S. Heather Duncan reports that for a long time, that amount of loss was considered acceptable:
"Where did it go?
A lot of it probably leaked out of pipes, some of it wasn't billed, some was used by cities themselves to water ball fields or test fire hydrants, and some might have been lost through inaccurate meters. The list goes on."
A new law, The Water Stewardship Act, is forcing water providers to account for their losses.
Duncan says "The impact on water resources could be significant."