Leach Fields

I'm hoping to get some help in understanding on leach/drain fields.

Despite my searching I can find very little information on the actual efficacy of leach fields in relation to simply dumping small amounts of waste water directly on to the surface of the ground.

To give some background, I plan on building a small house in a very rural area in Asia. In this location a septic system is typically installed but varies from its western counterparts. This setup does not have a leach field, they are simply not used here. I understand this is not a great solution and I'm hoping to do better than that.

In my own build, I'm considering skipping the septic tank entirely and flowing water directly into a vermiculture pile (see this link where I got the idea from initially https://www.permaculture.co.uk/readers-solutions/how-make-vermicomposting-flush-toilet)

My question is, is a leach field necessary? If the water filtering out of the bottom is well distributed but above ground instead of buried, what's the difference? As far as I can tell leach fields only disperse water over a wide area taking into account the percolation rate of the ground. It seems to me all they do is distribute and ensure the slow integration of water into the ground where it will be taken care of by bacteria. If I'm building on a sloped site, can I simply run water down a densely forested area and let it disperse before soaking in and nature do its work? Note this would not have direct solid waste and would have filtered through either a vermiculture compost or regular septic system if for some reason I can't get a vermicomposting setup working.

I assume I must be naiive and there is a pitfall I'm not understanding or accounting for, other than rain potentially washing it further downhill than it would on a dry day. Note that nobody lives downhill of this position for kilometres and it's densely forested, so I would hope this won't be an issue?

Hi Klaus,

One purpose of the leach/drain field is to prevent contact with pathogens carried in waste water. In a septic system septic tanks are designed to have a minimum hydraulic retention time of 3 days meaning the effluent from the tank is still probably carrying pathogens. In my jurisdiction leaching chambers have to be a minimum of 2 feet underground so the potential of humans or animals coming into contact with those pathogens are minimized.

If you're using a composting toilet and there's no human waste in your waste water I would be open to bypassing the leach/drain field. Note, I initially tried this with my gray water system and the drain area eventually became a boggy mosquito habitat so I upgraded to a branch drained system.

   

I would agree with Aaron,

If this is going to be Black water (human waste) then I would think the separation between humans and animals and the waste water would be a good thing. That said in your case it could be a very simple system. You could make a trench perpendicular to the slope and put drainage tile in the trench (say 1 -2 feet down, covered with sand/gravel). This would then allow the liquid to be spread over a larger area and keep the contamination of the surface to a minimum.

If it was gray water I would be less worried but something similar might spread the water over a bigger area so you would keep things drier.

Reasoning behind this:
there are pathogens that are carried in human waste that cause infections (cholera for example) that you would not want on the surface where it could contaminate things you would touch

An above ground system would have "crap" sitting on the surface? it would all pile up wherever the pipe ended and would eventually back up I suspect. A brick built septic tank without a leach field works fine waste water slowly drains out through the bricks and the sludge mainly composts in situ they need emptying from time to time, I remember growing up with one from the 30's It was pretty large, large enough to stand up in and walk around, it only needed emptying every 5-6 years when used by 3 people.

What happened on our homestead might help with the understanding of a leach field.  It also depends on the kind of septic system as an aerobic system does not need one.

When we bought our homestead we bought raw land.

I contacted a company to install a septic system.  Though after a few months of use we found that it was not working properly.

Not wanting to deal with the first company since they didn't install it properly, the people I contacted installed a leach field and we never had a problem with the septic system again.

Klaus, I appreciate that you are deeply exploring the rationale behind the current standardized approach that relies on leach fields. We need a more customized solutions that account for soil type, local land features, population densities, rainfall and so on. We need more options that are gentler on the land and local ecosystems.  We need solutions that use less plastic and toxic materials. There will be a better and less expensive approach some day and getting there requires real curiosity about how we arrived at our current costly, wasteful and invasive approach to managing waste water. While this book recommendation does not directly answer your question, my understanding of how we "moderns" got to be terrified of grey water was greatly enhanced by reading Steven Johnson's book, The Ghost Map: The Story of London's Most Terrifying Epidemic -- And How It Changed Science, Cities, and the Modern World. I urge you to keep exploring novel ideas, questioning "best practices" and looking for other ways to address the challenges that you identified. Please continue to share your discoveries!

I hope this is relevant.  We moved cross country a couple of years ago to a place with a high water table and clay soil.  It's not uncommon in this area to not have soil that percs.  When that is the case, there are 2 options that a person has, first is to haul in yards upon yards of "good" soil to a depth of 30-40 inches, let it settle for a year (the freeze/thaw cycles of winter are really what is needed here), retested for percolation, and then install a conventional septic system with a tank and then leach field. The leach field is laid out in your expensive known-good soil.  The second (more cost effective, but also more gross) option is to build a sewage lagoon.  This setup involves making a small pond (by small, I mean roughly the size of the house in footprint, based on what we were told by our health department) and fencing it in with a 6 foot fence.  Then the blackwater from the house goes into your septic tank, and instead of leach field, it goes into the sewage lagoon to either infiltrate the soil slowly or to evaporate depending on the time of year.  From what I hear from different people, sewage lagoons range from "not that bad" to "totally disgusting".


We have opted for the fill and wait pad, but the huge downsides are the time it takes before it can be set up and used, and the cost, it wasn't particularly cheap.  But we also live in a beautiful area and it seemed way better than looking out on sewage lagoon.

Years ago I installed a grey water only system in sandy soil by burying 5    55 gal drums filled with large rocks.   The system worked well.  Yes, we had a composting toilet.  The drums were connected with 4” pipe and shot full of holes.

Klaus Wolfgang wrote:

Despite my searching I can find very little information on the actual efficacy of leach fields in relation to simply dumping small amounts of waste water directly on to the surface of the ground.

Posters are assuming, but you haven't clearly stated, that this waste water will *not* have any urine and feces in it, so I just want to check that.

I have done a bunch of reading on this topic, including the Humanure Handbook: https://permies.com/wiki/44341/Humanure-Handbook-Joseph-Jenkins
And some of the references listed here: https://permies.com/wiki/113116/pep-greywater-willow-feeders/Give-Urine-Growies-PEP-BB

I've also done reading that suggests that the traditional leach field which is designed to handle urine and feces, actually can create a plume of nasty stuff underground that is capable of contaminating ground water. The articles stated sort of, that the issue was a lack of microbes at depth. That said, many places are concerned about pathogens being right at the surface. Most of the sources I read (including the one about vermicomposting you linked to) make so much more sense by suggesting a minimum of piping that leads to a series of mulch basins - really just a trench filled with wood-chips or some other high-carbon biodegradable waste product, that circles a tree or is like a banana pit or swale with trees planted to soak up both the water and any nutrients that made it through your vermicompost.

The take-away for me has been -  spread enough that things like soaps/grease don't build up in one area, with a covering of organic matter to keep any germs away from things we touch, and with something that grows fast and will enjoy any tasty treats you send their way.  

A big problem that people don't seem to get in my area, is that nitrogen is a fertilizer, regardless of it's source, and an atom - it doesn't magically "go away". Nitrogen that meets up with fungi, healthy soil, and a polyculture of plants, can be sequestered and turned into living, growing plants and animals. If it doesn't meet up with microbes etc, it travels to places we don't want it, particularly streams and wetlands which then cope by using algae and/or invasive plants and all the downsides that creates, such as dead lakes and rivers. It isn't just the E-coli we're worried about - it's the nitrogen and other goodies that need to be put to good use, rather than damaging ecosystems.

Klaus,

I would recommend sticking with a somewhat traditional septic. If properly sized, they last a lifetime with no maintenance. I used a septic for 20 years, opened the tank for inspection, and there was only a few inches of semi-solid waste on the bottom. The rest was fluid. Some places around here, because the soil is mostly sand and drains so well, you can place the drain field where the top of it is 6 inches below the surface to minimize digging. I would recommend, as mentioned above, that you install  your drain field pipe horizontally to the slope. Within a week or two the bacteria in the tank with establish itself and any smell from a vent will be gone.

Your biggest problem is going to be toilet paper, if you use it. You will need to use something that is easily biodegradable. Otherwise it will take a very long time to break down and will float on the surface in the tank depriving some of the bacteria of oxygen. Here in the USA some toilet paper is labeled "Septic Safe" and deteriorates much more quickly. If you studied traditional septics, you know the input and output are near the top of the tank, with a partial wall between them that extends down from the top to below the output level. This is so that paper and other floating items don't get into your drain field and plug it up. Alternatively, you can have your output pipe bend down a foot or so below the input level. Around here, they go one step further and put a T on the tank side of the output pipe, where one side of the T points down for waste fluid to enter, and the other side sticks above the output so that you can clean it. Then the vertical part of the T is filled with a plastic mesh that is removed once a year and washed out. This will prevent it from getting clogged if the level should ever drop below the output and solid waste reaches the output pipe.

For drainfield you can use any pipe with lots of holes in the bottom and sides, surrounded with at least 6 inches of stone or other material that doesn't pack hard, and wrap the whole thing (stones and pipe) in landscape fabric to keep dirt from washing into and filling up your drainfield. I would think the forest floor would be very porous and be able to absorb a lot of liquid. Even bath water contains feces, so you need to be sure everything is underground to keep people, animals, fruits and vegetables and erosion from your output. Never allow wastewater to come in contact with the edible parts of plants, and wait a month after applying waste water to the roots of plants before eating any part of them.

It seems to me, the solution you are considering can't be used with toilet paper, which may or may not be a consideration in your case. And is much more fragile than a traditional system. What happens if someone flushes some bleach down your toilet that kills all the worms? How fast does the mulch in your tank need to be replenished? Traditional septics will reestablish themselves after a catastrophe in a few weeks with no intervention. Best of luck!

My question is, is a leach field necessary? If the water filtering out of the bottom is well distributed but above ground instead of buried, what's the difference? As far as I can tell leach fields only disperse water over a wide area taking into account the percolation rate of the ground. It seems to me all they do is distribute and ensure the slow integration of water into the ground where it will be taken care of by bacteria.

If I'm building on a sloped site, can I simply run water down a densely forested area and let it disperse before soaking in and nature do its work? Note this would not have direct solid waste and would have filtered through either a vermiculture compost or regular septic system if for some reason I can't get a vermicomposting setup working.

It looks like people answered the leachfield question - keeping the water underground so it can percolate, be treated by the soil organisms while keeping pathogens out of reach of humans and animals.

I think one part that can be added is that the leachfield also compensates for excess water flowing into the system if it's getting a lot of use, like from running a washing machine. But again, that's still to keep human (and kitchen) pathogens underground where the soil organisms can do their work. It's a pretty nice system in the end. You don't have to tell friends or neighbors where not to walk, nor keep ducks from dabbling in it.

Since you've said you are in Asia, and in a place where they don't normally use Western-style septic systems, this seems like a great place to experiment and figure out what else works.  I looked at the pictures of the vermiculture toilet,  and I think that could be damaged by water coming from a kitchen.  I suspect that kitchen oils would end up smothering the worms.  Worms eat manure just fine, but loads of oil building up can be a serious issue for them.

In one of Geoff Lawton's videos on the Jordan project, he shows how their kitchen blackwater system works and that it started with a greasetrap.  There are many types but the principle is like in the image below.

Have you considered a biogas digester? They are becoming popular in a lot of third world countries.

The purpose of a septic tank is to allow solid waste to be broken down in an anaerobic environment and to buffer the amount of liquid being released into the leach system. In the leach system (field, trenches, chambers, sand filter, engineered wetland, etc) additional microbial action digests the remainder of organic waste and converts ammonium into nitrates. Dumping wastewater, including kitchen waste, directly on the ground is a horrible idea.

Before deciding on what type of system to install there are a lot of things to consider. Cost, availability of equipmentand materials and laborers, soil quality, water table depth and proximity to surface water and wells. If septic tanks are uncommon in the area, can you obtain one? You can build one, but there is no point unless its water tight. Can you hire or obtain heavy equipment, i.e. a backhoe? Can you get enough gravel for a common leach field?

A cheap and non-labor intensive option is a pit privy (i.e. outhouse) but I would still recommend a micro septic system for kitchen waste. If you want I can post a link to plans for an engineer approved pit privy design.

Jason Suttles wrote:

A cheap and non-labor intensive option is a pit privy (i.e. outhouse) but I would still recommend a micro septic system for kitchen waste. If you want I can post a link to plans for an engineer approved pit privy design.

Welcome to Permies, Jason!

I'd love to see those plans if you have time to share.

Perhaps I am misinterpreting the OP...

My read is that this is strictly for gray water; my understanding of gray water is "dirty" water from showers, laundry, sinks etc.; NOT toilet water.  Without clarification on exactly what the OP means by gray water I will respond based on my interpretation of what the OP meant.

Without knowledge of insects, wildlife etc. in Asia, my first question would be is it at all possible that there could be any negatives to just dumping the water to flow downhill through the forest:

1)  Could grease, food particles or other kitchen gray water components attract unwanted insects or animals?  Could the residue be an issue in any way?

2)  Regardless of how "environmentally friendly" the soaps/cleaners used, most still act as fertilizers.  Could there be negative repercussions on the environment if left exposed to the sun, or if birds or animals drank it, or if it entered the local surface water system such as rivers, lakes or ponds?  

3)  Is this enough nutrients to cause the gray water "stream" to inadvertently fertilize something you would rather not encourage?

4)  Is it actually legal to allow gray water to free run at surface level, where you live?

5)  Would there be any odor associated with the gray water that could be unpleasant or attract the wrong kind of attention from animals or neighbors?

These would just some of my concerns; and why at the very least, I would use an old drum.  Drill a bunch of holes in a 55 gallon drum, dig a hole, drop in the drum, line the outside with drain rock, fill the inside with drain rock, sand, maybe even some charcoal, and just have the gray water flow into this sump, and disperse naturally from there.

That said, I have a very small knowledge base regarding gray water management.  Perhaps someone else more knowledgeable can address the potential issues of surface eliminated, gray water.

This is a wonderful thread!!  great information here

Assuming it is just gray water

Worth reading Art Ludwig.  He writes on the long term use of gray water and the failures and benefits of various systems.

My suburban australian gray water system doesn't like fats so I now have two grease traps in tandem.  I find making them easily accessible encourages me to check them.  Otherwise the fats tend to cover the wood chip I use as a filter and the water runs down the outside or through a restricted channel.  You may find it difficult to keep the whole of your vermiculture pile wet enough if the water channels through it.  I have seen flood and empty systems that immerse the worm system and then immediately drain it.  I don't know how well they work.

Food scraps can attract vermin and open ended drains without traps might allow them access to the house.

Pooling surface water lets mosquitos breed.  If you have cold winters surface systems may just freeze up.

If you make a leach field try and keep rainwater out of the distribution pipe or trench.  This is a requirement where I am.  It is better to carefully level the down hill edge of the transverse pipe or trench.   This will help the even distribution into the leachfield. Here the leach field can be a 100mm thickness of sandy loam  with the top at ground level.

If it is dry then surface discharge may not stay wet enough for long enough to be broken down.

If it is wet, or monsoonal, there is a risk of material discharged on to the surface being washed into waterways while still relatively fresh.

If this includes toilet waste then a composting toilet may be the go.   I find powered positive ventilation to be essential (I use a solar panel) and easy access to allow removal of composted material to be a really good idea.  I have a rotaloo that has six bins so that when the bin in use fills up the next bin(longest since last used) is emptied and used to replace the bin in use.  A system with two bins at least seems like a good idea.  That could include two separate toilets with one in use at a time.

Look up “Tiger Toilet”  This is an OXFam / Bill Gate foundation designed toilet system . It was designed for third world countries . We are fire victims of CZU fire in Calif and have been using one for about 8 months now. Living rough in a dinky trailer. There is a lot of information available online including bacterial tests . No leach field used but broken bricks - broken dishes etc on bottom so urine is separated from feces. This is a worm composting system . I also put kitchen compost in there to help keep my worm friends happy. Let me know if you are interested in more detail.

I built a large number of both septic systems and leach fields when I was young.  The purpose of a properly designed septic tank was provided below, but I will attempt to both summarize and expand a bit here.  A septic tank is designed to provide an anaerobic central digester that degrades both solid and liquid effluent and removes many human pathogens.  It does not generally allow viruses to just cruise on through since the inlet and outlet are designed to reduce flow to near zero.  What enters is slowed and subjected to significant lag prior to water flowing back up the outlet and onward.  A properly operating septic tank should be passing fully digested material on to the drainage system.  An older drainage system was often called a dry well.  I got to stand in the bottom of the dry hole and catch concrete block to then build into a circular open tank that allowed even more residence time prior to letting the septage drain to the soil.  Generally, a fine grease residue was seen in older systems and that grease could plug the pores in surrounding soil, requiring re-excavation and construction of a new well or placement of a leach field.  The leach field is designed to allow excess fluid to pass through and to filter out any grease or residue particles that might plug the surrounding soil.  An engineer once told me that a properly operating septic tank drained through about 50 feet of fine sand should be potable.  Not something I would like to try, but there it is.

If one runs septage from human waste onto the surface in any area, there is a risk of spreading potential pathogens.  That said, I consider any material that a human flushes down a septic system to contain potential pathogens even though some may not have a significant virulence.  Digested runoff of a septic tank can still cause health issues.  A bit later in my youth, I resided at a communal group site where I heard the older residents tossing about a phrase related to summer stomach issues in the well water.  I did some investigation and realized that they were using a well within 50 feet of the septic tank and leach field.  I told them to rent a backhoe and provide certain piping and materials and I would remove that issue.  They did so and I piped the septic outflow over about a 100 feet downhill from the well and they never had a recurrence of the summertime stomach malady.  Too close to a well can allow contaminated material to flow down the cone of depression that develops when a well is pulled strongly.  Knowing the general subsurface hydraulic response can be vital in maintaining healthy people and, if that water is used for growing vegetables, healthy vegetables as well.  Some vegetables will happily pull pathogens in along with contaminated water and the results can range from unpleasant to deadly.

Hope this helps.

Kim Goodwin wrote:

Jason Suttles wrote:

A cheap and non-labor intensive option is a pit privy (i.e. outhouse) but I would still recommend a micro septic system for kitchen waste. If you want I can post a link to plans for an engineer approved pit privy design.

Welcome to Permies, Jason!

I'd love to see those plans if you have time to share.

https://legacy.azdeq.gov/function/forms/download/list/Engineering_Bulletin_No.2_The_Earth_Pit_Privy.PDF

Sorry it took so long, had to wait for my coworker to send it to me.

The engineering information provided for the Earth Pit Privy is good for construction, but a bit light on health information.  Here is a url from the Alaska DEP regarding pit privy design.   https://dec.alaska.gov/water/wastewater/engineering/pit-privy

I did note that the Alaska information did mention lime.  We did not have running water in the house until I was 11,and we always used lime to counteract the ammonia in the pit and to reduce odor in our outhouse.  It will also assist in keeping vermin out.  Do not allow rodents in your privy or you will likely have large snakes feeding on them and there is little more that gets your heart pumping than to sit on a stool and get up to find yourself staring a large snake in the eye.

Karen Hansen wrote:Look up “Tiger Toilet”  This is an OXFam / Bill Gate foundation designed toilet system . It was designed for third world countries . We are fire victims of CZU fire in Calif and have been using one for about 8 months now. Living rough in a dinky trailer. There is a lot of information available online including bacterial tests . No leach field used but broken bricks - broken dishes etc on bottom so urine is separated from feces. This is a worm composting system . I also put kitchen compost in there to help keep my worm friends happy. Let me know if you are interested in more detail.

Sounds interesting. Tell us more?

Karen, can you tell us about the approval process with the health department.  I would like to use the California approval as a reference with my county health department.

My advice based on own experience:

- Have separate plumbing for grey water and black water. That way, the system that deals with the black water (septic tank and leach field) can be smaller, it will be under much less pressure, and its bacteria will work better since they won't be disturbed by all the soaps and detergents from the kitchen sink, washing machine and shower.

My black water collects in a 1 cubic metre conventional (plastic) septic tank. The grey water goes directly out into the open some 10m outside the house, passing through an improvised grease trap that catches the gross particles, then disappears into a rubble trench about 50cm deep, which directs the water to a group of willows another 10m further down.

- DO install a leach field or equivalent. I chose an infiltration tunnel (see link below), which we placed so that its top is around 60cm under the surface, in a fairly wide & deep trench filled with rubble. The tunnel is about 4m long. We needed the large rubble-filled trench because our soil is heavy clay with poor percolation rate. Due to the slow percolation and the water-retentive properties of our soil and subsoil, there is almost always water inside the tunnel (a great part of it is ground water, especially during rainy periods / thawing of snow) - BUT despite all that, so far the system has never failed us (we've been using for 5 years).

https://www.google.com/search?q=infiltration+tunnel&tbm=isch&hl=en-GB&chips=q:infiltration+tunnel,g_1:graf:OOZYt6U_-Fk%3D&client=safari&sa=X&ved=2ahUKEwjdjpGyr-31AhUW4oUKHanSBYYQ4lYoA3oECAEQIQ&biw=823&bih=478

Klaus, a properly working leach field reduces pathogens at the surface by 6.5 log (99.99997%), which is helpful in the context of a septic system which only reduces pathogens by 0.5 log (68.4%).  Whether either is sufficient enough depends on the magnitude of pathogens in the starter material, which can vary by orders of magnitude.  To help answer the question of what would generically be considered safe enough, the World Health Organization put together a very helpful and detailed document titled WHO Guidelines for the Safe Use of Wastewater, Excreta and Greywater available for free online.  It covers the recommended levels of treatment based on the probability of getting sick from contact with effluent.  The data on leach fields (soil absorption systems) and septic systems provided above was pulled from Figure 2.1 description of Option H.

The data I've seen on vermicomposting flush toilets (known as a "vermifilter" in the scientific literature) shows a 1 to 2 log (90% to 99%) reduction in pathogens.  If you read the Wikipedia article on Vermifilter, you'll see that for at least one situation the net result of a single stage vermifilter (given the level of pathogens in their blackwater input) was sufficient to meet the World Health Organization threshold for the safe reuse in crops.  Note that treatment effectiveness of vermifilters can be influenced by factors like cold, the media used, density and type of worms, etc..  However, it is interesting that the Portugal design referenced sort of makes a virtual second stage vermifilter through adding similar media in their distribution mulch field.  In short, a working vermicomposting toilet/pile can reduce pathogens better than a septic tank but not nearly as good as a septic leach field.

If there is a need for additional reduction in pathogens, additional vermifilter stages can added as shown at Vermifilter.com, or subsurface distribution can be used.  Assuming pathogens are not the limiting factor for you, it's reasonable to ask, what else should I consider?  The scientific literature is mixed as far as whether vermicomposting has a significant effect on roundworm eggs.  As far as nitrogen pollution, from what I've read septic tanks remove virtually no nitrogen (basically only what gets pumped out during sludge removal), and by design septic leach fields keep large nitrogen absorbing roots away from the piping so they don't clog.  Having said that, there are leach field designs (like Presby at Infiltratorwater.com) that are more optimized for reducing nitrogen, but still require roots to be kept out of the system.  Denitrifying bioreactor type leach fields such as that described here use burried wood chips or other high carbon materials to treat nitrogen, but need to be replaced in the long haul, limiting the use of any nutrients by perennial plants.  Anna Edey's design, from which the Portugal system was based, showed a typical 95-99% reduction in nitrogen output (Green Light at the End of the Tunnel) and used plants.  Additional factors include whether there would be any risk of pooling, from which animals could drink, insects could breed, or guests/kids/neighbors might play in; ensuring the output doesn't rip a ravine into the hillside over time; proximity to groundwater, surface water, or a culinary well that might shortcut soil treatment if the nutrient load is not sufficiently reduced (there are more nutrients than nitrogen).  For reference, Art Ludwig's Builder's Greywater Guide Figure E.1 shows that bedrock fissures or other paths that shortcut soil treatment can allow contamination plumes to travel a mile or more underground.  I'm not saying that you need to go subsurface, but those are the side effects I'm aware of that you'll want to manage.

If your goal is to just discharge to benefit the environment and you can keep the worms at working temperatures, I recommend containing the worm treatment to eliminate animals bypassing the treatment, use at least 2 stages if you use blackwater (targeting conservatively clean enough for the safe use on crops), and ensuring the output will not rip a ravine in your hillside nor create any pooling.  I'm not a wastewater professional, but I've been preparing for the last couple years to submit for an experimental permit for surface discharge quality of treated blackwater and greywater in the hopefully not too distance future.  In our situation, we need to factor freezing, our culinary well, duck pond usage, and a ravine that can run with water at certain times.  Good luck, and let us know what you decide!

This is in reply to a question about ‘Tiger Toilets ‘ being permitted in Calif. We didn’t even try to get a permit for the toilet - because of state fire regulations and the multi- millions of dollars to bring the community roads up to present day fire standards and to buy right of way for second official , deeded second road out of community our community of a couple hundred people are just living our lives- We would also need a third road out through the State park for folks living further back- not likely to happen- We have had folks living back here for over 80 years now. My daughter and husband worked with the county building department to write up a classK - owner builder code that did pass into the county code though  . For example you can have a composting toilet but still need a septic system and would need your alternative system tested on a regular basis at a high cost to home owners- same for septic systems -regular pumping required at high cost to owner - Hope this answers your question

I have attached the Tiger Toilet manual - There is quite a bit of information online about this type of toilet - I hole this is helpful

Karen, thanks for the information.  The systems in this manual look quite a bit different from what is described here.  http://www.vermicompostingtoilets.net/
I will just have to see what our local health department is willing to look at.  greybeardmike. :0)

In more or less mainstream North America, the standard ways of handling domestic liquid waste are so nearly uniform, that most of us don't even question what goes in and what comes out.  But the plumbing of the human body and our daily use of water for purposes other than drinking are of course not closely matched to each other. We mostly have one waste stream out of our homes that carries everything, so that typically huge amounts of valuable, potable water are consumed just to transport a comparatively tiny amount of "dirt" - from baths, showers, kitchen sinks, laundry etc.  The more that the different waste streams from the different functions can be physically separated, the more easily and efficiently we can reduce the amount of water that's wasted, reduce the pollution we cause into our close environment, safeguard health consequences, and even retain the valuable nutrients of different kinds that are otherwise flushed away.

I installed a central composting system (Sun-Mar's Centrex 3000) when I was building a home for my family in 1983, that is in use today. That handles "black water" waste (pee+poo) with a very small additional quantity of water, 1-2 cupfuls/flush, from two SeaLand toilets (used in boats, RV's). Toilet paper is well composted in the unit's composting drum. All other waste (tampons, wipes, Kleenex etc) goes in garbage.  A small amount of bulking material is added to the drum every few days, chopped hemp stalk.

Local building regulations permitted me to reduce slightly the extent of the conventional drain-field used with the septic tank system, but I opted to stay with the regulat size - the difference was minimal, and avoided future complications. With no toilet waste in the septic system, and less cleaners, detergents, grease (we're vegetarian), or other contaminants, the septic tank maintains a good 'digesting' function, meaning it has a very long cycle between needing pump-out (decades).

Potable water is a majorly important issue on the quite small island I live on, so protection of that resource - not wasting, not polluting - has always been a motivation.  Reducing total quantity of water used is desirable of course, but so is reducing total quantity of contaminants of every type that goes into the greywater stream, whether in terms of grease, dish and laundry detergents, shampoos, soaps, bodycare products.  Every item or product "used up" or "thrown away" ultimately has nowhere else than "the environment" to end up in, of course.  So reduction of consumption is key.  

So is making good use of whatever methods are available that transform the "bad stuff" into "good" stuff, which means mostly biological action of one kind or another.  That can be in a septic tank, in a wetland which helps purify and transform water with nutrients into potable-grade water, as well as in other biological systems designed and installed to deal with specific domestic waste-streams or nutrient-streams.  An evapotranspiration bed is an example of one such of the latter, and an online search will no doubt lead you to useful examples.  Since some compost-toilet systems still have a small amount of leachate to be dealt with, from occasional heavy use or overflow contingencies, a contained evapotranspiration bed can be very helpful to turn that limited amount of water + nutrients into vegetative growth of grasses & forbs etc, water vapour and oxygen.

Last thought - it's a good idea to take as much care with creating systems to "get rid of" both water and "waste" leaving our homes, as we do in the systems we put in place for bringing that water and those nutrients into our home for consumption.  A great deal of what we treat as waste is really just biological nutrients that we (society) cannot be bothered to handle well enough for them to carry on around the cycle in places that they are actually helpful.  In consequence, waterways, lakes and wetlands around the world are too often being almost destroyed by algal blooms due to those nutrients accumulating undealt-with in the wrong places.  Wetlands and intact vegetated watersheds are a critically necessary part in us all having safe water supplies into the future.  Just tipping raw untreated grey water on the ground soon turns into a real problem, if not for the person doing it, then for everyone and everything downstream from it.

'Hope something of this is helpful to you.