The four penalty notices related to the Narrabri and Tarrawonga coalmines and were issued by acting chief environmental regulator Mark Gifford on March 1.

He said recent heavy rains led to high volumes of stormwater that exceeded the capacity of the mines to capture and store and overflows resulted.

“Although the recent wet weather has come after a long dry period, mine operators should have measures in place to deal with excess stormwater,” he said.

“The EPA is very concerned by the number of incidents that have occurred and has formally put Whitehaven Coal on notice to improve its environmental performance.”