Public works officials responded to nearly 5,000 reports of sewage backing up in Baltimore homes last year.
A Baltimore Sun investigation found that sewage backs up into Baltimore homes more than a dozen times a day on average.
The newspaper says the problem has gotten worse after the city agreed in 2002 to stop the chronic sewage directly into the Inner Harbor and Chesapeake Bay. That's how the city long relieved the system when it was overloaded.
Without the relief system, sewage can overwhelm the pipes and cause some of them to back up into homes.
Public works spokesman Jeff Raymond said the number of backups into homes was down last year.
But there were still significantly more than before the city closed most of its relief valves.
