A plan was announced Tuesday to upgrade two 30-year-old ships used to transport sewage away from New York City waters.

The ships will be replaced by three new "sludge ships," which were specially designed to sail into Newtown Creek, carry twice as much sewage and make fewer trips per year to save money on fuel costs. The city will use about $220 million in federal stimulus funds for the project.

Officials say clean water regulations in the area mean more sludge needs to be transported out. The project is expected to create truck driving, engineering and water treatment jobs, among others.

Construction on the new ships will begin in January 2010.