Garbage Disposals Provide An Alternative to Composting

Life Cycle Assessment study reveals advanced wastewater treatment plants can convert food scraps into renewable energy through a process called anaerobic digestion.

Renters want garbage disposals installed in their kitchens for convenience, but now the results of a new study point to the environmental advantages of disposals.

The Life Cycle Assessment study, conducted by an independent research firm, found that throwing food waste in a garbage disposal produces lower global warming potential than sending it to landfills, the most common method for managing waste. Food scraps down the drain go to a wastewater treatment facility where it can often be converted into renewable energy or natural fertilizer.

The report states that if a community of 30,000 households (the size of Newport Beach, Calif.) switched from sending scraps to the landfill to using a disposer instead, it could eliminate nearly 2,100 tons of carbon dioxide emissions, akin to eliminating about 4.6 million miles of car traffic.

“The cost to retrofit a garbage disposal ranges from approximately $100 to $400, depending on the model and the individual installation circumstances,” says Rob Grim, InSinkErator Sr. VP of Sales. “Installing in multiple housing units at once can lower the cost significantly.”

Few, if any, units can not have a disposal. “The National Green Building Standard grants a point for inclusion of a disposer,” says Grim. “Interestingly, according to a survey conducted by the Association of Home Appliance Manufacturers, housing units with a disposer installed report significantly fewer kitchen drain clogs than units without a disposer—a good thing for managers to remember.”

Many advanced wastewater treatment plants can convert food scraps into renewable energy through a process called anaerobic digestion. At these plants food scraps can also be turned into fertilizer products, also known as biosolids, which can help build healthy soils.

“In thinking about systems for managing food scraps, wastewater treatment systems are often overlooked despite their surprisingly effective role in turning liquid waste into valuable resources,” said Michael Keleman, senior environmental engineer, InSinkErator. “Composting is good but it isn’t the only option.”

The study also concludes that processing of food scraps at these advanced wastewater treatment facilities has lower energy demand—less than landfills, incineration and centralized composting. More information about the study and the InSinkErator environmental story is available at www.insinkerator.com/green.