subject: Overview Of Current Leak Detection Methods For Utilities [print this page] Utilities have some very real water loss issues, and now is the time to adopt an aggressive leak detection program. Over 6 billion gallons of water seem to be either blatantly lost, or completely unaccounted for each day.
Where is all of it going to? Are meter errors causing it? Perhaps billing problems? Leakage?
The Puzzle Of Leak Detection And Water Loss:
Utilities often ask, "How much leakage do I have in my system?" The answer to that question can be a mystery. Let's look at an easy way to solve this water loss puzzle. You can think of your water losses as a puzzle to be solved. A puzzle must have identifiable pieces.
Seven years ago, in the Journal AWWA published an article. That publication showed us a way to audit and isolate leakage a being a large piece of the Puzzle. The following formula clarifies:
Water Production (or Purchases) Water Sales = Non-Revenue Water.
Non-Revenue Water creates a Puzzle.
This puzzle has 3 pieces:
1. Un-billed, authorized use (cost of business water);
2. Apparent losses, for example; theft, billing errors, meter errors
3. Real losses - leaking and overflow.
Which Leak Detection Program To Choose:
When it comes to picking the correct methodology and leak detection technology, you will want to consider which will be the most cost-effective and which will most help you in reaching your baseline UARL.
Two options exist: one for non-metallic systems and one for metallic.
Leak Detection On Non-Metallic Pipe:
Noise is made by a pipe leak. You can create individual "zones" that can be isolated, creating one point of entry for the flow. Identifying the high-flow area and it's detecting its potential leakage can be assisted by exposing the main line and measuring the flow into the zone in question. Afterward one can do acoustic leak survey of each hydrant, valve and meter connection.
High flow areas can be detected by what is called "squeaking the valve", shutting it for a few minutes, and allowing leaks to run, then open it up again very slowly to only about a one-fourth of a rotation sized opening. A vibrating value key with doesn't stop vibrating means there is a leak in that zone. Probably there is not problem if the duration of the vibration is short. Developments in underground detection technology has resulted in some amazing detection technology, The Innspector 07, and will locate even non-metallic pipe up to 25 feet underground.
Permanent pits have been created by some utilities for measuring, as part of an effective measure of leak detection.
Metallic System Leak Detection:
It is quicker to perform an acoustic leak survey, instead of district measurements, on a metallic system. Larger cities with aging infrastructure are often the ones who will use DMAs (District Metered Areas). DMAs cost more to use.
In addition, it's time consuming, error prone process to measure the DMAs and frequently requiring corp stops, insertion meters or pilot rods, and multiple taps, and one still has to use acoustic leak detectors to isolate the location of the leak.
Acoustic leak detection is comprised of various technologies.
For information on the types of acoustic leak detectors which exists today, be sure to see the resource area and follow the links below.
Overview Of Current Leak Detection Methods For Utilities
