Summary of Findings and Comprehensive Recommendations Landfill Compliance Study presented to California Integrated Waste Management Board by GeoSyntec Consultants, Inc. Oakland,California 15 June 2004

Presenters / Collaborators Michael Minch, P.E., G.E. Senior Project Engineer GeoSyntec Consultants Julie Holmes Ryan, P.E. Project Engineer GeoSyntec Consultants Patrick Lucia, Ph.D., P.E., G.E. Principal GeoSyntec Consultants

Purpose of this Presentation Provide a general overview of the Landfill Facility Compliance Study Present the results of Tasks 4 and 5, which were recently completed Present the comprehensive findings of Phases I and II of the Study

Structure of the Study Phase I Task 1: Checklist of landfill regulations Task 2: Cross-media (air, water, land) database inventory of 224 California MSW landfills Task 3: Assessment of landfill performance based on Task 2 data

Structure of the Study Phase II Task 4: In-depth review of 53 landfills Task 5: Regulatory effectiveness based on performance of Task 4 landfills Task 6: Review of other states’ and countries’ landfill regulations Task 7: Review of emerging technologies Task 8: Final Report

Study Challenges Most comprehensive cross-media inventory ever undertaken of California landfills Broad scope: review of landfills, technologies and regulations implemented elsewhere Process complicated by heterogeneous nature of the physical and social conditions in California California’s complex regulatory structure Diverse nature of the tasks: different methods of performing each task

Phase I: Checklist of Regulatory Requirements (Task 1) Purpose Identify existing regulations specific to landfills to be considered in the Study Findings Complex regulatory structure – 3 agencies Broad spectrum of landfill regulations: multiple sources and media Air regulations vary widely across state

Phase I: Inventory of MSW Landfills (Task 2) 224 MSW Landfills 97 EAs, RWQCBs, APCDs, and AQMDs Reviewed by Owners, Operators, Regulators 237 Sets of Comments 25 Mb Database – Bigger than SWIS Over 1,000 Scanned Permits, Photos, and other Documents Over 1,500 Hours to Compile Data

Phase I: Landfill Characteristics Collected in Task 2 Setting Features Underlying Geologic Material Minimum Depth to Underlying Groundwater Physical Setting (Coastal, Alpine, Desert, etc.) Social Setting (Urban, Suburban, Rural) Annual Precipitation Operational Features Owner Type (Federal, State, County, Private, etc.) Age Size (Permitted Disposal Area, Remaining Capacity, etc.) Site Status (Active, Inactive, Closed, Combination) Design Features Liner Type Cover Type Landfill Gas Collection System

Phase I: Internet Accessible Cross-Media Inventory (Task 2)

Phase I: Goals of Task 3  Categorize California’s MSW landfills with respect site characteristics.  Develop screening indicators for evaluating the environmental performance of MSW landfills.  Perform analyses of the site characteristics to evaluate any commonality of factors pertaining to the environmental performance.  Recommend 40 MSW landfills for inclusion in the Phase II assessment.  Provide a brief overview of solid waste landfills in California that do not receive MSW.

Phase I: Example of Landfill Site Characteristic Data Presented in Task 3 Figure 2.13: Distribution of Liner Types (All 224 Landfills)) Liner Type Number of Landfills Percent of Total Fully Subtitle D41.8 Fully Lined— Partially non- Subtitle D Partially Unlined Fully Unlined Total224100

Phase I: Typical California Landfill (Task 3) Table 5-A: Profile of a “Typical” California MSW Landfill Landfill Site Characteristic Typical Value Owner TypePublicly owned (county) Site StatusActive Social SettingRural Fill MethodArea or combination Landfill Size (Permitted Disposal Area)55.5 acres Permitted Disposal Volume2.7 million cubic yards Permitted Maximum Daily Tonnage385 tons Remaining Capacity2.1 million cubic yards Physical SettingInland Underlying Geologic MaterialSand and/or gravel Minimum Depth to Underlying Groundwater34.5 feet Average Annual Precipitation16 inches Liner TypeFully unlined or partially unlined (active sites) Cover TypeFully uncovered Landfill Gas Collection SystemNone

Phase I: Remaining MSW Capacity (Task 3) 1.5 Billion Cubic Yards Statewide 44 Cubic Yards Per Person 11 ft

Phase I: Develop Indicators of Environmental Performance (Task 3) “Quantifying environmental performance is complex and difficult for any single site, and is even more complex and difficult when examining the performance of 224 sites with respect to each other.” Requirements for a State-wide Study: Data must be Quantifiable Available for Each Landfill Representative of Performance Uniform Measurement

Phase I: Regulatory Actions as Indicators of Environmental Performance (Task 3) Regulatory Agency Overseeing Environmental Performance Environmental Performance Indicator State OversightLocal Oversight State Water Resources Control Board Regional Water Quality Control Board “In Corrective Action” [Required to conduct a corrective action program] California Integrated Waste Management Board Enforcement Agency “Has Gas Inspection Report” [EA reported at least one gas related action] “Has Gas Enforcement Action” [EA issued at least one gas-related enforcement action] “Has Surface Water Action”. [EA reported at least one surface water action] California Air Resources Board Air Districts (SCAQMD and BAAQMD) “Air Quality Violation” [Reported at least one NOC or NOV]

Phase I: Environmental Screening Analyses (Task 3) Statistical Analyses Approach Independent Variable - Owner type - Landfill age and size - Social and physical setting, etc. Assumed Dependent Variable 1. “In Correction Action.” 2. “Has Gas Inspection Report.” 3. “Has Gas Enforcement Action.” 4. “Has Surface Water Action.” 5. “Has Air Quality Violation.”

Phase I CONCLUSIONS Sites most likely to be in corrective action or have water- related cleanup and abatement orders are larger, located in urban areas, are at least partially unlined, and are located in areas of higher than average precipitation. A larger volume of waste over a larger area with higher precipitation together produces a higher potential for a release. A larger volume of waste with higher precipitation together produces more landfill gas with a higher potential for a gas compliance issues.

Phase II: Goals of Tasks 4 and 5 In-Depth Look at 53 MSW Landfills Identify root of compliance issues Assess effectiveness of regulations in providing environmental protection

Phase II: Methods for Task 4 Review Task 2 cross-media inventory and Task 3 multi-variable analyses Contact landfill owners/operators and regulators (RWQCB, EA, and AQMD/APCD) regarding environmental performance of the landfill the application of the existing MSW regulations at the landfill Develop summary for each landfill of information collected from owner/operator and regulators (to be posted on the Landfill Study website)

Phase II: Summary of Site Data (Task 4)

Phase II: Methods for Task 5 Review results of Task 4, looking across all environmental media, for use in cross-site comparisons. Evaluate Task 4 data and identify recurring issues related to unsatisfactory environmental performance that may be associated with deficiencies in the existing California landfill regulations. Develop recommendations for changes to the existing California MSW landfill regulations based on the results of the evaluations that could lead to greater environmental protection.

Phase II: Methods for Task 5 Categories Considered for Selected Regulatory Topics Landfill Containment Systems Water Quality Monitoring Landfill Gas Monitoring and Control Other Control Systems (Surface Water Control) Landfill Closure and Post-Closure Care

Phase II: Methods for Task 5 Criteria for Evaluating Selected Regulatory Topics Description of Compliance Issue Comparison to Task 2 Cross-Media Inventory Current Regulatory Requirements Proposed Changes to Existing Regulations Environmental Protection Benefit Cost Impact Design and Operational Considerations

Phase II: Task 5 General Findings Landfill gas impacts on air quality: No recurring issues identified Containment systems and closure/post-closure care: No changes to regulations recommended Existing regulations address explosive gas impacts of landfill gas, but not groundwater impacts

Phase II: Proposed Changes to Regulations Based on Tasks 4 and 5 Landfill Gas Monitoring and Control Landfill gas monitoring and control as comprehensive during active life as currently required during post-closure care Gas generation starts as soon as waste is placed. Active landfills more likely than closed landfills to have gas compliance issues. Monitoring for explosive gases in the vadose zone closer to the landfill mass at sites with large buffers. The migration of landfill gas is a precursor to groundwater impacts The distance to the property boundary may not allow migration of explosive gases to be effectively identified No actual changes to existing regulations, but promoted by the EA Compliance point for explosive gas concentrations remains at the property boundary

Phase II: Proposed Changes to Regulations Based on Tasks 4 and 5 Groundwater Quality Monitoring Landfill gas monitoring included in detection monitoring program Migration of landfill gas is a precursor to groundwater impacts. Landfill gas is typically easier to control than groundwater. 59% of the 53 landfills that have had impacts to groundwater have attributed those impacts at least in part to landfill gas migration. Surface Water Monitoring and Control Submission of an annual winterization plan Winterization plans helpful in complying with surface water regulations at sites with different climates. Storm-related surface water and leachate control compliance issues have occurred at sites with different climates. The cost to implement and enforce the plans may be lower than the cost of responding to storm-related impacts

Phase II: Methods of Task 6 Evaluation of States and Countries Regulations Selected 8 states and 5 countries for comparison of landfill regulations to California’s. Compiled the regulations from the selected states and countries and compared them to the California and federal regulations. Identify those elements that could possibly improve or enhance California’s multimedia regulation of MSW landfills. Compare incremental cost and environmental protection benefit of the selected regulations to California’s current state of practice.

Phase II: States Selected for Evaluation in Task 6

Phase II: Countries Selected for Evaluation in Task 6

Phase II: General Findings of Task 6 The California regulations appear to be less specific than the regulations from the 8 selected states The California regulations appear to be similar to the 5 countries reviewed in that they are all attempting to accommodate highly variable site conditions California appears to have found a balance between flexibility and specificity appropriate to the heterogeneity of the state

Phase II: Regulations from Task 6 States or Countries Proposed for Consideration in California Multiple prescriptions for base liner based on site conditions if it can be shown to be more environmentally protective than the current regulatory system (such as Size, Climate, Population Density, Subsurface Conditions, Proximity to Groundwater) Standard for defining the end of post-closure based on environmental performance if the standard can be shown to achieve greater environmental protection than current regulations (such as Leachate Quality, Landfill Gas Generation, Results of Groundwater Monitoring, and Level of Degradation of the Waste Mass) Waste Pre-processing (may be appropriate, but additional study required) Additional changes may be appropriate if existing regulations are not performing and if warranted by the results of a thorough review (Minimum distance from wetlands, Proximity to water supply wells and Concentration of explosive gases at the property boundary)

Phase II: Goals and Methods of Task 7 Study of Emerging Technologies  Identify emerging technologies in waste management to be considered for application in California.  Develop a set of topics by which all technologies may be evaluated.  Perform extensive review of technologies, using existing documentation as primary resource.  Summarize applicability of each technology for application in California.  Recommend technologies which are most likely candidates for application in California.

Phase II: Emerging Technologies (Task 7) Pre-Disposal Waste Treatment Technologies Mechanical Pre-Processing Biological Pre-Treatment Thermal Pre-Treatment Landfill Design Technologies Anaerobic Bioreactor Landfill Aerobic / Semi-aerobic Landfill Alternative Base Containment Systems Alternative Cover Systems Landfill Remediation Technologies Landfill Gas Applications Passive Aeration Air Injection Leachate Recirculation Landfill Mining Industry Standards, Certifications, and Guidance Documents

Phase II: Topics for Evaluation of Technologies (Task 7) General Description Detailed Description and Process Options Global Application and Case History Research Studies Technologies in Combination Application in California Evaluation of Benefits and Barriers

Mechanical Pre-Processing Anaerobic Bioreactor Landfills Alternative Base Containment Systems (especially electrically conductive geomembranes and encapsulated GCLs) Alternative Cover Systems (especially non-barrier cover systems) Landfill Gas Applications (especially for medium BTU applications) Leachate Recirculation Industry Standards, Certification and Guidance Documents  The following technologies are recognized to have considerable potential for successful implementation in California Phase II: Most Likely Technologies for Application in California (Task 7)

Phase II: Task 8 Goals Compile the findings of the previous tasks Develop a comprehensive set of recommendations for possible improvements or enhancements to California’s multimedia regulation of MSW landfills that could result in greater environmental performance

Phase II: Organization of Task 8 Report Provides a summary of Tasks 3, 5, 6 and 7 Identifies those recommendations from previous Tasks that are expected to have the most immediate tangible benefits to the environmental performance of landfills

Phase II: Task 8 Conclusions Prior to this study, previous studies have focused primarily on the performance of containment systems The recommendations developed in Task 5 with respect to landfill gas impacts and surface water control are expected to have the most immediate tangible benefits Many changes recommended in previous tasks are not expected to have immediate tangible benefits because: environmental protection benefit is not readily apparent when compared to current practices or regulations, or substantial additional study is required prior to implementing the change

Phase II: Task 8 Conclusions “Immediate Tangible Benefits” Landfill gas monitoring and control as comprehensive during active life during post- closure care Landfill gas monitoring included in detection monitoring program for water quality Monitoring for explosive gases in the vadose zone closer to the landfill mass at sites with large buffers Submission of an annual winterization plan

QUESTIONS