Ordot Dump Gas Collection and Control System Plan and Startup, Shutdown and Malfunction Plan

Transcription

1 Ordot Dump Gas Collection and Control System Plan and Startup, Shutdown and Malfunction Plan Prepared for Gershman, Brickner & Bratton, Inc. (GBB), Receiver for the Guam Solid Waste Authority January West Soledad Avenue, Suite 500 Hagatna, Guam 96910

2 Ordot Dump Gas Collection and Control System Plan and Startup, Shutdown and Malfunction Plan Prepared in Accordance with the New Source Performance Standards for MSW Landfills Prepared for Gershman, Brickner & Bratton, Inc. (GBB), Receiver for the Guam Solid Waste Authority 542 North Marine Corps Drive Tamuning, Guam January 2014 Douglas B. Lee, P.E. Brown and Caldwell 1/3/14 Date This work was prepared by me or under my supervision. 414 West Soledad Avenue, Suite 500 Hagatna, Guam 96910

3 Table of Contents List of Figures... ii List of Abbreviations... iii 1. Introduction The Ordot Dump and the New Source Performance Standards Landfill Gas Generation Modeling GCCS Compliance with Design Requirements of the New Source Performance Standards Compliance with 40 CFR Specification for Active Collection Systems Gas Extraction Components Gas Conveyance Components Condensate Management Compliance with 40 CFR Gas Control Components Gas Mover and Control Device Landfill Blower System Landfill Gas Flare Operations and Maintenance of the GCCS Gas Extraction and Control System Description Operations Procedures General Flare Operation General Operation Gas Collection System Performance Testing LFG Component Measurements Temperature Measurements Vacuum Measurements Flow Rate Measurements Water Level/Well Depth Measurements System Maintenance Blower Maintenance Knockout Pot Maintenance Condensate System Maintenance Flare Maintenance Gas Extraction Wellhead Maintenance Condensate Management Plan Staffing Plan Fire Control Construction Plan Documentation Construction Stages i

4 Ordot Dump Gas Collection and Control System Plan Table of Contents Construction Plan Landfill Gas Sampling and Testing Condensate Sampling and Testing Annual Report GCCS Startup, Shutdown and Malfunction Plan Introduction Plan Contents Equipment Covered by this SSM Plan System Start-Up Collection System Control Device Automatic Start-Up Manual Start-Up GCCS Shut-Down General Procedures System Decommissioning Malfunction Plan Common Malfunctions Timeframes for NSPS Exceedances Operational Contingencies General Responses to GCCS Malfunctions Surface Emissions Monitoring Protocol General Description Procedures Weather Conditions Recording and Reporting Action Levels and Follow-up Sampling SEM Survey Frequency References... REF-1 Appendix A: Ordot Landfill Gas Generation Potential... A Appendix B: Manufacturer s LFG Control Device Operations and Maintenance Manual... B List of Figures Figure 7-1 Surface Emissions Monitoring Route Plan ii

5 Ordot Dump Gas Collection and Control System Plan Table of Contents List of Abbreviations BC Brown and Caldwell FID flame ionization detector Ft feet GBB Gershman, Brickner & Bratton, Inc. GCCS gas collection and control system GEPA Guam Environmental Protection Agency GSWA Guam Solid Waste Authority HASP Health and Safety Plan HDPE high density polyethylene pipe HP horsepower km kilometers LandGem Landfill Gas Emissions Model LEL lower explosive limit LFG landfill gas LMOP Landfill Methane Outreach Program Mg megagram MSW municipal solid waste NESHAPS National Emissions Standards for Hazardous Air Pollutants NMOC non-methane organic compounds NSPS New Source Performance Standards O&M Operation and Maintenance OVA organic vapor analyzer ppm parts-per-million SCFM standard cubic feet per minute SEM surface emissions monitoring SSM Startup, Shutdown and Malfunction USEPA United States Environmental Protection Agency UXO Unexploded Ordnance w.c. water column iii

6 Section 1 Introduction On behalf of Gershman, Brickner & Bratton, Inc. (GBB), Receiver for the Guam Solid Waste Authority (GSWA), Brown and Caldwell (BC) has been authorized to develop plans and conduct design studies in support of the closure of the Ordot Dump (Dump) located in Ordot-Chalan Pago, Guam, under the Consent Decree Order (US District Court of Guam, Civil Case No , Document Number 55). In addition to the Consent Decree, Title 10, Chapter 51, Article 1 Solid Waste Management, 51101(4) of the Guam Code Annotated, mandated that the Dump be closed. The purpose of this document is to describe the plan for landfill gas (LFG) collection and control in accordance with the New Source Performance Standards (NSPS) for municipal solid waste (MSW) landfills, promulgated March 12, 1996 (40 CFR 60 Subpart WWW) for the Ordot Dump. The NSPS includes requirements for landfill gas collection and control systems (GCCS). The GCCS plan consists of this document, Section 5 of the Design Report, Ordot Dump Closure Construction And Dero Road Sewer Improvements, Ordot- Chalan Pago, Guam, dated July 1, 2013 (the Design Report), Appendix R to the Design Report titled Landfill Gas Generation Modeling And Gas Collection System Design Calculations, and the GCCS engineering design drawings provided as Drawing Numbers C13, C23, and C26 through C29 of the plan set titled Ordot Dump Closure Plan and Dero Road Sewer Improvements dated July 1, 2013 (the engineering drawings). 1-1

7 Section 2 The Ordot Dump and the New Source Performance Standards NSPS applicability is a function of the design capacity and the quantity of waste in a MSW landfill, as well as the ability of the landfill to generate and emit organic gases. The Ordot Dump has been estimated by BC to hold approximately 4.5 million cubic yards or 3.44 million cubic meters of material, which includes waste and cover soil (BC s Topographic Surveys and Airspace Report, 2012). Accurate records regarding disposal rates, types of waste, and cover soil use prior to June 2009 are not available; hence, reasonable assumptions were made based on the results of BC s investigations and reviews of available historical information to estimate the mass of waste in place. This estimation process indicated the range of in-place waste tonnage is approximately 3.5 million tons to 5.2 million tons (3.18 megagrams (Mg) to 4.72 Mg). This range is greater than the 2.5 Mg upper limit for a size exemption from the NSPS. The Ordot Dump is therefore subject to the NSPS. There is no evidence the Ordot Dump ever had a design capacity, as defined in 40 CFR , specified in a construction or operational permit issued by an authority having jurisdiction. No initial or amended design reports were submitted to the United States Environmental Protection Agency (USEPA) or Guam EPA (GEPA). Similarly, no initial or annual non-methane organic compound (NMOC) emission rate reports were submitted. Tier 1/Tier 2 emissions of non-methane organic compounds (NMOC) have not been calculated. Landfill gas generation modeling, however, projects that the Ordot Dump has an estimated uncontrolled non-methane organic compound emission range greater than or equal to 50 Mg per year. The facility's proposed methods for complying with the operational standards, test methods, procedures, compliance measures, monitoring, record keeping and reporting requirements of the NSPS are presented in this plan. 2-1

8 Section 3 Landfill Gas Generation Modeling Landfill gas is generated by the anaerobic decomposition of organic landfill waste. Landfill gas generally consists of methane and carbon dioxide, with small concentrations of nitrogen and other balance gases, as well as small concentrations of sulfur compounds and aromatics that contribute to landfill odor. Landfill gas generation is generally modeled with the widely-used USEPA Landfill Gas Emissions Model (LandGEM). LandGEM is an automated estimation tool that is used to estimate emission rates for total LFG, methane, carbon dioxide, non-methane organic compounds, and individual air pollutants from municipal solid waste landfills and is generally regarded as the mainland United States industry standard model for regulatory and non-regulatory applications. The USEPA Landfill Methane Outreach Program (LMOP) developed a version of the LandGEM for the Philippine Islands, which is a tropical location in the western Pacific at a similar latitude as Guam and with similarities in location, temperature, and precipitation as compared to Guam. The Philippine LandGEM provides a more developed gas generation calculation, and a more developed estimate of the fraction of LFG available for capture, than does the Standard LandGEM. The Philippines LandGEM was used to estimate landfill gas generation at the Ordot Dump for GCCS design purposes as it is considered the most appropriate method for estimating LFG production at Ordot Dump.. A complete discussion of calculating the amount of landfill gas produced at the Ordot Dump is found in the report titled, Ordot Landfill Gas Generation Potential, dated January 2013 provided in Appendix A, also provided as Appendix R in the Design Report. To summarize the findings, the landfill gas at the Ordot Dump is approximately 50% methane and the current recoverable generation rate should be from 300 standard cubic feet per minute (SCFM) to 500 SCFM. This quality of gas is sufficient to sustain combustion in a control device such as a flare. The rate of LFG generation is declining rapidly such that in 10 years, the landfill will be producing only 30% of its current rate. At that time, the LFG generation may be reduced to the level whereby the LFG can be passively vented from the landfill. This determination should be based only on documented conditions at that time and will need to be approved by GEPA. 3-1

9 Section 4 GCCS Compliance with Design Requirements of the New Source Performance Standards The final GCCS design for the Ordot Dump is based on the proposed final grades of the facility, as presented in the Design Drawings and discussed in the Design Report. The Ordot Dump GCCS will be constructed in conformance with this design and in conjunction with the installation of the final cover as presented in the Design Drawings and Design Report. This Section details compliance of the Ordot Dump GCCS with relevant portions of the federal regulations at 40 CFR 60 Subpart WWW, known as the New Source Performance Standards. 4.1 Compliance with 40 CFR Specification for Active Collection Systems Gas Extraction Components The LFG collection system includes the following gas extraction components: Vertical Extraction Wells - the vertical wells are comprised of an 8-inch-diameter perforated highdensity polyethylene (HDPE) well screen and a 6-inch-diameter telescoping solid upper riser installed within a 24-inch-diameter gravel-filled borehole, drilled to a depth of 25 to 60 feet (ft) depending on the location of the well. The spacing between the wells ranges from 150 to 300 ft. Horizontal Collectors the horizontal collectors are comprised of a 6-inch-diameter HDPE perforated collection pipe placed in gravel-filled collection trenches immediately beneath the geocomposite LFG interception layer component of the final cover. Migration Control Trench - A gravel-filled migration control trench is located outside the footprint of the waste disposal area, along the northerly property boundary, to address subsurface LFG migration. The bottom of the trench is at least 15 feet below existing ground surface in order to be below the bottom of the waste on the northerly side of the site. A 6-inch-diameter perforated HDPE collector pipe is placed within the gravel. Vertical wells, horizontal collector pipes, and the migration control trench pipe are furnished with control wellheads to control the flow of LFG into the conveyance piping system. Each wellhead has a manuallycontrolled valve to regulate applied vacuum and flow, and sample ports by which to monitor flow, vacuum and LFG characteristics. Backfill for the well and collector risers has a bentonite-cement seal layer to prevent LFG from escaping and to prevent air from entering the borehole or trench. Pipe boots are furnished where each collection system pipe passes through the geomembrane of the final cover system Gas Conveyance Components The piping system for conveying collected LFG consists of a looped 8-inch-diameter HDPE main collection header line to convey LFG from the vertical wells, horizontal collectors, and migration control 4-1

10 Ordot Dump Gas Collection and Control System Plan Section 4 trench to the flare station. Each well-head is connected to the header by a 6-inch-diameter HDPE lateral pipe. The header and lateral pipes are installed beneath the geomembrane of the final cover system, and generally have a minimum pipe slope of 5 percent. One section of the header will follow the alignment of an access road on the surface of the Dump and will have a minimum pipe slope of 3 percent Condensate Management Condensate resulting from the collection of LFG will be managed in a series of structures at the low point in the LFG collection header system, adjacent to the flare, and at the western end of the migration control trench. Prior to the flare station is a condensate drop-out structure, and the flare station itself includes a condensate knockout pot. Both structures discharge the condensate to a condensate sump, which discharges to the perimeter leachate collection drain. The migration control trench sump also discharges to the perimeter leachate collection drain; flow from the perimeter leachate collection drain is managed with the leachate collection system. The condensate volume will be a small fraction of the daily leachate flow entering the leachate collection system. 4.2 Compliance with 40 CFR Gas Control Components Gas Mover and Control Device The two primary components of the LFG control device are the gas mover, which is used to apply vacuum to the Dump to remove the LFG, and the control device, which is used to combust and destroy the LFG. The gas mover is a blower system, which includes a vacuum blower and its electric motor, and a knockout pot for condensate control. The control device is an open flame utility-type flare unit. Both components are mounted on a skid, which is placed on a reinforced concrete slab. Also on the concrete slab are a control box and panels to operate and monitor the gas control unit s performance Landfill Blower System The blower system is located on the skid and the LFG will flow through the following processes: The blower creates a vacuum, which is distributed through the header system to the wells and horizontal collectors. The interior of the Dump will be under a slight vacuum when the system is operating, and the header pipe vacuum should be approximately 30 inches w.c. (water column) when the system is running. The header system pipes bring LFG to the flare. As the LFG approaches the blower it passes through a condensate knockout pot, which is a short vertical pipe section with a demister screen at the outlet. The knockout pot serves to remove water droplets entrained in the incoming LFG. It may also slightly dry the LFG since there is a pressure loss of about 10 inches w.c. vacuum across the pot, which cools the LFG and condenses out additional moisture. Condensate collects at the bottom of the knockout pot and there is a drain at the base for condensate removal. The LFG is then drawn into the blower and discharged at the required flare pressure to the outlet gas stream. The blower unit has the following parameters: Allows for variable speed operation to most closely match the required flow rate generated by the Dump; Inlet vacuum of 30 inches w.c.; Outlet pressure typically 15 inches w.c. (or as required by the flare manufacturer for flare operation); Flow rate at these pressures 50 to 500 SFCM; 15 horsepower (HP) (typical), variable speed motor to power the blower; and 4-2

11 Ordot Dump Gas Collection and Control System Plan Section 4 Vacuum and pressure gauges are located each side of the blower to monitor performance. GSWA also has a spare blower in storage for use in the event the original blower fails or components wear out. In addition there is an emergency generator at the site to provide electricity at the site in the event of power outages Landfill Gas Flare The landfill gas flare is a skid-mounted candlestick type open flare. Once the LFG is discharged from the blower, it flows through a horizontal pipe to the base of the flare. At the flare base, LFG will pass through a flame arrestor, which is designed to prevent the flame from propagating back up the pipe into the blower when the flare is shut down. At the top of the vertical flare pipe is an automatic ignition system using propane gas to fuel a pilot light. A wind shield surrounds the flare head assembly and ignition system to prevent wind blow-out during normal operations. The flare has a destruction efficiency of 98% overall destruction of total hydrocarbons at the design flow with gas methane content 30% to 50%. This is guaranteed by the manufacturer to meet EPA emission standards for landfill gas disposal in utility "candle type" flares, per the US EPA AP-42 Supplement D, Table The flare unit comes equipped with the required controls needed for long-term automated operation of the flare. Typical controls include: Weatherproof electrical control panel boxes, Blower motor control center with starters and circuit protectors, Main power disconnect and step-down transformer, Thermal dispersion flow meter and paperless chart recorder to record flame temperature and LFG flow, Automatic flare controller with a touch-screen interface, and blower amperage and blower hours displays, and Telecommunication interfaces for remote notification and monitoring the flare s operation; computer software (PC based) is provided to allow monitoring of flare operation remotely. 4-3

12 Section 5 Operations and Maintenance of the GCCS This Operations and Maintenance Section has been prepared to summarize steps necessary to operate and maintain the Gas Collection and Control System at the Ordot Dump (the Dump) in Ordot-Chalan Pago, Guam. This Operations and Maintenance Section and the manufacturer s O&M Manual provided in Appendix B are integral parts of the post-closure care of the Ordot Dump. Therefore, a copy of this GCCS Plan and any subsequent revisions must be maintained at the site and also with the Ordot Dump's operating records. 5.1 Gas Collection and Control System Description The Landfill Gas Extraction and Control System is designed to collect gases generated within the Ordot Dump waste mass as waste decomposes, and to combust the gas with an open flare. Positive pressure is generated in the waste mass by anaerobic decomposition of the refuse, which produces primarily methane and carbon dioxide. If not relieved, pressure within the waste mass can force these gases into the atmosphere or laterally through the ground, potentially causing hazardous conditions to develop in underground structures. The gas extraction and collection system will relieve the positive pressure by applying a vacuum throughout the waste mass. The gas will be conveyed to the skid-mounted open flare, located on the eastern side of the Dump, adjacent to the access road. The gas collection system is capable of handling LFG quantities greater than the maximum expected 500 SCFM, in order to allow for variances in the LFG generation. The system consists of the following main components: 24 LFG extraction wells. 13 connections to horizontal collectors. 8 connections to the gas migration control trench. A piping network through which a vacuum can be applied to all collection points. Condensate management structures to separate water vapor from the LFG. Blower to apply a vacuum to the LFG extraction points and to send the LFG to the flare. A flame arrestor to prevent flashbacks from the flare to the piping network. A flare system to destroy the LFG. The Ordot Dump gas collection and control system consists of two stages or phases. Phase 1 of the system includes the installation of all components on the eastern half of the Dump, including the flare, and Phase 2 consists of all components on the western half of the Dump. Phase 1 of the gas collection system will be installed when approval to construct is received from GEPA. Installation of the Phase 2 gas system is scheduled to commence during the second stage of construction. The gas extraction system incorporates strategically placed valves and a cross-lateral line (also known as a transverse header) to provide a degree of flexibility in the application of vacuum at the extraction points. Therefore, the vacuum can be selectively applied based upon actual LFG generation at specific 5-1

13 Ordot Dump Gas Collection and Control System Plan Section 5 gas extraction points. The design also allows for sections of gas lines to be segregated for maintenance while the remainder of the system is operated. When LFG is extracted from a waste mass, a change in temperature and pressure occurs that results in the condensation of moisture within the LFG and the production of condensate within the gas extraction system piping. The majority of the condensate from the GCCS will travel through the gas collection lines to the subsurface condensate drop-out structure located adjacent to the flare station. Condensate collected by this structure will flow by gravity to the condensate sump, which discharges directly into the perimeter leachate drain. Condensate will also be collected at the above-ground knockout pot at the flare skid (also referred to as the moisture separator) and routed through the sump for disposal. The screens in the knockout pot must be cleaned periodically to ensure unhindered performance. The cleaning frequency may vary based on the amount of condensate collected and temperature changes. Once the system is operational, the LFG will be collected and combusted at the skid-mounted open flare. The makeup of the LFG and its combustion are further described in detail in the Air Pollution Control Permit Application, submitted to the GEPA. 5.2 Operations Procedures General Vacuum adjustments throughout the GCCS can be made by operating the valves at each wellhead and in the system piping. By adjusting the valves, the system can be balanced so that the maximum amount of LFG can be collected without pulling air into the waste mass, which would diminish anaerobic decomposition and increase the potential for internal fires. To assist with system balancing and verify efficient operation of the GCCS, the following will be periodically measured. LFG flow rates at each wellhead and to the flare. Methane, carbon dioxide, oxygen, and balance gas concentrations at each wellhead and the flare. Vacuum at each wellhead. LFG temperature at each wellhead. There are also monitoring ports in the header lines where these constituents may be measured for diagnostic purposes. Initially, to balance the gas system, daily measurements may be necessary. As the system begins to stabilize and the LFG stored in the waste mass is removed, measurements may be taken less frequently. Weekly measurements are proposed until stabilization is reached, and then, to maintain a balanced system, monthly well measurements will be adequate. The vacuum, the LFG temperature and the methane, carbon dioxide, oxygen, and balance gas concentrations will be recorded. Periodic LFG flow rates at the wells will be recorded so that the correlation between the vacuum applied and the LFG flow rate can be established for each well. The amount of vacuum applied at each well will vary through time and is influenced by the type of cover. Typically, the vacuum applied at exterior gas extraction wells should be approximately one to three inches of water column to provide adequate gas control and avoid excessive air infiltration along the surface slopes of the Dump. The vacuum that can typically be applied to interior gas extraction wells is three to seven inches of water column without producing excessive air infiltration. Where final cover is not in place, much lower vacuums ought to be applied to the gas extraction points to avoid excessive air infiltration. Some experimentation will be required to find the proper vacuum to apply to these wellheads. 5-2

14 Ordot Dump Gas Collection and Control System Plan Section 5 As a starting point, the valves should be nearly closed at the wellheads and opened slightly until the LFG readings are within the required ranges. In this way, excessive air infiltration into the LFG system can be avoided. The required ranges for each constituent of the LFG are discussed in the following sections. Gas Readings The concentrations of various gases at each wellhead are the primary indicators of how much vacuum should be applied at the gas collection location. LFG typically contains approximately 50% methane and 50% carbon dioxide, with trace amounts of sulfur compounds, aromatics and other NMOCs. If the concentration of methane is high at a particular wellhead, then the volume of LFG available at that location may be greater than what is currently collected and the vacuum applied should be increased. If the concentration of methane is 45% or less, the concentration of oxygen is above 1%, or the balance gas concentration is above 12%, excess air may be entering the waste mass and the vacuum should be decreased at that gas collection point. Vacuum Readings The vacuum readings are used to develop an understanding of the relationship between the flow rate and the vacuum applied. Vacuum measurements are also useful to monitor the gas collection system for pipe blockage or failure. The monitoring ports in the header lines can be used to locate pipe blockages or pipe failure. Temperature Readings The temperature of the LFG at each wellhead is an indicator of the amount of air infiltrating into the waste mass. The temperature at a wellhead should remain relatively constant. If the temperature at a well increases sharply or exceeds 130 degrees Fahrenheit, excessive air may have infiltrated into the waste mass, especially if the concentration of methane has decreased. Over time this situation increases the possibility of an internal fire and requires immediate attention. Isolation Valves Valves are located at the junction of the cross-lateral line and the perimeter header to provide the ability to isolate portions of the gas system for maintenance or repair. Therefore, portions of the gas system can be shut down while other portions remain in operation. Condensate Collection Condensate is a by-product of the collection of LFG from the waste mass. At the ambient pressure and temperature inside the body of the waste mass, LFG is usually saturated with water vapor. Once released or extracted, LFG is subject to different environmental conditions that result in condensation within the gas collection system. The amount of condensate generated in the GCCS will be dependent on system operations and seasonal temperatures. If not properly managed, condensate can accumulate to the extent where it disrupts the flow of LFG. To avoid this problem, all gas collection pipelines are sloped to direct condensate flow to the condensate drop-out structure near the flare station. The knockout pot on the flare skid will collect additional condensate that is not removed at the drop-out structure. Both these structures drain to the condensate sump for discharge to the perimeter leachate collection drain. LFG from the header line will slow down as it enters the drop-out structure and the knockout pot. The knockout pot contains baffles to allow moisture to collect and fall to the bottom. The migration control trench collection header slopes to the west, where condensate is collected by a condensate sump and discharged to the perimeter leachate drain in that location. 5-3

15 Ordot Dump Gas Collection and Control System Plan Section Flare Operation General Operation The Flare will operate in the following modes: Normal flow mode: All of the collected LFG will be conveyed to the flare for combustion. This mode of operation is expected to occur nearly 100 percent of the time. Flame-out mode: On occasions, the flare might be unavailable (due to maintenance, the flame going out, or other reasons). In this mode, the programmable logic controller at the flare would attempt to automatically re-ignite the flare. In the event that the flare does not re-ignite, the vacuum blower would shut down and the pressure within the GCCS would begin to equalize to atmospheric pressure. The loss of vacuum would trigger an alarm, alerting personnel that the flare is not ignited. The operator of the facility would then correct any problems and re-ignite the flare. On a weekly basis, the system operators will monitor the operation of the flare and record LFG flow rates, temperatures and other data. Open flares can operate for extended times with a minimum of maintenance. Standard maintenance activities will include periodic inspections, cleaning of the flame arrestor, repairs as needed and replenishment of the supply of propane ignition fuel and of nitrogen for actuating the control valve (also known as the slam-shut valve or the automatic block valve). GSWA personnel and/or their Operation and Maintenance (O & M) contractor will be trained to perform these tasks per the manufacturer s recommendations. 5.4 Gas Collection System Performance Testing System performance testing is an essential component in the efficient and safe operation of the GCCS. Performance testing will be conducted regularly and the results recorded in a permanent logbook. Once the system is balanced, monthly measurements of the following parameters should be made at the wellheads: Temperature Vacuum Methane concentration Carbon dioxide concentration Oxygen concentration Balance gas concentration LFG flow rates will be measured at the wellheads monthly and when modifying wellhead valve positions. Weekly measurements of the following parameters should be made at the flare: LFG flow rate Temperature at the knockout pot Methane concentration Carbon dioxide concentration Oxygen concentration Balance gas concentration The following sections describe performance testing in more detail LFG Component Measurements The measurements of the following LFG components are the principal parameters in system balancing: 5-4

16 Ordot Dump Gas Collection and Control System Plan Section 5 Methane concentration Carbon dioxide concentration Oxygen concentration Balance gas concentration Measurements of these components at the wellheads will be conducted at least monthly and maybe more frequently during system balancing. The concentrations of the gases should also be determined at the following locations at the flare: The knockout pot inlet The blower inlet The flare inlet The methane production of each gas extraction point will change over time, requiring periodic adjustments in the vacuum applied to the wellheads to maintain optimal system efficiency. The oxygen concentrations should be less than 1% at the wellheads, while the balance gas should remain below 12%. Oxygen greater than 1% and/or balance gas levels above 12% may indicate air leaks in the wellfield components or excessive vacuum on extraction wells and horizontal collectors. If the data indicates that atmospheric air is entering the system, the cause must be evaluated by performing diagnostic readings and observations at the wellheads and access ports to determine the likely source. A diagnostic approach includes measuring and comparing gas component concentrations at the wellhead, lateral, and the main header line. Visual and auditory senses may be helpful in isolating wellfield air leaks Temperature Measurements Measurements of temperature will be used in conjunction with the gas component measurements to determine the positioning of the wellhead valves. The temperature of the LFG at each collection point can be used as an indication of air infiltration into the waste mass. The temperature at a wellhead should remain relatively constant but below 130 degrees Fahrenheit. If the temperature at a wellhead increases sharply, excessive air may have infiltrated into the waste mass, especially if the concentration of methane has decreased. This situation indicates an increased possibility of an internal fire and requires immediate attention Vacuum Measurements Vacuum measurements indicate the amount of extraction energy being applied at each LFG collection point. Vacuum measurements in inches of water column should be collected during system balancing at the wellheads, the inlet to the knockout pot, and the blower inlet and outlet. Vacuum measurements may also be taken at the monitoring ports on the header lines. Vacuum measurements indicate possible problem conditions. Reduced wellhead vacuum may indicate a plugged lateral in isolated instances, or a plugged or broken header, if reduced vacuums occur at two or more well locations. Isolated low vacuum conditions may be alleviated by repeatedly closing and opening the valve, thus surging the well. In many cases, a minor blockage can be alleviated by surging, followed by re-adjusting the flow to the established optimal performance level. The monitoring ports will facilitate assessment of such conditions Flow Rate Measurements The flow rates measured in the GCCS are used to confirm well and horizontal collector performance and overall system performance. Typical well and horizontal collector performance will be evident over time 5-5

17 Ordot Dump Gas Collection and Control System Plan Section 5 at each location. If the flow rate drops at a particular collection point, a blockage in the well or lateral line may exist. Due to a build up of LFG within the waste mass, it is likely that the flow rates of the system will be greater when the system is first operated or turned on after a system shutdown. Once this positive pressure within the waste mass is eliminated and the system is balanced, the system will equalize and remain relatively constant Water Level/Well Depth Measurements Leachate in the waste mass may cause blockages in the gas extraction wells and horizontal collectors. For this reason, water levels and total depth of the wells may be measured. Water level measurements may be used to determine if water within an extraction well is covering the perforated section of the well screen and inhibiting the free flow of LFG to the well. An electronic water level indicator may be used for this purpose. Well depth measurements may be used to check for well blockages due to sediments from the waste or pipe disturbances due to lateral forces within the waste mass. Even partial blockages of a well can affect its ability to effectively extract LFG. 5.5 System Maintenance Blower Maintenance The blower provides the vacuum that pulls the landfill gas from the extraction wells and horizontal collectors, through the header piping, and through the knockout pot. The blower also pushes the LFG into the flare where it is combusted. Therefore, it is essential to the overall system performance that the blower is functioning properly. The blower should be on a preventative maintenance program in accordance with the procedures recommended by the blower manufacturer and outlined in the manual provided with the equipment. Some of the more common maintenance items are listed below. 1. Bearing and motor lubrication. 2. Valve operation. 3. Pipe and valve leak detection. 4. Tightness of connectors which could vibrate loose. 5. Electrical connections Knockout Pot Maintenance The knockout pot removes remaining condensate that was not extracted by the condensate drop-out structure. As the LFG enters the knockout pot, it slows down to allow moisture to collect on baffles within the pot. The condensate then flows by gravity to the condensate sump, which discharges to the perimeter leachate drain. Since LFG and condensate are corrosive by nature, the knockout pot will be made from a HDPE material or will be carbon steel coated with a phenolic painting system. The HDPE material will eliminate the need to coat the knockout pot with the corrosion-resistant material. If entrance to the knockout pot is required, confined space entry procedures must be followed in accordance with applicable regulations Condensate System Maintenance The condensate drop-out structure allows condensate to drop out of the header line and trickle out to the condensate sump, which discharges to the perimeter leachate drain, where it will be collected by the leachate collection system. The knockout pot also discharges to the condensate sump. The condensate drop-out structure decreases the volume of condensate conveyed to the knockout pot. If the operation of the drop-out structure is compromised, excess moisture will be conveyed to the knockout pot and the 5-6

18 Ordot Dump Gas Collection and Control System Plan Section 5 flare, compromising the ability to sustain a flame. If excess condensate collects in the drop-out structure, gas flow will be blocked and vacuum will not be able to be conveyed to the LFG extraction points. The condensate sump will be monitored on a quarterly basis by measuring the depth to liquid below the measuring point. The depth to water will be compared to the depth of the sump outlet to confirm that the pipe is not clogged. The following procedure will be followed to measure the water level at the sump: 1. Close the valve. 2. Remove the sump riser cap. 3. Turn on the water level indicator and lower the probe down the sump riser pipe until the instrument signals. 4. Determine the top of the water by slowly raising and lowering the probe observing the point at which the instrument signals relative to the measuring point. Read the graduated scale on the instrument cable to the nearest 0.1 feet and record the reading in the logbook. 5. Determine the total depth of the sump liquid by slowly lowering the water level probe to the sump bottom. Record the depth at which the probe can no longer be lowered. 6. Subtract the depth to water from the depth to the bottom the sump. The result should be less than 5.0 feet. If the result is greater, corrective action should be undertaken Flare Maintenance The LFG collected by the gas collection system will be burned in the open flare. The flare will be maintained in accordance with the procedures provided by the manufacturer. Under normal conditions, the flare will be operated in the automatic mode and the following will be monitored. The pilot gas supply will be checked weekly and replenished, as necessary. The gages and valves on the flare and control panel will be checked for leakage and operation weekly. The manual operation of the flare will be tested quarterly. The pilot will be manually sparked, and the thermocouples will be inspected. Electrical equipment will be checked monthly for proper operation. The flame arrestors will be removed and cleaned as indicated by the manufacturer. The flare may extinguish due to the following potential situations. Low methane concentration in the LFG delivered to the flare. A clogged flame arrestor. High wind velocity. A malfunctioning thermocouple Gas Extraction Wellhead Maintenance During the previously mentioned monthly routine performance monitoring, the following will be conducted at each wellhead. 1. Check valve operation. 2. Observe piping, flex-hose, valves, and fittings for leakage. 3. Check the wells and piping for accumulated liquid and repair, as necessary. 5.6 Condensate Management Plan Condensate will be conveyed through the gas lateral and header piping system and disposed of with the use of the condensate drop-out structure and the knockout pot. Both structures discharge to the 5-7

19 Ordot Dump Gas Collection and Control System Plan Section 5 condensate sump, from where the condensate will flow directly into the perimeter leachate drain. There is also a condensate sump at the western end low-point of the migration control trench collection header, which discharges to the perimeter leachate drain at that location. The condensate will then join the leachate flow from the perimeter leachate drain, and will be managed with the leachate. Condensate will form a small portion of the total flow from the perimeter leachate drain. 5.7 Staffing Plan The GCCS should require only routine maintenance once it is operating and balanced. The flare will be operated continuously in the automatic mode and should provide efficient and effective LFG management. Operation in the manual mode will be performed infrequently when testing equipment and during some equipment maintenance. In the automatic mode, the flare is designed to shut down automatically in the event that the flame is extinguished or if the flare temperature or gas quality is above or below a specified operating range. A block or "slam-shut" valve located between the flare and the blower will automatically close in the event the flare or the blower shuts down. Staff assigned to the GCCS will be principally concerned with routine system performance monitoring and maintenance. One part-time technician should be devoted to these duties. Additional manpower may be necessary for initial balancing of the system, repairs, and confined space entry. 5.8 Fire Control Procedures for handling fires must be posted at an appropriate location on-site and must include names and telephone numbers of authorities to be called during an emergency. The GSWA, GEPA, and local police and fire departments must be notified whenever any fire, smoldering, or smoking materials are discovered at the site. Dump operations and construction activities shall be suspended in the vicinity of smoldering, smoking, or burning areas. Any disruption of the finished grade or covered surface as a result of fire-fighting activities must be repaired or replaced immediately upon termination of fire-fighting activities. Fire extinguishers will be provided at the flare skid. The GCCS will be shut down in the event of any fire at the flare skid except for normal flaring. Additional fire protection will be provided via a fire hydrant located along Dero Road near to the entrance to the Dump. The nearest fire station is located in Barrigada, approximately 9 kilometers (km) away. 5.9 Construction Plan Documentation During construction, careful documentation must be maintained by the contractor and verified by an experienced construction inspector. The information to be gathered as the system is constructed includes the following: Extraction well and horizontal collector locations and construction details. Pipe sizes and types. As-built pipe and appurtenance locations, elevations, and slope verifications. Pressure testing of installed solid pipes. Documentation of installation, operation, and maintenance procedures for all items supplied by the contractor. As-built drawings for all materials installed. 5-8

20 Ordot Dump Gas Collection and Control System Plan Section 5 Borehole logs and well construction diagrams for all gas extraction wells and horizontal collectors installed. At the completion of the construction phase of the project, a professional engineer's certification must be submitted to the GSWA Construction Stages The GCCS is to be installed in two stages, as described below. The installation schedules and scope will be determined based on site operations. Gas system construction will be coordinated with the other closure construction, and must precede the installation of the final cover geosynthetics. Stage 1 Construction 1. Install Phase 1 horizontal collectors and collector risers with wellheads HC1-1 through HC Install Phase 1 gas extraction wells, GV1-1 through GV Install Phase 1 migration control trench and extraction wells MCT-1 and MCT Install Phase 1 lateral and header lines, and appurtenant piping and valves. 5. Install the condensate drop-out structure and sump. 6. Install gas flare skid, complete with a knockout pot, blower, and controls Stage 2 Construction 1. Install Phase 2 horizontal collectors and collector risers with wellheads HC2-1 through HC Install Phase 2 gas extraction wells, GV2-1 through GV Install Phase 2 migration control trench, migration control wells MCT-3 through MCT-8, and the migration control header condensate sump. 4. Install Phase 2 lateral and header lines, and appurtenant piping and valves Construction Plan Health and Safety Performing construction work on and around a landfill requires adherence to certain precautionary measures to ensure the safety of all workers. GSWA or the O & M contractor must develop and maintain a Health and Safety Plan (HASP) that meets or exceeds minimum regulatory requirements and procedures. The contractor must have supervisory personnel on-site to monitor construction activities and to assess the environmental condition of the workspace. The personnel will be responsible for establishing the hazard level of the workspace and establishing hazard level classifications for different areas of the site for the contractor. In addition, an Unexploded Ordnance (UXO) Monitoring Plan must be developed and followed during drilling or excavation into solid waste at Ordot Dump. Since the project involves excavation of cover materials and previously deposited solid wastes, the progress of the work should be observed to provide an indication of potential problems. The excavations should be limited to a depth necessary to install the structures and provide the desired slope on the piping systems. To minimize the depth of excavations, the gas collection pipe network is designed to follow the surface contours of the Dump as much as possible. Workers must undertake all necessary safety precautions and comply with all applicable provisions of federal, state, and local safety laws, regulations, and codes to prevent accidents and injury to personnel in the vicinity of the work area. 5-9

21 Ordot Dump Gas Collection and Control System Plan Section 5 The contractor must inform his personnel that the construction site is a landfill and that inherent dangers exist. Workers must be required to utilize appropriate personnel protective devices and to observe safe working practices. Smoking is strictly prohibited at the work site. Workers must be advised of the hazards associated with the work to be accomplished. Of particular concern are physical hazards associated with heavy equipment and excavations, and hazards of landfill gasses including methane, carbon dioxide, hydrogen sulfide, volatile organics, and any other known or suspected gas or vapor which may be encountered. Precautions must be taken based upon known or suspected hazards. The contractor must designate a Site Health and Safety Officer. The Site Health and Safety Officer should be trained in the use of gas detection instruments, safety equipment, and health and safety procedures associated with the work conducted. The Health and Safety Officer should be present at all times when construction work is being conducted and periodically monitor the atmosphere within the breathing zone of the workers. At a minimum, the Site Health and Safety Officer should monitor the concentration of oxygen, the percent of the lower explosive limit for methane, and hydrogen sulfide. Welding will not be permitted in trenches or other enclosed spaces unless properly performed over ground mats and approved by the Site Health and Safety Officer. As construction progresses, valves, pipe, and other openings must be closed as soon as possible after installation to prevent gas migration through the pipeline network and to prevent foreign material from entering. Excavations and boreholes greater than two feet in depth may not be left unattended unless covered so that entrance is prohibited in accordance with applicable regulations. Storm water must be prevented from entering excavations and boreholes. Extreme caution in accordance with confined space entry procedures must be exercised if manholes or other types of vaults must be entered. Fire extinguishers rated at least A, B, and C should be readily available at the work area. Construction equipment should be equipped with vertical exhaust and spark arrestors. Spark arrestors may not be required if motors are powered by diesel fuel. Motors used in excavated areas should be explosion proof. Start up and shut down of equipment should be conducted outside of excavations. Soil stockpiles should be situated in the vicinity of work areas for fire fighting purposes Spoils Disposal and Handling Spoils from excavation areas must be treated and handled as solid waste. This means all special handling procedures associated with normal landfill-type operations must be adhered to and all necessary protective clothing (hard hats, coveralls, gloves, etc.) should be worn by working personnel. The spoils must be inspected as they are removed from the excavation to assess workspace conditions and to assure proper management of the spoils. Spoils which are comprised of municipal solid wastes must be taken from the working area and transported to a relocation area within the Dump footprint approved by the Construction Manager. Emergency Situations All personnel working on the Ordot Dump and flare system must be informed of the location of the closest medical facility and the telephone numbers for the local police and fire departments, and the local ambulance service. A list of emergency telephone numbers is provided below. 5-10

22 Ordot Dump Gas Collection and Control System Plan Section 5 Ambulance Service 911 Police Department 911 Fire Department 911 Guam Memorial Hospital, Tamuning (671) Directions to Guam Memorial Hospital from Ordot Dump: 1. Head east on Dero Road for 1.6 km. 2. Turn left at Route 4 Intersection onto Route 4 for 3.7 km. 3. Turn right onto Route 1 for 2.7 km 4. Turn left onto Route 30/Gov Carlos G Camacho Road for 2.2 km to Guam Memorial Hospital located at 850 Gov Carlos G Camacho Road Landfill Gas Sampling and Testing Source testing will be performed after the gas system is operational to characterize the quality of the LFG generated by the waste mass. The objective of this testing will be to monitor the constituents of the LFG and the combustibility of the LFG. Sampling will be performed at the inlet to the gas flare. Testing will include determinations of concentrations of methane, nitrogen, oxygen, and balance gas. Testing will also continued to be performed to monitor subterranean LFG migration. This will involve continued quarterly monitoring of the soil gas monitoring probes around the perimeter of the Dump. The soil gas monitoring probes will be tested for percent methane and the lower explosive limit (LEL) for methane. The sampling point locations and monitoring results will continue to be recorded, summarized, and submitted to the GEPA as required in the closure approval Condensate Sampling and Testing Condensate may be sampled from the condensate sump or the knockout pot located at the flare. Condensate sampling and testing will be performed as directed in the air quality and/or solid waste permits issued by GEPA Annual Report As required by the NSPS, annual reports must be submitted to the governing authority, in this case GEPA, with an initial report within 180 days of LFG collection and control system startup including results of the initial performance test. Reports must include the following: The volume of LFG extracted The value and length of time for exceedance of monitored parameters including temperature, pressure, and concentrations of oxygen and nitrogen. A description and duration of all periods when the control device was not operating for a period exceeding 1 hour. All periods when the collection system was not operating in excess of 5 days. The location of each exceedance of the 500 parts per million methane concentration detected during surface emissions monitoring, as described in Section 6 of this GCCS Design Plan, and the concentration recorded at each location for which an exceedance was recorded in the previous month. The date of installation and the location of each well or collection system expansion, if any. 5-11

23 Section 6 GCCS Startup, Shutdown and Malfunction Plan 6.1 Introduction This Startup, Shutdown and Malfunction (SSM) Plan has been prepared in order to comply with the requirements of 40 CFR 63.6(e)(6), as the Ordot Dump is subject to 40 CFR Part 63, Subpart AAAA, the National Emissions Standard for Hazardous Air Pollutants (NESHAPS) for municipal solid waste landfills. The Ordot Dump is an affected source under this rule as it has accepted waste since 1965, has a capacity greater than 2.5 million Mg, and has an estimated uncontrolled non-methane organic compound emission range greater than or equal to 50 Mg per year. The start-up and shutdown procedures will be posted at the main control panel. Personnel designated with GCCS operational responsibility will be trained in the specific procedures related to the systems. 6.2 Plan Contents This SSM Plan is divided into three sections comprising the primary elements relating to the startup, shutdown and malfunction of the GCCS. Startup and shutdown are generally planned events associated with GCCS maintenance, testing, and repair, and may or may not be related to a malfunction of the GCCS. Startup procedures are provided in Section 6.3, shutdown procedures in Section 6.4, and malfunction procedures in Section 6.5. Malfunction events are distinct events when the GCCS is not operating in accordance with NSPS requirements and which result, or have the potential to result, in an exceedance of one or more emission limitations or operational standards under the NSPS Equipment Covered by this SSM Plan The GCCS equipment covered by this SSM Plan includes the following: 1. Gas Collection System (wellfield, conveyance piping, valves, condensate structures, etc); 2. Flare; 3. Blower; 4. Pumps; 5. Gas Treatment Equipment; 6. Gas Monitoring Equipment 6.3 System Start-Up System startup means setting in operation any affected source or portion of affected source, including startup of gas mover equipment (for example, the blower), control devices (for example, the flare), gas treatment equipment (for example, the knockout pot), and any ancillary equipment that could affect the operation of the GCCS. The Ordot Dump GCCS start-up must be conducted carefully to prevent emissions of gas to the atmosphere, maximize gas flow, and prevent excessive vacuum application at the gas extraction points. 6-1

24 Ordot Dump Gas Collection and Control System Plan Section Collection System The following activities have the potential to emit regulated air pollutants to the atmosphere during startup of the GCCS: Purging of gases trapped in the piping system; Repair of system leaks at wellheads, system piping, and condensate structures. During such activities, work shall progress such that air emissions are minimized by the following: Temporarily capping pipes venting gas; Minimize surface areas where gas may emitted to the atmosphere, such as open trenches in the waste mass; Assuring other sections of the GCCS are operating properly; and Limiting the purging of gas in the piping network to as short a duration as possible. Once the blower and the flare are in operation, the system must be gradually balanced by adjusting the valves at the wellheads. As a starting point, the valves should be nearly closed at the wellheads and opened slightly until the LFG readings are within the required ranges. In this way, excessive air infiltration into the LFG system can be avoided. The wellhead valves should be adjusted according to their distance from the blower, as the available vacuum will be at its highest nearest the blower and lower at distance from the blower. After the initial start-up, measurement of methane, carbon dioxide, oxygen, balance gas, pressure, temperature, and flow rate will be used for fine vacuum adjustments at the wellheads to balance the system Control Device The control device is a skid-mounted candlestick type open flare designed for unattended operation. Automatic and manual startup procedures are provided in the manufacturer s Operation and Maintenance Manual in Appendix B. On occasions, the flare might be unavailable (due to maintenance, the flame going out, or other reasons) and will operate in flame-out mode. In this mode, the programmable logic controller at the flare would direct a signal to the flare to automatically re-ignite the flare. In the event that the flare does not reignite, the vacuum blower would shut down and the pressure within the GCCS would begin to equalize to atmospheric pressure. The loss of vacuum would trigger an alarm, alerting personnel that the flare is not ignited. The operator of the facility would then correct any problems and re-ignite the flare Automatic Start-Up The automatic start-up procedure is followed to start the blower and ignite the flare with the system control switch set to the automatic position. A general procedure for beginning flare operations in automatic mode is described below. The flare manufacturer's specific procedures must be consulted and used to start the flare. 1. Open the inlet valve to the knockout pot by 50 percent. 2. Open the inlet and outlet valves on the blower. Open the main line valves. 3. Set the blower switch to automatic at the motor control panel. 4. Open the flare gas pilot supply as recommended by the flare manufacturer. 5. Open the knockout pot inlet slowly to 100 percent. 6. Set the flare pilot switch to automatic at the flare control panel. The pilot light should illuminate. After a short warm-up period, the blower should start and the flare should light. After several minutes, the pilot should extinguish. 6-2

25 Ordot Dump Gas Collection and Control System Plan Section Manual Start-Up The manual start-up procedure is followed to start the blower and ignite the flare with the system control switch set to the manual position. A general procedure for beginning flare operations in manual mode is described below. The flare manufacturer's specific procedures must be consulted and used to start the flare. 1. Open the inlet and outlet valves on the blower. 2. Open the main line valves. 3. Open the valve inlet to the knockout pot by 50 percent. 4. Open the flare gas pilot supply as recommended by the flare manufacturer. 5. Set the flare pilot switch to manual at the flare control panel. 6. Start the flare pilot by pressing the flare spark control until it ignites. 7. Shut the pilot gas valve. 8. Position the flare pilot switch to off. 9. Open the knockout pot valve slowly to 100 percent. 6.4 GCCS Shut-Down System shutdown means the planned cessation of an affected source or portion of an affected source. Shutdown events will generally include the planned shutdown of gas mover equipment (for example, the blower), control devices (for example, the flare), gas treatment equipment (for example, the knockout pot), and any ancillary equipment that could affect the operation of the GCCS. A shutdown event should not exceed more that five days unless an alternative timeframe has been established. The following activities and events may necessitate a manual shutdown of the GCCS. Some may not require a full shutdown if the portion of the GCCS can be isolated by closing off appropriate header valves, leaving the balance of the GCCS in operation: 1. Flare maintenance, cleaning or repair; 2. Addition of new GCCS components, such as a new well; 3. Well decommissioning; 4. Relocation or realignment of conveyance piping; 5. Source testing; 6. Blower/motor maintenance, cleaning or repair; 7. Gas treatment structure maintenance, cleaning or repair; 8. Planned electrical outages; 9. Ancillary equipment maintenance, cleaning or repair; 10. New equipment testing. Portions of the GCCS may be isolated by closing valves in the main header piping, lateral piping, or wellheads. Such activities are not considered a shutdown unless they last for more than five days and cause exceedances of the provisions of the NSPS General Procedures The following general procedure should be followed to shut down the gas collection and control system. The flare manufacturer's specific procedures must be consulted and used to shut down the flare. 1. Turn off the blower at the motor control panel. 2. Close the knockout pot inlet valve. 3. Extinguish the flare at the flare control panel. 6-3

26 Ordot Dump Gas Collection and Control System Plan Section 6 4. Close the pilot gas valve. 5. Close the blower inlet and outlet valves. 6. Verify that all valves associated with the blower/flare system are closed and tight. Close any open blower/flare system valves and replace any leaking valves immediately. In the automatic mode, the flare is designed to shut down automatically in the event that the flame is extinguished or if the flare temperature or gas quality is above or below a specified operating range. A block or "slam-shut" valve located between the flare and the blower will automatically close in the event the flare or the blower shuts down System Decommissioning The GCCS can be relatively easily decommissioned, if the system sustains irreparable damage or the facility is no longer needed to manage gases generated in the waste mass. To safely and properly decommission the facility, the following general tasks will be performed. 1. Shut down the gas flare and appurtenant equipment. The flare manufacturer's specific procedures must be consulted and used to shut down the flare. 2. Open the in-line control valve at each gas well to allow gases still in the collection system to passively vent to the atmosphere and relieve residual pressure in the system. 3. Locate the inlet pipe to the blower. Once located and verified to be free of explosive gases, this pipe will be cut and sealed. Measurements will be taken to be sure the location can be re-established in the future. 4. Disassemble and remove the flare skid equipment. 5. Disassemble yard piping at the gas flare skid. Remove the gas flare from the support base and cut the flare as needed for salvage or disposal. 6. Remove the disassembled equipment from site for salvage or disposal. 7. If LFG collection is no longer necessary, reconstruct LFG wellhead assemblies to allow passive venting. 6.5 Malfunction Plan Malfunction means any sudden, infrequent, and not reasonably preventable failure of air pollution control, monitoring or process equipment, or any process, to operate in a normal or usual manner which causes, or has the potential to cause, emission limitations of an applicable standard to be exceeded. Failures that are caused in part by poor maintenance, careless operation, human error, or which are reasonably preventable, are not malfunctions. For a malfunction event to be addressed by this SSM Plan, it must result in, or have the potential to result in, an exceedance of one or more of the NSPS operational and compliance requirements. If the procedures in this SSM Plan do not address or do not adequately address the malfunction that has occurred, the operator should attempt to correct the malfunction using the best resources available. 6-4

27 Ordot Dump Gas Collection and Control System Plan Section Common Malfunctions Common malfunctions of the GCCS include the following: 1. Loss of gas flow to the control device, including flare and blower; 2. Gas extraction well and pipe failures; 3. Loss of electrical power; 4. Malfunction of the flare; 5. Malfunction of flare temperature monitoring and recording equipment; and 6. Malfunction of flow measuring devices Timeframes for NSPS Exceedances Breakdown or failure events have different timeframes to be considered malfunctions for the purposes of this SSM Plan, as follows: GCCS downtime of greater than five days; Free venting of landfill gas for more that one hour; Any downtime of flare temperature monitoring or recording equipment; Downtime of gas flow to the monitoring or recording equipment greater than fifteen minutes Operational Contingencies The gas flare system designed for the Ordot Dump will be equipped with the following contingency items to deal with unusual circumstances: A fail-safe valve, also known as the "slam-shut" or automatic block valve, will be situated between the blower and the gas flare. If either the blower or the flare fails to operate, the fail-safe valve will automatically close, cutting off the LFG flow to the flare. The flare is typically designed with a self-checking flame scanner to monitor the pilot and LFG flames to detect the presence or lack of flame within the unit. If a flame is not detected, the system will automatically shut down. Flame safeguard controls typically include a self-checking flame scanner and panel-mounted flame relay. A pilot gas control system typically includes a pressure regulator, fail-safe shut down valves, and a manual block valve. Additionally, a pressure indicator will be incorporated into the flare system. The control panel typically will contain indicator lights to monitor flare conditions during start-up, normal operations, and automatic shutdown events. The system will typically contain an automatic start/restart control mode. In the automatic operating mode, the unit will automatically start when power is applied. If the unit shuts down for any reason except high stack temperature, the auto mode will allow the unit to attempt to purge and restart for a specified time period. A remote signal will be sent if the unit fails to restart. The flare will be equipped with an inlet flame arrestor. The control panel typically has a chart recorder to continuously record the flare temperature and a flow meter to measure the LFG flow. There will be a dedicated standby blower for the GCCS. There will be an emergency power generator at the Dump. 6-5

28 Ordot Dump Gas Collection and Control System Plan Section General Responses to GCCS Malfunctions The causes of malfunctions should be investigated immediately to determine the best course of action to correct the malfunction. Each malfunction may have multiple causes that need to be identified and corrected. The initial response to a malfunction of the GCCS is to determine if there has been an exceedance of any applicable emission limitation in the NSPS or NESHAPS. In addition, it should be determined whether there has been or will be excess emissions to the atmosphere. If emissions are occurring, take immediate steps to reduce or eliminate emissions. After these initial steps have been taken, the operator should proceed with malfunction diagnosis corrective procedures contained in the manufacturer s O&M Manual provided in Appendix B. Additional requirements for GCCS malfunctions include the following: 1. If the malfunction cannot be corrected within the timeframes listed above, define the appropriate alternative timeframe for corrective action that is reasonable for the type of repair or maintenance required; 2. If the GCCS malfunction cannot be corrected within the alternative timeframe, conduct the appropriate record keeping and reporting required for deviations of 40 CFR Part 63, Subpart AAAA. 6-6

29 Section 7 Surface Emissions Monitoring Protocol This protocol presents the methods utilized to assess migration of landfill gas through the surface of the Ordot Dump, in accordance with 40 CFR (d), (c) and (d), and (f). 7.1 General Description The surface emissions monitoring (SEM) survey consists of monitoring surface emissions for methane as an indicator of landfill gas emissions from the waste mass. The SEM survey will be conducted along the perimeter of the landfill gas collection area and within the footprint of the waste disposal area. The waste disposal area is depicted on the attached Figure 1, Surface Emissions Monitoring Route Plan. The SEM survey will utilize an organic vapor analyzer, flame ionization detector or other portable monitoring equipment. Sampling will be performed at intervals of approximately 30 meter intervals (or a sitespecific established alternative spacing) for each collection area within the landfill footprint. Sampling will also be performed at locations where ground surface conditions, such as stressed vegetation or surface cracks or seeps, indicate the potential for gas emissions. 7.2 Procedures The route of the SEM survey is depicted on Figure 7-1, Surface Emissions Monitoring Route Plan. This route will generally be followed unless field conditions on the day of the SEM survey necessitate a change. Personnel safety will be a paramount concern in any decision to alter the route or omit an area of the landfill from the SEM survey. The SEM survey will consist of surface monitoring along a pattern that traverses the Dump at approximately 30 meter intervals. A perimeter path will be followed that approximately follows the limit of the waste, with sampling taking place approximately every 30 meters. Within the limits of the waste, interior paths will be surveyed following a traverse pattern roughly parallel to the perimeter, with each path approximately 30 meters from the previous path, with samples tested at approximately 30 meter intervals. The SEM survey will cover the entire limit of waste disposal. Sampling instruments will be consistent with Section 3 of EPA Method 21 (40 CFR 60, Appendix A). Sampling will be carried out using a portable flame ionization detector (FID), a portable organic vapor analyzer (OVA), or similar instrument capable of quantifying methane at parts-per-million (ppm) levels, and having a response time of thirty seconds or less. An example of an acceptable instrument is the Photovac Micro FID. The instrument will be calibrated to a methane standard of a nominal concentration between 100 and 500 ppm, or as recommended by the manufacturer. Calibration will be conducted immediately before field sampling if possible, and in no case greater than 24 hours prior to field sampling. The instrument will be routinely checked during sampling to assure that it is functioning properly (for instance, that the flame is lit in the FID). Surface samples will be taken with the probe inlet placed 5 to 10 centimeters above the ground surface. Any areas encountered during the SEM survey that exhibit signs of potential LFG emissions will be 7-1

30

31 Ordot Dump Gas Collection and Control System Plan Section 7 tested, irrespective of whether the location falls on the regular 30-meter testing interval. These areas include stressed vegetation, cracks, fissures or other holes in the cover soil, any locations where LFG is visibly or audibly venting from the final cover, or liquid seeps. Field personnel will be trained to recognize these indicators of potential emissions. Background readings of ambient air will be determined by moving the probe inlet upwind and downwind outside the boundary of the waste at a distance of at least 30 meters from the perimeter LFG extraction wells or horizontal collectors. 7.3 Weather Conditions Every attempt will be made to conduct SEM surveys on days with typical meteorological conditions. Typical conditions include days with predicted wind speeds between 5 and 15 miles per hour. In addition, attempts will be made to carry out the SEM surveys when the land surface is dry and no rain is falling. Meteorological data from the weather station located at Hagatna, which is available on the National Weather Service web site, may be utilized prior to and during the SEM survey to determine and document meteorological conditions. Local weather conditions on site, including approximate wind speed, wind direction, cloud cover, and ambient temperature, will be recorded by field personnel before, during, and after the SEM survey. In order to assure that valid samples are taken and wind does not unduly influence SEM survey results, shields will be utilized to protect sampling locations from wind. Large plastic trash barrels cut in half lengthwise and placed on the ground, with the opening facing downwind and the instrument probes inserted through the opening into the protected area, are convenient and have been proven effective for this purpose. These wind shields may also be used to protect aboveground sampling locations from excess wind. Unless the atmosphere is calm, wind shields will be utilized during the SEM surveys. 7.4 Recording and Reporting During the course of the SEM survey, the field crews will record results at every sample location where a reading is 500 ppm or more above background. Results from samples taken at locations other than routine ground shots (that is, if sampling is prompted by surface conditions) will be accompanied by a note indicating what prompted sampling at that location. Results of the SEM survey will be presented in tabular manner, accompanied by a Survey Route Plan showing all sample locations. A full report of each SEM survey will be presented to the GEPA. 7.5 Action Levels and Follow-up Sampling All results will be reported. All results greater than 500 ppm above background will be targeted for follow-up actions. Surface samples that exceed background by 500 ppm will first be addressed by checking the efficiency of the GCCS and by altering the vacuum on the system and/or on individual wells adjacent to the exceedance. Investigations into final cover integrity will also be performed if there is indication that a failure in the final cover may be responsible for the exceedance. The location will then be re-sampled within ten days of the exceedance. If re-sampling discloses a second exceedance, additional corrective action will be taken and the location will again be re-sampled within ten days of the second exceedance. If the re-sampling shows a third exceedance for the same location, a new well or collection device will be installed within 120 days or an alternative remedy to the exceedance with a corresponding timeline for installation or corrective action will be submitted to GEPA for approval. 7-3

32 Ordot Dump Gas Collection and Control System Plan Section 7 If re-sampling discloses that concentrations have fallen below the 500 ppm action level, re-sampling will be performed one month from the initial exceedance. If the one-month re-sampling continues to show no exceedance, no additional monitoring will be required until the next regularly scheduled SEM survey. 7.6 SEM Survey Frequency SEM surveys will be carried out on a quarterly basis. If no samples exceed background levels by 500 ppm for three consecutive quarterly monitoring periods, SEM survey frequency will be changed to annual. Any methane reading of 500 ppm or more above background detected during the annual monitoring returns the frequency to quarterly monitoring. 7-4

33 References Brown and Caldwell, Ordot Landfill Gas Generation Potential, January Brown and Caldwell, Topographic Surveys and Airspace Report, Technical Memorandum, September 8, Brown and Caldwell Team, Design Drawings, Ordot Dump Closure Construction and Dero Road Sewer Improvements, July 1, Brown and Caldwell Team, Design Report, Ordot Dump Closure Construction and Dero Road Sewer Improvements, July 1, Brown and Caldwell Team, Final Post Closure Maintenance Plan, Ordot Dump Closure Construction, Permitting Copy, March 2013 EPA, User s Manual, Philippines Landfill Gas Emissions Model (LandGEM), Version 1.0, Eastern Research Group USA and Organic Waste Technologies, December USEPA LMOP, Summary of Landfill Gas Energy Potential for the Ordot Dump, February, REF-1

34 Ordot Dump Gas Collection and Control System Plan Appendix A: Ordot Landfill Gas Generation Potential A

35 Ordot Landfill Gas Generation Potential Prepared for Gershman, Brickner & Bratton, Inc. (GBB), Receiver for the Guam Solid Waste Authority January 2013

36 Ordot Landfill Gas Generation Potential Prepared for Gershman, Brickner & Bratton, Inc. (GBB), Receiver for the Guam Solid Waste Authority 542 North Marine Corps Drive Tamuning, Guam Revision 1 January 2013 Douglas B. Lee Brown and Caldwell 1/8/2013 Date This work was prepared by me or under my supervision. 414 W. Soledad Avenue, Suite 500 Hagatna, Guam 96910

37 Table of Contents List of Figures... iii List of Tables... iii List of Abbreviations... iv 1. Introduction Background Landfill Gas Generation Potential Introduction Annual Waste Disposal Rates Gas Collection System Efficiency Methane Generation Rate Constant (k) Ultimate Methane Generation Potential (Lo) Model Sensitivity Landfill Gas Generation Model Results Landfill Gas Recovery Potential Energy Output Potential Overview of Landfill Gas End Uses Landfill Gas Project Feasibility Model Conclusions and Recommendations References... REF-1 Appendix A: Philippines Model Results... A Appendix B: LFG to Energy Results... B Appendix C: Project Feasibility Evaluation Using LMOP LFGcost-Web... C Final Ordot Landfill Gas Generation Potential v docx ii

38 Ordot Landfill Gas Generation Potential Table of Contents List of Figures Figure 1. Estimated Landfill Gas Recovery Rates List of Tables Table 3-1. Criteria for Determining Collection Efficiency (used in all modeling scenarios) Table 3-2. Various Values for Methane Generation Rate Constant, k (per year) Table 3-3. Various Values for Ultimate Methane Generation Potential Lo (m 3 /Mg of Waste) Table 3-4. Philippines Model Scenarios Considered Table 4-1. Landfill Gas Recovery Rates Summary at 67% Collection System Efficiency Table 4-2 Energy Output for Each Scenario Considered Table 4-3 LFG to Energy Technology Specific Requirements Table 4-4. LFG Project Economic Feasibility Estimates Final Ordot Landfill Gas Generation Potential v docx iii

39 Ordot Landfill Gas Generation Potential Table of Contents List of Abbreviations av BC Btu CAA CH4 CNG ft 3 /min GBB GHG gpd GSWA in/yr k average Brown and Caldwell British Thermal Unit Clean Air Act methane compressed natural gas cubic feet per minute Gershman, Brickner & Bratton, Inc. Green House Gas gallons per day Guam Solid Waste Authority inches per year Methane Generation Rate Constant LandGem Landfill Gas Emissions Model lbs lbs/ yd 3 LFG LMOP Lo m 3 Mg MJ/hr MTCO2e MW NMOC psig TM USEPA pounds pounds per cubic yard landfill gas Landfill Methane Outreach Program Ultimate Methane Generation Potential cubic meter megagram megajoule per hour megatonnes of carbon dioxide equivalent megawatt non-methane organic compounds pounds per square inch gauge Technical Memorandum United States Environmental Protection Agency iv Final Ordot Landfill Gas Generation Potential v docx

40 Section 1 Introduction On behalf of Gershman, Brickner & Bratton, Inc. (GBB), Receiver for the Guam Solid Waste Authority (GSWA), Brown and Caldwell (BC) has been authorized to develop plans and conduct design studies in support of the closure of the Ordot Dump (Dump) located in Ordot-Chalan Pago under the Consent Decree Order (US District Court of Guam, Civil Case No , Document Number 55). In addition to the Consent Decree, Title 10, Chapter 51, Article 1 Solid Waste Management, 51101(4) of the Guam Code Annotated, mandated that the Dump be closed. This Report presents the estimated landfill gas (LFG) generation potential after closure of the Dump in Guam, for the purposes of evaluating LFG energy project feasibility, and for estimating gas collection and control system design parameters. The Report is based on historical information, previous reports pertaining to LFG at the Dump, and on the results of field investigations performed by BC between May 2011 and September In December 2011, three LFG generation potential wells (LFGW-1, LFGW-2, and LFGW-3) were drilled through the top of the Dump into the underlying waste mass. LFG from these 3 wells was sampled periodically over a six-week period between February and April 2012, resulting in an average methane (CH4) measurement of 55 percent by volume. Based on the observed LFG composition, the Dump, which is 70 years old, is in the final stages of anaerobic decomposition and, not surprisingly, the detected gas composition is similar to what would be expected from an older, more mature biomass. The full data set from the field work is contained in a Technical Memorandum (TM) titled Ordot Dump Preliminary Field Report of Landfill Gas Generation Potential prepared by BC. Final Ordot Landfill Gas Generation Potential v docx 1-1

41 Section 2 Background Guam, the largest and southernmost island in the Marianas Archipelago, is located approximately 3,800 miles west of Hawaii and 1,500 miles south of Japan. Guam is approximately 212 square miles in area with a length of 30 miles and a width ranging between 4 and 11.5 miles. The Dump is located approximately 2.5 miles south of Guam s capital, Hagatna, and about 1 mile southwest of the Dero Road-Route 4 intersection. The Dump is an unlined disposal facility and has few to no control systems to manage landfill gas, leachate, surface water, erosion, and vectors. The disposal area has been estimated to be approximately 43.4 acres, based on the limits of waste delineation performed by BC in The area surrounding the Dump is covered by dense brush and wooded areas, and is sparsely developed with scattered residences. The Dump is situated in a former ravine that was a surface water drainageway to the Lonfit River, located to the south. The Dump occupies and borders a mix of private properties and property of the Government of Guam on the east, south, and west. The north side of the limits of the Dump border public land in the form of the Dero Road right-of-way. The Dump started approximately in the early 1940s. The Dump reportedly began operation for military forces early in World War II, and was turned over to civilian authorities in The Dump was the primary solid waste disposal facility for civilian residents of Guam until waste acceptance ceased in August For most of that time, the Dump operated as an open dump. Numerous fires have been recorded since about 1990, but it is generally accepted that there has been an average of at least one fire every one to two years for decades. This includes a major tire fire that was essentially allowed to burn out over a fourmonth period in Subsurface (deep-seated) fires fueled by the generation of flammable (methane) and combustible gases during the decomposition of waste within the landfill have also been reported. With the exception of the tire fire of 1998, documentation of the type, size, location, and duration of the fires is mostly unavailable. However, observations of certain test pits in the northwest corner indicate that open burning of trash occurred, and neighbors have reported that burning of the waste was a standard practice for a period of time. There was little control over waste type acceptance and limited sanitary landfill practices, such as regular applications of cover material, until the Solid Waste Management Division of the Guam Department of Public Works went into Receivership in In June 2009, a truck scale was installed by the Receiver to track the incoming waste material and other operational improvements were implemented. The Dump is unlined, no LFG collection system has been installed, and no final cover or cap has been installed. The Dump has been estimated by BC to hold approximately 4.5 million cubic yards of material, which includes waste and cover soil (BC s Topographic Surveys and Airspace Report, 2012). Accurate records regarding disposal rates, types of waste, and cover soil use prior to June 2009 are not available; hence, in many cases reasonable assumptions were made based on the results of BC s investigations and reviews of available historical information and used in the completion of this study. Final Ordot Landfill Gas Generation Potential v docx 2-1

42 Section 3 Landfill Gas Generation Potential 3.1 Introduction The most widely used LFG generation model in the United States is the United States Environmental Protection Agency s (USEPA s) Landfill Gas Emissions Model (LandGEM). LandGEM is generally regarded as the mainland United States industry standard model for regulatory and non-regulatory applications. LandGEM is an automated estimation tool with a Microsoft Excel interface that is used to estimate emission rates for total LFG, methane, carbon dioxide, non-methane organic compounds, and individual air pollutants from municipal solid waste landfills. LandGEM can be used to generate emission estimates for use in emission inventories and air permits. In 2009, the Landfill Methane Outreach Program (LMOP) of the USEPA developed a version of the LandGEM Model for the Philippine Islands to help landfill owners and operators, end users of LFG, and other interested parties evaluate the feasibility and potential benefits of collecting and using LFG for energy recovery in the Philippines. The Philippines LandGEM provides a more developed gas generation calculation, and a more developed estimate of the fraction of LFG available for capture, than does the Standard LandGEM. The Philippine Model provides recommended values for input variables based on climatological data, landfill configurations, landfill operations practices, observable leachate characteristics, waste characteristics specific to the Philippines, and the estimated effect of these conditions on the amounts and rates of LFG generation. Similar to the Standard LandGEM, the Philippines Model also allows users to specify their own values for these input variables if reliable site specific data are available. The Philippines are a tropical location in the western Pacific with mean annual temperature of 80 degrees Fahrenheit and mean annual rainfall of 99 inches/year (in/yr) ( Guam is also a tropical location in the western Pacific at similar latitude with mean annual temperature of 81 degrees Fahrenheit and a mean annual rainfall of 95 in/yr ( Due to the similarities in location, temperature and precipitation, the Philippines Model was used to estimate potential LFG generation rates for the Dump. The Philippines Model input parameters are discussed in more detail below while model output results are provided in Appendix A. 3.2 Annual Waste Disposal Rates LandGEM Models require annual waste disposal quantities as input parameters. However, reliable annual waste disposal quantities for the Dump are only available for the last two years of the Dump s operation, from June 2009 through August 2011 after scales were installed to weigh incoming waste loads and cover soil. For the purpose of this study, historical annual disposal quantities were estimated using available population data and unit waste generation rates. While not uncommon for older landfills, actual data are limited and several assumptions had to be made to generate LandGEM Model input. Similarly, reliable sources of per capita waste generation rates for Guam were not available and had to be estimated based on published sources described in more detail below. Two sources of population data were considered in this evaluation, including US Census data, which included data for each decade between 1940 and 2010, and The World Factbook CIA government library. [US Census Population Data (2000, 2010), Final Ordot Landfill Gas Generation Potential v docx 3-1

43 Ordot Landfill Gas Generation Potential Section 4 census-bureau-]; (The World Factbook, Two per capita waste generation rates were considered in this evaluation. A rate of 1.68 pounds (lbs)/person/day (World Bank, 1999) was noted as the average solid waste generation rate for middle income countries (Indonesia, Philippines, Thailand and Malaysia) and a rate of 3.7 lbs/person/day was noted as the average waste generated in the United States from 1960 to 2010 (EPA MSW 2012). These are considered reasonable estimates of per capita waste generation, so waste generation rates of similar magnitude were used to compute the annual waste disposal quantities for years prior to Using the known volume of waste, as determined from the Waste Thickness Isopach Map, 2012 and the Topographic Surveys and Airspace Report, 2012, in-place waste densities were then calculated and ranged from approximately 1,600 pounds per cubic yard (lbs/yd 3 ) to 2,300 lbs/yd 3. These densities are reasonable, given the wet climate and the natural consolidation expected to have taken place in the waste mass over the years. Annual waste disposal quantities were estimated using population and unit waste disposal information in conjunction with the actual in-place volume. Population and unit waste disposal data were used on a pro-rata basis to spread the waste intake over the years the Dump was in operation (with the exception of the period of 2009 through 2011). This estimation process indicated the range of in-place waste tonnage is approximately 3.5 million tons to 5.2 million tons. Both ends of the range were used in the LandGEM Model to estimate LFG generation. Because of the nature of organic waste degradation, which reaches a relatively rapid rate quickly and then decreases over time, the wastes placed in the most recent years of the Dump s life represent the most significant contribution to the present and future LFG generation. Similarly, waste placed more than 15 years ago does not significantly influence the results of the model. Therefore, knowing the most recent waste intake and estimating that for earlier years contributes positively to the confidence in the model results. Waste intakes at the Dump decreased in more recent years because the Receiver instituted a successful recycling program for the island. 3.3 Gas Collection System Efficiency The Philippines Model considers the efficiency of a LFG collection system in the landfill, based on a number of physical and environmental features of the landfill modeled. The highest collection efficiency used in the Philippines Model is 85%, which is then reduced, or discounted, based on the answers to eight questions. Table 3-1 shows the eight questions, the collection efficiency reduction factors, and the responses used for the Dump to establish an estimated collection system efficiency. The discount reduces the collection efficiency value of 85% to 67%. A brief explanation for each response follows Table 3-1. Final Ordot Landfill Gas Generation Potential v docx 3-2

44 Ordot Landfill Gas Generation Potential Section 4 Table 3-1. Criteria for Determining Collection Efficiency (used in all modeling scenarios) No Question Response Collection Efficiency Discount (below 85%) for Response 1 Is the waste placed in the Dump properly compacted on an ongoing basis? No 3% 2 Does the Dump have a focused tipping area? Yes 0% 3 Are there leachate seeps appearing along the Dump sideslopes? Or is there ponding of water/leachate on the Dump surface? Yes 10% 4 Is the average depth of waste 10 meters or greater? Yes 0% 5 Is any daily or weekly cover material applied to newly deposited waste? Yes 0% 6 Is any intermediate/final cover applied to newly deposited waste? Yes 0% 7 Does the Dump have a geosynthetic or clay liner? No 5% 8 In which bracket (I to V) does LFG System Area Coverage Percentage fall? I (80-100%) 0% Question #1 The waste has only been properly compacted for the past couple of years, therefore, the answer to this question is no. Question #2 It is assumed that even prior to operation by the Receiver, the dumping activities were confined to one area at a time. Question #3 Leachate seeps are present on the side slopes. Question #4 Recent borings into the Dump have confirmed that the average depth of waste is considerably more than ten meters. Question #5 Prior to operation by the Receiver, it is evident that cover material was only used during the last two-three years at the Dump, and since LFG generation is largely from relatively newly deposited waste, the answer to this question is yes. Question #6 Intermediate or final cover has been applied. Question #7 No liner is present at the Dump. Question #8 The LFG extraction and control system will cover more than 80% of the area. The Philippines Model also takes into consideration historical landfill fires and uses a default input value of 30% for previous methane destruction due to fire. 3.4 Methane Generation Rate Constant (k) The methane generation rate constant k is a measure of the rate at which the organic fraction of the waste can be transformed into methane. The value of k can be within a wide range that is derived from four factors: 1. Moisture content of the waste mass (which ranges from near zero in arid landfills to nearly saturated in wet bioreactors) 2. Availability of the organic and carbon nutrients in the waste for microorganisms to break down and generate methane and carbon dioxide 3. ph of the waste mass, which depends on part on its moisture content and organics percentage 4. Temperature of the waste mass, which in turn depends on the temperatures achieved by exothermic and endothermic reactions prior to methanogenesis Final Ordot Landfill Gas Generation Potential v docx 3-3

45 Ordot Landfill Gas Generation Potential Section 4 LandGEM Models, including the Philippines Model, provide default values for k based on research and previous studies. Table 3-2 lists the default values of k under various conditions. The value of k has units of 1/year, so that, for example, if the methane generation rate constant k = 0.05 the biodegradable fraction of waste would essentially be degraded in 20 years (i.e., 1/0.05). Relatively warm, moist landfills will have higher k values, and therefore faster biodegradation of waste and increased LFG generation rates than cooler, drier landfills. Both the Philippines and Guam are wet, tropical environments, and the recommended default value for k in the Philippines Model is k = Table 3-2. Various Values for Methane Generation Rate Constant, k (per year) Emission Type Landfill Type k Value CAA 1 Conventional 0.05 (default) CAA 1 Arid Area 0.02 Inventory 2 Conventional 0.04 Inventory 2 Arid Area 0.02 Inventory 2 Wet (Bioreactor) Philippines Model Conventional 0.18 (default) 1 CAA Clean Air Act Compliance default values 2 Inventory LandGEM default values 3 LandGEM uses 0.7 yr -1 as the default value for wet landfills which was recognized in the solid waste industry as an over estimate of the methane generation rate from actual field measurement. Recently, several studies were published for wet landfills including Kim H, Townsend T, 2012, where k ranged from 0.1 to 0.3 yr 1 for wet landfills 3.5 Ultimate Methane Generation Potential (Lo) The ultimate methane generation potential Lo is a measure of the total amount of methane that can be generated from a waste mass. The value of Lo depends only on the amount of biodegradable organic content in the waste; the greater the concentration of biodegradable material, the higher the value of Lo. The LandGEM Models also provide default values for Lo that are typical of average municipal solid waste streams. The value of Lo is measured in volume of methane generated per mass of waste, generally given as cubic meters per metric ton, or megagram. Due to historical landfill fires and the reported 25% content of construction and demolition waste (Summary of Landfill Gas Energy Potential for the Ordot Dump, USEPA LMOP, February, 2009); the recommended default value for the Philippines Model for Lo is 60 cubic meter per megagram (m 3 /Mg) of Waste. The Lo values used under various conditions and assumptions are provided in Table 3-3. Table 3-3. Various Values for Ultimate Methane Generation Potential Lo (m 3 /Mg of Waste) Emission Type Landfill Type Lo Value CAA 1 Conventional 170 (default) CAA 1 Arid Area 170 Inventory 2 Conventional 100 Inventory 2 Arid Area 100 Inventory 2 Wet (Bioreactor) 96 Philippines Model Conventional 60 (default) Final Ordot Landfill Gas Generation Potential v docx 3-4

46 Ordot Landfill Gas Generation Potential Section 4 1 CAA Clean Air Act Compliance default values 2 Inventory LandGEM default values Note: With respect to methane gas generation potential (Lo), 1 cubic meter of methane gas per megagram of waste is equal to approximately 32 cubic feet of methane gas per ton of waste. 3.6 Model Sensitivity The two variables, k and Lo, have significant impact on projected LFG generation and annual generation rates. A sensitivity analysis was performed to model the impact of these variables on LFG generation for the Dump. The previously discussed range of waste densities was also considered in the analysis. The Lo, k, and waste density values used in the sensitivity analysis are given in Table 3-4. The alternate value of k =0.11 (waste decay over 9.1 years) was used instead of the default value of the Philippine Model of k = 0.18 (waste decay over 5.5 years) and Lo =100 was used instead of the default Lo =60 to represent the range of reasonable LFG generation scenarios for the Dump. The results from the model are summarized in Section 4.1 below. Appendix A presents the full output from USEPA s Philippines Model. Waste Density lbs/ yd 3 Table 3-4. Philippines Model Scenarios Considered Methane Generation Rate Constant, k (per year) Ultimate Methane Generation Potential Lo (m 3 /Mg of Waste) 1 Collection System Efficiency (%) 1, , , , , , , , Section 4 Landfill Gas Generation Model Results 4.1 Landfill Gas Recovery Potential A summary of the results from the LFG generation modeling using the Philippines Model is listed below in Table 4-1 and shown in Figure 1. Recovery rates from an abbreviated period (2013 to 2023) are highlighted. Eight different Philippines Model scenarios were considered with varying waste densities (1,600 to 2,300 lb/ yd 3 ), methane generation rate constants (0.11 to 0.18 per year), and methane generation potentials (60 to 100 m 3 /Mg). The results are summarized below. Table 4-1. Landfill Gas Recovery Rates Summary at 67% Collection System Efficiency Final Ordot Landfill Gas Generation Potential v docx 4-5

47 Ordot Landfill Gas Generation Potential Section 4 Waste Density lbs/cu yd 3 Methane Generation Rate Constant, k (per year) Ultimate Methane Generation Potential Lo (m 3 /Mg of Waste) LFG recovery rates for 2013, (ft 3 /min) 1 LFG recovery rates for 2023, (ft 3 /min) 1 1, , , , , , , , Note: 1. ft 3 /min=cubic feet per minute Landfill Gas Rate, ft 3 /min LFG recovered rates at L o = 100 m 3 /metric ton LFG recovered rates at L o = 60 m 3 /metric ton Year Figure 1. Estimated Landfill Gas Recovery Rates (at Lo=100 m 3 /metric ton and Lo=60 m 3 /metric ton) Figure 1 summarizes the variation in LFG recovery rates for the various assumed scenarios. Using Lo=100 m 3 /metric ton estimates the gas recovery rates at more than 80% greater than at Lo=60 Final Ordot Landfill Gas Generation Potential v docx 4-6

48 Ordot Landfill Gas Generation Potential Section 4 m 3 /metric ton. The variations in k values and waste densities assumed in the model have less impact on the results. 4.2 Energy Output Potential This section provides an estimate of the amount of recoverable energy that will be available over time to fuel a LFG energy project. Table 4-2 provides the potential energy output for each of the LFG generation scenarios considered above. Energy output is based on 67% collection efficiency and is shown as ranges based on the variables of waste density, k, and Lo. Detailed energy output from the LandGEM model is included in Appendix B. The expected initial energy output ranges from an optimistic 1.5 megawatts (MW) for the optimal scenario considered above (i.e., lowest k, highest Lo, and highest waste density) to 0.8 MW for the more conservative scenario. Under any scenario, LFG production, and therefore energy content of the LFG, experiences an initial rapid decline and continues to decline rapidly over the next 10 years. Table 4-2 Energy Output for Each Scenario Considered Waste Density lbs/cu yd 3 Methane Generation Rate Constant, k (per year) Ultimate Methane Generation Potential Lo (m 3 /Mg of Waste) Energy Output from direct use projects a 2013, (MW) Energy Output from direct use projects a 2023, (MW) 1, , b 0.1 b 2, , , , , c 0.5 c 2, a assumes gas is combusted in a boiler with 85% efficiency to produce steam b presents worst case scenario c presents best case scenario 4.3 Overview of Landfill Gas End Uses The type of LFG energy project and the success of such a project depends on several economic, environmental, and political factors, plus local site conditions, and the quantity and the quality of the LFG. Several viable LFG energy techniques currently employed include: Generate electric power on-site from LFG and sell the power to the electric utility. Purify the LFG on site to make pipeline quality methane. Sell it to the natural gas utility. Sell the medium-btu LFG directly to a nearby industrial natural gas user. Sell the medium-btu LFG directly to a nearby offsite electric power plant. Purify the LFG on site to 90 percent methane quality and compress it to high pressure for fleet vehicle use as a compressed natural gas (CNG) substitute for diesel fuel. Use the LFG onsite for evaporation of leachate. A brief summary of the salient features of each technique is presented below: Final Ordot Landfill Gas Generation Potential v docx 4-7

49 Ordot Landfill Gas Generation Potential Section 4 On-site Power Generation. On-site Power generation is by far the most common LFG energy recovery application. Electricity is a valued, flexible commodity that is an expensive form of energy and the economics of LFG to electricity are usually more attractive than other LFG applications. The generated electricity is absolutely clean and is completely free from potentially adverse public perceptions about landfill sites or landfill products. Many electric utilities are actively looking for more renewable energy; some utilities sell LFG electricity as Green Power at a cost premium. The LFG electric power generation equipment is mature and well proven; several major reciprocating gas engine and gas turbine manufacturers have dozens of successful operating projects. Technically, LFG to electricity has less risk than many other LFG applications. Purify and Compress the LFG On-Site for Gas Pipeline Injection. For some locations and in certain sites, cleaning the LFG for direct injection into a nearby natural gas pipeline is the most appropriate application. The LFG is purified to 90 to 95 percent methane and compressed to the high pressure needed for the gas pipeline utility. Several techniques have been successfully used to clean LFG to pipeline quality, including amine treatment, cryogenic refrigeration, pressure swing adsorption, selexol treatment, and temperature swing adsorption. Direct Medium-British Thermal Unit (Btu) LFG Sales to an Industrial User. One of the simplest applications is to pipe the raw, medium Btu gas, with a minimum of treatment, directly to an adjacent industrial user. This application is extremely site-specific and the applicability is dependent on an appropriate industrial user and securing a long-term agreement to purchase the LFG. Direct Medium-Btu LFG Sales to an Off-Site Electric Power Plant. LFG may be piped to an adjacent electric power plant or a combined heat and power facility where it is used with natural gas to lower the cost of generating electricity. On-site LFG Cleanup and Compression to Produce Gas for Fleet Vehicle Fuel. LFG may be cleaned or scrubbed to essentially pure methane, and compressed to the very high pressures [over 2000 pounds per square inch gauge (psig)] required for CNG fleet vehicle users. On-site LFG Use. An additional end use of LFG that would have a potential net economic value is using LFG as fuel to evaporate leachate collected at the Dump. There are several ways to use LFG for economic benefit as described above. All would require active management of a LFG extraction and collection system in the Dump. A brief tabular presentation of some of the limiting factors affecting the various technologies is presented below in Table 4.3. Final Ordot Landfill Gas Generation Potential v docx 4-8

50 Ordot Landfill Gas Generation Potential Section 4 Table 4-3 LFG to Energy Technology Specific Requirements On-site Power Generation in a combustion engine or micro-turbine Purify and Compress the LFG On-site for Gas Pipeline Injection Direct Medium- Btu LFG Sales to an Industrial User Direct Medium-Btu LFG Sales to an Off-site Electric Power Plant On-site LFG Cleanup and Compression to Produce Gas for Fleet Vehicle Fuel Requires an electrical interconnection at a power substation with the utility Requires the electric industry to sign an electric power purchase agreement Requires an air permit Might not be able to use all of the LFG all the time LFG requires some treatment prior to combustion Requires specialized engines Presence of contaminants may substantially shorten the expected life of system components LFG must be cleaned to better than 90 percent pure methane Significant energy required to compress the gas Requires periodic gas sampling and laboratory testing Some of the LFG is lost by the purification process, often about 10 percent of the methane Requires adjacent or nearby end user who will sign a long-term purchase agreement Might not always use all the available LFG Might be necessary to perform additional periodic LFG sampling and testing Contract payments depend on gas flow meters that are frequently very unreliable The lower heating value of LFG will often require a modified burner on the user s boiler Requires adjacent or nearby gas burning electric power plant who will sign a long-term purchase agreement May require additional period LFG sampling and testing Contract payments depend on gas flow meters that are frequently very unreliable Pipeline is required to convey the low-pressure untreated gas The lower heating value of the gas will often require a modified LFG burner on the boiler Requires extremely clean gas quality to protect the very high pressure gas compressors and fleet vehicle engines Very site specific, and requires a nearby CNG fleet vehicle operation May mean modifying many fleet vehicles to operate on cleaned compressed LFG Increases heavy truck traffic to the landfill site Transit time to and from the LFG site for refueling reduces the vehicles fuel cost savings benefits 4.4 Landfill Gas Project Feasibility Model The economic returns of three potential LFG projects (two energy projects and one leachate evaporation project) were estimated using the Landfill Gas Energy Cost Model LFGcost-Web, version 2.2, dated July LFGcost-Web is a landfill gas energy project cost estimating tool developed for use by USEPA's LMOP partners. The scenarios were evaluated to determine the preliminary economic feasibility of three landfill gas projects considered for the Dump, given its history and location. The costs estimated by LFGcost-Web are based on typical project designs and for typical landfill situations. For the most part, variables needed for the model have been determined through the LandGEM modeling or, program- Final Ordot Landfill Gas Generation Potential v docx 4-9

51 Ordot Landfill Gas Generation Potential Section 4 defined default values were used. LFGcost-Web does not have Guam as one of the project locations, so Hawaii was used to consider potential employment benefits and monetary impacts to the local economy. The LFGcost-Web model attempts to include all equipment, site work, permits, operating activities, and maintenance that would normally be required for constructing and operating a typical project. Unique design modifications required because of site-specific constraints would add to the cost estimated by LFGcost-Web. Analyses performed using LFGcost-Web are considered preliminary and should be used for guidance only. A detailed final feasibility assessment would typically be conducted prior to preparing a system design, initiating construction, purchasing materials, or entering into agreements to provide or purchase energy from a landfill gas project. Site-specific considerations are addressed in this preliminary evaluation by way of selection of the three scenarios that were evaluated. The scenarios considered include Leachate Evaporation, Direct Use, and use of a Small Engine-Generator Set (see Table 4-4). Leachate evaporation is considered appropriate for evaluation since the Dump will continue to produce leachate after the final capping is implemented. Leachate evaporation utilizes LFG, which reduces the ultimate liquid volume and mass of waste requiring disposal. Direct use would typically involve firing LFG in an industrial boiler modified to burn low Btu gas. The direct use scenario assumes costs to transport the LFG via pipeline to an end-user within 0.5-mile of the Dump, as well as costs for a skid-mounted filter, compressor, and dehydration unit. The small engine-generator set scenario would generate electricity to use on-site for potential future power needs or to feed into the Guam Power Authority s electric grid. The small engine scenario includes gas compression and treatment, engine and generator, site work, housings, and electrical interconnect equipment. LFG Scenario Installed Capital Cost ($) Table 4-4. LFG Project Economic Feasibility Estimates First Year Operation and Maintenance Cost ($) Net Present Value ($) Internal Rate of Return ($) Leachate Evaporation 1,000, ,400 (5,540,632) Negative Notes: Direct Use 974,100 34,600 (830,236) Negative Small Engine- Generator Set 146,100 13,700 (37,574) 1% Capital costs shown do not reflect installation of a LFG collection and backup control system (flare) which are, for the purposes of this report, considered to be part of closure costs. $1,000,000 was added to the installed capital cost and the net present value to cover the cost of a leachate evaporation system since the LFGcost-Web Model did not automatically add one. Costs are based on 50,000 gallons per day (gpd) of leachate. Detailed economic output for each of the scenarios considered is included in Appendix C. With the exception of the Small Engine-Generator Set, each of the scenarios considered has a negative internal rate of return, meaning simply that there are more costs than revenue over the lifetime of the project. The 1% return associated with the Small Engine-Generator Set scenario is a marginal return at best and the investment not likely warranted given the higher opportunity cost or return if those same dollars were invested elsewhere. Environmental benefits are assumed to be roughly equivalent for each of the scenarios considered since the same volume of LFG will be destroyed, thereby reducing Green House Gas (GHG) and non-methane organic compounds (NMOC) emissions. Environmental benefits for each project are identified in Appendix C. Two other scenarios were mentioned in Table 4-3 but not modeled above, and include the Purify and Compress the LFG On-site for Gas Pipeline Injection and On-site LFG Cleanup and Compression to Final Ordot Landfill Gas Generation Potential v docx 4-10

52 Ordot Landfill Gas Generation Potential Section 4 Produce Gas for Fleet Vehicle Fuel. The LFGcost-Web does not have the ability to evaluate these scenarios specifically. Intuitively, these scenarios are even less feasible compared to those shown in Table 4-3 based on the higher capital costs associated with cleaning the gas, converting the gas to a high Btu fuel, and the need for achieving higher compression. Final Ordot Landfill Gas Generation Potential v docx 4-11

53 Section 5 Conclusions and Recommendations LFG generation rates for the Dump after closure were projected using the current modified version of LandGEM, known as the Philippines Model. This Model best simulates Guam s climatology as compared to the older version of LandGEM which was developed for use on the mainland. Ranges of LFG rates were projected based upon a sensitivity analysis of key variables. These ranges, provided in Table 4-1, can be utilized for design of the site s gas collection and treatment system. On balance, developing a LFG energy project would not be a prudent use of capital as demonstrated by the preliminary economic feasibility evaluation. The expected LFG generated from the Dump is not sufficient to recommend pursuing any of the projects considered. The results of this report are consistent with conclusions made in the April 2011 report by the United States Department of Energy, which were that a gas to energy project would be questionable given the sharp decline in gas generation over a relatively short duration. The reasons for the general infeasibility of LFG energy projects are numerous. The anticipated volume of LFG for the Dump after closure is not only relatively low, but it is also of short duration. The maximum potential of LFG recovered at the Dump could range from 300 ft 3 /min to 500 ft 3 /min, reducing to 40 ft 3 /min to 180 ft 3 /min within the first 10 years. Due to the age of the Dump, most of the expected gas generation has already taken place. The tropical climate and large yearly precipitation has contributed to the rapid degradation of the waste and generation of gas, and the numerous fires that have occurred over the years have depleted a significant portion of the LFG that was generated. The physical and operational characteristics of the Dump contribute to the probability that an LFG collection system would operate at a low collection efficiency. In addition, substantial uncertainties exist regarding the confidence of the projected LFG generation, due to the early use of the Dump by military forces and the subsequent uncontrolled nature of the operation, and such conditions could have a negative impact on the quality of methane production. Regarding the specific energy projects evaluated, each had a negative return on investment. The Small Engine-Generator Set scenario presents the lowest Net Present Value. Leachate evaporation has the lowest capital cost but the highest operating costs (which generally increases with time). Avoided costs for leachate treatment and disposal have not yet been quantified nor are they reflected in this evaluation. With respect to the capital costs reflected in the Leachate Evaporation scenario model results, it is BC s experience that total capital costs shown in the model do not reflect the capital cost of a leachate evaporation unit, which could be as much as double that shown by the model. Both Direct Use and Small Engine-Generator Set projects have similar order of magnitude capital costs and first year operation and maintenance costs. Final Ordot Landfill Gas Generation Potential v docx 5-1

54 References World Bank, Report, 1999, Solid Waste Management in Asia. EPA Municipal Solid Waste Publication, July 2012, Landfill Methane Outreach Program (LMOP), Summary of Landfill Gas Energy Potential for the Ordot Dump, February 23, Dueñas & Associates Project Team, Ordot Dump, Ordot-Chalan Pago, Guam Environmental Data Summary Report, July 2005 EPA, User s Manual, Philippines Landfill Gas Emissions Model (LandGEM), Version 1.0, Eastern Research Group USA and Organic Waste Technologies, December Daniel Duffy, LandGEM: the EPA s Landfill Gas Emissions Model, Combining art and science in projecting LFG production, MSW Management, February Amini HR, Reinhart DR, Mackie KR, Determination of first-order landfill gas modeling parameters and uncertainties, Waste Management 2012 Feb, 32(2):305-16, Epub 2011 Oct 14. Kim H, Townsend TG, Wet landfill decomposition rate determination using methane yield results for excavated waste samples, Waste Management 2012 Jul, 32(7): , Epub 2012 Apr 17. CIA government library, The World Factbook, Brown and Caldwell, Waste Isopach Thickness, Technical Memorandum, September 8, Brown and Caldwell, Topographic Surveys and Airspace Report, Technical Memorandum, September 8, Brown and Caldwell, Ordot Dump Preliminary Field Report of Landfill Gas Generation Potential, Technical Memorandum, September Ian Baring-Gould, Misty Conrad, Scott Haase, Eliza Hotchkiss and Peter McNutt, Guam Initial Technical Assessment Report, National Renewable Energy Laboratory of the U.S. Department of Energy, April USEPA LMOP, Summary of Landfill Gas Energy Potential for the Ordot Dump, February, US Census Population Data (2000, 2010), DRAFT for review purposes only. Final Ordot Landfill Gas Generation Potential v docx REF-1

55 Ordot Landfill Gas Generation Potential Appendix A: Philippines Model Results A Final Ordot Landfill Gas Generation Potential v docx

56 Ordot Landfill Gas Generation Potential Table A-1. Lo = 60 meters 3 /metric ton at 67% Collection System Efficiency Estimated Waste in Place 3,480,706 (metric tonnes ) Estimated Waste in Place 5,186,383 (metric tonnes ) Year k=0.18 yr -1 k=0.11 yr -1 k=0.18 yr -1 k=0.11 yr -1 1,600 lb/yd 3 2,300 lb/yd 3 LFG Generation Rate LFG Generation Rate LFG Generation Rate LFG Generation Rate (av ft 3 /min) (av ft 3 /min) (av ft 3 /min) (av ft 3 /min) Notes: 1 megagram is equal to 1 metric ton; 1 metric ton is equal to short ton (or ton). av = average, A-1 Final Ordot Landfill Gas Generation Potential v docx

57 Ordot Landfill Gas Generation Potential Table A-2. Lo = 100 meters 3 /metric ton at 67% Collection System Efficiency Estimated Waste in Place 3,480,706 (metric tonnes ) Estimated Waste in Place 5,186,383 (metric tonnes ) k=0.18 yr -1 k=0.11 yr -1 k=0.18 yr -1 k=0.11 yr -1 Year 1,600 lb/yd 3 2,300 lb/yd 3 LFG Generation Rate LFG Generation Rate LFG Generation Rate LFG Generation Rate (av ft 3 /min) (av ft 3 /min) (av ft 3 /min) (av ft 3 /min) Note: 1 megagram is equal to 1 metric ton; 1 metric ton is equal to short ton (or ton). A-2 Final Ordot Landfill Gas Generation Potential v docx

58 Ordot Landfill Gas Generation Potential Appendix B: LFG to Energy Results B Final Ordot Landfill Gas Generation Potential v docx

59 Ordot Landfill Gas Generation Potential Table B-1. Lo = 60 cubic meters/metric Ton Estimated Waste in Place 3,480,706 (metric tonnes ) Estimated Waste in Place 5,186,383 (metric tonnes ) k=0.18 yr- 1 k=0.11 yr- 1 k=0.18 yr- 1 k=0.11 yr- 1 Year 1600 lb/yd lb/yd lb/yd lb/yd 3 Energy Output Energy Output Energy Output Energy Output Energy Output Energy Output Energy Output Energy Output From Direct From Electric From Direct From Electric From Direct From Electric From Direct From Electric Generation Use Project a Generation Project b Use Project a Generation Project b Use Project a Project b Use Project a Generation Project b MTCO2e c (MJ/hr) d (MW) MTCO2e (MJ/hr) (MW) MTCO2e (MJ/hr) (MW) MTCO2e (MJ/hr) (MW) a assumes gas is combusted in a boiler with 85% efficiency to produce steam b assumes gas is combusted in an engine with 30% efficiency to produce electricity c abbreviation for megatonnes of carbon dioxide equivalent d abbreviation for megajoule per hour B-1 Final Ordot Landfill Gas Generation Potential v docx

60 Ordot Landfill Gas Generation Potential Table B-2. Lo = 100 cubic meters/metric Ton Estimated Waste in Place 3,480,706 (metric tonnes ) Estimated Waste in Place 5,186,383 (metric tonnes ) k=0.18 yr- 1 k=0.11 yr- 1 k=0.18 yr- 1 k=0.11 yr- 1 Year 1600 lb/yd lb/yd lb/yd lb/yd 3 Energy Output Energy Output Energy Output Energy Output Energy Output Energy Output Energy Output Energy Output From Direct From Electric From Direct From Electric From Direct From Electric From Direct From Electric Use Project a Generation Project b Use Project a Generation Project b Use Project a Generation Project b Use Project a Generation Project b MTCO2e (MJ/hr) (MW) MTCO2e (MJ/hr) (MW) MTCO2e (MJ/hr) (MW) MTCO2e (MJ/hr) (MW) a assumes gas is combusted in a boiler with 85% efficiency to produce steam b assumes gas is combusted in an engine with 30% efficiency to produce electricity c abbreviation for megajoule per hour Final Ordot Landfill Gas Generation Potential v docx B-2

61 Ordot Landfill Gas Generation Potential Appendix C: Project Feasibility Evaluation Using LMOP LFGcost-Web Leachate Evaporation (Input and Output) Direct Use (Output Only) Small Engine-Generator Set (Output Only) C Final Ordot Landfill Gas Generation Potential v docx

62 Copy of Copy of LFGcost-Web V2 2.xls 12/17/2012 LFGcost-Web Model (Version 2.2) LFGcost-Web is a spreadsheet tool developed for EPA's Landfill Methane Outreach Program (LMOP) to estimate the costs of a landfill gas (LFG) energy project. The tool is designed for parties interested in obtaining an initial economic feasibility analysis for a specific type of LFG energy project. These project types include electricity generation, direct use, combined heat and power, leachate evaporation, and high Btu production. Analyses performed using LFGcost- Web are considered preliminary and should be used for guidance only. Go to Table 1. Glossary of Input Parameters Go to Table 2. Glossary of Output Parameters Go to Table 3. LFG Energy Project Types and Recommended Sizes Go to Important Notes Go to Inputs/Outputs LFGcost-Web also provides an estimate of the local and state-wide economic benefits and job creation resulting from the installation of a direct use or recriprocating engine project. LFG energy projects generate benefits for the communities and states in which they are located, as well as for the United States. These benefits include new jobs and expenditures directly impacting the local and state-wide economies as a result of the construction and operation of an LFG energy project. In addition, there are indirect economic benefits when the direct expenditures on an LFG energy project flow through the economy resulting in increased overall economic production and economic activity within the local, state, and national economies. This tool consists of 10 required inputs to characterize the age and size of the landfill, the type of LFG energy project, and other input parameters relating to the project. Fifteen additional optional inputs are available to incorporate more site-specific data about the landfill and LFG energy project. LFGcost-Web also documents several default model inputs used to conduct the economic analysis. These default parameters should provide a reasonable economic evaluation of the project. However, you may wish to contact LMOP to run the model with different defaults based on site-specific circumstances (see For Further Assistance section below). The model provides the economic analysis and environmental benefits based on your inputs. Descriptions of the required and optional user inputs are in Table 1, and descriptions of the model outputs are listed in Table 2. You should use Table 3 when selecting the type of LFG energy project appropriate for the size of your project. Within these size ranges LFGcost-Web is estimated to have an accuracy of ± 30-50%. Using LFGcost-Web to evaluate projects outside of these recommended ranges will likely provide cost estimates with a greater uncertainty. Table 1. Glossary of Input Parameters Required Input Year landfill opened Year of landfill closure Area of LFG wellfield to supply project Average annual waste acceptance rate Waste acceptance rate calculator: Waste-in-place Year representing waste-in-place Annual waste disposal history Four-digit year that the landfill opened or is planning to open. Four-digit year that the landfill closed or is expected to close. Acreage of the landfill that contains waste and generates LFG to be collected and utilized by the LFG energy project. The model assumes one well per acre to determine well, wellhead, and pipe gathering system costs for the collection and flaring system. Acreage should represent area of landfill for gas collection to feed project, not total landfill area. Average annual tons of municipal solid waste (MSW) accepted each year the landfill is open. Total tons of MSW accepted and placed in the landfill. Four-digit year that corresponds to the waste-in-place tonnage. Definition If you do not know the average annual waste acceptance rate, then you can use the calculator to estimate this rate. The waste disposal history should be used only when year-to-year waste acceptance is known for each year that the landfill operates. The annual waste acceptance rate, in short tons, should be entered for all years beginning with the landfill open year and ending with the landfill closure year. LFG energy project type Will LFG energy project cost include collection and flaring costs? Amount of leachate collected (for leachate evaporator projects only) Distance between landfill and direct end use, pipeline or CHP unit (for direct use, high Btu and CHP projects only) Distance between CHP unit and hot water/steam user (for CHP projects only) Year LFG energy project begins operation Indicates which of the 10 types of LFG energy project types you want to analyze. Enter the bolded letter in parentheses to select the project type. Determines whether costs for vertical well collection and flaring equipment are included in the total LFG energy project cost. Enter Y (for yes) if the landfill does NOT have collection and flaring equipment installed. Enter N (for no) if the landfill already contains a collection and flaring system or you do not want to include collection and flaring costs in the total LFG energy project cost. Gallons of landfill leachate that is collected and treated annually. For direct use projects, the number of miles between the landfill, where the LFG is collected, and the end user of the LFG. For high Btu projets, the distance between the landfill, where the LFG is collected, and the natural gas pipeline or the end user of the high Btu gas. For CHP projects, the distance between the landfill, where the LFG is collected, and the CHP engine, turbine, or microturbine. To maintain integrity of the cost estimates, the distance should be limited to 10 miles or less. Number of miles between the CHP engine, turbine, or microturbine and the end user of the hot water/steam. To maintain integrity of the cost estimates, the distance should be limited to 1 mile or less. The CHP unit and the hot water/steam user are typically co-located, which would be a distance of zero (0) miles. Four-digit year that the LFG energy project will be installed and begin operating. INSTRUCTIONS - 1 of 11