As eco-conscious people, we all know that composting is effective when done properly. In an ideal world, it is probably one of the best ways to manage waste. The problem is, many people around the world simply cannot compost given where they live: in crowded urban settings and high-rise buildings amid frigid weather. For those who are lucky enough to have a garbage disposal in their homes, this seems to be an ideal solution to the problem. Just grind up your garbage and rinse it away. It is one of the many small approaches we take to handling the issue of waste on our planet and one that many people implicitly rely upon. We know that organic material eventually turns into biogas, which is about 60 percent methane, but what happens to food that is washed down the drain?
According to experts, about 70 percent of food scraps are water, so that leaves us with 30 percent solid matter that is heading into our pipes. Some of that remaining material is immediately screened out at wastewater treatment plants. However, the majority of it is sent to landfills, where it will decompose. The dissolved solids that make it into the treatment plant are either turned into carbon dioxide or methane by enzymes. The additional demand on the plant carries a cost, as increased biological oxygen demand (BOD) and levels of dissolved solids increase the amount of treatment required, which translates into higher costs, more chemicals, and additional energy. The quandary is, would we just be better off putting it straight into a landfill, or does the disposal add value?
Prevent clogged drains
Food waste washed down the drain also increases the chance of clogs, especially if the material contains unsaturated fats that will solidify at room temperature and build up in the pipes over time. These types of blockages not only create headaches for homeowners and city maintenance workers, but they also cause roughly 75 percent of all sanitary sewer overflows, resulting in untreated sewage skipping the treatment process altogether and heading straight into bodies of water. Of course, when this happens, it adds considerable expense to the overall process, as demonstrated by San Francisco’s annual bill of $3.5 million for grease-related sewage issues alone.
As proponents of garbage disposals, we are led to believe that the reduced amount of waste going down our sinks must translate into fewer landfills and garbage trucks. However, this is not necessarily the case. In order for food to properly convey itself down the pipe, it needs the help of our most precious commodity—water—which has to come from somewhere. In a recent report, the California Energy Commission attributed nearly half of its electricity and natural gas use to pumping wastewater.
Throw it in the trash
So, what are we supposed to do with all our food waste now that we know that the garbage disposal is not ideal, and we aren’t fated for composting? The first step is to employ a strategy for dealing with unwanted food. Although a disposal has the ability to chew up all sorts of gunk, it’s always a good idea to remove as much organic material from the sink as possible before running it down the drain. So, if you are cleaning out a container of unwanted leftovers, don’t smash it all down the pipes and relish the sound of grinding. Throw it in the trash before rinsing out the container. Although it will end up in a landfill, it is the ideal solution, given the value of water and energy. It is better for the planet to bury it than to waste precious resources breaking it down.
Now if this doesn’t sound like a great option, there is a better one. There are some modern indoor automatic composters made from recycled materials that include a small heater and mixer to maintain industrial-grade composting conditions. What this means is that you can actually compost everything—meat, vegetables, egg shells, and dairy. The unit fits conveniently under your sink or on a kitchen shelf, so you can avoid sending food waste down your drain, all while producing up to 120 pounds a month of rich, organic compost. When looking at the problem from a distance, it really is the only sound solution to the management of kitchen waste.
So, the next time you reach for the disposal switch, make sure you have given some thought to what exactly is going on down there. Out of sight does not mean out of mind, as all of our decisions have long-term consequences. While it can be tempting to get rid of that mystery container that’s been hanging out in your fridge for months as quickly as possible, you should try to put as little as possible down your disposal, and it should always be just that material that can be properly “digested.”