Ralph and Diana Salgado said their water bill usually falls between $21 and $110 each month, but their July 2008 bill from the Tampa Water Department totaled $21,600, indicating that 3.5 million gallons of water were used by the couple during that month, The Tampa (Fla.) Tribune reported Tuesday.
"They just billed us; they didn't even question it," Diana Salgado said.
The couple said they soon determined that the erroneous amount was the result of a new water meter that had not been calibrated to match the old reading.
However, they said the water department continued to demand the money for months after the problem was identified.
"It took several months to settle," Diana Salgado said.