, a Supplemental EIR was finalized in July 1992, which focused on a revised analysis of the surface water and groundwater section of the original EIR (MBA, 1990b). Following approval of the Supplemental EIR and revision of the various permits, the County constructed a portion of the vertical expansion. The County began placing solid waste in the vertical expansion area in 1993. On May 9, 1995, the City alleged that the County was not in compliance with Conditional Use Permit ("CUP") No. 92-173 and ordered the Landfill closed by March 11, 1997. The County filed suit regarding the closing, but in October 1996, the Court upheld the City's right to revoke the CUP. The prior EIRs include Mitigation, Monitoring, and Reporting Programs associated with the proposed horizontal and vertical expansion. Many of these mitigation measures are no longer applicable, since no horizontal expansion took place, and only a portion of the vertical expansion had occurred when the City ordered the early closure of the Landfill. Due to the Proposed Project including an engineered altemative cover system instead of a prescriptive cover system, the County determined that the Proposed Project requires the preparation of a Project EIR per CEQA Guidelines Section 15162(a), because: Substantial changes have occurred with respect to the circumstances under which the Proposed '. the Court. Proposed Project is undertaken. The Landfill was required to close early, as upheld by P Subsequent changes are proposed in the Proposed Project which will require important revisions of the previous EIR, due to the involvement of new potentially significant impacts not considered in the previous EIR, which addressed vertical and horizontal expansions. No horizontal expansion took place, and only a portion of the vertical expansion has occurred (approximately 55 feet of the 200-foot vertical expansion previously planned). San Marcos Landfill Closure and 1-2 Post-Closure Maintenance Plans HER. m m II m m m m pi li ii Draft EIR - April 2002 Project Description, Location, and Environmental Setting • A Court-ordered revegetation plan was prepared by LSA Associates, Inc. in May 1998 ("LSA Plan"). Various components of the LSA Plan were modified in a July 2001 Settlement Agreement between the City of San Marcos and County ("Modified LSA Plan"). The Modified LSA Plan includes requirements for soil characteristics, types of vegetation to be planted, and supplemental irrigation. pi Landfill Infrastructure mi Figure 1-4 shows the existing topography of the Landfill. The Landfill was initially constmcted within a canyon that drained fi'om east to west. The western side of the Landfill is a relatively steep face. The west face rises from the base of the canyon, vdth landfiUed solid waste covered with a layer of intermediate cover soil. The west face is benched every 20 to 40 feet (vertical elevation). The present base and waste fill of the west face comes no closer than eight feet to the retaining wall that separates the Landfill from the North County Resource Recovery Facility ("NCRRF") property. The elevation along the west side of the 30-foot-high retaining wall is approximately 530 feet above mean sea level ("AMSL"). When the vertical expansion began, the upper elevation of the west face was about 710 feet AMSL at the midpoint. The fill area east of the west face is raised above the sides of the canyon, with side slopes that form a relatively flat mesa (the top deck) that was used for solid waste landfilling. At the time the vertical expansion was started, the top deck sloped from about elevation 750 feet AMSL along the east to 710 feet AMSL at the west. Two benches were in place between the north and east edges of the canyon and the top deck. Preparation for the vertical expansion included the following: • Reconstmction of an access road that starts at the northwest comer, rises up the west face towards the southeast, doubles back, and continues rising up the west face to the northwest edge of the west face. San Marcos Landfill Closure and 1 -3 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Project Description, Location, and Environmental Setting In 1992 a new lined drainage ditch (downchute) was constmcted fi-om the center of the ^ top deck down the west face to a new south retention basin. As filling in the vertical expansion raised the elevation of the Landfill, the downchute was extended upward; the ^ extension was not lined. ^ Off-site runoff water is collected and routed around the perimeter of the fill area. On-site — drainage flows as sheet flow fi-om the top deck of the completed fill from the high point, — at approximate elevation 805 feet AMSL, at the easteriy edge of the site, in a westerly direction toward the low point at the west CMP inlet. The overall Landfill runoff is — collected in a series of downdrains and channels and conveyed to the retention basins on the northwesteriy (North Pond) and southwesterly (South Pond) comers of the site. The - drainage system was designed to accommodate the 100-year, 24-hour storm event. The North and South Ponds, which serve to desilt the runoff, are sized to detain runoff resulting fi-om the 24-hour storm during the 100-year storm event. The retention basins were constmcted wdth a clay base and gabion side slopes, concrete weirs, and spillways. * The Ponds will be modified to serve as sedimentation basins after closure constmction is completed. " MH A new concrete drainage ditch was constmcted in 1992 that drains a portion of the south ^ side slopes, the east side slopes, and the north side slopes to the North Pond. A second concrete drainage ditch was constmcted in 1992 that diverts runoff past the South Pond. * in Figures 1-5 and 1-6 depict the drainage system and drainage details. P Itt A new clay liner and Leachate Collection and Removal System ("LCRS") was placed on top of the top deck in 1992. This serves as the base for the vertical expansion. A leachate collection sump was constmcted at the west low point to provide drainage firom the LCRS. During landfilling operations, a similar sump was placed on top of the first vertical lift, approximately 20 feet above the first sump. Figure 1-7 depicts the leachate collection and perimeter berm area. A leachate pipe was extended down the west face to San Marcos Landfill Closure and 1 _4 Post-Closure Maintenance Plans EIR m In m m m m m m pm Draft EIR - April 2002 Project Description, Location, and Environmental Setting m ^ empty into a new leachate storage tank located east of the retaining wall and south of the m NCRRF buildings. P il The Landfill has an active landfill gas ("LFG") collection and control system (Figure 1-8), with ^ LFG wells penetrating the top deck and various side-slope benches. The wells are connected to Ita one of two piping systems that convey LFG to a recovery/destmction complex located east of the fill area. LFG migration probes (to detect the migration of LFG) are installed outside the waste iii limits and between the landfill boundary and the NCRRF building. Monthly LFG monitoring is Pi conducted throughout the Landfill, and includes monitoring and inspection of gas migration probes, surface emission data, and wellhead data; reporting of surface emission data; and m maintenance as determined by inspection. This ensures that the LFG collection system operates ^ efficientiy and safely. 1.1.3 Project Description The Proposed Project consists of implementing the Final Closure and Post-Closure Maintenance Plans for the Landfill. The main components of the Proposed Project include the final closure ^ plan design; soil hauling, mixing, and placement; revegetation plan; and post-closure monitoring " and maintenance. Proposed Project components are discussed in detail below. IM " 1.1.3.1 Final Closure Plan Design MM* *" Figure 1-9 shows the proposed final Landfill configuration, v^dth the completed Landfill top deck ranging from approximate elevations 760 to 805 feet AMSL. The limits of the waste fill are also shown. The top deck has an area of approximately 42 acres. The total acreage of the side slopes is approximately 60 acres. North/south and east/west cross-sections are presented in ^ Figure 1-10. The majority of the side slopes were constmcted at a 3:1 slope, with the exception of the northem end of the west slope. In that location, the steepest overall slope in this area is 2.7:1, with individual slopes no steeper than 1.75:1. CCR Titie 27 requires side slopes to be no San Marcos Landfill Closure and 1-5 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Project Description, Location, and Environmental Setting ^ steeper tiian 1.75:1; tiius, the Proposed Project complies v^dth CCR Titie 27. The final grading ^ plan is shown in Figure 1-11. mm 1.1.3.2 Final Cover Soil Requirements and Sources mm Witiiin approximately 18 months of the approval of the Final Closure Plan by all of the — permitting agencies (see Section 1.3.1), the final cover soil will be put into place. The final — cover soil system will be an engineered altemative evapo-transpiration (evaporation plus plant — transpiration) cover system with a minimum soil thickness of five feet m all areas except the — north slope and a portion of the east slope, which will have a total thickness of up to eight feet. The final cover wiU require placement of approximately 600,000 cubic yards of imported soil, of •• which approximately 180,000 cubic yards are currentiy witiiin tiie Landfill boundary; tiierefore, 420,000 cubic yards of cover soil will be imported for the Proposed Project. » m The Modified LSA Plan, which represents the modified revegetation plan agreed upon by the County and City, specifies certain chemical and physical characteristics for the soil. These include the grain size distribution, electrical conductivity ("ECe"), sodium absorption ratio " ("SAR"), pH, and boron. The specifications are summarized in Table 1-1. In addition to the requirements of the Modified LSA Plan, the soil is required to have a low permeability, which in P combination with evapo-transpiration, provide protection firom moisture infiltration into the solid waste fill. The on-site soil will provide the additional silt and clay content necessary to obtain the required permeability when mixed with the DG or silty sand soil. The County is considering a variety of possible sources for the DG and/or silty sand soil, including but not limited to the County-owned San Marcos Landfill Closure and 1.6 Post-Closure Maintenance Plans EIR m m m The County has conducted extensive searches for sufficient quantities of soil that will meet both * the Modified LSA Plan requirements and the permeability requirement. There is no single soil * source identified that meets all of the requirements. Therefore, the cover soil will be a mixture * of a silty clay soil with decomposed granite ("DG") and/or silty sand soil classified as silty sand. P P m p p pi p IP p Draft EIR - April 2002 Project Description, Location, and Environmental Setting buffer property adjacent to the Ramona Landfill, Maddock Nursery, public works constmction projects, private development constmction projects, existing commercial borrow pits, and undeveloped County-owned land. The site for the source material will be required to have previously complied with CEQA and obtained any necessary pemiits or approvals, or subsequent environmental documentation will be required of the source site prior to obtaining or transferring the source material to the Landfill site. The difficulty identifying sources is created by the fact that the County will not haul cover soil until August 2003 due to regulatory agency reviews. Those regulatory agency reviews cannot be completed until the EIR process is complete. Sources that have currentiy performed CEQA analysis and would be acceptable cannot wait until August 2003 to have soil removed. Because of the large quantity, the soil profile, and the delay in hauling until 2003, it is likely that soil sources will be identified several months from now. Since the County continues to seek and identify acceptable sources for DG soil, but has yet to finalize the source or sources, evaluation of the soil to determine whether the soil is contaminated will be conducted on a site-by-site basis as acceptable sites are identified. Any provider of DG soil will be required to certify that the provider has no knowledge of the existence of hazardous materials in the soil. In the event that a potential soil source presents a significant risk of importation of contaminated material, the source will be rejected. It is the County's intent not to import soil that would pose an adverse risk to human health or the environment. The DG and/or silty sand will be mixed with the on-site soil at a ratio of approximately 30 percent on-site soil and 70 percent DG. Table 1-2 lists the characteristics of the soil mixture. The soil mix will be tested during mixing to determine ECe and SAR content. Testing frequency varies depending on the soil mix being prepared. Prior to planting, the upper one foot of cover soil will be tested for agricultural suitability and organic content. San Marcos Landfill Closure and 1-7 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Project Description, Location, and Environmental Setting Soil will be delivered to tiie Landfill in either single-bottom or double-bottom dump trailers. Each load will contain up to 21 tons (approximately 14 in-place cubic yards) of soil. A maximum of 30,000 tmck trips will be required to transport the imported soil. Up to an average of 300 daily tmck trips, witii peaks up to 400 tmck trips, will be scheduled. Constmction activities are proposed to be restricted to 7:00 a.m. to 4:00 p.m, Monday through Friday. Entrance to the Landfill will be through the main entrance off of San Elijo Road. If tiie soil is located along the Interstate Highway 15 ("1-15") or State Route 78 ("SR78") corridor, the anticipated routing choices to the Landfill would be one of the following: • I-15/Highway 78/Rancho Santa Fe Road/San Elijo Road • I-15/Highway 78/El Camino Real/OHvenhain Road/Rancho Santa Fe Road/San Elijo Road • I-15/Ninth Avenue/Auto Park Way/Howard Avenue/Harmony Grove Road/Elfm Forest Road/San Elijo Road If the soil is located along the Interstate Highway 5 ("1-5") corridor, the anticipated routing choices to the Landfill would be one of the following: • I-5/Palomar Airport Road/El Camino Real/Olivenhain Road/Rancho Santa Fe Road/San IP P P Elijo Road ^ P I-5/La Costa Avenue/El Camino Real/Olivenhain Road/Rancho Santa Fe Road/San Elijo ' Road P ii I-5/Encinitas Boulevard/El Camino Real/Olivenhain Road/Rancho Santa Fe Road/San Elijo Road 2 P P P San Marcos Landfill Closure and 1_8 Post-Closure Maintenance Plans EIR m wm Draft EIR - April 2002 Project Description, Location, and Environmental Setting ^ 1.1.3.3 Revegetation Plan m ^ The revegetation plan for the Landfill stirfaces is included in the Final Closure Pian. The p selection of plant materials is based on the requirements of the Modified LSA Plan. The Landfill revegetation also includes provision of a temporary irrigation system, coast live oak screening, and vegetation performance standards. Figure 1-12 depicts the revegetation plan. The plant species were selected by LSA to replicate as closely as possible the existing vegetation IP community surroimding the Landfill. The goal is to provide an aesthetically pleasing landscape pp that blends with the surrounding area and provides habitat for native species with minimum maintenance. Roadways and side-slope benches will not be vegetated, because maintenance pi vehicle traffic precludes sustaining vegetation on those surfaces. k m The Modified LSA Plan includes the planting of Coastal Sage Scmb ("CSS") and Mixed Southem Chaparral ("chaparral"). Both seed mixes and container plants will be utilized. 1^ Table 1-3 lists the types and specifications of CSS species that will be planted by seed. CSS ^ species and number of plants to be planted per acre from container stock are listed in Table 1-4. ^ The CSS will be planted on the top deck, west slope, south slope, and a portion of the east slope (approximately 83 acres, 70 acres excluding the bench and roads). Table 1-5 lists the chaparral species and specifications that will be planted by seed, while chaparral species listed in Table 1-6 ^ will be transplanted from containers. Chaparral will be planted on the north slope and part of the east slope in the areas where there is adequate soil depth (15 acres, excluding the benches and roads) to support these species. Off-Fill Revegetation Areas tm The Final Closure Plan also designates five non-filled disturbed areas for revegetation (Figure 1-12). These areas are within the property botmdary, but did not receive waste fill. These are excavated or disturbed areas, some containing stockpiled cover material, and occupy a total of approximately 16 acres. All are adjacent to native habitats. These sites will be revegetated v^dth native plants that are suitable to the area and the rocky surfaces that are San Marcos Landfill Closure and 1-9 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Project Description, Location, and Environmental Setting available. The revegetation will also be enhanced by natural reseeding from adjacent native plants. The following is a summary of the approach to these areas: • Area A will be revegetated witii chaparral seed (Table 1-5). Area A has some vegetative cover soil already in place and, therefore, can be expected to have medium to sparse vegetation. • AreaB will be kept as a maintenance stockpile during the post-closure maintenance period, but will be reseeded annually for erosion control. • Area C is tiie slope above tiie North Pond, and has already been planted. Soil was obtained for an approximate four to six inches of cover to encourage a denser growth to enhance the visual quality. The slope has been seeded witii select CSS species from Table 1-3. The vegetation in Area C is expected to be medium to sparse, due to the site's rocky nature and low available water capacity. • Area D is on the northem slope above tiie drainage collector ditch. This area will be disturbed as a resuh of excavation (possibly with blasting). Following the completion of the excavation, select CSS seed species from Table 1-3 will be planted. • Area E is the LFG recovery facility and flare station, and has been covered with varying depths of soil and seeded with CSS species. Coast Live Oak Screening As per the Modified LSA Plan, coast live oaks will be planted along the retaining wall at the west edge of the Landfill and on the northern and nortiieastem edge (outside the limit of waste) as shown on Figure 1-13. Planting will include both 15-gallon container plants and acom plantmg. The container plantmg is proposed to provide early screening. In the long term, acom plantings are expected to develop stronger tap roots and outgrow the container plantings. A total P P W H San Marcos Landfill Closure and 1_10 Post-Closure Maintenance Plans EIR m p p ta Draft EIR - April 2002 Project Description, Location, and Environmental Setting of 135 container plants and 140 acom plantings (three acoms each) will be planted. Container plants will be spaced 15 feet apart, with acom plantings interspersed between the container plants. Planting/Seeding Period and Methods pi After the cover soil has been placed and in time for planting in the October through January period, the soil will be prepared for planting, as specified by the Modified LSA Plan. Soil m preparation includes scarifying (ripping) the soil to a depth of 12 inches and adding sufficient organic matter (humus) to raise the organic content of the upper soil to 2.5 percent. IP Commercially available mycorrhizal species {Glomus intraradices) will be applied at a rate of 60 liters per acre during the imprinting process. Planting will occur between October 1 and Febmary 1, to take advantage of seasonal precipitation and plant dormancy. Any areas of the side slopes that are not accessible to the imprinter will be planted by broadcasting the seed. Prior to seed broadcasting, the mycorrhizal inoculum will be broadcast with a hand spreader, organic matter will be applied, and the soil vdll be ripped to a depth of 12 mches and trackwalked. The seed v^ll then be planted with a hand spreader. Temporary Irrigation System A temporary irrigation system will be installed on the top deck and most of the slopes, with the exception of south slopes and the southwest comer (Figure 1-13). The irrigation system will be installed as soon as the seed is imprinted. This 20-acre (approxunate) area will be irrigated by water tmck. Irrigation will be used, as necessary, to prepare the top deck and side slopes for imprinting (by water tmck if required), establish early season surface erosion control vegetation, supplement the annual rainfall during dry periods in the rainy season, and counteract the effects of compaction by encouraging downward root growth during initial development of the vegetation. San Marcos Landfill Closure and 1-11 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Project Description, Location, and Environmental Setting m mm Vegetation Performance Standards ^ Vegetation will be monitored to ensure tiiat it meets tiie following performance standards: - • The overall shmb cover is 60 percent or greater and the overall native plant cover, ^ including grasses and forbs, is at least 80 percent. Witiiin these overall coverage — parameters, there should be no spaces larger than 200 square feet tiiat are devoid of - shmbs and no spaces larger than five square feet that are devoid of native grasses and forbs. Exceptions: (1) Side-slope benches and roadways (including access roads to the ^ LFG recovery system pipes) are not included in tiie areas to be planted and monitored. (2) Shmbs will not be allowed to grow under the LFG System pipes. •* Ml • The Landfill blends with tiie surroimding area and lends the overall appearance of being "* one of tiie surrounding hills. This will be accomplished by the vegetation achieving adequate size to reasonably obscure the benches, LFG pipes, irrigation pipes, and drainage pipes and ditches. • m • Non-natives will not represent more than 25 percent cover. ^ P Vegetation Monitoring and Maintenance * P Following planting, the vegetation installation contractor will be responsible for the plants during * a four-month establishment period. The County will also have a vegetation specialist to oversee the establishment period, and conduct monitoring and direct maintenance after the establishment period. Additionally, weed control during the establishment period and a period extending until performance standards have been met will be conducted to meet the performance standard of no more than 25 percent non-natives. Weed control would focus on the non-native species listed in Table 1-7. P ip m San Marcos Landfill Closure and 1_12 Post-Closure Maintenance Plans EIR PP p Draft EIR - April 2002 Project Description, Location, and Environmental Setting 1.1.3.4 Post-Closure Maintenance Post-closure activities are detailed m the Final Post-Closure Maintenance Plan ("FPCMP"). P Post-closure maintenance and monitoring of the Landfill will be conducted by the Coimty as described in the FPCMP that has been submitted to the San Diego Regional Water Quality P Control Board ("RWQCB") and the San Diego County Department of Environmental Health, pi Local Enforcement Agency ("LEA") for approval. The primary purpose of the FPCMP is to P facilitate the effective performance of the engineered evapo-transpiration cover system, which is pi designed to minimize the infiltration of water into the waste, thereby decreasing the production of leachate and LFG until such time as the waste no longer constitutes a potential threat to water quality. The monitoring, inspection, and maintenance of the Landfill will comply with the requirements of CCR Title 27. The Post-Closure Maintenance Plan includes provisions to maintain the integrity of the groundwater monitoring and extraction system, the surface water control system, the leachate system, the LFG system, and the vegetative cover. Monitoring, inspection, reporting, and maintenance requirements are summarized in Table 1-8. Groundwater Monitoring and Extraction System Groundwater is monitored at the Landfill on a quarterly basis in accordance with CCR Titie 27 and as stipulated in the RWQCB Order Nos. 92-02, 93-86, and 95-112. During quarterly sampling events, groundwater monitoring wells will be inspected and general maintenance will be performed. The condition of the well head, monitoring well interior, and dedicated sampling system will be noted. Equipment in need of repair or replacement will be corrected. Leachate System Leachate is collected and piped to a leachate storage tank. The leachate collection system will be inspected once a month, receiving maintenance as needed to maintain its integrity. Inspection San Marcos Landfill Closure and 1-13 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Project Description, Location, and Environmental Setting wiW include checking for system leaks and clogs, as well as determining tiie level of leachate present in the storage tank. All leachate collected is disposed off-site at an approved facility. Landfill Gas System Landfill gas generated in the Landfill is monitored quarterly. Monitoring reports are submitted to the San Diego County Air Pollution Control District ("APCD"), LEA, Califomia Integrated Waste Management Board ("CIWMB"), and RWQCB for review. Quarterly tasks include: • Monitoring of the areas throughout the Landfill site; • Inspection of wellhead and random monitoring of collection pipes for leaks; • Inspection of gas migration probes; • Monitoring of the Landfill site for explosive gases using a portable explosive gas monitor; • Inspection of tiie piping, extraction wells, and gas probes for leaks and damages; and • Exercise and lubrication of all isolation and routing valves in the collection system. Armual monitoring for toxic air contaminants will also be conducted. Cover Soil Maintenance Program The final evapo-transpiration cover system, which includes the cover soil and the vegetation, is the only barrier between the waste material and any water above the fill in the form of rain or ponding. Integrity of the cover system is critical to the overall performance of the closure plan and the primary method of preventing leachate production within the Landfill. Quarterly inspections will evaluate cover performance to ensure there is no evidence of ponding or a depressed area on the top deck, no failure or cracking in the drainage stmcture, no substantial changes in grade, and no evidence of excessive LFG leakage through the cover system. P p San Marcos Landfill Closure and 1-14 Post-Closure Maintenance Plans EIR P p p p p mm Draft EIR - April 2002 Project Description, Location, and Environmental Setting ^ Vegetative Cover Maintenance Program m ^ The primary goal of vegetation monitoring and maintenance is to establish and maintain a fully m self-sufficient, self-reproducing, permanent vegetative cover comparable to similar naturally ^ vegetated sites in the region. The County will maintain the plantings with a program that P includes the control of weeds, erosion, and herbivores; the application of fertilizers; and P, maintenance of the temporary irrigation system. Root depth controls will also be utilized to P ensure that paths for LFG release are not created. Maintenance will be tailored to meet the IP vegetation perfonnance standards. The revegetation will be considered successful when the overall shmb cover is 60 percent or greater and the overall native plant cover is at least IP 80 percent, and when the Landfill visually blends with the surrounding area, leading to an overall *" seamless transition across the landscape. Annual reports will be prepared until the performance mm standards are met. ^ 1.2 Proiect Objectives The objectives of the Proposed Project are as follows: - • Close and maintain tiie Landfill in compliance witii CCR Title 27, CIWMB, RWQCB, and LEA. The closure will minimize the infiltration of water into the waste, thereby minimizing the production of leachate and gas as per CCR Title 27, Section 20950 (a)(2). • Maintain the Landfill in compliance with the Superior Court writ of mandate. The writ of mandate requires that the County permanentiy close and revegetate the Landfill consistent with the Modified LSA Plan. Close and maintain the Landfill at a reasonable cost consistent with protecting the health and safety of residents and the environment. San Marcos Landfill Closure and 1-15 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Project Description, Location, and Environmental Setting • Implement the Final Closure and Post-Closure Maintenance Plans utilizing procedures to protect public health and safety. • Revegetate the closed Landfill with native habitats that provide visual compatibility with adjacent natural habitats, and add to the regional biological value of the site as passive open space. 1.3 Intended Use of the EIR This EIR is a Project EIR, because the discretionary actions are site-specific approvals. As per State CEQA Guidelines, Section 15121, an EIR is an informational document which will inform public agency decision makers and the public of tiie significant environmental effects of a proposed project, identify possible ways to minimize the significant effects, and describe reasonable altematives to the project. The public agency shall consider the information in the EIR, along with other information that may be presented to the agency. The basic purposes of this EIR are to (Section 15002, CEQA Guidelines): "(1) Inform governmental decision makers and the public about the potential, significant environmental effects of proposed activities. San Marcos Landfill Closure and 1.16 Post-Closure Maintenance Plans EIR P P (2) Identify ways that environmental damage can be avoided or significantly reduced. P (3) Prevent significant, avoidable damage to the environment by reqiuring changes in projects through the use of altematives or mitigation measures when the governmental agency finds the changes to be feasible. ^ P P P P Draft EIR- April 2002 Project Description, Location, and Environmental Setting m m m P IP P P (4) Disclose to the public the reasons why a governmental agency approved the project in the maimer the agency chose if significant environmental effects are involved." This draft EIR is being prepared and processed concurrently with the adoption of the Final Closure and Post-Closure Maintenance Plans. The decision-makers will consider the infonnation contained in the draft EIR when considering the Proposed Project. The discretionary actions associated with the Proposed Project include the San Diego County Board of Supervisor's adoption and certification of the EIR and the approval of the Final Closure and Post-Closure Maintenance Plans; RWQCB, CIWMB, and LEA approval of tiie Plans; and RWQCB issuance of a new Waste Discharge Permit and APCD approval for installing new wells and exposing waste during closure constmction. 1.3.1 Matrix of Project Approvals/Permits The following matrix summarizes the required approvals and permit. AGENCY/ORGANIZATION APPROVAL REQUIRED STATUS San Diego County Board of Supervisors Certification of Final Environmental Impact Report; approval of funding for closure project; approval of contract for constmction of final cover and post- closure maintenance. Lead Agency Califomia Integrated Waste Management Board Approval of the Landfill Final Closure and Post- Closure Maintenance Plans. Responsible Agency San Diego Regional Water Quality Control Board Approval of new Waste Discharge Requkements incorporating the Landfill Final Closure and Post- Closure Maintenance Plans. Responsible Agency San Diego County Department of Environmental Health, Local Enforcement Agency Approval of the Landfill Final Closure and Post- Closure Maintenance Plans. Responsible Agency San Diego County Air Pollution Control District Permit for the Operation of Methane Gas Control System (existing). Approval of installation of any new Landfill Gas Wells, and any exposure of trash during final closure constmction. Responsible Agency San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 1-17 Draft EIR - April 2002 Project Description, Location, and Environmental Setting 1.4 Environmental Setting The Landfill covers approximately 328 acres, with approximately 102 acres representing the site of past landfilling activities. The vicinity surrounding tiie Landfill is predominantiy a blend of vacant land, low-density residential, and planned residential land uses on variable topography. Figure 1-3 is an aerial photograph depicting the Landfill and tiie relationship of other land uses in the vicinity. The San Elijo Hills Specific Plan Area encompasses approximately 2,149 acres north of the Landfill. At buildout, San Elijo Hills will include 3,398 residential units, 40 acres of community services, 13 acres of commercial, a golf course, and 1,050 acres of open space. Constmction of residential units is underway at San Elijo Hills. The future University Commons project will be north and west of the Landfill she. At buildout, the University Commons project will include 1,176 residential units. The La Costa Meadows Industrial Center is 1.25 miles northwest of the Landfill. Lake San Marcos and the Lake San Marcos community are approximately 3.5 miles northwest of the Landfill. The Elfm Forest residential development is east of the Landfill and is characterized by large ranch-style homes in an equestrian-and-orchard-oriented environment. The closest Elfin Forest resident is approximately 600 feet from the Landfill boundary. The Olivenhain Municipal Water District's Gaty I and II Reservoirs are located about 1,500 feet south of the Landfill boundary. The current Landfill configuration is characterized as a mound, with side slopes around the perimeter of the waste fill, which extends from native ground up to a relatively flat top deck area. Elevations on the west-facing side slope range from about 540 feet AMSL along the west edge to about 805 feet AMSL at the northem and southem extent of the east edge. Much of the area surrounding the former waste fill area and top deck contains native vegetation, CSS species, and chaparral. HB P P San Marcos Landfill Closure and 1-18 Post-Closure Maintenance Plans EIR m Draft EIR - April 2002 Project Description, Location, and Environmental Setting m ^ The Landfill is located about six miles east of 1-5, approximately six miles west of 1-15, and four ^ miles south of SR 78. Primary access to the Landfill is from the west via Rancho Santa Fe Road ^ to San Elijo Road (Questhaven Road). From the east, the Landfill is accessed via Elfin Forest m Road and Harmony Grove Road. IP P 1.4.1 Consistency of Project With Applicable Regional and General Plans Pi P In August 1987, the San Marcos City Council certified an EIR and approved a general plan pi amendment, zoning ordinance, and map amendment designating the Landfill property as "Solid Waste Management". Thus, the existing land use is in compliance with the City's General Plan m and Zoning Ordinance. m The Proposed Project area falls within the City's Questhaven/La Costa Meadows Community *• Plan. The Community Plan has designated the project area as Solid Waste Management, and the Proposed Project is consistent with that designation. to The Proposed Project is located within the boundaries of the Draft Multiple Habitat Conservation ^ Program ("MHCP") for northem San Diego County. The Landfill area is part of the Southem ^ Focused Planning Area ("FPA") of the Natural Community Conservation Plan ("NCCP") for tiie City of San Marcos. The Landfill area has been assigned a 100 percent conservation rate and "* will contribute to biological cormectivity to the County Core gnatcatcher area and the City of Carlsbad. Therefore, the Proposed Project is consistent with the Draft MHCP. to The Final Closure and Post-Closure Maintenance Plans have been prepared in accordance with tiie requirements of tiie CIWMB, RWQCB, LEA, APCD, and CCR, Titie 27, Division 3, Ml Chapter3, Subchapters, Articles 1 and 2. Based upon the County's interpretation of these requirements, the Proposed Project is consistent with these requirements. It should be noted that PI the ultimate authority rests with these Agencies. San Marcos Landfill Closure and 1-19 Post-Closure Maintenance Plans EIR San Diego County Marine Corps Base Camp Joseph H, Pendelton Vista Valley Center Oceanic Cartsbad Project Site Diion I San Marcos \ Reservoir / A_/ L / ^ Wo. Escondido- Lake Hodges Lake Wohlford 78! £ndnitas\»\ Del Mar Rancho Santa Ramona • Rancho Bernardo • Poway P a e i f i e Q e t a n ,Mira Mesa <3 San Vicente Reservoir Miramar Reservoir Santeg San Diego ^ El Cajon La Mesa (94) Lemon Grovey (78\ .National Cit// Chula Vista ' Sweerwaier Reservoir Warner Springs lake^ Henshaw Julian Morena Reservo \\ Reservoir r X.-- Mexico Regional Map 0BvscD Environmental Services Figure 1-1 Source: U.S.G.S., Rancho Santa Fe Quadrangle, Photorevised 1983 4 W 1:24,000 Vicinity Map P&D Environmental Services Figure 1-2 CO ts CD CO t 05 2 U CD O CO u > a» fi s fl o u > fl PL, •Mini «>mii"ii»i r r f r r L r 9Cf MOE PUGUC ROW EASOEKT 160* WOE EAsaen-10 &o.ai£.' iff WOE ROAD EASEUENT- SC MOE ROM) Jc tnUTY EASEMEtfT. TO M)OEN CANYON ROAD ««• MDE PUeUC RCMD EASEHCNr EMSTMC CONCRETE BOX ssLiia t OKRVEM PUN -' ' 2 RNAL OtAOWC PLAN 3 FMAL ORAOe CROSS SECWWS 4 TmCAL OUCMG PCTAIS AMO SECTKMS 5 DRAiME PUN e DRAMAflE OETAftJS 7 MONTRMNG AND LFC OOWBSKH SYSTEM 8 REWGerAnoN PUN » LEACHATE COLLECDCN MEA AM) PEMMETER BERM OETALS 10 IBMWtY IMCAIICM SYSTEM NOTES: 1. TOTAI. STTE AREA - 32S ACRES Z TOTAL MASTE FKL AREA - 102 ACRES 3. SEE SWET 7 FDR METHANE UOWTORMG ANO OOUKIKM SYSTEM ——SOLID "Mil LMTS — - UHOnu BOUHDWV siwciURES nrrnn loo- of snt PEBWEIH' Q - HOUSE O • TANK HI - 'W MOE PRMOE ROAD CASEHENT SAN WARCOS iJvNDFILL CCUNTr CF SAN DIESC. DEPT. OF PUBtC WORKS 60" MOE PRWAIE ROM) ft UTUTT EASaCNT TO COUNTY OF SAN OCOO FUMAfiC CASaCKT TO COUNTY OF SAN DCOO »15TiNG TOPOGRAPHIC MAP IS FURNiSHED BV THE COUNP- C SAN DIEGO, DEPARTMENT Or PUBUC WORKS. THE TOPOGRAPHY DATA IS BAS€0 ON 3-Z1-200i AEHIAL PHOTOGRAPHY. remWENT SURVEY HONUWnS •HimNC EAXIMG QfV STA1KN NAME OESC »3t«u33 iTiosectsn nu« HAVCH r OKASS OSC m KMUKR SIMRD "anes' 33DS7S.WS ITOMMMZ 83SJe SMLF 40 2* AUMMMM CtP SVtiKD "SDCO tNGR* <M t/T REBMt 17)0083.438 S34X>3 9Mr 41 7 MiMMUU CAP STAMPD "SOCO EHOr CM l/T liaAR 33m8J.«3 170*431^ TOSJO 9V S3 T AUSMUM CAP Srw«D "SOCO WW ON 1/3" lOAIt 3388*1100 nOBTSeJSO 7KL4S SMLT M T ALUUMUM CAP SfMHD *COUNTr OF SAM SCOO SUnClW 33a«7.«37 1710874.428 S*2M SMLT 60 r AIMMAI CAP STAI«tD XOMTY OF SAM DCOO SUnTtCir AP.N. 223-082-04 4a00 ACRES Source: Brown and Caldwell 1 lnch-500feet Landfill Overview 0 P&D Enviromneiital Services Figure 1-4 f } f f r •••N 0 R' T K p Q n D'-H X OVERSIDE DRAINS ARE 24" UNLESS SHOWN OWERWISE • POND ; : • S 0 U T MAiNAGE OlftECnON O CHP MLET I i Source: Brown and Caldwell 1 inch =300 feet Drainage Plan &D Environmental Services Figure 1-5 r r r r P r f nasD 0-2* m snux niMISnHH TO IWM KK CtPIM. IM. SbCK vr we mtnu MUM m K PIACCD ON OMR eOWBKB 9DU> wm M MUUW.SOL TYPICAL OVERSIDE DRAIN DETAIL moSS. «a«n (K" CUP) PTE SMd •>« AMOW* AS9aH.Y rM>) «» cutnma otK (xr we «* oip) DETAIL COTHUGATEO METAL PIPE INLET TYPE A MODIFIEO GRATE »0« •> MU TOP DECK BERM INLET 1 1 ML* ^ ^ " M TOP DECK BERM INLET SECTION' ^ MTN KMC il TOP DECK CHANNEL SECTION TOP DECK DRAINAGE BERM SECTION 515, MT W KME Soun»: Brown and Caldwel No Scale Drainage Details Enviromnental Services Figure 1-6 r r f b r i L -r sn, lUPuvMuu m SUMP BERM SECTION i 4 01. flin^ynjF r nt. w»aMiB> toe i £ 4MMUM BMM-PKir. Mm SUMP PIPE DETAIL 9|9; BERM DETAIL RFRM DETAIL • OMMM B—ll HWr. UDOI —| RISER PIPE DETAIL r-5- LEACHATE COLLECTION AREA IfACMOE COU£CnOH PPE MOMED nSSt GAwa FIL NOT SHOWN SOURCE: HOR ENGINEERING Source: Brown and Caldwefl No Scale Leachate Collection and Perimeter Berm Areas &D Environmental Services Figure 1-7 r r i i Source: Brown and Caldwell 1 inch = 300 feet Landfill Gas Monitoring and Collection System '&D Environmental Services Figure 1-8 r r i r i r r Source: Brown & CakJweB 1lnch=400feet Proposed Project &D Environmental Services Figure 1-9 L L NORTH 850 800 : 750 r 700 > 650 600 - 550 r 500 - SEE SKmON I—J—I FOR NORTH 5ETTLEMEMT 4 3/ CRACK REPAIR OF nNAL COVER EX. GRADE :TOI> .imCCHANNEL -. 100 SEE SECnON {-^—1 FOR TrPIOt NORW/EAST A-f-PERKOLR-^RQAO/DRAMtCE-CHANNEl. 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 SOUTH •A 3/ DRAWACe CHANNEL • NORTH-SOUTH SECTION (_T SCALE: 1" - 80* Vjls, WEST FOR LANOna ACCESS ROAD SECTION FOR TtplCAL SIDE SLOPE RNAL COVER 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 -SEE SECTION FOR WEST SLOPE TIE-IN wFST-FAcrr 5^rcTinN rz, SCALE: r - 80- VTfs, Source: Bnawn and Caldwell 1 inch = 200 feet Grading Cross Sections '&D Environmental Services Figure MO r r r r w L I HI I M Source: Brown and Caldwell 1 inch=300feet Grading Plan P&D Environmental Services Figure 1-11 r Source: Brown and Caldwell 1 inch = 350feet Conceptual Revegetation Plan with Off-Fill Revegetation Areas 0 P&D Environmental Services Figure 1-12 L r f r S 0 1} J H'l VTATER- MAfN;: L-^'' IRRIGATION UNE WFTH SPRINKLER HEAD WATER VALVE Source: Bnwvn and Caldwell 1 inch=300feet Temporary Irrigation System 0 P&D Environmental Services Figure 1-13 Draft EIR-April 2002 Project Description, Location, and Environmental Setting m Table 1-1 Physical and Chemical Soil Characteristics Required by the Modified LSA Plan ii p if Gravel (%) Coarse Sand (%) Medium to Fine Sand (%) Silt (%) Clay (%) ECe* (dS/m) SAR^ (%) pH Boron (ppm) >3 but >8 but <55 <22 <22 <4.6 <8 6.0 to 7.5 <1.0 m <15 <25 average, m <40% <10all samples 1 SAR - Sodium Absorption Rate. There are specific sampling requirements which depend on the soil sources being used. ^1 Table 1-2 Soil Mix Characteristics p m Description Gravel (%) Coarse Sand (%) Medium to Fine Sand (%) Silt and Clay (%) ECe* (dS/m) SAR^ pH Boron (ppm) Permea- bility (cm/sec) 80% DG"- with 20% onsite clay/silt -0-3 ~5 -54-64 -35-3 8 -0.8 -2.7 -6.9 -0.20 -7x10"^ hi Modified LSA >3 >5 <55 <40 <4.6 <8.0 6.0 to 7.5 <1.0 NA pa Plan Specifications £15 <25 average, <10 peak 1 SAR = Sodium Absorption Rate. DG = Decomposed Granite. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 1-43 Draft EIR - April 2002 Project Description, Location, and Environmental Setting Table 1-3 Coastal Sage Scrub Seed Mix Scientific Name Common Name Founds per Acre Purity/ Germination Artemisia californica Califomia sagebrush 1.5 15/50 Baccharis pilularis consanguinea Coyote brush 0.2 2/40 Calochortus splendens Splendid mariposa lilly O.l 90/70 Dichelostemma capitatum Blue dicks 0.3 95/50 Encelia californica Califomia encelia 2.0 40/60 Eriogonum fasciculatum Califomia buckwheat 7.0 10/65 Eriophyllum confertiflorum Golden yarrow 1.0 30/60 Eschscholzia californica Califomia poppy 0.5 98/75 Gnaphalium califomicum Califomia everlasting 0.5 10/25 Hazardia squarrosa Saw tooth goldenbush 1.0 10/20 Lasthenia californica Califomia goldfields 2.0 50/60 Lotus scoparius Deenveed 0.8 90/60 Nassella lepida Foothill needlegrass 1.0 60/60 Nassella pulchra Purple needlegrass 2.0 70/60 Phacelia parryi Parry's phacelia 0.1 95/70 Planta^o ovata Woolly plantain 5.0 98/75 Salvia apiana White sage 1.0 70/50 Viguiera laciniata San Diego sunflower 0.2 40/50 Total 26.2 Table 1-4 Coastal Sage Scmb Container Plants Scientific Name Common Name Plants per Acre Artemisia californica Califomia sagebrush 60 Baccharis pilularis consanguinea Coyote brush 30 Encelia californica Califomia encelia 30 Eriogonum fasciculatum Califomia buckwheat 30 Hazardia squarrosa Saw tooth goldenbush 50 Malosma laurina Laurel sumac 40 Salvia apiana White sage 20 Sambucus mexicana Mexican elderberry 2 Total 262 Hi m p P p San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR P 1-44 Draft EIR - April 2002 Project Description, Location, and Environmental Setting Table 1-5 Southem Mixed Chaparral Seed Mix p Iti p m ll Scientific Name Common Name Pounds per Acre Purity/ Germination Allium praecox Early onion 0.3 95/85 Baccharis pilularis consanguinea Coyote brush 0.5 2/40 Bromus carinatus Califomia brome 1.0 95/80 Bloomeria crocea Common goldenstar 0.3 95/70 Dichelostemma capitatum Blue dicks 0.3 95/50 Encelia californica Califomia encelia 2.5 40/60 Eriophyllum confertiflorum Golden yarrow 1.0 30/60 Gnaphalium califomicum Califomia everlasting 0.5 10/25 Helianthemum scoparium Califomia msh rose 0.2 99/85 Lasthenia californica Califomia goldfields 2.5 50/60 Lotus scoparius Deerweed 1.0 90/60 Malacothamnus densiflorus Many-flowered bushmallow 2.0 15/60 Mimulus aurantiacus Bush monkeyfiower 0.3 5/70 Nassella lepida Foothill needlegrass 2.0 60/60 Nassella pulchra Purple needlegrass 3.0 70/60 Plantago ovata Woolly plantain 5.0 98/75 Salvia melifera Black sage 1.0 70/50 Sisyrinchium bellum Blue-eyed grass 1.0 95/75 Vulpia microstachys Gray's fescue 1.0 95/85 Yucca whipplei Chaparral yucca 1.0 90/65 Total 26.4 Table 1-6 Southem Mixed Chaparral Container Plants Scientific Name Common Name Plants per Acre Adenostoma fasciculatum Chamise 100 Heteromeles arbutifolia Toyon 100 Lonicera subspicata Southem honeysuckle 100 Malosma laurina Laurel sumac 200 Quercus berberidifolia Scmb oak 50 Rhamnus ilicifolia Holly-leaved redberrv 50 Total 600 San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 1-45 Draft EIR - April 2002 Project Description, Location, and Environmental Setting Table 1-7 II -III Non-Native Plants Scientific Name Common Name MU Atriplex semibaccata Australian saltbush •H Avena sp. Wild oats Brassica and Hirschfeldia spp. Mustard Bromus sp. Brome grasses mm Carpohrotus edulis Hottentot-fig Centaurea sp. Tocolote and yellow star thistle ™ Chrysanthemum coronarium Garland chrysanthemum Cortaderia jubata Pampas grass Cortaderia selloana Selloa pampas grass — Cynara cardmculus Cardoon Cynodon dactylon Bermuda grass Cytisus scoparius Scotch broom Eucalyptus spp. Eucalyptus Foeniculum vulgare Sweet fennel •i Genista monspessulans French broom Marrubium vul^are Horehound Melilotus sp. Sweet clover m Mesembryanthemum crystallinum Crystalline iceplant m Mesembryanthemum nodiflorum Small-flowered iceplant Oxalis pes-caprae Bermuda buttercup m Raphanus spp. Radish m Ricinus communis Castor bean Rumex crispus Curly-dock m Salsola tra^ Russian thistle mm Senecio mikanoides German ivy Ulex europaeus Gorse wm Vinca major Pink periwinkle mm San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 1-46 p IM Draft EIR-April 2002 Project Description, Location, and Environmental Setting Table 1-8 Monitoring, Inspection, Reporting, and Maintenance Requirements m P Monitoring Inspection Reporting Maintenance Groundwater Quarterly - includes purging three well volumes, collection of groundwater and blank samples, transport to laboratory under chain-of-custody procedures. Quarterly - condition of wells and pumps is inspected to ensure that well heads and seals are intact, wells are secure, dedicated samplmg systems are functional. Quarterly - includes laboratory analysis, data evaluation, groundwater elevation tables and contour maps, and recommen- dations for additional work if necessary. Quarterly - mainte- nance will be com- pleted as determined by inspections. May include repair or re- placement of pumps and repair or abandon- ment and reinstallation of wells. Surface Water Variable - includes monitoring Copper Creek and pond water. Quarterly - condition of drainage facilities and the two ponds. Annually - results of Copper Creek analyses. As requu^ed - results of pond analyses. Quarterly - mainte- nance will be com- pleted as determined by inspection. May include repair of drain- age channels, pond cleaning, etc. Leachate Quarterly - includes collection of sample, transport to laboratory under chain-of-custody procedures. Monthly - includes checking system for leaks and clogs, and determining level of leachate in tank and over liner. Quarterly - includes laboratory analyses, data evaluation, and recommendations for additional work if necessary. Quarterly - mamte- nance will be com- pleted as determined by inspections. May include repair or replacement of pipes, valves, or tanks. Landfill Gas Quarterly (or per permit requirements) - includes monitoring all gas migration probes, surface emission data, and wellhead data. Quarterly - inspect condition of probes and wellheads as part of typical monitoring. Also inspect the gas collection system for leaks. Quarterly - includes surface emission data, probe data, and any recommendations for additional work if necessary. Quarterly - mainte- nance will be com- pleted as determined by inspections. May include repair or replacement of wells or probes. Cover Soil Erosion or Settlement See cover soil moisture below. As needed - inspect foiiowing a one (1) inch rainfall within 24 hours. Monthly - inspect Landfill surfaces for erosion and settlement. As necessary. As necessary - main- tenance will be com- pleted as determined by inspections. Cover Soil Moisture Continuously - data fi-om the moisture probes and meteorological station. Quarterly - inspect condition of probe system and meteorological station. Annual - includes evaluation of soil moisture data. Maintenance will be completed as determined by the inspections. Vegetation Variable. Variable. Variable. Maintenance will be completed as determined by the inspections. Source: Brown and Caldwell, 2002b. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 1-47 Draft EIR - April 2002 Project Description, Location, and Environmental Setting (This page intentionally left blank.) P P P P P P San Marcos Landfill Closure and 1.48 Post-Closure Maintenance Plans EIR P il p p m P P Draft EIR - April 2002 Significant Environmental Effects CHAPTER 2.0 SIGNIFICANT ENVIRONMENTAL EFFECTS This chapter of the EIR provides a detailed discussion of subject areas that could be significantly impacted by the Proposed Project. This includes information developed during the Initial Study and the response period for the Notice of Preparation ("NOP"). 2.1 Transportation/Circulation A traffic study was prepared by Linscott, Law and Greenspan (2002) to determine and evaluate potential traffic impacts associated with implementation of the final closure plan for the San Marcos Landfill ("Landfill"), including the import of cover soil for placement on the Landfill surfaces. The complete traffic study is included in Appendix B. The source of the cover soil is imknown at this time; therefore, the traffic analysis considered six potential haul routes. The haul routes were selected based on the potential source locations of the cover soil, taken into consideration with the Landfill location and the existing circulation network. Figure 2.1-1 provides an overview of the haul routes. If the cover soil is located along the hiterstate Highway 15 ("1-15") or State Route 78 ("SR78") corridor, three potential haul routes have been identified. Truck Routes 1 through 3 are shown on Figures 2.1-2 through 2.1-4 and summarized below. If the cover soil is located along the Interstate Highway 5 ("1-5") corridor, three different potential haul routes have been identified. Truck Routes 4 through 6 are detailed on Figures 2.1-5 through 2.1-7 and summarized below. Tmck Route 1 Truck Route 1 assumes that trucks would be coming via SR 78 and exiting the freeway at Rancho Santa Fe Road. Trucks would proceed south on Rancho Santa Fe Road through the cities of San Marcos and Carlsbad until reaching the "T" intersection of Rancho Santa Fe Road/San Elijo Road, where trucks would turn east to the Landfill. The retum trip would be a reversal of this same haul route. According to the City of San Marcos, Rancho Santa Fe Road San Marcos Landfill Closure and 2-1 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects between Island Avenue and Mebose Drive may be closed to truck traffic between April 2002 and April 2004, due to a major reconstruction project on Rancho Santa Fe Road. Truck Route 1 was still analyzed, as it provides the most direct route to the Landfill firom the 1-15 corridor. Figure 2.1 -2 depicts Truck Route 1. Truck Route 2 Using Truck Route 2, trucks would proceed via SR 78 and exit the fi-eeway at EI Camino Real. Tmcks would proceed south on El Camino Real through the City of Carlsbad until reaching the intersection of El Camino Real/Olivenhain Road, where tmcks would make a left tum. Tmcks would continue on Olivenhain Road (which turns into Rancho Santa Fe Road) until reaching the "T" intersection of Rancho Santa Fe Road/San Elijo Road. Tmcks would then tum right and go east until reaching the Landfill The return trip would be a reversal of this same haul route. Figtire 2.1-3 depicts Tmck Route 2. Tmck Route 3 Using Tmck Route 3, tmcks proceeding along 1-15 would exit the freeway at Ninth Avenue in the City of Escondido. Tmcks would tum firom Ninth Avenue onto Auto Park Way and proceed northwesterly on Auto Park Way imtil reaching the intersection of Auto Park Way/Howard Avenue, where tmcks would make a left tum and proceed west until reaching Harmony Grove Road. Tmcks would proceed west on Harmony Grove Road, which becomes Elfin Forest Road. Once on Elfin Forest Road, tmcks would make a left tum at the intersection of San Elijo Road/Elfin Forest Road and proceed imtil reaching the Landfill. The return trip would be a reversal of this same haul route. Figure 2.1-4 depicts Tmck Route 3. Tmck Route 4 Usmg Tmck Route 4, tmcks proceedmg on 1-5 would exit at Palomar Airport Road. Tmcks would proceed east on Palomar Airport Road through the City of Carlsbad imtil reaching the mtersection of Palomar Airport Road/El Camino Real, where tmcks would make a right tum and San Marcos Landfill Closure and 2-2 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects ^ proceed south on El Camino Real until reaching the intersection of El Camino Real/Olivenhain p Road, where tmcks would make a left tum. Tmcks would continue on Olivenhain Road (which p, turns into Rancho Santa Fe Road) until reaching the "T" intersection of Rancho Santa Fe li Road/San Elijo Road. Tmcks would then tum right and go east until reaching the Landfill. The p, retum trip would be a reversal of this same haul route. Figure 2.1-5 depicts Tmck Route 4. P m Truck Route 5 p m Using Tmck Route 5, tmcks proceeding along 1-5 would exit at La Costa Avenue. Tmcks would *• proceed east on La Costa Avenue through the City of Carlsbad until reaching the intersection of m La Costa Avenue/El Camino Real, where trucks would make a right tum and proceed south on * El Camino Real until reaching the intersection of El Camino Real/Olivenhain Road, where tmcks would make a left tum. Tmcks would continue on Olivenhain Road (which tums into Rancho Santa Fe Road) until reaching the "T" intersection of Rancho Santa Fe Road/San Elijo Road. Tmcks would then tum right and go east imtil reaching the Landfill. The retum trip would be a reversal of this same haul route. Figure 2.1-6 depicts Tmck Route 5. Truck Route 6 Using Tmck Route 6, tmcks proceeding firom 1-5 would exit at Encinitas Boulevard. Tmcks would proceed east on Encinitas Boulevard through the City of Encinitas until reaching the intersection of Encinitas Boulevard/El Camino Real, where tmcks would make a left tum and proceed north on El Cammo Real until reaching the intersection of El Camino Real/Olivenhain mm Road, where tmcks would make a right tum. Tmcks would continue on Olivenhain Road (which tums into Rancho Santa Fe Road) until reaching the "T" intersection of Rancho Santa Fe Road/San Elijo Road. Tmcks would then tum right and go east until reaching the Landfill. The retum trip would be a reversal of this same haul route. Figure 2.1-7 depicts Tmck Route 6. San Marcos Landfill Closure and 2-3 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects 2.1.1 Existing Conditions Standards for classification of Public Roads consist of the following. Freeways are divided arterial highways with full control of access. Highways generally do not have controlled access. Primary Arterials provide six through lanes, a raised median, and curbside parking. Major Arterials provide four through lanes, a raised median, and curbside parking. Collector Roads provide four through six lanes with curbside parking or four through lanes with a left-tum lane. Bike lanes add 10 feet to both the road width and the right-of-way. The Landfill is located within the City of San Marcos, south of San Elijo Road between Rancho Santa Fe Road and Elfin Forest Road. The roadways which are included in the proposed tmck routes are summarized below. Interstate Highway 5 is a north/south freeway which extends fi-om the Mexican border through the entire length of Califomia. In the vicinity of the Landfill, eight lanes of divided travel are provided. Interchanges on 1-5 which could be impacted by cover soil hauling Tmck Routes include Encinitas Boulevard, La Costa Avenue, and Palomar Airport Road. State Route 78 is an east/west highway which extends from 1-5 to 1-15 as a freeway. Along the segment that tmcks would travel, there are six lanes of divided travel provided. Interchanges which tmcks may use as part of the Proposed Project include Rancho Santa Fe Road and El Camino Real. Palomar Airport Road is classified as a Primary Arterial within the City of Carlsbad Circulation Element. Palomar Auport Road is generally a six-lane divided roadway, with three lanes in each direction, providing striped bike lanes and bus stops. Curbside parking is prohibited. Palomar Airport Road has a posted speed limit of 55 miles per hour ("mph"). La Costa Avenue is classified as a Major Arterial within the City of Carlsbad Circulation Element. La Costa Avenue is constmcted as a four-lane divided roadway, with two lanes San Marcos Landfill Closure and 2-4 Post-Closure Maintenance Plans EIR p Draft EIR-April 2002 Significant Environmental Effects provided in each direction from 1-5 to El Camino Real. La Costa Avenue also provides striped bike lanes and bus stops, with no curbside parking permitted. The posted speed limit is 55 mph. Encinitas Boulevard is classified as a Primary Arterial east of 1-5 on the City of Encinitas Circulation Element. Encinitas Boulevard is constmcted as either a four-lane or a six-lane roadway, with portions having a raised median, a Two Way Left Tum Lane ("TWLTL") median, and a striped median. Striped bike lanes and bus stops are provided on both sides of Encinitas Boulevard. The posted speed limit is 45 mph. Olivenhain Road is classified as a Primary Arterial witiiin tiie City of Encinitas Circulation Element. It is constmcted as a six-lane roadway, providing three lanes of travel in each direction. Olivenhain Road provides striped bike lanes and bus stops on both sides of the road. The posted speed limit is 45 mph, and curbside parking is prohibited. El Camino Real is classified as a Prunary Arterial within the City of Encmitas and City of Carlsbad Circulation Elements. It is constmcted as a six-lane divided roadway, with three lanes of travel generally provided in each direction. El Camino Real provides striped bike lanes and bus stops, with curbside parking prohibited. The posted speed limit is 55 mph. Rancho Santa Fe Road is classified as a Primary Arterial within the City of Carlsbad and the City of San Marcos Circulation Elements. Rancho Santa Fe Road is constmcted as a four-lane roadway between SR 78 and Melrose Drive, and narrows to two lanes between Melrose Drive and La Costa Avenue. The speed limit is generally 45 to 50 mph. Traffic signals are provided at various intersections along Rancho Santa Fe Road. San Marcos Boulevard is classified as a Primary Arterial within the City of San Marcos Circulation Element. The roadway provides four lanes of travel near Rancho Santa Fe Road. San Marcos Boulevard extends from the terminus at Palomar Airport Road eastward through the City of San Marcos. San Marcos Boulevard has a posted speed limit of 45 mph west of Rancho Santa Fe Road and 40 mph east of Rancho Santa Fe Road. San Marcos Landfill Closure and 2-5 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects San Elijo Road is classified as a Collector Road and provides direct access to the Landfill. The road is constmcted as a two-lane undivided roadway, with curbside parking generally not allowed. Striped bike lanes and bus stops are not provided. It is signalized at Rancho Santa Fe Road. San Elijo Road has a speed limit of 40 mph. Harmony Grove Road is classified as a Collector Road on the County of San Diego Circulation Element. The road is constmcted as a two-lane undivided roadway providing no striped bike lanes or bus stops. Since Harmony Grove Road is a winding road, the posted speed limit ranges from 25 to 40 mph. Elfin Forest Road is classified as a Collector Road on the County of San Diego Circulation Element. The road is constmcted as a two-lane undivided roadway, providing no striped bike lanes or bus stops. Posted speed limits range from 25 to 40 mph. In addition, Elfin Forest Road has a maximum gross weight limit of 14,000 pounds from Harmony Grove Road westerly to the San Marcos City Limits. Existing average daily traffic volumes for Routes 1 through 6 are presented in Table 2.1-1. Existing Intersection Operation Level of Service ("LOS") is one standard by which the operating conditions of a given roadway segment or intersection are evaluated. Level of service is defined on a scale of A to F, where: • LOS A represents free-flowing traffic conditions with no restrictions on maneuvering or operating speeds, low traffic volumes, and high speeds; • LOS B represents stable flow, more restrictions, and operating speeds beginning to be affected by traffic volumes; San Marcos Landfill Closure and 2-6 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects P P ii LOS C represents stable flow, more restrictions, and speed and maneuverability more closely controlled by higher traffic volumes; LOS D represents conditions approaching unstable flow, witii traffic volumes profoundly affecting arterials; LOS E represents unstable flow, and some stoppages; and m P • LOS F represents forced flow, many stoppages, and low operating speeds. Tables 2.1-2(a) tiirough 2.1-7(a) show the existing AM and PM peak-hour operations at the key intersections affected by Tmck Routes 1 through 6. AM peak-hour operations are 7:00 AM to 9:00 AM, and PM peak-hour operations are 4:00 to 6:00 PM. The majority of tiie intersections on Routes i tiirough 6 currently operate at LOS C or better (A or B) during botii tiie AM and PM peak hours, witii a few intersections operating at below LOS C. The following intersections are currentiy operating at LOS D, LOS E, or LOS F: Rancho Santa Fe Road/SR 78 Westbound Ramps, AM and PM peak hours (LOS D & F) Rancho Santa Fe Road/SR 78 Eastbound Ramps, AM and PM peak hours (LOS F) Rancho Santa Fe Road/San Marcos Boulevard, AM and PM peak hours (LOS E and F) Rancho Santa Fe Road/Mekose Drive, AM peak hours (LOS D) Rancho Santa Fe Road/San Elijo Road, PM peak hours (LOS D and E) El Camino Real/SR 78 Westbound Ramps, AM and PM peak hours (LOS D) El Camino Real/SR 78 Eastbound Ramps, PM peak hours (LOS D) El Camino Real/Palomar Airport Road, AM and PM peak hours (LOS E) El Camino Real/Garden View Road, PM peak hours (LOS D) El Camino Real/Olivenhain Road, AM and PM peak hours (LOS D&E) Encinitas Boulevard/El Camino Real, AM and PM peak hours (LOS E) Valley Parkway/Auto Park Way, PM peak hours (LOS D) San Marcos Landfill Closure and Post-Closure Mamtenance Plans EIR 2-7 Draft EIR - April 2002 Significant Environmental Effects - Existing Daily Roadway Segment Operations ^ Tables 2.1-2(b) through 2.1-7(b) summarize the existing daily street segment operations in the wm project area. The majority of the street segments currently operate at LOS C or better on a daily •« basis, with some segments operating below LOS C. The following roadway segments currentiy wm operate at LOS D, LOS E, or LOS F: - Rancho Santa Fe Road: Descanso Boulevard to Grand Avenue (LOS E) Rancho Santa Fe Road: La Mirada to Linda Vista Drive (LOS D) Rancho Santa Fe Road: San Marcos Boulevard to Lake San Marcos Drive (LOS D) "* Rancho Santa Fe Road: Lake San Marcos Drive to Melrose Drive (LOS F) "* Rancho Santa Fe Road: Melrose Drive to San Elijo Road (LOS F) Rancho Santa Fe Road: Calle Barcelona to La Costa Avenue (LOS F) mm Rancho Santa Fe Road: Tmck Bypass to San Elijo Road (LOS F) El Camino Real: Levante Street to Calle Barcelona (LOS D) La Costa Avenue: Piraeus Street to Saxony Road (LOS D) Palomar Airport Road: Paseo Del Norte to Armada Drive (LOS E) Encinitas Boulevard: Interstate Highway 5 to Saxony Road (LOS E) Auto Park Way North (One Way): Andreasen Drive to Howard Avenue (LOS D) ^ Freeway Segment Operation ^ p Table 2.1-8 summarizes the peak freeway segment LOS. Interstate Highway 15, Interstate p Highway 5, and State Route 78 currently experience degraded LOS. During peak hours, ^ Interstate Highway 15 operates at LOS F between Valley Parkway and Ninth Avenue, Interstate m Highway 5 operates at a LOS F for the segments between Santa Fe Drive and Encinitas ^ Boulevard and between Palomar Airport Road and Cannon Road, and State Route 78 operates at m LOS D between El Camino Real and College Boulevard and LOS E between Rancho Santa Fe » Road and San Marcos Boulevard. w San Marcos Landfill Closure and 2-8 Post-Closure Maintenance Plans EIR p p m P P P Draft EIR-April 2002 Significant Environmental Effects 2.1.2 Thresholds of Significance Appendix G to tiie State CEQA Guidelines defines project traffic impacts as tiiose which "cause an increase in traffic which is substantial in relation to the existing traffic load and capacity of tiie street system". Additionally, it must be determined if tiie project would "exceed, eitiier individually or cumulatively, a level of service standard estabhshed by tiie county congestion management agency for designated roads and highways". CEQA allows tiie significance of impacts to be determined by a variety of methods. Ordinances, regulations, or plans adopted by tiie lead agency can be used to set tiiresholds of significance. This concept was upheld by the Courts [National Parks and Conservation Association vs. County of Riverside (1999) 71 CA 4* 1341, 1358, 84 CR 2d 563]. In that case, tiie County residential noise standards were used. For the purpose of tiiis EIR, compliance with Section 4 of the County of San Diego Public Facility Element of tiie San Diego County General Plan was analyzed. The County of San Diego has an LOS goal of C, which allows for stable traffic flow with room to maneuver. For the purposes of this EIR, if an intersection or roadway cun-ently operates at LOS C and the addition of project traffic degrades an intersection or roadway to LOS D or below, a significant impact would occur. Additionally, if an intersection or roadway segment currently operates at a degraded level of service (LOS D, E, or F), die addition of project traffic would be considered a significant impact, because it would further exacerbate the degraded condition. 2.1.3 Analysis of Project Effects and Determination of Significance Project Trafiic Generation The generation rates were based on the assumption of 400 tmcks per day entering the Landfill, witii 50 tmcks entering the site during a one-hour period witiiin peak commuter hours. San Marcos Landfill Closure and 2-9 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects Peak commuter hours are defined as: • AM Peak = 7:00 to 9:00 AM. • PM Peak = 4:00 to 6:00 PM. A Passenger Car Equivalence ("PCE") was applied to the generated tmck trips. A PCE is defined as the number of passenger cars that are displaced by a single heavy vehicle of a particular type under the prevailing traffic conditions. Heavy vehicles have a greater traffic impact than passenger cars, due to the fact that tiiey are larger than passenger cars, and therefore, occupy more roadway space. Additionally, their performance characteristics are generally inferior to passenger cars, leading to the formation of downstream gaps in the traffic stream (especially on upgrades) which cannot always be effectively filled by normal passing maneuvers. All of the project-generated traffic consists of heavy vehicles (tmcks); therefore, a PCE was applied to the generated tmck trips. Assuming that every tmck counts as two cars, the project is calculated to generate the equivalent of 1,600 ADT (800 inbound tmcks/800 outboimd tmcks), with 100 inbound/outbound tmcks during both the AM and PM peak hours. The following section discusses the impact of adding project traffic to the existing traffic conditions under each haul route scenario. Each route is discussed separately (Tmck Routes 1 through 6) and is analyzed m terms of both intersection and roadway segments. If a significant impact was identified, an impact number was assigned to the impact (e.g.. Impact 2.1.3.a). Since some of the haul routes include the same intersections and roadway segments, the same impact identification number was retained throughout the analysis. For example, Tmck Routes 2, 4, 5, and 6 will utilize and result in the same significant impact on the Rancho Santa Fe Tmck Bypass to San Elijo Road. The impact number will be assigned to the roadway segment under the analysis of Tmck Route 2, and retamed through the analysis discussions of Tmck Routes 4 through 6. These impacts are associated with the transport of cover soil to the site. Post-closure maintenance, which is also included as part of the Proposed Project, will require periodic activity at the Landfill (remedial actions and monitoring). The anticipated traffic San Marcos Landfill Closure and 2-10 Post-Closure Maintenance Plans EIR PI Draft EIR - April 2002 Significant Environmental Effects generation related to these activities will be minimal, consisting primarily of monitoring and maintenance crews arriving in light-duty vehicles. Occasional deliveries of cover soil may be required to replace lost cover soil over time. Current monitoring and maintenance activities generate tmck traffic for occasional soil hauling. The monitoring and post-closure maintenance activities described in the post-closure maintenance plan are very similar to the cuirent activities, and will not result in changed conditions. Therefore, the long-term post-closure maintenance activities are not considered to have a significant traffic impact. (Please see Section 1.1.3.4 and Table 1-8 for a description of the post-closure maintenance activities.) Tmck Route 1 Intersection Impacts Table 2.1-2(a) summarizes the results of adding the project traffic to the existing intersection conditions under the Tmck Route 1 scenario. The foUowing intersections were subject to a degradation of LOS to D, E, or F or experienced a substantial increase on a street segment currentiy operating at LOS D, E, or F. This represents a significant intersection impact. • Impact 2.L3.a: Rancho Santa Fe Road/SR 78 WB Ramps, AM and PM peak hours (LOSE and F) • Impact 2.1.3.b: Rancho Santa Fe Road/SR 78 EB Ramps, AM and PM peak hours (LOSF) • Impact 2.1.3.C: Rancho Santa Fe Road/San Marcos Boulevard, AM and PM peak hours (LOSE and F) • Impact 2.1.3.d: Rancho Santa Fe Road/Melrose Drive, AM peak hours (LOS D) • Impact 2.1.3.e: Rancho Santa Fe Road/San Elijo Road, PM peak hours (LOS E) San Marcos Landfill Closure and 2-11 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects Roadway Segment Impacts Table 2.1-2(b) summarizes the results of adding project traffic to existing roadway segments under the Tmck Route 1 scenario. With the addition of project traffic, all but one of the segments will be significantly impacted by the Proposed Project. These impacts result from adding project traffic to an already degraded roadway, thus exacerbating the condition. • Impact 2.1.3.f: Rancho Santa Fe Road - Descanso Boulevard to Grand Avenue (LOS F) • Impact 2.1.3.g: Rancho Santa Fe Road - La Mirada Drive to Linda Vista Drive (LOS E) • Impact 2.1.3.h: San Marcos Boulevard to Lake San Marcos Drive (LOS D) • Impact 2.1.3.i: Rancho Santa Fe Road - Lake San Marcos Drive to Melrose Drive (LOS F) • Impact 2.1.3 .j: Rancho Santa Fe Road - Melrose Drive to San Elijo Road (LOS F) Truck Route 2 Intersection Impacts Table 2.1-3(a) summarizes the results of adding the project traffic to the existing intersection conditions under the Tmck Route 2 scenario. With the addition of project traffic, the majority of the intersections will continue to operate at LOS through C, with the exception of the following mtersections, which currently operate at LOS D or E and will experience a substantial delay increase. This represents a significant impact. Impact 2.1.3.k: El Camino Real/SR 78 WB Ramps, AM and PM peak hours (LOS D) Impact 2.1.3.1: El Camino Real/SR 78 EB Ramps, PM peak hours (LOS D) Impact 2.1.3.m: Palomar Airport Road/El Camino Real, AM and PM peak hours (LOS E) Impact 2.1.3.n: El Camino Real/Olivenhain Road, AM and PM peak hours (LOS D&E) Impact 2.1.3.e: Rancho Santa Fe Road/San Elijo Road, PM peak hours (LOS D) San Marcos Landfill Closure and 2-12 Post-Closure Maintenance Plans EIR Mb Draft EIR-April 2002 Significant Environmental Effects Roadway Segment Impacts Table 2.1-3(b) summarizes the addition of project traffic to tiie existing roadway traffic conditions under the Tmck Route 2 scenario. Witii the addition of project traffic, all roadway segments on El Camino Real will operate at LOS C or better. However, two of the segments on Rancho Santa Fe Road that presently operate at LOS F will experience a substantial increase in Hi the volume to capacity ("V/C") ratio. This represents a significant roadway segment impact. P P • Impact 2.1.3.0: Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue (LOS F) • Impact 2.1.3.p: Rancho Santa Fe Road - Tmck Bypass to San Elijo Road (LOS F) rm p p p Tmck Route 3 Intersection Impacts Table 2.1-4(a) summarizes the results of adding tiie project traffic to the existing intersection conditions under the Tmck Route 3 scenario. With the addition of project traffic, the majority of the intersections will continue to operate at LOS through C, with the exception of two intersections. During the AM peak hour, tiie intersection of Valley Parkway and Auto Park Way operates at a degraded level of service (LOS D). Witii tiie addition of traffic from the Proposed Project, the degradation at this intersection will be further exacerbated. This represents a significant impact. During the PM peak tiiis mtersection currently operates at LOS C. With the addition of traffic from the Proposed Project, this mtersection will drop to LOS D. This represents a significant impact. • Impact 2.1.3.q: Valley Center Parkway/Auto Park Way, AM and PM peak hours (LOS D) San Marcos Landfill Closure and 2-13 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Signifwant Environmental Effects Roadway Segment Impacts Table 2.1-4(b) summarizes the addition of project traffic to the existing roadway traffic conditions under the Tmck Route 3 scenario. With the addition of project traffic, the segments along Auto Park Way will be degraded to LOS D (Impact 2.1.3.r) or an existing LOS D segment will be fiirther degraded (Impact 2.1.3.s). This represents a significant roadway segment impact. • Impact 2.1.3.r: Auto Park Way - Ninth Avenue to Valley Parkway (LOS D) • Impact 2.1.3.S: Auto Park Way North (one-way) - Andreasen Drive to Howard Avenue (LOS D) Truck Route 4 Intersection Impacts Table 2.1-5(a) summarizes the results of adding project traffic to the existing intersection conditions under the Tmck Route 4 scenario. With the addition of project traffic, the majority of the intersections will continue to operate at LOS C, except for the following intersections, which currently operate at a degraded LOS that will be further exacerbated by the Proposed Project (Impacts 2.1.3.m and 2.1.3.n), or will drop to LOS D (Impact2.1.3.e). This represents a significant impact. • Impact 2.1.3.m: Palomar Auport Road/El Camino Real, AM and PM peak hours (LOS E) • Impact 2.1.3.n: El Camino Real/Olivenhain Road, AM and PM peak hours (LOS D&E) • Impact 2.1.3.e: Rancho Santa Fe Road/San Elijo Road, PM peak hours (LOS D) Roadway Segment Impacts Table 2.1-5(b) summarizes the results of adding project traffic to existing traffic conditions under the Tmck Route 4 scenario. With the addition of project traffic, the roadway segments on San Marcos Landfill Closure and 2-14 Post-Closure Maintenance Plans EIR P Draft EIR-April 2002 Significant Environmental Effects Palomar Airport Road are calculated to operate at LOS C, witii one exception, Paseo del Norte to Armada Drive. Two of the tiiree segments on Rancho Santa Fe Road currently operate at LOS F, and will be fiirther degraded witii tiie addition of traffic from tiie Proposed Project. This il represents a significant rnipact. P P • Impact 2.1.3.t: Palomar Auport Road - Paseo Del Norte to Armada Drive (LOS E) • Impact 2.1.3.0: Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue (LOS F) • Impact 2.1.3.p: Rancho Santa Fe Road - Tmck Bypass to San Elijo Road (LOS F) Tmck Route 5 Intersection Impacts Table 2.1-6(a) summarizes the results of adding project traffic to existing mtersection conditions under the Tmck Route 5 scenario. With the addition of project traffic, the majority of the intersections will continue to operate at LOS C, witii tiie exception of tiie followmg intersections, which currently operate at LOS D or E and will experience a substantial increase in delay. This represents a significant impact. • hnpact 2.1.3.n: El Camino Real/Olivenhain Road, AM and PM peak hours (LOS D&E) • Impact 2.1.3.e: Rancho Santa Fe Road/San Elijo Road, PM peak hours (LOS D) Roadway Segment Impacts Table 2.1-6(b) summarizes tiie results of adding project traffic to existing roadway conditions under tiie Tmck Route 5 scenario. Witii the addition of project traffic, those roadway segments currentiy operating at a degraded LOS (D and F) will be fiirther degraded. This represents a significant roadway impact. San Marcos Landfill Closure and 2-15 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects • Impact 2.1.3.U: La Costa Avenue - Piraeus Street to Saxony Road (LOS D) • Impact 2.1.3.V: El Camino Real - Levante Street to Calle Barcelona (LOS D) • Impact 2.1.3.0: Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue (LOS F) • Impact 2.1.3.p: Rancho Santa Fe Road - Tmck Bypass to San Elijo Road (LOS F) Truck Route 6 Intersection Impacts Table 2.1-7(a) summarizes the results of adding project traffic to the existing intersection conditions under the Tmck Route 6 scenario. With the addition of project traffic, three intersections will drop from LOS C to D (Impacts 2.1.3.w, 2.1.3.x, and 2.1.3.e), and three intersections currently operating at a degraded LOS (D or E) will be further degraded with the addition of project traffic (Impacts 2.1.3.y, 2.1.3.Z, and 2.1.3.n). This represents a significant intersection impact. • Impact 2.1.3 .w: Encinitas Boulevard/I-5 SB Ramps, PM peak hours (LOS D) • Impact 2.1.3.x: Encinitas Boulevard/I-5 NB Ramps, PM peak hours (LOS D) • Impact 2.1.3.y: Encirutas Boulevard/El Camino Real, AM and PM peak hours (LOS E) • Impact 2.1.3 .z: El Camino Real/Garden View Road, PM peak hours (LOS D) • Impact 2.1.3 .n: El Camino Real/Olivenhain Road, AM and PM peak hours (LOS D&E) • Impact 2.1.3.e: Rancho Santa Fe Road/San Elijo Road, PM peak hours (LOS D) Roadway Segment Impacts Table 2.1-7(b) summarizes the results of adding the project traffic to existing roadway segments under the Tmck Route 6 scenario. With the addition of project traffic, the segments on Encinitas Boulevard and El Camino Real will operate at LOS C, with the exception of one intersection that will be reduced from LOS E to F. Two of the segments on Rancho Santa Fe Road currentiy San Marcos Landfill Closure and 2-16 Post-Closure Maintenance Plans BIR Draft EIR - April 2002 Significant Environmental Effects ^ operate at LOS F and will be fiirther degraded witii tiie addition of traffic from the Proposed p Project. This represents a significant roadway impact. wm P • Impact 2.1.3.aa: Encinitas Boulevard - Interstate Highway 5 to Saxony Road (LOS F) m • Impact 2.1.3.0: Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue (LOS F) • Impact 2.1.3.p: Rancho Santa Fe Road - Tmck Bypass to San Elijo Road (LOS F) P P m P p P Freeway Segment Operations Peak-hour freeway segments are summarized m Table 2.1-8. All freeway segments on Interstate Highway 15, Interstate Highway 5, and State Route 78 currently operate at a degraded LOS (D, E, and F). With the addition of traffic from the Proposed Project, all freeway segments will be fiirther degraded. This represents a significant freeway segment operations impact. Impact 2.1.3.ab: Interstate Highway 15 - Valley Parkway to Nintii Avenue (LOS F) Impact 2.1.3.ac: Interstate Highway 5 - Santa Fe Drive to Encmitas Boulevard (LOS F) Impact 2.1.3.ad: Interstate Highway 5 - Palomar Airport Road to Cannon Road (LOS F) Impact 2.1.3.ae: State Route 78 -El Camino Real to College Boulevard (LOS E) Impact 2.1.3.af: State Route 78 - Rancho Santa Fe Road to San Marcos Boulevard (LOS E) 2.1.4 Mitigation Measures Significant impacts were identified for all six tmck haul routes. Table 2.1-9 summarizes the significant intersection, roadway, and freeway impacts and associated tmck route. Because many of tiie routes have common segments, some of the impacts are redundant (would have similar impacts on more than one route). Because tiie impacts will be short term, several mitigation measures which could be included for a project would not be feasible for the Proposed Project. They include the addition of travel lanes, and imposing additional peak-hour San Marcos Landfill Closure and 2-17 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects restrictions. The following discussion analyzes the feasibility of implementing these measures and rationale for not adopting these measures. In theory, all significant transportation/circulation impacts could be mitigated by adding lanes at the impacted intersections and on impacted roadways; however, since the project haul duration is short term (approximately seven months), this type of mitigation is not considered practical or feasible. Constmcting new lanes would require the acquisition of property, preparation of environmental documents, acquisition of permits, mitigation of potential significant impacts, and constmction of the improvements. The majority of the roadways have been built out to their ultimate design. Thus, development (housing, industrial, and commercial uses) has been built with the anticipation that the roads have been constmcted to their ultimate widths. To expand the roads would result in takings of property, demolition of stmctures, and expansion of an infrastmcture that is not needed in the long term. Limituig the amoimt of tmcks per day would not likely reduce significant impacts, as even reducing the number of tmck trips to 100 loads per day would still cause a significant impact on roadway segments. Additionally, the reduction of the number of trips per day would significantly extend the length of time it would take to import the material. This would extend the impacts over a greater time period and additionally create expense to the County. Reducing the number of trips is infeasible, because the time required to haul the cover soil to the Landfill also increases in a proportional manner. The reduction in number of daily trips, thereby lengthening the duration of the project, would create several undesirable consequences. Due to fixed overhead costs, it is a proven principle in the constmction industry that extending the duration of a constmction project will result in increased expense to complete the project. With a landfill closure, extending the duration of closure results in an mcreased time period during which the landfill is not covered by a permanent cover system. During the constmction process, the Landfill is more vulnerable to erosion of existing cover and infiltration of water into the layers of trash. Therefore, extension of the duration of mstallation of the permanent cover increases the possibility of undesirable environmental events, such as erosion or water San Marcos Landfill Closure and 2-18 Post-Closure Maintenance Plans EIR P P P Ml P Draft EIR-April 2002 Significant Environmental Effects infiltration. CCR Titie 27 regulations require that tiie permanent cover be installed within 180 days of commencement of constmction. While this will not be possible, and an extension must be obtained due to tiie magnimde of tiie task for tiiis Landfill, tiie policy of tiie Regulations is clear: the application of tiie permanent cover should proceed as expediently as possible once started. The design of the evapo-transpiration cover system also dictates tiiat a slower/longer soil hauling procedure is not environmentally desirable. The potential for infiltration of water into the landfill trash is significantly slowed and prevented by the vegetative cover, which draws moisture out of tiie vegetative soils before it can infiltrate. Delaying tiie planting of tiie vegetative cover would also delay implementation of tiiis key design feature. Finally, imposing additional peak-hour (AM) restrictions would lengtiien the overall constmction period, thus extending the tune period during which significant impacts would be experienced. Nighttime tmcking is not feasible, due to tiie fact tiiat potential haul routes pass by sensitive noise receptors (residential land uses) and significant noise impacts would occur. Additionally, night lighting to illuminate Landfill work areas would create a light nuisance to residences in the vicinity. Mitigation for Impacts 2.1.3.a through 2.1.3.af The following mitigation measures were analyzed and determmed to be feasible, are proposed for implementation to partially mitigate project unpacts, and are applicable to all traffic route scenarios. However, the measures will not mitigate short-temi impacts to below a level of significance. • Tmcked soil will only be accepted at tiie Landfill between 7:00 AM and 4:00 PM. • Notify local bicycle clubs of the haul period schedule and routing associated with the Proposed Project. San Marcos Landfill Closure and 2-19 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects 2.1.5 Conclusions The import of cover soil will cause a significant, short-term impact on a number of roadway segments and intersections (see Table 2.1-9). In total, six potential haul routes were analyzed. AU routes identified significant impacts on roadway segments and intersections, as discussed in Section 2.1.3. Partial mitigation measures have been included to assist in reducing impacts; however, these measures will not reduce short-term traffic impacts to below a level of significance. Even limiting the number of tmck trips to 100 per day would stUl not reduce significant impacts on some roadway segments or intersections because they currently operate at unacceptable levels (LOS D), as discussed in Section 2.1.4. Reducing the number of trips, thereby lengthening the duration of the project, is not considered feasible because this would result in increased expense to complete the project. Increasing the duration of final cover constmction could increase the possibility of erosion at the site or water infiltration. There is no altemative design that reduces the impacts to below a level of significance, because of the large quantities of soil required to properly close the Landfill, and the need to accomplish the closure as soon as possible. The No Project Altemative, while reducing short-term traffic impacts, could possibly create long-term risks for infiltration of water into the Landfill (see discussion in Section 4.2.1). The No Project Altemative was rejected for the reasons stated in Section 4.2.3. In addition, the Landfill stopped receiving waste on March 11, 1997. Pursuant to CCR Title 27, Section 21110, a landfill operator is to begin implementation of a closure plan within 30 days of the last receipt of refuse. Therefore, the implementation of a closure plan for the Landfill is required as soon as possible. The Superior Court issued a writ of mandate on October 8, 1996, directing the County of San Diego ("County") to develop a Landscape Program that complies with mitigation monitoring required by the City of San Marcos ("City") when it approved the use permit for expansion of the Landfill. Subsequent litigation and post-litigation issues between the County and the City conceming the details of the revegetation plan which delayed moving San Marcos Landfill Closure and 2-20 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects ^ forward with closure have recentiy been resolved, permitting the closure plan to move forward, p Under tiie CCR Titie 27 provisions [as overseen by the Regional Water Quality Control Board ^ ("RWQCB")] and tiie Superior Court writ of mandate, the County is legally required to P permanentiy close and revegetate the Landfill. P Ifthe closure of the Landfill and revegetation are not perfonned, the County could be subject to p. civil fines or contempt of court proceedings. Therefore, for legal and financial reasons, transport ii of the cover soil (that generates the significant impact) is necessary to properly close and wm maintain the Landfill. m For all of the above reasons, the project is being proposed notwitiistanding the impacts identified P P in Chapter 2.0 and Chapter 3.0 of tiiis EIR. San Marcos Landfill Closure and 2-21 Post-Closure Maintenance Plans EIR 1-15/SR 78 ROUTES* mmm Truck Route 1 -o-o-o- Truck Route 2 -o-o-o- Truck Route 3 1-5 ROUTES* -•H- Truck Route 4 -OOO- Truck Route 5 Truck Route 6 Notes a: Truck Routes 2,4,5 and 6 will utilize Rancho Sania Fe Road from Olivenhain Road to San Elijo Road b: Alt Tnjclc Routes except Route 3, utilize San Elijo Road from Rancho Santa Fe Road to the Landfrll. ' Individual routes are detailed in Figures 2.1-2 through 2.1-7 Interstate/Freeway No Scale Overview of Truck Routes Figure 2.1-1 m mm ii ii ii mm ii ii ii ii ; SAN MARCOS UiJ^DFILL LEGEND - Truck Route Source: Linscott Law and Greenspan, 2002 m P 4 • No Scale Truck Route 1 P&D Environmental Services Figure 2.1-2 SAN MARCOS LANDFILL LEGEND - Truck Route Source: Linscott, Law and Greenspan, 2002 4w No Scale Truck Route 2 0 &F&D Environinental Services Figure 2.1-3 p mm mm mm mm mm mm mm it ii vi ti mm m t m % ii ri rt ri ii AUTO PARK WAY N. -. SAN MARCOS LANDHU. LEGEND - Truck Route Source: Linscott, Law and Greenspan, 2002 No Scale Truck Route 3 I^P&D Environmental Services Figure 2.1-4 SAN MARCOS LANDniL LEGEND -Truck Route Source: Linscott, Law and Greenspan. 2002 4W No Scale Truck Route 4 0 &P&D Environmental Services Figure 2.1-5 p p ^•Hl^ SAN MARCOS lANDfTLL LEGEND - Truck Route Source: Unscott, Law and Greenspan, 2002 4P NO Scale Truck Route 5 0 P&D Environmental Services Figure 2.1-6 LEGEND SAN MARCOS LANDFOl - Truck Route m Source: Linscott, Law and Greenspan, 2002 nw No Scale Truck Route 6 p p p p 0 &P&D Environmental Services Figure 2.1-7 Draft EIR - April 2002 Significant Environmental Effects Table 2.1-1 Existing Daily Traffic Volumes Street Segment Year 24-Hour Volume (ADT) Route 1 Rancho Santa Fe Road Descanso Boulevard to Grand Avenue 2000 39,400 La Mirada Drive to Linda Vista Drive 2000 33,600 Security Place to San Marcos Boulevard 2000 25,300 San Marcos Boulevard to Lake San Marcos Drive 2000 30,900 Lake San Marcos Drive to Melrose Drive 2000 27,500 Melrose Drive to San Elijo Road 2000 28,800 Route 2 El Camino Real Plaza Drive to Marron Road 2000 34,556 Faraday Avenue to Palomar Airport Road 2000 32,590 Palomar Airport Road to Alga Road 2000 27,645 Alga Road to La Costa Avenue 2000 37,201 Levante Street to Calle Barcelona 2000 30,373 Rancho Santa Fe Road Olivenhain Road to Avenida La Posta/Calle Acervo 2000 15,600 Calle Barcelona to La Costa Avenue 2000 25,800 Tmck Bypass to San Elijo Road 2000 26,214 Route 3 Auto Park Way Ninth Avenue to Valley Parkway 1995 9,300 Harmony Grove Road Kauana Loa Drive to Elfin Forest Road 1995 2,200 Elfin Forest Road Harmony Grove to Questhaven Road 1998 2,200 Route 4 Palomar Airport Road Paseo Del Norte to Armada Drive 2000 54,941 Yarrow Drive to El Camino Real 2000 31,070 El Camino Real Palomar Airport Road to Alga Road 2000 27,645 Alga Road to La Costa Avenue 2000 37,201 Levante Street to Calle Barcelona 2000 30,373 Rancho Santa Fe Road Olivenhain Road to Avenida La Posta/Calle Acervo 2000 15,600 Calle Barcelona to La Costa Avenue 2000 25,800 Tmck bypass to San Elijo Road 2000 26,214 San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-29 Draft EIR-April 2002 Significant Environmental Effects Table 2.1-1 (Continued) Street Segment Year 24-Hour Volume (ADT) MU Ml Route 5 La Costa Avenue m Piraeus Street to Saxony Road 2000 29,388 El Camino Real Levante Street to Calle Barcelona 2000 30,373 «• Rancho Santa Fe Road Olivenhain Road to Avenida La Posta/Calle Acervo 2000 15,600 Calle Barcelona to La Costa Avenue 2000 25,800 Ml Truck bypass to San Elijo Road 2000 26,214 Route 6 Encinitas Boulevard 1-5 to Saxony Road 2000 35,100 Balour Drive to El Camino Real 2000 26,200 El Camino Real Encinitas Boulevard to Mountain Vista Drive 2000 39,600 Garden View Road to Olivenhain Road 2000 38,300 Rancho Santa Fe Road MH Olivenhain Road to Avenida La Posta/Calle Acervo 2000 15,600 Calle Barcelona to La Costa Avenue 2000 25,800 wm Truck bypass to San Elijo Road 2000 26,214 wm Source: Jurisdiction count records. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-30 P P Draft EIR - April 2002 Significant Environmental Effects Table 2.1-2. Route 1 Intersection and Segment Operations (a) Route 1 Signalized Intersection Operations Intersection^'^ Peak Hour Existing Conditions Existing Conditions with 400 Trucks Significant Impact?^^^ Intersection^'^ Peak Hour Delay (Seconds) LOS<^> Delay (Seconds) LOS*^^ Significant Impact?^^^ 1. Rancho Santa Fe Road/ SR 78 WB Ramps A.M. 53.8 D 59.3 E Yes 1. Rancho Santa Fe Road/ SR 78 WB Ramps P.M. 108.1 F 114.1 F Yes 2. Rancho Santa Fe Road/ SR 78 EB Ramps A.M. 98.5 F 137.6 F Yes 2. Rancho Santa Fe Road/ SR 78 EB Ramps P.M. 86.3 F 118.2 F Yes 3. Rancho Santa Fe Road/ San Marcos Boulevard A.M. 64.0 E 68.4 E Yes 3. Rancho Santa Fe Road/ San Marcos Boulevard P.M. >150.0 F >150.0 F Yes 4. Rancho Santa Fe Road/ Melrose Drive A.M. 41.0 D 43.8 D Yes 4. Rancho Santa Fe Road/ Melrose Drive P.M. 29.9 C 30.3 C No 5. Rancho Santa Fe Road/ A.M. 26.3 C 34.8 C No San Elijo Road P.M. 34.2 C 62.1 E Yes Notes: Intersections 1-3 are in the City of San Marcos jurisdiction. Intersections 4 and 5 are in the City of Carlsbad jurisdiction. Delay/LOS thresholds are as follows: Delay in Seconds LOS <10.0 A I0.1to20.0 B 20.1 to 35.0 C 35.1 to 55.0 D 55.1 to 80.0 E >80.1 F (3) Significance is defined in Section 2.1.2. San Marcos Landfill Closure and Post-Closiu-e Maintenance Plans EIR 2-31 Draft EIR- April 2002 Significant Environmental Effects (b) Route 1 Daily Roadway Segment Operations Street Segment Existing Conditions Existing Conditions with 400 Trucks Significant Impact?^'* mr m m Volume LOS Volume LOS Rancho Santa Fe Road Descanso Boulevard to Grand Avenue 39,400 E 41,000 F Yes mm La Mirada Drive to Linda Vista Drive 33,600 D 35^00 E Yes Security Place to San Marcos Boulevard 25,300 C 26,900 C No San Marcos Boulevard to Lake San Marcos Drive 30,900 D 32,500 D Yes Lake San Marcos Drive to Melrose Drive 27,500 F 29,100 F Yes Melrose Drive to San Elijo Road 28,800 F 30,400 F Yes Note: (I) Significance is defined in Section 2.L2. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-32 P P « P Draft EIR-April 2002 Significant Environmental Effects Table 2.1-3. Route 2 Intersection and Segment Operations (a) Route 2 Signalized Intersection Operations Intersection'*' Peak Hour Existing Conditions Existing Conditions with 400 Tmcks Significant Impact?*^' Intersection'*' Peak Hour Delay (Seconds) LOSf^^ Delay (Seconds) LOS'^' Significant Impact?*^' 1. El Camino Real/ SR 78 WB Ramps A.M. 43.4 D 49.0 D Yes 1. El Camino Real/ SR 78 WB Ramps P.M. 39.7 D 41.9 D Yes 2. El Camino Real/ SR 78 EB Ramps AM. 17.9 B 18.6 B No 2. El Camino Real/ SR 78 EB Ramps P.M. 42.3 D 51.1 D Yes 3. El Camino Real/ College Boulevard A.M. 10.3 B 11.0 B No 3. El Camino Real/ College Boulevard P.M. 25.8 C 26.3 C No 4. EI Camino Real/ Palomar Airport Road A.M. 68.6 E 73.1 E Yes 4. EI Camino Real/ Palomar Airport Road P.M. 62.3 E 64.6 E Yes 5. El Camino Real/ La Costa Avenue A.M. 27.2 C 29.1 C No 5. El Camino Real/ La Costa Avenue P.M. 30.0 C 31.7 C No 6. El Camino Real/ Olivenhain Road AM. 43.4 D 44.5 D Yes 6. El Camino Real/ Olivenhain Road P.M. 60.7 E 77.7 E Yes 7. Rancho Santa Fe Road/ La Costa Avenue A.M. 28.0 C 28.3 C No 7. Rancho Santa Fe Road/ La Costa Avenue P.M. 29.4 C 30.1 C No 8. Rancho Santa Fe Road/ San Elijo Road A.M. 26.3 C 34.6 C No 8. Rancho Santa Fe Road/ San Elijo Road P.M. 34.2 C 51.1 D Yes Notes: Intersections 1 and 2 are in the City of Oceanside jurisdiction. Intersections 3-5 and 7-8 are in the City of Carlsbad jurisdiction. Intersection 6 is in the City of Encinitas jurisdiction. (2) Delay/LOS thresholds are as follows: Delay in Seconds LOS <10.0 A 10.1 to 20.0 B 20.1 to 35.0 C 35.1 to 55.0 D 55.1 to 80.0 E >80.1 F (3) Significance is defined in Section 2.1.2. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-33 Draft EIR - April 2002 Significant Environmental Effects (b) Route 2 Daily Roadway Segment Operations Street Segment Existing Conditions Existing Conditions with 400 Trucks Significant Impact?*'' Street Segment Volume LOS Volume 1 LOS Significant Impact?*'' El Camino Real Plaza Drive to Marron Road 34,556 C 36,156 C No Faraday Avenue to Palomar Airport Road 32,590 C 34,190 C No Palomar Airport Road to Alga Road 27,645 B 29,245 B No Alga Road to La Costa Avenue 37,201 C 38,801 C No Levante Street to Calle Barcelona 30,373 C 31,973 C No Rancho Santa Fe Road Olivenhain Road to Avenida La Posta/Calle Acervo 15,600 B 17,200 B No Calle Barcelona to La Costa Avenue 25,800 F 27,400 F Yes Truck Bypass to San Elijo Road 26,214 F 27,814 F Yes Note: Significance is defined in Section 2.1.2. P Ml P P San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-34 m m m Draft EIR - April 2002 Significant Environmental Effects Table 2.1-4. Route 3 Intersection and Segment Operations (a) Route 3 Signalized Intersection Operations P Intersection*" Peak Hour Existing Conditions Existing Conditions with 400 Trucks Significant Impact?*^' Intersection*" Peak Hour Delay (Seconds) LOS*'' Delay (Seconds) LOS*" Significant Impact?*^' 1. Ninth Avenue/ 1-15 SB Ramps A.M. 7.0 A 9.0 A No 1. Ninth Avenue/ 1-15 SB Ramps P.M. 15.6 B 19.8 B No 2. Ninth Avenue/ 1-15 NB Ramps A.M. 15.8 B 18.1 B No 2. Ninth Avenue/ 1-15 NB Ramps P.M. 15.9 B 17.8 B No 3. Valley Parkway/ Auto Park Way AM. 38.4 D 40.7 D Yes 3. Valley Parkway/ Auto Park Way P.M. 34.5 C 35.3 D Yes 4. Harmony Grove/ Questhaven Road*'*' A.M. 10.2*^' B 11.4*^' B No 4. Harmony Grove/ Questhaven Road*'*' P.M. 11.5*^' B 14.1*^' B No Notes: *'' Intersections 1-3 are m the City of Escondido jurisdiction. Intersection 4 is in the County of San Diego jurisdiction. *^' Delay/LOS thresholds for signalized intersections are as follows: Delay in Seconds LOS <I0.0 A 10.1 to 20.0 B 20.1 to 35.0 C 35.1 to 55.0 D 55.1 to 80.0 E >80.1 F Significance is defined in Section 2.1.2. Unsignalized intersection. Delay/LOS thresholds for unsignalized intersections are as follows: Delay in Seconds LOS <10.0 A 10.1 to 15.0 B 15.1 to 25.0 C 25.1 to 35.0 D 35.1 to 50.0 E >50.1 F San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-35 Draft EIR - April 2002 Significant Environmental Effects (b) Route 3 Daily Roadway Segment Operations Street Segment Existing Conditions Existing Conditions with 400 Trucks Significant Impact?*" Volume LOS Volume LOS \ Auto Park Way Ninth Avenue to Valley Parkway 9,300 C 10,900 D Yes Auto Park Way North (One-Way) Andreasen Drive to Howard Avenue 12,300 D 13,900 D Yes Harmony Grove Road Elfin Forest Road to Kauana Loa Drive 2,200 A 3,800 B No Elfin Forest Road Harmony Grove Road to Questhaven Road 2,200 B 3,800 B No Note: (1) Significance is defined in Section 2.1.2. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-36 Draft EIR - April 2002 Significant Environmental Effects Table 2.1-5. Route 4 Intersection and Segment Operations (a) Route 4 Signalized Intersection Operations p P Intersection*" Peak Hour Existing Conditions Existing Conditions with 400 Tmcks Significant Impact?*^' Intersection*" Peak Hour Delay (Seconds) LOS*" Delay (Seconds) LOS*" Significant Impact?*^' 1. Palomar Airport Road/ 1-5 SB Ramps A.M. 15.2 B 15.5 B No 1. Palomar Airport Road/ 1-5 SB Ramps P.M. 14.3 B 15.4 B No 2. Palomar Airport Road/ 1-5 NB Ramps A.M. 33.1 C 34.8 C No 2. Palomar Airport Road/ 1-5 NB Ramps P.M. 33.1 C 34.6 C No 3. Palomar Airport Road/ College Boulevard A.M. 18.9 B 19.1 B No 3. Palomar Airport Road/ College Boulevard P.M. 32.6 C 34.2 C No 4. Palomar Airport Road/ El Camino Real A.M. 68.6 E 70.7 E Yes 4. Palomar Airport Road/ El Camino Real P.M. 62.3 E 65.3 E Yes 5. El Camino Real/ La Costa Avenue A.M. 27.2 C 29.1 C No 5. El Camino Real/ La Costa Avenue P.M. 30.0 C 31.7 C No 6. El Camino Real/ Olivenhain Road AM. 43.4 D 44.5 D Yes 6. El Camino Real/ Olivenhain Road P.M. 60.7 E 77.7 E Yes 7. Rancho Santa Fe Road/ La Costa Avenue AM. 28.0 C 28.3 C No 7. Rancho Santa Fe Road/ La Costa Avenue P.M. 29.4 C 30.1 C No 8. Rancho Santa Fe Road/ San Elijo Road AM. 26.3 C 34.6 c No 8. Rancho Santa Fe Road/ San Elijo Road P.M. 34.2 C 51.1 D Yes Notes: (1) (2) (3) Intersections 1-5 and 7-8 are in the City of Carlsbad jurisdiction. Intersection 6 is in the City of Encinitas jurisdiction. Delay/LOS thresholds are as follows: Delay in Seconds LOS <10.0 A 10.1 to 20.0 B 20.1 to 35.0 C 35.1 to 55.0 D 55.1 to 80.0 E >80.1 F Significance is defined in Section 2.1.2. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-37 Draft EIR - April 2002 Significant Environmental Effects (b) Route 4 Daily Roadway Segment Operations Street Segment Existing Conditions Existing Conditions with 400 Trucks Significant Impact?*" Street Segment Volume LOS Volume LOS Significant Impact?*" Palomar Airport Road Paseo Del Norte to Armada Drive 54,941 E 56,541 E Yes Yarrow Drive to El Camino Real 31,070 C 32,670 C No El Camino Real Palomar Airport Road to Alga Road 27,645 B 29,245 B No Alga Road to La Costa Avenue 37,201 C 38,801 C No Levante Street to Calle Barcelona 30,373 C 31,973 C No Rancho Santa Fe Road Olivenhain Road to Avenida La Posta/Calle Acervo 15,600 B 17,200 B No Calle Barcelona to La Costa Avenue 25,800 F 27,400 F Yes Truck Bypass to San Elijo Road 26,214 F 27,814 F Yes Note: *" Significance is defmed in Section 2.1.2. P II San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-38 P P m Draft EIR-April 2002 Significant Environmental Effects Table 2.1-6. Route 5 Intersection and Segment Operations (a) Route 5 Signalized Intersection Operations Intersection*" Peak Hour Existing Conditions Existing Conditions with 400 Trucks Significant Impact?*^' Intersection*" Peak Hour Delay (Seconds) LOS*" Delay (Seconds) LOS*" Significant Impact?*^' I. La Costa Avenue/ 1-5 SB Ramps A.M. 26.8 C 27.0 C No I. La Costa Avenue/ 1-5 SB Ramps P.M. 25.8 c 26.9 C No 2. La Costa Avenue/ 1-5 NB Ramps A.M. 21.9 c 22.5 C No 2. La Costa Avenue/ 1-5 NB Ramps P.M. 23.4 c 25.8 C No 3. La Costa Avenue/ EI Camino Real A.M. 27.2 c 28.2 C No 3. La Costa Avenue/ EI Camino Real P.M. 30.0 c 33.4 C No 4. El Camino Real/ Olivenhain Road A.M. 43.4 D 44.5 D Yes 4. El Camino Real/ Olivenhain Road P.M. 60.7 E 77.7 E Yes 5. Rancho Santa Fe Road/ La Costa Avenue A.M. 28.0 C 28.3 C No 5. Rancho Santa Fe Road/ La Costa Avenue P.M. 29.4 C 30.1 C No 6. Rancho Santa Fe Road/ San Elijo Road AM. 26.3 C 34.6 c No 6. Rancho Santa Fe Road/ San Elijo Road P.M. 34.2 C 51.1 D Yes Notes: Intersections 1-3 and 5-6 are in the City of Carlsbad jurisdiction. Intersection 4 is in the City of Encinitas jurisdiction. Delay/LOS thresholds are as follows: Delay in Seconds <10.0 10.1 to 20.0 20.1 to 35.0 35.1 to 55.0 55.1 to 80.0 >80.1 LOS A B C D E F (3) Significance is defined in Section 2.1.2. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-39 Draft EIR-April 2002 Significant Environmental Effects (b) Route 5 Daily Roadway Segment Operations Street Segment Existing Conditions Existing Conditions with 400 Trucks Significant Impact?*" Volume LOS Volume LOS La Costa Avenue \ Piraeus Street to Saxony Road 29,388 D 30,988 D Yes El Camino Real Levante Street to Calle Barcelona 30,373 D 31,973 D Yes Rancho Santa Fe Road Olivenhain Road to Avenida La Posta/Calle Acervo 15,600 B 17,200 B No Calle Barcelona to La Costa Avenue 25,800 F 27,400 F Yes Truck Bypass to San Elijo Road 26,214 F 27,814 F Yes Note: *" Significance is defined in Section 2.1.2. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-40 Draft EIR-April 2002 Significant Environmental Effects Table 2.1-7. Route 6 Intersection and Segment Operations (a) Route 6 Signalized Intersection Operations Intersection*" Peak Hour Existing Conditions Existing Conditions with 400 Tmcks Significant Impact?*" Intersection*" Peak Hour Delay (Seconds) LOS<" Delay (Seconds) LOS*" Significant Impact?*" 1. Encinitas Boulevard/ 1-5 SB Ramps AM. 31.2 C 34.8 C No 1. Encinitas Boulevard/ 1-5 SB Ramps P.M. 32.7 C 37.9 D Yes 2. Encinitas Boulevard/ 1-5 NB Ramps AM. 20.3 C 24.0 C No 2. Encinitas Boulevard/ 1-5 NB Ramps P-M. 31.0 C 42.2 D Yes 3. Encinitas Boulevard/ Balour Drive AM. 21.2 c 23.0 C No 3. Encinitas Boulevard/ Balour Drive P.M. 25.3 c 29.3 C No 4. Encinitas Boulevard/ El Camino Real A.M. 60.7 E 65.1 E Yes 4. Encinitas Boulevard/ El Camino Real P.M. 63.2 E 76.2 E Yes 5. El Camino Real/ Garden View Road A.M. 27.8 c 28.6 C No 5. El Camino Real/ Garden View Road P.M. 43.8 D 46.4 D Yes 6. El Camino Real/ Olivenhain Road AM. 43.4 D 45.2 D Yes 6. El Camino Real/ Olivenhain Road P.M. 60.7 E 72.9 E Yes 7. Rancho Santa Fe Road/ La Costa Avenue A.M. 28.0 C 28.3 C No 7. Rancho Santa Fe Road/ La Costa Avenue P.M. 29.4 C 30.1 C No 8. Rancho Santa Fe Road/ San Elijo Road A.M. 26.3 c 34.6 C No 8. Rancho Santa Fe Road/ San Elijo Road P.M. 34.2 c 5L1 D Yes Notes: (2) Intersections 1 -6 are in the City of Encinitas jurisdiction. Intersections 7 and 8 are in the City of Carlsbad jurisdiction. Delay/LOS thresholds are as follows: Delay in Seconds LOS <10.0 A 10.1 to 20.0 B 20.1 to 35.0 C 35.1 to 55.0 D 55.1 to 80.0 E >80.1 F (3) Significance is defined ui Section 2.1.2. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-41 Draft EIR- April 2002 Significant Environmental Effects (b) Route 6 Daily Roadway Segment Operations Street Segment Existing Conditions Existing Conditions with 400 Trucks Significant Impact?*" I Street Segment Volume LOS Volume LOS Significant Impact?*" I Encinitas Boulevard^ ' 1-5 to Saxony Road 35,100 E 36,700 F Yes Balour Drive to El Camino Real 26,200 C 27,800 c No El Camino Real'^'^ Encinitas Boulevard to Mountain Vista Drive 39,600 c 41,200 c No Garden View Road to Olivenhain Road 38,300 c 39,900 c No Rancho Santa Fe Road^ ' Olivenhain Road to Avenida La Posta/Calle Acervo 15,600 B 17,200 B No Calle Barcelona to La Costa Avenue 25,800 F 27,400 F Yes 1 Truck Bypass to San Elijo Road 26,214 F 27,814 F Yes Note: *" Significance is defined in Section 2.1.2. *^^ City of Encinitas jurisdiction. *^* City of Carlsbad jurisdiction. P P San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-42 P P Draft EIR-April 2002 Significant Environmental Effects Table 2.1-8 Peak Hour Freeway Segment Summary ip m li p Ml Street Segment One- Direction Capacity*" Existing Conditions Existing Conditions with 400 Trucks Significant Impact?*" One- Direction Capacity*" Volume LOS Volume LOS Significant Impact?*" Interstate Highway 15 Between Valley Parkway and Ninth Avenue 8,000 8,040 F 8,140 F Yes Interstate Highway 5 Between Santa Fe Drive and Encinitas Boulevard 8,000 8,700 F 8,800 F Yes Between Palomar Airport Road and Cannon Road 8,000 8,400 F 8,500 F Yes State Route 78 Between El Camino Real and College Boulevard 7,200 6,600 D 6,700 E Yes Between Rancho Santa Fe Road and San Marcos Boulevard 6,000 5,640 E 5,740 E Yes Note: *'' Capacity based on 2,000 vehicles per hour per main lane, 1,200 vehicles per hour per auxiliary lane. *^' Significance is defined in Section 2.1.2. Soiu"ce: Existing Traffic Volumes - CALTRANS Traffic Volumes Book for State Highways, 1999. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-43 Draft EIR-April 2002 Significant Environmental Effects Table 2.1-9 Summary of Transportation/Circulation Impacts Impact Number Intersection or Roadway Segment*" Existing LOS LOS With Project Truck Route 2.1.3.a Rancho Santa Fe Road/SR 78 WB Ramps, AM peak hours (I) D — •* E 2.1.3.b Rancho Santa Fe Road/SR 78 EB Ramps, AM and PM peak hours (I) F F 2.1.3.C Rancho Santa Fe Road/San Marcos Boulevard, AM and PM peak hours (I) E&F E&F 2.i.3.d Rancho Santa Fe Road/Melrose Drive, AM peak hours (I) D D I 2.1.3.e Rancho Santa Fe Road/San Elijo Road, PM peak hours (I) C D&E 1,2,4,5,6 2.l.3.f Rancho Santa Fe Road - Descanso Boulevard to Grand Avenue(R) E F 2.1.3.g Rancho Santa Fe Road - La Mirada Drive to Linda Vista Drive (R) D E 2.l.3.h Rancho Santa Fe Road - San Marcos Boulevard to Lake San Marcos Drive (R) D D 2.1.3.i Rancho Santa Fe Road - Lake San Marcos Drive to Mehose Drive (R) F F 2.1.3.j Rancho Santa Fe Road - Melrose Drive to San Elijo Road (R) F F 2.1.3.k El Camino Real/SR 78 WB Ramps, AM and PM peak hours (I) D D 2 2.1.3.1 EI Camino Real/SR 78 EB Ramps, PM peak hours (I) D D 2 2.1.3 .m Palomar Airport Road/El Camino Real, AM and PM peak hours (I) E E 2,4 2.1.3.n El Camino Real/Olivenhain Road, AM and PM peak hours (I) D&E D&E 2,4,5,6 2.1.3.0 Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue(R) F F 2,4,5 2.1.3.P Rancho Santa Fe Road - Truck Bypass to San Elijo Road (R) F F 2,4,5 2.1.3.q Valley Parkway/Auto Park Way, AM and PM peak hours (I) D&C D 3 2.1.3.r Auto Park Way - Ninth Avenue to Valley Parkway fR) C D 3 2.1.3.S Auto Park Way North (one-way) - Andreasen Drive to Howard Avenue (R) D D 3 2.1.3.t Palomar Airport Road - Paseo Del Norte to Armada Drive (R) E E 4 2.1.3.U La Costa Avenue - Piraeus Street to Saxony Road (R) D D 5 2.1.3.V El Camino Real - Levante Street to Calle Barcelona (R) D D 5 2.1.3.W Encinitas Boulevard/I-5 SB Ramps, PM peak hours (I) C D 6 2.1.3.x Encinitas Boulevard/1-5 NB Ramps, PM peak hours (I) C D 6 2.1.3.y Encinitas Boulevard/El Camino Real, AM and PM peak hours (I) E E 6 2.1.3.Z El Camino Real/Garden View Road, PM peak hours (I) D D 6 San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-44 P P Draft EIR - April 2002 Significant Environmental Effects Table 2.1-9 (Continued) m m Impact Number Intersection or Roadway Segment*" Existing LOS LOS With Project Truck Route 2.1.3.aa Encinitas Boulevard - Interstate Highway 5 to Saxony Road (R) E F 6 2.1.3.ab Interstate Highway 15 - Valley Parkway to Ninth Avenue (R) F F 1-3 2.1.3.ac Interstate Highway 5 - Santa Fe Drive to Encinitas Boulevard (R) F F 4-6 2.1.3.ad Interstate Highway 5 - Palomar Airport Road to Cannon Road(R) F F 4-6 2.1.3.ae State Route 78 - El Camino Real to College Boulevard (R) D E 1,2 2.1.3.af State Route 78 - Rancho Santa Fe Road to San Marcos Boulevard (R) E E 1,2 Note: (1) T = I = Intersection Impact, R = Roadway Segment Impact. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-45 Draft EIR-April 2002 Significant Environmental Effects 2.2 Air Oualitv The following analysis is based upon a technical report prepared by Giroux and Associates (2002a). The complete technical report is included as Appendix C of the EIR. 2.2.1 Existing Conditions This section introduces the regulatory framework and meteorology/climate for tiie Landfill. The regulatory framework is presented to provide tiie basis for addressing tiie consistency of tiie Proposed Project with the existing regulations that establish air quality standards. The meteorology/climate section presents tiie physical setting and pollutant levels currently in existence in the proximity of the Proposed Project. Ambient Air Quality Standards ("AAQS"). To gauge tiie significance of tiie air quality impacts of tiie implementation of tiie Proposed Project, tiiose impacts, together with existing background air quality levels, must be compared to tiie applicable ambient air quality standards. Califomia standards supplement tiie national AAQS by adding otiier pollutants or exposure periods. For those pollutants which have both state and federal standards. State standards are equally restrictive, and, in most cases, are more conservative tiian tiieir federal counterparts. State and national standards are based on the levels of pollutant exposure considered safe to protect the public health and welfare. They are designed to protect those people most susceptible to further respiratory distress such as asthmatics, the elderiy, very young children, people abready weakened by other disease or illness, and persons engaged in strenuous work or exercise, who are called "sensitive receptors." National AAQS were established in 1971 for six pollutant types. States have the option to add other pollutants, require more stringent compliance, or to include different exposure periods. Because Califomia had established state AAQS before tiie federal action and because of unique air quality problems introduced by tiie restrictive dispersion meteorology, tiiere is considerable San Marcos Landfill Closure and 2-46 Post-Closure Maintenance Plans EIR P P P P P Draft EIR - April 2002 Significant Environmental Effects difference between state and national clean air standards. Those standards currently in effect in Califomia are shown in Table 2.2-1. The entries in Table 2.2-1 include the federal standards for chronic (eight-hour) ozone exposure or for ultra-small-diameter particulate matter of two-and-a-half microns or less in diameter (called "PM2.5"). Implementation of these standards had been put on hold through an order issued by the U.S. Circuit Court of Appeals. This order was appealed to the U.S. Supreme Court, which heard the case in late 2000. In late Febmary 2001, the Supreme Court mled imanimously that U.S. Environmental Protection Agency ("EPA") did not require specific congressional approval to adopt national clean air standards, and that a cost^enefit analysis is not required for health-based standards. The Court also ruled, however, that there was an implementation schedule inconsistency between "new" and "old" standards. This schedule issue must be resolved before implementation actions can begin. Until this attainment schedule conflict is resolved, data collection for these two standards is ongoing, but no attainment planning or enforcement is occurring at this time. Air Quality Management Planning. The San Diego Air Basin ("SDAB") is presently in attainment of all national and state AAQS, except ozone and particulate matter less than or equal to 10 microns (PMio). Due to violations of the state AAQS for ozone in the SDAB, state law requires that a plan be developed to outline the pollution controls that will be undertaken to improve air quality. In San Diego County, this attainment planning process is embodied in a regional air quality management plan developed by the San Diego Air Pollution Control District ("APCD"). Several plans had been adopted in tiie late 1970s and early 1980s under the title Regional Air Quality Strategies ("RAQS"). More recent planning efforts have been modifications, improvements, and updates of the earlier RAQS efforts. Specifically, a plan to attain the state standard for ozone as qinckly as possible was developed in 1994 through an update of the 1991 RAQS. A Triennial Revision updating the RAQS was adopted by the SDAPCD governing board on August 8, 2001. Federally enforceable local mles are combined with those from all other Califomia ozone non-attainment areas to create the San Marcos Landfill Closure and 2-47 Post-Closure Maintenance Plans EIR P Draft EIR-April 2002 Significant Environmental Effects California State Implementation Plan ("SIP"), which is acmally tiie federal attainment plan. The SIP is adopted by tiie Air Resources Board ("ARB") after public hearings , and forwarded to the EPA for its approval. The SIP includes all control measures needed for tiie Califomia air basins to attain tiie national AAQS for ozone by respective attainment deadlines. During the planning process and smog formation modeling, it was anticipated that the SDAB could meet tiie federal ozone standard by tiie year 1999 without the creation of any new control programs not already in progress. Airsheds demonstrating an ability to meet standards by the end of 1999 (in tiie absence of transport from one basin to another) may be classified as having a "serious" ozone problem instead of being classified as "severe". The APCD requested tiiat the EPA reclassify the air basin from "severe" to "serious". This request was subsequently approved. All progress towards attainment, including offsetting the effects of growtii, is expected to be derived from existing local, state, and federal mles and regulations. Witii tiie continuation of year-to-year vehicular exhaust pollution reduction and witii continued implementation of stationary source mles, small additional fiiture emissions reductions are anticipated despite forecast increased basinwide population growtii. Any violations of federal ozone standards in the year 2000 or beyond are forecast to occur only on days when air transport from the Los Angeles Basin creates substantially elevated baseline levels upon which any local basin impacts would be superimposed. Transport of smog precursor emissions from Mexico into San Diego County has been expressed as a concern, but wind conditions on days with high smog potential usually do not lead to substantial cross-border transport into San Diego County. With continued emissions reduction, and with moderately favorable meteorology, the SDAB met tiie federal ozone standard for tiie first time in history in 1999 at every air monitoring station. A continued history of attainment is necessary for redesignation as an "attainment area" (no more tiian three violations in a tiiree-year data record). The South Coast Air Quality Maintenance District ("SCAQMD") has received two one-year extensions of its ozone attainment deadlines from the EPA, and the SDAB reached attainment of the federal ozone standard at the end of San Marcos Landfill Closure and 2-48 Post-Closure Maintenance Plans EIR m p Draft EIR - April 2002 Signifu^ant Environmental Effects 2001. The EPA is finaHzing the redesignation of the SDAB to be in attainment for ozone. The official status of attainment will occur in early 2002. The SDAB will still be in non-attainment for tiie state AAQS for ozone. However, it is clear that air quality in the SDAB has improved dramatically in the last two to three decades, and both the severity and frequency of unhealthful air quality has declined significantiy. Meteorology/Climate. The climate of the Proposed Project area is characterized by a repetitive pattern of frequent early moming cloudiness, hazy afternoon sunshine, and clean daytime onshore breezes. Because of the distance to the ocean and intervening terrain, San Marcos has slightiy greater fluctuations of temperature than locations closer to tiie ocean. Limited rainfall occurs in winter, while summers are often completely dry. An average of 10 inches of rain falls each year from November to early April. Atmospheric conditions create a desirable living climate, but limit the ability of the atmosphere to disperse air pollution. Many air quality standards have reached attainment status only in the last decade. The onshore winds across the coastline diminish quickly when they reach the foothill communities of San Diego County, and the sinking air within the offshore high pressure system forms a massive temperature inversion that traps all air pollutants near the ground. The resulting horizontal and vertical stagnation, in conjunction with ample sunshine, cause a number of reactive pollutants to undergo photochemical reactions and form smog that degrades visibility and irritates tear ducts and nasal membranes. High smog levels m coastal communities occasionally occur when polluted air from the South Coast (Los Angeles) Air Basin drifts seaward and southward at night, and then blows onshore the next day. Such weather patterns are particularly firustrating because no matter what San Diego County does to achieve clean air, such interbasin transport will cause occasionally unhealthy air over much of the County. The Proposed Project area air quality can be best characterized from ambient measurements made by the APCD, the agency responsible for air quality planning, monitoring, and enforcement in the SDAB. The APCD air quality monitoring station located in Escondido is the closest station to the project area that monitors the fiill spectrum of air quality. Table 2.2-2 San Marcos Landfill Closure and 2-49 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects summarizes tiie last five years of monitoring data from the Escondido station. Healthful air quality is seen in almost every pollution category. The one-hour national ozone standard has not been exceeded witiiin tiie last five years. The new national eight-hour ozone standard was met for the first time in 1999. The more stringent State standards for ozone and tiie State standard for respirable particulates (PMio) were exceeded on a limited number of days. Ozone, and to some extent particulates, are pollutants whose precursors are generated elsewhere and then carried into tiie local area by prevailing wind patterns. Levels of carbon monoxide or nitrogen oxides, which are more indicative of local source/receptor relationships, are seen in Table 2.2-2 to be very low in the Proposed Project area. 2.2.2 Thresholds of Significance Appendix G of the CEQA Giudelines specifies five evaluation criteria listed below in identifying potentially significant impacts. Where available, the significance criteria established by the applicable air quality management or air pollution control district may be relied upon to determine if the project would: a. Conflict with or obstmct implementation of the applicable air quality plan, b. Violate any air quality standard or contribute substantially to an existing or projected air quality violation, c. Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is in non-attainment under an applicable federal or state ambient air quality standard (including releasmg emissions that exceed quantitative thresholds for ozone precursors), d. Expose sensitive receptors to substantial pollutant concentrations, or e. Create objectionable odors affecting a substantial number of people. San Marcos Landfill Closure and 2-50 Post-Closure Maintenance Plans EIR P P P P P P P P Draft EIR-April 2002 Significant Environmental Effects 2.2.3 Analysis of Project Effects and Determination of Significance The air quality analysis includes activities associated with the constmction of the cover system and post-closure maintenance. Therefore, air quality emissions from constmction equipment, P travel, and fugitive dust have been quantified. The landfill gas ("LFG") collection and recovery IP system will continue to operate. Because the LFG collection and recovery system is an existing P condition and will continue operation in accordance with an existing APCD permit, there will be no change in air quality emissions from this source. Additionally, since the LFG collection and recovery system is operating under an approved permit, any emissions wotild not conflict with an approved regional air quality plan. There are no changed conditions requiring any fiirther analysis. m p P P m m The following analysis will address each of the significance thresholds individually. As related to whether the Proposed Project will obstmct implementation of the applicable air P quality plan, the SDAB air quality plan does not include any provisions for constmction activities such as those associated with the Proposed Project. The air quality plan does include P all mles and regulations of the APCD. The Proposed Project will comply with any applicable rules on dust control and use of low-sulfur fuels. The on-site power generation plant and flare system using LFG are APCD-permitted sources. Because the Proposed Project complies with all existing rules and has permitted all applicable facilities, project impacts relative to au: quality plan consistency are therefore less than significant. The second threshold addresses whether a project will violate any air quality standards or contribute substantially to an existing or projected air quality violation. The APCD is the "applicable air quality management or air pollution control district" for the Proposed Project under CEQA. The APCD has not adopted significance thresholds for project-related sources of air pollution. Consequentiy, there are no quantitative emissions-based sigiuficance thresholds to be applied to an indirect source of emissions, such as project constmction activities ui San Marcos Landfill Closure and 2-51 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects implementing the final closure plan. In tiie absence of any local air quality agency guidelines on what constitutes a "cumulatively considerable net increase" of emissions associated with a consUiiction project, criteria from tiie SCAQMD have been used as a guide. For those pollutants whose impact can not be directly determined, i.e., tiiose tiiat require additional transformation after leaving their source, tiie following project-related emission levels are considered a "cumulatively considerable net increase in criteria pollutants": Reactive Organic Gases ("ROG") 55 lb/day Nitrogen Oxides 250 lb/day Particulate Matter 100 lb/day Sulfur Oxides 250 lb/day Carbon Monoxide ("CO") 550 lb/day For projects that create mainly combustion exhaust whose emissions require complex photochemical reactions to reach tiieir most harmful state, there is no way to measure the impact to establish a "substantial contribution" under the threshold, because individual impacts will be dispersed to immeasurably dilute levels. It is the cumulative impact, however, of thousands of such small individual soiu-ces that leads to regionally degraded air quality. Various air pollution control/management agencies have therefore developed guidelines using total project emissions instead of ambient air quality as a surrogate for determining regional unpact potential. Section 40002 of the Califomia Health & Safety Code delegates jurisdiction for regulation of air emissions from non-mobile sources within San Diego County to the APCD. As part of their air quality permitting process, tiie APCD has established thresholds for the preparation of Air Quality Impact Assessments (AQIA). APCD Rule 20.2, which outlines tiiese tiiresholds, states that any project "which results in an emissions increase equal to or greater than any of these thresholds, must demonstrate through an AQIA ... that the project will not (A) cause a violation of a state or national ambient au* quality standard anywhere San Marcos Landfill Closure and 2-52 Post-Closure Maintenance Plans EIR P m mm Draft EIR - April 2002 Significant Environmental Effects mm ^ that does not already exceed such standard, nor (B) cause additional violations of m a national ambient air quality standard anywhere the standard is already being ^ exceeded, nor (C) cause additional violations of a state ambient air quality Mi standard anywhere the standard is already being exceeded ... nor (D) prevent or ^ interfere with the attainment or maintenance of any state or national ambient air Mi quality standard." •< For projects whose stationary-source emissions fall below these thresholds, no AQIA is typically Hi required, and emissions are presumed to be minimal. Ml m In the absence of formally adopted CEQA significance thresholds, these screening criteria have been used as numeric methods to demonstrate that a project's total emissions (e.g., stationary and m fugitive emissions, as well as emissions from non-road mobile sources) would not result m a *' significant impact to air quality. In the event that emissions exceed these thresholds, additional p modeling would be required to demonstrate that the project's air quality impacts are less than significant. Since APCD does not have AQIA tiiresholds for emissions of volatile organic P compounds (VOC), the threshold for reactive organic compotmds (ROC) from the CEQA Air P Quality Handbook for the former Southeast Desert Air Basin (SEDAB), which has ozone levels P similar to the SDAB, will be used. The screening thresholds are included in Table 2.2-3. ^ Air quality impacts may also derive from "non-criteria" (pollutants with clean air standards). ^ Such impacts could derive from emissions that have no known safe expostire level, or those that may cause a nuisance while not exceeding any relevant numerical emissions standard. * For toxic air contaminants (TAC), the SCAQMD, in its CEQA Air Quality Handbook, identifies P an excess individual cancer risk of one in one million to be a minimal risk. Risk levels of up to " ten in one million are considered acceptable if toxics best available control technology ("T-BACT") is used. Any individual cancer risk from project-related TACs of less than one in * one million would be considered a less-than-significant risk. P mm P San Marcos Landfill Closure and 2-53 wm Post-Closure Maintenance Plans EIR P m Draft EIR-April 2002 Significant Environmental Effects Most project-related air quality impacts will derive from tiie mobile sources operating on tiie Landfill and on public roads. Equipment movement on unpaved soils and earth handling activities will create fugitive dust. Small dust particles will be carried off-site, and large particles will be redeposited near tiieir source. The emissions will be widely dispersed in space and time by tiie nature of the source itself Any associated photochemical smog generated by these activities will occur hours later and many miles away. Emissions data from constmction activities are often imprecise as to both location and magnitude of emissions. It is therefore not possible to reliably calculate off-site exposure without a better knowledge of tiie exact location and character of any project-related emissions. These source characteristics change hour by hour and day by day. Project-related impact significance was tiierefore determined from tiie emissions-based thresholds for ROG, NOx, PMio, SOx, and CO, assuming that a violation of those thresholds represents an incremental, but significant, impediment to existing regional non-attainment of air quality standards for ozone and particulate matter. Project-related constmction activity emissions were calculated for a fleet of 18 pieces of consttuction equipment, for the import of up to 400 tmckloads of cover soil, for on-site excavation of cover soil, and for work crew commuting. Project-related exhaust emissions are summarized in Table 2.2-4. The corresponding PMio emissions burden is shown in Table 2.2-5. NOx exhaust emissions from on-site equipment and on-road haul tmcks will exceed the adopted significance tiireshold by approximately 50 percent. The PMio standard will be exceeded by 550 percent. The third threshold is whether a project will result in a cumulatively considerable net increase of any criteria pollutant for which tiie project region is in non-attainment. This is actually a cumulative discussion tiiat is presented in Section 3.3.3; however, air quality impacts that exceed the thresholds for an individually significant impact are considered to have a cumulatively significant impact as well. Therefore, significant cumulative impacts will occur. San Marcos Landfill Closure and 2-54 Post-Closure Maintenance Plans EIR P m p p p p p p p p Draft EIR-April 2002 Significant Environmental Effects The fourth threshold is whether the Proposed Project woitid expose sensitive receptors to substantial pollutant concentrations. Toxic air contaminants would have a "substantial" exposure risk if they were generated by site activities, and if there was a sensitive population in tiie project vicinity. Carcinogenic diesel exhaust impacts adjacent to constmction activities have been demonstrated to be less than significant (Giroux and Associates, 2000) for residents adjacent to tiie project property line with comparable diesel exhaust particulate levels. Witii greater source/ receptor separation at the project site, diesel exhaust exposure will be a mmimal public health risk. Therefore, there are no significant impacts associated with toxic air contaminants. The fiftii threshold is whether a project would create objectionable odors affecting a substantial number of people. The Proposed Project is designed to mmimize local odor risk by insuring long-term landfill cover integrity. No substantial quantities of buried refiise will be disturbed by the Proposed Project; therefore, no significant impact is identified. P In summary, based upon the air quality analysis, the emissions associated wiih the Proposed Project would cause the following significant impacts: • Impact 2.2.3.a - Project-related constmction emissions will exceed NOx thresholds. • Impact 2.2.3.b - Project-related constmction emissions will exceed PMio thresholds. 2.2.4 Mitigation Measures Reducing the number of trips by 33 percent could reduce NOx emissions to below a level of significance. However, a much larger reduction in project intensity would be needed to reduce PMio emissions to below a level of significance. The constmction schedule would need to be extended more than sixfold to reduce PMio levels to a less than significant level. Such a completion delay would not meet project objectives. Reducing the number of trips is infeasible, because the time reqmred to haul the cover soil to the Landfill also increases in a proportional manner. The reduction in number of daily trips, thereby San Marcos Landfill Closure and 2-55 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects lengtiiening tiie duration of tiie project, would create several undesirable consequences. Due to fixed overhead costs, it is a proven principle in the constmction industry that extending the duration of a constmction project will resuh in increased expense to complete the project. With a landfill closure, extending the duration of closure results in an increased time period during which the landfill is not covered by a permanent cover system. During the constmction process, the Landfill is more vulnerable to erosion of existing cover and infiltration of water into the layers of trash. Therefore, extension of the duration of installation of the permanent cover increases the possibility of undesirable environmental events, such as erosion or water infiltration. CCR Titie 27 regulations require that the permanent cover be installed wdthin 180 days of commencement of constmction. While this will not be possible, and an extension must be obtained due to tiie magnitude of the task for this Landfill, the policy of tiie Regulations is clear: the application of the permanent cover should proceed as expediently as possible once started. The design of the evapo-transpiration cover system also dictates that a slower/longer soil hauling procedure is not environmentally desirable. The potential for infiltration of water into the landfill trash is significantly slowed and prevented by the vegetative cover, which draws moisture out of tiie vegetative soils before it can infiltrate. Delaying the planting of tiie vegetative cover would also delay implementation of this key design feature. 2.2.5 Conclusions Project-related constmction emissions will exceed NOx thresholds (Table 2.2-4) and PMio thresholds (Table 2.2-5), and result in significant short-term au: quality unpacts. NOx emissions will be generated from mobile sources operatmg at the Landfill and on public roads. PMio emissions will be generated from the excavation, loading, and transport of cover soil, and soil mixing, grading, and placement at tiie Landfill. Design features, including adherence to applicable dust control measures of tiie San Diego APCD and adherence to applicable low-sulfur fuel requirements of tiie APCD, have been included in the project to reduce air emissions San Marcos Landfill Closure and 2-56 Post-Closure Maintenance Plans EIR m P Draft EIR - April 2002 Significant Environmental Effects generated to the extent feasible. However, there is no feasible mitigation to reduce the short- term air quality impacts to below a level of significance. As discussed in Section 2.2.4, reducing the number of trips by 33 percent could reduce NOx emissions to below a level of significance. However, a much larger reduction in project intensity would be needed to reduce PMio emissions. The constmction schedule would need to be extended more than sixfold to reduce PMio emissions to below a level of sigiuficance. Reducing the number of trips, and hence the duration of the project, is not considered feasible because this would result in increased expense to complete the project. Increasing the duration of final cover constmction could increase the possibility of erosion at the site or water uifiltration. There is no altemative design that reduces the impacts to below a level of significance because of the large quantities of soil required to properly close the Landfill, and the need to accomplish the closure as soon as possible. The No Project Altemative, while reducing short-term air quality impacts, could possibly create long-term risks for infiltration of water into the Landfill (see discussion in Section 4.2.1). The No Project Altemative was rejected for the reasons stated in Section 4.2.3. As noted in Section 2.1.5, the Landfill stopped receiving waste on March 11, 1997. Pursuant to CCR Title 27, Section 21110, a landfill operator is to begin implementation of a closure plan within 30 days of the last receipt of refuse. Therefore, the implementation of a closure plan for the Landfill is required as soon as possible. The Superior Court issued a writ of mandate on Octobers, 1996, directmg the County to develop a Landscape Program that complies with mitigation monitoring required by the City when it approved the use permit for expansion of the Landfill. Subsequent litigation and post-litigation issues between the Coimty and the City conceming the details of the revegetation plan which delayed moving forward with closure have recentiy been resolved, permittmg the closure plan to move forward. Under the CCR Title 27 provisions (as overseen by the RWQCB) and the Superior Court writ of mandate, the County is legally required to permanently close and revegetate the Landfill. San Marcos Landfill Closure and 2-57 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects Ifthe closure of tiie Landfill and revegetation are not performed, the County could be subject to civil fines or contempt of court proceedings. Therefore, for legal and financial reasons, transport of tiie cover soil (tiiat generates tiie significant impact) is necessary to properly close and maintain the Landfill. For all of tiie above reasons, tiie project is being proposed notwitiistanding the impacts identified in Chapter 2.0 and Chapter 3.0 of this EIR. San Marcos Landfill Closure and 2-58 Post-Closure Maintenance Plans EIR p P Draft EIR - April 2002 Significant Environmental Effects Table 2.2-1 Pollutant Averaging Time California Standards' Federal Standards^ Pollutant Averaging Time Concentration^ Method* Primary^'* Secondary^'^ Method^ Ozone (O3) 1 hour 0.09 ppm (180;zg/mY Ultraviolet Photometry 0.12 ppm (235 /.g/m')' Same as Primary Standard Ethylene Chemiluminescence Ozone (O3) 8 Hour — Ultraviolet Photometry 0.08 ppm (157 /ig/m^) Same as Primary Standard Ethylene Chemiluminescence Respirable Particulate Matter (PMio) Annual Geometric Mean 30 //g/m^ Size Selective inlet Sampler ARB Method P (8/22/85) — Same as Primary Standard Inertial Separation and Gravimetric Analysis Respirable Particulate Matter (PMio) 24-Hour 50 fig/m^ Size Selective inlet Sampler ARB Method P (8/22/85) I50Mg/m^ Same as Primary Standard Inertial Separation and Gravimetric Analysis Respirable Particulate Matter (PMio) Annual Arithmetic Mean - Size Selective inlet Sampler ARB Method P (8/22/85) 50 Mg/m^ Same as Primary Standard Inertial Separation and Gravimetric Analysis Fine Particulate Matter (PMj s) 24-Hour No separate State Standard 65 fj-g/m^ Same as Primary Standard Inertial Separation and Gravimetric Analysis Fine Particulate Matter (PMj s) Annual Arithmetic Mean No separate State Standard 15Mg/m^ Same as Primary Standard Inertial Separation and Gravimetric Analysis Carbon Monoxide (CO) 8-Hour 9.0 ppm(10mg/m^ Non-Dispersive Infrared Photometry (NDIR) 9.0 ppm(10mg/m^ None Non-Dispersive Infrared Photometry (NDIR) Carbon Monoxide (CO) 1 Hour 20 ppm (23 mg/m"*) Non-Dispersive Infrared Photometry (NDIR) 35 ppm (40 mg/m'*) None Non-Dispersive Infrared Photometry (NDIR) Carbon Monoxide (CO) 8-Hour (Lake Tahoe) 6 ppm (7 mg/m') Non-Dispersive Infrared Photometry (NDIR) - None Non-Dispersive Infrared Photometry (NDIR) Nitrogen Dioxide (NO2) Annual Arithmetic Mean -Gas Phase Chemiluminescence 0.053 ppm (50/ig/m^) Same as Primary Standard Gas Phase Chemiluminescence 1 Hour 0.025 ppm (470 Mg/m^ Gas Phase Chemiluminescence - Same as Primary Standard Gas Phase Chemiluminescence Lead 30 days average 1.5/ig/m^ AIHL Method 54 (12/74) Atomic Absorption --High Volume Sampler and Atomic Absorption Lead Calendar Quarter AIHL Method 54 (12/74) Atomic Absorption 1.5 ^g/m' Same as Primary Standard High Volume Sampler and Atomic Absorption Sulfiir Dioxide (SO2) Armual Arithmetic Mean - Fluorescence 0.030 ppm (80 Mg/m^) •• Pararosoaniline Sulfiir Dioxide (SO2) 24-Hour 0.04 ppm (105 ng/m*) Fluorescence 0.14 ppm (365 Mg/m^) — Pararosoaniline Sulfiir Dioxide (SO2) 3-Hour - Fluorescence -0.5 ppm (1300;^g/m^) Pararosoaniline Sulfiir Dioxide (SO2) 1 Horn-0.25 ppm (655 ^ig/m^) Fluorescence - Pararosoaniline Visibility Reducing Particles s-Hour (10 am to 6 pm, PST) In sufficient amount to produce an extinction coefficient of 0.23 per kilometer—visibility of 10 miles or more (0.07-30 miles or more for Lake Tahoe) due to particles when the relative humidity is less than 70%. Method: ARB Method V (8/18/89) No Federal Standards Sulfates 24-Hour Turbidimetric Barium Sulfate- AIHL Method 61 (2/76) No Federal Standards Hydrogen Sulfide 1 Hour 0.03 ppm (42 ^g/m^ Cadmium Hydroxide STRactan No Federal Standards Notes: 1. Califomia standards for ozone, carbon monoxide (except Lake Tahoe), sulfur dioxide (1 and 24 hour), nitrogen dioxide, suspended particulate matter-PMio, and visibility reducing particles, are values that are not to be exceeded. All others are not to be equaled or exceeded. Califomia ambient air quality standards are hsted in the Table of Standards in Section 70200 of Title 17 of the Califomia Code of Regulations. In addition. Section 70200.5 lists vinyl chloride (chloroethene) under "Ambient Air QuaUty Standards for Hazardous Substances." In 1978, the Califomia Air Resources Board (ARB) adopted the vinyl chloride standard of 0.10 ppm (26 ;ig/m^) averaged over a 24-hour period and measured by gas chromatography. The standard notes that vinyl chloride is a San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-59 Draft EIR-April 2002 Significant Environmental Effects "known human and animal carcinogen" and that "low-level effects are undefined, but are potentially serious. Level is not a threshold level and does not necessarily protect against harm. Level specified is lowest level at which violation can be reliably detected by die method specified. Ambient concentrations at or above the standard constitute an endangerment to the health of the public." hi 1990, the ARB identified vinyl chloride as a Toxic Air Containment and detennined that there was not sufficient available scientific evidence to support the identification of a threshold exposure level. This action allows the implementation of health- protective conti-ol measures at levels below the 0.010 ppm ambient concentration specified in tiie 1978 standard. 2. National standards (other than ozone, particulate matter, and those based on annual averages or annual arithmetic mean) are not to be exceeded more than once a year. The ozone standard is attained when tiie fourth highest eight-hour concentration is a year, averaged over tiiree years, is equal to or less tiian tiie standard. For PMio, the 24-hour standard is attained when 99 percent of the daily concentrations, averaged over 3 years, are equal to or less than tiie standard. For PM2i, the 24-hour standard is attained when 98 percent of tiie daily concentrations, averaged over 3 years, are equal to or less tiian tiie standard. Contact U.S. EPA for further clarification and cuirent federal policies. 3. Concenu-ation expressed first in units in which it was promulgated. Equivalent units given in parentiieses are based upon a reference temperature of 25 °C and a reference pressure of 760 mm of mercury. Most measurements of air quality are lo be corrected to a reference temperamre of 25X and a reference pressure of 760 mm of mercury (1,013.2 millibar); ppm in tiiis table refers to ppm by volume or micromoles of pollutant per mole of gas. 4. Any equivalent procedure which can be shown to the satisfaction of tiie ARB to give equivalent results at or near the level of the air quality standard may be used. 5. National Primary Standards. The levels of air quality necessary, with an adequate margin of safety to protect tiie public health. 6. National Secondary Standards: The levels of air quality necessary to protect tiie public welfare from any known or anticipated adverse effects of a pollutant. 7. Reference metiiod as described by tiie EPA. An "equivalent metiiod" of measurement may be used but must have a "consistent relationship to the reference method" and must be approved by the EPA. 8. ^g/m^ = micrograms per cubic meter. 9. New federal 8-hour ozone and fine particulate matter standards were promulgated by U.S. EPA on July 18, 1997. The federal 1-hour ozone standard continues to apply in areas tiiat violated tiie standard. Contact U.S. EPA for fiirtiier clarification and current federal policies. Source: Califomia Au- Resources Board, 1999 San Marcos Landfill Closiu-e and 2-60 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects Table 22-2 Air Quality Monitoring Summary*''*^* Key: (S) = state standard, (F) = federal standard. wm Pollutant/Standard 1996 1997 1998 1999 2000 Ozone (O3) P 1 hr, >0.09 ppm (S) 12 5 9 1 6 wm lhr,>0.12ppm(F) 0 0 0 0 0 8 hr, >0.08 ppm (F) 9 2 5 0 m Max. 1-hr cone, (ppm) 0.12 0.11 0.12 0.10 0.12 wm Carbon Monoxide (CO) 1 hr, >20 ppm (S) 0 0 0 0 0 m 1 hr, >9 ppm (F) 0 0 0 0 0 Max. 1-hr cone, (ppm) 11 9 10 10 9 Max. 8-hr cone, (ppm) 7.3 5.0 4.6 5.3 4.9 p Nitrogen Dioxide (NO2) 1 hr, >0.25 ppm (S) 0 0 0 0 0 Max. 1-hr cone, (ppm) 0.10 0.12 0.09 0.10 0.08 p Respirable Particulates (PMio) 24-hr, >50jig/m^CS) 2/61 3/58 1/61 1/60 (3) m 24-hr, >I50^g/m^ (F) 0/61 0/58 0/61 0/60 (3) m Max. 24-hr cone, (jxg/m^) 53 63 51 52 65 Notes: *" Number of days standards were exceeded and maxima for periods indicated. Entries shown as ratios = samples exceeding standard/samples taken. Year 2000 data not yet available. Source: San Diego Air Pollution Control District, Escondido Monitoring Station. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-61 Draft EIR-April 2002 Significant Environmental Effects Table 2.2-3 Screening-Level Criteria for Air Quality Impacts Pollutant Total Emissions Pollutant Lbs/Hour Lbs/Day Tons/Year Respirable Particulate Matter (PMio) — 100 15 Oxides of Nitrogen (NO^) 25 250 40 Oxides of Sulfiu-(SOx) 25 250 40 Carbon Monoxide (CO) 100 550 100 Lead and Lead Components — 3.2 0.6 Volatile Organic Compounds (VOCs)*" — 75 10*^' Notes: (i) (2) Threshold for VOCs based on the threshold of significance for reactive organic gases fi-om Chapter 6 of the CEQA Air Quality Handbook of the South Coast Air Quality Management District for the Southeastern Desert Air Basin. 10 tons per year threshold based on 55 lbs/day times 365 days/year divided by 2,000 lbs/ton. Source: Soudieast Desert Air Basin Handbook. Table 2.2-4 Regional Mobile Source Exhaust Emissions (Pounds/Day) P Hi 1 Source ROG NO, CO PMio On-Road Tmck Exhaust*" 20 185 160 18 Commuter Vehicles (Crews and Mgmt.)*'^' 2 3 22 <1 On-Site Diesel Equipment'^' 4 62 14 2 Off-Road Trucks'** 6 131 57 14 Total 32 381 253 35 Significance Threshold*'' 55 250 550 100 Significant Impact? No Yes No No Notes: 0) (2) (3) (4) (5) 400 trips X 20 miles/round trip = 8,000 miles/day. 20 trips X 50 miles/round trip = 1,000 miles/day. 18 pieces x 100 each x 8 hours x 0.5 load = 7,200 HP/hour. (630 trips X 0.5 mile/trip)-r 10 miles/hour = 31.5 hours/day. San Diego Air Pollution Control District. San Marcos Landfill Closm-e and Post-Closure Maintenance Plans EIR 2-62 P P P P Draft EIR-April 2002 Significant Environmental Effects Table 2.2-5 Daily PMio Emissions (Pounds/Day) Activity Emissions Basis Daily I Dirt Pushing 21.8 Ib/hr X 8 hr/day 174 Tmck Filling 10,000 ton/day x 0.02205 lb/ton 220 Tmck Dumping 10,000 ton/day x 0.09075 lb/ton 91 Unpaved Roads 31.5 mi X 2.3 lb/mi (90% control) 72 On-Road Dust 8,000 mi/day x 0.012 lb/mi 96 Total 653 Threshold 100*" 1 Significant Impact Yes Note: San Diego Air Pollution District. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-63 Draft EIR-April 2002 ^ Significam Environmental Effects 2.3 Noise This section is a summary of the acoustical technical study prepared for tiie Proposed Project by Giroux and Associates (2002b). The technical study is included in Appendix D to tiiis EIR. 2.3.1 Existing Conditions Background Noise is often called unwanted sound. Sound is generally described in terms of the sound pressure level created by vibrating air molecules. The most common descriptor is tiie ratio of tiie ambient sound pressure level to tiie level detectable by a young person witii good auditory acuity. Because tills ratio can vary by over one million witiiin tiie range of human hearing, a logaritiimic ratio is used to keep values at an easily manageable level. This logarithmic ratio is called a decibel ("dB"). Decibels are also typically weighted to most closely approximate the response of tiie human ear, in a process called A-weighting, referred to as dB(A). Any fijrther references to decibels in tins report are understood to be A-weighted. Sound levels vary rapidly in an ambient environment. The most common descriptor of time-varying sound is the "equivalent level", or "Leq", a steady-state sound level that has tiie same acoustic energy as the average of all tiie mstantaneous variable levels. One hour is the most common averagmg period for Leq. Noise Elements of General Plans, as reqmred by State law, use a noise parameter called the Community Noise Equivalent Level ('CNEL"). CNEL is a weighted 24-hour exposure where noise events during tiie evening, and especially at night, are assigned an artificial penalty during times of greater noise sensitivity. Each noise event from 7:00 PM to 10:00 PM is assigned a +5 decibel "penalty" m tiie CNEL calculation. Each noise event from 10:00 PM to 7:00 AM is assigned a +10 decibel penalty. Each car, U^ck, etc. m the evening is tiie "noise equivalent" of approxunately three vehicles m the CNEL descriptor. Each vehicle at night carries the same weight as 10 daytime vehicles in detemiining CNEL. San Marcos Landfill Closure and 2-64 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects The State of Califomia has developed model noise exposure levels that are proposed for local adoption. These model standards contain multiple categories of acceptability and category overlaps. They also do not address interior standards required under Titles 24/25 of tiie Califomia Code of Regulations. San Diego Coimty, m the Noise Element of the General Plan, therefore condensed this matrix of noise exposure goals mto a much simpler format. Baseline Noise Levels On-site noise generation occurring on one land use that may affect an adjacent use is governed by the San Diego County Code of Regulatory Ordinances (Section 36.401 et seq.). For the Proposed Project, ordinance limits would apply for on-site constmction activities, and for any on-site chronic sources such as tiie landfill gas ("LFG") recovery and flare station. Off-site haul tmck noise on public streets would thus be evaluated through the General Plan (CNEL-based) guidelines, but on- site noise is regulated by County ordinance. Existmg noise levels near the Proposed Project site are dominated by automobile and light-duty vehicle ttaffic on San Elijo Road and Elfin Forest Road. Travel speeds are 45-50 mph, dependmg upon the amount of roadway curvature and sight Ikies. Most of the Landfill mterior is shielded by terrain. Noise measurements were made at three locations on or around the Landfill on October 1, 2001, including the Landfill entrance, LFG Recovery Flare Facility, and adjacent to Cotmty-owned residences located in the eastem Landfill buffer land. The noise measurements near the Landfill entrance were affected by constmction activities associated with the current San Elijo Hills residential consOiiction project. The other two test locations were more representative of ambient levels at the Landfill site. The results of these measurements are presented in Table 2.3-1. The highest noise level was recorded at the entrance to the Landfill. The lowest noise levels were recorded at the areas adjacent to the Coimty-owned residences. San Marcos Landfill Closure and 2-65 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects 2.3.2 Thresholds of Significance Noise impacts are considered significant (State CEQA Guidelines Appendix G) if a project: • results in a violation of standards or guidelines contained in applicable ordinances or general plans; • substantially increases an already existing excessive noise level; or • creates a nuisance by virtue of character, frequency, or time of day, regardless of the numerical decibel value created by the noise. The Coimty and the City use very similar noise compliance criteria as a basis for determining noise unpact significance. Both jurisdictions have established a noise exposure goal of 60 dBA CNEL for residences and other noise-sensitive land uses. The CNEL meUic and the associated noise goal apply to those sources that are pre-empted for local conttol such as on-road vehicles, trains, or aircraft. The City or County regulates tiie noise exposure and types of land uses exposed to such noise. If site-related ttaffic were to cause the traffic noise to exceed 60 dB CNEL (65 dB CNEL in tiie jurisdictions of Oceanside, Carlsbad, and Escondido) at locations where this standard is not presently exceeded, the noise impacts would be potentially significant. At many developed locations in San Diego County, existing noise levels already exceed 60 dB CNEL and, therefore, already exceed the threshold. For a project to add a significant noise impact, a substantial noise increase would have to occur. No local jurisdiction defines "substantial increase" in terms of specific decibel limits. The consensus definition in most environmental documents is -^3 dB. However, a +3-dB increase typically requires a doubling of U-affic volumes, because of the logarithmic relationship between noise levels and traffic volumes. Few projects individually create a doubling of volumes. Most typically, significant off-site traffic increases are cumulative in nature. San Marcos Landfill Closure and 2-66 Post-Closure Maintenance Plans EIR m m m p Draft EIR - April 2002 Significant Environmental Effects Noise generation for constmction equipment operating off-road is a regulated activity in both the City and County noise ordinances. The allowable noise level on an industrial property, such as the Landfill, is 75 dBA (one-hour Leq). The allowable noise level on a residential receiving property is 45 dBA at night and 50 dBA by day. At the boundary between two zoning districts, the noise standard is equal to the mathematical average between the different districts. Many of the proposed closure and post-closure maintenance activities are in the form of temporary constmction noise. Such noise is regulated slightly differently in each applicable noise regulation. The County of San Diego, in Section 36.410 of the San Diego Code of Regulatory Ordinances, establishes a performance standard not to exceed 75 dBA at the boundary of any constmction site averaged over eight hours. The ordinance also requires that constmction activities be restricted to the hours from 7:00 AM to 7:00 PM, Monday though Saturday. The City of San Marcos has no numerical performance standard; however, the allowable constmction hours are slightiy more stringent. Work must cease by 6:00 PM and Saturday work cannot begin before 8:00 AM. Both City and County code prohibit operation of constmction equipment or machinery on Sundays or major holidays. Project-related impacts would be considered significant if: • Traffic noise exceeds 60 dB CNEL in the County or City of San Marcos, if existing noise levels are less than 60 dB (65 dBA in other jurisdictions); • If noise levels currentiy exceed 60 dB CNEL in the County or City of San Marcos (65 dBA in other jurisdictions), then traffic noise at any sensitive receptor is increased by 3 dB or more; or On-site operations occur during noise-sensitive periods, or the County performance standard of 75 dB (eight-hour average) is exceeded at the Landfill perimeter. San Marcos Landfill Closure and 2-67 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significam Environmental Effects 2.3.3 Analysis of Project Effects and Determination of Significance A Final Closure Plan noise impact study was prepared by Dr. Alexander Segal (working jointiy with tiie San Diego County Departments of Planning and Land Use and Public Works in 1998). This study contained an analysis of tiie equipment operations and tiieir associated noise needed to implement the Landfill closure plan. Currentiy proposed closure and post-closure activities are similar to tiiose analyzed. The results of tiiis study, and the traffic projection for tiie various haul route altematives, were used to evaluate Proposed Project impacts relative to the thresholds of significance for noise. On-Site Construction Equipment Noise Impacts The existing on-site noise levels for the types of equipment operating closest to tiie eastem Landfill property line near tiie existing Elfin Forest community residences is 87 dB(A) at a 50-foot reference level. This level was determined from an extensive literature review and from field measurements. For noise propagation across an irregular and vegetated surface, tiie 75 dB (eight-hour average) is met witiiin 150 feet of tiie activity under direct line-of-sight conditions. Witii tiie topographical screening presented by tiie residual ridgeline along tiie eastem Landfill boundary, the noise compliance distance is even shorter. Two constmction crews were assumed to be working simultaneously in proximity to existing homes. The combined reference noise level for two crews is 90 dB(A) at 50 feet. Under direct line-of-sight conditions and an acoustically "soft" surface, the theoretical 75 dB (eight-hour * average) contour distance is 200 feet. The nearest Elfin Forest residences are at least 250 feet from any proposed activity, and these residences are in a buffer zone owned by the County of San Diego. The residences were purchased by tiie County as a noise buffer area for previous Landfill expansion activities. The nearest non-County residences are 600 feet from any activity. On-site equipment operations (haul tmcks, loader, dozers, compactor, grader, and water tmck) from two simultaneously operating remediation crews will not cause the significance threshold to San Marcos Landfill Closure and 2-68 Post-Closure Maintenance Plans EIR MM Draft EIR - April 2002 Significant Environmental Effects be exceeded, even under worst-case line-of-sight conditions. Therefore, on-site closure and post- closure activities will not cause a significant noise impact. Some blasting is anticipated which will require drilling for placement of charges. The blast itself is designed to fracture rock, but not eject it from the ground. The reported reference noise level from a single blast is 94 dB(A) at 50 feet from the blast site. Over an eight-hour workday, this translates into a 49 dB(A) level at 50 feet. With considerable spreading losses, and with the blast site shielded from the closest homes by intervening tertain, the blast contribution to the eight- hour average constmction noise exposure is negligible and therefore not significant. Longer-term blasting activity noise will result from the drill used to the place the charges. The reference noise level from a drill is 89 dB(A) at 50 feet averaged over an hour. The County of San Diego eight-hour standard of 75 dB(A) may be exceeded to a distance of 260 feet from the drill site. The nearest non-County residences are well beyond 260 feet from any drilling activity, and screened by intervening tertain. There is no potential for exceedmg the applicable significance threshold for drilling to place blasting charges; therefore, no sigruficant impacts related to drilling are noted for the Proposed Project On-Road Noise Impacts The Proposed Project will require a maximum of 400 daily tmck trips of soil delivery. At arterial travel speeds, one tmck generates about as much noise as 12 cars. The on-road noise impact from Proposed Project traffic is therefore the noise-equivalent of almost 10,000 cars per day. Any tmcks on the road before 7:00 AM further coimts as 10 "noise-equivalent" tmcks in the CNEL calculation; therefore, a single tmck before 7:00 AM is the noise-equivalent of 120 cars. If the Landfill access route already carries high traffic volume, the haul tmck noise will be masked by the baseline. The Proposed Project will create a short-term incremental impact, but not at levels that exceed the +3-dB significance threshold for individual impact significance. If, San Marcos Landfill Closm-e and 2-69 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects however, baseline volumes are less tiian 10,000 vehicles per day, tiie truck noise increment will ^ create a temporary doubling or more of noise generators. Such impacts are significant. wm Table 2.3-2 summarizes the no project and witii Proposed Project traffic noise for the six tmck - routes. The resultant noise increases were calculated by using the Federal Highway Traffic noise wm prediction model (FHWA-RD-77-108). Significant traffic noise impacts will occur along tiie roadway segment between tiie San Elijo Road/Rancho Santa Fe Road intersection and tiie Landfill on Tmck Routes 1, 2, 4, 5, and 6, because tiie existing baseline traffic volumes are less than 10,000 vehicles per day. A significant noise increase would occur for the entire length of — the alignment for Tmck Route 3, as this route currently has a low ambient noise level, including the portion of San Elijo Road east of the Landfill. «• wm Post-Closure Maintenance IM Mi The Proposed Project includes a Landfill post-closure maintenance program. These activities include monitoring, inspection, and maintaining the groundwater monitoring wells; surface water "* collection areas; LFG collection, recovery, and monitoring systems; cover soil; and vegetation. " These activities wiW occur on a limited basis for a short duration. These activities will be site specific to small portions of the Landfill, as activities are required. The noise associated with " these activities will be infrequent, and of a short duration, and therefore is not considered to be significant. Post-closure maintenance noise levels will not significantly exceed noise levels from P ... p current mamtenance activities. In summary, two significant noise unpacts were identified for tiie Proposed Project. • Impact 2.3.2.a - Roadway segment from Rancho Santa Fe Road/San Elijo Road intersection to the Landfill will experience a 4.4-dBA increase (Tmck Routes 1, 2, 4, 5, and 6). P P P San Marcos Landfill Closm-e and 2-70 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects • Impact 2.3.2.b - Roadway segments along Tmck Route 3 will experience a noise increase greater than 3 dBA. 2.3.4 Mitigation Measures Mitigation for Impact 2.3.2.a The following mitigation measure is proposed to mitigate noise impacts from tmck traffic on San Elijo Road between Rancho Santa Fe Road and the Landfill (Tmck Routes 1, 2, 4, 5, and 6). • Prohibit tmck traffic on San Elijo Road between Rancho Santa Fe Road and the Landfill before 7:00 AM. This mitigation measure will reduce noise levels to 68.6 dB (a 2.8-dB decrease). This would reduce short-term noise impacts to below a level of significance for Tmck Routes 1,2,4, 5, and 6. 2.3.5 Conclusions No sigruficant noise impacts from on-site activities were identified for the Proposed Project. Significant short-term noise related to the hauling of cover soil has been identified along San Elijo Road between Rancho Santa Fe Road and the Landfill for Tmck Routes 1, 2, 4, 5, and 6 and for all of Tmck Route 3. Restricting tmcks from hauling before 7:00 AM will reduce the short-term noise impacts on San Elijo Road to below a level of significance; however, all segments of Tmck Route 3 will remain significant and unmitigable. There is no altemative design that reduces the impacts to below a level of significance, because of the large quantities of soil required to properly close the Landfill, and the need to accomplish the closure as soon as possible. The No Project Altemative, while reducing short-term noise impacts, could possibly create long-term risks for infiltration of water into the Landfill (see San Marcos Landfill Closure and 2-71 Post-Closiu-e Maintenance Plans EIR Draft EIR-April 2002 Significant Environmental Effects discussion m Section 4.2.1). The No Project Altemative was rejected for the reasons stated in Section 4.2.3. The Landfill stopped receiving waste on March U, 1997. Pursuant to CCR Titie 27, Section 21110, a landfill operator is to begin implementation of a closure plan within 30 days of tiie last receipt of refuse. Therefore, the implementation of a closure plan for tiie Landfill is required as soon as possible. The Superior Court issued a writ of mandate on October 8, 1996, directing tiie County to develop a Landscape Program tiiat complies with mitigation monitoring required by tiie City when it approved tiie use permit for expansion of tiie Landfill. Subsequent litigation and post-litigation issues between the County and tiie City concenung tiie details of the revegetation plan which delayed moving forward witii closure have recently been resolved, permitting tiie closure plan to move forward. Under tiie CCR Title 27 provisions (as overseen by the RWQCB) and the Superior Court writ of mandate, tiie County is legally required to permanentiy close and revegetate the Landfill. If tiie closure of the Landfill and revegetation are not performed, tiie County could be subject to civil fines or contempt of court proceedings. Therefore, for legal and financial reasons, transport of tiie cover soil (that generates tiie significant impact) is necessary to properly close and maintain the Landfill. For all of the above reasons, the project is being proposed notwitiistanding the impacts identified in Chapter 2.0 and Chapter 3.0 of this EIR. P P San Marcos Landfill Closure and 2-72 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Significant Environmental Effects Table 2.3-1 Existing Noise Conditions*'' Location L« Lmax Lmin Lso L90 1 Landfill Entrance 62 68 54 60 57 LFG Recovery/Flare Facility 59 60 28 59 58 County-Owned Homes 44 53 40 43 40 1 Note: *" Measurements given in dBA. Source: Gu-oux and Associates, 2002b. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-73 Draft EIR- April 2002 Significant Environmental Effects Table 2.3-2 Haul Traffic Noise Impact Assessment Existing Condition With Proposed Project Change Significant Impact? ROUTE 1 Descanso Boulevard - (jrand Avenue 73.8 74.9 1.1 No La Mirade Drive - Linda Vista Drive 73.1 74.3 1.2 No Security Place - San Marcos Boulevard 71.9 73.4 1.5 No San Marcos Boulevard - Lake San Marcos 72.7 74.0 1.3 No Lake San Marcos - Mehose Drive 72.2 73.7 1.5 No Mehose Drive - San Elijo Road 72.4 73.8 1.4 No San Elijo Road - Landfill 65.8 70.2 4.4 Yes ROUTE 2 Plaza Drive - Marron Road 73.2 74.4 1.2 No Faraday Avenue - Palomar Airport Road 73.0 74.2 1.2 No El Camino Real - Alga Road 72.3 73.7 1.4 No Alga Road - La Costa Avenue 73.5 74.7 1.2 No La Costa Avenue - Calle Barcelona 72.7 74.0 1.3 No Olivenhain Road- La Posta 69.8 72.1 2.3 No Calle Barcelona - La Costa Avenue 72.0 73.5 1.5 No Tmck Bypass - San Elijo Road 72.0 73.5 1.5 No San Elijo Road - Landiiil 65.8 70.2 4.4 Yes ROUTE 3 Auto Park Way 67.5 70.9 3.4 Yes Harmony Grove Road 61.3 69.0 7.7 Yes Elfin Forest Road 61.3 69.0 7.7 Yes ROUTE 4 Paseo del Norte - Armada Drive 75.2 76.0 0.8 No Yarrow Drive - El Camino Real 72.8 74.1 1.5 No Palomar Airport Road - Alga Road 72.3 73.7 1.4 No Alga Road - La Costa Avenue 73.5 74.7 1.2 No La Costa Avenue - Calle Barcelona 72.7 74.0 1.3 No Olivenhain Road- La Posta 69.8 72.1 2.3 No Calle Barcelona - La Costa Avenue 72.0 73.5 1.5 No Truck Bypass - San Elijo Road 72.0 73.5 1.5 No San Elijo Road - Landfill 65.8 70.2 4.4 Yes ROUTE 5 Piraeus Street - Saxony Road 72.5 73.9 1.4 No La Costa Avenue - Calle Barcelona 72.7 74.0 1.3 No Olivenhain Road- La Posta 69.8 72.1 2.3 No Calle Barcelona - La Costa Avenue 72.0 73.5 1.5 No Tmck Bypass - San Elijo Road 72.0 73.5 1.5 No San Elijo Road - Landfill 65.8 70.2 4.4 Yes p p p San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-74 Draft EIR-April 2002 Significant Environmental Effects Table 2.3-2 (Continued) P Ml P P - Existing Condition With Proposed Project Change Significant Impact? p ROUTE 6 Interstate Highway 5 - Saxony Road 73.3 74.5 1.2 No Ml Balour Drive - El Camino Real 72.0 73.5 1.5 No Encinitas Boulevard - Mountain Vista 73.8 74.9 I.l No Garden View Road - Olivenhain Road 73.7 74.8 1.1 No P Olivenhain Road- La Posta 69.8 72.1 2.3 No m Calle Barcelona - La Costa Avenue 72.0 73.5 1.5 No Tmck Bypass - San Elijo Road 72.0 73.5 1.5 No m San Elijo Road - Landfill 65.8 70.2 4.4 Yes Sotirce; Giroux and Associates, 2002b. Note: *" Noise in dB CNEL at 50 feet to centeriine. P m San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 2-75 Draft EIR-April 2002 Significant Environmental Effects (This page intentionally left blank.) San Marcos Landfill Closure and 2-76 Post-Closure Maintenance Plans EIR Ml P P P Draft EIR - April 2002 Cumulative Impacts CHAPTER 3.0 CUMULATIVE IMPACTS Section 15130(a) of the State CEQA Guidelines requires that "cumulative impacts shall be discussed when they are significant". As defined by CEQA Guidetines, Section 15355, a cumulative impact consists of an impact that is created as a result of the combination of the project evaluated in the EIR, together with other projects, causing related impacts. Cumulative impacts typically are the result of the combined collective impacts of a number of local projects. In evaluating cumulative effects, an EIR should focus on a list of past, present, and reasonably anticipated future projects producing related impacts. The evaluation can also be based upon a summary of projections contained in the adopted general plan or related planning documents. For each identified impact, the basis of the cumulative analysis will be described. Some impacts are discussed using a combination of general plan projections and adjustments if any projects propose increases over the projections of the general plan. An EIR must discuss cumulative impacts when they are significant and the project's incremental contribution is cumulatively considerable [CEQA GuideUnes, Section 15130(a)]. If the combination of the Proposed Project's incremental effect and the related effects from other projects is not significant, the EIR should briefly explain why the cumulative effect is not significant [CEQA Guidelines, Section 15130(a)(2)]. An EIR need not discuss significant cumulative impacts in as great detail as is provided for project impacts alone [CEQA GuideHnes, Section 15130(b)]. The discussion should be guided by standards of practicality and reasonableness [CEQA Guidelines, Section 15130(b)]. The potentially significant cumulative impacts associated with the Proposed Project are transportation/circulation, air quality, and noise. p The Proposed Project consists of preparing and implementing final closure and post-closure maintenance plans for an existing landfill. The Proposed Project does not change the land use p designation or land use for the site. Since the Proposed Project is a closure of an existing IM P landfill, the completion of the project will result in a reduction in intensity of activities. The P Proposed Project includes landscaping not currentiy present on the Landfill surface. San Marcos Landfill Closure and 3-1 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Cumulative Impacts CEQA Guidelines, Section 15130(a) states that where a lead agency is examining a project with an incremental effect that is not cumulatively considerable, the lead agency need not consider that effect significant, but shall briefly describe its basis for concluding that the impact is not cumulatively considerable. As noted in the Initial Study for the project dated October 23, 2001 (included in Appendix A of this EIR), and as discussed in Section 6.2, the project will have no incremental effect, or the incremental effect will not be cumulatively significant, in the following areas. References to tiie Initial Study are to Pages 1-17 of the Environmental Analysis Form ("EAF') attached to the Initial Study. The basis for the conclusion in each area is stated briefly below. • Aesthetics The Proposed Project will not have an incremental effect, because the topographical visual appearance of the Landfill will remain proportionally the same. The addition of vegetation that blends with the surrounding native vegetation creates a beneficial visual improvement to the site. There are no other aesthetic impacts of the Proposed Project. Agricultural Resources The Proposed Project will not have an incremental effect. The Proposed Project does not convert any existing agricultural land to otiier uses. The site is not zoned for agricultural land uses. Any disturbance of former agricultural use was created when tiie property use was converted to landfill use in 1977. Biological Resources The Proposed Project will not have an incremental effect. Because the Landfill currentiy has little vegetation, but will be landscaped with native vegetation, the Proposed Project will improve the biological value of tiie site. There will be no other incremental biological effects from the Proposed Project. San Marcos Landfill Closure and 3^2 Post-Closure Maintenance Plans EIR P P Draft EIR - April 2002 Cumulative Impacts Cultural/Paleontological Resources As described in the EAF for the Initial Study (Pages 6 and 7), the Proposed Project will not have an incremental effect. The project will cap the existing Landfill and will not disturb any cultural or paleontological resources. Geological Hazards As described in the EAF for the Initial Study (Pages 7 and 8) the Proposed Project will nol have an incremental effect. It will not increase erosion (but will decrease it); will not affect mineral resources; will not create unstable soil conditions; nor will it cause people to be exposed to geological hazards. • Hazards and Hazardous Materials The existing landfill gas ("LFG") control system will be continued and maintained by the Proposed Project. With regard to fire hazards, as discussed in Section 6.2, the addition of vegetation will have the incremental effect of adding "fuel" to the site. The maintenance plan for the Landfill requires proper maintenance of the vegetation near the LFG wells and piping, and the buffer area around the Landfill prevents the increase in vegetation from creating a significant hazard to surrounding properties. Other projects in the vicinity are not contributing to an increase in fire-related hazards. The incremental effect of the vegetative cover is not cumulatively considerable. There are no other incremental effects creating hazards or producing hazardous materials. • HydrologyAVater Quality The Proposed Project will not have an incremental effect. As discussed in Section 6.1, the Proposed Project will create a beneficial impact upon water quality by reducing the risk of water infiltration into the Landfill, thereby preventing potential adverse water quality impacts from the trash buried in the Landfill. The vegetative cover and drainage system improvements will reduce risks from surface storm water. All impacts upon hydrology/water quality from the Proposed Project are beneficial. San Marcos Landfill Closure and 3-3 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Cumulative Impacts m • Planning and Land Use pp The Proposed Project will not have an incremental effect upon land use or planning. As stated in the EAF for the Initial Study (Pages 11 and 12), the Proposed Project is consistent witii the City of San Marcos ("City") General Plan, including community plans, land use designations, and zoning. It is consistent with environmental plans and policies of agencies having jurisdiction over the Proposed Project. • Population/Housing The Proposed Project will not have an incremental effect. As stated in the EAF for the Initial Study (Pages 13 and 14), it will not directiy or indirectly induce growth. The Proposed Project will not displace any existing housing. • Public Services/Utilities The Proposed Project will not have an incremental effect. As stated in the EAF for the Initial Study (Pages 14 and 15-16), it will not create a new burden on public service agencies, or create the need for new facilities. Significant incremental and cumulative impacts from the Proposed Project for traffic/circulation, noise, and air quality are identified and discussed below. 3.1 List of Past, Present and Reasonably Anticipated Future Projects in the Proiect Area For tiiis EIR, files from the cities of Encinitas, Carlsbad, Escondido, and San Marcos, and the County of San Diego ("County"), were reviewed to identify projects tiiat could contribute to the cmnulative impacts. Staff from each jurisdiction were consulted during the preparation of the cumulative projects list. Comments received in response to the Notice of Preparation were reviewed and considered in this analysis, when appropriate. The parameters for selecting a project for inclusion in the cumulative assessment included the following: p p P San Marcos Landfill Closure and 3^ Post-Closure Maintenance Plans EIR P P Draft EIR - April 2002 Cumulative Impacts • Projects currentiy in the process of completing their environmental review, or new projects for which applications have been submitted. • Projects that would likely generate traffic that would be distributed on one or more of the tmck route altematives. • Projects in this geographic area that would be under constmction, or completed and occupied, between November 2001 (date that the analysis was initiated) and the estimated time during which the hauling of cover soil will occur and the Proposed Project will have its maximum impact (August 2003 through March 2004). Although the Proposed Project will continue through June 2005, the significant project and cumulative impacts will occur during the soil hauling phase. The geographic area considered in the analysis is bounded by Interstate Highway 15 ("1-15"), Interstate Highway 5 ("1-5"), State Route 78 ("SR 78"), and Encinitas Boulevard. Transportation/circulation, noise, and air quality impacts have been evaluated in Chapter 2.0, and the EIR has concluded that those impacts will be significant. Thus, the projects identified for this cumulative analysis were selected for their potential to contribute to the magnitude of the Proposed Project's impacts. Since the timing of the constmction or completion of these cumulative projects is unknown, reasonable assumptions were made, based upon cmrently available information, as to the likelihood that a project would be contributing impacts concurrent with the Proposed Project. Sixteen projects were determined to meet the geographic criteria described above and are included in the cumulative analysis (Table 3-1 and Figure 3-1). Table 3-1 includes a summary of the potential impacts for those projects that have completed their environmental review. San Marcos Landfill Closure and 3-5 Post-Closure Maintenance Plans EIR Draft EIR-AprU 2002 Cumulative Impacts 3.2 Transportation/Circulation 3.2.1 Existing Conditions The Landfill is located within the City, south of San Elijo Road between Rancho Santa Fe Road and Elfin Forest Road. The roadways that could potentially be affected for each tmck route by importing soil to the Proposed Project site are listed below. Interstate Highway 15 ("1-15") - Tmck Routes 1 through 3 Interstate Highway 5 ("1-5") - Routes 4 through 6 State Route 78 ("SR 78") - Routes 1 and 2 Palomar Airport Road - Route 4 La Costa Avenue - Route 5 Encinitas Boulevard - Route 6 Olivenhain Road - Routes 1, 2,4, 5, and 6 El Camino Real - Routes 2,4, 5, and 6 Rancho Santa Fe Road - Routes 1, 2, 4, 5, and 6 San Marcos Boulevard - Route 1 San Elijo Road - Routes 1 through 6 Harmony Grove - Route 3 Elfin Forest Road - Route 3 The configuration of each of tiie roadways/intersections, Level of Service ("LOS"), and Average Daily Trips ("ADT") (witii and without the Proposed Project) are presented in detail in Section 2.2.1, and in tiie complete Traffic Study in Appendix B. p 3.2.2 Thresholds of Significance " wm The Proposed Project was analyzed in conjunction with past, current, and probable future projects. Cumulatively, tiie impacts would be significant if elements (segments or intersections) ^ * San Marcos Landfill Closure and 3_6 Post-Closure Maintenance Plans EIR P P P P P P Draft EIR - April 2002 Cumulative Impacts of the proposed circulation network are degraded to LOS D or below (LOS E or F). If roadway segments or intersections curtently operate at an unacceptable LOS (D, E, or F), a substantial increase in delay caused by cumulative growth would also be considered significant. These thresholds are discussed in detail in Section 2.1.2. 3.2.3 Analysis of Project Effects and Determination of Significance P The import of cover soil will cause a significant, short-term impact on a number of roadway segments and intersections. In total, six potential haul routes were analyzed. Tmck traffic creates a significant impact upon roadway segments and intersections along portions of all tmck routes analyzed. Significant impacts were noted at the following intersections (I) and roadway segments (R): Mi P P Rancho Santa Fe Road/SR 78 WB Ramps, AM peak hours (I) Rancho Santa Fe Road/SR 78 EB Ramps, AM and PM peak hours (I) Rancho Santa Fe Road/San Marcos Boulevard, AM and PM peak hours (I) Rancho Santa Fe Road/Melrose Drive, AM peak hours (I) Rancho Santa Fe Road/San Elijo Road, PM peak hours (I) Rancho Santa Fe Road - Descanso Boulevard to Grand Avenue (R) Rancho Santa Fe Road - La Mirada Drive to Linda Vista Drive (R) Rancho Santa Fe Road — San Marcos Boulevard to Lake San Marcos Drive (R) Rancho Santa Fe Road - Lake San Marcos Drive to Melrose Drive (R) Rancho Santa Fe Road - Melrose Drive to San Elijo Road (R) El Camino Real/SR 78 WB Ramps, AM and PM peak hours (I) El Camino ReaySR 78 EB Ramps, PM peak hours (I) Palomar Airport Road/El Camino Real, AM and PM peak hours (I) El Camino Real/OHvenhain Road, AM and PM peak hours (I) Rancho Santa Fe Road - Calle Barcelona to La Costa Avenue (R) Rancho Santa Fe Road - Tmck Bypass to San Elijo Road (R) Valley Parkway/Auto Park Way, AM and PM peak hours (I) San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 3-7 Ml Draft EIR-April 2002 Cumulative Impacts P wtk Auto Park Way - Ninth Avenue to Valley Parkway (R) m Auto Park Way North (one-way) - Andreasen Drive to Howard Avenue (R) Palomar Airport Road - Paseo Del Norte to Armada Drive (R) La Costa Avenue - Piraeus Street to Saxony Road (R) El Camino Real - Levante Street to Calle Barcelona (R) Encinitas Boulevard/I-5 SB Ramps, PM peak hours (I) Encinitas Boulevard/I-5 NB Ramps, PM peak hours (I) Encinitas Boulevard/El Camino Real, AM and PM peak hours (I) El Camino Real/Garden View Road, AM peak hours (I) Encinitas Boulevard - Interstate Highway 5 to Saxony Road (R) Interstate Highway 15 - Valley Parkway to Ninth Avenue (R) Interstate Highway 5 - Santa Fe Drive to Encinitas Boulevard (R) Interstate Highway 5 - Palomar Airport Road to Cannon Road (R) State Route 78 - El Camino Real to College Boulevard (R) State Route 78 - Rancho Santa Fe Road to San Marcos Boulevard (R) Table 3-2 summarizes tiie ADT generation and circulation network impacts at buildout for the cumulative projects. These data were taken from existing environmental documents, or traffic generation was estimated using standard traffic generation rates. Some of the projects are phased residential developments. San Elijo Hills is under constmction and some units are occupied. Although at buildout, up to 40,000 ADT could be generated, it would be expected that less than 5,000 ADT would be generated during 2003 and 2004. This number would include partial occupation, sales, and marketing of new products and ongoing constmction. Since San Elijo Hills is located to the north of the Landfill, traffic accessing the site will generally be expected from 1-5 (Palomar Airport Road, La Costa Avenue, or Encinitas Boulevard) or from 1-15 or SR 78 (Rancho Santa Fe Road or El Camino Real). Due to the circuitous route, limited traffic would be expected to utihze Harmony Grove Road or Elfin Forest Road (City of San Marcos, 1998a). San Marcos Landfill Closure and 3_8 Post-Closure Maintenance Plans EIR P P Draft EIR - April 2002 Cumulative Impacts University Commons has recentiy completed its environmental review process and is anticipated to be under constmction in 2003. It is also located north of the Landfill. Similar to San Elijo Hills, constmction traffic will generally be expected from 1-5 (Palomar Airport Road, La Costa Avenue, or Encinitas Boulevard) or from 1-15 or SR 78 (Rancho Santa Fe Road or El Camino Real). Constmction traffic would be expected to be less than 1,000 ADT. Due to the circuitous route, limited traffic would be expected to utilize Harmony Grove or Elfin Forest (City of San Marcos, 2001b). The Rancho Santa Fe Road widening project may be under constmction at the same time as this Proposed Project (City of San Marcos, 1998b). Predominantiy, constmction on Rancho Santa Fe Road would most significantly affect the cumulative traffic if it were closed, thus precluding tmck traffic from utihzing that roadway segment. If that were to occur, traffic normally utilizing Rancho Santa Fe Road would be distributed over the local circulation network. However, based upon discussions with Carlsbad and San Marcos officials, it is not anticipated that the road will be completely closed to vehicular traffic. It is possible that the San Marcos portion of the project (the section north of Melrose Avenue) may be open to four lanes of traffic when the project soil- hauling phase begins. However, if that section has not been completed, or if the soil source requires utilization of the Carlsbad portion of Rancho Santa Fe Road (Tmck Routes 1, 2, 4, 5, and 6), the additional impact of constmction and the impact of cumulative traffic from the identified projects in the vicinity will be significant during the soil-hauling phase of the Proposed Project. Additionally, constmction traffic (probably a few hundred ADT for'employees and supplies) would also utilize the same network as described above. Manzanita Apartments, Carlsbad Research Center, and the Fox/Miller Property are all located adjacent to El Camino Real near Palomar Airport Road. At buildout, these projects will contribute about 9,500 ADT. Cumulatively, traffic from these projects will exacerbate traffic on El Camino Real, Palomar Airport Road, 1-5, and SR78 (City of Carlsbad, 2001b, 2000, and 1999). San Marcos Landfill Closure and 3-9 Post-Closure Maintenance Plans EIR p Draft EIR-April 2002 Cumulative Impacts ^ Villages of La Costa was being litigated at the time that the NOP had concluded the public m review. It is questionable as to whether this project would be able to proceed until after the Utigation activities have been concluded. If litigation is concluded and the project proceeds, then m constmction traffic would likely be occurring at the same time as the Landfill. With nearly " 2,400 units approved (subject to any changes resulting from the litigation), traffic would be P generated on many of the roadway elements adversely affected by the Landfill. These would "* likely include Rancho Santa Fe Road, San Elijo Road, El Camino Real, La Costa Avenue, Palomar Airport Road, Encinitas Boulevard, SR-78, and 1-5. The Draft EIR for the Bressi Ranch project began public review in January 2002 (City of Carlsbad, 2001). Altiiough it is unlikely that the project will complete all of the entitlement processes (map approvals, permits from all entities, etc.), it is feasible that tiie project could be under constmction at the same time as the Landfill. Traffic impacts would likely be exacerbated on Palomar Airport Road, El Camino Real, SR-78, 1-5, La Costa Avenue, and Encinitas Boulevard. Shelley Carlsbad and Colina Roble are located in Rancho Santa Fe, between Olivenhain Road and La Costa Avenue. Anotiier 2,800 ADT will be generated at buildout from tiiese projects. Traffic from these projects is going to predominantiy affect the cumulative conditions on 1-5 (La Costa Avenue and Encinitas Boulevard) and tiie Rancho Santa Fe Road and Olivenhain Road segments (City of Carlsbad, 1998a and 1998b). The Encinitas Ranch project is located adjacent to El Camino Real and La Costa Avenue. Cumulative traffic (3,700 ADT) from this project will affect Encinitas Boulevard, El Camino Real, and La Costa Avenue (City of Encinitas, 1999). Constmction traffic for tiie Emergency Storage Project is utilizing Harmony Grove Road. Nearly 500 ADT has been estimated for this project. Thus, traffic from that project will cumulatively affect Route 3 (San Diego County Water Autiiority, 1997). San Marcos Landfill Closure and 3_10 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Cumulative Impacts Portions of 1-5, 1-15, SR78, Rancho Santa Fe Road, El Camino Real, San Marcos Boulevard, Palomar Airport Road, Olivenhain Road, and Encinitas Boulevard are all operating at LOS D, E, or F (Section 2.1). Other portions of the circulation network operate at acceptable levels. With or without the Landfill project, the circulation network will not function at acceptable levels (LOS A through C). During the approximately seven months of constmction, the contribution of the Proposed Project's traffic on the circulation network will result in significant project-level impacts. With tiie contribution of additional traffic over and beyond that included in the project-specific analysis (Section 2.1.3), the impacts will be exacerbated, resulting in a significant cumulative impact. Partial mitigation measures have been included to assist in reducing impacts; however, these measures will not reduce short-term transportation/circulation impacts to below a level of significance. 3.2.4 Mitigation Measures Project-level mitigation measures are proposed to partially reduce significant impacts during constmction, and include restricting deUvery of cover soil to the Landfill between 7:00 AM and 4:00 PM and notifying local bicycle clubs of haul period schedule and routing. The feasibility of fully mitigating the short-term impacts is discussed in detail and was found to be infeasible. For the same reasons presented in Section 2.1.4, mitigating cmnulative impacts during the period of the Proposed Project is infeasible. A summary of transportation/circulation mitigation measures is also provided on Page 9-1 of this EIR. 3.2.5 Conclusions The import of cover soil will cause a significant, short-term cumulative impact on a number of roadway segments and intersections as discussed in Section 3.2.3. In total, six potential haul routes were analyzed. All routes identified significant cumulative impacts on roadway segments and intersections. Partial mitigation measures have been included to assist in reducing impacts; San Marcos Landfill Closure and 3-11 Post-Closure Maintenance Plans EIR p Ml P Draft EIR-AprH 2002 Cumulative Impacts however, these measures will not reduce cumulative short-term transportation/circulation impacts lo below a level of significance. Reducing the number of daily trips, thereby lengthening Ihe duration of the project, is not considered feasible because this would increase constmction time, and result in increased expense to complete the project. Increasing the duration of final cover constmction could increase the possibility of erosion at the site or water infiltration. There is no altemative design that reduces the impacts to below a level of significance, because of the large quantities of soil required to properiy close the Landfill, and the need to accomplish • the closure as soon as possible. The No Project Alternative, while reducing short-term transportation/circulation impacts, could possibly create long-term risks for infiltration of water " into the Landfill (see discussion in Section 4.2.1). The No Project Altemative was rejected for the reasons stated in Section 4.2.3. ^ In addition, the Landfill stopped receiving waste on March 11, 1997. Pursuant to CCR Title 27, " Section 21110, a landfill operator is to begin implementation of a closure plan within 30 days of the last receipt of refuse. Therefore, the implementation of a closure plan for the Landfill is " Ml required as soon as possible. The Superior Court issued a writ of mandate on October 8, 1996, directing the County to develop a Landscape Program that complies with mitigation monitoring " wm required by tiie City when it approved tiie use pemiit for expansion of the Landfill. Subsequent litigation and post-litigation issues between the County and the City conceming the details of the mm revegetation plan which delayed moving forward with closure have recentiy been resolved, permitting the closure plan to move forward. Under the CCR Titie 27 provisions [as overseen by * •I tiie Regional Water Quality Control Board ("RWQCB")] and the Superior Court writ of mandate, the County is legally required to permanentiy close and revegetate the Landfill. *" If the closure of the Landfill and revegetation are not performed, tiie County could be subject to civil fines or contempt of court proceedings. Therefore, for legal and financial reasons, transport of the cover soil (that generates the significant impact) is necessary to properly close and ^ maintain the Landfill. P P San Marcos Landfill Closiu-e and 3_ 12 Post-Closure Maintenance Plans EIR P P Draft EIR - April 2002 Cumulative Impacts For all of the above reasons, the project is being proposed notwithstanding the impacts identified in Chapter 2.0 and Chapter 3.0 of this EIR. 3.3 Air Quality 3.3.1 Existing Conditions The regional meteorological and air quality parameters are presented in Section 2.2.1. The San Diego Air Basin ("SDAB") is currentiy in non-attainment for the Federal and State Standards for ozone and PMio. As noted in Section 2.2.1, the SDAB will be reclassified by the EPA as in attainment for federal ozone standards in early 2002. 3.3.2 Thresholds of Significance In accordance with State CEQA Guidelines (Appendix G), the Proposed Project would have a significant cumulative air quality impact if the incremental effects of a project were considerable when viewed in connection with the effects of past projects, other current projects, and probable future projects. Additionally, a significant impact would occur if the Proposed Project, in combination with the cumulative projects considered, would result in the following: A cumulatively considerable net increase of any criteria pollutant for which the project region status is nonattainment under an applicable federal or state ambient air quality standard (including release of emissions which exceed quantitative thresholds for ozone precursors). 3.3.3 Analysis of Project Effects and Determination of Significance As discussed in Section 2.2.3, the Proposed Project would result in significant short-term NOx and PMio impacts. Short-term project-level NOx impacts are associated with constmction San Marcos Landfill Closure and 3-13 Post-Closure Maintenance Plans EIR Since Rancho Santa Fe Road is expected to be under constmction at the same time as the Landfill, PMio emissions would be likely. Contributions of NO^ would also occur. Cumulative mobile source emissions were identified for Carlsbad Research Center, the Fox/Miller Property, and Encinitas Ranch. IB Draft EIR-AprU 2002 Cumulative Impacts emissions. Short-term PMio impacts are associated with the excavation, loading, transporting, and placement of cover soil for the Landfill closure. Table 3-2 identifies the air quahty impacts associated with the cumulative projects. Air quality impacts for these projects are primarily short-term constmction-related impacts, and impacts related to vehicle emissions generally associated with increased vehicles due to the development of residential land uses. p m Of the 16 potential cumulative projects, at least 10 have been determined to likely be under P constmction or occupied at the time that the constmction activities are occurring (Section 3.1). Others may be under constmction if they complete the entitlement process or litigation. Several of the other projects have been evaluated (during the preparation of previous environmental review) and significant project-level air quality impacts (either during constmction or operation) have also been identified. San Elijo Hills will be under constmction and partially occupied. Short-term constmction impacts were identified, including PMio emissions, CO-related vehicular emissions, and inconsistency with the Regional Air Quality Standards. Short-term constmction impacts from PMio were reported for University Commons. These impacts would occur during the same time as the constmction activities on the Landfill. HI P P If Villages of La Costa proceeds, subject to tiie litigation, and/or Bressi Ranch completes tiie entitlement process, air quality impacts would be contributed. These impacts would include fugitive dust and NOx- * P P P P P P P San Marcos Landfill Closure and 3.I4 Post-Closure Maintenance Plans EIR P P Draft EIR - April 2002 Cumulative Impacts Significant and unmitigable short-term impacts were reported for the Emergency Storage Project, related to PMio and NOx emissions from the constmction activities. These emissions would be added to the airshed concurrent with the constmction activities at the Landfill. The short-term project-level significant impacts, when combined with the other projects located in proximity to the Landfill, will result in significant short-term cimiulative impacts to air quality. These projects will be contributing to the regional NOx and PMio levels through constmction activities and vehicular emissions. 3.3.4 Mitigation Measures Design measures are proposed to partially reduce air quality impacts during constmction. A summary of those measures is presented on Page 9-2 of the EIR, and include adherence to APCD requirements for dust control and the use of low-sulfur fuel. However, as discussed in Section 2.2.4, it is infeasible to reduce the project-specific impacts, as well as the cumulative impacts, to below a level of significance. 3.3.5 Conclusions As discussed in Section 3.3.3, project-related constmction emissions will exceed NOx thresholds and PMIO thresholds and will result in significant short-term air quality impacts. NOx emissions will be generated from mobile sources operating at the Landfill and on public roads. PMio emissions will be generated from the excavation, loading, and transport of cover soil, and soil mixing, grading, and placement at the Landfill. The short-term project-level air quality impacts, when combined with air quality impacts associated with constmction of other identified projects in the proximity of the Landfill or from vehicle emissions resulting from these projects, will result in significant short-term cumulative air quality impacts. Design features, including adherence to applicable dust control measures of the San Diego APCD and adherence to applicable low-sulfur fuel requirements of the APCD, have been included in the project to reduce air emissions generated during project constmction to the extent feasible. However, there is no San Marcos Landfill Closure and 3-15 Post-Closure Maintenance Plans EIR Draft EIR-AprU 2002 Cumulative Impacts P San Marcos Landfill Closure and 3.j5 Post-Closure Maintenance Plans EIR P feasible mitigation to reduce the short-term cumulative air quality impacts to below a level of m significance. M m As discussed in Section 3.2.4, reducing the number of daily trips by 33 percent could reduce NOx emissions to below a level of significance. However, a much larger reduction in project intensity MI would be needed to reduce PMio emissions. The constmction schedule would need to be extended more than sixfold to reduce PMio emissions to below a level of significance. Reducing P the number of daily trips, thereby lengthening the duration of the project, is not considered feasible because this would increase constmction time and result in increased expense to complete the project. Increasing the duration of final cover constmction could increase the possibility of erosion at the site or water infiltration. There is no altemative design that reduces the impacts to below a level of significance because of the large quantities of soil required to properiy close the Landfill, and the need to accomplish the closure as soon as possible. The No Project Altemative, while reducing short-term air quality impacts, could possibly create long-term risks for infiltration of water into the Landfill as discussed in Section 4.2.1. The No Project Altemative was rejected for the reasons stated in Section 4.2.3. As noted in Section 2.1.5, the Landfill stopped receiving waste on March 11, 1997. Pursuant to CCR Titie 27, Section 21110, a landfill operator is to begin implementation of a closure plan within 30 days of the last receipt of refuse. Therefore, the implementation of a closure plan for the Landfill is required as soon as possible. The Superior Court issued a writ of mandate on Octobers, 1996, directing the County to develop a Landscape Program that complies witii mitigation monitoring required by the City when it approved the use permit for expansion of the Landfill. Subsequent litigation and post-litigation issues between the County and the City conceming the details of the revegetation plan which delayed moving forward with closure have recentiy been resolved, permitting the closure plan to move forward. Under tiie CCR Titie 27 provisions (as overseen by tiie RWQCB) and tiie Superior Court writ of mandate, the County is legally required to permanentiy close and revegetate the Landfill. P P Draft EIR - AprU 2002 Cumulative Impacts m If the closure of the Landfill and revegetation are not performed, the County could be subject to 1. civil fines or contempt of court proceedings. Therefore, for legal and financial reasons, transport «• of the cover soil (that generates the significant impact) is necessary to properly close and maintain the Landfill. Hi For all of the above reasons, the project is being proposed notwithstanding the impacts identified ^ in Chapter 2.0 and Chapter 3.0 of this EIR. I" ^ 3.4 Noise m 1^ 3.4.1 Existing Conditions p p The noise environs for the Landfill vicinity and adjacent to the Tmck Routes are presented in P P P P Section 2.3.1, and the noise technical study is included in Appendix D. 3.4.2 Thresholds of Significance The Proposed Project would have a significant cumulative noise impact if the incremental effects of a project when viewed in connection with the effects of past projects, other current projects, and probable future projects, exceeds thresholds identified in Section 2.3.2, Noise. In addition, under State CEQA GuideHnes, when evaluating the cumulative noise-related issues of a proposed project in combination with other development, a significant cumulative effect would normally occur if the project were to result in: • Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies. • Exposure of persons to or generation of excessive groundbome vibration or groundbome noise levels. San Marcos Landfill Closure and 3-17 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Cumulative Impacts • A substantial permanent increase in ambient noise levels in the project vicinity above ••'> levels existing without the project. m •Ht • A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project. 3.4.3 Analysis of Project Effects and Determination of Significance Significant project-level impacts were identified for noise resulting from hauling cover soil to the site. Significant noise impacts were identified on the portion of San Elijo Road between Rancho Santa Fe Road and the Landfill on Tmck Routes 1, 2, 4, 5, and 6. Additionally, significant noise ^ impacts related to hauling of cover soil were also identified for the entire portion of Tmck Route 3. Impacts associated with on-site activities (during the constmction of the cover and post-closure maintenance) were determined to be less than significant. Table 3-4 identifies tiie noise impacts for the cumulative projects. Noise impacts for these projects include short-term constmction noise and also vehicle noise. The cumulative projects are generally located adjacent to the major circulation network; however, the San Elijo Hills, University Commons, and Emergency Storage Projects are located in proximity or conveying additional traffic to San Elijo (Questhaven) Road and Elfin Forest Road. The conttibution of additional noise with the short-term project-level significant (and mitigated) impacts associated mm with tile transport of cover soil will not result in a significant cumulative noise impact on San •MM Elijo Road (between Rancho Santa Fe Road and the Landfill) for Tmck Routes 1, 2, 4, 5, and 6. However, tmck traffic associated with the hauling of cement for the Emergency Storage Project will further exacerbate the significant and unmitigable noise impacts along Tmck Route 3, therefore resulting in a significant cumulative noise impact. •MM Based upon tiie project-level analysis in Table 2.3-2, other segments will generally be subject to noise increases of between 1 and 2dB. A 3-dB increase is considered to be significant San Marcos Landfill Closure and 3_ g Post-Closiue Maintenance Plans EIR P P Draft EIR - April 2002 Cumulative Impacts (Section 2.3.2). The addition of the tmck route traffic to traffic generated by the cumulative projects (Section 3.2) wiU not likely increase noise levels by an additional 1 to 2 dB (which would result in a cumulative 3-dB increase). Noise impacts generated at the project site were evaluated in Section 2.3.3. Noise levels were found to be reduced at the nearest sensitive receptor. Additional noise from constmction activities on San Elijo Hills and University Commons (nearest projects in the vicinity of the Landfill) would not result in a significant increase in noise levels, because noise from two sources is not strictly "additive" (i.e., a 50-dB noise source plus a 50-dB second noise source do not result in 100 dB). On-site constmction noise would be sufficientiy attenuated before it reaches sensitive receptors (nearby residents) that the two constmction projects would not cause an additive (or cumulative) exceedence of thresholds. 3.4.4 Mitigation Measures The Proposed Project includes measures to partially reduce noise impacts during constmction. A summary of those measures is presented in Section 2.3.4 and on page 9-2 and includes prohibiting tmck traffic on San Elijo Road between Rancho Santa Fe Road and the Landfill before 7:00 AM. However, as discussed in Section 2.3.4, it is infeasible to reduce all project- specific noise impacts, and therefore the short-term cumulative noise impacts, to below a level of significance. 3.4.5 Conclusions As discussed in Section 3.4.3, no significant cumulative noise impacts from on-site activities during constmction of the final cover and post-closure maintenance were identified for the Proposed Project. The Proposed Project will result in significant and unmitigable short-term noise impacts related to the hauling of cover soil to the Landfill along Tmck Route 3. The short- term project-level noise impacts, when combined with noise generated by tmck traffic associated with the hauling of cement for the constmction of the Emergency Storage Project, will result in significant short-term cumulative noise impacts along Tmck Route 3. A mitigation measure San Marcos Landfill Closure and 3-19 Post-Closure Maintenance Plans EIR Draft EIR-AprU 2002 Cumulative Impacts m wm prohibiting the hauling of cover soil before 7:00 AM has been proposed. This measure will not reduce significant short-term cumulative noise impacts along Tmck Route 3 to below a level of m significance. IM •I There is no altemative design that reduces the impacts to below a level of significance, because of the large quantities of soil required to properiy close the Landfill, and the need to accomplish * the closure as soon as possible. The No Project Altemative, while reducing short-term noise impacts along Tmck Route 3, could possibly create long-term risks for infiltration of water into P the Landfill (see discussion in Section 4.2.1). The No Project Altemative was rejected for tiie reasons stated in Section 4.2.3. ^ The LandfiH stopped receiving waste on March 11, 1997. Pursuant to CCR Title 27, Section 21110, a landfill operator is to begin implementation of a closure plan within 30 days of the last receipt of refuse. Therefore, the implementation of a closure plan for the LandfiH is required as soon as possible. The Superior Court issued a writ of mandate on October 8, 1996, " directing the County to develop a Landscape Program that complies with mitigation monitoring required by the City when it approved the use pemiit for expansion of the Landfill. Subsequent P litigation and post-litigation issues between the County and the City conceming the details of the revegetation plan which delayed moving forward with closure have recentiy been resolved, permitting tiie closure plan to move forward. Under the CCR Title 27 provisions (as overseen by the RWQCB) and the Superior Court writ of mandate, the County is legally required to permanentiy close and revegetate the Landfill. If the closure of the Landfill and revegetation are not performed, the County could be subject to civil fines or contempt of court proceedings. Therefore, for legal and financial reasons, transport of the cover soil (that generates the significant impact along Tmck Route 3) is necessary to properly close and maintain the Landfill. For all of the above reasons, the project is being proposed notwithstanding the impacts identified in Chapter 2.0 and Chapter 3.0 of this EIR. p San Marcos Landfill Closure and 3_20 Post-Closure Maintenance Plans EIR fl KI VI 11 •! If fl mm II VI il II il il 11 II 1 1 I 1 r i % 1. San Elijo Hills 2. University Commons* 3. San Elijo Ridge 4. Rancho Santa Fe Widenini 5. Villages of La Costa A. The Ridge B. The Oaks C. The Greens 6. Manzanita Apartments 7. Cantarini Ranch 8. Holly Springs 9. Bressi Ranch 10. Shelley Carisbad 11. Colina Roble 12. Carisbad Research Center 13. Fox/Miller 14. Encinitas Ranch A. South Mesa TM 00-94 B. South Mesa TM 00-93 C. South Mesa TM 00-128 15. Quail Ridge 16. Emergency Storage Project * Project is located on both sides of San Elijo Road. O La Cos San Marcos^ Grove Landfill Source: Cities of San Marcos, Endnitas, Carlsbad and County of San Diego No Scale Cumulative Projects ^ P&D Environmental Services Figure 3-1 Draft EIR - April 2002 Cumulative Impacts Table 3-1 Cumulative Projects Map Label Project Name Project Location Description Impacts Identified Document Prepared'" Status Cityof San Marcos 1 San Elijo Hills Planned Community San Eiijo Road/Elfin Forest Road 3,398 residential units, 40 acres of community services, 13 acres of commercial, golf course, and 1,050 acres of open space Air Quality, Biological Resources, Cultural Resources, Geology/Soils, Hydrology, Land Use, Noise, Public Services, Traffic, and Visual Quality/ Landform Alteration. EIR/SEIR Project under construction. Some occupied units. 2 University Commons Rancho Santa Fe Road/San Elijo Road 471 single-family residential units, 705 multifamily residential units Aesthetics, Air Quality, Biological Resources, Cultural Resources, HydrologyAVater Quality, Land Use, Noise, Public Services, and Traffic/ Circulation. All impacts mitigated to below a level of significance except aesthetics, noise, and traffic. EIR/ SEIR Approved 09/01, City finalizing Development Agreement. Project likely to be under construction. Limited, if any, occupied units. 3 San Elijo Ridge Questhaven Road 260 single-family residential units Preparing Initial Study. TBD Preparing Initial Study. Unlikely to be through entitlement process. Limited potential for construction activities to be concurrent with Proposed Proiect. 4 Rancho Santa Fe Roadway Expansion Rancho Santa Fe Road between Island and Melrose Lane additions Biological Resources, Cultural Resources, Geophysical, Public Services, Transportation/Circulation, and Utilities and Service Systems MND Construction planned for 04/02 through 04/04. May be under construction during Proposed Proiect. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 3-22 r 1 I 1 I I I I I I f I f 1 iiiiiiiiiiiiiPi II VI KI Bl VI VI VI i • 1 mm mm iVIilllftllllll Draft EIR - April 2002 Cumulative Impacts Table 3-1 (Continued) Map Label Project Name Project Location Description Impacts Identified Document Prepared*'* Status City of ( 'Carlsbad 5A 5B 5C Villages of La Costa Master Plan The Ridge: Rancho Santa Fe Road/ Melrose Avenue The Oaks: Rancho Santa Fe Road/San Elijo Road The Greens: El Camino Real/Alga Road The Ridge: 493 acres/ 320 residential units riieOait^: 712 acres/ 1,032 residential units The Greens: 660 acres/ 1,038 residential units Air Quality, Archaeological Resources, Biological Resources, Geology/Soils, Health/Safety, Hydrology/Water Quality, Landform Alteration, Noise, Paleontological, Public Services, Transportation, and Visual Quality. EIR Approved 10/01, litigation pending. Unlikely to be through entitlement process. Limited potential for construction activities to be concurrent with Proposed Project. 6 Manzanita Apartments El Camino Real north of PoinseUia Lane 157 apartments Air Quality and Traffic/Circulation. MND Approved 9/99, litigation pending with Coastal Commission. Project may be under construction concurrently with Proposed Project. Limited, if any, occupied units. 7 Cantarini Ranch Future intersection of College and Cannon 150 single-family residential units, 80 multifamily residential units, and open space lot Preparing Initial Study. TBD Preparing Initial Study. Unlikely to be through entitlement process. Limited potential for construction activities to be concurrent with Proposed Project. 8 Holly Springs Future intersection of College and Cannon 44 single-family residential units and open space lot Preparing Initial Study. TBD Preparing Initial Study. Unlikely to be through entitlement process. Limited potenfial for construction activities to be concurrent with Proposed Project. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 3-23 Draft EIR - April 2002 Cumulative Impacts Table 3-1 (Continued) Map Label Project Name Project Location Description Impacts IdentiHed Document Prepared"* Status 9 Bressi Ranch South of Palomar, east of El Camino Real, and west of Melrose 595-acre Master Plan including 6 industrial areas, 9 residential areas (maximum of 632 residential units), and 6 open space lots Biological Resources/Wetlands and Traffic/Circulation. EIR Public review of Draft EIR began 01/02. Unlikely to be through entitlement process. Limited potential for construction activities to be concurrent with Proposed Proiect. 10 Shelley Carlsbad Northeast corner of Rancho Santa Fe and Calle Acervo intersection 251 single-family residential units and 8 open space lots Aesthetics, Air Quality, Archaeology, Biological Resources, Flooding, Geology, Land Use, Noise, Public Services (Schools), Traffic/Circulation, and Water Quality. EIR Approved 10/98, project grading completed. Assume project is occupied. 11 Colina Roble Rancho Santa Fe between Olivenhain and Calle Acerno 28 single-family residential units Air Quality, Biological Resources, and Cultural Resources. MND Approved 09/98, completed. Assume project is occupied. 12 Carlsbad Research Center El Camino Real between Faraday and Palomar Airport Road 102,000 square feet planned industrial Air Quality and Traffic/Circulation. MND Completed. Assume project is occupied. 13 Fox/Miller Property El Camino Real between Faraday and College 390,300 square feet light industrial Aesthetics, Air Quality, Biological Resources, Cultural Resources, Geological Issues, Noise, Transportation/Circulation, and Water Resources. MND Pending Planning Commission and City Council Hearing. Project may be under construction concurrent with Proposed Project. Limited, if anv, occupied units. City o f Encinitas 14 A'' Encinitas Ranch/ South Mesa TM (00-94) South of Encinitas Ranch Golf Course 31 acres/ 103 residential lots Aesthetics, Agricultural Resources, Air Quality, Biological Resources, Cultural Resources, Geologic Hazards, Land Use and Planning, Population and Housing, Public Services, Transportation/Circulation, Uti lities MND Under construction. Assume project is occupied. I4B*'' Encinitas Ranch/ South Mesa TM (00-93) South of Encinitas Ranch Golf Course 84 residential lots Aesthetics, Agricultural Resources, Air Quality, Biological Resources, Cultural Resources, Geologic Hazards, Land Use and Planning, Population and Housing, Public Services, Transportation/Circulation, Uti lities MND Map recorded, under construction. Assume project is occupied. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 3-24 11 11 II I I I iririiiiiiiiiii iiiiiiiiiiiiriFiiiiiiiiiriiiiiiiriiiii Draft EIR - April 2002 Cumulative Impacts Table 3-1 (Continued) Map Label Project Name Project Location Description Impacts Identified Document Prepared*'' Status 14C*^> Encinitas Ranch/ South Mesa TM (00-128) South of Encinitas Ranch Golf Course 72 residential lots and Service Systems, and Water Resources. MND Map to be recorded. Assume project is occupied. County of San Dieeo 15 Quail Ridge Specific Plan and Subdivision Elfm Forest Road (1.5 miles west of San Elijo Road) 69 residential lots, 126 acres of biological open space, and 3-mile trail system Aesthetics, Air Quality, Biological Resources, Cultural Resources, Geological Issues, Land Use and Planning, Noise, Traffic/Circulation, and Water Resources. EIR Preparing Draft EIR. Unlikely to be through entitlement process. Limited potential for construction activities to be concurrent with Proposed Project. Other Jurisdictions 16 Emergency Storage Project (SDCWA/ Olivenhain MWD) Mt. Israel/Elfin Forest Storage reservoir Air Quality, Biological Resources, Cultural Resources, Energy, Geology/ Seismicity, Land Use, Noise, Paleontology, Public Safety, Recreation. Socioeconomic, Traffic, Visual Quality, and Water Resources. EIR Under construction. *'* EIR = Environmental Impact Report. MND = Mitigated Negative Declaration. SEIR = Supplemental Environmental Impact Report. TBD = The jurisdiction is completing the Initial Study for these projects. Final environmental documentation requirements are to be determined. These three projects were processed under one MND, and impacts identified in the MND are presented. Note: Information researched at the cities of San Marcos, Carlsbad, and Encinitas and the County of San Diego. Detailed project information on the cumulative projects is available at the Planning Department of each jurisdiction. San Marcos Landfill Closure and Post-CloSure Maintenance Plans EIR 3-25 Draft EIR - AprU 2002 Cumulative Impacts m Table 3-2 Cumulative Project Traffic Generation Map Label Project BuUdout ADT Generation Adjacent Truck Route(s) Circulation Network Impacts 1 San Elijo Hills Planned Community Up to 40,000 1, 2, 4, 5, and 6 Intersection - Rancho Santa Fe Road/San Marcos Boulevard (cumulative) Roadway - San Marcos Boulevard east of Rancho Santa Fe (cumulative) 2 University Commons 15,255 1,2,4,5, and 6 Intersections (Near-Term 2004) - Palomar Aiiport Road/El Camino Real - Rancho Santa Fe Road/Lake San Marcos Drive - Olivenhain Road/El Camino Real 3 San Eh jo Ridge 2,600*'* 3 Environmental review pending. 4 Rancho Santa Fe Roadway Expansion NA 1 Roadway (2002 through 2004) - Rancho Santa Fe Road between Island Avenue and Mehose Drive 5A-5C Villages of La Costa Master Plan 32,620 1, 2,4, 5, and 6 Intersections (Near-Term 2005) - Mehose Drive/Rancho Santa Fe Road - El Camino Real/Camino Vida Roble - El Camino Real/La Costa Avenue - Rancho Santa Fe Road/Linda Vista Drive 6 Manzanita Apartments 1,256*'* 2 and 4 No significant unpacts identified. 7 Cantarini Ranch 1,140*'* 2 Preparing Initial Study. 8 Holly Springs 440*'* 2 Preparing Initial Study. ' Bressi Ranch 31,230*'* 1 and 4 All impacts anticipated to be below a level of significance. 10 Shelley Carlsbad 2,510*'* 2,4, 5, and 6 Intersections - Rancho Santa Fe Road/Melrose Ehive - Rancho Santa Fe Road/San Elijo Road Roadways Rancho Santa Fe Road Olivenhain Road [ 11 Colina Roble 280*'* 2 and 4 Roadways 1 Significant impacts (cumulative) 12 Carlsbad Research Center 1,250*'* 2 Roadways Significant impacts to Palomar Airport Road and EI Camino Real (cumulative). 13 Fox/Miller Property 4,700*'* 2 Environmental review pending. p p m p San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 3-26 P P il Draft EIR - April 2002 Cumulative Impacts Table 3.2 (Continued) Map Label Project BuUdout ADT Generation Adjacent Truck Route(s) Circulation Network Impacts 14A Encinitas Ranch/South Mesa TM (00-94) 3,700 2,4, 5, and 6 Intersections - Saxony Road/La Costa Avenue - Saxony Road/Encinitas Boulevard - El Camino Real/La Costa Avenue - El Camino Real/Calle Barcelona - El Camino Real/Olivenhain Road 1-5 Northbound Ramp at Encinitas Boulevard 14B Encinitas Ranch/South MesaTM (00-93) 3,700 2,4, 5, and 6 Intersections - Saxony Road/La Costa Avenue - Saxony Road/Encinitas Boulevard - El Camino Real/La Costa Avenue - El Camino Real/Calle Barcelona - El Camino Real/Olivenhain Road 1-5 Northbound Ramp at Encinitas Boulevard 14C Encinitas Ranch/South MesaTM (00-128) 3,700 2,4, 5, and 6 Intersections - Saxony Road/La Costa Avenue - Saxony Road/Encinitas Boulevard - El Camino Real/La Costa Avenue - El Camino Real/Calle Barcelona - El Camino Real/Olivenhain Road 1-5 Northbound Ramp at Encinitas Boulevard 15 Quail Ridge Specific Plan and Subdivision 690*'* 1 through 6 Environmental review pending. 16 Emergency Storage Project (SDCWA/OMWD) 474 3 No significant impacts identified. Notes: *'* Based on a generation rate of 10 ADT for single-family residential and 8 ADT for multiple-family residential. *^* Based on a generation rate of 12 ADT for l,(X)0-square-foot building space. NA = Not applicable. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 3-27 Draft EIR-AprU 2002 Cumulative Impacts Table 3-3 Cumulative Project Air Quality Analysis Project Adjacent Truck Route(s) Significant Impacts San Elijo Hills Planned Community 1,2,4, 5, and 6 Unmitigated Impacts: - Short-term related to constmction activities and use of rock cmsher (PMjo). CO related to vehicle emissions. - Inconsistency with RAQS. University Commons 1,2,4, 5, and 6 Mitigated Impact: - Short-term related to constmction activities and use of rock cmsher. San Elijo Ridge 3 Environmental review pending. Rancho Santa Fe Roadway Expansion I ~ • * ^ — Short-term constmction. Villages of La Costa Master Plan 1,2,4,5, and 6 Mitigated Impacts: - Consmiction-related CO and NO^ emissions. - Constmction-related fugitive dust. Unmitigated Impact: - Mobile source emissions (cumulative). Manzanita Apartments 2 and 4 Unmitigated Impact: - Operational emissions (cumulative). Cantarini Ranch 2 Preparing Initial Study. Holly Springs 2 Preparing Initial Study. Bressi Ranch 1 and 4 Mitigated Impact: - Short-term PMjo, CO, NO^, and ROC related to constmction activities. Unmitigated Impact: - PMio, CO, NOx, and ROC (cumulative). Shelley Carlsbad 2, 4, 5, and 6 Unmitigated Impacts: - CO, NOx, hydrocarbons. Short-term PMio due to constmction. Colina Roble 2 and 4 Unmitigated Impact: - Operational emissions (cumulative). Carlsbad Research Center 2 Unmitigated Impact: - Mobile source emissions (cumulative). Fox/Miller Property 2 Unmitigated Impact: - Mobile source emissions (cmnulative). Encinitas Ranch/South Mesa TM (00-94) 2,4, 5, and 6 Unmitigated Impact: - CO and NOx fi'om vehicle emissions. Encmitas Ranch/South Mesa TM (00-93) 2,4, 5, and 6 Unmitigated Impact: - CO and NOx fi'om vehicle emissions. Encinitas Ranch/South Mesa TM (00-128) 2,4, 5, and 6 Unmitigated Impact: - CO and NOx fi'om vehicle emissions. Quail Ridge Specific Plan and Subdivision 1 through 6 Environmental review pending. Emergency Storage Project (SDCWA/OHvenhain MWD) 3 Unmitigated impact: - Consdiiction emissions. p p p p m m m m p m p San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 3-28 Draft EIR - April 2002 Cumulative Impacts Table 3-4 Cumulative Project Noise Analysis Project Adjacent Truck Route(s) Noise Issues San Elijo Hills Planned Community 1,2,4, 5, and 6 No Significant Impacts identified in SEIR. University Commons 1,2,4, 5, and 6 Vehicle noise to exterior spaces of adjacent residential land uses. - Vehicle noise to interior spaces of adjacent residential land uses. San Elijo Ridge 3 Environmental review pending. Rancho Santa Fe Roadway Expansion 1 Short-term constmction noise. Villages of La Costa Master Plan 1,2,4, 5, and 6 Short-term constmction noise. On-site vehicular noise. Cumulative vehicle noise impacts. Portions of project will fall within the Palomar Airport Noise Impact notification area. Manzanita Apartments 2 and 4 - Vehicular noise along Rancho Santa Fe Road to exterior and interior residential spaces. Cantarini Ranch 2 Preparing hiitial Study. Holly Springs 2 Preparing Initial Study. Bressi Ranch 1 and 4 No Significant Impact Shelley Carlsbad 2,4,5, and 6 Short-term related to constmction. Exterior residential spaces. Colina Roble 2 and 4 No Significant Impact Carlsbad Research Center 2 No Significant Impact Fox/Miller Property 2 Environmental review pending, noise study being prepared. Encinitas Ranch/South Mesa TM (00-94) 2, 4, 5, and 6 No Significant Impact Encinitas Ranch/South Mesa TM (00-93) 2, 4, 5, and 6 No Significant Impact Encinitas Ranch/South Mesa TM (00-128) 2, 4, 5, and 6 No Significant Impact Quail Ridge Specific Plan and Subdivision 1 through 6 Environmental review pending. Emergency Storage Project (SDCWA/Olivenhain MWD) 3 Potential impact to gnatcatcher breeding areas. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 3-29 Draft EIR - April 2002 Cumulative Impacts m m m P iM n p (This page intentionally left blank.) P p m p p p p San Marcos LandfiU Closure and Post-Closure Maintenance Plans EIR 3-30 P P m li Draft EIR - AprU 2002 Project Altematives CHAPTER 4.0 PROJECT ALTERNATIVES Pursuant to State CEQA Guidelines Section 15126.6(a), an EIR must describe and evaluate a range of reasonable altematives to the Proposed Project or to the location of the project, which would feasibly attain most of the basic objectives of the project, but would avoid or substantially lessen any of the project's significant effects. This section discusses five alternatives to the Proposed Project, including a No Project Altemative. 4.1 Rationale for Altematives Selection The altematives evaluated in this EIR were selected based on their ability to possibly reduce significant impacts while generally meeting the Proposed Project's basic purpose and objectives. As such, to provide the decision-makers with a full range of altematives, this EIR focused on potentially significant impacts and the ability to reduce those impacts. After preparation of the Initial Study, it was concluded that transportation/circulation, air quality, noise, and surface water quality were the identified potentially significant impacts associated with the required closure and post-closure maintenance of the San Marcos Landfill ("LandfiU"). Thus, altematives were identified that had the potential to reduce these impacts. It is not possible to consider an altemative location for the Proposed Project, since it is the permanent closure of an existing solid waste landfill. Each of the altematives, with the exception of the No Project Altemative, analyzes the importation and application of cover soil at the Landfill, since the Coimty of San Diego ("County") is required by Califomia Code of Regulations ("CCR") Titie 27 to implement permanent closure of the Landfill. The altematives are distinguished by the amoimt of cover soil to be placed on the top deck and side slopes of the Landfill. The amount of cover durectiy correlates to the total number of tmck trips to deliver cover soil, associated air quality (emissions and fugitive dust), and noise (traffic and onsite constmction). Additionally, the amount of cover directly cortelates to the duration of cover constmction at the Landfill. The depth of the cover and installation of a Flexible Membrane Liner ("FML") were evaluated as to their potential San Marcos Landfill Closure and 4-1 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Project Alternatives effect on water quality. Table 4-1 provides a summary and comparison of tiie different cover configurations. In accordance witii State CEQA Guidelines Section 15126(e), analysis of the No Project Altemative is required. Table 4-2 compares significance for the Proposed Project and Project Altematives, including tiie No Project Altemative. The altematives evaluated in the EIR are as follows: 4.2 Analvsis of the No Proiect/No Development Altemative 4.2.1 No Project Alternative Description and Setting CEQA Guidelines, Section 15126.6(e), require tiie discussion of the No Project Altemative. Pursuant to Section 15126.6(e)(2), this analysis will discuss the existing conditions at the time of the publication of tiie Notice of Preparation ("NOP"), which was October 23,2001. The Landfill stopped accepting refuse in 1997, and since that time has been an inactive landfill, designated for final closure pursuant to CCR Title 27. The No Project Altemative would consist of the Landfill remaining m its present state witii an intermediate cover, and no final closure cover system in place. The term "final closure cover system" means the Proposed Project's monolithic permanent cover soil, with the vegetation as described m tiie final closure plan. The existmg Landfill surfaces support a limited coverage of non-native grasses. p lb P P P P m No Project/No Development Altemative Altemative A: Prescriptive Cover Altemative as Modified by RWQCB Order No. 92-02 P Altemative B: Prescriptive Cover Altemative vritii Flexible Membrane Liner as Top *" Deck Barrier Layer p Altemative C: Prescriptive Cover Altemative as Modified by RWQCB Order No. 92-02 with Court-Mandated Vegetative Cover P Altemative D: Prescriptive Cover with Flexible Membrane Liner as Top Deck Barrier Layer and Court-Mandated Vegetative Cover San Marcos Landfill Closure and 4_2 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Project Alternatives Legal Requirement to Close The Landfill stopped receiving waste on March 11, 1997. Pursuant to CCR Title 27, Section 21110, a landfill operator is to begin implementation of a closure plan within 30 days of the last receipt of refuse. Therefore, the implementation of a closure plan for the Landfill is required as soon as possible. The Superior Court issued a writ of mandate on October 8, 1996, directing the Coimty to develop a Landscape Program that complies with mitigation monitoring required by the City of San Marcos ("City") when it approved the use permit for expansion of the Landfill. Subsequent litigation and post-litigation issues between the County and the City conceming the details of the revegetation plan have recently been resolved, permitting the closure plan to move forward. Under the CCR Title 27 provisions [as overseen by the Regional Water Quality ConU-ol Board ("RWQCB")] and tiie Superior Court writ of mandate, tiie County is legally required to pennanently close and revegetate the Landfill. The closure plan must be accomplished under CCR Title 27, and the landscaping/revegetation plan must be accomplished as directed by the writ of mandate. Ifthe closure of the Landfill and revegetation are not performed, the Coimty could be subject to civil fines or contempt of court proceedings. Therefore, for legal and financial reasons, the No Project Altemative is not feasible. However, the No Project Altemative will be discussed. As shown below, the Proposed Project or any of the altematives will provide a greater degree of protection to the environment in the vicinity of the Proposed Project than would the No Project Altemative. 4.2.2 Comparison of the Effects of the No Project Alternative to the Proposed Project Under the No Project Altemative the Landfill site would remain in its ciurent condition. The cmrent condition of the Landfill site is the mound of previously landfiUed refiise and daily cover soil applied during active operation, along with a top layer of unvegetated intermediate cover soil of at least two feet in depth. Under the No Project Ahemative, the monolithic soil would not be applied to the Landfill; however, supplemental cover soil would be imported to replace cover San Marcos Landfill Closure and 4-3 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Project Alternatives lost through normal erosive actions (wind and precipitation). A minimum of two feet of cover must be maintained. The following sections discuss the environmental impacts of the No Project Altemative, as applicable. Transportation/Circulation The No Project Altemative would reduce tiie significant short-term impact of increased tmck traffic U-ansporting the large quantity of cover soil for the final closure cover system. With the No Project Altemative some tmck traffic would still occur, for importmg supplemental cover soil as needed, depending upon tiie rate of erosion of soil fi-om tiie intermediate cover. The number of tmck trips would be minimal in contrast to the Proposed Project. Ifthe Proposed Project is completed, the vegetation on the final closure cover system will reduce the amount of soil erosion and therefore reduce the fi-equency of soil replacement, and related tmck traffic; P therefore, impacts to transportation/circulation as a result of implementation of the No Project Altemative would be below a level of significance. P p Air Quality p p The No Project Altemative would eliminate tiie short-term air quality impacts (fiigitive dust and * vehicle emissions) generated by tmck traffic and equipment used in importing and placing the permanent cover soil. It would also eliminate the potential short-term impact of possible • P temporary landfill gas (LFG) emissions firom the refiise during the placement of soil and reconfiguration of the LFG collection system. However, a potential longer-term effect of not placing the final closure cover system is greater airbome dust particles (fugitive dust), because the unvegetated cover would not be landscaped and thus would be subject to the effects of wind. There would also be a greater risk of LFG emissions, because the existmg intermediate cover is less efficient. Under the No Project Ahemative, air quality impacts are considered less than significant. P P P San Marcos Landfill Closure and 4.4 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Project Alternatives Noise The No Project Altemative would reduce the short-term impact of noise fi-om tmcks and equipment used in importing and placing the fmal closure cover system at the Landfill. Some noise will still occur under this altemative, from the occasional importation and placement of replacement soil to maintain the minimum of two feet of intermediate cover soil on the Landfill. Ifthe Proposed Project is completed, the vegetative cover will reduce the rate of soil erosion and, therefore, reduce the fi-equency of the impacts of importing replacement soil. Some continuing post-closure maintenance of the final closure cover system will be required, but it is anticipated to decrease from current continuing maintenance requirements. The noise impacts under the No Project altemative are not significant, because of the limited number of tmck trips associated vrith the hauling of cover soil. Hydrology/Water Quality The final closure cover system will improve the control of storm water runoff The Proposed Project has been designed such that precipitation vrill be absorbed by the landscaping, captured in tiie cover (where the rate of absorbed precipitation is generally equal to evaporation), and surface storm water flow controlled using the proposed stormwater drainage system. Precipitation fallmg under the No Project condition would flow on unvegetated surfaces. Precipitation falling on unvegetated soil typically results in increased erosion and uncontrolled drainage patterns. Not adding the final closure cover system would increase the possibility of intmsion of water into the Landfill, which could significantiy affect groundwater quality. The permanent cover system is designed to minimize the possibility of infiltration; so, by not constmcting the Proposed Project, the risk of groundwater degradation is mcreased. This is a potentially significant impact that can not be mitigated under the No Project Altemative. San Marcos Landfill Closure and 4-5 Post-Closure Maintenance Plans EIR P M P Draft EIR-April 2002 Project Altematives 4.2.3 Staffs Rationale for Rejection of the No Project Alternative The rationale for rejection of tiie No Project Altemative is fourfold. First, tiiere is a legal requirement to place a permanent cover upon the Landfill, as discussed above, and the potential penalties for noncompliance make the No Project Altemative infeasible for legal and economic m reasons. m p Secondly, the No Project Altemative is rejected because it could cause significant impacts that the Proposed Project is designed to prevent [CEQA Guidelines, Section 15126.6(e)(3)(B)]. Ifthe m Proposed Project were not approved, the Landfill would contmue to exist in its current state, with a nonpermanent intermediate cover, and with little or no vegetation. This increases the p possibUity of infiltration of water into the refiise, and if that occurs in sufficient volume, leachate •* contamination of the groundwater in the area can occur. In addition, infiltration carries an m increased risk of the production and release of LFG. The principal objective of the Proposed Project is to minimize the infiltration of water into the waste, thereby minimizing the production P of leachate and gas [CCR, Titie 27, Section 20950(a)(2)]. The principal objective would not be achieved under the No Project Altemative. p P Additionally, without the Proposed Project, there is a greater likelihood of erosion of the existing cover soil due to the absence of vegetation. The introduction and mamtenance of the vegetative cover included in tiie Landfill Closure Plan and Post-Closure Maintenance Plan will significantiy P reduce soil erosion by wind and water. Leaving only the existing intermediate cover soil on the Landfill would limit the type and amount of vegetative cover that could be sustained, due to the low permeability of the intermediate cover soil. The likely vegetative cover to be supported in the long term would be nonnative grasslands that are adapted to periodic disturbances. The proposed monolithic cover balances the need to minimize infiltration mto the Landfill with the court-ordered mandate to vegetate the Landfill witii Diegan coastal sage scmb ("CSS") and chaparral. The vegetative soil layer of tiie Proposed Project will sustain CSS and chapartal species. P P P San Marcos Landfill Closure and 4_6 Post-Closure Maintenance Plans EIR Draft EIR-AprU 2002 Project Altematives Under the No Project Altemative, the appearance of the Landfill would not be enhanced. The Proposed Project would provide for a more seamless transition to siurounding native vegetation. As noted, the vegetative cover will also improve the aesthetics of the Landfill mound. Some short-term impacts, such as transportation/circulation, air quality, and noise, would be eliminated by the No Project Altemative. However, the Proposed Project will mitigate those short-term impacts to the extent reasonably possible and, more importantiy, provide long-term environmental benefits required by law that would not be provided by the No Project Altemative. Therefore, the No Project Altemative should be rejected. 4.3 Analvsis of Alternative A: Prescriptive Cover Altemative as Modified bv RWOCB Order No. 92-02 4.3.1 Alternative A Description and Setting Under Altemative A, the Landfill closure would be completed by utilizing the cover system prescribed by CCR Titie 27, Section 21090, as modified by tiie requirements of RWQCB Order No. 92-02, unless an altemative engineered cover is approved by the RWQCB. Figure 4.3-1 depicts the configuration of the Ahemative A prescriptive cover, showmg cross sections of the cover layers. This mcludes a two-foot foundation soil layer overlain by a two-foot clay barrier soil layer, a FML, and a one-foot vegetative soil layer on the top deck. Side slopes above the vertical expansion include a two-foot foundation soil layer overlain by a two-foot clay barrier layer, and a one-foot vegetative soil layer. Side slopes below tiie vertical expansion would be covered with a two-foot foundation soil layer overlaui by a one-foot barrier soil layer and a one- foot vegetative soil layer (Table 4-1). The Landfill surfaces would be revegetated with a mixture of grasses and forbs. The amount of cover soil (approximately 390,000 cubic yards of soil) and the number of tmck trips represent approximately a seven percent reduction as compared to the Proposed Project (Altemative A, 27,856 trips vs. Proposed Project, 30,000 trips). As witii tiie Proposed Project, source material will be imported from an approved bortow site. The six altemative tmck routes could also be used for this altemative. All other design components (e.g.. San Marcos Landfill Closure and 4-7 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 AU — • Project Altematives Stonn water management, post-closure maintenance, and LFG cont-ol) of tiie Proposed Project would remain the same for this altemative. 4.3.2 Comparison of the Effect of the Alternative A to the Proposed Project Transportation/Circulation Altemative A would result m a short-tenn impact of a similar magnitude to tiie Proposed Project caused by tmck traffic. This altemative would require tiie importation of approximately 390,000 cubic yards of soil over an approximate eight-montii time period. While this represents a seven-percent reduction in tiie number of tmck trips, it does not represent a significant reduction in tmck traffic. The daily levels of service for traffic would not improve to acceptable levels even if tiie number of tuck trips is reduced by a greater percentage, for example, to 100 per day. Thus, a seven-percent reduction in tiie overall number of trips would not substantially reduce tiie significant short-term transportation/circulation impacts identified for the Proposed Project. Overall, tiie impacts would be limited in duration. (It would take seven percent less time to deliver tiie cover soil, or a reduction in daily trips by seven percent.) As with the Proposed Project, proposed mitigation measures for tiiis altemative include notifying local bicycle clubs of tiie haul period schedule and routing, and accepting cover soil haul tmcks at tiie LandfiH between 7:00 AM and 4:00 PM only. The incorporation of tiiese mitigation measures would not reduce significant transportation/circulation impacts to below a level of significance. Air Quality Because tiie amount of cover soil and associated tmck trips would be only seven percent less tiian for tiie Proposed Project, Altemative A would have air quality unpacts similar to tiie Proposed Project. The Proposed Project would result in significant air quality impacts associated witii PMio and NOx, as would Altemative A. Altiiough there would be an overall reduction in tiie number of trips, tiie modest reduction of seven percent dictates tiiat tiiis altemative would San Marcos Landfill Closiu-e and ~ ^ Post-Closure Maintenance Plans EIR p p Draft EIR-April 2002 Project Alternatives still result in similar impacts to air quality. Although the emissions would be reduced by seven percent, this would not reduce the impacts to below a level of significance. Noise The amount of cover soil and associated tmck trips are only seven percent less than the Proposed Project. Occasional blasting could still be required for this altemative. Therefore, the noise impacts associated with this altemative are the same as for the Proposed Project, except for the slight decrease in magnitude attributable to the seven-percent reduction in tmck trips. As discussed previously, significant and mitigable noise impacts would occur on San Elijo Road from Rancho Santa Fe Road to the Landfill (Tmck Routes 1, 2, 4, 5, and 6) while significant and immitigable impacts were identified along the entire length of Tmck Route 3 from Valley Parkway to the LandfiU. Noise levels on the freeway segments (1-5, 1-15, and SR78) are not significant, because of the existing noise levels. To reduce noise impacts would require a substantial reduction in the number of daily trips. This would effectively lengthen the constmction time and has been determined to be infeasible. The mitigation measures proposed for transportation/circulation would not significantly help reduce the impacts for noise. Therefore, similar to the Proposed Project, Altemative A would have significant unmitigable noise impacts. Hydrology/Water Quality Impacts to surface water quality and runoff associated with the constmction of Altemative A would be the same as for the Proposed Project, because both will include the same engineered drainage control systems protecting the quality of surface water runoff and ensuring that the peak surface water runoff is accommodated with mitumal erosion or siltation. Similarly, erosional impacts for Altemative A are expected to be the same as for the Proposed Project, because both altematives include final grading of the cover, a vegetative cover, and an engineered drainage system designed to capture surface water run-on and runoff, and limit run-on velocities that San Marcos Landfill Closure and 4-9 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 ^ Project Altematives UHU) might otiierwise cause soil erosion. However, impacts to groundwater quality will be different, „ based upon the performance of the final cover system and its ability to limit surface water mm infiltration and the production of leachate. ^ The prescriptive cover system proposed (Altemative A) for the Landfill was modeled using wm LEACHM (Leaching Estimating and Chemistry Model) to evaluate tiie amount of water that would pass tiirough the cover system as a means of measuring cover performance (GeoLogic and m Associates, 2002). The United States Army Corps of Engineers ("ACOE") HELP3 computer - program was used to calculate the infiltration rates through the top deck cover system m (GeoLogic, 2002). HELP3 was used for tiie top deck modelmg (instead of LEACHM) because •* of its ability to model cover systems tiiat include FMLs, whereas LEACHM can only be appUed •» to soil systems. wm In calculating potential infiltration through the liner, conservative assumptions were made, " including the assumption of a pinhole density of one per acre and an installation defect density of 10 per acre. A pinhole is defined by HELP3 as a hole one millimeter in diameter and is tiie resuh of flaws in tiie manufacturing of tiie FML, while an installation defect is defined as a hole one centimeter in diameter and is the result of punctures or seaming holes created during the *" deployment of tiie FML. This modeling and these assumptions are consistent with the " methodology established by the ACOE, and give a conservative estimate of the actual amount of water that is likely to pass through the cover to the underlying refiise. p The results of this modelmg mdicate the average infiltration rate through the top deck cover is P n 0.05 mm per year. For the side slopes within the vertical expansion area, the average annual rate of infiltration tiu-ough the cover system is calculated to be 1.06 mm. For slope areas outside of the vertical expansion area, the flux is calculated to be 2.36 mm per year. However, typically the clay barrier degrades over time, allowing more water to infiltrate to the underlying cover (Dwyer, 2000; Dwyer, 1998; and Melchior, 1997). These model results do not account for tiiis substantial loss of performance anticipated for a clay barrier layer constmcted in an arid envu-onment (i.e., increased infiltration rates that develop over time in response to desiccation San Marcos Landfill Closure and 4.10 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Project Alternatives cracks and root penetrations). As a result, the infiltration rates calculated are considered "best case" results. Over the last several years, the performance of and loss of cover clay have become issues of concem. In fact, EPA design guidelines recognize that using a barrier layer composed of clay, such as is included in this prescriptive cover system, is not very effective in arid regions (such as San Diego and the vicinity of the Landfill). This is because the soil is compacted with more moisture than is needed to achieve optimum density and as the soil dries, it experiences a high level of volume reduction, which leads to cracking caused by shrinkage. Water balance data collected over time on this type of cover system found that while this type of cover system functioned well initially, performance decreased severely within only a few years, resulting in increased percolation of water as a function of the development of desiccation cracking and root penetration (Dwyer, 2000; Dwyer, 1998; and Melchior, 1997). In fact, at the conclusion of the Melchior study (carried out over a period of eight years), about 50 percent of the water that reached the surface of the system infiltrated through it to the underlying refiise. Since infiltration through the Proposed Project cover system is calculated to be equivalent to the prescriptive system (under the modeled "best case" scenario of no desiccation cracking and root penetrations, as described above) for the top deck and significantiy less on the side slopes (0.03 mm per year for the side slopes with three feet of vegetative cover soU, and 0.14 mm per year for side slopes with six feet of vegetative cover soil) and will be significantly less prone to development of desiccation cracks and cover degradation, it is concluded that the Proposed Project provides greater protection to groundwater than Altemative A. By limiting the amount of water that infiltrates through the cover to the underlymg refiise, the Proposed Project will provide the best opportunity for preventing fiiture degradation of water quality, and avoiding violation of water quality standards and waste discharge requirements, through reduced leachate generation. San Marcos Landfill Closure and 4-11 Post-Closure Maintenance Plans EIR Draft EIR-AprU 2002 Project Alternatives 4,3.3 Staffs Rationale for Rejection of Altemative A Altemative A would not meet the requirements of tiie Modified LSA Plan, because the one-foot vegetative layer proposed with this altemative will not support CSS and chapartal species as required by the Superior Court writ of mandate. A one-foot vegetative soil layer would support grasses and forbs. The vegetative communities in the area surrounding the Landfill are CSS and chaparral. Thus, by utilizing this altemative, the visual appearance of the LandfiH would contrast substantially with the adjacent natiiral areas. A large expanse of normative grassland would negatively contrast with the texture and color of the surrounding CSS and chaparral communities. Since the Landfill is a major topographic feature, visible from pubHc and private vistas, tiie contrast would be considered a significant visual impact as compared to the Proposed Project. Altemative A would substantially degrade a scenic vista when compared to the aesthetic benefit of the Proposed Project. Any increase in the depth of the vegetative layer to comply with tiie Modified LSA Plan would negate the reduction in tmck trips associated with this altemative and, therefore, negate any mitigation of impacts when compared to the Proposed Project. In any event, the County must comply witii the Superior Court writ of mandate, which requires revegetation witii CSS and chaparral species. These species require a minimum of three feet of vegetative soil on the Landfill surfaces. Additionally, this alternative would utilize a clay barrier layer. Clay is subject to shrinking and cracking in warmer and drier climates, such as that existing in the vicinity of the Landfill. Cracking of tiie clay layer could increase the potential for water infiltration into the waste layers, and introduction of leachate to groundwater. The introduction of leachate into the groundwater can cause significant water quality impacts. Additionally, cracking of the clay layer would require major maintenance by the County. The Proposed Project will eliminate the clay layer, and therefore remove this potentially expensive, long-term maintenance issue. San Marcos Landfill Closure and 4_12 Post-Closure Maintenance Plans EIR P P P Draft EIR-AprU 2002 Project Alternatives 4.4 Analvsis of Altemative B: Prescriptive Cover Alternative with Flexible Membrane Liner as Top Deck Barrier 4.4.1 Altemative B Description and Setting Under Altemative B, tiie Landfill closure would be completed by utilizing the same cover system as Altemative A, except that the two-foot clay barrier layer is not included on the top deck. Instead, the FML is placed directly over the foundation soil (Table 4-1). Figure 4.4-1 depicts tiie Landfill cover design utilizing Altemative B, showing cross sections of the cover layers. Approximately 254,000 cubic yards of cover soil would be imported, representmg a 40-percent reduction in tiie number of tmck trips (30,000 trips for Proposed Project vs. 18,143 tiips for Altemative B). The haulmg schedule could be reduced from approximately seven months to four months with the same number of daily trips. As with the Proposed Project, the cover soil will be imported from an approved borrow site. The six tmck routes could also be used for this altemative. The site would be revegetated with a mixture of grasses and forbs. All other design components (e.g., stormwater management, post-closure maintenance, and LFG control) of the Proposed Project would remain the same for this altemative. 4.4.2 Comparison of the Effects of Alternative B to the Proposed Project Transportation/Circulation Altemative B would reduce the short-term impact from tmck traffic transportuig the large quantity of cover soil for the fmal closure cover system by reducing the number of tmck trips by 11,857 trips. Under Altemative B the amount of imported cover soU would be approximately 254,000 cubic yards, hauled over an approxunate two- to four-month period with an average of 400 to 200 tmck trips per day. While this represents a 40-percent reduction in tiie number of tmck trips, this reduction is not substantial enough to reduce short-term transportation/circulation impacts to below a level of significance. The daily levels of service would not improve to acceptable levels, even ifthe number of tmck Uips is reduced to 100 per day. Thus, a 40 percent San Marcos Landfill Closure and 4-13 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 ^ Project Alternatives reduction in tiie overall trips (altiiough it is a substantial reduction) would not reduce tiie short- ^ term impacts to below a level of significance. It would reduce tiie time from almost seven to *m four montiis (or on an expedited schedule, tiu-ee-and-a-half to two montiis). As witii tiie m Proposed Project, proposed mitigation measures for tiiis altemative include notifying local *- bicycle clubs of the haul period schedule and routing, and accepting cover soil haul tmcks at tiie m Landfill between 7:00 AM and 4:00 PM only. The incorporation of tiiese mitigation measures - would not reduce significant impacts to below a level of significance. Although tiie daily wm impacts are tiie same (significant and unmitigated), because of tiie substantial reduction in the duration that tiie impacts would have when contrasted against the Proposed Project, this -« altemative is considered environmentally superior to the Proposed Project witii regard to transportation/circulation impacts. M wm Air Quality «v m Although the amount of cover soil and associated mick trips are 40 percent less than for tiie Proposed Project, Altemative B would still have tiie same daily emissions, because tiie number " of dips per day would stay the same. The time frame for tiie constmction could be reduced from seven to four montiis (or on an expedited schedule, tiiree-and-a-half to two montiis). The daily emissions would still exceed tiiresholds for NOx and PMio; however, for fewer days. Although " tiie daily impacts are tiie same (significant and unmitigated), because of tiie substantial reduction in the duration tiiat the impacts would have when contrasted against the Proposed Project, this P p altemative is considered envuronmentally superior to the Proposed Project with regard to air quality impacts. p P Noise P p The amount of cover soil and associated tmck trips would be 40 percent less than for the " p Proposed Project. Occasional blastmg would still be required for this altemative. As discussed previously, significant and mitigable noise impacts would occur on San Elijo Road from Rancho Santa Fe Road to tiie Landfill (Tmck Routes 1, 2, 4, 5, and 6) while significant and unmitigable San Marcos Landfill Closure and 4. J4 Post-Closure Maintenance Plans EIR P P P P m Draft EIR-April 2002 Project Altematives impacts were identified along the entire length of Tmck Route 3 from Valley Parkway to the Landfill. Noise levels on the freeway segments (1-5, 1-15, and SR78) are not significant, because of the existuig ambient noise levels. To reduce noise impacts would require a substantial reduction in the number of daily trips. This would effectively lengtiien the constmction time frame, which has been determined to be mfeasible. The mitigation measures proposed for transportation/circulation would not significantly help reduce the unpacts for noise. However, because of the substantial reduction in duration for the impacts, this altemative is considered to be environmentally superior to the Proposed Project with regard to noise impacts. Hydrology/Water Quality Impacts to surface water quality and runoff associated with the constmction of Altemative B would be the same as for tiie Proposed Project, because both will include the same engmeered drainage control systems protecting the quality of surface water runoff and ensuring that the peak surface water runoff is accommodated without erosion or siltation. Similarly, erosional impacts for Altemative B are expected to be the same as for the Proposed Project, because botii altematives include final grading of tiie cover, a vegetative cover, and an engmeered drainage system designed to capture surface water run-on and runoff, and limit run-on velocities that might otherwise cause soil erosion. However, impacts to groundwater quality will be different, based upon the performance of the final cover system and its ability to limit surface water infiltration and the production of leachate. For this altemative, modeling of infiltration through the top deck was conducted using the HELP3 computer program, and LEACHM was used for the side slopes. The modeling completed on the top deck cover system mdicates that on average about 1.02 mm per year of water will infiltrate through the top deck final cover profile. Because the side-slope San Marcos Landfill Closure and 4-15 Post-Closure Maintenance Plans EIR Draft Em-April 2002 Project AUematives MM constmction under tiiis altemative is tiie same as for Altemative A, tiiere is no difference in tiie ^ infiltration rate tiirough those portions of the cover system. ^ wm Since infiltration tiirough tiie Proposed Project system is calculated to be significantiy less tiian tiie FML prescriptive system (0.03 mm per year for the top deck and tiie side slopes witii tiu-ee «. feet of vegetative cover soil, and 0.14 mm per year for tiie side slopes with six feet of vegetative cover soil) and will be less prone to post-constmction distress, it is concluded that the Proposed wm Project provides greater protection to groundwater than Altemative B. By limiting the amount of "» water tiiat infiltrates through tiie cover to tiie underlying refuse, tiie Proposed Project will m, provide tiie best opportunity of preventing future degradation of water quality, and violation of water quality standards and waste discharge requirements, tiu-ough reduced leachate generation. - Mt 4,4.3 Staffs Rationale for Rejection of Alternative B M mm This altemative would not meet tiie requirements of tiie Modified LSA Plan because tiie one-foot vegetative layer proposed witii tius altemative will not support CSS and chaparral species. Under this altemative, the Landfill surfaces would include one foot of vegetative cover soil. ^ This does not meet tiie tiiree- to six-foot soil deptii required to support tiie CSS and chaparral species mandated by tiie court-ordered Modified LSA Plan. A one-foot vegetative soil layer ^ would support grasses and forbs. The vegetative communities in tiie area surrounding the LandfiH are CSS and chaparral. Thus, by utilizing tiiis altemative, the visual appearance of tiie P site would contrast substantially witii the adjacent natural areas. A large expanse of non-native *" grassland would negatively contrast witii tiie texture and color of tiie CSS and chapan-al P communities. Since the Landfill is a major topographic feature, visible from public and private vistas, tiie conti-ast would be considered a significant impact as compared to tiie Proposed " Project. Altemative B would substantially degrade a scenic vista when compared to the aesthetic benefits of tiie Proposed Project. An increase in die depth of tiie vegetative layer to comply witii ^ the Modified LSA Plan would negate tiie reduction m tmck tips associated witii this altemative. "* Altiiough tius altemative is considered tiie environmentally prefcrted one with respect to " transportation/circulation, air quality, and noise, it is not in respect to tiie Proposed Project. In " San Marcos Landfill Closure and 4.|g Post-Closure Maintenance Plans EIR P P ™ Draft EIR - April 2002 Project Altematives ^ addition, the Coimty must comply with the Superior Court writ of mandate, which requires M revegetation with CSS and chaparral species. These species require three to six feet of ^ vegetative soil on the LandfiU surfaces. Additionally, this altemative would utUize a clay barrier layer on side slopes. Clay is subject to P shrinking and cracking m warmer and dryer climates, such as that experienced in the vicinity of M the LandfiU. Cracking ofthe clay layer would require major maintenance. The Proposed Project P will eliminate the clay layer and, therefore, remove this potentially expensive, long-term «• maintenance issue. Ml ^ 4.5 Analvsis of Altemative C: Prescriptive Cover Altemative as Modified bv RWOCB Order No. 92-02 with Court-Mandated Vegetative Cover mm 4,5.1 Altemative C Description and Setting Under Altemative C, the Landfill closure would be completed utilizing the prescriptive cover "" system described in Altemate A, with the addition of an additional three to six feet of vegetative cover soil as mandated by the court-ordered Modified LSA Plan. Figure 4.5-1 depicts the ^ configuration of the Landfill cover system described as Altemative C, showing cross sections of the cover layers. A total of 696,000 cubic yards of imported cover soil would be required, necessitating a total of 49,714 tmck trips over an approximate seven- to 11-month period with an average of 400 to 200 trips per day. The foundation soil and barrier soil layers will be the same ^ as for Altemative A (Table 4-1). There are approximately 66 percent more tmck trips (30,000 trips for the Proposed Project vs. 49,714 for Altemative C). The Landfill surfaces would ^ be revegetated with a mixture of CSS and chapanal species. As with the Proposed Project, cover soil will be imported from an approved borrow site. The six altemative tmck routes could also be used for this altemative. AU other design components of the Proposed Project (e.g., stormwater management, post-closure maintenance, and LFG control) would remain the same for this altemative. San Marcos Landfill Closure and 4-17 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Project Alternatives 4.5.2 Comparison of the Effects of Altemative C to the Proposed Project Transportation/Circulation Altemative C would have more significant short-term impacts caused by tmck traffic than those identified for the Proposed Project. This altemative would require the importation of approximately 696,000 cubic yards of soil over an approximate 11-month time period. This represents a 66 percent increase in the amount of soil import and related tmck traffic. As with the Proposed Project, proposed mitigation measures for this altemative include notifymg local bicycle clubs of the haul period schedule and routing, and accepting cover soil haul tmcks at the Landfill between 7:00 AM and 4:00 PM only. The incorporation of these mitigation measures would not reduce significant transportation/circulation impacts to below a level of significance. Air Quality Altemative C would increase the amount of cover soil by 66 percent that would be imported. Vehicular emissions and fugitive dust impacts associated with the transportation and placement of cover soil would be proportionally greater than for the Proposed Project under Altemative C; short-term sigruficant and immitigated air quality impacts would occur for NOx and PMio. Noise The amount of cover soil and associated tmck trips are 66 percent greater than for the Proposed Project. Occasional blastmg would still be required for this altemative. Therefore, the noise impacts associated with this altemative are greater than for the Proposed Project. As discussed previously, short-term significant and mitigable noise impacts would occur on San Elijo Road from Rancho Santa Fe Road to the Landfill (Tmck Routes 1, 2, 4, 5, and 6) while short-term significant and unmitigable impacts were identified along the entire length of Tmck Route 3 from Valley Parkway to the LandfiH. Route 3 passes by a large number of residential land uses, San Marcos Landfill Closure and 4-18 Post-Closure Maintenance Plans EIR •Mi Draft EIR - April 2002 Project Altematives which are considered sensitive noise receptors. Noise levels on the freeway segments (1-5,1-15, and SR 78) are not significant, because of the existing ambient noise levels. To reduce significant noise impacts would require a substantial reduction in the number of daily trips. This would effectively lengthen the consUiiction time frame and has been determined infeasible. The mitigation measures proposed for transportation/circulation would not significantly help the impacts for noise. Therefore, this altemative will have a significant and unmitigable noise impact. Hydrology/Water Quality This altemative increases the vegetative layer to three to six feet to support a deeper rooting plant community (i.e., CSS and chapanal). Otherwise, this altemative is the same as Altemative A. Impacts to surface water quality and runoff associated with the constmction of this altemative would be the same as for the Proposed Project, because both will include the same engineered drainage control systems protecting the quality of surface water runoff and ensuring that the peak surface water runoff is accommodated without erosion or siltation. Similarly, erosional impacts for Altemative C are expected to be the same as the Proposed Project, because both altematives include final grading of the cover, a vegetative cover, and an engineered drainage system designed to capture surface water run-on and runoff, and limit run-on velocities that might otherwise cause soil erosion. However, impacts to groundwater quality will be different, based upon the performance of the final cover system and its ability to lunit surface water infiltration and the production of leachate. Modeling (LEACHM for the side slopes and HELP3 for the top deck) was performed to evaluate the performance of this cover system configuration, and the results indicate that an average of 0.04 mm per year of liquid infiltration will result on the top deck. For the side slopes, since the cover configurations are sunilar to those proposed in Altematives A and B, the model results calculate a similar to slightiy better performance, with the amount of San Marcos Landfill Closure and 4-19 Post-Closure Maintenance Plans EIR Draft EIR-AprU 2002 Project Alternatives m mi liquid infiltration of 1.06 and 1.20 mm per year for the areas above and below the vertical ^ expansion, respectively. As described in Chapter 4.2.3 above, numerous studies have shown that li- the use of a clay barrier in arid envirorunents such as at the Landfill is likely to result in the development of desiccation cracks with time; however, the model results do not account for this cracking. Based on recent studies, the barrier layer would be expected to result in a loss of w performance and a significantly higher amount of water passing through to the imderlying refuse over time (one study showed up to about 50 percent of the water that reached the surface of the wm system passed through it). " •• Since infiltration through the Proposed Project cover system is calculated to be less than for " Altemative C for the top deck (0.03 mm per year) and sigruficantly less than the prescriptive «• system on the side slopes (0.03 mm per year for the side slopes with three feet of vegetative cover soil, and 0.14 mm per year for the side slopes with six feet of vegetative cover soil) and " will be significantly less prone to development of desiccation cracks and cover degradation, it is concluded that the Proposed Project provides greater protection to groundwater than ^ Ahemative C. By limiting the amount of water that infiltrates through the cover to the underlying refuse, the Proposed Project will provide the best opportunity for preventing future " degradation of water quality, and violation of water quality standards and waste discharge *" reqiurements, through reduced leachate generation. ^ WM 4,5,3 Staffs Rationale for Rejection of Altemative C P P Altemative C will increase the amount of tmck traffic and associated noise and air quality P li impacts by increasing haul traffic by 66 percent. Under this altemative, the hauling and placement schedule for cover soil would increase by approximately three to four months, * P resulting in a lengthened timeframe for roadway and intersection impacts. This altemative would also extend the time period for NOx and PMio impacts. A longer haul period would * extend the length of noise impacts along the haul routes. Finally, Altemative C results in a significant cost increase for the County. " San Marcos Landfill Closure and 4-20 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Project Alternatives Additionally, this altemative would use utilize a clay barrier layer. Clay is subject to shrinking and cracking in warmer and drier climates, such as that experienced in the vicinity of the Landfill. Cracking of the clay layer can allow water infiltration into the waste layers and introduction of leachate to groundwater. The introduction of leachate into the groundwater can cause significant water quality impacts. Cracking of the clay layer would reqiure major maintenance. The Proposed Project will eliminate the clay layer, and therefore remove this potentially expensive maintenance issue. 4.6 Analvsis of Altemative D: Prescriptive Cover Altemative With Flexible Membrane Liner as Top Deck Barrier Layer and Court-Mandated Vegetative Cover 4.6,1 Altemative D Description and Setting Under Altemative D, the Landfill closure would be completed by utilizing the cover system described in Altemative B, the one foot of vegetative soil being replaced with three to six feet of vegetative soil, as mandated by the court-ordered Modified LSA Plan. Figure 4.6-1 depicts the configuration of the Landfill cover system described as Altemative D, showing cross sections of the cover layers. The LandfiH surfaces would be revegetated with a mixture of CSS and chaparral species. This altemative would require importing 560,000 cubic yards of fill and require approximately 40,000 tmck trips over a four-and-a-half- to nine-month period (assuming 400 to 200 trips per day). As with the Proposed Project, the cover soil will be imported from an approved bortow site. The six altemative tmck routes could also be used for this altemative. All other design components of the Proposed Project (e.g., stormwater management, post-closure maintenance, and LFG control) would remain the same for this altemative. San Marcos Landfill Closure and 4-21 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Project Altematives 4.6,2 Comparison ofthe Effects of Altemative D to the Proposed Project Transportation/Circulation This altemative would require tiie importation of approximately 560,000 cubic yards of soil over an approximate nine-montii time period. Altemative D would have a 33-percent mcrease in short-term impacts caused by the increased duration and number of tmck trips compared to the Proposed Project. This represents a 33-percent increase in the amount of soil import and related tmck traffic, which is a significant and unmitigated impact. As with the Proposed Project, mitigation measures proposed for this altemative include notifying local bicycle clubs ofthe haul period schedule and routing, and accepting soil haul tmcks at the LandfiU between 7:00 AM and 4:00 PM only. The incorporation of tiiese mitigation measures would not reduce significant transportation/circulation impacts to below a level of significance. Air Quality Altemative D would increase, by 33 percent, the amoimt of cover soil that would be imported. Fugitive dust (PMio) and NOx impacts associated witii tiie transportation and placement of cover soil would be greater tiian for the Proposed Project. Therefore, air quality impacts would be significant and immitigable. Dust suppression techniques, similar to those required for the Proposed Project, would also be required for Altemative D; however, air quality impacts would not be reduced to below a level of significance. Noise The amount of cover soil and associated tmck trips are 33 percent greater than for the Proposed Project. Occasional blasting could still be requured for this altemative. Therefore, the noise impacts associated with this altemative are greater than for the Proposed Project. As discussed previously, short-term significant and mitigable noise impacts would occur on San Elijo Road from Rancho Santa Fe Road to tiie Landfill (Tmck Routes 1, 2, 4, 5, and 6) while short-term San Marcos Landfill Closure and 4.22 Post-Closure Maintenance Plans EIR an Draft EIR-AprU 2002 Project Alternatives significant and unmitigable impacts were identified along the entire length of Tmck Route 3 from Valley Parkway to the LandfiU. Noise levels on the freeway segments (1-5, 1-15, and SR 78) are not sigiuficant, because of the ambient noise levels existing. Reduction of noise impacts would require a substantial reduction in the number of daily trips. This would effectively lengthen the constmction time frame and has been determined infeasible. The mitigation measures proposed for transportation/circulation would not significantiy help reduce the short-term noise impacts. Similar to the Proposed Project, short-term noise impacts for this altemative would be significant and unmitigable. Hydrology/Water Quality Impacts to surface water quality and runoff associated with the constmction of Altemative D would be the same as the Proposed Project, because both will include the same engineered drainage control systems protecting the quality of surface water runoff and ensuring that the peak surface water runoff is accommodated without erosion or siltation. Similarly, erosional impacts for Altemative D are expected to be the same as the Proposed Project, because both altematives include final grading of the cover, a vegetative cover, and an engineered drainage system designed to capture surface water run-on and runoff, and limit run-on velocities that might otherwise cause soil erosion. However, impacts to groimdwater quality will be different, based upon the performance of the final cover system and its ability to limit surface water infiltration and the production of leachate. For this altemative, because this cover system includes an FML rather than a clay barrier layer on the top deck, modeling of fluid flow through the top deck was performed using the HELP3 computer program, while LEACHM was used for the side slopes. Results of the modeling indicate that the amoimt of water that will infiltrate through the top deck FML final cover section is estimated to be about 1.64 mm per year. For the side slopes, since they are the same as in Altemative C, the amount of water passing through the cover is the same. San Marcos Landfill Closure and 4-23 Post-Closure Maintenance Plans EIR Draft EIR-AprU 2002 Project Alternatives Since infiltration through the proposed monolithic cover system is calculated to be significantiy less tiian the FML prescriptive system (0.03 mm per year for the top deck and the side slopes witii tiu-ee feet of vegetative cover soH witiiin the vertical expansion area, and 0.14 mm per year for the side slopes with six feet of vegetative cover soil) and wiU be less prone to post- constmction distress, it is concluded that the Proposed Project's cover system provides greater protection to groundwater tiian Altemative D. By limiting the amount of water that infiltrates tiirough the cover to tiie underiying refuse, the Proposed Project will provide the best opportunity for preventing future degradation of water quality, and violation of water quality standards and waste discharge requirements, through reduced leachate generation. 4.6.3 Staffs Rationale for the Rejection of Alternative D Altemative D will increase the amount of tmck traffic, and noise and air quality impacts associated with increased haul traffic. Under this altemative, the hauling schedule for soil would increase by approximately two to three months, resulting in a significant cost increase for the County. Additionally, the performance of the cover system is better for the Proposed Project than under this altemative. San Marcos Landfill Closure and 4-24 Post-Closure Maintenance Plans EIR . :::..".•..:-•&»;:.••." •'^S*Mt:::fkPA5iSl^^^ .' V-' I !:•• • ...TQR DECK' -7:-, •-. "- -"•""-^Sr'" '\ "•• % \"'" -•'.>>••' xA ^z/'-' ' ••••• '-V • ; ' ;1 ^; """"""7" j^^— \ "iS^'; ^ • LEGEND FILL BOUNDARY FML FLEXIBLE MElr^W4E LMER NOTE: ALL AREAS PLAMtO) TO GRASSES AW FORBES. 2* amtei son. r FOUNOATION SOL (SEE NOTQ NOTE; THREE FEET OF EXISni^ ir^TERIM TOP DECK COVER SOIL WILL BE REMOVED AND USED FOR BARRIER lAYER SOIL. NEW FOUNDATION SOIL WILL BE USED. Soupca: Brown & Caldwel 1^=400 leet '&D Environmental Services Alternative A Figure 4,3-1 r r I. Source: Brown & CaMwelt 1 inch =400 feet 0p '&D Environmental Services Alternative B Figure 4.4-1 Scxirce: Browl & CaldweU 1lnch=400feet Alternative C 0p '&D Environmental Services Figure 4.5-1 w r '&D Environmental Services Alternative D Figure 4,6-1 lllllllllll lifllllllllllllllti t llllll Draft EIR-April 2002 Project Alternatives Table 4-1 Summary and Comparison of Alternative Cover Requirements Proposed Proiect Alternative A Alternative B Alternative C Alternative D Tnn Dprk - 42 acrfcs Vegetative Soil Minimum 3 feet w/CSS Minimum 1 foot w/grasses and forbs Minimum 1 foot w/grasses and forbs Minimum 3 foot w/CSS Minimum 3 foot w/CSS Flexible Membrane Liner None Yes Yes Yes Yes Barrier Soil None 2 feet None 2 feet None Foundation Soil 2 feet (existing) 2 feet (replace existing) 2 feet (replace existing) 2 feet (replace existing) 2 feet (replace existing) SiHp Slnn(>.« Ahnve Vertical Exnansion - 20 acres Vegetative Soil See Note (a) Minimum 1 foot w/grasses and forbs Minimum 1 foot w/grasses and forbs See Note (a) See Note (a) Barrier Soil None 2 feet 2 feet 2 feet 2 feet Foundation Soil 2 feet (existing) 2 feet (existing) 2 feet (existing) 2 feet (existing) 2 feet (existing) IsiiHp s:innA« R«lnw Vertical Exnansion - 40 acres Vegetative Soil See Note (a) Minimum I foot w/grasses and forbs Minimum 1 foot w/grasses and forbs See Note (a) See Note (a) Barrier Soil None 1 foot 1 foot I foot I foot Foundation Soil See Note (a) See Note (b) See Note (b) See Note (b) See Note (b) Hflulinff Reouirements . . —— Total Cubic Yards Imported 420,000 390,000 254,000 696,000 560,000 Total Tmck Trips 30,000 27,857 18,143 49,714 40,000 Estimated Time for Import in Months at 200 Trips/Day 6.8 6.3 4.1 11.3 9.1 Estimated Time for Import in Months at 300 Trips/Day 4.5 4.2 2.7 7.5 6.1 Estimated Time tor Import in Months at 400 Trips/Day*°' 3.4 3.2 2.1 5.7 4.6 Notes- (a) The side slopes, except for the north and portions ofthe east (18 acres total), will receive three feet of vegetative soil with CSS. The slopes, excluding benches and access roads) will receive five to six feet of vegetative soil and will be revegetated with chaparral. (b) There is a minimum of two feet of existing interim cover soil (foundation soil) on all of the side slopes. The areas to the east and north side slopes below the first bench have up to 10 feet of foundation soil. (c) All impact analyses have been conducted at the maximum number of trips anticipated daily. Source: Brown and Caldwell, 2002a. San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 4-33 Draft EIR-April 2002 Project Alternatives Table 4-2 Comparison of Proposed Project and Alternatives Alternatives Issue Areas Alternatives Transportation/ Circulation Air Quality Noise Hydrology/ Water Quality Proposed Project: Monolithic Cover Significant, Unmitigable Significant, Unmitigable Significant, Unmitigable Less than Significant No Project/No Development Alternative Less than Significant Less than Significant Less than Significant Potentially Significant, Unmitigable Alternative A: Prescriptive Cover Altemative as Modified by RWQCB Order No. 92-02 Significant, Unmitigable Significant, Unmitigable Significant, Unmitigable Less than Significant Alternative B: Prescriptive Cover Altemative with Flexible Membrane Liner as Top Deck Barrier [Environmentally Preferred Alternative] Significant, Unmitigable Significant, Unmitigable Significant, Unmitigable Less than Significant Alternative C: Prescriptive Cover Alternative as Modified by RWQCB Order No. 92-02 with Court- Mandated Vegetative Cover Significant, Unmitigable Significant, Unmitigable Significant, Unmitigable Less than Significant Alternative D: Prescriptive Cover Altemative with Flexible Membrane Liner as Top Deck Barrier Layer and Court-Mandated Vegetative Cover Significant, Unmitigable Significant, Unmitigable Significant, Unmitigable Less than Significant San Marcos Landfill Closure and Post-Closure Maintenance Plans EIR 4-34 il li ii 11 El mm il 11 II II II II li II il il ii il Draft EIR - April 2002 Long-Term Environmental Effects CHAPTER 5.0 LONG-TERM ENVIRQNMENTAL EFFECTS 5.1 Growth-Inducing Impacts Section 15126.2(d) of the State CEQA Guidelines requires that an EIR evaluate the growth- inducing impacts of a proposed project and discuss "the ways in which the Proposed Project could foster economic or population growth, or the constmction of additional housing, either directly or indurectiy, m the sunounding environment." Section 15126.2(d) also requires the analysis of those project characteristics that may encourage or facilitate activities that, either individually or cumulatively, could significantly affect the environment. Chapter 3.0 presents the cumulative impact analysis. Induced growth is any growth that exceeds planned growth and results from new development that would not have taken place without the implementation ofthe Proposed Project. Typically, the growth-inducing potential of a project would be considered significant if it results in growth or population concentration that exceeds those assumptions included in pertinent general plans, land use plans, or projections made by local or regional planning authorities. However, the creation of growth-inducing potential does not automatically lead to growth. Addhionally, the State CEQA Guidelines Section 15126.2(d) also states that the lead agency must not assume that growth in any area is necessarily beneficial, detrimental, or of littie significance to the environment. The enviroimiental effects of induced growth are secondary or indirect impacts ofthe Proposed Project. Secondary effects of growth could result in significant, adverse environmental impacts, which could include mcreased demand on community or public services, increased traffic and noise, degradation of air and water quality, and conversion of agricultural land and open space to developed uses. This increase in demand for services would be the result of residential growth within the area. That creates the need for additional development of adequate services to accommodate the growing community. San Marcos Landfill Final Closure and 5-1 Post-Closure Maintenance Plans EIR m The use of the soil-hauling tmcks to import the required cover soil will cause a significant short- term transportation/circulation impact. Roadway and intersection improvements are not feasible or practicable for these unpacts, since they are short term (approximately seven months). Transportation/circulation mitigation measures that are proposed for the Proposed Project include limiting the delivery of cover soil to the Landfill from 7:00 AM to 4:00 PM, to avoid the PM peak traffic hours and notifying local bicycle clubs of the proposed route and schedule. San Marcos Landfill Final Closure and 5.2 Post-Closure Maintenance Plans EIR m Ml Draft EIR-April 2002 Long-Term Environmental Effects Implementation ofthe Proposed Project is not considered growth inducing, because it involves tiie final closure and post-closure maintenance of the San Marcos Landfill ("Landfill"). The Landfill closure is mandated pursuant to Califomia Code of Regulations ("CCR") Titie 27, and wm tiie County of San Diego has a legal requirement to close tiie LandfiH. The Proposed Project «• includes revegetation of tiie Landfill surface witii native vegetation, including coastal sage scmb wm and chapanal species. The LandfiH wiU become part of tiie Southem Focused Planning Area »• ("FPA") of tiie Natural Community Conservation Plan ("NCCP") for the City of San Marcos. « The Landfill area has been assigned a 100 percent conservation rate. Because of tiiis, future •* activity at the site is severely limited, and development would not be permitted to occur onsite. •M As a result, there is no net effect on regional growth associated with the implementation of the Proposed Project, and tiie impacts are therefore not considered to be adverse or sigiuficant. Ml 5.2 Significant Environmental Effects which Cannot be Avoided if the Proposed Proiect "* is Implemented State CEQA Guidelines Section 15126.2(b) requires tiiat an EIR analyze tiie significant envu-onmental effects that cannot be avoided if the Proposed Project is implemented. The *" Proposed Project will have significant short-term project-level impacts related to transportation/circulation, air quality, and noise. The Proposed Project will also have significant short-term cumulative impacts related to transportation/circulation, air quality, and noise. * IW m m Draft EIR - AprU 2002 Long-Term Environmental Effects Significant and unmitigable short-term project-level air quality impacts have been identified related to NOx emissions and PMio- A reduced project intensity of 33 percent could reduce NOx emissions to below a level of significance. However, a very massive reduction in project intensity would be needed to reduce PMio emissions to below a level of significance. The constmction schedule would need to be extended more than sixfold to reduce daily dirt handling and unpaved surface travel to a less than significant level. This was deemed infeasible. Therefore, the Proposed Project will have a significant and unmitigable short-term project-level air quality impact. Significant and unmitigable short-term project-level noise impacts were identified for the Proposed Project. Noise impacts were related to the hauling of cover soil along routes witii sensitive noise receptors (residential land uses). This included all of Tmck Route 3. Due to the short-term nature of the project, it was deemed infeasible to reduce noise impacts to below a level of significance. Significant short-term cumulative impacts related to transportation/circulation, air quality, and noise were identified for the Proposed Project. Sixteen projects are proposed in the vicinity of the Landfill that could contribute to the transportation/circulation, air quality, or noise impacts. Cumulative projects primarily consist of large-scale residential or mixed-use development projects (see Table 3-1). Some of these projects may be under constmction or occupied during the time that the Landfill closure program is being implemented. Since the Proposed Project is of a short duration, mitigation measures for cumulative impacts were deemed infeasible. San Marcos Landfill Final Closure and 5-3 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Long-Term Environmental Effects m m HI Ml (This page intentionally left blank.) li P H il il m San Marcos Landfill Final Closure and 5.4 Post-Closure Maintenance Plans EIR p Draft EIR - April 2002 Environmental Effects Found Not to be Significant CHAPTER 6.0 ENVIRQNMENTAL EFFECTS FOUND NOT TQ BE SIGNIFICANT 6.1 Effects Found not to be Significant as Part of the EIR Process During the preparation of the Draft EIR, the environmental issue of hydrology/water quality was found not to be significant. The following sections discuss the subject area and the determination as to not significant. 6.1.1 Hydrology and Water Quality Hydrology effects are defined by the volume and velocity of water flowing from the site. TypicaHy when precipitation falls on the land, it will "sheet flow" (water that travels in an undefined manner) until the water encounters changed conditions causing the water to flow in a defined drainage course. Naturally, water wiH flow downhill. When the volume or velocity of water reaches a certain level (depending upon soil conditions), drainage courses become defined. Water quality effects are defined as the chemical, physical, or biological changes to water as a result of flowing over and through soil, rock, or the landfill material. 6.1.1.1 Existing Conditions Hydrology. The following discussion identifies the characteristics of water flow surrounding and on the San Marcos Landfill ("Landfill"). The Landfill is situated in a canyon that drains westward toward Copper Creek (Figure 1-2). Copper Creek flows seasonally to the south along the Landfill's westem boundary into Escondido Creek, approximately three miles southwest of the site. Although a small portion of tiie County of San Diego ("County") property near the westemmost boundary is located within the 100-year floodplain, none of the existing Landfill facilities are located within the floodplain limits. San Marcos Landfill Final Closure and 6-1 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Environmental Effects Found Not to be Significant Surface mnoff at the site occurs primarily during and shortly after periods of precipitation. The existing Landfill storm water control system includes engineered drainages and storm water channels that direct surface water flow to two detention ponds (North and South Ponds) on the west side of the Landfill (Figure 1-5). Perimeter drainage ditches have been constmcted around the Landfill to intercept potential mn-on water (water that drains onto the Landfill) from up- slope areas and direct it to either Copper Creek or the North Pond. Similarly, mnoff water (water that drains off of the Landfill) is diverted from the top deck with trapezoidal channels (drainage channels), as well as other engineered drains on site that convey water to the two ponds. The majority of this surface mnoff is directed to the South Pond. Storm drain systems are designed to coHect and divert rainfall. The amount and duration of the rain for any storm will affect the size of the drainage facilities for a site. The State [under Califomia Code of Regulations ("CCR") Title 27 §20365(c)(l)] requires that drainage facilities be designed to accommodate the rainfall that would occur over a period of 24 hours for a storm event that occurs on the average of once in 100 years. The Landfill's storm water control system has been designed to collect and convey rainfall resulting from the projected 100-year-frequency storm events. This design is intended to ensure that stonn water is adequately controlled and flooding and washout would not occur, with the exception of highly unusual storm events (greater than the 100-year storm event). Water Quality. Physical, chemical, and biological changes can occur as water passes through the soil/bedrock or landfill material. The physical action of water flowing into the soil/bedrock or landfill is called infiltration. The County, as part of its ongoing monitoring program, monitors groundwater levels and water quality (surface water and groundwater). The following is a discussion of the monitoring programs. m In the vicinity of the LandfiH, groundwater flows through inegular joints and fractures in the bedrock. The groundwater system is recharged primarily by infiltration of precipitation and " mnoff from the surrounding mountain areas. Water level data are obtained quarterty from the IP on-site groundwater monitonng wells (Figure 6.1-1, included at the end of Chapter 6.0). These ^ monitoring data indicate that groundwater occurs at depths of less than 20 feet below the ground ^ • San Marcos Landfill Final Closure and 5^2 Post-Closure Maintenance Plans EIR P ll m m Draft EIR - April 2002 Environmental Effects Found Not to be Significant surface on the west side of the site (e.g., wells SMGW-36 and SMGW-37S), to about 350 feet below the ground surface on the southwest side of the Landfill (well SMGW-34). Groundwater elevations range from about 360 feet above mean sea level ("AMSL") (wells SMGW-30D, SMGW-39, and SMGW-40) to as much as about 660 feet AMSL (wells SMGW-23 and SMGW-26 (Figure 6.1-1). As shown on Figure 6.1-1, water level data indicate an approximate gradient of between 0.04 and 0.37 foot (vertical) per foot (horizontal), with the direction of groundwater flowing toward the westem toe of the Landfill. In bedrock systems, groundwater occurrence and movement will depend upon the size and density of fractures in the rock, and whether the fractures are connected so that the water can flow through them. Knowing the hydraulic conductivity (a measure of the abiUty of the geologic material to transmit water) helps to assess the average velocity of groundwater flow through the bedrock. However, the hydraulic conductivity will vary within the aquifer based on the size and shape of the fractures and their interconnection, and, therefore, it will not be uniform across the aquifer. For the Landfill, the hydraulic conductivities in wells tested range from 550 feet per day in well SMGW-30 (equivalent to a medium to coarse sand) to 0.00001 foot per day in well SMGW-33 (consistent with relatively unfractured bedrock). The Landfill has been operating under Waste Discharge Requirements ("WDRs") Nos. 92-02, 93-86, and 95-112, and Technical Change Order T-l to Order No. 92-02 ('TCO No. T-l") established by the Califomia Regional Water Quality Control Board, San Diego Region ("RWQCB"). The monitoring and reporting program ("M&RP") included in the WDRs establishes site-specific water quality protection standards ("WQPSs"). Specifically, the WQPSs include developing a monitoring system for groundwater, surface water, and the unsaturated zone, with background and comphance monitoring points for each medium. The WQPSs also require developing a list of monitoring parameters and constituents of concem and establishing the comphance period. Each element of the WQPSs is described below. The current M&RP for groundwater at the Landfill includes six background monitoring wells (SMGW-17, SMGW-24, SMGW-26, SMGW-36, SMGW-37S, and SMGW-37D), and three comphance monitoring wells (SMGW-33, SMGW-39, and SMGW-40; Figure 6.1-1). The background monitoring weHs are San Marcos Landfill Final Closure and 6-3 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Environmental Effects Found Not to be Significant m located hydrologically up-gradient of the Landfill and are designed to characterize groundwater before it is potentially impacted by the Landfill (i.e., water not influenced by the Landfill). The compliance wells are hydrologically downgradient of the Landfill and are designed to identify potential landfill impacts to groundwater. Because volatile organic compounds were identified in several groundwater monitoring wells at the Landfill in 1987 (as noted in RWQCB Order No. 92-02), the groundwater monitoring program also includes a Conective Action Program ("CAP") monitoring network under RWQCB Order No. 95-112 to mitigate impacts to groundwater and retard off-site migration of impacted groundwater from the Landfill. This network consists of monitoring wells SMGW-16, SMGW-30, and SMGW-31 on the west side of the Landfill and weH SMGW-35 north of the Landfill. Wells SMGW-16, SMGW-30, and SMGW-31 are pumped about 12 hours per day at an average total rate of 42 gallons per minute, and this water is used for on-site dust control or discharged to the South Pond or Copper Creek. Well SMGW-35 is pumped twice a day, with about 200 gallons of water pumped per day, and this water is recycled for irrigation of native vegetation outside tiie northem waste fill boundary (Geosyntec, 2001). To assess the effectiveness of the corrective action network, these CAP wells are also sampled routinely, along with the nine detection monitoring wells. In addition to the on-site detection and CAP groundwater monitoring systems, an off-site groundwater monitoring program is implemented at four privately owned wells, including OFSM-1, OFSM-2, OFSM-24, and OFSM-27 (Figure 6.1-2, included at the end of Chapter 6.0). Similar to the groundwater monitoring program, surface water monitoring is performed upstream and downstream of the Landfill to evaluate impacts of the Landfill on surface water. As part of RWQCB Order No. 92-02, the M&RP includes surface water sampling and analysis from Copper Creek at upstream (background) surface water sampling point SMSP-2 and downstream (comphance) surface water sampling point SMSP-4, when sufficient flow exists. The County installed an underdrain system in the canyon beneath the western portion of tiie Landfill, originally to drain areas that were thought to be wet from seeps in the underiying bedrock San Marcos Landfill Final Closure and 5_4 Post-Closure Maintenance Plans EIR P Ki m p Draft EIR - AprU 2002 Environmental Effects Found Not to be Significant (observed during a site investigation in 1977) and convey the water to the South Pond. RWQCB Order No. 92-02 requires collection of samples from this underdrain system, if sufficient liquid is present, and from the South Pond before tiie water is discharged to Copper Creek; however, the underdrain system has been dry. RWQCB Order No. 92-02 also requires monitoring of the unsaturated zone monitoring system (moisture probes) installed beneath the clay layer that was constmcted as part of the vertical expansion. Finally, RWQCB blanket Order No. 93-86 requires that a leachate sample (water that has percolated through the refuse to the collection and removal system sump) be collected each year during October, and retested in April if necessary, at all landfills in the region that are equipped with a liner and leachate collection and removal system ("LCRS"), such as the LandfiU. Because the County disposes of the leachate into a sanitary sewer system, the site industrial wastewater discharge permit also requires collection of an effluent sample to verify that the leachate is suitable for disposal. The routine monitoring parameters for the groundwater and surface water monitoring points include ammonia (as nitrogen), chemical oxygen demand, chloride, iron, nitrate as nitrogen, pH, sulfate, total dissolved solids ('TDS"), total kjeldahl nitrogen ("TKN"), and volatile organic compounds ("VOCs"). The effluent sample is analyzed for VOCs, semi-VOCs, organic pesticides, polychlorinated biphenyls, oil and grease, cyanide, and nine metals (antimony, arsenic, beryUium, cadmium, chromium, copper, lead, nickel, and zinc). The leachate sample is also analyzed for the list of effluent sample constituents and for phosphoms pesticides, chlorinated herbicides, and eight additional metals (barium, cobalt, mercury, selenium, silver, thalHum, tin, and vanadium). The list of constituents included for the leachate sample is also referred to as the Constituents of Concem ("COC") list, as defined by the Code of Federal Regulations (40 CFR Part 258, Appendix II). This more extensive analytical program is also included as part of the monitoring program every five years for all media (e.g., groundwater monitoring wells, surface water, leachate, and underdrain water), and each constituent identified at a measurable concentration that is not on the cunent list of routine monitoring parameters may be added to the list of routine analyses. San Marcos Landfill Final Closure and 6-5 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Environmental Effects Found Not to be Significant In accordance with the WDRs, the monitoring program is performed quarteriy, and the results are provided quarteriy in a water quality monitoring report that is submitted to the RWQCB. The monitoring program will continue for the duration of the closure and the post-closure maintenance period, or until there is no risk of future environmental impacts to groundwater or surface water from the LandfiH as determined by the RWQCB. Regulatory. The Porter-Cologne Water Quality Control Act and the Federal Water Pollution Control Act Amendments of 1972 require that Water Quality Control Basin Plans be prepared for the nine state-designated hydrologic basins in the State of Califomia. The Landfill is located in the San Diego Hydrologic Basin (Region 9). The San Diego Region Basin Plan ("Basin Plan") was approved by the State Water Resources Control Board ("SWRCB") on March 20, 1975, and an update to the Basin Plan was drafted in 1994 (RWQCB, 1994). The purpose of the Basin Plan is to identify beneficial water uses, establish water quality objectives, implement a program to meet these objectives, and establish a surveillance program to monitor the effectiveness of the plan. The SWRCB has designated hydrologic units to define groundwater basins using surface drainage divides (highlands) to classify total watershed areas, including water-bearing and non- water-bearing formations. Each hydrologic unit is further divided into hydrologic areas (and hydrologic subareas) with unit boundaries generally based on surface drainage boundaries (RWQCB, 1994). The Landfill is located in the Carlsbad Hydrologic Unit, an approximately 210-square-niile triangular-shaped area extending from Lake Wohlford on tiie east, Vista on the ^ north, and Cardiff-by-the-Sea on the south. The Carlsbad Hydrologic Unit is subdivided into six Hydrologic Areas ("HAs"), including tiie San Marcos HA and the Escondido Creek HA. While tiie LandfiH is situated in the San Elijo Hydrologic Subarea ("HSA") of the Escondido Creek HA, groundwater beneatii portions of the Landfill flows in a nortiiwesteriy direction into the Batiquitos HSA of the San Marcos HA immediately north ofthe San Elijo HSA (Figure 6.1-3). San Marcos Landfill Final Closure and Post-Closure Maintenance Plans EIR Hi P m Draft EIR - April 2002 Environmental Effects Found Not to be Significant Existing beneficial uses and water quality objectives have been established by the RWQCB for groundwater in the San Elijo and Batiquitos HSAs. Groundwater in both HSAs is used for municipal, agricultural, and industrial service supply purposes, although municipal supply is only a potential beneficial use within the San Elijo HSA. The Basin Plan also establishes beneficial uses and water quality objectives for the surface water in the San Elijo HSA, including municipal, agricultural, contact and non-contact water recreation, warm and cold freshwater habitat, and wildlife habitat (RWQCB, 1994). Groundwater, such as in the San Elijo HSAs, which is designated for use as domestic or municipal supply, is typically of good quality with chemical constituents below the primary and secondary maximum contaminant levels ("MCLs") as specified by both state and federal regulations. However, since elevated concentrations of chloride, sulfate, and total dissolved solids ('TDS") exist naturally witiiin the San Elijo HSA, the RWQCB has relaxed the water quality objectives for the HSA. The variable geochemistry of the metavolcanic rocks is believed to conUibute to the variable hydrochemistry within the HSA. Based on the regional condition and historical monitoring data at the Landfill, it may be concluded that, though varied, groundwater quality near the Landfill is only of fair quality. The RWQCB has also estabhshed water quality objectives for surface water within the San Elijo HSA. The water quality objectives for groundwater in the San Elijo and Batiquitos HSAs, and for surface water in the San Elijo HSA, are indicated in Table 6.1-1 (at the end of Chapter 6.0). Water quality samples have been collected and chemically analyzed quarteriy. General water quality results are presented in tabular form on Table 6.1-2 (at the end of Chapter 6.0). As shown on this table, the general chemistry constituents included in the monitoring programs are highly variable in concentration. For the detection monitoring wells, in several cases the background wells contain higher concentrations than the downgradient comphance wells, suggesting that the water chemistry is likely being affected by the natural geologic conditions of the site. Comparison of groundwater sample results with the water quality objectives established by the RWQCB for the area indicates that beginning in December 1998 concentrations of San Marcos Landfill Final Closure and 6-7 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Environmental Effects Found Not to be Significant chloride, sulfate, and TDS have been increasing, and exceed the water quality objectives, in background detection monitoring wells SMGW-17, SMGW-36, and SMGW-37S, located on the west side of the site in close proximity to Copper Creek. In addition, the constituent concentrations were found to exceed the concentrations measured in the downgradient corrective action wells. Following observation of sporadic surface water in Copper Creek during periods when the creek was historically dry, the surface water flow was traced back to an upstream constmction site. Additional sampling of this off-site surface water led to the conclusion that these increasing inorganic impacts to the Landfill background groundwater were related to infiltration of surface water from the upsuream off-site constmction site. Review of the more recent analytical data (over the past eight years) for the con-ective action wells indicates that only well SMGW-35, located on the north side of the Landfill, has routinely contained inorganic constituent concentrations (chloride, iron, sulfate, and TDS) tiiat exceed water quality objectives, while only off-site monitoring well OFSM-24 has periodically contained chloride concentrations that exceed the water quality objective. During each quarteriy monitoring event, if surface water flow is observed in Copper Creek, a surface water sample is collected at locations upstream (SMSP-2) and downstream (SMSP-4) of tiie Landfill. The most significant recent change in the Copper Creek water quality is the measurement of elevated concentrations of chloride, sulfate, and TDS for both surface water sample locations exceeding their respective San Elijo HSA water quality objectives, beginning with the surface water samples obtained in March 1998. As noted above, these impacts have been attributed to an upstream constmction site. In addition, for the June 2001 sampling event, the iron concentration in upstream sample SMSP-2, and tiie ammonia, chloride, nitrate, and TDS concentrations in both surface water samples exceeded currentiy established water quality objectives for the San Elijo HSA (Geosyntec, 2001). Overall, the concentrations of general chemistry constituents are very similar in the upstream and downstream samples, altiiough overall, concentrations of general chemistry parameters are lower in tiie downstream sample, indicating that the landfill is not impacting Copper Creek. P San Marcos Landfill Final Closure and g_g Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Environmental Effects Found Not to be Significant In addition, storm water mnoff that collects in the two detention ponds is sampled as necessary prior to discharge to Copper Creek. Results of samples from the detention ponds indicate that the water quality has been acceptable to allow the RWQCB to approve discharge to Copper Creek. Samples are also analyzed for volatile organic compounds ("VOCs"). Since VOCs are not common in nature, VOCs are a good indicator of potential impacts to water quality by the Landfill. VOC impacts may result either from leachate (water that has percolated through the Landfill) tiiat flows to water or landfill gas ("LFG") migration (LFG generated by the Landfill may contain VOCs, migrate outside of the refuse, and mix directly with shallow water, or warm water vapor associated with the LFG may condense, forming liquid-canying VOCs with it outside of the Landfill). Review of the water quality data obtained over the past eight years indicates that, with the exception of the four corrective action wells (SMGW-16, SMGW-30D, SMGW-31, and SMGW-35), confirmed VOCs are not being detected in groundwater or surface water samples at the Landfill. Table 6.1-2 provides a summary of the range of VOC concentrations measured in the conective action wells at the Landfill and a comparison of the data with RWQCB-established water quahty objectives (based on Federal primary MCLs). In response to detection of significant VOCs in these four monitoring wells, the County implemented CAP groundwater pumping beginning in December 1993. The purpose of this CAP was to mitigate impacts to groundwater and retard off-site migration of impacted groundwater. The County is continuously evaluating and optimizing the conective action system to ensure that it is operating effectively. In addition, the County commenced upgrades to the LFG collection system on the top deck and the westem side slope in September 2000, and this is expected to enhance the removal of VOCs in the unsaturated zone and to support long- term improvement of groundwater quality. The County plans additional upgrades to the LFG collection system as part of the final closure constmction. The July 2001 water quahty monitoring report states that overall VOC concentrations are decreasing in the CAP wells (Geosyntec, 2001). In this report, the results of tiie June 2001 monitoring event indicate concentrations of 1,1-dichloroethane in wells SMGW-31 and SMGW-35, and of San Marcos Landfill Final Closure and 6-9 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Environmental Effects Found Not to be Significant 1,1-dichloroethene, benzene, and vinyl chloride in well SMGW-35, exceed the RWQCB water quality objectives. 6.1.1.2 Thresholds of Significance Appendix G of the CEQA Guidelines provides thresholds for determining significant environmental impacts. A project may be deemed to have a significant impact on hydrologic resources if the project would: • Violate any water quality standards or waste discharge requirements; or • Otherwise substantially degrade water quahty. In accordance with the RWQCB WDR No. 92-02 prepared specifically for the Landfill, the concentration limits for each of the constituents of concem included in the quarterly detection monitoring program is equal to the background value of that constituent at the Landfill. Following each quarteriy event, that analytical data must be evaluated statistically. Results of these analyses must not show a statistically significant increase in the monitoring parameters over the RWQCB-established WQPSs (the water quality objectives established for the San Elijo and Batiquitos HSAs provided in the 1994 Basin Plan) at or beyond the downgradient point of compliance. If the exceedance is verified, the County must notify the RWQCB within seven days, establish a program to evaluate the nature and extent of the constituent(s) exceedance, and implement appropriate corrective actions. The purpose of the final cover system is to isolate the wastes from surface water, to minimize infiltration and the generation of leachate and LFG that might pose a threat to water quality. The lowermost layer of the final cover system must consist of a minimum two-foot foundation layer over the waste. This material is equivalent to the current cover soil placed on the Landfill as intermediate cover. CCR Title 27 §21090(a)(2) includes the constmction of a low-hydrauUc- conductivity (low-flow-tiu-ough-rate) layer above the existing foundation layer to protect water quality by minimizing the generation of leachate and LFG. This low-hydraulic-conductivity San Marcos Landfill Final Closure and g_jO Post-Closure Maintenance Plans EIR P P P P Draft EIR - April 2002 Environmental Effects Found Not to be Significant layer must have a flow-through rate of one foot per year or less. Under CCR Title 27 §21090(a)(3), at least a one-foot-thick erosion-resistant layer must be placed directiy over the low-hydraulic-conductivity layer and as a vegetative layer, it must be capable of sustaining native or other suitable plant growtii. However, CCR Titie 27 §21090(a) states that the RWQCB can allow any altemative final cover design that it finds will continue to isolate the waste in the Unit from precipitation and irrigation waters at least as well as would a final cover built in accordance with applicable prescriptive standards under §21090(a)(l-3). Therefore, the final cover system that provides the best performance (i.e., least amount of water infiltration to the waste) will provide the greatest protection to water quality and exceedance of the site-specific WQPSs. 6.1.1.3 Analysis of Project Effects and Determination as to Significance Hydrology. The existing surface water (storm water) drainage system has been engineered to control the quantity of surface water mnoff (water that falls on the Landfill and mns off), and to ensure that peak surface water mnoff could be accommodated without erosion or siltation (fast- moving water occurring during a significant storm can cause erosion and cany away finer sUt particles from the cover). The drainage system also includes perimeter drains around the Landfill to capture and convey surface water mn-on (water that flows on site from adjacent areas) that would otherwise flow onto the LandfiH. Most surface water is conveyed to the two detention ponds on the west side of the Landfill. In accordance with State solid waste landfill regulations, the existing drainage control system has been designed and constmcted to accommodate the maximum precipitation that would be generated during a 24-hour period occurring on average once every 100 years. The Proposed Project will include the placement of an additional three to six feet of cover materials on the existing intermediate cover system, resulting in a slight increase (three to six feet) in the surface elevations across the Landfill. In addition, as with the cmrent Landfill design, the Proposed Project includes grading of the cover to drain to the existing drainage system. The proposed landfill grades are designed to minimize potential changes in the peak San Marcos Landfill Final Closure and 6-11 Post-Closure Maintenance Plans EIR mn Draft EIR - April 2002 Environmental Effects Found Not to be Significant ,^ wm flow rate. The quantity of surface water flow into the drainage system is approximately the ^ same; therefore, surface water flows will be accommodated by the existing drainage system, and m no significant changes to the surface water drainage system will be required. The surface water ^ drainage system would be expected to continue to function effectively and accommodate at least w the 100-year storm events. ^ Hi In addition, no grading or clearing is proposed within 50 feet of any watercourse or 100-year M floodplain. Therefore, no additional erosion or soil loss is expected in these areas of the site. "« WW Water Quality. A pooriy designed and constmcted final cover system has the potential to cause degradation of surface and subsurface waters. If not controlled, potential impacts to water m quality could result from soil loss and erosion of tiie cover system. Leachate potentially could be generated from the infiltration of surface water through refuse. The moisture could percolate » through the landfill mass, leaching high levels of dissolved soHds and soluble organics from tiie "* waste if not controlled. These effects have the potential to degrade water quality, if environmental control systems are not in place to prevent contact of contaminants with the " siurounding surface and subsurface waters. During the constmction period, best management practices for erosion control will be practiced. * In addition, the North and South Ponds will be used as detention ponds throughout the * constmction period. p P Foiiowing completion of constmction, while the native vegetation is being estabhshed, surface H water quality could potentially be impacted by mnoff from tiie Landfill top deck and slopes * diuing periods of heavy precipitation, which could increase the amount of suspended soil * ii particles carried by surface mnoff into drainage channels. As a resuh, a short-term direct impact associated with minor erosion is anticipated during the first year. However, planting of the " m naUve vegetation will occur during the optimum planting period and, if necessary, supplemental irrigation will be used to promote early establishment of the grasses within tiie native plant Mi community. As the vegetation matures, soil loss should decline significantiy and ultimately San Marcos Landfill Final Closure and 5_12 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Environmental Effects Found Not to be Significant return to natural levels. Post-closure maintenance activities, including inspection of the drainage system, cover, and vegetation, will be implemented to maintain the final grade and control erosion and soil loss. Final grading, revegetation of the proposed cover system with a native plant community, and minor improvements to the drainage system to enhance control of storm water mnoff have been incorporated into the Proposed Project design. The drainage system will capture surface water mn-on and mnoff, limit mnoff velocities that might otherwise cause soil erosion and impact surface water quality, divert recharge to the detention ponds located outside of the limits of the Landfill, and prevent leachate generation. The final deck area has been designed to have a minimum grade of three percent to promote drainage and allow for future settlement. Closure design includes drainage routes and collection points in areas where additional future settlement is anticipated during the post-closure period. These improvements are intended to optimize site drainage control and erosion protection. Additional modification to the final contours may also be required over time to prevent ponding (which might create additional opportunities for infiltration into the refuse and generate leachate) and/or erosion and to reduce impacts associated with settlement anticipated throughout the post-closure maintenance period. This ongoing Landfill monitoring and maintenance is part of the Final Post-Closure Maintenance Plan and will be implemented to ensure that no ponding of storm water on the Landfill surface or erosion of the protective final cover system occur. The off-site drainage (mn-on) will be routed via perimeter drains around the Landfill. On-site drainage (mnoff) will be diverted from the top deck of the completed landfill by drainage channels and from the final face by a system of drains. The surface water will be routed through a drainage system that also includes downstream energy dissipators and the two detention basins (which are being converted to operate as sedimentation basins after final closure constmction is completed). The energy dissipators reduce the velocity of the water exiting the Landfill to the detention/sedimentation basins. By reducing the water velocity, there will only be minimal erosive impacts associated with surface water flows within the drainage system. Once the surface water reaches the detention/sedimentation basins, fine particles of sediment carried in the San Marcos Landfill Final Closure and 6-13 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Environmental Effects Found Not to be Significant « m water will drop out of suspension and be deposited in the bottom of the basin. In addition, the ^ two detention/sedimentation basins are sized to contain the 24-hour storm mnoff during the m 100-year storm event while maintaining an additional two feet of additional capacity (freeboard). ^ Because of these drainage system design measures, there will be no significant impacts to the m cover system and surface water quality. ^ HI Groundwater. Although the Landfill received only solid waste, some groundwater impacts from MI the Landfill have been identified by the groundwater monitoring program. SpecificaHy, as described above, the four CAP wells (SMGW-16, SMGW-30D, SMGW-31, and SMGW-35) m contain measurable concentrations of VOCs, with several concentrations exceeding RWQCB estabhshed water quality objectives. One of the purposes of the landfill final cover system is to Hmit future groundwater impacts associated with surface water infiltration and the generation of " additional leachate. Placement of the tiiree- to six-foot-thick final cover system over the Landfill's existing two- to three-foot-thick intermediate cover will provide a significant barrier " between refuse and surface water mnoff, thereby significantiy reducing the amount of surface " water that cunently infiltrates through the existing intermediate cover system at the Landfill. The additional establishment of a native plant community on the cover, capable of thriving under P existing climatic conditions, provides a way of removing surface water that enters the final cover system before it has an opportunity to reach the underiying refuse, thereby preventing the generation of leachate and reducing additional potential groundwater impacts. The Proposed Project cover design includes additional elements to control infiltration by creating a drainage system that directs surface water off of the Landfill as quickly as feasible (discussed above) and increasing the evaporation/removal of water by the native plant community. Specifically, the plant community will use tiie water within the cover system for its own survival. The proposed cover system has been designed in part using the computer program LEACHM (Leaching Estimation and Chemistry Model). The LEACHM model simulates water and Hquid transport in unsaturated or partially saturated soils. Estimates of plant growth and absorption of water by plant roots are included in the model, as are climatic factors such as precipitation and evaporation. The resuhs indicate, given tiie proposed cover depths and materials, water m San Marcos Landfill Final Closure and g_j4 Post-Closure Maintenance Plans EIR P P Draft EIR - April 2002 Environmental Effects Found Not to be Significant infiltration into the underlying waste is virtually eliminated. Model results for typical soils that might be used for the Proposed Project indicate that the average infiltration rate is calculated to be 0.03 mm per year for the top deck and side slopes with three feet of vegetative cover soil, and 0.14 mm per year for the side slopes outside of the vertical expansion area for the final cover design (See Appendix E). Infiltration through the existing intermediate cover soil is estimated to be significantly greater than that which will occur after final closure constmction, with Landfill inspection records noting areas of cracking and ponding that have required periodic repair and would be expected to transmit surface water to the underlying refuse. The depth of the vegetative layer has been designed to allow for an adequate root depth to sustain natural vegetation while giving protection from potential root penetration. The addition of a properly designed and constmcted final cover system over the cunent intermediate cover will form a significant low-permeability barrier between the refuse and surface water, and as a result there wiH be less infiltration of water than is occurring today. During the construction period, the North and South Ponds will continue to be operated as detention ponds. Therefore, the water quality impacts are lower than the existing conditions and reduced below a level of significance. Regulatory. AH discharges, whether to land or water, are subject to WDRs issued by the RWQCB as regulated under CCR Title 27. WDRs for all Class III landfills ensure consistency witii the state (CCR Title 27) and federal (CFR Parts 257 and 258, "Subtitle D") regulations, which require groundwater and surface water monitoring to identify potential water quality degradation. The WDRs for the Landfill outline many of the components and methods to be used to monitor groundwater, surface water, the unsaturated zone, and leachate. These have been discussed previously and have identified VOC impacts to groundwater in four CAP weUs. The remainder of the monitoring wells and surface water monitoring points, though potentially containing concentrations of inorganic constituents (chloride, sulfate, TDS) above RWQCB- estabhshed water quality objectives, do not contain VOCs that would indicate impacts associated with the Landfill. Closed landfills such as the San Marcos LandfiH must be monitored for a minimum of 30 years, or as long as the wastes pose a threat to the environment. San Marcos Landfill Final Closure and 6-15 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Environmental Effects Found Not to be Significant up an The cmrent water quality monitoring system at the Landfill will remain in place to monitor ^ groundwater and surface water quality at and in the vicinity of the Landfill. The groundwater «• monitoring program ensures that in the event of an impact to one or more of the downgradient wells, the impact will be identified at the earliest possible stage. If contamination were detected m in one or more of the wells located adjacent to the Landfill, the County would be responsible for treatment of contaminated water. As mandated by law (Sections 20425 and 20430 of CCR •• Titie 27), if a landfill release is detected, the applicant shall implement an Evaluation Monitoring M Program ("EMP") and a CAP under the regulatory guidance of the RWQCB. The EMP shall be * used to assess the nature and extent of the release, and to design the CAP. The CAP will consist m of engineering measures (e.g., pump-and-treat, bio-remediation, air-sparging, in-place reactive ~ treatment) aimed at treating groundwater so that it meets the water quahty standards set by the RWQCB for the San Elijo/Batiquitos HSAs. In the absence of water quality objectives, such as for VOCs, background water quality wiH serve as the baseline to which groundwater quality will be compared. In summary, since the final cover system will be constmcted to drain in a manner consistent with " the existing intermediate cover system, no significant changes to the Landfill drainage system are " proposed. The existing drainage system will continue to convey surface water (storm water) " resulting from the maximum precipitation that would be generated during a 24-hour period " occurnng on average once every 100 years. The additional three- to six-foot-thick final cover system with native vegetation placed over the existing two-foot-thick intermediate cover system ^ will minimize infiltration to the underiying refuse. Once the native vegetation has been established, it will assist in controHing soil erosion on the cover, and draw water out of the cover, ^ limiting the ability of water to fiow to the refuse and generate leachate, thereby reducing additional potential impacts to water quality. As modeled, the Proposed Project infiltration rate is calculated to be 0.03 mm per year for the top deck and side slopes with three feet of vegetative cover soil, and 0.14 mm per year for the side slopes outside of the vertical expansion area. Nevertiieless, Landfill environmental controls include quarterly groundwater and surface water monitoring to ensure tiiat water quality is protected. By regulation, the County must respond quickly to evaluate and implement appropriate cortective action measures in the event of impacts P San Marcos Landfill Final Closure and g.^^ Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Environmental Effects Found Not to be Significant to water quality throughout the closure and post-closure period and until the RWQCB detennines that the LandfiU no longer poses a threat to the environment. 6.1.1.4 Conclusions With the incorporation of the following design measures, hydrology and water quality impacts will be improved over the existing conditions. There are no significant impacts associated with hydrology or water quality. Hydrology • The existing Landfill storm water control system includes engineered drainages and storm water channels to control surface water flow and direct water to the two existing detention ponds which will serve as sedimentation ponds during the post-closure maintenance period. Potential sediments in the surface water wiH fall out of suspension within the ponds before water is discharged to Copper Creek. • The post-closure maintenance pian includes procedures that wiH be followed to maintain the surface drainage system. Post-closure maintenance activities also include inspection of the cover and vegetation to maintain the final grade and control erosion and soil loss. • Grading procedures to minimize erosion will continue to be implemented as part of the post-closure maintenance plan. • The coastal sage scmb and chaparral vegetation wiU provide resistance to erosion of the Landfill surfaces. San Marcos Landfill Final Closure and 6-17 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Environmental Effects Found Not to be Significant Groundwater Quality • A comprehensive Constmction Quality Assurance ("CQA") Plan has been developed and included in the Final Closure Plan for placement of the final cover system. The primary puipose of this CQA Plan is to ensure that the constmcted cover meets project specifications and to provide evidence that suitable materials and good practices were used in constmction. When properiy constmcted, the final cover system will limit surface water infiltration, minimize the production of leachate and LFG, and protect groundwater quality. The cun-ent CAP, required under RWQCB Order No. 95-112, will continue until such time as no statistically significant concentrations of monitored constituents are detected in tiie CAP wells for a period of one year, at tiie discretion of the RWQCB. Any significant change in tiie water quahty that is identified will be reported to the RWQCB and will require that appropriate corrective measures be implemented, as necessary. San Marcos Landfill Final Closure and g.lg Post-Closure Maintenance Plans EIR m wm The cover system will be maintained in accordance with the post-closure maintenance plan, including a well-maintained native plant community. The development of the plant community is designed to prevent soil erosion and assist with the removal of water stored within the cover system (by plant uptake) to minimize the amount that reaches the underiying refuse and forms leachate. Water quality monitoring and reporting will continue to be conducted in accordance with RWQCB WDRs for tiie Landfill throughout the closure and post-closure maintenance period. In the event that water quality data indicates evidence of impacts from the Landfill, the County wiH be responsible for the treatment and disposal of impacted water. The County must perform an evaluation as to the nature and extent of the impacts, and * implement appropriate conective action measures to mitigate these water quality impacts. P P P m Draft EIR - April 2002 Environmental Effects Found Not to be Significant 6.2 Effects Found not to be Significant During Initial Study State CEQA Guidelines Section 15128 requires the identification of impacts of a project that were determined not to be significant during the Initial Study and that were not discussed in detail in the impact section of the EIR. An Initial Study was prepared for the Proposed Project and is included in Appendix A of the Draft EIR. As detailed in the Initial Study, the following environmental issues were found not to be significant: aesthetics, agricultural resources, biological resources, cultural/paleontological resources, geology and soils, geologic hazards, hazards and hazardous materials, land use and planning, population/housing and pubUc utilities and service systems. Therefore, a brief discussion of environmental issues that were not found to be significant for the Proposed Project is presented below. 6.2.1 Aesthetics There were three aspects of aesthetics evaluated during the Initial Study: visual quality, landform alteration, and lighting. Visual Quality The Landfill is cunently unvegetated, and therefore visually contrasts with the surrounding naturally vegetated tenain. The Proposed Project will improve the existing visual quality of the site through the implementation of a final closure plan, including planting and maintenance of landscaping. The City of San Marcos ("City") required a revegetation plan in permitting the last expansion of the Landfill. The proposed revegetation plan, the LSA Plan, is required by a writ of mandate issued by the Califomia Superior Court, as modified by agreement with the City, the Modified LSA Plan. In accordance with the Modified LSA Plan, chaparral species will be planted on the north- and some northeast-facing slopes, and CSS species will be planted on the remaining side slopes and the top deck of the Landfill. These species are consistent with the sunounding natural vegetation and, therefore, will blend with the native vegetation in the San Marcos Landfill Final Closure and 6-19 Post-Closure Maintenance Plans EIR m Draft EIR - April 2002 Environmental Effects Found Not to be Significant vicinity. The resulting visually consistent landscape will be more aesthetically attractive than tiie cunent appearance of the Landfill and sunounding area. Landform Alteration The site was an operating Landfill. The potential for landfonn alteration would occur due to the import of cover. Although substantial import of cover soil is proposed, this fill will be evenly distributed over the Landfill surfaces. A substantial topography change will not be noted from offsite views, because the plan does not propose to alter the existing slopes. The Proposed Project does not propose any new cut and fill slopes. Additionally, as discussed previously, Landfill surfaces will be landscaped in accordance with requirements of the Modified LSA Plan; thus, the resulting change in visual quality is beneficial. Lighting There is no proposed change to the lighting. Any existing security lighting will be maintained. Therefore, tiie Proposed Project would not produce any new excessive tight, glare, or dark sky impacts. 6.2.2 Agricultural Resources Since the Proposed Project site has already been disturbed due to landfilling activities, any lands of agricultural importance have already been impacted. The Proposed Project does not create any ^ P new impacts upon agricultural resources. P 6.2.3 Biological Resources M While sensitive habitat lands are found within the Landfill property boundary, project activity will be confined to areas that do not contain sensitive habitats. Witiiin the LandfiU property boundary there are some sensitive biological resources (wetiands and coastal sage scmb); P P San Marcos Landfill Final Closure and g_2o Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Environmental Effects Found Not to be Significant however, no disturbance of these resources will occur. The areas where activities will occur as part of the Proposed Project has been completely disturbed and contains no native vegetation or habitats. Therefore, no endangered, threatened, or rare plant or animal species protected by the County of San Diego or State and Federal wildlife agencies exist within the area of disturbance. Additionally, Landfill surfaces will be revegetated with native vegetation, including CSS and chaparral species. This will improve the biological value of the site. The Proposed Project is located within the boundaries of the Draft Multiple Habitat Conservation Program ("MHCP"). The Landfill area is part of the Southem Focused Planning Area ("FPA") of the Natural Community Conservation Plan ("NCCP") for the City (City of San Marcos, 2001a). The Landfill area has been assigned a 100 percent conservation rate and will be a part the open space of the Southem FPA. The revegetated portions of the LandfiH will also provide biological connectivity to the County Core area and the City of Carlsbad. The LandfiH will provide a Hnkage between wildlife corridors provided by adjacent jurisdictions. Finally, no biological impacts are associated with the Proposed Project, so biological mitigation will not be required. The Proposed Project will not degrade the quality of the environment and will not substantially reduce the habitat of a fish or wildlife species. The Proposed Project will not cause a fish or wildhfe population to drop below self-sustaining levels and will not threaten to eHminate a plant or animal community. Also, the Proposed Project would not reduce the number or restrict the range of a rare or endangered plant or animal. Through the implementation of the revegetation plan, CSS and chapanal species will be planted, which are beneficial to wildlife in creating potential wildlife habitat that does not cunently exist at the non-vegetated areas of the Landfill. 6.2.4 Cultural/Paleontological Resources The Proposed Project will not impact significant archaeological resources, since prior grading and filhng of the proposed LandfiH cover area has eHminated any potential for identification of buried archaeological features within the footprint of the actual Landfill. San Marcos Landfill Final Closure and 6-21 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Environmental Effects Found Not to be Significant 6.2.5 G^logy and Soils There are four aspects of Geology and Soils evaluated as part of the Initial Study: geologic hazards, expansive soils, erosion, and unique geologic features. Geologic Hazards The Proposed Project is not located in a hazard zone identified by the Alquist-Priolo Earthquake Fauh Zoning Act, Special Publication 42, Revised 1994, Fault-Rupture Hazards Zones in Califomia. The Proposed Project is the closure of a Landfill that includes the import of fill, revegetation, and maintenance and monitoring. The Proposed Project will not create any geologic hazards not already in existence. Minimal human activity will take place once the Landfill is closed, other than routine maintenance and monitoring. Therefore, there are no impacts associated with geologic hazards. Expansive Soils The closure includes importing soil as part of the final cover for the LandfiH. Expansive soils are not proposed as part of the final cover. No potentially significant unstable soil conditions are anticipated as a result of the Proposed Project. Erosion The Proposed Project includes importing cover soil as part of tiie final cover for the Landfill. Most existing side slopes of the LandfiH are at an overall slope of 3:1 or flatter. With the implementation of the County-mandated Storm Water Pollution Prevention Plan and the Statewide Industrial Storm Water Pemiit requirements, erosion control mechanisms will be required and erosion wiU be minimized. Additionally, existing sedimentation basins on tiie site will act to prevent downstream deposition of sediment. Post-constmction conditions will be San Marcos Landfill Final Closure and 5.22 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 Environmental Effects Found Not to be Significant improved because the Proposed Project proposes vegetation cover, which will reduce erosion. The post-closure maintenance plan includes maintenance of the Landfill surfaces and vegetation as necessary. Therefore, the Proposed Project creates a less than significant impact. Significant Geologic Features It is assumed that any significant geologic features associated with the Proposed Project area would have been altered during the creation of the Landfill. Since no unique geologic features are currentiy present on the site, no adverse impacts will result from the Proposed Project. 6.2.6 Hazards and Hazardous Materials During the Initial Study three aspects of hazards or hazardous materials were considered: potential increase in wildfires both onsite and offsite, methane associated with decomposing organics in the Landfill, and dam inundation. No other additional health or safety hazards have been identified in the review of the Proposed Project. Wildfire The Proposed Project will not introduce any new uses at the project site; therefore, no new uses will be in jeopardy of wildfires. The Proposed Project is proposing to landscape the Landfill with native vegetation. It will be necessary to properly maintain the vegetation height near the Landfill Gas ("LFG") Collection System wells and LFG piping to reduce the potential for accidental wildfires. With proper maintenance of vegetation (as proposed by the project), this is considered a less than significant impact. The landscaping will generate additional "fuel"; however, there is an existing native habitat buffer surrounding the Landfill in proximity to residential uses. Therefore, the Proposed Project would not generate a substantial increase in fire hazards. No additional health or safety hazards have been identified in the review of the Proposed Project. San Marcos Landfill Final Closure and 6-23 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Environmental Effects Found Not to be Significant ^ Methane mm Decomposing waste generates LFG, a major component of which is methane. Methane can be ^ explosive at concentrations between 5 and 15 percent volume in air if it accumulates in enclosed m spaces and is exposed to ignition sources. At higher concentrations, methane is flammable. ^ The Landfill currently has systems in place to detect and control the presence of LFG. By ^ controlling LFG, these systems are designed to prevent fires and explosion and control off-site >• migration and surface emissions. The LFG collection and recovery system will continue to be M maintained by the County during the post-closure maintenance period. Therefore, no significant impacts are identified. m mm Dam Inundation m m The Proposed Project lies outside any mapped dam inundation area for major dams/reservoirs «» within the County, as identified on inundation maps prepared by the dam owners. Therefore, there are no hazard impacts associated with the Proposed Project. Mi 6.2.7 Land Use and Planning • an The Proposed Project will not conflict with any element of the City of San Marcos General Plan P including community plans, land use designations or zoning. The site has a General Plan and zoning designation of Solid Waste Management Area (SWM). The project is consistent with P P these designations. The Proposed Project will be reviewed by the Califomia Integrated Waste Management Board (CIWMB), San Diego Regional Water Quality Control Board (RWQCB), San Diego County Department of Environmental Health, Local Enforcement Agency (LEA), and the Air Pollution Control District (APCD). Approvals will be acquired from these agencies. Permits will not be required from the United States Fish and Wildlife Service, Cahfomia Department of Fish and P •I San Marcos Landfill Final Closure and 6-24 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Environmental Effects Found Not to be Significant Game, or United States Army Corps of Engineers, since there will be no impacts to sensitive biological resources or jurisdictional waters. No conflicts with environmental plans or policies adopted by these agencies have been identified. The project site already exists as a LandfiU. The Proposed Project will complete the closure of the Landfill. This action will not be incompatible with existing or planned land uses or the character of the community. Therefore, no significant impact is identified. The project site already exists as a LandfiH. The Proposed Project will not significantiy dismpt or divide the physical arrangement of an established community. Therefore, no significant impact is identified. 6.2.8 Population and Housing The Proposed Project does not involve extending utilities such as water, sewer, or new road systems into previously underserved areas. The Proposed Project will not induce substantial growth, either directly or indirectly. The County owns an 800-foot buffer zone around the Landfill area. Residential uses exist within this area, however, the Proposed Project will not impact any of these stmctures. Therefore, there are no impacts to population and housing. 6.2.9 Public Utilities and Service Systems The Proposed Project is a Landfill closure. The Landfill stopped accepting waste in 1997. The Sycamore Canyon Landfill now services most of the communities that previously utilized the San Marcos Landfill. The Proposed Project does not propose development that would require additional pubhc services. The Proposed Project will not result in the need for new or significantly altered services or facilities. The Proposed Project will not significantly increase the burden of fire or police protection agencies, nor adversely impact response times or performance objectives. The Landfill closure will not increase the burden of schools or park services, since an increase in population is not associated with the Proposed Project. Finally, the Proposed Project will not result in inadequate emergency access. Therefore, there are no adverse impacts associated with pubHc services or utihties. San Marcos Landfill Final Closure and 6-25 Post-Closure Maintenance Plans EIR Draft EIR - AprU 2002 Environmental Effects Found Not to be Significant Mi (This page intentionally left blank.) P m m m San Marcos Landfill Final Closure and 6-26 Post-Closure Maintenance Plans EIR ai •I 1 ^SMGW-24 (558.70) LEGEND -<^SMGW-35^^^N^SITE CORREGTt.k ^SMGW-39 /OT^-SITE DET^TlbN~MDNJTOR\WEU>- ^SMGW-2^,.-^AgiGR©UND\ra^Tj^ W^LL ©SMGW- • SMSP-4V^ •^SMGW^=^> NEXISTING^N^OVEWINI 500 0.04 (475.02) .GROUNDWAJTERWVATIOXI (F\EE^ /WEAN SEA/LEVBL) ^ ' ! ^ APPROXIMATE APPROXIMATE FILL BOUNDARY GROUNDWATER ELEVATION CONTOUR IN FEET ABOVE MSL (CONTOUR INTERVAL - 20 FEET) (APPROXIMATE GROUNDWATER FLOW DIRECTION AND HYDRAULIC GRADIENT (ft/ft) ^l«* Source: Geosyntec, ^ly 2001 1 inch = 400feet Groundwater Elevations and Flow Directions A-&D Enviromnental Services Figure 6.1-1 Source-. U.S.G.S., Rancho Santa Fe Quadrangle, Photorevised 1983; Geosyntec 6/2001 4 • 1 inch = 2000 feet Off-Site Well Locations |@P&D Environinental Services Figure 6.1-2 Source: San Diego Association of Governments, 1994. rs No Scale Hydrologic Subareas P&D Environmental Services Figure 6.1-3 ei Ii II ii p« mm mm ii ii li ii ii ii ii ii ii FI PI Draft EIR-April 2002 Environmental Effects Found Not to be Significant Table 6.1-1 Water Quality Objectives Established by the RWQCB j Constituent San Elijo HSA Batiquitos HSA j Constituent Surface Water Groundwater Groundwater Total Dissolved Solids 500 mg/L 2,800 mg/L 3,500 mg/L Chloride 250 mg/L 700 mg/L 800 mg/L Percent Sodium 60% 60% 60% Sulfate 250 mg/L 600 mg/L 500 mg/L Nitiate (as NO3) — 45 mg/L 45 mg/L Iron 0.3 mg/L 0.3 mg/L 0.3 mg/L Manganese 0.05 mg/L 0.05 mg/L 0.05 mg/L MBAS*'^ 0.5 mg/L 0.5 mg/L 0.5 mg/L Boron 0.5 mg/L 1.0 mg/L 2.0 mg/L Odor None None None Turbidity 20NTU^'^ 5 NTU^'^ 5 NTU*'* Color 20 Units 15 Units 15 Units Notes: MBAS = Methol Blue Active Substances. NTU = Nephelometric Turbidity Units. Table 6.1-2 Comparison of Historical VOC Concentrations in Corrective Action Wells And RWQCB-Established Water Quality Objectives ("WQOs") Volatile Organics (in ne/L) WQO SMGW-16 SMGW-30D SMGW-31 SMGW-35 1,1,1 -Trichloroethane 200 ~ — ~ <0.01 -0.06 1,1 -DichloroethaHe 5 <1 -9 <1 -13 <5-50 32-110 1,1 -Dichloroethane 6 — <0.15-1 <0.15-22 3.6-21 1,4-Dichlorobenzene 5 <0.17-0.8 <0.2 - 2 <0.2 - 0.9 1-2 Benzene 1 <0.2 - 0.6 <0.3 - 0.8 <0.I4-3.1 <0.3 - 6.5 Chloroethane NE — ~ <0.2 - 4.8 <0.2 - 5 cis-1,2-Dichloroethene 6 <0.15- I <0.2 - 1 <0.2 - 1 <0.2 - 2 Dichlorodifluoromethane NE <0.2 - 27 <0.2 -19 <0.2-29 2-36 Methylene Chloride 5 — <0.2-21 <0.2 - 360 <1.2-85 Tetrachloroethene 5 <0.2 - 2 <0.2 - 2 <0.2 - 6.6 2-7 Tetrahydrofuran NE — — — <2.7-135 Trichloroethene 5 <0.2 - 2 <0.2 - 2 <0.2 - 9.6 <0.2 - 8.3 Trichlorofluoromethane 150 <0.1 -7 <0.1 -3 <0.1 -13 3.6-38 Vinyl Chloride 0.5 <0.2 - 0.9 <0.2 - 0.9 <0.2-2.5 <l-6 Xylenes, Total 1750 — <0.31-1.3 <0.4-2.1 Note: NE = No water quality objective has been established. San Marcos Landfill Final Closure and Post-Closure Maintenance Plans EIR 6-31 Draft EIR-April 2002 Environmental Effects Found Not to be Significant m (This page intentionally left blank.) P P P n San Marcos Landfill Final Closure and 6-32 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 List of References LIST OF REFERENCES Bennett, John. 2002. San Diego County Dept. of Planning and Land Use, private communication. Brown & Caldwell. 2002a. San Marcos Landfill, Joint Technical Document, Volume 1, Amended Report of Waste Discharge and Final Closure Plan, Volume 2, Appendices. January. 2002b. San Marcos Landfill, Joint Technical Document, Volume 3, Final Post-Closure Maintenance Plan. January. Califomia Air Resources Board. 2000a. Califomia Ambient Air Quality Data (1980-1999), CD No. PTSD-00-013-CD. 2000b. MVEI7G, Version LOC Computer Model (EMFAC7G). 1999. Ambient Air Quality Standards Chart. http://www.arb.ca.gov/aqs/aaqs2.pdf City of Carlsbad. 2001a. Bressi Ranch Master Plan Draft EIR. December. 2001b. Fox-MiUer Initial Study, Part n. October. 2001c. Villages of La Costa Master Plan EIR. October. 2000. Carlsbad Research Center - Lot 12 Mitigated Negative Declaration. January. 1999. Manzanita Apartments Mitigated Negative Declaration. March. 1998a. Shelley Carlsbad Final EIR. 1998b. Colina Roble Mitigated Negative Declaration. April. San Marcos Landfill Final Closure and 7-1 Post-Closure Maintenance Plans EIR Draft EIR-April 2002 Ust of References m City of Encinitas. 1999. Encinitas Ranch, South Mesa and Quail Gardens East Planning Areas Mitigated Negative Declaration. October. City of San Marcos. 2001a. Natural Community Conservation Plan for City of San Marcos (Draft). 2001b. University Commons Specific Plan Amendment No. 1. Final Supplemental Environmental Impact Report. September. 2000. Lake San Marcos EIR. 1998a. Final Subsequent EIR for the San Elijo Hills Planned Community. 1998b. Negative Declaration for Capital Improvement Plan No. 179. October. 1997. General Plan, Volumes I, H, and m. Municipal Code, Article n. Section 17-18 et seq.. Ordinance No. 71-95. County of San Diego. 2001. Notice of Preparation of an Environmental Impact Report and Initial Study Form for the Quail Ridge Specific Plan and Subdivision. October. IM Mi P P 1998. Final Landfill Closure Noise Analysis. Department of Planning and Land Use (Dr. Alex Segal). • P P P P 1993. Amended PubHc Facility Element of tiie San Diego County General Plan. October. 1990. Final EIR for San Marcos Landfill Expansion Project. County Code Section 36-401 et seq. Dwyer, S.F. 2001. Finding a Better Cover. CivH Engineering. January. ^ 1998. Altemative LandfiU Covers Pass tiie TesL CivH Engineering. September. m m San Marcos Landfill Final Closure and 7_2 Post-Closure Maintenance Plans EIR P P Draft EIR - April 2002 List of References GeoLogic & Associates. 2002. Altemative Cover Evaluation Study. Febmary. GeoSyntec Consultants. 2001. Quarterly Monitoring Report, Detection and Corrective Action Monitoring and Reporting Programs, San Marcos II LandfiH, San Diego County, CA. Prepared for County of San Diego. April-June. Giroux & Associates. 2002a. Air Quality Analysis for the San Marcos Landfill Closure. January. 2002b. Noise Analysis for the San Marcos Landfill Closure. January. 2000. Lake San Marcos Estates Air Quality Impact Analysis (GPA 99-02/R98-003/TM5131/MUP P98-012). Harris, CM. (ed.). 1979. "Handbook of Noise Control" (Second Edition), McGraw-Hill, Inc. Linscott, Law and Greenspan. 2002. Traffic Impact Analysis, San Marcos Landfill, County of San Diego. January. LSA Associates, Inc. 1998. San Marcos LandfiH Revegetation Plan. May. MBA. 1992. Mitigation Monitoring Program for San Marcos LandfiU Expansion Project Phase n - Horizontal Expansion. Prepared for the County of San Diego. 1990a. DEIR/FEIR, San Marcos Landfill Expansion Project. October. San Marcos Landfill Final Closure and 7-3 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 i^t of References 1990b. Supplemental Environmental Impact Report for San Marcos Landfill Expansion Project. October. Melchior, S. 1997. In situ Studies on the Perfonnance of Landfill Caps, in Proceedings from the Intemational Containment Technology Conference, St. Petersburg, Florida. San Diego Air Pollution Control District. 2002. Web site, http://www.sdapcd.co.san-diego.ca.us San Diego Association of Govemments 1994. Digital Boundary Files and Layers - Hydrologic Basin. http;//www.sandag.org/ris/gis/senlu.html San Diego County Water Authority. 1997. Emergency Water Storage Project EIR/EIS. January. South Coast Air Quality Management District. 1993. CEQA Air Quality Handbook. United States Environmental Protection Agency. 1995. Compilation of Air Pollutant Emission Factors, AP-42, OAQPS. 1978. FHWA Highway Traffic Noise Prediction Model. FWWA-RD-108. 1971. "Noise from Constmction Equipment and Operations, Building Equipment, and Home AppHances", NTTID 300.1, Washington, D.C. San Marcos Landfill Final Closure and 7_4 Post-Closure Maintenance Plans EIR Draft EIR - April 2002 List of EIR Preparers and Persons and Organizations Contacted LIST OF EIR PREPARERS AND PERSONS AND ORGANIZATIONS CONTACTED EIR Preparers Environmental Consultants Environmental Impact Report P&D Environmental Services 401 West A Street, Suite 2500 San Diego, CA 92101 Betty Dehoney, CEP, Principal-in-Charge Sophia Habl, Environmental Analyst Josephine Gabriel, Environmental Analyst Clayton Kraft, GIS/Mapping Analyst Carolyn Darga, Document Production Specialist Transportation and Circulation Study Linscott, Law & Greenspan 1565 Hotel Circle South, Suite 310 San Diego, CA 92108 John Boarman, Principal Jose Nunez, Transportation Planner Air Quality Study and Noise Study Giroux and Associates 17744 Sky Park Circle, Suite 210 hvine CA 92614 Hans Giroux, Principal Hydrology/Water Quality Analysis GeoLogic Associates 16885 W. Bemardo Drive, Suite 305 San Diego, CA 92127 Sarah Battelle, Vice President San Marcos Landfill Closure and 8-1 Post-Closure Maintenance Plans EIR Olivas, Nelson. Environmental Services Unit, County of San Diego Department of PubUc Works. Quinn, JuHa M. Environmental Services Unit, County of San Diego Department of PubHc Works. RoUin, Jon. SoHd Waste Management, County of San Diego Department of PubHc Works. Solomon, Brett. Environmental Management Specialist. County of San Diego, Department of Planning and Land Use. Vandrew, Susan. Planner. City of San Marcos Planning Division. Westman, Christer. Planner. City of Carlsbad Planning Department. m mn. m in, IV Draft EIR - April 2002 List of EIR Preparers and Persons and Organizations Contacted Persons and Organizations Contacted Acuff, David. Contract Planner. City of San Marcos Planning Division. Bennett, John. Environmental Management Specialist. County of San Diego Department of Planning and Land Use. Blackbum, Elaine. Planner. City of Carlsbad Planning Department. Bloom, Laura, Environmental Management Specialist. County of San Diego Department of Planning and Land Use. Bradley, Lorrie. Environmental Management Specialist. County of San Diego Department of _ Planning and Land Use. Ml DelgadiHo, Diana, AICP. Associate Planner. City of Escondido Planning Department. ^ Hoffman, Mark. Planner. City of Encinitas Community Development Department " Kennedy, Barbara. Planner. City of Carlsbad Planning Department. * Langager, Diane. Associate Planner. City of Encinitas Community Development Department. Lynch, Van. Associate Planner. City of Carlsbad Planning Department. Monzon, Cheryl. Environmental Management Specialist. County of San Diego Department of • Planning and Land Use. m Nesheim, Ervin. Consultant. Brown & Caldwell. P Neu, Don. Principal Planner. City of Carlsbad Planning Department. P P P San Marcos Landfill Closure and g_2 Post-Closure Maintenance Plans EIR List of Mitigation Measures and Draft EIR - April 2002 Environmental Design Considerations LIST OF MITIGATION MEASURES AND ENVIRONMENTAL DESIGN CONSIDERATIONS Mitigation Measures Proposed for the Proiect Transportation/Circulation The following mitigation measures are proposed to partially mitigate impacts to intersections and roadway segments from the hauling of cover soil. Mitigation for Impacts 2.1.3.a through 2.1.3.af • Tmcked soil will only be accepted at the LandfiH between 7:00 AM and 4:00 PM. • Notify local bicycle clubs of the haul period schedule and routing associated with the Proposed Project. Noise The following mitigation measure is proposed to mitigate noise impacts resulting from tmck traffic hauling cover soil along San Elijo Road, between Rancho Santa Fe Road and the Landfill (Tmck Routes 1, 2,4, 5, and 6). Mitigation for Impact 2.3.2.a • Prohibit tmck traffic on San Elijo Road between Rancho Santa Fe Road and the Landfill before 7:00 AM. San Marcos Landfill Final Closure and 9-1 Post-Closure Maintenance Plans EIR List of Mitigation Measures and Draft EIR - April 2002 Environmental Design Considerations Environmental Design Considerations for the Proiect Air Quality • Adherence to aH applicable dust control measures of the San Diego County Air Pollution Control District ("APCD"). • Adherence to all appHcable low-sulfur fuel requirements of the APCD. Noise • No constmction activities will be conducted prior to 7:00 AM daily. Water Quality Hydrology The post-closure maintenance plan includes procedures that will be followed to maintain the surface drainage system. Post-closure maintenance activities also include inspection of the cover and vegetation to maintain the final grade and control erosion and soil loss. Grading procedures to minimize erosion will continue to be implemented as part of the post-closure maintenance plan. P P The existing Landfill storm water control system includes engineered drainages and storm water channels to control surface water flow and direct water to the two existing * sedimentation ponds. Potential sediments in the surface water will fall out of suspension within the ponds before water discharges to Copper Creek. P Ml San Marcos Landfill Final Closure and 9.2 Post-Closure Maintenance Plans EIR List of Mitigation Measures and Draft EIR - April 2002 Environmental Design Considerations Groundwater Quality • A comprehensive Constmction Quality Assurance ("CQA") Plan has been developed and included in the Final Closure Plan for placement of the final cover system. The primary purpose of this Plan is to ensure that the constmcted cover meets project specifications and to provide evidence that suitable materials and good practices were used in constmction. When properly constmcted, the final cover system wiU hmit surface water infiltration, minimize the production of leachate and LFG, and protect groundwater quahty. • The cover system will be maintained, including establishment of a native plant community on the cover, in accordance with the post-closure maintenance plan. The development of the plant community is designed to prevent soil erosion and assist with the removal of water stored within the cover system to minimize the amount that reaches the underlying refuse and forms leachate. • Water quality monitoring and reporting will continue to be conducted in accordance with Regional Water Quality Control Board ("RWQCB") Waste Discharge Requirements ("WDRs") for the Landfill throughout the closure and post-closure maintenance period. In the event that water quality data indicates evidence of impacts from the Landfill, the County will be responsible for the treatment and disposal of impacted water. The County must perform an evaluation as to the nature and extent of the impacts, and implement appropriate corrective action measures to mitigate these water quality impacts. • The current Corrective Action Program ("CAP"), required under RWQCB Order No. 95-112, will continue until such time as no statistically significant concentrations of monitored constituents are detected in the CAP wells for a period of one year, at the discretion of the RWQCB. Under this program, water quality sampHng wHl also be performed and reported to the RWQCB. Any significant change in the water quality will be identified, and appropriate corrective measures will be implemented, if necessary. San Marcos Landfill Final Clositte and 9-3 Post-Closure Maintenance Plans EIR List of Mitigation Measures and ^ Draft EIR - April 2002 Environmental Design Considerations (This page intentionally left blank.) San Marcos Landfill Final Closure and 9.4 Post-Closure Maintenance Plans EIR P Citv of Carlsbad Public Works Engineering May 17, 2002 Julia M. Quinn County of San Diego Department of Public Works Environmental Services 5469 Kearny Villa Road, Suite 305 San Diego, CA 92123 SAN MARCOS LANDFILL FINAL CLOSURE AND POST-CLOSURE MAINTENANCE PLANS PROJECT (UJ1750), SCH NO. 2001101126 - DRAFT EIR Thank you for the opportunity to provide comments on the referenced project. The City of Carlsbad has the following comments. • The Draft EIR falls to address the impacts and mitigation to the roadway structural section, regardless of the route selected, that will occur from the large number of heavily loaded trucks using the road over a short period of time. It would be expected that the pavement/subgrade will be degraded and the overall pavement life will be shortened. This must be addressed and mitigated through remedial constmction or payment of impact fees. • In some locations, the existing roadway structural section may not be able to carry the projected truck traffic. Mitigation measures should be identified and implemented on the selected route prior to truck usage. • Rancho Santa Fe Road south of San Elijo Road is being considered in several of the truck routes. The Draft EIR does not address the fact that a portion of this road is designated NOT A TRUCK ROUTE. Additionally, the taick bypass shown on Rancho Santa Fe Road north of La Costa Avenue is closed and no longer available. • The proposed mitigation of restricting truck hauls from 7:00 a.m. to 4:00 p.m. coincides with the morning peak hour commute patterns. The trucks should not be in route prior to 8:30 a.m. Additionally, the proposed mitigation states that trucked soil will be accepted beginning at 7:00 a.m. This implies the trucks will be in-route prior to 7:00 a.m. and further exacerbating the a.m. peak hour congestion. • The traffic analysis only addresses the level of service at intersections and road segments. There must be an analysis of impacts to traffic operations, such as queuing lengths at intersections, weaving areas, safety analysis, travel through school pedestrian crossing locations, and locations with limited sight distance. 1635 Faraday Avenue • Carlsbad, CA 92008-7314 • (760) 602-2720 • FAX (760) 602-8562 May 17, 2002 SAN MARCOS LANDFILL FINAL CLOSURE AND POST-CLOSURE MAINTENANCE PLANS PROJECT (UJ1750), SCH NO. Z001101126 - DRAFT EIR Page 2 • The City of Carlsbad will be reconstructing Rancho Santa Fe Road beginning in Fall 2002 and continuing for several years. If the selected route is in Carlsbad, it is important to coordinate with Carisbad staff to minimize impacts to the construction zone and commuter traffic. • The realignment of Rancho Santa Fe Road includes the replacement of the bridge over the San Marcos Creek. Traffic control during this phase of the project is complex. The City of Carisbad suggests considering delaying, or suspending the hauling operations until this critical phase of construction can be completed. • No consideration is given to using several routes to mitigate impacts instead of using one route only. This concept should be analyzed. • Additional mitigation measures that would be needed and are not addressed would include additional signs, changeable message signs, flaggers, and a traffic control plan that addresses the entire truck haul operation, including truck driver training and weekly briefings. Also, monthly meefings with the affected agency through which the truck route traverses should be held to discuss safety concerns and operational issues and the appropriate mitigation. Your consideration of these comments will be appreciated. Please contact me at (760) 602-2752 if you have any questions. ROBERT T. JOHNSON, JR., P.E. Deputy City Engineer, Transportation RTJ:Jd c: Public Works Director Planning Director Deputy Public Works Director, Engineering Services Deputy City Engineer, Engineering Inspection Deputy City Engineer, Planning & Programs Sr. Civil Engineer, Planning & Programs ^^^^^^'^^ of San Diego ?muiu^^^y^m^ Citv 01 'a OIULAJL CoSlm'flRPORTS / ^Ut^wVr'*>^3*''**^tRTIVIENT OF PUBLIC WORKS COUNTY ROAD COMMISSIO^NER JOHN L. SNYI , TRANSIT SERVICES' DIRECTOR COUNTY SURVEYOR FAx",86r268-0461 "55 OVERLAND AVE, SAN DIEGO, CALIFORNIA 92123-1295 WASTEWA?ER''SJIASEMENT April 4, 2002 NOTICE OF AVAILABILITY OF A DRAFT ENVIRONMENTAL IMPACT REPORT NOTICE IS HEREBY GIVEN that the County of San Diego is circulating for public review a draft Environmental Impact Report (EIR) in accordance with the California Environmental Quality Act for the following project. The draft EIR can be reviewed at the Department of Public Works (DPW), Environmental Services, located at 5469 Kearny Villa Road, Suite 305, San Diego, California 92123, and at the Public Libraries listed below. Comments on the draft EIR should be sent to the DPW address that is listed above and should reference the project name. If you wish to challenge the County's action on the EIR in court, you may be limited to raising only those issues that you, or someone else, have raised in written correspondence. San Marcos Landfill Final Closure and Post-Closure Maintenance Plans Proiect (UJ1750). SCH No. 2001101126. The County of San Diego (County) Department of Public Works (DPW) is proposing to implement the Final Closure and Post-Closure Maintenance Plans for the San Marcos Landfill (Landfill) using a monolithic soil cover system or other system as required by regulatory authorities. The soil cover will range in depth from five (5) feet to eight (8) feet. The project will require the importafion of approximately 420,000 cubic yards of soil over an approximate 7-month period. The Imported soil will be mixed with approximately 120,000 cubic yards of on-site soil and placed over the Landfill surfaces. Closure of the Landfill will be in accordance with requirements from Title 27 of the California Code of Regulations. The Landfill is located adjacent to San Elijo (Questhaven) Road between Rancho Santa Fe Road and Elfin Forest Road within the inborporated City of San Marcos in northern San Diego County. The total acreage of the Landfill covers approximately 310 acres. The area that has received waste and requires closure Is approximately 102 acres. The Final Closure and Post-Closure Maintenance Plans will require approvals from the County Board of Supervisors, California Integrated Waste Management Board (CIWMB), San Diego Regional Water Quality Control Board (RWQCB), San Diego Air Pollution Control District (APCD), and County of San Diego Department of Environmental Health, Local Enforcement Agency (LEA). Significant environmental effects anticipated as a result of the project are related to the hauling of cover soil to the Landfill and include project level and cumulative short-term transportation/circulation, air quality, and noise impacts. Comments on this proposed draft EIR must be received no later than May 20, 2002 at 4:00 p.m., a 45-day public review period. The EIR can also be reviewed at the Carlsbad City Library, located at 1775 Dove Lane, Carlsbad, California, 92009; Encinitas Library, located at 540 Cornish Drive, Encinitas, California, 92024; Escondido Library, located at 239 South Kalmia Street, Escondido, California, 92025; and San Marcos Library, located at 2 Civic Center Drive, San Marcos, California, 92069. For additional information, please contact Julia M, Quinn at (858) 874-4054 or by e-mail: Julia.Quinn@sdcounty.ca.gov,