Water Usage per unit? Water Co says 2000 gallons a month!!!!

[Michael Knaus]

So I have been reviewing my water bill. The usage seems high so I am taking a closer look. I have a 3 unit building. 

Unit 1: 1br with 1 tenant

Unit 2: 2br with 2 tenants

Unit 3: 3br with 2 tenants

The building is on one meter. The water company has billed me for 6000 gallons this past month. That's an average of 2000 gallons a month(67 gallons per day) per unit.

My question is: Is it possible to have this kind of usage? It doesn't seem possible. The older tenant doesn't even have a dishwasher. Yes each unit has laundry but 67 gallons a day? Per unit on average? I checked and there are no leaks or toilets running and no outside hoses for tenants. It isn't new. It has averaged this for months now. Now it's only just under .01 Cent/per gallon so the bill isn't horrible, I just question that usage. Any advice?