1.The operator shall determine the activity data of a source stream in one of the following ways:
(a)based on continual metering at the process which causes the emissions;
(b)based on aggregation of metering of quantities separately delivered taking into account relevant stock changes.
2.For the purposes of point (b) of paragraph 1, the quantity of fuel or material processed during the reporting period shall be calculated as the quantity of fuel or material purchased during the reporting period, minus the quantity of fuel or material exported from the installation, plus the quantity of fuel or material in stock at the beginning of the reporting period, minus the quantity of fuel or material in stock at the end of the reporting period.
Where it is technically not feasible or would incur unreasonable costs to determine quantities in stock by direct measurement, the operator may estimate those quantities based on one of the following:
(a)data from previous years and correlated with output for the reporting period;
(b)documented procedures and respective data in audited financial statements for the reporting period.
Where the determination of activity data for the entire calendar year is technically not feasible or would incur unreasonable costs, the operator may choose the next most appropriate day to separate a reporting year from the following one, and reconcile accordingly to the calendar year required. The deviations involved for one or more source streams shall be clearly recorded, form the basis of a value representative for the calendar year, and be considered consistently in relation to the next year.