Course: GFM 103 Exterior Environmental Management

Reading and Audio-Visual Assignments

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Accounting for Water Water Loss Control

Water Loss Control—National studies indicate that, on average, 14 percent of the water treated by water systems is lost to leaks. Some water systems have reported water losses exceeding 60 percent. Accounting for water and minimizing water loss are critical functions for any water utility that wants to be sustainable.

- EPA's Control and Mitigation of Drinking Water Losses in Distribution Systems (PDF) (176 pp., 3MB, About PDF), EPA 816-R-10-019
- National Environmental Service Center Tech Brief: Leak Detection and Water Loss Control (PDF) (4 pp., 203K, About PDF)

Identifying system leaks can pose a challenge. While operating personnel might identify some leaks in the distribution system during routine field inspections, not all leaks are visible, and targeted leak detection efforts are needed to detect hidden leaks in the water distribution system. Planned maintenance will help identify leak occurrences.

To better understand how water leaks are detected, water managers should look at three major water loss leak detection categories:

(1) leak detection through appearance,

(2) leak quantification through flow monitoring,

(3) locating hidden leaks with leak detection equipment (acoustic, thermal, electromagnetic, tracer, etc.).

Leak Appearance Estimates of the average lifetime of a slowly developing leak, from its inception until its repair can be up to two years (AWWA M36, 1999). Development of a leak depends on many variables and not every leak is immediately detected. In the absence of an active leakage control program, the presence of a leak in the distribution system is identified only when it appears on the road surface, in utility chambers, building basements, etc. and is reported by a utility employee or customer (i.e., reported leaks). It is best if a PWS can locate leaks in the hidden (unreported) phase via active leakage control; however, reporting from customers is very valuable. An educated and motivated customer, as well as a trained field inspector, is an indispensable resource for this mode of detection. Appearance of a leak may take a variety of forms from the subtle to the spectacular. The ways that leaks may be recognized and reported in the field include: (see you tube video via weblinks