anaerobic digestion
food recycling
power grid
scott evans
April 25, 2014

Food Recycling


Maggie: When it comes to helping the environment we know the big three: reduce, reuse and recycle. Well, Scott Evans shows us one school that is doing all of that and more, starting in the lunchroom.

Scott: We waste a lot of food in this country. It is estimated that Americans throw away 40% of the food they buy. It adds up to almost 36 million tons of food waste a year. And almost all of it – 95% of it – ends up in a landfill. Well, now some revolutionary recycling is changing that.

It is a smelly scoop of trash – food waste, mostly – that instead of going into a landfill, like other trash, is being fed into a giant machine with a cool-sounding name. The bio-digester.

Ruihong Zhang: The bio-digester uses microbes to convert organic waste, like food waste and animal waste, into bio-gas.

Scott: It is a process called anaerobic digestion. Methane is then extracted from that bio-gas and used to supply power to the UC Davis campus electrical grid.

Linda Katehi: For us to do it and demonstrate it on a campus of this size, that has about 65,000 people coming here everyday, really shows a way of doing this on a very large scale.

Scott: How large? The bio-digester plant, which went online last month, is designed to chew up 50 tons of campus waste each day. Food thrown out by students and faculty and other organic materials, like yard waste, will find its way here.

Man: If you look inside, that’s where it’s all mixed up.

Scott: All that mixing produces 12,000 kilowatt-hours of energy each day. That is enough to power an average household for an entire year.

UC Davis in California is the first university in the nation to turn leftovers into light. But it is also happening in the country’s largest city.

Ron Gonen: There is no reason why we should be spending taxpayer money sending something to sit in a hole someplace. It’s completely absurd and we need to move away from that as a society.

Scott: The residents of New York City generate more than 3 million tons of garbage every year. That is more than Boston, Philadelphia, Washington, D.C., Baltimore, Miami and Charlotte combined. One-third of that is food scraps and other organic material. And now the city has started its own anaerobic food recycling program. Sanitation workers pick it up, take it to a facility where any remaining non-organics are separated out and turned into a thick sludge and pumped into one of these 130-foot tall silver eggs where micro-organisms from the city’s sewage break down the sludge, turning it into fertilizer and methane gas that will be used to power homes.

It is a win-win! Less shipping, more renewable energy for homeowners.

Gonen: People have oftentimes looked at recycling as the right thing to do for the environment – which it is – but they’re now starting to recognize that it’s also the right thing to do for the local economy.

Scott: Where going green can actually save some green.

Scott Evans, Channel One News.

Maggie: For easy ways to make your day just a little bit greener, head to


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