It may not be legal, (heck I don't know if it's legal where I live and the house has been this way for at least 50+ years) but my kitchen sink empties into a 4 cinderblock high dirt bottom 8'x 6' pit that is covered with a cement slab.
I can just picture my local authorities flippin' out if they saw that.
I have 22 acres and it took more than 10 test pits to find a suitable primary and secondary septic drain field. Even then the 2 sites were only approved for a sand mound system. $$$$
