Homestead Septic System Primer (Anaerobic, Mound, Aerobic)

A homestead in an area where there is no public sewer system will need to have an approved septic system.

The purpose of this septic system is to remove wastes from the home, safely convert them to effluent and return the water from the effluent to the ground water.

The septic system is usually approved by the County Health or Sanitation Department or by a Regional Health Department.

In the 21st Century there are three commonly used types of Septic Systems:

anaerobic systems also called gravity systems
mound septic systems which operate with a pump
aerobic systems which commonly have an aeration stage and some also have a pump

In this article we will do a brief review of the history of human waste disposal and then look at the three types of septic systems and discuss them in detail.

The goal is to educate homesteaders so they can make the best decision about a septic system for their homestead.

A Brief History Of Human Waste Disposal

The ancient Persians, Greeks and Romans each had systems of sewage removal from their capitol cities.

The Romans had underground pipes that removed the wastes and deposited them in the river.

In the country areas there were primitive facilities similar to outhouses or people just dug a small hole or went behind a tree.

During the Dark Ages, roughly the 6th through the 18th Century, the progress in sanitation languished.

And there were several outbreaks of sickness with many resultant deaths because the cause and effect of sanitation on drinking water was not understood.

In the early days of America, a common form of waste disposal was the outhouse or privy.

A building usually a little ways away from the house that was built over a pit.

Here the family members would go to relieve themselves of bodily wastes.

Perhaps a little known portion of this history would be the snake stick.

A stick that was usually leaning against an inside wall of the outhouse.

Before sitting down to use the facility, a user would take the stick and poke it down the hole and move it around for a few moments to see if a snake tried to bite it.

Many a person were saved the indignity of a doctors visit to inspect teeth marks on their backside by the use of the snake stick.

In the 19th Century, people began to realize that there was a direct relationship between the location of the Outhouse and contamination of the Drinking water source which was usually a well.

This was the beginning of the science of sanitation.

The first flush toilet was built for Queen Elizabeth I in 1596 by Sir John Harrington, the Queen’s godson.

It consisted of an oval bowl two foot deep, made waterproof with pitch, resin and wax and fed by water from an upstairs cistern.

Alexander Cummings, in 1775 was issued the first patent for a flushing toilet.

In the late-19th century, Thomas Crapper, a London plumber manufactured one of the first successful lines of flush toilets.

They were called Crappers.

The early models had a tank that set about 6 feet above the floor and you flushed the toilet by pulling a chain.

Thomas Crapper’s specific contribution to flush toilets was his development of the ballcock.

This is a tank filling mechanism still in use today in flush toilets.

With the use of flush toilets indoors there came the need for a method of holding the flushings outdoors.

One early method was called a cesspool or cesspit. It was basically a hole in the ground lined with rocks into which the flushings were directed.

It was covered with boards. This was the forerunner of the septic systems of today.

In America and Europe between the 1860s and WWI, science made large strides in health and sanitation.

With these strides came improvements in septic waste disposal and positioning waste disposal with respect to drinking water sources.

Anaerobic Septic Systems

This is the traditional septic system in use in multiple locations around the world.

They are also called gravity systems because they are designed so the flow of wastes into, through and out of these systems is by passive gravity flow.

The person credited with inventing this septic system is a Frenchman named John Mouras.

In 1860 he designed a tank made of concrete and pipes made of clay that led from his home to the tank in his yard.

Ten years later he dismantled the unit and discovered that the tank was essentially empty of any solid waste material.

All that was there was a layer of scum over a liquid we today call effluent!

Mouras consulted with a scientist and applied for and was granted a patent in 1881 for his septic tank. The septic tank system made its way to America in 1883.

Even though the septic tank came to America in 1883, it was the 1940s before septic tank usage became widespread.

Many of the early tanks were made by wood forms placed in the ground and concrete poured into the forms.

Some had a concrete lid and some had a wooden lid.

Another form of septic tank was the Dickey Tank.

This was a 500 gallon metal container with a metal lid.

Many of these tanks are still in usage today in some parts of the country.

In the 1960’s, precast, single compartment tanks in 750, 1000 and 1200 gallon size became standard.

In the 1970’s, the 1000 and 1200 gallon tanks were precast as two compartment tanks.

At this time many County Health or Sanitation Departments began overseeing septic system installation.

In the 1990’s came regulations relative to separation between septic systems and sources of water and set backs from property lines.

How An Anaerobic System Works

There are basically 3 parts of the anaerobic septic system.

The tank, drain lines or field lines and the drain field or leach field.

The tank size is dependent upon the house size.

A typical 3 bedroom house will have a 1000 gallon tank.

Tanks now have two chambers and are concrete or a special type of plastic.

In the tank, solid wastes settle to the bottom where anaerobic microbes, microbes that do not need oxygen to live, begin digesting the solid wastes.

As the waste water comes into the tank it separates into three layers.

The top layer is scum and consists of grease and light solids.

The bottom layer is the heavy wastes and is called sludge.

The middle layer is a clear zone of mostly water.

Much of the sludge layer is partially decomposed by the bacteria and microbes present.

Many of the microbes needed come from the human intestine.

With each flush a new supply is added to the tank.

It is very rare for the microbes to break down all the sludge.

So the tank needs to be pumped out every 3 to 7 years.

The tank is designed with baffles that only allows the middle layer, the water, to go from the tank into the field lines.

As new water and wastes flow into the inlet side of the tank, an equal amount of water is pushed out the outlet side and into the field lines.

From the field lines the water, called effluent, trickles through a layer of gravel and into the soil below.

The soil is an amazing living system.

Among those things that live in the soil are bacteria, fungi and protozoa.

The soil also contains mites, earthworms and insects.

As the effluent trickles into the soil, the bacteria, fungi, protozoa, mites, earthworms and insects remove nutrients and other compounds.

Metals and minerals in the effluent bind to soil particles and are removed from it.

The water, treated by soil and the living organisms is now pure and joins with the water in the underground stream or aquifer.

Maintaining An Anaerobic Septic System

The most common cause of septic system failure is improper maintenance.

When a system fails it is the homeowner who gets to pay for the repairs.

Failing septic systems can be expensive to repair or replace.

When made a priority, a septic system is easy to maintain.

Know exactly where the tank is and have it pumped every 3 to 7 years.

Do not drive over the drain field or tank or park on top of them.

This can decrease the efficiency of the system by collapsing the tank, field lines or compacting the soil making it harder for the effluent to be absorbed into the soil.

Sinks and toilets are not trashcans.

So do not put anything down them except toilet wastes and what is washed off the body, dishes or spit out of the mouth!

The following should never go into a septic system: cooking oil, paper towels, hygiene products, household chemicals, paint, kitty litter, coffee grounds or cigarette butts.

These increase the sludge layer and make pumping out of the system more frequent.

Using a garbage disposal increases the frequency of pumping out septic systems.

Things like egg shells, bones and even vegetables are hard for the microbes to digest.

They just add more sludge to the tank.

To landscape and plan a garden you must know exactly where the septic system is located.

Never plant trees or shrubs over the drain field or close to the tank.

Their roots can grow into the drain lines and even into the tank!

Never plant a garden, berry bushes or an orchard over or near a drain field!

If you do you are just asking for frequent cases of food poisoning for your family, e coli type food poisoning.

Practice wise water usage.

Don’t stress the septic system with a lot of water in a short period of time.

Remember, a saturated drain field may not be able to absorb water from several loads of laundry on a rainy day!

What Is Grey Water?

Grey water is water from sinks, tubs/showers and washing machines if no caustic detergents are used.

It does not include water from electric dishwashers when commercial detergents, which can contain caustic chemicals, are used.

Some people include toilet water that does not contain human fecal waste as grey water.

I do not include this because I known that coli form bacteria such as e coli which is present in human feces is also present in what appears to be clear toilet water.

The severe sickness caused by e coli bacteria is not to be lightly dismissed.

Those who include toilet water that does not contain human feces are risking their health and the health of those who follow such ill advised ideas.

In some parts of the Country and World it is possible to plumb a house where the grey water collects into a separate tank.

This grey water can then be used to water the base of trees and garden plants where the edible produce does not grow on the ground or under the ground such as lettuce and carrots.

Grey water can also be used to water shrubs and flowers on the homestead.

Using grey water can improve the homestead output of produce with no increase in potential sickness when used properly.

If you divert grey water into a tank and your homestead is in mountainous or snow country you will want to have the tank buried below the frost line to prevent the water from freezing.

If you can not use gravity to empty the grey water tank you will need some method of getting the water out. Such as a hand pump.

Grey water can make a big difference in the water available on a homestead.

More about grey water can be read in an article I wrote titled, “How Can Insufficient Homestead Water Supply Be Improved?”

Another simple method of catching water that can be used to water lettuce carrots and other produce that grey water should not be used on is to catch tub or shower water in a bucket while waiting for the water to turn warm.

This water caught in a bucket from the tub/shower is clean water, not grey water.

So it can safely be used on produce that touches the ground or grows underneath the ground.

A Mound Septic System

A mound septic system is not a passive, gravity flow system.

It is a system that requires 24/7 electricity to pump effluent from a holding tank up to a mound where the drain field is located.

As such, a mound septic system is not the best choice for an off grid homestead!

Why is a Mound System Necessary?

The reason for a mound septic system is claimed to be not enough soil to effectively clean the effluent before it reached the ground water table.

The cure? Dump truck loads of sand, gravel and soil being brought in to construct a large mound to filter the effluent.

Sometimes this remedy is claimed to be the only way to replace a failing anaerobic septic system.

This explanation can be very suspect if there is plenty of room to put in a new drain filed with new field lines.

Or an Infiltrator Chamber System made of molded, chambered plastic 15 to 30 inches wide and up to 10 feet long.

Anytime the replacement of a failing anaerobic septic system is said to be a very expensive fix, it is time to have a very high level of suspicion that it is the money earned off of the fix that is the driving motivator.

In virtually every case, the fix is merely a new drain field and drainage lines connected to the old septic tank!

Those people who end up needing a mound septic system are usually those who bought land without knowing whether or not it would percolate sufficiently for an anaerobic septic system.

Wise purchasers of land in areas where there are no public utility sewer systems never purchase land without it having passed a current perc (percolation) test and be currently approved for a septic system.

The approval for an anaerobic septic system needs to be current meaning a septic system can be installed now.

Approval for a septic system does not last forever.

All septic approval is for a limited period of time.

Once that time has expired, it requires a new percolation test and permit fees for approval.

It is not possible to look at the surface of land and to know that the soil will successfully percolate.

If the soil is hard and cracked, it might not percolate.

If it is easy to push a stick or piece of rebar down several inches into the soil, it might percolate.

If a Seller has land for sale, it is the Seller’s responsibility to prove to the buyer that the land is suitable for a dwelling.

Suitability for a dwelling includes at a minimum, three critical factors. Those factors are:

A proven source of good quality water
Soil suitable for a septic system
Soil that will support a house.

Notice that 2 of the 3 critical factors necessary for land to be suitable for a dwelling involve the soil.

Things To Consider Before Installing A Mound Septic System

If there is an existing septic system that has failed, why has it failed?

Is the failure one of neglect of maintenance?

Is the failure caused by repeated driving over the field lines causing either crushing of the field lines or compaction of the soil around the field lines?

The type of failure just described does not warrant a mound septic system replacement if there is sufficient space to install another drainage field.

Installation of new drainage field will cost pennies on the dollar of the cost of installing a mound septic system.

When evaluating a septic system before purchasing property, know exactly where the septic system is in relationship to the water source.

If the source is a well, no portion of the septic system or an area set aside for drain field replacement, if needed, should be closer to the well than 100 feet if on level ground.

If the septic field is uphill from the well there needs to be a lot more than 100 feet separating them.

Where is the septic drain field in relation to the garden, berry patch or orchard?

These food producing areas should be well away from both the drain field and the area set aside for a replacement drain field.

Food production over or close to a septic drain field is just asking for a case of food poisoning.

If this situation is discovered or if the well is too close to a drain field, do not buy the land!!!

I have friends who were looking at rural property last year and were shown property with only one neighbor on one side of the property being shown.

While looking at the property they noticed what looked like a newly placed mound close to the property line on the neighbor’s property.

Inquiry revealed it was the neighbor’s new mound septic system.

Problem was, it was on land slightly above the level of land on the property they were looking at.

Plus, you guessed it, the new mound septic system was less than 100 feet away from the well on the land that was for sale!

That placement of the new mound septic system has essentially made the neighboring land unsalable due to the very real possibility of contamination of its well by coli form bacteria from the mound septic system placed too close to the neighbor’s well!

This situation has all the makings of a very expensive law suit.

One more story before getting back to mound septic systems.

Several years ago we purchased a parcel of land and built a house.

During the construction of the anaerobic septic system we obtained permission from the County Sanitation Department to add an extra 100 feet of field lines to the system.

The house had an unfinished basement and we wanted plenty of field lines to later add a bathroom in the basement.

So far so good, right?

You won’t believe what happened.

The operator of a trencher, hired to dig a trench for the hard line phone lines to the house cut across the field lines and his trencher pulled up field lines as well as effluent from them.

We had permission to place a mobile home on the septic system and live in it while the house was being built.

As a result of that trencher operators lack of rational thinking, we had a mess in the yard and lost the extra 100 feet of field lines!

Fortunately for us we had added an extra 100 feet of field lines and had sufficient drainage field left to not cause a problem.

We never did build a bathroom in that basement.

If you are looking at land and learn that the soil will not percolate and you need to install a mound septic system or pump the effluent to another area of the property where the soil percs do not buy the land!!!

The installation of a mound septic system can easily cost $40,000 or more instead of $10,000 or so for an anaerobic septic system!

Back To The Mound Septic System

As can be seen from the picture of a mound septic system you have the usual septic tank but from there everything changes.

The effluent flows from the septic tank to a pump tank which contains an electric pump that has to pump effluent over and up into the mound which contains the drain field.

Once the effluent in the pump tank reaches the preset level that activates the pump, each time the toilet is flushed, the washing machine spins out water or a shower is taken, that pump kicks on and pushes effluent up into the mound field lines.

It does not take long for one to realize that this type of a septic system has an ongoing expense much higher than an anaerobic septic system.

Then if the pump burns out, it has to be replaced.

Guess what backs up into your drains while you are waiting for the pump to be replaced?

Smelly effluent!

This is not the type of septic system I would ever want to deal with on my homestead!

Aerobic Septic System Or Aerobic Treatment System

This is a high tech system that many suburban areas and some rural areas are beginning to require as the septic system that has to be installed.

This is a sewage treatment system similar to the sewage treatment system of a city but on a much smaller scale.

This system consists of at least three different phases and in some instances a fourth phase is added.

These phases are:

A pre-treatment stage, where large solids and other undesirable substances are remove
An aeration stage, where aerobic bacteria (bacteria that require oxygen to live) digest biological waste
A settling stage, where undigested solids settle and form a sludge that must be removed at periodic intervals, and some systems hav
A disinfecting stage, where a form of chlorine, calcium hypochlorite, is mixed with the water to produce a clean effluent (treated water) safe enough to be used to water the lawn.

Calcium hypochlorite breaks down quickly in the sunlight where often more stabilized forms of chloride can kill plants if in the effluent used to water them.

In some aerobic treatment systems in the fourth phase the pump moves the cleaned effluent through sprinklers which water the lawn and plants near those sprinklers.

How The Aerobic Treatment System Works

Solids and liquids from the bathroom, kitchen and laundry room enter the pre-treatment tank where large solids and other substances are removed.

The solids in this tank have to be removed from time to time to prevent them from keeping the effluent from leaving this tank.

From there the effluent enters the aerobic treatment tank where there is an aerator that constantly injects oxygen into the tank.

Also present in this tank is a paddle, which may resemble a large egg beater, that constantly churns the effluent.

This churning action provides the aerobic bacteria with a constant flow of needed oxygen and keeps the smaller solids from settling to the bottom of the tank.

This allows the aerobic bacteria to break down the solids faster than if the solids were allowed to settle to the bottom of the tank.

An aerobic treatment system requires a dedicated 240 volt 30 amp electrical circuit.

This is necessary to power the aerator, the paddle and the pump if a fourth phase is added.

Brief Review Of How An Anaerobic Septic System Works

In the traditional septic system, the effluent reaches the septic tank and the solids sink to the bottom.

Anaerobic bacteria, (bacteria that live without oxygen), go to work, cleaning the fluid on top first.

The solids in this system break down slower, due in part to the solids sinking to the bottom of the tank.

In both the anaerobic system and in an aerobic system without a fourth phase the fluid, effluent, exits the tank through a pipe that leads to a leach field or drainage field that has field lines or diffusers also known as infiltrator chamber systems.

Here the cleaned effluent is filtered through sand, gravel, soil and clay between the leach field and the underlying water table.

In both instances it is pure filtered water that enters the underlying water table.

Differences Between Aerobic And Anaerobic Systems

The aerobic system requires electricity to power the aerator and paddle
The anaerobic system does not require electricity to function
Some aerobic systems with a fourth phase have permanently placed sprinklers through which the effluent is pumped under pressure to water the lawn. This phase requires electricity also. There have been instances where a lawn party has been sprinkled with effluent! When it is time to sprinkle, the pump comes on. These sprinklers can not be placed on a conventional timer
The anaerobic system does not have this problem
The aerobic treatment tank, the 2nd tank, requires careful placement and insulation around the electrical components to keep users and maintenance personnel safe from electrical shock
There are no electrical components to the anaerobic system so there is no danger of electrical shock.

Claimed Advantages For The Aerobic Treatment System

Breaks down wastes faster than an anaerobic system.
Reduced potential for noxious odors.
Can be installed in a smaller area than an anaerobic system, especially if the system has the fourth phase negating a drainage field.
With the addition of the fourth phase, disinfection phase, a pump and sprinklers allows for sprinkling of the lawn with the clean effluent.
Possibly more environmentally friendly.

Disadvantages Of The Aerobic Treatment System

Initial cost is 5 or more times that of a conventional anaerobic treatment system.
There is a 24/7 cost of 240 volts, 30 amps, of electricity. This additional need for electricity can be cost prohibitive for an alternative energy system.
Requires meticulous preventative maintenance to assure proper operation. This meticulous maintenance requires test instruments and record keeping many homesteaders do not have the time to do.
If the fourth phase, disinfection phase, is present it can cost between $400 and $1,000/year just for disinfection tablets.
The systems mechanical components; aerator, paddle, motor and if present the fourth phase’s pump need costly preventative maintenance and are very costly to replace when they break down.
An aerobic treatment system does not work in power outages unless there is immediate generator backup. With the lack of oxygen to the aerobic bacteria they begin to die almost immediately.
Once the power comes back on, it can be a period of days before the aerobic treatment system shows that it needs fixing. In an area with a lot of aerobic treatment systems needing fixing after a power outage, it can be several days before it gets attention. During that time you do not have a functioning septic system!

An anaerobic septic system has no mechanical components to break down, does not need electricity 24/7 to function, and has no bacteria that die in a power outage causing the system to have to undergo expensive maintenance to begin functioning again.

When properly installed and maintained, a anaerobic treatment system functions reliably for years at a time.

It is much simpler to install and costs thousands of dollars less with minimal cost other than to be pumped out every 3 to 7 years.

Is An Aerobic System Worth The Extra Cost And Maintenance?

In my research for this article, I had opportunity to sit down and talk with a gentleman who for years installed and maintained aerobic treatment systems.

He was currently installing an anaerobic septic system for a close friend of mine.

This former installer and maintainer of aerobic treatment systems said he would never install an aerobic system on his own property.

Unless he just had to live on that property and the only system allowed by law was an aerobic system!

I asked him if he would ever advise a homesteader who may want to live off the electrical grid to install an aerobic treatment system.

His answer was a definite NO!

In his professional opinion, the costs and the inconvenience of maintaining an aerobic treatment system did not come close to justifying the claimed benefits.

Where Are Some Areas Requiring Aerobic Treatment Systems?

There are areas in California, Oregon, Texas and Washington as well as other States that are either requiring aerobic treatment systems on all new construction.

Or they are considering making aerobic treatment systems mandatory on all new construction.

This is one of those very important areas that the potential purchaser of country or homestead property needs to research ahead of time to know whether there are regulations requiring all new construction to have aerobic treatment systems.

Likewise, if looking at existing homes, you need to inquire as to what type of septic system is present before considering making an offer on the property.

If the septic system is an aerobic system, that might be enough to scratch that property off your list of potential places to live.

Should I Move To An Area Requiring Aerobic Treatment Systems?

To Many potential purchasers of country or homestead property, particularly those wanting to live off the grid, the presence of an aerobic treatment system may be enough reason to remove that property from consideration.

If research of an area of the Country turns up a regulation requiring all new construction to install an aerobic treatment system, that may be sufficient reason to scratch that part of the country off your list of potential places to homestead.

Signs A Septic System Is Failing

Sinks and toilets are draining slowly
Effluent backs up through the plumbing into the tub or shower
There are gurgling sounds from the drain when the sink or tub is emptying
You have sewage odors in the house or yard
Standing water in the yard is a grey color
Grass grows faster and greener in one area of the yard
There is the presence of bacteria in the well water

At the appearance of any of these signs, call your local health department or sanitation department.

They can send someone out to help you diagnose the problem and what is the best way to cure the problem.

In some counties any repairs to the septic system must have a permit stating what is to be done.

And then after the repairs are made there must be an inspection of the repairs.

It is a good idea to be present when the inspector and the repair man are discussing what needs to be done to fix the problem.

Failure to address septic problems will lead to the release of only partially treated household wastes into your environment.

Untreated human waste is a serious health risk that can contaminate nearby wells, groundwater, streams and ponds and even springs of water.

The smell of a failed system can alert others to the fact that there is a problem and bring the health inspector knocking at your door.

In some instances, a health inspector may declare your house unsafe to live in until the septic problem is cured.

If that is the case, you will have to move out until the problem is fixed!

That will just add more expense to what is needed to make the problem go away.

It can be expensive to fix a failed septic system but a well functioning one is essential for your family’s health.

In the final analysis, a septic system is an efficient and inexpensive way to treat and dispose of human wastes.

When it is properly maintained, a septic system protects both your family and the health of your environment for years.