Los Angeles wants to turn wastewater sludge into energy using a process that would cut greenhouse emissions and reduce truck traffic.

The city says the renewable energy project, which is expected to cost $3 million to $4 million, and begin running by next spring, is a first-of-its-kind in the United States, The Los Angeles Times said.

The project, unveiled Thursday at the Terminal Island Water Reclamation Plant, would use sludge to produce electricity for about 3,000 homes, the newspaper said.

Organic material left over from treated wastewater would be injected into depleted oil and gas reservoirs underground. High temperatures and pressure will create methane gas to power fuel cells on the surface.

The process will also dissolve carbon dioxide, removing the equivalent of exhaust from 3,200 cars each year over the next five years. It will also reduce by half the 750 tons of treated solid waste trucked out of Los Angeles each day, the newspaper said.

Copyright 2007 by United Press International