We had same problem in production facility I work for. Costs were rising, but there were no visible signs of a problem. Management turned to the specialists at Mayaglobal, who work with utilities as a Professional leak detection company, though not exclusively. They found a leak under the asphalt near the warehouse that we would never have been able to find on our own. The best part is that we didn’t have to dig everything up. They reinforced the pipe from the inside, which seemed “magical” to me. That’s why I think it’s worth bringing in specialists right away, especially if there’s a problem with a gas line, but if it’s a water issue, then you can still try to find the leak yourself.