Out of whack city sewer cost

[Trever Good]

We are looking at a 4plex in a strong C area. Our realtor just got us the utility bill info and I’m taken aback at the expenses for the water/sewer. The city quarterly bill has broken down the expenses into separate water and sewer costs, and the sewer is hovering around 400% more than the water.

For example,

2018 water -

Flat rate of $709.60

Excess usage charge of $1,040.76

Total of $1,750.36

2018 Sewer -

Flat rate of $272

Excess usage charge of $4,367.20

Total of $4,639.20

Anyone have any experience with something similar, or the ability to point me in the right direction?