Wambo applied to modify its existing development consent to mine the three new coal areas.
The new panels are located directly underneath already approved mining areas in the Whybrow Coal Seam.
A departmental spokesman said there would be no additional surface disturbance and the new longwall panels would use existing surface infrastructure.
“This modification will allow the company to produce around 5.6 million tonnes of extra coal with only a minor increase in coal processing waste,” he said.
“The project was exhibited during August for public input. Feedback received helped form conditions of consent, including strengthening conditions around rehabilitation.”
The modification approval will generate approximately 14 months of additional employment for the mine’s 670 employees and contractors, according to the company.
The Department has recently doubled the number of compliance officers, who conduct spot checks and regular audits to ensure mines in NSW are adhering to their consent conditions, it said.