Q Which is the better choice: garbage down the garbage disposal (and into the river) or garbage into the trash (and into a landfill)?
A The very best choice is neither trash can nor garbage disposal. Rather, recycle and compost as much as possible. Composting could even include using a worm bin in the house. But that will not take care of meat, fats and dairy products that cannot go into compost bins because of odor and vermin problems.
So whether the garbage disposal or landfill is better for kitchen scraps depends on where you live and where your waste or wastewater goes. It also depends on whether you are more worried about:
• The effects of landfills: methane production and links to global warming, and the rare possibility of a liner leak in a landfill causing groundwater contamination.
• The effects of using a garbage disposal: The probability of nutrients or harmful chemicals that may not be filtered out at the wastewater treatment plant ending up polluting lakes and rivers.
Wastewater treatment plants don't remove all nutrients, but these facilities must meet state and federal standards for phosphorus. Over the past few years, these standards have been tightened to reduce the amount of phosphorus in the discharge from wastewater treatment plants. These standards are designed specifically to protect lakes, streams and wetlands from excess nutrient pollution. If you have a septic system, however, you should not use a garbage disposal at all, because a septic system cannot treat these wastes.
Landfills have a small risk of liner failure, but a leak could cause pollution to spread by contaminating groundwater. Food waste in landfills also creates a significant amount of methane, a greenhouse gas. Food decomposes very rapidly (starting in your trash can on a warm day) and begins releasing methane gas almost immediately, long before the gas collection system at a landfill is operating. Methane is 21 times more potent a greenhouse gas than carbon dioxide and is a targeted emission for reducing the impact of climate change. All of the big landfills in Minnesota are required to capture methane emissions, reducing the risk of their release.
If you live in the metro area, 45 percent of the garbage picked up goes to resource recovery facilities, where it is turned into energy, so it won't be emitting methane into the atmosphere or sending excess nutrients into lakes and rivers.
