BROCKTON, Mass. -- Ayanna Yancey Cato's water bill is not for the faint of heart.

"I am looking at a total bill of over $100,000," said the Brockton resident.

Cato has been disputing her water bill for over a year, since the city decided to retroactively bill her for the last 12 years of water usage. The city claimed it had been underestimating her bills since she moved in to her home.

"From the time that I purchased the house, from the time that I started getting water bills, I was just paying the bills as they came in," said Cato, who wonders how she could have possibly used that much water.

She does not have a pool and her hot tub sits empty. Three plumbers have inspected her home and failed to find any leaks.

Brockton Public Works Commissioner Mike Fersons admits their current meter reading system is antiquated and many of its devices are faulty. The city is going through 25,000 customer accounts to try to determine what its customers really owe.

"We are committed to working with residents on a case-by-case basis to resolve these retroactive bills and in most cases, the city is willing to forgive a significant portion of the bill," said Fersons.