The procedures specified in the determination are based on internationally recognised standard methods, which are substantially different from the methods used for estimating fugitive emissions.

Fugitive emissions are the largest source of greenhouse gas emissions from the Australian coal industry, most of which are associated with the ventilation air from underground mining.

Under the requirements of the act, Australian coal mines must report annual greenhouse gas emissions, including fugitive emissions.

ACARP research found that methods used by mines to measure ventilation airflow and composition for fugitive emissions reporting may be subject to significant errors, yielding emission estimates with high uncertainties.

Some mine operators are considering installing continuous emissions monitoring systems for measuring fugitive emissions because these systems potentially yield the most accurate results.

“Despite the apparent advantages of continuous monitoring for measuring fugitive emissions, the instrumentation must be suited to mine use,” ACARP said.

“Moreover, it may be difficult to calibrate continuous flow measuring systems according to the requirements of some standards relating to such systems.”

In the project the requirements of instrumentation suitable for continuous monitoring of fugitive emissions were examined and a review of relevant standards was undertaken.

Further examination of the use of anemometers for measuring ventilation airflows for fugitive emission estimation was examined specifically to assess the accuracy of the method and define the uncertainties for greenhouse reporting.

A robust anemometer method may also be of value in checking the performance of continuous flow sensors, especially where full pitot tube traverses of surface duct work is difficult or impractical, according to ACARP.