The audit, which looked at three years but focused on the fiscal year that ended in June 2010, found that more than 18,000 households dependent on the city water system had received at least four consecutive quarterly bills that were estimated — and some received only estimated bills for more than four years.
McCarty recommended that the water and wastewater employees take actual meter readings at the homes before sending them to the tax sale.
Councilwoman Clarke said she hoped some of the problems would have been eliminated following the passage last year of a bill she wrote that prevents the city from sending out bills on estimated costs.
She said her office has been deluged with complaints from residents of her North Baltimore district regarding inaccurate water bills.
Clarke said residents often receive alarming water bills, such as an elderly woman in Waverly who received a $6,000 bill for the home in which she lives alone. After public work employees checked the account, the bill was reduced to $134, Clarke said.
Clarke praised Rudolph S. Chow, who has served as the city's water and waste water chief for the past year, for his work to remedy the problem.
"It's just a daunting catch-up that Mr. Chow and his team are trying to do," she said.
Baltimore resident Linda Stewart, who has been tracking errant water bills for years, called the audit a "relief."
"I'm glad to see this is finally coming to light," she said. "People have lost their homes over this. It's kind of a relief that the city is finally admitting they have a problem. They kept sweeping it under the rug for years."
She said she emailed the city every day for months at a time after she discovered erroneous water bills on three of her properties.
"It's been frustrating," she said. "It's a major problem and no one was doing anything about it."