Tenant got charged $3000 water bill! What would you do/recommend?

[Quan Chau]

Hi guys!

My tenant of a year is having an issue with the city. The tenant recently got a $3000 water bill, and their normal usage is $300-$400. I called a local plumbing company to inspect and do a leak detection test and found no leaks. The city came out to the property and checked the meter and determined there was no leaks. So after a water bill adjustment, the city is still charging the tenant $2200 for the water bill. Is there anything I need to do? What should I recommend to my tenant? Any help, suggestions are greatly appreciated!