Wasting Food

by Robert Glover / November 9th, 2024

It has been suggested that to reduce landfill greenhouse gas emissions, food wastes should be ground up and sent to the sewer. This is the worst possible attempt to reduce greenhouse gases, and will, in fact, increase the amount of greenhouse gases released to process those food wastes.

I have worked at a wastewater treatment plant for the last five years. These facilities are located in every small, medium and large city, with public sewer systems, across the world. They are designed to process human fecal waste, capture organic matter and metals, and release treated water back into the environment. They primarily process those wastes using a biological system of bacteria and microorganisms.

Heavy particles or debris that come in with the wastewater will be filtered or collected at the front of the plant and taken to a landfill. That filtration or collection requires energy. That energy is provided with electricity, often created by burning fossil fuels.

Any lighter particles that stay suspended in water or float on the surface will also be collected. Any carbon will be converted into methane by bacteria in an anaerobic digester or processed by bacteria into carbon dioxide in an aeration basin. Either solution also requires additional energy, either to heat the anaerobic digesters or to pump air into the water to add oxygen to it.

The amount of carbon coming into the treatment plant will exactly equal the amount going out as carbon dioxide, methane or as sewage sludge. Sewage sludge is the leftover solids, bacteria and organic matter that will need to be removed from the treatment plant. The sludge will either be land applied on farms as fertilizer, or sent to a landfill. As regulations tighten on land application across the world, landfills will be the ultimate destination of all sewage sludge in the near future.

The food waste you send down the drain, instead of throwing it into the garbage, will ultimately still end up at the landfill. The carbon in that food will still be released as methane or carbon dioxide. Except, instead of the two steps of collection and delivery to the landfill, it will compound the effects of that food waste by sending it through a wastewater treatment plant, increasing the energy costs of the treatment plant and increasing the amount of greenhouse gases released to process that food waste.

If you want to reduce the amount of greenhouse gases from your food waste, compost it or turn it into biochar by burning it in a low heat environment with a lack of oxygen. That is the only way to lock in the carbon for long term storage. Don’t send excess food wastes to a treatment plant, we have enough carbon to deal with, just with the feces.Email

Robert Glover was born in North Carolina and spent most of his life in Texas. He is educated in Environmental Science and a writer by profession, mainly novels. But politics is also a passion. He can be reached at: author.robert.glover@gmail.com. Read other articles by Robert.