running a drain line through outside wall?

Hey all,

Long story short - we hope to put in a wet bar sink and possibly a utility sink in our daylight basement. Getting hot/cold supply water is very easy. But we have absolutely zero way to reach any drain in the area we want to put it all. The sinks will be used pretty infrequently - rinsing beer mugs, soaking kid clothes, etc. Our backyard is actually all downhill from this area.

I figure I could take the drain right out the wall.

Soaps will be seldom used - I figure I could just tap into a downspot which pours into a french drain, then into a ditch, then into a huge rainwater cistern that runs off to unknown places. I had to go in there once - the pipe down there is like 3.5 feet in diameter.

But yeah - that's probably not allowed. Still, I wash my car and other things with soap outside in the driveway FAR more often than this sink would be used.

I would considere some kind of greywater runoff area. Or - just running this new drain to a decorative garden and letting it run into the ground.

If I wanted to cut a hole in my wall through to the outside for a small drain line, how would I do it? The obvious way? Cut a hole, run a pipe through, then caulk it up?

What kind of pipe would I run through the wall? Secondly, would hose-clamped rubber hose work on the outside running to where ever? Or should it be PVC?

My concern is that while we live in Atlanta, we do get freezing temps. It seems irregular to just have a pipe running from inside to outside, but maybe not. And - bugs and frogs could crawl through the other end and come inside unless there is some kind of filter.

Any ideas here?