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HomeMy WebLinkAbout7803_Robeson_CDLF_Expansion_LFGMonitoringPlan_DIN27635_20170331 PREPARED FOR: ROBESON COUNTY SOLID WASTE DEPARTMENT P. O. BOX 366 ST. PAULS, NC 28384 ROBESON COUNTY LANDFILL PERMIT NUMBER 78-03 LANDFILL GAS MONITORING PLAN REVISED MARCH 2017 PREPARED BY: 2211 WEST MEADOWVIEW ROAD, SUITE 101 GREENSBORO, NORTH CAROLINA 27407 NC LICENSE NUMBER C-0782 PHONE: (336) 323-0092 FAX: (336) 323-0093 JOYCE PROJECT NO. 820.1703.11 LANDFILL GAS MONITORING PLAN ROBESON COUNTY LANDFILL PERMIT # 78-03 ROBESON COUNTY, NC MARCH 2017 Prepared by: 2211 West Meadowview Road, Suite 101 Greensboro, North Carolina 27407 NC LICENSE NUMBER C-0782 Prepared by: _____________________________ G. Van Ness Burbach, Ph.D., P.G. NC License # 1349 Landfill Gas Monitoring Certification Statement: We certify that the Landfill Gas Monitoring Plan presented in this report, when implemented, will be effective in providing early detection of migration of explosive gases, so as to be protective of public health and the environment. JOYCE Project # 820.1703.11, Task 01 Landfill Gas Monitoring Plan Joyce Engineering Robeson County Landfill, Permit # 78-03 i Rev. March 2017 LANDFILL GAS MONITORING PLAN Robeson County Landfill Permit No. 78-03 TABLE OF CONTENTS 1.0 INTRODUCTION ............................................................................................................1 1.1 Background ..............................................................................................................1 1.2 Site Geology and Hydrogeology ..............................................................................1 1.3 Regulatory Limits ....................................................................................................2  2.0 LANDFILL GAS MONITORING ...................................................................................2 2.1 Landfill Gas Monitoring Network ...........................................................................2 2.2 Structure Sampling...................................................................................................3 2.3 Landfill Gas Monitoring Frequency ........................................................................3 3.0 LANDFILL GAS SAMPLING PROCEDURES..............................................................4  3.1  Detection Equipment ...........................................................................................4 3.2  Landfill Gas Sampling Procedure ........................................................................4 4.0 RECORD KEEPING AND REPORTING .......................................................................5 4.1  Notifications .........................................................................................................5 4.2  Sampling Reports .................................................................................................5  4.3  Permanent Record Keeping .................................................................................5 5.0 CONTINGENCY PLAN ..................................................................................................5 6.0 REFERENCES .................................................................................................................6    Drawings Drawing LFGMP-01 Landfill Gas Monitoring Plan Appendices Appendix A Solid Waste Section – Landfill Gas Monitoring Guidance Appendix B Landfill Gas Monitoring Data Form Landfill Gas Monitoring Plan Joyce Engineering Robeson County Landfill, Permit # 78-03 1 Rev. March 2017 1.0 INTRODUCTION This Landfill Gas Monitoring Plan (LGMP) will serve as a guidance document for collecting and monitoring of landfill gas at the Robeson County Landfill Permit No. 78-03. Landfill gas will be monitored quarterly to ensure that methane and hydrogen sulfide concentrations do not exceed the regulatory limit at the facility boundary or in facility structures. The LGMP was prepared in accordance with the North Carolina Department of Environmental Quality (NC DEQ) Division of Waste Management, Solid Waste Section (SWS) Landfill Gas Monitoring Guidance Document, to assure performance standards are met and to protect public health and the environment. 1.1 Background The Robeson County Landfill is located at 246 Landfill Road, just off of Route 20, in St. Pauls, North Carolina. The facility is owned and operated by Robeson County under Permit Number 78-03, issued by the North Carolina Department of Environmental Quality (DEQ) Solid Waste Section (SWS). The facility occupies 462 acres, with the permitted landfill boundaries consisting of approximately 90 acres. The permitted area is comprised of three active municipal solid waste (MSW) landfill phases (Phase 2, 3 and 4) and one closed phase (Phase 1). See Drawing LFGMP-01, for site layout and features. Phase 1 was opened in 1985 and was closed in accordance with applicable regulations in 1997. Phases 2 through 4 are lined Subtitle-D landfills. Currently, Robeson County has a permit to operate Phases 2 through 4 and a construction and demolition (C&D) debris landfill on top of the closed Phase 1 landfill. A future C&D waste cell is planned for the area west of Phase 1. Currently, all MSW is being disposed in Phase 4 and C&D waste is being disposed in Phase 1. This LGMP is prepared to include the existing facility and for the proposed Phase 1 C&D expansion and Phase 5 Permit to Construct. 1.2 Site Geology and Hydrogeology The Robeson County Landfill is located in the Coastal Plane geologic province. According to the geologic map of the area, the landfill is underlain by the late-Cretaceous (Campanian) Bladen Formation of the Black Creek Group, which is comprised of black clay and light colored micaceous sand deposited in a delta-shelf environment. The Bladen Formation dips gently toward the east and is underlain by the Tar Heel Formation which is comprised of cross bedded sands and variegated clays with some gravel. Previous reports indicated that on-site borings encountered surficial geology made up of sand and clay, consistent with the description of the Bladen Formation. A mixture of sand and clay is present in the shallower portions of borings. Distinct clay layers were identified at approximately 25 feet and 40 feet below grade. The primary aquifer at the site is an unconfined, relatively homogeneous sedimentary aquifer, approximately 4 feet below ground surface (ft-bgs), to the first confining clay layer at a depth of approximately 25 ft-bgs. The aquifer is comprised of silt and fine sand and clayey silts and clayey fine sands. Secondary, partially or largely confined aquifers are present below the clay layers. Landfill Gas Monitoring Plan Joyce Engineering Robeson County Landfill, Permit # 78-03 2 Rev. March 2017 Depth to water ranges from approximately 4 feet at the downgradient, south end of the property to approximately 24 feet at the upgradient, north end of the property. Groundwater flows to the south and southeast, toward Big Marshy Creek. 1.3 Regulatory Limits North Carolina Solid Waste Management Rules 15A NCAC 13B require quarterly monitoring of methane gas at MSW landfills and quarterly monitoring of methane and other explosive landfill gasses generated at C&D landfills to ensure that landfill gas does not exceed the lower explosive limit (LEL) at the facility boundary or 25 percent of the LEL in facility structures. The LEL for methane equals 5% by volume at standard temperature and pressure. Current regulations and requirements for C&D landfills state that concentration of methane gas, as well as hydrogen sulfide, generated by the facility should not exceed 25% of the lower explosive limit (LEL) in facility structures or that the concentrations of gasses do not exceed the LEL at the facility property boundary. The LEL for methane equals 5% by volume at standard temperature and pressure. The LEL for hydrogen sulfide equals 4% by volume at standard temperature and pressure. This LGMP prescribes a routine monitoring program to ensure standards are met and the actions to be taken if methane or hydrogen sulfide concentrations exceed specified limits. 2.0 LANDFILL GAS MONITORING Gas monitoring at the Robeson County Landfill will be performed throughout the active and post-closure care period for the facility. At a minimum, quarterly monitoring will be conducted at all subsurface gas detection wells and facility structures. 2.1 Landfill Gas Monitoring Network The locations of the landfill gas monitoring wells and structures are shown on Drawing LFGMP-01. The current landfill gas monitoring network consists of 18 wells (MMW-1A, MMW-2, MMW-3, MMW-4, MMW-4A, MMW-6, MMW-7, MMW-8, MMW-9, MMW-10, MMW-11, MMW-12, MMW-13, MMW-14, MMW-15, MMW-16, MMW-17R, and MMW-18R) and four structures (office, maintenance building, leachate treatment building, and animal shelter). For the proposed C&D landfill expansion, MMW-1A, MMW-2, MMW-3 and MMW-6 will be abandoned; and for the Phase 5 landfill expansion, MMW-16 and MM-17R will be abandoned. Three gas monitoring wells MMW-19, MMW-20, and MMW-21 are proposed to replace the abandoned MMWs to monitor landfill gas on the west side of the proposed C&D Cell and Phase 5. The wells MMW-19 and MMW-20 will be located near the property boundary northwest of Phase 5, and MMW-21 will be located on the west side of the C&D landfill as shown on Drawing LFGMP-01. They will be spaced approximately 500 feet apart and will be installed to the static groundwater table, estimated at 20 feet deep. They will be constructed in accordance with the November 2010 Landfill Gas Monitoring Guidance, issued by the NCDEQ and included as Appendix A to this LGMP. The following table describes the methane monitoring wells. Landfill Gas Monitoring Plan Joyce Engineering Robeson County Landfill, Permit # 78-03 3 Rev. March 2017 Monitoring Probe Status Screened Interval Total Depth MMW-1A To be abandoned Unknown Unknown MMW-2 To be abandoned Unknown Unknown MMW-3 To be abandoned Unknown Unknown MMW-4 ACTIVE Unknown Unknown MMW-4A ACTIVE Unknown Unknown MMW-6 To be abandoned Unknown Unknown MMW-7 ACTIVE Unknown Unknown MMW-8 ACTIVE Unknown Unknown MMW-9 ACTIVE Unknown Unknown MMW-10 ACTIVE Unknown Unknown MMW-11 ACTIVE Unknown Unknown MMW-12 ACTIVE Unknown Unknown MMW-13 ACTIVE Unknown Unknown MMW-14 ACTIVE Unknown Unknown MMW-15 ACTIVE Unknown Unknown MMW-16 To be abandoned Unknown Unknown MMW-17R To be abandoned 5.0’ to 20.0’ 20.0’ MMW-18R Installed 7/27/2009 5.0’ to 20.0’ 20.0’ MMW-19 PROPOSED 5.0’ to 20.0’ * 20.0’ * MMW-20 PROPOSED 5.0’ to 20.0’ * 20.0’ * MMW-21 PROPOSED 5.0’ to 20.0’ * 20.0’ * * = approximate anticipated depths. 2.2 Structure Sampling There are currently four structures on the facility property that will be monitored for landfill gas. The office, maintenance building, leachate treatment building, and animal shelter are shown on Drawing LFGMP-01. 2.3 Landfill Gas Monitoring Frequency The landfill gas wells included in this LGMP will be monitored at least quarterly in accordance with current regulations. Landfill Gas Monitoring Plan Joyce Engineering Robeson County Landfill, Permit # 78-03 4 Rev. March 2017 3.0 LANDFILL GAS SAMPLING PROCEDURES Landfill gas samples will be collected in accordance with Solid Waste Section’s (SWS) Landfill Gas Monitoring Guidance document. Details of detection equipment and sampling procedures are outlined below. 3.1 Detection Equipment A portable combustible gas monitor, measuring the concentration of combustible gases in units of percent of LEL, shall be used to conduct gas monitoring. The LEL is the lowest percent by volume of a mixture of combustible gas in air that will propagate a flame at 25 degrees Celsius and atmospheric pressure. The LEL for methane is 5%. If the portable combustible gases monitor measures methane concentration in percent volume, it shall be converted to LEL in the field using the following formula: 100% LEL Methane = 5% by Volume Methane % by Volume Methane X 20 = % LEL Methane A portable hydrogen sulfide gas (H2S) monitor, or add-on H2S sensor pod for the combustible gas monitor, shall also be used to conduct gas monitoring. The LEL for H2S is 40,000 ppm, or 4% by volume; however, hydrogen sulfide is dangerous to human health at levels well below the LEL. Most portable instrumentation reads hydrogen sulfide in parts per million as a volume-to-volume unit, so an approximate conversion of 1% Volume H2S is 10,000 ppm. It is advisable to monitor and record H2S in accordance with the portable instruments range and units for comparison to health and safety limits; however, the regulatory standard is the LEL for gas probes and 25% of the LEL for structures. The combustible gas monitor shall be calibrated to methane using the manufacturer's calibration kit and procedure before the monitoring activities begin. The calibration gas to be used depends on the expected levels of methane in landfill gas monitoring wells. If low levels of methane are expected, 15% CO2/15% CH4 calibration gas should be used. If high levels of methane are expected, 35% CO2/ 50% CH4 calibration gas should be used. Verification that the equipment was calibrated in accordance with the manufacture’s specifications is required. Calibration information must be recorded on the Landfill Gas Monitoring Data Form. The H2S monitor or pod shall be calibrated to H2S using the manufacturer's calibration kit and procedure before the monitoring activities begin. Most instruments monitor for, and are calibrated in, the 0-500 ppm range for H2S for purposes of human health and safety. This range is more protective than the explosive limit monitoring requirement, and should provide warning of H2S migration long before exceedance of the LEL. 3.2 Landfill Gas Sampling Procedure The portable combustible gas monitor will be turned on and allowed to warm up prior to gas sampling. The static pressure should show a reading of zero before taking the initial sample. The sample tube shall be purged for at least one minute prior to connecting the sample tube to the detection well, and then the initial concentration will be recorded. Gas monitoring will continue Landfill Gas Monitoring Plan Joyce Engineering Robeson County Landfill, Permit # 78-03 5 Rev. March 2017 until the reading has stabilized. A stable reading is considered to be +/- 0.5% by volume on the instrument’s scale. Once the reading has stabilized for 5 seconds, the reading will be recorded and the tubing will be disconnected from the valve. These steps will be repeated for each landfill gas monitoring well. 4.0 RECORD KEEPING AND REPORTING The landfill gas data will be recorded in accordance with the SWS’s Landfill Gas Monitoring Guidance document included as Appendix A. The records will be maintained in the landfill operating record. An example Landfill Gas Monitoring Data Form is included as Appendix B. 4.1 Notifications In the event that an exceedance of the regulatory levels is observed, the NC DEQ shall be notified within 24 hours of the observation, and the monitoring results and a description of the steps taken to protect human health, shall be placed in the facility’s operating record within seven calendar days of the observation. 4.2 Sampling Reports The Landfill Gas Monitoring Data Form will be prepared in accordance with the NC DEQ Division of Waste Management Solid Waste Section Landfill Gas Monitoring Guidance document. The form will describe the method of sampling, the date, time, location, sampling personnel, atmospheric temperature, reported barometric pressure, equipment calibration information, exceptions noted during sampling, and general weather conditions at the time of sampling, in addition to the concentration of combustible gases. 4.3 Permanent Record Keeping A copy of the landfill gas monitoring results and any remediation plans will be maintained in the landfill operating record. The reports will be maintained at an alternative location near the facility approved by the Division of Waste Management (Division). 5.0 CONTINGENCY PLAN If methane or hydrogen sulfide levels that exceed the regulatory limits are detected, the results shall be reported to the Robeson County Landfill immediately. The County shall immediately take all necessary steps to insure protection of human health. The Robeson County Landfill will notify the SWS in writing (fax or email are acceptable) within 24 hours. If methane or hydrogen sulfide levels exceed the LEL in existing gas wells, the need for additional gas wells will be evaluated, as well as the need for monitoring within any nearby structures in the direction of the gas migration. If the exceedance is in a gas well not located at or near a property boundary, additional investigation including use of bar-hole probes or temporary gas wells may be implemented to determine whether or not the exceedance extends to Landfill Gas Monitoring Plan Joyce Engineering Robeson County Landfill, Permit # 78-03 6 Rev. March 2017 the property boundary. If necessary, additional permanent gas wells may be installed between the exceeding well(s) and the property boundary to demonstrate that the site is in compliance. If the compliance level (25% LEL) is exceeded in an on-site structure, options will be evaluated to reduce the current methane levels and to prevent further migration of methane into the structure. At a minimum, the following actions will be taken if the methane concentration exceeds 25% of the LEL in any structure:  Put out all smoking materials and turn off all ignition sources;  Evacuate all personnel;  Vent the structure;  Do not allow personnel to reenter the building except to perform gas monitoring until the results of additional monitoring indicate that methane concentrations are sustained or stabilized below 25% of the LEL;  Begin continuous monitoring within the structure; and  Undertake an assessment to determine the origin and pathways of the gas migration Within seven days of detection, the monitoring results will be placed in the operating record and Robeson County will indicate actions taken and actions proposed to resolve the problem. Within 60 days of detection, Robeson County will develop and implement a landfill gas remediation plan for the combustible gas releases and notify the Division that the plan has been implemented. The plan will describe the nature and extent of the problem and the proposed remedy and will include a schedule for implementation of the remedy. Hydrogen sulfide becomes dangerous to human health at concentrations well below the Lower Explosive Limit. The OSHA Personal Exposure Limit (PEL) for H2S is 10 ppm for 8-hours or 50 ppm peak exposure, and the NIOSH Immediately Dangerous to Life and Human Health (IDLH) limit for H2S is 100 ppm. North Carolina Solid Waste Management Regulations only require monitoring for explosive gas levels, not hazardous levels; however, we recommend voluntary monitoring for H2S in the potentially hazardous range. If H2S is detected at concentrations above 10 ppm in any gas probe or outdoor ambient air monitoring point, or above 2.5 ppm inside any structure, we recommend that the County be notified immediately and appropriate action will be taken to protect human health, similar to the actions described above. 6.0 REFERENCES Brown, Philip M., Chief Geologist, 1985, Geologic Map of North Carolina, The North Carolina Geologic Survey, scale 1:500,000. Fetter, C.W., 2001, Applied Hydrogeology, Fourth Edition: Prentice-Hall, Inc.. Johnson, A.I., 1967, Specific Yield - Compilation of Specific Yields For Various Materials: U.S. Geological Survey Water Supply Paper 1662-D. Landfill Gas Monitoring Plan Joyce Engineering Robeson County Landfill, Permit # 78-03 7 Rev. March 2017 North Carolina Department of Environment and Natural Resources, 1990-2011, Solid Waste Management Regulations. North Carolina Department of Environment and Natural Resources, November 2010, Landfill Gas Monitoring Guidance. United States Department of Labor, Occupational Health and Safety Commission, Standards – 29 CFR Part 1926, 1970, Occupational Health and Environmental Controls, 29 CFR 1926.55 Appendix A - 1970 American Conference of Governmental Industrial Hygienists' Threshold Limit Values of Airborne Contaminants, Threshold Limit Values of Airborne Contaminants for Construction, Hydrogen Sulfide. DRAWING BIG MA R S H SW A M P PHASE 1 (CLOSED MSW) N C S T A T E H I G H W A Y 2 0 B U F F E R ( T Y P ) 3 0 0 ' - 0 " PHASE 1 (ACTIVE C & D) PHASE 3 (PERMITTED MSW) PROPERTY LINE PHASE 2 (PERMITTED MSW) BUFFER (TYP) 100'-0" M H TOC = 155.18GROUND = 151.92 RCL04 RCL05 RCL01 RCL07 RCL06 1 3 0 1 5 0 OW-9 OW-9A PZ-G8 PZ-G7 PZ-G9S PZ-G9D SW-2 SW-1 MMW-3 (TO BE ABD) MMW-2 (TO BE ABD)MMW-1A (TO BE ABD) MMW-4 MMW-11 MMW-10 MMW-9MMW-8MMW-7 MMW-4A MMW-14 MMW-12 MMW-13 MMW-16 MMW-17R MMW-18R PHASE 4 (ACTIVE MSW) 2024500 E 2025000 E 2025500 E 2026000 E 2026500 E 2027000 E 2027500 E 2028000 E 2028500 E 3 7 6 0 0 0 N 3 7 6 5 0 0 N 3 7 7 0 0 0 N 3 7 7 5 0 0 N 3 7 8 0 0 0 N 3 7 8 5 0 0 N 3 7 9 0 0 0 N 3 7 9 5 0 0 N 3 8 0 0 0 0 N 3 8 0 5 0 0 N 3 8 1 0 0 0 N 3 8 1 5 0 0 N 3 8 2 0 0 0 N 2022500 E 2023000 E 2023500 E 2024000 E2024000 E 2024500 E 2025000 E 2025500 E 2026000 E 2026500 E 2027000 E 2027500 E 2028000 E LEACHATE PRE-TREATMENT AND STORAGE FACILITY ANIMAL SHELTER ENTRANCE VEHICLE FUELING STATION VEHICLE WASH YARD WASTE STORAGE SEDIMENT BASIN NO.1 WHITE GOODS HANDLING AREA TIRE STORAGE AREA 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 0 0 1 9 0 1 8 0 1 7 0 1 6 0 1 5 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 1 0 2 0 0 1 9 0 1 8 0 1 8 0 1 7 0 1 6 0 150 150 1 5 0 16 0 170 1 7 0 1 6 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 1 5 0 160 170 18 0 1 5 0 1 5 0 1 5 0 15 0 1 5 0 1 5 0 150 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 150150160 170180 190 2 0 0 210 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 1 0 2 0 0 1 9 0 1 8 0 1 7 0 1 6 0 1 3 0 1 4 0 130 1 3 0 1 5 0 1 4 0 1 4 0 1 5 0 160 1 6 0 1 5 0 1 6 0 1 5 0 1 5 0 1 5 0 150 1 5 0 1 5 0 150 180 170160 2 0 0 1 6 0 150 1 6 0 170 1 8 0 190 1 5 0 1 5 0 150 140 150 1 4 0 1 3 0 1 3 0 1 3 0 14 0 15 0 1 3 0 1 3 0 130 1 3 0 150 1 5 0 1 5 0 1 5 0 UNDISTURBED ARCHAEOLOGICAL SITE CLOSED LCID LANDFILL PROPOSED MW-19R MW-20 (TO BE ABD) MW-21 MW-22 MW-13R MW-14R MW-15A MW-16 MW-17R MW-18 MW-4A MW-12 MW-10 MW-2 MW-11 MW-8 MW-9 MW-3R MW-7 PZ-G10S/10D MW-23 MW-24 MW-25R MW-26 MW-5 MW-5A MW-1 (AB) MW-6MW-25(ABANDONED) (ABANDONED) (ABANDONED) (ABANDONED) PZ-31D PZ-31S PZ-34 PZ-32S PZ-32D MW-30 PZ-33S PZ-33D MMW-15 MMW-6 (TO BE ABD) PROPOSED MMW-21 PROPOSED MMW-20 PROPOSED MMW-19 PROPOSED MW-20R MW-19 (TO BE ABD) BUFFER CURRENTLY IN PROCESS OF PURCHASE PROPOSED PHASE 5 LIMITS OF WASTE PROPOSED C & D EXPANSION LIMITS OF WASTE PROJECT NO. AP P R O V E D CH E C K E D DR A W N DE S I G N E D DA T E DA T E RE V I S I O N S A N D R E C O R D O F I S S U E BY NO AP P CK SCALE A l l r i g h t s r e s e r v e d . Ó J o y c e E n g i n e e r i n g , I n c . DRAWING NO. L: \ R o b e s o n c o u n t y \ 2 0 1 6 C & D L A T E R A L E X P A N S I O N \ L F G A N D W Q M P 2 0 1 7 \ L F G 0 1 A N D W Q M P 0 1 L . d w g L a y o u t = L a y o u t 1 ( 2 ) 22 1 1 W . M E A D O W V I E W R O A D GR E E N S B O R O , N C 2 7 4 0 7 PH O N E : ( 3 3 6 ) 3 2 3 - 0 0 9 2 820 RO B E S O N C O U N T Y L A N D F I L L ST . P A U L S , N O R T H C A R O L I N A 20 1 7 LFGMP-01 AS SHOWN LA N D F I L L G A S MO N I T O R I N G P L A N RW H RW H VB VB 04 / 0 1 / 1 7 0 (FEET) GRAPHIC SCALE 600300150 Appendix A Solid Waste Section – Landfill Gas Monitoring Guidance                                                           Appendix B Landfill Gas Monitoring Data Form Landfill Gas Monitoring Data Form Facility Name: ____________________ Permit Number: ___________________ Date of Sampling: ____________________ Personnel: ___________________ Gas Monitor Type & Serial No: ____________________ Calibration Date: ___________________ Field Calibration Date & Time: ____________________ Calibration Gas Type: ___________________ General Weather Conditions: ____________________ Barometer : ___________________ Location or LFG GP ID Instr. purged Time Probe Pressure (InWg) Time Pumped (sec.) CH4 (%LEL) CH4 (%Vol) Notes Abbreviations: GP = Gas Probe LEL = Lower Explosive Limit