I am on city water and swear. Don't know how old ouse is, how do I find out ? What city department keeps the recors of where the main dran is?

Call your city building department to see if they have records going back to your homes construction. The main may be below your basement floor. Do you see a 4" black verticle pipe coming into the basement?

I don't have a basement.

How about a crawl space?