A lot of times the water company will adjust the bill. I know Fairfax Water would adjust for those who had a polybutylene pipe from the street leaking. This happened in a rental I had. The week after I moved out, the pipe had burst, after leaking for a month or longer. When I received the water bill of $1200 (since it was at the tail end of the 3 mo billing cycle when I moved) they readily adjusted the bill as long as it was fixed.