Today's question: How does a water utility detect a major leak in the distribution piping system?
Plain Talk answer: A major leak can be detected by
Visual observation (water on the ground or spraying water)
A loss in water pressure
A depression in the ground or road over a water main
Reports by public-minded citizens
Sensitive listening devices that detect the sound of the leaking water underground
Also, in metered systems, water utilities regularly compare the amount of water produced to the amount that passes through customer meters. This method provides an excellent accountability of overall water loss.
Stopping leaks is important to water supplies because leaks waste water, adding costs to both the water supplier and you. Water utilities don’t get paid for the water that is lost to leaks, but the cost for treatment and distribution must still be passed along to customers. The national average for unaccounted water from all sources is 15 percent of treated water, although many suppliers keep such losses lower. Gas companies only lose about 5 percent of their product.
The water utility is responsible for the underground pipes from the street up to the water meter, but if your pipes leak within the boundary of your property after the meter, it is your responsibility to repair them. Prompt repair is to your benefit: a leaking pipe means a higher water bill.
For more information on this and many other water-related topics, check out Plain Talk About Drinking Water by Dr. James M. Symons.