Over the next six months a large drilling rig will be collecting soil samples and testing groundwater in the Blue Mountains.
Duplication works have begun on the $45 million project to upgrade the Great Western Highway in New South Wales.
The Great Western Highway, near the Meadow Flat public school is set to undergo and $8 million upgrade over two kilometres, starting Monday.
The jointly funded $250 million Great Western Highway safety upgrade between Katoomba and Lithgow has been delivered, with safety works at Blackheath now complete.
Upgrades at the Great Western Highway and Pitt Street intersection in Parramatta are now finished, with more improvements on the way.