Drain line for water softener into cleanout

Question

House is in southern California and was built in the 1950s with cast iron drain pipes.

I'll be installing a water softener and backflushing carbon filter on the patio in the near future. I am trying to determine best practice for getting the flush water from both the softener and filter into a drain. I'd rather not run it out into the garden. There is a cleanout located right next to where the softener/filter setup will go. From my initial research a trap, standpipe, and air gap should be used.

Here is what the cleanout looks like:

Is there a good way to still maintain access to the cleanout but add on the additional sections needed for draining the water conditioning units?

Is there another approach I should be taking?

Thank you.

Answer 1

Yes. You connect a Y from this cleanout. Cap one of the output for use as cleanout and from the other connect a santee ! Connect the top output of santee with a vent — could be AAV; and connect the side output of santee with a ptrap — add a riser and connect your air gap. Then finally hook your softener drain into that airgap fitting.

Do something so that critters don’t access through airgap and aav vent.