Dr. Biswas clearly points out the issues regarding desalination (and recycling) of water. It should additionally be pointed out that water distribution systems already lose significantly more to water main leakage than their most ambitious desalination or water recycling projects might generate. (Currently AWWA studies indicate average losses of ~20%, but planned desalination projects would supply less than 10% of the required additional water, at very high costs. For example, the California Public Utility Commission determined that the delivered cost for water from conventional sources averages USD 793/acre-foot; desalinated water has an estimated average cost of USD 3,889/acre-foot (with a maximum of USD 5,400/acre-foot); and recycled water has an estimated average cost of USD 2,869/acre-foot (with a maximum of USD 5,800/acre-foot). Recovery of the water lost to water main leakage would be far less costly than putting the desalinated or recycled water into the water mains that continue to leak. Not enough effort is being done on the very basic problem of minimizing water leakage losses. The California Department of Water Resources points out that a very major problem is the fact that the accuracy of large water main type metering systems are difficult to determine. The solution is "obvious": Simply build aerospace-grade flow calibration systems (+/- 0.05% uncertainty) on water main size scale. It is do-able, and leak detection by metering zone leak detection by mass/volume balance would then be easier. The cost for establishing low uncertainty large water flow calibration systems suitable for leak detection would we less than several months water loss of many distribution companies.
Published by Arnold Liu, CEO & Scientific Director at Quantum Dynamics, Inc.
Dr. Biswas clearly points out the issues regarding desalination (and recycling) of water.
It should additionally be pointed out that water distribution systems already lose significantly more to water main leakage than their most ambitious desalination or water recycling projects might generate. (Currently AWWA studies indicate average losses of ~20%, but planned desalination projects would supply less than 10% of the required additional water, at very high costs.
For example, the California Public Utility Commission determined that the delivered cost for water from conventional sources averages USD 793/acre-foot; desalinated water has an estimated average cost of USD 3,889/acre-foot (with a maximum of USD 5,400/acre-foot); and recycled water has an estimated average cost of USD 2,869/acre-foot (with a maximum of USD 5,800/acre-foot).
Recovery of the water lost to water main leakage would be far less costly than putting the desalinated or recycled water into the water mains that continue to leak. Not enough effort is being done on the very basic problem of minimizing water leakage losses.
The California Department of Water Resources points out that a very major problem is the fact that the accuracy of large water main type metering systems are difficult to determine.
The solution is "obvious": Simply build aerospace-grade flow calibration systems (+/- 0.05% uncertainty) on water main size scale. It is do-able, and leak detection by metering zone leak detection by mass/volume balance would then be easier.
The cost for establishing low uncertainty large water flow calibration systems suitable for leak detection would we less than several months water loss of many distribution companies.