I am in the process of installing a water softener and trying to figure out a good discharge point for the waste water. I am installing the softener in my crawl space. My laundry area is on the second floor so routing the discharge line there is not an option, or at least not one I want to attempt. There is no reasonable place to install a new stand pipe in the living area on the first floor besides maybe a closet, but I’d rather not do that. It is my understanding to be code compliant I cannot have a standpipe drain in the crawl space. I have considered maybe installing a dual air gap at my kitchen sink and routing the discharge line there. Not sure if this would be to code or if there would be problems with a softener and dishwasher hooked to the same air gap with standard sink plumbing. Any suggestions? Thanks.