F’ing Septic Tanks

Sounds like it will be cheaper and easier to install some supplemental drains around your property to prevent rain water from permeating your leach field. Rent a ditchwitch and get yourself some 4” perforated sewer and drain pipe and create an escape path for the excess water. Only needs to be 12-18” deep. Backfill the ditch with #2 river gravel and just a skim of topsoil so the grass will grow. Lead it to the edge of your property and daylight it if possible or if not lead it to a drypit.
Only happens when it rains a lot right? There’s your problem.