Not sure your location (codes can vary by jurisdiction), but here are some general things to pay attention to (at least around my parts):
- Sh*t flows downhill, you'll want your house higher than your septic field.
- are there any wetlands in the area? ...you'll likely need to maintain a "buffer" from them.
- does the site have shallow ledge or ground
water (or mottling)? ...there are certain seperating distances that the septic field needs to "sit above" in order to properly leach the effluent.
- what type of soil do you have (clay, sand, hardpan)? What is the percolation rate? ...this willl determine the size of your leach field.
- how many bedrooms? ...septics are sized accordingly.
- are there any significant
trees or other site features you wish to preserve?
- are there eany easements? ...do you know where your property lines are? Might be a good idea to consult with a Professional
Land Surveyor.
I find it odd they are sending out an 'assessor'. Typically the Town Sanitarian or health department reviews these sort of things.
Don't be afraid to ask questions. It's also a good idea to get any answers in writing. Maybe take notes and send them questions by email or letter after the site walk so you have a paper trail.
Wishing you the best of success in your build!