Mike Leo wrote:How deep is your leach field, how deep is your surface water, and do you live in a place where you are allowed to install a new septic system by virtue of the old one being there?
If you saturate your leach field so that it cannot drain it will "fail" for purposes of how they test such things.
If underground surface water table is 20' down you'd probably be ok in almost any circumstances. If your property barely passed a perc test to get the original system installed the last thing you want to do is turn your leach field into a saturated soil mass, unless you want to find out how difficult the local authorities make septic replacements or the permitting of outhouses/composting toilets.
After speaking with a septic company guy, he told me that my leach field would have to be huge due to my clay soil. That will eat up very valuable real estate that I planned to use for gardening. I'm seriously considering a composting toilet.