Basically Macquarie University and the EPA are partnering in citizen science programs to receive soil and dust samples for testing. This is to provide them with contamination data around lead and other metals, and in return you receive a report about the safety of your soil and what to do if it’s unsafe.
VegeSafe through the Environmental Science staff at Macquarie is open to all Australians and they request a donation starting at $20. Victorians are encouraged to go through GardenSafe.
GardenSafe through the EPA is geared at Victorians, apparently has some extras and is free other than the postage to submit soil samples.
There’s another one less relevant to this instance called DustSafe that tests household dust. They have testing facilities in England, Australia and USA, and ask for a donation starting at $20.
All three programs and links to submit samples can be seen here.
Edit: Soil contamination also affects backyard chickens and their eggs