We have totally no perc-ing clay at our house. The board of health specified a sand filter. It is a 60' long X 12' wide X 5' deep hole filled with sand. Near the surface are some perforated pvc pipes which distribute the output of the 1500 gallon conventional septic tank across the top of the sand filter. Another set of perforated pipes are at the bottom of the sand filter to collect the filtered stuff and outputs it to a small clorinator tank, where we drop a couple of swimming pool type chlorine tablets every once in a while. The output of the chlorinator then flows out to the environment.
Our house is in Ohio, which has just recently changed its policy on septics, and now no longer permits sand filters for new installations. They are now calling for mound systems, which I am not familiar with.
In any case, it is possible to have a septic system in non perc-ing soil. You just have to convince your board of health to approve it. They should be aware of these alternate systems. Good luck.
Stop financing a government that doesn't support your values. Sell your U.S. Savings Bonds and Treasuries. Money talks.