SEATTLE -- What begins as truck-loads of trash will soon provide electricity to more than 20,000 homes across King County.

And the plant that will create that energy at King County's Cedar Hills landfill, is the third largest landfill gas to energy facility in the country.

Before, dangerous landfill gas would be produced from trash decomposing underground. To get rid of it, King County burned the gas, which produced high levels of carbon dioxide.

"And all that energy for 15 - if not more years was literally gone up in smoke," said Chuck Packard with Ingenco Energy. "That won't be happening at the end of April."

This new plant will take all that bad gas and turn it into good, clean gas that Puget Sound Energy will use to create electricity.

And all that renewable energy will be the equivalent of eliminating the emissions from 22,000 cars.

The facility is impressive -- there are all kinds of gauges and valves and levers and cranks and all of that comes together to produce energy -- but also to improve the air quality, reduce health risks and create jobs.

The plant employs 12 new workers. Add a few dozen more for construction and maintenance.

It cost $50 million to build the facility, but plant managers say it will pay for itself in 4 to 5 years.