Calculations, extent of exceedances
 24. (1) If a calculation required under section 23 indicates that a discharge of sulphur dioxide from a sulphur recovery unit at a petroleum facility may result in a contravention of section 9 or 10, the person who discharges or causes or permits the discharge of sulphur dioxide into the air from the petroleum facility shall ensure that the following amounts are calculated: 1. Using the measurements required under subparagraphs 1 v and 6 i of subsection 22 (1), the amount of sulphur dioxide discharged into the air from the sulphur recovery unit in the 24-hour period before the most recent measurement used in the calculation was taken. 2. Using the measurements required under subparagraph 6 i of subsection 22 (1), the amount of sulphur dioxide that would have been discharged into the air from the sulphur recovery unit in the same 24-hour period if the concentration of sulphur dioxide being discharged from the sulphur recovery unit had been equal to the concentration set out in section 9 or 10, as applicable. 3. The difference between the amount calculated under paragraph 1 and the amount calculated under paragraph 2. (2) If a calculation required under section 23 indicates that a discharge of sulphur dioxide from a general combustion device at a petroleum facility may result in a contravention of clause 11 (1) (a), the person who discharges or causes or permits the discharge of sulphur dioxide into the air from the petroleum facility shall ensure that the following amounts are calculated: 1. Using the measurements required under subparagraphs 1 vi and 6 i  of subsection 22 (1), the amount of sulphur dioxide discharged into the air from the general combustion device in the 24-hour period before the most recent measurement used in the calculation was taken. 2. Using the measurements required under subparagraph 6 i of subsection 22 (1), the amount of sulphur dioxide that would have been discharged into the air from the general combustion device in the same 24-hour period if the concentration of sulphur dioxide being discharged from the general combustion device had been equal to the concentration set out in clause 11 (1) (a). 3. The difference between the amount calculated under paragraph 1 and the amount calculated under paragraph 2. (3) If a calculation required under section 23 indicates that a discharge of sulphur dioxide from an air pollution control device mentioned in section 12 may result in a contravention of clause 12 (2) (a) or subsection 12 (4) or (7), the person who discharges or causes or permits the discharge of sulphur dioxide into the air from the petroleum facility shall ensure that the following amounts are calculated: 1. Using the measurements required under subparagraphs 1 vii and 6 i of subsection 22 (1), the amount of sulphur dioxide discharged into the air from the air pollution control device in the 24-hour period before the most recent measurement used in the calculation was taken. 2. Using the measurements required under subparagraph 6 i of subsection 22 (1), the amount of sulphur dioxide that would have been discharged into the air from the air pollution control device in the same 24-hour period if the concentration of sulphur dioxide being discharged from the air pollution control device had been equal to the concentration set out in clause 12 (2) (a) or subsection 12 (4) or (7), as applicable. 3. The difference between the amount calculated under paragraph 1 and the amount calculated under paragraph 2. (4) If a calculation required under section 23 indicates that a discharge of total reduced sulphur from a sulphur recovery unit at a petroleum facility may result in a contravention of subsection 14 (1) or section 15, the person who discharges or causes or permits the discharge of total reduced sulphur into the air from the petroleum facility shall ensure that the following amounts are calculated: 1. Using the measurements required by paragraph 2 and subparagraph 6 ii of subsection 22 (1), the amount of total reduced sulphur, expressed as the sulphur dioxide equivalent, discharged into the air from the sulphur recovery unit in the 24-hour period before the most recent measurement used in the calculation was taken. 2. Using the measurements required under subparagraph 6 ii of subsection 22 (1), the amount of total reduced sulphur, expressed as the sulphur dioxide equivalent, that would have been discharged into the air from the sulphur recovery unit in the same 24-hour period if the concentration of total reduced sulphur being discharged from the sulphur recovery unit had been equal to the concentration represented by the equivalent concentration of sulphur dioxide set out in subsection 14 (1) or section 15, as applicable. 3. The difference between the amount calculated under paragraph 1 and the amount calculated under paragraph 2. (5) If a calculation required under section 23 indicates that the concentration of hydrogen sulphide in fuel gas conveyed to a general combustion device at a petroleum facility may result in a contravention of clause 16 (1) (a), the person who discharges or causes or permits the discharge of sulphur dioxide into the air from the petroleum facility shall ensure that the following amounts are calculated: 1. Using the measurements required under subparagraphs 5 iii and 6 i of subsection 22 (1), the amount of sulphur dioxide discharged into the air from the general combustion device in the 24-hour period before the most recent measurement used in the calculation was taken. 2. Using the measurements required under subparagraph 6 i of subsection 22 (1), the amount of sulphur dioxide that would have been discharged into the air from the combustion device in the same 24-hour period if the concentration of hydrogen sulphide in the fuel gas conveyed to the general combustion device had been equal to the concentration set out in clause 16 (1) (a). 3. The difference between the amount calculated under paragraph 1 and the amount calculated under paragraph 2. (6) For the purposes of this section, (a) all amounts shall be calculated in kilograms; and (b) an amount calculated under subsection (5) shall assume a hydrogen sulphide to sulphur dioxide conversion rate of 98 per cent.