Integra Coal has been fined for dumping excessive levels of waste at its mine in the Hunter Valley.
In September the coal miner pleaded guilty to constructing a waste rock dump that exceeded the approved height by more than ten metres.
The Land and Environment Court this week convicted and fined Integra $84,000.
This is the fourth time Integra has come under fire, having previously been fined twice this year for exceeding blasting limits as well as for excessive dust on site.
In February it was fined $3000 for recording a blast of more than 125 decibels, above the 120 decibel limit.
It was again fined in August for a blast that measured 126 decibels.