NEW YORK (FOX5NY) - A huge congealed lump of fat is being blamed for overflows of a Baltimore sewer that discharged nearly 1.2 million gallons of waste onto the streets in the city's midtown area.
It happened twice, and most recently on Sept. 21 on Charles Street near Baltimore Penn Station.
Sanitation officials say the so-called 'fatberg' also included wet wipes and other items that do not breakdown in sewer systems. The massive plug of grease has been growing far below the surface before the system became too clogged.
Public works engineers decided to explore the sewer in that area to determine the cause. They sent a machine with a closed-circuit television camera into the sewer, and soon discovered the walls of the sewer pipe were caked with congealed fats, oils, and grease.
The buildup was so thick that it slowed sewer water moving through that area. Engineers estimate that 85 percent of the pipe, which is 24 inches across and more than 100 years old, was blocked.
This resulted in sanitary sewer overflows happening underground, in a structured overflow that was designed more than 100 years ago as a sort of pressure-release valve in the event the sewers backed up.
The fatberg has been mostly scraped off and sent to a landfill.
A fatberg estimated to weigh more than 140 tons was recently discovered in London's sewer system. Officials say it could take weeks to destroy.