Checking your system for leaks
There is a simple test you can perform to use your water meter to detect leaks. First, turn off all your faucets and water-using appliances (such as dish and clothes washers) and be sure no one is using any water. Then go to your water meter and lift the cover of the meter dial. Note the position of the sweep-hand by using a piece of tape, or by using a marker on the lens cover.
Then, wait 20-30 minutes and check the sweep-hand location again. If the sweep-hand has moved, you probably have a leak somewhere in your system. If the small red diamond shaped indicator on the face of the meter is moving, it also means you probably have a leak. Retest to be certain; then locate the leak by inspecting all the pipes, fixtures and appliances that use water.