Now, of course, it's unconstitutional because its "legally vague" since your water does not necessarily equal your sewage use (e.g- watering lawns). The only accurate way to measure would be to put a meter in your sewage line- which I understand some states do.
To all you Red-staters---welcome to my world. -:)
Here is Maryland we pay sewage rates based on our water usage. Doesn’t matter if the water is going into an in-ground pool and will never see the sewer line, you pay sewage rate on that water also.