Document ID: chunk:federal_register_of_legislation:F2024C00833:reg:22:p22
Version: federal_register_of_legislation:F2024C00833
Segment Type: reg
Provision Reference: reg 22 (pt 22/29)
Character Range: 287849–290435

gas bearing strata
  Analysis of a gas and a gas bearing strata, including the mass and gas content of the strata, must be done in accordance with:
 (a) the minimum requirements for data collection and gas testing mentioned in section 2 of the ACARP Guidelines; and
 (b) the data validation, analysis and interpretation processes mentioned in section 3 of the ACARP Guidelines; and
 (c) the method of applying the gas distribution model to develop an emissions estimate for an open cut mine mentioned in section 4 of the ACARP Guidelines.

3.25A  Method of working out base of the low gas zone
 (1) The estimator must:
 (a) take all reasonable steps to ensure that samples of gas taken from the gas bearing strata of the open cut mine are taken in accordance with the minimum requirements for data collection and gas testing mentioned in section 2 of the ACARP Guidelines; and
 (b) take all reasonable steps to ensure that samples of gas taken from boreholes are taken in accordance with the requirements for:
 (i) the number of boreholes mentioned in sections 2 and 3 of the ACARP Guidelines; and
 (ii) borehole spacing mentioned in section 2 of the ACARP Guidelines; and
 (iii) sample selection mentioned in section 2 of the ACARP Guidelines; and
 (c) work out the base of the low gas zone by using the method mentioned in subsection (2); and
 (d) if the base of the low gas zone worked out in accordance with subsection (2) varies, in a vertical plane, within:
 (i) a range of 20 metres between boreholes located in the same domain of the open cut mine—work out the base of the low gas zone using the method mentioned in subsection (3); or
 (ii) a range of greater than 20 metres between boreholes located in the same domain of the open cut mine—the method mentioned in subsection (4).

Preliminary method of working out base of low gas zone
 (2) For paragraph (1)(c), the method is that the estimator must perform the following steps:
Step 1  For each borehole, identify the depth at which:
         (a) the results of greater than 3 consecutive samples taken in the borehole indicate that the gas content of the gas bearing strata is greater than 0.5 m3/t; or
         (b) the results of 3 consecutive samples taken in the borehole indicate that the methane composition of the gas bearing strata is greater than 50% of total gas composition by volume.
Step 2  If paragraph (a) or (b) of step 1 applies, identify, for each borehole, the depth of the top of the gas bearing strata at which the first of the 3 consecutive samples in the borehole was taken.
        Note   The depth of