Hunter Valley Operations (HVO) open cut coal mine near Singleton has seen part of its operations impacted by contractors who were on-site last week and have tested positive to COVID-19.
HVO is run as a joint venture by Chinese miner Yancoal and Glencore.
A spokesperson for Hunter Valley Operations said they can confirm that two contractors working at the site's Coal Handling and Preparation Plant (CHPP) have been identified as positive COVID cases.
"HVO immediately enacted their COVID-19 response plan after receiving notification on Friday evening and the site continues to follow this protocol, which includes contact tracing and deep cleaning in and around the CHPP," they said
NSW Health has advised that they will notify any potential close contacts, who will then be instructed to undergo testing and remain isolated for 14 days.
Casual contacts of the two workers will be advised to undergo testing and remain isolated until they receive a negative test result.
HVO has worked over the weekend to shut down the CHPP while awaiting test results and will continue to follow the advice of health authorities in implementing appropriate protocols.
All other operational activities, including mining, maintenance and train loading, will continue as normal.