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Love Food, Hate Waste

2009 May 29

About the author: Cara Peck is an Environmental Scientist in EPA Region 9. For the past three years she has worked on the recycling of organic materials, but is now working on reducing the climate change and energy implications from the Agriculture Industry.

I love food. At various points along the day, it is a safe bet that I’m thinking about what to eat for my next meal. This could be the product of growing up in Northern California where we have amazing food, or it could be because I love to cook and eating logically follows cooking. Whatever the reason, I’m a huge fan of food.

While many share my love of the culinary world, there is an ugly and harmful side to the delicacies we enjoy- food waste. Organic waste, which includes food, currently makes up 25% of what is going to landfills. In addition to a host of other problems, landfills emit methane, a potent greenhouse gas. In an effort to try to get this food waste out of landfills, I started researching the anaerobic digestion of food waste. Basically, in an atmosphere without oxygen, bacteria feed on the food waste, break it down, and produce biogas in the process. Amazingly, biogas is an energy source, so in the process of reducing waste, energy is produced!

To further explore this project, I managed a few projects that investigated using this technology at wastewater treatment facilities. Many wastewater treatment facilities already use anaerobic digesters to break down sewage sludge. In addition, most of these digesters have excess capacity for something like… food waste!

Here’s a snapshot of how the process works: food scraps are collected at nearby restaurants. Then are sent to a local wastewater treatment facility, processed and injected into the anaerobic digesters. The bacteria go to work, break down the waste and produce biogas. The biogas is captured and used on site to power the facility, or even sent back to the grid. The residual that is left after the bugs have done their job is reduced, making it much easier to truck to the compost facility. Upon further composting, the material can be used as a soil amendment to grow more food. It’s a true closed-loop, sustainable system.

This technology has national applicability and I’m excited to see it more widely adopted in an effort to reduce waste and to combat climate change.

Since I do love food so much, I must admit that there isn’t often much waste left on my plate. However, I feel a little better about my love affair with food knowing that the waste that is left is going to a higher use and not contributing to climate change.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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14 Responses leave one →
  1. Josh Howard permalink
    May 29, 2009

    Personally, I think municipal composting would be a better alternative to biogas. By capturing all of the valuable nutrients (not just the carbon) and then delivering them to farms, we could enrich local food production (reducing the GHG produced by shipping), reduce waste, and sustain the fertility of our valuable farmland. Healthy environments, food, and people!

    On a related note, how can we reclaim the nutrients that are left behind in the sewage sludge?

  2. Johnny R. permalink
    May 30, 2009

    Answer: by 100% safe recycling of all sewage and trash. Otherwise,
    we will be overwhelmed by mountains of landfill and oceans of sludge
    and plastic slurry.

  3. loly permalink
    May 31, 2009

    That’s a good idea!! We should reuse as much as possible!

  4. Bum-Chong Yoo permalink
    June 1, 2009

    Thank you for posting this! After my geology professor mentioned not using the attachment bag for lawn-mowing (if it is at all possible), I have been thinking about what happens to all the waste that is collected as I work at my part-time job. I’ve seen it being thrown out, and I have thrown out trash as I am told. However, I do not know the trash’s future afterwards. I will only say that the trash is most likely taken to a landfill.

    It would be great if the corporation I work for practiced a sustainable method of dealing with food waste.

    Is there any way that I may assist EPA in notifying the restaurant chain I am working for about my ideas on helping the company be more sustainable ?

  5. Johnny R. permalink
    June 1, 2009

    So, the question is: does EPA have a program for recycling 100% of
    industrial waste and consumer trash and sludge, or must we wait for
    an ecocidal disaster?

  6. Bum-Chong Yoo permalink
    June 2, 2009

    Well, recycling 100 percent of industrial garbage is a bit far-fetched for now. I believe there are numerous projects within organizations that are delving in total recycling. Any one as a consumer can help bring about awareness of the issue, so a patient combined effort is necessary. However, if part of the waste can be converted into energy through biogas as Environmental Scientist Peck mentioned, a reduction in fossil fuels is possible.

    Nevertheless, I will look into the use of biogas. Thanks for your input, Johnny.

  7. Henry permalink
    June 2, 2009

    The idea of composting waste is something we’ve put to practice in recent months. Also, you can always feed leftovers to pets! With enough planning and forethought I have been able to greatly reduce any leftover wastes we have.

  8. Faye permalink
    June 3, 2009

    While using anaerobic respiration to create can create beneficial biogas, it should be considered carefully. Reduction can be simply defined as “gain of electrons”, where oxygen is typically the electron acceptor in aerobic conditions. In the absence of oxygen (anaerobic conditions) microbes must find an alternate electron acceptor. These reactions create dangerous greenhouse gasses such as Methane (CH4) and Nitrogen Oxides (NOx), which are several times more effective than Coarbon Dioxide (CO2).

    CO2 + 8H+ + 8e- ———-> CH4

    NO3- + 2H+ 2e- ———–> NO2- +H2O

  9. Cara Peck permalink
    June 3, 2009

    It has been great to read the comments over recycling. I’m glad the blog solicited some discussion! It is true that composting our food waste is needed in order to return nutrients back to the soil and sustainably produce food. Anaerobic digestion can be a precursor to composting. The process will first capture the energy and the residual can be further processed for composting. Methane is emitted by this process, but it is in an enclosed vessel, so the methane is captured and used for an energy source. Lastly, Bum-Chong, please feel free to email me at if you would like tips on how to help your workplace become more sustainable.

  10. Amrita permalink
    July 22, 2009

    Hi !

    Food crisis in incresing around the world and this also forces us to think about the amount of food we waste. Food waste is caused by cooking too much and then throwing away.

    Many people think that throwing food in the landfill is simply fine …It’s biodegradable after all, so doesn’t create problems but, but it is neccessary to make them know that the biodegradable food gets wrapped inside a non biodegradable plastic bag. If the air doesn’t get to the food then it won’t rot down and In the absence of oxygen, biodegradable materials decompose and produce methane gas, which contributes to global warming.

    With Regards

  11. BeWaterWise Rep permalink
    August 12, 2009

    Great to see a detailed explanation of what happens to food waste. Since we are talking about climate change and how food waste plays its role, did you know that we can also contribute a bit by what we eat to water shortage issue? Water is consumed more to cook meat, good to go vegetarian once in a while – completely giving it up would be too much to ask and difficult too. Its also good for our health to go vegetarian sometimes. Since water shortage is becoming a serious issue, especially in SoCal, we need to make amends in some way to address the issue. Visit for some water saving tips.

  12. mike permalink
    December 11, 2009

    it is scandalous….here in the UK we have three big wheelie bins for recycling, and yet even vegetable peelings we cannot put in the “green bin” for garden refuse it has to go to landfill.

    Take any of my favorite recipe and you are hard put to find any of them you can cook in one or two portions without leaving waste, of half a pepper, an onion or so on…

  13. linda permalink
    July 23, 2010

    Your love affair with food is commendable. This is really called for a this time. We need to recycle and lessen our waste production. So I appreciate your love affair to food as I too have a love affair with food.

  14. Kim - Best Restaurant Chelsea permalink
    October 5, 2010

    one cool technology! We need that spread across continents. Our clients should consider doing the same. Thank you for taking the initiative. thumbs up!!

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