Last Updated: 23 Apr 2014


   Dry Toilets

Resources, Links, Bibliography 

Links, Books, Notes

Useful links and bibliography, along with some footnotes, are provided at right, divided into categories.


You may want to jump to one of these other pages:

⇩                 ⇩
Why the Dry Toilet?  Pros and cons discussed.

Site-Built Units  Start with some explanations and decisions.

Manufactured Units you can buy and install.

Media and Videos.

Research.
explore..>>


You can skip to the following categories:

General           Composting           Agricultural           Sanitation
Base and Structure        UDDT Toilet Seats
Plumbing and Containers          Vent Pipes
Volume Calculation           Insect Mitigation        Photo/Image Credits



General Links and References Wikipedia informative entry on urine diversion.

Sustainable Sanitation and Water Management (SuSanA) gives good explanation and has very comprehensive list of references, including materials used to advocate switching from water-born sewage systems. 

EcoSan/SuSanA Dry Toilet construction of all parts of unit, detailed plans, containers, traps, use.

Note:  There are multiple ways to find the very helpful SuSanA/EcoSan publications (they have altered their name over the years); can also use this link.

General technology review with detailed references.

Del Porto, D. and C. Steinfeld (2000). Composting Toilet System Book. Concord, MA: Center for Ecological Pollution Prevention (CEPP).

Some good explanations and graphics (partly taken from Del Porto & Steinfeld.

Overview of composting toilets: projects at Michigan Tech Dept of Civil and Environmental Engineering.

Projects Reported

Technology Review of Urine-diverting dry toilets (UDDTs): Overview of design, operation, management and costs.

GRUPO DE TECNOLOGÍA ALTERNATIVA S.C. Central/North-American dry toilet projects and research.  Research results

The Mexican Center for Innovation in Alternative Technology has a dry toilet project.

UDDT projects in Eastern Europe, includes refs to additional studies by WECF.

EcoSan Club Austria description of projects in East Africa.

EcoSanRes (Swedish partner of SuSanSa), several projects, forums.

Excellent photos and step-by-step descriptions for a double-vault project in Bulgaria [in Russian and Bulgarian].

Global Dry Toilet Association of Finland; alternate site.

Case studies from U.S. Appellation Trail sites, some UD, moldering, composting.


Agricultural Uses:

Europe's sanitation problems, UDDTs, use of excreta in agriculture [brief WECF paper].

Description of WECF use of urine.

Before flush toilets, human waste was valuable and widely used in agriculture.

See http://www.treehugger.com/bathroom-design/crapping-bill-gates-reinvent-toilet-winner.html and also commentary on Gates Foundation toilet project.

Story of a failed project in China.

Successful urban project in China using excreta collected from UDDTs in urban dwellings.

Productive reuse of wastes & wastewater, solid and liquid urban waste products safely and economically used in agriculture: RAUF Foundation.

An excellent resource: Humanure Handbook, is mostly about composting, but also includes some toilet tips.


Composting:
Aerobic and anaerobic decomposition explained; research here on mesophilic and thermophilic composting, including microorganism counts.

Pathogen destruction in composting toilets: Explained; researched.

Also see Agricultural Uses.

The composting chapter from Humanure handbook; toilet tips, too.

“One may also "precharge" the toilet with a "biological sponge," a thick layer of absorbent cellulose material filling the bottom of the compost chamber…” (Retrieved from Humanure Handbook.)   “Priming” the chamber with material from the previous chamber material or a commercially available compost starter may also improve composting activity if the temperature is sufficient.

WECF document on  composting.


Sanitation Notes:

Note:  “When planning systems, pathogens and vectors need to be considered. This is particularly a concern in areas with endemic diseases, such as warm regions, where pathogens flourish."

World Health Organization guidelines for safe use of human excreta (Guidelines for the Safe Use of Wastewater, Excreta and Greywater. Volume IV – Ecxreta and Greywater Use in Agriculture).

National Water Center discussion of dry toilets vs. water-born systems.  (More here.)

Diseases possible from failure to isolate human excrement.

Bacteria can be tested how?  [Search the web for water testing methods.]

Note:  Parasites are often mentioned as a significant risk where human feces are not treated. Specifically what parasites should we make sure to eliminate? Not an easy question to answer.  cite a very large number of parasites that can cause harm in humans (e.g., Health care sources offer extensive explanations). Testing of stool for parasites may offer ideas for testing to determine safety of desiccated feces from dry toilets (general explanation of tests ; most websites describe how stool is collected but don’t describe how the laboratory tests themselves are done; use of slides, dying, centrifuge, microscopic inspection).

The most common intestinal parasites in North America that cause infections are:
  • roundworms:  Ascaris lumbricoides
  • hookworms:  Necator americanus
  • pinworms:  Enterobius follicularis
  • tapeworms:  Diphyllobothrium latum, Taenia saginata, and Taenia solium
  • protozoa:  Entamoeba histolytica (an amoeba), and Giardia lamblia (a flagellate)
Full listing of pathogens in EcoSan report, page 27.

Base and Structure:

National Water Center plans for 55-gal drum UDDT stand-alone unit.

UDDTs in cold climates.

Omick composting toilets with photos.

State-approved composting toilet in MA farm house.


UDDT Toilet Seats:

UD toilet unit and accessories: Berger Biotechnik; UD insert/seat.

List of sit-down UDDTs. However many on this site are available only in China, India, Africa.

Separett toilet seats and associated UDDT fittings; UDDT toilets and seat inserts are also available from Ecovita, 978-318-7033.

Unit where one pumps on a pedal to activate a conveyor belt.  [photos repository];
an application of this pedal-activated unit in Canada.

Other models available from U.K.: Freerange Designs, Dunster House.

Urine-diverting dry toilet (UDDT) Technology review: overview of design, management, maintenance and costs.

"UD flush toilets" use small amounts of flush water and are described in Urine Diversion Components.

Discussion of alternatives to urine diversion in Humanure book.  

An example of non-urine diversion "dry" toilet appears to be the Crapper (see the Buying Commercial Units page); email from principal says: “Regarding the pee question: For urine, we have a separate unisex urinal. The urinal is for whenever the user just has to pee. The CRAPPER is designed for pooping (and peeing when you're pooping). If there is some liquid that passes through the drum (called leachate [any solution resulting from leaching, often contaminated]) it will drain out the back through drainage holes and a funnel system into the ground. If there is no ground to drain into (i.e. communities living on water), this leachate can be filtered with an ash pebble mixture.”


Plumbing and Containers:
Separett toilet seats and associated UDDT fittings.

Plastic bins and containers; more of same, cheaper water-tight tote bins.

Seepage bed  specifications, p. 5.

Also see below, Volume Calculations.


Vent Pipes:
An updraft-enhancing top can be fitted to the top of the vent pipe;  also a smaller-sized whirlybird, ditto,

Stand-off bracket to secure vent pipe in position.


Volume Calculations:

By one estimate, one cubic meter will hold the feces of a group of 7 adults and 3 children over one year, considering shrinkage as dehumidification occurs; another estimate is 0.25 cubic meter will hold 250 kg of material produced by 5 adults in one year, or 0.5 cubic meters for 10 adults [this seems too little; the conversion from kg to liter depends on density so is unclear in this case]. One adult can be expected to produce approximately 0.25 liters (250 cc) of feces in one day (range of 0.12 – 0.4 [1 cubic meter = 1000 liters, so the range is 0.04 - 0.15 m3/year per person]. Note that these estimates do not seem to account for toilet paper or the dry material added after each bowel movement.

Urine container alternatives and volume calculations, see Urine Diversion Components, see GTZ Sustainable Sanitation EcoSan (Deutsche Gesellschaft für Technische Zusammenarbeit).  Also includes info on "UD flush toilets", urine pipes, containers, etc.

Feces container volume calculations, see GTZ/GIZ publication.  Also includes other aspects.

More volume calculations including reduction due to drying, composting.


Insect Mitigation:

Note:  Dry toilets must be managed to assure little or no odor and to encourage decomposition, by taking into account circumstances and patterns of usage, being sure ventilation and temperature are adequate, enough absorbent bulking material is added, and perhaps leveling the mound of feces so it remains covered and odorless. The chutes or feces holes from the toilet may require cleaning from time to time. In the event that insects penetrate and begin to breed, they must be exterminated; most common (when they occur) are small black flies (larger than fruit flies, smaller than house flies) - usually Ephydridae fly larve; be sure air intakes and vent pipes have netting; lengthen vent pipe to increase flow, install fly traps within vault.

Ideas for preventing insects: Del Porto and Steinfeld, Composting Toilet System Book, pp 59-60;

Organic insecticides such as Rotenone/Pyrethrin concentrate might be used if necessary.

“Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled algae. It is used as a filtration aid, mild abrasive in products including toothpaste, mechanical insecticide…” Inexpensive, safe, etc. quoted from here; available here.   Zeolite diatomic earth is said to be a positive amendment to compost.

Omick Insect trap with photos; includes info on non-UD versions, legal issues, aesthetics, secondary processing, agriculture.

Fly traps available.

Miscellaneous

Proceeds of dry toilet conference in Finland.

Legal issues discussed in Omick; projects to explore legal composing toilets.

A somewhat skeptical appraisal of composting toilets in the popular press, (although not speaking of UDDTs in particular).

Colorful posters and explanatory material, were once available from George Anna Clark, Espacia de Salud, A.C., A.P. 1-1576, Cuernavaca, Morelos, 62001 Mexico, or esac@laneta.apc.org . Search for César Añorve for another source.


Photo and Image Credits

CIAT Center for Innovation in Alternative Technology

DTS Dry Toilet Savvy

ESR (EcoSanRes, Stockholm Environment Institute)

GIZ Deutsche Gesellschaft für Internationale Zusammenarbeit GmbH; archives listed.

GTA GRUPO DE TECNOLOGÍA ALTERNATIVA S.C.

GWA Grey Water Action

MTU Michigan Tech Dept of Civil and Environmental Engineering

OMK Omick: Living Outside the Box - A Few Simple Technologies for Daily Living

RVS Riversong HouseWright

SSWM Sustainable Sanitation and Water Management

SSA SuSanA Secretariat - Sustainable Sanitation

WECF Women in Europe for a Common Future

Creative Commons license (used by GWA, SSA, and others)


Research

GRUPO DE TECNOLOGÍA ALTERNATIVA  -  Research results

Microbial Exposure and Health Assessments in Sanitation Technologies and Systems.

Results of Stockholm Environmental Institute project to produce organic fertilizer from UDDTs in China.




[yet to be categorized:]

   Biorealis Systems, Inc Low Cost Site-Built Composting Toilet System, partially discussed; plans for sale.

   University of Colorado hi tech toilet funded by Gates Foundation.

   RETHINKING SUSTAINABLE SANITATION FOR THE URBAN ENVIRONMENT, history of sanitation over last 150 years, discussion of sustainable approaches by region of the world.

   Sustainable Sanitation Alliance (SuSanSa) list of publications, includes sanitation as a business, role of different players in sustainable sanitation, capacity development, case studies, etc.

   Urine Diverting Toilets in Climates with Cold wide temperature variations; includes general discussion and case descriptions.

   Discussion of post-processing and vermicomposting.




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