Septic availability property analysis

[Chase Brumfield]

My wife and I are interested in leveraging a 2-10 acre single family property into a longer term RV park with 8-15 pads.

We've been in communication with the county.  Long story short, they recommend a process that basically looks like...

Soil scientist --> (septic engineer IF needed) --> site plan --> county approval...

We've spoken to a few soil scientists and they all quote 2k-5k to analyze the property for an appropriately sized septic system.  However, there's obviously no guarantee in what they'll find... so - how do folks mitigate the risk of the 2k-5k loss when looking to purchase a new property for a plan like this?

Also - is it appropriate to add a contingency related to this in an offer - specifically something like "earnest money will be returned if property soil is not found suitable to support 15 RV pads" sort of thing?  Or is this basically a guaranteed way to not get an offer accepted?

All advice and opinions welcome!!!