(a) Avoided methane emissions from agricultural manure management operations. To qualify for the award of CO₂ offset allowances under this Subpart, offset projects that capture and destroy methane from animal manure and organic food waste using anaerobic digesters shall meet the requirements of this subdivision and all applicable requirements of this Subpart.

1. (1) Eligibility.

   1. (i) Eligible offset projects shall consist of the destruction of that portion of methane generated by an anaerobic digester that would have been generated in the absence of the offset project through the uncontrolled anaerobic storage of manure or organic food waste.
   2. (ii) Eligible offset projects shall employ only manure-based anaerobic digester systems using livestock manure as the majority of digester feedstock, defined as more than 50 percent of the mass input into the digester on an annual basis. Organic food waste used by an anaerobic digester shall only be that which would have been stored in anaerobic conditions in the absence of the offset project.

   3. (iii) The provisions of section 242-10.3(c)(2) and (3) of this Subpart shall not apply to agricultural manure management offset projects provided either of the following requirements are met.

      1. (a) The offset project is located in a state that has a market penetration rate for anaerobic digester projects of five percent or less. The market penetration determination shall utilize the most recent market data available at the time of submission of the consistency application pursuant to section 242-10.4 of this Subpart and shall be determined as follows: MP (%) = MG_AD / MG_STATE where: MG_AD = Average annual manure generation for the number of dairy cows and swine serving all anaerobic digester projects in the applicable state at the time of submission of a consistency application pursuant to section 242-10.4 of this Subpart. MG_STATE = Average annual manure production of all dairy cows and swine in the state at the time of submission of a consistency application pursuant to section 242-10.4 of this Subpart.
      2. (b) The offset project is located at a farm with 4,000 or less head of dairy cows, or a farm with equivalent animal units, assuming an average live weight for dairy cows (lbs/cow) of 1,400 lbs., or, if the project is a regional-type digester, total annual manure input to the digester is designed to be less than the average annual manure produced by a farm with 4,000 or less head of dairy cows, or a farm with equivalent animal units, assuming an average live weight for dairy cows (lbs/cow) of 1,400 lbs.

2. (2) Offset project description. The offset project sponsor shall provide a detailed narrative of the offset project actions to be taken, including documentation that the offset project meets the eligibility requirements of paragraph (1) of this subdivision. The offset project narrative shall include the following information:

   1. (i) owner and operator of the offset project;
   2. (ii) location and specifications of the facility where the offset project will occur;
   3. (iii) owner and operator of the facility where the offset project will occur;
   4. (iv) specifications of the equipment to be installed and a technical schematic of the offset project; and
   5. (v) location and specifications of the facilities from which anaerobic digester influent will be received, if different from the facility where the offset project will occur.

3. (3) Emissions baseline determination. The emissions baseline shall represent the potential emissions of the CH₄ that would have been produced in a baseline scenario under uncontrolled anaerobic storage conditions and released directly to the atmosphere in the absence of the offset project.

   1. (i) Baseline CH₄ emissions shall be calculated as follows: CO₂e (tons) = (V_m x M)/2000 x GWP where: Eb = Potential CO₂e emissions due to calculated CH₄ production under site-specific anaerobic storage and weather conditions tons V_m = Volume of CH₄ produced each month from decomposition of volatile solids in a baseline uncontrolled anaerobic storage scenario under site-specific storage and weather conditions for the facility at which the manure or organic food waste is generated (ft³) M = Mass of CH₄ per cubic foot (0.04246 lb/ft³ default value at one atmosphere and 20°C) GWP = Global warming potential of CH₄ (28)
   2. (ii) The estimated amount of volatile solids decomposed each month under the uncontrolled anaerobic storage baseline scenario (kg) shall be calculated as follows: VS_deg = VS_avail x f where: VS = volatile solids as determined from the equation: VS = M_m x TS_% x VS_% where: M_m = mass of manure or organic food waste produced per month (kg) TS_% = concentration (percent) of total solids in manure or organic food waste as determined through EPA 160.3 testing method (U.S.EPA Method Number 160.3, Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020)) (see table 1, section 200.9 of this Title) VS_% = concentration (percent) of volatile solids in total solids as determined through EPA 160.4 testing method (U.S.EPA Method Number 160.4, Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020)) (see table 1, section 200.9 of this Title) VS_avail = volatile solids available for decomposition in manure or organic food waste storage each month as determined from the equation: VS_avail = VS_p + ½ VS_in - VS_out where: VS_p = volatile solids present in manure or organic food waste storage at beginning of month (left over from previous month) (kg) VS_in = volatile solids added to manure or organic food waste storage during the course of the month (kg). The factor of ½ is multiplied by this number to represent the average mass of volatile solids available for decomposition for the entire duration of the month. VS_out = volatile solids removed from the manure or organic food waste storage for land application or export (assumed value based on standard farm practice) (kg) f = van't Hoff-Arrhenius factor for the specific month as determined using the equation below. Using a base temperature of 30°C, the equation is as follows: f = exp{[E(T₂ - T₁)]/[(GC x T₁ x T₂)]} where: f = conversion efficiency of VS to CH₄ per month E = activation energy constant (15,175 cal/mol) T₂ = average monthly ambient temperature for facility where manure or organic food waste is generated (converted from °Celsius to °Kelvin) as determined from the nearest National Weather Service certified weather station (if reported temperature °C > 5°C; if reported temperature °C < 5°C, then F = 0.104) T₁ = 303.16 (30°C converted to °K) GC = ideal gas constant (1.987 cal/K mol)
   3. (iii) The volume of CH₄ produced (ft³) from decomposition of volatile solids shall be calculated as follows: V_m = (VS_dec x B_o) x 35.3147 where: V_m = volume of CH₄ (ft³) VS_dec = volatile solids decomposed (kg) B_o = manure or organic food waste type-specific maximum methane generation constant (m³ CH₄/kg VS decomposed). For dairy cow manure, B_o = 0.24 m³ CH₄/kg VS decomposed. The methane generation constant for other types of manure shall be those cited at U.S. EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2017, Annex 3, Table A-179 (U.S. EPA, April 11, 2019) (see table 1, section 200.9 of this Title), unless the project sponsor proposes an alternate methane generation constant and that alternate is approved by the department. If the project sponsor proposes to use a methane generation constant other than the ones found in the above-cited reference, the project sponsor must provide justification and documentation to the department.

4. (4) Calculating emissions reductions. Emissions reductions shall be calculated as follows: ER_t = E_b-E_p where: ER_t = CO_2e emissions reductions due to project activities (tons); E_b = Potential Co_2e emissions due to calculated CH₄ production under site-specific anaerobic storage and weather conditions (tons); E_p = CO_2e emissions due to project activities additional to baseline (tons), including, but not limited to, manure transportation, flaring, venting, and effluent management; storage and weather conditions (tons); Emissions reductions may not exceed the potential emissions of the anaerobic digester, as represented by the annual volume of CH₄ produced by the anaerobic digester, as monitored pursuant to paragraph (5) of this subdivision. CO₂ emissions due to transportation of manure and organic food waste from the site where the manure and organic food waste was generated to the anaerobic digester shall be subtracted from the emissions reduction calculated pursuant to subparagraphs (3)(i) through (iii) of this subdivision. Transport CO₂ emissions shall be determined through one of the following methods.

   1. (i) Documentation of transport fuel use for all shipments of manure and organic food waste from off-site to the anaerobic digester during each reporting year and a log of transport miles for each shipment. Off-site is defined as a location that is not contiguous with the property where the anaerobic digester is located. CO₂ emissions shall be determined through the application of an emissions factor for the fuel type used. If this option is chosen, the following emissions factors shall be applied as appropriate.

      1. (a) Diesel fuel: 22.912 lbs. CO₂/gallon.
      2. (b) Gasoline: 19.878 lbs. CO₂/gallon.
      3. (c) Other fuel: submitted emissions factor approved by the department.

   2. (ii) Documentation of total tons of manure and organic food waste transported from off-site for input into the anaerobic digester during each reporting year, as monitored pursuant to subparagraph (5)(i) of this subdivision, and a log of transport miles and fuel type used for each shipment. CO₂ emissions shall be determined through the application of a ton-mile transport emission factor for the fuel type used. If this option is chosen, the following emissions factors shall be applied as appropriate for each ton of manure delivered, and multiplied by the number of miles transported.

      1. (a) Diesel fuel: 0.131 lbs. CO₂ per ton-mile.
      2. (b) Gasoline: 0.133 lbs. CO₂ per ton-mile.
      3. (c) Other fuel: submitted emissions factor approved by the department.

5. (5) Monitoring and verification requirements. Offset projects shall employ a system that provides metering of biogas volumetric flow rate and determination of CH₄ concentration. Annual monitoring and verification reports shall include monthly biogas volumetric flow rate and CH₄ concentration determination. Monitoring and verification shall also meet the following requirements.

   1. (i) If the offset project is a regional-type digester, manure and organic food waste from each distinct source supplying to the anaerobic digester shall be sampled monthly to determine the amount of volatile solids present. Any emissions reduction will be calculated according to mass of manure and organic food waste (kg) being digested and percentage of volatile solids present before digestion, consistent with the requirements at paragraph (3) of this subdivision and subparagraph (iii) of this paragraph, and apportioned accordingly among sources. The project sponsor shall provide supporting material and receipts tracking the monthly receipt of manure and organic food waste (kg) used to supply the anaerobic digester from each supplier.
   2. (ii) If the offset project includes the digestion of organic food waste eligible pursuant to subparagraph (1)(ii) of this subdivision, organic food waste shall be sampled monthly to determine the amount of volatile solids present before digestion, consistent with the requirements at paragraph (3) of this subdivision and subparagraph (iii) of this paragraph, and apportioned accordingly.

   3. (iii) The project sponsor shall submit a monitoring and verification plan as part of the consistency application that includes a quality assurance and quality control program associated with equipment used to determine biogas volumetric flow rate and CH₄ composition. The monitoring and verification plan shall be specified in accordance with the applicable monitoring requirements listed in Table 3 below. The monitoring and verification plan shall also include provisions for ensuring that measuring and monitoring equipment is maintained, operated, and calibrated based on manufacturer's recommendations, as well as provisions for the retention of maintenance records for audit purposes. The monitoring and verification plan shall be certified by an independent verifier accredited pursuant to section 242-10.6 of this Subpart. Table 3 Monitoring Requirements

      Parameter	Measurement Unit	Frequency of Sampling	Sampling Method(s)
      Influent flow (mass) into the digester	Kilograms (kg) per month (wet mass)	Monthly total into the digester	a) Recorded mass
      			b) Digester influent pump flow
      			c) Livestock population and application of American Society of Agricultural and Biological Engineers (ASABE) standard (ASAE D384.2, March 2005) (see table 1, section 200.9 of this Title)
      Influent total solids concentration (TS)	Percent (of sample)	Monthly, depending upon recorded variations	U.S. EPA Method Number 160.3, Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020) (see table 1, section 200.9 of this Title)
      Influent volatile solids (VS) concentration	Percent (of TS)	Monthly, depending upon recorded variations	U.S. EPA Method Number 160.4, Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020) (see table 1, section 200.9 of this Title)
      Average monthly ambient temperature	Temperature °C	Monthly (based on farm averages)	Closest National Weather Service-certified weather station
      Volume of biogas produced by digester	Standard cubic feet (scf)	Continuous totalized monthly	Flow meter
      Methane composition of biogas produced by digester	Percent (of sample)	Quarterly	Bag sampling and third party laboratory analysis using applicable U.S. EPA test methods