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Home My WebLink About2509_CRSWMALFGPlan_DIN26124_20151209 PREPARED FOR: COASTAL REGIONAL SOLID WASTE MANAGEMENT AUTHORITY P.O. BOX 128 COVE CITY, NORTH CAROLINA 28523 COASTAL REGIONAL SOLID WASTE MANAGEMENT AUTHORITY TUSCARORA LANDFILL PERMIT NUMBERS 25-04 & 25-09 LANDFILL GAS MONITORING PLAN REVISED: DECEMBER 2015 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. 00618.1601.12.02 Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 i LANDFILL GAS MONITORING PLAN CRSWMA Tuscarora Long Term Regional Landfill Permit Nos. 25-04 & 25-09 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 ...................................................................................3 2.1 Landfill Gas Monitoring Network ....................................................................................3 2.2 Structure and Ambient Sampling ......................................................................................5 2.3 Landfill Gas Monitoring Frequency .................................................................................5 3.0 LANDFILL GAS SAMPLING PROCEDURES..............................................................5 3.1 Detection Equipment ........................................................................................................5 3.2 Landfill Gas Sampling Procedure .....................................................................................6 4.0 RECORD KEEPING AND REPORTING .......................................................................6 4.1 Landfill Gas Monitoring Data Form .................................................................................6 4.2 Sampling Reports ..............................................................................................................6 4.3 Permanent Record Keeping ..............................................................................................7 5.0 CONTINGENCY PLAN ..................................................................................................7 6.0 CERTIFICATION OF PROFESSIONAL GEOLOGIST OR ENGINEER .....................8 7.0 CERTIFICATION OF REGISTERED LAND SURVEYOR ..........................................8 8.0 REFERENCES .................................................................................................................8 Drawings Figure No. 1 Site Location Map Drawing No. 1 Shallow Aquifer Potentiometric Surface Contour Map Drawing No. 2 Landfill Gas Monitoring Locations Boring Logs GP-8 Well Construction Record Appendices Appendix I Solid Waste Section – Landfill Gas Monitoring Guidance Appendix II Landfill Gas Monitoring Data Form Appendix III Certification of Professional Geologist or Engineer Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 1 1.0 INTRODUCTION This Landfill Gas Monitoring Plan (LGMP) will serve as a guidance document for collecting and monitoring of landfill gas at the Coastal Regional Solid Waste Management Authority (CRSWMA) Tuscarora Landfill. Landfill gas will be monitored quarterly to ensure that methane does not exceed the regulatory limit at the facility boundary or in facility structures. The LGMP was prepared in accordance with the rules written in 15A NCAC 13B .1626, Operational Requirements for municipal solid waste landfill (MSWLF) facilities, to assure performance standards are met and to protect public health and the environment. 1.1 Background The Tuscarora Landfill is owned and operated by the Coastal Regional Solid Waste Management Authority (CRSWMA) and is currently operating under North Carolina Solid Waste Permit Nos. 25-04 and 25-09. The landfill is located off of Old Highway 70, near the town of New Bern in northwestern Craven County, North Carolina. The property boundary is indicated on an excerpt from the 7.5 minute USGS topographic map for Jasper, North Carolina. The Tuscarora Landfill includes four contiguous waste cells; the closed Tuscarora Interim Regional Landfill (Permit 25-04-MSWLF-1993) and Phases 1, 2, and 3 of the Tuscarora Long- Term Regional Landfill (Permit 25-09-MSWLF-1999). The Interim Regional Landfill (IRL) was constructed in accordance with the Federal Subtitle D regulations with a composite liner and leachate collection and removal system. The IRL began receiving waste in 1993, and stopped receiving waste by November 1999. The Tuscarora Long-Term Regional (LTR) Landfill (LTR) is constructed in accordance with Subtitle D requirements, beginning with Phase 1, which was constructed and began receiving waste in November 1999 and stopped receiving waste in 2005. Phase 2 was constructed in 2005 and was active from 2005 until June 2013. Phase 3 is the current, active cell and began receiving waste on June 20, 2013. The Permit to Operate Phase 3 was approved by NC DENR Solid Waste Section on June 6, 2013. The current waste footprint comprises approximately 79 acres of the 101 acres approved in the permit. 1.2 Site Geology and Hydrogeology The Tuscarora Landfill is located in the Coastal Plain physiographic province. The Coastal Plain consists of a wedge of continental and marine sediments that are Cretaceous, Tertiary, and Quaternary in age. These sediments are approximately 1,500 feet thick in the area of the Tuscarora Landfill according to the North Carolina State Geologic Map (Brown, 1985). Surface water is directed through a network of constructed drainage ditches to the north-northeast towards Jumping Run, a tributary of Bachelor Creek. Shallow groundwater flow is to the east- southeast towards Beaverdam Branch, which is another tributary of Bachelor Creek located approximately 2.25 miles away. Bachelor Creek flows to the east to its confluence with the Neuse River. The uppermost (shallow) aquifer at the site consists of Miocene to Pleistocene age silty sands, clayey sands, and sandy clays. The uppermost aquifer is separated from a lower aquifer by a Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 2 lean to fat clay associated with the Pungo River Formation. The Pungo River Formation is Miocene in age and consists mainly of marine fat clay to silty clay, which represents a regressive marine sequence that grades from sandy clay to silty sand at the bottom of the formation (Harris, 1991). The lower aquifer is middle to upper Eocene in age and is part of the Castle Hayne Formation. It consists of a combination of coquina and a weakly cemented calcarenite. Both the upper and lower aquifers at the site are primarily made up of coarse sand and silty sand. The aquifers are separated by a confining layer consisting of marine clays, silty clays, and very fine silty sands. Groundwater elevation contours for the shallow aquifer are shown on Drawing 1, and were interpreted from the April 2015 water level measurements. Groundwater flow of the shallow aquifer is predominantly to the east-southeast. Groundwater in the deep aquifer usually flows primarily to the northwest due to dewatering in the borrow area excavations, creating a cone of depression. However, beginning September 1, 2014, pumping in the borrow area excavations stopped, allowing the deep aquifer to revert to a more gradual potentiometric surface, and flow to the southeast. The hydrogeological conditions will continue to be monitored and reported semiannually. Horizontal groundwater gradients were estimated based on April 2015 groundwater levels. The groundwater contours and the groundwater flow lines were used to calculate hydraulic gradients for the site. The horizontal gradients were estimated to range from 0.0027 to 0.0036 ft/ft for the shallow aquifer and 0.0082 to 0.0185 ft/ft for the deep aquifer. The gradients generally reflect the uppermost aquifer underlying the site, the flat topography of the site, and wet storm water drainage ditches and basins located within the site. The borrow pit area was not actively being dewatered. Linear groundwater flow velocities were computed using the following modified Darcy equation: V = Ki/n where V = average linear velocity (feet per day – ft/day), K = hydraulic conductivity (ft/day), i = horizontal hydraulic gradient, and n = effective porosity. The hydraulic conductivity used to calculate flow velocities was based on the geometric mean of hydraulic conductivities derived from slug tests for the shallow and deep aquifers. The calculated linear groundwater flow velocities from the April 2015 groundwater monitoring event range from 0.009 to 0.012 ft/day for the shallow aquifer and from 0.177 to 0.399 ft/day for the deep aquifer. These results are consistent with historical results for the facility. The linear velocity equation is based on the simplified assumption of a homogeneous and isotropic aquifer. 1.3 Regulatory Limits This LGMP is designed in accordance with Rule 15A NCAC 13B .1626 to ensure that the concentration of methane gas generated by the facility does not exceed 25 percent of the lower Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 3 explosive limit (LEL) for methane in facility structures or that the concentration of methane gas does not exceed the LEL for methane at the facility property boundary. The LEL for methane equals 5% by volume at standard temperature and pressure. This LGMP prescribes a routine methane monitoring program to ensure standards are met and actions to be taken if methane concentrations exceed specified limits. 2.0 LANDFILL GAS MONITORING Gas monitoring at the CRSWMA Tuscarora Landfill will be performed during the active life of the landfill and throughout the post-closure care period. At a minimum, quarterly monitoring will be conducted at the subsurface gas detection boundary probes, soil bar-hole probes, and in all structures located on the landfill property. 2.1 Landfill Gas Monitoring Network The Tuscarora Landfill does not pose the potential for subsurface methane migration since the constructed base grades of the landfill are elevated above the surrounding ground to achieve the required separation from groundwater. Therefore any lateral migration of landfill gas would be released to the atmosphere within the landfill property. Moreover, the water table, which is near ground surface, and the ditches around the landfill that hold water year-round, serve as barriers to subsurface migration. The current landfill gas monitoring network locations are shown on Drawing No. 2. The network currently consists of 3 permanent probes (GP-6, GP-7, and GP-8), and 15 soil bar-hole probes (BHP-1 through BHP-15). Facility Structures are also monitored including a small shed in the composting area, the scalehouse and office building, the maintenance shop and a storage shed. In the past, the Interim Regional Landfill (IRL) was monitored by permanent Landfill Gas Monitoring Wells LFG-MW-1 through LFG-MW-7, which were installed immediately outside of waste limits of the IRL, Permit 25-04. Three leachate collection system manholes were also monitored for landfill gas, as well as the facility structures at the time including an office trailer, scalehouse, shop, and storage shed. LFG-MW-1 was damaged and/or removed during the Phase 1 expansion of Long-term Regional Landfill (LTRL), Permit 25-09, and the well/probe is no longer monitored. The LTRL and IRL cells are contiguous with each other; however, each phase is constructed as a self-contained waste cell, and each Phase was constructed so that the landfill bottom is above the surrounding ground and at or above elevation 50 feet above mean sea level. Due to the above ground design and shallow aquifer, temporary soil bar-hole probes are used for the monitoring network around the LTRL. A soil bar-hole probe (BHP) is made at the time of monitoring in the soil at the approximate location indicated by the Landfill Gas Monitoring Locations Drawing for the purpose of sampling soil gas for methane. The BHP is further described below. Since LFG-MW-02, LFG-MW-03, LFG-MW-04, and LFG-MW-05 were installed immediately adjacent to the IRL waste cell, they do not monitor conditions at the facility boundary. LFG- MW-02, LFG-MW-03, LFG-MW-04, and LFG-MW-05 have historically yielded methane Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 4 detections and exceedances, and in the past the action taken at the time of monitoring was to perform additional soil bar-hole probes between the permanent probe and the closest property line or structure to delineate the extent of the methane migration beyond the probe. In 2011 CRSWMA proposed to install a new permanent probe, to be designated GP-8, near the property boundary where it comes closest to the waste to serve as a permanent boundary monitoring probe to supersede LFG-MW-02, LFG-MW-03, LFG-MW-04, and LFG-MW-05 for future quarterly monitoring. The installation of GP-8 was approved by the SWS dated January 20, 2012. Joyce installed GP-8 on February 18, 2012, and submitted the installation report and well record to SWS on February 20, 2012. Quarterly Monitoring results for GP-8 have consistently shown no methane even when there were detections or exceedances monitored in LFG-MW-02, LFG-MW- 03, LFG-MW-04, and LFG-MW-05 demonstrating methane from the IRL is not migrating beyond the facility boundary. Monitoring Probe Summary Probe ID 1. Monitoring Status Total Depth (ft) Screen Interval (ft) 2. Depth to GW (ft) Lithology LFG-MW-01 Abandoned N/A N/A - All Probes: Silty Sand, Clayey Sand, Sandy Clay of Pungo River Formation. LFG-MW-02 Inactive 13 3 to 13 Appx. 6 LFG-MW-03 Inactive 12 3 to 12 Appx. 6 LFG-MW-04 Inactive 14 4 to 14 Appx. 6 LFG-MW-05 Inactive 12.3 2.3 to 12.3 Appx. 6 GP-6 Active boundary 12.5 2.5 to 12.5 Appx. 6 GP-7 Active boundary 12.8 2.5 to 12.8 Appx. 6 GP-8 Active boundary 7 2 to 7 Appx. 7 BHP-1 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-2 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-3 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-4 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-5 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-6 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-7 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-8 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-9 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-10 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-11 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-12 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-13 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-14 Active boundary 1.5 – 3.0 N/A Appx. 4 BHP-15 Active boundary 1.5 – 3.0 N/A Appx. 4 Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 5 1. Probe Identification: The old permanent gas monitoring probes and are tagged as GMP-06; they have also been referred to in past documentation as Landfill Gas Monitoring Wells (LFG-MW-06), or more recently as Gas Probes (GP-06). 2. Estimated based on typical 10-feet of screen. N/A = Not Applicable The old LFG-MWs were constructed circa 1994, with a 1-inch diameter PVC Schedule 40 screen and flush-thread riser pipe and has been fitted with a quick-connect coupling with a shut-off valve. The old LFG-MWs have 1-foot by 1-foot concrete well pads and 4-inch PVC Schedule 40 outer casings with PVC caps. GP-8 was constructed in 2012 in accordance with the Section Guidance Document, with 2-inch schedule-40 PVC screen with 0.010 slot and flush-threaded riser pipe, PVC cap fitted with “quick-connect” shut-off valve, a concrete well pad, and an outer protective casing, and driller’s well tag. The soil BHPs are made by driving a quarter-inch steel rod 18 to 36 inches below the ground surface, but staying above the groundwater table, followed by the insertion of a tube connected to the methane gas monitoring instrument. 2.2 Structure and Ambient Sampling There is over 1,200 feet to the nearest temporary structure, and over 2,000 feet to the permanent facility structures; however, the structures will be monitored for safety due to the proximity of the older closed Craven County Landfill. Four structures are currently monitored for explosive gases. The applicable regulatory limit for structures is less than 25% of the LEL for methane. The structures include the CRSWMA offices and scalehouse building, the maintenance shop, a storage shed behind the shop, and a small shed in the compost area. The monitored structures are identified on Drawing No. 2. 2.3 Landfill Gas Monitoring Frequency The landfill gas probes and on-site structures included in this LGMP are monitored at least quarterly in accordance with Rule 15A NCAC 13B .1626(4)(b)(ii). 3.0 LANDFILL GAS SAMPLING PROCEDURES Landfill gas samples will be collected in accordance with Solid Waste Section’s Landfill Gas Monitoring Guidance Document. Details of detection equipment and sampling procedures are outlined below. 3.1 Detection Equipment A portable combustible gas analyzer, measuring the concentration of combustible gases in units of percent of LEL and/or percent volume, shall be used to conduct gas monitoring. The LEL (lower explosive limit) means 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. If an instrument gives readings only in percent volume, a conversion into % LEL will be made in order to complete the Landfill Gas Monitoring Data Form. Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 6 The 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 locations. If low level methane is expected 15% CO2/15% CH4 calibration gas should be used; but if high level methane is 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. 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 instrument 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 monitoring probe then the initial concentration will be recorded. Gas monitoring will continue 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 tube will be disconnected from the valve. These steps will be repeated for each landfill gas monitoring well. These steps will also be followed for each soil bar-hole probe except that a probe location has to be created by driving a 1/4-inch rod into the soil up to 36 inches deep, then the sampling tube will be immediately inserted into the depth of the bar-hole for sampling soil gas. Gas monitoring in the facility’s buildings will attempt to identify the "worst case" concentrations. The monitoring locations will be in corners along floors and ceilings, at cracks in the floor, and at other areas likely to accumulate gas. Gas monitoring will also be conducted in any confined space requiring the entry of personnel for maintenance or inspection. Such monitoring will take place prior to entry by personnel in accordance with OSHA regulations. 4.0 RECORD KEEPING AND REPORTING The landfill gas data will be recorded in accordance to the SWS’s Landfill Gas Monitoring Guidance Document included as Appendix I. The records will be maintained in the landfill operating record. 4.1 Landfill Gas Monitoring Data Form A landfill gas monitoring form is included as Appendix II. 4.2 Sampling Reports The landfill gas monitoring report will be prepared in accordance 15A NCAC 13B. 0500 and .1600 Rules. The SWS Landfill Gas Monitoring Guidance Document in Appendix I covers the current SWS rules pertaining to landfill gas monitoring. The report 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 Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 7 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 the facility or an alternative location near the facility approved by the Division. 5.0 CONTINGENCY PLAN If methane gas levels exceeding the regulatory limits specified in 15A NCAN 13B .1626(4)(a) are detected, the results shall be reported to CRSWMA immediately. The Authority will notify the NCDEQ, SWS in writing and will take immediate steps to ensure safety and protection of human health. If methane levels exceed the LEL in existing gas probes, the need for additional gas probes will be evaluated, as well as the need for monitoring within any nearby structures in the direction of the gas migration. If the exceedence is in a gas probe not located at or near a property boundary, additional investigation including use of bar-hole probes or temporary gas probes may be implemented to determine whether or not the exceedence extends to the property boundary. If necessary, additional permanent gas probes may be installed between the exceeding probe(s) and the property boundary to demonstrate that the site is in compliance. If the compliance level 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% 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% 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 the County will indicate actions taken and actions proposed to resolve the problem. Within 60 days of detection, the Authority 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. Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 8 6.0 CERTIFICATION OF PROFESSIONAL GEOLOGIST OR ENGINEER The Certification of Professional Geologist or Engineer is included as Appendix III. 7.0 CERTIFICATION OF REGISTERED LAND SURVEYOR All future landfill gas monitoring probes will be surveyed for location and elevation by a North Carolina Registered Land Surveyor. 8.0 REFERENCES Brown, Philip M., Chief Geologist, 1985, Geologic Map of North Carolina, The North Carolina Geologic Survey, scale 1:500,000. Fetter, C.W., 1994, Applied Hydrogeology, Third Edition: Macmillan College Publishing Company. Harris, W. Burleigh and Zullo, Victor A., 1991, Eocene and Oligocene Stratigraphy of the Outer Coastal Plain, in Horton, J. W., Jr., and Zullo, V. A., eds., The Geology of the Carolinas: Carolina Geological Society Fiftieth Anniversary Volume: The University of Tennessee Press, p. 251-262. HDR Engineering, Inc., 1995, Site Study: The Tuscarora Long-Term Regional Landfill; The Coastal Regional Solid Waste Management Authority, Craven County, North Carolina, November 1995. HDR Engineering, Inc., 1997, Construction Permit Application: Phase I The Tuscarora Long- Term Regional Landfill: The Coastal Regional Solid Waste Management Authority, Tuscarora, North Carolina, March 1997. Joyce Engineering, Inc., 2003, Design Hydrogeological Report & Groundwater Monitoring Plan, Tuscarora Long-Term Regional Landfill Phase 2 Expansion, July 2003. McKim & Creed, P.A., 1997, The Tuscarora Long-Term Regional Landfill: Subtitle D Landfill Construction Plan Application Modification for The Coastal Regional Solid Waste Management Authority, Tuscarora, North Carolina, March 1997. McKim & Creed, P.A., 1999, The Tuscarora Long-Term Regional Landfill: Subtitle D Landfill Site Application Modification for The Coastal Regional Solid Waste Management Authority, Tuscarora, North Carolina, September. Joyce Engineering, Inc., July 2015. First Semiannual Groundwater Quality Monitoring Report of 2015, CRSWMA Tuscarora Landfill, Craven County, North Carolina. Landfill Gas Monitoring Plan Joyce Engineering CRSWMA Tuscarora Landfill December 2015 Permit No. 25-04& 25-09 9 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. Drawings Figure No. 1 Site Location Map Drawing No. 1 Shallow Aquifer Potentiometric Surface Contour Map Drawing No. 2 Landfill Gas Monitoring Locations M W - 1 3 S M W - 1 3 D M W - 1 4 R I R L - 1 S I R L - 1 D I R L - 2 D ( A B A N D O N E D ) I R L - 3 S I R L - 3 D I R L - 4 S I R L - 4 D I R L - 5 S I R L - 5 D L S T - 1 S L S T - 1 D L S T - 2 S L S T - 2 D L S T - 3 S L S T - 3 D L S T - 5 S L S T - 5 D M W - 1 2 D M W - 7 F A C I L I T Y S C A L E S H O P / O F F I C E A N D S C A L E H O U S E L E A C H A T E L A G O O N E X I S T I N G L E A C H A T E F O R C E M A I N S E D I M E N T B A S I N S B - 1 P U M P S T A T I O N ( S E M I - A N N U A L L E A C H A T E S A M P L I N G L O C A T I O N ) T I R E D I S P O S A L A R E A M M M M P R O P O S E D A C C E S S R O A D E D G E O F L I N E R / L I M I T S O F W A S T E L S T - 4 S L S T - 4 D L S T - 6 S L S T - 6 D M A N H O L E ( T Y P I C A L ) 3 0 0 ' P R O P E R T Y B U F F E R S E D I M E N T B A S I N S B - 4 E X I S T I N G A C T I V E L A N D F I L L G A S S Y S T E M M W - 1 2 S 3 0 0 ' - 0 " P Z - 3 6 P Z - 3 7 I N G E N C O L A N D F I L L G A S T O E N E R G Y F A C I L I T Y P U B L I C C O N V E N I E N C E C E N T E R S E D I M E N T B A S I N S B - 2 S E D I M E N T B A S I N S B - 5 S E D I M E N T B A S I N S B - 3 S E D I M E N T B A S I N S B - 6 L A N D F I L L E N T R A N C E N E W - B M T U S - 7 T U S - 6 T U S - 1 T U S - 9 T U S - 2 T U S - 3 T U S - 4 T U S - 5 x x x x x x M W - A M W - 1 0 M W - 1 1 D M W - 1 1 S M W - 1 4 ( A B A N D O N E D ) I R L - 2 D A I R L - 2 S A S W P T - 1 S W P T - 2 U D - 2 U D - 3 L A N D F I L L G A S F L A R E M W - 1 8 D M W - 1 8 S M W - 1 9 D M W - 1 9 S M W - 1 5 D M W - 1 5 S M W - 1 6 D M W - 1 7 D M W - 1 7 S M W - 2 0 D M W - 1 6 S R M W - 2 1 D A P P R O X I M A T E W H I T E G O O D S D I S P O S A L A R E A G P - 6 G P - 7 G P - 8 B H P - 1 1 B H P - 1 2 B H P - 1 3 B H P - 1 5 B H P - 1 4 B A R H O L E L O C A T I O N S A R E A P P R O X I M A T E . S T O R A G E S H E D L E G E N D : B A R H O L E P R O B E L O C A T I O N A C T I V E L A N D F I L L G A S M O N I T O R I N G L O C A T I O N S G R O U N D W A T E R C O N T O U R ( F R O M 1 0 - 1 5 E L E V A T I O N D A T A ) G R O U N D W A T E R F L O W V E C T O R ( 1 0 - 1 5 G R O U N D W A T E R R E P O R T ) B H P - 1 1 G P - 8 C O M P O S T F A C I L I T Y S H E D B H P - 1 B H P - 2 B H P - 3 B H P - 4 B H P - 5 B H P - 6 B H P - 1 0 G M W - 5 G M W - 3 S T O R M W A T E R C H A N N E L 45 4 4 4 3 42 40 3 9 40 39 46 4 5 4 6 44 44 40 4 0 G M W - 2 4 3 I R L - 2 S ( A B A N D O N E D ) G M W - 4 P R O J E C T N O . APPROVED CHECKED DRAWN DESIGNED DATE DATE REVISIONS AND RECORD OF ISSUE BYNO APPCK S C A L E All rights reserved. Joyce Engineering, Inc. D R A W I N G N O . L:\CRSWMA\dwg\2015 lfg plan\LFG-01 LFG MONITORING PLAN.dwg Layout=Layout1 NC CORP LIC: C-0782 0 ( F E E T ) G R A P H I C S C A L E 8 0 0 4 0 0 2 0 0 N O T E : 1 . N O R E S I D E N T I A L W E L L S A R E L O C A T E D W I T H I N 5 0 0 F E E T O F T H E F A C I L I T Y B O U N D A R Y . 2 . N O P R I V A T E R E S I D E N C E S A R E L O C A T E D W I T H I N 5 0 0 F E E T O F T H E F A C I L I T Y B O U N D A R Y . 3 . A C C O R D I N G T O T H E F E D E R A L E M E R G E N C Y M A N A G E M E N T A G E N C Y , N O F L O O D P L A I N S A R E L O C A T E D W I T H I N T H E C U R R E N T F A C I L I T Y B O U N D A R Y . CRSWMA- TUSCARORA LANDFILL TUSCARORA, NORTH CAROLINA 2015 2 A S S H O W N LANDFILL GAS MONITORING LOCATIONS DG RWH AE DG 6 1 8 . 1 6 0 1 . 1 1 11/30/152211 W. MEADOWVIEW ROAD GREENSBORO, NC 27407 PHONE: (336) 323-0092 2/23/16 REVISED PER DEQ COMMENTS RWH1 DGDG Boring Logs NON RESIDENTIAL WELL CONSTRUCTION RECORD North Carolina Department of Environment and Natural Resources-Division of Water Quality WELL CONTRACTOR CERTIFICATION #__:p+".....i"'-'O<-..:g""'---"S""--__ :d.TOP OF CASING IS -+3 l FT Above Land Surface* *Top of casing terminated at/or below land surface may require .a variance in accordance with 15A NCAC 2C .0118, ~e.YIELD (gpm):NM _~ETHOD OF TEST _ :f.DISINFECTION:Type N ~Amount _.. ~g.W~ZONES (depth): :Top Bottom,_ ;Top Bottom,_ :Top Bottom,_ CITY:~e.W BeX\A--COUNTyC.C?\Vevt TOPOGRAPHIC I LAIj0 SETIING:(checkappropriatebox) OSlope OValle~J1flat oRidge o Other LATITUDE ~olQ't.{'f)~"OMS OR 3x.xxxxxxxxx DO LONGITUDE .,7/0 13,9<17 "OMS OR 7x.xxxxxxxxx DO Latitudellongitude source:i9(ps Dropographic map (location of well must be shown on a USGS tapa map andattached to this form if not using GPS):11.DRILLING LOG 5.FACILITY (Name of the business where the well is located.).Top Bottom 7US(4X:D'[6...\.L.wQ fdl -10...&-:1,__7#---1 _ Facility Name 0 Facility 10#(i~pplicable):1._7t.{oo 01($ttL'()V 10 t".)(,&f7 _---.'1 _ Street Address "7 ,{J?uJ BE'.>r\A./lJ(d-(f5hd.---'1--- City or Town State Zip Code 1 _-Pat 6'CO(W2~6{,,..---- Contiilft Name ~(]•Il -J.....-:1----dd/!LA7.YY/e.UYOWV1 e.IA)'rcy ai)/Ie/~/_----,',--_- ~~~~1I'::>CUdA6bovo 'biG ()..'L(O·)1====== City or Town State Zip Code (.3bb)'llfl./63ga. Area code Phone number 1.WELL CONTRACTOR: Well Contractor (Individual) Street Ad~s 'I'---::-,..--~::..t-=-r.:....;l{~'Vt.S:w.a...J,--"TI..•..(-14J<=.J,I.l.'HI...L'JLliAl"---LI\fC0<5?0 ~ City or Town State Zip Code (70(()J.?:;2 C)t9..13 Area code Phone number 2.WELL INFORMATION:.£ WELL CONSTRUCTION PERMIT#·--I,~':Lta~~_-._ OTHER ASSOCIATED PERMIT#(lf appllcable),..!.'¥....lI,,L/lJ;J4:.=._ SITE WELL 10 #(if apPlicable),_-,,(b__..•P_--<·g~_ 3,WELL USE (Check One Box)Monitoring 0 Municipal/Public 0 Industriai/Commercial9 Agricultural 0 Reco,!ery 0 Injection D IrrigationD Other ~list use)VOw+Ji)'C /ems PCb 'b~ DATE DRILLED a.-(J-I'd.I 4.WELL LOCATION: 6.WELL DETAILS:~?'a.TOTALDEPTH:,__~~~~__~__~__ NO~b,DOES WELL REPLACE EXISTING WELL?YES D c.WATER LEVEL Below Top of Casing:,JJ~ (Use "+"if Above Top of Casing), FT. Top Bottom,_ Top Bottom,_ Top Bottom,_ :7.CASING:Depth ,Diameter'._"1 •II~Torr:±3--Bottom_lX __Ft._tX~__ :Top Bottom Ft._ :Top Bottom Ft.,_ Thickness/ Weight Materialtf..h40 -tP--IC\II.!.....<..L-<__ :8,GROU.T:Depth I I M.at~eri.~AI,n Mvethod :TOP~Bottom~Ft.~=WY ?a,c...l.: ~TOP~Bottomi'6!tt.Be~'~iAIre.<;vc{)r :Top Bottom Ft._ :9.SCREEN:DePth~/'Diameter.I)I "1 '1:Top~Bottom Ft.~in, :Top Bottom Ft.__in. :Top Bottom Ft.__in, Slot Size Material,t)IOin.-Py(/ in._ in,_ :10.SAND/GRAVEL PACK: .'jl Depth J I Size :Top I (,Bottom"Ft.#/2 :Top Bottom Ft.._ :Top Bottom Ft._ ~aterial01f,(.(.., Formation Description ~l1f~1 ((ez; :12.REMARKS: :I DO HEREBY CERTIFY THAT THIS WELL WAS CONSTRUCTED IN ACCORDANCE WITH :15A NCAC 2C,WELL CONSTRUCTION STANDARDS,AND THAT A COPY OF THIS :RECORO HAS BEEN P:OVYWO THE WEL~OWNER:h.).t.~J'~~f)..J ~-1& :SIGNATURE OF CERTIFIED WELL CONTRACTOR DATE~Q /(f(!---YM-~"'~1e~v,----_ :PRINTED NAME OF PERSON CON~ING THE WELL Submit within 30 days of completion to:Division of Water Quality -Information Processing, 1617 Mail Service Center,Raleigh,NC 27699-161,Phone:(919)807-6300 Form GW-1bRev.2/09 Appendices Appendix I Solid Waste Section – Landfill Gas Monitoring Guidance Appendix II Landfill Gas Monitoring Data Form Appendix III Certification of Professional Geologist or Engineer Appendix I Solid Waste Section – Landfill Gas Monitoring Guidance 1 NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES DIVISION OF WASTE MANAGEMENT SOLID WASTE SECTION LANDFILL GAS MONITORING GUIDANCE NOVEMBER 2010 TABLE OF CONTENTS Section 1 – Introduction ………………………………………………………...............................Page 2 Section 2 – Factors Influencing Landfill Gas Generation and Migration …………………………Page 3 Section 3 - Current Solid Waste Section Rules Pertaining to Landfill Gas Monitoring ……….….Page 5 Section 4 – Landfill Gas Incidents and Explosions ………………………………………………..Page 9 Section 5 – Landfill Gas Monitoring Wells……………..………………………………………….Page 11 Section 6 – Landfill Gas Monitoring Instrumentation ……………………………………………..Page 14 Section 7 – References ……………………………………………………………………………..Page 17 Section 8 – Suggested Outline for a Landfill Gas Monitoring Plan ………………………………..Page 18 Section 9 – Checklist of Items to be Included in a Landfill Gas Monitoring Plan ………………....Page 19 2 SECTION 1 - Introduction 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 gases (LFG) (at C&D and other landfills) to ensure that landfill gas does not exceed the lower explosive limit (LEL) at the facility property boundary or 25 percent of the lower explosive limit in facility structures. If the concentration exceeds the specified limits, steps must be taken to ensure the protection of public health and a remediation plan must be implemented immediately. A landfill gas monitoring plan is necessary to ensure that these performance standards are met and this guidance document was developed to assist in establishing a standardized procedure for the monitoring of landfill gas. Background Organic matter in landfills begins to decompose almost immediately after being placed in a disposal site. Putrescible wastes such as food products and sewage sludges begin to break down by biological processes very rapidly whereas paper, cardboard or cellulose based materials are slower to decompose. However, when conditions become favorable, most organic matter will decompose. The decomposition process typically goes through several stages that depend on conditions such as pH, temperature, and moisture content. The final stage results in the production of methane and although the rate of production may vary, most landfills produce methane. Landfill Gas Generation Landfill gas is a natural by-product of the anaerobic decomposition of organic waste in a landfill. The composition, quantity and rate of landfill gas generation are dependent on the types of waste that are decomposing and the level of microbial activity within the wastes. The decomposition of biodegradable waste begins with aerobic decomposition which lasts until the oxygen in the landfill is depleted. The anaerobic phase then begins, resulting in landfill gas production. There are four stages of landfill gas composition: the first stage is characterized by elevated nitrogen levels and occurs when the landfill is new. The second stage is characterized by elevated carbon dioxide levels and occurs for a relatively short period of time after the initial stage is complete. The third and fourth stages are characterized by elevated methane concentrations and represent the active life of a landfill and the post-closure time frame. Landfill gas is generally composed of 50-55% methane (CH4); 45-50% carbon dioxide (CO2); less than 5% nitrogen (N2); and less than 1% non-methane organic compounds. These individual gases generally remain co-mingled and do not naturally separate. The Solid Waste Section (SWS) Rules typically focus on methane (CH4) and its explosive properties due to public safety issues. Hydrogen sulfide (H2S) is also of particular concern in landfills and is typically recognized by its rotten egg odor. H2S is immediately dangerous to life and health at concentrations of 100 parts per million (ppm). Landfill Gas Migration The production of landfill gas creates a positive pressure within the landfill that forces the gas to migrate. Landfill gas migrates from place to place by diffusion and pressure gradient and will follow the path of least resistance. Subsurface gas typically migrates above the groundwater table and is restricted laterally by streams. Porous soils lying above the bedrock can serve as pathways to transmit large volumes of gas. Underground off-site migration is common and can be facilitated by the presence of pipelines, buried utility corridors or trenches located within or adjacent to the landfill boundaries. Movement depends on soil type and moisture, and migration distances of 1,500 feet have been observed. Barometric pressure also influences movement. Falling barometric pressure allows methane to migrate out of the landfill and into surrounding areas. 3 SECTION 2 - Factors Influencing Landfill Gas Generation and Migration Factors that affect landfill gas generation and migration through the subsurface include the following: Waste Composition The production of landfill gas is directly related to the amount of organic matter present in waste. The bacteria that break down the waste require small amounts of specific minerals such as calcium, potassium, magnesium and other micronutrients. Bacteria are able to thrive and produce landfill gas if the minerals/micronutrients are present. If the minerals/micronutrients are not present or if substances that inhibit bacterial growth exist, landfill gas production will occur at a reduced rate. Some forms of organic matter such as cellulose break down quickly whereas matter such as lignin breaks down more slowly. The rate at which landfill gas is produced depends on the proportions of each type of organic matter present in the waste. Moisture Content Landfills with higher moisture content generate higher concentrations of landfill gas in earlier stages of development (such as during leachate recirculation). Moisture accelerates the methanogenic process. Temperature Landfill bacteria are temperature dependant. They are able to survive and function below the freezing point, but they also function well at temperatures up to 65°C. Anaerobic bacteria produce small amounts of heat and may not be able to maintain the temperature of a shallow landfill when external temperatures decrease, so LFG generation may exhibit seasonal variations. Saturated landfills may not achieve ideal temperatures because the bacteria do not generate sufficient heat to raise the temperature of the excess water. Higher temperatures promote volatilization and chemical reactions with the waste so the trace gas component of landfill gas tends to increase with higher landfill temperatures. Age of Landfill Typically, landfills have an increasing generation of landfill gas for a number of years until closure at which time landfill gas generation reaches a peak and begins to subside. An evaluation of the age of the landfill and use of a landfill gas generation curve can be helpful in determining the likelihood of significant landfill gas concentrations from the landfill. Landfill Cap The type or presence of landfill cover can influence landfill gas generation and migration. Although a low permeability cap will reduce moisture and landfill gas generation over the longer term, initially, the installation of a landfill cap could drive landfill gas migration further from the landfill in the subsurface without proper ventilation (either passive or active). This is especially true in the case of unlined (unvented) landfills. Water Table Landfill gas movement in unlined landfills may be influenced by groundwater table variations. A rising water table could cause displacement and force upward movement of landfill gas. 4 Man-made and Natural Conduits Structures such as drains, trenches, and buried utility corridors can act as conduits for landfill gas migration. Geologic features including fractured bedrock, porous soil, and permeable strata also provide conduits for landfill gas migration Landfill Liner Conditions The presence of a Subtitle-D (or equivalent) landfill liner has the capability to limit the lateral migration of landfill gas in the subsurface. Unlined landfills have no barrier to prevent lateral landfill gas migration in the subsurface. Weather Conditions Barometric pressure and precipitation have significant effects on landfill gas migration. Increased barometric pressure yields decreased landfill gas venting from the subsurface, until the pressure within the subsurface is greater than the atmospheric (barometric) pressure. Conversely, as the barometric pressure decreases, the landfill will vent the stored gas until pressure equilibrium is reached. Capping of a landfill can influence the effect of barometric pressure on landfill gas migration. Generally, a more permeable landfill cap will allow greater influence by barometric pressure than a less permeable landfill cap. 5 SECTION 3 – Current Solid Waste Section Rules Pertaining to Landfill Gas Monitoring Web link to the 15A NCAC 13B rules - http://portal.ncdenr.org/web/wm/sw/rules 15A NCAC 13B .0101- DEFINITIONS .0101 (14) "Explosive gas" means Methane (CH4) .0101(25) "Lower explosive limit" (LEL) means the lowest percent by volume of a mixture of explosive gases which will propagate a flame in air at 25 degrees Celsius and atmospheric pressure. .0503 - SITING AND DESIGN REQUIREMENTS FOR DISPOSAL FACILITIES .0503(2) A site shall meet the following design requirements: (a) The concentration of explosive gases generated by the site shall not exceed: (i) twenty-five percent of the limit for the gases in site structures (excluding gas control or recovery system components); and (ii) the lower explosive limit for the gases at the property boundary; .0543 - CLOSURE AND POST-CLOSURE REQUIREMENTS FOR C&DLF FACILITIES .0543(e) Post-closure criteria. (1) Following closure of each C&DLF unit, the owner and operator must conduct post-closure care. Postclosure care must be conducted for 30 years, except as provided under Subparagraph (2) of this Paragraph, and consist of at least the following: (C) maintaining and operating the gas monitoring system in accordance with the requirements of Rule .0544 of this Section; and (2) The length of the post-closure care period may be: (A) decreased by the Division if the owner or operator demonstrates that the reduced period is sufficient to protect human health and the environment and this demonstration is approved by the Division; or (B) increased by the Division if the Division determines that the lengthened period is necessary to protect human health and the environment. .0544 - MONITORING PLANS AND REQUIREMENTS FOR C&DLF FACILITIES .0544(d) Gas Control Plan (1) Owners and operators of all C&DLF units must ensure that: (A) the concentration of methane gas or other explosive gases generated by the facility does not exceed 25 percent of the lower explosive limit in on-site facility structures (excluding gas control or recovery system components); (B) the concentration of methane gas or other explosive gases does not exceed the lower explosive limit for methane or other explosive gases at the facility property boundary; and (C) the facility does not release methane gas or other explosive gases in any concentration that can be detected in offsite structures. (2) Owners and operators of all C&DLF units must implement a routine methane monitoring program to ensure that the standards of this Paragraph are met. (A) The type of monitoring must be determined based on soil conditions, the Hydrogeologic conditions under and surrounding the facility, hydraulic conditions on and surrounding the facility, the location of facility structures and property boundaries, and the location of all offsite structures adjacent to property boundaries. 6 (B) The frequency of monitoring shall be quarterly or as approved by the Division. (3) If methane or explosive gas levels exceeding the limits specified in Subparagraph (d)(1) of this Rule are detected, the owner and operator must: (A) immediately take all steps necessary to ensure protection of human health and notify the Division; (B) within seven days of detection, place in the operating record the methane or explosive gas levels detected and a description of the steps taken to protect human health; and (C) within 60 days of detection, implement a remediation plan for the methane or explosive gas releases, place a copy of the plan in the operating record, and notify the Division that the plan has been implemented. The plan must describe the nature and extent of the problem and the proposed remedy. (4) Based on the need for an extension demonstrated by the operator, the Division may establish alternative schedules for demonstrating compliance with Parts (3)(B) and (3)(C) of this Paragraph. (5) For purposes of this Item, "lower explosive limit" means the lowest percent by volume of a mixture of explosive gases in air that will propagate a flame at 25 C and atmospheric pressure. .0566 - OPERATIONAL REQUIREMENTS FOR LAND CLEARING/INERT DEBRIS (LCID) LANDFILLS .0566(13) The concentration of explosive gases generated by the facility shall not exceed: (a) Twenty-five percent of the lower explosive limit for the gases in facility structures. (b) The lower explosive limit for the gases at the property boundary. .1626 – OPERATIONAL REQUIREMENTS FOR MSWLF FACILITIES .1626(4) Explosive gases control. (a) Owners or operators of all MSWLF units must ensure that: (i) The concentration of methane gas generated by the facility does not exceed 25 percent of the lower explosive limit for methane in facility structures (excluding gas control or recovery system components); and (ii) The concentration of methane gas does not exceed the lower explosive limit for methane at the facility property boundary. (b) Owners or operators of all MSWLF units must implement a routine methane monitoring program to ensure that the standards of (4)(a) are met. A permanent monitoring system shall be constructed on or before October 9, 1994. A temporary monitoring system shall be used prior to construction of the permanent system. (i) The type and frequency of monitoring must be determined based on the following factors: (A) Soil conditions; (B) The hydrogeologic conditions surrounding the facility; (C) The hydraulic conditions surrounding the facility; and (D) The location of facility structures and property boundaries. (ii) The minimum frequency of monitoring shall be quarterly. (c) If methane gas levels exceeding the limits specified in (4)(a) are detected, the owner or operator must: (i) Immediately take all necessary steps to ensure protection of human health and notify the Division; (ii) Within seven days of detection, place in the operating record the methane gas levels detected and a description of the steps taken to protect human health; and (iii) Within 60 days of detection, implement a remediation plan for the methane gas releases, place a copy of the plan in the operating record, and notify the Division that the 7 plan has been implemented. The plan shall describe the nature and extent of the problem and the proposed remedy. (iv) Based on the need for an extension demonstrated by the operator, the Division may establish alternative schedules for demonstrating compliance with (4)(c)(ii) and (iii) of this Rule. (d) For purposes of this Item, "lower explosive limit" means the lowest percent by volume of a mixture of explosive gases in air that will propagate a flame at 25°C and atmospheric pressure. .1626(10) Recordkeeping requirements. (a) The owner or operator of a MSWLF unit must record and retain at the facility, or an alternative location near the facility approved by the Division, in an operating record the following information as it becomes available: (iii) Gas monitoring results and any remediation plans required by Item (4) of this Rule; .1627 – CLOSURE AND POST CLOSURE REQUIREMENTS FOR MSWLF ACTIVITES .1627(d) Post-Closure Criteria (1) Following closure of each MSWLF unit, the owner or operator shall conduct post-closure care. Post-closure care shall be conducted for 30 years, except as provided under Subparagraph (2) of this Paragraph, and consist of at least the following: (D)-Maintaining and operating the gas monitoring system in accordance with the requirements of Rule .1626 of this Section. (2) The length of the post-closure care period may be: (A) Decreased by the Division if the owner or operator demonstrates that the reduced period is sufficient to protect human health and the environment and this demonstration is approved by the Division; or (B) Increased by the Division if the Division determines that the lengthened period is necessary to protect human health and the environment. (3) Following completion of the post-closure care period for each MSWLF unit, the owner or operator shall notify the Division that a certification, signed by a registered professional engineer, verifying that post-closure care has been completed in accordance with the post-closure plan, has been placed in the operating record. NOTES: Based on the referenced rules above, the following words / phrases are presently in the Solid Waste Section rules pertaining to methane and explosive landfill gas. Rule .0101(14) states: “Explosive gas means Methane (CH)”. Rule .0503 (2)(a) refers to “explosive gases”. Rule .0544(d) refers to “Gas Control Plan” Rule .0544(d)(1) refers to “methane or other explosive gases”. Rule .0544(d)(2) refers to “methane monitoring program” Rule .0544(d)(3) refers to “methane or explosive gas levels” Rule .0566 (13) refers to “explosive gases”. Rule .1626 (4) refers to “explosive gases control” Rule .1626(4)(a-b) refers to “methane monitoring” and “methane monitoring program”. 8 Monitoring Goals Landfill design and landfill gas monitoring regulations in North Carolina require that there not be an exceedance of 100% of the Lower Explosion Limit (LEL) (equivalent to 5% methane) at the property boundary, or 25% LEL in on-site structures. These regulations were developed over time to protect the health and safety of the citizens of North Carolina and the U.S. from the asphyxiation and explosive hazards of landfill gas. NC Rule History A review of NC landfill guidance documents and regulations from 1972 to the present indicates that from 1972 through 1982, there was no mention of design requirements regarding the control of landfill gas, nor were there any landfill monitoring requirements for landfill gas. In 1982, the regulations were changed to require that sanitary landfill design prevent landfill gas concentrations of 100% LEL at the property boundary line and 25% inside on-site structures. Although a design requirement was added, no design requirement was established to determine if the design requirement was being met. In 1993 with the establishment of .1600 rules, requirements for designs to limit landfill gas levels to below 100% at the property boundary line and 25% in on-site structures and monitoring of landfill gas concentrations around the perimeter of the landfill and inside on-site structures were adopted. 9 SECTION 4 – Landfill Gas Incidents and Explosions Hazards Involving Landfill Gas Landfill fires may or may not be directly caused by landfill gas. The primary concern with these fires is air contamination from the resulting smoke; however they also present a variety of additional problems. In addition to concerns with containing and extinguishing landfill fires, potential reactions involving unknown chemicals in the landfill can cause uncertain hazards. Discarded consumer products in a landfill, such as pesticides, paints, solvents, cleaners, and other material can be the source of chemical releases. Heat from the fire can cause chemicals to volatilize, breakdown, and enter the environment. Also to be considered is the presence of other combustible gases in addition to methane. Whenever an environmental investigation of a landfill is prompted by odorous compounds or explosive gases, the presence of toxic substances should also be investigated. One example is hydrogen sulfide (H2S) that can cause asphyxiation and is flammable. An analysis should include alkyl benzenes, sulfur compounds, vinyl chloride, and methane, and other products associated with industrial wastes, construction and debris waste, and normal organic and inorganic waste. Fires and explosion hazards become a concern when gases collect in confined spaces. Buildings, basements, and pits are typically regarded as confined spaces. However, landfill gases also collect in and migrate to cracks in the landfill cover, leachate “springs”, cracks in adjacent structures, paved parking areas, etc. Fires can occur on the surface and underground. Surface fires involve recently buried waste near the surface in an aerobic decomposing layer, typically 1 to 4 feet below ground. These fires can be intensified by subsurface landfill gas and spread throughout the landfill. Subsurface fires occur deeper within the landfill, involve material buried for months or years, and can burn for days and months. The following is a brief summary of some incidents involving landfill gas migration from landfills: 2007 Four employees died as a result of exposure to high concentrations of hydrogen sulfide while attempting to repair a leachate pump at a C&D landfill in Superior, Wisconsin (Journal of Environmental Heath 2008). 1999 An 8-year old girl was burned on her arms and legs when playing in an Atlanta, Georgia playground. The area was reportedly used as an illegal dumping ground many years ago (Atlanta Journal-Constitution 1999). 1994 While playing soccer in a park built over an old landfill in Charlotte, North Carolina, a woman was seriously burned by a methane explosion (Charlotte Observer 1994). 1987 Offsite landfill gas migration is suspected to have caused a house to explode in Pittsburgh, Pennsylvania (EPA 1991). 1984 Landfill gas migrated to and destroyed one house near a landfill in Akron, Ohio. Ten houses were temporarily evacuated (EPA 1991). 1983 An explosion destroyed a residence across the street from a landfill in Cincinnati, Ohio. Minor injuries were reported (EPA 1991). 1975 In Sheridan, Colorado, landfill gas accumulated in a storm drain pipe that ran through a landfill. An explosion occurred when several children playing in the pipe lit a candle, resulting in serious injury. 10 1969 Methane gas migrated from an adjacent landfill into the basement of an armory in Winston-Salem, North Carolina. A lit cigarette caused the gas to explode, killing three men and seriously injuring five others (USACE 1984). 11 SECTION 5 - Landfill Gas Monitoring Wells Locations Landfill gas monitoring well locations will be site specific depending upon site geology, depth to groundwater, surface water features, on-site and off-site structures and sensitive receptors. The landfill gas monitoring wells must be spaced no more than 500 feet apart depending upon site specifics. A readily accessible, unobstructed path must be maintained so that landfill gas monitoring wells are always accessible using four-wheel drive vehicles. Regardless of site specifics, the permittee must obtain approval from the Solid Waste Section for the design and installation of any landfill gas monitoring well system. Well Construction and Installation Landfill gas monitoring wells are the same as groundwater monitoring wells with two exceptions. Landfill gas monitoring wells are installed just above the water table within the unsaturated zone and are equipped with a stopcock valve or a quick connect coupling on the cap, which allows for accurate landfill gas measurements. The stopcock valve must be equipped with flexible tubing and a barb connection that will fit the gas meter’s inlet tube. The stopcock valve or a quick connect coupling must be closed between monitoring events. The landfill gas monitoring well must also be capped, locked, and labeled with a permanently affixed identification plate stating the well contractor name and certification number, date of well competition, total depth of well, screen length and well ID number. See detailed schematics of a landfill gas monitoring well (Figure 1). The depth of each landfill gas monitoring well will be site specific depending upon depth to groundwater. Landfill gas monitoring wells must be constructed the same as groundwater monitoring wells as described in 15A NCAC Subchapter 2C. Typically landfill gas monitoring wells must be installed using 2” PVC piping and screen. The screen length, also site specific, must span the majority of the unsaturated zone while still allowing for proper well construction. A North Carolina Professional Geologist or Professional Engineer must be present to supervise the installation of all landfill gas monitoring wells. The exact locations, screened intervals, and nesting of the wells must be approved by the Solid Waste Section Hydrogeologist prior to landfill gas monitoring well installation. Each landfill gas monitoring well must be surveyed for location and elevation by a North Carolina Registered Land Surveyor. Within thirty (30) days of the completed construction of each new landfill gas monitoring well, the boring log and a diagram of each well including, but not limited to total depth, screened interval and distance above seasonal high water table must be submitted to the Solid Waste Section. The submittal must also include a scaled topographic map showing the location and identification of new, existing and abandoned landfill gas monitoring wells. Nested and Clustered Landfill Gas Monitoring Wells Nested and/or clustered landfill gas monitoring wells may be required in unsaturated zones of 45 feet or more to measure specific depths of the unsaturated zone. Initially, the installation of one long screen shall be sufficient. If a monitoring event shows an exceedance of the lower explosive limit, then the Solid Waste Section may require the installation of nested and/or clustered landfill gas monitoring wells. Abandonment of Wells An abandonment record must be submitted to the Solid Waste Section within 30 (thirty) days of the abandonment of a landfill gas monitoring well. The landfill gas monitoring well(s) must be overdrilled and sealed with grout in accordance with 15A NCAC 2C .0113(d) and certified by a North Carolina Professional Geologist or Professional Engineer. 12 Professional Certification The certification statement below must be signed and sealed by a North Carolina Professional Geologist or Professional Engineer and submitted with the Landfill Gas Monitoring Plan. The landfill gas monitoring plan for this facility has been prepared by a qualified geologist or engineer who is licensed to practice in the State of North Carolina. The plan has been prepared based on first-hand knowledge of site conditions and familiarity with North Carolina solid waste rules and industry standard protocol. This certification is made in accordance with North Carolina Solid Waste Regulations, indicating this Landfill Gas Monitoring Plan should provide early detection of any release of hazardous constituents to the uppermost aquifer, so as to be protective of public health and the environment. No other warranties, expressed or implied, are made. Signed _______________________________ Printed _______________________________ Date _________________________________ Not valid unless this document bears the seal of the above mentioned licensed professional. In addition, the boring logs and/or well diagram must be signed and sealed with the stamp of a North Carolina Registered Land Surveyor. 13 Figure 1 – Landfill Gas Monitoring Well Detail 14 SECTION 6 – Landfill Gas Monitoring Instrumentation The person using the landfill gas monitoring instrument must understand the principles of operation and follow the manufacturer's instructions. This includes calibrating the instrument according to the manufacturer’s specifications. Include the following on the top portion of the landfill gas monitoring form (See example below) : facility name, permit number, type and serial number of gas monitoring instrument, calibration date of the instrument, date and time of field calibration, type of gas used for field calibration (15/15 or 35/50), expiration date of field calibration gas canister, date of landfill gas monitoring event, name and position of sample collector, pump rate of instrument being used, ambient air temperature, and general weather conditions. Verification that the equipment was calibrated in accordance with the manufacturer’s specifications is also required. When determining which field calibration gas to use, take into consideration the expected levels of methane in the landfill gas monitoring wells. If the methane levels are expected to be low, use the 15/15 gas canister (15% CO2/15% CH4). If the methane levels are expected to be high, use the 35/50 gas canister (35% CO2/50% CH4). For every landfill gas monitoring well, please include the following: verification of sample tube purge prior to each sample taken (should be one minute), the time pumped in seconds (should be at least one minute), barometric pressure, time stabilized reading collected, percent lower explosive limit, percent methane by volume, percent oxygen, percent carbon dioxide, and any observations or comments. The landfill gas monitoring data form (See example below) and results should be retained in the facility’s operating record unless an exceedance has occurred and/or is requested by the Solid Waste Section. Landfill gas monitoring readings from non-calibrated or inaccurately calibrated instruments are not reliable, and will therefore be rejected by the Solid Waste Section. Landfill gas monitoring readings collected with monitoring equipment that was not designed for landfill gas monitoring will also be rejected by the Solid Waste Section. There are several different landfill gas monitoring instruments on the market which may be used in order to obtain all of the information required by the Solid Waste Section. Monitoring Times Monitoring times are also important when conducting landfill gas monitoring. Proper landfill gas monitoring should include sampling during times when landfill gas is most likely to migrate. Landfill gas can migrate and accumulate not only in landfill gas monitoring wells; it can also migrate and accumulate in buildings and other structures. Because subsurface gas pressures are considered to be at a maximum during the afternoon hours, monitoring should be conducted in the afternoon or whenever the barometric pressure is low. Scientific evidence also indicates that weather and soil conditions influence the migration of landfill gas. Barometric pressure and precipitation have significant effects on landfill gas migration. Increased barometric pressure generates decreased landfill gas venting from the subsurface, until the pressure within the subsurface is greater than the atmospheric (barometric) pressure. On the other hand, when the barometric pressure decreases, the landfill will vent the stored gas until a pressure equilibrium is reached. Capping of a landfill can influence the effect of barometric pressure on landfill gas migration. Generally, a more permeable landfill cap will allow greater influence by barometric pressure than a less permeable landfill cap. As a result, landfill gas monitoring should be conducted when the barometric pressure is low and soils are saturated. During the winter season when snow cover is just beginning to melt or when the ground is frozen or ice covered, landfill gas monitoring should be conducted when the barometric pressure is low. 15 Landfill Gas Sampling Procedures Any accumulation of landfill gas in the landfill gas monitoring wells is the result of landfill gas migration. The following procedure is a recommended example for conducting landfill gas monitoring well sampling, but always read and follow the manufacturer’s instructions because each instrument will be different. Step 1 – Calibrate the instrument according to the manufacturer’s specifications. In addition, prepare the instrument for monitoring by allowing it to properly warm up as directed by the manufacturer. Make sure the static pressure shows a reading of zero on the instrument prior to taking the first sample. Step 2 – Purge sample tube for at least one minute prior to taking reading. Connect the instrument tubing to the landfill gas monitoring well cap fitted with a stopcock valve or quick connect coupling. Step 3 – Open the valve and record the initial reading and then the stabilized reading. A stable reading is one that does not vary more than 0.5 percent by volume on the instrument’s scale. Step 4 - Record the stabilized reading including the oxygen concentration and barometric pressure. A proper reading should have two percent oxygen by volume or less. If levels of oxygen are higher, it may indicate that air is being drawn into the system giving a false reading. Step 5 – Turn the stopcock valve to the off position and disconnect the tubing. Step 6 – Proceed to the next landfill gas monitoring well and repeat Steps 2 – 5. Landfill Gas Constituent Sampling and Analysis Sampling of landfill gas to determine volume percentages/concentrations of each constituent can be accomplished through the use of canisters which are specifically designed for landfill gas analysis. Several analytical methods are available to determine the concentrations of a variety of constituents. Typically, landfill gas analysis of this type is performed to determine the non-methane organic compounds emission rate for Tier 2 testing under the Clean Air Act (Title V Subpart WWW 60.754). Isotropic identification of landfill methane can be accomplished to identify one source of methane from another. In this case, isotopes of carbon and hydrogen in the methane are analyzed to determine the methane source. 16 NC Division of Waste Management - Solid Waste Section Landfill Gas Monitoring Data Form Notice: This form and any information attached to it are "Public Records" as defined in NC General Statute 132-1. As such, these documents are available for inspection and examination by any person upon request (NC General Statute 132-6). Facility Name: ______________________________________________ Permit Number: ____________________________ Date of Sampling: ___________________ NC Landfill Rule (.0500 or .1600): _____________________________________ Name and Position of Sample Collector: _________________________________________ Type and Serial Number of Gas Meter: _______________________________ Calibration Date of Gas Meter: ___________ Date and Time of Field Calibration: _____________________ Type of Field Calibration Gas (15/15 or 35/50): ____________ Expiration Date of Field Calibration Gas Canister: ________ Pump Rate of Gas Meter: _____________ Ambient Air Temperature: __________ Barometric Pressure: ______________ General Weather Conditions: _____________ Instructions: Under “Location or LFG Well” identify the monitoring wells or describe the location for other tests (e.g., inside buildings). A drawing showing the location of test must be attached. Report methane readings in both % LEL and % methane by volume. A reading in percent methane by volume can be converted to % LEL as follows: % methane by volume = % LEL/20 If your facility has more gas monitoring locations than there is room on this form, please attach additional sheets listing the same information as contained on this form. Certification To the best of my knowledge, the information reported and statements made on this data submittal and attachments are true and correct. I am aware that there are significant penalties for making any false statement, representation, or certification including the possibility of a fine and imprisonment. _________________________________________ _________________________________________ SIGNATURE TITLE 17 SECTION 7 - References Agency for Toxic Substances & Disease Registry. “Landfill Gas Primer- An Overview for Environmental Health Professionals. 2001.” http://www.atsdr.cdc.gov/HAC/landfill/html/toc.html (accessed February 24. 2010). California Environmental Protection Agency. “Landfill Gas Monitoring Well Functionality at 20 California Landfills, 2008”. http://www.calrecycle.ca.gov/Publications/Organics/2008022.pdf (accessed February 24 2010). Florida Department of Environmental Protection. Gas Management Systems, under Rule 62-701.530. http://www.dep.state.fl.us/waste/quick_topics/rules/default.htm (accessed February 24, 2010). Missouri Department of Natural Resources, Flood Grant Team. “An Analysis of Landfill Gas Monitoring Well Design and Construction, 2007”. http://www.clu- in.org/conf/itrc/directpush/prez/Missouri_Study.pdf (accessed February 24, 2010). Missouri Department of Natural Resources. “Design and Construction of Landfill Gas Monitoring Wells”. http://www.dnr.missouri.gov/pubs/pub2054.pdf (accessed February 24. 2010). Wisconsin Department of Natural Resources. Environmental Monitoring for Landfills, under Chapter NR 507.22. http://www.dnr.state.wi.us/org/aw/wm/information/wiacsss.htm (accessed February 24, 2010). “Landfill Gas-an Overview” Landfill-gas.com. Web, 22, Feb. 2010 http://www.landfill-gas.com/webpage -LFG-overview.doc 18 SECTION 8 – Suggested Outline for a Landfill Gas Monitoring Plan 1. Introduction 1.1. Background (project overview, site observations, NCDENR rules referenced) 1.2. Site Geology with discussion of groundwater depth and flow (potentiometric surface map) 1.3. Regulatory Limits 2. Landfill Gas Monitoring 2.1. Landfill Gas Monitoring Well Locations (discussion of reasoning behind proposed locations, discussion of well construction, reference map showing proposed locations, reference table displaying well ID, well depth, screen interval and depth to groundwater) 2.2. Structure and Ambient Sampling 2.3. Landfill Gas Monitoring Frequency 3. Landfill Gas Sampling Procedures 3.1. Detection Equipment Used (discussion of calibration procedures) 3.2. Landfill Gas Sampling Procedure 4. Record Keeping and Reporting 4.1. Landfill Gas Monitoring Data Form 4.2. Sampling Reports 4.3. Permanent Record Keeping 5. Contingency Plan 6. Certification of Professional Geologist or Professional Engineer 7. Certification of Registered Land Surveyor Figures Map displaying proposed landfill gas monitoring well locations Potentiometric Surface Map Diagram showing construction of stopcock valve or quick connect coupling on well cap Diagram showing well construction of each landfill gas monitoring well Table Table displaying well ID, well depth, screen interval, depth to groundwater Example of landfill gas monitoring data form 19 SECTION 9 – Checklist of Items to be Included in a Landfill Gas Monitoring Plan 1. Depth to groundwater discussion 2. Well locations a. Number of wells b. Well spacing 3. Instrumentation being used a. Calibration procedures 4. Sampling procedures as per the manufacture’s instructions 5. Map of well locations 6. Table describing each well location a. Well ID b. Well depth c. Screen interval d. Depth to groundwater e. Subsurface lithology 7. Diagram of cap construction w/ stopcock valve or quick connect coupling 8. Diagram of well construction 9. Potentiometric surface map 10. Professional Geologist or Professional Engineer certification 11. Registered Land Surveyor certification Appendix II Landfill Gas Monitoring Data Form Landfill Gas Monitoring Data Form Coastal Regional Solid Waste Management Authority Permit Number(s): 25-04 & 25-09 CRSWMA Tuscarora Landfill Date of Sampling: NC LF Rule: .1624 Sampled by: Instrument(s): Mfg. Calibration Date: 05-20-2015 Field Calibration (Date & Time): Calibration Gas: 15% CH4/ 15% CO2 , Exp. Date: Weather: Barometer: Location Static Press. %LEL CH4 ID In.-Wc. % % GP-06 60 GP-07 60 GP-08 60 BHP-1 15 na BHP-2 15 na BHP-3 15 na BHP-4 15 na BHP-5 15 na BHP-6 15 na BHP-7 15 na BHP-8 15 na BHP-9 15 na BHP-10 15 na BHP-11 15 na BHP-12 15 na BHP-13 15 na BHP-14 15 na BHP-15 15 na Compost Shed contin. na Maint. Building contin. na Maint. Shed contin. na Certification: Purged before sample?Time Time Pumped (sec.) Notes Offices & Scalehouse contin. na Landfill Gas Monitoring Data Form Coastal Regional Solid Waste Management Authority - Landfill Permit Number(s): 25-04 & 25-09 Date of Sampling: 05-12-2015 NC LF Rule: .1600 Sampled by: Dan Girdner/Gretta Eller- JOYCE Engineering Landtec G.E.M. 2000, Serial No. 5194 Mfg. Calibration Date: 11-13-2014 Field Calibration: 05-12-2015 13:45 Weather: Mostly Sunny, temperatures in the 80's, Barometer 30.01. Inches of Hg Location Static Press. %LEL CH4 ID In.‐Wc. % % GMP‐02 Y 14:02 60 0.11 0 0 GMP‐03 Y 13:58 60 0.03 0 0 GMP‐04 Y 13:54 60 0.00 0 0 GMP‐05 Y 13:48 60 ‐0.65 188 9.4 not a boundary probe GMP‐05A Y 15:50 20 na 0 0 Barhole 20 ft South, 2.5ft depth GMP‐05B Y 15:51 20 na 0 0 Barhole 20 ft West, 2.5ft depth GMP‐06 Y 15:15 60 0.10 0 0 GMP‐07 Y 15:11 60 0.07 0 0 GMP‐08 Y 14:08 60 0.04 0 0 ManHole‐1 Y 15:21 60 na 0 0 ManHole‐2 Y 14:03 60 na 0 0 ManHole‐3 Y 15:07 60 na 0 0 BHP‐1 Y 14:13 15 na 0 0 BHP‐2 Y 14:18 15 na 0 0 BHP‐3 Y 14:21 15 na 0 0 BHP‐4 Y 14:24 15 na 0 0 BHP‐5 Y 14:27 15 na 0 0 BHP‐5A Y 13:50 15 na 0 0 BHP‐6 Y 14:33 15 na 0 0 BHP‐7 Y 14:37 15 na 0 0 BHP‐8 Y 14:41 15 na 0 0 BHP‐9 Y 14:45 15 na 0 0 BHP‐10 Y 14:48 15 na 0 0 BHP‐11 Y 14:50 15 na 0 0 BHP‐12 Y 14:53 15 na 0 0 BHP‐13 Y 0:00 ‐‐‐‐WET‐ Not measured BHP‐14 Y 14:56 15 na 12 0.6 BHP‐15 Y 15:00 15 na 16 0.8 Compost MH Y 15:30 45 na 0 0 manhole near composting Maint. Building Y 15:40 contin. na 0 0 Shed Y 15:45 contin. na 0 0 Offices Y 15:50 contin. na 0 0 Scale house Y 15:55 contin. na 0 0 Certification: Purged before sample?Time Time Pumped (sec.) Notes Calibration Gas 15% CH4/ 15% CO2 , Exp. 09-16 Landfill Gas Monitoring Data Form Coastal Regional Solid Waste Management Authority - Landfill Permit Number(s): 25-04 & 25-09 Date of Sampling: 08-06-2015 NC LF Rule: .1600 Sampled by: Dan Girdner- JOYCE Engineering Landtec G.E.M. 2000, Serial No. 5194 Mfg. Calibration Date: 05-20-2015 Field Calibration: 08-06-2015 13:45 Calibration Gas 15% CH4/ 15% CO2 , Exp. 09-16 Weather: Mostly cloudy, 90° F; Barometer 20.90 In-Hg Location Static Press. %LEL CH4 ID In.‐Wc. % % GMP‐02 Y 15:21 60 0.00 0 0 GMP‐03 Y 15:19 60 0.00 0 0 GMP‐04 Y 15:14 60 0.01 0 0 GMP‐05 Y 15:07 60 0.00 114 5.7 not a boundary probe GMP‐05A Y 15:09 20 na 0 0 Barhole 20 ft South, 3 ft depth GMP‐05B Y 15:10 20 na 0 0 Barhole 20 ft West, 2.8ft depth GMP‐06 Y 14:22 60 0.00 0 0 GMP‐07 Y 14:25 60 ‐0.02 0 0 GMP‐08 Y 15:02 60 ‐0.02 0 0 Boundary Probe ManHole‐1 Y 15:06 60 na 0 0 ManHole‐2 Y 15:22 60 na 0 0 ManHole‐3 Y 14:27 60 na 2 0.1 BHP‐1 Y 14:59 15 na 0 0 BHP‐2 Y 14:57 15 na 0 0 BHP‐3 Y 14:55 15 na 0 0 BHP‐4 Y 14:53 15 na 0 0 BHP‐5 Y 14:51 15 na 0 0 BHP‐6 Y 14:49 15 na 0 0 BHP‐7 Y 14:47 15 na 0 0 BHP‐8 Y 14:45 15 na 0 0 BHP‐9 Y 14:43 15 na 0 0 BHP‐10 Y 14:41 15 na 0 0 BHP‐11 Y 14:39 15 na 0 0 BHP‐12 Y 14:37 15 na 0 0 BHP‐13 ‐14:35 16 na 0 0 BHP‐14 Y 14:33 15 na 2 0.1 BHP‐15 Y 14:30 15 na 2 0.1 Compost MH Y 14:16 45 na 2 0.1 manhole near composting Maint. Building Y 14:05 contin. na 0 0 Shed Y 14:08 contin. na 0 0 Offices Y 13:55 contin. na 0 0 Scale house Y 13:57 contin. na 0 0 Certification: Purged before sample?Time Time Pumped (sec.) Notes Appendix III Certification of Professional Geologist or Engineer Certification of Professional Geologist or Engineer The landfill gas monitoring plan for this facility has been prepared by a qualified geologist or engineer who is licensed to practice in the State of North Carolina. The plan has been prepared based on first-hand knowledge of site conditions and familiarity with North Carolina solid waste rules and industry standard protocol. This certification is made in accordance with North Carolina Solid Waste regulations, indication this landfill gas monitoring plan should provide early detection of landfill gas migration, so as to be protective of public health and the environment. No other warranties, expressed or implied, are made. Signed Printed Dated