Water Bill eating away at my rental income!!!!

[Michael Mckeavin]

Hello folks. I'm new to the app, but happy to be here. I rent out a property in Markham,IL and the water bill shot up from $75, to $145 now for the last couple months. My tenant swears nothing changed with their usage, just claims the handle on the toilet sticks often. The city came out to inspect for leaks, and claims they found none. Am I missing something or can a handle that sticks a little really shoot up the water bill so high?!!!! Also, I would imagine if someone notices they have a sticky handle, they would just shake it do it won't run. Anyway, should I replace the handle, or dies there have to be another reason why this water bill is outrageous. It's a 3bedroom single family home with 2Adults and 2 Kids occupying it. What should I do?