Buying a lot - has wetlands and no county sewer so septic tank?

[Kelvin J.]

Hi. i have my eye on a lot that is 100' by 140' in a great area, zoned for' village mixed use' (highest density so splitting is allowed) for 79k. Unfortunately, 30% of the back half is wetlands and with the 25' setback rule in Florida a real big chunk is lost. At first I thought I could split the lot into 2 x 50'x140' lots making it a great buy, but the wetlands would leave one of those with about 50'x20' buildable space, the other about 50'x 90'. It is in a flood zone so I would have to build up. My questions are: 

1. What kind of space would I lose for the septic tank(s) would i lose?

2. Could i even put septic tanks near wetlands? If so are there any restrictions?

3. Could I still split the lot in 2 and somehow use a 50'x20' buildable space with a septic tank?

4. Any creative ways to use this lot?

5. If i make an offer (cash OR loan) what kind of contingencies could I include to allow me to pull out if I discover problems in due dilligence?

Thanks, kelvin