Black Water Disposal

Human waste, fecal coloforms, urine, all the good stuff that nobody wants to deal with. but living in a Tiny house you are forced to deal with it. Unless you are going to be permanently installed on the grid you don't really have the option to just install a toilet and not think about it. There are a couple of things you can do to dispose of your waste. You can burn it, you can compost it, you can digest it or you can dehydrate it.

Burning/incinerating it: This is the best treatment for human waste as it reduced to sterile ash. Unfortunately this requires a large amount of fuel to reduce the waste. You can reduce both urine and feces using incineration. and building an incinerating toilet can be really simple, all you need is a heavy bottomed metal container to hold the excrement. To incinerate, just add heat and vent the exhaust and remove from heat when excrement has been reduced. Of course building an incinerating toilet can be extremely complex but now that you understand the basics of incineration you can do whatever you want.

Composting it: This is probably the most common waste disposal method as it is simple, requires only a bucket and sawdust. the downfall is that while it does compost eventually, most compost isn't fully decomposed by the time the toilet needs to be emptied. The compost also needs to be aerated to aid in decomposition. The upside is that you can build one for $10, just take a 5 gallon bucket, add sawdust, every time you do your business, cover it with sawdust. When it's full, take it out. Of course you have to have a compost pile outside, or a place to add your "humanure". You shouldn't add this to any plant that bears food as it may cause health problems.* 

*NOTE: some people say that they have been doing it just fine for years with no ill effects, so the door could swing either way.

Digesting it: This is probably the largest system of the group and it involves anaerobic digestion of the bacteria in your excrement. It is the opposite of aerobic digestion [composting] in that there is no oxygen required for digestion to take place. One advantage to this is that methane is produced with this digestion. This methane can be burned for heat, cooking, hot water, grey water distillation, pretty much anything that you need heat for. Granted you won't yield an abundant amount of gas unless you add an abundant amount of excrement. Once the excrement has completed digestion it becomes what is called slurry, which is completely decomposed and ready to be used as compost. it can be diluted and sprayed over grass as a fertilizer but, like humanure, it shouldn't be used on food bearing plants.

Dehydrating it: This is similar to incineration only the excrement isn't heated to the point of combustion, instead it is heated enough to remove all the water so the waste is light and can be disposed of easily in a trash bag, or ground up and spread around as fertilizer another thing you can do with the excrement is to burn it The more dry it is, the more readily it will burn. You can burn the fuel in a wood stove to produce heat or to cook on. An advantage of dehydration is that you don't need a large amount of heat if you have a long amount of time. The heat from a simple solar convection heater is enough to dehydrate one persons waste using nothing but the sun. A disadvantage is that a solar convection heater is large, and you could be using it to heat your house instead. Its your call.

If you have any other methods for disposing of your waste feel free to comment below! I will expand more on each method at a later time and hopefully get some video's up of me building and demonstrating these disposal methods. 

The reason I didn't include septic is that would be a permanent utility and I am more focusing on portable utilities that can be taken with your tiny house. However if you are interested in installing a small, do it yourself septic system you can read about how here.

1 comment:

  1. Another waste disposal method is vermicomposting. Worms eat the bacteria and make nutrient dense dirt. This dirt can be spread around trees and rose bushes for accelerated growth! (try it with bamboo!)