Trash Talk

With all the recent talk of being “green”, many people have begun to make small changes to do their part. Living on my own I have vowed the same. Since I live in a duplex, without a yard, I am unable to compost so I have begun using my garbage disposal religiously.

Have you ever thought about how your garbage disposal works? Well, neither had I. Most people view their garbage disposals as being mysterious, you flip a switch and it works. That’s all most people care to know, though how a garbage disposals works is actually quite simple.

It is commonly thought that a garbage disposal works like a blender, with spinning blades chopping and breaking down the food. In reality disposals work in a different way and there are NO blades involved. Instead, impellers (or lugs) mounted on a spinning plate use centrifugal force, at a speed of almost 2,000 RPM, to continuously force food waste particles against a sharp-toothed inner wall. The wall breaks down the food waste into very fine particles, practically liquefying them. This process is most commonly interrupted, causing a jam, when the food placed in the disposal is either too large or too firm for the machine to handle. In these instances, the food will usually fall beneath the plate where it cannot be broken down properly. Keeping this in mind, large or firm pieces of food should not be placed directly into the disposal, but should first be broken down by hand into a workable size. Once pulverized, the running water flushes the particles through the inner wall, out of the disposer, and into your wastewater pipe. From there it flows into your septic system or to the wastewater treatment plant.

There are two common types of garbage disposals available that differ slightly from one another; continuous feed and batch feed. A continuous feed disposal operates, once switched on, by feeding food and water from the spinning plate to the inner wall and then finally to the drainage pipe. Batch feed disposals work in a similar way, except for the fact that a stopper is placed in the disposal. After loading a batch feed disposal, the stopper activates a switch which turns it on. Continuous feed disposals are considered to be more user-friendly, and are therefore more common, than batch feed disposals.

I hope you enjoyed learning about a little bit about your garbage disposal, but if you’re craving a bit more, here are some fun facts…
• John W. Hammes invented the garbage disposal in 1927 for his wife (apparently she didn’t want a vacuum cleaner). He spent eleven years refining his invention before starting his own garbage disposal business. The name of his company? The In-Sink-Erator Manufacturing Company.
• In nations with ready access to water and an industrial base, such as the United States, garbage disposals are common fixtures.
• In the US approximately 50% of homes had garbage disposal units in2009, compared with only 6% in the UK.
• Garbage Disposal Energy usage is not high; typically 500 to 1500 watts of power are used. This is comparable to an electric iron, but only for a very short time. Per year, this totals to approximately 3-4 kilowatt hours of electricity per household. Daily water usage varies, but is typically one gallon of water per person per day, comparable to an additional toilet flush.
• Food scraps range from 10 – 20% of household waste, and can be a problematic component of municipal waste. Burned in waste-to-energy facilities, the high water-content of food scraps does not generate energy; buried in landfills, food scraps decompose and generate methane gas, which is considered to be a potent greenhouse gas.
• The premise behind the proper use of a disposal is to effectively regard food scraps as liquid (averaging 70% water, like human waste), and utilize existing infrastructure (underground sewers and wastewater treatment plants) for its management. Modern wastewater plants are effective at processing organic solids into fertilizer products (known as biosolids), with advanced facilities also capturing methane for energy production.

Formisano, Bob. “Anatomy of a Garbage Disposal.” Home Repair. Web. 26 Nov. 2011. .
“Garbage Disposal: Facts, Discussion Forum, and Encyclopedia Article.” Web. 27 Nov. 2011. .
In-Sink-Erator Staff. “How Garbage Disposals Work.” InSinkErator. Web. 26 Nov. 2011. .
Larsen, Kurt. “How A Garbage Disposal Works.” Home & Garden Ideas. The Writers Network, 24 Feb. 2011. Web. 26 Nov. 2011. .
Vandervort, Don. “Home Tips : How a Garbage Disposal Works.” Home Tips. Web. 26 Nov. 2011. .


7 thoughts on “Trash Talk

  1. Trash talk: Ditch the garbage disposal.

    After reading this post, I was interested in what options people have for composting when they live with no space, no garden, and no time to compost. A quick answer appeared: Get a Green Bin!
    I found that a few cities were starting this initiative, where just like the city comes around to pick up garbage and recycling, the city will also pick up food straps. The two most notorious cities for accomplishing this idea are San Francisco and Ottawa, Canada. Once the city picks up these food scraps they deliver them to local farmers who then use them on their gardens or fields. It has actually shown to cut down on a few city costs such as water filtering (have to get the food separated from the water when using a disposal), landfill overfilling, and the travel required to get the “green garbage” to the landfill. Most of the time there are local organic farmers that would love to use our nutrient rich food scraps. Not only is this option green and cut city costs it can also cut your costs at home: less water is involved, you never have to worry about garbage disposal repair, there are lower energy costs, and you can have the feeling that you are helping the environment. The Hilton San Francisco, the largest hotel on the West Cost, recently removed all of its garbage disposals. The manager of the project says he has seen a big difference in mechanical and water expenses. The hotel serves anywhere from 2,000 to 7,500 meals a day and therefore has daily green bin pickup service.
    Another benefit is that more items can go in the green bin than down the disposal. Of course you can put the “softer” food that you would normally put down the disposal but you can also put bones, crab shells, starchy or fibrous materials, and even soiled paper. The farmers welcome it all!
    While there is no “green bin city pickup service” here in Greencastle or in most cities around the US, there typically are plenty of farmers within a cities general range. An option discussed by Perice is to go talk with a local farmer. You can ask them if they would be interested in your “trash” for their fields. They might just say yes and create a win win for both you and themselves.
    This is a great option and idea for people that either cannot or just do not want to deal with composting but wish to be a little more green and potentially cut some costs themselves along the way.

    Green Bin Program, Ottawa, Canada, 2011

    Ditch the garbage disposal, use a green bin. Farmers will thank you. 2007

    Overview of Ottawa’s Program, PDF, Best Practice: Green Bin Program: City-Wide Composting, 2010

  2. Good job on your blog post Lindsey! Similar to Ginny, I looked a little bit into ways that composting may still be a viable option for individuals living in duplexes or apartments. One option I came across is worm composting.

    First of all, just in case someone isn’t familiar, composting is a process in which you allow your food scraps to be broken down in order to form a rich soil product. This allows you to form a potentially re-useable soil product and generate less trash. Typically, composting requires a decent amount of space, but worm composting has arisen as an option that allows composting to occur in potentially smaller spaces and indoors. In order to compost using worms, a container (roughly 1 square foot per pound of food scraps) is lined with wet materials and the worms that will allow the process to occur. Typically, either Eisenia foetida or Lumbricus rubellus worms are used. These earthworms are common in manure and compost heaps. Other types of worms may not be able to effectively survive or facilitate composting.

    Why does worm composting work? Worms feed on organic materials present within food scraps and excrete them as vermicompost. The vermicompost, as well as the worm tunneling, helps improve soil drainage, aeration, and nutrients and oxygen accessibility. This process facilitates a quick, controlled breakdown of food products that could occur in areas as small as a closet. While we may typically associate worms with disease and feel uncomfortable allowing them into our homes, many earthworms feed on some microbes, which may cause their environments to be less likely to spread pathogens.

    While, understandably, not everyone may be comfortable with having a closet containing a pound of earthworms breaking down food scraps, this is an option that people may look into if they are incredibly eager to benefit the environment from a small home!

    If you’re interested in finding out more, I recommend the following websites…

    • Bryan, I thought this was pretty fascinating. Frankly, I’ve never heard of this composting I decided to youtube it: Worm Composting 101. Two points primarily stuck out to me. First, apparently 30% of the waste that goes into the landfills could have been composted and rescued by these worm bins. Second (and much to my surprise), the worm bins don’t actually smell at all. They apparently smell just like…dirt. I guess when you have a bin full of waste, worms, and dirt, the last thing that I imagined smelling was dirt. So, I guess you are right in saying if only people can overcome the notion of having a box full of worms in their house, worm composting can be a viable and effective alternative.

      Also–check out this clip of an enormous vermicomposting facility (don’t mind the creepy foreign guy at the beginning):

  3. Hey Lindsey!

    I liked the post! It taught me about the mechanics of a garbage disposal and gave me some insight into green ways to discard extra food waste. I actually found this other article weighing the benefits and faults of putting your scraps in the garbage to be taken to a landfill versus putting them down the garbage disposal to be put into the water supply. The big conclusion was that you should just compost, but also that it depends on where you live- ie how far the landfill is from your house, so how much gas is required to take your garbage away, and the water supply in your area. The conclusion was therefore kind of split.

    In the end…good to know that there aren’t slicing knives in the garbage disposal like I thought before. Thanks for the post!

  4. I thought that this was really interesting! Like you mentioned in your post, I have always imagined that my garbage disposal had a rotating blade in it (kind of like the blades of a blender). Like Sarah, I’m glad that there aren’t sharp blades involved in a garbage disposal. Though the idea of have lugs that can liquify veggies, meat, etc. isn’t actually that much more comforting. While I’m a big fan of garbage disposals (especially after not having one last year), I looked into the idea of in-home composting a bit. From what I found, there are some compost bins that claim to be odor-free (You can just type odor free composting into google, and get a bunch of different options. I personally can’t attest to how well these work since I’ve never composted before.) and are compact enough to fit under the kitchen sink. So if you were dedicated to the idea of composting, these might be a plausible option to look into.

  5. Good post Lindsey,
    From reading your article, I didn’t really understand what happened to the food after it went through the garbage disposal and why it was a better alternative to simply throwing the food away. I looked around a little bit and managed to find a helpful site that included a short presentation on the process that the food goes through from putting it into the sink until it can be used to generate power and fertilizer. It is the fourth option in the scrolling menu, and their are other intersting links.

  6. Great post, Lindsey. I don’t know what is more comforting…a disposal with rotating blades or impellers mounted on a spinning plate that uses a centrifugal force speed of nearly 2,000 RPM, to continuously slam food waste (or fingers) against a sharp-toothed inner wall. Yikes. Either way, sticking your hand down the disposal is a bad idea. I liked your post because we normally don’t think how normal, everyday household machines actually work. You inspired me to start questioning my understanding about other household systems…and I began thinking about septic tanks (I know this might a bit off topic, sorry!). I randomly decided to ask my father if he knew anything. Surprisingly (and quite oddly), he knew a lot about our septic tank, which is apparently eco-friendly. Here is what I retained from my “interview” with my dad about septic tanks: our human waste gets distributed from our house to the septic tank via pipelines. The septic tank holds the waste deep below ground level. As the waste gets dumped (no pun intended) into the tank, the waste at the bottom of this tank gets funneled into a pipe. This pipe branches out into several other pipes (like our capillary system) deep beneath our beautiful yards. These finger-like pipes are surrounded by sand and all have holes in them. So as waste travels down the length of the pipe, it exits into the sand through these tiny holes. The sand acts as a natural sieve, filtering out pathogens and bacteria while allowing the fluid to continue to seep back into the water bed. The waste then acts as a natural fertilizer, nourishing not only the trees and plants around us, but also…the grass of our yards…the same grass in which we might sometimes sunbathe, roll around in, play soccer in, etc. Awesome!

    The septic system I described is just one of many…but in the following clip, Bob the Builder describes the anatomy of a general septic tank. Check it out! (and sorry for the deviation from garbage disposals and food waste…human waste seems to just be so interesting).

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