The issue is multiple septic tanks in a small area with drinking water wells also in that small area.
two acres is plenty for a septic system ... the real trick for any co-existing well on such a small site is that it has to draw from an independent aquifer that is MUCH than the surface septic leach field, AND to make sure the well is cased, with the casing fully sealed by completely grouting it ...
there are whole neighborhoods of “ranchettes” near me configured like that ...