This is by no means an exhaustive list of alternative waster handling systems out there. This is just a starting point to give you an idea of some options you might want to look into if a conventional septic system or mound septic system (probably the 2 most popular rural septic systems in the US) is impossible to install.
In the end at will come down to what your building and land use departments will allow. And with good reason, ultimately. There is a LOT of pathogenic bacteria and viruses that are found in human waste. Preventing that stuff from getting into the ground water is serious business.
Some Reasons to Install an Alternative System
You have a very steep site. A conventional system need a bit of a slope to it, but not too much. The point is to allow the effluent to leak out of the system slowly so it has time to decompose properly. A steep grade wouldn’t allow a nice slow seepage.
Very rocky soil, or very permeable soil. Soil with large particles lets water seep through too quickly. A specially designed sand bed may be needed.
Bedrock too close to surface. A thin layer of soil on top of bedrock just doesn’t have enough soil for effluent to properly leach into before it goes horizontally along the bedrock to the nearest water source.
Clay soils. Too much clay in the soil prevents water from percolating through in a timely manner. If the clay in the soil prevents the effluent in your system from draining out fast enough, you’re going to end up with a backed up system pretty quickly.
Wet soils, or high water table. This should be logical. If the soil is already damp or waterlogged it won’t be able to take in any more water from a septic drainage field.
Cost. Face it, putting in a septic system and a well (to replace municipal water and sewer) will account for a significant chunk of your home building budget. If you can install a less expensive system that does the same job, and it’s permitted, then why not?
Environmental consciousness. For some folks digging up a half acre or more of land to install a septic system just rubs them the wrong way (actually it does for me, too). We do research and wonder if there’s a less-invasive way to set up a sewage treatment system on the land.
As with just about anything in life that requires a big decision or a great outlay of money it’s best to get more than one opinion on how to solve your particular septic system problem. And even though you may be building in a rural area that has only one septic system installer, you can still take your plans to another business further away and just hire them as a one-time consultant.
Even if it would cost you a couple hundred dollars for this kind of consultation in the end it’s far less than what you’ll have to pay if you install the wrong system. It’s always worth your time and money to get this kind of professional opinion.
Here are some of the systems that you may want to consider:
Aerobic system. This is like a mini version of a municipal waste treatment facility. It will basically stir and aerate your waste material to facilitate decomposition. Read more on aerobic septic systems from Inspectapedia.
A drywell set up to handle water from a downspout.
Drywell, seepage pit, or “soak-away”. This simple system is really just for grey water disposal, and may not be permitted in some jurisdictions. It’s simply a container with holes placed underground which the grey water can slowly seep into the ground through. Here’s some great instruction on putting in a drywell.
Holding tank. You guessed it. This is just a tank. There’s no drainage field. Which means it has to be pumped out with a sewage truck whenever it gets full. It should come standard with a float alarm to tell you when the liquid inside is high enough to be pumped out. Hopefully the alarm or float will never fail you.
Disinfection systems. These kind of systems will add either chlorination or UV light (or some variation) to disinfect the sewage coming through. Read more about disinfecting sewage systems.
Composting toilet. I’ve heard several anecdotal stories over the years about composting toilets not really composting the waste within them. For some the experience seems to be more of a dehydration process. As far as I am aware composting toilets need direct venting of the collection chamber, which can cause problems with odor in the house if it’s turned off for awhile or there’s some serious downdraft issues.
If you’re serious about getting a composting toilet you may want to consider designing the bathroom, or at least a room for the toilet, as far away from the main living area as possible. This may help prevent unwanted odor from sneaking in when you have guests over.
There are many resources for composting toilets and systems out there so I’ll leave it up to you to do your research on designs and manufacturers.
Mound septic systems. These are becoming much more common these days, but some still do consider it an “alternative” septic system for handling waste. In a sense they are. When all conditions are right (soil, water table, slope, etc.) then a conventional system is preferred by most home builders. But, the next best option in many cases is turning out to be the mound system. Read more about mound septic systems.
Putting in a septic system for a home that’s out of reach of municipal waste treatment systems is something that just has to be dealt with in building in a rural location. If you do your homework and consult with at least 2 septic installation businesses you’ll get a much better idea about what system is best, at the best price, for your land and building site.
If you have other ideas for alternative septic systems and waste handling please feel free to drop me a line.