4) The department shall review the information submitted under subd. 2. a. 1) to 3) and either approve it, disapprove it, or request that additional information be submitted. Because of the many site-specific factors involved with landfill gas system design, alternative systems may be necessary. A wide variety of system designs are possible, such as vertical wells, combination horizontal and vertical collection systems, or horizontal trenches only, leachate collection components, and passive systems.
NR 440.75(3)(b)2.b.b. Install a collection and control system that captures the gas generated within the landfill within 30 months after the first annual report in which the emission rate equals or exceeds 50 megagrams per year, unless Tier 2 or Tier 3 sampling demonstrates that the emission rate is less than 50 megagrams per year, as specified in sub. (8) (c) 1. or 2. 1) An active collection system shall:
a) Be designed to handle the maximum expected gas flow rate from the entire area of the landfill that warrants control over the intended use period of the gas control or treatment system equipment.
b) Collect gas from each area, cell or group of cells in the landfill in which the initial solid waste has been placed for a period of 5 years or more if active, or 2 years or more if closed or at final grade.
c) Collect gas at a sufficient extraction rate.
d) Be designed to minimize off-site migration of subsurface gas.
2) A passive collection system shall:
a) Comply with the provisions specified in subd. 2. b. 1) a), b) and d).
b) Be installed with liners on the bottom and all sides in all areas in which gas is to be collected. The liners shall be installed as required under 40 CFR 258.40. NR 440.75(3)(b)2.c.c. Route all the collected gas to a control system that complies with one of the following: 1) An open flare designed and operated in accordance with s. NR 440.18. 2) A control system designed and operated to reduce NMOC by 98% by weight, or, when an enclosed combustion device is used for control, to either reduce NMOC by 98% by weight or reduce the outlet NMOC concentration to less than 20 parts per million by volume, dry basis as hexane at 3% oxygen. The reduction efficiency or parts per million by volume shall be established by an initial performance test to be completed no later than 180 days after the initial startup of the approved control system using the test methods specified in sub. (5) (d).
a) If a boiler or process heater is used as the control device, the landfill gas stream shall be introduced into the flame zone.
b) The control device shall be operated within the parameter ranges established during the initial or most recent performance test. The operating parameters to be monitored are specified in sub. (7).
3) A treatment system that processes the collected gas for subsequent sale or use. All emissions from any atmospheric vent from the gas treatment system shall be subject to the requirements of subd. 2. c. 1) or 2).
NR 440.75(3)(b)2.d.d. Operate the collection and control device installed to comply with this section in accordance with the provisions of subs. (4), (6) and (7). NR 440.75(3)(b)3.3. The collection and control system may be capped or removed provided that all of the following conditions are met: NR 440.75(3)(b)3.a.a. The landfill shall be a closed landfill. A closure report shall be submitted to the department as provided in sub. (8) (d). NR 440.75(3)(b)3.b.b. The collection and control system shall have been in operation a minimum of 15 years. NR 440.75(3)(b)3.c.c. Following the procedures specified in sub. (5) (b), the calculated NMOC gas produced by the landfill shall be less than 50 megagrams per year on 3 successive test dates. The test dates shall be no less than 90 days apart, and no more than 180 days apart. NR 440.75(3)(c)(c) For purposes of obtaining an operating permit under Title V of the Act (42 USC 7661 to 7661f), the owner or operator of a MSW landfill subject to this section with a design capacity less than 2.5 million megagrams or 2.5 million cubic meters is not subject to the requirement to obtain an operating permit for the landfill under ch. NR 407, unless the landfill is otherwise subject to ch. NR 407. For purposes of submitting a timely application for an operating permit under ch. NR 407, the owner or operator of a MSW landfill subject to this section with a design capacity greater than or equal to 2.5 million megagrams and 2.5 million cubic meters, and not otherwise subject to ch. NR 407, becomes subject to the requirements of s. NR 407.04 (1), regardless of when the design capacity report is actually submitted, no later than the following: NR 440.75(3)(c)1.1. June 10, 1996 for MSW landfills that commenced construction, modification, or reconstruction on or after May 30, 1991 but before March 12, 1996. NR 440.75(3)(c)2.2. Ninety days after the date of commenced construction, modification or reconstruction for MSW landfills that commence construction, modification or reconstruction on or after March 12, 1996. NR 440.75(3)(d)(d) When a MSW landfill subject to this section is closed, the owner or operator is no longer subject to the requirement to maintain an operating permit under ch. NR 407 for the landfill if the landfill is not otherwise subject to the requirements of ch. NR 407 and if either of the following conditions are met: NR 440.75(4)(4) Operational standards for collection and control systems. NR 440.75(4)(a)(a) Each owner or operator of an MSW landfill with a gas collection and control system used to comply with the provisions of sub. (3) (b) 2. b. shall: NR 440.75(4)(a)1.1. Operate the collection system such that gas is collected from each area, cell or group of cells in the MSW landfill in which solid waste has been in place for: NR 440.75(4)(a)2.2. Operate the collection system with negative pressure at each wellhead except under the following conditions: NR 440.75(4)(a)2.a.a. A fire or increased well temperature. The owner or operator shall record instances when positive pressure occurs in efforts to avoid a fire. These records shall be submitted with the annual reports as provided in sub. (8) (f) 1. NR 440.75(4)(a)2.b.b. Use of a geomembrane or synthetic cover. The owner or operator shall develop acceptable pressure limits in the design plan. NR 440.75(4)(a)2.c.c. A decommissioned well. A well may experience a static positive pressure after shut down to accommodate for declining flows. All design changes shall be approved by the department. NR 440.75(4)(a)3.3. Operate each interior wellhead in the collection system with a landfill gas temperature less than 55°C and with either a nitrogen level less than 20% or an oxygen level less than 5%. The owner or operator may establish a higher operating temperature, nitrogen or oxygen value at a particular well. A higher operating value demonstration shall show supporting data that the elevated parameter does not cause fires or significantly inhibit anaerobic decomposition by killing methanogens. Nitrogen and oxygen level shall be determined as follows: 1) The span shall be set so that the regulatory limit is between 20 and 50% of the span.
2) A data recorder is not required.
3) Only 2 calibration gases are required, a zero and span, and ambient air may be used as the span.
4) A calibration error check is not required.
5) The allowable sample bias, zero drift and calibration drift are ± 10%.
NR 440.75(4)(a)4.4. Operate the collection system so that the methane concentration is less than 500 parts per million above background at the surface of the landfill. To determine if this level is exceeded, the owner or operator shall conduct surface testing around the perimeter of the collection area and along a pattern that traverses the landfill at 30 meter intervals and where visual observations indicate elevated concentrations of landfill gas, such as distressed vegetation and cracks or seeps in the cover. The owner or operator may establish an alternative traversing pattern that ensures equivalent coverage. A surface monitoring design plan shall be developed that includes a topographical map with the monitoring route and the rationale for any site-specific deviations from the 30 meter intervals. Areas with steep slopes or other dangerous areas may be excluded from the surface testing. NR 440.75(4)(a)5.5. Operate the system such that all collected gases are vented to a control system designed and operated in compliance with sub. (3) (b) 2. c. In the event the collection or control system is inoperable, the gas mover system shall be shut down and all valves in the collection and control system contributing to venting of the gas to the atmosphere shall be closed within one hour. NR 440.75(4)(a)6.6. Operate the control or treatment system at all times when the collected gas is routed to the system. NR 440.75(4)(b)(b) If monitoring demonstrates that the operational requirements in par. (a) 2., 3. or 4. are not met, corrective action shall be taken as specified in sub. (6) (a) 3. to 5. or (c). If the specified corrective actions are taken, the monitored exceedance is not a violation of the operational requirements in this subsection. NR 440.75(5)(a)1.1. ‘Emission rate calculation.’ The landfill owner or operator shall calculate the NMOC emission rate using either of the equations provided in subd. 1. a. or b. as appropriate. Both equations may be used if the actual year-to-year solid waste acceptance rate is known for part of the life of the landfill and the actual year-to-year solid waste acceptance rate is unknown for part of the life of the landfill. The values used in both equations shall be 0.05 per year for k, 170 cubic meters per megagram for Lo and 4,000 parts per million by volume as hexane for CNMOC. For landfills located in geographical areas with a 30 year annual average precipitation of less than 25 inches, as measured at the nearest representative official meteorologic site, the k value used shall be 0.02 per year. NR 440.75(5)(a)1.a.a. The following equation shall be used if the actual year-to-year solid waste acceptance rate is known: where:
MNMOC is the total NMOC emission rate from the landfill in megagrams per year
k is the methane generation rate constant in year-1
Lo is the methane generation potential in cubic meters per megagram of solid waste
Mi is the mass of solid waste in the ith section in megagrams. The mass of nondegradable solid waste may be subtracted from the total mass of solid waste in a particular section of the landfill when calculating the value for Mi if documentation of the nature and amount of such wastes is maintained.
ti is the age of the ith section in years
CNMOC is the concentration of NMOC in parts per million by volume as hexane
3.6 x 10-9 is a conversion factor
NR 440.75(5)(a)1.b.b. The following equation shall be used if the actual year-to-year solid waste acceptance rate is unknown: where:
MNMOC is the mass emission rate of NMOC in megagrams per year
Lo is the methane generation potential in cubic meters per megagram of solid waste
R is the average annual acceptance rate in megagrams per year. The mass of nondegradable solid waste may be subtracted from the total mass of solid waste in a particular section of the landfill when calculating the value or R, if documentation of the nature and amount of such wastes is maintained.
k is the methane generation rate constant in year-1
t is the age of landfill in years
CNMOC is the concentration of NMOC in parts per million by volume as hexane
c is the time since closure in years. For active landfill c = O and e-kc = 1.
3.6 x 10-9 is a conversion factor
NR 440.75(5)(a)2.2. ‘Tier 1.’ The owner or operator shall compare the calculated NMOC mass emission rate to the standard of 50 megagrams per year and then do one of the following: NR 440.75(5)(a)2.a.a. If the NMOC emission rate calculated in subd. 1. is less than 50 megagrams per year, the landfill owner shall submit an emission rate report as provided in sub. (8) (b) 1., and shall recalculate the NMOC mass emission rate annually as required under sub. (3) (b) 1. NR 440.75(5)(a)2.b.b. If the calculated NMOC emission rate is equal to or greater than 50 megagrams per year, the landfill owner shall either comply with sub. (3) (b) 2., or determine a site-specific NMOC concentration and recalculate the NMOC emission rate using the procedures provided in subd. 3. NR 440.75(5)(a)3.3. ‘Tier 2.’ The landfill owner or operator shall determine the NMOC concentration using the sampling procedures in this subdivision. The landfill owner or operator shall install at least 2 sample probes per hectare of landfill surface that has retained waste for at least 2 years. If the landfill is larger than 25 hectares in area, only 50 sample probes are required. The sample probes shall be located to avoid known areas of nondegradable solid waste. The owner or operator shall collect and analyze one sample of landfill gas from each probe to determine the NMOC concentration using Method 25 or 25C in 40 CFR part 60, Appendix A, incorporated by reference in s. NR 440.17 (1). Method 18 in 40 CFR part 60, Appendix A, incorporated by reference in s. NR 440.17 (1), may be used to analyze the samples collected by the Method 25 or 25C sampling procedure. Taking composite samples from different probes into a single cylinder is allowed; however, equal sample volumes shall be taken from each probe. For each composite, the sampling rate, collection times, beginning and ending cylinder vacuums, or alternative volume measurements shall be recorded to verify that composite volumes are equal. Composite sample volumes may not be less than one liter unless evidence can be provided to substantiate the accuracy of smaller volumes. The owner or operator shall terminate compositing before the cylinder approaches ambient pressure, where measurement accuracy diminishes. If using Method 18, the owner or operator shall identify all compounds in the sample and, as a minimum, test for those compounds published in the Compilation of Air Pollutant Emission Factors, AP-42, incorporated by reference in s. NR 440.17 (2) (i) 2., minus carbon monoxide, hydrogen sulfide and mercury. As a minimum, the instrument shall be calibrated for each of the compounds on the list. The concentration of each Method 18 compound shall be converted to CNMOC as hexane by multiplying by the ratio of its carbon atoms divided by 6. If more than the required number of samples are taken, all samples shall be used in the analysis. The landfill owner or operator shall divide the NMOC concentration from Method 25 or 25C by 6 to convert from CNMOC as carbon to CNMOC as hexane. If the landfill has an active or passive gas removal system in place, Method 25 or 25C samples may be collected from these systems instead of surface probes provided the removal system can be shown to provide sampling as representative as the 2 sampling probe per hectare requirement. For active collection systems, samples may be collected from the common header pipe before the gas moving or condensate removal equipment. For these systems, a minimum of 3 samples shall be collected from the header pipe. The landfill owner or operator shall recalculate the NMOC mass emission rate using the equations in subd. 1. and using the average NMOC concentration from the collected samples instead of the default value for the equation provided in subd. 1., and then do one of the following: NR 440.75(5)(a)3.a.a. If the resulting mass emission rate calculated using the site-specific NMOC concentration is equal to or greater than 50 megagrams per year, the landfill owner or operator shall either comply with sub. (3) (b) 2., or determine the site-specific methane generation rate constant and recalculate the NMOC emission rate using the site-specific methane generation rate constant and using the procedure specified in subd. 4. NR 440.75(5)(a)3.b.b. If the resulting NMOC mass emission rate is less than 50 megagrams per year, the owner or operator shall submit a periodic estimate of the emission rate report as provided in sub. (8) (b) 1. and retest the site-specific NMOC concentration every 5 years using the methods specified in this subsection. NR 440.75(5)(a)4.4. ‘Tier 3.’ A landfill owner or operator electing to determine the site-specific methane generation rate constant and to recalculate the NMOC emission rate under this subdivision shall follow the procedures in this subdivision. The site-specific methane generation rate constant shall be determined using the procedures provided in Method 2E in 40 CFR part 60, Appendix A, incorporated by reference in s. NR 440.17 (1). The landfill owner or operator shall estimate the NMOC mass emission rate using the equations in subd. 1. as appropriate and using a site-specific methane generation rate constant, k, and the site-specific NMOC concentration as determined in subd. 3. instead of the default values provided in subd. 1. The landfill owner or operator shall compare the resulting NMOC mass emission rate to the standard of 50 megagrams per year, and then do one of the following: NR 440.75(5)(a)4.a.a. If the NMOC mass emission rate as calculated using the site-specific methane generation rate constant and concentration of NMOC is equal to or greater than 50 megagrams per year, the owner or operator shall comply with sub. (3) (b) 2. NR 440.75(5)(a)4.b.b. If the NMOC mass emission rate is less than 50 megagrams per year, the owner or operator shall submit a periodic emission rate report as provided in sub. (8) (b) 1. and shall recalculate the NMOC mass emission rate annually, as provided in sub. (8) (b) 1. using the equations in subd. 1. and using the site-specific methane generation rate constant and NMOC concentration obtained in subd. 3. The calculation of the methane generation rate constant is performed only once, and the value obtained from this test shall be used in all subsequent annual NMOC emission rate calculations. NR 440.75(5)(a)5.5. ‘Alternative methods.’ The owner or operator may use other methods to determine the NMOC concentration or a site-specific k as an alternative to the methods required in subds. 3. and 4. if the method has been approved by the administrator. NR 440.75(5)(b)1.1. After the installation of a collection and control system in compliance with sub. (6), the owner or operator shall calculate the NMOC emission rate for purposes of determining when the system can be removed as provided in sub. (3) (b) 3., using the following equation: where:
MNMOC is the mass emission rate of NMOC in megagrams per year
QLFG is the flow rate of landfill gas in cubic meters per minute
CNMOC is the NMOC concentration in parts per million by volume as hexane
