Document ID: chunk:federal_register_of_legislation:F2022C00227:reg:35:p1
Version: federal_register_of_legislation:F2022C00227
Segment Type: reg
Provision Reference: reg 35 (pt 1/2)
Character Range: 87105–90074

35  Emissions from anaerobic digester leakage or venting events

       (1) The emissions from anaerobic digester leakage or venting events at project treatment facility t during a reporting period are worked out:
          (a) if Subdivision 4 of Division 2 is used to work out baseline emissions for the project treatment facility for the reporting period—using equation 14; or
          (b) if Subdivision 5 of Division 2 is used to work out baseline emissions for the project treatment facility for the reporting period—as follows:
 (i) if the volume of all ineligible material treated in anaerobic digesters at the project treatment facility during the reporting period (ƩwQMat,w,t) is less than 10% of the total volume of material treated in anaerobic digesters during the reporting period (QMat,t), where QMat,w,t and QMat,t are worked out in accordance with the monitoring requirements and w is a type of ineligible material for the project treated in anaerobic digesters at the project treatment facility during the reporting period—the emissions have a default value of zero;
 (ii) otherwise—worked out using equation 14.

       (2) The emissions from anaerobic digester leakage or venting events at project treatment facility t during the reporting period, EAD,t (in tonnes CO2-e) is worked out using the formula (equation 14):

       where:

       t is a project treatment facility.

       EAD,t means the emissions from anaerobic digester leakage or venting events at project treatment facility t during the reporting period, in tonnes CO2-e.

       γ means the factor, set out in Part 5.3 of the NGER (Measurement) Determination, that converts cubic metres of methane to tonnes CO2-e at standard conditions.

            Note: In 2022, γ was 6.784 x 10-4 x 28.

       CF means the correction factor to reflect the proportion of EAD,t that is not accounted for in the calculation of baseline emissions, which is:
          (a) if Subdivision 4 of Division 2 is used to work out baseline emissions for project treatment facility t for the reporting period—1; and
          (b) if Subdivision 5 of Division 2 is used to work out baseline emissions for project treatment facility t for the reporting period—1 minus WEW,t.

       CE means the biogas collection efficiency of an anaerobic digester, (that is, the percentage of biogas generated in an anaerobic digester that is sent to a combustion device), which is 0.98.

       h means:
          (a) a combustion device used at project treatment facility t; or
          (b) a biogas upgrading system of a project biomethane facility.

       MSent t,h means the methane from project treatment facility t sent to combustion device or biogas upgrading system h during the reporting period, in cubic metres,  worked out in accordance with section 30.

       q means a major venting event associated with an anaerobic digester at project treatment facility t during the reporting period.

       MVent,q