SDMSDocID 2031780 POOR LEGIBILITY ONE OR MORE PAGES IN THIS DOCUMENT ARE DIFFICULT TO READ DUE TO THE QUALITY OF THE ORIGINAL University and Community College System of Nevada 2031780 DOE/NV/11508-52 SUNRISE LANDFILL GAS EMISSIONS AND ENERGY PRODUCTION POTENTIAL prepared by Hampden Kuhns, Glenn V. Wilson, Mark Green, and David Shafer submitted to Nevada Operations Office U.S. Department of Energy JANUARY 2000 Publication No. 45173 This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or any third party's use or the results of such use of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, mark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof or its contractors or subcontractors. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. This report has been reproduced directly from the best available copy. Available to the public from: U.S. Department of Commerce National Technical Information Service 5285 Port Royal road Springfield, VA 22161 (703) 487-4650 Available electronically at hrtp://www.doe.gov/bridge/ Available to the U.S. Department of Energy and its contractors in paper form: U.S. Department of energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831 (423) 576-8401 University and Community College System of Nevada July 12, 2000 MEMORANDUM TO: Distribution FROM: Marjory r ' J yf x Enclosed for your information is a cop/of the final report entitled "Sunrise Landfill Gas Emissions and Energy Production Potential," by H. Kuhns, G. Wilson, M. Green and D. Shafer, DRI Pub. No. 45173, DOE/NV/11508—52. January 2000. 2687 2215 Raggio Parkway Reno, NV 89512-1095 775-673-7300 DOE/NV/11508-52 SUNRISE LANDFILL GAS EMISSIONS AND ENERGY PRODUCTION POTENTIAL prepared by Hampden Kuhns, Glenn V. Wilson, Mark Green, and David Shafer Desert Research Institute University and Community College System of Nevada Publication No. 45173 submitted to Nevada Operations Office U.S. Department of Energy January 2000 The work upon which this report is based was supported by the U.S. Department of Energy under Contract #DE-AC08-95NV11508. Approved for public release; further dissemination unlimited. EXECUTIVE SUMMARY The Sunrise Landfill is located on the eastern side of the Las Vegas Valley and covers an area of approximately 720 acres. The landfill operated from 1963 to 1993 when the last load of refuse was delivered to the site. During this period of operation, waste streams consisted of non-hazardous municipal waste, asbestos-containing materials, medical wastes, septic sludges, and hydrocarbon-impacted soils. While no records of the amount of refuse placed prior to 1991 were available, data on the most recent waste acceptance volumes and population growth trends have been used to estimate the annual disposal rate over the life of the landfill. Recently, residents have filed complaints with the Clark County Health District regarding the uncontrolled emissions of methane from the landfill. The U.S. Department of Energy requested that the Desert Research Institute assess the current and projected methane emissions of the Sunrise Landfill, identify methane extraction methods, and estimate the power generating potential of the emitted methane. Several proven gas collection system designs are described in terms of their appropriateness for the Sunrise location. Once collected, methane from the landfill can either be flared or used for heating or power production. These options were evaluated to determine a cost-effective method for mitigating the landfill gas emissions. Methane emissions were estimated for the landfill using U.S. Environmental Protection Agency's Energy Project Landfill Gas Utilization Software (E-PLUS). Sensitivity tests were applied to the various input parameters to estimate the modeled emissions uncertainty. The analysis suggests that both power generation and sale to nearby users and gas enrichment for injection into existing natural gas pipelines are financially viable uses for the landfill gas over a wide range of expected methane production rates. The net present value of these projects is estimated to be between $6 and $8 million. The gas enrichment option offers environmental benefits in that no substantial emissions from gas combustions are produced on site. Federal regulations mandate that a gas collection and flaring system be installed at the Sunrise Landfill. We recommend that the issue of landfill gas use is revisited when the collection system is in place and methane production rates are known with a higher degree of certainty. 11 CONTENTS EXECUTIVE SUMMARY ii LIST OF FIGURES v LIST OF TABLES viii ACRONYMS ix 1.0 INTRODUCTION 1 1.1 Stage of Decomposition 2 1.2 Manipulation of Decomposition 2 1.3 Landfill Gas to Energy 3 1.4 Regulatory and Economic Drivers 4 2.0 SUNRISE LANDFILL BACKGROUND 6 2.1 Climate and Geologic Setting 7 2.2 Sunrise Landfill Operations and Closure 9 2.3 Post-Closure Conditions and Hydrogeologic Impacts 9 2.4 Regulatory and Community Actions 13 3.0 STUDY OBJECTIVES AND PROJECT ACTIVITIES 14 4.0 GAS TESTING AND RECOVERY OPTIONS 16 4.1 Lysimetry 16 4.2 Flux Testing 18 4.3 Well Testing 20 4.3.1 Single Well with Gas Probes 21 4.3.2 Well Clusters 24 4.3.3 Borehole Site Characterization 25 4.4 Anaerobic Sampling 26 5.0 METHANE EMISSIONS FROM SUNRISE LANDFILL 27 5.1 Methane Emission Estimates 27 5.2 Emissions of Non-Methane Organic Compounds (NMOC) Gases 32 6.0 METHANE USE OPTIONS 35 6.1 Case Studies 35 6.2 Sunrise Landfill Methane Use Options 36 6.2.1 Power Generation Potential 37 6.2.2 Nearby Energy Consumers 37 6.2.2.1 Sunrise Station 37 6.2.2.2 Las Vegas Sewage Treatment Plant (STP) 38 6.2.2.3 Clark County STP 38 6.2.2.4 Clark Station 39 7.0 FINANCIAL ANALYSIS OF METHANE USE OPTIONS 39 7.1 Default Model Inputs 40 7.2 Case 1: Collect and Flare Gas to Achieve Compliance with EPA Regulations 40 in 7.3 Case 2: Collect Gas and Sell to Southwest Gas for Use at Sunrise and Clark Power Stations 41 7.4 Case 3: Collect Gas and Produce Power to Sell to a Power Company Such as Nevada Power 43 7.5 Case 4: Collect Gas and Produce Power to Sell to a Nearby User Such as the Clark County STP 46 7.6 Summary of Economic and Environmental Analysis of Methane Utilization 47 8.0 CONCLUSIONS AND RECOMMENDATIONS 48 9.0 REFERENCES 50 Appendix A Letter to BLM and Letters of Support A-l Appendix B Email Responses from Alan Gaddy of Republic Silver State Disposal B-l Appendix C Letter Submitted to EPA Region 9 C-l Appendix D Model Input and Results for Gas Enrichment and Pipeline Injection D-l IV FIGURES 1-1. Typical LFG composition during decomposition of MSW (recreated from Farquar and Rovers, 1973) showing the five stages of LFG production (from Ward, 1988) 1 1-2. LFG-to-energy projects and average yearly price of oil per stock-tank barrels (STB), recreated from Hutchinson (1993) 5 2-1. Contour map of the Sunrise Landfill site with the lease boundary depicted by red line and the approximate boundary of the watershed contributing runon to the site depicted by blue line 7 2-2. Schematic of the conceptual framework of the hydrogeology at Sunrise Landfill 11 4-1. Schematic of the lysimeter facility used in ACAP (from Wilson et al., 1999) 17 4-2. The flux chamber design reported by Reinhart etal. (1992) 19 4-3. Single gas withdrawal well in center of three concentric circles of boreholes with probes, noted by solid circles 22 4-4. Two types of multi-level borehole testing 22 4-5. Five-well dice pattern for gas rate production testing 25 5-1. Clark County population and Sunrise Landfill Waste Acceptance (Mg/yr) 28 5-2. Empirically derived versus predicted methane production rates Mm3/yr (EPA,1997b) 29 5-3. Effect upon Sunrise Landfill methane emissions of varying methane generation rate constant k 30 5-4. Effect upon Sunrise Landfill methane emissions of varying methane generation potential LO 30 5-5. Estimated methane emissions rates from Sunrise Landfill for three cases used in economic analysis 32 5-6. NMOC emissions from Sunrise Landfill for ranges of NMOC concentration and methane generation rate constant k 34 5-7. Same as 7-8, except y-axis scale is reduced to show more detail at lower emission levels 34 6-1. Aerial view of Sunrise Landfill and potential users of methane and power produced from the landfill gas 38 7-1. Process diagram for gas enrichment and injection system 41 7-2. Process diagram for energy production and sale 43 D-l. Project financial assumptions D-l D-2. Landfill waste acceptance and methane emissions using parameters LO = 100 m3/Mg and k = 0.02 yr"1 D-2 D-3. Landfill gas collection stage parameters D-2 D-4. Landfill gas splitter parameters D-3 D-5. Case 2: Landfill gas treatment stage D-3 D-6. Case 2: Landfill gas treatment stage costs D-4 D-7.