Customer stated that city called him and said that there was a water leak to where he was losing 25 gallons per minute. Did a quick test to see where water leak can potentially be. Shut off, main house water valve, and meter continued to spin. Stated the customer that there is a leak between the meter and that valve. Also, main waterline goes under slab. Recommended customer to call national leak detection and once they pinpoint where leak is, give us a call back to come and make a repair.