Did you know your septic system can limit the size, location, and design of your home? And that the health of your soil is the determining factor for those limitations?
Did you know your soil IS the system?
If you want to design a home that’s going to support your life and the lives of your family, you’ll want to pay attention to the life underground.
Yes, we’re talking about soil again. Because soil has THAT much of an impact on your life and the design of your home.
In this 11th post of the Regenerative Design series, we discuss how soil impacts your septic system and how your septic system impacts your home design.
60+ Million People in the U.S. Rely on Septic
According to the most recent census that collected data about how many people in the U.S. rely on septic, it was found that about one quarter of all homes in the U.S. are using a septic system! Those numbers are from 1990 and the building booms we’ve experienced since then has increased those numbers significantly. That means, we, as a nation, are relying on the soil to clean the water being flushed down the drains of over 60 million people all day, every day. That’s A LOT of soil doing A LOT of work!
If the soil is not healthy enough or structurally capable of filtering the quantity and type of materials being forced through it, your septic system will fail.
In 2007, the U.S. Census Bureau reported that at least 10 percent of septic systems have stopped working. Some communities report failure rates as high as 70 percent. These failed systems are one of the leading sources of ground water contamination.
If you don’t know if you have a septic system or not sure if you need a septic system, read our article How to Know if You Need a Septic System Permit to find out. Hint, this is one of the crucial pieces of information you’ll need before designing a renovation or new home. If your home is connected to municipal water and sewer, you can pass this blog along to a friend who has or needs a septic system.
Basics of a Septic System
There are many different types of septic systems. Here we will be discussing a conventional system. Click HERE to see a more comprehensive list of septic system types from the EPA.
When talking about a septic system, many people just think about a septic tank. However, the septic tank is just the preliminary holding vessel. Your septic system is actually comprised of three main components that can take up a large portion of your property. And each component of the system employs the work of living organisms!
The 3 main components of a septic system are:
3.Repair Area (if necessary)
Septic Tank (think of this as an ecosystem!)
Wastewater flows from your home into a septic tank where heavier solids sink to the bottom to create sludge, while lighter material float to the top to create a layer of scum.
Bacteria that live in the tank break down organic matter. Without these bacteria your septic system will fail. These living organisms need to remain alive and healthy in order to do their job. Your septic tank is an enclosed ecosystem much like an aquarium! And it’s your job to keep these critters alive and well.
Drain field aka Leach Field
After the bacteria in the tank have initially treated the wastewater in your septic tank, the liquid effluent flows out of the tank and into a network of perforated pipes buried underground. The section of your property that houses this network of pipes is referred to as the drain field or leach field.
No construction or heavy vehicle traffic is allowed in this area. The drain field relies entirely on the health and structure of the soil beneath it. More on this in a minute.
A repair area is a secondary drain field that can be used if the original drain field fails. Since the 1980s, most homes are legally required to have a repair area or replacement area designated when building new, renovating, or designing an addition.
No construction or heavy vehicle traffic is allowed in this area either.
Learn more about how soils on a construction site get destroyed by compaction, erosion, and sedimentation HERE.
The Soil is the System
You can’t always put a drain field and repair area anywhere on your property. These components of your septic system require the right soil that has the right structure and healthy microbes. Your soil IS the filter for the effluent leaving your septic tank. It’s the soils job to clean this liquid before it hits the groundwater. Your soil IS the system!
The structure of the soil determines how well the soil filters the effluent. Soil is comprised of organic material, microbes, sand, silt, clay, and air. The ratio of these components determines how well the soil is able to hold water and how well it will eventually allow it to flow into the ground.
Remember those bacteria, algae, protozoa, fungi, rotifers, and nematodes we talked about in The Story of Soil: What It Is, What It Isn’t, and Why You NEED to Protect Soils on Your Property? Those are the unsung heroes of your septic system. These microbes digest and break down the organic material in the effluent.
If your soil has not been cared for and has experienced too much compaction, erosion, deposition, or has been exposed to too many chemicals it will not be healthy enough for a successful septic system.
How Septic Impacts Home Design
If you’re planning to build a new home or renovate an existing one, first you’ll have to determine the buildable space (aka building envelope) on your lot before your designer draws any concepts for your home. There are many factors that come into play that determine what portion of your property can be built upon. Your septic system is a BIG one! And will create limitations and setbacks that your home cannot encroach upon.
Determining the location of your septic system, and therefore the setbacks around it, will be up to a soil scientist and/or your local County Environmental Health Department. In order to obtain a septic permit from the Environmental Health Department, a soil scientist will have to survey your property and perform a number of soil tests to determine porosity, soil structure, and water table. The results of these test will determine the best location with the adequate space available to size your septic system. Once you obtain your septic survey, you may apply for permitting approval.
Check out our blog Overcome Building Envelope Challenges to get more details on possible setbacks, topography, and other building envelope challenges.
Number of Bedrooms
Your septic system will determine how many people and therefore bedrooms your home can reasonably have. Overloading a septic system with too much wastewater is one of the easiest ways to destroy it and cause unnecessary pollution. Because of this, there are laws that regulate how many people can live full time in a residence based on how robust their septic system is.
If you have poor soils on your property and your soil scientist determines that your soil can only handle a 2-bedroom house, then you are limited to a 2-bedroom house regardless of the hopes and dreams you may have had for a home with more bedrooms.
Placement on Your Lot
Likewise, if the soils in the area you were assuming your septic system would go are insufficient then you may need to use the location on your property where you had planned to put the home.
Shape of Home
Your septic system also needs to be placed a distance (typically 50-100ft) away from any body of water like a lake, stream, pond, or on-site well. It cannot be in an area where the water table is too high. It must be a minimum distance of 10’ from the house and must adhere to other setbacks as determined by your specific lot.
Because of these factors, you could be left with an oddly shaped building envelope that will require a unique approach to design.
Impact on Views
If your home can only be placed on a specific area on your lot due to septic or other setbacks, your designer will have to know how to maximize the views that you may have limited access to.
Location of Outdoor Living Space
If you were planning to have a pool, hot tub, deck, patio, or any other hardscaping in the location where your soil scientist has determined the septic system needs to be, you will need to be flexible on redesigning these elements elsewhere or getting creative on new ideas for interfacing with nature.
Caring For Your Soil and System
Ultimately, the location of your septic system is determined by the health of those microscopic organisms in the soil who silently impact our lives so heavily. It may be fascinating to learn that much of your home design is determined by these microbes.
It may also be incredible to learn that you have an ongoing relationship with those organisms even after your home has been constructed. It’s up to you to make sure these microbes around and inside your septic system remain healthy and thriving.
Stay tuned for our next blog when we discuss how to care for your septic system to minimize maintenance costs and maximize lifetime of your system.
I intend you get acquainted with the life underground that cleans the wastewater you put down your pipes.
Supportive of you and your land,
Jenny Pippin, CPBD, FAIBD, CGP
Pippin Home Designs
I am Jenny Pippin, founder of Pippin Home Designs and creator of my own inspired living. I grew up as an ordinary southern girl, working in the fields of my family’s tobacco farm. It didn’t take me long to realize I had greater gifts and so I chose to step into my power and create my own path in life, inspired by my heart’s true passion. (More on my personal story HERE!)