I have already written about how to develop a solid waste (garbage) management plan. If you are interested in living off grid, in a long term self sustainable way, you also need a solution to your liquid waste (sewage and others). There are two generic steps to accomplish this. The first is to separate the solids from the water and the second is a biological reduction of the organic material in the water and biosolids. If you are releasing into surface water there is frequently a disinfection stage as well and a dechlorinating stage after that.
There are two key groups of liquid waste. Biological waste, and industrial/chemical waste.
Biological waste comes from humans and animals and with a few exceptions it entirely treatable with living biological processes. Bacteria can and will eventually break this down until it is completely inert. This is exactly what happens in a composter, biological material is broken down into it’s component elemental compounds for re-uptake into the ecosystem and food chain.
Industrial and chemical waste is significantly more difficult to treat. Each chemical will need to be treated with a chemical reaction to remove the contaminant or to change it into a form that the biological process can handle. You may think I don’t have any of this so I don’t have to worry about it, well there is a good chance you do. Things like cleaners, fuel, oils, lubricants, paints and dyes all fall into this category. This list is also by no means complete, there are also many substances that readily dissolve into water becoming hazardous waste as well, a perfect example of this is road salt. Whenever possible, keep these out of your biological treatment system as they can disrupt it to the point of collapse. Often each type needs it’s own solution, many will disrupt the solid waste system as well. Improper treatment of these can contaminate your water supply and kill your lawn, just to name a few.
At one of the sewage facilities I operate we receive waste from a cheese factory, an abattoir (slaughterhouse) and numerous egg washing facilities. The more self-reliant people become the more likely they are to have these kinds of wastewater to deal with.
Now that I have covered types of waste water, it is time to cover how do we treat them in a sustainable way. The easiest way to do this is technically with a cesspool or cesspit. Cesspools are little more than tanks that need to be emptied. This is antiquated technology, I don’t recommend a cesspool because there are better options today and you are then dependent on a waste hauler to empty your tank.
Cesspools were replaced with modern septic tanks sewers. Sewers are not conducive to off grid living as they are one of the grids we depend on. However, if you live somewhere that has sewers they may be your only option. In many jurisdictions it is illegal to not connect to the sewer this is for public health reasons, and it is one of the reasons cities are clean places to live today.
Septic tanks are the most common self contained wastewater treatment systems. The have a holding tank to allow for solids to settle and a baffle to prevent floating scum from leaving the tank. There is then a delivery system, usually by gravity into a biological system, usually a drain field. There are many different types of designs for septic systems which will be covered in another article. With proper maintenance a septic system can be used In many rural areas this is the only legal way to treat wastewater. Bren.
Other ways to treat wastewater water are lagoons and constructed wetlands. The main difference between the two is the vegetation allowed inside. Lagoons use microscopic organisms both plants and animals to break down the waste. Constructed wetlands use every and any organism to break down the waste in a complete ecosystem. This seems like a good thing, except for two things; one is the plants and animals take up capacity away from the wastewater and two, burrowing animals can cause collapse of the berms containing the water. Both of these options differ from septic systems in that they use aerobic conditions and septic systems use anaerobic conditions. I will write more about the specifics of all three later, for just know that these are your three best options for sustainable self-reliant off grid living.
In general wastewater is strictly regulated. Always follow you local regulations. Also use a licensed installer, there are many of them around. And the risk associated with improper construction will then fall onto them (depending on local regulations). Other than that, chooseyour system and enjoy a more self-reliant way of living.