water and sewer bill seems too high

[Diego La Rotta]

I will be closing on my first four plex rental and I am running into the issue that the water and sewer bill is sky rocket high. looks like the tenants use up a lot of water. From talking to people around the area the neighbors pay anywhere from 40-80$ every three months per unit. some of the neighbors i asked have their own house two bed room one bath or two bath, the four plex i will be getting are all 1/1's.  when I did the math the tenants are using almost $100 a month on water. Since there are no meters in the property the landlord (in this case me) has to pay the water bill every three months. How should I go about this. Thanks