I'm not sure what's going on. Typically for my 2-unit buildings the quarterly water bill is around $40. Both apartments are 2 bedrooms and fully occupied for this price.

Last year, I dealt with a huge leak because of a failing supply line in the yard. Had the line replaced and a nice big credit of around $300 put on my water bill account.

Got my next bill after that and it was normal around $36. I didn't have to pay because of my $300 credit.

Now the most recent bill comes in at around $260. I call and they send someone to check the meter out. I call back days later (today) to ask about the findings. The meter reads at a consumption of 8753 (gallons?). She said they saw no sign of a leak. 

I tell her we have no interior leaks. She says, "sometimes you can't see a leak. get a licensed plumber to check out the property." So I will do this and if he finds nothing wrong, what will I do?

She said I couldn't get another hearing because I had one already within a year. But if I send a repair receipt, they may adjust it. If nothing is wrong, do I just send whatever receipt for the inspection?

Also, I find it odd that the water bill for next door (who shares the same access well as my meter) constantly has a bill of $14 for the same type of property, fully occupied.

Any advice is appreciated.