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EPA Sketch of an aerobic septic tank design using an aspirated mixer in the treatment tankTypes of Septic Systems & Septic Designs
List of septic designs for various sites & conditions

  • POST a QUESTION or COMMENT about the different types of septic systems, onsite wastewater disposal systems used for private onsite wastewater and graywater treatment & disposal

Types of septic systems: onsite waste disposal system types.

This septic system design reference lists and describes all of the types of septic systems, including both conventional septic tank and drainfield systems and alternative septic system designs for difficult building sites such as wet sites, steep sites, rocky sites, limited space, bad soils with no percolation or sandy soils with too fast percolation, and other difficult site conditions.

We provide detailed articles about each alternative septic system design choice, listing its features, design requirements, inspection details, maintenance needs, product sources.

We include links to septic design engineers, advanced septic system products and septic design books and building codes. This document is a chapter provides in our Septic Systems Online Book.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Definitions of Septic System Types & Onsite Wastewater Treatment Alternative Designs

Photo of septic tank sludge and scum layer being broken up prior to septic tank cleanout.Daniel Friedman, Massachusetts Title 5 Licensed Septic System Inspector, & New York State H.I. License # 16000005303 (inception to 2008).

This document catalogs conventional and alternative septic system designs and provides links to detailed descriptions of these designs for onsite wastewater treatment.

"Septic System Alternative Designs" refers to any onsite wastewater disposal method other than the widely used conventional septic tank and leach field. In the U.S. most states require that an "alternative septic system" be designed by a professional and submitted to the local health department for approval.

Examples of advanced septic designs include aerobic septic systems, chemical, composting, incinerating & waterless toilets, evaporation-transpiration (ET) septic systems, septic media filters, greywater systems, holding tank septic systems, mound septics, raised bed septics, pressure dosing septic systems, sand bed filters, peat beds, constructed wetlands, wastewater lagoons, constructed wetlands, and septic disinfection systems.

Each of the links below presents a document with more in-depth information about each of these alternative septic system designs.

Septic Tank Types

Septic tanks are responsible for retaining solid waste in a residential onsite wastewater treatment system (septic system), and for partial treatment of sewage and septic effluent to improve its sanitation.

In a typical conventional septic tank waste water is treated to about 40% of total treatment required before discharge to the environment.

The remaining effluent treatment normally occurs in the soils around and under the drainfield or absorption system. Some more advanced or alternative-design private septic systems achieve much higher levels of treatment by oxygenation (aerobic septic systems), chemical treatment (disinfection systems), or other methods.

See SEPTIC SYSTEM DESIGN ALTERNATIVES.

Septic tanks of Single vs. Multiple Compartments

More septic tank compartments means that solid waste (floating scum, settled sludge) are better-separated from septic effluent before it is discharged to a drainfield.

Below we illustrate single compartment (below left) and two-compartment (below right) septic tank designs. Image source: USDA.

Advanced treatment septic tanks may use more compartments, including a final pumping chamber, as well as other features such as aerobic systems (shown at the top of this page), media filters, or effluent filters that both improve the level of wastewater treatment and also improve the life expectancy of the absorption field or drainfield.

One compartment septic tank USDA - DJF

You may also notice that our septic tank shown above has inlet and outlet baffles constructed of concrete while the septic tank below shows an inlet baffle constructed using plastic pipe - a common repair method if septic tank baffles are damaged.

One compartment septic tank USDA - DJF

...
One compartment septic tank USDA - DJF

This USDA sketch of a different two-compartment septic tank design illustrates how additional compartments can help retain solid waste in the septic tank and improve the quality of wastewater discharged to the drainfield or soakaway bed or absorption bed.

Septic Tank Materials & Construction

LARGER IMAGE: of a plastic or fiberglass septic tank.

Typical septic tank materials of construction include

Basic septic system designs are discussed in the articles listed just below

Conventional septic system using a septic tank and leach field or drainfield receiving effluent by gravity - US EPA edited at InspectApedia.comBasic septic tank and drainfield systems are discussed

at SEPTIC SYSTEM DESIGN BASICS.

Image source: - U.S. EPA, Types of Septic Systems, retrieved 2019/04/22 original source: https://www.epa.gov/septic/types-septic-systems

Here are some more detailed articles about basic septic system design, installation, inspection, maintenance, cleaning or pumping, & repair.

Alternative or Advanced Septic System Design Types (for Difficult Sites)

Definitions of Types of Septic Systems, Toilets, Components

SKETCH of a typical aerobic septic system treatment unit tank or ATU

Drip distribution septic system US EPA at InspectApedia.com

Evaporation Transipiration septic system US EPA at InspectApdia.com

Sand filterseptic system US EPA at InspectApedia.com

NO Rock or gravelless or chamber septic system US EPA at InspectApedia.com

Mound septic system US EPA at InspectApedia.com

Hoot aerobic system

Septic tank with optional effluent filter US EPA at InspectApedia.com

Sequencing batch reactor septic system - at InspectApedia.com

Constructed Wetlands or Natural septic system US EPA at InspectApedia.com

Research on Types of Septic Systems - Basic & Alternative Designs

Composting Toilets - Books & References

Design Manuals for Septic Systems

Greywater System Books

Effluent Dosing Septic System References & Products

Evapotranspiration and Evapotranspiration / Infiltration Systems for Septic Effluent Disposal

Media Filters - Septic Media Filter System References & Products

Peat Media - Septic Peat Moss Bed Designs & Suppliers

Sand Filters - Septic Sand Filter System References & Products

Sequencing Batch Reactor Septic System References & Products

Vermiculture & Worm-based Septic Systems

Question: can you tell me about worm-based septic systems?

2021/11/04 Lisa King

I read once about a septic system made by a student that uses worms to break down waste. Is is available for purchase?

Moderator reply: Vermiculture, worm-based septic treatment systems & composting toilets

@Lisa King,

There are worm-based septic system designs and some commercial or industrial worm based organic waste processing systems. The principal or most-widely used and successful of these appear to us to be commercial or industrial-level systems but residential worm-septic designs and worm-based or vermiculture-based composting toilet designs are also available.

OPINION: From what we've read you would not be advised to try to set up such a system for a private septic treatment system unless you're in the right climate and are prepared to pay attention to the worm-based septic inspection, maintenance, and media care/replacement requirements.

You'll might that the system capacity is limited, the cost may be high, the life short, and the maintenance or replacement costly, AND you may find, from what we've researched to date, that the system may not be legal - not approved by your local septic authority.

There are also some graywater treatment systems that have proposed using worms or earthworms to improve the breakdown of the greywater constituents (worms added to a pine-bark filter), again not an approved design in most locations.

Watch out: To avoid confusion with a true earthworm septic system design, we note that there are also companies advertising "Earthworm Septic & Cesspool Treatment" that are simply an enzyme septic additive. We note that for conventional septic systems no additives or treatments are necessary and some are illegal and unsafe (though enzymes are generally safe or harmless in that application). See those details

at SEPTIC TREATMENTS & CHEMICALS

There are also composting toilet designs that make use of worms. If you research "Vericomposting" you'll find both vendors of such worm-toilet designs and research on Vericomposting.

We've discussed Vericomposting at COMPOSTING TOILETS

Bottom line:

In our OPINION vermiculture septic systems and vermicuilture composting toilets: worm-septics and worm-composting toilets can work successfully if properly designed, installed, and maintained, and if they are in a suitable climate and at a suitable (well-drained, non-freezing) site,
but
like quite a few other alternative septic or toilet designs with which we've worked over the last 50 years,
ANY system that requires an extra level of owner/occupant attention and maintenance tends to be un-attended and to perform less-reliably than a simpler, hands-off design.

It's also our opinion and experience that enthusiasts installing a worm based septic system or vermiculture composting toilet may be un-prepared for the extra attention and extra costs of periodic inspection, cleaning, media replacement, reduction in wastewater volume or other attentions that are required to keep any septic or toilet system working properly. Where such systems are reliably and regularly maintained by a trained expert technician they tend to perform better and last longer - at the cost of such service.

 

Examples and information on Vermiculture & Worm Septic Media Systems

Worm-based septic systems or graywater / greywater system opinions, designs & suppliers

Australia:

WORM-BASED SEWAGE TREATMENT [PDF] Western Australia Department of Health, Water
Department of Health Telephone: 9388 4999 Email: ehinfo@health.wa.gov.au - original source: ww2.health.wa.gov.au/Articles/U_Z/Worm-based-sewage-treatment-systems

A&A Worm Farm Waste Systems 5/2135 Frankston Flinders Road Hastings VIC 3195 Tel: 03 5979 1887
Website excerpt:
Worm farm septic tank systems are a natural, biological septic tank solution that effectively processes sewage, all household wastewater and organic waste, including food and vegetation, as well as weeds using humble septic tank worms. Combined with naturally occurring organisms, the worm liquid opens up and improves the quality of your soil – enabling you to reuse and recycle it as liquid fertiliser under your garden, lawns and bushland.

Wormsmart Australia, 1300 Wormsmart - 1300 967 676 Tel: Mobile - 0437 497 284
New Zealand & Pacific Islands
Mobile - 0274 372 089
Web: www.wormsmart.com.au/
Website excerpt: "Based upon entirely natural processes, the WormSmart system was conceived in Australia and it’s swiftly drawing international recognition as the cleanest, most sustainable, cost-effective and ecologically balanced waste conversion system available; an unobtrusive, practical and economical alternative to those smelly septic systems of days gone by.

WormSmart is the only system of its type to receive full government approvals from every state and territory of Australia, together with New Zealand and as far afield as heavily-populated India."

Chile: worm-septic systerms

BioFiltro, CHILE, Tel: +56 2 3224 3648 Hernando de Aguirre 201, Of 1301, Providencia, Santiago, Chile

EcoWatch, cites a successful worm-based wastewater treatment system used in Chile:

"... since 1995, Chilean company BioFiltro has recycled more than 28 billion gallons of water to date with this humble organism: the worm. ...
BioFiltro currently has 129 facilities installed in six countries. They process the wastewater from the Chilean Air Force Base on Antarctica as well as the Atacama Desert, which is the driest desert in the world. The company is currently constructing plants in California to serve the needs of food processors, wineries, waste haulers and sanitary waste..." Chow, Lorraine, "The Role of the Worm in Recycling Wastewater" EcoWatch, 2016/04/23 - source: www.ecowatch.com/the-role-of-the-worm-in-recycling-wastewater-1891122409.html

United States + Chile, Peru & New Zealand worm based septic systems

BioFiltro, UNITED STATES
+530 564 4260
1949 5th Street, Suite 101,
Davis, CA 95616
---

Peru - worm-based septic systems

BioFiltro, Peru, Tel: +51 944 579 292, Calle Miguel Dasso 139, Of 701, San Isidro, Lima

New Zealand Vermiculture / Worm-based septic systems

BioFiltro, New Zealand, Tel: +530 564 4260 81 Springs Road, East Tamaki, Auckland, New Zealand

Wormsmart Australia, 1300 Wormsmart - 1300 967 676 Tel: Mobile - 0437 497 284
New Zealand & Pacific Islands, Mobile - 0274 372 089 Web: www.wormsmart.com.au/

Portugal - worm septic systems

Vericomposting Toilets, www.vermicompostingtoilets.net/why-worms/
Recent installations in Portugal;
Contact:
wendy (at) permaculturinginportugal.net
or
Arq. Vera Filipa Rocha
Phone: +351 912533876 / 235728061
Email: eco.vfr (at) gmail.com

UK Worm Septic Systems

Biocell, Web: biocellwater.com/septic-tank-worms-additives-explained/
Tel: +442080128198 Ireland Flag +35391705964 Email sales@biocellwater.com
[We could not find a mailing or physical address at the Biocell website - ed.]

WTE Ltd, Water Technology Engineering, Unit 2, Bolton LaneBoltonYORKYorkshireYO41 5QX United Kingdom
Telephone: 01759 369915 Email: sales@wte-ltd.co.uk
Web: www.wte-ltd.co.uk/contact_us.html
Website excerpts:

We get many calls regarding septic tank and soakaway worms and if they actually work?
... if the environment in your septic system is able to support a worm colony, wild worms WILL appear in it, without the need to buy them. If you need to buy them, then the environment is not able to sustain them.
...
So, a website that sells these worms and which states that worms do not drown in water and that most septic tanks and soakaways have an aerobic process that takes place, are WRONG. Septic tanks are an anaerobic system and soakaways are also very oxygen depleted, so HOW can these worms stay alive? Also, I have seen many worms that have drowned in puddles and I am sure that you have too.
...
We asked for a sample of these worms to test on our test site and despite reminding the seller twice, they were never delivered.
...
Make your own mind up.

Composting Toilet System using Worms - Vermiculture

VERICOMPOSTING TOILET DESIGN [PDF] retrieved 2021/11/04 original source: www.vermicompostingtoilets.net/design-construction/
at InspectApedia at

Website excerpt:
...
There are many good fully-referenced studies now available on earthworms’ role in soil creation and waste treatment. Here are a few for further reading …

Sewage treatment by vermifiltration with synchronous treatment of sludge by earthworms: a low-cost sustainable technology over conventional systems with potential for decentralization. Sinha, R K, Bharambe, G & Chaudhari, U. Environmentalist, December 2008, Volume 28, Issue 4.

An Overview of the Environmental Applicability of Vermicompost: From Wastewater Treatment to the Development of Sensitive Analytical Methods. Pereira, M G et al. The Scientific World Journal Volume 2014 (2014).

A Review on Effectiveness of Earthworms for Treatment of Wastewater. Gupta, H. International Journal of Engineering Development and Research, Volume 3, Issue 3 (2015).
Worming the Way to a Greener Future: Vermicomposting for Municipal Organic Waste Disposal. Katie Kilpatrick. Senior Thesis Environmental Studies, Dr. Liz Gron, Mentor March 15, 2013

Design and Suitability of Modular Vermifilter for Domestic Sewage Treatment. Bhise H S, Anaokar G S. International Journal of Emerging Engineering Research and Technology, Volume 3, Issue 4, April 2015.

Vermicomposting of source-separated human faeces by Eisenia fetida: effect of stocking density on feed consumption rate, growth characteristics and vermicompost production. Yadav K D, Tare V, Ahammed M M. Waste Management, Volume 31, Issue 6, June 2011, Pages 1162–1168

The life-cycle of the compost worm Eisenia fetida (Oligochaeta). Venter, J M & Reinecke, A J. South African Journal of Zoologyy, 23:3, 161-165 (1988)


 




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2020-08-29 by Elie

Can a sealed septic tank be changed to a septic tabk with a secondary?
How much would that cost approx.
Do i need city approval to change the type of tank?

On 2020-07-26 - by (mod) -

Ben I don't know what brand of aerobic septic system aerator you've got. Look for a brand on its label or data tag and the manufacturer will certainly have an installation & operation manual; or call the people from whom you bought it.

On 2020-07-25 by Ben Baldwin

I just took delivery of a 770++L Aerator and there was no instruction or any paperwork in the box. Now I want to assemble the 770++L and need a diagram with measurements to put it together. Thank you, Ben at benbaldwin2@gmail.com.

On 2020-03-02 - by (mod) -

Joey

You need a local septic design engineer who knows what particular septic systems your local board will accept: such as a mound or raised bed septic that is installed atop and sufficiently above the clay.

On 2020-03-02 by Joey c.

In va. Home built 1957 failed drain feild. Failed soil test (clay) other side of the back yard is to close to an abandant well. No where else to put it. No county water/sewar in this area. What do I do?

On 2020-01-05 - by (mod) -

Jeff

Moving a septic system into a building basement is not a reasonable plan

On 2020-01-05 by Jeff billips

I have a small yard where my traditionss as l septic system takes it all up. I’d like to put a system in my basement to free up the yard for a pool. How do I do this?


...

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