AWWA ACE70687

This powerpoint presentation begins by providing a brief overview of the relevance to North American utilities and background to Trinidad and Tobago water loss assessment. Methods for determining unmeasured consumption are presented, along with estimating unmeasured consumption, validating system input meters, assessing accuracy of large revenue meters, validated water balance, and water efficiency surveys. Conclusions indicate the following: it is possible to determine a reasonably accurate validated water balance in a largely unmeasured system suffering from intermittent supplies; in systems with large numbers of sources, the confidence in the system input volume can be high, even though confidence in individual meters is not; there are benefits in undertaking a water efficiency survey as a part of an NRW assessment; and, the high level of consumption from storage tank overflows was an unexpected outcome of the water efficiency survey. Includes tables.