HONOLULU (HawaiiNewsNow) - Imagine getting a $900 water and sewer bill.
That's what recently happened to a Waialae Nui woman.
"You get a bill like this and the first thing you're shocked because it's so high," said local attorney Karin Holma.
Holma said the bill from the Board of Water Supply was based not on actual readings of her water meter but was based on estimates from her water and sewer bill from last year.
The problem: Her water usage spiked last year due to a leak.
She said a Board of Water Supply staffer later assured her that she didn't have a leak now and told her that a new computerized billing system was the reason for the big increase.
Typically, Holma and her husband use between 20,000 and 40,000 gallons a month and her monthly bill has ranged between $100 and $200.
But due to the leaking problem she experience last year, the board billing system estimated that the couple used more than 100,000 gallons last month.
"The amount was just unbelievable," she said.
This is not the first time that the new billing system has come under fire. When it was first installed in January, the system experienced a big spike in customer complaints.
Some lawmakers say that using estimates raises questions about the reliability of the board's billing policies.
"Some months you may use more than the other months. Sometimes you have a leak," said City Councilwoman Ann Kobayashi.
"How can you estimate based on that?"
The board said estimates are used for just 2 percent of the bills and that estimates are used only when the board's computerized meter reading devices -- which rely on radio signals to read the meters -- are unable to get a clear signal.
"A mistake could be made somewhere but if customers bring it to our attention we can look at it," said spokesman Dymian Racoma.