I have my washing machine going to the trees... everything else to septic. We even have a couple old school cesspits... one connected to a modern outhouse/bathroom... other to the guest house/modified single wide. Come to think of it kitchen sink in the party barn dumps to trees as well. I am feeling very green all of a sudden.
Truth is black is all biodegradable too. Jus stinkier.
The septic dude in town was telling me in the old days to get a new septic charge burning on good bacteria folks would toss a dead rabbit in the tank. Cheaper than yeast I guess.