pack in ... pack-out !

You are correct, no services on site, we took trash with us when we went to Saguaro and into town to shop. Regarding water (it's been a while since we were there) but I believe we filled up before down near the Snyder Hill BLM (we were initally going to stay there but that place was dirty and didn't feel safe). There might be some water spigots in the national park if you have containers to fill.