I'm sure conventional plumbing wisdom would say this is a dumb question, but I live up in the mountains and the guy who built the house just ran several of the drain lines out into the woods (kitchen, laundry, etc). They all have traps, but none are vented. I want to hook them all up to the existing septic system, but trying to put in vent pipes would be quite a challenge. They drain fine now, but would I be creating a problem if I didn't run vent pipes?