In 2018 the EPA undertook a special operation targeting Hunter Valley coal mines to tackle excessive dust levels.

Operation Dust Patrol involved frequent inspections of mines on hot, dry and windy days to check that extra controls were in place at the mines to minimise dust.

This operation found most mines were compliant with EPA requirements.

"Despite the dry conditions in that period, mine dust emissions were at their lowest since monitoring began in 2012," the NSW Department of Planning, Industry and Environment said in its NSW Clean Air Strategy 2021-30 draft report.

Throughout the spring periods of 2019 and 2020, the EPA's Bust the Dust compliance campaign in the Hunter Valley included the use of drones to help EPA officers better identify the source of dust plumes and observe impacts on air quality.

This campaign was supported by officers from the DPIE.

"Both the EPA and the department frequently inspect mines to ensure they are meeting the conditions and requirements, including that extra precautions be in place on days when there is a higher risk of dust," the DPIE said.