As a way of controlling fouling in water distribution lines, utilities often conduct system-wide flushing cycles to clear lines of sediment, biofilm, and other accumulated material to maintain good water quality for customers. This can be done on an annual basis or as dictated by water technicians if more frequent flushing is needed.
Take the city of Parker, Colorado (Population = 46,363) as an example. As part of their annual flushing activities, they would flush each hydrant for an average of 1.5 hours at 276 USgpm for a total of 24,840 US gallons. The total flushing time across the entire distribution system was roughly equivalent to 1582 hours, or a total flush volume of 26 million gallons of water. At a nominal water cost of $2/1000 USgal (source: US EPA), this is equivalent to over $52,000 of water that is flushed away. Similarly, the city of Colorado Springs (Population = 426,388) uses a total of approximately 50 million USgal of water for flushing which carries a value of $100,000. Clearly, distribution system flushing can be an expensive endeavor, especially considering that the examples above do not consider the costs associated with the field technicians carrying out flushing activities or laboratory staff conducting microbiological tests.
Since conventional microbiological tests are slow and cannot be done in the field, technicians tend to flush for predetermined time intervals or rely on turbidity measurements which can be misleading since low turbidity does not guarantee low microbial levels. As such, field technicians must often leave their equipment in the field until microbiological test results are returned to confirm adequate cleanliness before moving on to a new location.
LuminUltra’s 2nd generation ATP monitoring technology provides the best of both worlds for field testing in flushing operations: an easy-to-use field test that provides a true total measure of microbial content. With results being available on-the-spot, flushing efficacy can be assessed as you go so that you can immediately tell when enough is enough. With reliable information on microbiological cleanliness being available on-site, flushing technicians can move on with confidence that they have done a sufficiently good job while avoiding excessively high flush volumes. As such, the return on investment for LuminUltra’s monitoring products can often be realized by saving as little as 10% of the water volume used for flushing with additional savings being quickly realized by getting the job done faster and avoiding the wait times associated with laboratory testing.