If this sizing figure is Average Dry Weather Flow, you are talking about a very large plant. 1000ML/day ADWF is equivalent to the load from a city of around 4 million people. Is this correct?
I strongly suggest you engage a consultant to prepare you some concept layouts for a plant this size, as there could be big differences in footprint, depending on the process selected.
It seems you will have some very important land acquisition issues depending on the answer!
Mail me back if you need more help.
Aussie Mike.