With every water use shut off, read the meter, wait an hour and read it again, or watch its leak indicator. Movement means a leak somewhere downstream of the meter. Soggy ground between the meter and the building points to the buried service line, and the meter itself is where city responsibility ends.
What does the meter test show?
EPA's guidance for commercial facilities says to read the facility meter when all water-using equipment is off and nobody is using the restrooms, then read it again an hour later. A significant change means a leak somewhere in the distribution system or the building. Many meters also have a leak indicator, such as a spinning dial or flashing symbol, that is active when water is moving.
The test doesn't say where the leak is. It only says water is moving when it shouldn't. Running the test step by step helps avoid false readings, and comparing bills can show how long it has been happening.
What points to the buried line?
EPA lists wet spots on sidewalks, in parking lots and in grassy areas around the facility as signs to look for. If soggy ground is unexpected, it says to contact the water utility to determine whether there is a leak in the distribution line.
Next, close the building's main valve and read the meter again. If it still moves, the leak is between the meter and that valve, which means the buried service line. If it stops, the leak is inside.
Whose repair is it?
Phoenix Water Services says it is responsible for leaks, broken pipes and mains on the street side of the water meter, and that leaks on private property, the customer's side, are the property owner's responsibility. The meter is the dividing point. Other utilities draw the line elsewhere, so confirm yours. Who owns the service line covers the details.
Phoenix also says to contact it for emergencies that need field staff to turn off water at the meter, and not to shut off at the meter yourself.
What happens next?
A plumber confirms the leak, locates it, and excavates or reroutes the line. A sewer camera is meant for drain lines, so water-line leaks call for other methods. Ask in writing what the quote includes; this checklist helps.