A dripping hose, dripping water faucet or a leaking toilet can waste a lot of water. Even the smallest leak could translate to several gallons of water wasted every hour.
To check for a leak, turn off all water using fixtures inside and outside your home or building, lift the meter lid, then record the position of the triangular shaped flow detector and all of the numbered digits on the totalizer. Wait about 15 minutes and then record the position of the flow detector and the numbered digits again. If the position of the flow detector and the digits has not changed, your plumbing system is leak free. If there is a change, water must be passing through the meter in spite of your fixtures being turned off; in other words there must be a leak somewhere on the property. Check your fixtures and pipes for leaks or call a qualified plumber.