That sounds VERY high for water only. You ask if that could include waste water and storm run off. Water companies meter water in and their waste water departments meter water out…that is the figure that could include surface water infiltration. Which meter are they giving you readings for…the master water main, the wastewater flow meter or both?
I had a small park that had huge HUGE water bills and just as Frank said, submetering solved the problem. We even got the water company to read the meters, which is sometimes difficult to get them to do. Meters were a little over $100 each (but that was 15 years ago) with fittings and we required tenants to redo their own heat tapes after we installed the meters
amazing how toilet flaps started getting repaired and sprinklers got put away in the summer and the master meter readings dropped every month.
One guy had a $700 water bill the first month from a running toilet, needless to say, that dropped FAST
there may still be an underground water leak, but I’d bet that it’s more excess usage by tenants who have NO idea how much water costs