OAR 340-239-0800: Test Methods and Procedures

When required as provided in OAR 340-239-0100 through 340-239-0700, the owner or operator of a landfill must comply with the test methods and procedures for monitoring and measurements in this rule. (1) Hydrocarbon Detector Specifications. Any instrument used for the measurement of methane must be a gas detector, or other equivalent instrument approved by DEQ, that meets the calibration, specifications, and performance criteria of EPA Reference Method 21, Determination of Volatile Organic Compound Leaks, 40 C.F.R. Part 60, Appendix A, except that those rules shall be applied with the following adjustments: (a) “Methane” replaces all references to volatile organic compounds (VOC); (b) The calibration gas shall be methane, diluted to a nominal concentration of 500 parts per million in air; (c) To meet the performance evaluation requirements in section 8.1 of Method 21 of 40 C.F.R. Part 60, Appendix A, the instrument evaluation procedures of section 8.1 of Method 21 of 40 C.F.R. Part 60, Appendix A must be used; and (d) The calibration procedures provided in sections 8 and 10 of Method 21 of 40 C.F.R. Part 60, Appendix A must be followed immediately before commencing a surface monitoring survey. (2) Determination of methane generation rate. The methane generation rate must include wastes received up to December 31 of the previous year. The methane generation rate must be determined as follows, as applicable: (a) For Landfills without Carbon Adsorption or Passive Venting Systems, the methane generation rate must be calculated using the procedures specified in 40 C.F.R. § 98.343(a)(1) or 40 C.F.R. 98.463(a)(1). DEQ may request additional information as may be necessary to verify the methane generation rate from the landfill. Site-specific data may be substituted when available. (b) For Landfills with Carbon Adsorption Systems, the methane generation rate must be determined by measuring the actual total landfill gas flow rate, in standard cubic feet per minute (scfm), using a flow meter or other flow measuring device such as a standard pitot tube and methane concentration (percent by volume) using a hydrocarbon detector meeting the requirements of OAR 340-239-0800(1). The total landfill gas flow rate must be multiplied by the methane concentration to determine the methane generation rate. (c) For Landfills with Passive Venting Systems, the methane generation rate must be determined pursuant to both of the following and is the higher of these determined values: (A) OAR 340-239-0800(2)(a); and (B) The owner or operator must measure actual landfill gas flow rates (in units of scfm) by using a flow measuring device such as a standard pitot tube and methane concentration (percent by volume) using a hydrocarbon detector meeting the requirements of OAR 340-239-0800(1) from each venting pipe that is within the waste mass. Each gas flow rate must then be multiplied by its corresponding methane concentration to obtain the individual methane flow rate. The individual methane flow rates must be added together to determine the methane generation rate. (3) Surface Emissions Monitoring Procedures. The landfill owner or operator must measure the landfill surface concentration of methane using a hydrocarbon detector meeting the requirements of OAR 340-239-0800(1). The landfill surface must be inspected and monitored quarterly using all of the following procedures: (a) Monitoring Area. The entire landfill surface must be divided into individually identified 50,000 square foot grids and include the entire perimeter of the collection area. The grids must be used for both instantaneous and integrated surface emissions monitoring. The monitoring must comply with all of the following requirements: (A) Surface monitoring must be performed in accordance with section 8.3.1 of EPA Method 21 of appendix A of 40 C.F.R. Part 60, except that the probe inlet must be placed within two inches of the landfill surface while traversing the grid. (B) The walking pattern must be no more than a 25-foot spacing interval and must traverse each monitoring grid and: (i) If the owner or operator has no exceedances of the limits specified in OAR 340-239-0200 after any four consecutive quarterly monitoring periods, the walking pattern spacing may be increased to 100-foot intervals. The owner or operator must return to a 25-foot spacing interval upon any exceedances of the limits specified in OAR 340-239-0200 that cannot be remediated within 10 days or upon any exceedances detected during a DEQ inspection; and (ii) If an owner or operator of a landfill can demonstrate that in the past three years before the effective date of this division that there were no measured exceedances of the limit specified in OAR 340-239-0200(1)(a) by annual or quarterly monitoring, the owner or operator may increase the walking pattern spacing to 100-foot intervals. The owner or operator must return to a 25-foot spacing interval upon any exceedances of the limits specified in OAR 340-239-0200 that cannot be remediated within 10 days or upon any exceedances detected during a DEQ inspection. (C) The owner or operator must use a wind barrier, similar to a funnel, when onsite average wind speed exceeds 4 miles per hour or 2 meters per second or gusts exceeding 10 miles per hour. Average on-site wind speed must also be determined in an open area at 5-minute intervals using an on-site anemometer with a continuous recorder and data logger for the entire duration of the monitoring event. The wind barrier must surround the SEM monitor, and must be placed on the ground, to ensure wind turbulence is blocked. SEM cannot be conducted if average wind speed exceeds 25 miles per hour. (D) Monitoring must be performed during typical meteorological conditions. (b) Instantaneous Surface Emissions Monitoring Procedures must comply with the following: (A) The landfill owner or operator must record any instantaneous surface readings of methane 100 ppmv or greater. The landfill owner or operator must document if the reading is a confirmed reading or whether it is a nonrepeatable, momentary reading; (B) Surface areas of the landfill that exceed a methane concentration limit of 500 ppmv, or 200 ppmv if this is to determine compliance with OAR 340-239-0100(6)(b), must be marked and remediated pursuant to OAR 340-239-0600(1)(a); (C) Surface areas of the landfill that exceed a methane concentration limit of 250 ppmv, or 100 ppmv if this is to determine compliance with OAR 340-239-0100(6)(b), must be monitored in a five foot grid around the location to determine the extents of the methane leak.; (D) The wind speed must be recorded during the sampling period; (E) The landfill surface areas with cover penetrations, distressed vegetation, cracks or seeps must also be inspected visually and with a hydrocarbon detector meeting the requirements of OAR 340-239-0800(1). If a landfill would not be subject to quarterly penetration monitoring as otherwise required pursuant to another state or federal regulation such as, including: OAR 340-236-0500, 40 C.F.R. Part 63 Subpart AAAA, 40 C.F.R. 60 Subpart WWW or XXX, and if no methane is detected with the hydrocarbon detector at a specific penetration point for four consecutive quarters, then the landfill may reduce monitoring to annually at that penetration. If any methane concentration is detected during annual monitoring, the penetration location must return to quarterly monitoring; and (F) The location of each monitored exceedance must be marked and the location and concentration recorded. The location must be recorded using an instrument with an accuracy of at least four meters. The coordinates must be in decimal degrees with at least five decimal places. (c) Integrated Surface Emissions Monitoring Procedures must comply with the following: (A) Integrated surface readings must be recorded and then averaged for each grid; (B) Individual monitoring grids that exceed an average methane concentration of 25 ppmv must be identified and remediated pursuant to OAR 340-239-0600(1)(b); and (C) The wind speed must be recorded during the sampling period. (4) Gas Collection and Control System Leak Inspection Procedures. Landfill owners and operators must measure leaks using a hydrocarbon detector meeting the requirements of OAR 340-239-0800(1). (5) Determination of Expected Gas Generation Flow Rate. Landfill owners and operators must determine the expected gas generation flow rate as prescribed in 40 C.F.R. §§ 98.343(1)(a) or 63.1960(a)(1), which are incorporated by reference herein. (6) Control Device Destruction Efficiency Determination. Landfill owners and operators must use the following methods of analysis to determine the efficiency of the control device in reducing methane: (a) For Enclosed Combustors, one of the following test methods, all of which are incorporated by reference herein (and all as promulgated in 40 C.F.R., Part 60, Appendix A), must be used to determine the efficiency of the control device in reducing methane by at least 99 percent, or in reducing the outlet methane concentration for lean burn engines to less than 3,000 ppmv, dry basis, corrected to 15 percent oxygen: (A) U.S. EPA Reference Method 18, Measurement of Gaseous Organic Compound Emissions By Gas Chromatography; (B) U.S. EPA Reference Method 25, Determination of Total Gaseous Nonmethane Organic Emissions as Carbon. EPA Reference Method 25A, Determination of Total Gaseous Organic Concentration Using a Flame Ionization Analyzer; or (C) U.S. EPA Reference Method 25C, Determination of Nonmethane Organic Compounds in Landfill Gases; (b) The following equation must be used to calculate destruction efficiency: Destruction Efficiency = [1-(Mass of Methane_outlet)/(Mass of Methane_inlet)]x100% (7) Wellhead monitoring. (a) Landfill owners and operators must determine wellhead nitrogen levels using EPA Reference Method 3C, Determination of Volatile Organic Compound Leaks, 40 C.F.R. Part 60, Appendix A, unless an alternative test method is approved by DEQ. (b) Unless an alternative test method is established and approved by DEQ, landfill owners and operators must determine wellhead oxygen levels by an oxygen meter using EPA Reference Method 3A or 3C, 40 C.F.R. Part 60, Appendix A, or ASTM D6522-20, except that, if sample location is prior to combustion: (A) The span must be set between 10 and 12 percent oxygen; (B) A data recorder is not required; (C) Only two calibration gases are required, a zero and span; (D) A calibration error check is not required; and (E) The allowable sample bias, zero drift, and calibration drift are ±10 percent. (c) Landfill owners and operators may use a portable gas composition analyzer to monitor wellhead oxygen levels provided that the analyzer is calibrated and the analyzer meets all quality assurance and quality control requirements for 40 C.F.R. Part 60, Appendix A-1, Method 3A or ASTM D6522-11. (d) Determination of Gauge Pressure. Landfill owners and operators must determine wellhead gauge pressure using a hand-held manometer, magnahelic gauge, or other pressure measuring device approved by DEQ. The device must be calibrated and operated in accordance with the manufacturer’s specifications. (e) Landfill owners and operators must calibrate wellhead temperature measuring devices annually using the procedure in 40 C.F.R. Part 60, Appendix A-1, Method 2, Section 10.3 except that a minimum of two temperature points, bracket within 10 percent of all landfill absolute temperature measurements or two fixed points of ice bath and boiling water, corrected for barometric pressure, are used. (8) Enhanced monitoring. The landfill owner or operator must initiate enhanced monitoring at each well with a measurement of landfill gas temperature greater than 62.8 degrees Celsius (145 degrees Fahrenheit) as follows: (a) Visual observations for subsurface oxidation events (smoke, smoldering ash, damage to well) within the radius of influence of the well; (b) Monitor oxygen or nitrogen concentration as provided in OAR 340-239-0110(3)(a); (c) Monitor temperature of the landfill gas at the wellhead as provided in OAR 340-239-0600(3); (d) Monitor temperature of the landfill gas every 10 vertical feet of the well as provided in OAR 340-239-0600(3); (e) Monitor the methane concentration with a methane meter using EPA Method 3C of Appendix A-6 to 40 C.F.R. Part 60, EPA Method 18 of Appendix A-6 to 40 C.F.R. part 60, or a portable gas composition analyzer to monitor the methane levels provided that the analyzer is calibrated and the analyzer meets all quality assurance and quality control requirements for EPA Method 3C or EPA Method 18; (f) Monitor carbon monoxide concentrations, as follows: (A) Collect the sample from the wellhead sampling port in a passivated canister or multi-layer foil gas sampling bag (such as the Cali-5-Bond Bag) and analyze that sample using EPA Method 10, 40 C.F.R. Part 60, Appendix A-4, or an equivalent method with a detection limit of at least 100 ppmv of carbon monoxide in high concentrations of methane; and (B) Collect and analyze the sample from the wellhead using EPA Method 10, 40 C.F.R. Part 60, Appendix A-4 to measure carbon monoxide concentrations; (g) The enhanced monitoring must begin 7 days after the first measurement of landfill gas temperature greater than 62.8 degrees Celsius (145 degrees Fahrenheit); (h) The enhanced monitoring must be conducted on a weekly basis. If four consecutive weekly carbon monoxide readings are under 100 ppmv, then enhanced monitoring may be decreased to monthly. If monthly carbon monoxide readings exceed 100 ppmv, the landfill must return to weekly monitoring; (i) The enhanced monitoring can be stopped once a higher operating value is approved, at which time the monitoring provisions issued with the higher operating value must be followed, or once the measurement of landfill gas temperature at the wellhead is less than or equal to 62.8 degrees Celsius (145 degrees Fahrenheit); and (j) For each wellhead with a measurement of landfill gas temperature greater than or equal to 73.9 degrees Celsius (165 degrees Fahrenheit), annually monitor temperature of the landfill gas every 10 vertical feet of the well. This temperature can be monitored either with a removable thermometer, or using temporary or permanent thermocouples installed in the well. (9) Bioreactor moisture content. The bioreactor moisture content calculation must consider the waste mass, moisture content of the incoming waste, mass of water added to the waste including leachate recirculation and other liquids addition and precipitation, and the mass of water removed through leachate or other water losses. Moisture level sampling or mass balances. The landfill owner or operator must document the calculations and the basis of any assumptions. Keep the record of the calculations until liquids addition ceases. (10) Alternative Test Methods. Notwithstanding any other provision in this division, landfill owners and operators may use alternative test methods for any of the test methods described in this rule provided that the alternative methods are approved in writing by DEQ pursuant to OAR 340-239-0500.