Method 2C - Determination of Stack Gas Velocity and Volumetric Flow Rate in Small Stacks or Ducts (Standard Pitot Tube)

1. Applicability and Principle

1.1Applicability.

1.1.1The applicability of this method is identical to Method 2, except this method is limited to stationery source stacks or ducts less than about 0.30 meter (12 in.) in diameter or 0.071 m2 (113 in.2) in cross-sectional area, but equal to or greater than about 0.10 meter (4 in.) in diameter or 0.0081 m2 (12.57 in.2) in cross-sectional area.

1.1.2The apparatus, procedure, calibration, calculations, and biliography are the same as in Method 2, Sections 2, 3, 4, 5, and 6, except as noted in the following sections.

1.2Principle. The average gas velocity in a stack or duct is determined from the gas density and from measurement of velocity heads with a standard pitot tube.

2. Apparatus

2.1Standard Pitot Tube (instead of Type S). Use a standard pitot tube that meets the specifications of Section 2.7 of Method 2. Use a coefficient value of 0.99 unless it is calibrated against another standard pitot tube with an NBS-traceable coefficient.

2.2Alternative Pitot Tube. A modified hemispherical-nosed pitot tube (see Figure 2C-1), which features a shortened stem and enlarged impact and static pressure holes, may be used. This pitot tube is useful in liquid drop-laden gas streams when a pitot “back purge” is ineffective. Use a coefficient value of 0.99 unless the pitot is calibrated as mentioned in Section 2.1 above.

EC01JN92.095 3. Procedure

Follow the general procedures in Section 3 of Method 2, except conduct the measurements at the traverse points specified in Method 1A. The static and impact pressure holes of standard pitot tubes are susceptible to plugging in PM-laden gas streams. Therefore, the tester must furnish adequate proof that the openings of the pitot tube have not plugged during the traverse period; this proof can be obained by first recording the velocity head (Δp) reading at the final traverse point, then cleaning out the impact and static holes of the standard pitot tube by “back-purging” with pressurized air, and finally by recording another Δp reading at the final traverse point. If the Δp reading made after the air purge is within 5 percent of the reading during the traverse, then the traverse is acceptable. Otherwise, reject the run. Note that if the Δp at the final traverse point is so low as to make this determination too difficult, then another traverse point may be selected. If “back purging” at regular intervals is part of the procedure, then take comparative Δp readings, as above, for the last two back purges at which suitable high Δp readings are observed.

Method 2D—Measurement of Gas Volumetric Flow Rates in Small Pipes and Ducts 1. Applicability and Principle

1.1Applicability. This method applies to the measurement of gas flow rates in small pipes and ducts, either before or after emission control devices.

1.2Principle. To measure flow rate or pressure drop, all the stack gas is directed through a rotameter, orifice plate or similar flow rate measuring device. The measuring device has been previously calibrated in a manner that insures its proper calibration for the gas or gas mixture being measured. Absolute temperature and pressure measurements are also made to calculate volumetric flow rates at standard conditions.

2. Apparatus

Specifications for the apparatus are given below. Any other apparatus that has been demonstrated (subject to approval of the Administrator) to be capable of meeting the specifications will be considered acceptable.

2.1Flow Rate Measuring Device. A rotameter, orifice plate, or other flow rate measuring device capable of measuring all the stack flow rate to within 5 percent of its true value. The measuring device shall be equipped with a temperature gauge accurate to within 2 percent of the minimum absolute stack temperature and a pressure gauge accurate to within 5 mm Hg. The capacity of the measuring device shall be sufficient for the expected maximum and minimum flow rates at the stack gas conditions. The magnitude and variability of stack gas flow rate, molecular weight, temperature, pressure, compressibility, dew point, corrosiveness, and pipe or duct size are all factors to consider in choosing a suitable measuring device.

2.2Barometer. Same as in Method 2, Section 2.5.

2.3Stopwatch. Capable of incremental time measurement to within 1 second.

3. Procedure

3.1Installation. Use the procedure in Method 2A, Section 3.1.

3.2Leak Check. Use the procedure in Method 2A, Section 3.2.

3.3Flow Rate Measurement.

3.3.1Continuous, Steady Flow. At least once an hour, record the measuring device flow rate reading, and the measuring device temperature and pressure. Make a minimum of twelve equally spaced readings of each parameter during the test period. Record the barometric pressure at the beginning and end of the test period. Record the data on a table similar to Figure 2D-1.

Plant_______________ Date_______ Run number____ Sample location___________ Barometric pressure, mm (in.) HgStart___ Finish___ Operators __________ Measuring device number___Calibration coefficient___ Calibration gas_____ Last date calibrated____ TimeFlow rate readingStatic pressure mm (in.) HgTemperature °C ( °F)°K (°R)Average

Figure 2D-1. Flow rate measurement data.

3.3.2Noncontinuous and Nonsteady Flows. Use flow rate measuring devices with particular caution. Calibration will be affected by variation in stack gas temperature, pressure, compressibility, and molecular weight. Use the procedure in Section 3.3.1. Record all the measuring device parameters on a time interval frequency sufficient to adequately profile each process cyclical or noncontinuous event. A multichannel continuous recorder may be used.

4. Calibration

4.1Flow Rate Measuring Device. Use the procedure in Method 2A, Section 4, and apply the same performance standards. Calibrate the measuring device with the principal stack gas to be measured (e.g., air, nitrogen) against a standard reference meter. A calibrated dry gas meter is an acceptable reference meter. Ideally, calibrate the measuring device in the field with the actual gas to be measured. For measuring devices that have a volume rate readout, calculate the measuring device calibration coefficient, Ym, for each run as follows:

EC16NO91.114 where:

Qr=reference meter flow rate reading, m3/min (ft3/min).

Qm=measuring device flow rate reading, m3/min (ft3/min).

Tr=reference meter average absolute temperature, ° K (° R).

Tm=measuring device average absolute temperature, ° K (° R).

Pbar=barometric pressure, mm Hg (in. Hg).

Pg=measuring device average static pressure, mm Hg (in. Hg).

For measuring devices that do not have a readout as flow rate, refer to the manufacturer's instructions to calculate the Qm corresponding to each Qr.

4.2Temperature Gauge. Use the procedure and specifications in Method 2A, Section 4.2. Perform the calibration at a temperature that approximates field test conditions.

4.3Barometer. Calibrate the barometer to be used in the field test with a mercury barometer prior to the field test.

5. Gas Flow Rate Calculation

Calculate the stack gas flow rate, Qs, as follows:

EC16NO91.115 where:

Kl = 0.3858 for international system of units (SI); 17.64 for English units.

6. Bibliography

1. Spink, L.K. Principles and Practice of Flowmeter Engineering. The Foxboro Company. Foxboro, MA. 1967.

2. Benedict, Robert P. Fundamentals of Temperature, Pressure, and Flow Measurements. John Wiley and Sons, Inc. New York, NY. 1969.

3. Orifice Metering of Natural Gas. American Gas Association. Arlington, VA. Report No. 3. March 1978. 88 p.

Method 2E—Determination of Landfill Gas; Gas Production Flow Rate 1. Applicability and Principle

1.1Applicability. This method applies to the measurement of landfill gas (LFG) production flow rate from municipal solid waste (MSW) landfills and is used to calculate the flow rate of nonmethane organic compounds (NMOC) from landfills. This method also applies to calculating a site-specific k value as provided in § 60.754(a)(4). It is unlikely that a site-specific k value obtained through Method 2E testing will lower the annual emission estimate below 50 Mg/yr NMOC unless the Tier 2 emission estimate is only slightly higher than 50 Mg/yr NMOC. Dry, arid regions may show a more significant difference between the default and calculated k values than wet regions.

1.2Principle. Extraction wells are installed either in a cluster of three or at five locations dispersed throughout the landfill. A blower is used to extract LFG from the landfill. LFG composition, landfill pressures near the extraction well, and volumetric flow rate of LFG extracted from the wells are measured and the landfill gas production flow rate is calculated.

2. Apparatus

2.1Well Drilling Rig. Capable of boring a 0.6 meters diameter hole into the landfill to a minimum of 75 percent of the landfill depth. The depth of the well shall not exceed the bottom of the landfill or the liquid level.

2.2Gravel. No fines. Gravel diameter should be appreciably larger than perforations stated in sections 2.10 and 3.2 of this method.

2.3Bentonite.

2.4Backfill Material. Clay, soil, and sandy loam have been found to be acceptable.

2.5Extraction Well Pipe. Polyvinyl chloride (PVC), high density polyethylene (HDPE), fiberglass, stainless steel, or other suitable nonporous material capable of transporting landfill gas with a minimum diameter of 0.075 meters and suitable wall-thickness.

2.6Wellhead Assembly. Valve capable of adjusting gas flow at the wellhead and outlet, and a flow measuring device, such as an in-line orifice meter or pitot tube. A schematic of the wellhead assembly is shown in figure 1.

EC01JN92.306

2.7Cap. PVC, HDPE, fiberglass, stainless steel, or other suitable nonporous material capable of transporting landfill gas with a suitable wall-thickness.

2.8Header Piping. PVC, HDPE, fiberglass, stainless steel, or other suitable nonporous material capable of transporting landfill gas with a suitable wall-thickness.

2.9Auger. Capable of boring a 0.15 to 0.23 meters diameter hole to a depth equal to the top of the perforated section of the extraction well, for pressure probe installation.

2.10Pressure Probe. PVC or stainless steel (316), 0.025 meters. Schedule 40 pipe. Perforate the bottom two thirds. A minimum requirement for perforations is slots or holes with an open area equivalent to four 6.0 millimeter diameter holes spaced 90° apart every 0.15 meters.

2.11Blower and Flare Assembly. A water knockout, flare or incinerator, and an explosion-proof blower, capable of extracting LFG at a flow rate of at least 8.5 cubic meters per minute.

2.12Standard Pitot Tube and Differential Pressure Gauge for Flow Rate Calibration with Standard Pitot. Same as Method 2, sections 2.1 and 2.8.

2.13Gas flow measuring device. Permanently mounted Type S pitot tube or an orifice meter.

2.14Barometer. Same as Method 4, section 2.1.5.

2.15Differential Pressure Gauge. Water-filled U-tube manometer or equivalent, capable of measuring within 0.02 mm Hg, for measuring the pressure of the pressure probes.

3. Procedure

3.1Placement of Extraction Wells. The landfill owner or operator shall either install a single cluster of three extraction wells in a test area or space five wells over the landfill. The cluster wells are recommended but may be used only if the composition, age of the solid waste, and the landfill depth of the test area can be determined. CAUTION: Since this method is complex, only experienced personnel should conduct the test. Landfill gas contains methane, therefore explosive mixtures may exist at or near the landfill. It is advisable to take appropriate safety precautions when testing landfills, such as installing explosion-proof equipment and refraining from smoking.

3.1.1Cluster Wells. Consult landfill site records for the age of the solid waste, depth, and composition of various sections of the landfill. Select an area near the perimeter of the landfill with a depth equal to or greater than the average depth of the landfill and with the average age of the solid waste between 2 and 10 years old. Avoid areas known to contain nondecomposable materials, such as concrete and asbestos. Locate wells as shown in figure 2.

Because the age of the solid waste in a test area will not be uniform, calculate a weighted average to determine the average age of the solid waste as follows.

$ER12MR96.027$ where, Aavg=average age of the solid waste tested, year fi=fraction of the solid waste in the ith section Ai=age of the ith fraction, year ER12MR96.019

3.1.2Equal Volume Wells. This procedure is used when the composition, age of solid waste, and landfill depth are not well known. Divide the portion of the landfill that has had waste for at least 2 years into five areas representing equal volumes. Locate an extraction well near the center of each area. Avoid areas known to contain nondecomposable materials, such as concrete and asbestos.

3.2Installation of Extraction Wells. Use a well drilling rig to dig a 0.6 meters diameter hole in the landfill to a minimum of 75 percent of the landfill depth, not to exceed the bottom of the landfill or the water table. Perforate the bottom two thirds of the extraction well pipe. Perforations shall not be closer than 6 meters from the cover. Perforations shall be holes or slots with an open area equivalent to 1.0 centimeter diameter holes spaced 90 degrees apart every 0.1 to 0.2 meters. Place the extraction well in the center of the hole and backfill with 2.0 to 7.5 centimeters gravel to a level 0.3 meters above the perforated section. Add a layer of backfill material 1.2 meters thick. Add a layer of bentonite 1.0 meter thick, and backfill the remainder of the hole with cover material or material equal in permeability to the existing cover material. The specifications for extraction well installation are shown in figure 3.

ER12MR96.020

3.3Pressure Probes. Shallow pressure probes are used in the check for infiltration of air into the landfill, and deep pressure probes are used to determine the radius of influence. Locate the deep pressure probes along three radial arms approximately 120 degrees apart at distances of 3, 15, 30, and 45 meters from the extraction well. The tester has the option of locating additional pressure probes at distances every 15 meters beyond 45 meters. Example placements of probes are shown in figure 4.

The probes located 15, 30, and 45 meters from each well, and any additional probes located along the three radial arms (deep probes), shall extend to a depth equal to the top of the perforated section of the extraction wells. Locate three shallow probes at a distance of 3 m from the extraction well. Shallow probes shall extend to a depth equal to half the depth of the deep probes.

ER12MR96.021

Use an auger to dig a hole, approximately 0.15 to 0.23 meters in diameter, for each pressure probe. Perforate the bottom two thirds of the pressure probe. Perforations shall be holes or slots with an open area equivalent to four 6.0 millimeter diameter holes spaced 90 degrees apart every 0.15 meters. Place the pressure probe in the center of the hole and backfill with gravel to a level 0.30 meters above the perforated section. Add a layer of backfill material at least 1.2 meters thick. Add a layer of bentonite at least 0.3 meters thick, and backfill the remainder of the hole with cover material or material equal in permeability to the existing cover material. The specifications for pressure probe installation are shown in figure 5.

EC01JN92.307

3.4LFG Flow Rate Measurement. Determine the flow rate of LFG from the test wells continuously during testing with an orifice meter. Alternative methods to measure the LFG flow rate may be used with approval of the Administrator. Locate the orifice meter as shown in figure 1. Attach the wells to the blower and flare assembly. The individual wells may be ducted to a common header so that a single blower and flare assembly and flow meter may be used. Use the procedures in section 4.1 to calibrate the flow meter.

3.5Leak Check. A leak check of the above ground system is required for accurate flow rate measurements and for safety. Sample LFG at the wellhead sample port and at a point downstream of the flow measuring device. Use Method 3C to determine nitrogen (N2) concentrations. Determine the difference by using the formula below.

Difference=Co−Cw where, Co=concentration of N2 at the outlet, ppmv Cw=concentration of N2 at the wellhead, ppmv

The system passes the leak check if the difference is less than 10,000 ppmv. If the system fails the leak check, make the appropriate adjustments to the above ground system and repeat the leak check.

3.6Static Testing. The purpose of the static testing is to determine the initial conditions of the landfill. Close the control valves on the wells so that there is no flow of landfill gas from the well. Measure the gauge pressure (Pg) at each deep pressure probe and the barometric pressure (Pbar) every 8 hours for 3 days. Convert the gauge pressure of each deep pressure probe to absolute pressure by using the following equation. Record as Pi.

Pi=Pbar+Pg where, Pbar=Atmospheric pressure, mm Hg Pg=Gauge pressure of the deep probes, mm Hg Pi=Initial absolute pressure of the deep probes during static testing, mm Hg

3.6.1For each probe, average all of the 8 hr deep pressure probe readings and record as Pia. The Pia is used in section 3.7.6 to determine the maximum radius of influence.

3.6.2Measure the LFG temperature and the static flow rate of each well once during static testing using a flow measurement device, such as a Type S pitot tube and measure the temperature of the landfill gas. The flow measurements should be made either just before or just after the measurements of the probe pressures and are used in determining the initial flow from the extraction well during the short term testing. The temperature measurement is used in the check for infiltration.

3.7Short Term Testing. The purpose of short term testing is to determine the maximum vacuum that can be applied to the wells without infiltration of air into the landfill. The short term testing is done on one well at a time. During the short term testing, burn LFG with a flare or incinerator.

3.7.1Use the blower to extract LFG from a single well at a rate at least twice the static flow rate of the respective well measured in section 3.6.2. If using a single blower and flare assembly and a common header system, close the control valve on the wells not being measured. Allow 24 hours for the system to stabilize at this flow rate.

3.7.2Check for infiltration of air into the landfill by measuring the temperature of the LFG at the wellhead, the gauge pressures of the shallow pressure probes, and the LFG N2 concentration by using Method 3C. CAUTION: Increased vacuum at the wellhead may cause infiltration of air into the landfill, which increases the possibility of a landfill fire. Infiltration of air into the landfill may occur if any of the following conditions are met: the LFG N2 concentration is more than 20 percent, any of the shallow probes have a negative gauge pressure, or the temperature has increased above 55 °C or the maximum established temperature during static testing. If infiltration has not occurred, increase the blower vacuum by 4 mm Hg, wait 24 hours, and repeat the infiltration check. If at any time, the temperature change exceeds the limit, stop the test until it is safe to proceed. Continue the above steps of increasing blower vacuum by 4 mm Hg, waiting 24 hours, and checking for infiltration until the concentration of N2 exceeds 20 percent or any of the shallow probes have a negative gauge pressure, at which time reduce the vacuum at the wellhead so that the N2 concentration is less than 20 percent and the gauge pressures of the shallow probes are positive. This is the maximum vacuum at which infiltration does not occur.

3.7.3At this maximum vacuum, measure Pbar every 8 hours for 24 hours and record the LFG flow rate as Qs and the probe gauge pressures for all of the probes as Pf. Convert the gauge pressures of the deep probes to absolute pressures for each 8-hour reading at Qs as follows:

P=Pbar+Pf where, Pbar=Atmospheric pressure, mm Hg Pf=Final absolute pressure of the deep probes during short term testing, mm Hg P=Pressure of the deep probes, mm Hg

3.7.4For each probe, average the 8-hr deep pressure probe readings and record as Pfa.

3.7.5For each probe, compare the initial average pressure (Pia) from section 3.6.1 to the final average pressure (Pfa). Determine the furthermost point from the wellhead along each radial arm where Pfa ≤ Pia. This distance is the maximum radius of influence (ROI), which is the distance from the well affected by the vacuum. Average these values to determine the average maximum radius of influence (Rma).

The average Rma may also be determined by plotting on semi-log paper the pressure differentials (Pfa-Pia) on the y-axis (abscissa) versus the distances (3, 15, 30 and 45 meters) from the wellhead on the x-axis (ordinate). Use a linear regression analysis to determine the distance when the pressure differential is zero. Additional pressure probes may be used to obtain more points on the semi-long plot of pressure differentials versus distances.

3.7.6Calculate the depth (Dst) affected by the extraction well during the short term test as follows. If the computed value of Dst exceeds the depth of the landfill, set Dst equal to the landfill depth.

Dst=WD + Rma2 where, Dst=depth, m WD=well depth, m Rma=maximum radius of influence, m

3.7.7Calculate the void volume for the extraction well (V) as follows.

V=0.40 Rma2 Dst where, V=void volume of test well, m3 Rma=maximum radius of influence, m Dst=depth, m

3.7.8Repeat the procedures in section 3.7 for each well.

3.8Calculate the total void volume of the test wells (Vv) by summing the void volumes (V) of each well.

3.9Long Term Testing. The purpose of long term testing is to determine the methane generation rate constant, k. Use the blower to extract LFG from the wells. If a single blower and flare assembly and common header system are used, open all control valves and set the blower vacuum equal to the highest stabilized blower vacuum demonstrated by any individual well in section 3.7. Every 8 hours, sample the LFG from the wellhead sample port, measure the gauge pressures of the shallow pressure probes, the blower vacuum, the LFG flow rate, and use the criteria for infiltration in section 3.7.2 and Method 3C to check for infiltration. If infiltration is detected, do not reduce the blower vacuum, but reduce the LFG flow rate from the well by adjusting the control valve on the wellhead. Adjust each affected well individually. Continue until the equivalent of two total void volumes (Vv) have been extracted, or until Vt=2 Vv.

3.9.1Calculate Vt, the total volume of LFG extracted from the wells, as follows.

$ER12MR96.028$ where, Vt=total volume of LFG extracted from wells, m3 Qi=LFG flow rate measured at orifice meter at the ith interval, cubic meters per minute tvi=time of the ith interval, hour (usually 8)

3.9.2Record the final stabilized flow rate as Qf. If, during the long term testing, the flow rate does not stabilize, calculate Qf by averaging the last 10 recorded flow rates.

3.9.3For each deep probe, convert each gauge pressure to absolute pressure as in section 3.7.4. Average these values and record as Psa. For each probe, compare Pia to Psa. Determine the furthermost point from the wellhead along each radial arm where Psa ≤ Pia. This distance is the stabilized radius of influence. Average these values to determine the average stabilized radius of influence (Rsa).

3.10Determine the NMOC mass emission rate using the procedures in section 5.

3.11Deactivation of pressure probe holes. Upon completion of measurements, if pressure probes are removed, restore the integrity of the landfill cover by backfilling and sealing to prevent venting of LFG to the atmosphere or air infiltration.

4. Calibrations

Gas Flow Measuring Device Calibration Procedure. Locate a standard pitot tube in line with a gas flow measuring device. Use the procedures in Method 2D, section 4, to calibrate the orifice meter. Method 3C may be used to determine the dry molecular weight. It may be necessary to calibrate more than one gas flow measuring device to bracket the landfill gas flow rates. Construct a calibration curve by plotting the pressure drops across the gas flow measuring device for each flow rate versus the average dry gas volumetric flow rate in cubic meters per minute of the gas. Use this calibration curve to determine the volumetric flow from the wells during testing.

5. Calculations

5.1Nomenclature.

Aavg=average age of the solid waste tested, year Ai=age of solid waste in the ith fraction, year A=age of landfill, year Ar=acceptance rate, megagrams per year CNMOC=NMOC concentration, ppmv as hexane (CNMOC=Ct/6) Ct=NMOC concentration, ppmv (carbon equivalent) from Method 25C D = depth affected by the test wells, m Dst=depth affected by the test wells in the short term test, m DLF=landfill depth, m f = fraction of decomposable solid waste in the landfill fi=fraction of the solid waste in the ith section k=methane generation rate constant, year−1 Lo=methane generation potential, cubic meters per megagram Lo=revised methane generation potential to account for the amount of nondecomposable material in the landfill, cubic meters per megagram Mi=mass of solid waste of the ith section, megagrams Mr=mass of decomposable solid waste affected by the test well, megagrams Mw=number of wells Pbar=atmospheric pressure, mm Hg Pg=gauge pressure of the deep pressure probes, mm Hg Pi=initial absolute pressure of the deep pressure probes during static testing, mm Hg Pia=average initial absolute pressure of the deep pressure probes during static testing, mm Hg Pf=final absolute pressure of the deep pressure probes during short term testing, mm Hg Pfa=average final absolute pressure of the deep pressure probes during short term testing, mm Hg Ps=final absolute pressure of the deep pressure probes during long term testing, mm Hg Psa=average final absolute pressure of the deep pressure probes during long term testing, mm Hg QB=required blow flow rate, cubic meters per minute Qf=final stabilized flow rate, cubic meters per minute Qi=LFG flow rate measured at orifice meter during the ith interval, cubic meters per minute Qs=maximum LFG flow rate at each well determined by short term test, cubic meters per minute Qt=NMOC mass emission rate, cubic meters per minute Rm=maximum radius of influence, m Rma=average maximum radius of influence, m Rs=stabilized radius of influence for an individual well, m Rsa=average stabilized radius of influence, m ti=age of section i, year tt=total time of long term testing, year V=void volume of test well, m3 Vr=volume of solid waste affected by the test well, m3 Vt=total volume of solid waste affected by the long term testing, m3 Vv=total void volume affected by test wells, m3 WD=well depth, m ρ=solid waste density, m3 (Assume 0.64 megagrams per cubic meter if data are unavailable)

5.2Use the following equation to calculate the depth affected by the test well. If using cluster wells, use the average depth of the wells for WD. If the value of D is greater than the depth of the landfill, set D equal to the landfill depth.

D=WD+Rsa

5.3Use the following equation to calculate the volume of solid waste affected by the test well.

Vr=Rsa2† D

5.4Use the following equation to calculate the mass affected by the test well.

Mr=Vrρ

5.5Modify Lo to account for the nondecomposable solid waste in the landfill.

Lo′=f Lo

5.6In the following equation, solve for k by iteration. A suggested procedure is to select a value for k, calculate the left side of the equation, and if not equal to zero, select another value for k. Continue this process until the left hand side of the equation equals zero, #0.001.

$ER12MR96.029$

5.7Use the following equation to determine landfill NMOC mass emission rate if the yearly acceptance rate of solid waste has been consistent (±10 percent) over the life of the landfill.

Qt = 2 Lo′ Ar (1 − e−k A) CNMOC / (5.256 × 1011)

5.8Use the following equation to determine landfill NMOC mass emission rate if the acceptance rate has not been consistent over the life of the landfill.

$ER12MR96.030$ 6. Bibliography

1. Same as Method 2, appendix A, 40 CFR part 60.

2. Emcon Associates, Methane Generation and Recovery from Landfills. Ann Arbor Science, 1982.

3. The Johns Hopkins University, Brown Station Road Testing and Gas Recovery Projections. Laurel, Maryland: October 1982.

4. Mandeville and Associates, Procedure Manual for Landfill Gases Emission Testing.

5. Letter and attachments from Briggum, S., Waste Management of North America, to Thorneloe, S., EPA. Response to July 28, 1988 request for additional information. August 18,1988.

6. Letter and attachments from Briggum, S., Waste Management of North America, to Wyatt, S., EPA. Response to December 7, 1988 request for additional information. January 16, 1989.