InspectAPedia ^®

Master List of Types of Septic Systems & Septic System Designs InspectAPedia®  -

• Types of Septic Systems, Alternative Septic System Designs, Master List & Descriptions of Kinds of Septic Systems
• Alternative septic system designs for problem sites
• Description of alternative septic systems, design criteria, product sources
• Aerobic septic systems, cesspools, dosing systems, drywells, evaporation/transpiration, gravelless, & graywater systems
• Media filter systems, septic filters, graywater filters, septic mound systems, raised bed septics, sand bed septic systems
• Residential sewage treatment systems, waterless or low-water toilet alternatives, product sources

This document lists and describes all 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.

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. Also see The Septic System Information Website. Massachusetts Title 5 Licensed Septic System Inspector, & New York State H.I. License # 16000005303 (inception to 2008).

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

ALTERNATIVE SEPTIC SYSTEM DESIGNS - Onsite Wastewater Treatment Methods for Difficult Sites

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.

Master List of Septic System Types & Onsite Wastewater Treatment Alternative Designs

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

• Basic septic system design is discussed at:
    SEPTIC SOIL & PERC TESTS
    SEPTIC TANK SIZE
    SEPTIC TANK DEPTH
    SEPTIC TANK TEES
    SEPTIC DRAINFIELD SIZE
    SEPTIC DRAINFIELD SHAPE
    SEPTIC CLEARANCES
    SEPTIC TANK PUMPING FREQUENCY
    SEPTIC TANK PUMPING PROCEDURE
    SEPTIC PUMPING REPAIR
    SEPTIC TREATMENTS
    STEEP SLOPE SEPTIC DESIGNS
  
  
• Chemical Toilets: use a chemically treated reservoir located directly below the toilet seat. The chemicals reduce odors and perform partial (incomplete) disinfection of the waste. Chemical toilets have limited storage capacity and must be pumped and periodically cleaned by a septic company. Similar to simple chemical toilets but more sophisticated in design are recirculating toilets which separate the waste from the chemical and then re circulate the fluid through the toilet tank. Also see TOILET ALTERNATIVES.
  
  
• Composting Toilets: may be used where the water supply is limited or not available at all, or where a building owner for other reasons wishes to conserve water use. Other wastewater treatment will still be required for handling graywater from sinks and showers. Also see TOILET ALTERNATIVES for details.
  
  
• Continuous Flow, Suspended Growth Aerobics - The activated sludge process is an aerobic suspended-growth process that maintains a relatively high population of microorganisms (biomass) by recycling settled biomass back to the treatment process. The biomass converts soluble and colloidal biodegradable organic matter and some inorganic compounds into cell mass and metabolic end products. The biomass is separated from the wastewater through settling in a clarifier for recycling or wasting to sludge handling processes. Preliminary treatment to remove settleable solids and floatable materials is usually provided by a septic tank or other primary treatment device. Most onsite designs are capable of providing significant ammonia oxidation and effective removal of organic matter.
  
  
• Disinfection Septic Systems: use chlorination or ultraviolet light (UV) to disinfect wastewater effluent before it is discharged to the environment.
  
  
• Dosing Systems, Pressure or Gravity: Dosing septic systems permit the septic system drain field to rest between effluent doses and, depending on design, may alternate use of drainfield sections. Two broad types of dosing systems are Gravity-Dosing (effluent flows from an effluent tank to the absorption system by gravity) or Pressure-Dosing (effluent is pumped from a dosing chamber to the absorption field).
  See Gravity Dosing Septic Systems
  and Pressure-dosed Drainfield Septic Systems for details.
  
  
• Drainfields: a generic term for septic effluent disposal, usually referring to "conventional-design" septic leach fields or septic leaching beds, leach fields, septic gravity trenches, septic leach lines, septic seepage beds or septic system drainaway fields. See SEPTIC DRAINFIELD SIZE for design specifications for septic drainfields.

• Effluent Disinfection Systems for septic system designs - see SEPTIC EFFLUENT DISINFECTION SYSTEMS. The process of disinfection destroys pathogenic and other microorganisms in wastewater. A number of important waterborne pathogens are found in the United States, including some bacteria species, protozoan cysts, and viruses. All pretreatment processes used in onsite wastewater management remove some pathogens, but data are scant on the magnitude of this destruction.
  
  
• Evaporation-Transpiration (ET) Septic Systems: and Evapo-Transpiration Absorption Septic Systems (ETA) dispose of septic effluent from the septic tank by providing a surface area intended to allow the effluent to evaporate. ET systems depend entirely on evaporation while ETA systems make use of both evaporation and (limited) soil absorption of septic effluent. (Jantrania/Gross wastewater system type IX if effluent is treated to level 2 or better).
  
  ET beds may be used with or without intermediate storage tanks and with or without effluent recycling systems. In this discussion of evaporation/transpiration septic systems we include the advanced Tafgard soil based wastewater treatment systems - developed in Japan by Taisei Kogyo Co., Ltd., this system uses a combination of a five-chamber waste treating septic tank designed by Taisei, effluent disposed-of by an evaporation-transpiration system through aerated soil (effluent spread horizontally and upwards from distribution piping).
  
  
• Filter bed effluent treatment septic systems (if treated to level 2 effluent or better, Jantrania/Gross wastewater system type VIII) - see various filter media types listed here such as sand beds, fabric filters, etc. Filter beds may be
  MOUND SEPTIC SYSTEMS or
  Raised Bed septic systems,
  Media Filter septic systems, septic systems or Sand-Bed filter septic systems.
  Readers should distinguish between types of septic filter beds (listed above) and other septic filter products such as
  in-tank septic filters.
  
  
• Fixed-film processes septic system designs (FFS) are biological treatment processes that employ a medium such as rock, plastic, wood, or other natural or synthetic solid material that will support biomass on its surface and within its porous structure. At least two types of fixed-film systems may be considered--those in which the medium is held in place and is stationary relative to fluid flow (trickling filter) and those in which the medium is in motion relative to the wastewater (e.g., rotating biological disk). A third classification includes dual-process systems that encompass both fixed and suspended biomass together or in series. This approach is covered in Fact Sheet No. 1 on continuous-flow suspended-growth aerobic systems (CFSGAS).

• Greywater Septic Systems: refer to systems which reduce the liquid effluent load on a septic system by separating greywater (or graywater) from sinks and showers from blackwater (black water) from toilets. When we inspect a home which uses a separate drywell to handle greywater we presume that the owners discovered that their septic system, or at least its leach field, was of limited capacity or life. See Greywater Septic Systems for details. Also see TOILET ALTERNATIVES.
  
  
• Gravity or Siphon Dosing Septic Systems: move septic effluent from the septic tank to a final effluent treatment/dispersal/disposal system such as a drainfield by accumulating septic effluent in a dosing tank or chamber and periodically sending the "dose" of effluent to the drainfield. To move effluent from the dosing tank to the drainfield a "gravity" dosing system uses a mechanical device such as a bell siphon system, tipping tank, or float valve to determine when the dosing tank is full and ready to send effluent to the drainfield at intermittent frequencies or in "doses".
  
  Effluent flows from the dosing tank to the drainfield by gravity. Gravity/siphon dosing systems usually require a larger effluent holding tank or chamber than pressure dosing systems. While some gravity dosing systems do not require electricity to operate, other "gravity" dosing system designs which place the dosing tank uphill and distant from the septic tank, can require an effluent pump to move wastewater from the septic tank to the remote dosing chamber/tank. Dosing systems permit the drain field to rest between doses and, depending on design, may alternate use of drainfield sections. See Gravity or Siphon Dosing Septic Systems for details.
  
  
• "Gravity trench septic systems" is a generic term to describe distribution of septic effluent into a treatment and dispersal/disposal system using perforated pipes buried in gravel-filled trenches dug into the soil. An example is the conventional septic drainfield but gravity trenches can be used in other designs such as with gravity or pressure dosing systems. Gravity trench effluent systems may also be designed for "level 2 or better" effluent treatment (Jantrania/Gross wastewater system type V). Septic gravity trenches and their design specifications are discussed in detail at SEPTIC DRAINFIELD SIZE.
  
  
• Greenhouse treatment of septic effluent to level 3 or better (Jantrania/Gross wastewater system type XI). Greenhouses, like ET beds, may be used with or without storage tanks and effluent recycling systems. The system uses an enclosed "greenhouse" constructed around plants and a mini "constructed wetlands" to treat effluent. Greenhouse wastewater treatment systems permit maintaining the treatment system at a higher temperature than otherwise might be possible, such as in a cold or cool climate area.
  Also see Constructed and Natural Wetland Septic Systems
  and also Lagoon Systems.

• Holding Tank Septic Systems: use a sealed tank to hold household waste and wastewater until the tank can be pumped out by a septic pumping company. Most jurisdictions do not permit septic holding tanks as a permanent wastewater handling method for full-time occupied residences, but holding tanks may be permitted during new home construction and in other special cases. In New York State we've seen holding tank systems in use on small-lot properties located along the Hudson River. Generally such systems will not be acceptable for full time occupied residences as even a large tank of several thousand gallons will require frequent and costly pumping and disposal.
  
  
• Incinerator Toilet Septic Systems: incinerating toilets use electricity or gas to burn the waste placed into these systems. Like chemical toilets and holding tanks they have limited capacity, are used where water is not available or must be conserved, and they do not address the handling of remaining graywater from sinks and showers. My favorite of this type was the "Destroylet" incinerator toilet which was electric/propane fueled and which is no longer on the market. Each flush resulted in a more than 10-minute burn cycle which produced a pretty smelly exhaust. See TOILET ALTERNATIVES for details.
  
  
• Inspection and Testing of septic systems is discussed at
    SEPTIC FAILURE CAUSES
    SEPTIC TANK INSPECTION PROCEDURE
    SEPTIC DRAINFIELD FAILURES
    SEPTIC D-BOX INSPECTION
    SEPTIC FIELD INSPECTION
    SEPTIC DYE TESTS
    SEPTIC FAILURE SPOTS
    SEPTIC INSPECTION WORK SHEETS
    ALTERNATIVE SEPTIC DESIGNERS
    ALTERNATIVE SEPTIC PRODUCTS
  

• Latrine or simple trench systems, useful in remote and impoverished areas to improve sanitation and thus the quality of drinking water and other special, extremely low-cost waste handling, wastewater treatment systems are ignored by most modern texts on onsite wastewater treatment, excepting perhaps military manuals which address field toilets and sanitation for military operations. This topic needs considerably more attention as a step in assisting rural, poor areas in developing nations. Articles, illustrations, and text contributions are wanted; additions to this special topic will be provided as they are developed at this website. Inadequate disposal and treatment of human and animal waste in poor areas is a major cause of dysentery and often high infant and child mortality. Meanwhile see the helpful but inadequate resource sketches at http://www.africanwater.org/ecosan_main.htm"the African Water Page and Ecological Sanitation" and http://peacecorps.mtu.edu/erda/links.htm a peace corps site on composting latrines
  
  
• Lagoon systems: also known as "pond systems" for onsite wastewater treatment are less often found in use for single family residential wastewater treatment. A residential lagoon system may use a conventional septic tank, but effluent from the tank flows to a storage pond or lagoon for further treatment. Lagoon systems require comparatively large land areas and are more likely to be found therefore in rural areas or where a common wastewater treatment system has been designed to serve multiple dwellings. Also see Constructed Wetland Septic Systems
  
  
• Media Filter Septic Systems: use a conventional septic tank followed by any of several methods to further filter and treat septic effluent before it is discharged to the soil, soil surface, or waterway. Treatment is by both actual filtration and ultimately by a biochemical process as the filter "matures" and includes its own biomass. Both natural media filter septic systems (such as sand, gravel, or peat) and synthetic media filter septic systems (foam cubes, glass, slag) are used.
  
  
• Mound Septic Systems: a wastewater absorption trench system which has been constructed using "suitable soil-fill material" which has been placed on top of the natural soil on a building lot. Mound systems are often confused with "raised systems" (see below) but have different design requirements, are generally smaller in total size, and depend on the fill material for successful wastewater treatment. Also see "Raised Systems" below.
  
  
• Peat-Filtered Septic systems: Septic effluent treatment systems using peat as the filter media include an effluent dosing system, peat filter media, and a drainage system. Unlike sand bed filters, peat filtration systems are sold as prepackaged systems which provide modular peat units enclosed in containers or "pods" ready to install. Also see MEDIA FILTER SEPTIC SYSTEMS
  
  
• Pressure-dosed Drainfield Septic Systems: pressure dosing systems use a separate dosing chamber and pump, located downstream from the septic tank, to move effluent into a drainfield which in turn distributes effluent through a pressure-fed network of distribution pipes. (Jantrania/Gross wastewater system type II or if treated to level 2 or better effluent, system type VI) Pressure dosing is used in a variety of disposal field designs including mounds and sand beds, and have the advantage of being able to distribute effluent uniformly throughout the absorption system, and the disadvantage of added system cost and complexity, along with the requirement for electricity for system operation.
  An alternative but possibly less long-term reliable version of a drainfield dosing system that may not require electricity is the siphon system. Also see Dosing Systems, Gravity/Siphon.
  
  
• Raised Septic System: a wastewater absorption trench system which has been constructed in soil-fill material which has been placed on top of the natural soil on a building lot. Raised systems are often confused with "mound systems" (see below) but have different design requirements, and make at least partial use of existing soils for wastewater treatment. Also see "Mound Systems" above.
  
  
• Sand: Intermittent Sand Filter Septic System: wastewater effluent from the septic tank is intermittently distributed over the surface of a specially prepared bed of sand placed atop the existing soil surface. Effluent which has passed through the sand is collected by additional pipes at the bottom of the sand bed. The sand is not visible as it's covered by topsoil.
  
  
• Spray effluent dispersal systems, treating effluent to level 3 or better (Jantrania/Gross wastewater system type X). Spray systems are normally above ground septic effluent dispersal systems. A pump and pipe system combined with spray heads disperses pre-treated effluent above ground where a combination of evaporation and absorption dispose of the effluent liquid.
  
  
• Septic Tanks: septic tank types are described at TANK INSPECTION PROCEDURE and include
  • steel septic tanks,
  • concrete septic tanks,
  • plastic and
  • fiberglass septic tanks, and
  • home-made septic tanks that we've found constructed of stone, concrete block, bamboo, brick, and wood.
    Also see Septic Tank Suppliers: a directory list of septic tank suppliers and see ALTERNATIVE SEPTIC PRODUCTS for directory lists of other septic system component suppliers.
    
    
• Septic tank and graywater filters are products used at a septic tank outlet or at a graywater tank inlet or outlet to prevent suspended solids from reaching and clogging the soil absorption system. Readers should distinguish between in-tank septic or graywater filters and types of septic media filter and bed systems such as:
  MOUND SEPTIC SYSTEMS or
  raised bed septic systems,
  media filter septic systems, septic systems or sand-bed systems.
  
  
• Sequencing batch reactor systems - The sequencing batch reactor (SBR) process is a sequential suspended growth (activated sludge) process in which all major steps occur in the same tank in sequential order (figure 1). There are two major classifications of SBRs: the intermittent flow (IF) or "true batch reactor," which employs all the steps in figure 1, and the continuous flow (CF) system, which does not follow these steps.
  
  
• Steep Slope Septic Designs - how to install sewer lines from building to septic tank; how to install septic drainfields, leach field systems at steep or sloped sites.
  
  
• Trenches for effluent dispersal, gravity fed or pressure dosed, with gravel or gravelless systems are discussed under conventional septic and drainfield pages, pressure dosing, or gravelless systems. Also see "Gravity Trenches" above.
  
  
• Vegetated submerged beds and other high-specific-surface anaerobic reactors - A high-specific-surface anaerobic reactor is any tank or cavity filled with solid media through which wastewater flows with a high hydraulic retention time (HRT). In onsite treatment the two primary types are vegetated submerged beds (VSBs) and anaerobic upflow filters (AUFs). The first is characterized by horizontal flow and prolific growth of macrophytes on the surface. The second comes in a variety of forms from upflow sludge blanket systems and fixed media anaerobic filters to partially fluidized beds of fine media. Both have long HRTs, produce anaerobic effluents, generally treat either high-strength or minimally pretreated wastewater, and usually require some form of posttreatment to meet surface discharge or water reuse requirements
  
  
• Waterless toilets and graywater systems: see the various toilet types and greywater/graywater links on this page such as chemical toilets, composting toilets, and incinerating toilets. (Jantrania/Gross wastewater system type IV). Also see Greywater Septic Systems. See See TOILET ALTERNATIVES for details of all of these systems.
  
  
• Wetland Septic Systems or "natural" septic systems use a constructed wetlands area (or a greenhouse) to treat septic effluent. These systems are more common in Louisiana, Mississippi, Tennessee, South Dakota, and Florida where both municipal wetland septic designs and private homeowner wetland septic system designs are in use. "Wetlands" may include both visible water such as open ponds, and underground water located in constructed beds which are covered with soil. Also see Lagoon Systems.

Share this Article      

...

Technical Reviewers & References

Search InspectAPedia

• Daniel Friedman - principal author/editor of the InspectAPedia^® Website
• InspectAPedia Bookstore lists recommended books, organized by topic & available for purchase. Most of our articles also include a list of recommended books for the specific article topic as well as other references, and information sources.
• Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
• Additional technical contributors & reference sources for this article are listed below.

Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

SEPTIC SYSTEMS HOME
SEPTIC INFO ARTICLES
HOME BUYERS GUIDE to SEPTIC SYSTEMS
SEPTIC SYSTEMS ONLINE BOOK
INTRODUCTION
SEPTIC SYSTEM SAFETY WARNINGS
SEPTIC SYSTEM DESIGN BASICS
  SEPTIC SOIL & PERC TESTS
  SEPTIC TANK SIZE
  SEPTIC TANK DEPTH
  SEPTIC TANK TEES
  SEPTIC DRAINFIELD SIZE
  SEPTIC DRAINFIELD SHAPE
  SEPTIC CLEARANCES
  SEPTIC TANK PUMPING FREQUENCY
  SEPTIC TANK PUMPING PROCEDURE
  SEPTIC PUMPING REPAIR
  SEPTIC TREATMENTS
  STEEP SLOPE SEPTIC DESIGNS
SEPTIC DESIGN ALTERNATIVES
  Wastewater Treatment Levels
  Wastewater Dispersal Methods
  Master List of Septic System Types
  AEROBIC SEPTIC SYSTEMS
  ALTERNATING BED SEPTIC SYSTEMS
  CESSPOOLS
  DOSING SYSTEMS GRAVITY/SIPHON
  DOSING SYSTEMS PRESSURE
  DRYWELLS
  SEPTIC EFFLUENT DISINFECTION SYSTEMS
  EVAPORATION-TRANSPIRATION SEPTIC SYSTEMS
  FIXED-FILM PROCESS SEPTIC SYSTEMS
  GRAVELLESS SEPTIC SYSTEMS
  GREYWATER SYSTEMS
  HOLDING TANK SEPTIC SYSTEMS
  LAGOON SEPTIC SYSTEMS
  MEDIA FILTER SEPTIC SYSTEMS
  SEPTIC & GREYWATER FILTERS
  SEQUENCING BATCH SEPTIC SYSTEMS
  MOUND SEPTIC SYSTEMS
  RAISED BED SEPTIC SYSTEMS
  SAND BED SEPTIC SYSTEMS
  SEWAGE TREATMENT SYSTEMS
  STEEP SLOPE SEPTIC DESIGNS
  TOILET ALTERNATIVES
  VEGETATED SUBMERGED SEPTIC BEDS
  WETLAND SEPTIC SYSTEMS
  ALTERNATIVE SEPTIC DESIGNERS
  ALTERNATIVE SEPTIC PRODUCTS
SEPTIC INSPECTIONS
SEPTIC SYSTEM DEFINITIONS
SEPTIC FAILURE LAWSUIT
SEPTIC FLOOD RESPONSE
SEPTIC REFERENCES
SEPTIC CONSULTANTS
SEPTIC AUTHORITIES
SEPTIC SYSTEM BOOKS REFS CODES

• Alan Carson Carson Dunlop Associates, Toronto, Ontario. Mr. Carson is a home inspection professional, educator, researcher, writer, and a principal of Carson Dunlop Associates, a Toronto home inspection and education firm. Mr. Carson is a past president of ASHI, the American Society of Home Inspectors
• Tafgard soil based wastewater evaporation / transpiration system by Taisei Kogyo Co., Ltd., Japan. Contact Shuichi Sato, Manager of Taisei Kogyo Co., Ltd., 15-36 Yonehara 6-chome, Yonago, Tottori, 683-0804 Japan Tel. +81-859-32-1135 Fax. +81-859-34-0933, info@taisei-wastewater.jp

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
• ...

More Information on Building Diagnostic Inspections and Repairs

• The Septic System Information Website home page for this topic
• Septic Systems Inspection, Testing, & Maintenance- online textbook. Detailed how to inspect, maintain, repair information
• The Home Buyer's Guide to Septic Systems
• Septic Tank Pumping Guide: When, Why, How to pump the septic tank
• Home & Outdoor Living Water Requirements
• Septic Tank Capacity vs Usage in Daily Gallons of Wastewater Flow, calculating required septic tank size, calculating septic tank volume from size measurements
• How Big Should the Leach Field Be? - table of soil percolation rate vs. field size
• Septic System Drainfield Absorption System Biomat Formation - what leads to drain field clogging and expensive drainfield repairs
• Table of Required Septic & Well Clearances: Distances Between Septic System & Wells, Streams, Trees, etc.

InspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest.

The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

Use this simple, economical mold test kit by following our instructions on how to collect and mail mold samples to our lab

Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.

Building Inspection, Problem Diagnosis, Forensic Investigation & Testing, Repair Consulting

Contact Daniel Friedman for website content suggestions or for fee-paid consulting