I bought 5 Acres fo some awesome mtn property... view wise... Location for building a home/cabin.... not so great. but the price was unbeatable. $25,000. and its really 7.5 acres but the buildable area is only 5. Anyways I need to figure out how to do as small of a spetic system as posible. It will be a one bedroom/ one bathroom cabin. I've thought about doing a composting toilet but the county says I still have todo some type of leach field. What are my options for keeping it small. Im at 11,000' I'll get good sun in the summer but not in the winter. I've thought about trying to find a way to do some type of evap system. but im not sure how that works of if it really does. I have a natural spring on site as well as a running creek. Any ideas?

probably not approved for your location, but the complete systems are much smaller than standard designs.
http://www.thecleansolution.com

I'd ask the county - they seem to be driving the requirements.

You don’t normally get to size a septic system how you desire. The size of the holding tanks and field typically is a function of the number of bedrooms and how the soil perk tests. There are also typically setbacks from streams, wells and property lines which can limit the acceptable location. In short, the county will set the minimum requirements and hopefully you can use gravity system and not a pumped or sand filtration system.

There is a company that just moved from California to somewhere in the southeast (Nashville perhaps), that makes what I joking called the turdburner. It's an incinerator type of "septic" tank. A friend bought one when they were moving for his ID property in a narrow valley with a stream running down the center. There was no room for a leach field, and it was the only way he could build on his land. I don't know the company, but I can ask him this weekend.
Generally, you have to have your leach field 100' from a water source. On 5 acres you should be able to do that, even if the stream bisects the property.

Found it- www.ecojohn.com

Your county is telling you only the answers that make their jobs easier.  Or they just don't know what it is because they've never seen it before. A composting toilet, by its very nature, does not require a drain field.  I can't even envision how it could be connected to one.  But maybe there are some other types of composting toilets than the ones I am familiar with.

Here's what I did:
1. Read the actual state statute for OSTDS first.  Mark the provisions that seem like they would apply to your situation.
2. Read the state administrative code for OSTDS.  Confirm that the provisions you marked in the statute actually have a section in the code explaining how those provisions shall/should/may/shan't be done.  If the statute says you can do something, but the code never got written to explain how, then all you have to do is show that your execution of that thing meets some accepted standard.  More likely, you will find that the code has a very loose procedure that you can use in your favor.
3. Read the county ordinances to be sure there aren't any special modifications to the state rules.  In FL, the counties and municipalities have essentially zero authority to change the state rules regarding OSTDS.
4. Verify that other regulatory jurisdictions like EPA, state DEP, water management districts, NPS, BLM, etc. don't have special requirements due to your proximity to some ecosystem or water source.

I actually had to teach a 30-year inspector in the county health department about the state's rules for greywater and cisterns because no one uses them here.

I would continue investigating composting toilets and waterless urinals.  Also look at aerobic treatment units (ATUs), the effluent from which can in many cases be used as greywater for subsurface irrrigation.  And the ultimate in doing it your way is the "performance-based system", which is quite logical when you think about it: the purpose of OSTDS is to turn nasty stuff into reasonably safe stuff.  However you make the effluent meet the standard of "reasonably safe" doesn't matter, as long as you can prove it with lab results.  It's simply product verification instead of process validation.

Or like Jon said, go back and ask the county... It is them you will have to either go along with or decide to fight. Depending on how stubborn/entrenched they are, that could be a time consuming affair requiring you to have your ducks in a row to teach them a new path as Bill Described above. This property have any neighbors? I would go ask about their systems...

The county will most likley require an approved engineered system and a passing perk test providing you don't have any watershed or wetland conflict issues. If you have these you may need a mound system They should have a list of who they usually work with to perform these tests and design services.

A gravity septic for a one bedroom one bath is not going to be very large. Main line out to holding/setteing tank. Outflow from tank to drainfield. For this size system maybe two 40-50' drain field runs? In my county the setback from the drainfield to wells is I think 100' and I think 30' from structures and property lines. You will probably find they require something similar. You should have no problem fitting this into any number of locations on 5 acres. If any of the "unbuildable area" is down slope, and if it will perk acceptably you can remote the drainfield from the tank a pretty long distance to place it on some of that unbuildable property since it is a bit underground anyway line slope is usually not an issue... That is how mine is setup with drainfield down over a hillside. I still have a bunch of other options on a lot with similar conditions(5acre buildable 7.5 total) and that with 5 structures and a winding driveway already in place... About the only restrictions with the drainfield is you cannot build or drive heavy vehicles over it, but grass or even landscaping is just fine...

Keep in mind also with state EPA's getting more possesive of the groundwater, you may also need a drainfield(gravel drywell) for the roof gutter runoff to insure the roof water makes it back below ground. One of my 5 structures is the new house I am building. It's 2500SF of roof is going to cost me 13CU/YD of drain-rock buried below ground to form a dry-well for my roof runoff to be injected back below ground...

In what state are you located?
In CO, the septic systems are state regulated. I think CO will allow composting toilets. I do not know if they would allow a home made composting toilet.

The human waste that goes down a toilet is a very small fraction of the volume of the liquid waste produced by the laundry, sinks, dishwasher, shower/tub and yes a flush toilet...

I don't see you having a building department approved residence with running water that does not incorporate a drain field or mound for effluent processing...

Posted By ronmar on 25 Feb 2017 02:03 PM
The human waste that goes down a toilet is a very small fraction of the volume of the liquid waste produced by the laundry, sinks, dishwasher, shower/tub and yes a flush toilet...

I don't see you having a building department approved residence with running water that does not incorporate a drain field or mound for effluent processing...

You are assuming that all of the liquid waste will be going into the OSTDS.  Depending on the state's greywater rules, the only drains that have to go into the OSTDS are toilets, urinals, floor drains, dishwashers, and the kitchen sink.  The rest may be fed into a greywater system.  This is adding another layer of complexity to the project, of course.

Just for fun, here's a configuration that eliminates any need for a drain field and theoretically could be contained in a basement (or buried under the basement floor).  It would certainly require a very committed person to conform to the lifestyle required by such a system.  Of course, your AHJ's rules may vary...

1. Eliminate some liquid effluent sources completely:
a. No dishwasher - wash dishes by hand.
b. No clothes washing machine - wash by hand.
c. Composting toilet.
d. Waterless urinal.
e. No floor drains.

2. Implement a greywater system for the following sources classified (in most jurisdictions) as such:
a. Shower/bath.
b. Lavatory.

3. Use an ATU (aerobic treatment unit) for the only remaining source classified as blackwater:
a. Kitchen sink.

The greywater and ATU effluent, after whatever filtration/decontamination steps are required, can be discharged directly to the world in various ways but drip irrrigation is the most logical.  Assuming you have a healthy gut microbiome and aren't excreting vast populations of nasty critters, the small volume of effluent from each system can be diluted with a rainwater collection system that should easily and consistently keep your results from the required periodic lab testing well below the critical levels.

Practical? Of course not.  Stimulating to design and implement? Definitely.

Yep, not very practical, but it is interesting

Gunnygreenbuilder Don't sweat it, once you find out how much drainfield you need for a 1B1B and walk your property with a tape measure, I think you will find you can fit that into a bunch of out of the way places.