Apr 13, 2007

L.A. to Create Energy from Wastewater Sludge

Los Angeles city officials recently broke ground on a renewable energy project in San Pedro that will use treated wastewater to produce electricity for about 3,000 homes. The new plan will also save money and reduce truck traffic on local roads.

According to the Los Angeles Times, officials unveiled the five-year plan at the city's Terminal Island Water Reclamation Plant, calling it a first-of-its-kind in the country that could serve as a model for other cities.

When announcing the plan, Mayor Antonio Villaraigosa pointed out that it is a part of a broader effort to increase the city's use of alternative energy sources.

Engineers reported to the Los Angeles Times that the renewable energy project will inject spongy organic material left over from treated wastewater into depleted oil and gas reservoirs more than a mile underground. Then, high temperatures and pressure in those pockets will compress the biosolid material, creating methane gas that will be captured to power fuel cells on the surface. The underground processes also will dissolve carbon dioxide that the organic material would normally release into the air, removing the equivalent of exhaust from 3,200 cars each year over the next five years.

Homayoun Moghaddam, project director, estimated that the system is expected to cost about $3 million to build. Construction will begin in the spring of 2008.

After the new plant is fully operational, in about three years, it should produce 3.5 megawatts of electricity, which is enough power to run nearly 3,000 homes. The energy is worth $2.4 million a year. At the start of the project, the energy will go to the port-related facilities around Terminal Island.

The sludge for the system will come from the Terminal Island treatment plant and the Hyperion sewage treatment plant in El Segundo. It will be combined with treated water from the Terminal Island plant that would otherwise be pumped into the Los Angeles Harbor.

The project has been approved by the U.S. Environmental Protection Agency and the head of Santa Monica Baykeeper.

The L.A. Public Works Department is coordinating the project with Terralog Technologies USA Inc., which will operate the system during the initial five years. The city must obtain a permit from the EPA to continue operations permanently.