Obviously it is best to compost food scraps, but that is not always an option.

A recent ABC news article claimed that food scraps were contributing to 'fatbergs' in Brisbane's sewage system. I've heard of wet wipes being a huge problem, and oils make sense, but food scraps is more surprising. So if you can't compost, what's the best way to dispose of food scraps?

  • In some places sewage sludge goes to an anaerobic digester. In that case it would definitely be worth using the disposal. But that's not very common.
    – Chris H
    Commented Dec 18, 2016 at 14:46
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    Related: sustainability.stackexchange.com/q/1028/15 Commented Dec 18, 2016 at 20:48
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    Go for a pig. Cute, friendly, and at the end of the year, tasty.
    – RedSonja
    Commented Dec 20, 2016 at 15:11
  • I guess it depends on how the sewage sludge and the general rubbish are processed in that catchment. Some places could discharge the sludge into waterways, others could digest, produce energy and compost. Some places could send rubbish to landfill (the case for Brisbane), others could incinerate it and produce electricity.
    – stragu
    Commented Dec 20, 2016 at 21:51

3 Answers 3


If you find that certain foods are contributing to a lot of "scraps," try googling that specific item to find if there is an alternate use for them. If there is none, and you can't find a creative way to reuse or reduce the production of the scrap (see more on this below), then you can consider garbage vs. disposal. In regards to those options, you could find out what happens to items in the garbage in your area - do they go to an incinerator or landfilled? Does your landfill have a compost? Does it have methane capture? etc. Only with that info can you really decide between those two options. But, I hope you would have a lot less "scrap" material if you seek out ways to reduce them to begin with.

The best way to eliminate food scraps is to rethink the idea of a food scrap. I don't mean to be cheeky, but just to suggest that you could find ways to reduce scraps.

For example, some scraps can be fed to your dog or other pet. Some scraps can be reused in another recipe, such as using carrot greens in pesto. Some scraps aren't scraps at all, such as many root peels. Try rinsing/scrubbing carrots or potatoes rather than peeling them and throwing away the peels. Some people cut off the stems of broccoli not realizing they are just as edible as the tops. Apple cores can be used to make apple cider vinegar, blended into applesauce, or even just eaten raw. The bottoms of leafy greens can be planted and will grow more greens again, etc. Eggshells are nutritious and can be broken up and blended into potting soil.

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    Your last few sentences answer the question (better than the others here, IMO), while the first paragraphs are useful advice, but don't really help someone who has already reduced scraps as much as possible. You may want to consider editing to highlight the last bit, or move it to the top.
    – LShaver
    Commented Jan 8, 2017 at 23:57

Good day,

The Clean Water Act prohibits the discharge of sludge into U.S. waterways.

Some states prohibit organics from being land-filled, and garbage disposals can contribute to blockages in sewer systems. It is best to contact your local Public Works Department for guidance.

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    Can you be more specific on some solution(s)? This kind of answer is more like a reference, but has too little "real" content.
    – Peter Ivan
    Commented Dec 22, 2016 at 9:12
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    Food scraps are not what the 1972 Clean Water Act defined as sludge. The USC states: "Sewage sludge means any solid, semi-solid, or liquid residue removed during the treatment of municipal waste water or domestic sewage." That's not what the question referenced. Fats in garbage disposals may wind up being sludge, but not necessarily so. Onion skins probably won't. Bacon fat may. Commented Dec 31, 2016 at 2:02

The composition of food scraps depend largely on the household's eating habits, so the answer may vary from household to household. Furthermore, the treatment of refuse and sewage differs from location to location.

One can only give some general guidelines, some of which will be within the domain of knowledge of the customer service departments of sewer and refuse organizations in your community. Other concepts may require inquiring in the environmental departments of your state or perhaps university researchers.

I'll assume you are interested in sustainable living in the wider sense and hope I am correct in that assumption.

Sustainability of a human circulatory system with regard to some fatty acids has one thing in common with the sustainability of a sewage system. Anything that enters in particulate or liquid form and, over time, forms attachments to the inner walls of the conduit will ultimately increase flow resistance until a complete blockage forms.

In the first case, flow resistance generally leads to high blood pressure and possible clot formation with the associated complications. Such a situation may lead to valve wear or heart fatigue, both of which can further lead to lethal malfunction.

In the second case, flow resistance eventually leads to sewage backup and expensive blockage removal procedures.

Whether in sewage or refuse, most fatty acids are biodegradable, meaning they are decomposed by microorganisms, mostly bacteria. What impact that has on buried refuse, exposed refuse, sewage in pipes, or sewage treatment will vary by climate and other factors.

One clear conclusion that a sustainability minded person can draw is basic and invariant by region or municipality: If you shop and cook in such a way that a drop of soap brings your cookware and dishes to squeaky clean (a simple test for fatty acids that cling to and lubricate smooth surfaces) two benefits are likely to co-occur.

  1. Your family will have lower risk of several chronic diseases.
  2. Your own home's plumbing and your municipality's sewer system will have fewer risks of malfunction too.
  • So are you recommending that food scraps be sent down the drain, rather than thrown in the garbage?
    – LShaver
    Commented Dec 29, 2016 at 4:06
  • @LShaver, no. I don't think I said or implied that. My main points were that one cannot give a blanket answer to the question, that changing food habits will impact the sustainability of scrap disposal more than any other household choice, and that what is good for the sustainability of the sewage system tends to also be good for the human body. Commented Dec 31, 2016 at 1:57
  • I used to have Fatburgs in my own drain before I started thinking about the sustainability of my own family's health. I agree that there's a strong relationship between the causes of both types of clogs. Commented Dec 31, 2016 at 22:43

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