Yeah, and if they're in a multi-household building (apartments) vs. a single household (house), they may go through some truly fucky billing system where the water bill is distributed per sq. ft. of apartment unit. So, let's say you have a duplex, and in this duplex, it's only you and... i dunno... maybe two cats. And since you work from home, and might be a bit of a shut in, you only have to shower once every 2 ish days... **BUT** your next door neighbor is Pakistani (or whatever, it's just an example) and likes to cook curry (at least it isn't durian... often. sorry, this is just for flavor text.) and happens to be exceeding the maximum occupancy of 4 adults (it's a 2 bedroom) by double (so, 12 adults (met=4) + (exceed by double=8) for a total of 12)...
you happen to have the larger apartment by square footage by almost 100 sq feet...
Suddenly your water bill is absurd, and it's not even for water that you are using.
Not saying this ever happened... it's just a for instance... because landlords that using third party utility billing companies for utilities that are "part of rent" as in... you can't dispute them and can be evicted for disagreeing... are utter assholes.
(seriously, they weren't Pakistani, and it was a 12 unit building, not a 2 unit building, and I think it was only 8 guys there regularly, with an occasional extra or two as their work shifts fell into/out of alignment.)