Hi William,
Thanks for your questions!
We are not aware specifically of any money being spent on treating greywater in Cape York, however this could be an area you and your team research further into.
The question of budget for your project can be found in our FAQs: Big Tricky Questions document (which can also be found in Resources). In short – the budget is decided by you, based on what you think is reasonable for the value it delivers, and depending on who the stakeholders are who would need to fund that project (including who pays for any ongoing maintenance if required, etc.). If the community is expected to pay for it, depending on what you are implementing, then you might look at the average income in that area using the Census and calculate what you think would be affordable for them to pay over the lifecycle of the project. Or, if it needs organisations or local governments or probono corporate involvement to deliver it, your budget can be higher and perhaps you can look for grants in the region for these types of projects to find estimated funds available.
Hope this helps, please reach out with any further questions!
Thanks,
Rachel