you are interested in opening a car wash and those are your only questions?
where did you come up with these questions?
why don't you ask about some more 'meaty' topics like skills required, work and duties required, pitfalls, mistakes owners made that they would change if they did it over again???
Many of these questions are locality specific ones. I have operated washes in rural areas, which requires everything to leave in a truck. or urban areas which have a connecting sewer system which you can leech water into (check local laws). Disposal of car wash waste is a very important factor when purchasing the wash since it is any on going issue. I think that your question is well placed, since it can be a major cost depending on the location.
A good water recycling system can help reduce costs as they will reuse larger amounts of water multiple times. Most car wash waste can be considered hazardous and should be dealt appropriately.