Planning to build a drive thru and am not certain what kind of plumbing system to use. Not from pacific NW (central Arkansas) and have no prototypes in this area to check out. I assume plumbing is similar to a camper in some and others are hooked up to city sewer/water. What would be advantages/disadvantages. I want to have a private bathroom in 10X20 building. Are there any books out there that diagram drive thru construction? Haven't been able to find anything over internet.