re: anyone have a sink on their patio?

I sell this stuff for a living and I know how much the stuff in the picture cost.

If your house isnt that old and you can find a clean out for the sewer, you can put a male adapter to the clean out and tie onto the sewer. There is usually one behind the kitchen sink and behind at least one of the bathrooms.

There are several ways to tie onto a water line. any way you do it, you can put a small instant hot water heater under the sink for hot water. You will need electricity for this though.

If your patio is near your main drain line, that would be an easy tie-in. Otherwise, you could make your own drain field for it. I doubt you'd ever run enough water down it to fill 12, or so, feet of drain line before it could be absorbed. Just be sure to put a good pit of gravel in it. I ran 20 feet of that for the wife's washing machine. Never backed up.