Sanitation Forum
Composting toilets, greywater, and staying clean and healthy off the grid without a septic hookup.
Nothing here yet.
This board is open and waiting for its first question. If you have one about sanitation, ask it here and it becomes the start of the thread.
What this board is for
Septic systems, composting toilets, outhouses, incinerating toilets, greywater, and the rules that govern all of them. This is the least discussed of the five departments and the one most likely to stop a build, because in most jurisdictions the legal right to occupy a dwelling is tied to an approved way of handling what leaves it.
It is also the department where the rules have the clearest public health reasoning behind them, since waste handled badly contaminates groundwater, which off grid is very often the water you drink from a well a short distance away.
The questions that come up most
Will this parcel perc? Only a soil evaluation by a licensed evaluator can say, and it is the test that decides what you can build. Where soils are poor, engineered alternatives exist and cost substantially more, which is a price negotiation rather than a dead end.
Is a composting toilet legal here? Varies enormously. Some states recognize certified units for permanent dwellings, some recognize them only alongside an approved system for greywater, and some do not recognize them at all. The composting toilet also does not solve greywater, which is most of the volume.
What can I do with greywater? Depends entirely on the state. Several have well-developed permitted greywater rules; many make no distinction and treat all wastewater the same. Kitchen waste behaves differently from bathroom waste in any case, because of grease and solids.
How often does a septic tank need pumping? Depends on size and household, and the drain field lasts far longer when it receives less water and no grease, solids, or harsh chemicals.
What a useful answer looks like here
Name the state and county, because this is the most locally variable subject on the site and a confident general answer is usually a wrong one somewhere. Say whether there is an existing permitted system and whether you have its records, since an unrecorded system of unknown age and design is a liability rather than an asset.
For composting and greywater questions, distinguish between what is physically workable and what is legally approvable. Both matter, and they are frequently different. The laws pages carry the eight-topic verdict for each jurisdiction with the sources listed, and the questions-for-the-county sheet is built for the call that settles it.
The mistakes that cost the most here
Buying a parcel without a soil evaluation or existing septic records. This is the test that decides what can be built and occupied, and a failed evaluation changes the design, the budget, or the parcel.
Assuming a composting toilet removes the need for an approved system. In many jurisdictions it does not, because greywater is most of the volume and is regulated separately, and in some the composting toilet is not recognized for a permanent dwelling at all.
Treating a drain field as maintenance-free. Fields fail early when they receive grease, solids, harsh chemicals, or simply more water than they were sized for, and the cheapest habit in the whole system is keeping water out of it that does not need to be there.
Plumbing greywater outdoors before checking the state rule, and designing an irrigation scheme with nowhere legal for the water to go in January.
And inheriting an unrecorded system with a property without inspecting it. An unknown tank of unknown age and design is a liability that came with the deed.
Protecting the well from your own system
The most important geometry on an off-grid parcel is the relationship between where wastewater goes and where drinking water comes from. Every jurisdiction sets minimum separations between septic components and wells, property lines, and surface water, and those distances are the accumulated answer to a public health problem rather than a bureaucratic invention.
Pay attention to slope and to the likely direction of groundwater movement, not only to the tape measure. Uphill of the well is the wrong place for a drain field regardless of the distance.
Test the well for bacteria and nitrates annually and after any work on either system. It is inexpensive and it is the only way you will learn about a problem before somebody in the household does.
What the rules actually vary on
Whether a composting toilet is recognized for a permanent dwelling, and under what conditions the finished material may be handled or disposed of. Whether greywater may be reused, and if so with what discharge method and what storage limit. Whether a pit privy is permitted, and as a sole facility or only as a secondary one. Whether the county administers septic permitting itself or acts as agent for a state program, which determines who you deal with.
Those four questions have different answers in adjacent counties, which is why a confident general answer on this subject is usually wrong somewhere. The laws pages record what public sources say for each place and mark what could not be confirmed, and the printable county questions sheet is built for the call that settles it properly.
How much of this is regional
This is the most locally variable subject on the site. Soil type decides what system is possible, the health department decides what is permitted, and the two are not the same question. Adjacent counties routinely differ on composting toilets, greywater, and whether a pit privy is recognized at all.
Climate matters too. Freezing changes how greywater systems behave and where they can discharge in winter, and a scheme that irrigates beautifully in July needs a legal destination in January.
So the answer to nearly every question here begins with the state and county, and ends with a call to the health department. The laws pages record what public sources say for each place, and mark what could not be confirmed.
What it costs, and what it decides
A conventional septic system is a known number in most districts. An engineered alternative for poor soils can be several times that, which is a price negotiation on the parcel rather than a reason to walk away. Either way it is usually the single largest infrastructure cost after the building itself, and it is the one that decides whether the building may be occupied.
The recurring costs are small and skipping them is expensive: pumping on schedule, keeping grease and solids out, and not overloading the field with water it was not sized for.
The public health reasoning behind the rules is worth taking seriously even where nobody is checking, because the well you are protecting is usually your own.
What has already been written about this
Before asking, it is worth knowing what is here. These are the most recent guides on sanitation, each of them long enough to actually answer the question rather than gesture at it. If one of them is wrong, or misses the case you are in, that is an excellent thing to post about.
- Menstrual and incontinence waste off-grid: a real plan
Pads, tampons, adult briefs, and catheter supplies don't compost like the rest of your waste stream. Here's how to handle them cleanly, discreetly, an... - Sanitizing shared tools and surfaces off-grid without a
Wiping down a shovel handle, a milking stand, or a shared outhouse latch is easy to skip off-grid. Here's how to actually kill germs on tools and surf... - Managing odor and pathogens in off-grid sanitation without
Smell and germs, not the toilet itself, are what actually sink an off-grid sanitation setup. Here's how to manage both so your system stays livable ye... - Sanitizing without a septic tank: safe waste disposal for
No septic system doesn't mean no plan. Here's how to handle blackwater and solid waste safely and legally when you're living small, off-grid, and with... - Handwashing and hygiene stations off-grid: staying sanitary
No tap over the sink doesn't mean no handwashing. Here's how to build a hygiene station that actually gets used, cuts illness, and doesn't waste your ... - Off-grid laundry and dishwashing wastewater: the sanitation
Laundry and dish water carry grease, lint, and chemicals your greywater bed was never built for. Here's how to handle them without fouling your soil o... - Building a proper off-grid outhouse: pit design, siting
A well-built pit outhouse still beats most composting setups for cost and simplicity. Here's how to site it, dig it, and build it so it lasts and neve... - Composting toilets explained: how they work and which ones
No plumbing, no septic tank, no smell if you do it right. Here's the honest, unglamorous truth about composting toilets: the science behind them, the ... - Greywater basics for an off-grid cabin or homestead
Every gallon you use for dishes, showers, or laundry has to go somewhere. Here's how to handle greywater legally, safely, and without turning your yar...
The full set is in the sanitation section of the journal, which is updated regularly.
The lesson that covers this
Lesson 9: Sewage, greywater, and the toilet question in the free course works through this subject in the order the decisions actually arrive. Pick a sanitation approach that is legal where you are, sized to the household, and honest about the work it takes.
The whole course is twelve lessons, free, with no account required to read any of it: start at the beginning if you are new to this, or jump straight to the lesson above if you are not.
Tools for this topic
Most questions on this board come down to a number somebody has not worked out yet. These do the arithmetic and show their working, so an answer here can be checked rather than taken on faith.
- Tools/septic calculator: size a system and see what a soil type implies
- Off grid laws: check what your county actually permits
How this board works
Posting needs an account, which exists so that answers have a name attached and so that the same person can be asked a follow-up six months later. It costs nothing and it is not used for anything else.
The conventions here are the ones that make a small forum useful. Say where you are, at least to the state or region, because almost every answer on this site depends on climate or on local rules. Say what you have already, and what you have already tried. Give numbers where you have them, and say when you are guessing. And when something works or fails, come back and say which, because the thread is read by far more people than post in it.
Answers here should be able to say where they came from. Experience is welcome and so is a rule of thumb, as long as it is labeled as one. Where a claim is about safety, code, or law, it wants a source, because the reader on the other end may be about to spend money or wire something themselves.
Boards next door
Off-grid questions rarely stay inside one department. A water question is often a power question underneath, and a land question is usually several at once. These boards field the neighboring subjects:
- Water: Collection, storage, filtration, and pumps: getting clean, reliable water when there is no tap to turn on.
- Land & Real Estate: Finding, vetting, and buying off-grid land and cabins: access and easements, title, perc tests, water rights, zoning and...
- Shelter & Structures: Cabins, tiny homes, insulation, and building for the long haul in a place the grid does not reach.
- Health & First Aid: Staying healthy far from a hospital: first-aid and trauma kits, remote medical skills, telehealth, prescriptions, and a ...
New here, or not sure where this fits? Start here walks through the whole thing in order.